Patent ID: 11879035
Assignee: SABIC GLOBAL TECHNOLOGIES B.V.
Field: Macromolecular chemistry, polymers (Chemistry)
Classification: CPC C  B | IPC B  C

Claim 0:
1. A method for the continuous multi-stage manufacture of an end-capped polycarbonate comprising,
i) preparing a monomer mixture in a monomer mixing stage by mixing a bisphenol, a diphenyl carbonate and optionally a transesterification catalyst in at least one monomer mixing device,
ii) preparing a carbonate oligomer in an oligomerisation stage by reacting said monomer mixture in at least one oligomerisation reactor,
iii) preparing the polycarbonate in a polymerisation stage by further reacting the carbonate oligomer of the oligomerisation stage in at least one polymerisation reactor,
wherein an end-capping agent is added to the monomer mixture in the monomer mixing stage and/or to at least one oligomerisation reactor in the oligomerisation stage, the endcapping agent is selected from paracumyl phenol, dicumyl phenol, p-tert-butyl phenol and mixtures of at least two of said endcapping agents; and
wherein said polycarbonate having
a melt volume rate of at least 20 cm3/10 min determined in accordance with ISO 1133 (300° C., 1.2 kg)
a terminal hydroxyl group content of at most 800 ppm by weight
a Fries branching content of at most 1300 ppm by weight
a content of bulky end groups of at least 20 mol % defined as the sum of the mol % of end-groups based on said bisphenol and the mol % of end-groups based on said endcapping agent.