Paints & Coating Industry January 2012

January 2012 VOLUME 28, NUMBER 1

INSIDE Improving Powder Coatings Carbon Nanotube-Based Additives

Paint

Coatings Industry

Converting to a Low- or No-VOC Tinting System

Globally Serving Liquid and Powder Formulators and Manufacturers

New Pigment Options

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We are thinking about the same thing you are… How to make your products greener and their performance pure gold. Our customers come to us to help them stay ahead of competitive pressures by helping to re-formulate existing products and innovate new ones – meeting “green” goals while preserving and even enhancing performance. We call it Greenability. You’ll call it genius. 2 Another fine result of the Innovation Principle – . Let us help you work through the formula for Greenability.

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.EXEO3OLUTIONS ,,#s OPTIONsWWWNEXEOSOLUTIONSCOM ™Trademark, Nexeo Solutions or its subsidiaries, registered in various countries ©2011, Nexeo Solutions AD-1062

Save the Date

Indianapolis, Indiana May 8-10, 2012 American Coatings CONFERENCE May 7-9, 2012 www.american-coatings-show.com

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CONTENTS PA I N T & C O AT I N G S I N D U S T RY, V O L U M E 2 8 , N U M B E R 1

January 2012

FEATURES 16 Conductive Coatings Using Carbon Nanotubes, BYK-Chemie GmbH 20 The Low-VOC Future: New Opportunities in Tinting System Design, CPS Color 24 Siloxane Based Multifunctional Additives, Evonik Industries 30 Improving Powder Coating Aesthetics and Performance, Clariant Produkte (Deutschland) GmbH 32 Environmental Challenges Demand New Color Solutions, Rockwood Pigments

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ONLINE FEATURES www.pcimag.com

Stylish, Clever, Scratch-Resistant Paint Systems Featured on Smart Forvision, BASF GM Eliminates Solvent from Suppliers’ Paint Process, General Motors New Waterborne Self Healing Coating for Use on Wood and Polymer Substrates, NEI Corporation Tnemec Coatings Protect Steel Canopy of Expanded Pennsylvania Convention Center, Tnemec Company, Inc.

DEPARTMENTS 6 Viewpoint 8 Industry News 10 Calendar of Events 11 Company News 14 Names in the News 44 Products 45 Classifieds 46 Advertiser Index

36 Novel Additives to Extend Open Time in Low-VOC Latex Paints, Eastman Chemical Company

ON THE COVER: Photo from istockphoto.com. Photographer: www.odonnellphotograf.com.

40 Selecting Resins for Wood Coating Applications, Bayer MaterialScience LLC

PCI - PAINT & COATINGS INDUSTRY (ISSN 0884-3848) is published 12 times annually, monthly, by BNP Media, 2401 W. Big Beaver Rd., Suite 700, Troy, MI 48084-3333. Telephone: (248) 362-3700, Fax: (248) 362-0317. No charge for subscriptions to qualified individuals. Annual rate for subscriptions to nonqualified individuals in the U.S.A.: $115.00 USD. Annual rate for subscriptions to nonqualified individuals in Canada: $149.00 USD (includes GST & postage); all other countries: $165.00 (int’l mail) payable in U.S. funds. Printed in the U.S.A. Copyright 2012, by BNP Media. All rights reserved. The contents of this publication may not be reproduced in whole or in part without the consent of the publisher. The publisher is not responsible for product claims and representations. Periodicals Postage Paid at Troy, MI and at additional mailing offices. POSTMASTER: Send address changes to: PCI - PAINT & COATINGS INDUSTRY, P.O. Box 2145, Skokie, IL 60076. Canada Post: Publications Mail Agreement #40612608. GST account: 131263923. Send returns (Canada) to Pitney Bowes, P.O. Box 25542, London, ON, N6C 6B2. Change of address: Send old address label along with new address to PCI - PAINT & COATINGS INDUSTRY, P.O. Box 2145, Skokie, IL 60076. For single copies or back issues: contact Ann Kalb at (248) 244-6499 or [email protected].

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VIEWPOINT

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For several years now, nanotechnology has been on the forefront of research at both the academic and corporate levels. According to a study by Global Industry Analysts, Inc., although the recent global economic recession dampened the optimistic expectations and strong growth patterns of previous years, the global market for products incorporating nanotechnology is projected to grow at a compound annual growth rate of 11.1 percent between 2010 and 2015 to reach $2.4 trillion. The report also states that products incorporating nanotechnology make up the largest product segment of the chemicals industry. As researchers are discovering new ways that nanoparticles can alter the performance of coatings, the possibilities seem almost endless. I recently read about two such examples. Researchers at the University of Michigan have developed a “perfect black” carbon-nanotube coating that conceals an object’s three-dimensional geometry and makes it look like a flat black sheet. The 70-micron coating, or carbon-nanotube carpet, is about half the thickness of a sheet of paper and absorbs 99.9 percent of the light that hits it. According to Jay Guo, a professor in the Department of Electrical Engineering and Computer Science, and principal investigator, “It’s not cloaking, as the object can still cast a shadow. But if you put an object on a black background, then with this coating, it could really become invisible.” The refractive index of this new coating is similar to that of air, meaning light traveling through air doesn’t scatter or reflect when it hits the coating, causing the human eye not to perceive it. The coating could have a variety of applications, including display screens with ultrahigh contrast and a crisper picture, solar heating devices, and a new type of camouflaging paint for stealth aircraft. Farther south, researchers at North Carolina State University are examining the use of conductive nanocoatings on simple textiles, like woven cotton or even a sheet of paper. According to Dr. Jesse Jur, Assistant Professor of Textile Engineering, Chemistry and Science, finding a way to apply conductive nanocoatings to textiles would represent a cost-effective approach and framework for improving current and future types of electronic devices. The potential for this research lies heavily in health and monitoring applications, including a uniform with cloth sensors embedded in the actual material that could track heart rate, body temperature and movement in real time. Nanotechnology is one of our topics in this issue of PCI. Be sure to read the article by BYK-Chemie on page 16, which reports on recent advances in using additives based on carbon nanotubes to enhance the electrical conductivity of several coating systems. Carbon nanotubes can offer an interesting alternative to the typical conductive pigments like carbon black or metallic particles. This truly is an exciting time to be in the coatings industry. At the rate that nano research is moving, perhaps turning a piece of paper into a computer tablet or creating Harry Potter’s invisibility cloak aren’t that far away from becoming reality!

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JANUARY 2012 | W W W . P C I M A G . C O M

By Kristin Johansson, Editor | PCI

Markets:

Architectural Coatings

Industrial Coatings

Container Automotive

Civil Aerospace Engineering

Coatings Technologies:

SolventBorne Coatings

WaterBorne Coatings

Powder Coatings

Surface/Substrate:

Wood

Brick

Concrete

Marine & Maintenance

UV Coatings

Metal

Stucco

High Solids Coatings

Vinyl

Plastic

Brenntag understands change is normal for the Coatings Industry. As the Coatings Industry has evolved through the years, Brenntag’s Paint and Coatings Team continues to provide our customers with the products and services to stay competitive in the marketplace. Whether you face different markets, technologies, or substrate applications, Brenntag’s Paint and Coatings Team can help you to adapt and make change work to your advantage.

Brenntag offers a complete specialty and industrial product portfolio, technical assistance with product development, formulations and applications know-how, superior logistics with versatile blending and re-packaging capabilities, and last, but not least, commitment to quality and safety. Change demands innovation and creativity. Brenntag Understands. Brenntag North America, Inc. (610) 926-6100 Ext: 3858 [email protected] brenntagnorthamerica.com

The Glocal® Chemical Distributor.

INDUSTRY NEWS Strong Demand Expected for U.S. Coatings Market CLEVELAND – U.S. demand for coatings is forecast to increase 7.8 percent annually to $26.2 billion in 2015. The market is expected to expand strongly in both volume and value terms, rebounding from the declines of the recession-impacted 2005-2010 period. During this time, construction spending and manufactured goods output both fell, reducing coatings demand in the key architectural and manufacturing markets. Accelerated growth in product pricing over the period prevented more significant declines in market value. The U.S coatings market will continue to be impacted by the trend toward sustainability. Due to growing environmental concerns, the industry has been subject to increasingly stringent government regulations, which are driving coatings manufacturers to invest heavily in the development of innovative, higher-value formulations. These and other trends are presented in Paint & Coatings, a new study from The Freedonia Group Inc., a Cleveland-based industry market research firm. The large architectural market will advance at an annual rate of 10.8 percent through 2015, reaching more than $14

billion. Demand will be promoted by renewed strength in the housing market, particularly as homebuilding activity rebounds from low 2010 levels. The interior component of the architectural paint market will remain larger and grow faster than its exterior counterpart. Sales of coatings in manufacturing markets will expand at a respectable rate through 2015, reversing the downward trend of the 20002010 period. Among the various market segments, furniture and fixtures will enjoy one of the best growth prospects and will remain the leading outlet for coatings over the forecast period. However, the motor vehicle sector will post more rapid gains, recapturing its position as the secondlargest outlet for coatings among manufacturing markets. Maintenance and specialty coatings will remain the smallest market through 2015. Key outlets include industrial maintenance, and road and bridge markets. Both are expected to advance at above-average rates, promoted by increased nonresidential improvement and repair activity and by greater spending directed toward the maintenance of the nation’s aging infrastructure. For further information, e-mail [email protected].

New Association for UV LED Applications

Prepaint Has Bright Future in Renewable Energy

HILLSBORO, OR – Phoseon Technology, Integration Technology Limited and Lumen Dynamics have joined together to form the UV LED Curing Association. The new association has been established to address a growing need within the market for current and potential researchers, suppliers, integrators and end users to gain a better understanding about UV LED technology and the significant benefits it brings to numerous applications. The UV LED Curing Association is focused on providing greater insight into the various UV LED solutions currently in the marketplace and developing applications that are well suited to the technology. One of the goals of the association is to demonstrate how system developers around the world can effectively integrate UV LED technology into applications and, where possible, achieve better efficiencies while saving costs. The founders of the association will work together to help define and establish UV LED-based guidelines for UV LED curing applications. This goal will become increasingly important as the adoption rate of UV LED technology continues to rise and the need for industry collaboration becomes critical. The association will also serve as a forum for fostering communication within the UV industry in order to facilitate the exchange of information and enable the entire industry to better address market needs. While complimentary to other existing and well-established associations, the UV LED Curing Association focuses only on UV LED curing technology and its applications. To learn more about the association and its offerings, visit www.uvledcuring.org.

CLEVELAND – Coil coating is the method of choice for applying many types of coatings in a wide variety of industries. Now it’s being used to apply coatings that help capture the power of the sun. Coil coating is being used to apply selective absorber coatings to aluminum strip for thermal energy applications at solar power plants. The process provides the precise layers of coatings needed for high-performing solar-absorber coatings. The coil coating process is ideal for specialty coatings used for solar energy because of the optimal surface prep, coating adhesion and continuous control that are unique to this process. By using the coil coating process, thin coatings can be uniformly applied to metal strip so that a highly selective coating and several functional coats can be applied in very precise, thin layers. The functional coats often include functional particles, such as nanoparticles, metal particles, metallic oxide particles and pigments. Each coat has a job. For example, one layer may absorb short-wave solar radiation while also being transparent for long-wave radiant heat. The result is conduction of short-wave solar radiation converted into long-wave radiant heat, so that the absorber plate is heated up as needed. Outside coats can be reflective for radiant heat so that the absorbent coat emits little radiant heat to the outside. Additional coating layers provide humidity and temperature resistance to protect against corrosion. Other layers provide adhesion-promoter properties, which substantially improve the endurance of the coating in the intense sun. With the coil coating process, the coating thickness can be adjusted precisely by means of the gravure on the roller coat-

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JANUARY 2012 | W W W . P C I M A G . C O M

INDUSTRY NEWS

ers and relative speed of line. After coating, it is also possible to apply embossing to the painted metal in order to increase the absorbent surface without tears developing in the coating. In addition, the coil coating process makes it possible to produce absorber panels at a much lower cost than previously necessary PVD or CVD processes.

Double-Digit Growth Expected for Radiation-Curing Inks LEATHERHEAD, UK – The total market for radiation-curing ink for packaging will grow 24 percent from its 2011 base to almost 37,500 tonnes by 2016. In value terms, growth above 60 percent will take the market to over $883 million in the same period according to a new study by Pira International and Radtech Europe. The study, The Future of Radiation Curing for Packaging, provides quantitative market sizes and forecasts for each key material, end use, region and country. The study is based on extensive primary research, including in-depth interviews with suppliers, packaging converters, printers and end users, including brand owners and retailers. This new study also analyzes the latest technologies shaping the industry. According to the study, the technologies of UV and EB curing provide several advantages for printers and converters. The ink, varnish or coating is cured immediately, allowing subsequent finishing operations to be carried out without having to wait for drying. A high-gloss finish may result that can sometimes save additional processes, such as special lamination. The cured ink film can be tailored to provide excellent tough and resistant finishes with specific abrasion and chemical resistance. Inkjet using UV inks is a fast-growing sector in signage and is becoming established in labels and packaging applications. According to the study, inkjet in labels, cartons and flexible packaging is expected to be the fastest-growing sector to 2016, with a 250 percent increase on the 2011 volume predicted. In the medium term, Pira expects that digital print will provide benefits to packaging supply chains in similar ways that graphics has benefited, and UV inkjet will take a significant portion of this. The technology will allow for economic short runs as brands develop more versions and run lengths decline. UV label printing is growing quickly. There are many narrow web print systems that compete directly with flexo and electrophotography, together with systems that effectively develop and improve the coding and marking functions. These provide the potential for supply-chain improvement across many sectors, as manufacturers see advantages in direct printing on demand rather than buying in pre-print. As manufacturing methods develop, Pira expects to see opportunities for UV inkjet labeling, blister packaging and carton print to replace pre-printed static versions. For more information about the study, e-mail Stephen Hill at [email protected].

industry leaders and thinkers. In addition, there will be expertled conference sessions, an Emerging Technology Showcase, exclusive plant tours and a celebration of key technology developments. For more information, visit www.westeconline.com.

Submit Your Paper for CTT 2012 TROY, MI – Papers are now being accepted for Coatings Trends & Technologies, to be held September 11-12, 2012, in Oak Brook, IL. Coatings Trends & Technologies is a two-day event that provides a resource-rich environment where attendees gain the most current technical knowledge that will help them in their coatings formulations, as well as connect with key suppliers in an interactive exhibit hall and network with coating professionals. Presenters at the conference will be able to educate new and existing customers, engage customers in future projects, share new ideas, and connect with key decision makers. The deadline for submission is March 16. For more details, visit www.coatingsconference.com.

Coatings Event Takes Place in Indonesia JAKARTA, Indonesia – The Indonesian Paint Manufacturers Association, the Indonesian Synthetic Resin Association, the Federation of the Indonesian Chemical Industry and the China National Chemical Information Center are jointly organizing INACOAT, Indonesia’s coatings, paint, ink, adhesive and surface finishing expo and conference. The event will take place in Jakarta, Indonesia, July 11-13, 2012. The three-day industry event is held alongside the second edition of INACHEM, Indonesia’s largest chemical, petrochemical, fine and specialty chemical expo and conference. For additional information, visit www.ina-coatingpaint.com.

Spray Finishing Workshop Takes Place in March TOLEDO – DeVilbiss, Binks and Owens Community College have teamed up to present a Spray Finishing Technology workshop. The training program is scheduled for March 7-9, 2012, in Toledo. Classes meet from 8:30 a.m. to 4:00 p.m. daily and include both classroom and hands-on sessions. Two continuing education units are awarded. For additional information, visit www.owens. edu/workforce_cs/spray2012-brochure.pdf.

CICE Features Leading Technology SHANGHAI, China – As an important global professional exhibition, the 2012 China International Coatings Exposition (CICE) will focus on finished coatings products, raw materials, coating preparation equipment, and the latest products and technologies in the coatings industry. The exposition will take place at the Shanghai New International Expo Centre in Shanghai, China, from April 1-3, 2012. For additional information, visit www. coatshow.cn/yqh_en. 

WESTEC Returns to Los Angeles LOS ANGELES – WESTEC returns to Los Angeles on March 27-29 with a new look, new content and a renewed commitment to area industry. WESTEC will premiere several new features in 2012, including a New Product Presentation Center and Learning Lounges where experts from specialized industries can provide education and insight in small-group settings. The show will also host unique networking events for attendees to connect with

Follow PCI on Facebook at www.facebook.com/PCIfan on Twitter at http://twitter.com/PCIMag and on Linkedin at www.linkedin.com PA I N T & C O AT I N G S I N D U S T RY



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CALENDAR Meetings, Shows and Educational Programs JAN. 30-Feb. 2 SSPC 2012 Tampa, FL www.sspc.org

FEB. 6-10 Polymers and Coatings Introductory Short Course San Luis Obispo, CA www.polymerscoatings.calpoly.edu

13-17 Waterborne Symposium New Orleans www.psrc.usm.edu/waterborne 22-24 Smart Coatings Orlando, FL www.smartcoatings.org 28-29 RadTech Annual Winter Meeting Miami Beach, FL www.radtech.org

MARCH 7-9 Spray Finishing Technology Workshop Toledo www.owens.edu/workforce_cs/spray2012brochure.pdf 11-14 SSCT 2012 Annual Technical Meeting St. Augustine, FL www.ssct.org 11-15 Pittcon 2012 Orlando, FL www.pittcon.org 12-14 The Middle East Coatings Show Dubai, United Arab Emirates www.coatings-group.com

Our full spectrum of products and services gives you the best integrated tinting system possible. CPS Color specializes in all facets of the tinting process from start to ¿nish. We work in partnership with you to design a system that perfectly matches your needs while ensuring compliance with ever-changing environmental regulations. Harness the full power of a customized Integrated Tinting System—accurate and repeatable color, less maintenance, and increased productivity. For more information, please visit: www.cpscolor.com.

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14-15 MN Paint & Powder Coating EXPO ’12 White Bear Lake, Minnesota www.ccatc.com/expo.htm 20-22 FABTECH Canada Toronto, Canada www.fabtechcanada.ca 22 Metropolitan New York Coatings Association Symposium East Rutherford, NJ www.mnypca.org 26-30 Basic Composition of Coatings Rolla, MO http://coatings.mst.edu/index.html 27-29 WESTEC 2012 Los Angeles, CA www.westeconline.com

7295 West Winds Blvd. Concord, NC 28027 800-728-8408 x240

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13-14 Professional Paint Formulation Hampton, UK www.pra-world.com

JANUARY 2012 | W W W . P C I M A G . C O M

APRIL 1-3 2012 China International Coatings Exposition Shanghai www.coatshow.cn/yqh_en

COMPANY NEWS AkzoNobel Powder Coatings Achieves Platinum Status with SMaRT Certification A MST ER DA M, The Netherlands – AkzoNobel Powder Coatings has become the first coatings manufacturer to achieve SMaRT certification, attaining platinum status. An acronym for Sustainable Materials Rating Technology, SMaRT is the major external standard for product sustainability. It is a carefully considered global certification that evaluates sustainability performance over a product’s lifecycle and supply chain. Products receiving SMaRT

Extech Instruments Moves to New Headquarters NASHAU, NH – Extech Instruments has relocated its headquarters to a new facility in Nashua, NH. The headquarters was moved, along with the Billerica, MA, operations of parent company FLIR Systems’ Commercial Systems division, to 9 Townsend West, Nashua, NH. The new location will house the eastern U.S. operations for FLIR’s Commercial Systems division, supporting the FLIR and Extech brands, as well as FLIR’s marine systems division, Raymarine. FLIR’s educational institute, the Infrared Training Center, will also be moving to the new location.

DKSH to Distribute for Master Additives in Southeast Asia ZURICH – DKSH’s Business Unit Performance Materials and Malaysia-based Master Additives have signed an exclusive agreement under which DKSH will provide sales, marketing, distribution and logistics services to Master Additives to help the company enter and expand into the southeast Asian countries of Cambodia, Indonesia, Malaysia, Myanmar, the Philippines, Thailand and Vietnam.

Improvements at Dow Unlock Additional Capacity MIDLAND, MI – The Performance Monomers business of The Dow Chemical Co. (Dow) announced that an incremental expansion strategy has unlocked an additional 15 percent of crude acrylic acid (CAA) capacity at its Deer Park, TX, facility. The capacity increase is a result of various improvement projects implemented in the CAA oxidation facility. These projects not only increased capacity, but also enhanced process safety and improved technology and reliability.

SCS Plans New Coating Center in Texas INDIANAPOLIS – Specialty Coating Systems (SCS) announced the expansion of its Parylene coating service operations into the southern United States. Build-out is underway for a new 13,000-square-foot facility located in Austin, TX. The new coating center will begin full production operations in early 2012.

Evonik Establishes Additives R&D Center in Asia ESSEN, Germany – Evonik will open its first research and development center for additives for coatings in Asia. The Tego

certification have openly documented their performance over a number of sustainability indicators ranging from minimizing the use of natural resources to reducing waste and carbon footprint. Companies achieving SMaRT accreditation must complete a thorough application process. A third-party audit is also required, and applicants must also renew and verify certification every three years in order to stay current with environmental trends.

Innovation Center will have two locations, in Singapore and Shanghai, as part of the global Evonik innovation network. The center will cater to manufacturers in the coatings industry in India and Asia. In the Singapore location, Indian, Southeast Asian and northern Asian nationals will look after customers in their home markets. Chinese specialists based in Shanghai will serve the Chinese market. Besides intensifying the cooperation with business partners, the center will expand research collaboration with top local universities.

Eiger Machinery Changes Name to Engineered Mills, Inc. GRAYSLAKE, IL – Eiger Machinery's name has changed to Engineered Mills, Inc. (EMI), as it expands its line of equipment for wet milling, fine grinding and dispersing of liquid and paste products. EMI will continue to manufacture and support the industry from its Grayslake, IL, facility, where it also has test facilities and a new product development lab. EMI continues to help customers with bead milling and mixing equipment for product research, quality control and technical service applications. Recently introduced is the Microtron™ Mill developed for producing nano dispersions using mill media sizes from 0.05 mm to 0.8 mm diameter.

BASF Moves Dispersions & Pigments Division Headquarters to Hong Kong LUDWIGSHAFEN, Germany – BASF has established the global headquarters of its Dispersions & Pigments division in Hong Kong. The division head and about 50 global positions, located in Ludwigshafen, Germany, and Basel, Switzerland, are now transitioning to Hong Kong. Transfer of positions will be realized over a period of about 12 months.

CAS-MI is Now EAG Coatings Solutions YPSILANTI, MI – CAS-MI has been renamed EAG Coatings Solutions. The rebranding emphasizes the strong commitment to coatings product development and analytical problem solving, while also reflecting the company’s recent inclusion as one of Evans Analytical Group’s 20 worldwide laboratories. The company became CAS-MI Laboratories in 2004 and launched the CAS-MI Innovation Center in 2009. Evans Analytical Group (EAG) acquired the company in April 2011. PA I N T & C O AT I N G S I N D U S T RY



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COMPANY NEWS Coatex Recognized at GICA GENAY, France – Coatex received the Best Coating Raw Materials Environmental Friendly Award at the Green Industrial Coating Asia (GICA) 2011. During the two-day event, Coatex showed how its new, eco-friendly coatings additives technologies enable customers to reduce their environmental impact. Olivier Guerret, Director of Innovation and Development for Coatex group, and Charlie Xiong, General Manager of Coatex Asia Pacific Technical Center, gave a themed presentation, “The importance of the rheological waterborne additives in the low-VOC coatings formulations.”

Lonza Reaches Agreement with Sumitomo Seika Chemicals BASEL, Switzerland – Arch Chemicals Inc. has reached an agreement in which Sumitomo Seika Chemicals Co. Ltd. of Japan has licensed Arch under certain patents in the United States, Europe, Japan and China covering an advanced method of manufacturing 1, 2 benzisothiazolin 3-one. Under the agreement, Arch has the right to sub-license the technology to third parties, and to enforce the licensed patents against direct and indirect infringement.

Perstorp and PTT Global Chemical Plan JV PERSTORP, Sweden – Perstorp and PTT Global Chemical announced plans to launch a joint venture dedicated to the manufacture and sale of aromatic (TDI) and aliphatic (IPDI, HDI and derivates) isocyanates serving the polyurethane industry.

The planned joint venture includes the former Perstorp Coating Additives business group with its manufacturing sites at Pont-deClaix, France, and Freeport, TX. PTT Global Chemical will retain 51 percent of the joint venture’s shares, and Perstorp 49 percent. The joint venture will invest in new manufacturing capacities and facilities to capitalize on the growing polyurethane market.

Lubrizol to Expand Portfolio CLEVELAND – The Lubrizol Corp. has signed an agreement to purchase Merquinsa, a leader in specialty thermoplastic polyurethanes. Located in Barcelona, Spain, Merquinsa serves the specialty polymer market, and its products are used in a wide range of applications.

Arizona Chemical Establishes Legal Entity in China JACKSONVILLE, FL – Arizona Chemical announced the formation of the legal entity, Arizona Chemical Limited, a China trading company. Arizona Chemical Limited will operate out of the company’s office in Shanghai, China, and will provide local sales, marketing, technical support, customer service and supply-chain services to its Chinese customers.

Dover Buys RedScrew® Pump DOWNERS GROVE, IL – Pump Solutions Group, a business unit operating within the Dover Fluid Management Segment of Dover Corp., announced the acquisition of Tianjin RedScrew

C OMPANY NEWS

Pump Manufacturing Technology Co. Ltd. The RedScrew Pump manufacturing facility is located in Tianjin, China, in the Hua Yuan Technology Park.

Clariant Strengthens Presence in Asia MUTTENZ, Switzerland/SINGAPORE – Swiss-based specialty chemicals company Clariant strengthened its presence in Asia with the opening of its new regional headquarters for Southeast Asia and the Pacific and its new Global Textile Chemicals headquarters, both located in Singapore. The company also celebrated the inauguration of its newly built ethoxylation plant and application laboratory in Guangdong, China.

Celanese to Buy Product Lines from Ashland Inc. DALLAS – Celanese Corp. announced an agreement to acquire certain assets from Ashland Inc. The agreement includes two product lines, Vinac ® and Flexbond ®. Vinac products are used to make a variety of adhesives for use in woodworking and paper packaging and converting applications. Flexbond products are used to make interior and exterior architectural paints.

LANXESS Purchases U.S. Biocide Specialist LEVERKUSEN, Germany/PITTSBURGH – LANXESS has acquired Verichem Inc., Pittsburgh, PA. The acquisition bolsters the company’s position in the U.S. material protection market

and broadens its global biocide-manufacturing network. LANXESS will gain access to a complementary portfolio of biocides, as well as active ingredients registered with the EPA. The products are used to protect coatings, adhesives, construction materials, and pulp and paper.

Arkema Plans to Buy Specialty Chemicals Business from SEPPIC COLOMBES, France – Arkema announced plans to acquire the industrial applications specialty alcoxylate business of SEPPIC. This new product range would allow Arkema to extend its surfactant range and bolster its positions in industrial niche markets. Plans includes the acquisition of an industrial site located in Antwerp, Belgium, which would become part of the Performance Products business segment and its Specialty Chemicals business unit.

Thermo Fisher Compliant With New ISO Standard for Bromate Analysis SUNNYVALE, CA – Thermo Fisher Scientific Inc. announced that its bromate analysis solutions are fully compliant with the new ISO standard for bromate analysis by ion chromatography (IC) titled, Water quality - Determination of dissolved bromate - Method using ion chromatography (IC) and post column reaction (PCR) (ISO 11206:2011(E)). The standard adds improved limits of detection and simplifies the lab work compared to ISO 15061:2001. 

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technology that’s really deep.

Visit www.arkemacoatingresins.com/SNAP for more information about SNAP™ Structured Nano-Acrylic Polymers. At Arkema Coating Resins, we’re focused on your future.

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NAMES IN THE NEWS  Michael Brice has joined INX International Ink Co. as Director of Business Development. Brice has 26 years of experience in the printing ink industry.

 The Adhesive and Sealant Council (ASC) announced that John J. McLaughlin, President and CEO of DAP Inc., has joined the ASC Board of Directors.

 Pump Solutions Group (PSG), a business unit operating within the Dover Fluid Management Segment of Dover Corp., announced the appointment of Karl Buscher to the newly created position of Senior Vice President, PSG Commercial. Buscher will report directly to PSG President Dean Douglas.

 Robert “Robbie” J. Monlezun Jr. has joined Hoover Materials Handling Group Inc. as Regional Operations Manager for Hoover’s Louisiana Service Center in Broussard, LA. He will be responsible for sales, operations and customer service as well as the expansion of the Broussard facility.

Brice

Buscher

 IMCD Group has opened a regional headquarters in Singapore and appointed Albert Stevens  Arkema Coating Resins has formed a new business function, the Customer Experience Group, as Vice President Asia. The regional office in Sindedicated to building more proactive relation- Fearrington gapore will oversee the corporate and business Sweeney ships with coatings formulators and other cusstrategies in this region. tomers. Karen Fearrington, the previous Business Services Manager for Arkema, will lead the group in her new position as  Color-Logic has named John Sweeney to the Color-Logic AdviDirector of Customer Experience. sory Board. Sweeney has an extensive background in bringing new technologies to market.  Shaleen Freeman has joined Sika as Customer Service Representative responsible for the Transportation, A&C and FFI Busi-  Fusion UV Systems Inc. announced the appointment of Mark ness Unit. Matthew Blain has joined Sika Automotive as Key Tilley to Vice President for Business Development. Before joining Account Manager, OES Sales Group. Fusion, Tilley was the President and CEO of Unidym Inc. 

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Creating Additive Value

COMBINED COMPETENCE

» » » » » » »

MÜNZING Chemie GmbH Salzstrasse 174 74076 Heilbronn GERMANY Phone +49 7131 987-0 Fax +49 7131 987-125 E-Mail [email protected]

Wax dispersions Micronized waxes Defoamers Wetting and Leveling Agents Dispersants Rheology Modiƥers Powder Additives

MÜNZING Liquid Technologies GmbH

MÜNZING Micro Technologies GmbH

Neckartal 140 78628 Rottweil GERMANY Phone +49 741 942 52-0 Fax +49 741 942 52-50 E-Mail [email protected]

Dr.-Bergius-Strasse 18–24 06729 Elsteraue GERMANY Phone +49 3441 829 10-22 Fax +49 3441 829 10-20 E-Mail [email protected]

› www.munzing.com

Conductive Coatings Using Carbon Nanotubes

I

n recent years, requirements for modern coatings have dramatically increased. Besides optical appearance, new functionalities like improved mechanical properties, anti-static behavior or electrical conductivity are desired. To achieve this, several materials can be incorporated into the coating film. For enhanced electrical conductivity, substances like copper or silver particles, conductive organic polymers, or carbon black can be used. In many cases, such materials have to be used in the form of nanoparticles to achieve even distribution inside the film and low percolation thresholds. There are several synthesis routes known to produce such nanoparticles, but they often result in either low yields or in materials that need further processing to show optimum performance. This can lead to high material

TABLE 1 | Two-component clearcoat based on Bayhydrol

A 145.

Material

Content [g]

Component A Bayhydrol A 145 BYK-011 BYK-346 BYK-425 Water

82.5 1.8 0.9 0.2 14.6

Component B Bayhydur 3100 Dowanol MPA

24.7 5.3

Note: Ratio A:B = 3.3:1, adjust pH to 8.2 to 8.5

TABLE 2 | One-component clearcoat based on Worleesol

61 A.

Material Worleesol 61 A Cymel 327* Butyl glycol* Dimethylethanolamine Water BYK-020 BYK-333

Content [g] 47.7 8.6 3.9 2.4 36.7 0.5 0.2

Note: * Premix curing conditions, 20 min flash-off, 30 min at 130 °C, adjust pH to 8.2 to 8.5

prices, and in combination with increasing raw material costs, the overall costs can become prohibitive for some applications. An example of this would be the use of silver. The average price of silver has been steadily increasing during the last few years, and silver nanoparticles are even more expensive. For coatings applications, most companies now focus on non-metallic compounds, like carbon materials, to achieve electrical conductivity. Carbon exists as different allotropes, e.g., diamond, graphite, fullerenes and carbon nanotubes. While diamond consists of sp3 hybridized carbon with a cubic crystal lattice, all other known allotropic forms contain sp2 hybridized carbon atoms, and thus they are preferred for electrical conductivity. Since their observation in 1991 by Iijima, carbon nanotubes have been the focus of considerable research.1 Scientists have since reported remarkable physical and mechanical properties for this fascinating allotrope of carbon.2

By T. Tinthoff, N. Hanitzsch, M. Pickave, J. Tecklenburg, N. Willing and M. Berkei | BYK-Chemie GmbH, Wesel, Germany 16



JANUARY 2012 | W W W . P C I M A G . C O M

From unique electronic properties to mechanical properties that exceed any current material, carbon nanotubes offer tremendous opportunities for the development of new material systems. In particular, the excellent electrical conductivity of carbon nanotubes combined with their high aspect ratio offer potential for the development of functional coatings. This article reports on recent advances in using additives based on carbon nanotubes to enhance the electrical conductivity of several coating systems.

FIGURE 1 | Clear coatings based on Bayhydrol D155 with different concentrations of MWCNT (0%, 0.5%, 1%, 2% from left to right).

Experimental All coatings were applied on glass panels or PET foils with wire bars at 75 μm wet film thickness. After a curing procedure, all panels were stored for 24 h in an acclimatized chamber, and surface resistivity was measured three times at each panel. Starting formulations are shown in Tables 1-3. Multiwall carbon nanotubes from different suppliers were used in the form of aqueous dispersions.

FIGURE 2 | Surface resistivity of different clear coatings with different concentrations of MWCNT 1.

To determine the performance of multiwall carbon nanotubes (MWCNT) in different aqueous coating systems, we used a two-component clearcoat based on Bayhydrol A 145, and two one-component baking systems based on Worleesol 61 A or Bayhydrol D155, respectively. The A 145 system started curing immediately after application, while curing of the baking systems was initiated by elevated temperature. The two baking systems offer different resin chemistries; alkyd/melamine in Worleesol 61 A and polyester/melamine in Bayhydrol D155. The difference between the three systems had an influence on the distribution of MWCNT inside the coating, resulting in different percolation thresholds. In all coatings, dosages of 0.5% to 8.0% MWCNT (calculated on solid resin) were incorporated, and films were applied on glass and PET substrates using wire bars to achieve 75 μm dry film thickness. Films with 0.5% to 2% MWCNT were already quite dark but still translucent, while higher MWCNT concentrations resulted in nontransparent coatings (Figure 1). As seen in Figure 2, the lowest percolation thresholds were observed in the D155 system, followed by the Worleesol 61 A system. Even at low MWCNT concentrations of 0.5% to 2%, anti-static properties were achieved, and concentrations of 2% to 4% MWCNT resulted in electroconductive coatings with surface resistivity below 105 Ω.

TABLE 3 | One-component clearcoat based on Bayhydrol

D155.

Material

Content [g]

Bayhydrol D 155

50.0

Cymel 327 Butyl glycol Dimethylethanolamine Water BYK-025 BYK-307

7.8 4.0 2.0 35.6 0.3 0.3

Note: Curing conditions 20 min flash-off, 30 min at 130 °C, adjust pH to 8.2 to 8.5

Surface Resistivity Ω

Results and Discussion

1.00E+14 1.00E+13 1.00E+12 1.00E+11 1.00E+10 1.00E+09 1.00E+08 1.00E+07 1.00E+06 1.00E+05 1.00E+04 1.00E+03 1.00E+02 1.00E+01 1.00E+00

Worleesol 61 A Bayhydrol A 145 Bayhydrol D 155

0

0.5

1

2

4

6

8

MWCNT 1 Content in %

A possible explanation for this finding follows. The MWCNT were incorporated into the coatings in the form of dispersions in which the carbon nanotubes were homogeneously dispersed and stabilized by wetting and dispersing additives. This perfect distribution was transferred into the coating system. In the two-component system, curing started directly after application, which kept the carbon nanotubes in a very well-dispersed state. It resulted in a higher percolation threshold since many MWCNT were in an isolated position and were not contributing to the percolation network. The baking systems started curing after the flash off time and while applying heat. This enabled the MWCNT to agglomerate on a very small scale to achieve percolation. It can also be described as a kind of self-organization, and it seems that the resin chemistry also contributed to this process. Unfortunately, we could not yet clearly see differences in distribution by REM microscopy to prove this theory. In addition to the influence from the resin chemistry or curing process, there was a significant contribution due to the particle size, aspect ratio and surface chemistry of the conductive pigment itself. We used two different kinds of multiwall carbon nanotubes. The first one, MWCNT 1, exhibited some structural defects and some oxygencontaining groups on the surface. The second one, MWCNT PA I N T & C O A T I N G S I N D U S T R Y



17

Conductive Coatings Using Carbon Nanotubes

2, had less structural defects and a less polar surface, as well as a slightly longer particle length. As a comparison, we used a conductive carbon black, which offered a polar surface and particle agglomerates with low aspect ratios compared to MWCNT. Figure 3 shows that MWCNT 2 offered lower percolation thresholds compared to MWCNT 1 in the D155 system. To achieve the same level of surface resistivity, one would have to use between 8% to 10% carbon black, 2.5% MWCNT 1 or 1.5% MWCNT 2. This effect becomes even more predominant in the Bayhydrol A 145 system where MWCNT 1 gave almost no surface resistivity improvement. Due to their more polar particle surface, the carbon nanotubes kept their well-dispersed status inside the two-component clearcoat system and even at high concentrations of 8%, there was almost no improvement in conductivity. The MWCNT 2 had a higher aspect ratio and resulted in a percolating network, exhibiting surface resistivity of 106 Ω at a MWCNT 2 concentration of 6%. It is obvious that the performance of carbon nanotubes as well as any other conductive pigment strongly depends on several parameters. First, is the interaction between the conductive pigment and the coating matrix. If the affinity of the resin to the conductive pigment is too high and the conductive pigment stays in a perfectly dispersed status, the formation of a percolating network is hindered. Therefore, the conductive pigments should be used in the form of dispersions to guarantee a good initial dispersion status. In addition, the wetting and dispersing additives used have to guarantee good stabilization as

Surface Resistivity Ω

FIGURE 3 | Surface resistivity of clearcoat system based on Bayhydrol D155 with 1.5% different conductive pigments. 1.00E+13 1.00E+12 1.00E+11 1.00E+10 1.00E+09 1.00E+08 1.00E+07 1.00E+06 1.00E+05 1.00E+04 1.00E+03 1.00E+02 1.00E+01 1.00E+00

FIGURE 5 | SEM image of a coating surface containing 0.1% carbon nanotubes.

1 μm

well as suitable compatibility towards the coating matrix. Percolation will take place when the conductive pigments are allowed to agglomerate on a molecular state, still keeping a good distribution. Strong flocculation has to be avoided; otherwise the necessary amount of conductive pigments would be too high. There has to be a good balance between optimum distribution and minimum agglomeration. The second point to be considered is to use conductive pigments with high aspect ratios to achieve percolation at low concentrations. Therefore we believe that carbon nanotubes can offer a strong benefit compared to carbon blacks due to their structural uniqueness (Figure 4). Compared to organic anti-statics (for example, those based on quaternary ammonium salts), conductive pigments offer permanent anti-static or electro-conductive behavior to coatings. Quaternary ammonium salts can create a thin water film on the surface due to their high polarity, but their ions can migrate out of the coating matrix, often resulting in decreasing performance over time. Carbon nanotubes, especially, can overcome this drawback due to their high aspect ratio and their entanglement tendency. Figure 5 shows the surface of a clearcoat with 0.1% carbon nanotubes. The carbon nanotubes appear on some spots on the surface and disappear into the matrix again to form a three-dimensional network. This guarantees good surface conductivity, and the carbon nanotubes are strongly fixed into the matrix.

Conclusion Control

Carbon Black

MWCNT 1

MWCNT 2

FIGURE 4 | Structural differences between agglomerated carbon black (left) and a skein of carbon nanotubes (right) shown by SEM micrographs.

To increase the conductivity of coatings, carbon nanotubes can offer an interesting alternative to the classical conductive pigments like carbon black or metallic particles. To get the optimum benefit from this fascinating material they should be incorporated into the coating in the form of dispersions to guarantee optimum distribution. In addition, the right wetting and dispersing additives have to be used to enable percolation and compatibility with the coating matrix. Further investigations will be done to enable coatings manufacturers to predict the interaction between coating ingredients and the carbon nanotubes and the resulting performance. 

References 1

200 nm

18



200 nm

JANUARY 2012 | W W W . P C I M A G . C O M

2

Iijima, S. Nature 354 (1991) 56−58. Collins, P.G.; Avouris, P. Scientific American 283 6 (2000) 62–69.

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Editor’s Note: This article is the second installment in a four-part series on Integrated Tinting Systems.

ITS)SERIES

The Low-VOC Future New Opportunities in Tinting System Design

I

n the past, retailers were fined for selling paint that exceeded the legal VOC limits. Limits are set both for ready-to-use paint and for the colorants used in the tinting of base paints. In 2011, the South Coast Air Quality Management District (SCAQMD) introduced a regulation to reduce VOC levels in colorants for architectural coatings (excluding maintenance coatings, which are not water-based) to 50 g/L effective January 1, 2014. The VOC limit for colorants used for tinting solvent-based industrial maintenance coatings remains at 600 g/L. Action is therefore required by paint producers to convert their tinting systems to low- or no-VOC colorants. Most U.S. paint producers operate a standardized, universal, 12-colorant tinting system, for which VOC-free alternatives are readily available to pour over the existing set. While this sounds easy and convenient, paint producers are well advised to seek the support of tinting systems experts with many years of experience in low-VOC tinting system conversions. European legislation started setting VOC limits for colorants as early as 1999, which is why there are companies that have been carrying out successful conversions for more than a decade.

FIGURE 1 | Ingredients of different colorant technologies.

VOC-containing solvents (e.g. Glycol) Water

Colorants that Deliver a Competitive Advantage

Additives and thickeners Fillers and extenders Colored pigment

Glycol-based colorant

Certainly for the professional end user, paint properties are as important as color accuracy. Professional users demand consistency in gloss levels, dry times and application characteristics such as viscosity, brush feel or sag resistance. These properties can all be affected by colorants, particularly colorants that contain a higher percentage of water such as is found in low- or no-VOC colorants. Low- or no-VOC colorants may be coloristically identical to their glycol-containing counterparts, however, they will behave differently in the dispensing equipment and in the base paint. This may only become apparent months after the pour-over conversion; after the freshly introduced colorant has been in the machine for a period of time. Paint producers frequently start to notice clogged-up nozzles or deteriorating colorant quality in the canisters. This is because VOC-free colorants no longer contain the glycol that acted as both a lubricant and a preservative. What’s more, the additive package in low- and no-VOC colorants has also been altered to achieve the necessary VOC levels. These chemical adaptations will inevitably perform differently in the base paint and may become noticeable in the performance of the tinted product (Figure 1). Any potential long-term problems resulting from these differences can be best managed by choosing the right colorant provider who can take long-term responsibility for the functionality of the complete system. Such a partner should be able to provide support for the tinting system as a whole, including colorants, equipment, color formula development, database management and color control software. Importantly, when trouble happens in the field, paint retailers need an extensive, professional service team equipped to diagnose and resolve tinting system problems, quickly and accurately, regardless of origin.

Zero-VOC colorant

Because the mandatory conversion to a low-VOC future necessitates a colorant technology change, this is the ideal time for paint producers to look beyond the standard 12-colorant offering for tinting system solutions that deliver sustainable advantages. Having the exact same colorant set as your competitor may give a sense of security; it does not offer a competitive advantage. Working with a partner who can design a system tailored for your unique business objectives will elevate the performance of your tinting system from “staying alive” to “soaring above.”

By Bart Wilbanks, Technical Account Manager, Colorants, and Emily Koch Valencia, Senior Manager Global Marketing | CPS Color, Concord, NC 20



JANUARY 2012 | W W W . P C I M A G . C O M

Increasing Color Space Each tinting system has a maximum achievable color space: in other words, the hues and shades that can be created by mixing together the different colorants within the set. Paint retailers aim to offer the widest possible range to satisfy every conceivable customer demand. However, most U.S. paint vendors offer exactly the same color space because they use identical sets of 12 universal colorants. A paint manufacturer able to tempt customers with a larger, more differentiated color offering will have a clear competitive advantage. By modernizing a colorant set to include some of the newer pigment options, paint producers can expand their available color space while achieving technical superiority versus conventional pigment types. As an example, Red 254 is a clean shade, able to reach important trend colors in the red range, at a good price performance ratio. Selectively altering just a couple of well-chosen colorants can provide paint manufacturers with a broader color space in key ranges such as yellow/orange or vibrant reds while still maintaining a 12-colorant set. For producers seeking an even more dramatic increase in color space, expanding from a 12-colorant set to a 16-colorant set can provide the richness and variety of colors that will help attract discerning customers such as designers and architects. This sort of change requires careful planning and partnership with your tinting solutions provider, as it has impact downstream on the entire tinting system operation. Implementation of an expanded tinting system isn’t easy, but it is also not easily duplicated. Therefore, forward-looking producers and retailers can expect a sustainable competitive advantage in color. Figure 2 compares the standard 12 colorants used in the United States to a 16-colorant system optimized to enhance color space. It shows three slices along the L (lightness) axis: • L = 90: Here we see that the 16-colorant system allows for approximately 50% greater color space in the yellow/green quadrant. This is particularly beneficial to paint manufacturers looking to expand color space in the pastel region. • L = 65: We see a noticeable increase in color space in two quadrants with this 16-colorant system. It shows approximately 15% additional color space in the yellow/ green region and about 10% increased color space in the yellow/red quadrant. This allows paint shops to offer brighter, cleaner oranges, reds, yellows and greens. • L = 40: In the darker region, it is sometimes difficult to match custom shades with the standard 12-colorant system. Dark violets and rich blues are growing in popularity, and this chart shows that the 16-colorant system allows an additional 35% - 40% color space in the red/ blue quadrant to achieve these popular colors.

Benefits of High- and Low-Strength Colorants Colorant types can be differentiated in terms of pigment load. Low black, for example, may contain 5% pigment,

medium black 15% and high black 30%. Obviously, less colorant of a high-strength variety is needed to achieve the same, or greater, richness of color than would be the case with a low-strength colorant. Highstrength colorants therefore create a more economical system when highly saturated colors are important to a paint manufacturer’s business. Additionally, creating a highly saturated color using a standard colorant system requires adding a very high colorant load to the base paint. The result can often have a negative effect on paint properties such as gloss level, dry time and application characteristics. There are equally good reasons for adding low-strength colorants to a tinting system. They are invaluable for manufacturers with a high demand for tinting pastel shades. Smaller store keepers using manual dispensers, in

FIGURE 2 | Color space analysis; 12 versus 16 universal colorant system. 90 b* 80 70 60 50 40 30 20 a* -80 -70 -60 -50 -40 -30 -20 -10 0 1010 20 0 -10 -20 -30 -40 -50 -60 -70 -80 -90 90 b* 80 70 60 50 40 30 20 a* -80 -70 -60 -50 -40 -30 -20 -10 0 1010 20 0 -10 -20 -30 -40 -50 -60 -70 -80 -90 90 b* 80 70 60 50 40 30 20 a* -80 -70 -60 -50 -40 -30 -20 -10 0 1010 20 0 -10 -20 -30 -40 -50 -60 -70 -80 -90

30 40 50

60

70

80

30 40 50

60

70

80

30 40 50

60

70

80

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



21

The Low-VOC Future: New Opportunities in Tinting System Design

particular, may find it difficult to compete with the big boxes that can offer sample sizes of all colors. Manual dispensers dispense in minimum units of 1/48 of a fluid ounce, which is well below the precision achievable with modern automatic dispensing equipment. The dispensable unit size is simply too large to achieve accurate lighter shades, especially in small containers such as sample sizes. Low-strength colorants are therefore an extremely useful addition to a colorant set to improve tinting accuracy. Even retailers with modern, high-precision dispensers find that formulating pastel shades with low-strength colorants enhances both accuracy and reproducibility. This is because it minimizes the negative consequences of poorly maintained dispensing equipment that can cause mis-tints, which are particularly noticeable in light or pastel shades. Using low-strength formulations for slower-moving colorants can also improve turn over, keeping the colorant in the canisters fresh and, therefore, limiting the chances of mold growth and clogging. Depending on the individual needs of the paint manufacturer, a colorant set utilizing a combination of high- and lowstrength colorants may be the optimal solution to increase competitiveness and reduce cost.

Façade Applications There are special product lines, for example façade coatings, where the colorants need to be fine-tuned for optimal product performance. Specialized façade tinting systems are formulated

to have lower surfactant amounts and therefore less impact on the physical properties, such as viscosity and water resistance, of these very thick materials. Colorants that are optimized for use in these highly alkaline product technologies are extremely durable and stand up well to exterior exposure without fading. That is because façade systems are manufactured with inorganic pigments, which have larger particle sizes than organic pigments and won’t break down or wash out like organic materials. Façade colorants also have high chemical resistance and weather better than their organic counterparts.

Technology-Specific Colorants for High-Performance Coatings In order to achieve the best technical performance in highperformance coatings, compatibility between base product and colorant system needs to be optimized. One method of optimizing compatibility is to formulate the colorants with the same resins and solvent system that is found in the base paint. Even in color formulas that require a large pigment load, such as deep or highly saturated colors, technology-specific colorants help protect the paint’s performance characteristics. Importantly, colorants formulated with resins require base paints formulated and filled to accept those resins. In this way, paint manufacturers have a higher level of color control since they can ensure that their products will be tinted with the specified colorants.

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JANUARY 2012 | W W W . P C I M A G . C O M

Resins are particularly beneficial in specialist applications; for example epoxy-based products, such as those used for floor coatings. Adding an epoxy resin to the colorant will make the colorant link in with the chemical composition of the base material and improve its physical properties. However, epoxy resins only work with epoxy coatings. Again, the use of resins therefore needs to be matched carefully to the base formulation and designed to achieve the producer’s business objectives.

FIGURE 3 | A TDF line.

In-Plant Tinting Solutions In-plant tinting with liquid colorants is an excellent way of adding color to base paints in large batches that achieves much more accurate, repeatable and reliable results than pastes or dispersions. The amount of colorants to be added can be either controlled gravimetrically, just like traditional pastes, or volumetrically, which enhances the speed of the operation while maintaining a high level of accuracy. Point-of-sale (POS) tinting typically serves a large color space for a wide variety of paint products that are dispatched in small amounts. In-plant tinting, in contrast, typically deals with fewer colors but larger amounts of paint. There are tailor-made colorant ranges specifically designed for in-plant use, which are available in both solvent- and water-based technologies, such as the Solvasperse and Hydrasperse lines from CPS Color. These in-plant systems generally offer a more competitive price in the end tint than equivalent point-of-sale product lines. The high concentration of these colorants provides a lower overall tinting cost, while the high turnover associated with in-plant equipment ensures that the less desirable effects of high concentrated colorants, namely tip-drying and clogging of canisters, are avoided. Inplant tinting also deals with a more finite color range than POS tinting. Manufacturers who maintain a strong ready mix assortment find in-plant colorants to be an economical and highly efficient way to support these programs since they ensure a good balance between price and performance.

Tinting During Filling Tinting during filling (TDF) is an innovative way to produce and fill tinted paint directly into the final packaging, treating each can as an individual batch. Dispensing the right amount of base paint and colorants directly into the can eliminates many further steps in the production process, such as cleaning and rinsing of movable tanks. Tinting during filling is more economical and efficient than producing small batches of tinted paint product in the factory through traditional production methods. Small batches of frequently used colors, such as those in new home construction, or specified colors for large construction jobs, are ideal candidates for TDF. Producing these colors in a traditional production process requires smaller, inefficient batch sizes, which create a drain on production and quality control lab resources. Exact color specifications are highly controlled even when multiple pails are required to complete an order. This high level

of accuracy is achieved through a combination of both gravimetrically and volumetrically controlled dispensing mechanisms. In addition, TDF lines minimize color inconsistencies as human errors are eliminated from the automated process (Figure 3). TDF lines allow manufacturers to produce the right amount of any color, just-in-time, reducing finished goods stock. This is important for large construction jobs, where often the original color spec may change after the job has begun, creating wasted paint that has to be disposed of or reworked. By placing a TDF line in a central distribution center, the delivery speed of the final product to the end user is improved, and order lead times are minimized.

Conclusions Converting to a low- or no-VOC system requires careful analysis of the needs of the individual business, aligning business objectives with system capabilities. Working with a partner who has experience in converting customers from glycol-containing systems to VOCfree colorant systems will ensure a smooth transition. Additionally, choosing a partner with the comprehensive resources necessary to implement a truly integrated tinting system will prepare the business for current and future regulations, while providing a system that will serve the paint manufacturers’ business needs for years to come. Such a partner can also help find a solution that is more powerful and cost-effective than the previous system. When looking for a new set of VOC-free colorants, best price may not equal best value. In the next article in this series, we will explore the contribution made by equipment within the tinting system. Choosing the right dispensers, mixers and shakers to match your colorant set while best serving your customers’ needs will further enhance your business competitiveness.  For additional information, contact Bart Wilbanks, Technical Account Manager, Colorants, CPS Color, at 800/728.8408, ext. 240. PA I N T & C O A T I N G S I N D U S T R Y



23

Siloxane Based Multifunctional Additives An Innovative Approach Toward Formulating

T

he challenges of substrate wetting and flow are especially problematic for formulators of water-based coatings.1-4 Creating a closed, defect-free aqueous coating film is difficult not only on common low-energy substrates like plastics, but also when wetting a high-energy substrate such as metal, since it may not always be clean or free of surface contaminants. Wetting on wood can be critical because wood needs proper penetration into pores and grains, and often contains natural oils. Substrate wetting additives – special surfactants that modify interfacial tensions – are commonly used to overcome such problems. Generally, they reduce the surface tension of a coating to a homogeneously low level, enabling the coating to wet the substrate successfully. Very strong surface tension reduction is required to achieve satisfactory wetting over oily and greasy contaminants. However, the same substrate wetting additives that dramatically reduce surface tension often cause a significant degree of foam and air entrapment. Through an innovative development in additive technology, a siloxane based multifunctional approach can now achieve surface tension reduction while providing a defoaming effect.

Existing Additive Technologies Many different technologies5,6 are used to supply the coating and ink industries with effective substrate wetting additives. As seen in Table 1, different property

TABLE 1 | Classes of conventional substrate wetting additives. Surfactant Oligomeric siloxane Special branched polyether Sulfosuccinate Fluorocarbon Acetylenic diol derivative

Substrate Wetting Properties (Static)

Defoaming Properties

Additive Levels

Excellent Neutral Good Excellent Neutral

Inferior Good Very Poor Very Poor Good

Good Neutral Neutral Excellent Neutral

profiles make the various classes more or less suitable for diverse applications. Some of these additives provide very strong surface tension reduction, enabling substrate wetting even on contaminated substrates. At higher addition levels they also tend to stabilize foam. This is especially true for fluorocarbon surfactants, but may, to a lesser degree, also apply to siloxane based surfactants. There are some organic surfactants that show hardly any foaming or are even slightly defoaming. However, these are not very effective surface tension reducers and tend to fail when applied to very low-energy substrates or contaminated ones. As with most additives, usage level is critical. When considering the degree of surface tension reduction needed, effectiveness at low usage levels must also be considered. An additive that is effective at low usage levels is ideal both with regard to cost benefit ratio as well as successful creation of a defect-free coating film.

Development of a Defoaming and Highly Surface-Active Substrate-Wetting Additive When discussing targets for development, Evonik’s team considered the following criteria most important: • Providing strong surface tension reduction for good substrate wetting; • Being effective at very low addition levels; • Providing a distinct defoaming or foam-neutral effect in most water-based coatings; • Being ecologically friendly. The development team knew that siloxane based surfactants could provide strong reduction of surface tension. Studying literature about surfactant behavior, it found that “Gemini” structures, discussed by Fredric Menger8 in 1991, can show high effectiveness at very low levels and potentially contribute to low foaming properties.9,10 The selection of relatively hydrophobic structures suggested additional defoaming properties. As a result, the idea of a multifunctional additive based on a combination of siloxane and Gemini technology was devel-

By Christopher Howard, Wernfried Heilen, Kai Steenweg and Susanne Struck | Evonik Industries, Coating Additives, Hopewell, VA 24



JANUARY 2012 | W W W . P C I M A G . C O M

oped. This combination allowed for dramatic surface tension reduction while also aiding defoaming and avoiding air entrapment. As such, Evonik’s “Twin” technology was born. When selecting potential raw materials and resulting structures, the team paid particular attention to the structure’s ecological impact, such as water pollution. Developing a molecule with minimal to no influence on the VOC of the finished coating system was also important.

FIGURE 1 | Conventional single-tail surfactant and a Gemini surfactant.

Selecting the Right Structure

Initial Test Results Comparing the characteristics of this additive group with existing technologies produced impressive data that underline the special behavior of this new Twin technology. The siloxane based multifunctional additives D and E show very low critical micelle concentration as well as the lowest static surface tension readings of all surfactants tested (Table 3). However, this data is suitable only for characterizing the additive’s behavior when it is the only ingredient in water. To be an effective substrate wetting agent in coatings formulations requires that the additive show the same properties in the presence of other surface-active ingredients, such as an emulsifier or dispersing agent. This is especially true since some of the tested additives, including the Twin siloxane based multifunctional types, are hydrophobic and not homogenously soluble in pure water. What ultimately matters is performance in a practical application.

FIGURE 2 | Twin siloxane based multifunctional additive structures.

FIGURE 3 | Static surface tension reduction of various water-based coat-

ings.

50

Silicone-Based Multifunctional Structure D

45 mN/m

Gemini surfactants in literature are also called bis- or double-tailed surfactants.7,8,10 They are characterized by at least two hydrophobic chains, two ionic or polar groups, and the presence of a spacer. The spacer can be of various chemical natures, such as a simple alkyl chain, a polyoxyalkylene segment or an aromatic unit. Most Gemini surfactants are symmetrical structures, as shown in Figure 1. Compared to conventional surfactants, Gemini types display very different aggregation behavior. This results in significantly lower critical micelle concentration (CMC) and far higher surface activity (a factor up to 100x/1000x), making them quite efficient.11-13 Depending on their structure, they can also significantly reduce foam stabilization. By combining different in-house technologies, Evonik’s team was able to synthesize structures of the Twin siloxane based multifunctional additives for evaluation, as shown in Figure 2. Varying the structural parameters, the nature of the polar groups and the overall molecular weight, several different species were obtained that displayed distinctly different performance. For screening purposes, all structures were tested in multiple water-based resins for desired properties. Table 2 summarizes the variety of performance obtained. It is clear that Structure D and Structure E provided specific properties that perfectly matched the team’s original criteria. Structures D and E were selected for the basis of this experiment as the optimal molecules for further evaluation.

Silicone-Based Multifunctional Structure E

40 35

Acetylene Diol Derivative

30

Organic Gemini Type

25 20

Control

Acrylic Styrenated Aqueous UV Urethane Wood Plastic Urethane Acrylic Coating Coating Wood Overprint Coating Varnish

Modified Acrylic Coating

TABLE 2 | Comparing siloxane based multifunctional additives in a waterbased resin. Surface Tension Reduction (DuNouy) Structure A Structure B Structure C Structure D Structure E

Good Excellent Good Excellent Good

Substrate Effectiveness Wetting Inferior Excellent Neutral Good Excellent

Good Neutral Good Good Good

Defoaming Properties Excellent Inferior Neutral Good Neutral

TABLE 3 | Properties of surfactants in water. Surfactant Siloxane based multifunctional Structure D Siloxane based multifunctional Structure E Oligomeric siloxane Polyether Sulfosuccinate Fluorocarbon Acetylenic diol derivative

Static Surface Tension (mN/m)

CMC (mg/L)

Appearance 0.5% Additive in Water

20.4

89.4

Very turbid

22.1

147.3

Very turbid

24.2 29.4 25.6 22.3 29.2

848.5 370.8 1194.3 31.6 547.5

Very turbid Turbid Clear Clear Turbid

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



25

Siloxane Based Multifunctional Additives

Surface Tension Measurements Comparing the surface tension reduction of both siloxane based multifunctional additive structures to other commercially available substrate wetting additives clearly demonstrates how effective they are. As seen in Figure 3, the siloxane based multifunctional additives D and E provide an exceptionally strong reduction of static surface tension throughout a range of water-based coatings (measured at an addition level of 0.2% surfactant by the DuNouy ring method). Yet, because every resin and coating system performs differently, it was important to capture data from a variety of test formulations. In all five coating systems, both siloxane based multifunctional

FIGURE 4 | Static surface tension in water-based acrylic urethane wood

coating.

Wetting Properties

40.0 38.0 36.0 mN/m

additives reduced static surface tension significantly better than the other competitive additive systems. As discussed previously, effectiveness at low addition levels is very important for both the cost benefit ratio as well as achievement of a defect-free coating film. At different addition levels, the extreme effectiveness becomes even more obvious. The tested siloxane based multifunctional additives already create a very strong surface tension reduction at addition levels below 0.1%, as shown in Figure 4. Multifunctional TEGO® Twin 4000 (Structure D) produces a slightly lower static surface tension than multifunctional TEGO Twin 4100 (Structure E). In addition, these siloxane based multifunctional structures improve wetting properties in a variety of application tests and spray methods.

34.0 32.0 30.0 28.0 26.0 24.0

0.00%

0.05%

0.1%

0.2%

0.3%

0.5%

Concentration (%) Siloxane Based TEGO Twin 4000 (Structure D)

Conventional Siloxane

Siloxane Based TEGO Twin 4100 (Structure E)

Organic Gemini Type

FIGURE 5 | Microscopic view of a metallic topcoat on a white primer. Closed Film

For spray application, the coating should ideally form a closed film at low film thicknesses. This ensures a defectfree film and maximizes the application window of the coating. Formulators can achieve this result by using a substrate wetting additive that ensures fine atomization at the spray nozzle and good wetting of coating droplets upon hitting the substrate surface. Interesting results were obtained with spray robot application of a metallic topcoat on filler-coated panels at a very low film thickness (approx. 15 μm dry) (Figure 5). As demonstrated in the photomicrographs, TEGO Twin 4000 (Structure D) created a completely closed film at very low film thickness. It is important to note that this closed film was achieved with very low usage levels of the siloxane based multifunctional additive. This system used only 0.1% of this novel additive structure as compared to other candidate products. Although not shown, the siloxane based multifunctional additive TEGO Twin 4100 (Structure E) also had excellent wetting and a closed film. Figure 6 illustrates the excellent wetting properties of the twin structures compared to a conventional siloxane for a water-based flexo ink.

FIGURE 7 | Foam test in an acrylic urethane water-based

coating.

Control (Without Additive)

Conventional Siloxane

TEGO Twin 4000 (Structure D)

FIGURE 6 | Water-based flexographic ink on polyolefin release film.

Complete wetting!

Control (Without Additive)

26



Conventional Siloxane

Siloxane Based TEGO Twin 4000 (Structure D)

Complete wetting!

Siloxane Based TEGO Twin 4100 (Structure E)

JANUARY 2012 | W W W . P C I M A G . C O M

Control (Without Additive)

TEGO Twin 4000 (Structure D)

A quick test to demonstrate foaming properties of a coating is the Tego standard stir test. In this test, 50 g of coating are stirred at 3000 rpm for 1 minute by a 3 cm dissolver blade. Immediately after mixing, 45 g of coating are poured into a graduated cylinder and the volume is read. Lower volume reading results in less foam that has been entrained. Performing this stir test with a waterbased wood coating based on an acrylic urethane emulsion produced impressive results. The control without any additives had a reading of 76 mL/45 g, whereas the sample containing 0.1% of TEGO Twin 4000 (Structure D) had a reading of 46 mL/45 g (Figure 7). Considering the density of the formulation, it was nearly foam-free. As shown in Figure 8, the siloxane based multifunctional additive TEGO Twin 4000 (Structure D) provided effective foam prevention at low usage levels. As performed with previous formulations, this one was also tested in a variety of coatings systems. The chart displays TEGO Twin 4000 influence on the foaming behavior of various water-based coatings in comparison with additive TEGO Twin 4100 (Structure E), an oligomeric classical siloxane surfactant, an acetylenic diol derivative, and an organic Gemini surfactant. TEGO Twin 4000 (Structure D) performs quite well in all five water-based coatings systems. Similar to the previous testing in Figure 3, the additive usage level was 0.2%. As shown in Figure 8, some additive types actually contributed to more foaming than occurred in the control, which had no additive at all. This once again illustrates the need for a multifunctional additive that not only lowers static surface tension but also possesses a defoaming to foam-neutral mechanism. Although the siloxane based multifunctional additive TEGO Twin 4100 (Structure E) possessed slightly weaker defoaming ability, it was either foam-neutral or foam-stabilizing in all coatings systems tested. Figure 9 compares the defoaming effect of the Twin 4000 (Structure D) compared to an oligomeric siloxane in a urethane wood coating spray application. Another interesting property with regard to foaming is the much faster foam break-down that could be observed in water-based coatings and inks containing either TEGO Twin 4000 or the TEGO Twin 4100 formulation (Figure 10). Figure 11 illustrates complete wetting when using TEGO Twin 4100 (Structure E) compared to an acetylenic diol.

Summary We can state that TEGO Twin 4000 (Structure D) significantly reduces the build-up of macro- and microfoam, and speeds up the foam-break and deaeration in water-based coatings and inks. Siloxane based multifunctional additives have been successfully introduced in the market. Surface defects were rarely obtained and those occurred only in a few formulations with very low solids content. TEGO Twin 4000 (Structure D) has greater defoaming efficiency than TEGO Twin 4100 (Structure E) due to its more hydrophobic nature. However, TEGO Twin 4100 (Structure E) has superior substrate wetting while creating a defoaming or foam-neutral environment. To evaluate these additives, Evonik highly recommends adding these products without any other substrate wet-

FIGURE 8 | Results of the Tego foam test with various water-based coatings. Volume in mL

Defoaming Properties

70 65 60 55 50 45 40

Siloxane Based TEGO Twin 4000 (Structure D) Siloxane Based TEGO Twin 4100 (Structure E) Siloxane Surfactant Acetylene Diol Derivative Organic Gemini Type Control

Acrylic Styrenated Aqueous UV Urethane Wood Plastic Urethane Acrylic Coating Overprint Coating Wood Varnish Coating

Modified Acrylic Coating

FIGURE 9 | Comparison of defoaming effect in a urethane wood coating.

Control (Without Additive) Oligomeric Siloxane

TEGO Twin 4000 (Structure D)

*Air-Assisted Airless Spray Application

FIGURE 10 | Foam prevention after 15 minutes of high-shear stirring of an overprint varnish.

Control (Without Additive)

TEGO Twin 4000 (Structure D)

FIGURE 11 | Overprint varnish on lithographic printing ink. Complete Wetting

Control (Without Additive)

Acetylenic Diol

TEGO Twin 4100 (Structure E)

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



27

Siloxane Based Multifunctional Additives

ting additive and defoamer. Further addition of defoamer either may or may not be necessary. When using one of these siloxane based multifunctional additives, an overall reduced additive amount in the coating or printing ink formulation can be expected due to the “two-in-one” character of this additive class.

Initial tests in energy-curable and somewhat polar solvent-based coatings indicate that the siloxane based multifunctional additives act as amphiphilic surfactants in these formulations as well. Even though the surface tension reduction is significantly lower than in water-based formulations, it contributes

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to improved substrate wetting and flow characteristics. Additional advantages of this innovative surfactant are its good ecological qualities. The product is free of organic solvent additions and therefore, will have minimal contribution to the VOC of the coating system.

Conclusion The tested siloxane based multifunctional additives each combine very high surface activity, good substrate wetting and effective defoaming in one molecule. It is most promising for water-based formulations that would normally require both a substrate wetting additive and a defoamer. The testing isolated two unique molecules that provide a multifunctional, “two-inone” property profile. TEGO Twin 4000 (Structure D) provides both good substrate wetting and high defoaming efficiency. TEGO Twin 4100 provides superior substrate wetting while creating a defoaming or foam-neutral environment. With this unique and patented technology, property profiles can be obtained that were impossible to achieve with any conventional technology. It is highly probable that this innovative siloxane multifunctional technology will enable us to develop further powerful additives with unique property profiles. 

References 1 2 3 4

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r

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Freedonia, Phaenomen Farbe 4 2001. Monteny, J.P. Farbe & Lack 4 2002, 18. Koenig, G. and Lazerme, P., Farbe & Lack 11 2002, 76-82. Streitberger, H.J. and Goldschmidt, A. Besser Lackieren 19 2002. Dorfler, H.D. Grenzflaechen und kolloiddisperse Systeme, Springer-Verlag Berlin Heidelberg 2002, 329-340, 368-371. Ingenieurbüro Kern, Das Wasser, Infos zu Tensiden www.spiralex.de. Kim, Y.K. Dissertation an der Universität Freiburg/Breisgau, 2001. Menger, F.M. and Littau, C.A. J. Am. Chem. Soc. 1991, 113, 1451-1452. Castro, M.J.L.; Kovensky, J. and Cirellie, A.F. Tetrahedron Letters 1997, 38, 39953998. Rosen, M.J. and Lio, L. JAOCS 1996, 73, 885-890. Pestman, J.M.; Terpstra, K.R.; Stuart, M.C.A.; Van Doren, H.A.; Brisson, A.; Kellogg, R.M.; and Engberts, J.B.F.N. Langmuir 1997, 13, 6857-6860. Rnouf, P.; Mioskowski, C.; and Lebeau, L. Tetrahedron Letters 1998, 39, 1357-1360. Menger, F.M. and Keiper, J.S. Angew. Chem. 112 (200), 1980-1996.

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Photo: Clariant

Improving Powder Coating Aesthetics and Performance

T

he term “wax” does not actually describe a class of chemical substances. Rather, it is a collective term for all materials that display typical wax properties. Waxes are used to provide abrasion resistance in printing inks to ensure that the ink remains on the substrate and is not rubbed off. In conventional paint systems and in powder coatings, waxes provide improved scratch resistance, very good matting and good slip properties. Used as a dispersion aid in master batches, waxes permit an even distribution of the pigments.

New PTFE-Free Structuring Agent In recent years, Clariant introduced Licocene®, a range of polyolefin waxes that act as dispersing and carrier agents for pre-mix formulations. Licocene grades are low-molecular-weight polyolefins, and are produced with the help of metallocene catalysts. This proprietary process makes it possible to produce custom-made solutions to meet specific industry requirements. Now Clariant has introduced a new PTFE-free structuring agent. Licocene PE MA 4351 FG (Fine Grain) makes it possible to create powder coatings with unique structuring effects, matt finishes and exceptional edge covering for surface protection. Based on the company’s Metallocene Technology platform, this fine grain, maleic anhydridemodified PE wax additive offers a combination of benefits. Tobias Niederleitner, Technical Marketing Manager at Clariant, explains, “Although initially the development was started to create an effective solution that does not rely on PTFE, which is currently in short supply, Licocene PE MA 4351 has brought a step-change in performance to the powder coatings market. From now on, coatings manufacturers no longer need to compromise on effects such as structured surfaces, degassing and adhesion improvement when developing high-performance powder coatings.”

Powder coatings are used extensively to coat metal in a wide range of end-user applications, from washing machines to bicycle frames. In order to do this, powder coatings formulators traditionally use PTFE to help create a structured surface that has good matting characteristics and avoids fingerprints. A key benefit of Licocene PE MA 4351 is that, by adjusting the wax concentration, powder coatings producers can create different gloss and structuring properties. As a result, coatings that meet market preferences for structured, glossy surfaces or rough, textured surfaces with a no-fingerprint effect can be achieved. Moreover, by improving the flow properties of a powder coating during curing, the wax additive eliminates the potential for bead formation along edges and lips of the metal component being coated. This allows the coating to flow smoothly over the edge for a consistent finish, helping to remove potential corrosion attack points and achieving a consistent finish. It should be noted that the Licocene PE MA structuring effect only works in combination with TiO2. Clariant is currently introducing the new Licocene product around the world, and customers are in the process of sampling it in a number of applications. According to Niederleitner, the market has welcomed the fact that there is an alternative solution to using PTFE. “In addition, Licocene PE MA 4351 also opens up a number of new application opportunities. For instance, formulators can now also create a sandpapersmooth modified surface – and some customers are already using it to improve flow properties.” While there are a number of minor drawbacks (powder coatings will have to be reformulated, and there are some issues creating black powder coatings), the benefits are significant. Licocene PE MA 4351 can be used to make glossy, structured surfaces ‘glossier’ by adjusting

By Tobias Niederleitner, Technical Manager | Clariant Produkte (Deutschland) GmbH, Gersthofen, Germany 30



JANUARY 2012 | W W W . P C I M A G . C O M

the formulation, meeting a current market trend. And with better flow properties for improved edge covering, better coatings are now possible.

Ceridust® In addition to Licocene PE MA 4351, Clariant also recently introduced wax additive Ceridust 6050 M, which represents a pioneering advance in surface adhesion without compromising high-level protection and/ or aesthetics. The term Ceridust is used exclusively for micronized waxes which, due to a special process, take the form of extremely fine powder and are consequently very easily dispersible. The d50-value for this type of wax can be as low as 5 μm. This micronized polypropylene (PP) wax offers an unrivalled combination of effects for powder coatings due to the narrow molecular weight distribution, which is created by the metallocene technology. Ceridust 6050 M delivers improved surface adhesion: silicone-based sealants remain permanently adhered to a powder coating with 2% Ceridust 6050 M. In addition to being able to apply silicon sealant permanently, Ceridust is also able to deliver better adhesion of overcoatings.

Ceridust 6050 M acts as a degassing agent in powder coatings, creating no pinholes (at 2%) and a consistent surface with better protection. The lack of pinholes improves surface appearance, and low gloss levels meet market trends for matt surfaces.

Sustainability A key consideration today is minimizing the gap between ecology and economy by focusing on sustainability aspects such as the environmental, safety and health impacts of our activities at all life cycle stages, from the development of product concepts, to disposal and recycling. Clariant applies its sustainable chemistry to create solutions that save money, improve products and the impact on the environment. Ceridust 7820 TP is one example – a renewable-based micronized wax with interesting properties for powder coating applications. Its combination of properties includes excellent degassing and almost no matting. Niederleitner concludes, “We can expect yet more innovation both in the field of metallocene technology as well as in sustainability. The possibilities of the technology have not yet been exploited fully. There is plenty more innovation to come.” 

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31

Environmental Demand New

T

he increasing pressure placed on the use of metals through legislation and risk assessment has significantly affected the way in which color targets are achieved. Colorists are more restricted than ever and are concerned about impending legislation limiting color choice, particularly where there are long lead times between design and production. Bright yellow, orange and red shades are particularly challenging, with reformulation moving away from cadmium pigments and lead chromates within the plastic and surface coating markets. Customers face the challenge of matching traditional color targets with alternative pigment systems, while remaining competitive and protecting their margins. Inevitably, the attractive bright shades are the most difficult to reformulate, since heavy metal formulations often come hand-in-hand with color brilliance, technical performance and ease of use. Reformulation is, therefore, more than just a color issue. High performance is of paramount importance to many plastic and surface coating industries, where pigments must endure harsh environments during processing or usage. The pigment itself often acts as a functional compo-

FIGURE 1 | Solaplex product range.

Tint shades are 1:4 in titanium dioxide Color reproduction: For technical reasons connected with color reproduction, the colors shown may not exactly match the pigment colors and do not represent a particular finish.

nent, protecting and prolonging the lifetime of the coating. A good example of pigment functionality is in urban developments, where exterior coatings used in construction often contribute to the Heat Island Effect, in which the metropolitan area is significantly warmer than its surrounding rural areas because of its poor reflectivity. Minimum reflectivity requirements are being stipulated in building regulations to minimize the negative effects caused by disturbances to air currents, as well as energy consumption in terms of air conditioning costs and regular replacement of lowpitched or flat roofs. The demand for high-performance reflective pigments is growing in this area.

Pigment Options Pigment suppliers have developed their own approach to the problem, but all are working within the confines of the traditional pigment types available. All approaches have their own advantages, but no single pigment appears to be meeting every need. Is there room for another pigment type in the raw material palette? Rockwood Pigments believes there is. Lead chromates have been predominantly replaced by organic/inorganic pigment blends. This is being accelerated by the inclusion of these pigments as SVHC (substances of very high concern), and likely phase out is expected by 2015. In most cases, organic pigments are combined with titanium dioxide, mixed metal oxide titanates, yellow iron oxide, or a combination, to impart opacity to the coating or polymer. Due to the low color strength of the inorganic component, high organic pigment loadings are usually required to achieve bright colors. The overall performance of these formulations is determined by the organic component selected. From our observations, the following problems may be encountered, particularly for high-performance applications: • The heat stability of the organic component may not be sufficient, particularly for engineering polymers (ABS, PEI, PEEK, PA, PBT, PC) or dark-colored coatings where heat build up may generate high temperatures in use; • The chemical resistance of organic colorants may not always be adequate for reactive polymers, for example, polyamides, acid-catalyzed systems or coatings exposed to acid environments;

By Peter Mullen, Global Product Manager, Coatings | Rockwood Pigments, Kidsgrove, UK 32



JANUARY 2012 | W W W . P C I M A G . C O M

Challenges Color Solutions • The high oil absorption of the organic pigment may present rheology problems in coatings when high loadings are used to achieve bright yellow color targets; • Organic pigments can be prone to migration, bleeding and warpage; and • Conventional inorganic pigments lack color brightness and intensity and, therefore, color options are restricted for brighter shades. Organic pigment producers continue to work on brighter colors with improved performance and hiding power, and several new developments have been introduced recently. On the inorganic side, bismuth vanadate is a popular choice. Although attractive from a color perspective, options are limited in single pigment formulations; bismuth vanadate is often combined with organic pigments to achieve the full range of colors from yellow through to red. In general, the redder the color target, the higher the organic pigment loading required, increasing the cost and probably compromising on performance. Bismuth vanadate is weatherfast and opaque to UV light, but may exhibit thermal and chemical stability problems in very challenging applications. In summary, there is a gap in the high-performance yellow-orange color space.

Innovative Colors Rockwood Pigments’ Solaplex® range (Figure 1) offers

Application Polyolefins

Engineering Polymers

Styrenics

Vinyls Silicone Rubber

Polymer PP LDPE HDPE PC PA PBT PMMA PEEK ABS SAN ASA PS p-pVC u-PVC

Recommended                   

Potential  

      



unique color properties, exceptional performance and the excellent durability associated with our Colourplex® range of mixed metal oxides. Solaplex pigments offer environmentally acceptable solutions at an affordable price, in the challenging yellow-orange color space. Solaplex pigments are a new chemistry offering an environmentally acceptable alternative to pigments that contain cadmium, lead, chromium, nickel, antimony and molybdenum. The chemistry falls within the rutile tin zinc family of compounds and the CI reference number, Pigment Yellow 216.

Unique Color Space Solaplex pigments lie in a completely unique color space, with a color shade and intensity between lead chromates and conventional titanates. The pigment range has been extended to include the Bright Orange 34H1004 grade, which is redder and significantly stronger in tint than the existing 34H1003 grade. This new product enables Rockwood to extend its color range further into the red-shade area of this challenging yellow-to-orange color space.

Applications Prior to the launch of the Solaplex range, a significant amount of testing was performed and presented to demonstrate how robust these pigments were in terms of gloss retention, weathering, temperature and chemical

Application

Recommended

Industrial



Coil



ACE



Architectural



Powder



Decorative



Potential

Road Markings



Yacht/marine



Artist colors



Automotive



Can coatings

 



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



33

Environmental Challenges Demand New Color Solutions

As internal testing predicted, Solaplex pigments are suitable for even the most demanding applications in coatings, plastics and artist colors. The universal nature of Solaplex pigments means that all parts can be colored with the same pigment system, reducing color variation and metamerism.

FIGURE 2 | Color space of yellow inorganic pigments.

Environmentally Friendly Solaplex technology offers an environmentally friendly alternative to cadmium and lead-containing pigments. They are not classified as hazardous under either CHIP3 2002 or CLP 2008 legislation, and the attendant EU directives and regulations (67/548/EEC, 88/379/EEC, 1272/2008/EC), neither are they classified as “special waste”. Solaplex pigments comply with TSCA, with some restrictions, and the European Guideline for Indirect Food Contact (AP (89) 1) and Toys Test for Plastics (EN71: Part 3), based on the analysis of typical batches. Additionally, food contact notification is in progress via the FDA. resistance. In all cases, Solaplex pigments matched the performance of the established pigments, and in at least one aspect, the performance of Solaplex pigments was superior to each of the established color types. These pigments have greater color brightness than titanates, are more chemically and thermally resistant than bismuth vanadate and are more durable than organics (Figure 2).

Summary The Solaplex range of pigments offers new color options, affordable and robust for any application, complementing and enhancing the formulator’s raw material palette.  For more information, visit www.solaplex.com.

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Visit ads.pcimag.com 34



JANUARY 2012 | W W W . P C I M A G . C O M

Painting is a cinch ...

With a paint that works with you! Introducing Eastman Optifilm™ additive OT1200 Extends open time, for improved wet edge and workability in paint Today’s paint has less workability time making it difficult to easily fix or paint over a mistake. Eastman Optifilm™ additive OT1200 — the newest addition to Eastman’s Optifilm portfolio — enables formulators to create low-VOC paints with improved open time and wet edge without negatively affecting other properties. OT1200 performs under a wide range of application conditions. The result is compliant paints with significantly improved workability and easier cleanup. For more information on Eastman Optifilm™ additive OT1200, visit us at www.eastman.com/optifilmOT1200 or call 1.800.EASTMAN for a free sample.

From the Eastman Optifilm™ family of products. Enabling performance, aesthetics, and compliance in architectural paints.

Eastman and Optifilm are trademarks of Eastman Chemical Company. © Eastman Chemical Company, 2011.

Novel Additives to Extend Open Time in Low-VOC Latex Paints

O

ne of the challenges of formulating waterborne architectural coatings is achieving an acceptable balance of properties both during application and in the final film. Over the past decade, this has become increasingly more difficult because of the significant changes in VOC regulations. Although VOC definitions differ from region to region, the propylene and ethylene glycol used to improve open time and wet edge are universally considered to be VOCs. Since glycols are one of the primary VOC sources, they are often reduced or eliminated in lower-VOC paints, thus compromising

FIGURE 1 | Typical test method for open time and wet

edge evaluation.

Wet Edges Drawdown Brush Path

open time, wet edge and paint workability. This creates the need for a solution that enhances paint workability without contributing significant VOCs and without negatively impacting film properties such as scrub resistance and wet adhesion. This article describes a new, low-VOC additive that improves open time, wet edge and workability in lowVOC latex paints. Paint performance properties are demonstrated in a typical architectural formulation, and mechanisms for the enhanced performance are outlined through use of novel rheological techniques.

Evaluating Open Time There are numerous methods to characterize open time and wet edge time. Open time is defined as the period of time during which irregularities in a freshly applied coating can be repaired, while the period in which a coating can be applied over an existing paint film without leaving lap marks is the wet edge time. One of the most common techniques requires a paint film to be drawn down on a sealed chart with a series of ‘X’ marks in the center of the drawdown. After fixed periods of time, paint is brushed four cycles back and forth across the film. The point at which the edge of the drawdown can no longer be worked into the body of the paint is referred to as the wet edge time, while the time at which the ‘X’ begins to show through the paint is the open time. This method is illustrated in Figure 1.

Development of Low-VOC Additives Increasing Time

This work focused on designing a low-VOC, low-emission additive to improve the wet edge and open time of latex paints without compromising performance. The initial target was to provide performance observed in 150 g/L paints (U.S.) at a reduced VOC of 50 g/L. The work started with the screening of potential materials for impact on open time and wet edge when post-added to a commercial semigloss paint. From this work, a subset of promising, low-VOC materials was identified. Subsequent work was

By Jennifer Cogar, Kevin W. McCreight, Rebecca Stockl, Carlo Testa and Kab Sik Seo | Eastman Chemical Company Research Laboratories, Kingsport, TN 36



JANUARY 2012 | W W W . P C I M A G . C O M

carried out in an acrylic semigloss formulation to allow a more direct comparison of the experimental materials with the propylene glycol. The formulation is presented in Table 1. Using a designed study, an optimized composition was determined for an open time additive (OTA) with a good balance of properties at reduced VOC. The properties of this OTA are defined in Table 2.

Evaluation of Paints Containing a Low-VOC OTA Performance of paints made with 3% active OTA compares favorably to paints with 3% propylene glycol. Table 3 compares the properties of the two paints. The OTA provides a reasonable balance of properties compared to the higher-VOC control formulation. Another challenge for waterborne architectural paints is the variation in the workability that is observed at different environmental conditions. Since most of the development work was completed at standard lab conditions, open time and wet edge times were evaluated on both the control and paint containing the OTA at five different temperature/humidity combinations. As expected, the humectant propylene glycol in the control paint provides poor wet edge and open time at higher temperature/low humidity and good wet edge/open time at higher humidity. In contrast, the paint with the OTA provides excellent wet edge time regardless of temperature and humidity. Open times were superior for the lower-VOC paint containing the OTA except at 21 °C and 50% RH, where the results were similar. These results are summarized in Figures 2a and 2b. Rheological changes during drying can also affect the workability of a latex paint. The short open time and limited window of workability can potentially be correlated with a rapid increase in the viscosity at the edge of an applied coating. A modification of a novel rheology technique developed at Eastman Chemical Company2 was used to define the drying and rewetting behavior of paints compared to wet edge/open time testing. Beginning about 40 seconds after the paint sample was prepared, a dynamic time sweep at a fixed frequency was run. At fixed times, the drying paint was rewetted with a few additional drops of the same paint. This allowed the rewetting behavior of each coating to be quantified. Four coatings based on the formulation from Table 1 were tested. Paints with propylene glycol (PG) at 3% and 6% loadings were compared to paints with 3% of a commercial 400 molecular weight polyethylene glycol (PEG) and 3% actives of the OTA. Figure 3 provides a comparison of the viscosity build and rewetting behavior of the four paints at 5 min (300 sec). The sample containing 3% OTA builds viscosity rapidly, which may be associated with improved sag resistance, but shows significant rewetting with an 82% reduction in viscosity. The other three paints showed minimal reduction in viscosity upon rewetting (15-20%), suggesting that it is unlikely that these paints had any significant workability remaining. These viscosity traces correspond closely to concurrent open time measurements of 7.5 min open time for the paint with 3% OTA, 5.5 min for the paint with 6% PG, 4 min for the paint with 3% PG, and 3.5 min for the paint with 3% PEG.

TABLE 1 | Control formulation used for additive development.1 Ingredient

Pounds

Ti-Pure R-746 slurry Aerosol OT-75 Rhoplex SG-30 Kathon LX1.5% BYK-022 Water Propylene glycol Eastman Texanol™ ester alcohol Acrysol SCT-275 Acrysol RM-2020NPR Total

Gallons

324.63 1.57 505.79 1.89 2.09 138.13 31.42 11.52 4.92 25.24 1047.19

16.73 0.17 57.48 0.22 0.25 16.58 3.65 1.46 0.57 2.89 100.00

Properties PVC, %: 21.2 NVV, %: 34.9 VOC 133 g/L (U.S., less water) 39 g/L (Europe, ready to use)

TABLE 2 | Properties of a low-VOC OTA. Property

Typical Value

Active content, % Density, lb/gal (g/cm3) Viscosity, cps pH Appearance

69 9.0 (1.08) 8500 8.3 Hazy

TABLE 3 | Summary of control paint performance properties vs. paint formulated with OTA.

VOC (U.S.) VOC (Europe), ready to use Open time Wet edge Gloss, 20°/60° Scrub resistance (% of control) Block resistance Wet adhesion Stormer viscosity ICI viscosity

Control Paint (3%)

Paint (3% OTA)

133 g/L 39 g/L 5 min 2 min 40/71 100 7 5 96 1.1

50 g/L 3 g/L 7 min 4 min 58/84 101 6 4 96 1.0

FIGURES 2A/2B | Workability at a variety of environmental conditions. A

21 °C, 75% RH  

28 °C, 35%   RH 8 6 4 2 0

21 °C, 50% RH

B

10 21 °C, 30% RH

32 °C, 50% RH

Wet Edge Time (min) Control (PG) OTA

28 °C, 35% RH 15 5

21 °C, 75% RH

21 °C, 30% RH

0

  21 °C, 50% RH

32 °C, 50% RH

Open Time (min) Control (PG) OTA

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



37

Novel Additives to Extend Open Time in Low-VOC Latex Paints

FIGURE 3 | Complex viscosity traces of paints rewetted after 300 sec as

measured by drying rheology.

3% OTA 3% PG Viscosity, (a.u.)

6% PG 3% PEG

0

100

200

300

400

500

600

Time (seconds) FIGURE 4 | Complex viscosity traces of paint with 3% OTA rewetted after 4, 5, 6 and 8 min. Rewet at 4 min Rewet at 5 min Rewet at 6 min Rewet at 8 min

Conclusions

Viscosity, (a.u.)

0

200

400

600

Time (seconds) FIGURE 5 | Workability testing for a control paint with PG and a paint with

38

A

B Control Paint (3% PG) Paint (3% OTA)

2 3 4 5 6

8 10 12

Time (minutes)



# of Cycles to Eliminate “X”

# of Cycles to Eliminate Wet Edge

OTA.

50 45 40 35 30 25 20 15 10 5 0

Figure 4 shows additional viscosity traces for the paint samples containing 3% OTA, with rewetting after 4, 5, 6 and 8 min. The viscosity prior to rewetting continues to increase with increasing dry time. Beyond 5 min, the viscosity after rewetting continues to increase but, even after 8 min, there is still more than a 60% reduction in viscosity with rewetting. This suggests that the OTA provides improved workability through a unique mechanism beyond that of simply reducing the evaporation rate of the continuous phase. The rewetting behavior of the control paint with 3% PG and the paint with 3% OTA was further studied using a variant of the open time test method illustrated previously in Figure 1. At each time period, the paints were brushed until the edge could be worked in (up to a maximum of 50 cycles). Figure 5 provides a summary of the results for both the wet edge (a) and open time (b). The paints with 3% PG require more strokes to eliminate the wet edge, and beyond 6 min the edge can no longer be worked in. The wet edge of the paint with 3% OTA can still be worked in after 12 min. Results were similar for the open time testing. Paint formulated with the OTA exhibits typical viscosity development characteristics, but the paint can be rewetted and reworked for a significantly longer time.

50 45 40 35 30 25 20 15 10 5 0

Control Paint (3% PG) Paint (3% OTA)

A low-VOC additive that improves wet edge and open time of latex paints without compromising paint performance has been developed. This material was identified based on the combination of an initial screening process with more extensive formulation and testing work in conjunction with a large designed experiment. The open time additive provides more robust workability over a range of temperature and humidity as compared to propylene glycol. A novel rheological technique demonstrated that paint formulated with the open time additive exhibits a typical viscosity increase during the early stage of drying, but was unique in that the paint film would thin back down remarkably upon rewetting with several drops of fresh paint. This rewetting behavior was further examined by open time and wet edge testing in which samples were brushed until the edge or ‘X’ could be eliminated. Paint formulated with propylene glycol could only be reworked for about 5 min, while paint with the open time additive could be rewetted and reworked up to 12 min. The mechanism for this behavior is not fully understood, but the data suggests that the OTA provides improved workability through a unique mechanism beyond that of simply reducing the evaporation rate of the continuous phase. 

References 1

2

2 3 4 5 6

8 10 12

Time (minutes)

JANUARY 2012 | W W W . P C I M A G . C O M

Formulation adapted from Dow 150 g/L SG-30 Quality Interior Semi-Gloss Formula. Seo, K.S.; Posey-Dowty, J. D, US 7,185,530 B2 and US 7,4s72,584 B2.

For more information, contact [email protected], or call 423/229.2747.

P R O D U C E D BY:

“Session topics were relevant & informative.” 2011 Attendee

SEPTEMBER 11-12, 2012

Benefits of Speaking:

OAK BROOK, IL

• Educate your customers • Engage potential customers in future projects • Share ideas • Connect with key www.coatingsconference.com decision makers

Coatings Trends & Technologies is now accepting papers covering the following topics.

Call for Papers

• Renewable Technology

• Resins and Polymers

• Architectural Coatings

• Mixing/Milling

• UV-curing Technology

• Industrial Coatings

• Calibration Standards

• Waterborne Systems

• Marine Coatings

• Improvements in Adhesion

• Nanotechnology

• Automotive Coatings

• Pigments/Extenders/Colorants

• Solventborne Systems

• Legislation and Regulatory Issues

• Solvents

• Accelerated Weathering

• Additives

• Powder Coatings

• Test Methods, Materials Characterization and Performance Evaluation

How to Submit your Paper: Include the title and abstract of your proposed paper (100 words) and speaker contact information. Identify three take-away points for attendees; what can attendees learn from your talk? How can they apply your information to their job? For consideration, submit your abstract online at www.coatingsconference.com

Deadline: March 16, 2012 Questions? Email Kristin Johansson, Editor, PCI Magazine, at [email protected]

Selecting Resins for Wood A Guide for Formulators

F

ormulating wood coatings can be challenging, given the variety of resins available and the diverse applications in the industry. The key to finding the optimal one-component (1K) waterborne (WB) polyurethane resin for a wood coating application requires a thorough understanding of two factors: the properties of the resin itself and the critical criteria for the particular end-use market. These two factors are inextricably linked and, as such, they must be considered together – not independently – in order to best solve this dilemma. Bayer MaterialScience LLC researchers have categorized the company’s 1K WB polyurethane technologies as well as the key performance properties for different applications, to provide formulators with an overview of the resins and their applicability to specific wood coating applications. This article presents an overview of the findings, which are designed to help streamline the resin selection process for wood coatings.

Types of Polyurethane Dispersions (PUDs) There are different types of backbones, or building blocks, for polyurethane dispersions: polyether, polyester and polycarbonate. Sometimes, two types of backbones are combined to formulate a PUD. It is possible to generalize about the advantages and disadvantages offered by each (Table 1). There are self-crosslinking PUDs. These dispersions contain segments that will crosslink when initiated. Some types of self-crosslinking materials contain fatty acid segments, enabling them to oxidatively cure over time.

Critical Testing for the Wood Market After becoming familiar with the combination of properties generally exhibited by the different types of PUDs, it is beneficial to understand the critical tests that should be conducted to determine which resins are best suited

TABLE 1 | Overview of the advantages and disadvantages of PUD backbones.

Polyether Polyester Polycarbonate

Advantages

Disadvantages

• Good mechanical properties • Less expensive • Excellent mechanical properties • Weathers well • Excellent mechanical properties • Hydrolytic stability • Good weathering

• Poor weathering characteristics • Issues with hydrolytic stability • Cost

for the different end-use wood coating markets. Common tests are as follows: • Dry time; • Surface hardness (pendulum); • Taber abrasion (CS-10, 1,000-cycles, 1,000-gram weight) to determine scratch and wear resistance; • Chemical resistance (ethanol/water, acetone, Formula 409, water); • Black Heel Mark Resistance (BHMR); • Exterior durability.

Solvent-Free PUDs After determining which tests are critical to the wood coatings market, researchers subjected a variety of solvent-free PUDs to these tests. Table 2 is a matrix researchers developed that plots how these PUDs performed to the tests outlined in the section above. While these are a l l solvent-f ree PUDs, it is important to be mindful of co-solvents, which are often required to form a film at room temperature. Resin UH XP 4, however, is a unique material in that it does not require any co-solvents. As such, it can be formulated with very low (less than 50 g/L) VOCs, which is a particularly attractive attribute for some end-use markets. It is important to remember, however, that UH XP 4 is an oxidatively curing material, and therefore requires a dryer, or catalyst, to initiate the oxidative curing mechanism. This catalyst often contains a metal, such as cobalt, although newer, more environmentally friendly materials, such as iron, may also be used.

End-Use Application Table 2 offers a good overview of how different PUDs perform in tests used by wood manufacturers. However, there is another important aspect that should be evaluated: the end-use application. Scuff resistance, for

By Margaret Kendi, Associate Scientist | Bayer MaterialScience LLC, Pittsburgh, PA 40



JANUARY 2012 | W W W . P C I M A G . C O M

Coating Applications: example – would likely be very important for flooring, but not for cabinetry. With this in mind, researchers also took a look at the requirements for several application areas: flooring, cabinetry, furniture, interior windows and doors, and exterior wood in an effort to aid formulators in selecting the optimal resin.

Wood Flooring The researchers determined that BHMR, which evaluates if a scuff can be removed, is a critical test for wood flooring. For this application it is also important for coatings to be abrasion resistant (Taber abrasion). They should also be hard (pendulum hardness), because if the coating is soft, dirt will wear in, resulting in undesirable dirt paths. Based on these applicationspecific performance requirements, researchers again referred to the matrix in Table 2, concluding that UH 3 was the most optimal product for this market.

Kitchen Cabinets One of the key properties for this market is chemical (stain) resistance. The primary test for this market is set forth by the Kitchen Cabinet Manufacturers Association (KCMA), in which coatings are exposed to such agents as mustard, coffee and vinegar. After a period of time, the agents are removed to determine if staining has occurred. Also important for cabinetry is superior abrasion resistance (Taber abrasion) and superior resistance to dirt (pendulum hardness).

Furniture Superior resistance to dirt (pendulum hardness), abrasion (Taber abrasion) and water (water spot) were the most significant properties for furniture coatings. Additionally, superior chemical (stain) resistance to shoe polish, nail polish remover, soft drinks and other agents that might be commonly found in office environments was also identified as an important criterion for office furniture coatings.

Interior Doors and Windows In addition to superior water and chemical resistance, good blocking time is also a key consideration for interior door and window coatings.

Exterior Wood As may be expected, superior weathering properties – including good gloss retention, and no chipping, chalking, splitting or yellowing – are the most vital to the exterior wood market.

TABLE 2 | Performance of solvent-free PUDs in various tests. Bayhydrol®

UH 1

UH 2

UH 3

UH XP 4

UH 5

Co-solvent demand

3.5%

3.5%

5%

0

5%

4%

MFT (ºC)

>25

>30

>50

0

45

>25

Dry time

UH XP 6

1h

1h

45 min

3.25 h

30 min

30 min

Pendulum hardness (1 day/7 days)

56/85 sec

53/67 sec

76/137 sec

21/79 sec

96.6/148.4 sec

71/133 sec

Ethanol/water resistance (30 min)* (on metal)

4

4

4

5

3-4

4

Water resistance (24 h)* (on metal)

5

4

5

4

5

3-4

BHMR (Black Heel Mark Resistance)*

1

4

4

3

2

3

Taber abrasion (CS-10, 1,000 g, 1,000 cycles)

18.2 mg (lost)

27.8 mg

42.8 mg

136 mg

18.9 mg

7.4 mg

Elongation (%)

350

280

40

NA

180

250

* Scale: 5 - Excellent to 1 - Poor

TABLE 3 | Resins recommended for particular applications. Bayhydrol UH 1 UH 2 UH 3 UH XP 4 UH 5 UH XP 6

Windows Exterior Wood Wood Wood Flexibilizer Floors Cabinets Furniture and Doors Wood ● ● ● ● ● ●

● ● ● ● ● ●

● ● ● ● ● ●

● ● ● ● ● ●

● ● ● ● ● ●

● ● ● ● ● ●

● Recommended ● Possible (blending) ● Not recommended

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



41

Selecting Resins for Wood Coating Applications: A Guide for Formulators

Optimal PUDs for Various Markets Researchers took the properties most pertinent to the key application areas and integrated them with the solventfree PUD property matrix (Table 2), creating a chart (Table 3) that indicates which resins might be a good fit for particular applications.

Researchers emphasize that this chart is intended to serve as a starting point for formulators, because the optimal material may not be a single material at all, but a blend.

Effect of Crosslinker Addition While 1K WB dispersions offer a number of desirable properties, chemical resis-

Check it Out!

tance, adhesion or other properties can be further enhanced through the addition of crosslinkers. There are several chemistry options from which to choose – polyaziridine, polycarbodiimide and water-dispersible polyisocyanates. Polyaziridine and polycarbodiimide offer easy dispersibility and low viscosity, but are pH sensitive and must have acid functionality for the polyaziridine/polycarbodiimide, respectively, to crosslink. First-generation polyisocyanates are hydrophilically modified and therefore offer easy dispersibility. This option typically has lower isocyanate content and higher viscosity. A second-generation polyisocyanate, another patented technology, is solvent free and ionically modified. One of the advantages of this technology is its high isocyanate content (23%) and very low viscosity, making it possible to formulate coatings with ultra-low VOCs. It is important to keep in mind that to help ensure the optimal coating formulation, both the PUD being utilized and the end-use application should be considered when selecting a crosslinker.

Conclusion

pcimag.com MORE information. MORE resources. MORE ways to do your job better.

There are a variety of 1K WB polyurethane resin options for wood coating applications. Finding the optimal technology requires a thorough understanding of not only resin properties, but also the applications in which the wood coatings will ultimately be used, such as flooring, cabinetry, furniture, interior windows and doors, and exterior wood. While 1K WB resins offer a good balance of desirable properties, it is also important to keep in mind that the properties of WB coatings can be enhanced by the addition of a crosslinker into a formulation. Selecting the appropriate crosslinker may be dependent on the PUD being utilized. Research and testing that have been conducted should help streamline the resin selection process. For formulators, this should translate into the ability to save valuable time, money and resources. Furthermore, it should facilitate the selection of the optimal resins that will achieve the desired performance for specific wood coating applications.  For more information, e-mail [email protected]. This paper was presented at the Southern Society for Coatings Technology Annual Meeting in 2010.

42



JANUARY 2012 | W W W . P C I M A G . C O M

global links for coatings professionals

The Coatings Group Events www.coatingsgroup.com Middle East Coatings Show 2012 Dubai International Convention & Exhibition Centre, UAE 12 – 14 March 2012 Asia Pacific Coatings Show 2012 Balai Sidang Jakarta Convention Centre, Indonesia 19 - 20 September 2012

NACC NORTH AFRICAN COATINGS CONGRESS

North African Coatings Congress 2012 Hyatt Regency Hotel, Casablanca, Morocco 17 – 18 October 2012 Middle East Coatings Show 2013 Cairo International Convention and Exhibition Centre, Egypt 26 – 28 February 2013

3

Asia Coatings Congress 2013 Windsor Plaza Hotel, Ho Chi Minh City, Vietnam 14 – 15 May 2013 Latin America Coatings Show 2013 World Trade Centre, Mexico 17 – 18 July 2013 3

Asia Pacific Coatings Show 2013 BITEC, Bangkok, Thailand 12 – 13 September 2013 3

For up-to-date information on any of the above events, please contact the Coatings Group Tel: +44 (0)1737 855021 Email: [email protected] or visit our Website: www.coatingsgroup.com

PRODUCTS Optimism in the Air at ABRAFATI 2011b Optimism for the coatings industry was the hallmark of ABRAFATI 2011, held November 21-23, 2011, in Sao Paulo, Brazil. The event brought together the 12th International Coatings Congress and the 12th International Exhibition of Coatings Industry Suppliers.

CLARIANT A quinacridone magenta pigment, Hostaperm® Pink E2Y has high color strength and excellent light and weather fastness at a wide range of concentrations. Following strict quality control procedures and specifications, this product fulfills the requirements of many coatings applications, including decorative, general industrial, automotive, powder and coil coating. It is equally well suited for water- and solvent-based paint systems, and is subject to Clariant’s stringent product safety guidelines, which ensures that heavy metal regulations are met for both RoHS and toy paints. Visit www.clariant.com.

 Emulsion

THE LUBRIZOL CORP. With its patent-pending technologies, Carboset® CA-600 is a water-based, 100-percent acrylic, self-crosslinking emulsion that enhances the appearance and performance of most mineral-based horizontal masonry surfaces. It provides excellent blush resistance and superior weathering protection on driveways, sidewalks, decorative concrete and similar surfaces. Visit www.lubrizolcoatings.com.

 Silicone Resin

WACKER SILRES® IC 368 is a new solvent-free (