CATIONIC ELECTROPHORETIC COATING COMPOSITION AND COATING METHOD

摘要

The invention provides (a) a cationic electrophoretic coating composition comprising: (i) a water-soluble to water-dispersible resin containing primary or secondary hydroxyl, tertiary amino and an isocyanate adduct residue having alpha , beta -unsaturated carbonyl and (ii) at least one specified curing catalyst; or (b) a cationic electrophoretic coating composition comprising a water-soluble to water-dispersible resin containing an isocyanate adduct residue having alpha , beta -unsaturated carbonyl, primary or secondary hydroxyl and at least one onium organic acid salt selected from among quaternary ammonium, quaternary phosphonium and tertiary sulfonium organic acid salts. In alternative embodiments, the hydroxyl groups and isocyanate adduct residues may be present in separate resins in composition (a) or (b), with the tertiary amino or onium groups being incorporated in either or both of the resins.