Powder coating composition and coating film forming method

摘要

The present invention provides a powder coating composition, which can ensure excellent smoothness, scratch resistance, water resistance and humidity resistance, when formed into a thin film, and a coating film forming method. The powder coating composition contains an epoxy group-containing vinyl copolymer (A) having a glass transition temperature of 40 DEG C or higher and a number-average molecular weight of 1,000 to 2,500, an epoxy group-containing vinyl copolymer (B) having a glass transition temperature of 0 DEG C or lower, and a polycarboxylic acid (C). 30 to 90% by weight of a polymerization unit of the epoxy group-containing vinyl copolymer (B) originates in a methacrylic acid alkyl ester (b-1) which has an alkyl group having 8 or more carbon atoms.