COPOLYMERS OF ETHYLENICALLY UNSATURATED MONOMERS TO BE USED IN POWDER COATINGS

摘要

Curable powder coating composition, comprising (a) a copolymer obtainable from ai) an alkyl diester of an ethylenically unsaturated dicarboxylic acid, comprising an alkyl group, having from 1 to 4 carbon atoms; aii) a glycidylester of ethylenically unsaturated carboxylic acid; aiii) a phenylalkylene monomer having from 8 to 12 carbon atoms; aiv) an alkenyl ester of a branched tertiary carboxylic acid the acid moiety of which contains 9 carbon atoms; av) an alkyl ester of an ethylenically unsaturated carboxylic acid, having from 3 to 4 carbon atoms in the acid moiety, and wherein the alkyL group contains from 1 to 12 carbon atoms; b) a blend of an aliphatic or cycloaliphatic dicarboxylic acid comprising from 4 to 16 carbon atoms and a polyester resin (bii), derivable from a branched polyhydroxyalkane having from 5 to 12 carbon atoms and an aliphatic or cycloaliphatic dicarboxylic acid, having from 4 to 16 carbon atoms, or an anhydride thereof; in a molar ratio of from 0.2 to 0.4 mol of polyhydroxy alkane per mol of aliphatic or cycloaliphatic dicarboxylic acid, and the polyester (bii) having an acid value of from 4500 to 4900 mmol/kg and the blend having an acid value from 5000 to 10.000, while the molar ratio between the acid groups and epoxy groups is in the range of from 0.70 to 1.10; acrylic copolymers to be used therein, a process for the preparation of said acrylic copolymers, and cured coating compositions.