Patent ID: 7452611

Claim:
photochromic article comprising, in combination: (a) an organic polymeric substrate, (b) a photochromic organic polymeric coating appended to at least one surface of the polymeric substrate, said polymeric coating comprising a photochromic amount of at least one organic photochromic material and having a Fischer microhardness ranging from 15 to 80 Newtons per mm 2 , (c) a radiation-cured, acrylate-based film coherently superimposed on the photochromic polymeric coating, said radiation-cured acrylate-based film being prepared from a polymerizable composition comprising more than 50 weight percent of acrylic functional monomers, and (d) an abrasion resistant coating coherently superimposed on the radiation-cured, acrylate-based film; wherein the radiation-cured, acrylate-based film of (c) is harder than the photochromic organic polymeric coating of (b), the abrasion resistant coating of (d) is harder than the radiation-cured, acrylate-based film of (c), and the radiation-cured, acrylate-based film of (c) is resistant to removal by aqueous inorganic caustic.