| 摘要 |
PROBLEM TO BE SOLVED: To efficiently produce the subject polycarbonate with improved tint by subjecting dihydroxy compound and carbonic diester to the multi-step poly- condensation reaction between them in which different catalysts are used in the first step reaction and in the second step reaction. SOLUTION: When (A) dihydroxy compound and (B) carbonic diester are subjected to multi-step polycondensation reaction with two or more steps, (C) 1×10-7-1×10-1 mole, per mole of the component A, of a catalyst comprising an ammonium compound and/or a phosphonium compound is used in the first step, and (D) a catalyst comprising alkali metal or alkaline earth metal phosphorus-containing inorganic salt is used in the second step, preferably in an amount of 1×10-7-1×10-6 mole per mole of the component A. As the component C, are preferably cited a quaternary ammonium compound and quaternary phosphonium compound. The first polycondensation step is preferably carried out at a temperature <=270 deg.C.
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