| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical material which has a negative double refraction and a considerably small change in the double refraction under the use environment. SOLUTION: The optical material is comprised of (I) a copolymer of a vinyl aromatic hydrocarbon and a conjugated diene and/or the hydrogenated product thereof and (II) a styrenic polymer having a syndiotactic structure, characterized in that the component (I) has a ratio by weight of the vinyl aromatic hydrocarbon to the conjugated diene of 50/50 to 95/5, a number-average molecular weight by the measurement with a gel permeation chromatography (GPC) of 30,000-800,000 and a block percentage of the vinyl aromatic hydrocarbon of 10-100% by weight. COPYRIGHT: (C)2007,JPO&INPIT
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