METHOD FOR PRODUCING POLYCARBONATE RESIN

摘要

PROBLEM TO BE SOLVED: To provide a method for continuously producing a polycarbonate resin obtained by a melting method and being excellent in hue in high productivity with a high yield by suppressing occurrence of a highly discolored product after a start of production. SOLUTION: The method for producing the polycarbonate resin comprises continuously producing the polycarbonate resin by carrying out melt polymerization of a carbonic acid diester with a divalent dihydroxy compound in the presence of a transesterification catalyst. In the production method, a reaction liquid of a reacting tank is pulled out after stopping melt polymerization reaction and one or more kinds of compounds selected from the same monohydroxy compound as compound produced as a by-product in the course of the reaction within 24 hr, a carbonic acid diester used as a raw material and a raw material mixed liquid are fed as a washing liquid and the resin remaining in the reacting tank and piping connecting the reacting tank, valves and a liquid feeder is dissolved and washed and the interior of the apparatus is kept under an inert gas atmosphere in which oxygen does not substantially exist until the temperature of at least the interior of the apparatus becomes normal temperature. COPYRIGHT: (C)2005,JPO&NCIPI