US 8,536,259 B2
USG Interiors, LLC has been awarded a patent for a curable, formaldehyde-free coating composition comprised of a composition comprised of a polyacid copolymer comprised of at least two carboxylic acid groups, anhydride groups, or salts thereof, a hydroxyl group-containing compound bearing at least two hydroxyl groups as an independent compound or incorporated into the polyacid copolymer backbone and  a phosphorus-containing catalyst; andncalcium aluminosilicate powder having a total alkali content of less than about 2% weight based on the total weight of the calcium aluminosilicate powder, a median particle size of approximately 250 microns or less and a surface area from approximately 1 m2/g to  3 m2/g, wherein the ratio of the number of equivalents of the carboxylic acid groups, anhydride groups or salts thereof to the number of equivalents of the hydroxyl groups is from 1/0.01-1/3.