FIELD: chemistry.
SUBSTANCE: present invention relates to a group of inventions: a polycarbonate production method, a combination of catalysts for use in a polycarbonate production method, and the use of a combination of catalysts. This method includes following stages: a) a stage of transesterification of one or more diaryl carbonates with one or more aromatic hydroxyl compounds in at least one transesterification reactor, b) pre-polycondensation of a transesterification reaction product in at least one pre-polycondensation reactor, c) polycondensation of a pre-polycondensation reaction product in at least one polycondensation reactor. The first component is added before or during transesterification (stage a)). The third component is added after the stage a) and before pre-polycondensation (stage b)). The fourth component is added after the stage b) and before polycondensation (stage c)). A combination of catalysts is used in the method. The combination of catalysts includes: the first component including one or more quaternary nitrogen compounds; the second component including one or more quaternary phosphorus compounds; the third component including one or more alkali metal compounds; and the fourth component including one or more sulfur-containing organic compounds.
EFFECT: specific combination of quaternary nitrogen compounds, quaternary phosphorus compounds, alkali metal compounds and a sulfur–containing organic compound leads to a highly efficient and cost-effective conversion of initial substances into high-quality polycarbonate and at the same time to high stability of the resulting polycarbonate.
17 cl, 2 dwg, 2 ex
