Patent ID: 6313221
Filing Date: 2001-11-06
Classification: B05D,C08G,C09D

Abstract:
A thermosetting powder coating composition prepared by a wet process, said composition containing a mixture comprising:(a) epoxy-containing acrylic resin A and epoxy-containing acrylic resin B, said resins A and B satisfying the properties:(1) (SP.sub.A -SP.sub.B) is within the range of from 0.2 to 1.5, wherein SP.sub.A is the solubility parameter of resin A and SP.sub.B is the solubility parameter of resin B;(2) T.sub.g (A)-T.sub.g (B).gtoreq.10.degree. C., wherein T.sub.g (A) is the glass transition temperature of resin A and T.sub.g (B) is the glass transition temperature of resin B;(3) T.sub.g (A) is within the range of from 40 to 100.degree. C. and T.sub.g (B) is within the range of from 20 to 50.degree. C.; and(4) a solids weight ratio of resin A to resin B is within the range of from 5:95 to 50:50;(b) a polycarboxylic acid compound curing agent; and(c) fine crosslinked resin particles.(d) a resin in liquid form in an amount of from 5-70 parts by solids weight per 100 parts of the total solids weight of epoxy-containing resin (a) and resin (d), wherein (SP.sub.B -SP.sub.d) is within the range of from 0.01 to 1.5, SP.sub.d being the solubility parameter of resin (d);said wet process comprising the steps of:(1) allowing components (a), (b), (c) and (d) to dissolve or disperse in an organic solvent to provide a solution;(2) adding said solution to an aqueous solution containing a water-soluble polymer having a cloud point of from 30 to 90.degree. C. and mixing them at a temperature below said could point to provide a suspension containing primary oil particles; and(3) heating said suspension to a temperature equal to or higher than the cloud point to form secondary oil particles and distilling off said organic solvent from a system to collect he particles.