Production of high molecular weight, essentially uncrosslinked polychlorophosphazenes
US5152971A · kind A · utility
10Cited by
9References
7Claims
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Key dates
| Filing date | May 21, 1990 |
| Grant date | Oct 6, 1992 |
| Priority date | — |
| Expiry date | May 21, 2010 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01J2219/00094
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
High molecular weight, essentially uncrosslinked polychlorophosphazenes are prepared by bulk polycondensing a monomer of the formula P.sub.2 NXCl.sub.2, in which X is an oxygen or sulfur atom, e.g., N-dichlorophosphoryl- or N-dichlorothiophosphoryl-P-trichlorophosphazene, and wherein at least that final stage of polycondensation following cessation of evolution of PXCl.sub.3 is carried out in a stirred reaction zone, such stirred reaction zone including means to prevent the accumulation of polycondensate on the stirrer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.