Powder coating resin process

Claim 1

A curable powder resin composition with a sintering temperature above 40°C. and curable in the temperature range of 120° to 220°C., comprising: A. from about 15 to 30 parts by weight of a condensate of a methylolamino compound, an aliphatic alcohol containing from 1 to 4 carbon atoms and an aromatic sulfonamide of number average molecular weight less than 500; wherein the methylolamino compound is a methylolurea or methylolaminotriazine containing no more than one unmethylolated N-H bond per molecule, wherein the molar ratio of aliphatic alcohol to methylolamino compound is at least 2, wherein the molar ratio of the methylolamino compound to the aromatic sulfonamide is from about 1:0.5 to about 1:2 when the reactive compound contains one reactive group per molecule and is from about 1:0.5 to about 1:1.5 when the aromatic sulfonamide contains 2 or more reactive groups per molecule, wherein at least about 50 percent of the methylol groups of the methylolamino compound have been condensed with the aliphatic alcohol or the aromatic sulfonamide and wherein the glass transition temperature of the condensate is in the range of from -10° to 100°C.; and B. from about 85 to 70 parts by weight of a polyester resin or an acrylic resin wherein the resin has a glass transition temperature in the range of from 60° to 100°C., and a number average molecular weight in the range of 500 to 25,000, and contains alcoholic hydroxyl groups, carboxyl groups or amide groups, heat reactive with the condensate of the methylolamino compound, wherein the polyester resin has an acid number in the range of 1 to 25 or a hydroxyl number in the range of 11 to 200, and wherein the acrylic resin contains from 0.13 to 18 percent by weight of hydroxyl, carboxyl, or amide groups.