| abstract |
Powder coating compositions for metal substrates, a method of powder coating a metal substrate, and a metal article are disclosed. The powder coating composition is a thermoplastic material and comprises: (a) a first polyester having a weight average molecular weight of about 10,000 to about 80,000 and a Tg of greater than 45° C. to about 100° C., (b) a second polyester having a weight average molecular weight of about 10,000 to about 70,000 and a Tg of about -10° C. to about 45° C., and optionally, (c) a modifying resin, such as an epoxy resin having an epoxy equivalent weight of about 500 to about 15,000, wherein the Tg of the first and second polyesters differ by about 5° C. to about 60° C. The powder coating composition is applied to a metal substrate to provide a composition film having a thickness of about 1 to about 200 microns. |