(19) | |
| (11) | EP 0 004 878 A3 |
(12) | EUROPEAN PATENT APPLICATION |
(88) | Date of publication A3: | | 14.11.1979 Bulletin 1979/23 |
(43) | Date of publication A2: | | 31.10.1979 Bulletin 1979/22 |
(22) | Date of filing: 23.03.1979 |
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(84) | Designated Contracting States: | | BE DE FR GB IT NL SE |
(30) | Priority: | 20.04.1978 US 897993
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(71) | Applicant: THE FIRESTONE TIRE & RUBBER COMPANY | | () |
| (72) | Inventor: | | - Fieldhouse, John William
()
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(54) | Purification of crude chlorophosphazene compounds by treatment with water |
(57) A process for the purification of crude chlorophos-" phazene involves the use of an intermediate purification stage in which the crude chlorophosphazene is subjected to at least two water-washings, following which a final purification step is conducted utilizing a conventional chlorophosphazene purification procedure, such as recrystallization, sublimation, distillation, or melt-filtering and at least a very high purity cyclic chlorophosphazene trimer is then recovered. In a preferred process, the crude chlorophosphazene is subjected to three water-washings prior to the final purification step.