Abstract: A polymerizable composition containing (A) a compound having two or more mercapto groups; (B) a NCO-terminated polyurethane prepolymer; (C) a polyisocyanate compound; and (D) an episulfide compound. The episulfide compound D has in its molecule at least one structural group represented by the following formula 1: wherein R1 is a divalent hydrocarbon group having from 1 to 10 carbon atoms or a single bond, R2, R3 and R4 are each independently a hydrocarbon group having from 1 to 10 carbon atoms or hydrogen, Y is O or S, m is an integer of from 1 to 5, and n is an integer of from 0 to 5. Optical materials produced by curing the polymerizable composition by polymerization have a high refractive index and a high Abbe's number and are excellent in impact strength.

Abstract: A polycarbonate resin with a polystyrene-converted weight average molecular weight (Mw) of 20,000 to 200,000 obtained by forming a carbonate bond from a dihydroxy compound represented by the general formula (1), a dihydroxy compound represented by the general formula (2) and bis(hydroxyphenyl) methane and a carbonic acid diester or phosgene, having higher stiffness and better balance of mechanical properties than conventional aromatic polycarbonate resin to be derived from 2,2-bis(4-hydroxyphenyl)propane.

Abstract: A polycarbonate resin composition obtained by blending a polycarbonate resin (A) obtained by forming a carbonate bond from 95 to 5 mol % of a dihydroxy compound having a fluorene structure represented by the general formula (1) and 5 to 95 mol % of a dihydroxy compound having a dimethanol structure represented by the general formula (2) and a carbonic diester and a polycarbonate resin (B) obtained by forming a carbonate bond from bisphenol A and a carbonic acid diester or phosgene in a ratio of (100×(A)/((A)+(B))=1 to 99% by weight and a polarizing sheet used the same.

Abstract: A polycarbonate resin composition obtained by blending a polycarbonate resin (A) obtained by forming a carbonate bond from 95 to 5 mol % of a dihydroxy compound having a fluorene structure represented by the general formula (1) and 5 to 95 mol % of a dihydroxy compound having a dimethanol structure represented by the general formula (2) and a carbonic diester and a polycarbonate resin (B) obtained by forming a carbonate bond from bisphenol A and a carbonic acid diester or phosgene in a ratio of (100×(A)/((A)+(B))=1 to 99% by weight and a polarizing sheet used the same.

Abstract: A polycarbonate resin with a polystyrene-converted weight average molecular weight (Mw) of 20,000 to 200,000 obtained by forming a carbonate bond from a dihydroxy compound represented by the general formula (1), a dihydroxy compound represented by the general formula (2) and bis(hydroxyphenyl) methane and a carbonic acid diester or phosgene, having higher stiffness and better balance of mechanical properties than conventional aromatic polycarbonate resin to be derived from 2,2-bis(4-hydroxyphenyl)propane.