Patent · US Expired

Process for preparing low molecular weight linear phosphonitrilic chloride oligomers

US4198381A · kind A · utility

0Cited by
6References
8Claims
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Assignee

Inventors

Key dates

Filing dateAug 21, 1978
Grant dateApr 15, 1980
Priority date
Expiry dateAug 21, 1998

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC01B21/098
  • WIPO fieldMaterials, metallurgy
  • WIPO sectorChemistry

Abstract

In the first step of a two step process, PCl.sub.3 and Cl.sub.2 are reacted in a suitable medium. In the second step, PCl.sub.3, Cl.sub.2 and NH.sub.3 are concurrently fed into said medium while keeping the temperature at 100.degree. C. to 140.degree. C. The feeds of the reactants are controlled so that until the first 1/2 of the NH.sub.3 has been reacted the molar ratio of PCl.sub.3 :NH.sub.3 (including the PCl.sub.3 of the first step) is kept above 2. Thereafter, the feeds are adjusted so that with respect to the total amount of ammonia, said molar ratio is between 1.2 and 1.5. Linear phosphonitrilic chloride oligomers having a number average degree of polymerization from 2 to 9 are produced in high yield.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.