Method for manufacturing polycarbonate for optical use
US6197917A · kind A · utility
4Cited by
0References
7Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 18, 1999 |
| Grant date | Mar 6, 2001 |
| Priority date | — |
| Expiry date | Aug 18, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G64/307
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The specification provides a method for the manufacture of a high-quality optical polycarbonate that contains few inorganic or organic impurities or other microparticles, and that has a superior hue. Specifically, the specification provides a method for the manufacture of a polycarbonate by the melt polycondensation of a bisphenol and a carbonic diester, wherein the molten mixture of a bisphenol and a carbonic diester is filtered with a membrane filter made of a fluororesin, after which melt polycondensation is conducted.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.