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 linking and highly polymerizing reaction, wherein even an aliphatic diol compound having a comparatively low boiling point can be allowed to efficiently contribute to the linking and highly polymerizing reaction, and a high molecular weight polycarbonate resin of superior quality can be produced both economically and advantageously. Provided is a method which comprises producing an aromatic polycarbonate prepolymer by a polycondensation reaction between an aromatic dihydroxy compound and a diester carbonate, adding thereto an aliphatic diol compound having an aliphatic group that bonds to a terminal hydroxyl group to obtain a prepolymer mixture, and subjecting the resulting prepolymer mixture to a linking and highly polymerizing reaction under a reduced pressure condition, wherein the aliphatic diol compound is added at a pressure exceeding 200 torr, and then, the prepolymer mixture is subjected to a linking and highly polymerizing reaction before the terminal hydroxyl group concentration of the aromatic polycarbonate prepolymer in the prepolymer mixture reaches 2000 ppm.