COMPOSITION FOR THERMOSETTING POWDER COATING

摘要

A composition for thermosetting powder coating, which comprises (a) an acrylic copolymer of high softening point having an epoxy equivalent of 250-1,000 g/eq and a softening point of 90-160C, (b) an acrylic copolymer of low softening point having an epoxy equivalent of 200-600 g/eq and a softening point of 30-70C, (c) a polycarboxylic acid, and (d) optionally, a phosphoric acid ester compound and/or a phosphorous acid ester compound, and wherein the difference in softening point between (a) and (b) is 60-120C, the weight ratio of (a)/(b) is 95/5 to 60/40, and the equivalent ratio of [the total epoxy groups of (a) and (b)] : [the acid group of (c)] is 0.5 : 1 to 1 : 0.5. Said composition has excellent storage stability and, when used as a coating for automobiles, gives a film superior in appearance, solvent resistance and acid resistance.