METHOD FOR CONTINUOUS PRODUCTION OF POLYCARBONATE-POLYORGANOSILOXANE COPOLYMER

摘要

The present invention provides a method for the producing a polycarbonate-polyorganosiloxane copolymer in an economical and stable manner. Specifically, this method for the continuous production of a polycarbonate-polyorganosiloxane copolymer comprises: a step (A) in which a polymerization reaction solution, which is obtained by polymerizing a dihydric phenol compound, a carbonate precursor and polyorganosiloxane in the presence of an aqueous solution of an alkaline compound and a water-insoluble organic solvent, is continuously or intermittently extracted from a reactor; a step (B) in which the polymerization reaction solution extracted in step (A) is separated into an aqueous phase and a water-insoluble organic solvent phase; and a step (C) in which the water-insoluble organic solvent phase separated in step (B) is washed with an acidic aqueous solution, and then separated into an aqueous phase and a water-insoluble organic solvent phase. The method for the continuous production of a polycarbonate-polyorganosiloxane copolymer involves controlling the process in such a manner that the content of the polycarbonate-polyorganosiloxane copolymer in the aqueous phase separated in step (C) is 2 percent by mass or less, and reusing some or all of an extract obtained by extracting the aqueous phase separated in step (C) with the water-insoluble organic solvent in step (A).