European Coatings Journal 2010-11

Primer 11 | 10

Performing well Acrylic-based gloss paints have performance limits. They cannot match the high gloss levels of traditional solventbased alkyd paints. Dr Denis Ruhlmann explains how reformulating acrylic emulsions systems with specific dispersant and thickener can resolve problems with gloss retention and storage stability (16). To obtain optimal pressure-sensitive performances with UV-crosslinkable adhesives, it is necessary to find process settings that result in values of tack, peel and shear resistance that are suitably balanced for the target application. The photoinitiator is one of the key components in achieving this balance. How this can be obtained is described Dr Zbigniew Czech and his co-authors in their article (34). Damir Gagro

Sustainability was the defining theme of the CEPE Annual Conference in the Turkish metropolis of Istanbul. All kinds of different approaches and views regarding the sustainability of companies, products and processes were discussed to lead the coatings industry with high performance into a green future (40).

Jean-Paul Demolin - Fotolia.com (left) Sandro Götze - Fotolia.com (bottom)

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Market Watch Industry news Waterborne coatings

 Emulsion paints

“Understanding trends”

Meffert inaugurates new site in Moscow and leaves Turkey Source: Meffert AG Farbwerke

Interview

Erin Bernhardt, Eastman Chemical Company Waterborne coatings have quickly taken hold in some product-coating market segments due to legislative regulations and customer demands. Erin Bernhardt, Global business manager coatings additives at Eastman, speaks about further trends in the market to switch from solvent-based to water-based systems. _How do you rate the market development for waterborne coatings? Erin Bernhardt: The trends vary as each region and application is different. Eastman is focused on understanding these trends. Europe and Japan are the leaders in terms of waterborne systems. In developed countries these systems account for 90+% of the architectural, refinish, and field applied coatings. In regions with high humidity, such as Southern Europe or India, the percentage is much lower due to the energy required to driveoff the water. Likewise for OEM production, one solution does not fit all. The developed countries utilize more waterborne basecoat technology, while the paint shops being built in developing BRIC countries will be divided between high-solid solventborne and waterborne technologies. Formulators continue to make investments to improve the economics and productivity of waterborne coatings. _To what extent do you see potential to open new markets or new segments with waterborne systems? Bernhardt: The shift to waterborne coatings is driven largely by legislative decisions and sustainability initiatives. Therefore the direc direction that is taken in new markets and regions will depend on the opposed forces of greenhouse gas legislation and VOC regulations. Waterborne coatings will continue to expand into inks, wood coatings, and package coatings as VOC legislation is expanded. However, in energy and throughput intensive industries like automotive and industrial equipment, the desire to minimize carbon footprint and limit greenhouse gas emissions is causing some OEMs to choose high-solid solventborne coatings technologies. These evolving demands are creating both a push and pull effect for advancements in coatings technologies.

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_What applications can benefit from _ a switch from solvent- to water-based? Bernhardt: The conversion from solvent borne to waterborne can be a significant capital investment; spanning millions of dollars of impact to OEMs depending on scale and other factors. However, these waterborne coatings can offer advantages in appearance and lower VOCs. Producers make site specific choices based on balancing the benefit to cost ratio of this technology. Waterborne technologies are expected to gain share in inks and package coatings. Across all markets, there is a drive for improved productivity, performance and compliance and these drivers are accelerating the rate of innovations in additives for waterborne systems and other technologies. _What trend do you expect for waterborne coatings? Bernhardt: It depends on the angle you look at it. We have to look at costs, productivity, performance and compliance. As mentioned, the choice between waterborne or solventborne coatings will depend on the region and application. The productivity and efficiency of waterborne coatings is often not as good as solventborne systems. Waterborne technologies tend to deliver a superior appearance and VOC profile but may not have as favorable a result when examining their carbon footprint or associated green house gas emissions. In order to balance these drivers, we’ll see the continued need for both solvent borne and waterborne systems for the foreseeable future. A more apparent and unified trend we see at OEMs is the move towards compact or integrated paint processes that remove a bake step, lessen the energy burden, and lower capital and operating costs. These processes will dominate the design of all new OEM paint booths globally, and are pushing the limits of both waterborne and solventborne coatings capabilities by requiring faster film formation between layers, better rheology control, and more robust, defect-free paint systems. Coating systems that enable these compact paint processes will be the winners in the market. (gag)

Meffert invested EUR 18 million in the new Noginsk-site Located in the industrial park “Technopark” in Noginsk close to Moscow/Russia, the new production site of Meffert AG has finally started up production. The paint producer invested EUR 18 million in the production site of its Russian subsidiary Meffert Production. The actual product range of the new plant in includes emulsion paints followed by plasters, primers and white varnishes shortly. The annual production capacity lies at 70,000 tonnes. Additionally, the paint producer has withdrawn from its business activities in Turkey. "The management of our Turkish partner Kayalar Kimya has incorrectly evaluated the market and after a considerable loss we have decided to stop our activities in the region”, explained the company’s CEO Klaus Meffert his decision to the editors of European Coatings Journal. Meffert has invested about EUR 5 million in its Turkish joint venture. www.meffert.com

 Expansion Perstorp doubles production capacity at its UK-site Specialty chemicals company Perstorp, supplier of caprolactones and its derivatives, has announced the investment to double the production capacity of its Warrington, UK site is on track to reach mechanical completion by the end of the year and begin commissioning in early 2011. The full capacity expansion is expected be on stream in the summer of 2011. According to the company, the market for caprolactonebased technology is growing rapidly by more than 5 % per year. Caprolactones are used in coatings, adhesives, sealants and elastomers applications. www.perstorp.com

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Market Watch Industry news Coatings and adhesive resins

“Offering a broad portfolio from one source”

 Divestment BASF Coatings Spa sells production site Source: BASF Coatings GmbH

Interview

Dr Dietmar Wewers, Evonik Industries Dr Dietmar Wewers, Senior Vice President Coating & Adhesive Resins business line, talked to the editors of European Coatings JOURNAL about the set up and scope of Evonik's new business line. _How have the new units been set up in the business line? Dr Dietmar Wewers: As the name of our new business line Coating & Adhesive Resins suggests, we are geared to provide solutions for customers in the coatings and adhesives industries. Crucial to the new setup is that we are absolutely convinced that we will be able to leverage enormous synergies by bringing the businesses together. Take, for example, the matter of technology platforms. For the first time, we are able to offer a broad portfolio covering polyester, acrylics, amorphous poly-alpha-olefins, and polybutadienes, all from one source. At the same time, the reorganization is allowing us to strengthen our key regions of North America and Asia and also benefit from common synergies—such as sales and applications technology. _North America and Asia are important regions for you. What’s the growth potential in these markets? Wewers: In Asia, we achieve an average market growth of over 10 %. In the North American market, growth is more around the low single digits. In general, in Europe and NAFTA, we’ve seen a migration of production capacity to Asia, especially China. For example, the production of applications for marine and container coatings is already mainly located in China. _What other improvements are you _ expecting the reorganization to bring? Wewers: Our strategy is built as follows. First, recognize the trends and developments in the market early on, so as to pre-

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vent any possible teething pains. As a result of our experience in binders for coating formulations, we know what is feasible and what is not. We are able to deliver a unique service, beyond our product portfolio itself, namely to recognize the problems that occur in emerging technologies early. You could say that we offer solutions today for the problems of tomorrow. _Can you be more specific in terms of individual market segments? Wewers: Take for example the shift in the construction sector. Here, there is a clear trend towards triple glazing. We’re already developing raw materials for sealants and adhesives that make windows more durable and hard-wearing. We’ve also observed a trend towards the increased use of adhesives in the automotive industry. Another example is polyester for packaging coatings such as the interior coatings used in food cans. On the one hand, a coating has to be able to withstand mechanical stresses during production, and in some cases the sterilization conditions needed when filling and canning food. But the critical factor is that it must comply with the highest standards when it comes to protecting the product itself— even where it is corrosive, such as acidic foods. This is a challenging task, but one that can be solved. _What other trends and market developments are you expecting? Wewers: Efficient use of resources and environmental responsibility and sustainability will continue to gain in importance. Furthermore, I believe that issues such as lightweight construction in aircraft and automobiles, the use of renewable energy, and efficient production processes, especially in emerging markets, will continue to play a greater role. (gag)

BASF Coatings’ Burago-site near to Milan. BASF Coatings Spa will sell its production site in Burago Molgora/Italy for the manufacturing of industrial coatings to Alcea Industries Srl. In addition to the manufacturing facility for liquid paint, the transaction encompasses the business of BASF Coatings Spa in Italy with anodic, electrodisposition coatings for home appliances, heating and general industry and liquid paints for Automotive Supply Metal (ASM) as well as the related customer portfolio. Employees working in these businesses will transfer to the acquiring company. The agreement with Alcea Industries Srl includes a distribution contract for cathodic technology and a license agreement related to liquid paints for ASM and Commercial Transport. BASF’s business in Italy for Automotive OEM coatings and Refinish coatings are not affected by the transaction. The coatings producer will keep all other industrial coatings businesses in the Italian market including cathodic and all coil coatings. www.basf-coatings.de

 Market study Epoxy resins market to grow The global epoxy resins market will reach 1.93 million tons by the year 2015. According to the recently released study “Epoxy Resins: A Global Strategic Business Report” by Global Industry Analysts Inc., factors such as rising demand from various end-use segments including electrical laminate, especially in developing markets, and increasing consumer demand for decorative powder coatings are influencing the market. AsiaPacific represents the largest and fastestgrowing regional market for epoxy resins worldwide. www.strategyr.com

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Market Watch

Source: ©ewe/pixelio.com

Russia

Continuing growth The Russian paint market in the first half-year 2010

* Contact: Dr. Vladimir Stokozenko JSC "NPF "Spectr LK" T +7 495 457-1081 Vladimir.Stokozenko@ yandex.ru

Sergey Byrdin Dr. Marina Polyakova Dr. Vladimir Stokozenko* At the equator of 2010 - the year of economy recovery after the crisis in 2009 according to Russia’s Federal State Statistics Service (FSSS) Russian GDP growth in the first half-year 2010 is estimated at 4.2 %. In comparison, in first half-year 2009 GDP shrank by 10.2 %, (half-year on half-year).

T

he index of industrial production is put at 10.2 % (-14.5 %), while population’s real income is estimated to have risen by 4.8 % (2.1 %). Freight turnover rose 12.2 % (-17.5 %), including railway freight, which was up 12.9 % (- 21.0 %). Find more information on paint markets: www.europeancoatings.com/ markets

10

All figures are rising in the Russian paint market As noted in previous publication [1], FSSS estimates that in Q1 2010, Russian paint production amounted to 158,700

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tonnes (+ 24.0 % on Q1 2009), paints exports were 9,200 tonnes (+ 29.6 %), while paint imports were running at 32,200 tonnes (+40.0 %). Domestic paint consumption was 181,700 tonnes (+ 26.3 %), while domestic paints made up 82.3 % of the number of all paints market. This growth continued into Q2 2010 (see Table 1). FSSS estimated GDP growth in the second quarter of 2010 at 5.2 % (in the first quarter of 2010 at 3.1 %). As the table shows, growth in production, exports, imports and domestic consumption of paints and varnishes, as well as the volume of domestic paints of market in the second quarter continued. The general situation in Russian paints market in the first half-year 2009 and 2010 is as follows (see Table 2) [2]. High growth rates of production and consumption of paints in Russia in 1st half-year 2010 clearly associated with high rates of pre-crisis recovery of production in key sectors - consumers of paints. So, in the first half-year 2010 index of machinery and equipment production amounted to 121.0 % for this indicator for 1st half-year 2009. At 16.8 % increased production of refrigerators, for 10.5 % of washing machines. Index of production of vehicles and equipment amount-

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Market Watch Russia ed to 128.1 % for this indicator for 1st half-year 2009.The production of passenger cars increased by 67.9 %, 38.8 % for buses, trucks at 51.1 %.

Foreign trade turnover has increased by 41.5 % Foreign trade turnover of Russia (by the method of the Central Bank of Russia) in 1st half-year 2010 amounted to USD 293.9 billion (+ 41.5 % on 1st half-year 2009). Herewith the total volume of exports amounted to USD 189.7 billion (+ 51.4 %), imports of USD 104.2 billion (+ 26.5 %). In June 2010, imports of chemical products from foreign countries amounted to USD 2813.7 million (+30 % by June 2009). Foreign trade turnover of Russia paint and varnish materials in half-year 2010 amounted to USD 401.4 million (+ 35.8 % on 1st half-year 2009). Herewith the export of paints and varnishes was USD 51.6 million (+ 19.2 %), imports of paints USD 349.8 million (+ 38.7 %).

REFERENCES [1] Polyakova M., Listova O., Stokozenko V.; European Coatings Journal number 7-8, p. 9-11, August 2010 [2] Koftjuk V., Polyakova M., Bublik L., Listova O., Stokozenko V.; Lakokrasochnye materialy i ikh primenenie, number 8, p. 7-9, August 2010

Table 1: Continuing growth in the second quarter of 2010 Index

2nd quarter 2009,

2nd quarter 2010,

(1,000 t)

(1,000 t)

Production

268.6

337.9 (+ 25.8 %)

- Export

21.9

24.9 (+ 13.7 %)

+ Import

50.0

65.8 (+ 31.6 %)

Inside consumption

296.7

378.8 (+ 27.7 %)

Volume of domestic paints market

246.7 (83.1 % of total paints)

313.0 (+ 26.9 %) (82.6 % of total consumption)

Table 2: Russian paints market in 1st half-year 2009 and 2010 Index

1st half-year 2009, (1,000 t)

1st half-year 2010, (1,000 t)

Production

396.6

496.6 (+25.2 %)

- Export

29.0

34.1 (+ 17.6 %)

+ Import

73.0

98.0 (+34,2 %)

Inside consumption

440.6

560,5 (+27.2 %)

Volume of domestic paints market

367.6 (83.4 % of total paints)

462.5 (+ 25.8 %) (82.5 % of total paints)

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Association Bosad

Protecting sectoral rights Bosad represents the Turkish paint industry nationally and internationally

The foundation process of Bosad has started in February 2003 by the participation of representatives coming from nine companies of the paint and coatings sector. After the completion of the related legal procedures by early June 2003, the association initiated its activities to meet the demand for sectoral co-operation and representation which was lacking throughout the years both in national and international areas.

sector get more conscious about the actual issues. On the other hand, the association desires to provide closer relationships within the participant companies and members of the sector to enable better co-operation and professional support. Bosad’s main target is to contribute to the development of the Turkish paint industry on the basis of production areas and to the growing of the Turkish paint market

The number of members has reached 70 on the basis of participant companies by October 2010 and Bosad has obtained a very significant production power under its roof. In line with that, the sectoral production power of participant companies has exceeded 80 % of the national capacity. The association is represented by the leading companies and members of the paint industry concerning the national and international legal standards, and respectful to environment issues and consumer rights.

Recently, Bosad’s activities about technical and occupational foundations of the sector are intensely carried on in order to contribute to development and growth of the Turkish paint market. Project based studies are carried on by approximately 20 technical working groups related to the working areas. Creating sectoral database of paint industry and collecting the production areas based on economic data of the sector are taking the priority of the studies. Furthermore, projects about occupational education, labor force and integrated studies about national standards are to be other prior issues among Bosad studies. Bosad works on increasing reputation, competitive power and displaying of economic power of the Turkish paint industry by national and international based studies. One of the latest project on this scope is Paint Istanbul 2010 Paint Industry and Auxiliary Products Congress & Exhibition, which took place on 23 to 26 September, 2010 in Istanbul/Turkey. Besides, Bosad works closely with government entities, public institutions and aims to solve the bureaucratic problems of the sector.

Main sectoral targets of Bosad Main target of Bosad, as also stated in its Rules and Regulation Book, is to gather the major Turkish paint producers, raw material suppliers and service providers under a single sectoral roof; to provide the cooperation of the participating companies appropriate to national issues, to express the problems of the paint sector with a common language and to protect the sectoral rights and benefits. The companies and individuals in the sector are obliged to continue production according to all the related laws and regulations and have accepted the responsibility of taking part and contribute to the sector under several obligations such as providing the necessary technical and hygienic working conditions, obeying sectoral rivalry rules, protecting the consumer and manufacturer rights and not giving harm to the environment.

President of the Board, Bosad - The Association of Turkish Paint Industry

12



Contact: Bosad - The Association of Turkish Paint Industry T +90 216 384 74 53 F +90 216 384 69 34 [email protected] www.bosad.org

Enabling co-operation and support Besides, Bosad also carries out several professional studies which aim to increase the paint consumption in Turkey according to national and international standards, to provide healthy and good quality paint and to make the

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www.european-coatings.com

Source: Bosad

Ahmet Faik Bitlis,

Increasing competitive power

?

Expert Primer Voices

Architectural coatings

Reflecting on limits Pigments for architectural coatings will be more than colourful

The availability of natural pigments is limited and will lead to big challenges in the future, as Albert Roessler, Adler-Werk Lackfabrik Johann Berghofer GmbH & Co KG, Austria, explains. And they are not always suitable, due to natural base colour changes, Martin Moore, Kreate Europe, Belgium, adds. Both experts think that the future will show further developments regarding the light reflexion for energy savings in order to keep buildings cool.

“The need for reflective coatings is not only an environmental one.”

1 2pigments What are the challenges for these for the 21st century?

What are the technical limits of pigments for architectural coatings?

Martin Moore Commercial Director Kreate Europe Herentals, Belgium [email protected]

1mandBesides the ongoing increase in the deof colouring of architectural coatings

and the demand for brighter and deeper interior as well as exterior colours, there is also a trend to make classical natural effect colours in a variety of different coating technologies. Natural effect type coatings demand not only a carefully chosen pigment selection, but also very careful consideration in how these pigments are used and their ability to make a palette of evergrowing demand of colours. The practical limitations of the products themselves, their underlying natural colour, and often changing natural base colour cause some fundamental problems in matching the demand for colours with a technically limited pigment selection. A suitable pigment selection and available colour spectrum is drastically changed mainly due to the alkaline nature of the coating. Besides some very expensive automotive grades of pigment, the only really suitable pigments tend to be the less bright and duller inorganic pigments, which makes certain colour areas difficult, if not impossible to achieve. However, the problem area is still in the clean yellow colour areas, the bright orange

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colour areas as well as the bright or clean red colour areas.

2chemical Currently criteria for colour, durability, resistance and other technical pro-

perties will often get another criteria, solar reflectance. Ideally you want high solar reflectance, with a low temperature heat build up in summertime, which of course in sun rich areas of the world helps to reduce the cooling cost of building. This therefore has huge environmental benefits since the cost of cooling both in value and environment impact plays a major part in climate change and emissions. Such coatings also help protect your applications longer. By far the biggest impact on temperature and heat build up is created by the type of pigment used in the coating. A lot of applications and application techniques, which are common in the automotive industry, are finding their way into architectural coatings and architectural applications. The need for reflective coatings is not only an environmental one; in fact this often tends to be a positive ‘spin off’ of such applications. These developments are slowly but surely finding their way into the standard applications and into the more mainstream coatings and tinting / colouring systems.

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Primer Voices Expert Architectural coatings

“Availability and reliability of supply are of high concern.”

Dr. Albert Roessler Head of Research and Development Adler-Werk Lackfabrik Johann Berghofer GmbH & Co Schwaz, Austria

“Special Effect Pigments ” Dr. Gerhard Pfaff www.europeancoatings.com/books

[email protected]

1

Although a lot of progress has been performed by the chemical industry in the last decades, still the classic skills like light fastness, weather resistance, and chemical resistance are important. Better effectiveness, meaning higher tinting strength, easy grinding and dispersability as well as a widening of the application field are the hot topics giving customer enhanced values. Especially in the field of architectural coatings inorganic high performance pigments (like titanates with spinel or rutil structure) exhibit today sufficient stability for long-term outdoor application. Therefore, costumer concerns regarding brilliant orange, red or green facades can be satisfied much better than a few years ago. However, many organic members of the field show still not enough light fastness or heat stability and the versatility is limited. In addition, availability and reliability of supply are of high concern. The present situation with stringency of raw materials as well as conveyance of products is unsatisfying and the chemical industry has to take over their product stewardship in the future much more than today.

2

Due to increasing energy costs, it is important to use all tools available to reduce our energy usage. Therefore, specialities of yesterday will be the norm for coating applications in the future! More and more physical effects will appear to dominate over the classical color shade. Think about IR-reflecting pigments, leading to cool roofs or facades, photovoltaic coatings or triggered color shades, which provide significant benefits for the end user as well as the environment.

Sebastian Duda / Fotolia.com www.european-coatings.com

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ECJ

Technical Paper Waterborne alkyds

H f

Y

Reflections on water New dispersants and rheology modifiers for gloss emulsion systems

Corresponding author: Dr. Denis Ruhlmann Coatex SAS [email protected]

Denis Ruhlmann Acrylic emulsion paints cannot match the high gloss levels of traditional solventbased alkyd paints. Waterborne alkyds can achieve the required gloss and low VOC levels, but formulation problems may include poor gloss retention and viscosity stability. Ways to resolve these problems by using specifically adapted thickeners and dispersants are discussed.

W

Video interviews on waterborne technology: www. european-coatings. com/videos/

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aterbased formulations are gaining market share due to the increasing demand for reduction or complete removal of solvents and VOCs. In the field of decorative coatings, formulators now have several decades of experience in the formulation of water-based high PVC (pigment volume concentration) paints, and have developed some accurate knowledge of how to formulate lower PVC systems. It remains more challenging to formulate low PVC waterbased paints because the number of key parameters and therefore the range of technical compromises available are reduced. The final result is more dependent on the intrinsic properties and qualities of each of the raw ma-

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terials used. As soon as higher gloss becomes the target, formulators must make an accurate selection of the binder, pigments, coalescing system and additives.

Acrylic-based gloss paints have performance limits Very well-designed acrylic based gloss paints, once coated and dry, can show 20 ° gloss levels reaching 6065 %. Aiming for a higher level of gloss while achieving a mechanically stable and tack-free film is very challenging. It is even more challenging when also trying to reduce the levels of solvents or coalescing agents in order to comply with regulations or ecolabels, which place ever stricter limits on the use of these components. Gloss levels of well above 65 % are required for these paints to be properly termed high gloss. Until recently, high gloss decorative coatings could only be obtained using solventbased alkyd paints containing mineral spirit or xylene. These can be formulated to show a gloss level of more than 85 % at 20 ° after application, meeting the market expectation for high gloss paints. Of course, solventba-

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Technical Paper Waterborne alkyds Table 1: Comparison of rheology, gloss and gloss retention for alkyd and acrylic emulsion based gloss formulations When tested

Test type

After 24 hours

Brookfield

Test conditions

Gloss acrylic emulsion paint

Gloss alkyd emulsion paint

10 rpm

3100

3500

100 rpm

2250

2780

Stormer (KU)

100

106

ICI (cone & plate, P)

2.8

2.8

10 rpm

3200

3200

After 1 month

Brookfield (mPa.s)

100 rpm

2330

2520

After 3 days

Gloss

@ 60 °

81

97

@ 20 °

52

90

After 1 month

Gloss

@ 60 °

80

99

@ 20 °

52

91

emulsification processes. The emulsification package generally consists of several surfactants. Stress is also put on the precise process to follow for the emulsification: concentration of each of the surfactants, means and conditions of stirring (speed, type of stirrer, temperature). The aim is to obtain a stable emulsion of the alkyd resin which should retain most of its original properties. A stable emulsion is more easily achieved if the average size of the emulsified particles is small enough, which requires relatively large amounts of surfactants, generally about 10 % or more. Such high amounts will also impact on the properties of the alkyd resin once emulsified in water, and thus the properties of the coated film: mechanical and optical properties, drying speed and process, scrub and water resistance.

Surfactants interact with thickeners and dispersants

Figure 1: Alkyd emulsion based high gloss formulations: viscosity stability as a function of the dispersant used

Significant amounts of surfactants in the emulsified alkyd resins also modify the interaction with rheology modifiers. Associative thickeners bear hydrophobic end groups adapted for adsorption onto hydrophobic particles, generally binder particles, through direct, competitive adsorption or ion-dipole interaction mechanisms. The presence of high levels of surfactants can either boo st or weaken the thickener response in term of overall effectiveness. It can also profoundly modify the rheology balance, to the detriment of the rheology adjustment, storage stability or coating properties of the final paint. The same holds true when considering the dispersant. Dispersants are used to protect and stabilise the fillers

sed alkyd paints are no longer able to comply with current regulations on solvent and VOC reduction.

Emulsifying alkyds in water may impair performance

"Waterborne Acrylates for Decorative Coatings" M. Schwarz / R. Baumstark www.europeancoatings.com/books

18

As indicated above, high gloss paints are generally meant to provide gloss values of more than 85 % at 20 °. These high gloss values should now be achieved with water-based paints in order to comply with the most recent regulations on VOC content and with ecolabels. About ten years ago, alkyd resin producers started to anticipate this future strengthening of regulations on solvents and VOCs in low PVC systems. Their idea was to stabilise alkyd resins, similar to those already used for solventbased paints, in water. Alkyd resins can be emulsified into water in different ways. They can be made more “water compatible”, i.e., by grafting on hydrophilic functions such as carboxylic groups. Hydrophilic modifications help facilitate their dispersion in water with reduced amounts of surfactants, but also modify the characteristics of the initial alkyd resin, which can affect final application and optical properties. Such modifications require extensive knowledge to resolve the resulting performance issues. Other ways seem more accessible. Some surfactant manufacturers are able to offer emulsifier systems and

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Results at a glance Despite their generally good properties, acrylic emulsion paints cannot match the high gloss levels achieved by traditional solventbased alkyd paints. However, evolving regulations and market demands make it necessary to produce low VOC waterborne decorative gloss paints. The required gloss levels can be achieved by using waterborne alkyd resins, but there may be issues with gloss retention and storage stability (in terms of both viscosity changes and sedimentation). In particular, the emulsification system used to render the alkyds water-compatible may affect the performance of pigment dispersants and rheology modifiers as well as impairing performance of the applied film. Some ways to resolve these problems by reformulation with thickeners and dispersants specifically adapted to this task are described.

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Technical Paper Waterborne alkyds Table 2: Performance comparison of three different dispersants in a high gloss alkyd emulsion paint, using equilibrated viscosities (after 24 hours) Component/test type

BR 85 dispersant

Comparison 1

Comparison 2

Water

69.4

70.0

70.4

"Coadis BR 85" (35 %)

8.0

--

--

Competitive dispersant 1 (38 %)

--

7.4

--

Competitive dispersant 2 (40 %)

--

--

7.0

Biocide

2.0

2.0

2.0

Add while stirring

Neutralising amine

0.5

0.5

0.5

"Coapur XS 22"

35.0

35.0

35.0

2.0

2.0

2.0

TiO2

Antifoam

265.0

265.0

265.0

Waterbased alkyd resin

615.0

615.0

615.0

Drier

3.1

3.1

3.1

Total

1000.0

1000.0

1000.0

Brookfield 10 rpm (mPa.s)

2900

2600

2600

Brookfield 100 rpm (mPa.s)

2200

2290

2170

Stormer (KU)

101

102

101

ICI (cone & plate, P)

2.7

2.6

2.8

Viscosity tests after 24 hours

Figure 2: Comparison of gloss levels obtained in an alkyd emulsion based high gloss paint using different dispersants

and pigments. In the case of low PVC paints such as high gloss paints, the dispersant must be adapted for the dispersion and stabilisation of TiO2. Most of the time, these dispersants are slightly hydrophobically modified to generate a stronger interaction with the small TiO2 particles, which can be specifically

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surface treated. The presence of high levels of surfactants can weaken the effectiveness of the dispersant through competition and re-adsorption, thus creating risks of flocculation of the pigment and finally storage stability and gloss development issues. So there is a real need for rheology modifiers and dispersants that are better adapted for waterborne alkyd emulsion paints and more specifically for those aiming for the highest levels of gloss. Reaching the highest gloss possible also means that the coating properties of the paint should be near-perfect in respect of flow and levelling. Among the various types of rheology modifiers available, HEUR (Hydrophobic Ethoxylated Urethane) types are the only ones which can impart that highest standard of flow and levelling.

Rheology of acrylic emulsions can readily be matched Alkyd emulsion formulations are not necessarily more complicated, nor do they require more ingredients than acrylic emulsion formulations. On the contrary, gloss acrylic paints often incorporate significant amounts of VOC due to the use of glycols, and specifically propylene glycol, to facilitate deflocculation and to improve gloss. Gloss waterbased alkyd paints require no coalescing agents, which allows the VOC content to be reduced. Using a global formulation approach, one can design short and simple formulations in which each single compound is specifically selected and brings its optimum contribution to the whole. As can be seen from the examples in Table 1, the rheology of both types of paint can appear very similar based on the measurement: »»of Brookfield viscosities, which can be correlated with the behaviour of paints at rest, in storage or just after coating; »»of the Stormer viscosity, which is correlated with the appearance of paints when hand stirring; »»of the ICI viscosity, which is correlated with the spatter resistance, the brush drag and the film build. The same holds true regarding the storage stability and considering the viscosity changes after one month. In both cases, the viscosities remain stable. The main difference concerns the gloss level. Using acrylic binders, gloss values higher than 60 (at 20 °) are barely achievable, whereas values over 90 can be reached using the best alkyd emulsion binders. It becomes possible to target a gloss level previously only provided by solventbased paints, using waterbased alkyd emulsion based paints instead. Gloss retention can also be excellent for well-designed alkyd emulsion based formulations.

Dispersants may show instability on storage High gloss topcoat formulations need a well-adapted dispersant, which must be able to lower the viscosity of the millbase to facilitate the incorporation of the ingredients and to ensure a good stability of the viscosity in storage. Table 2 shows data obtained using different dispersants: two from competitors which are recommended in exis-

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RZ Wa

Technical Paper Waterborne alkyds Table 3: Proposals for ingredients changes in order to improve stability, coating and optical properties of an alkyd emulsion based high gloss topcoat formulation Original

Reformulation

Water

 81.0

 78.4

PU thickener (35 % solids; 39 % MPG)

  4.0

Remarks

Add while stirring

"Coapur XS 52" Antifoam

 14.9   1.0

Anti foamer A Dispersant (38 %)

  1.3  12.5

"Coadis BR 85" (35 %)

0.45 % dispersant solids replaced by 0.28% Coatex dispersant solids   8.0

240.0

239.2

Water

 69.5

 70.4

Waterbased alkyd resin

530.0

528.3

PU thickener (35 % solids; 39 % MPG)

  7.5

PU thickener (20 %)

 29.0

TiO2 Disperse at high speed (30 min/1500 rpm) then add while stirring

"Coapur XS 52"

Two PU thickeners (1 %) replaced by 1.1 % solvent-free Coatex thickener  29.6

Waterbased drier

 10.0

 10.0

Surface active agent

  3.0

  3.0

MPG (monopropylene glycol)

 12.5

Solvent-free polyglycol Total

1.7 % MPG in thickeners and as additive replaced by 1.7 % solventfree polyglycol  16.9

1000.0

1000.0

Figure 3: Enhancement of storage stability (viscosity retention) of an alkyd emulsion based paint by substitution of dispersant and thickener: left, original formulation; right, reformulation using recommended additives

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ting starting point formulations and one specially developed by Coatex. As can be seen from the results, the values of viscosity obtained after 24 hours are quite similar and well adapted for gloss paints: high ICI viscosity for good film build and low Brookfield values for better levelling. At this stage, one can consider that all the dispersants tested are satisfactory. The development of viscosity over time has been followed (see Figure 1). It corresponds to the second and very important function of any dispersing agent: to help stabilise viscosities of the finished paint during a given period of storage. The graph shows that viscosities evolve quite strongly after an ageing test carried out for one week at 50 °C for the paint which incorporates the competitive dispersing agents: the 100 rpm Brookfield viscosity increa­ses by more than 30 % in presence of both competitive dispersing agents while it increases only by about 9 % in presence of the Coatex dispersing agent “Coadis BR 85”. This indicates better compatibility of “BR 85” with the TiO2 and the latex. It is confirmed by the in-can appearance of the paint: some hard or soft sediment is visible after the ageing test for the paints which incorporate the competitive dispersants whereas there is nothing to observe about the appearance of the paint that incorporates the new dispersant. This significant improvement it shows how important the selection of the dispersant is. The gloss level of these high gloss topcoats was also measured as a function of the dispersant (see Figure 2). Gloss levels are good for all three paints, but here again some improvement can be highlighted with the new dispersant: the gloss level is slightly higher, which confirms the excellent level of compatibility of that specific dispersing agent both with the TiO2 and the binder of the formulation.

Optimising a gloss alkyd formulation The dispersant selection is one important step towards improving waterbased high gloss systems, but a global approach should be considered when designing such formulations. A global approach means that each of the ingredients should be specifically selected to provide the highest level of performance in its field, and to interact as well as possible with the other ingredients. Table 3 illustrates that approach, starting from an existing starting point formulation promoted by a well-known alkyd emulsion resin maker. It is probably optimised to provide the high level of gloss required for such a paint, but some significant issues with that paint can be highlighted. Attempts will be made to improve the behaviour of that paint based on its current limitations. A global approach means that the work achieved involves not only substitutions by this company’s own additives, but also changes of some other critical ingredients. In this case, the antifoam, the monopropylene glycol, the dispersant and the thickeners have been replaced. Two polyurethane thickeners were replaced by only one, the dosage of dispersant was significantly decreased, and the VOC was dramatically decreased as a consequence. Effects of the changes are immediately visible after the making of the paint. Viscosities are higher after manufacture, and as a consequence change less within 24 hours compared to the original formulation. Viscosities are considered as

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Technical Paper Waterborne alkyds equilibrated after 24 hours. Less overnight viscosity increase facilitates quality control at the end of production and helps in predicting what the final figure will be. Most high gloss alkyd emulsion paints based on existing starting formulations tend to show a significant viscosity decrease over time. The tendency is even more when exposed to higher temperatures, which simulates a longer period of storage. Viscosity drop is particularly visible at low shear rates as shown in Figure 3. Here it can reach about 50 %, which means that issues of sedimentation, phase separation and sagging after coating can be expected. Making the recommended changes leads to much better storage stability, the viscosity drop at low shear rates being reduced from 50 % to about 20 %.

Figure 4: Enhancement of gloss and gloss retention of an alkyd emulsion based paint by substitution of dispersant and thickener: left, original formulation; right, reformulation using recommended additives

Gloss retention and levelling are improved Changes to the dispersant and thickening systems are also beneficial to gloss retention (see Figure 4). High gloss alkyd emulsion paints made by following currently available starting point formulations often show a very good initial level of gloss, but significantly poorer gloss retention. Gloss retention is the ability to maintain a given level of gloss over time; it may be based either on following up the gloss evolution of the paint after application, or on following up the gloss evolution of the aged wet paint when applied again. The use of the chosen specific dispersant and thickener helps maintain a better level of gloss over time. Some other coating properties were also checked (see Figure 5). For high gloss systems, the sag/levelling compromise is one of the critical points. Levelling must be as high as possible in order to achieve a homogeneous reflection of the light to the benefit of gloss. Achieving a very good levelling becomes challenging when also considering the sag resistance. Reformulation following these recommendations leads to better sag resistance while maintaining very good levelling, and an improved film appearance after drying.









  

Figure 5: Enhancement of sag resistance and surface appearance of an alkyd emulsion based paint by substitution of dispersant and thickener: left, original formulation; right, reformulation using recommended additives

                 

     

   

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European Coatings J OURNAL

23

Technical Paper Polyurea coatings

Ring opening opens the path to easier-to-use polyureas Novel ways of making polyurea coatings simplify their use

Corresponding author: Dr. Paul Duncan HywelEvans Adbruf Ltd T +44 1963 3626 40 [email protected]

Paul Duncan Hywel-Evans Polyurea coatings are now becoming the performance standard in their field across the coatings industry. However, use of these coatings is often limited either by chemical hazard issues, the high reactivity of the isocyanate-amine reaction or the low reactivity of the aliphatic variants. A novel reaction pathway forms the basis for homogeneous or heterogeneous coatings prepared from low-hazard, single or multi-pack formulations which react in situ without the need for complex process equipment.

A

"Coatings from A to Z" Paolo Nanetti www.europeancoatings.com/books

lthough the physical characteristics of some polyurea-based polymers are highly desirable, there are many obstacles to making a coating from them in practice. This is due to the constraints placed on their end use either by the toxicity of the raw materials or the need for complex processing equipment. Similarly, the speed of the isocyanate and amine reaction often requires the use of specialist spray equipment. Furthermore, it is obvious from the very nature of the technology that specific amine-isocyanate reactants cannot be supplied as a single-pack system. Aliphatic isocyanates tend to have restricted use in the coatings industry as they do not easily react at ambient temperatures. Any attempts to accelerate these reactions often entail a significant investment in process equipment or the use of acceleration systems which can limit the shelf life of the final product. Isocyanates decompose to the amine by reacting with water to form the metastable carbamic acid moiety. Aliphatic isocyanates are often considered to be unreac-

Figure 1: Proposed isocyanate-aziridine reaction pathway

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tive due to their much slower rate of decomposition to the amine. The reason for this is, however, more to do with the inability of the aliphatic carbamic acid to rearrange to eliminate carbon dioxide rather than a very slow formation of carbamic acid. By using the carbamic acid to perform the ring opening of an aziridine, the reactivity of aliphatic isocyanates can be greatly increased which leads to higher reaction velocities than those of aromatic, single-pack systems. Further, as the aziridine and isocyanate groups are completely inert in their anhydrous forms, they can be safely mixed together to form a single-pack formulation with a normal pack life which can be measured in years. This licensable technology is the subject of several international patent applications and the pathway is illustrated in Figure 1. On exposure to moisture, the carbamic-acid-species achieve the ring opening of aziridines to form a second metastable urethane species. The electro-negativity of the second amine grouping causes the urethane to decompose rapidly, thus ejecting carbon dioxide and forming a short secondary diamine linkage. The nascent secondary diamine is then made available to the excess isocyanate to form a dense polyurea. It is therefore possible using this technology to form almost any polymers from single-pack systems by selecting specific isocyanate- and aziridine-functional raw materials and combining them in stable single-pack formulations.

Two factors control the difference in the reaction rate Additionally, the nature of the isocyanate functionality can have an effect on the rate of reaction. HDI (hexane diisocyanate) based preopolymers apparently react faster than IPDI (isophorone diisocyanate) based prepolymers. The difference in the observed reaction rate between various isocyanate groupings appears to be controlled by two major factors: the rate at which the isocyanate generates the carbamic acid moiety and steric hindrance involved in bringing the groupings in close proximity. Partial evidence for this is the rate of reaction at different temperatures and levels of humidity. An environment of high humidity gives greater reaction rates than one of low-humidity. However, the rate of reaction at different temperatures does not vary as much as expected at constant humidity. This suggests that, even when water is available, there is a steric-hindrance component to the reaction rate. The measurement of the ring-opening rate of any specific isocyanate-aziridine system enables a whole range

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Technical Paper

® coatingsECM DYNOPolyurea -MILL of cure times to be established. This allows the cure time of the system to be tailored to the application in question. Three isocyanates are consumed for each aziridine grouping. One is involved in the ring opening and two in the reaction with the nascent secondary diamine (see Figure 2). Thus, it is possible to be selective in the reaction sequence of the different reaction sites with different isocyanates at different times from the same initial mixture. In the simplest case this would be a single isocyanate at 3:1 ratio with the aziridine. In more complex systems, the aziridine ring-opening reaction could be undertaken with one isocyanate prepolymer using reactivity selection. The secondary diamine could be reacted with a second prepolymer with lower reactivity (see Figure 3).

High-efficiency agitator bead mill

Efficient and modern grinding & dispersion technology for your production

"Interbranch" polymer structures enable adding of functionality Being able to select which prepolymer reacts at each site makes it possible to achieve “interbranch” polymer structures. These are polymers which have secondary chains reacted into the backbone, but not as part of the backbone itself, which is the case in the segment approach found in linear-block copolymers. These “interbranch” structures are usually the result of the reaction between two remote reactive sites within the polymer. This is an exceedingly effective way of adding functionality without destroying a polymer’s physical characteristics and without reducing the final polymer’s physical performance. In this way, the opportunity exists, to react specific groupings selectively within single-pack formulations, thereby forming heterogeneous systems from single, homogeneous formulation. An example of this technique in a single-pack, marine, foul-release coating using this technology is shown in Figure 4, where a mixture of IPDI-functional, longchain, poly-dimethyl siloxanes, hexane di-isocyanate

Results at a glance A novel technology has been developed which is the basis for an infinitely customisable performance. It potentially shows very fast aliphatic isocyanate reactivity. The crosslink density can be varied as required. “Interbranch structures” are part of the technology. They give the ability to vary functionality without deleterious effects on performance.

The unique high-efficiency DYNO®-MILL ECM agitator bead mill with patented DYNO®-Accelerators is used for continuous dispersion and wet-grinding of low to high viscosity flowable products in the micron to nano-range. For very high flow rates in a recirculation or passage process, the DYNO®-MILL ECM provides excellent performance with highest product quality.

Other features are high in-can stability, one- or multi-pack technology with in-situ reactivity controlled curing. The technology is registered low hazard and classified as a polymer under REACH.

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Mixing and grinding technology Willy A. Bachofen AG Maschinenfabrik Junkermattstrasse 11 CH-4132 Muttenz 1 / Switzerland Tel. +41 (0)61 6867 100, Fax +41 (0)61 6867 110 [email protected], www.wab.ch

25

Technical Paper Polyurea coatings Good physical, environmental and adhesive properties

Figure 2: Final, fully crosslinked aziridine-isocyanate diamide linkage

The ability reliably to vary the cross-link density of the polymer and its final structure using a low hazard, long shelf life, single pack product allows for the simple formulation of high-performance coatings. As the reactivity of the components is the controlling factor in the formation of the final polymer, it largely removes dependence on the skill of the person applying the product to obtain the final desired result. It is therefore possible to formulate mission-critical performance coatings which can be applied in adverse conditions and still attain their required performance criteria. For example, a product may be designed as a touch-up repair product for use in large installations where the factory coat has been damaged prior to or during installation. In addition to the application characteristics, the physical performance of the final polymer makes it an ideal solution for use in extreme environmental conditions and industrial applications. Samples of such formulations have so far withstood over 15000 hrs QUV [1] testing while a 500 µm coating of the same formulation has stood up to 8,000,000 passes as a road-marking paint [2]. Coatings based on this technology show a wide range of secondary properties such as water impermeability, excellent adhesion characteristics to a most surfaces, including glass and, depending on the design of final polymer produced, chemical resistance.

Solutions with protective and decorative functions possible

Figure 3: Reactivity based on group selection

Video interviews on innovations: www.europeancoatings.com/ videos/

26

trimer (HDT is an isocyanurate of HDI) and a commercial polyaziridine such as 1-Aziridinepropanoicacid,1,1'-[2-[[3(1-aziridinyl)-1-oxopropoxy]methyl]-2-(hydroxymethyl)1,3-propanediyl]ester could be used. On exposure to moisture, and after application to the surface, the HDI trimer, which has higher reactivity towards the aziridine, performs the ring-opening reaction to form a primary backbone. The secondary diamine created by the ring opening would then be available to the IPDI prepolymers, which have lower reactivity, leading to a heterogeneous, inter-branched coating. The silicone-oil loops would be forced to the surface of the coating during the initial backbone formation from the HDT and the commercial polyaziridine, leading to a bound silicone-oil layer coating chemically bonded to a moisture-impermeable, HDT based polymer.

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Combining the good physical, environmental and adhesive properties under extreme conditions, it is possible to offer permanent, single-coating solutions for construction, marine and automotive use which have both protective and decorative functions. For example, coatings for buildings would only need to be applied once during construction, as the interbranch functionality would enable graffiti-repellent and self-cleaning properties to be built in to them. In the marine environment, coatings are continuously exposed to aggressive attack from intense light, heat and cold. Here the coating must protect the underlying metal which will corrode rapidly when even a minute perforation occurs. Coatings based on the new technology are by their very nature water impermeable and show substantial resistance to penetration and abrasion. Further, it is possible, for example, to produce abrasion-resistant, anti-slip coatings based on polycarbonate backbones for walk ways which occur as regional inclusions within what appears to be a uniform contiguous surface for yacht cockpits. Further, theoretically, the interbranch technology can be used in fibre manufacture leading to fabrics with special “designed in” functionality. Some examples are water-repellent sails or self-aligning, high-performance sports suits. The toxicity and REACH status of the isocyanate-aziridine system is an important consideration. The toxicity of the aziridine system can be addressed by increasing the molecular weight of the aziridine-functional component. Typically, this can be achieved by pre-reacting the aziridine functionality of the system onto the prepolymer. In this way, the overall toxicity of the system may be

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LoVOCo

Technical Paper Polyurea coatings reduced to the level of an irritant. One of the first versions of this solution was a mixture of an irritant, lowfree-isocyanate prepolymer with a commercial grade 1-Aziridinepropanoicacid,1,1'-[2-[[3-(1-aziridinyl)-1-oxopropoxy]methyl]-2-(hydroxymethyl)-1,3-propanediyl]ester. The OH functionality of the commercial polyaziridine was selcted so that the aziridine functionality could be simply included in the backbone by allowing the formation of a urethane linkage between the preopolymer and the polyaziridine, effectively adding the aziridine functionality to 10 % of the available isocyanate prepolymer. The prepolymer formed by this reaction was extremely stable with storage tests showing stability beyond the three-year mark. Also as the prepolymer is classification under REACH as a polymer and the commercial polyaziridine is itself classified under REACH, the reaction product again would be registered under REACH as a polymer.

References [1]

British Standard BS 2782: Part 5, Method 540B Annex D, “Methods

of testing plastics, optical and colour properties, weathering. Methods of exposure to laboratory light sources, (Xenon arc lamp, enclosed carbon arc lamp, open flame carbon arc lamp, Fluorecent tube lamps)”. [2] British Standard BS En 13197:2001 “Roadmarking materials. Wear simulators”.

LoVOCoat ad English 06-10 (half page):Layout 1

LoVOCoat polymeric surfactants for high performance, low VOC coatings

28/6/10

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Figure 4: Use of the formation of “interbranch” structures in a single pack marine foul release coating

Formulating cost effective, low VOC alkyd based coatings with minimum effort LoVOCoatTM Form 100 and LoVOCoatTM Stable 100 polymeric surfactant technology offers the ability to formulate solvent borne alkyd resins into high quality, low VOC trim paints, varnishes and stains. Recommended surfactants allow the incorporation of up to 30% water as a partial hydrocarbon replacement. Performance benefits easy formulation of low VOC coatings � no compromise on performance versus conventional alkyd coatings � easy to handle & apply - minimal effect on rheology and flow characteristics � cost efficient VOC compliance �

For more information please visit: www.crodacoatingsandpolymers.com or email: [email protected]

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_ Europeannatural Croda Coatings & Polymers choice 11 l 2010 your Coatings J OURNAL

Technical Paper

W

Corrosion-protective coatings

A one-pack comes back New air-drying coatings for corrosion protection

* Corresponding author: Leila Khatai Cytec T +43 50 399-1409 [email protected]

Leila Khatai* Roland Feola Florian Lunzer Corrosion can seriously damage a substrate and can lead to significant repair or replacement costs. Good corrosion protection for metal coatings is traditionally achieved by using two-component (2K) systems. However, they show certain disadvantages that do not exist for one-component (1K) systems. A new ambient-curing, cationic, epoxy-amine adduct fills the gap between 1K and 2K anti-corrosion coatings.

T

he annual cost of corrosion repair and corrosion inhibition in the United States amounts to $ 276 billion [1]. In addition to the economic cost implications, corrosion can also lead to technical delays and structural failures in the construction and maintenance of bridges, aircraft, buildings and pipelines. Corrosion is thus an important topic for research, development, education and training. There are several corrosion prevention methods used in metal protection, for example, protective coatings, corrosion-resistant metals and alloys, corrosion inhibitors, polymers, anodic and cathodic protection and periodic corrosion monitoring. Here the main focus is on protective coatings. Various organic coatings are used to provide protection against corrosion of metallic substrates.

Table 1: Corrosion categories after ISO 12944 Corrosion category

Salt spray resistance

Humidity resistance

Typical environments

ISO 12944-2

ISO 7253

ISO 6270

(examples)

C1 : very low

Heated building with clean atmospheres, e.g. offices, shops, schools, hotels.

C2 : low

Medium 48 h

Atmospheres with low levels of pollution. Mostly rural areas.

C 3 : medium

Medium 240 h

Medium 120 h

Urban and industrial atmospheres, moderate SO₂ pollution. Coastal areas with low salinity.

C4 : high

Medium 480 h

Medium 240 h

Industry and coastal areas with moderate salinity.

C5-I : very high, industry (+168 h chemical resistance)

Medium 720 h

Medium 480 h

Industrial areas with high humidity and aggressive atmosphere.

C5-M : very high, marine

Medium 720 h

Medium 480 h

Coastal and offshore areas with high salinity.

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Metallic substrates, especially steel and alloys thereof, will corrode in the absence of the coating, resulting in the shortening of service life. Metals are exposed to a range of environmental conditions which is divided up into various categories. ISO  12944 “Coating and varnishes-corrosion protective coating systems” [2] divides the environment into three types of exposure: immersion, atmospheric and splash zone. As far as atmospheric exposure is concerned, there are different conditions regarding temperature, moisture, ultraviolet radiation, pollutions, salt and gas concentrations. The corrosion categories as well as examples of typical environments consist of six levels according to ISO  12944. They range from very low (C1) to very high corrosion (C5-I and C5-M) (Table 1).

Crosslinking is the basis for coating systems Currently, 1K systems are used only for light corrosion protection of metal coatings (C1- C3); i.e. being capable of withstanding the salt spray test for about 250 hours. If higher protection is needed, a 2K system with corrosion protection over 1000 hours (C5) [2], has to be used. However, the components of 2K systems, such as traditional epoxy coatings, need to be mixed together prior to application. Once the mixing has taken place, chemical crosslinking starts. This results in the disadvantage of a limited ‘pot life’. This can lead to waste generation if plural component spray equipment is not available. In addition, the preparation of the mixture of the two components is a source of possible errors during everyday use and stock keeping of two components has to be assured. Also, the amine hardeners used in 2K epoxy protective coatings are expensive and have a potential for sensitization problems. In general, coating systems need chemical crosslinking in order to achieve good properties. Purely physically drying systems, such as acrylic emulsions and polyurethane dispersions, have the advantage of hardening very quickly, but have always been thought to be inferior in anticorrosion performance. Alkyd resins which are crosslinked by oxidative drying show better performance than non-crosslinked 1K systems. In polyurethane and acrylic dispersions, condensation reactions of keto-functionalities with amines or hydrazides are used to improve the performance. However, the crosslinking reactions found in current 1K systems are usually less efficient than the highly reactive 2K systems. The development of full hardness takes generally seven days or more in both 1K and 2K systems.

Increasing performance of 1K coatings 2K epoxy coatings based on amine-functional curing agents are widely used in the protective coatings in-

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Technical Paper Corrosion-protective coatings Table 2: Technical data of the binder Properties pH

4 to 6

Viscosity

25 to 1000 mPa·s

Solids content

45 %

MFFT

5 °C

Glass transition temperature (Tg)

30 °C

Grams

I pigment paste

Table 3: 1K cationic epoxy dispersion primer formulation: 1. preparing I (pigment paste), 2. mixing II (let down)

Components

7.50

Water, deionised

3.42

Substrate and pigment wetting agent

1.80

Methoxy propoxy propanol

0.26

Defoamer

4.50

Titan dioxide

4.50

Talcum

4.50

Feldspar

4.77

Zinc phosphate

4.50

Kaolin clay

0.65

Flash rust inhibitor

63.00

1K cationic epoxy dispersion Pigment paste (see I)

II let down

0.10

Defoamer

0.50

Rheology additive

“Anticorrosive Coatings” Joerg Sander et al. www.europeancoatings.com/books

30

The epoxy structure is necessary for 1K paint Building on the experience in electrophoresis lacquers, epoxy-amine resins with their good anticorrosion properties, a high level of corrosion protection can be achieved with physically drying 1K material by anticipating the postapplication crosslinking reaction during the resin synthesis. Unlike acrylic dispersions, the molecular weight build up of the epoxy-amine backbone is not achieved using linear chain growth, but rather in a highly branched way, as in the crosslinking of traditional 2K epoxy systems. As a result, a new family of 1K, cationic, epoxy dispersions has come into being. Depending on the nature of the modifications of the resin, it is possible to achieve different properties which make this family suitable for a variety of applications. One example is the use of primers for decorative wood applications. Wood primers based on this novel technology also provide very good barrier properties against tannin migration (bleeding) to the topcoats. Tannins can bleed from wood substrates into various layers of applied paints. In addition to causing discolouration or staining, tannins can negatively affect the oxidative curing of alkyd paints by deactivating certain metal driers.

100.00

Properties

Table 4: Technical data of 1K cationic epoxy dispersion formulation

proximately seven days to harden make the idea of having a 1K binder performing like a 2K epoxy coating very attractive.

Solids content

52 %

VOC content (ASTM D 3960)

73 g/L

Dust free time

30 min

Tack free time

50 min

Block resistance

After 2 h drying degree 4 [3] After 24 h drying degree 6

Pendulum hardness 7d

45 s

dustry. Besides good corrosion protection, they provide a good balance of mechanical and physical properties such as hardness, flexibility, adhesion and chemical resistance. Even though 2K epoxies can offer very good properties, they also have the drawbacks of a 2K system and the related labelling issues, especially concerning amine hardeners. The minimum film formation temperature (MFFT) of 2K epoxy systems increases during pot life, which is a big limitation for field-applied paints especially if the temperature in the working area is lower than the MFFT. The changing MFFT strongly affects film formation which can influence properties such as gloss, mechanical properties and chemical resistance. All these limitations and the fact that 2K paints need ap-

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Results at a glance A new technology, based on 1K cationic, epoxydispersion chemistry, outperforms standard 1K coatings, especially in corrosion and water resistance. The new technology can be applied on a variety of commonly used substrates with satisfying results. It closes the gap between high performance 2K and standard 1K systems used in primers and monocoats for corrosion protection. There are no pot-life restrictions and it is fast drying and can be dried at temperatures down to 10 °C. There are no labelling restrictions and it is non corrosive and contains no sensitizing amine hardener. The binder has very low VOC binder (< 1 % methoxy propanol). In addition, new high molecular weight, epoxybased waterborne cationic primers show excellent barrier properties on tannin-rich wood that can prevent topcoats effectively from tannin bleeding, staining and retarded drying. Nicotine stain blocking is another interesting application field for this new technology.

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Technical Paper Corrosion-protective coatings Cationic resins also show promising results in nicotine stain-blocking [4]. Focusing on the use in metal coatings, this dispersion is a cationically stabilized, high-molecular-weight epoxyamine adduct as described above. It is designed for the use in 1K waterborne primers for metal substrates. It provides a level of corrosion protection which so far has been unachievable with 1K materials. The product is purely physically drying and consequently has very fast development of properties such as water resistance, corrosion resistance and chemical resistance. Table 2 shows the technical characteristics of the binder which was tested on metal. Just as the change from solventborne to waterborne systems was accompanied by challenges in finding the right formulations and additives, the move from the traditional anionic waterborne resins to a cationically stabilised system entails some restrictions in the freedom of formulation.

Compatibility of the 1K epoxy dispersion The pH of the binder lies between 5 and 6 and is thus acidic. Therefore, any product to be combined with it should have a similar degree of acidity to avoid a pH shock and incompatibility (kick-out). Additives, especially those used in rather high concentrations, such as the wetting and dispersing agents for the pigment pastes, must be carefully chosen and should ideally be non-ionic or cationic in nature. If the requirements profile for a given technical situation is such that the product must be combined with another resin to impart special properties to the formulation, anionically stabilised polymers cannot be used.

Pigments and fillers are going together well Amongst the pigments used, zinc phosphate was found to be an appropriate active pigment. Titanium dioxide, china clay and mica were found to be good choices for hiding and filling pigments. However, their compatibility and effectiveness should be tested before use. Some otherwise common fillers, such as calcium carbonate, have to be avoided due to the basic pH range of the pigment. Even iron oxide pigments may cause problems in cataphoretic systems which have a similar pH range to this new technology. Of course, the stability of a pigment or filler in any given formulation is also strongly influenced by the dispersing agent used and has to be verified on a case to case basis. Although the shear stability of the product would allow a direct pigmentation in the binder, the wetting power of the pigment is not sufficient for preparing pigment concentrates. Instead it is recommended to prepare binder-free pigment concentrates with a suitable wetting and dispersing agent and to prepare the letdown with the 1K cationic epoxy dispersion (see example table 3). The optimum pigment/binder ratio is 0.8/1. To avoid pH-shock, the pigment paste should be stirred into to the resin.

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European Coatings J OURNAL

CLOSER TO YOU. AT THE HIGHEST LEVEL. Outstanding achievements are only really worthwhile if our customers can enjoy them effortlessly. This is why we have developed WACKER E-Solutions: online services that we offer via our customer portal and as an integrated process solution. Thus, you order using your own system. Your order is automatically forwarded and the shipping agent contracted – quickly, reliably and highly efficiently. And at the other end of the fast connection, you always know there will be a real person waiting. www.wacker.com/e-business

31

CREATING TOMORROW’S SOLUTIONS

Technical Paper Corrosion-protective coatings Table 5: Results of salt spray and humidity testing of 1K epoxy formulation on various substrates 500 h salt spray test

500 h humidity test

delamination at the scribe

amount (a) and size (s) of blisters 1=low 5=high [5]

Untreated steel RT drying

1-2 mm

a1 s2

a2 s1 [4]

Untreated steel 10 °C drying

1-2 mm

a3 s2

a2 s2

Iron phosphated steel RT drying

6-12 mm

a2 s1

a2 s1

Zinc phosphated steel RT drying

0-1 mm

a/s OK

a3 s1

0 mm

a/s OK

a3 s1

Aluminium RT drying

amount (a) and size (s) of blisters 1=low 5=high [5]

RT=room temperature

Sb alkyd

Wb 1 pack epoxy

Sb 2 pack epoxy

500 h

700 h

1000 h

Figure 1: Test panels of two different solventborne (Sb) coatings compared with the waterborne (Wb), 1K epoxy coating after salt spray test.

Wb epoxy modified alkyd

Wb 1 pack epoxy

Wb 2 pack epoxy

700 h

700 h

1000 h

Figure 2: Test panels with different waterborne (Wb) coatings compared with the 1K epoxy coating after salt spray test.

Attention with fast drying The fast drying behaviour of this high-molecular weight resin requires a well balanced formulation to allow good film formation, good de-aeration and complete evaporation of water throughout the entire film. If the coating dries too quickly,

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the surface closes before all the water has evaporated, thus trapping water in the film, and possibly leading to flash-rust formation. As the system is purely physically drying without any post-application crosslinking, care has to be taken to choose a solvent which evaporates completely from the formed film under the given drying conditions, otherwise the glass transition (Tg) temperature of the coating is lowered and thus moisture and electrochemically active species such as oxygen and chloride can penetrate and migrate through the coating, resulting in an increased rate of corrosion.

A special mix of coalescing agents researched Several coalescing agents were tested, and a good compromise was found in the combination of methoxy propanol which is inside the binder and the addition of 1-2 % of butyl glycol, butoxy propanol or methoxy pro-poxy propanol. Due to the very low solvent content of this resin, the addition of organic solvents should be carried out in diluted form or with the pigment paste. This helps to avoid concentration shocks. The MFFT of 5 °C makes this resin very suitable for field application, no cross linking is involved and therefore MFFT stays constant during the drying time. This is a clear advantage over 2K systems.

Comparative study A comparative study was carried out between this new 1K cationic epoxy dispersion and standard coating systems: a solventborne, alkyd, solventborne 2K epoxy, a waterborne, epoxy-modified alkyd and a waterborne, 2K epoxy, resin-amine hardener combination. Table 3 shows a formulation guide for the test. Untreated steel panels were coated with primer formulations based on the standard coating systems mentioned above. Salt spray and humidity resistance were compared to the waterborne 1K formulation shown in Table 4. Figures 1 and 2 show the comparative results after the salt spray test. While the solventborne alkyd shows severe delamination after 288 h of salt spray testing, the waterborne, epoxy-modified alkyd maintains protective action up to 288 h. The new waterborne, 1K epoxy coating shows even less delamination at the scribe than solventborne or waterborne 2K epoxies up to 500 h. However, when tested for more than 700 h, delamination occurs more than with 2K epoxy systems (not shown). Table 5 shows the comparison of salt spray and humidity testing of different substrates coated with the waterborne 1K epoxy coating. The results on aluminium are especially noteworthy, as the adhesion of traditional 1K systems on an aluminium substrate is usually quite problematic. Also galvanized steel is a very challenging substrate for good adhesion but it would seem that the pure physical drying enables this new technology to show very good adhesion to it.

Satisfying results after drying 1K under non-ideal conditions To study the drying behaviour of the novel technology under non-ideal conditions, panels were dried at 10 °C and 60 % humidity. Because of the very low MFFT of this

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Pre-c

F w p

P p

7

   

D a w

Technical Paper Corrosion-protective coatings Table 6: Water immersion test of the different primer formulations on untreated steel and under different drying conditions Waterborne 1K epoxy 7 d room temperature drying

Waterborne 1K epoxy 2 h room temperature drying

Waterborne 1k epoxy 7 d 10 °C drying

Waterborne epoxy modified alkyd 7 d room temperature drying

Solventborne alkyd 7 d room temperature drying

24 h

a/s OK Slight discolouration

a/s OK medium discolouration

a/s OK Slight discolouration

a/s OK Strong discolouration

a1, s2 *

500 h

a2, s2 * slight discolouration

a2, s2 * medium discolouration

a3, s2 * slight discoloration

a5, s5 * strong discolouration, loss of adhesion

a5, s5 * loss of adhesion

* amount (a) and size (s) of blisters – 1=low 5=high

resin, it is possible to achieve similar end properties at 10 °C drying temperature. The results in the water-immersion test are given in Table 6. As the system is purely physically drying, the film is water resistant once it is completely dry – usually after about two hours. This rapid achievement of water resistance is a very attractive feature compared to 2K or oxidatively drying systems, which usually need at least seven days to develop their final properties.

References [1] http://www.corrosioncost.com, October 1. 2010 [2] DIN EN ISO 12944 [3] DIN 53150:2002-09 [4] Ming Tsang, Feola R., Gobec M., Khatai L., Rossmann K. and Sundberg K. at The Water Symposium “Advances in Sustainable Coatings Technology”, February 18 - 20, 2009, New Orleans, LA, USA. [5] EN ISO 4628-2:2003

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Polyurethanes for high performance coatings

Easy-to-clean/selfcleaning coatings III

7/8 December 2010

8/9 February 2011

 VOCs and renewables also matter  Selected crosslinking  Non-isocyanate PUR  Modifications on Elastomers

 Water repellent surfacs  Sol-Gel technology with easy to clean performance  Biomolecular responsive wettability switching  Durability of nanostructured superhydrophobic coatings

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Biobased Coatings II 10/11 February 2011

 Biobased technology for UV coatings  Sustainability in the focus of developments  The status quo for biobased and the possibilities in the near future

European Coatings J OURNAL

Technical Paper Pressure-sensitive adhesive

Getting on the right tack How photoinitiator type, amount and curing affect PSA performance

* Corresponding author: Prof.Dr. Zbigniew Czech University of Technology Szczecin, Poland [email protected]

Zbigniew Czech* Agnieszka Butwin Janina Kabatc Tests were carried out to examine the effects of variations in photoinitiator type and UV dose on the properties of a UV curable pressure-sensitive adhesive formulation. Six Type II free radical photoinitiators were evaluated. The best balance of the three key properties tack, shear strength and peel adhesion was obtained when using 0.6-1.0 % Michler’s ketone.

U

ltraviolet equipment such as UV-lamps and UV-lasers emit light in the UV region from 100 to 400 nm of the electromagnetic spectrum. The growing success of UV crosslinking technologies in a wide variety of industrial products and processes can be attributed to the productivity and environmental benefits that it offers. UV technology is well established in the PSA (pressure-sensitive adhesive) market and allows the production of a wide

Table 1: Basic properties of the PSA synthesised for this experimental work

Property

Values

Viscosity

12.8 Pa•s

Weight average molecular weight MW

708 000 Dalton

Number average molecular weight Mn

369 000 Dalton

Polydispersity Pd = MW/Mn

1.92

range of UV-crosslinkable PSAs with interesting features. Industrial applications of UV crosslinkable pressure-sensitive adhesive (PSA) materials have grown tremendously over the past decade. The advantages of UV-crosslinking over thermal crosslinking include rapid network formation (in a fraction of a second when using high-intensity light sources) and the ability to utilise heat-sensitive substrates. The balance between adhesive and cohesive strengths within the crosslinked adhesive coatings is critical for their performance [1-3]. To obtain optimal pressure-sensitive performances with UV-crosslinkable adhesives, it is necessary to find process settings that result in values of tack, peel and shear resistance that are suitably balanced for the target application [4-6].

Photoinitiator types and functions The photoinitiator is one of the key components in achieving this balance of properties in a UV-crosslinking application, and the outcome of such a polymerisation is critically dependent on the choice of the photoinitiator, including its chemical nature and the amount used [7-8]. The majority of UV curing systems are based on what is known as free radical chemistry, and there are two basic categories of free radical photoinitiators. The first group is termed Type I photoinitiators [9] which in the excited state undergo a direct photo-fragmentation process into free radicals. The second group is known as Type II [10]. Materials in this second class undergo a primary process of hydrogen atom abstraction (R-H) from the environment, which may be the resin itself or a solvent, to produce a ketyl radical. These intermolecular H-abstraction photoinitiators include benzophenone and its derivatives such as xanthone, thioxanthone, and 4,4'-bis-(N,N'-dimethylamino) benzophenone, as well as benzil and quinines [11]. As shown in Figure 1, photoinitiators of this type abstract Hatoms from the environment (which, as considered here, may be an acrylic PSA) to produce a benzophenone ketyl radical [12].

Polymer synthesis and test procedures

Figure 1: Reactions in hydrogen atom abstraction and photocrosslinking of acrylic PSA using benzophenone

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The following experiments were carried out to study the influence of different Type II photoinitiators on the main performance parameters of solventborne acrylic pressure-sensitive adhesives, such as tack, peel adhesion (“external adhesion”) and shear strength (internal cohesion). The base weight of the adhesive layer covering the polyester test foil was 60 g/m2. The influence of the crosslinking agents or crosslinking methods is usually determined in relation to the reaction time and to the photoinitiator concentration versus adhesion properties, considering these three properties: tack, adhesion and cohesion.

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ECJ_BY

Technical Paper Pressure-sensitive adhesive Table 2: Names and structures of the intermolecular hydrogen abstractors tested as photoinitiators Photoinitiator (Supplier)

Chemical formula

BP (Transol)

benzophenone

O C

Trigonal 12 (Akzo)

4-phenyl benzophenone

O C

BZ (Pflatz & Bauer)

MK = Michler's ketone (BASF)

Chemical name

O

O

C

C

benzil

O (CH3)2

Esacure DETX (Lamberti)

C

(CH3)2

4,4'-bis(N,N'-dimethylamino) benzophenone 2,4-diethyl thioxanthone

O C

C2H5

S C2H5

MAQ (American Cyanamid)

2-methyl anthraquinone

O C

CH3

C O

Fluorenone (Rütgerswerke)

O

fluorenone

C

The photo-reactive PSAs evaluated were crosslinked using an “Aktiprint-mini 18-2” UV lamp from Technigraf and the UV exposure was measured using a “Dynachem Model 500”, integrating radiometer. The experiments described below were conducted using a standard solventborne acrylic PSA synthesised in ethyl acetate at 77 °C with 50 wt.% polymer content, composed of 65 wt.% 2-ethylhexyl acrylate, 30 wt.% methyl acrylate and 5 wt.% acrylic acid in the presence of 0.1 wt.% 2,2'-azobisisobutyronitrile (AIBN) on the total monomer amount, used as thermal radical initiator. All these starting materials were technical grade. The final synthesised solventborne basic acrylic pressure-sensitive adhesive was characterised by the main properties shown in Table 1.

Marked differences found in photoinitiator efficiency Details of the Type II photoinitiators tested here are shown in Table 2. The crosslinking effect of various amounts (ranging from about 0.2 to 3.0 wt.%) of these H abstractor photoinitiators on peel adhesion and shear strength under the same 100 mJ/cm2 UV dose and a crosslinking time of 3 min is presented in Figures 2 and 3. Crosslinking with UV radiation also leads immediately to a strong decrease in tack, from the lowest photoinitiator addition level upwards. However, at a low photoinitiator content, ranging from about 0.5 to 1.0 wt.%, the peel adhesion reaches a maximum value (see Figure 2). For the two most efficient hydrogen atom abstractors, Michler's ketone and “Trigonal 12”, the highest peel adhesion values were observed (Figure 2) at 0.8 wt.% and 1.2 wt.% respectively. Michler's ketone is a specific photoinitiator and functions like a tertiary amine. It is used as hydrogen donor and not only as a typical hydrogen abstractor. For the acrylic PSA without photoinitiator addition, a partially cohesive failure (pcf) was observed. The cohesion of UVcrosslinked acrylic PSAs was measured at both 20 °C and 70 °C. When the acrylic PSA is cured with benzophenone, 2-me-

Results at a glance Tests were carried out to examine the effects of variations in photoinitiator type and curing time on the key properties of a UV curable pressure-sensitive adhesive formulation. All of the six photoinitiators tested were of what is known as Type II free radical photoinitiators, which operate via hydrogen abstraction. The tack of the adhesives decreased steadily from the lowest photoinitiator concentration and curing time, while the shear strength increased steadily. Figure 2: Peel adhesion versus level and type of H-abstractor photoinitiator

These properties were determined by standard AFERA (Association des Fabricants Européens de Rubans AutoAdhesifs) procedures. Full details can be found in the standards AFERA 4015 (tack), AFERA 4001 (peel adhesion) and AFERA 4012 (shear strength).

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However, the other key property of peel adhesion reached a maximum which was dependent on the photoinitiator type, level and curing cycle. The maximum values in this series of tests were obtained with additions of 0.6-1.0 % Michler’s ketone. Thus it is concluded that this material offers the best balance of properties in this type of PSA system.

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Technical Paper Pressure-sensitive adhesive thyl anthraquinone (MAQ) or fluorenone, at 70 °C a cohesive failure (cf) was observed at a relatively low value. The effect of the photoinitiator concentration on the shear strength is clear: the higher the photoinitiator amount the higher the cohesion (Figure 3). The shear strength test results reveal that the highest cohesion of UV-crosslinked acrylic pressure-sensitive adhesive can be obtained using Michler's ketone and “Trigonal 12” at very high concentrations (about 2-3 wt.%). In summary, the best H-abstractor photoinitiators, from those shown in Table 1, give unexpectedly high shear properties and relatively high tack and peel adhesion to the UV-crosslinked acrylic PSA.

Further tests carried out with Michler’s ketone The UV crosslinking time determines the tack, peel adhesion and shear strength of a UV-crosslinked acrylic PSA. For further tests, to investigate the effect of UV-crosslinking times up to three minutes on the above-mentioned key properties, Michler's ketone was selected in amounts ranging from about 0.6 to 1.4 wt.%. The results obtained for an acrylic solventborne PSA containing Michler's ketone crosslinked at 100 mJ/cm2 UV dose are shown in Figures 4 and 5. The tack of UV-crosslinked acrylic pressure-sensitive adhesives is very sensitive to the variation of the crosslinking time and the variations of H-abstractor amount. Once again, in general, the surface of the adhesive suffers a decrease of tack with an increase of the free radical yield, from the shortest curing time onwards. Figure 4 reveals that a maximum of peel adhesion occurs with 0.8 wt.% photoinitiator after 1 min 30 s curing. The use of 1.2 and 1.4 wt.% Michler's ketone decreases the peel adhesion values. Figure 5 is a graph illustrating the relationship between varying crosslinking time and shear strength, for different concentrations of Michler's ketone. Here it should be noted that an almost linear relationship exists between the cohesion values experimentally obtained and the time of UV-crosslinking. During the UV-crosslinking, free radicals come into being which are used to link the polymer chains. The UV-crosslinking time then directly determines the shear strength of the acrylic adhesive.

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Figure 3: Shear strength versus level and type of H-abstractor photoinitiator

Figure 4: Effect of UV-crosslinking time on peel adhesion of an acrylic PSA containing different amounts of Michler’s ketone The influence of UV dose on tack, peel adhesion and shear strength of the PSA crosslinked using Michler's ketone at addition rates ranging from about 0.6 to 1.4 wt.%

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Technical Paper Pressure-sensitive adhesive

Figure 5: Effect of UV-crosslinking time on the shear strength of acrylic PSA containing different amounts of Michler’s ketone

and UV light dose varying between 50 and 250 mJ/cm2 was then examined. Figure 6 shows that at higher ultraviolet doses, the acrylic PSAs are more crosslinked, the surface tack property is reduced to a steady value which is hardly affected by further exposure. However, as in the earlier test results shown in Figure 4, the peel adhesion reaches a maximum; in this case at an energy density between 100 mJ/cm 2 and 150 mJ/cm 2. The fact that in the case of tack what is almost a plateau is obtained above 150 mJ/cm 2 of UV dose is interesting, because an even stronger variation of the dose still leads to substantial changes in peel adhesion. As illustrated in Figure 7, an increase of UV dose affects the cohesion of UV-crosslinked acrylic PSA positively. Using higher levels of Michler's ketone, the shear strength increases because more free radicals suitable for the crosslinking process are generated. In summary, the best balance within the acrylic PSA properties investigated (ie, tack, peel adhesion and shear strength) was registered in the case of the Type II photoinitiator Michler's ketone in amounts of about 0.8 to 1.0 wt.%.

Michler’s ketone offers best balance of properties

Figure 6: Effect of UV dose on tack of acrylic PSA crosslinked with different amounts of Michler’s ketone

The following conclusions may be derived from the experiments carried out with these intermolecular hydrogen abstraction photoinitiators: »»There is a clear dependence of shear strength of a UVcrosslinked acrylic PSA on the level of photoinitiator. »»An increase of the photoinitiator concentration reduces the tack of the cured acrylic adhesives, while the peel adhesion reaches its maximum at about 0.6 to 1.0 wt.% of Type II photoinitiator. »»From the hydrogen atom abstractors studied, the best overall performance was observed in the case of the benzophenone derivative Michler's ketone. UV-crosslinkable acrylic PSAs containing Michler's ketone can be used for example in the manufacture of selfadhesive materials in form of mounting tapes, masking tapes or a wide range of sign and marking films.

REFERENCES [1] Oldring P. K., Chemistry and Technology of UV and EB Formulation for Coatings, Inks and Paints, SITA Technology Ltd, London, 1991, Vol. 1-4. [2] Matijasic C., Adhesives Age, 2002, Vol. 12, pp 129-32. [3] Bisges M., Adhesives Age, 2002, Vol. 11, p 34. [4] Czech Z., Int. Jnl. Adhes. Adhes., 2004, Vol. 24, pp 119-125. [5] Czech Z., Urbala M., Martysz D., Polym. Adv. Techn., 2004, Vol. 15, pp 387-392. [6] Czech Z., Martysz D., Int. Jnl. Adhes. Adhes., 2004, Vol. 24, pp 533-534. [7] Czech Z., Milker R., Farbe und Lack, 2004, Vol. 110, pp 18-20. [8] Czech Z., Polimery, 2003, Vol. 48, pp 375-377. [9] Allen N. S. et al, Jnl. Oil Colour Chem. Assoc. 1987, Vol. 70, No. 11, p 332. [10] Brockmann W., Meyer-Roscher B., Relation of pressure-sensitive properties and UV crosslinking technology, Hot Melt Symposium, Atlanta, USA, 1998, pp 174-184. [11] Vesley G., Patent WO 81/02262, assigned to 3M, 1982.

Figure 7: Effect of UV dose on shear strength of acrylic PSA crosslinked with different amounts of Michler’s ketone

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[12] Allen N. S., Photopolymerisation and Photoimaging Science and Technology, Elsevier-Applied Science, Barking, USA, 1989.

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HEX-77

Events CEPE Annual Conference

High performance in a green future CEPE Annual Conference highlights sustainability trends and viewpoints

Miriam von Bardeleben Sustainability was the defining theme of the CEPE Annual Conference in the Turkish metropolis of Istanbul. More than 140 attendees were shown future trends and their implications for the coatings industry by experts in sustainability. All kinds of different approaches and views regarding the sustainability of companies, products and processes were discussed. “It may be that we can’t see particularly sustainable growth right now, but perhaps sustainability will pave a new way forward for us, into a future characterised by high performance,” said Jan van der Meulen, stressing the importance of sustainability on agenda of the European paints and coatings manufacturers. An electronic survey – a first for CEPE - of attending paints and coatings manufacturers also showed that 76 % of companies and associations present had their own sustainability programmes in place. CEPE itself, the European umbrella organisation for the coatings sector, established a dedicated Task Force in 2010 to address the issue of sustainability, under the aegis of Tony Mash, BCF.

It’s the way forward, but it’s expensive

Watch CEOs of European SME discuss sustainability at www.europeancoatings.com/ videos/

40

The majority of conference attendees viewed sustainability as being the way forward, with more than 74% of surveyed company representatives indicating that renewable resources were already built into their research and development programmes. And yet there remained the question of who would ultimately bear the cost of these eco-friendly products. As Martin Sutcliffe pointed out in his talk on the prospects for renewable raw materials for paints and coatings, despite a general trend towards “LOHAS” (Lifestyles of Health of Sustainability), a survey of Danish consumers revealed that they were not prepared to pay a premium of more than 5% for eco-certified paints. This meant that the coatings industry would be unable to meet the challenge of providing sustainable, environmentally friendly products in one fell swoop, he noted. Instead, the goal of sustainability would have to be achieved from fine-tuning thousands of separate innovation screws. In this regard, the coatings industry saw itself as being less of a materials supplier, and more an agent of change. Dr. Tobias Lewe, A.T. Kearney, stressed in his presentation that the current severe economic crisis was over, even if

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there were still “Doubting Thomases” who were expecting a double-dip in the short term. A biannual survey of coatings manufacturers and their customers by A.T. Kearney had shown that companies were returning to profitability: If one took the value of the 1st half-year of 2008 as 100%, companies had gone from a figure of 48 % profitability in HY1 2009 to 94 % profitability in HY1 2010. This assessment was corroborated by more than half of attending company representatives, who indicated in the electronic survey that there had again been slight growth in 2010 (0 to 10%), relative to the prior year. Nonetheless, said Lewe, the coatings industry would naturally have to prepare for the next crisis, whenever that might be. In his view, “sustainability” constituted a genuine competitive advantage. The key factors for a successful future, according to Lewe, were the “regional footprint", a balanced portfolio, innovations and the financial health of the companies.

The mood within the industry Discussions with the decision makers in the European sector – those attending the CEPE 2010 Annual Conference in Istanbul – clearly revealed that the majority of European paints manufacturers were convinced they had turned the corner. The upward trend in global industry and the global economy this year was very much evident to the paints and coatings sector, too. After the slump in industrial coatings business last year, namely in metallic and powder coatings, manufacturers were again seeing a positive trend. Decorative paints were continuing to trend up, as well, but then this segment had not suffered as badly as industrial coatings. The signs in the markets of Eastern Europe were also pointing to recovery and thus to growth. This was most evident in Russia, where the effects of the collapse in the paint and coatings business during the global economic crisis were palpable. Markets such as Poland, which were not so badly affected, were continuing to grow at a moderate rate, with good potential for more. The Baltic States remained a concern, though. Expectations were not being met and there was no sign of any upward trend. The Greek market, too, was in a precarious situation. One industry representative indicated that it was not yet clear at what point the market would start to recover. Industrial coatings business is a mixed bag in central European markets. Paints manufacturers in some segments were posting good results that compensated for the slow pace of development in areas such as machinery and equipment making, with the result that the overall outlook was positive. For Turkey, the host country at this

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Events CEPE Annual Conference year’s CEPE Annual Conference, growth of about 10 % was expected in 2010. This would mainly come from the powder, metallic and decorative sectors, according to Gavsi Özarpak who gave a presentation on the status quo of the Turkish coatings market on behalf of the Turkish industry association BOSAD, which represents about 80% of Turkish coatings industry. Expectations for printing inks were some 7 % up on those from the prior year. The only stagnant segment was marine paints.

Sustainability kick-off

In an interview with the editorial board of the European Coatings Journal, the President of the Decorative Coatings

"Sustainability is becoming increasingly important in public debate, with legislators, customers and clients. Nevertheless, significant differences are emerging both in the perception and in the in-house implementation of this topic by our member companies. Especially, some SMEs were experiencing very difficult times here.” – Dr Hans-Joachim Güttler, Meffert AG, Chairman Decorative Coatings Sector Group (CEPE)

The plenary session and its presentations were followed by a “Sustainability Kick-Off” which was attended by all. Dr. Kenneth Sundberg, Group Vice President of Research and Development, Tikkurila Oy, ruminated on the extent to which the market would accept higher prices for renewable raw materials for paints and surface coatings. He made it clear that there would EXCELLENCE FOR YOUR PLANT be difficulties trying to enforce price increases by highlighting the sustainability aspect. Sundberg provided an interesting insight into the Scandinavian eco-label landscape, and he stressed the need for paints and coatings manufacturers to adopt a pro-active stance towards sustainability in order to gain the trust of customers. Discussions about price and performance were the biggest hurdles to overcome, he said. The sustainability of various coating resin technologies was the focus of the presentation by Jan Besamusca, Innovation Director, DSM NeoResins+. Using easily understood examples, he explained the different methods currently being employed to evaluate product sustainability in the coatings market, and he illustrated the dearth of comparability between the results. The best technology was found to depend on whatever parameters were substituted into the Complete plant for the production of water base equation. Therefore, warned Besamusca, it was paints and additives always essential to exercise caution when conducting a sustainability evaluation. COMEC has been producing machines and systems for the chemical The speakers in the two focus sessions on decoand paint industry for over 35 years, designing specific solutions for all rative coatings and industrial coatings devoted customer needs. themselves to the role of sustainability in the The only STANDARD way: QUALITY first! various segments. Comec machines manage every step of the production process: raw materials and additives STORING and DOSING, MIXING, GRINDING, Sustainability gaining FILTERING, PAINT METERING, PACKING and PALLETIZING.

importance in decorative paints

In order to examine the extent to which a paints and coatings manufacturer could fully integrate sustainability into its corporate management, Dr. Peter Grochal used the example of Sto AG. A renowned expert in sustainability, one of the key planks of his presentation was that environmental and social sustainability were essential, but they should not exonerate the company from continuing its quest for sustainability from within. Rather, they needed to be balanced by sustainably structured and managed departments within the company, sustainable use of human resources by management, and financial sustainability.

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Events CEPE Annual Conference Sector Group, Dr. Hans-Joachim Güttler Güttler, voiced his concern that not all members of the sector group were tackling the issue of sustainability with the necessary determination.

“The plethora of information, viewpoints and proposals emanating from the presentations on the complex topic of sustainability has brought home to me both the significance of this challenge and all its implications for the small and mediumsized players in the industrial coatings sector.” – Peter Rieck, Sonneborn & Rieck, Chairman of the session “Sustainability in Industrial Coatings Sector” “Architects don’t need to use grassed roofs to demonstrate sustainability,” said Jörg Filip Roscam, Chairman Europe of the Colour Marketing Group, describing a current architectural trend. With high-tech, it was now possible to create forms which were inspired by Nature and had an almost natural look. The current widespread trend for individuals and companies to identify more and more with their buildings, thereby giving rise to an interaction between house and residents, ultimately offered potential for the paints and surface coatings industry. Often, the front of a building was conceived of as a “calling card”, a fact which not only offered interesting prospects but brought up the question of colour, according to Roscam. Martin Essl Essl, CEO of Austrian bauMax AG and board member of EDRA (European DIY Retail Association), started his presentation with a review of EDRA’s paint activities in

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this area since it started operating independently of the association since in late 2009. He then transitioned into an overview of the development of the global market for home improvements, which was worth a total of EUR 359 billion. In the discussion following his presentation on EDRA, Essl used his own DIY chain to illustrate how in-house environmental friendliness (and the cost balance, too) could benefit over the long term from simple but efficient measures to improve, for example, logistics management and lighting in stores.

Challenging: Sustainability in industrial coatings Sustainability is a challenging issue for industrial coatings, even more so than for decorative paints. “Sustainability means meeting the needs of the present, without compromising the ability of future generations to meet their own needs.” It was with these words from the British Coatings Federation (BCF), that Peter Rieck, Sonneborn & Rieck, introduced the session on sustainability in the industrial coatings sector. There was nothing radically new about ideas of sustainability in the industrial coatings segment. This was the contention of Gerard de Vries, Regional Manager, Middle East, Turkey and Africa, PPG Protective and Marine Coatings. The industrial coatings sector had addressed this topic in the past, too. But now it was being widely used for positioning purposes. De Vries defined three key areas of sustainability: First, business performance, subdivided into vision, goals, and communications; second, the employees (SHE) and community (loans, training); and third, the environment consisting of business efficiency, good products as well as simplification, e.g. through the use of larger paint

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drums. The examples which de Vries mentioned of areas in industrial coatings which offered potential for sustainability included ultra-tough anticorrosion topcoats that lasted roughly ten years when applied in three coats on-site. The primary target for the future was less than VOC (55%) and shorter downtimes. A single day of missed production, he said, incurred costs of EUR 7,500. The latest technological approach of using two coats of polysiloxane was expected to yield a lifespan of 20 years. Furthermore, VOC values, too had fallen, said the industrial paints expert, because the solids content was 90%. Dr. Marianna Pierobon from the Competence Centre Environment, Safety, Health of BASF SE, stated that strategic analyses at BASF always looked at life-cycle analyses first, in which the input, output and impact were determined and then evaluated. This is followed by an ecoefficiency analysis to compare products or processes. Pierobon said that this analysis, which included figures for energy consumption during production and application, global warming potential, resource consumption, toxicity potential, risk potential, land use, and costs, was a standard tool at BASF. The company had already conducted 400 such analyses. A discussion then ensued on how to calculate the raw materials input for an analysis when various binders from different regions were used. Participants in this discussion drew attention to the fact that there were dedicated software programmes for this as well as generally accepted average values for different raw materials.

More food for thought As part of the CEPE’s General Assembly on 24 September, CEPE treasurer Jochen Stotmeister proposed that the fee for ordinary members of CEPE not be increased in 2011. This proposal was approved by the voting members of CEPE but, in so doing, they also acknowledged that this decision would lead to a negative result in the 2011 budget. “If the current trend continues, we can expect a negative result for 2012, too,” added Stotmeister, providing some food for thought. The next CEPE Annual Conference and General Assembly will take place 5-7 October 2011 in Dublin/Ireland.

CEPE board members after GA 2010: René Riu, Materis Paints (Chairman) Hubert Culik, Rembrandtin Lack Antoine Fady, AkzoNobel Herbert Forker, Siegwerk Group Giorgio Rupnik, Boero Group Jochen Stotmeister, Sto AG Armodios St Yannidis, Vitex Aram Manoukian, Lechler Kevin O‘Connor, General Paints Pekka Rantamäki, Teknos Group Felipe Mellado, SunChemical Francisco Perello, Valresa Helmut Rödder, BASF Coatings Henner Stratenwerth, Feidal Marlies van Wijhe, Van Wijhe Verf.

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A free Web Seminar presented by BYK

NANOBYK® – Innovative additives using nanotechnology for sustainable coating applications 09. 12.2010 · 14.00 H Nanotechnology is a key driver for new and innovative coating applications. For many applications, highly transparent films and high-quality performance are required. To maintain the appearance as long as possible, the coating has to show certain protective properties. One of those properties is scratch and abrasion resistance. The ability of coatings to provide scratch resistance can be influenced by adding nanoparticles into the clear coat without affecting transparency. Surfaces which are exposed to direct sunlight are damaged by UV radiation. Conventional UV absorbers usually do not offer a sufficient longterm solution to this problem, as they degrade over time with the effect of the sunlight and lose their efficiency. Don’t miss this outstanding opportunity to update your knowledge or to gain a deeper understanding of new and innovative coating applications right form your desktop and free of charge!

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Events Asian Paint Industry

How to make a difference APIC meeting: The Asian paint industry on its way to more eco-friendly coatings

Miriam von Bardeleben

M

ore than 60 representatives from different Asian Associations and coatings companies attended the 14th APIC Meeting, which took place 18-20 October 2010 in Suzhou/China. Reporting from the different markets several representatives from Asian associations were able to show positive figures - either refering to production volumes or to the increasing share of ecofriendly coatings. The Chinese National Coatings Industrial Association CNCIA, which was hosting the APIC meeting this year, also saw the meeting as a gateway for other countries to understand the Chinese paint and coatings market. There could be more than one reason for that wish, because the Chinese paint and coatings manufacturers looked back on a successful year

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with steadily increasing production volumes (Table). In China, according to CNCIA, 48% of the whole coatings market volume comes from architectural coatings, Waterborne architectural coating stand for 34% of the overall market volume.

Dealing with regulations During the APIC meeting it became clear that the Asian paint and coatings manufacturers as well as their national associations are getting more and more eager to comply with international regulations. Bai Eason from TPMA, who gave a vivid presentation on the issue "APEC Chemical Dialog Report" left no doubt about the importance of embracing the international regulations for the Asian paint industry: "REACH, GHS, OECD, ROO, GLP, ICCA, [...] - if you do not know these abbreviations you should diversify your business, because then you are at high risk!", she warned.

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Events Asian Paint Industry GHS Update Pamela Phua from the Singapore Paint Manufacturers Association stated that she found it difficult to engage Asian SME’s in GHS. “They would have to invest in this task and give undivided attention to this topic”, she said. However, her home country is ambitious in its goals: “SPMA’s members plan to implement the system until 2013.” Julina Bt Zainal Abidin, chairman of the Malaysia Paint Manufacturers Association, does not expect GHS to be implemented in her country before the year 2019.

“It is important to share information. We have related issues in the different countries. The knowledge which the APIC meeting provides is really helpful. We can learn from the more advanced economies, especially when it comes to regulation.” – Julina Bt Zainal Abidin, chairman of the Malaysia Paint Manufacturers Association China sees itself in special situation when it comes to GHS: It does not have any NGO which is engaging in the GHS issue. The paint manufacturers can only refer to documents provided by the Chinese ministry of transportation. JPMA will implement GHS not only for industrial coatings but also for consumer paints, starting in January 2011. Andrew Doyle and Steve Sides, who talked about possible global coordination of tasks like GHS through closer cooperation between the two associations IPPIC and APIC, aim at achieving harmonization through understanding.

Lead risk reduction Figures presented and Issues addressed by national associations as well as representatives of IPPIC also included the topic of lead risk reduction. Providing a positive ex-

"The APIC meeting is a great opportunity to further align the activities of IPPIC and APIC and to extend international cooperation amongst the industry's trade associations." – Andrew Doyle, American Coatings Association (hosting IPPIC's secretariat) ample of addressing the lead issue, Pamela Phua stated that in Singapore the use of lead-added paint was banned from all newly-built homes. Still, even Singapure is still facing a problem with lead in primers, she explained. Talking about the Indian market, Pangulury Mohan Murty (Indian Paint Association) said that 80 % of the paints produced in India were free of lead: "The rest is used on products which are not in contact with humans." In the following discussion some attendants were looking for clarification on the definition of paint without lead. Steve Sides explained on behalf of IPPIC that "no added lead" would be the proper definition to start with, meaning that no lead is added on purpose. A common statement of intent by all APIC member associations about their commitment towards the lead issue may be agreed on during next year's meeting, which will be held at Pattaya, to be hosted by Thailand's association.

Official APIC logo Each of the attending associations had one vote to decide about the new official APIC logo. Out of 16 logo drafts, which the members had handed in before the conference, a colorful version, suggested by the Indian association, turned out to be the most favorite in the end. The new logo will be published after its official registration.

APIC Paint Production Figures (in tons) Data Year

2004

2005

2006

2007

2008

2009

Australia

271.317

256.147

264.501

264.426

262.942

0

Bangladesh

43.204

48.550

56.515

62.515

69.989

91.620

5.926.937

6.379.964

China

2.980.000

5.090.000

India

1.320.000

1.500.000

Indonesia

7.555.000 2.298.350

470.000

586.000

Japan

1.832.547

1.904.595

1.950.881

1.939.044

1.838.173

1.484.425

0

Korea

917.658

851.458

920.208

988.524

973.478

925.000

Malaysia

179.285

187.466

196.805

166.302

146.111

128.120

Pakistan

0

Philippines

288.000

288.000

264.000

282.000

115.200

117.000

120.000

120.000

130.800

120.000

0

0

0

0

0

0

Taiwan

464.000

435.000

474.000

464.000

415.836

364.613

Thailand

403.500

387.000

375.000

371.700

428.950

333.630

Vietnam

155.640

199.200

225.420

283.200

289.200

316.800

Singapore Sri Lanka

Source of data: APIC

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Market Place Novel products Protective properties based on hybrid technology

Fast mixing, dispersion and degassing

Microcapsules embedded in anti-friction coating

DYO is launching a new product onto the market, introducing hybrid technology to the decorative paint sector. “DYO Hybrid Soft Matt Interior Paint” has been developed using this technology. Its innovative stainrepellent properties are generated using two different, yet complementary resins in its structure. The paint is consumer-friendly, with its special easy-to-clean features, and has time- and labour-saving benefits. In addition, the product is resistant to impact and scratches, due to its good chemical composition, derived from the benefits of implementing hybrid technology. This feature protects against any possible deformation that may occur after cleaning the paint surface. With the new product the surface of the paint is protected during cleaning, against any possible local shining. As a consequence of this protecting property, the paint maintains its unique texture for many years to come. Furthermore, the paint demonstrates good spreading properties and provides a smooth surface appearance, without leaving any brush or roller marks.

The “Thinky ARV-5000” is a contactless planetary mixer which is suitable for any conceivable formulation. In a matter of seconds or just a few minutes, users can mix, disperse and degas their material in the laboratory, for a pilot, or scaled up for production. Typical applications include the formulation and mixing of highly viscous materials or multi-component systems such as adhesives, epoxy resins, sealing compounds, cosmetics, injection moulding compounds, ceramic slips, lubricants, abrasives, foodstuffs, dental cements and soldering pastes. The mixing bowl has a capacity of 5 kg and can be filled to a maximum of 3 litres. During mixing, standard or indeed customised material containers simultaneously perform rotary and gyratory movements at high speed, with the result that the sample is accelerated at up to 400 G and undergoes a thorough mixing during which air and gas inclusions are reliably removed, with absolutely no need for stirrers or similar agitating instruments.

With “Berucoat MC”, Bechem is presenting a new type of anti-friction coating. This is the first product to use innovative microcapsule technology in a formulation ready for production. Shells resembling balls, which are only visible under a microscope, are filled with lubricant and embedded in the actual coating film. Under load, they release their charge of lubricant at the point of friction, so forming a touch-dry film of lubricant between the two surfaces undergoing friction. The new product has an impressive service life: the manufacturer reports that the new microcapsule coating has a service life up to three times as long as that of commercially available high-performance anti-friction coatings based on the principle of adding solid lubricants. The coating is also very safe to use in the working environment, since there is no possibility of flammable solvent vapours being produced, for example. Embedded in a waterborne coating, the microcapsules can be applied precisely at the point where lubrication is needed. As in the case of conventional anti-friction coatings, dipping, spraying and bulk application coating are possible application methods.

DYO TR-Izmir [email protected] www.dyo.com.tr

Range of two-stage pumps made of plastic There is growing demand in the area of flue gas cleaning, gas scrubbing or surface cleaning for vertical submersible pumps that can cope with high delivery pressures. However, state-of-the-art technology used in metal

C3 Prozess- und Analysentechnik GmbH DE-Haar [email protected] www.c3-analysentechnik.de

pumps cannot simply be applied to the design of plastic pumps without further modification, due to the technical characteristics of the material. Since the heat resistance of plastic is limited, plastic pumps cannot hand­ le the same high bearing loads as a metal pump. As impeller dimensions increase, so too do the demands placed on main and intermediate bearings in single-stage pumps with immersion depths greater than 2000  mm when it comes to balancing the high radial forces these high-speed pumps generate. This is where the limitations of thermoplastic materials become apparent. A modular system has now been applied to develop the “B80 KGK G3”, a range of twostage pumps with a nominal speed of 1450 rpm which meet the requirements of operational safety and system availability even when used in continuous operation. Two impellers arranged one behind the other achieve pumping heads of up to 85 m. Lutz Pumpen GmbH DE-Wertheim [email protected] www.lutz-pumpen.de

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Carl Bechem GmbH DE-Hagen [email protected] www.bechem.com

Additive gives cost-effective pigment concentrates Especially in decorative paints, a well-balanced cost calculation is very important. The new wetting and dispersing additive “Tego Dispers 741 W” enables formulators to develop cost-efficient pigment concentrates with good colour strength. The additive can be used for the formulation of organic, inorganic and carbon black pigment pastes and displays good compatibility with an enormous variety of binder systems. It stabilises pigment particles effectively, giving pigment pastes with long-term stability. The product is an aqueous solution of a polymeric wetting and dispersing additive based on renewable resources. It is free of organic solvents, NCO and of course alkylphenol ethoxylates. Evonik Tego Chemie GmbH DE-Essen [email protected] www.tego.de

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Market Place Novel products Manual weighing system for small quantities Bench-top or floor balances are often used when weighing items that are prepared and added to mixing processes by hand. To ensure that the required batch documentation is recorded and that reproducibility is guaranteed in manual processes even when the dosed quantities are small or minimal, the “ManDos” manual weighing system can be used. This is available in different versions: for example, the “Rolli” variant comprises a portable wheeled container incorporating the system’s PC. The balance is connected directly to the PC. The wheeled container can be used flexibly at various sites within the production process; all that is required is a power supply and if necessary a network connection. The manual weighing system provides recipe-supported prompts that allow users to avoid errors when carrying out weighing tasks and at the same time document them and hence make the batch traceable. This means that losses or faulty batches can be reduced.

HSH-Systeme für Prozess-IT DE-Neckarsulm [email protected] www.hsh-systeme.com

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Flow metering using ultrasound The clamp-on ultrasonic flow meter “Sitrans FST020” from Siemens Industry Automation Division has been designed specifically as an entry-level model, offering flow reading with simple data communication capabilities. The device measures practically any liquid and meets the requirements of industries such as water and wastewater, HVAC (heating, ventilating and air conditioning), power and chemical. It can be installed on pipes up to DN 9000 (360 inches) in diameter, and because of the simplified configuration and setup options it can be commissioned quickly. The meter offers features specially tailored to the requirements of basic industry applications in the sectors of water and wastewater, HVAC, power and chemical. It also meets the general requirements of the processing indus-

try: these include single channel measurement and simplified configuration options that make product selection straightforward, while still offering solutions that fit sectorspecific requirements.

Photocatalyst breaks down pollutants

Rapid detection of bacterial contamination

One of the latest developments from Kronos is the “KronoClean” range, including “KronoClean 7000” photocatalysts. Based on titanium dioxide, these allow pollutants to be broken down in a controlled way, to give harmless substances such as carbon dioxide and water. A specific modification means that it is effective over the broadest possible range of conditions, so it will operate even in enclosed rooms or under diffuse light. Possible applications include coatings of all kinds, textiles and synthetic films, right through to cement – wherever it is advantageous for the product to have high specific surface area and superhydrophilicity. The products are used where conventional photocatalysts fail because their range of effectiveness is significantly smaller: so they even work under glass, in normal indoor illumination, in twilight or in scattered light. Tests have demonstrated their effectiveness on numerous everyday odours, pollutants, stains and soiling.

Microbiological contamination in process fluids, such as cooling lubricants or paint baths, can result in disruptions to process operations. This can shorten the service life of the fluids and impair product quality. “HyLite Plus”, for monitoring biological films, has been particularly designed for tests in the specific matrix of paint and other coating baths, cooling lubricants in the metalworking industry, and for activated sludge in water purification plants. The new test provides clear, reproducible results after only two minutes. It measures the metabolic activity of bacteria, yeasts, moulds and highly specialised anaerobic microbes by detecting the adenosine triphosphate which is present in all living cells. ATP is detected in a controlled manner by means of reaction with a luciferin/luciferase mixture in a buffer solution. The emitted light is measured in the photometer and provides an indicator of the level of microbiological activity in the sample.

Kronos International, Inc. DE-Leverkusen [email protected] www.kronosww.com

Merck KGaA DE-Darmstadt [email protected] www.merck.de

Siemens-Division Industry Automation DE-Nuremberg www.automation.siemens.com

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Market Place Novel products Program for more certainty in measurement

System increases sieving capacities

With its “Good Weighing Practice” (GWP) guideline, Mettler Toledo is the first manufacturer of balances to offer a program individually tailored to each customer and each weighing process for increasing the reliability of measurement and maintaining the required process tolerance. This is a risk-based, practice-oriented guideline that encompasses all the usual quality systems (GMP, GLP, ISO, HACCP, etc.) and offers users a high level of certainty, from the selection of the balance, through its initial qualification to periodic testing during routine operation. With GWP, customers receive a seamless package of measures to minimise the work associated with testing, eliminate any divergence from requirements, regulations and quality standards, and offer more assurance on audit. Depending on the acceptable risk level and the required precision, it gives clear answers to questions such as the type of balance testing, the necessary frequency of tests or the traceability of documentation.

The “Rotex Ultrasonex” binding control system is a field-proven system that minimises mesh blinding and bridging when screening difficult or sticky materials such as metal powders, ceramics, powder paints, powder coatings, plastic resins, toner powders, food, and various chemicals. The system significantly increases sieving capacities by enabling powders to pass through screens faster, providing higher throughput, finer screen separation, consistent product quality, and longer mesh life. The system is available on new Rotex Screeners, and can be field-retrofitted to existing machines. Unlike mechanical deblinding systems, the binding control system does not use abrasive mechanical actions that cause wear. Instead, the system applies an ultrasonic frequency directly to the screening mesh via an ultrasonic probe. The action injects a secondary, high-frequency, low-amplitude vibration that breaks down surface tension, preventing particles that are slightly greater and smaller than the apertures from blinding or blocking the screen mesh.

Mettler Toledo GmbH DE-Gießen [email protected] www.mt.com

Rotex Global, LLC USA-Cincinnati [email protected] www.rotex.com

Phthalate-free fast-solvating additive

UV cure ink for printing systems

Lanxess offers a range of products enabling interested users of phthalate-based additives to switch to alternative safer products. As well as the established plasticizer “Mesamoll”, these include the new product “Mesamoll TP LXS 51067”. This phthalate-free product is a fast-solvating additive for PVC manufacture – particularly for the production of floor coverings and wall coatings. It will help, among other things, to replace the plasticizers dibutyl phthalate (DBP) and benzyl butyl phthalate (BBP). Both of these are regarded as toxic for reproduction and are subject to considerable limitations on use. To make the product a good alternative, the active “Mesamoll” ingredient – alkane sulfonic acid ester of phenol – was combined with another plasticizer. This component is also phthalate-free and has been approved for food contact applications.

Xennia launched its “XenInx” range of high performance ink products earlier in 2010. “XenInx Diamond” CMYK ink, along with a range of other UV cure inks, has now been released for use in third party inkjet printing systems. According to the company, the product gives good colour performance and good adhesion and durability when printed onto a wide range of non-porous substrates. The general purpose CMYK UV cure ink set exhibits high vibrancy and extended colour gamut combined with reliable jetting in a range of industrial piezo printheads. The ink shows good flexibility, adhesion and durability, with high levels of chemical, abrasion and temperature resistance and good lightfastness. It is designed for printing onto a wide variety of rigid and flexible graphics, packaging and label substrates as well as most plastics, glass and metal foil.

Lanxess AG DE-Leverkusen [email protected] www.lanxess.com

Xennia Technology Ltd GB-Letchworth [email protected] www.xennia.com

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Gauge detects fine dust at the workplace Fine dust in the workplace represents a hazard to health. To detect it quickly and easily, the specialist sensor company Helmut Hund GmbH has developed a range of gauges in a collaborative project with leading research institutes in the field of environmental engineering. For use on the move Hund offers “TM data”. It comes equipped with a scattered light photometer for measuring the fine dust, and needs no pump for taking samples. This means there is no influence on the medium to be measured, and the usual pump maintenance operations are dispensed with. The gauge detects particles of dust, smoke and carbon black, all of which may be taken into the lungs through the airways. Measurement takes only five seconds, and the result appears on the unit display. Measurement over a longer period, up to 24 hours, is also possible. The stored measurement values can be exported to PC and processed by analytical software. Helmut Hund GmbH DE-Wetzlar [email protected] www.hund.de

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Calendar of Events 2010 Conferences 3 – 4 November 2010 Car Body Painting 2010 Bad Nauheim/Germany www.automotive-circle.com 9 – 10 November 2010 EC European Coatings CONFERENCES: Smart coatings VI Berlin/Germany www.european-coatings.com/ events/ecc.cfm 9 – 11 November 2010 XXX FATIPEC Congress Genoa/Italy www.fatipec2010.com/default. html 16 - 18 November 2010 Carbon Black World 2010 Rome, Italy www.carbonblackworld.com 23 – 25 November 2010 Advances in Coatings Technology ACT’10 Katowice/Poland www.impib.pl 28 November - 1 December 2010 European Symposium on Photopolymer Science Mulhouse, France www.dpg.uha.fr 6 – 8 December 2010 Radiation Curing Technology Hampton, Middlesex, UK www.pra-world.com

7 – 8 December 2010 EC European Coatings CONFERENCES: Polyurethanes for high performance coatings VI Vincentz Network Berlin/Germany www.european-coatings.com/ events/ecc.cfm 8 - 9 February 2011 EC European Coatings CONFERENCES: Easy-to-clean/ self-cleaning coatings III Berlin/Germany www.european-coatings.com/ events/ecc.cfm

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10 - 11 February 2011 EC European Coatings CONFERENCES: Biobased coatings II Berlin/Germany www.european-coatings.com/ events/ecc.cfm

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28 - 30 March 2011 European Coatings Congress 2011 Nuremberg/Germany www.european-coatings-show. com/en/congress/

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31 March – 1 April 2011 EuPIA Annual Conference Vienna/Austria www.eupia.org

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New events in our list 

or events with changes.

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Exhibitions 9 – 11 November 2010 Eurocoat 2010 Genoa/Italy www.eurocoat-expo.com 29 – 31 March 2011 European Coatings Show 2011 Nuremberg/Germany www.european-coatings-show. com/en/

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11 – 13 May 2011 COAT EXPO 2011 Wise Exhibition (Guangdong) Co., Ltd Guangzhou/China www.coatexpo.cn/en/

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More coatings events at www.european-coatings.com events/coatings_calendar

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In the focus

Powder coatings – trends and perspectives  The market share and the use of powder coatings have since their industrial introduction in the sixties of the last century steadily grown in market share and concerning technical usage areas. Due to the intensive discussions about energy consumption, powder coatings will have to master the reduction of curing temperature. In other items powder coatings were, are and will be advantageous

The rheological demands placed on automotive coatings are severe. A new class of rheology modifiers known as PMPU provides the required fast pseudoplastic recovery of structure after spraying, as well as high temperature stability.

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Editors: Damir Gagro (gag) Sonja Specks (sos) Kirsten Wrede (wr)

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A new chrome-free coating technology shows better performance than commercial chrome-free corrosion inhibitors in corrosion tests on the aluminium alloys in aerospace applications. Source: AkzoNobel

and . . . Lifting the barrier to new technologies  Predicting future consumer color preferences: Color and design group “Foresee” 

11 l 2010

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Protection for high flyers 

European Coatings J OURNAL

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High-temperature sagacity 

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Source: Wagner

Editorial Team

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