Phosphonitrilic chloride polymers
US4447408A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 7, 1982 |
| Grant date | May 8, 1984 |
| Priority date | — |
| Expiry date | Dec 7, 2002 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B21/0986
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Linear phosphonitrile chloride polymers are produced from linear phosphonitrilic chloride oligomers by means of a two-step proess. In the first step a mixture of linear phosphonitrilic chloride oligomer having an average degree of polymerization of at least 3 and preferably at least 4 is heated with an excess of ammonia or ammonium chloride having a relatively small particle size such that the Mean Value is within the range of from about 1 micron to about 110 microns. Cyclic phosphonitrilic chloride oligomer formed during the course of the first step is removed from the reaction mixture. After the removal of the cyclic oligomer the reaction mixture is subjected to the second step which involves heating the mixture in an inert liquid solvent (optionally in the presence of ammonia or ammonium chloride having a relatively small particle size) whereby the molecular weight of the linear phosphonitrilic chloride polymer is increased.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.