Process for producing polycarbonate

摘要

PCT No. PCT/JP92/00231 Sec. 371 Date Nov. 2, 1992 Sec. 102(e) Date Nov. 2, 1992 PCT Filed Feb. 28, 1992 PCT Pub. No. WO92/16577 PCT Pub. Date Oct. 1, 1992.In a process for producing a polycarbonate by subjecting a dihydroxy compound and a diester of carbonic acid to melt polycondensation through transesterification, after a polycarbonate prepolymer is prepared in the first-stage reaction, polycondensation is conducted as the second-stage reaction at a residence time in the range of from 15 to less than 60 min or through the use of at least one paddle-type self-cleaning twin-screw extruder. This process enables a colorless, transparent polycarbonate having a high molecular weight to be produced at a high efficiency on an industrial scale.