COATING CONTAINING ACRYLOSILANE POLYMER TO IMPROVE MAR AND ACID ETCH RESISTANCE

The present invention relates to a coating composition particularly useful as a clear coating used over a pigmented base coat that has improved cure, which provides increased out of oven hardness, as well as improved mar and scratch resistance, and increased environmental chemical resistance. The composition is comprised of 40 - 70% by weight of film forming binder and 30 - 60% by weight of a volatile liquid carrier for the binder; wherein the binder contains a 25 - 98.5% by weight, based on the weight of the binder, of a silane polymer, 1 - 40% by weight, based on the weight of the binder, of an alkylated melamine crosslinking agent, 0.5 - 5% by weight, based upon the weight of the binder, of an aryl or alkyl acid phosphate curing agent, and 0 - 30% by weight, based upon the weight of the binder, of a non aqueous dispersed polymer, a urethane polymer, a polyester resin, an acrylic polyol resin, or any mixture thereof. The composition may be used, in particular, as a finish for automobiles and light trucks. La presente invencion se relaciona con la composicion de revestimiento particularmente util como revestimiento transparente usado sobre la capa base pigmentada que tiene cura mejorada, la cual proporciona dureza incrementada fuera del horno, asi como resistencia mejorada a manchas y raspones, y resistencia incrementada a quimicos del medio ambiente. La composicion comprende 40-70% en peso del aglutinante filmogeno y 30-60% en peso del portador liquido volatil para el aglutinante, en donde el aglutinante contienen 25-98.5% en peso, basado en el peso del aglutinante, del polimero de silano, 1-40% en peso, basado en el peso del aglutinante, del agente de reticulacion de melamina alquilada, 0.5-5% en peso, basado en el peso del aglutinante, del agente de curado de fosfato acido de arilo o alquilo, y 0-30% en peso, basado en el peso del aglutinante, del polimero dispersado no acuoso, el polimero de uretano, la resina de poliester, la resina de poliol acrilico, o cualesquier mezcla de los mismos. La composicion puede usarse, en particular, como acabado para automoviles y luz de camiones.