Abstract: A curable powder film-forming composition which includes: (a) about 55 to 80 percent by weight based on the total weight of resin solids in the film forming composition, of an epoxy functional copolymer having a Tg of about 77° F. to about 158° F. formed by free radical initiated polymerization of: (i) about 25 to about 75 percent by of a glycidyl functional ethylenically unsaturated monomer, and (ii) about 25 to about 75 percent by weight of a copolymerizable ethylenically unsaturated monomer or mixture of monomers free of glycidyl functionality; (b) about 15 to about 35 percent by weight of a polycarboxylic acid; and (c) about 1.0 to about 4.0 percent by weight of a polyisocyanate at least partially capped with a capping agent. A multi-component composite coating composition is also provided, which includes a pigmented film-forming base coat and a transparent top coat of the film-forming composition described above.

Abstract: N-acyl aminomethylene phosphonates are provided having a group defined by the following general formula: ##STR1## wherein R.sub.1 is hydrogen, an aliphatic radical having 1 to 25 carbon atoms, or an aromatic radical having 6 to 25 carbon atoms; R.sub.2 is hydrogen, an aliphatic radical having 1 to 25 carbon atoms, or an aromatic radical having 6 to 25 carbon atoms; and R.sub.3 is a group remaining after reaction of a hydroxyl group-containing or epoxy group-containing polymer with an acidic hydrogen of a ##STR2## group. Also provided are waterborne coating compositions containing metallic pigments which are normally reactive with water or moisture to release hydrogen gas, stabilized against gassing by incorporation of these N-acyl aminomethylene phosphonates into the waterborne coating compositions.