摘要 |
<p>The invention relates to photochromic transparent organic materials presenting an index of refraction of more than 1.55, which are free of optical distortions and are prepared by radical polymerization of a polymerizable composition comprising: a) 80-95 wt. % of at least one monomer represented by general formula (I), where R = H or CH3, and m and n are independently 1 or 2; b) 5-20 wt.% of at least one aromatic monovinyl monomer represented by general formula (II) where R1 = H or CH3; c) an effective quantity of at least one dye that imparts photochromic properties to the material, selected from the groups of spiroxazines, spiropyrans and chromenes; d) an effective quantity of a chain transfer agent; and e) an effective quantity of a radical polymerization initiator, characterized in that the chain transfer agent is a linear alkanethiol and the radical polymerization initiator is a diazo compound.</p> |