Low gloss powder coating composition and method for coating therewith

Abstract

A powder coating composition for forming a low gloss coating film based on thermosetting polyester resins exhibiting only a little fluctuation of the resultant low gloss value even if an unequality in the mixing proportion of components or in the baking condition exists, comprising three thermosetting polyester resins (A), (B) and (C) and a hardener (D), wherein the weight ratio of the polyester resin (A) to the polyester resin (B) is in the range of 90/10-70/30 and that of the polyester resin (A) to the polyester resin (C) is in the range of 85/15-60/40 and the equivalent ratio of the polyester resin (A, B or C) to the hardener (D) is each in the range of 0.8 to 1.25 and wherein the polyester resins (A), (B) and (C) are selected from those in which the moduli of elasticity E.sub.a, E.sub.b and E.sub.c for the products of the curing reaction of these resins with the hardener (D), respectively, after 3 minutes' curing with the hardener (D) at 200.degree. C. hold a relatioship that the differences between the moduli of elasticity E.sub.b-a =E.sub.b -E.sub.a and E.sub.c-a =E.sub.c -E.sub.a are maintained in the following ranges, respectively: 20 dyn/cm.sup.2 <E.sub.b-a <10.sup.3 dun/cm.sup.2 and 1 dyn/cm.sup.2 <E.sub.c-a <10 dyn/cm.sup.2

Dependencies are inferred from the claim text.