Abstract: Composite articles are prepared by a spray up operation. In a first step, a gel coat is applied onto a mold surface. Next, a barrier coat is applied over the gel coat in the mold and thereafter a laminate formula is applied over the barrier coat. In a preferred embodiment, the multilayer composite has a thickness of about 15 mm or less, and is useful as an automobile body panel. The gel coat contains a curable polyester polyurethane acrylate resin, and the composite article has a surface that has high gloss and color retention after prolonged exposure to ultraviolet radiation.

Abstract: A gel coat for a surface of a composite article contains a curable urethane acrylate resin preferably based on aliphatic polyester polyols and aliphatic polyisocyanates. The gel coat provides a surface that has high gloss and color retention after prolonged exposure to ultraviolet radiation. The gel coat composition contains resin and acrylic diluents, including optional difunctional and trifunctional diluents. The gel coat is optionally pigmented to produce an article that may be used without further surface treatment.

Abstract: Composite articles are prepared by a spray up operation. In a first step, a gel coat is applied onto a mold surface which has been optionally pretreated with a mold release coating. Next, a barrier coat is applied over the gel coat in the mold and thereafter a laminate formula is applied over the barrier coat. The laminate contains from 20-60% by weight reinforcing fibers. In a preferred embodiment, the multilayer composite has a thickness of about 15 mm or less, and is useful as an automobile body panel. The gel coat contains a curable polyester polyurethane acrylate resin, and the composite article has a surface that has high gloss and color retention after prolonged exposure to ultraviolet radiation. The laminate preferably comprises a low shrink, low density glass fiber filled polyester resin.