Powder coating compositions containing glycidyl ester copolymers and organic carboxylic acid anhydride crosslinking agent

A powder coating composition which, exclusive of pigments and other nonreactive components, comprises a coreactable mixture of:

• (A) a copolymer of about 5 to about 20 weight percent of a glycidyl ester of a monoethylenically unsaturated acid and about 95 to about 80 weight percent of other monoethylenically unsaturated monomers consisting essentially of monofunctional, alpha-beta olefinically unsaturated monomers, said copolymer having a glass transition temperature in the range of 40.degree. C to 90.degree. C and a molecular weight (M.sub.n) in the range of 2500 to 8500;
• and (B) an organic carboxylic acid anhydride selected from the group consisting of anhydrides of saturated aliphatic carboxylic acids containing between about 4 and about 20 carbon atoms, unsaturated aliphatic carboxylic acids containing between about 4 and about 20 carbons, atomatic carboxylic acids;
• saturated, alicyclic carboxylic acids;
• unsaturated, alicyclic carboxylic acids;
• heterocyclic carboxylic acids;
• and polymers of saturated or unsaturated carboxylic acids, said anhydride being included in an amount ranging from about 0.4 to about 1.0 anhydride groups per epoxy group in the copolymer.