Method for producing an aromatic polycarbonate
US5952449A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 2, 1998 |
| Grant date | Sep 14, 1999 |
| Priority date | — |
| Expiry date | Apr 2, 2018 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01J2219/00168
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method for producing an aromatic polycarbonate, which comprises subjecting to a transesterification polymerization reaction at least one polymerizable material for an aromatic polycarbonate. The transesterification polymerization reaction is performed in one or more polymerizers which is or are connected through a pipeline system. The pipeline system comprises one or more pipes through which a molten aromatic polycarbonate having a number average molecular weight increased by the transesterification polymerization reaction is passed while contacting an inner wall of the pipe or pipes. The pipeline system has at least one viscous polycarbonate passage region in which a molten aromatic polycarbonate having a number average molecular weight of 4,000 or more is passed through the pipe. The pipes in the viscous polycarbonate passage region of the pipeline system have no bent portion or not more than 50 bent portions in total. A high quality aromatic polycarbonate is produced, which is colorless and has a low foreign matter content.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.