To provide a copolycarbonate which is produced by using a specific dihydric alcohol having a side-chain fluorene structure as a comonomer and is suitable for optical materials such as optical disk substrates.
This copolycarbonate mainly comprises repeating units represented by formula I (wherein R1 to R8 are each H, a 1-20°C alkyl, an alkoxy, a 6-20C cycloalkyl, an aryl, a cyloalkoxy, or an aryloxy; and X is a 2-10C alkylene, a 6-20C arylene, or a 7-12C aralkylene), has a reduced viscosity (ηsp/c) of 0.2dl/g or higher in methylene chloride at a concn. of 0.5g/dl, at 20°C, and is produced by reacting a compd. represented by formula II with a carbonic ester-forming compd. in the presence of a polymn. catalyst and adding, after the completion of the polymn., a terminal blocking agent and a catalyst neutralizer to the reaction system.
ABE MASANORI
FUNAKOSHI WATARU
SASAKI KATSUJI
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