Patent ID: 8586695

Claim:
A polymerization composition for polythiourethane optical material, comprising: a polymerization catalyst; isocyanate; and thiol, wherein said polymerization catalyst is at least one amine hydrochloride selected from the group consisting of triethylamine hydrochloride, triisobutylamine hydrochloride, and N-methyldicyclohexylamine hydrochloride, wherein the isocyanate is at least one compound selected from the group consisting of m-xylylenediisocyanate, 2,5-bis(isocyanatomethyl)-bicyclo-[2.2.1]-heptane, and 2,6-bis(isocyanatomethyl)-bicyclo-[2.2.1]-heptane, wherein the thiol is at least one compound selected from the group consisting of 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, and pentaerythritol tetrakis(3-mercaptopropionate), wherein the amount of the amine hydrochloride is in a range of 0.05 to 0.3 parts by weight, based on total 100 parts by weight of the isocyanate and the thiol, and wherein said polymerization catalyst contained in said polymerization composition consists of said amine hydrochloride.