Purification of crude polyorganophosphazenes
US4889910A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 14, 1988 |
| Grant date | Dec 26, 1989 |
| Priority date | — |
| Expiry date | Oct 14, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G79/025
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Crude polyorganophosphazenes, produced by the nucleophilic cosubstitution of polydichlorophosphazenes and contained in a reaction medium which includes such polyorganophosphazenes, reaction solvent for the cosubstitution reaction, excess nucleophilic reagent and/or product of neutralization thereof, and, when present, any alkali metal salts of neutralization, are efficiently and facilely purified, in a single treatment zone, advantageously under agitation in a discontinuous malaxator, by both eliminating the reaction solvent and thereafter washing the resulting reaction medium with a liquid which is a nonsolvent for the polyorganophosphazenes, but miscible with the other products present in said reaction medium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.