Polycarbonate resin, method for producing the same, and optical lens

A polycarbonate resin, comprising a structural unit expressed by general formula (1) below:

• (where R1 and R2 independently represent a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group having a carbon number of 1 to 6, a mono- or polycyclic aryl group having a carbon number of 6 to 36, a mono- or polycyclic hetaryl having a total of 5 to 36 atoms, which are ring members, where 1, 2, 3 or 4 of these atoms are selected from nitrogen, sulfur and oxygen, while the remainder of these atoms are carbon atoms, an alkenyl group having a carbon number of 2 to 6, an alkoxy group having a carbon number of 1 to 6, or an aralkyl group having a carbon number of 7 to 17,
• where the mono- or polycyclic aryl and mono- or polycyclic hetaryl are unsubstituted or carry 1 or 2 radicals Ra, which are selected from the group consisting of CN, CH3, OCH3, O-phenyl, O-naphthyl, S-phenyl, S-naphthyl and halogen,
• where R1 and R2 do not all represent a hydrogen atom;
• X represents an alkylene group having a carbon number of 1 to 8, a cycloalkylene group having a carbon number of 5 to 12 or an arylene group having a carbon number of 6 to 20;
• where alkylene group and cycloalkylene group are unsubstituted or carry a phenyl ring, and
• a and b each represent an integer of 1 to 10).