Patent ID: 8304507

Claim:
A polymerizable composition for a polythiourethane optical material, comprising: (A) a polymerization catalyst for a polythiourethane optical material, (B) at least one compound selected from m-xylylene diisocyanate, 2,5-bis(isocyanatomethyl)-bicyclo[2.2.1]heptane, 2,6-bis(isocyanatomethyl)-bicyclo[2.2.1]heptane, 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, and hexamethylene diisocyanate, and (C) at least one compound selected from 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, pentaerythritol tetrakis(3-mercaptopropionate), 1,1,3,3-tetrakis(mercaptomethylthio)propane, 1,1,2,2-tetrakis(mercaptomethylthio)ethane, 4,6-bis(mercaptomethylthio)-1,3-dithiane, and 2-(2,2-bis(mercaptodimethylthio)ethyl)-1,3-dithietane, wherein said polymerization catalyst for a polythiourethane optical material (A) comprises (a1) one or two or more kinds of zinc compound selected from the group consisting of zinc dithiocarbamates, zinc sulfonates, zinc salts of mono- or di-alkyl phosphoric acid esters, bis(substituted acetylacetonato) zinc, and zinc halides, (a2) a compound represented by the following general formula (1), and (a3) a sulfonic acid represented by the following general formula (2): wherein R 1 , R 2 , R 3 , and R 4 each independently represent hydrogen, or linear-chained aliphatic residue, cyclic aliphatic residue, or aromatic organic residue which is monovalent or higher valent, R 1 , R 2 , R 3 , and R 4 may be bonded to each other to form a ring, X represents a halogen atom and Y represents a nitrogen or phosphorous atom, R 5 SO 3 H) n (2) wherein n represents an integer of 1 or 2, and R 5 represents linear-chained aliphatic residue, branched aliphatic residue, cyclic aliphatic residue, or aromatic organic residue, which is a monovalent or higher valent and which may contain a hydroxyl group or an amino group wherein the molar ratio of the compound (a2) represented by the general formula (1) to the zinc compound (a1) is in the range 0.01 to 100, and the molar ratio of the sulfonic acid (a3) represented by the general formula (1) is in the range 0.01 to 100, wherein the total amount of the zinc compound (a1), the compound (a2) represented by the general formula (1), and the sulfonic acid (a3) represented by the general formula (2) is in the range of 0.0005 parts by weight to 5 parts by weight, based on 100 parts by weight of the total amount of the compound (B) and the compound (C).