Process for the preparation of polycarbonates
US6232432A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 29, 2000 |
| Grant date | May 15, 2001 |
| Priority date | — |
| Expiry date | Jun 29, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G64/307
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The present invention relates to a process for the preparation of polycarbonates, more specifically to a process for the preparation of polycarbonates by a solid polymerization of prepolymers obtained by the polymerization between aromatic dihydroxides and diarylcarbonates, which comprises: PA1 a) preparing said prepolymer having a viscosity average molecular weight of 4,000-18,000 g/mole; PA1 b) preparing a microporous foam by injecting high-pressure inert gas; and PA1 c) preparing polycarbonates by a solid polymerization, which facilitates the removal of phenol, a by-product, and enhances molecular weight of polycarbonates without using any catalyst due to the relatively high polymerization rate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.