SEARCH FOR A CHROMATE-FREE WASH PRIMER

Due to the toxicity concerns associated with chromates and chromate pigments (known carcinogens), a chromate-free wash primer has been developed. The chromate-free wash primer is a two-component system based on a polyvinyl butyral resin containing a combination of phosphate and borate anticorrosive pigments, coloring pigments, alcohol solvents, and an organofunctional silane. Laboratory evaluations have shown that the chromate-free wash primer has similar anticorrosive properties to the traditional wash primer under salt fog, salt water immersion, and atmospheric exposure conditions.