Thermosetting acrylic powder coating compositions

Abstract

A thermosetting powder coating composition comprising: A. a functional glycidyl group-containing graft copolymer of I. 10 to 40 percent of a linear polyester having a number average molecular weight of 600 to 3,000 and containing one terminal carboxyl group and Ii. 60 to 90 percent of acrylic copolymer of ii-a) 6.5 to 60 percent of at least one of glycidyl esters having the formula ##STR1## wherein R.sub.1 is hydrogen or methyl, ii-b) 10 to 93.5 percent of at least one of acrylic monomers having the formula CH.sub.2 .dbd.C(R.sub.2)COOR.sub.3 wherein R.sub.2 is hydrogen or methyl and R.sub.3 is alkyl having 1 to 14 carbon atoms, cyclohexyl or hydroxyalkyl having 1 to 4 carbon atoms, and ii-c) 0 to 65 percent of additional monomers selected from the group consisting of acrylonitrile, methacrylonitrile and styrenes having the formula ##STR2## wherein R.sub.4 is hydrogen or alkyl having 1 to 4 carbon atoms, said graft copolymer having a softening point of 70.degree. to 110.degree. C and a number average molecular weight of 2,000 to 30,000 and containing glycidyl group in an amount of 0.35 to 2.35 moles per kilogram of the graft copolymer; and B. at least one of polycarboxylic acids and anhydrides thereof in an amount of 0.6 to 1.2 moles in terms of carboxyl group per mole of the glycidyl group contained in the graft copolymer.

Dependencies are inferred from the claim text.