Process of preparing polycarbonates
US6423812B1 · kind B1 · utility
Assignees
Inventors
Key dates
| Filing date | Jul 11, 2001 |
| Grant date | Jul 23, 2002 |
| Priority date | — |
| Expiry date | Jul 11, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G64/307
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The present invention relates to a process of preparing polycarbonates and more particularly, to the process of preparing polycarbonates through a melt polymerization reaction of dihydroxyaryl compounds with diarylcarbonate, wherein said melt polymerization is performed in the presence of a mixed catalyst composed of an oxygen (O) or sulfur (S) containing compound having lone-pair electrons and an alkali metal or alkaline earth metal salt in an appropriate ratio at a reduced temperature by accelerating a reaction rate to obtain high quality polycarbonates with higher than 15,000 g/mole of a viscosity average molecular weight and improved color.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.