Coatings Industry Responses to Regulation

Reduction of Solvent Emission by Selection of Application Method 

Transfer efficiency is reported [14] to be an important consideration for controlling solvent emission levels. Estimated transfer efficiency for various methods to be viewed as only a general guideline [14] are shown in Table 6.4. Transfer efficiency is defined as the percentage of paint that is actually deposited on 

Electrodeposition coating in its present form was developed mainly for applying corrosion-resistant primers to automobile body assembly. It is evident in Table 6.4 that it provides very high transfer efficiency. Other advantages are discussed in Section 6.7.2 

As recently as the 1970s and early 1980s, solvent-based primers were recommended for the do-it-yourself house painter for good adhesion over highly weathered (chalky) surfaces. Improvements in formulation have resulted in much improved adhesion of waterborne primers over chalky exterior walls. Now waterborne latex is used by nearly all do-it-yourself house painters for both primer and topcoat. 

As noted in Section 6.5.2, the hydrolysis resistance of latex films from emulsion polymers prepared from the vinyl acetate (VA) monomer is marginal for ontdoor use. In Europe and recently in the United States, vinyl versatate (II) (Ri = —CH2CH2CH2CH2CH2CH2CH3 and R2 = R3 = —CH3) has been introduced for use along with vinyl acetate for improved outdoor performance of latex coatings. Vinyl versatate is the vinyl ester of versatic acid, a 10-carbon carboxylic acid of the highly branched structure sometimes called neo  

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Solvent Recovery. Most of the activated carbon used in gas-phase applications is employed to prevent the release of volatile organic compounds into the atmosphere. Much of this use has been in response to environmental regulations, but recovery and recycling of solvents from a range of industrial processes such as printing, coating, and extmsion of fibers also provides substantial economic benefits. 

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