Patent ID: 7517944
Filing Date: 2009-04-14
Classification: C08G

Abstract:
1. A process for producing a polycarbonate, comprising: reacting an aqueous alkali solution of a dihydric phenol with phosgene in the presence of an organic solvent to obtain a polycarbonate oligomer; and polycondensing the polycarbonate oligomer; wherein: reacting the dihydric phenol with phosgene yields an emulsion solution of a polycarbonate oligomer-containing organic solvent; the emulsion solution is subjected to separation in a coalescer to separate the emulsion solution into a polycarbonate oligomer-containing organic solvent phase and an aqueous phase; and polycondensing the polycarbonate oligomer comprises polycondensing polycarbonate oligomer in the polycarbonate oligomer-containing organic solvent phase.