Abstract: Described is a photochromic composition which is a polymerizate of acrylate monomer(s), a crosslinking amount of anhydrous acrylic anhydride and/or anhydrous methacrylate anhydride and a photochromic amount of pyrido benzoxazine. Depending on the amount of crosslinking agents and the other components selected to form the polymerizate, the polymerizate will exhibit improved temperature stability with regard to photocolorability and/or prevention of activation in sunlight.

Abstract: An improved method for authenticating articles is described. A mixture of at least two photochromic compounds that have different absorption maxima in the activated state and also preferably other different properties are incorporated into a carrier composition, e.g., ink, paint, fiber or polymer used to form the authenticating display data on the article. The authenticating display data is subjected to various steps of the authenticating method that may include preferential activation of less than all of the photochromic compounds, activation of all the photochromic compounds, preferential bleaching of less than all of the photochromic compounds, and bleaching of all the photochromic compounds. Subsequent examination of the display data following the various activation and bleaching steps by verifying means enables the article to be authenticated.

Abstract: Described are novel reversible photochromic naphthopyran compounds substituted at the number eight carbon atom on the naphtho portion of the naphthopyran ring with, for example, a methoxy group. Also described are organic host materials that contain or that are coated with such compounds. Articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel naphthopyran compounds are also described.