Patent ID: 6034193
Filing Date: 2000-03-07
Classification: C08F,C08K,G02B

Abstract:
Photochromic transparent organic materials presenting an index of refraction of more than 1.55, which are free of optical distortions, and prepared by radical polymerization of a polymerizable composition comprising:a) 80-95 wt % of at least one monomer represented by the general formula (I): ##STR11## where R=H or CH.sub.3, and m and n are independently 1 or 2; b) 5-20 wt % of at least one aromatic monovinyl monomer represented by the general formula (II): ##STR12## c) an effective quantity of at least one dye that imparts photochromic properties to the material, selected from the group consisting of spiroxazines, spiropyrans and chromenes;d) an effective quantity of a linear alkanethiol chain transfer agent; ande) an effective quantity of a diazo compound as a radical polymerization initiator.