| 摘要 |
PROBLEM TO BE SOLVED: To obtain a curable composition high in refractive index, low in specific gravity and excellent in handleability, useful for an optical material, etc., by including bis[(mercaptoethyl)thioethyl]propanethiol and a compound copolymerizable with the compound. SOLUTION: This composition comprises (A) 5-90wt.% of 2,3-bis[(2- mercaptoethyl)thioethyl]-1-propanethiol of the formula and (B) 1-95wt.% of any (one or two) (i) a polyisocyanate compound such as xylylene diisocyanate, a polyisothiocyanate such as 1,2-diisothiocyanatobenzene or an isocyanate group- containing isothiocyanate compound such as 1-isocyanato-3- isothiocyanatopropane, (ii) a polymerizable unsaturated bond-containing monomer such as styrene or methyl (meth)acrylate and (iii) an epoxy compound such as ethylene glycol diglycidyl ether. |
