| 摘要 |
PROBLEM TO BE SOLVED: To provide a polymerizable composition which can give an optical material having a refractive index of around 1.60 and Abbe's number of around 40, and high strength (impact resistance). SOLUTION: The polymerizable composition comprises (A) a compound having two or more mercapto groups, (B) a polyurethane prepolymer having an NCO terminal group, (C) a polyisocyanate compound, and (D) an episulfide compound, wherein the episulfide compound (D) has one or more structures expressed by formula (1) (wherein, R<SP>1</SP>is a 1-10C divalent hydrocarbon group or a single bond: R<SP>2</SP>, R<SP>3</SP>, and R<SP>4</SP>are each a 1-10C hydrocarbon or hydrogen; Y is O or S; m is an integer of 1-5; and n is an integer of 0-5) in one molecule. COPYRIGHT: (C)2007,JPO&INPIT |
