Patent ID: 7893185

Claim:
A polycarbonate copolymer, comprising: 0.1 to 50 mol % of a monomer unit represented by a formula (1) as follows; and a monomer unit represented by a formula (2) as follows, wherein a content of a biphenyl compound having three phenolic hydroxyl groups in one molecule is 200 mass ppb or less, where R 1 and R 2 each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms or a halogen atom, where: R 3 and R 4 each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms or a halogen atom; and X represents any one of bonding groups represented by —O—, —S—, —SO—, —SO 2 —, —CO—, 9,9-fluorenylidene group and formulae (2a), (2b) (2c) and (2d) as follows, where R 5 and R 6 each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, R 5 and R 6 being allowed to be bonded together to form a cycloalkylidene group having 4 to 12 carbon atoms, where R represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, at least one of R representing an alkyl group having 1 to 3 carbon atoms, where a bonding position is allowed to be any one of o-, m- and p-, and where R 7 to R 12 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a single bonding or a bonding group formed of an alkylene group, on condition that two of R 7 to R 12 each represent a bonding group while the rest of R 7 to R 12 each represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.