| 摘要 |
PROBLEM TO BE SOLVED: To obtain a silicone composition suitable as an optical material having excellent transparency, a high refractive index and a small double refraction and a lens. SOLUTION: This silicone composition for optical use and a lens comprises (A) an organopolysiloxane of the general formula Ra(R1)2SiO[(R2)2SiO]nSi(R1)2Ra [Ra is an alkenyl group; R1 and R2 are each an alkyl group, a cycloalkyl group or an aryl group; (n) is an integer of >=30], (B) an organopolysiloxane composed of siloxane units of the formula Rb(R3)2SiO0.5, (R4)3SiO0.5, R5SiO1.5 (Rb is an alkenyl group; R3, R4 and R5 are each an alkyl group, a cycloalkyl group or an aryl group) and SiO2, (C) an organohydrogenpolysiloxane containing at least two hydrogen atoms bonded to Si in which an organic group R6 bonded to Si in the molecule is shown by an alkyl group, a cycloalkyl group or an aryl group (>=5 mol.% of organic group of the total of the groups R1 to R6 is a cycloalkyl group) and (D) a platinum-based catalyst.
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