Method for preparing a photochromic polyurethane latex and application to ophthalmic optics

摘要

Described are photochromic polyurethane coatings that meet commercially acceptable "cosmetic" standards for optical coatings. Also described are articles having such coatings. The coatings exhibit a Fischer microhardness of from 50 to 150 Newtons per mm and improved photochromic properties, i.e., the formation of darker activated colors and faster rates of photochromic activation and fade when irradiated with ultraviolet light.