Abstract: Curable film-forming compositions containing epoxy functional copolymers, polycarboxylic acid crosslinking agents, and triaryltin compound having the chemical structure of (Ar).sub.3 SnOR wherein the aryl groups are the same or different and at least one aryl group is substituted with at least one atom or group selected from the group consisting of carbon, nitrogen, oxygen, sulfur, phosphorous, silicon and halogen and R is selected from the group consisting of hydrogen, alkyl, and acyl groups are disclosed. The compositions do not release benzene during cure. The compositions may be powder or liquid and are useful as clear coats, particularly in a color-plus-clear composite coating system.

Abstract: A powder coating composition comprises (a) from 60-90 percent by weight of an epoxy functional copolymer having a Tg of from 25.degree.-70.degree. C. formed by polymerizing from 50-75 percent by weight of a glycidyl functional monomer and from 35-50 percent by weight of a monomer free of glycidyl functionality, and (b) from 10-40 percent by weight of a polycarboxylic acid crosslinking agent, wherein the ratio of epoxy:acid functionality is about 1:0.8 to 1.

Abstract: Powder coating compositions based on epoxy functional copolymers and polycarboxylic acid curing agents are disclosed. The compositions have high epoxy content providing for excellent physical and chemical properties. In addition, the compositions are formulated such that they have a relatively low melt viscosity which provides for good flow and excellent coating appearance. The compositions are useful as clear coats.