Basecoat coating composition having low volatile organic content and composite coating prepared therefrom

摘要

The invention provides a thermosetting aqueous basecoat coating composition with a pigment to binder ratio of at least about 0.5 that includes a polyurethane polymer, an acrylic polymer, and a crosslinking component that is reactive with at least one of the polyurethane polymer and the acrylic polymer. The polyurethane polymer has a glass transition temperature of 0° C. or less. The acrylic polymer has a glass transition temperature that is at least about 20° C. higher than the glass transition temperature of polyurethane resin. The invention further provides a composite coating on a substrate having as a basecoat layer a cured layer of the basecoat composition of the invention and having at least one clearcoat layer over the basecoat layer.