| 摘要 |
PROBLEM TO BE SOLVED: To manufacture a polycarbonate resin by a simplified process which is little in content of impurities, volatile impurities in particular, and excellent in thermal stability, color stability and hydrolysis resistance. SOLUTION: In the process for manufacturing a polycarbonate resin using a twin-screw extruder with multi step vents, a polycarbnate and water fed to the twin-screw extruder with multi step vent ports are kneaded under an absolute pressure of 0.3 to 10 MPa and then are subjected to a pressure reducing treatment. If the polycarbonate is obtained by a melt polycondensation reaction of an aromatic dihydroxy compound and an aromatic carbonic acid diester in the existence of a polymerization catalyst, the effect of the present invention is particularly remarkable and in this case the polycarbonate in the melted state is fed to the twin-screw extruder directly after the polycondensation reaction.
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