Patent GB-633678-A (GB)
Title: Improvements in or relating to the production of organic fluorine compounds
IPC: C07C17/10
Filed: 1947-11-17
Abstract: Chlorine trifluoride, for use as a fluorinating agent (see Group IV (b)), is prepared by passing chlorine with excess fluorine through a tube at 280 DEG  C. and condensing the product at subnormal temperatures.  By-product hydrogen fluoride may be removed by passing the trifluoride vapours through anhydrous sodium or potassium fluoride.ALSO:Organic compounds containing hydrogen at least part of which is directly attached to carbon are fluorinated by treatment with chlorine trifluoride in the presence of a substantially inert solvent.  Solvents instanced are perfluoromethylcyclohexane, products of the reaction which it is desired to effect and particularly carbon tetrachloride.  Organic compounds instanced are white spirit, paraffin oil, straight and branched chain aliphatic hydrocarbons, e.g. n-heptane and trimethylpentane, aromatic hydrocarbons, e.g. naphthalene and decalin, chlorinated paraffin wax, chlorinated naphthalene and chlorinated rubber.  The reaction may be effected by passing vaporized chlorine trifluoride, optionally mixed with an inert gas such as nitrogen, into the solution of the organic compound or the latter, optionally dissolved in a solvent, may be added to a solution, e.g. 10 per cent, of chlorine trifluoride in the solvent. The temperature of reaction varies widely and depends upon the solvent and organic compound employed, temperatures instanced with carbon tetrachloride being between -22 DEG  and +50 DEG  C., although to effect further halogenation temperatures up to 160 DEG  C. may be used. Products are obtained which usually contain chlorine as well as fluorine.  Reaction vessels used should be of inert materials such as recrystallized alumina or nickel.  The reaction may have a bleaching effect, thus a dark brown chlorinated paraffin wax dissolved in carbon tetrachloride and treated with 2 per cent of vaporized chlorine trifluoride diluted with nitrogen gives a pale yellow oil. In examples in which carbon tetrachloride is the diluent, chlorine trifluoride vapour is passed into (2) a 10 per cent solution of chlorinated paraffin wax for 10 minutes and a further period of an hour; (3) 10 per cent solution of paraffin oil for 15 minutes; (4) chlorinated naphthalene at 20 DEG  C. for varying times; (8) refined white spirit at 35 DEG  C. for 6 hours and, after removal of some solvent, at 100 DEG  to 110 DEG  C.; (9) 50 per cent decalin solution at 28 DEG  C. for 4 hours and the product at 120 DEG  C.; (10) 50 per cent n-heptane solution at 32 DEG  C. for 2 1/4 hours and the product at 130 DEG  C.; (11) 50 per cent trimethyl pentane solution at 30 DEG C. for 4 hours and the product at 120 DEG  C.; (12) 20 per cent chlorinated paraffin wax solution at varying temperatures and concentrations of reactants; (13) benzene; (14) aniline and (15) nitrobenzene, and refined white spirit in carbon tetrachloride is treated with chlorine trifluoride in carbon tetrachloride in (6) at 33 DEG  C. for 50 minutes, the product being further treated, and (7) at 46 DEG  C. for one hour in all cases final products are obtained containing fluorine and chlorine.ALSO:Rubber is among the compounds that may be fluorinated and chlorinated by treatment with chlorine trifluoride in the presence of a substantially inert solvent (see Group IV (b)).  In examples chlorine trifluoride vapour is passed (1) for half an hour into a three per cent solution of crepe rubber in carbon tetrachloride and (5) for 2 to 3 hours into a solution of chlorinated rubber in p  carbon tetrachloride to give a fluorinated and chlorinated rubber of improved heat stability; colour and light transmission.