Patent ID: 7662433

Claim:
A process for obtaining an impact resistant, abrasion and/or scratch resistant photochromic article comprising a substrate having two main faces comprising: preparing a curable coating composition comprising at least one unblocked polyisocyanate terminated polyurethane pre-polymer, at least one polyol, and at least one photochromic agent; wherein the polyurethane pre-polymer has a number average molecular weight of from 1,000 to 6,000 g/mol depositing the prepared curable coating composition onto at least part of a main face of the substrate; curing said curable coating composition for 10 minutes or less, at a temperature lower than or equal to 100° C. so as to form an impact resistant photochromic coating; and forming an abrasion and/or scratch resistant coating on the impact resistant photochromic coating or forming a protective coating on the impact resistant photochromic coating and then forming an abrasion and/or scratch resistant coating on said protective coating.