Method for producing an aromatic polycarbonate
US5912318A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 3, 1998 |
| Grant date | Jun 15, 1999 |
| Priority date | — |
| Expiry date | Apr 3, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G64/205
- WIPO fieldMacromolecular chemistry, polymers
- 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 reaction being performed in one or more polymerizers which is or are connected through a pipeline system toward an outlet for a final aromatic polycarbonate product, wherein 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 having at least one viscous polycarbonate passage region in which a molten aromatic polycarbonate having a number average molecular weight of 6,000 or more is passed through the pipe, wherein the pipe in the at least one viscous polycarbonate passage region is heated to provide a temperature difference in the range of from -3.degree. C. to 50.degree. C. between the temperature (.degree.C.) of the outer wall of the pipe and the temperature (.degree.C.) of the aromatic polycarbonate in the polymerizer from which the aromatic p…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.