Clearcoat composition with improved adhesion

摘要

Clearcoat coating composition for automotive exterior coatings with improved intercoat adhesion to a subsequently applied coating layer and improved flexibility contains (a) a first vinyl copolymer prepared from a monomer mixture including no more than about 35% by weight of nonfunctional monomers that has carbamate functionality and hydroxyl functionality, at least part of the hydroxyl functionality being on monomer units including an optionally branched alkyl group having at least about six carbon atoms; (b) a second vinyl copolymer having hydroxyl functionality, preferably primary hydroxyl functionality; and (c) a curing agent component that includes at least an aminoplast curing agent and optionally a polyisocyanate curing agent. The polyisocyanate curing agent is preferably blocked with a blocking agent that volatilizes during the cure reaction, regenerating a reactive isocyanate group.