Cyclic polycarbonate oligomers and methods for their preparation and use
US4644053A · kind A · utility
78Cited by
6References
13Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 22, 1985 |
| Grant date | Feb 17, 1987 |
| Priority date | — |
| Expiry date | Feb 22, 2005 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G75/28
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Cyclic polycarbonate (or thiol analog) oligomer mixtures are prepared by the reaction of bishaloformates or their thio analogs or mixtures thereof with dihydroxy or dimercapto compounds, with alkali metal hydroxides and various amines. The oligomer mixtures may be converted to polycarbonates or their thiol analogs by a method which is particularly adaptable to integration with polycarbonate processing operations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.