Patent ID: 7847051

Claim:
A continuous process for preparing a polycarbonate having a weight average molecular weight M w of 15,000 to 200,000 g/mol, the process comprising reacting a dihydroxydiarylalkane and phosgene in the presence of a catalyst in a phase boundary process comprising: continuously dispersing in a disperser an organic phase and an aqueous phase to form a mixture, the organic phase comprising at least a portion of the phosgene and a solvent suitable for the polycarbonate, and the aqueous phase comprising the dihydroxydiarylalkane, water and an alkali solution present in an amount of 1.5 to 2.5 moles per mole of the dihydroxydiarylalkane; reacting the mixture in a first reactor with a residence time of less than 0.5 seconds; further reacting the mixture in a second reactor with addition of a further amount of an alkali solution and, optionally, a chain terminator; and effecting further condensation in a third reactor with addition of a second further amount of an alkali solution and, optionally, a chain terminator, in the presence of the catalyst.