Abstract: By using a method for producing a composition for an optical material using (a) sulfur, (b) a compound having two intramolecular episulfide groups, (c) a compound having one or more (preferably two) SH groups, and (d) an amine compound having a specific structure, in which compound (a) and compound (c) are pre-polymerized in the presence of compound (b) using compound (d) as the pre-polymerization catalyst, the present invention provides a polymerizable composition for an optical material in which the viscosity elevation speed during pre-polymerization is slow and the reaction temperature is approximately room temperature, and that has a low viscosity and shows little increase in viscosity.

Abstract: The present invention is able to provide an optical material composition containing: a polythiol compound satisfying one of the below mentioned i) through iii); and a polyepoxy compound and/or a polyepisulfide compound of which i) the ammonium cation concentration is 0.1-150 ?mol/kg, ii) the thiocyanate anion concentration is 0.1-300 ?mol/kg, or iii) the ammonium cation concentration is 0.1-150 ?mol/kg, the thiocyanate anion concentration is 0.1-300 ?mol/kg, and furthermore the ion concentration product of the ammonium cations and the thiocyanate anions is 0.01-15000 (?mol/kg)2.

Abstract: By using a method for producing a composition for an optical material using (a) sulfur, (b) a compound having two intramolecular episulfide groups, (c) a compound having one or more (preferably two) SH groups, and (d) an amine compound having a specific structure, in which compound (a) and compound (c) are pre-polymerized in the presence of compound (b) using compound (d) as the pre-polymerization catalyst, the present invention provides a polymerizable composition for an optical material in which the viscosity elevation speed during pre-polymerization is slow and the reaction temperature is approximately room temperature, and that has a low viscosity and shows little increase in viscosity.