Phosphonitrilic chloride polymers
US4522796A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 22, 1983 |
| Grant date | Jun 11, 1985 |
| Priority date | — |
| Expiry date | Apr 22, 2003 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B21/0986
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Linear phosphonitrilic chloride polymers are produced from phosphonitrilic chloride oligomers by means of an improved process wherein a mixture of phosphonitrilic chloride oligomers enriched in linear oligomer is heated with at least a stoichiometric amount (and preferably an excess) of ammonia or ammonium chloride while concurrently removing hydrogen chloride to produce a higher molecular weight polyphosphonitrilic chloride product. Cyclic phosphonitrilic chloride oligomer may be and preferably is present in the initial oligomer. Preferably, cyclic phosphonitrilic chloride oligomer is recovered from the reaction mixture during (but more preferably after) completion of the polymerization reaction. At least a portion of the recovered cyclic oligomer may be used in a subsequent polymerization reaction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.