Photochromic polyurethane coating and articles having such a coating

摘要

Described are photochromic polyurethane coatings having improved durability as demonstrated by reduced swelling upon exposure to alcoholic solvents in the Percent Swelling Test. The coatings are prepared using polycarbonate polyols alone or in combination with different polyols as the source of hydroxyl groups. Also described are articles having such coatings. The coatings exhibit a Fischer microhardness of from 50 to 150 Newtons per mm2 and good photochromic properties.