| 摘要 |
<p>A process for coating substrate is disclosed. In particular, a process is disclosed for painting metal objects such as automobile bodies by electrostatic spray of specifically limited powder coating compositions. More particularly, this invention is concerned with a process for painting metal objects by electrostatic spray of powder coating compositions which utilize as the thermosetable component a blend of a polymer of an anhydride of a dicarboxylic acid and an epoxyfunctional, anhydride-functional, self-crosslinking copolymer of ethylenically unsaturated monomers. This copolymer is deficient in anyhdride-functionality. This copolymer has a glass transition temperature in the range of 40.degree.C to 90.degree.C, preferably 50.degree.C to 70.degree.C, and a molecular weight (Mn) in the range of about 2,000 to about 10,000. The polyanhydride of the blend has a molecular weight in the range of about 300 to about 4,000, preferably about 1,500 to about 2,500.</p> |
