Catalytic melt condensation preparation of polycarbonate
US5151491A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 21, 1989 |
| Grant date | Sep 29, 1992 |
| Priority date | — |
| Expiry date | Sep 21, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G64/307
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Disclosed herein are processes for the production of polycarbonates by melt polycondensation of an aromatic dihydroxy compound and a carbonic acid diester or a diphenyl carbonate compound wherein said polycondensation is carried out in the presence of from 0.05 to 15 mol %, based on 1 mole of the aromatic dihydroxy compound, of a phenol having from 10 to 40 carbon atoms, a carbonic acid diester having from 17 to 50 carbon atoms, or a carbonic acid diester having from 13 to 16 carbon atoms, using a catalyst comprising (a) a nitrogen containing basic compound, (b) from 10.sup.-8 to 10.sup.-3 mole, based on 1 mole of the aromatic dihydroxy compound, of an alkali metal or alkaline earth metal compound, and (c) boric acid or boric ester. Also disclosed is a polycarbonate in which from 5 to 30% of its terminal groups are hydroxy groups and it has a sodium content of not more than 1 ppm and a chlorine content of not more than 20 ppm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.