| 摘要 |
In a first embodiment a polyoxetane-polyester polymer comprising a hydroxyl terminated polyoxetane prepolymer containing repeat units derived from polymerized oxetane monomers having one or two pendant -CH2-O- (CH2)n-Rf groups wherein Rf is partially or fully fluorinated, where the polyoxetane prepolymer is esterified with polyester forming reactants to form the polyoxetane-polyester polymer, and said polymer is mixed with a reactive lower alkyl etherified melamine formaldehyde to form a thermoformable coating composition. In a second embodiment, the coating composition is based on a polyester mixed with the lower alkyl etherified melamine formaldehyde and is substantially free of the polyoxetane. The coating composition is partially cured in a first stage heating at less than about 180° F. to provide a thermoformable partially cured, tack-free, non-blocking, coating layer, followed by application to generally a contoured substrate and thermoformed to conform thereto. The contoured partially cured coating layer is then heat cured at temperatures above at least 180° F. for time sufficient to form a cured coating.
|
