Patent ID: 7678875

Claim:
A method for producing a polycarbonate copolymer comprising repeating units represented by the following formulas (I) and (II): where: R 1 and R 2 are each independently a halogen atom or an alkyl group having 1 to 6 carbon atoms; when there are two or more R 1 s, each R 1 can be different from or the same as the other(s); when there are two or more R 2 s, each R 2 can be different from or the same as the other(s); a and b are each independently an integer from 0 to 4; and X represents a single bond, an alkylene group having 1 to 8 carbon atoms, an alkylidene group having 2 to 8 carbon atoms, a cycle alkylidene group having 5 to 15 carbon atoms, —S—, —SO—, —SO 2 —, —O—, —CO—, or a bond represented by the following formula (III-1) or (III-2): where: R is an alkyl group having 1 to 3 carbon atoms; Y is a straight chain or branched alkylene group having 2 to 15 carbon atoms; m is an integer of 0 to 4; and r is an integer of 2 to 450; the method comprising: reacting a diester diol-containing monomer, a divalent phenol, and a carbonate precursor by interfacial polymerization, wherein; the diester diol-containing monomer is a mixture of a diester diol according to the following formula (3) and a monoester diol represented by the following formula (4) the mixture is obtained by reaction of a hydroxybenzoic acid or an esterified product thereof represented by the following formula (1) and a polyalkylene glycol represented to by the following formula (2): where R′ is a hydrogen or a lower alkyl group; an esterification degree of hydroxyl groups of the polyalkylene glycol is 50 to 90 mol %.