Phosphonitrilic halide polymers
US4551317A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 28, 1983 |
| Grant date | Nov 5, 1985 |
| Priority date | — |
| Expiry date | Apr 28, 2003 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B21/0986
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Halophosphazene polymers such as linear phosphonitrilic chloride polymers are prepared in two stages by (i) heating a nitrogen source (e.g., NH.sub.3 ; NH.sub.4 Cl; etc.) with an excess of a phosphorus source (e.g., PCl.sub.5 ; PCl.sub.3 +Cl.sub.2 ; P+Cl.sub.2 ; etc.) so that hydrogen halide is evolved and halophosphazene is formed, and (ii) heating at least a portion of the halophosphazene with at least a stoichiometric amount (preferably an excess) of a nitrogen source (e.g., NH.sub.3 ; NH.sub.4 Cl; etc.) so that hydrogen halide is evolved and halophosphazene polymer of higher molecular weight is formed. Preferably, a third stage is utilized wherein the resultant halophosphazene polymer is then heated, most preferably in an inert solvent or diluent which enhances the fluidity of the reaction mixture, to increase the molecular weight of the polymer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.