Patent No. U.S. 7,141,308 B2
PPG Industries has received a patent for a crosslinking agent comprised of an ungelled reaction product of the following reactants: at least one aminoplast resin; and at least one aromatic heterocycle containing at least one ring nitrogen atom with an active hydrogen attached thereto; wherein the crosslinking agent has a glass transition temperature of at least 10°C and is substantially free of active hydrogen-containing groups and wherein the aromatic heterocycle is comprised of at least 10% weight of the weight of reactants.