Patented Nov. 19, 1946 2,411,159 UNITED STATES PATENT OFFICE ‘ 2,411,159 LUBRICANT William Edward Hanford, Easton, Pa., assignor to E. I. du Pont de Nemours & Company, Wil mington, Del., a corporation of Delaware No Drawing. Application July 22, 1943, 1 Serial No. 495,767 13 Claims. (Cl. 252-29) 2 This invention relates to a new class of stable and the terminal substituents contribute to. their Lubricating oils, transformer oils and other re merizable organic compound" designates any or- ' ?uorine-containing lubricants. lubricating properties. The phrase “non-poly ?ned mineral oils suffer a marked deterioration in use and when exposed to air at elevated tem ganic compound containing one or more carbon atoms which is free from ethylenic or acetylenic unsaturation. peratures. Generally, such petroleum oils when in'use darken in color and eventually may be The preferred stable lubricating compositions come saturated and deposit a ?nely divided oil of this invention vary from relatively high boil insoluble carbonaceous material, commonly ing liquids to solids melt‘ g below 300 C. which known as sludge. Under some conditions, the 10 have molecular weights wit _' the range of from oils deposit an insoluble ?lm on hot metal sur 250 to 2500 and contain from about 60 to '15 per ' faces. Such oils, in addition, develop an acidity cent of ?uorine. after some period of use, particularly when used v The following examples are given by way of il under high temperature conditions. In attempts lustration of the superior lubricating properties to prevent this deterioration of lubricating or 15 of these lubricants, but since the conditions may transformer oils, use has been made of oxida be varied I do not wish to be limited to the exact tion inhibitors. Such materials are useful for a aipparatus, machine or other conditions men short time, but they themselves are soon oxidized t oned. and lose their e?ectiveness. Exmrrr: I It is an object of the present invention to pro 20 The ?lm strengths of a number of reaction vide very stable, highly ?uorinated lubricants. products of tetra?uoroethylene with various A further object is the preparation of very stable, non-polymerizable compounds were compared highly ?uorinated non-?ammable lubricants for with that of a commercial SAE 30 oil by apply the purpose of lubricating moving parts under ex ing them directly to the bearing of a Cornell fric treme conditions such as those imposed at ele tion tester and noting the jaw load on said tester vated temperatures, at extreme pressures, or by at which seizure occurred. The Cornell friction corrosive chemicals and the like. It is a principal tester is described in U. S. Patent 2,279,560. object of the invention, therefore, to provide lu These materials exhibited ?lm strengths superior bricating compositions characterized by the afore-mentioned improvements. Additional ob 30 to the SAE 30 oil as shown in the‘ following table. iects will become apparent from an examination Table I of the following description and claims. These and other objects and advantages are accomplished by a lubricant comprising the re action product of tetra?uoroethylene and a non 35 polymerizable organic compound as more fully Ap roximate melting or Reactmt b0 g point of product Jag loadll me friction on tester at seizure described hereinafter. The ‘reaction products of tetra?uoroethylene prepared by reacting tetra?uoroethylene at a tem perature between 50° C. and 350° C. with a sat ' Dioxane _______________ -_ 40 urated non-polymerizable organic compound of the general formula XY, wherein X is a member of the group consisting of hydrogen and halogen and Y is a monovalent saturated organic radical, have been found to be exceptionally stable, non 45 ?ammable lubricants. Said products, which are preferably prepared in a closed system and in the - D ____________ __ 1,2-d1methoxyethaue __________ __ Ethyl propionatc. n-Butyric acid. _ Pound: M. P. l70-175° C .......... .. 2,250 .M. P. 75-00° C. (F, 64.6%)__ M. P. 80° 0 ............... -. 1,600 1,250 M. P. 120" O__.--___..._-_-_ 2,500 _ Soft low melting solid _____ -_ _ Sticky low melting solid. _ __ l, 375 3, 000, Cycl0hexane_._ _ ___________ ._ 1, 750 n-Butane--- _ M. P. 125° C (F, 70.3%)_-__ 2,000 chloroform ___________ -. M. P. 90-120 - P. 290-295 .......... -_ 2,000 Control SAE 30 oil .................................. _- 760 Exmrtr II presence of a catalyst, have the general formula The reaction products of tetra?uorethylene X(CF2CF:)»Y in which X is a member of the with non-polymerizable organic compounds im group consisting of hydrogen and halogen, n is 50 proved the ?lm strength of an ordinary‘ com a positive integer greater than 1 and Y is the mercial SAE 30 oil when added to the oil in complementary portion of the organic reactant, the amount of only one per cent as shown by being a monovalent saturated organic radical. the following table which records the jaw load The ?uoro-carbon atom chain present in these at which seizure occurred when a commercial products contributes to their extreme stability I55 SAE 30 oil containing 1% by weight of a reaction 2,411,159 3 - A Reactmt 4 variety of isomeric products arevobtained in which product of tetra?uoroethyli ne with a non-poly merizable reactant was applied directly to the bearing of a Cornell fristion tester. Table II all the tetra?uoroethylene units are not neces sarily connected together. For example, the above products may react with more tetra?uoro ethylene as illustrated below: Jagorne loaduon roximate melting or brfl‘ing point of product machine at seizure ‘ 10 DM an _______________ __ 8 C . (F M. P. 75-90" However, it will be observed that the sum total of the atoms other than those in the tetra?uoro ethylene units is equivalent to one unit of the 7) __ pomldgm 64.6 B. P. 171-19o° 0-1---- " _. B. P. 211-230“ C _____ -. B. P. 86—92° 0/42 mm__ 11250 1, 125 - 1,250 o ______________ __ B. P. 127-145‘? 0/42 111111.... Control SAE 30 oil __________________________________ -- 1,250 800 original \non-p‘olymerizable organic compound XY. The saturated non-polymerizable organic com pounds include acids, esters, anhydrides, nitriles, amides, imides, ketones, aldehydes, acetals, ketals, alcohols, glycols, hydrocarbons, ethers, EXAMPLE III Considerable di?iculty was encountered on at tempting to distill or store corrosive chemicals 20 mercaptans, sul?des and disul?des. The com such as antimony trichloride, antimony penta pounds mentioned above may be straight or chloride, and boron tri?uoride in glass apparatus branched chains or may be cyclic. The preferred containing ground glass joints or stopcocks due to type of non-polymerizable organic compounds the rapid attack of the chemicals on the com for preparing stable lubricants from tetra?uoro mercial lubricants causing sticking or freezing 25 ethylene are saturated aliphatic hydrocarbons. of the joints. A glass apparatus containing Examples of said hydrocarbons are methane, numerous ground glass joints and stopcocks ethane, propane, n-butane, isobutane, cyclohex which was designed for distilling and storing cor ane, pentanes, hexanes, saturated petroleum hy rosive chemicals such as aluminum bromide, boron drocarbons, and isooctane. These reaction prod tri?uoride, and antimony halides was found to 30 ucts are exceptionally stable and exhibit ex be practically inoperable using the highest grade commercial lubricants due to the rapid sticking cellent lubricating properties. The lubricants of this invention have m’any and freezing of the glass joints which actually oc curred in a few hours. However, when the‘ joints were lubricated with a mixture of graphite and distinct advantages over the commercial mineral H(CF2CF2) 11C4H9, where n averaged about 7, the deterioration, or sludge formation even under extended severe conditions of elevated tempera tures or pressures, and their relatively low vis oils including non-?ammability, extreme thermal and chemical stability, freedom from acidity, ground glass joints and stopcocks operated smoothly for over a week while distilling alumi- ' num bromide under high vacuum. This lubricant was also superior to commercial lubricants in that co'sity also facilitates their rapid circulation and 40 penetration between metal, glass, or other sur it was unattacked by the corrosive chemicals and imparted no color or contamination to the puri?ed materials. Similar results were obtained when the stopcocks, present in an apparatus used for the storage of bromine, were lubricated with this 45 material. The present invention comprises'the discovery of a new class of stable lubricants which are applicable for use on bearing surfaces, e. g. on faces. Two samples of H(CF2CF2)11C4H9 where n averaged about 3 and 7 were passed through a 26 inch furnace which was heated to 500-550" C. and the color and lubricating properties of the heated samples remained unchanged. The lubricants vary from liquids to waxy solids ' which makes them applicable as lubricants for moving parts in a wide variety of different ma chines and apparatus. The liquid lubricants are metals, glass, ceramics, plastics, wood, leather, 50 particularly useful as lubricating oils where the or other materials. The lubricating compounds lubricant may be subjected to extreme condi which are the subject of this invention may be tions such as elevated temperatures, for example represented by the formula X(CF2CF2)..Y, where X is hydrogen or halogen, XY constitutes a non polymerizable organic compound and n is a in internal combustion. engines of the spark and compression-ignition types, such as airplane, positive integer greater than 1 which generally 65 Diesel, marine and automobile engines; as well as for cutting oils, turbine lubricants, wire-drawing varies from 2 to about 25. In the preferred prod ucts, because of the superior results thereby ob lubricants, etc. They are also applicable as stable insulating and lubricating oils in trans formers, switch boxes and the like. The higher their greater utility, the preferred products are liquids or solids which melt below 300° C. and 60 molecular weight waxy lubricants may be applied directly to the bearing surfaces or may be blended contain at least 60% ?uorine by weight. The with the high boiling liquid lubricants to give following examples are given to illustrate the greases which are particularly adapted for use preparation of the compounds. , tained, n is in the range of 2 to 15. In view of “ “or, = or, +'xY -_-» xwrzorna nor, = or, + co]. -_-» cuoricrmcoh CH: Cg! CH3 “CF, : CF, + JJH: C (I'J‘H: 1 Since the structure of these products has not been de?nitely determined, it is possible that a large as lubricants for metal or glass surfaces. A few 65 speci?c examples ‘of uses for which these lu bricants are especially‘ suited include ammuni tion lubrication, glass stopcock lubricants, mill greases, extreme pressure lubricants, cutting oils and as lubricants for various types of electrical 70 motors. They may be employed as lubricants ' alone or in conjunction with other oils, lu bricants, or agents added to the oil for various purposes such as fatty acid esters, organic phos phites, organic phosphates, halogenated aro matic compounds, pour point depressants, vis 2,411,109 6 cosity index improving agents, anti-ring sticking agents ‘and the like. erai formula. H(CF:CF5) "04H: in which n is a pos itive integer greater than 1. _ 7. A lubricating composition comprising a sat As many apparently widely different embodi urated organic poly?uoro compound of the gen ments oi’ this invention may be made without departing from the spirit and scope thereof, it is to be understood that I do not limit myself to the speci?c embodiments thereof except as eral formula H(CF2CFz)nC4Ho in which n is about ‘I. . 8. A lubricating composition comprising a lu bricating oil and a saturated organic poly?uoro compound of the general formula X(CF:CF2) “Y defined in the appended claims. Having described the present invention, the 10 wherein X is a member selected from’the group following is claimed as new and useful: 1. A lubricating composition comprising the reaction product of tetrafluoroethylene with a consisting of hydrogen and halogen, n is :a posi tive integer greater than 1, ‘and Y is a molovalent saturated non-polymerizable organic compound saturated organic radical. 9. A lubricating composition comprising a lubri selected from the group consisting of hydrogen 15 cating oil and a saturated organic poly?uoro and halogen and Y is a monovalent saturated compound which contains from about 60% to 75% organic radical, said reaction product consisting of ?uorine, has a melting point of less than 800' of from two to about 25 tetra?uoroethylene units C. and a molecular weight within the range 01' per unit of organic compound. ' from 250 to 2500, and is or the general formula 2. A lubricating composition comprising a sat 20 H(CF2CFI)1IY wherein n is a positive integer urated organic poly?uoro compound of the gen within the range of from 2 to 15 and Y is a mono of the general formula XY where X is a member eral formula X(CF2CF2) "Y in which X is a mem valent saturated hydrocarbon radical. ber selected from the group consisting of hy drogen and halogen, n is a positive integer greater 10. A lubricating composition comprising a lubricating oil and a saturated organic poly?uoro than 1, and Y is a monovalent saturated organic 25 compound of the general formula radical. I 3. A lubricating composition comprising a. sat-v urated organic poly?uoro compound containing ~ at least 60% ?uorine and having the general ‘ ' H(CF2CF2) 1043's wherein n is about "I. 11. A lubricating composition comprising formula X(CF2CFi)nY in which X is a member 30 graphite and a saturated organic poly?uoro com selected from thagroup consisting of hydrogen pound of the general formula xicraorai ‘Y and halogen, n is a positive integer greater than 1, and Y is a monovalent saturated organic rad ical. 4. A lubricating composition comprising a sat urated organic poly?uoro compound which con wherein x is a member selected from the group consisting of hydrogen and halogen, n is a posi tive integer greater than 1, and Y is a monovalent tains at least 60% ?uorine, has a melting point oi’ less than 300° 0., and is of the general formula saturated organic radical. 12. A lubricating composition comprising graphite and a saturated organic poly?uoro com pound which contains from about 60% to 75% of ?uorine, has a melting point of less than 800° C. xwrscra) nY inv which X is a member selected from the group consisting 01 hydrogen and halo 40 and a molecular weight within the range of from 250 to 2500, and is of the general formula gen, n is a positive integer greater than 1, and Y H(CF'=CF:) ‘Y wherein n is a positive integer is a monavalent saturated organic radical. 5. A lubricating composition comprising a sat within the range of from 2 to 15 and Y is a mono urated organic poly?uoro compound ofthe gen eral formula H(CF2CF2)1|Y in which n is a posi tive integer greater than 1 and Y is a monovalent saturated hydrocarbon radical. 6. A lubricating composition comprising a sat urated organic poly?uoro compound of the gen valent saturated hydrocarbon radical. 13. A lubricating composition comprising graphite and a saturated vorganic poly?uoro com pound ot the general formula H(CF:CF:) ‘C48: wherein n is about '7. WILLIAM EDWARD HANFORD. '