| 摘要 |
<p>1443444 Tetrafluoroethylene telomers containing bromine IMPERIAL CHEMICAL INDUSTRIES Ltd 21 Feb 1974 [9 April 1973] 16879/73 Heading C2C Bromine - containing telomers of tetrafluoroethylene are prepared in the vapour phase at elevated temperature by reacting with a fluoroalkyl bromide of general formula wherein X is F, Cl or Br and Y is F, Cl, Br or a perfluoro-, perfluorochloro-, perfluorobromo- or a perfluorobromochloro-methyl group. Suitable fluoroalkyl bromides are CF 3 Br, CF 2 Br 2 , CF 2 BrCl and C 2 F 5 Br. The proportion of fluoroalkyl bromide is preferably at least one mole per mole of tetrafluoroethylene, especially at least 3 moles per mole. The process may be conducted at 250-500‹ C., particularly 300- 400‹ C. Amongst the examples C 2 F 5 Br is reacted with CF 2 = CF 2 to give mainly C 2 F 5 CF 2 CF 2 Br with a small amount of C 2 F 5 (CF 2 CF 2 ) 2 Br.</p> |
