Silver halide activated photochromic plastics

摘要

Photochromic plastic materials are disclosed which comprise a polymeric matrix containing a multiplicity of activated silver halide particles less than 1000 Angstroms in size. The matrix may contain a retained amount of plasticizer which optimizes the desirable photochromic properties and may be sealed to prevent loss of plasticizer. The materials are made by forming activated silver halide particles in the presence of a film forming polymer dissolved in a plasticizer and removing the plasticizer to produce a supple, shape-retaining element.