COATINGS CONTAINING HYDRAZIDE COMPOUNDS FOR ENHANCED DURABILITY

摘要

A coating composition comprising a) a polymer having at least one functional group that is reactive with a crosslinking agent; b) a crosslinking agent; c) a hydrazide group that is attached to the polymer a), the crosslinking agent b), or part of a compound different from a) or b). Basecoat, clearcoat and color-plus-clear composite coatings which comprise the above described composition provide good resistance to surface degradation caused by exposure to ultraviolet or visible light, or to severe weathering conditions. Likewise, the coatings demonstrate good retention of distinctness of image (DOI) and gloss upon extended exposure to severe weathering. When the hydrazide compound is utilized in a clearcoat of a color-plus-clear composite coating, good intercoat adhesion was obtained. A method for improving the resistance of a cured film to environmental degedation comprises applying to a substrate a coating composition a basecoat or a clearcoat comprising the above described coating composition.