Process for producing aromatic polycarbonate
US6320015A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 1, 2000 |
| Grant date | Nov 20, 2001 |
| Priority date | — |
| Expiry date | Nov 1, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G64/307
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Disclosed is a method for producing an aromatic polycarbonate, which comprises treating a molten aromatic polycarbonate prepolymer (obtained by reacting an aromatic dihydroxy compound with a diaryl carbonate) with an inert gas under a predetermined pressure to thereby cause the molten prepolymer to absorb the inert gas, and subjecting the resultant molten prepolymer having the inert gas absorbed therein to polymerization, under a pressure lower than the above-mentioned predetermined pressure employed for the inert gas absorption, to thereby polymerize the prepolymer to a predetermined degree of polymerization. By the method of the present invention, a high quality aromatic polycarbonate which is colorless and has excellent mechanical properties can be produced at high polymerization rate even without using a large amount of an inert gas. Further, even if the production of an aromatic polycarbonate is conducted in a continuous manner, the molecular weight of the produced aromatic polycarbonate can be maintained at a desired level, so that the high quality polycarbonate can be stably produced for a prolonged period of time. Therefore, the method of the present invention is commercial…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.