In recent years, the solvent market has experienced less-than-impressive growth rates, with overall world demand for solvents forecast to grow at 2.3% per year through 2007, according to a recent study by The Freedonia Group. "For many products, this would be bad news, but for solvents it represents a reversal of fortune following a lengthy period of decline in developed regions," said Mike Richardson, industry analyst for The Freedonia Group. "Overall, per unit usage is declining, but less dramatically than in the 1980s and 1990s."
The Asia-Pacific region holds the best prospects, with demand for solvents projected to expand 4.8% per year through 2007.
According to Richardson, declining numbers, especially in the U.S. and western Europe, were the result of environmental regulations that forced paint formulations to shift from solvent-based to water-based versions. "Although waterborne products continue to increase their market shares, it is happening more gradually now," he said.
The slowing rate of decline, coupled with renewed vigor in production levels for paint, ink and cleaning products, has led to an overall increase in solvent usage.
"Overall, industry growth is strengthening," agreed John Butler, product manager global solvents, Eastman. "As people have more confidence in the economy, they begin buying more durable goods, which in turn contributes to more demand for coatings. We are seeing this happen already." While Butler acknowledged concerns over oil and feedstock prices, overall he said the solvents market is faring well. "We are seeing an increase in demand, and are optimistic for the future," he said.
The solvent market does have bright spots, namely in developing export markets and green technology.
The solvents market is showing signs of recovery, particularly so in Latin America and Mexico, where the auto industry is strengthening due to growing exports to the U.S.," said Butler. "In the U.S. we are also seeing growth in demand for ester solvents, which are used in aerosol coatings, such as spray paints and adhesives in the construction market in North America."
Growth in demand for ester solvents can be attributed to the fact they meet MIR (maximum incremental reactivity) constraints, which are just taking effect in California and in other states.
While demand for conventional solvents is expected to register only modest gains, the green solvents segment will continue to post healthy advances, according to a study on green solvents from The Freedonia Group. Growth for these types of solvents, such as propylene glycol, terpenes and hydrogen peroxides, has been driven mainly by environmental and regulatory concerns.
As developing countries begin to feel the pressure to meet environmental regulations, green solvent demand will continue to expand into these regions. "As governments in developing countries are forced to set stricter environmental guidelines, green solvents will become more popular," said Anand Mehta, industry analyst for The Freedonia Group. "Technological advances and price reductions in green solvents will also contribute to their popularity in industrializing nations."
"The trend near-term will be to replace regulated solvent with solvents that perform better and are more environmentally friendly," said Ranae Anderson, senior technical service representative, Eastman. "Eastman's line of performance solvents such as our specialty ketones�MAK, MPK, and MIAK, propionates and EEP will afford coatings formulators a good range of options."
Eastman methyl acetate is a non-HAP, VOC-exempt fast-evaporating, mild odor, active solvent for a broad range of coatings, such as aerosol, automotive, industrial, furniture and ink resins. Because of its fast evaporation rate, methyl acetate is useful in high-low solvent systems and in other applications where fast solvent release and quick dry-to-touch time are needed.
Demand for dibasic esters has been very positive, according to Surface Specialties. "This can be attributed to the fact that many users want safer products," said Gary Winfield, global business manager for additives and specialty products, Surface Specialties. "Aromatics and ketone are coming under increasingly tighter exposure regulations and users are forced to evaluate and use alternatives. People can buy solvents that are less costly but are not as good for the environment or people. Dibasic esters offer a balance of performance attributes and cost and are an effective alternative to more regulated solvents."
Surface Specialties' Santosol dibasic ester is offered in eight different grades. The product is readily biodegradable (it breaks down into naturally occurring by-products), is not flammable or corrosive, has a mild sweetish odor and is photochemically non-reactive.
Solvent producers have been working to deliver high-performing products that meet diverse regulatory standards and needs in different markets.
Eastman's n-butyl propionate, a non-HAP, slow-evaporating urethane grade solvent with good solvency for most coating resins, provides an alternative to customers seeking to enhance performance and reduce overall solvent usage, according to the company. N-butyl propionate has low surface tension for better wetting, flow and leveling. It offers high electrical resistance for ease of transfer in electro-statically-applied coatings and improved atomization in sprayed coatings. Its low water solubility helps minimize water pick up during storage, thereby increasing its storage shelf life.
In Europe, Eastman's EEH solvent, a non-HAP solvent, was made available for the first time earlier this year. Colorless and hydrolytically stable, Eastman EEH solvent brings performance and processing benefits to architectural, OEM and special purpose coatings such as cathodic electrodeposition primers.
Cost vs. Safety
When choosing solvents safety remains a prime concern.
"Some factors to consider are flammability, corrosivity, solubility, odor and toxicity," said Winfield. "All solvents have different characteristics for these attributes."
Although greener solvents are slightly higher in cost, in some applications they can be worth the added expense. "You have to look at these factors and determine the total cost to use a chosen solvent," said Winfield. "What is the user willing to pay for something that is better for people and the environment?"
Winfield continued, "In coil coatings, you can use less costly solvents which are more toxic for people and not as easy to handle versus Santosol. In general, Santosol is priced in the middle in the range of commonly used solvents. These esters can be used for things like paint strippers, saturated and unsaturated polyester, as well as polyurethane cleanup blends, chemical intermediates for plasticizers, foundry binders and coil coatings."
These greener solvents give manufacturers more latitude in formulating their products. "Ultimately," said Winfield, "the producer must decide what is the best balance of safety and cost."