Abstract: A window for use in a vehicular convertible top comprises a thin, flexible, optically transparent plastic substrate sheet, and a thin, flexible, optically transparent abrasion-resistant protective outer film layer adherently bonded as a permanent coating to both sides of the plastic substrate sheet. The protective outer film layer comprises a weatherable polymer which is transparent in thin film form reacted with a cross-linking agent and blended with a dispersed lubricant to provide a level of abrasion-resistance and a self-lubricating exterior surface to the finished protective outer film. The window withstands repeated folding and unfolding without self-adhesion of the contacting surfaces owing to the release properties provided by the lubricant. In one embodiment, the weatherable polymer comprises a solvent based solution of a polyurethane material reacted with a polyisocyanate cross-linking agent and blended with a polyol-ester glycol-based external lubricant.

Abstract: A window for use in a convertible top comprises a thin, flexible, optically transparent plastic sheet and a thin, flexible, optically transparent thermoplastic abrasion-protective coating applied to both faces of the plastic sheet. The abrasion-protective coating comprises a weatherable polymer such as an acrylic polymer which is transparent in thin film form and adhered to the plastic sheet as a semi-permanent coating removable by an alkaline water-based cleaning agent. The thin-film form coating provides a level of abrasion protection by preferentially abrading while protecting the underlying clear plastic window from scratching. A preferred coating comprises a water-based emulsion of an acrylic polymer such as an acrylic floor polish diluted with water and applied to the window by a dipping process.