Patent ID: 7101590

Claim:
A method of coating a metal substrate comprising: (a) heating the metal substrate to a temperature of about 120° C. to about 250° C. to provide a pre-heated metal substrate; (b) heating a solid, thermoplastic coating composition to a sufficient temperature to melt the coating composition and provide a molten coating composition, while avoiding curing and degradation of the composition, said coating composition comprising: 50% or more, by total weight of the composition, of a polyester having a weight average molecular weight of about 10,000 to about 50,000, and a glass transition temperature of about −30° C. to about 120° C.; (c) extruding the molten coating composition onto a surface of the preheated metal substrate to provide a layer of molten coating composition less than about 40 microns thick on the preheated metal substrate and provide a coated metal substrate; (d) postheating the coated metal substrate after the extrusion step at a temperature of up to about 550° C.; and (e) allowing the coated metal substrate to cool.