| 摘要 |
1,144,948. Perfluoroacrylyl fluoride. E. I. DU PONT DE NEMOURS & CO. 5 Sept., 1967 [6 Sept., 1966], No. 40468/67. Heading C2C. [Also in Division D1] Perfluoroacrylyl fluoride is prepared by pyrolysing α-hydrotetrafluoropropionic acid anhydride under substantially anhydrous conditions at a temperature of at least 350‹ C. An inert contact mass, such as glass, quartz, silica &c., and/or a catalyst such as boron phosphate or an alkali metal fluoride may be present. In the examples the anhydride is converted to perfluoroacrylyl fluoride in the presence of (1) boron phosphate at 400‹ C., (2) quartz at 577-600‹ C. and (3) NaF at 550‹ C. α-Hydrotetrafluoropropionic anhydride is prepared by heating α-hydrotetrafluoropropionic acid with PO 5 followed by vacuum distillation. |
