Patent ID: 11945909
Assignee: EPC ENGINEERING & TECHNOLOGIES GMBH
Field: Chemical engineering (Chemistry)
Classification: CPC C  B | IPC B  C

Claim 0:
1. A process for producing a polycarbonate, the process comprising:
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;

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; and
c) polycondensation of the reaction product of the pre-polycondensation in at least one polycondensation reactor,
wherein the first component is added before or during the transesterification (step a)), the third component is added after step a) and before or during the pre-polycondensation (step b)) and the fourth component is added after step b) and before or during the polycondensation (step c)).