Polycarbonate
AssigneeSabic Global Technologies B.V.
InventorsIgnacio Vic Fernandez, David Del Agua Hernandez, Helena Varela Rizo
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Abstract
The present invention relates to an aromatic polycarbonate obtained via the melt transesterification of a diaryl carbonate, a bisphenol and an endcapping agent selected from paracumyl phenol, dicumyl phenol, p-tert-butyl phenol and mixtures of at least two of said endcapping agents, said polycarbonate having a melt volume rate of at least 20 cm3/10 min (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 and 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.
Claims2
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.
Dependencies are inferred from the claim text.