POLYURETHANE LAYER FOR A LIGHT DIRECTING ARTICLE

摘要

The disclosed aliphatic thermoplastic polyurethane composition is well suited for use in thin, flexible light directing articles to impart flexibility, toughness, or protection to the light directing articles that contain optically active elements. The disclosed aliphatic thermoplastic polyurethanes have improved thermostability at higher temperatures. Specifically, the disclosed aliphatic thermoplastic polyurethanes have a cross-over temperature greater than 110°C. In one embodiment, the cross-over temperature is greater than 130°C. In one embodiment, the cross-over temperature is less than 170°C and a Tg greater than 35C and less than 70C.