PRODUCTION OF POLYCARBONATE

摘要

PROBLEM TO BE SOLVED: To produce polycarbonate having a good hue. SOLUTION: When a polycarbonate obtained by polycondensation of carbonic acid diester and a dihydroxyaryl compd. in the presence of an interesterification catalyst pelletized by a twin-screw extruder while an acid compd. is added to polycarbonate, the operation conditions of the extruder satisfies the formula: (NLD2/Q)1/2×T2<15,000 [wherein N is the number of rotations (rpm), L is the length (m) of the screw of the twin-screw extruder, D is the outer diameter (m) of one screw, Q is emitting quantity (kg/h) and T is the highest resin temp. ( deg.C) in the extruder to be set to a range of 250 deg.C<=T<=330 deg.C].