Patent ID: 8188173

Claim:
A polyvinyl acetal powder coating material comprising: a polyvinyl acetal resin; and 0.2 to 3% by weight of an antioxidant relative to the weight of the polyvinyl acetal resin, wherein the antioxidant is at least one selected from the group consisting of hexamethylene-bis [3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, N,N′-hexane-1 ,6-diylbis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionamide, 4,4′-butylidenebis(6-t-butyl-3-methylphenol) and 3,9-bis {1,1-dimethyl-2-[β(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy)ethyl}2,4,8,10-tetraoxaspiro [5,5]-undecane.