Patent ID: 9605103
Date: 2017-03-28
CPC Classifications: C08F,C09K,G02B,G02C

Claim:
1. A process for producing photochromic optical materials, comprising: a step (i) of reacting at least one polymerizable monomer (A) having two or more ethylene-based unsaturated groups with at least one polythiol (B) having two or more mercapto groups to obtain a prepolymer; a step (ii) of mixing the prepolymer and a photochromic compound (C) to obtain a polymerizable composition; and a step (iii) of polymerizing the polymerizable composition, wherein, before the reaction of the step (i), the molar number of the mercapto groups included in the polythiol (B) is smaller than the molar number of the ethylene-based unsaturated groups included in the polymerizable monomer (A).