Patent ID: 6100342
Filing Date: 2000-08-08
Classification: C08F,C09D

Abstract:
A method for producing a powder coating based on acrylate copolymers containing epoxy groups comprising:(a) producing carboxy-functional acrylate copolymers by radical copolymerization in an inert solvent;(b) separating said carboxy-functional acrylate copolymers and reacting said carboxy-functional acrylate copolymers with at least one epihaloalkane in the presence of a catalyst, wherein said at least one epihaloalkane is used in a molar excess of 10:1 based on the moles of carboxylic groups of said copolymers;(c) removing excess epihaloalkane;(d) adding toluene and subsequently reacting said acrylate copolymers with a sodium hydroxide solution to produce acrylate copolymers containing epoxy groups, wherein said acrylate copolymers containing epoxy groups have an epoxide number of from 0.018 to 0.501 (equiv./100 g copolymer), a weight average molecular weight of from 1000 to 30,000 and a glass transition temperature of from 20 to 120.degree. C.; and(e) extruding said acrylate copolymers containing epoxy groups together with a hardener selected from the group consisting of aliphatic polybasic acids, anhydrides of cycloaliphatic polybasic acids, polyol-modified anhydrides of cycloaliphatic polybasic acids, amorphous carboxy-functional copolyester resins, semi-crystalline carboxy-functional copolyester resins, carboxy-functional acrylate resins, and mixtures thereof, along with optional pigments, fillers, or additives other than pigments or fillers or mixtures thereof;to form a thermosetting powder coating.