mhurhangee/patent-ind-claim-en huggingface dataset:
A process for preparing a polycarbonate by reacting one or more diaryl carbonates with one or more aromatic hydroxy compounds, wherein in the process a catalyst combination is employed which comprises: - a first component comprising one or more quaternary nitrogen compounds, - a second component comprising one or more quaternary phosphorus compounds, - a third component comprising one or more alkali metal compounds and - a fourth component comprising one or more sulphur-containing organic compounds, the method comprising at least the following steps: a) transesterification of one or more diaryl carbonates with one or more aromatic hydroxy compounds in at least one transesterification reactor, b) pre-polycondensation of the reaction product of the transesterification in at least one pre-polycondensation reactor, c) polycondensation of the reaction product of the pre-polycondensation in at least one polycondensation reactor, characterized in that the first component is added before or during transesterification (step a)), components 2 and 3 are added after step a) and before or during pre-polycondensation (step b)) and the fourth component is added after step b) and before or during polycondensation (step c)). - a first component comprising one or more quaternary nitrogen compounds, - a second component comprising one or more quaternary phosphorus compounds, - a third component comprising one or more alkali metal compounds and - a fourth component comprising one or more sulphur-containing organic compounds, a) transesterification of one or more diaryl carbonates with one or more aromatic hydroxy compounds in at least one transesterification reactor, b) pre-polycondensation of the reaction product of the transesterification in at least one pre-polycondensation reactor, c) polycondensation of the reaction product of the pre-polycondensation in at least one polycondensation reactor,