| abstract |
The purpose of the present invention is to appropriately control the rate of polymerization of a composition in which a thiol compound and an isocyanate compound are added to an episulfide compound and thereby provide an optical material which has high transparency. This composition for use as optical material comprises (a) an episulfide compound, (b) an isocyanate compound, (c) a thiol compound, and (d) a benzyl halide compound represented by formula (1):wherein: X is a halogen; L is selected from the group consisting of a hydrogen atom, a methyl group, a halogen, a mercaptomethyl group, and an isocyanate methyl group; and n is 1 or 2. |