Phosphate salts of monomers for PBZ and their use in preparing PBZ polymers
US5138020A · kind A · utility
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66Claims
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Key dates
| Filing date | Apr 21, 1989 |
| Grant date | Aug 11, 1992 |
| Priority date | — |
| Expiry date | Apr 21, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G73/18
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
PBZ polymers are synthesized by the reaction of AA- and BB-monomers. The BB-monomer is conveniently synthesized and isolated as a phosphate salt having a uniform number of phosphate ions associated with each BB-monomer ion. Such high purity monophosphate and diphosphate salts can be obtained by precipitating the monomer from an aqueous acid solution by adjusting the pH balance or from a mixture of phosphoric acid and a volatile, polar, saturated organic liquid at a relatively low temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.