Powder Coatings

摘要

Powder coating composition which can prevent the occurrence of blocking therein and can be formed into a coating film having both good appearance and good flexibility,comprises a fluorinated copolymer and a curing agent.The fluorinated copolymer is prepared by the polymerisation of a monomer mixture comprising(A)45 to 55 mol% of chlorotrifluoroethylene and/or tetrafluoroethylene,(B)2 to 40 mol% of a vinyl ether,which has an alkyl group having 4 or 5 carbon atoms and containing a tertiary carbon atom,(C)5 to 20 mol% of a vinyl ether having a crosslinkable functional group,and(E)0 to 32 mol% of a vinyl ester which has an alkyl group having 3 to 5 carbon atoms and containing a tertiary or higher carbon atom,wherein the sum total of the components(B)and(E)is 30 to 50 mol%.The fluorinated copolymer also has a glass transition temperature of 50°C or higher and a number average molecular weight of 10,000 to 22,000.The curing agent can react with the crosslinkable functional group.