Thermosetting powder coating composition

Abstract

The present invention provides a polyester-based powder coating composition for coating a shaped or shaped article that exhibits improved properties, such as weather resistance and flexibility. Typically, the polyester is composed of a residue of 2, 2, 4, 4-tetramethyl-1, 3-cyclobutanediol; a diol residue selected from the group consisting of neopentyl glycol, cyclohexanedimethanol, 1, 6-hexanediol, 1, 4-butanediol, hydroxypivaloyl hydroxypivalate, and combinations thereof; a trimethylolpropane residue; and hexahydrophthalic anhydride residues. The polyester component of the composition is formulated predominantly in carboxyl functional form and has an acid number of from about 20 mg KOH / g to 90 mg KOH / g resin, thus being suitable for crosslinking in thermoset powder coating composition systems with crosslinking compounds known to react with such carboxyl groups.