A HIGH SOLIDS COATING COMPOSITION OF A BLEND OF A LOW MOLECULAR WEIGHT ACRYLIC POLYMER AND A MEDIUM MOLECULAR WEIGHT ACRYLIC POLYMER AND AN ALKYLATED MELAMINE CROSS-LINKING AGENT

摘要

The high solids coating composition contains at least 50% by weight of a binder of film-forming constituents in which the constituents are of (A) a medium molecular weight acrylic polymer that has a number average molecular weight of about 5,000-20,000, a hydroxyl content of at least 2% by weight, a glass transition temperature of about -20 DEG C. to +25 DEG C., and is of an alkyl methacrylate, a hydroxy alkyl acrylate or a hydroxy alkyl methacrylate, and optionally, an alkyl acrylate or styrene; (B) a low molecular weight acrylic polymer that has a number average molecular weight of about 500-7,500 a hydroxyl content of at least 2% by weight, a glass transition temperature of about -20 DEG C. to +25 DEG C., and is of an alkyl methacrylate, a hydroxy alkyl acrylate or a hydroxy alkyl methacrylate, and optionally, an alkyl acrylate and styrene; (C) an alkylated melamine formaldehyde cross-linking agent; and an acid catalyst; the composition is particularly useful as an exterior finish for automobiles, trucks, airplanes and can be used as an appliance finish and for coil coatings.