Quaternary bisphenolates, methods for their preparation, and uses thereof
US5969086A · kind A · utility
4Cited by
6References
8Claims
0Family size
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Key dates
| Filing date | Dec 15, 1997 |
| Grant date | Oct 19, 1999 |
| Priority date | — |
| Expiry date | Dec 15, 2017 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01J2531/98
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Quaternary salts having a double helix structure are prepared by the reaction of dihydroxyaromatic compound, preferably a bisphenol, with an alkali metal hydroxide and a quaternary salt, such as a tetraalkylammonium or hexaalkylguanidinium chloride. The quaternary salts and their alkaline hydrolysis products are useful as catalysts in various reactions, including imide formation from bisphenol salts and halo- or nitro-substituted phthalimides and redistribution and equilibration of polycarbonates.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.