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April 6, 1948, R. S. HOVEY ETAL 2,439,299 PRODUCTION OF HALOGENATED HYDROCARBONS CONTAINING FLUORINE Filed July 26, 1946 wr vir - INVENTORS - ult R. S. HOVEY U d t P. H. CARNELL U W1 BY M ATTORNEYs / Patented Apr. 6, 1948 2439,299 UNITED STATES PATENT OFFICE PRODUCTION OF BALOGENATED BY ORO CARBONS CON ANNG FUORNE Roger S. Hovey, Charleston, W. War, and Paul H. Carneli, Bartlesville, Okla, assignors to Philips Petroleum Company, a corporation of Delaware Application July 26, 1946, Seria No. 686,374 12 Claims. (CI. 260-653) 2 This invention relates to the production of Or kanes that are valuable as refrigerants and dis ganic fluorine compounds, more particularly persants. In addition to having properties that fluorinated hydrocarbons. In a more specific aS make them suitable as refrigerants and dispers pect it relates to the production of halogenated ants, these compounds have faint, nonobjection hydrocarbons containing fluorine and another able odors and are nontoxic and noninflammable. halogen from halogenated hydrocarbons contain Several fluorochloroalkanes used as "refrigerants ing a plurality of atoms of halogen other than are listed in the following table: fluorine. In one aspect it relates to the produc tion of mixed fiuoro-chloro-methane and -ethane fron corresponding chlorinated hydrocarbons, for 0. Formula Trade example the production of dichlorodifioroneth Name ane and/or trichloromonofluoromethane from -29.8 Freon, carbon tetrachloride, dichloromonofluoronethane 23.7 F-11 from chloroform and dichlorotetraiuoroethane CICEF 8.9 F-21. from hexachloroethane. 5 CsClaF---- 3. F-14, The principal object of the present invention is to fuorinate hydrocarbon derivatives. Another Our investion is a process of producing halo object is to replace organically bound chlorine, genated hydrocargo as, particularly the alkanes bromine and/or iodine atoms with fluorine atoirs. and especially the lower alkanes such as methane Another object is to produce fluorinated hydro 20 and ethane, containing fluorine and another hal carbon derivatives. Another object is to produce ogen, which comprises contacting a halogenated organic fiuorine compounds useful as refriger hydrocarbon containing a plurality of atoms of ants and dispersants. Another object is to pro halogen other than fluorine With a fluorinating wide a novel fuorinating agent. Another object agent comprising 8, major proportion of substan is to provide an improved method of manufac 25 tially anhydrous hydrofluoric acid and a minor turing dichlorodifiuoromethane. Another object proportion of titanium tetrafluoride under con is to provide an improved method of producing ditions such that at least one, but usually less . trichloromonofluoromethane. Still another ob than all, of said atoms of halogen other than ject is to provide an improved method of pro fluorine is replaced with fluorine. ducing dichloromonofluoromethane. Another 30 For example in accordance with one embodi object is to provide an improved method of mak ment of our invention, dichlorodifluoromethane, ing dichlorotetrafluoroethane. Many other ob CCl2F2, and/or trichloromonofluoromethane, jects will more fully appear from the following de CCl3F, are prepared by treating carbon tetrachlo Scription. ride with a fluorinating agent comprising sub The accompanying drawing portrays diagram stantially anhydrous hydrofluoric acid containing matically one specific embodiment of the present 35 a minor proportion of titanium tetrafluoride. invention. The drawing is a simplified flow di Similarly, dichloromonofluoromethane may be agram. Of One arrangement of apparatus for pro produced from chloroform, and dichlorotetra ducing dichlorodifiuoromethane from carbon fluoroethane may be produced from hexa tetrachloride. 40 chloroethane in accordance with our invention. Broadly the present invention comprises treat These examples are illustrative only and are by ing organic chlorine, bromine and/or iodine com no means exclusive, since our invention may be pounds with a novel fluorinating agent to replace employed to effect replacement of any number of halogen atoms of these compounds with fluorine. atoms of halogen other than fluorine in a halo The novel fluorinating agent of this invention 45 genated hydrocarbon with fuorine. Our inven comprises substantially anhydrous hydrofluoric tion is chiefly applicable to replacement of chlo acid containing a minor proportion of titanium rine with fiuorine. However, it may be employed tetrafluoride. The titanium tetrafluoride acts as to replace bronine and/or iodine with fluorine. a promoter for the hydrogen fluoride, the mixture The fluorinating agent of the present invention functioning as a new and improved catalyst in an 50 comprises a major proportion of substantially an old reaction, it being old to use other promoters, hydrous hydrofluoric acid and a minor proportion particularly antimony halides, in conjunction of titanium tetrafluoride. Usually the catalyst with hydrofluoric acid in this type of reaction. consists essentially of, i. e. the only active ele Among the products obtainable by the process ments of the catalyst are, hydrogen fluoride and . of this invention are low-boiling fluoro-chloroal 5. titanium tetrafluoride. 2,489,299 3 4 The proportions of hydrogen fluoride and ti substantially anhydrous or completely anhydrous tanium tetrafluoride employed may vary within conditions. By "substantially anhydrous" we wide limits. The preferred concentration of ti mean the presence of not more than about 1.0 tanium tetrafluoride in the fluorinating agent is Weight per cent of water in the reaction zone. from 1 to 10 weight per cent based on the weight Numerous types of apparatus are suitable for of titanium tetrafluoride and hydrogen fluoride. carrying out our invention. Mechanically-agi Concentrations of titanium tetrafluoride outside tated or jet agitated contactors may be used, or these limits may, however, be used if desired. It the halogenated hydrocarbon may be dispersed is ordinarily not desirable to use less than 1 per and allowed to rise through the body of the cat cent of titanium tetrafluoride because the pro 0 alyst. Intimate contacting of the catalyst and moting action at such concentrations is not suffi the reactant is desirable. In many cases the cient. More than 10 per cent of titanium tetra reaction mixture will comprise two phases. fluoride may be used if desired. For example con namely, a hydrofluoric acid phase and a halo centrations ranging from 10 per cent up to 50 per genated hydrocarbon phase, and it will be nec cent of titanium tetrafluoride, based on the 5 essary to provide means for intimately contact weight of titanium tetrafluoride plus hydrogen ing these two phases. fluoride, may be used. Ordinarily, however, the While our invention may be carried out in a promoting action is not sufficiently enhanced by batchWise manner, we prefer continuous oper the use of concentrations of titanium tetrafluo ation. Continuous operation may be practiced ride above 10 per cent to make use of such con 20 by continuously charging to a suitable pressure centrations economically feasible. In fact the resisting vessel the original halogenated hydro promoting activity appears to be as great within carbon and the fluorinating agent of our inven the 1 to 10 per cent range as it is at Concentrations tion, maintaining these materials under reac above 10 per cent. tion conditions for a suitable length of time, The reaction temperature employed may vary continuously withdrawing from the reaction over wide limits. We use temperatures above at zone the resulting reaction mixture, continu mospheric and We prefer to use temperatures Ously recovering the fluorinated hydrocarbon within the range of from 50 to 200° C. Likewise product and recycling unreacted and partially the pressure used may vary widely but is prefer reacted material as well as catalyst to the reac ably sufficiently high to maintain the reaction 30 tion Zone. Any conventional apparatus for Con mixture in the liquid phase, Ordinarily the pres ducting reactions involving anhydrous or Sub sure is such that substantially all of the react stantially anhydrous hydrofluoric acid, such as ants and reaction products are maintained in the equipment commonly used for alkylating the liquid phase. The pressure required to isoparaffins with olefins with this acid, may be accomplish this will depend upon the temper 35 used. Suitable recycle arrangements for the ature and the proportions of the various ingre fluorinating agent, for unreacted materials, and dients charged to the reaction zone. The reac for other components of the reaction effluent may tion is ordinarily carried out in a closed pres be provided as desired. sure-resisting vessel of such size that the ma In one embodiment of our invention which is jor proportion and usually substantially all of 40 especially desirable in continuous operation, the the materials are in the liquid phase. The rela fluorinating agent of Our invention is prepared tive amounts of materials in the liquid phase by adding titanium tetrachloride to liquid an and in the gas space thereabove will depend upon hydrous hydrofluoric acid which converts the the relative volumes of the reaction vessel and titanium tetrachloride to the tetrafluoride in the liquid charge. In view of the much greater 45 situ. Since titanium tetrachloride is normally concentration of material in the liquid phase a liquid, whereas titanium tetrafluoride is nor than in the gaseous phase, nearly all may be in mally a solid, difficulties

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