Coatings Connection – Newsletter of The Dow Chemical Company's Coatings Businesses – November, 2003

Welcome to our inaugural issue of Coatings Connection, a newsletter designed for our North American paint and coatings customers. We are pleased to provide you with information, news and resources related to the industry on a semiannual basis. You are receiving this newsletter because you are a customer of The Dow Chemical Company or may be interested in Dow products and services. If you find our newsletter helpful and informative, we encourage you to subscribe (at no cost) and to forward it to others interested in paint and coatings. Please be assured that we do not share our subscription list with other companies and that each future issue of Coatings Connection will offer an unsubscribe option. Please send us your suggestions about what you'd like to see in future issues of Coatings Connection.

Contact Dow any time to discuss your application, formulation, or product needs. We look forward to hearing from you.

Please select:
The Definition of High-Quality Paint
Dow Introduces New Biocide for Use in Paint and Coatings
DOWICIL* QK-20 - A Solution for Bacterial Hygiene Problems
Propionate Ester Solvents - Great Solvency, Non-HAPs and Low Odor
Dow Surfactants
Solvents for Industrial and Architectural Latex Coatings
High Performance Architectural Coatings

The Definition of High-Quality Paint

"High quality paint is a good investment." Customers shopping for paint are told that better paint will look brighter, last longer, and, over time, cost less than paint of lower quality. "High quality paint," though, is a slippery and ill-defined concept. What characteristics afford a recognizably superior paint formulation?

Interior and exterior paints, although both are intended to cover, enhance, and protect a surface, have slightly different requirements for meeting a high quality standard. Exterior paint is evaluated on its ability to adhere to a surface and its chalk, dirt, and mildew resistance. A high quality exterior paint, therefore, must not blister, flake, or peel once it dries. Additionally, the paint should retain its intended color, and should not only look "fresh" but also discourage microbiological growth that can discolor the painted surface. Interior paint is more likely to be assessed on aesthetics and ease of application. A high quality interior paint should spread smoothly and readily onto a surface, without spattering or exhibiting brush or roller marks. The paint should cover a surface in a single coat and should resist dirt and staining once it is dry. High quality interior gloss and semigloss paints should resist blocking, so that freshly painted windows and doors will not stick together once the paint dries.

More and more, high quality paint must meet "low-odor" or "solvent-free" standards. Although many existing paint formulations nominally meet federal specifications for low-odor, the newest generation of low-odor paint has been formulated almost completely without the aid of organic solvents. Traditionally, organic solvents have been used to prevent the paint from drying too rapidly and to help the binder (latex) in the coating to form a continuous film. The evaporating solvent is responsible, in part, for the odor associated with freshly painted surfaces. The inclusion of water in place of organic solvents in the paint formulation will, of course, reduce the solvent odor, but this substitution profoundly changes the nature and chemistry of the paint formulation.

Formulation of water-based paints that equal or exceed the performance of their solvent-based counterparts is a formidable challenge. The Dow Chemical Company has the raw materials and the expertise to help you formulate the very best interior and exterior paints that will meet performance and regulatory requirements.

For an overview of Dow's paints and coatings businesses, please see Products & Services, Paints & Coatings.

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Dow Introduces New Biocide for Use in Paint and Coatings

The Biocides business of The Dow Chemical Company has announced the introduction of a new addition to their product line for paint and coatings. DOWICIL 96 Antimicrobial is a broad spectrum liquid bactericide that is uniquely suited for emulsion products. And because it is both oil- and water-soluble, DOWICIL 96 is equally effective in aqueous or oil/solvent-containing paints, inks, emulsions and adhesives. In addition to its antimicrobial functionality, DOWICIL 96 has excellent stability, and efficacy at high pH. It also works when used in combination with other preservatives. All of these performance benefits make DOWICIL 96 an excellent candidate for in-can preservation. "The introduction of DOWICIL 96 Antimicrobial reinforces Dow's commitment to develop and market specialty products designed to meet the performance needs of the coatings industry," said Jerry Konst, North American Marketing Manager for biocides at Dow. "Product samples as well as commercial quantities are readily available."

For more information, contact The Dow Customer Information Group: United States and Canada; 1-800-447-4369/1-989-832-1560; Europe 800-3-694-6367/32-3-450-2240; Other Global Areas 1-989-832-1560.

For more information, please go to Dow Biocides.

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DOWICIL QK-20 - A Solution for Bacterial Hygiene Problems

Fast, Economical, Easy-to-Use Antimicrobial for Paint and Coatings

For bacterial hygiene problems in paint manufacturing environments, DOWICIL QK-20 Antimicrobial is the solution. DOWICIL QK-20 Antimicrobial is a fast-acting and economical biocide used to clean up potential sources of contamination without requiring shutdowns or production delays. It also works well in enhancing the performance of in-can preservatives allowing for lower use concentrations and a potential decrease in overall preservation costs.

According to Jerry Konst, North American Marketing Manager for Biocides at Dow, "Many manufacturers who use long-term biocides for in-can preservation of finished products employ the same biocide to treat recycle/wash water, stored raw materials and contaminated finished product. Although these long-term preservatives may eventually get the job done, they may take too long to work - resulting in costly production delays."

Konst adds, "DOWICIL QK-20 is an ideal solution to the industry need for a targeted, customized biocide that is faster acting and less expensive in these applications." DOWICIL QK-20 is formaldehyde-free, completely miscible with water and easily dispersed upon introduction. Effective at low concentrations, DOWICIL QK-20 provides broad-spectrum control of bacteria, fungi and yeast, and often achieves this within minutes, rather than hours.

Clean Up of Recycle/Wash Water
In alkaline aqueous environments, DOWICIL QK-20 decomposes quickly and will not adversely affect a finished formulation. In addition, DOWICIL QK-20 typically yields a 99.9 percent microbial kill before it degrades to non-effective levels.

According to Konst, many manufacturers recycle process water for use as make up water in future batches of product. This water, as well as incoming water, may contain high microorganism counts. Recommended plant operation practices require treatment of the water first. Using chlorine or other oxidizers to clean this water can interfere with the finished formulation. DOWICIL QK-20 is a non-oxidizing biocide and will not alter the properties of the end use formulation.

DOWICIL QK-20 is active against biofilm (organisms which grow on surfaces). If biofilm is knocked loose from tank or pipe surfaces, it can inoculate a batch of finished product with microorganisms, causing a preservative failure downstream. Many long-term in-can preservatives may allow biofilm to build up, which in turn often requires a plant shutdown for cleaning and decontamination.

Clean Up of Contaminated Raw Materials/Finished Products
In a variety of industries, water-based raw materials such as latex, surfactants and mineral slurries (i.e., TiO₂, Kaolin clay and calcium carbonate) are used. These materials can become contaminated in the heels of storage tanks or in contaminated mixed/recycled tanks.

"The rapid antimicrobial activity of DOWICIL QK-20, combined with quick chemical breakdown, presents one of the most cost-effective ways of eliminating microbiological contamination with minimal effect on the final product," says Konst.

Preservation Enhancer
In finished products, DOWICIL QK-20 also can be used effectively in combination with a long-term preservative to reduce the bio-burden on the long-term preservative and minimize the likelihood of organism tolerance. This lowers the chances for field failure, product recall, product rework, or downtime. In some cases, overall preservative costs may also be reduced.

"Often, long-term preservatives alone do not consistently demonstrate a broad spectrum of control. DOWICIL QK-20 is faster acting and helps broaden the spectrum of control," maintains Konst. "This increased level of control prevents the organism from developing a resistance to the biocide, resulting in biocide creep, excessive product use, and rising preservation costs. With a typical 99.9 percent microbial kill, DOWICIL QK-20 is ideal for cleaning up tolerant house bugs."

Short-Term Preservation
DOWICIL QK-20 quickly and economically cleans up potential sources of contamination to provide excellent short-term protection of stored materials. It also offers excellent compatibility with other formulation components and preservatives, ensuring the solution or prevention of contamination problems without production delays or undesirable effects on the finished product.

For more information, contact The Dow Customer Information Group: United States and Canada 1-800-447-4369/1-989-832-1560; Europe 800-3-694-6367/32-3-450-2240; Other Global Areas 1-989-832-1560.

For more information, please go to Dow Biocides.

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Propionate Ester Solvents - Great Solvency, Non-HAPs and Low Odor

Over the last few years, The Dow Chemical Company realized the growing need for lower odor solvents for use in the coatings industry. Surprisingly, this need was first voiced by automotive OEM coatings houses, and not by the architectural paint makers. Automotive manufacturing facilities responsible for applying paint found that the odor of some solvents was unacceptable and they began seeking replacements. Of course, the replacement solvents had to be not only 1) lower in odor, but 2) have similar or better performance, and 3) qualify as non-hazardous air pollutants ("non-HAPs"). In response, Dow was able to recommend three recently developed propionate ester solvents: UCAR™ n-Propyl Propionate, UCAR n-Butyl Propionate, and UCAR n-Pentyl Propionate. These three products offer a range of evaporation rates, from fast to slow, making them suitable for a variety of applications.

All three propionate ester solvents have the following advantages:

• Non-HAPs status
• Strong solvency, particularly for high solids coatings
• An evaporation rate suitable for many coatings and ink applications
• Linear structure, an advantage over branched solvents in diffusion through a film
• High electric resistivity, an important property for electrostatically applied coatings
• Low odor values
• Excellent polymerization solvent compared to ketones

UCAR n-Butyl Propionate
UCAR n-Butyl Propionate, which can also be used as a xylene substitute, is most commonly used as a methyl amyl ketone (MAK) replacement when a lower odor is desirable. It could also be used to replace the following: methyl isoamyl ketone (MIAK), cyclohexanone, methyl amyl acetate (MAAc) and p-chlorobenzotrifluoride (PCBTF).

UCAR n-Propyl Propionate
UCAR n-Propyl Propionate has the lowest odor of Dow's propionate esters. It is most commonly used as a substitute for xylene since their evaporation rates and solvency are very similar, yet UCAR n-Propyl Propionate has non-HAPs status. It may also be an appropriate substitute for t-butyl acetate, MIBK, VM&P naptha, isobutyl acetate and ethyl acetate.

UCAR n-Pentyl Propionate
UCAR n-Pentyl Propionate is a potential "drop-in" replacement for oxo-hexyl acetate (OHA), also marketed under the trade name EXXATE™ 600, and scheduled to be discontinued by 2005. This is not surprising since the two products are isomers. However, UCAR n-Pentyl Propionate has important advantages over OHA. First, resin dilution experiments have shown that it is superior to OHA in reducing viscosity. This means less solvent, and subsequently less VOC, to achieve the same viscosity in a formulation. Second, it has been shown that linear molecules like UCAR n-Pentyl Propionate diffuse through a film as it dries so that a better appearance is achieved. Third, branched solvents such as OHA typically have stronger odor than linear solvents like n-Pentyl Propionate.

The high boiling point of UCAR n-Pentyl Propionate is an advantage in acrylic polymerization, enabling the production of low molecular weight and low viscosity resins.

For more information, please call 1-800-SOLVENT or go to Organic Intermediates, Solvents and Monomers

EXXATE™ is a trademark of Exxon Mobil Corporation

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Dow Surfactants

No matter where you go in the world, you'll find paints, coatings, and inks formulated with Dow surfactants improving life in many ways. Dow is one of the world's leading suppliers of surfactants and related formulation expertise and support. Our broad and diverse portfolio of surfactant chemistries for paints, coatings, and ink formulations includes such well-recognize brands as:

• TRITON™ specialty nonionic and anionic surfactants
• DOWFAX* specialty anionic surfactants
• TERGITOL™ specialty and general purpose nonionic surfactants

The total package of value Dow surfactants brings to you goes beyond our brand names. Our investments in surfactant products and technology have created a capabilities platform unsurpassed in the industry:

A wide range of available chemistries enables us to deliver solutions that meet almost any performance requirement.

Experience across the full range of paints, coating, and ink products equips us to help you optimize surfactant performance and economy in your formulation.

Our knowledge and resources foster innovation, resulting in new products and technology in anticipation of our future requirements and in response to the challenges you face today.

Awareness of regulations and legislation allows us to provide reliable information as well as valuable product stewardship assistance for our products.

A global sales, distribution and technical support network means we are "on the ground" in your local area, ready to serve your surfactant needs.

World-class surfactant manufacturing facilities contribute to Dow operational excellence and ensure that our high performance solutions are available and cost-effective.

A broad portfolio of Dow ingredients for paint, coatings and ink formulations offers you the convenience of focused supply and equips us with in-depth knowledge of other formulation components.

Our Broad range of Surfactant Chemistries Expands Your Possibilities

Dow currently offers almost 200 surfactant products. Dow surfactants include many diverse products across several surfactant chemistries. The unique functional and economic characteristics of these materials open the door to innovative surfactant solutions for paints, coatings, and ink formulations - from high performance automotive paints, to waterborne colorant and ink systems for packaging applications.

The most recent Dow surfactant literature for paints, coatings, and inks information is available from Dow. Please call Dow's Customer Information Group at 1-800-447-4369 or go to Dow Surfactants.

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Solvents for Industrial and Architectural Latex Coatings

Most waterborne coatings have some organic solvent in their formulation, since most resins are not truly soluble in water. The Dow Chemical Company offers a variety of solvents for water-based coatings including alcohols, esters and glycol ethers. Alcohols are used as coupling agents in waterborne coatings. They help provide the proper balance of desired properties such as cure rate, flow and leveling, and viscosity in a formulation. Esters, with limited water solubility, are used as coalescing aids for latex paints.

For example, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate is the market leader in trade sale paints despite its odor and slow evaporation rate. Glycol ethers contain both ether and alcohol group in a single molecule. Therefore, they are miscible with most liquids and are mild-odor solvents for many resins. One can tailor glycol ether molecules by adjusting alcohol group chain length. The longer the alkyl chain length, the more closely the molecular structure of a glycol ether resembles a hydrocarbon, and the more its performance parallels a hydrocarbon. The ether group introduces hydrogen bonding with its attendant influence on solubility performance.

Glycol ethers offer a desirable combination of solubilizing, coupling, and leveling properties, so they are widely used in industrial waterborne coatings as coalescing solvents to promote film formation and improve wetting characteristics of the coatings.

Coalescing solvents are used in architectural and industrial latex coatings to promote film formation, and selection of the proper coalescing solvent is a key to the formulation of superior latex coatings. A coalescent is often used in water-based systems as a fugitive plasticizer to soften the resin particles, enabling them to fuse into a continuous film. During the drying process, most or all of the coalescent evaporates, allowing the film to achieve the desired hardness.

Physical properties of the coalescing solvent determine its efficacy in a particular formulation. Among the most important coalescent properties are its distribution coefficient in the latex, its plasticizing efficiency for the latex, and its rate of evaporation. The distribution coefficient, D, is the concentration of the solvent in the aqueous phase divided by the concentration of the solvent in the polymer phase, Eq.1. Large values of D mean there is not much of the solvent in the polymer phase to help with film formation.

Plasticizing efficiency is illustrated by the modified Fox equation, Eq. 2, which shows that the glass transition temperature, Tg, of a mixture is related to the molar volumes and glass transition temperatures of the component polymers and coalescing solvents. When the solvent can significantly lower the minimum filming temperature, MFT, by lowering the Tg at filming concentration, then the range of application conditions will be increased.

Distribution Coefficient, the ratio of the solvent concentration in the aqueous phase (Cw) to the solvent concentration in the polymer phase (Cp).

Plasticizing Efficiency, the degree to which a coalescing solvent lowers the MFT of a polymer.

The third factor that influences the efficacy of a coalescing solvent is its rate of evaporation. Too fast an evaporation rate can result in premature loss of coalescing solvent and poor film formation. Too slow an evaporation rate can leave coalescing solvent in the film imparting tack to the final film and causing blocking. So there is a trade-off of effective coalescence versus blocking resistance.

In addition, atmospheric humidity will have great impact on water evaporation. Therefore, formulators need to consider atmospheric humidity, and water and coalescent interactions in their formulations.

Each coating requires a solvent blend with an optimum distribution between the polymer and aqueous phases, coalescing efficacy, and plasticizing ability. That is why Dow offers a wide range of coalescing and coupling solvents to help formulators achieve coating performance properties such as low-temperature coalescence to promote film formation, optimum coating rheology, film property, and blocking resistance.

For more information about Dow Solvents, please call 1-800-447-4369 or go to Glycol Ethers.

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High Performance Architectural Coatings

Today's coatings chemists are challenged to formulate everything from contractor to high performance DIY coatings. The desired attributes for High Performance architectural coatings are high volume solids (>35%) and high film build properties (>1.4 poise). In addition, along with maintaining good application properties, consumers demand improved performance properties such as washability, touch up, and color development while complying with all current regulations. UCAR Emulsion Systems works with the broadest class of technologies to meet these formulation challenges.

All-acrylic technology is the most common in the industry for High Performance architectural coatings. UESM offers this technology plus many alternatives. One of UESM's newest offerings is UCAR Latex 629, representing a 100% acrylic technology that offers performance across the PVC and volume solids range. Formulations based on UCAR Latex 629 can meet current and future VOC requirements.

The graph below shows the scrub performance of UCAR Latex 629 versus leading commercially available paints. This formulation is a 40 volume solids, 40 PVC flat coating with excellent flow and leveling, spatter resistance, color development and superior washability while offering low VOCs. In addition to providing low VOC, UCAR Latex 629 also has low residual odor. Please contact your UESM representative for a full presentation on the performance properties and as well as any formulation assistance.

UESM has other technologies that can be considered for low VOC High Performance architectural coatings, such as NEOCAR™ Latex 2302. This polymer was created for interior coatings and offers outstanding performance in scrub resistance, wet adhesion and block resistance. UCAR Latex 419 represents another technology that provides extremely good block resistance when tinted with high levels of colorant, such as those used in tint base systems. UCAR Latex 300, a high scrubbing vinyl acrylic, has been a workhorse standard for low VOC coatings; coatings with exceptional touch up and scrub resistance can be created with this polymer.

In combination with these technologies, specific performance characteristics can be enhanced with proper selection of ingredients. For example, proper selection of the thickener system impacts flow and leveling, application properties and spatter resistance. Thickeners also impact washability, block resistance and viscosity drop. UESM offers a wide variety of associative thickener systems that improve a coating's performance. With the UCAR POLYPHOBE™ Tailored Rheology Series, a wide variety of technologies is available that can be combined in a formulation to achieve desired rheological properties. However, versus other thickener technologies, these coatings also exhibit inherent improvements in washability and block resistance. One of UESM's most recent advances is the UCAR POLYPHOBE Tint Series, a thickener system designed to prevent viscosity drop upon tinting. The Tint Series thickeners are not just limited to bases but can be incorporated across a product line.

Your UESM representative can tell you more about our latexes and rheology modifiers. We can work with you to meet your formulating needs.

For more information about Dow's UCAR Latexes, please call 1-800-447-4369 or go to UCAR Emulsion Systems.

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