Patent ID: 9212256
Filing Date: 2015-12-15
Classification: C08G

Abstract:
1. An unsaturated polyester resin comprising: a) at least one unsaturated polyester and b) at least one comonomer which is copolymerizable with said at least one unsaturated polyester a), characterized in that said at least one unsaturated polyester a) is an unsaturated polyester comprising lactic acid, an acid component, and a polyol component, wherein 25 to 90 mol % of phthalic anhydride of the acid component of said polyester is replaced with lactic acid, and the acid component of said unsaturated polyester a) comprises from 20 to 80 mol % of at least one of maleic anhydride (MA) and fumaric acid (FA), and from 80 to 20 mol % of phthalic anhydride (PA), and the polyol component of said unsaturated polyester a) comprises from 50 to 100 mol % of propylene glycol (PG), and from 0 to 50 mol % of an additional polyol selected from the group consisting of ethylene glycol (EG), diethylene glycol (DEG), dipropylene glycol (DPG), 1,3-butylene glycol, 1,4-butanediol and neopentyl glycol (NPG), wherein: said at least one unsaturated polyester a) has a molar ratio of lactic acid to total acid component of from 0.4 to 1.75; and the at least one unsaturated polyester a) is the reaction product in a one-step reaction mixture comprising said acid component, said polyol component and said lactic acid.