Color plus clear application of thermosetting high solids coating composition of hydroxy-functional epoxies and anhydrides
AssigneePPG Industries, Inc.
InventorsWilliam P. Blackburn, Ronald R. Ambrose, Samuel Porter, Jr., Mary Jo Burkholder
Life of this patent
Estimating the term…
Abstract
Disclosed herein is an improved process for preparing color-plus-clear coatings, the improvement comprising high solids thermosetting coating compositions comprising hydroxy-functional polyepoxides and anhydrides as effective curing agents therefor. Films of these coating compositions are of remarkable appearance and are attended by remarkably low volatile organic content (VOC).
Claims13
An improved process of applying a composite coating to a substrate, said process comprising applying to the substrate a colored film-forming composition to form a base coat, and applying to said base coat a clear film-forming composition to form a transparent top coat over the base coat;
- followed by heating the composite coating to a temperature sufficient to provide effective cure;
- the improvement comprising the clear and/or base coat containing a high solids solvent-based thermosetting composition comprising:
- (a) a low number average molecular weight hydroxy-functional polyepoxide,
- (b) a curing agent consisting essentially of an anhydride,
- (c) a cure catalyst selected from the group consisting of an onium salt which is a quaternary ammonium salt or a phosphonium salt, and a tertiary amine;
- said composition is characterized in that it is curable in the absence of a melamine curing agent.
Dependencies are inferred from the claim text.