Method for enhancing crystallinity of polycarbonates
US6031063A · kind A · utility
6Cited by
2References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 9, 1999 |
| Grant date | Feb 29, 2000 |
| Priority date | — |
| Expiry date | Aug 9, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G64/20
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The crystallinity of an amorphous precursor polycarbonate is enhanced by contact in the liquid or vapor state with a non-solvent which may be water, an alkanol or a mixture thereof and which is dialkyl carbonate-free. Contact temperatures are at least about 75.degree. C. and are further defined by the relationship EQU T.sub.c .gtoreq.T.sub.b -z, wherein T.sub.c is the contact temperature, T.sub.b is the boiling point of the non-solvent at the contact pressure employed (both in degrees C.) and z is a constant whose value is 60.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.