HITZEHAERTBARE, TEILCHENFOERMIGE BESCHICHTUNGSMASSE

摘要

1455336 Powder coating compositions EASTMAN KODAK CO 26 Feb 1974 [26 Feb 1973] 8679/74 Heading C3R A thermosetting powder coating composition having an average particle size of from 10 to 300 microns comprises (a) 100 parts by weight of a polyester derived from a dicarboxylic acid component, at least 50 mole per cent of which is terephthalic acid and/or isophthalic acid and a glycol component, at least 50 mole per cent of which is neopentyl glycol and modified with from 2-10 mole per cent (based on the polyester) of a polyol containing from 4 to 16 carbon atoms and having at least 3 primary hydroxyl groups, (b) from 2 to 15 parts by weight of a melamine crosslinking agent, and (c) from 0À1 to 3À0 parts by weight of a blocked curing catalyst which is the reaction product of an organic acid and a compound containing at least one oxirane group. The examples describe powder coating compositions comprising (a) a polyester derived from dimethyl terephthalate and neopentyl glycol, optionally with ethylene glycol, modified with trimethylolpropane or pentaerythritol, (b) hexamethoxy- or butoxymethylmelamine, (c) a blocked curing catalyst which is the reaction product of p-toluenesulphonic acid and a bisphenol A epichlorohydrin epoxy resin, (d) a plasticizer which is an alcohol terminated polyester of neopentyl glycol and adipic acid, (e) cellulose acetate butyrate, (f) titanium dioxide and (g) a stabilizer. The powder may be coated on steel panels.