SEPARATION OF BISPHENOL-A FROM THE ALKALINE PHASE GENERATED IN THE PRODUCTION OF POLYCARBONATES

摘要

This invention relates to polycarbonates and more particularly to separating unreacted bisphenol-A from the alkaline phase generated in the production of polycarbonates, comprising contacting the alkaline phase with phosgene in a secondary reaction stream in the presence of an organic solvent to convert the unreacted bisphenol-A to a low molecular weight polymer having chlorocarbonate end groups, separating the solvent solution of the low molecular weight polymer from the aqueous alkaline phase and, preferably, returning said solvent solution to the main reaction stream.