Process for the preparation of aliphatic diol polycarbonates
US3966788A · kind A · utility
6Cited by
6References
16Claims
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Key dates
| Filing date | Sep 24, 1974 |
| Grant date | Jun 29, 1976 |
| Priority date | — |
| Expiry date | Sep 24, 1994 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G64/205
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Hydroxy-telechelating oligomers of number average molecular weight 250 to 2,500 and containing carbonate groups, are prepared by first polycondensing a bis-chloroformate with a diol at a temperature below 150.degree.C and at a moderately reduced pressure while flushing the reaction mixture with an inert anhydrous gas, and then the oligomers formed are dissolved in a volatile, water-immiscible organic solvent and the solution washed with an aqueous base solution. In this way, oligomers may be prepared which have a low or zero sensitivity to water, are non-acidic and relatively inexpensive.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.