| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical material having characteristics such as high heat resistance, high transparency, low linear expansion coefficient and low water absorption. Ž<P>SOLUTION: A cyclized polymer is obtained by cyclization of a random copolymer containing a styrene derivative-based structural unit and a conjugated diene derivative-based structural unit, wherein the molar content ratio of the styrene derivative-based structural unit to the conjugated diene derivative-based structural unit (the styrene derivative-based structural unit/the conjugated diene derivative-based structural unit) is 50/50 to 95/5. The cyclized polymer has a cyclization ratio of ≥95% and a glass transition temperature of 100-170°C. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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