Polymerization catalyst for polythiourethane optical material, polymerizable composition containing the same, polythiourethane resin obtained from the composition, and process for producing the resin

Abstract

By using an amine hydrochloride represented by the formula (1) as a catalyst, a polythiourethane resin which is suitably used for a transparent resin for optical use, can be obtained without using an organotin compound which has been conventionally used as a catalyst for polythiourethane resins and without being affected by the acidity of an additive: wherein R 1 , R 2 and R 3 independently represent a monovalent or higher valent linear aliphatic, branched aliphatic, cyclic aliphatic or aromatic organic residue which may have a hydroxyl group or an amino group; and R 1 , R 2 and R 3 may be arbitrarily bonded to each other to form a ring.

1 . A polymerization catalyst for polythiourethane optical material, which is an amine hydrochloride represented by the general formula (1): 
     
       
         
         
             
             
         
       
       wherein R 1 , R 2  and R 3  independently represent an organic residue derived from a linear aliphatic compound, an organic residue derived from a branched aliphatic compound, an organic residue derived from a cyclic aliphatic compound or an organic residue derived from a aromatic compound, which may have a hydroxyl group or an amino group and is a monovalent or higher valent; and R 1 , R 2  and R 3  may be arbitrarily bonded to each other to form a ring. 
     
   
   
       2 . The polymerization catalyst as claimed in  claim 1 , wherein R 1 , R 2  and R 3  of amine hydrochloride represented by the general formula (1) are each an alkyl group having 1 to 8 carbon atom(s). 
   
   
       3 . The polymerization catalyst as claimed in  claim 2 , wherein the amine hydrochloride represented by the general formula (1) is triethylamine hydrochloride, tri-n-butylamine hydrochloride, triisobutylamine hydrochloride, N,N-dimethylcyclohexylamine hydrochloride or N-methyldicyclohexylamine hydrochloride. 
   
   
       4 . A polymerizable composition for a polythiourethane optical material, comprising: the polymerization catalyst as claimed in  claim 1 ; one or more kinds of isocyanates selected from a polyisocyanate compound, a polyisothiocyanate compound and a polyisothiocyanate compound having an isocyanato group; and one or more kinds of thiols selected from polythiol compounds. 
   
   
       5 . The polymerizable composition as claimed in  claim 4 , wherein the isocyanates is one or more compound(s) selected from the group consisting of m-xylylenediisocyanate, 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 the thiols is one or more compound(s) selected from the group consisting of 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. 
   
   
       6 . A polythiourethane resin obtained by curing the polymerizable composition as claimed in  claim 4 . 
   
   
       7 . An optical material comprising the polythiourethane resin as claimed in  claim 6 . 
   
   
       8 . A plastic lens comprising the optical material as claimed in  claim 7 . 
   
   
       9 . A method for producing a polythiourethane resin, comprising:
 obtaining a polythiourethane resin by cast-polymerizing the polymerizable composition as claimed in  claim 4 .