Method for producing an aromatic polycarbonate
US6037437A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 9, 1997 |
| Grant date | Mar 14, 2000 |
| Priority date | — |
| Expiry date | Dec 9, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G64/307
- 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 selected from a molten monomer mixture of an aromatic dihydroxy compound and a diaryl carbonate, and a molten prepolymer obtained from the monomer mixture, wherein the transesterification reaction is 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, and wherein a molten aromatic polycarbonate having a number average molecular weight of less than 2,500 is passed through the pipe or pipes at a velocity of 0.05 m/sec. or more and a molten aromatic polycarbonate having a number average molecular weight of 2,500 or more is passed through the pipe or pipes at a velocity of 0.005 m/sec. or more. By the method of the present invention, a high quality aromatic polycarbona…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.