VERFAHREN ZUR HERSTELLUNG VON POLYCARBONAT NACH DEM PHASENGRENZFLÄCHENVERFAHREN

摘要

Continuously producing polycarbonates by phase boundary process, comprises: (a) producing a mixture of organic- and aqueous-phases by continuously dispersing the organic phase in the aqueous phase or the aqueous phase in the organic phase; (b) reacting the mixture in a reactor; (c) further reacting the mixture by adding further alkali metal hydroxide solution and optionally chain terminator(s) in a further reactor; and (d) further condensing by adding further alkali metal hydroxide solution, optionally chain terminator(s) and in the presence of a catalyst in a further reactor. Continuously producing polycarbonates with an average weight average molecular weight of 15000-200000 g/mol, by phase boundary process from at least one dihydroxydiarylalkane, phosgene and at least one catalyst optionally in the presence of at least one chain terminator and/or chain-branching agent, comprises: (a) producing a mixture of organic- and aqueous-phases by continuously dispersing the organic phase in the aqueous phase or the aqueous phase in the organic phase by a disperser, where the organic phase contains at least one suitable solvent for the polycarbonate and complete or partial phosgene and the aqueous phase contains the dihydroxyalkane(s), water and an alkali metal hydroxide solution, and 1.5-2.5 moles of the alkali metal hydroxide solution are added per mole of dihydroxydiarylalkane; (b) reacting the mixture in a reactor with a dwell time of less than 0.5 second; (c) reacting the reaction mixture by adding further alkali metal hydroxide solution and optionally chain terminator(s) in an another reactor; and (d) further condensing by adding further alkali metal hydroxide solution, optionally chain terminator(s) and in the presence of at least one catalyst in at least a further reactor. An INDEPENDENT CLAIM is included for use of a disperser containing a pre-disperser, a homogenizing nozzle and at least three pumps for producing the mixture of organic and aqueous phases during the production of the polycarbonate.