Color-plus-clear composite coating and process and coated article for improved properties

摘要

A composite coating of a water-borne basecoat and an epoxy- acid clearcoat has improved performance characteristics of reduced yellowing or reduced tendency to chip through the formulation of the composite coating and the process for its application. The process comprises applying to the substrate a film-forming composition to form a basecoat and applying to the basecoat an epoxy-acid clear film-forming composition to form a transparent topcoat over the basecoat. The basecoat is a coating composition comprising a polymeric film-forming resin, aminoplast crosslinking agent and a pigment wherein the crosslinking agent is a partially or fully alkylated aminoplast and has a lower or higher imino content. The lower imino content promotes reduced yellowing of the clearcoat and the higher imino content promotes improved chip resistance when the pigment of the water-borne basecoat reduces yellowing effects. The transparent topcoat, or clearcoat, has an epoxy film forming resin and a polycarboxylic acid crosslinking agent.