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°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°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.
本发明提供了一种粉末涂料组合物,该组合物在形成薄膜时可确保优异的平滑性、抗划伤性、耐
水性和防潮性,还提供了一种涂膜形成方法。该粉末涂料组合物含有
玻璃化转变温度为 40°C 或更高且数均分子量为 1,000 至 2,500 的含环氧基
乙烯基共聚物(A)、
玻璃化转变温度为 0°C 或更低的含环氧基
乙烯基共聚物(B)和聚
羧酸(C)。含环氧基的
乙烯基共聚物(B)的聚合单元重量的 30%至 90%来自
甲基丙烯酸烷基酯 (b-1),该烷基酯具有 8 个或更多碳原子的烷基。