Document DGxG4MOaNDxZvM5BXz1zXqwbO

Patented Aug. 22, 1950 27-CV-10-28862 Filed in Fourth Judicial District Court 11/17/2017 6:21 PM Hennepin County, MN 2,519,983 UNITED STATES PATENT OFFICE 2,519,983 ELECTROCHEMICAL PROCESS OF MAKING FLUORINE-CONTAINING CARBON COM POUNDS Joseph H. Simons, State College, Pa., assignor to Minnesota Mining & M anufacturing Company, St. Paul, Minn., a corporation of Delaware Application November 29, 1948, Serial No. 62,496 20 Claims. (Cl. 204--62) 12 This application is a continuation-in-part of dltives to perm it of electrolyzing liquid hydrogen my copending application Ser. No. 677,407 (filed fluoride solutions thereof admixed with rela June 17,1946), since abandoned. The latter was tively insoluble organic starting compounds, such filed as a continuation-in-part of the following as alkanes, which do not provide adequate con prior applications which thereafter were aban S ductivity. Pure anhydrous liquid hydrogen fluo doned in its favor: Ser. Nos. 384,729 (filed M arch ride, per se, is non-conductive. The electrolyte 22, 1941), 569,265 (filed December 21, 1944), and is free from w ater in more th a n a small pro 626,434 (filed November 2,1945). portion but need not be anhydrous in a strict This invention relates to my discovery of a sense. basically new process of m aking fluorocarbons 10 Excellent results can be obtained w ith simple and other fluorine-containing carbon compounds. single com partm ent electrolytic cell arrange The process is simple in operation, does not in ments. No diaphragm is needed between elec volve the use or form ation of free fluorine a t any trodes. Fluorination can be completed in one stage, and has great versatility in enabling the step to directly obtain fully fluorinated product direct production of m any types of product com 15 compounds which are relatively insoluble and pounds using organic startin g compounds which either evolve with the cell gases or settle to the are readily available and relatively inexpensive. bottom of the cell from which they can be It is an electrochemical process and its utility drained, depending upon their boiling points. has been dem onstrated by extensive pilot p lan t The process is suitable for continuous as well as operations employing a 2000-ampere cell, as well 20 batch operation. The cell can be operated a t as by many laboratory experiments. atmospheric pressure. The cell and the cathodes This process was publicly disclosed in the oral can be made of iron or steel, and the anodes of presentation on September 15, 1948, a t th e P o rt nickel, and such cells have been satisfactorily land, Oregon, session of th e 114th m eeting of the operated a t 5 to 8 volts, D. C., in producing a wide American Chemical Society, of five papers au 25 variety of product compounds. thored by me and my assistants. Abstracts of The reaction mechanism is not fully under these papers had been previously published in stood but the electrolyzing process apparently th e advance "Abstracts of Papers" volume issued transform s the organic starting compounds a t or by the society (pp. 42-0 to 45-0). News items adjacent to the anode and may be regarded as an relating thereto and briefly describing th e process 30 anodic process. Hydrogen is evolved a t the cath have been published in th e society's magazine ode, being derived from the hydrogen fluoride; Chemical and Engineering News, vol. 26, p. 2428 and will also evolve in the cell by derivation from (Aug. 16, 1948) and pp. 2878-9 (Sept. 27, 1948). other hydrogen-containing compounds which These papers were subsequently published in th e m ay be present. Fluorine is not evolved, and the Journal of th e Electrochemical Society, vol. 95, 35 reaction mechanism does not involve the form a No. 2, pp. 47-67 (Feb. 1949). tion of molecular (free elemental) fluorine as an Briefly stated, this new and useful electro interm ediate agent. chemical process involves electrolyzing a liquid Product compounds are obtainable (both cyclic hydrogen fluoride (HF) solution containing a and non-cyclic) which have the same number of fluorinatable organic starting compound, a t an 40 carbon atoms and same carbon skeletal structure electrolyzing potential which is insufficient to as do the starting compounds, but with partial generate free fluorine under the existing condi or total fluorine atom replacement of hydrogen tions, but which is sufficient to cause th e pro atoms and other atoms and radicals bonded to duction of fluorine-containing carbon compound the carbon skeleton of the molecule. Fluorine products a t a useful rate. A wide variety of 45 addition occurs in the case of unsaturated and organic compounds are soluble in anhydrous aromatic types of starting compounds to produce liquid hydrogen fluoride and provide adequate fully saturated product compounds. Ncn-cyclic electrolytic conductivity. Use can also be made compounds (in addition to cyclic compounds) of soluble organic and inorganic conductivity ad- having the same number of carbon atoms are ob- 27-CV-10-28862 Filed in Fourth Judicial District Court 11/17/2017 6:21 PM Hennepin County, MN 8,510,068 34 talnablefrom cyclicstartingcompounds as the fewer or more carbon atoms than the parent result of bond cleavage and fluorine addition. hydrocarbon groups can also be obtained from Also,theuseofpolycarboncyclicandnon-cycllc suchcompounds. A featureofthepresentproc- starting compounds generally resultsin appre- essisthat itprovidesa simple and economical Mahiwyieldsofproductcompoundshavingfewer $ procedureformakingnormallyliquidfluorocar- cartxmatomsInthemolecule,duetofragments- bons,having fiveor more carbon atoms inthe tionofthecarbonskeletonandfluorineaddition. molecule. Compounds having a greaternumber ofcarbon Theformationoffluorocarbonsisaccompanied atoms than thestartingcompounds areobtain- by the formation offluorocarbon hydrides and ableastheresultofcouplingofcarbonradicals io partiallyfluorinatedhydrocarbons,duetoincom- formed inthesolution. The kinds and relative jfletehydrogenreplacementinthecaseofsome proportionsofproductcompoundsobtainablein molecules. The proportions depend upon the any given case will depend upon the starting conditions. The fluorocarbonmonohydridesand compound and the operating conditions. By .dihydridesare of particularvalue becausethey properselectionitispossibletoobtainexcellent is have a high degree of thermal stability and yieldsofdesiredproducts,which canbe readily chemicalinertnessandarenon-combustible,and separated by fractional distillation from each yetthehydrogenatomsofferpointsofattackfor otherandfromlow-yieldby-productcompounds. thesynthesisoffluorocarbonderivatives. Thus Incommercialoperations,usecanbemadeofthe these fluorocarbon hydrides can be thermally production of multiple products in buildingup 20 chlorinated and brominated toyield the corre- stocksofmany usefulcompounds from a much spendingfluorocarbonchloridesandbromides,as more limitednumber ofstartingcompounds. disclosedina paperpublishedintheJournalof In some casesresinous material isformed in theAmericanChemicalSociety,voL68,pp.968- thecellbutisgenerallysolubleintheelectrolyte 969 (June 1946) ofwhich Iwas aco-author, solutionand doesnotinterferewith theopera- gg Saturated fluorocarbonsand fluorocarbonde- Mnn Resinous products containing combined rtvatives are obtainable in good yields ranging fluorineinproportionsup to60% havebeenob- fromthesimplestcompound,CF,whichisalow- tained. In many casesno solidresidualmate- boilinggas,up tohigh-boilingcompounds hav- rlalsare found even afterextended useof the ingeightormore carbon atomsinthemolecule cell. Ingeneral,thereislittleornocorrosionqf u and having boilingpoints above 100* C. theelectrodes. The fluorocarbon and related compounds ob- To brieflyindicateatthispointtheversatility talnable by this process have utilityfor many of the process in enabling the production of purposes. The saturated fluorocarbons, fiuoro- fluorocarbon derivatives, mention Ismade (for carbon hydrides, fluorocarbon ethers, and tri- lllustrattonand notlimitation) ofthefollowing 3$ fluorocarbon amines, for example, have a high typesdesignatedbygenericformulaewhereinR degree of thermal stabilityand chemical lnert- representssaturatedfluorocarbonradicals(cyclic ness,they do notburn,and theyhaveuniquely or non-cycllc) consisting solely of carbon and low refractive indices and dielectric constants fluorineatoms:R'OR" (obtainablefromethers), as compared with ordinary organic compounds. R'R"R"'N (obtainable from tertiary amines), 40 The Uquld compounds (containingfiveor more R'R"NF (obtainable from secondary amines), carbon atoms) have exceptionally low surface RNFi (obtainablefromprimaryamines),RCOP tensionsandviscosities,coupledwithhighdensl- (obtainable from monocarboxylic acids), ties. These and other compounds can be used for such purposes (depending upon boiling R'COOR" go points) as refrigerants,Are extinguishers, inert solventsand diluents,heatexchangefluids,tur- (obtalnablefrom esters),RCN (obtainablefrom bineImpellents,dielectrics,hydraulicmechanism nitriles)andRSF (obtainablefrommercaptans). fluids,andlubricants. Theproductsofthisproc- Fluorocarbon compounds which contain com- esscanalsobeusedasIntermediatesinthesyn- blned chlorine can be obtained from chlorine- 60 thesisofotherchemicalcompounds. Inparticu- cont&inlng starting compounds (e. g., chloro- lar,thefluorocarbonacidfluorides(RCOF) pro acetic acid). Heterocyclic compounds contain- videthereactivestartingcompounds formaking ingoneormoreoxygenornitrogenatomsinthe avastnumber ofderivativecompoundscontain- rlng can be obtained by replacement of the ing a fluorocarbon radical and having unique hydrogen atoms by fluorine atoms in starting 55 propertiesonthataccount, compounds ofcorrespondingstructure. Allorganic compounds potentiallycapable of True fluorocarbons (carbonfluoridescontain- reacting with fluorinecan be employed topro- ing only carbon and fluorine atoms) can be ducefluorine-containingcarboncompoundprod- directly obtained from hydrocarbon starting uctsbythepresentprocess. FluorineIsthemost compounds, and also by electrolysing solutions 60 chemically activesubstance. No organicmate- of various hydrocarbon derivatives, to obtain rialiscompletelyresistanttofluorineexceptcar- substantial yields of fluorocarbons having the bon tetrafluorlde (CF). Even the polycarbon same number of carbon atoms as the starting saturated fluorocarbons can react by carbon- compounds. Forexample,alkanes,alcoholsand carbon bond cleavageand fluorineaddition,the monocarboxylic acids can be employed toyield 65 stableendproductbeingCF. fluorocarbonshavingthesamenumberofcarbon As a practicalmatter inrespecttothe corn- atoms. In addition,fluorocarbonshavingfewer mercialutilizationoftheprocess,thehydrogen- and more carbon atoms are produced. Fluoro- containingorganiccompounds which containat carbons having fewer carbon atoms than the leastonehydrogenatombondedtoacarbonatom starting compound can also be produced from 70 inthemoleculeareofmainInterest. Thesecan hetero compounds wherein carbon atoms are allbeused formMny fluorocarbons,and other linked by non-carbon atoms, as in the case of fluorine-containing carbon compounds which others and secondary and tertiary amines; the contain atleastone fluorineatom bonded toa hy groupsbeingreleasedtoform cor- carbon atom inthe molecule. The sub-classes fluorocarbons. Fluorocarbonshaving 70 oftheseorganicstartingcompounds ofparticu-