No title

Clean and Green Epoxy Formulating

Our hands-on support starts here . . . www.airproducts.com/easy Waterborne epoxy coatings are quickly becoming the first choice for industrial protection due to their combined high-performance, eco-friendly and cost benefits. And to simplify your formulating we’ve put 40 years of coatings experience at your fingertips with formulating demonstration videos, starting point formulations, data sheets and more . . . including online free sample ordering for Air Products’ leading line of Anquamine®/Anquawhite® curatives and Ancarez® resins. Call us at 800-345-3148 or e-mail us at [email protected].

V I EWPOINT

What to do With Leftover Paint? I h ave b een r eading, w riting a nd e diting a rticles about t he c oatings i ndustry fo r m any y ears, bu t it wasn’t until last March that I w as fac ed w ith m y f irst paint dil emma. A w eekend painting job e nded w ith a half-full c an of p aint t hat I didn’t know what to do with. O ur c ity’s r efuse a nd recycling cen ter o ffered good i nformation o n h ow to d ispose of o r r ecycle e mpty p aint c ans, however t here w as n o op tion fo r le ftover paint, other than to check w ith local theater groups, schools and churches to see if they might take it a s a donat ion. So down to the basement it went. After doing some research online, I discovered that I was not alone in my predicament. According to the Oregon Department of Environmental Quality’s website, “An e stimated 1 0 p ercent of t he mo re than 750 million gallons of architectural paint sold each year in the United States is u nused.” L eftover p aint c an b e c aptured f or re use, recy cling, en ergy reco very o r s afe d isposal. A nd old p aint c ans are recycled as well. Many communities do of fer paint reuse, recycling o r di sposal s ervices, h owever these a re mo stly lo cal, c ountywide p rograms. It looks like the issue has taken hold on a la rger, state-wide scale now. The O regon Department of E nvironmental Quality (DEQ) ha s ap proved a pla n t hat s ets i n motion the f irst paint product stewardship “take-back” p rogram i n t he nat ion. The PaintCare program, which officially began July 1 a nd i s f unded by p aint manufacturers, a llows co nsumers t o ret urn u nused paint t o p articipating r etailers a nd ot her sites for proper disposal. The pilot program is expected to collect as much as 600,000 gallons of leftover paint annually in Oregon and is expected to be rolled out nationally.

The A merican C oatings Association c reated t he n onprofit organization PaintCare to ad minister t he p rogram. Consumers w ill p ay fo r t he program by p aying a s urcharge on p aint a nd s tain containers. P aintCare, in turn, w ill p rovide a s eries of depots s tatewide whe re p eople can drop off unused paint. PaintCare p ays a n a dministrative fe e t o D EQ on b ehalf of manufacturers for plan approval and program enforcement/oversight. The c omplete, ap proved O regon P aint Stewardship P ilot P rogram P lan i s a vailable a t www .deq.state.or.us/lq/sw/prodstewardship/paint.htm. T he pag e a lso lists p articipating r etailers a nd bra nds i n the PaintCare program. Manufacturers of covered p roducts m ay n ot s ell t heir p roduct i n O regon u nless t hey a re p articipating in the PaintCare program. For t hose of u s n ot i n O regon, t here i s another source to turn to – Earth911. What started as a hot line for recycling has grown into a t remendous reso urce f or sta ying plugged i n t o t he g reen s cene. At w ww. Earth911.com, you w ill f ind new s, a rticles, ideas a nd bu siness s olutions fo r r educing your impact on the environment. One such resource is a database with over 100,000 recycling locations across the country. Simply e nter t he t ype of p roduct y ou w ish t o recycle and your zip code, and you are given a list of a ll of t he facilities or programs that recycle that product within a 30-mile radius of your location, as well as a map of each site and options for curb-side pickup. It i s g reat t o s ee t he g roundwork b eing laid to help consumers find an easy way to s olve t he le ftover p aint i ssue. The mo re hassle-free it becomes, the more people will stop sneaking half-full paint cans into their garbage c ans o r s toring old c ans i n t heir basements for years on end.

tell me more www.airproducts.com/easy © Air Products and Chemicals, Inc., 2010

(32661)

Visit ads.pcimag.com 6

䡲䡲䡲

006 Viewpoint.indd 6

By Kristin Johansson, Editor | PCI

OCTOBER 2010 | W W W . P C I M A G . C O M

9/20/10 11:36 AM

I NDUSTRY N EWS

Scientists Show There is Nothing Boring About Watching Paint Dry NEW H AVEN, C T – It t urns ou t t hat watching p aint d ry m ight n ot b e a s boring a s t he old ada ge cla ims. A t eam led b y Y ale U niversity r esearchers ha s come up w ith a new t echnique t o s tudy the mechanics of coatings as they dry and peel, and has discovered that the process is far from mundane. In t he A ugust 9- 13 e dition of t he Proceedings of t he N ational Ac ademy of Sciences, t he t eam p resents a new w ay to i mage a nd a nalyze t he me chanical stress t hat ca uses co lloidal co atings, those i n wh ich m icroscopic p articles of one s ubstance a re d ispersed t hroughout another, to peel off of surfaces. Understanding ho w a nd wh y c oatings fail ha s broad applications i n the physical and biological sciences, said Eric Dufresne,

the J ohn J . L ee A ssociate P rofessor of Mechanical En gineering at Yale and l ead author of the study. To v isualize t he m icroscopic mot ion of p aint i n 3 -D, t he t eam m ixed i n t iny fluorescent p articles t hat g low whe n illuminated by a la ser. By t racing t he motion of t hese p articles o ver t ime w ith a microscope, they captured in detail the

motion of the paint as it peeled and dried. In addition, the team was able to track the 3 -D fo rces g enerated by t he p aint as it d ried, p roducing a “ stress m ap” of t he me chanical d eformation of t he coating a s it fa iled. “ The t rick w as t o apply t he p aint t o a s oft s urface, m ade of silicone rubber, that is ever so slightly deformed by t he gentle forces exerted by the drying paint,” Dufresne said. Although th e c urrent s tudy f ocuses on c olloidal c oatings, t he t echnique could be applied to all kinds of c oatings, Dufresne said. Other a uthors of t he s tudy i nclude Ye Xu, Wi lfried E ngl, E lizabeth J erison a nd Callen H yland (Y ale U niversity); Kev in Wallenstein (P rinceton U niversity); a nd Larry Wilen (Unilever).

Graphic design by Wendolyn Hill with data from Ye Xu and Eric Dufresne.

IRL Publishes Pigments and Fillers Study LONDON – IRL has published a study entitled Pigments and Fillers in the European Coatings Industry. The s tudy provides an overview of t he m arket s izes a nd t rends t hat govern t he d emand fo r a ll of the key t ypes of p igments a nd f illers w ithin t he E uropean p aint and coatings sector. Pigment c onsumption by t he E uropean p aint a nd c oatings industry w as rat ed at 1 ,035,000 t onnes i n 2 009, w ith titanium d ioxide u se ac counting fo r ju st o ver 7 62,000 t onnes (approximately 7 3 p ercent). C arbon blac k i s t he s econd-largest single pigment type, with consumption at 77,500 tonnes, which is just slightly less than the combined use of other inorganic, organic and sp ecial-effect pig ments. Fu nctional pig ments repre sent a market of 116,000 tonnes. A n umber of d riving fo rces c ontinue t o shap e t he m arket fo r pigments. These include the elimination of heavy metals and heavy metal salts on the one hand and the greater ingress of competitively priced high-performance pigments from the Far East on the other. Inorganic pigments, although losing some appeal due to cadmium, chromium or barium content, will in general continue to be the preferred types where heat, light and chemical resistance properties are required. Organic pigments represent an area of modest growth. The volume of fillers and extenders consumed by the European coatings industry is placed at almost 1.65 million tonnes in 2009. The market is dom inated by c onsumption of c alcium carbonate at 960,000 tonnes, followed at a considerable distance by talc and kaolin applications. Most p arts of t he p aint p igments m arket a re g rowing at between 2 percent and 4 percent per annum (the exception being 8

䡲䡲䡲

008 IndustryNews.indd 8

chromium-containing t ypes, wh ich a re i n g entle d ecline), w ith metallics offering the best growth prospects. For ad ditional i nformation ab out t his s tudy, v isit w ww. informationresearch.co.uk.

ASTM Committee Approves New Lead Paint Standard WASHINGTON, D .C. – A new A STM I nternational s tandard will p rovide t he me ans t o qu ickly d etect a nd qua ntify t he le ad concentration i n t oys a nd ot her ch ildren’s p roducts. The new standard, F 2 853, T est Me thod fo r D etermination of L ead i n Paint L ayers a nd Si milar C oatings o r i n Sub strates a nd Homogenous Materials by E nergy Dispersive X-Ray Fluorescence Spectrometry U sing M ultiple Mon ochromatic E xcitation B eams, was developed by Subcommittee F40.01 on Test Methods, part of ASTM International Committee F40 on D eclarable Substances in Materials. The analytical technique described in this standard is commonly referred to as HDXRF.

TiO2 Industry Stabilizes/Heads for Recovery

PERTH, A ustralia – The $ 10 bi llion t itanium d ioxide i ndustry improved profitability in 2009 compared to 2008, as variable costs reduced at a faster rate than selling prices. Leading producers also id led h igh-cost pla nts du ring t he y ear, le ading t o i mproved asset portfolios. A r ebound in demand in the second half of 2009 had plants winding back to full production rates. TZ Minerals International P ty. L td. (T ZMI) a nnounced t hat, ac cording t o its i ndependent a nalysis of t he g lobal T iO2 s ector, t he w eighted average m anufacturing c ash c ost d ecreased by 1 1 p ercent i n 2009, wh ile at t he s ame t ime s ector r evenues c ontracted by

OCTOBER 2010 | W W W . P C I M A G . C O M

9/20/10 11:58 AM

Coating Thickness Gages for

Non-Metal Substrates

I NDUSTRY NEWS

only 4 .5 p ercent on a U .S. dol lar ba sis. The ne t r esult w as a f urther r ebound i n the i ndustry r evenue t o c ash c ost ( R/C) ratio t o 1 .21, t aking t he s ector bac k t o profitability levels last seen in 2006. On average, industry profitability expanded by over $100 per ton in 2009 relative to 2 008. M anufacturing ca sh costs d ropped s ubstantially r elative t o 2008 costs on the back of declines in raw m aterial a nd e nergy i nput c osts. Producers m anaged t o hold f ixed c osts flat, bu t p roduction rat es w ere do wn i n M o d e l sl e b the f irst ha lf of 2 009 a nd therefore, f ixed a l i Ava cash costs per ton increased. North American plants were the most profitable in 2009, followed by those in Asia-Pacific and Western Europe. There w as a s ignificant d ecrease i n the n umber o f p lants o perating i n a negative c ash-margin p osition in 2 009. In 2008, TZMI calculated that 27 percent of the output that year was operated with The Measure of Quality negative cash margins; in 2009, that had Ogdensburg, New York USA • Tel: 315-393-4450 • Fax: 315-393-8471 • Email: [email protected] decreased back to 11 percent, or 16 plants. In 2 009, g lobal p igment d emand w as Visit ads.pcimag.com estimated at 4 .68 m illion t ons, down 3.0 percent f rom 2008. Regionally, t he main PCI10101DFLSK.indd 1 8/18/10 9:24 AM consuming m arkets fo r T iO2 pig ment PCI11061DFLSK.indd 1 10/2/06 1:47:50 PM are t he m ajor i ndustrialized e conomies of N orth A merica a nd E urope, w ith a n increasing role for China.

NEW

Non-destructively measure single or multiple layer coatings on Wood, Plastic, Concrete, Composites & more

800-448-3835 or www.defelsko.com

Purity through innovation

Global Sieving and Filtration Specialists

Filtration without the Mess or Stress

The Self-Cleaning Russell Eco Filter®... • Improves the quality of your coatings • Tool free & easy disassembly • Reduces your time & labor costs

Call us at: USA: 704 588 9808

Regulations Lead to ASTM Standard for Carbon Black WASHINGTON, D .C. – The U .S. Environmental P rotection A gency h as set fo rth new r egulations t hat m andate greenhouse g as r eporting in t he U .S. carbon black industry. These regulations were the impetus for the development of a new A STM I nternational s tandard, ASTM D 7 633, T est Me thod fo r C arbon Black Carbon Content. The new standard was developed by Subcommittee D24.66 on En vironment, H ealth an d S afety, part o f AS TM I nternational Co mmittee D24 on Carbon Black. George J oyce, M anager, M aterials Analysis L aboratory, C olumbian Chemicals Co. said that the new standard may b e adop ted i nto U .S. a nd C anadian greenhouse ga s r egulations. It m ay a lso eventually b e adop ted by ot her nat ional environmental agencies. 䡲

www.pcimag.com

Visit ads.pcimag.com 10

䡲䡲䡲

008 IndustryNews.indd 10

OCTOBER 2010 | W W W . P C I M A G . C O M

9/20/10 11:58 AM

C O M PA N Y NEWS

Worlée Opens R&D Facility in China L AU E N BU RG, G er ma ny – W orlée China ha s r ecently la unched a n R &D a n d a p p l i c a t i o n /t e c h n o l o g i c a l service c enter i n S hanghai, Ch ina. The lab oratory w ill fo cus on t he development and application of binders and ad ditives i n e co-friendly a nd lo wVOC coating formulations. Located i n S hanghai i n th e X u H ui district, the laboratory is fully equipped

Momentive Performance Materials and Hexion Merge ALBANY, NY /COLUMBUS, O H – Momentive P erformance Mat erials Holdings I nc., t he p arent c ompany of Momentive P erformance Mat erials I nc., and Hex ion L LC, t he p arent c ompany of

with p rofessional t ools, mach inery a nd test i nstruments. T he f acility is r eady

to fo rmulate p aint a nd lac quer s ystems for decorative and industrial applications as w ell a s fo r c orrosion a nd w ood protection. Worlée-Chemie G mbH i s a p rivate producer of resins and additives with p lants in G ermany, s ubsidiaries in Asia (Mumbai, Kuala Lumpur and S hanghai) a nd a w orldwide distribution network.

Hexion Sp ecialty Che micals I nc., ha ve announced a n a greement u nder wh ich their newly fo rmed hold ing c ompanies will merge, creating a global leader in specialty che micals a nd m aterials. The new c ompany w ill op erate u nder t he Momentive Performance Materials name.

The capital structures of both Momentive Performance M aterials H oldings In c. and Hex ion L LC a nd t heir r espective subsidiaries w ill r emain s eparate a nd i n place. Upon closing, with 117 production facilities, more than 10,000 associates, pro forma ann ualized s ales o f a pproximately $7.5 bi llion a nd adjusted E BITDA of $ 1.24 billion, t he new Mome ntive w ill b e one of the world’s largest specialty chemicals and materials companies. The new c ompany w ill b e he adquartered i n C olumbus, OH, a nd w ill maintain a s ignificant p resence in Albany, N Y, whe re it s s ilicones bu siness will continue to be headquartered.

ADM Adds Isosorbide to Product Line DECATUR, I L – A rcher D aniels M idland Co. ( ADM) ha s b egun of fering i sosorbide under it s l ine of E volution Che micals™. Isosorbide is an industrial ingredient made from corn that is a potential alternative to the p etroleum-based che mical bi sphenol A. A DM i s t he f irst c ompany i n N orth America t o of fer r enewable i sosorbide on a commercial scale.

Distributor News Tronox Makes Changes in U.S. Distribution Network

Visit ads.pcimag.com 12

䡲䡲䡲

012 Company News.indd 12

OKLAHOMA C ITY – T itanium d ioxide producer T ronox a nnounced th at th e number of distributors representing Tronox T iO2 in the United States is being reduced from seven to four. In addition to its current territory, Hall Technologies w ill c over M innesota a nd

OCTOBER 2010 | W W W . P C I M A G . C O M

9/20/10 12:43 PM

C O M PA N Y NEWS Louisiana. D.H. Litter will add North Carolina, South Carolina, G eorgia a nd Florida to its current territory. M. F. Cachat will cover Wisconsin, eastern Tennessee, Alabama a nd M ississippi i n ad dition t o it s current t erritory. D owd a nd Gu ild w ill continue to serve the western states.

Double Bond Chemical Enters U.S. Coatings Market WEST S IMSBURY, C T – D ouble B ond Chemical Industries USA Inc. is adding its parent c ompany’s ad ditives p roducts t o it s business mix. Brenntag Specialties Inc.,

South Plainfield, NJ, will exclusively handle sales of D ouble B ond C hemical’s add itive products i n t he U nited St ates. I n C anada, the excl usive d istributor w ill b e U NIPEX Group, Mont real, C anada. B oth of t hese firms will also stock Double Bond products.

H.B. Fuller Names Archway Sales as a Distributor ST. LOUIS, MO – H. B. Fuller Co., St. Paul, MN, ha s ap pointed A rchway Sa les I nc., St. L ouis, MO, t o b e it s d istributor fo r t he company’s v inyl ac etate homop olymer, acrylic, v inyl ac rylic a nd s tyrene ac rylic emulsions i n t he s tates of N orth D akota, South D akota, Ne braska, Ka nsas, Minnesota, I owa, Mi ssouri, W isconsin, Illinois, M ichigan, I ndiana, Ke ntucky, Ohio, W est V irginia, a nd P ennsylvania and New Y ork w est of I-8 1. P rimary markets t hat A rchway Sa les w ill s erve include adhesives, coatings, construction, caulks, sealants, and arts and crafts.

TH Hilson is Expanding with Cabot WHEATON, IL – T H Hilson, Wheaton, IL, is expanding its territory with Cabot Corp. as of O ct. 1, 2010. The new t erritory w ill now i nclude s outhern I llinois, M issouri and Ka nsas. C abot C orp., B oston, M A, i s a g lobal p erformance m aterials c ompany that m anufactures f umed me tal o xides, including t reated a nd u ntreated f umed silica, and specialty carbon blacks.

Brenntag Americas Recognized by Wacker READING, PA – Wacker Chemie AG has recognized se veral B renntag A mericas companies fo r t heir ach ievements a s distribution p artners wi th i ts D istributor of the Year award. The award recognizes outstanding r esults a nd ach ievements by distributor partners. The B renntag A mericas c ompanies receiving a wards ar e: B renntag Specialties, B renntag G reat L akes w ith a platinum award; Brenntag Southeast with a g old a ward; a nd B renntag Canada, B renntag C olumbia, B renntag Guatemala, Br enntag M exico, Br enntag Mid-South a nd Brenntag Northeast w ith the silver award. For consolidated results, Brenntag N orth A merica r eceived t he gold award, and Brenntag Latin America received the silver award.

Visit ads.pcimag.com

䡲䡲䡲

PCI06084Shep.indd 1 14

012 Company News.indd 14

OCTOBER 2010 | W W W . P C I M A G . C O M

4/25/08 2:17:54 PM

9/20/10 12:44 PM

C O M PA N Y NEWS

Boysan to Distribute for Celanese Emulsion Polymers

Sudhir Makim to Distribute for Gelest

Color-Logic Appoints New Representatives

DALLAS – C elanese E mulsion P olymers, a le ader i n t he p roduction of w aterbased v inyl e mulsions, ha s s igned a n LOI w ith B oysan t o b e it s d istributor i n Turkey. A s of J uly 1, 2010, Boysan began distributing C elanese’s br oad ra nge of emulsion te chnologies in to th e c oatings, construction and adhesives industries.

MORRISVILLE, PA – Gelest Inc. has announced t hat Sud hir Ma kim ha s b een appointed t he excl usive d istributor fo r t he government a nd a ll i ndustrial m arkets fo r the c omplete l ine o f Ge lest s ilane, m etalorganic and silicone products serving India.

WEST CHESTER, OH – Color-Logic has na med S cott S ell & A ssociates a s its m anufacturers’ re presentative f or Arizona, C alifornia a nd Nevada. The firm ha s r epresented va rious h ightechnology e lectronic an d gr aphic-arts manufacturers i n t he r egion fo r mo re than 2 5 y ears, i ncluding X -Rite a nd G TI Graphic Technology. Color-Logic ha s a lso na med V izutek as i ts m anufacturers’ re presentative f or the northeastern United States, including the s tates of Ma ine, V ermont, N ew Hampshire, Massachusetts, Connecticut, New Y ork, New J ersey a nd e astern Pennsylvania. Color-Logic develops color communication s ystems a nd s oftware tool s ets fo r a va riety of s pecial-effect printing applications.

E.T. Horn Expands Industrial Products Territory LA MIRADA, CA – The E .T. Horn Co. has been ap pointed by C abot C orp., B oston, MA, t o r epresent it s p roducts i n t he southwest. The new territory will include Texas, Ok lahoma, A rkansas, L ouisiana, Colorado and New Mexico, amending the other n ine w estern s tates t hat E .T. H orn has managed since 2001. Products c overed i n t he d istribution agreement i nclude f umed s ilica, c arbon black and the nanogel lines.

E.W. Kaufmann to Represent Gellner Industrial LLC BRISTOL, PA – E.W. Kaufmann is representing G ellner In dustrial’s lin e of sp ecialty re sins. F ormulated w ith a precise ble nd of w ater-based p olymers, these r esins p rovide s uperior r esults when used in both water-based coatings and printing inks.

Van Horn, Metz & Co. to Distribute for Zhejiang Ruicheng CONSHOHOCKEN, PA – Van Horn, Metz & Co. I nc. ha s b een ap pointed t he exclusive distributor fo r Z hejiang R uicheng E ffect Pigment C o. L td. R uicheng p roduces a line of p earl p igments, i ncluding wh ite, interference, m etallic g old, D iamond Dream™ s ynthetic m ica a nd ex terior grades.

Malvern Instruments Extends Direct Operations in Japan MALVERN, U K – Ma lvern I nstruments i s extending i ts dir ect o perations in J apan and ha s c oncluded a n a greement w ith Sysmex Corp., the current distributor of it s laboratory-based p article cha racterization systems, to t ransfer re sponsibility f or sales a nd s upport t o Ma lvern I nstruments Japan. An expanded organization will now provide s ales, t echnical a nd ap plications support across the entire range of Malvern’s particle characterization systems.

Univar Expands in the Baltics BRUSSELS, B elgium – U nivar, a g lobal chemical d istributor, ha s s igned a distribution deal with Celanese Emulsion Polymers. The a greement e stablishes Univar’s position in the Baltic region, following t he r ecent op ening of it s of fice in Lithuania. Under this new agreement, Univar will distribute Celanese Emulsion products t o t he c oatings, ad hesives, nonwovens, g lass f ibers, t extiles, p aper and construction industries. 䡲



%H*UHHQDQG%HWWHU

70 2[\OLQN 

 7KHSHUIRUPDQFHDGGLWLYHIRU  • 6WURQJHU ZDWHUERUQHFRDWLQJV • )DVWHU  GU\LQJ • %HWWHU  EORFNLQJUHVLVWDQFH • +LJKHU  KXPLGLW\UHVLVWDQFH • ,QFUHDVHG SURGXFWLYLW\

)RUEHWWHU ZDWHUERUQH FRDWLQJV &DOOXVIRUDIUHHVDPSOH %XKOHU,QF17  2[\OLQN#EXKOHUJURXSFRP 86$&DQDGD (XURSH$VLD  ZZZEXKOHUJURXSFRP

Visit ads.pcimag.com 16

䡲䡲䡲

012 Company News.indd 16

OCTOBER 2010 | W W W . P C I M A G . C O M

9/20/10 12:44 PM

N AMES I N TH E N EWS 䡲 The C hemical C oatings di vision o f SherwinWilliams ha s a nnounced t he p romotion of

Territory Ma nager i n t he r egion a nd w ill w ork closely with Yoong.

Ganesh D esai t o t he p osition of T echnical Manager. D esai w ill h ave re sponsibilities f or the M ilitary G roup at t he A rthur W . St eudel Technical Center in Chicago, IL.

䡲 Arch Ch emicals ha

䡲 EYE Lighting International has appointed

Robert F reitag Vice President of Marketing. Freitag He will be responsible for product management, pricing, distribution and market communications.

䡲 Michael Hen g ha s b een na med C ommercial D irector

Nelson

s p romoted Mark Kenline to General Ma nager for A rch Biocides’ Preservation a nd P rotection bu siness. Ke nline will have lead management responsibilities for t he Bu ilding P roducts, Ma rine A ntifouling Paints, Me tal W orking F luids, P lastics a nd Custom Chemicals business units.

䡲 Dan N elson will l ead Gaco W estern’s re search a nd development a rm as the new V ice President of R &D at it s manufacturing facility in Waukesha, WI. Pat Hatem will join Gaco Western as the new Vice President of Operations, also at the manufacturing facility in Waukesha.

– A sia fo r Michelman In c. He will be responsible for developing a nd m anaging M ichelman’s sho rt- a nd lon gterm c ommercial s trategies fo r t he A sian m arkets. Allan Low has been hired to fill the position of Asia-Pacific Plant 䡲 Ted R oberts ha s j oined Deacom I nc. as Senior Sales Manager. George Lim has been appointed to the position of Roberts Manager, Asia Sourcing. Lim will develop relationships with Engineer. He will help drive integrated ERP software sales key supply-chain partners, with a focus on raw materials suppliers. for the company. Shenglan Cheng has been hired as Michelman’s newest Research Chemist ba sed i n t he c ompany’s Si ngapore R &D lab oratory. He r 䡲 NYCO Minerals ha s appointed Michael Wolfe to the position work will focus on M ichelman’s chemical specialty products. Linus of General Manager of Sales, Coatings. Wolfe will be responsible for Yoong has been promoted to Regional Sales Manager. Yoong’s new worldwide s ales t o t he c oatings m arket. He w ill a lso w ork clo sely responsibilities will in clude m anaging gr owth an d s ustainability with the sales team and a worldwide agent and distributor network initiatives i n t he A sia r egion. Janice N g ha s b een h ired a s a new to develop new opportunities for the company. 䡲

Colour Black FW 171 /FX
DPMPS
RVBMJUZ
GPS
XBUFSCPSOF

BVUPNPUJWF
DPBUJOHT

t
7FSZ
mOF
)JHI
+FU
$BSCPO
#MBDL
1JHNFOU
t
&YUSFNFMZ
OBSSPX
QBSUJDMF
TJ[F
EJTUSJCVUJPO
t
0øFST
IJHI
HMPTT
BOE
B
WFSZ
CMVF
VOEFSUPOF www. carbon-black-pigments.evonik.com

Visit ads.pcimag.com 18

䡲䡲䡲

018 Names.indd 18

OCTOBER 2010 | W W W . P C I M A G . C O M

9/20/10 12:00 PM

Applying Principles of Green

Engineering to

A

dditives ba sed on g reen che mistry a re no longer an illusive concept, but a reality. H igh-performance c oatings a re th e result of proper selection of many ingredients, a mong wh ich ad ditives pla y a very important role. Additives may represent only a small portion of the paint formulation. However, they can be the determining fac tor i n f inal ap plication a nd p erformance properties. A s environmental regulations get more stringent, t he p erformance r equirements a nd ex pectations of consumers are expanding. The coatings industry requires that additives based on green chemistry perform the same or better than the traditional additives. They should combine performance, sustainability and efficiency. Additives such a s e mulsion o r r enewable oi l d efoamers, A PEO-free dispersants, r enewable c oalescents, a nd h ighly e fficient rheology modifiers are some of t he paint ingredients that can help bring an emission-free paint concept to practicality. In this paper we discuss additives specifically designed with the 24 principles of green chemistry and engineering in m ind. We show how multi-functional a spects of t hese additives w ork in h armony t o p roduce p aints w orthy o f pro-environmental l abelling, wi thout s acrificing p erformance. In addition, it is important to note that there are certain synergies possible between various classes of these unique additives.

Green and High-Performing Additives In order to best meet the modern paint requirements and growing consumer expectations, technical advancements need to be in sync with the current definition of green

FIGURE 1 | Shear rate and paint properties.

Viscosity [mPa.s]

105

sedimentation storage

10

4

103

leveling and sag stirring and dipping

102

dispersing, brushing, spraying, rolling

10 0

1

10 102 D Shear Rate [s-1]

103

104

chemistry. However, when talking about green chemistry it is always difficult to define what exactly is “green”? In 1998, D r. Paul T. A nastas publ ished h is 12 P rinciples of Green Che mistry, wh ich a re g enerally ac cepted t oday.1 Cognis h as a dopted th ese i nternationally r ecognized principles along with the 12 Principles of Green Engineering2 a s c entral g uidelines fo r t he d evelopment of c oncepts, p roducts a nd p rocesses. Ac cording t o t he 24 p rinciples of g reen che mistry a nd e ngineering (Table 1), a mongst ot her t hings, a voiding c ontamination and wa ste, ma king ma ximum u se of r enewable ra w materials, ma ximizing ef ficiency t o u se le ss ma terials, ensuring e ventual b iodegradability o f en d pro ducts, a nd minimizing the energy needed to carry out reactions are part of this guideline. When t hinking ab out g reen che mistry i n architectural c oatings it ha s t o b e s tated that p igments ar e m ainly in organic, and t he d efinition of r enewable ra w materials do es n ot f it w ell he re. Re sins are ex tremely d iversified due t o all dif ferent kin ds o f s urfaces, application r equirements and p erformance c riteria, and a re m ainly ba sed on petrochemical r esources. B ut t h e s w i t c h t o water-based tec hnology represents t he g reen t rend by replacing non-renewable solvents with water and could go further by u sing renewable building blo cks. Ad ditives fo r water-based p aints a re a lready quite advanced with regard to the u se of g reen che mistry. I n ou r efforts o ver t he la st few y ears, w e have demonstrated that it is possible to develop renewable-based additives that o ffer h igher pe rformance l evels than th eir f ossil-based c ounterparts a n d r e p r e s e n t t r u e “ g r e e n” alternatives for the paint industry. Cognis, with more than 160 years of experience in nature-based chemistry, has c ombined th e l atest tec hnological advancement i n ad ditive de sign w ith a n in-depth k nowledge of r enewable che mistry t o

By Dr. Homer Jamasbi, Dr. Shailesh Shah | Cognis Corporation, Ambler, PA; and Michael Hoppe | Cognis Corporation, Cincinnati, OH 20

䡲䡲䡲

020 Cognis FT.indd 20

OCTOBER 2010 | W W W . P C I M A G . C O M

9/20/10 12:12 PM

Chemistry and

Design Additives Green Defoamers Based on Renewable Materials Most d efoamers u sed i n a rchitectural p aints a re ba sed on m ineral o ils w ith h igh b oiling po ints.3 M ineral oi l is n on-renewable a nd c ontains V OCs. C ognis explored s everal op tions t o c reate m ineral oil-free d efoamers, a mong wh ich w as t o use w ater a s a s ubstitute c arrier w ith polymeric d efoamer ac tive i ngredients. These new fo rmulations of fered equal o r b etter p erformance t han standard m ineral oi l d efoamers with lower odor. Another a pproach u sed in E urope w as t o r eplace mineral oil with natural oils l ike s oy b ean, rape s eed, s unflower and ri ce b ran o ils. The p erformance of paints ba sed on lat estgeneration of lat exes with def oamers made from n atural o ils w as then m onitored. T he results s howed t hat, while b eing m ade up of o ver 95 percent r enewable ra w m aterials, these d efoamer fo rmulations of fered improved d efoaming p erformance an d indoor a ir qua lity. T ests a lso sho wed that using natural-oil-based defoamers had n o i mpact on g loss a nd y ellowing after UV exposure. Mineral oi l d efoamers t ypically have had a V OC c ontent of 2% t o 6 % by weight, e ven th ough th ey c ontain 100% a ctive ingredients by c omposition. M ineral oi l t echnology produces a very effective and economical way to defoam

latex paints. For this reason, renewable resources have not b een a s uccessful a lternative u ntil r ecently i n defoamer t echnology. New lo w-VOC m ineral oi l-based defoamers a re b eing i ntroduced t hat a re a s e qually effective a s t he c urrent p roducts. The V OCs of t hese defoamers have b een lowered t o ≤ 0.5% by weight. We have a lso used h yper-branched po lymers as a w ay to boost defoamer efficiency by 50-100%. This approach is s imultaneously e conomical an d o ffers hi gher performance at much reduced VOC contribution. It also complies with one of t he principles of g reen chemistry: reduced use through higher efficiency.

Natural Oil-Based Coalescents

Historically, e sters ha ve m ade id eal c oalescents.3 One of the most widely used products is trimethyl pentanediol mon oisobutyrate. C oalescents ba sed on renewable s ources c ombine va rious lon g-chain ac ids with e ither the short-chain a lcohol l ike methanol (the most economical option) or higher-chain alcohols and glycols o r e ven g lycol e sters. G lycerol a s a n a lcohol i s not s uitable f or th is use , as gl ycerol es ters c an h ave a ne gative i mpact on t he ad hesion of t he p aint f ilm. Very sho rt-chained ac ids l ike C -8 a re a lso not s uitable as th ey c ontain V OCs. Lo nger-chain es ters w ith a higher mole cular w eight fo rm s ofter f ilms a nd ac t a s plasticizers. New “ green” c oalescents t hat a re h igh i n efficiency, lo w i n t oxicity a nd i mprove e arly ha rdness development are a step in the right direction for making better paints, especially outdoor paints. A h igh-purity v ersion of p ropylene g lycol mon ooleate ba sed on r enewable ole ic ac id w as i ntroduced

FIGURE 2 | Effect of green coalescent on efficiency of rheology modifiers. 120 115 Kus

create a br oad p ortfolio of g reen ad ditives. C urrently about 5 0% of ra w m aterials u sed by C ognis a re ba sed on r enewable r esources. T his e xtensive k now-how is captured under “Greenovating” philosophy. Greenovating provides g enuine g reen che mical s olutions w ith r eal benefits d efined ac cording t o s even d imensions a nd i n line with relevant market demands. Such an approach provides a cle ar f rame of r eference a nd a g uide fo r checking the sustainability, environmental compatibility and performance dimensions of green products (Table 2).

110 105 100 95

TMB Equilibrated

Green Coalescent Heat Aged

PA I N T & C O A T I N G S I N D U S T R Y

020 Cognis FT.indd 21

䡲䡲䡲

21

9/20/10 12:12 PM

Applying Principles of Green Chemistry and Engineering to Design Additives

to me et s tringent V OC r equirements i n t he c onsumer coatings m arket g lobally.4 B ased on c ustomer fe edback, a 2 nd-generation p ropylene g lycol mon oester w ith C -18 fatty ac id m ixtures w as i ntroduced t hat ha s b etter c olor and of fers a n i mproved va lue. A t hird p roduct ba sed on renewable t echnology i s a h igh-purity v ersion of l inear short-chain fat ty e sters, wh ich i s VOC-free ba sed on t he European definition but is over 90% VOC by E PA Method 24. Th is p roduct ha s b een fou nd t o b e o ver 3 0% mo re efficient t han trim ethyl p entanediol m onoisobutyrate ester (T MB) i n m any p opular t ypes of lat exes a nd offers i mproved ha rdness d evelopment a nd d irt p ick-up resistance. The se r enewable-based c oalescents a re naturally d erived, lo w-odor a gents a nd c an b e u sed i n all t ypes of d ecorative p aints a nd r esult i n i mproved performance and application properties, while helping to achieve compliance with new VOC regulations. These two coalescents a re r egistered i n s everal c ountries a round

TABLE 1 | Generally accepted Green Chemistry principles. 12 Principles of Green Chemistry1 Prevention It is better to prevent waste than to treat or clean up waste after it has been created. Atom Economy Synthetic methods should be designed to maximize the incorporation of all materials used in the process into the final product. Less Hazardous Chemical Syntheses Wherever practicable, synthetic methods should be designed to use and generate substances that possess little or no toxicity to human health and the environment. Designing Safer Chemicals Chemical products should be designed to effect their desired function while minimizing their toxicity. Safer Solvents and Auxiliaries The use of auxiliary substances (e.g., solvents, separation agents, etc.) should be made unnecessary wherever possible and innocuous when used. Design for Energy Efficiency Energy requirements of chemical processes should be recognized for their environmental and economic impacts and should be minimized. (Ambient temp). Use of Renewable Feedstocks A raw material or feedstock should be renewable rather than depleting whenever technically and economically practicable. Reduce Derivatives Unnecessary derivatization (use of blocking groups, protection/ unprotection, temporary modification of physical and chemical processes) should be minimized or avoided. Catalysis Catalytic reagents (as selective as possible) are superior to stoichiometric reagents. Design for Degradation Chemical products should be designed so that at the end of their function they break down into innocuous degradation products. Real-time Analysis for Pollution Prevention Analytical methodologies need to be further developed to allow for realtime, in-process monitoring. Inherently Safer Chemistry for Accident Prevention Substances used in a chemical process should be chosen to minimize the potential for chemical accidents, including releases, explosions and fires. 22

䡲䡲䡲

020 Cognis FT.indd 22

the world. Key p roperties of one of t hese new c oalescing agents are summarized in Table 3.

Highly Efficient, VOC-Free Rheology Modifiers In c ontrast t o d efoamers a nd c oalescents, t here i s on ly a l imited p ossibility t o i nclude r enewable ra w m aterials into m odern s ynthetic a ssociative r heology m odifiers f or aqueous c oatings. S o fa r, r enewable ra w m aterials a re included but a re limited by che mistry to the range of 10 – 30% (n ot i ncluding w ater). The fo cus of ou r d evelopment and va lue p roposition fo r r heology mo difiers i s fou nd i n two e lements: e fficiency a nd m ulti-functionality, wh ich i s in line with principles of green chemistry. However, an ideal rheology modifier portfolio should offer both efficiency and multi-functionality across the different shear rates in order to provide the best rheological properties (Figure 1). Hydrophobically mo dified w ater-soluble p olymers (HM-P) are polymers with hydrophobic groups chemically

12 Principles of Green Engineering2 Inherent Rather Than Circumstantial Designers need to strive to ensure that all material and energy input and output are as inherently non-hazardous as possible. Prevention Instead of Treatment It is better to prevent waste than to treat or clean up waste after it is formed. Design for Separation Separation and purification operations should be designed to minimize energy consumption and material use. Maximize Efficiency Products, processes and systems should be designed to maximize mass, energy, space and time efficiency. Output-Pulled Versus Input-Pushed Products, processes and systems should be “output pulled” rather than “input pushed” through the use of energy and materials. Conserve Complexity Embedded entropy and complexity must be viewed as an investment when making design choices on recycle, reuse or beneficial disposition. Durability Rather Than Immortality Targeted durability, not immortality, should be a design goal. Meet Need, Minimize Excess Design for unnecessary capacity or capability (e.g., “one size fits all”) solutions should be considered a design flaw. Minimize Material Diversity Material diversity in multicomponent products should be minimized to promote disassembly and value retention. Integrate Material and Energy Flows Design of products, processes and systems must include integration and interconnectivity with available energy and materials flows. Design for Commercial “Afterlife” Products, processes and systems should be designed for performance in a commercial “afterlife.” Renewable Rather Than Depleting Material and energy input should be renewable rather than depleting.

OCTOBER 2010 | W W W . P C I M A G . C O M

9/20/10 12:13 PM

Applying Principles of Green Chemistry and Engineering to Design Additives

attached t o a h ydrophilic p olymer bac kbone.5 The y a re often r eferred to as ass ociative po lymers o r ass ociative thickeners. The f irst s tudies on H M-P w ere m ade by Strauss a nd c oworkers mo re t han 5 0 y ears a go. They are d escribed i n a r eview a rticle.6 The w ork w as done with h ydrophobically mo dified p olyelectrolytes. The idea b ehind t he s tudies w as t hat s ince s oap mole cules associate t o fo rm m icelles i n a n aque ous s olution, t hen surfactants chemically grafted to a water-soluble polymer would form m icelles. That i ndeed was what t hey found. In addition they found that the “polysoaps” gave unique solubilizing e ffects a nd a s urprisingly la rge i ncrease i n viscosity t o a n aque ous s olution. The se t wo e ffects of HM-P a re w idely u tilized. The la rgest ap plication fo r HM-P is as a rheology modifier in waterborne coatings. Landoll and his coworkers described the first associative thickeners for waterborne paint i n the eighties.7-9 The y worked w ith h ydrophobically mo dified ( hydroxyethyl) cellulose (HM-HEC), which is a nonionic cellulose ether. Hydrophobically mo dified e thyl h ydroxyethyl c ellulose (HM-EHEC), h ydrophobically mo dified e thoxylated urethanes ( HEUR), h ydrophobically mo dified p olyether (HMPE) a nd h ydrophobically mo dified p olyacrylates (HM-PA) a re ot her exa mples of a ssociative t hickeners that ha ve b een d eveloped fo r p aint ap plication. I n recent y ears t he a rchitectural p aint fo rmulations ha ve gone t hrough s everal ev olutionary cha nges i n o rder t o meet a nd exc eed e nvironmental a nd V OC r egulations. There seem to be three main factors. First, as paint formulations mo ve t o lo wer a nd ev entually V OC-free formulations, r heology m odifiers, an d in p articular associative thickeners, follow the same pattern. Second,

FIGURE 3 | Comparative efficiency of the new (HMPE) rheology modifier vs. existing products. Equilibrium ICI New (HMPE) ICI Builder Existing (HMPE) ICI Builder Existing (HEUR) ICI Builder

3

ICI Poise

2.5 2 1.5 1 0.5 0 10

20

30

40

50

60

70

Lb Thickener/100 Gal

as green chemistry gains popularity and use of chemicals such as APEO (Alkyl Phenol Ethoxylates) have been restricted, associative thickeners also need to be APEO free. The t hird fac tor i s t he fac t t hat mo dern V OC-free architectural p aints r equire h ighly-efficient a ssociative thickeners, s o i n a V OC-free p aint fo rmulation t hey would deliver the same results under similar dosage and incorporation levels. The modern and next-generation associative thickeners from C ognis ha ve ad ded a fou rth d imension, wh ich i s multi-functionality t hrough i ncorporation of d iluents that w ould lo wer t he ne ed fo r ot her i ngredients i n t he paint. F inally, t here a re c ertain s ynergies b etween t hese modern rheology modifiers and other additives that could provide a definite advantage to the end user. For example, several s tudies6 d emonstrated t hat t he u se of a g reen, emission-free c oalescent ba sed on C -18 (m ixed ole icstearic) st ructure f rom ren ewable re sources o ffers m ore efficient r heology m odification th an T MB, a t b oth h igh (ICI) and medium (KU) shear rates (Figure 2). The C -18 (m ixed ole ic-stearic) s tructure of g reen coalescent e nsures t he lat ex p articles ha ve g reater hydrophobicity than is the case with C12-14 fatty alcoholbased polymerization surfactants or TMB, and as a r esult they associate better with associative thickeners. By using this e mission-free g reen c oalescent, r heology mo difier usage c an t ypically b e r educed by 1 0 t o 1 5 p ercent when c ompared w ith T MB. A ll of t hese a re of fered i n a broad ra nge of v iscosity p rofile v ersus she ar rat e. B elow we d iscuss t he g eneral cha racteristics of t hree cla sses of modern associative thickeners as high-shear or ICI builders, m id-shear o r K U bu ilders, a nd f inally s trongly pseudo-plastic associative rheology modifiers.

High-Shear Associative Rheology Modifier A new s tate-of-the-art h igh-shear a ssociative r heology modifier ha s b een d eveloped w ith a u nique ba lance of properties. This new of fering is based on hydrophobically modified p olyether ( HMPE) t echnology. Th is new rheology mo difier w ith a ne at v iscosity of 1 800-2800 mPa.s a nd a s olids lev el of 2 1% i s v ery e asy t o ha ndle and t o i ncorporate. I n ad dition t o b eing V OC f ree a nd APEO free, this new r heology modifier has a h igh degree of e fficiency i n bu ilding h igh-shear v iscosity bu t a lso provides medium-shear viscosity contribution. Therefore, lower incorporation levels are used to achieve the same ICI viscosity t arget, a nd r eduction i n K U-builder i s p ossible, hence r esulting i n a n exc ellent ba lance of p roperties. I n an all-acrylic semigloss interior 50 g/L VOC formulation, when t his new H MPE r heology mo difier w as c ompared against an existing HEUR rheology modifier, 40% higher

TABLE 2 | Cognis’ seven dimensions of benefit. Application

Efficiency

Health

Safety

Toxicity

Degradability

Labeling

We enhance the usability of products for commercial applications and everyday life.

We improve the efficiency of products in use: get more with less.

We increase health protection of people who come in contact with our products or their traces.

We increase safety on the job and in everyday product use.

We reduce harmful content.

We facilitate biodegradability of products.

We help customers to improve environmental friendliness of their products and to label them accordingly.

24

䡲䡲䡲

020 Cognis FT.indd 24

OCTOBER 2010 | W W W . P C I M A G . C O M

9/20/10 12:13 PM

Applying Principles of Green Chemistry and Engineering to Design Additives

FIGURE 4 | Effect of as-supplied dosage on viscosity in a clearcoat based on highgloss acrylic resin (Brookfield LVT spindle 4, 6 rpm).

Viscosity [mPa.s]

120,000

HGL3, new product

High-gloss latex 1, new product

100,000

High-gloss latex 1, reference

80,000 60,000

HGL1, new product

40,000

HGL2, new product

High-gloss latex 2, new product High-gloss latex 2, reference

HGL3, reference

High-gloss latex 3, new product

HGL1, reference

High-gloss latex 3, reference

20,000 HGL2, reference

0 0.4 0.6 0.8

1

1.2 1.4 1.6 1.8

2

2.2 2.4

Dosage in Clearcoat [ %]

FIGURE 5 | Excellent flow and leveling despite very high efficiency. 7 7 Flow and Leveling

6 5

4

4 3 2 1 0 New Strongly Pseudo Plastic (HEUR)

Low-Shear (HEUR) RM

FIGURE 6 | Dispersing-wetting agents: Performance profile of a polymeric vs. a smart combination of green actives. - Polymeric dispersant - Green dispersant

5 = excellent 4 = very good 3 = good 2 = fair 1 = poor 0 = bad Paste viscosity

Pigment concentration

Inorganic pigments

Organic pigments

0

Label

1

2

3

4

5

Cost efficiency Gloss

26

䡲䡲䡲

020 Cognis FT.indd 26

Compatibility

ICI viscosity was achieved at 10% lower rheology modifier use lev el. N ot on ly d id t his r esult i n s ignificant s avings in fo rmulation c ost, bu t a lso i n h igher s crub r esistance properties, b etter s ag r esistance at t he s ame f low a nd leveling rat ing, a nd c omparable p erformance p roperties in a ll other a spects. Figure 3 d emonstrates the efficiency of the new associative rheology modifier, which is based on hydrophobically mo dified p olyether ( HMPE) t echnology versus both an existing (HEUR) as well as an existing (HMPE) r heology m odifier in an all -acrylic s emigloss interior 50 g/L VOC formulation.

Mid-Shear Associative Rheology Modifier Just as in the high-shear ICI builders over the course of the la st few y ears, t here ha s b een s ignificant p rogress i n the chemistry a nd t he structure of m id-shear a ssociative rheology modifiers or KU builders. This progress has been in b oth hydrophobically mo dified e thoxylated u rethanes (HEUR) chemistry, as well as hydrophobically modified polyether (HMPE). In general these systems are VOC free, APEO f ree, o dor f ree a nd f ree f rom he avy me tals, w ith a h igh lev el of e fficiency. I n s ome p rototypes a s pecial built-in foa m-suppressing, r enewable w etting a gent/ coalescent is used that lowers the need for other additives in low-VOC paint formulations. Among several significant comparative studies, a couple of the mid-shear associative rheology modifier prototypes in an acrylic system, both in semigloss a nd f lat fo rmulations, d emonstrate s ignificant efficiency a dvantages o ver e xisting co mmercially available lo w- t o m id-shear r heology mo difiers, w ith superior sag resistance and lower KU drop upon colorant addition. In another study in a flat PVA formulation, up to 45% higher KU efficiency was found, with lower KU drop upon c olorant a ddition an d b etter s ag r esistance af ter colorant addition, in comparison to existing low- to midshear associative rheology modifiers.

Strongly Pseudo-Plastic Rheology Modifier The newly developed hydrophobically modified ethoxylated urethane (HEUR)3 associative rheology modifier provides a strongly pseudo-plastic rheology profile, as is typically achieved f rom a nionic ac rylic t hickeners o r c ellulosics. It sets a new standard with regard to efficiency as an associative t hickener. To ach ieve t he same v iscosity level (e.g., 2 0,000 m Pa.s), on ly 0 .14% of t he new p roduct i s needed, while with an existing product, more than twice as much active product is required (Figure 4). Figure 4 cle arly d emonstrates t hat t he r ecently developed po lyurethane th ickener tec hnology is m ore than t wice a s e fficient a s t he g iven r eference p roduct. This efficiency benefit can also be found in comparison with several other polyurethane thickeners available in the market. This new s trongly p seudo-plastic r heology mo difier i s supplied at a v iscosity of ab out 3000 m Pa.s a nd solids of about 30%. As a r esult, this associative thickener is easy to handle and easy to incorporate. In addition to an exceptionally high level of efficiency and b eing V OC f ree, A PEO f ree, o dor f ree a nd f ree f rom heavy metals, this new rheology modifier, in a comparative study a gainst ot her ex isting h ydrophobically mo dified

OCTOBER 2010 | W W W . P C I M A G . C O M

9/20/10 12:13 PM

Applying Principles of Green Chemistry and Engineering to Design Additives

Renewable Dispersing/Wetting Agents

TABLE 3 | Characteristics of a renewable coalescent. Chemical Description Viscosity, mPa•s Active substance Boiling range Volatiles % by EPA Method 2.1 (1 10˚C for 1 Hr. Forced air) Volatiles % by Method 1999/13 EU and 2004/42/EU

High Purity, Propylene Glycol Monoester 30 100% -284 ˚C =< 2% (mainly as propylene glycol) VOC free

ethoxylated u rethane (H EUR) a ssociative r heology modifiers, i n a s emigloss ac rylic a rchitectural p aint, demonstrated near-perfect flow and leveling (Figure 5) at the same sag resistance and better scrub resistance due to lower usage level. In a separate study, similar advantages were confirmed, in addition to lower KU drop upon colorant addition. The possibility to use less synthetic thickener in a paint formulation is not only beneficial from an ecological and economical p oint of v iew, it a lso helps t o avoid t echnical problems wi th w ater r esistance an d/or s crub r esistance in a g iven p aint fo rmulation. A ll t hese g reen b enefits make t he new t hickener g eneration t he id eal choic e fo r economical and ecological paint formulations.

Modern d ispersing ag ents f or wa ter-based h ighperformance o r h igh-gloss p aints a re u sually ac rylic or ot her c opolymers. The ir p olymer d esign c onsists of pigment a ffinic g roups t hat ‘ anchor’ on t he p igment surface. I onic g roups a re r esponsible fo r e lectrostatic stabilization but are minimized so as to not influence the water r esistance ne gatively, a nd f urthermore ad ditional nonionic groups are included for steric stabilization of the dispersions. In our extensive search for ‘green’ alternatives, we ha ve d iscovered t hat a ble nd of ac tives w ith t he necessary f unctional moie ties w as e qually e ffective a nd more f lexible t han it s p olymer c ounterparts. P igment anchoring groups are oleo-based and stand for the ‘green’ part of the molecules; steric stabilization is provided by (poly)ethylene o xide a nd ion ic f unctions i n t he fo rm of carboxyl, s ulfate o r pho sphate g roups. The mole cular structure of t he i ndividual ac tives i s a lready ol igomericpolymeric w ith mole cular w eights ra nging f rom 5 00 – 2 ,500. Th is f lexible p rinciple le d t o w ell-performing additive c ombinations t hat a re s uitable a lternatives t o their p etrochemical c ounterparts ( Figure 6 ). I norganic pigments a re e qually d ispersed a s w ith p olymeric one s, while some organics are slightly weaker. Here the pigment load and paste viscosity are a l ittle less, but compatibility is improved with excellent cost effectiveness.

Visit ads.pcimag.com PCI08081ELCM.indd 1

28

䡲䡲䡲

020 Cognis FT.indd 28

OCTOBER 2010 | W W W . P C I M A G . C O M

7/17/08 10:08:44 AM

9/20/10 12:13 PM

Type ZY Premium Type ZY

Conclusion

Type ZS

Superior p erformance a nd g reen che mistry a re n ot i n contradiction t o e ach ot her. O n t he c ontrary, t he i ntelligent use of renewable resources can lead us to green and innovative products t hat c reate u nique of ferings fo r t he i ndustry. It i s possible t o h ave i nnovative a dditive s olutions t hat s et n ew industry s tandards i n t he a rchitectural c oatings m arket. Not on ly r enewable-based c oalescents t hat sho w s uperior properties c ompared t o t heir p etro-based c ounterparts, bu t also d efoamers ba sed on r enewable m aterials a re a r eality today. Highly efficient, VOC-free and multi-functional rheology modifiers e nable t he fo rmulator t o p roduce g reen aque ous paints with superior properties. Renewable dispersing-wetting agents are an economical alternative to inflexible polymeric and APEO-based universal dispersants. Accelerated growth for environmentally f riendly g reen c oatings i s ex pected, a nd t he cooperation of s uppliers a nd p aint m anufacturers i s e ssential to ach ieving t he b est-performing p aints t hat a lso c arry t he most prestigious pro-environmental labelling. 䡲

Type Z Type GZ

®

SiLibeads

King of all Beads” strong powerfull

„

For more information, visit http://cognis.com/company.

References 1

Anastas, P. T.; Warner, J. C. “Green Chemistry: Theory and Practice”, Oxford University Press: New York, 1998, p.30.

2

Anastas, P.T.; Zimmerman, J.B. Design through the Twelve Principles of Green Engineering. Env. Sci. and Tech. 2003, 37, 5, 94A-101A.

3

Oestreich, S.; Schulte, H.G.; Schamp, A. “Green and High-Performing Additives for Architectural Coatings”, 2009.

4

Natesh, A.; Shah, V.; Schulte, H.G.; Frommelius, H.; Shah, S. “L owOdor, V OC-Free, Re newable C oalescents fo r L atexes Us ed i n V ery Low-VOC Paints”, 2007.

5

Karlson, L. “Hydrophobically Modified Polymers Rheology and Molecular Associations”. Lund University, 2002.

6

Strauss, U. P. In Polymers in aqueous media; Glass, J. E., Ed.; American Chemical Society: Washington DC, 1989; Vol. 223, p 317324.

7

Landoll, L. M. In U.S. Patent 4228277; Hercules Inc.: United States, 1979.

8

Landoll, L. M. J. Pol. Sci. 1982, 20, 443-455.

9

Sau, A. C.; Landoll, L. M. In Polymers in aqueous media; Glass. E., Ed.; American Chemical Society: Washington DC, 1989; Vol. 223, p 343-364.

than just grinding media nd ess a proc nalysis a cost ead gh b u o r s th aving ycling s t s co rec rs mina e s g illin ops wet m worksh and

This paper was presented at the American Coatings Conference, Charlotte, NC, 2010.

Follow PCI on Facebook at www.facebook.com/PCIfan on Twitter at http://twitter.com/PCIMag and on Linkedin at www.linkedin.com

SIGMUND LINDNER GmbH Oberwarmensteinacher Str. 38 D-95485 Warmensteinach / Germany Phone (++49) 92 77 - 99 40 Fax (++49) 92 77 - 9 94 99 E-Mail: [email protected] www.sili.eu

Your innovative and reliable partner for over 155 years

Visit ads.pcimag.com PA I N T & C O A T I N G S I N D U S T R Y

020 Cognis FT.indd 29

䡲䡲䡲

29

9/20/10 12:13 PM

Deep Color-Travel Effects with Organic Pigments

E

ffect c olorations a re mo stly ba sed on s ynergies b etween c onventional a bsorption pigments an d r eflective m etal f lakes o r transparent pearl luster pigments. Organic platelet effect pigments, on the other hand, behave like a link between conventional semi-transparent absorption pigments and inorganic interference systems.

FIGURE 1 | Chemical structure of 2,9-dichloroquinacridone.

O

H N

Cl

Unlike m ultilayer e ffect p igments, o rganic plat elets c annot p roduce m ulticolor i nterference e ffects, bu t i nstead two c olors, t he one ob served i n r emission a nd t he ot her in transmission. To obtain good results, it is important to en sure t hat bo th co loristic p henomena ( remission and t ransmission) a re w ell ba lanced fo r a n id eal o verall color e ffect. T o a llow t he c reation of t his id eal i nterference effect, the crystals must have a specific depth, width and le ngth. Su rprisingly, n umerous o rganic p igments are able to generate such effects; the bluish flop usually observed w ith qu inacridone p igments c an b e c onsiderably e xtended, an d e xotic c ombinations wi th di oxazine pigments switch color from green to violet.

Introduction CI

N H

O

FIGURE 2 | Particle shapes of a variety of 2,9-dichloroquinacridone products.

Crystal size Transparent ~50 nm

Semi-transparent 50-200 nm

Opaque >200 nm

Organic pigments have been well established in the coatings industry for many decades. They are well known for their high color strength and transparency, as well as for their chromatic effects. A wide range of chromophores have b een a vailable, a nd a ll k inds of i maginable shad es are of fered by p igment a nd c oating m anufacturers. New and u nique c olorations a re b ecoming mo re a nd mo re difficult t o ach ieve. O ver t he p ast few y ears t he i ndustry focus was mainly on new formulation technologies, niche products o r a few d istinct c ompounds. The i mpact of t he latter is r ather l imited i n c omparison w ith th e s uccess of t he la st m ajor chomopho re d iscovery, d iketo-pyrrolopyrrole pigments (DPP), in the late 1980s. Finally, there is a wide range of organic colorants available for coatings, so a lmost a ll c olor i nnovations a re l inked t o i norganic systems, i.e., multilayer effect pigments or highly reflective aluminum flakes. Thanks to experience acquired in both these domains – classic organic substances and inorganic effect pigments – new s tylings c an b e c reated t oday by ra ising o rganic pigments t o t he level of e ffect pigments. The new e ffects

By Marc Maurer, Philippe Bugnon, Tom Landuydt and Doug Swank | BASF SE, Basel Switzerland 30

䡲䡲䡲

030 BASF FT.indd 30

OCTOBER 2010 | W W W . P C I M A G . C O M

9/20/10 12:15 PM

are created by compounds that are manufactured in the form of “ organic plat elets.” The i ntrinsic c olor of t hese materials is still closely linked to their chemical structure and the alignment of the molecules in the crystal lattice. However, t he s pecific shap e of t he p articles a llows new phenomena t o ap pear, c aused by t he c ombined e ffect of light r eflection, t ransmission a nd s cattering. The new deep color effect produces subtle reflections w ith a h ueshifting color travel. Automotive c oatings a re t he ideal market for t his new generation of organic interference pigments. For example, the me tallic shad es c an b e at tractive a nd ey e-catching, but the impression of depth is increased thanks to the high chromaticity a nd shade of t he organic platelet. Thus, the final coating can appear much thicker than it actually is.

FIGURE 3 | Microscopy images of the platelet-formed quinacridone.

Scanning Electron Microscopy (SEM)

Average size of platelets circa 5-10 µm

FIGURE 4 | Color travel of Xymara Fireball versus a traditional quinacridone pigment.

Results

60

Measurements made using Datacolor Multi FX 10 spectrophotometer 75°/120° 45°/120° 75°/90° 45°/110° 45°/150° 45°/90° 25°/140°

50 Green<>Red

Xymara™ F ireball™ i s a new o rganic e ffect p igment fo r exterior automotive coating and other high-performance applications, i ncluding c onsumer g oods s uch a s mobi le phones a nd e lectronic d evices. The new e ffect p igment is ba sed on 2 ,9-dichloroquinacridone ( Figure 1 ), wh ich has b een k nown a nd u sed fo r m any d ecades i n c oating applications. The shad e a reas c overed by t his p igment are very popular, and products derived from it a re widely appreciated fo r t heir h igh va lue i n u se. A ll p roperties linked to the already commercialized pigments – weather fastness, g loss a nd s tability – r emain u nchanged whe n the pigment is modified to produce the platelet structure. The quinacridone class was primarily selected because the va rious c ommercialized p roducts d evelop a va riety of colors a nd effects, wh ich a re dependent on c rystal size and crystal shape (Figure 2). Thus, the transformation of a quinacridone into an organic effect pigment is inherent. In it s o riginal ne edle-shaped mo rphology ( >200 nm), red/violet shades with strong hiding power can be obt ained. At a n a verage s ize of ab out 2 00 n m, c olor strength increases and the hue becomes magenta. Finally, at a particle size of around 50 nm, the transparent orange crystals d evelop a bl uish f lop, wh ich i s v ery p opular i n automotive c oatings. Th roughout t hese s mooth cha nges from r ed t o m agenta t o o range, c olor s trength a lways remains v ery h igh, wh ich i s a s ignificant adva ntage of this chromophore over other red pigments. The e ffects a ttainable wi th 2 ,9-dichloroquinacridone are summarized in Figure 2. As already mentioned, three different c olors c an b e o btained wi th t he s ame ini tial chromophore. C ombining a ll t hese p roperties i n c rystal form becomes a w orthwhile way of obt aining novel color effects with existing chemistries. Additionally, s ince a ll t he cha nges hap pen i n t he same color space (reddish area), visual appeal is not impaired by abr upt c olor ju mps a s i s of ten t he c ase with the rainbow effects of some well-known inorganic multilayer effect pigments. Thanks t o a n i nnovative f inishing p rocess ba sed on crystal m anipulation, t he r espective p roduct i s g rown in p latelet f orm an d b ecomes an in terference p igment with th e e xpected d ifferences i n t ransmission a nd remission color (Figure 3).

Transmission Electron Microscopy (TEM)

Average thickness of the platelets circa 100-200 nm

40

45°/60°

30

45°/25°

20

25°/170° 45°/25°

10 0 -10

25°/140°

25°/170°

75°/90° 45°/120°

75°/120°

45°/90° 45°/60°

45°/110°

45°/150°

0

10

20

30

40

Fireball (interference)

Fireball (aspecular)

Traditional QA (interference)

Traditional QA (aspecular)

Illumination/observation angle conventions are in accordance with ASTM E 2194 & DIN 6175-2 standards for multi-angle measurement of effect pigment-containing materials.

FIGURE 5 | Xymara Fireball stand-alone or shading agent. Controlled re-crystallization of 2,9-dichloroquinacridone under very specific conditions generates platelet form: copper-bronze ‘face’ coloration, deep cherry red ‘flop’ coloration, subtle sparkling appearance, semi-transparent (more opaque than most micas).

PA I N T & C O A T I N G S I N D U S T R Y

030 BASF FT.indd 31

50

Blue<>Yellow

䡲䡲䡲

31

9/20/10 12:15 PM

Deep Color-Travel Effects with Organic Pigments

FIGURE 6 | Chemical structures of C.I. Pigment Violet 23 (left) and Pigment Violet 37. H5C2 O

N

CI

N CI

O O

HN

N N C2H5

O

N

H5C2O

NHCOCH3 N O NHCOCH3

OC2H5 NH O

FIGURE 7 | Color changes observed with two different dioxazine violet pigments in platelet form.

b*

Organic platelets: dioxazine CI Pigment Violet 37 – CI Pigment Violet 23 -5 -6 -7 -8 -9 -10 -11 -12 -13 -14 -15 -16 -17 -18 -19 -20 -21 -22

0

1

2

3

4

5

6

7

8

9

10 11

12

13 14 15

a*

Measurements made using Datacolor Multi FX 10

attractive a s o rganic e ffect p igments due t o t he s parkle they develop in platelet form. Another p igment cla ss d elivering u nusual e ffects i s dioxazine. The se c onventional c rystal fo rms w ere commercialized in the middle of last century, and remarkable e ffects c ould b e c reated w ith t he t wo m ain representatives, C .I. P igment V iolet 23 an d C .I. P igment Violet 37, me rely by s pecific mo dification of c rystal s ize and shape (Figure 6). In p latelet o r r od-like f orm, di oxazines a ppear vi olet in t ransmission, bu t i n r emission a va riety of d ifferent green, br own, r ed o r bl ue c olors c an b e c reated d espite identical che mistry. The ir abr upt ju mp f rom one c olor to a nother m akes d ioxazines mo re at tractive fo r i nk a nd plastic colorations than for automotive stylings. Therefore these fancy effects tend to be used for the design of smaller consumer goods such as toys or mobile phones. In these applications, where radical color changes (e.g., from green to v iolet) t ake plac e, at tention i s c aptured, c uriosity aroused, a nd t he c oated obje ct b ecomes t he c enter of interest. The ex tremely h igh c olor s trength d eveloped i n remission an d tr ansmission inhi bits s mooth tr ansition between t he shad es. The c olor t ravel e ffect i s r educed t o the r eflection of t he t wo ba sic c olors, d epending on t he viewing an gle. T he gr aphs o f tw o dif ferent di oxazines shown i n F igure 7 sho w t hat t he plat elets do n ot r eally develop a flop – the effect merely tends to become lighter in shade, shifting towards yellow or green, before it switches to t he ot her c olor. Mo dified C.I. P igment V iolet 3 7, fo r example, a llows c olorations w ith v ery h igh s trength i n remission and transmission; the jump in shade from violet to green or even brown allows eye-catching stylings.

Summary With th is p latelet f orm a nd b y v arying th e v iewing angle, t he c olor ob served i n r emission i s p rogressively replaced by t he one s een i n t ransmission. A s sho wn i n Figure 4, for the same ‘a’ value (a = 40) two distinct colors can be observed, depending on the orientation (b = 28 and b = 48). Such phenomena have never been observed with traditional t rade forms of qu inacridone pigments a lready on the market. Applied a s a s tand-alone p igment i n c oating applications, qu inacridone plat elets of fer a c olor ra nge that varies from orange/gold to a deep cherry red, as the a ngle of ob servation cha nges ( Figure 5 ). Wit h it s thin, f lake-like p articles ( Figure 3 ), X ymara F ireball adds a discreet sparkle when used in an effect color formulation. Inherent transparency makes it suitable for use in combination with different chromatic transparent pigments as well as in multilayer paint systems, giving new, u nusual ef fect shade s w ith exceptional dept h. The multilayer effect is also achieved by applying the new pigment t o t ransparent pla stic p arts e ither by c oating onto the surface or by mass coloration. A number of ot her r ed c ompounds g ive s imilar e ffects in coatings or plastics. Perylene pigments allow marked color-travel e ffects f rom r ed t o bl ue, bu t t hey a re le ss suitable fo r c oatings b ecause of t he i rregular f lop a nd sudden drop in strength at certain angles. DPPs are 32

䡲䡲䡲

030 BASF FT.indd 32

In summary, it has been demonstrated that it is still possible t o g enerate i nnovative c olor e ffects fo r c oating, plastic a nd i nk ap plications u sing ex isting, e stablished organic pigment chromophores. Through novel processes requiring c rystal m anipulation, nat ural shad es a re revealed with sparkle and hue-shifting characteristics. 䡲 Acknowledgments The authors would like to thank all team members for their contribution in this project, especially V. Herle and P. Brown. This a rticle i s b ased o n t he p resentation “ Deep c olor-travel e ffects w ith organic effect platelets,” given by Marc Maurer at the European Coatings Congress on April 1, 2009 in Nuremberg, Germany.

Follow PCI on Facebook at www.facebook.com/PCIfan on Twitter at http://twitter.com/PCIMag and on Linkedin at www.linkedin.com

OCTOBER 2010 | W W W . P C I M A G . C O M

9/20/10 12:15 PM

High-Performance Water-Repellent A

Exterior Wood C

L

ately, wood has seen an upsurge in popularity for new c onstruction and home r enovation. The nat ural ap peal of t his bu ilding material m akes it a n exc ellent choic e n ot only for exterior applications such as window f rames a nd clad ding, bu t a lso fo r ou tdoor l iving spaces such as patios and decks.1 However, as a composite of hygroscopic organic cellulosic elements, wood degrades under adv erse w eather c onditions. T o c ounteract t his failing, researchers have sought, over recent decades, to develop s ynthetic c oatings t hat c an p rolong t he l ife of wood while preserving its natural beauty. Despite ex haustive e fforts, t he d evelopment of effective w ood c oatings ha s r emained a cha llenge. Besides i mparting exc ellent weather resistance, such a coating must be flexible enough to follow the expansion and contraction of w ood. At t he same time the coating must be hard enough to prevent blocking issues. Other qualities, such as strong adhesion and easy application, round out t he l ist of key r equirements. Th is p articular set of obligatory features makes crafting coatings for wood problematic. Recently, mo st i mprovements i n e xterior w ood coating applications have focused on acrylic waterborne systems. The se bi nders le nd p rotection a gainst moisture a nd U V. F urthermore, t heir u se i s ga ining momentum u nder t he c urrent le gislative pu sh t oward the u se of “ green” p roducts. C ore/shell d ispersions – self-crosslinkable polymers based on multiphase acrylic particles – represent state-of-the-art binder technology.2 These structured particles enable the coexistence of hard

FIGURE 1 | Chemical structure of VeoVa-10 and 2-ethylhexyl acrylate (2-EHA). (R1 and R 2 = alkyl groups with a total of 7 carbon atoms).

C CH 2 CH O

O

CH 3

O

C R2

R1 CH C O

CH2

CH2 CH CH2 CH2 CH2 CH3 CH2 CH3

and soft polymer phases. Th is dua lity can overcome the paradoxical constraints that a wood coating be resistant to blocking, yet also be very flexible. Despite t hese adva nces, w ood c oatings’ moi stureprotection c apabilities s till n eed o ptimizing. In clusion of various s ubstances, s uch a s w ax a nd s iloxane compounds,3 can i ncrease t he w ater r epellency of coatings. More significantly, the use of highly hydrophobic monomers c an s et up a double -edged d efense a gainst moisture. The se mon omers e rect a n e ffective ba rrier against l iquid w ater, a nd a lso che mically i ncorporate this ba rrier i nto t he p olymer, wh ich of fers lon ger-term benefits than the use of additives. Copolymerization w ith h ighly hydrophobic monomers based on V ersatic™ ac id d erivatives c ontaining h ighly branched a lkyl g roups i s k nown t o g reatly e nhance t he ability of t he c orresponding p olymer t o r epel w ater a nd resist UV.4 These monomers have proven to be an excellent option for modifying acrylic core/shell polymers. Evaluation of n ew, s elf-crosslinkable, ha rd-core/softshell ac rylic p olymers mo dified w ith t he v inyl e ster of Versatic ac id (i.e. V eoVa 1 0™ mon omer) sho w t hem to b e h ighly e fficient bi nders fo r ex terior w ood s tain applications.5 L owering, t o a c ertain ex tent, t he g lass transition temperature (Tg) of the soft-shell hydrophobic monomer r esulted i n a fa vorable ba lance b etween t he hardness required for good blocking resistance and the s oftness ne eded fo r c oating f lexibility. W ood s tains formulated w ith th ese b inders h ave e xhibited e xcellent outdoor durability – more than two years in Belgium. This p aper d escribes r ecent w ork on op timized ha rdcore/soft-shell acrylic binders modified with either VeoVa 10 or 2-ethylhexyl acrylate (2-EHA) as the hydrophobic monomer ( Figure 1 ). The se lat ice s ystems ha ve b een synthesized, formulated and evaluated for exterior wood stain ap plications. A c omparison of t he mon omers’ performance w ith c ommercial ac rylic bi nders a nd commercial wood stains is also discussed. This s tudy a ims t o e lucidate t he i nfluence of s elect hydrophobic mon omers on t he ph ysical a nd che mical properties o f b inders, a nd u ltimately o n t he o verall performance of ex terior w ood c oatings der ived f rom such combinations.6

By Nathalie Havaux, David Vanaken and Francois Simal | Hexion Specialty Chemicals, Louvain-la-Neuve, Belgium 34

䡲䡲䡲

034 Hexion FT.indd 34

OCTOBER 2010 | W W W . P C I M A G . C O M

9/20/10 12:17 PM

Acrylic Latices for

d Coatings Experimental Modified Acrylic Core/Shell Latices Preparation The s eries o f s elf-crosslinkable c ore/shell a crylic l atices with a f ixed c ore Tg of ~ 50 °C a nd shell Tg of 0 ° C were prepared ac cording t o t he fol lowing p rocedure. U nder nitrogen, demineralized water and surfactant were placed in t he r eactor a nd he ated t o 8 5 ºC. The n, t he n itrogen flow w as s topped, a nd d emineralized w ater c ontaining part of t he i nitiator, p otassium p ersulfate, w as ad ded to t he i nitial r eactor cha rge ( IRC). Th is w as fol lowed by 2 .5% w eight of p re-emulsion I. T he t emperature was m aintained at 8 5 ºC, a nd a sl ight bl ue c olor a nd temperature increase were observed, which indicated that the polymerization was starting. After 15 min, when this charge had polymerized, the remainder of pre-emulsion I was added over the course of 1 h. The remaining initiator solution w as ad ded s imultaneously o ver a p eriod of 3 h 15 m in, v ia a s eparate l ine. I mmediately a fter a ll of p reemulsion I w as ad ded, p re-emulsion I I w as ad ded o ver a p eriod of 2 h. A fter 3 h of p re-emulsion ad dition, t he reactor was kept at 8 5 ºC fo r 1 hou r p ost c ooking. A fter post c ooking, t he lat ex w as c ooled down t o 55 ºC a nd a conversion booster was added in two separate doses, each lasting 30 min, followed by a 30-min post cook at 55 ºC. Finally, t he lat ex w as c ooled t o r oom t emperature a nd filtered. D uring c ooling, a mmonia w as ad ded slo wly t o neutralize the latex. At room temperature, a biocide and the crosslinker were added to the final polymer.

Particle Size Distribution of the Latices All lat ices were cha racterized by t heir mean particle size and by t he n umber of p articles s maller t han 1 m icron using t he B eckman C oulter Particle Si ze A nalyzer L S 13 320.

Viscosity Measurements of the Latices A B rookfield L VDV-I v iscometer w as u sed t o me asure latex v iscosity. The me asurements were carried out w ith spindle 1 at 20 rpm.

Minimum Film Formation Temperature (MFFT) A 3 0 m icron lat ex f ilm w as c ast on t he s urface of t he instrument ( Sheen In struments S S.3000), w hich w as covered with a non-porous material. The film was allowed to dry, and the MFFT was determined visually.

Early Water Spot A latex film was applied on a glass panel and dried for 1 h at 23 ºC. A 1 m L drop of d emineralized water was placed onto t he polymer f ilm a nd covered w ith a w atch g lass to prevent evaporation. A fter 1 h, t he water spot resistance was eva luated v isually. The wh itening e ffect w as rat ed between 0 a nd 10, whe re a va lue of 1 0 me ans t hat t he latex f ilm w as u naffected a nd 0 i ndicates a c ompletely white film.

Goniometry Demineralized w ater (4 µ l) w as ap plied t o cle ar p olymer films ap plied on g lass, a nd t he c ontact a ngle w as measured after 30 seconds using a PG-X Measuring Head Goniometer. Ten measurements were made on each panel and the average was recorded.

Exterior Protective Wood Stain Formulations The p repared lat ices were fo rmulated i nto c olored s tains following a s tandard fo rmulation (T able 1 ). The p aints were filtered at least two days before use.

Procedure Under g entle s tirring, t he lat ex w as m ixed w ith t he defoamers ( BYK 023 a nd Su rfynol 104E), d emineralized water, c oalescing a gent ( butyl d i-glycol), a nd f ungicide (Mergal S 99). At t he e nd, t he t hickener s olution w as added s tep by s tep u ntil a v iscosity of ab out 100 K U was obtained. A m ixture of t he t hree c olored p igments w as

TABLE 1 | Wood stain formulations. Wood Stain Formulation Polymer BYK 023 Demi water Butyl di-glycol Surfynol 104E Acrysol RM8-W Mergal S99 Tinting Napronyl red Napronyl yellow Luconyl black Total

Wt (g) 3

1

20 4.2 546.5 52 5.2 27 14.6 30.6 (18.8) (11.5) (0.3) 000

PA I N T & C O A T I N G S I N D U S T R Y

034 Hexion FT.indd 35

䡲䡲䡲

35

9/20/10 12:17 PM

High-Performance W ater-Repellent A crylic L atices fo r Exterior Wood Coatings

Best Under the Sun

FIGURE 2 | Hard-core/soft-shell hydrophobically modified acrylic polymers.

With exceptional tint retention, chalk resistance and photochemical stability, MINEX® additions can enhance the color and extend the service life of aqueous and solvent based architectural paint. Forty years of real time exterior exposure tests verify MINEX is the best functional filler under the sun. ®

FUNCTIONAL FILLERS AND EXTENDERS

Tg ~ 50 °C 1 MMA, BA, …

2

+

Hydrophobic Mon. BA, MMA, …

Tg ~ 0 °C Hydrophobic Monomer

made in order to obtain a consistent color. After 10 min of stirring, the p redetermined a mount of t inting m ixture w as ad ded, s till under slow stirring. Slow agitation was continued for another 15 min. The w ood s tains were a llowed t o e quilibrate at 2 3 ºC fo r 4 days before application.

Blocking Resistance of the Wood Stains Test p anels ( Leneta foi ls) of 7 .5 c m x 7 .5 c m, fac e t o fac e, w ere placed in the oven at 50 ºC for 30 min, with a weight of 2 kg on t op. A fter c ooling, t he t est p anels w ere pu lled ap art a nd a ny damage visually evaluated. The h ighest score, 10, means that no noise w as he ard a nd n o da mage w as s een whe n t he t est p anels were pulled apart. A rating of 0 means that 75-100% of the wood stain was removed from the test panel.

Water Vapor Transmission Rate This tes t d etermines th e r ate a t w hich w ater v apor p asses through a f ree p olymer f ilm (i.e., wet c up me thod). Water vap or transmission (W VT) me asurements w ere p erformed ac cording to ASTM D 1653 Test Method B, Condition A, consisting of 50% relative humidity at 23 ºC. A woodstain film of about 30 microns was applied on polyethylene panels and dried at 40 ºC for 1 week. The t est s pecimens w ere p eeled of f a nd s ealed t o t he op ening of a b ottle c ontaining 50 g d istilled w ater. The b ottle w as weighed after 1 , 2 , 3 a nd 4 w eeks t o d etermine t he rat e of w ater vap or movement t hrough t he s pecimen. The c alculated W VT i s t he weight cha nge per t ime per test a rea a nd is ex pressed i n g rams/ m² per 24 h.

Adhesion on Aged Alkyds

For more information and our complete product portfolio visit:

www.BrilliantAdditions.com

The ad hesion of w ood s tain on a ged a lkyd p aints w as t ested according to ASTM D 3359. A 200 micron film of wet wood stain was ap plied a nd d ried fo r one w eek at r oom t emperature on wooden panels coated with alkyd paint aged for two weeks in the oven at 5 0 ° C. A G itterschnitt ( 6 x 6 , 20 m m lon g) p attern w as prepared, a nd ad hesive tape was placed over t he g rid. To ensure good c ontact w ith t he f ilm, t he t ape was r ubbed f irmly w ith t he eraser e nd of a p encil. Wit hin 90 s econds t he t ape w as r emoved by pulling it off rapidly at an angle of 90º. The percentage of stain removed was evaluated and rated between 5B, an unaffected film, and 0B, where the affected area was 65% or more.

Preparation of Wooden Panels for Accelerated Weathering ® MINEX is a registered trademarks. All rights reserved. ©2009

SPECIALTY AND PERFORMANCE MINERALS

The w ood p anels w ere s elected ac cording t o t he E uropean standard EN 927-6. The panels of Scots pine had dimensions of 1 50 m m x 7 4 m m x 1 8 m m. The p anels w ere pla ned t o a smooth and uniform finish by gentle sanding, then three coats

Visit ads.pcimag.com 36

䡲䡲䡲

034 Hexion FT.indd 36

OCTOBER 2010 | W W W . P C I M A G . C O M

9/20/10 12:17 PM

of wood stain were applied. Only the front a nd t he s ides of t he p anels w ere painted. T he w ooden pa nels w ere d ried for 1 w eek at r oom t emperature b efore the s tart of t he ac celerated w eathering procedure. A r egular v isual eva luation of bl istering, cha lking, f laking a nd cracking w as p erformed on e ach of t he wooden painted panels.

Color Using t he Ult rascan X E, c olor cha nges between t he r eference a nd t he a rtificially aged panels were measured in CIELab (L*a*b*) c olor d ifference t erms. L * represents th e l ightness o f c olor, a * th e position between magenta and green, and b* the position between yellow and blue.

Results and Discussion Syntheses and Characterization of the Latices For t his r esearch, a s eries of fou r s elfcrosslinkable c ore/shell ac rylic lat ices with a f ixed c ore T g of ~ 50 ° C a nd she ll Tg of 0 °C (Binders 1-2) were prepared, characterized a nd fo rmulated i nto w ood stains. I n t hese s ystems, t he w eight rat io

Accelerated Weathering The w eathering t rial w as c arried ou t i n a QU V Ac celerated W eathering T ester from Q-Lab. 12 cycles of 24 h exposure to condensation (168 h t otal), a nd 48 cycles of 3 h, c onsisting of 2 .5 h of U V-A ( 340 nm) at 60 ºC a nd 0.5 h of w ater spraying 6-7 m L/min, were a lternated for a p eriod of 2016 h.

Water Spot Test Three c oats of w ood s tain w ere ap plied to the wooden panel and dried for 1 w eek at room temperature. A 1 mL drop of demineralized w ater w as pu t ont o t he stain a nd c overed w ith a w atch g lass t o avoid evap oration. A fter 2 4 h, t he w ater spot re sistance wa s e valuated v isually. The wh itening e ffect w as rat ed b etween 0 a nd 1 0, whe re a va lue of 1 0 me ans that t he lat ex f ilm w as u naffected, a nd 0 indicates a completely white film.

The World’s Most Widely Used Weathering Tester

Liquid Water Permeability Test The wood panels were selected according to the European standard EN 927-5. The panels (6 replicates) were planed to a smooth a nd u niform f inish by g entle sanding b efore t hree c oats of w ood stain w ere ap plied t o t he t est fac e on ly. The f ront a nd s ides of t he p anels w ere sealed with a solvent-based polyurethane white p aint. The w ooden p anels w ere conditioned u ntil c onstant m ass w as achieved. B efore s tarting t he ab sorption cycle, the panels were subjected twice to a leaching procedure. For the absorption test, th e tes t p anels w ere f loated f ace down on t he s urface of t he w ater fo r 7 2 h. The r esults w ere ex pressed a s w ater absorption of coated wood panels in g/m 2 test surface per 72 h.

Gloss Gloss measurements record the amount of light reflected at s pecified angles. Using a Rhopoint Statistical Novogloss apparatus, measurements on wood stains applied on pine were p erformed at a 60 º a ngle at 2 3 ºC and 50% humidity.

Accelerate the damaging effects of sunlight, moisture & high temperatures.

r


#FTU
TJNVMBUJPO
PG
TIPSUXBWF
67
TVOMJHIU r


.FFUT
XPSME
XJEF
UFTU
NFUIPET r


5SVTUFE
CZ
DVTUPNFST
XPSME
XJEF
GPS

ZFBST


40 th Anniversary QUV Weathering Tester 1970-2010

Q-Lab Corporation t The Most Trusted Name in Weathering 

t

JOGP!RMBCDPN

t

XXXRMBCDPN

Visit ads.pcimag.com PA I N T & C O A T I N G S I N D U S T R Y

034 Hexion FT.indd 37

䡲䡲䡲

37

9/20/10 12:17 PM

High-Performance Water-Repellent Acrylic Latices for Exterior Wood Coatings

of hard to soft material was fixed at 30/70. Two additional all-acrylic c ommercial bi nders ( Binders 3 -4) w ere included a s r epresentative w ood c oating b enchmarks. The polymerization process is depicted in Figure 2, and the d etailed p olymerization p rocedure i s g iven i n t he experimental section of this paper.

TABLE 2 | Binders description. Binder

Monomer

Level (%)

1 2 3 4

VeoVa 2-EHA Acrylics Acrylics

3 0 30 100 100

TABLE 3 | Latice characterizations. Binder

Solids Content Particle Size (%) (nm)

1 2 3 4

47.6 47.1 44.9 44.6

112 116 97 74

Viscosity (mPa•s)

MFFT (°C)

Water Contact Angle (°)

150 250 120 55

< 9 15.3 7

078.8 66.7 54.2 73.7

FIGURE 3 | Water contact angle with Binder 1 (left) and Binder 3 (right).

FIGURE 4 | Early water spot resistance. 10

Degree of Whitening

8

6

4

2

0 Binder 1

Binder 2

Binder 3

Binder 4

FIGURE 5 | Water resistance of wood stains (1-4 and SBAlk, from left to right).

38

䡲䡲䡲

034 Hexion FT.indd 38

The ou ter she lls of t he p olymer p articles w ere mo dified by va rying t he t ypes of mon omer (T able 2 ), wh ich w ere selected on the basis of their relative hydrophobic character. With th e h elp o f o nline s oftware,7 th e oc tanol-water partition coefficient values (LogKow) have been calculated for 2 -EHA (4.2) a nd VeoVa-10 (5.2). A s a h igher o ctanolwater coefficient indicates a more pronounced hydrophobic character, it can be concluded that VeoVa-10 is likely to be the most hydrophobic monomer in this series. All lat ices w ere eva luated on s olid c ontent, p article size, v iscosity a nd m inimum f ilm formation t emperature (Table 3). I n t erms of s olid c ontent, t he va lues measured for Bi nders 1 a nd 2 a re i n l ine w ith t he t heoretical solids c ontent of 4 6%, a nd sl ightly ab ove t hose of t he commercial b enchmarks ( Binders 3 a nd 4 ). The lo w level of r esidual monomer was achieved by u sing a r edox booster based on tertiary-butyl hydroperoxide (tBHP) and the r educing a gent B ruggolite® F F6 M i n t he p resence of FeIII catalyst. All of t he latices, including the commercial benchmarks, show a low particle size. Emulsions with small particle size were expected to facilitate b oth t he p rocess of f ilm fo rmation a s w ell a s good p enetration of t he c oating i nto t he w ood’s s urface. The s mallest p article s ize w as ob served fo r Bi nder 4 a nd caused the latex to appear translucent. Evaluation of the M FFT of t he s ynthesized lat ices r eveals va lues lo wer than 0 ºC, wh ich is in agreement w ith the targeted Tg of the she lls. Upon f ilm fo rmation, t he c oalescence of t hese core/shell particles is mainly driven by the soft shell, which allows for the rapid formation of a coherent coating without t he ne ed fo r a ny ad ditional c oalescing a gent. A lower M FFT w as a lso r ecorded fo r Bi nder 4 (c ore/shell morphology per TDS) compared to Binder 3. Water r esistance w as eva luated by e arly w ater s pot tests and water contact angle measurements. The contact angle of a w ater d roplet w as me asured on p olymer f ilms applied on g lass plat es, a s a me ans t o a ssess t he s urface polarity of the binders. As can be seen from Figure 3, the i ncorporation of a h ydrophobic mon omer s uch a s VeoVa-10 had a d ramatic i mpact on t he c ontact a ngle of t he w ater d roplet on t he p olymer. I n t hese s ystems, the h igher c ontact a ngles a re t herefore l ikely t o i ndicate greater water r epellency of t he p olymer f ilm, wh ich i s i n agreement w ith t he lower c ritical s urface t ension shown by the homopolymer of VeoVa-10 (24 dynes/cm) 8. In turn, the r eduction of s urface t ension i s a lso ex pected t o favor the w etting abi lity a nd p enetration of t he fo rmulated binder onto the wood surface.9 Overall, it can be stated that the all-acrylic binders, except Binder 4, seem to show reduced w ater r epellency. The w ater r epellency b ehavior of t he V eoVa 1 0-based s ystems i s cle arly i llustrated i n Figure 3, which shows pictures taken from a water droplet in c ontact w ith Bi nder 1 ( 30% V eoVa-10) a nd Bi nder 3 (all-acrylic Benchmark) applied on glass. The second evaluation of water resistance was obtained through t he e arly w ater s pot t est, whe reby a d roplet of water w as ap plied t o a cle ar f ilm fo r a f ixed p eriod of time a nd ra nked ac cording t o t he f ilm’s f inal d egree of whitening (0 = white to 10 = no visual change). As sho wn i n F igure 4 , whe reas mo st s ystems ( besides Binder 3) showed good resistance to water whitening, a

OCTOBER 2010 | W W W . P C I M A G . C O M

9/20/10 12:18 PM

High-Performance Water-Repellent Acrylic Latices for Exterior Wood Coatings

TABLE 4 | Blocking and adhesion of the wood stains. Wood Stains

Binder

Blocking

Adhesion on Alkyds

1 2 3 4 SBAlk

1 2 3 4 -

8 9 7 9 5

5B 4B 5B 5B 0B

FIGURE 6 | Liquid water permeability of wood stains (EN 927-5). Liquid Water Uptake (g/m2 after 72 h)

400 350 300 250 200 150 100 50 0 Wood Stain 1

Wood Stain 2

Wood Stain 3

Wood Stain 4

SB Alkyd

FIGURE 7 | Water vapor permeability of wood stains (ASTM D 1653-93). Water Vapor Permeability (g/m2 /24 h)

80 70 60 50 40 30 20 10 0 Wood Stain 1

Wood Stain 2

Wood Stain 3

Wood Stain 4

SB Alkyd

FIGURE 8 | Appearance of coated panels after 2000 h of accelerated weathering.

30% VeoVa 40

䡲䡲䡲

034 Hexion FT.indd 40

30% 2-EHA

Acrylic BM1

Acrylic BM2

SB Alkyd

superior r esistance w as ob served fo r t he ac rylic s ystem modified by VeoVa-10. On the basis of the results obtained in these different evaluations, it could be expected that the binder ba sed on t he mo re h ydrophobic p olymer ( Binder 1) is likely to result in the wood stain displaying the best protection against liquid water.

Evaluation of Wood Stain Properties The different binders were formulated into wood stains and applied in three coats to Scots pine. Soft pine wood is one of the mo st d emanding s ubstrates b ecause of it s s ignificant dimensional changes, which require the coating to adapt by expanding and contracting. A c ommercial wood stain from a le ading g lobal s upplier, ba sed on s olvent-based alkyd (SBAlk, VOC 2010 compliant), was included in this evaluation for comparison. The resistance to blocking was first me asured fo r t he d ifferent w ood s tains i nvestigated (Table 4 ). The b est blo cking r esistance w as obt ained fo r 2-EHA-modified ac rylic p olymer ( Binder 2 ) a nd fo r t he core/shell ac rylic b enchmark ( Binder 4 ), whe reas t he solvent-based a lkyd ( SBAlk) sho wed t he lo west blo cking resistance i n t he s eries. A nother i mportant p roperty fo r a wood c oating i s it s ad hesion t o a ged a lkyds. Bi nders 1, 3 a nd 4 sho w t he b est ad hesion lev els on a ged a lkyds. These excellent adhesion levels are in stark contrast with that of the SBAlk, which clearly lacks adhesion under the conditions applied. Water resistance was then assessed on the pine panels coated with the various wood stains. After 24 h of contact with a d roplet of w ater, wh itening w as ob served fo r t he wood s tain ba sed on t he b enchmark lat ex, [ (Binder 3 ) Figure 5]. In most cases, after drying, no damage could be found on the coated panels. Ideally, t he p ermeability of t he c oating shou ld b e lo w in o rder t o m inimize t he i ngress a nd ac cumulation of water i n t he w ood s ubstrate, wh ich m ay le ad t o w ood deterioration through the growth of mold and other fungi. Permeability of wood stains to liquid water was assessed according to EN 927-5. Water uptake by the coated panels was fol lowed for 3 da ys, t hen water r elease was fol lowed for 4 days (Figure 6). From th is se t o f e xperiments, th e w ell-known b arrier effect of S B A lkyd a gainst l iquid w ater i s c onfirmed, whereas Wood Stain 4 based on Binder 4 shows the highest level o f li quid pe rmeability in t his s eries. In terestingly, the h ydrophobized s ystems sho w lo w p ermeabilities, comparable to that of the commercial SB Alkyd wood stain. Another i mportant p roperty fo r a p olymer ac ting a s a binder i n a n ex terior w ood c oating i s it s abi lity t o a llow good p ermeability of w ater vap or ( MVTR) t hrough t he coating film so that water does not remain trapped in the wood s ubstrate a nd le ad t o da mage a nd r ot. H owever, high water vapor permeability of a c oating may also lead to s ubstantial ac cumulation of moi sture, wh ich i s n ot desirable. As can be seen in Figure 7, the SB Alkyd exhibits the lowest vapor permeability of all. This lack of water vapor p ermeability on t he p art of t he S B A lkyd s ystems typically results in wood degradation. Interestingly, Wood St ain 4, wh ich showed t he h ighest level of permeability towards liquid water, also displays the highest permeability towards water vapor. Wood Stain

OCTOBER 2010 | W W W . P C I M A G . C O M

9/20/10 12:18 PM

High-Performance Water-Repellent Acrylic Latices for Exterior Wood Coatings

FIGURE 9 | Accelerated weathering – gloss retention (2000 h EN 927-6). 80 70

Gloss Retention (%)

60 50 40 30 20 10 0 Wood Stain 1

Wood Stain 2

Wood Stain 3

Wood Stain 4

SB Alkyd

FIGURE 10 | Accelerated weathering – color changes (2000 h EN 927-6).

Color Change ( delta E*)

25

20

15

10

5

on Bi nder 2 c ontaining 30% of 2 -EHA, whe reas a sl ight effect w as ob served fo r t he s ystems ba sed on Bi nder 3 a nd S B A lkyd. The lat ter a lso sho wed sl ightly lo wer adhesion p erformance a fter a ging. The se t ests cle arly demonstrate t hat t he w ood s tains ba sed on Bi nder 1 and Bi nder 4 ou tperformed t he ot her s ystems i n t erms of g eneral ap pearance. The w ood s tain ba sed on t he 2-EHA-modified binder showed a strong discoloration. In a separate experiment, Wood Stain 2 was formulated with 1% of w ax (Aquacer 533). A lthough t he p erformance i n appearance of the coated panel after artificial weathering improved, it r emained inferior to that of t he panel coated with Wood Stain 1. Gloss a nd c olor me asurements w ere p erformed on t he aged p anels a nd c ompared w ith th e n on-aged sy stems in o rder t o b etter qua ntify t he ob served cha nges i n appearance. After accelerated weathering, the highest level of g loss retention w as ob served fo r t he 3 0% V eoVa-modified binder (Figure 9). Of note, the gloss retention of this wood stain i s fa r s uperior t o t hat of t he c ommercial S B A lkyd wood stain. Weathering s ignificantly a lters th e a ppearance o f wood a nd it s s urface p roperties. C olor cha nges (g reying) in w ood a re due t o t he ac cumulation of phot odegraded lignin constituents leached from the wood, and/or fungal growth. The g eneral ap pearance of t he va rious c oated panels is w ell r epresented b y th e c olor c hanges ( ∆E*). A major cha nge w as me asured fo r W ood St ain 2 , whe reas Wood Stain 1 showed the smallest change in color (Figure 10). A gain, t he e ffect of V eoVa-10 on c olor p rotection i s significant. The s uperior combination of U V stability with increased h ydrophobicity a s c onferred by t he V ersatic derivatives incorporated into the polymer are likely to have contributed to this improved preservation of appearance.10

Conclusions 0

Wood Stain 1

Wood Stain 2

Wood Stain 3

Wood Stain 4

SB Alkyd

1 ba sed on t he h ydrophobized bi nder ( Binder 1) sho ws a slightly higher WVTR (~60 g H 2O/m2/24 h) than those of the wood stains based on Binder 2 and Binder 3. Although this tes t is f requently pe rformed i n th e e xterior w ood coating i ndustry, a p recise op timum va lue fo r a c oating’s water vap or t ransmission rat e ha s y et t o b e d etermined. The balance between a relatively low permeability for liquid water and a r elatively high water vapor permeability may seem favorable for the durability of the wood stain based on Binder 1 containing 30% of VeoVa-10. Finally, the durability of the wood stains was evaluated with a n a ccelerated w eathering tes t pe rformed b y the C ATAS I nstitute. A fter 2 000 h o f th is a ccelerated weathering t reatment (EN 927-6), the panels were taken out a nd eva luated on t he ba sis of t heir f inal ap pearance (Figure 8 ). A fter 2 000 h, n o s ign of fa ilure ( blistering, cracking, f laking o r cha lking) c ould b e ob served fo r t he different w ood s tains ba sed on Bi nder 1 a nd Bi nder 4 . Severe cha lking w as ob served fo r t he w ood s tain ba sed 42

䡲䡲䡲

034 Hexion FT.indd 42

A s eries of h ydrophobically mo dified s elf-crosslinkable acrylic c ore/shell lat ices w ith ha rd c ore a nd s oft she ll was s uccessfully p repared. The se m aterials ha ve he lped us d evelop a mo re f undamental u nderstanding of t he benefits of i ncorporating h ydrophobic d erivatives i nto acrylic polymers, and of how these benefits correlate with improved durability in exterior wood coatings. From th is w ork i t c an be c oncluded th at w ater repellency a nd U V r esistance of a bi nder a re a mong t he main components that govern the durability of the class of c oatings s tudied he re. O f t he h ydrophobic mon omers tested, it c an b e c oncluded t hat t hose ba sed on t he vinyl e ster of v ersatic ac id s ignificantly e nhanced t he wood s tains’ p erformance ( Figure 1 1). Th is e ffect w as demonstrated by a notable preservation in appearance of the c oatings a fter a rtificial w eathering, a s qua ntified by gloss retention and color change measurements. Finally, a comparison with commercial wood stains has ex posed p otential l imitations of t hose c ommercial coatings, s uch a s i nferior w ater a nd che mical r esistance and r elatively p oor c olor r etention. The se ob servations demonstrate t he adva ntages of u tilizing lat ices incorporating mon omers ba sed on t he v inyl e ster of versatic acids to improve wood stain performance.

OCTOBER 2010 | W W W . P C I M A G . C O M

9/20/10 12:18 PM

High-Performance Water-Repellent Acrylic Latices for Exterior Wood Coatings

References

FIGURE 11 | Performance comparison summary of wood stains.

Pianoforte, K. Wood Coatings Market. Coatings World 2009, 2. Baumstark, R.; Tuchbreiter, A. Proceedings of PRA 6th W oodcoatings C ongress. p p 7 0-89, 2 008. L oze, J- Y. Proceedings of t he N üremberg C ongress. 7 -9 M ay 2 007, paper X X, 2, 2 007. Heuts, M. P.J.; le Febre, R.A.; va n H ilst, J. L.M.; Overbeek, G. C. ACS Symposium Series 648, pp 271285, 1996. 3 Grüll, G .; T ruskaller, M . P roceedings of PR A 6 th Woodcoatings Congress, pp 46-57, 2008. 4 ht tp://www.versatics.com 5 Simal, F.; Hendrickx; H.; Verwee, A.; Nootens, C.; Decocq, F. Proceedings of the American Coatings Show, pp 1-6, 2008. 6 Bulian, F .; M agagnoli, C. ; T irelli, P. P itture e V ernici, 8 1, pp 7 -18, 2 005. B ergamasco, D .; Bu lian, F .; Me lchior, A .; Menotti, D .; Sp agna, A .; Ta nelli, M .; T irelli, P.; T olazzi, M . Proceedings of PR A 6 th W oodcoatings C ongress, p p 2 58270, 2008. 7 Virtual M aterial a nd P rocess Si mulation C enter, T CPE: Thermo C hemical Pr operties Es timations. h ttp://www. pirika.com/chem/TCPEE/TCPE.htm. 8 Ba ssett, D. Journal of Coating Technology 2001, 73, 42-55. 9 Saija, L. M.; Becchi, D.; Finocchiaro, S.; Lugli, M. Proceedings of Eurocoat. 2002. 10 Decocq, F .; Sl inckx, M .; No otens, C. Journal of Pr otective Coatings & Linings 2001, 48-56. 1

2

Liquid Water Permeability Adhesion

Liquid Water Permeability

Water Spot

DE*

Adhesion

Blocking

Water Spot

DE*

Blocking

Gloss Retention

Gloss Retention

Liquid Water Permeability

Liquid Water Permeability

Adhesion

Water Spot

DE*

Adhesion

Blocking

DE*

Gloss Retention Wood Stain 1

Wood Stain 2

Water Spot Blocking Gloss Retention

Wood Stain 3

Wood Stain 4

SB Alkyd

NEW K-KAT® XK-622

®

K-KAT XK-622 Vs. DBTDL

Catalyst for Solventborne 2K PU Coatings

Comparison: 2K PU SB Acrylic Clearcoat

Air Dry Tack-free Times Circular recorder

DBTDL

K-KAT XK-622

Set to touch, hours*

3

2.5

Surface dry, hours**

5.7

5.1

*Time when paint stops flowing into the scribed channel. ** Time when the recorder’s teflon stylus no longer leaves a clear channel, but begins to rupture the dry upper layer of the curing film.

Film Hardness & Gloss (30 minutes at 80°, Cure Schedule) DBTDL

K-KAT XK-622

20° Gloss, %

95.4

99.3

60° Gloss, %

100

100

Pendulum Hardness, cycles (initial)

44

50

Pendulum Hardness, cycles (3 days)

78

84

NEW K-KAT® XK-622

A Friendly Alternative to Tin Catalysts x

Offering equivalent or improved performance over DBTDL*

x

Good pot life

x

Quicker tack-free time

x

Faster hardness development

x

Excellent hardness and gloss Request additional information today by: Emailing: [email protected] or Calling: 203-866-5551

* Performance can be system/formulation specific

www.kingindustries.com

Visit ads.pcimag.com 44

䡲䡲䡲

034 Hexion FT.indd 44

OCTOBER 2010 | W W W . P C I M A G . C O M

9/20/10 12:18 PM

Gelled Calcium Sulf Innovative and Versatile Corrosion Inhibitors

C

orrosion is like a cancer to metal – it leads to v ery he avy lo sses, i n a ny p art of t he world. The i nitiation of c orrosion i s n ot noticed however due to the electrochemical p rocess; i n a ggressive a tmospheric conditions it spreads very fast. The destruction is not only to the structures themselves but also may result in disastrous consequences. Some steel structures, dat ing back thousands of y ears, are s till i n g ood c ondition, w ithout lo sing me tal la yer, luster, o r t heir ae sthetic lo ok. The t echnique of m aking superior-quality s teel a nd p rotecting t he me tal ha s obviously been available for years. Today however, due to economic aspects, a variety of steel is used in many application areas from pipelines to bridges, transportation materials, marine, etc. However, due to severe corrosive conditions, these metal parts are subjected to many critical exposures such as humidity, salt spray, acid/alkaline chemical f umes, me chanical da mage a nd a tmospheric changes. The environment consists of a va riety of materials, which i nitiate a nd e nhance c orrosion. S evere c onditions further a ggravate a nd r esult i n da mage. The fol lowing discussion covers corrosion theory and different techniques available today to fight against corrosion.

Corrosion Theory and Concepts Various me tals, s uch a s s teel, a re fo rmed by s pecial h ightemperature treatment. However, these metals are unstable in ordinary aqueous environments. The me tal gets affected quickly, when exposed to water, humidity, salt water,

chemicals and chemical fumes, and then combines chemically to form compounds with these metals, finally resulting in rusting, corrosion or a tarnishing effect. The p rocess of c orrosion s tarts whe never a metal s urface i s ex posed. The che mical r eaction i s accompanied by t he p assage of e lectrical c urrent. It i s an e lectrochemical p rocess. The p rocess of c orrosion i s known a s an an odic r eaction p rocess, w hereby m etaldissolving ion s a re g enerated. The fol lowing fac tors a re primarily r esponsible a nd have i nfluence on t he p rocess of corrosion. • atmospheric conditions, environmental cycle; • too much humidity, salty conditions; • atmospheric chemical fumes; • oxygen availability; • composition and quality of the metal; • storage conditions, pretreatments; • chloride ion penetration and contact; and • sulfate content and conversion to sulphide.

Types of Corrosion The f irst s tep is es tablishing th e a nodic o r c athodic s ite. The process occurring at the anodic site is the dissolution of me tal a s me tallic ion s, a nd c onverting t hese ion s i nto insoluble corrosion products, such as rust. At this stage a process of metal destruction starts.

Pitting Corrosion The i nitiation of p itting occurs when a n electrochemical or che mical br eakdown ex poses a s mall lo cal s ite on t he metal surface to a damaging species such as chloride ions. The pit is the a node of a n electrochemical corrosion cell, and the cathode of the cell is the non-pitted metal surface.

Crevice Corrosion A portion of a metal surface is shielded in such a way that the shielded portion has limited access to the surrounding environment.

Stress Corrosion Cracking Localized c orrosion, wh ich p roduces c racks i n me tals, stresses the breakdown of the passive layer on the metal surface.

Inter-Granular Corrosion Formation of small crystal grains, thereby weakening the metal surface. By Dr. Ninad Kondekar, Executive Director | P&M Enterprise, India-KIMES USA 46

䡲䡲䡲

046 P&M FT.indd 46

OCTOBER 2010 | W W W . P C I M A G . C O M

9/20/10 12:20 PM

Sulfonates Uniform Corrosion Corrosion s pread u niformly o ver a ll t he surface.

Galvanic Corrosion Corrosion r esponsible whe n t wo d ifferent me tal surfaces are in contact or used in composition.

Erosion Corrosion Erosion c orrosion r esults f rom t he d isruption of t he protective p assive f ilms. The rat e of c orrosion i s h igher and fa ster on a n u ninhibited s urface a nd slo wer on a n inhibited surface due to the prevention of contact with air, oxygen and other elements.

Choices for Corrosion Prevention In t he old en da ys choic es fo r p reventing c orrosion w ere very limited. Today, due to technology developments and upgrades, a n umber of s olutions a re ap plied i n p ractice. Following are the four major solutions that are widely used. 1. Composition of the metal. In the steel, further modifications are done by i ncorporating various other non corrosive metals – SS304, SS316 are some examples. This, however, i s a v ery c ostly p roposal, but may ne ed t o b e used depending on the performance expectation. 2. Plastics o r po lymers a re fused , d eposited o r f ixed o n the me tal; fo r exa mple va rious p ipes, i nstruments, machinery c omponents, e tc. a re p revented f rom c orrosion in this manner. 3. Applications of a s acrificial c oat/deposit, l ike z inc ga lvanization, or tin coated; the process is very costly. 4. Barrier c oatings – Mo st w idely ac cepted a nd u sed t echnique, whe reby a p olymer o r a nti-corrosive c oating i s applied on a metal surface of any shape or size to cut off the corrosion-leading elements, thus forming a barrier coat.

The unique features of these coatings are: • minimal or no surface preparation is required; • a single coat, without any primer, intermediate application; • film thickness can be applied from 40-400 microns in a single coat; • w eldability; • resists undercutting; and • very high corrosion resistance.

FIGURE 1 | Sulfonic acid production.

R

+ SO3

SO3 Sulfonic acid

FIGURE 2 | Formation of the amorphous carbonate complex.

[R

Ca[OH] CO2 SO3]2 + Ca O 2

[R

SO3]2–Ca++ • n CaCO3 Amorphous

FIGURE 3 | Formation of the calcite structure.

[R

SO3]2–Ca++ • n CaCO3

Solvent

[R

SO3]2–Ca++ • n CaCO3

Amorphous

Calcite

FIGURE 4 | Simplified over-based calcium sulfonate micelle.

SO3

Range of Anti-Corrosive Coatings In t he p ast, a lkyd-based r ed o xide p rimers, z inc ch romate primers and micacious oxide-based coatings were in common use for corrosion prevention. Now, conventional high-solids two-component epoxy paint or solvent-free epoxy paints are used. E ven fo r h igh-performance ne eds g lass f lake e poxy coating is used. Epoxy zinc silicate is today a most acceptable product. S ometimes p olyurethanes a nd p olyureas a re applied fo r s pecific job s. H owever a ll t hese s ystems r equire too m uch s urface p reparation, p rimer, i ntermediate, a nd topcoat ap plications. The c omposite t hickness i s very h igh, and it t akes a lot of t ime, labor, skill etc. The lat est remedial solution that is popular, specifically in the United States, are anti-corrosive coatings based on gelled calcium sulfonates.

R

SO3 Ca SO3

Ca

SO3

CaCO3 SO3

Ca

SO3 Ca SO3

SO3

PA I N T & C O A T I N G S I N D U S T R Y

046 P&M FT.indd 47

䡲䡲䡲

47

9/20/10 12:20 PM

Gelled Calcium Sulfonates

A c omparison of a n e poxy m astic-coated p anel, 5 00 microns DF T, a nd a n a lkyd mo dified w ith g elled c alcium sulfonate i nhibitor, 2 60 m icrons DF T, w as c onducted fo r 50 months exposure time at a New Jersey (U.S. east coast site). The e poxy c oating fa iled a fter 5 0 mont hs ex posure, and t here w as n o e ffect on t he p anel ba sed on c alcium sulfonate-modified alkyd film.

Gelled Calcium Sulfonate Chemistry Features Gelled Calcium Sulfonates Thixotropic o ver-based g elled c alcium s ulfonates a re produced via a complex series of chemical reactions. Some of t he i mportant s teps of t he m anufacturing p rocess a re shown in detail in Figures 1-4.

FIGURE 5 | Calcium sulfonate – calcium carbonate complex functionalities.

[R

SO3]2–Ca++ • n CaCO3

Hydrophobicity

Polarity

Corrosion Inhibition

TABLE 1 | Features and benefits of gelled calcium sulfonates. Key Features Multiple Benefits Major binder in coating formulations Primary component in waterborne formulations Logical starting point for unique solventborne formulations Free from heavy metals Non-toxic as compared to other corrosion inhibitors Impart non-sagging, no drip properties Rheology modifier; viscosity controller Helps pigment dispersion Good wetting agent, improves flow properties Highly effective rustpreventive properties Excellent outdoor exposure, weathering resistance Anti-corrosive properties Improved substrate adhesion properties Reduces water penetration Displaces moisture Buffers the pH at metal surface No special surface preparation required 48

䡲䡲䡲

046 P&M FT.indd 48

Low-cost formulations Simplification of formulations Reduced number of raw materials Flexibility in formulations Eco-friendly formulations Suitability for various end uses Utilize low-cost aliphatic solvents and components Non-toxic, complies with eco-toxicity regulations Eco-toxicity compliance Reduced risk of health hazard Lower cost; one-coat application Improves transfer efficiency May replace rheology additives Raw material and labor cost saving May reduce additional dispersant in formulation May reduce use of wetting agents Fewer additives give less chance of error Excellent durability Reduced coating maintenance Lowered labor cost and high productivity Long life, savings from extended life, no reworking Long life of metal surfaces, equipment Long life, savings from extended life, no reworking Long life of metal structure, equipment Reduces failure rate due to film damage Long-lasting performance Long lasting Improves corrosion resistance Resists bio-degradation Less surface preparation Cost and time saving Inhibits corrosion Cost saving in the long run Quick completion of jobs (cost saving) More output with same labor force

Sulfonation Sulfonic acid is first formed by reacting an alkyd benzene compound with sulfur trioxide as shown in Figure 1.

Neutralization and Over-Basing The s ulfonic a cid is th en c onverted i nto th e s ulfonatecarbonate c omplex by neu tralizing t he s ulfonic ac id a nd reacting the metal salt with an excess of calcium hydroxide and c alcium o xide t o fo rm t he o ver-based c omplex. The c arbonate fo rmed i n t his r eaction i s a morphous i n structure (Figure 2).

Carbonate Modification The mo dification s tep c onverts t he s mall a morphous carbonate p article s tructure ( 9 n m a verage) t o a la rge particle s ize plat y c alcite c rystal ( 200-250 n m a verage). This calcite structure, shown in Figure 3, imparts thixotropic viscosity characteristics to all products.

Sulfonate Complex The calcium carbonate particles a re t ied t o t he sulfonate complex a nd w ill n ot s ettle ou t i n a c oating fo rmulation (Figure 4 ). C ompetitive m aterials a re of ten m ade by dispersing dry calcium carbonate, very fine mesh powder, into a s ulfonate ba se, fo r c ost r eduction. Th is ex ternally added carbonate is not chemically bonded to the sulfonate backbone and can thus settle down from suspension.

Various Functionality of Products The products contain the thixotropic over-based calcium sulfonate-calcium c arbonate c omplex d ispersed i n mineral spirits or in oil. These materials exhibit a va riety of functionalities, which relate to the chemical structure of o ver-based g elled c alcium s ulfonate: h ydrophobicity, polarity and corrosion inhibition. This is illustrated by the structure shown in Figure 5.

Hydrophobicity Alkyl groups attached to the aromatic ring face away from t he s ubstrate a nd r epel t he i ngress of moi sture. These mostly saturated aliphatic chains are completely nonpolar, c onferring on t he c omplex t he dua lity of being polar on one e nd and nonpolar on t he other side. They a lso m ake h ydrophobic c ompounds l ike w axes, oxidative p etrolatums, o ils a nd a sphalts c ompatible i n Jalpon coating formulations.

Polarity The aromatic ring and attached SO3 group form a h ighly polar entity, wh ich results i n coatings w ith superb metal wetting a nd moi sture d isplacement p roperties. The polar e nd of t he s ulfonate/carbonate c omplex at taches to m etallic s ubstrates an d d emonstrates e xceptional adhesion even when the coating film is damaged. Very thin, less than 1 mil-based coatings, can offer up to 1,000 hours of p rotection in the ASTM B 117 Salt Fog Test. The moisture d isplacement property a llows the application of coatings in less than optimal conditions.

Corrosion Inhibition The c alcium c arbonate p art of t he c omplex f unctions

OCTOBER 2010 | W W W . P C I M A G . C O M

9/20/10 12:20 PM

Gelled Calcium Sulfonates

primarily a s an alk alinity r eserve. T he carbonate is slightly soluble in water and acts as a corrosion inhibitor by buffering the pH at t he me tal s urface. A pH of approximately 1 0.0 c an b e m aintained at t he c oating/metal in terface, w hich delays t he i nitiation of t he c orrosion process.

Anti-Corrosive Barrier Coatings The s ize a nd shap e of t he c alcium carbonate particle is controlled during synthesis t o fo rm t he plat elet s tructure. These f lat plat elets fo rm a ba rrier t o a ir, moisture, a nd c arbon d ioxide t o r each the me tal s urface, t hereby s topping t he electrochemical reaction process, and thus

Performance in the United States

Less heat due to shorter required running time.

For t he r ehabilitation of t he h ighlevel br idges, t he F ederal H ighway Administration (FHWA) has studied 2000 bridges out of 200,000 total bridges in the United St ates who se c ondition i s c ritical. They have sought the help of polymer science and various laboratories including Turner-Fairbank H ighway Re search Centre (TFHRC), Powertech laboratories. Testing was conducted by Powertech Labs Inc., of Su rrey, B ritish C olumbia, whe re 16 coating systems were tested. Included were many multi-coat systems, some of which were single-component. A wide range of lab testing criteria were applied to each coating. Of p articular in terest ar e d urability tests conducted over aged alkyd substrates as w ell a s bla sted s teel. O ne of t he mo re interesting t ests w as a n e nvironmental/ weathering t est, “ Envirotest” d eveloped by KTA Tator, of Pittsburgh, PA. This tes t i ncludes i mmersion i n s alt water, exposure to heat and humidity and an ultraviolet light exposure. The test cycle consisted of ex posure at 60 ° C, used a 4% s alt s olution a nd ex posure t o U VB lamps. The cha mber provides a lternating exposure to the various environments by cycling 420° every 2 hours. A calcium sulfonate (alkyd) system was ranked f irst i n t wo of t he fou r du rability tests, i ncluding E nvirotest o n b lasted steel, ( SSPC-SP6) w ith tes t d uration o f more than 4,400 hours.

Excellent for high or low speed and high or low viscosity.

Conclusion

T

®

H E Patented blending/dispersing blade design makes radical improvement over old saw tooth designs

POLY

STAINLESS

*

Most efficient and aggressive blending/dispersing blade available.

*

Provides proper combination of pumping action and shear/ dispersion essential for fast consistent results.

* * * * *

Built in pumping action cuts processing time.

*

preventing c orrosion. Th ixotropic g elled calcium s ulfonates a re s uperior t han commonly a vailable c alcium s ulfonates. The features and benefits of gelled calcium sulfonates are shown in Table 1.

Longer life due to heavier gauge construction.

Supplied with hubs or mounting holes required to retrofit and upgrade present equipment. Pumping blades without teeth are available and are excellent for gentle blending and agitation. DESIGNERS AND MANUFACTURES OF INDUSTRIAL MIXING EQUIPMENT

Since 1948

CONN CO., L.L.C. AND

www.connblade.com

Stirrers Or Complete Units For: PAINTS URETHANE FOAMS ADHESIVES SLURRIES INKS GROUTS CEMENTS ETC. . . .

11 SOUTH MARION STREET • WARREN, PENNA. 16365 • PHONE 814/723-7980 FAX (814) 723-8502

s r

r

TM

Anti-corrosive coatings based on gelled calcium s ulfonates a re new p roven systems t hat a re n ow a vailable a nd used i n th e U nited S tates a nd o ther developed c ountries w ith a n umber of added advantages such as ease of application ac companied by h igh corrosion resistance. 䡲 Dr. Ninad Kondekar has worked for 38 years with various c ompanies, i ncluding A sian Pa ints I ndia; P idilite Industries; National Paints, UAE; and Apcotex India.

References

1. Dr. Cl iff K imes, US A, S SPC s ymposium, June 2010. 2. Dr. Ninad Kondekar, Paint India Jan. 2010. 3. Witco, L ubrizol, S oltex, US A t echnical data-bulletins.

Visit ads.pcimag.com 50

䡲䡲䡲

046 P&M FT.indd 50

OCTOBER 2010 | W W W . P C I M A G . C O M

9/20/10 12:20 PM

Nanoparticle Additives for Enhanced Scratch Resistance in UV-Cured Coatings

V

ast amounts of time, research and capitaken t o m arket by na notechnology c ompanies wh ich, tal have been invested broadly in nanowhile p erhaps ex pert i n t he s ynthesis a nd m anipulation technology over the past 20 years. The of n anomaterials, h ad li ttle t echnical, m arketing o r majority of this effort has been expended sales ex pertise i n t he c oatings i ndustry. I n ot her c ases, by g overnment lab oratories, ac ademia large, w ell-known che mical ad ditives c ompanies w ith a and industry, and many new nanomaterials, new routes to strong existing presence in coatings but little knowledge nano-versions of existing materials, and improved metrolof n anomaterials a ttempted to i nvent o r p urchase ogy and analytics have subsequently emerged. These new nanotechnology a nd rap idly d eploy it t hrough ex isting capabilities have resulted in the commercial utilization of channels t o m arket. Ne ither of t hese ap proaches ha s nanoproducts in industries as diverse as silicon wafer polbeen especially successful commercially; many small ishing and UV filters for personal care. However, the adopnanotechnology companies have simply disappeared, and tion of na nomaterials i n t he at le ast one la rge s pecialty coatings market has been less chemical company has ex ited FIGURE 1 | TEM of aluminum oxide prepared by physical rapid t han some forecasts had the na noadditives bu siness vapor synthesis with an average particle size of 40 nm. originally s uggested i t m ight altogether. The a uthors be, d espite t he p otential b enhave identified what they efits s uch m aterials c an of fer, believe to be th e p rimary including im proved s cratch barriers t o t he s uccessful resistance an d b etter UV p rotechnical a nd c ommercial tection. I t w ould a ppear th at use o f n anotechnology i n assumptions ab out “ drop i n” the c oatings in dustry, an d performance in t he e nd-use have a ssembled a mo del applications for na noparticlethat ha s b een sho wn t o b e containing additives have simsuccessful in gui ding t he ply b een t oo op timistic. Wh y development o f co mmercial is this? coatings prod ucts usi ng To a nswer th is q uestion, nanotechnology s olutions t o it i s i nstructive t o s tudy t he solve l ong-standing, unm et evolution of attempts to use challenges. A lthough th e nanoparticles in c oatings model i s g eneral, t he p resent applications i n g eneral. I n examples will be selected from some instances, products were the a rea of s cratch protection

By Roger H. Cayton, Patrick G. Murray and David Nelson | Nanophase Technologies Corporation, Romeoville, IL 52

䡲䡲䡲

052 Nanophase FT.indd 52

OCTOBER 2010 | W W W . P C I M A G . C O M

9/20/10 12:22 PM

in t ransparent U V-cured c oating s ystems, sho wing t he performance improvements possible with nanometric aluminum o xide-based ad ditives a nd a f ramework up on which t o c onsider p erformance, c ost a nd t ransparency simultaneously.

FIGURE 2 | Disc centrifuge particle size analysis of aqueous dispersions of aluminum oxide from physical vapor synthesis. 2500 20 nm Al2O3

Discussion A Prescriptive Three-Step Model for Success

Aluminum Oxide Nanoparticles It i s w ell k nown t hat t he i ncorporation of m icron-size alumina (grit) in applications such as pre-finished laminate f looring substantially improves the scratch and abrasion resistance. The extreme hardness of the alumina particles t ranslates i nto e ffective w ear r esistance whe n incorporated in to s uch c oatings; h owever, t he u se i s restricted to su bstrates w here t he h igh h aze re sulting

Intensity

Owing t o t he v ery h igh s urface a reas, t he s tabilization of na noparticulate me tal o xide d ispersions ( such a s aluminum o xide) c an b e cha llenging a nd of ten r equires both s pecialized che mistry a nd p rocess t echnology. I f the na noparticles a re not (o r c annot b e) d ispersed down to t heir p rimary p article s ize, t ransparency i n c oatings will not be achieved except in the event that the refractive index of t he c oating exac tly m atches t hat of t he p article. Because of t his, mo st u sers of na nometal o xides, ev en those ex perienced w ith p igment d ispersions, w ill fa il t o achieve the desired result when at tempting to work w ith nanomaterials i n p owder fo rm. I ncomplete o r i mproper dispersion will result in high viscosities, rapid gravimetric settling and large particle agglomerates. In addition to having a stable dispersion of primary particles to begin with, it is also necessary that the dispersion be c ompatible w ith th e c oating f ormulation i t is i ntended to b e i ncorporated i nto. B ecause of t he w ide va riety of coating in gredients ( resins, a dditives, p igments, e tc.) an d the number of va riables typically present (resin chemistry, solvency, pH, s olids load ings, e tc.), t he e ffective u se of nanoparticle ad ditives i s not a “ one s ize f its a ll” s ituation, and c ompanies t hat at tempt t o m arket na noparticle dispersions w ith bu t a l imited r epertoire of fo rmulation tools a re l ikely t o b e u nsuccessful. I n t he exa mples t o be c onsidered he re, fa ilure t o ach ieve c ompatibility w ith the target UV-cured formulation will result in opacity (haze) a nd p oor s cratch p rotection. It i s p rimarily fo r t his reason th at nanomaterial additive c ompanies th at s imply “throw samples over the wall” without the means to ensure compatibility wi th c ustomer f ormulations will , in m ost instances, disappoint their customers. Finally, g iven t hat sta ble d ispersions o f pr imary particles a re a vailable a nd t hat c ompatibility w ith the t arget c oatings fo rmulation c an b e ach ieved, it is n ecessary th en ( and o nly th en) to e mpirically determine t he i mpact of t he na noparticle t ype, s ize, loading lev el a nd s urface t reatment on t he c oating properties in o rder t o i dentify th e o ptimum s olution that balances performance, cost and transparency in a s ystem. Th is op timized s olution w ill l ikely va ry f rom formulation to formulation, and thus knowledge of b oth the n anomaterial p roperties as w ell as th e e nd-use application is critical if success is to be realized.

2000

40 nm Al2O3

1500 1000 500 0 0

100

200

300

nm from t he p article load ing c an b e t olerated, o r i n s ystems where the refractive index of the resin binder is sufficiently high so as to mask the presence of the alumina (e.g., melamine fo rmaldehyde). I n o rder t o a llow t he u se of alumina particles in clear topcoats while retaining a high level of t ransparency a nd g loss, it i s ne cessary t hat t he particle size be reduced to the nanometer size range. The li ght-scattering b ehavior o f s ub-micron-sized particles dispersed into a f luid medium such as a c oating matrix is described by M ie theory, and the relationship is summarized by Equation 1 where I s refers to the intensity of s cattered l ight, N = t he n umber of p articles, d = t he particle s ize, a nd ∆η = t he d ifference i n r efractive i ndex between the fluid medium and the particle. Is = (N)(d6)(∆η)2

(1)

Since t he r efractive i ndex of a luminum o xide ( 1.72) is s ubstantially h igher th an th at o f U V-cured c oating resins, e ither t he n umber of p articles o r t he p article s ize must b e min imized in o rder t o min imize t he am ount o f light sc attering ( which is pe rceived as h aze to th e e ye). Of t he t wo p arameters, t he p article s ize ha s t he s tronger influence on t he ex tent of l ight s cattering a nd r esulting haze; t he authors have fou nd t hat i n U V-cured c oatings, alumina with an average particle size of < 50 nm is required in order to retain a high level of transparency. One p rocess by wh ich na noscale a luminum o xide particles c an b e p repared i s t hrough ph ysical vap or synthesis (PV S) u sing a pla sma a rc. A t ransmission electron m icrograph (T EM) of a luminum o xide p repared by t his p rocess i s sho wn i n F igure 1 . The c rystal pha se of alumina made by this process is γ/δ, a nd the primary particles e merge w ith a s pherical mo rphology. A u nique aspect o f th e p lasma p rocess is th at e ach c rystalline alumina s phere fo rms a s a d iscrete e ntity w ithout a ny durable p article-particle s uperstructure t hat, i f p resent, could prevent full dispersion to primary particles. PA I N T & C O A T I N G S I N D U S T R Y

052 Nanophase FT.indd 53

400

䡲䡲䡲

53

9/20/10 12:22 PM

Nanoparticle Additives for Enhanced Scratch Resistance in UV-Cured Coatings

The ph ysical vap or p rocess y ields a log -normal distribution of the discrete alumina primary particles, as depicted by the particle size distributions shown in Figure 2, which were obtained using a CPS disc centrifuge particle sizer. The f igure sho ws t he r elative s ize d istributions of al umina p articles p repared b y tw o dif ferent p lasma processes. V ariation i n t he p lasma c onditions a llows control over the average particle size as well as the particle size distribution.

Particle Dispersions and Formulation Compatibility While the f irst step toward the production of a n alumina product suitable for use in transparent UV-cured coatings is t he s ynthesis of d iscrete na no-size p articles ex hibiting no significant secondary structure, the second step is the dispersion of those particles from the powder state, where they a re weakly a ssociated by e lectrostatic fo rces, i nto a format suitable for the coating application. Creating stable dispersions of nanomaterials can be a significant challenge owing t o t he s trong t endency fo r p rimary p articles of this s ize to ass ociate a nd f locculate i n f luids bec ause

FIGURE 3 | Two vials containing 20 nm aluminum oxide particles dispersed at 1 w t% in a 100% solids UV-curable coating formulation: (A) stabilized and compatible dispersion, (B) unstable dispersion showing incompatibility and flocculation of aluminum oxide particles.

A

B

of t he v ery h igh s urface a rea. It ha s b een d iscovered that s table d ispersions of na noparticles p repared v ia t he plasma vapor process can be achieved by surface treating the p rimary p articles w ith a s tability p ackage d esigned specifically fo r t he p article/liquid i nterface. I n o rder t o prepare c oncentrated a lumina d ispersions fo r u se i n 100% s olids U V-curable c oatings formulations, a s urface treatment w as d esigned t hat a llows s table d ispersions t o be generated directly in low-viscosity acrylate monomers such as t ripropyleneglycol d iacrylate ( TPGDA) a nd 1,6-hexanediol di acrylate ( HDDA). W ith s uch s tability packages, c oncentrated bu t f luid d ispersions c ontaining up to 30 wt% alumina can be prepared. The s urface t reatment p ackage u sed t o d isperse a nd stabilize t he a lumina p articles a gainst f locculation a nd settling in the concentrated dispersion must also be capable of p roviding compatibility when this concentrate is let down i nto t he coating formulation. A s a n exa mple, the v ials sho wn i n F igure 3 r epresent t wo ex tremes of compatibility. Starting with the same UV-cured coating formulation, vial A on t he left contains 1 w t% of a na noalumina p roduct, wh ich w as p repared w ith a s urface treatment t hat a llows fo r a f ully c ompatible a nd s table system, whe reas v ial B on t he r ight c ontains t he s ame concentration of na no-alumina bu t w as p repared w ith an i neffective s urface t reatment s ystem t hat ex hibits incompatibility a nd ha s b egun t o f locculate ou t of t he coating fo rmulation. The key t o g enerating c ompatible systems of na noparticles a nd c oatings i s a n i ntimate understanding of n ot on ly t he s urface che mistry of t he nanomaterial itself, but also of t he coating application in which the nanomaterial is to be incorporated.

Results Clarity and Scratch Resistance

FIGURE 4 | Film haze attributable to nano alumina particles (10 µm commercial UVcured coating on glass). 1.2 1.0

40 nm 20 nm

% Haze

0.8 0.6 0.4 0.2 0.0 0.0

54

䡲䡲䡲

052 Nanophase FT.indd 54

0.5

1.0

1.5 Al2O3, wt%

2.0

2.5

3.0

The p erformance o f alumina n anoparticles in im proving scratch resistance while having but a m inimal i mpact on clarity w as eva luated i n a c ommercial U V-cured c oating formulation. Aluminum oxides with mean particle sizes of 2 0 a nd 4 0 n m p repared v ia a ph ysical vap or synthesis p rocess w ere s urface t reated a nd d ispersed at 30 wt% in TPGDA monomer. These concentrated alumina dispersions w ere t hen ble nded i nto t he c ommercial coating fo rmulation at load ing lev els ra nging f rom 0 .5 to 2 .5 w t% a lumina s olids on t otal r esin. The r esulting formulations were applied to glass substrates at 10 µm film thickness, cured by U V exposure, and the ha ze measured to d etermine t he e ffect of t he a lumina p articles on t he clarity of the coatings. The results are depicted in the graph of haze versus alumina loading shown in Figure 4. At load ing lev els up t o 2 .5 w t% w ith t he 4 0 n m alumina p articles, t he h aze r emained a t l ess t han 1% i n t he c oating. A s ex pected, t he 2 0 n m a lumina particles had ev en le ss i mpact on t he f ilm cla rity w ith significantly lo wer ha ze whe n c ompared a gainst t he 40 nm system. Although haze values of less than 1% can b e me asured i n t hese na no-alumina c ontaining films whe n ap plied t o a t ransparent s ubstrate, i n actual practice haze readings of less than 1% are not perceptible t o t he ey e i n c oatings ap plied t o op aque substrates. It is th is very h igh clarity l evel, achievable

OCTOBER 2010 | W W W . P C I M A G . C O M

9/20/10 12:22 PM

Nanoparticle Additives for Enhanced Scratch Resistance in UV-Cured Coatings

TABLE 1 | Effect of nano-alumina particles on pencil hardness; 40 nm alumina particles in a 4 mil commercial UV-cured coating on glass. Nano Al2O3, wt% 0.0 H 0.5 F 1.0 2H 2.0 3H

Visit ads.pcimag.com

Selecting the best Additives is Child’s Play Serving the Paint and Coatings Industry with innovative silicone additives for better flow, leveling, slip, mar resistance, and foam control. Innovative Silicones for your Technology

Manufacturer of organo modified & reactive silicones. SILTECH CORPORATION 225 Wicksteed Avenue, Toronto, Ontario, Canada, M4H 1G5 Tel: (416) 424-4567 Fax: (416) 424-3158 www.siltechcorp.com

Visit ads.pcimag.com 56

䡲䡲䡲

052 Nanophase FT.indd 56

Pencil Hardness B

only wi th w ell-dispersed al umina p articles in t he n ano-size range, wh ich a llows fo r t heir u se i n t ransparent U V-cured coating applications. To eva luate t he e ffect of na no a lumina p articles on t he physical p roperties of U V-cured c oatings, a c ommercial c oating formulation w as load ed w ith 4 0 n m a lumina p articles at 0 .5, 1.0, and 2.0 wt% on resin (using a concentrated dispersion of the particles i n H DDA mon omer). The s ystem w as t hen ap plied at 4 mil t hickness t o a g lass s ubstrate, a nd t he p encil ha rdness w as measured after curing. In this test, a w eighted stylus containing a graphite “pencil lead” is pulled across the surface of the coating and t he s urface i nspected fo r a s cratch. The p rogression f rom softer to harder “lead’ in the stylus before a scratch is observed may be taken as an indication of improved relative hardness of the f ilm. The r esults fo r t he s ystem u nder d iscussion a re sho wn in Table 1. The i ncorporation of t he a lumina p articles i ncreased the c oating ha rdness f rom a lev el of H B i n t he u nfilled ( 0 w t% alumina) coating up to 3H (4 “lead” grades harder) with 2.0 wt% alumina l oading. W hile t he in crease in f ilm h ardness d oes n ot always c orrelate p ositively t o i ncreased w ear r esistance, it i s a good indication that the alumina nanoparticles are improving the scratch-resistant p roperties of t he c oating, even at r elatively low concentration, while not degrading the appearance of the coating by reducing gloss or contributing haze. The s cratch-resistant p roperties of a U V-cured c oating containing na no a lumina w ere a lso me asured u sing a s teel wool s cratch t est. I n t his t est, a s teel w ool p ad w as f itted w ith a one p ound weight a nd at tached t o t he a rm of a r eciprocating linear mot ion abrad er i nstrument. C oatings w ere ap plied t o a transparent s ubstrate a nd s ubjected t o r epeated s cratch c ycles with t he weighted s teel wool p ad. A fter a s et number of c ycles, the ha ze of t he f ilm w as me asured t o d etermine t he d egree of scratching as evidenced by the increase in haze of the coating. A s cratch t est w as c onducted on a c ommercial U V-cured coating i nto wh ich 4 0 n m a lumina w as i ncorporated at lev els ranging f rom 0.5 t o 2.5 w t% a lumina on r esin u sing a T PGDA concentrate as the vehicle to deliver the alumina nanoparticles. A #0000-grade steel wool pad was used, and the coatings were subjected to 1000 double cycles with the linear motion abrader. In t his c ase, t wo d ifferent s urface t reatment p ackages w ere applied t o t he a lumina p articles du ring t he d ispersion p rocess. Both t reatment s ystems p rovided f ull c ompatibility b etween the p articles a nd t he c oating fo rmulation i n t erms of cla rity; however, the treatments resulted in different performance with respect t o s cratch r esistance. The r esults of t he s cratch t ests are sho wn i n F igure 5 . The c oating c ontaining t he a lumina particles fe aturing s urface t reatment A sho wed a s ignificant improvement in s cratch r esistance wi th an al umina l oading of just 0.5 wt%, then a relatively flat response as the alumina loading was increased. With this surface treatment, the scratch resistance of the coating was more than doubled using as little as

OCTOBER 2010 | W W W . P C I M A G . C O M

9/20/10 12:22 PM

Nanoparticle Additives for Enhanced Scratch Resistance in UV-Cured Coatings

FIGURE 5 | Scratch resistance of a commercial UV-cured coating incorporating 40

% Haze from Scratch Test

nm alumina particles with different surface treatments; 10 µm coating on glass.

10 9 8 7 6 5 4 3 2 1 0

performance a nd/or t he mo st e conomical u se of t he nanoparticle additive in a particular system.

Conclusions 40 nm Al2O3, Treatment-A 40 nm Al2O3, Treatment-B

0.0

0.5

1.0 O Al2 3, wt%

1.5

2.5

1.0 wt% of the nano-alumina additive. The performance of t he a lumina s ystem u sing s urface t reatment B w as even more dramatic. The results indicate that the degree of s cratching c an b e r educed by a fac tor of 5 u sing alumina load ings i n t he 1 .5 t o 2 .5 w t% ra nge. Th is example i llustrates t he ne cessity t o c onduct t he f inal optimization s tep, a fter d ispersancy a nd c ompatibility have b een ach ieved, i n o rder t o r ealize t he m aximum

Successful incorporation of nanometric aluminum oxide particles into UV-cured coating formulations for improved scratch re sistance re quires a dherence to a t hree-step process: ( 1) P reparation of a s table, c oncentrated, l iquid dispersion o f p rimary al umina p articles dir ectly in an acrylate mon omer; ( 2) E nsuring c ompatibility of t he nanoparticle di spersion c oncentrate wi th t he c oating formulation; a nd ( 3) O ptimizing t he p erformance of the na noparticles w ith r espect t o cla rity (ap pearance), scratch resistance (performance) and loading (cost). If t he t hree-step mo del i s fol lowed, a luminum o xide nanoparticles c an e nable t ransparent U V-cured c oating formulations w ith s ubstantially i mproved s cratch resistance w hile e xpressing m inimal n egative i mpact on t he c oating cla rity o r g loss. Th rough s election of the p roper al umina p article s urface tr eatment, t he scratch resistance of t hese additives can be optimized for maximum performance. 䡲 This p aper w as p resented a t t he R adTech 20 10 T echnology E xpo a nd Conference, Baltimore, MD, www.radtech.org. For more information, visit www.nanophase.com.

FEATURING PRESENTATIONS FROM ALSTOM POWER ENERGY RECOVERY, US ARTIKOL, UK CHINA CARBON BLACK INSTITUTE, China CTC INTERNATIONAL, US DOODEH SANATI PARS COMPANY, Iran DORIGHT CO LTD, China EKSTROM & SON PROMETHEUS GMBH, Germany GANPADS CONSULTING, US HIMADRI CHEMICALS & INDUSTRIES, India HOSOKAWA MICRON POWDER SYSTEMS, US INSCX EXCHANGE, UK

16 - 18 November 2010

Crowne Plaza Hotel St. Peters Rome, Italy

Three easy ways to register:

(INTEGRATED NANO-SCIENCE & COMMODITY EXCHANGE)

Online: www.carbonblackworld.com Phone: +44 (0) 1372 802051 Email: [email protected]

MAKROCHEM, Poland NOTCH CONSULTING GROUP, US PCME Ltd., UK TAUBER OIL COMPANY, US W.L. GORE & ASSOCIATES GMBH, Germany

www.carbonblackworld.com

Sponsored by:

Visit ads.pcimag.com 58

䡲䡲䡲

052 Nanophase FT.indd 58

OCTOBER 2010 | W W W . P C I M A G . C O M

9/20/10 12:23 PM

Brenntag Offers New Applications Laboratory

B

renntag Sp ecialties, I nc., a s pecialty i ngredients distributor t o t he Ad hesives, C oatings, E lastomers and Sealants (ACES) industries, has announced the dedication of a new “ ACES” Ap plications L aboratory i n N orth W ales, P A. J oe M ulvey, T echnical Development Director, will oversee this new fac ility. The ad dition of Mr. Yanmin Zhong, Ph.D., ACES Technical Specialist, provides over 20 years of ACES formulation experience. Zhong brings with him exc eptional s kills a nd k nowledge i n p olymer s ynthesis a nd starting formulations. This new, fully equipped applications laboratory will focus on starting-point formulations to provide customers a n opportunity to c ommercialize t heir p roduct of ferings w ith m inimal t echnical investment on t heir p art. P olymer d evelopment w ill a lso b e accomplished t o p rovide new op tions t o t he i ndustry i ncluding green resin systems with outstanding properties. “Our goal is to assist customers in bringing new products to market faster, in response to rapidly changing environmental and c onsumer ne eds, a nd t o p romote u nique, new p roducts from our specialty suppliers. Key among new products are true green r esins – r esins t hat a re r enewable i n sho rt t ime s pans and t herefore s ustainable. E xamples a re r esins d erived f rom plant-based ra w m aterials, s uch a s r osin e sters fo r c oatings and plant-based curing agents for waterborne coatings, grouts and high-performance industrial and automotive coatings. We are a lso ex panding ou r w aterborne, U V-cure, a nd v ery-highsolids p roduct of ferings t o he lp m inimize o r e liminate s olvent emissions. W e a re p erforming sho rt- a nd lon g-term r esearch and d evelopment on t raditional r esins s uch a s p olyesters, acrylates a nd e poxies d erived f rom n on-traditional g reen ra w

60

䡲䡲䡲

060 Brenntag FT.indd 60

materials fo r c oating, ad hesive, i nk a nd e lastomer p roducts,” commented Mulvey. Among t he s ervices p rovided t o c ustomers a re t esting fo r thickness, h ardness, c hemical re sistance, v iscosity, d ispersion, color, d rying, U V a nd ba ke c uring, g loss, ad hesion, a nd va rious physical strength tests. Condensation and addition polymerization are also available. Brenntag Sp ecialties, I nc. ha s e stablished a nd w ill c ontinue t o develop strategic and exclusive relationships with premier vendors to the ACES market. The company expects to continue the growth development of t he p ast y ears by c arrying on i nvestment i n technical resources of great value to customers. Formulas created by t he ap plications lab w ill showcase multiple s uppliers w ith t he aim of providing a one-stop solution for customers. Brenntag Specialties, Inc. is a member of the Brenntag North America fa mily of c ompanies. L inking chemical manufacturers and che mical u sers, B renntag p rovides bu siness-to-business distribution s olutions of i ndustrial a nd s pecialty che micals globally. Wit h o ver 1 0,000 p roducts a nd a va st s upplier ba se, Brenntag offers solutions to more than 150,000 customers. Services i nclude ju st-in-time d elivery, p roduct m ixing, formulation, repackaging, inventory management, drum return handling as well as technical services. Headquartered i n M ülheim a n d er R uhr, G ermany, B renntag operates a g lobal network with more than 400 locations in more than 60 countries. In 2009 the company realized global sales of 6.4 billion ($8.9 billion) with approximately 11,000 people. Formulators in terested in l earning m ore a bout B renntag’s expanded capabilities in North America can contact the company at 800/732.0562 or visit www.brenntagspecialties.com.

OCTOBER 2010 | W W W . P C I M A G . C O M

9/20/10 12:25 PM

PA C K A G I N G / M AT E R I A L H A N D L I N G S H O W C A S E S

P RODUCTS ONE labeling solution for ALL types of containers From quart size to 5 gallon pails our revolutionary labeling machine can do it all. Cold glue and pressure sensitive capabilities. The LANGGUTH engineering team delivers custom solutions for labeling applications worldwide.

www.langguth-america.com See a demonstration at booth 2191 at PACK EXPO in Chicago Oct. 31-Nov. 3

MYERS ENGINEERING : T his small -batch mini v acuum mi xer is excellent for formulation trials and small-run batches. This laboratory tool eliminates the waste of raw materials, removes air bubbles and maximizes material strengths. E-mail [email protected].

Epoxy Packaging ADHESIVE P ACKAGING SP ECIALTIES I NC.: Pa ckaging f or reactive adhesives, sealants or resins in small, two-part epoxy delivery s ystems re quires o nly a minimal am ount of mate rial to b e disp ensed at o ne tim e. D ual s yringes p rovide o ndemand mixing and di spensing of t wo-component ma terials in a c ontrolled p rocess. Pre -mixed an d f rozen t wo-part resin systems in a sin gle s yringe are rea dy f or us e, o nce tha wed. E-mail [email protected].

Delta T Hygrometer ELCOMETER: The El cometer 30 9 D elta T h ygrometer is a quick, simple, accurate pass/fail gauge for determining the difference b etween th e d ew p oint te mperature an d th e sur face temperature ( Delta T ) an d th e re lative humi dity. D esigned to be th e e ntry-level climatic gau ge, inte rnal limi ts in th e gau ge warn th e us er w hen th e D elta T o r th e re lative humi dity is exceeded w ith an on -screen indic ation and re d-flashing LEDs . Visit www.elcometer.com.

Emulsion ICC The Compliance Center has a variety of UN Performance Packaging designs to help you ship your products safely by ground, air or ocean. Our most popular 1x1, 2x1 and 4x1 styles include a box and Ringlok and are air approved. We have a variety of other styles ranging from pint to 110 gallon salvage drums. Visit our website at www.thecompliancecenter.com for more information.

Packaging Innovation The ECO-PAIL™ by BWAY is the industry choice for sustainable packaging. It reduces non-renewable energy used and carbon emissions. It contains recycled resin and eliminates non-recyclable components. • Winner of the 2010 Greener Package Award from Summit Publishing. • Winner of the 2010 AmeriStar Package Award from the Institute of Packaging Professionals.

(800) 527-2267 • www.bwaycorp.com • [email protected] 76

Mini Vacuum Mixer

䡲䡲䡲

076 Showcases-Prod.indd 76

THE L UBRIZOL C ORP.: Permax® 8 05 vin ylidene c hloride emulsion is an APE-free, low-VOC, small-particle-size vinylidene chloride acr ylate c opolymer emul sion t hat e xhibits e xtremely low m oisture v apor p ermeability an d e xcellent ox ygen b arrier properties. R ecommended f or a v ariety of c oatings in O EM and industrial metal applications, it adheres well to a v ariety of metal substrates. E-mail [email protected].

Lab Notebook AGILENT T ECHNOLOGIES I NC.: A W eb-based s calable, integrated s ystem t o manage e xperiments and res ults, Op enLAB Electronic Lab Notebook (ELN) version 4.1 of fers scientists in anal ytical res earch an d d evelopment an o ptimized w ay to document an d share e xperiments an d result s. E xperimental templates enable scientists to create, share and reuse their own custom experiment views. Visit www.agilent.com.

Mixer CHARLES ROSS & SON CO.: The Laboratory Dual Shaft mixer is designed to mix a wide variety of products requiring a combination of l ow- an d hi gh-speed a gitation f or m edium- to hi gh-viscosity p roducts. S tandard f eatures in clude: reve rse ve rtical lift to raise mix can to mi xing position; self-contained control panel; variable-speed c ontrols an d in verter du ty m otors; an d ja cketed mix can with discharge valve. E-mail [email protected]. 䡲

OCTOBER 2010 | W W W . P C I M A G . C O M

9/20/10 12:29 PM