METHOD FOR CONTINUOUSLY PRODUCING HIGH-MOLECULAR-WEIGHT POLYCARBONATE RESIN

摘要

Provided is an improved method for continuously producing a high-molecular-weight polycarbonate resin by subjecting an aromatic polycarbonate prepolymer and an aliphatic diol compound to a molecular-weight-increasing linking reaction, whereby it becomes possible to allow an aliphatic diol compound having a relatively low boiling point to contribute to the molecular-weight-increasing linking reaction with high efficiency and it also becomes possible to produce a high-molecular-weight polycarbonate resin having excellent quality in an economically advantageous manner. The method comprises subjecting an aromatic dihydroxy compound and a diester carbonate to a polycondensation reaction to produce an aromatic polycarbonate prepolymer, adding an aliphatic diol compound having an aliphatic group capable of binding to a terminal hydroxy group to the aromatic polycarbonate prepolymer to produce a prepolymer mixture, and subjecting the prepolymer mixture to a molecular-weight-increasing linking reaction under pressure-reduced conditions, wherein the aliphatic diol compound is added under a pressure of higher than 200 torr and subsequently the prepolymer mixture is subjected to the molecular-weight-increasing linking reaction before the concentration of a terminal hydroxy group of the aromatic polycarbonate prepolymer in the prepolymer mixture reaches 2000 ppm.