US2153496A - Extreme pressure lubricant - Google Patents

Description

Patented 4,31939 UNITI-:o STATI-:s

PATENT OFFICE M. Seger, Pitman,

y N. I., aasignors to Socony-Vacuum 0i! Comf PIM, poration o! New York rated, New York, N. Y., a cor- No Drawing. application April s, 193s, Y

serial No, :00,910 v 1s clans, (ci. s'z-a:

'lhisinvenonhastodowiththeartof extraue lubrication and is more particularly concerned with the development of new and im f l n lubricant compositions which possess 5 the il rl a' `(If an eective lubricant nlm between surfaces under high load pressures and high rubbing speeds.

Asiswell hlowntothose familiar with the art, automobile design over the past several years has involved the use of smaller gears of the worm and hypoid type which operate imder extremely high loadsandathighrubbingspeeds, and asl a consequence have required lubricants capable of withstanding pressures much higher than those l5 at which an ordinary hydrocarbon lubricant lm of the so-called thick type will rupture.

This demand for extreme pressure lubricants has led tothe development of various additive ingredimts which can be incorporated in a carrym ingmediinnsnchasamineraIoiLwhichare capahle of withstanding, or of yielding a material whichyvill withstand; these extreme pressure con- Among the various types of extreme pressure (E. P.) agents which have been progsposedaretheso-calledchemically activetype,

which pomass the property of reacting with the lubricated metal surfaces under the conditions of extreme premura' engagement and forming on such engaged surfaces a lubricant lm or coatao ing capable 'of withstanding the extreme pressure loads, thus protecting the engaged metal surfaces against scoring and seizure. The present invenv, tion is concerned with the development of im- .proved extreme prsure agents of this general dass In order that some preliminary indication may he obtained as to the extreme pressure properties of agents or ts of this type various laboratory extreme pressure tests have been developed 40 by the automotive industry and the oil industry. Among the tests are the so-called Almen pin test. the S. A. E. test, and the 'Iimken test. These laboratory extreme' pressure tests involve the controlied and measln'ed application of load to relatively moving metal surfaces lubricated by the lubricant being tested. Failure of the lubricant isindicatedbyseizureorscoringofthetest pieces. Y Although laboratory scale tests of this charac'- ter olersome indication as to the relativel value of extreme prsure agents, they aiordlittle or no indication as to the practicablity or impracof a. particular lubrint `composition under actlml conditions of commercialization and me. In addition to the property of withstanding suleamionofextremelyhighbearingloads other factors which must be considered in the development of anl extreme pressure lubricant are: the tendency oi the extreme pressure agent to corrode the containers in which it is stored and the machine parts, such as bearings, housings, 5 and gears, with which the lubricant comes in contact when in use; the tendency of the extreme pressure agent to separate from the carrying medium on standing; the color of the lubricant composition obtained through the use of a particular l0 materials of a chemicallyl active nature which 1li' have beenproposed as extreme pressure agents and which will satisfy one or more of the laboratory extreme pressure tests.v Authorities are' in agreement, however, that satisfaction of these tests valone affords no conclusivel standard for judging the practical value of an extreme pressure lubricant composition, since many materials which satisfactorily pass such tests are valueless from a practical standpoint because they possess one or more of the undesirable properties enumerated above. It is generally believed, therefore, that actual eld andstorage tests aord the best means for iinal evaluation of an extreme pressure agent.

Among the numerous extreme pressure agents of the chemically active type which have been proposed are various metal soaps and compounds containing reactive chlorine, sulfur, and phos-v phorus. The present invention is concerned with compounds of the type which contain chlorine and sulfur. Y l

Numerous organic materials containing reac-` tive chlorine have been proposed as extreme pressure ingredients, such materials falling into two general classiiications. depending upon whether' the organic constituent is an aromatic or an aliphatic derivative. In. general we have found that in chlorinated compounds of the aromatic type, such as chlorinated naphthalene and chlorinated diphenyl, the' chlorine is too. iirmly bound to the. hydrocarbon molecule to have the requisite chemical action upon the bearing metals which will produce the necessary vthin lubricant' 'film for withstanding the extremely high pressures norbe very unstable o r highly reactive`so that it is l corrosive or in a form where it is not so stable as to have little or no practical E. P. value for the high load limits encountered in hypoid gears.

Ithas long been known that organiccompounds containing both sulfur and chlorine such as are obtained by treating mineral oils and fatty oils with sulfur chloride possess the property of' increasing the lubricity `of mineral lubricating oils, and compounds of this type were among the rst considered as possible extreme pressure ingredients. The French patent, No. 683,466 and the corresponding British patent, 454,552, which disclose a multitude of chlorinated organic compounds proposed as extreme pressure ingredients, mention the possibilityl of using a chlorine compound and a sulfur compound together and also suggest a limited number of compounds containing both sulfur and chlorine. The disclosures are somewhat indefinite as to the composition of these last-mentioned materials, but aryl compounds of sulfur and chlorine appear to be suggested.

As regards compositions or materials containing both sulfur and chlorine, we have found that in general the products obtained by the treatment of a mineral oil or fatty oil with sulfur chloride are too corrosive for practical commercial use. In other words, compounds of this type tend to corrode the containers in which the lubricants are stored and the equipment lubricated. Furthermore, certain of the compounds of this character tend to form highly corrsive .sludge on standing. We. have also found that as a general proposition the products obtained by chlorlnating certain aryl suldes such as dibenzyl disulfide andthe products obtained by chlorinating materials such as dichlordiethyl sulde are too highly reactive for commercial use in that they also break down to form products which attack the containers, the gear housings, etc.

These general observations which we have made as to sulfur-chlorine compounds of the type heretofore proposed have been conrmed by other workers in the eld of extreme pressure lubrication. Wolf and Mougey (Proc. A. P. I., 1932, pp. 118-131) have discussed various extreme pressure ingredients, including compounds containing both sulfur andchlorine, and inthe adf dendum to'that publication lthe authors have pointed out that corrosion of steel parts was found to have taken place with the sulfur-chlo- -rine extreme pressure lubricants. In one case the steel parts above the oil level were said to be covered with a heavy layer of iron rust, some of which was washed oil.' bythe lubricant and caused rapid bearing wear. The British Patent 431,434.

l causes pitting and rusting of the metal parts and forms oil-insoluble abrasive materials. Y In a more recentlyv discussion of chlorine .com-

pounds as extreme pressure lubricants (Industrial and Engineering Chemistry, vol. XX, No. 10, pp. 1191-1197) the authors have not mentioned or discussed any proposed extreme pressure ingredients which contain both chlorine and sulfur. It will thus be seen that while organic compounds containing both sulfur and chlorine have received i consideration as extreme pressure lubricants and have in fact been shown by the conventional laboratory extreme pressure tests to possess increased load-carrying properties, such compounds have in general been condemned because of their extremely high corrosive action, which makes their storage and use impracticable.

Mere load-carrying ability, therefore, is not the only criterion by which an extreme pressure ingredient can be judged. For commercial use an extreme pressure agent must contain a reactive ingredient or reactive ingredients in a form suillciently stable to be non-corrosive to the containers and to the machine parts and housings with which it is normally in contact, but atl the same time the chemical bond between the reactive ingredient or ingredients and the ng molecule must be sufciently unstable to permit a reaction with the metal parts when engaged under extreme pressure to form a lubricant iilm" which will carry these high pressure loads. The agents which will satisfactorily meet these requirements are apparently few, and, as stated above, the authorities in this field have generally looked with disfavor on organic compounds containing both sulfur and chlorine because of their highly corrosive action and their tendency to separate on standing.

It is primary object of this invention to provide an extreme pressure ingredient containing both chlorine and sulfur in chemical combination with hydrocarbon material. r It is a further object of this invention to produce hydrocarbon materials containing chlorine and sulfur in chemical combinations which possess highly effective extreme pressure lubricant properties and are at the same time devoid of the highly corrosive properties and the tendency to separate normally found present in sulfur-chloride materials which have heretofore been proposed. It is a further object of this invention to provide a method for synthesizing these improved extreme pressure agents.

The new and improved E. P. agents contemplated by this invention may be broadly described as polychlorinated aliphatic hydrocarbon materials in which the more reactive part of the chlorine has been replaced with a sulfur complex. More specifically, the materials contemplated by this invention are polychlorinated aliphatic materials or polychlorinated materials of-predominantly' aliphatic nature in which a part of the chlorine is replaced by a thiocarbonate group.

We have found that by obtaining-a predominantly aliphatic material which contains both chlorine and the thiocarbonate group in chemical combination with the hydrocarbon material, the resulting compositionhas extremely high loadcarrying properties, and extended storage and field tests have demonstrated that it has none of the disadvantages heretofore attributed to in synthesizing the E. P. agents contemplated by this invention involves substantial chlorination of an aliphatic compound or a predmninantly aliphatic material such as petroleumlnaphtha,

followed by the reaction oi the chlorinatedl material with an alkali or alkali earth metal salt o1' an alkyl thiocarbonic acid in such proportions and under such conditions that only a part of the chlorine (that is, Athe more reactive chlorine) is replaced by the alkyl thiocarbonate group. The reaction product thus obtained is ,analiphatic or predominantly aliphatic hydrocarbon material containing chlorine and thiocarbonate groups in chemical combination'l with the aliphatic hydrocarbon.

We have found that for the purpose of synthesizing these ingredients the .aliphatic material can be chosen from a relatively wide range of` aliphatic compounds or hydrocarbon materials which are predominantly aliphatic in nature. The range of aliphatic materials which may be chlorinated as the starting material has been found to extend from polychlorethanes to chlorinated petroleum wax, the former being acompound containing two carbon atoms and the latter being a predominantly aliphatic material corresponding to a compound having substantially twenty carbon atoms. We have found. however, that the extremely short chain com-y pounds represented by polychlorethanesand the extremely long chain compounds represented by petroleum wax are somewhat more difcult to react and are somewhat less eiiicient in their final A the chlorination is preferably carried to a point 'by the divalent group (OCSz).

at which the product has an average composition corresponding to a tetrachlornaphtha. In general it may be said that chlorination should be carried to the point at whichl the chlorine content is from about forty per cent to about sixty per cent, although materials of lower and higher chlorine content may be used, depending upon the aliphatic constituent. f

The thiocarbonate group which is used to replace a. part of the chlorine is, as has been indicated above, derived from an alkali or alkali earth metal salt of a. thiocarbonic acid, preferably an alkyl thiocarbonic acid. The thiocarbonatel radical may be a mono', di, or trithiocarbonate, but in general preference is given to the dithiocarbonate (xanthate) compounds, characterized The tri'thiocarbonate type of compounds, characterized by the divalent group (CSs) havel also been prepared and have been found to form effective extreme pressure agents in combination with the chlorinated aliphatic material, but from the standpoint of odor and cost preference is to products in which the thiocarbonate constituent is a xanthate (divalent OCSz) group.

As to the alkyl substituents in the thiocarxanthate `or thiocarbonate substituent from the standpoint of solubility, etc., and the lower molecular weight alkyl groups give a finished product in which the content of chlorine and characterizing divalent thiocarbonate groups (OzCS,

OCSz. or CSi)- is somewhat more highly concentrated.

As examples of the thiocarbonate or xanthate materials which may be reacted with chlorinated aliphatic materials to provide extreme pressure agents of the type contemplated by this invention, we may use sodiumor potassium methyl, ethyl, benzyl, butyl, or amyl xanthates or the corresponding monoor trithiocarbonates.

It is highly important. as stated above, that the proportions of reactants used and the conditions y of reaction be controlled so that the nal product contains both chlorineand thiocarbonate characterizing groups in chemical combination with the aliphatic hydrocarbon material. The relative amounts of chlorine and sulfur, or, more specifically, of chlorine and thiocarbonate characterizing groups, in the finished product may be varied over a relatively wide range, but in general it may be said that the finished product should preferably be one which contains from about twenty-ve to forty per cent chlorine and from about seven to fifteen per cent sulfur. Expressing the sulfur content as the equivalent' amount of characterizing tlxiocarbonate groups fpresent in the product, such preferred products are more accurately identified as containing from about ten per cent to about twenty-two per cent characterizlng dithiocarbonate or xanthate (divalent OCSz) groups or from about seven per cent to about seventeen per cent characterizing trithioerably one in which the chlorinated aliphatic material and the reaction product are highly soluble but in which the alkali thiocarbonate and the alkali chloride are of low solubility. As an example of such a solvent we have found acetone to be highly satisfactory, although other solvents,

-such as methyl ethyl ketone, may be used. Alcohols may also be used as solvents in this reaction. Solvents such as acetone and methyl ethyl ketone are particularly desirable since they permit the reaction to proceed but tend to precipitate residual alkali thiocarbonate and chloride, thus permitting the process to be performed and the product substantially purified all in one step.

The general preferred procedure followed in effecting the replacement of the more highly reactive chlorine in chlorinated aliphatic materials with the thiocarbonate group is to dissolve the chlorinated aliphatic material in the solvent and add the alkali alkyl thiocarbonte in an amoimt suillcient to give a product having the desired chlorine and sulfurratio. Under the conditions of reaction which we employ we have prepared materials using from about one-fourth to about twice as much alkali thiocarbonate (xanthatelas chlornaphtha. The preferred ratio, however, is to use a weighted amount of alkali thiocarbonate corresponding` to from about forty per cent to about seventy per cent of the weightof the chlornaphtha used. Itwill be understood, of course, that these ratios vary with other chlorinated alitemplated by this invention are those obtained phatic materials, depending upon their hydrocarbon and chlorine content, and should also take into consideration the 'alkyl substituent which is attached to the characterizing thiocarbonate group.

The procedure to be followed in the synthesis of the products lcontemplated bythis invention and the results obtained through `the use of such products asextreme pressure agents will behest appreciated from the following examples:

Example I As stated above, thepreferred products conby replacing a part of the chlorine in chlorinated petroleum naphtha with an alkyl xanthate group. These materials are preferred to others in this general class of materials because of their ease of synthesis, their cost, etc. An exemplary procedure for preparing such a product. which we may term chlornaphtha-xanthate reaction product" or xanthochlornaphtha", is as follows:

A chlorinated naphtha wasiirst prepared by chlorinating petroleum naphtha (Stoddard solvent) until it contained about nity-four percent by weight of chlorine. 200 parts of the chlornaphtha were dissolved in about-500 parts of acetone and placed in a reaction vessel heated by a water jacket and equipped with stirrer and reux condenser. To this solution 120 parts of .potassium ethyl xanthate were added and the mixture held at boiling temperature with stirring under reflux for about two hours. The resulting mixturewas cooled to room temperature, filtered, and the illtrate subjected to distillation to remove the acetone. Afterremoval of the acetone the product was washed to remove potassium salts and was dried and filtered. The finished reby varying the hydrocarbon substituent in the alkali xanthate. Thus products of widely varylng chlorine and' xanthate content are readily possible. In general, as indicated above, we prefer a product containing from about ten per cent to about twenty-two per cent oi' the characterizing xanthate group and from about twenty-five per cent to about forty per cent of chlorine.

In ten per cent concentration in mineral lubricating oil a chlorine-and-xanthate-substituted naphtha obtained as a product from a synthesis such as is described above produces excellent extreme pressure lubricants,'passing in a. satisfactory manner the usual evaluation tests used in the art. Actual gear tests show the blends to have Agood extreme pressure properties without any tendency to form sludge and withoutvcorrosive action towards the steel parts or towardscontainers.

To Vshow the load-carrying capacity of an extreme pressure agent of the type described in this example, a blend of mineral oil of 80-90 seconds Saybolt Universal viscosity at 210 F. and

ten per cent of chlornaphtha-ethyl xanthate re- `action product (the reaction product of the foregoing procedure) was subjected to the Almen pin test (described by Wolf and Mougey, Proc. A. P. I., 1932, pp. 118-430) and the S. A. E. test (described Anon. S. A. E. Journal 39. 23-4. 1936) with the following results:

. s. Anrlci. :at im en pm t. n. as: load lima, n. ,50 um R.P.M. ain-M hypoid gear loaded at 3500 pounds per linear inch y of tooth built up fromin thirty-five seconds and held for two hours.- 0nly very slight scratches appeared upon the gear surfaces as contrasted with other so-called extreme pressure lubricants' including the lead soap-'sulfur compounds, which permitted the gears to score badly under the same test. Y

At the end of 500 hours inthe hypoid gear test with a load of 1100 lb. per lin. in. on the ring gear, a pinion Speed of 2500 R. P. M. with intertransmissions and differentials of some `thirtythree automobiles operating under varying conditions and in varying localities. At the present time these tests have extended over periods of from about 5000 miles to about 17,000 miles per car, the service of the cars varying from moderate service to extremely severe service. Inspection of the parts so lubricated has been made from time to time, and in all cases the gear condition has been reported either as good or as excellent. In every case the axles were reported as being clean and bright and free from any sludge deposits, and in one instance where our improved lubricant had replaced anotherso-called extreme pressure lubricant a delinite improvement in the cleanliness of the axles was reported. One of the outstanding results obtained through the use of our extreme pressure ingredient was a complete absence of the highly corrosive action on housings and other parts which has been found in and attributed to sulfur-chlorine-containlng organic compounds heretofore suggested as extreme pressure agents. These observations are the result 'of over 800,000 miles of experience in actual service.

Another outstanding feature of the extreme pressure ingredient used in the field tests dereactive chlorine varying periods of service, and no appreciable loss in load-carrying capacity was observed. In one instance the car had been subjected to 17.474 miles of severe service in high speed operation over gravelled roads, and the lubricant which had been used in this car during such service passed the Almen pin test at 30,000 vand gave a load limit of 310 pounds at 1000 R.`P. M. on the S. A. E. machine.

In addition to a product pf the type 4described above, which is obtained by the reaction of chlorinated 'petroleum naphtha and potassium ethyl xanthate and which contains residual chlorine and the characterizing xanthate'(divalent OCSz) groups, we have prepared numerous other products of this general type in which:

(a) alkyl xanthates other than the ethyl xan thate group are substituted-l for the more highly reactive chlorine in chlornaphtha; I

(b) chlorinated aliphatic materials other than chlornaphtha aroused as the starting material;

and

A(c) thiocarbonate groups other than the xanthate group are substituted for the more highly terial.

Compounds or materials ofthese other types are illustrated by the following additional examples: Example II ture was reiluxed for one hour. The product obtained, which We may term chlornaphtha-methyl xanthate reaction product, contained 32.45 per-cent chlorine and 9.79 per cent sulfur (about fourteen per cent of the characterizing xanthate group). A mineral oil containing ten per cent of this product passed the 30,000 pound load limit in the- Almen 'pin test and showed a load limit f 370 poundsat ',155' R. P. M. in the S. A. E. test.

Example III I Y 251 parts 'of chlornaphtha (chlorinated Stqd dard solvent of forty-nine per cent chlorine content) and 120 parts of potassium butyl xanthate 'were reacted in acetone in the same manner as concentration in mineral oil passed the Almen pin test at 30,000 pounds and showed a load limit 0f 335 pounds at 755 R. P. M1. in the S. A. E. test.

-Ezample IV reaction product) 'containing 37.58 per cent chlorine and about thirteen per cent of the characterizing xanthate group. A ten per cent admixture of this product with mineral oil showed a in chlorinatedA aliphatic maaa limit of 17,000 pounds in the Al'mn pin test and of 425 pounds at 755 R. P. M. in the S. A. E. test.

Example V 84 parts of tetrachlorethane were reacted with 80 parts of potassium ethyl xanthate in the presence' of denatured alcohol as a solvent, the reaction mixture being refluxed f or two and onehalf hours to obtain a product containing 54.3 per cent chlorine' and about 15.9 per cent of the characterizing 'xanthate group. This product in 14o parts by weight of dicmor'pentane and 'zo parts .by weight of potassium ethyl xanthate in the presence of acetone as a solvent were reuxed for 11/ hours to yield a chlorpentane-ethyl xanthate reaction product containing about 27.6 per cent chlorine and about 19.3 per cent of the characterizing xanthate group. A ten per cent blend of this reaction product in a mineral oil of 80-90 seconds S. U. viscosity at 210 F. showed a load limit of 12,00014,0 00 pounds in the Almen test and. of 3 45 pounds at 1000 R. P. M. in the S. A. E. test.

Example VII As previously stated, the extreme pressure ingredients contemplated by this invention include products obtained by the chemical substitution of part of the chlorine ina chlorinated aliphaticv Petroleum naphtha (Stoddard solvent) was chlorinated by bubbling -chlorine gas therethrough until it contained about fty-two per cent Vby weight of chlorine. 225 partshby weight of the chlornaphtha were then admixed with about 400 parts of acetone and-100 parts of potassium amyl trithiocarbonate. The mixture was refluxed with stirring on a water bath and heated for about one and a half hours, after which it was cooled and nltered to remove the potassium chloride. The acetone was removed by distillation.- after which benzol was added and distilled oil to insure removal of water from the product. The resulting product was a bright liquid soluble in oil, and a typical analysis showed a chlorine content of thirty-ve per cent and`a 'sulfur content of about ten per cent, or more specically a trithiocarbonate (divalent CSa) content of about 11.2. per cent. 'As in the xanthate product, the proportion of chlorine and the proportion of the characterizing trithiocarbonate group in such reaction product may be varied by choice of reactants and proportions used. The nature of the alkyl radical in the alkali alkyl trithiocarbonate may be varied. It will also be understood that in all of the foregoing representative reactions that the alkali metal may be either sodium or potassium.

This trithiocarbonate product (chlornaphtha amyl trithiocarbonate reaction product), when blended in ten per cent concentration with a mineral oil of eighty to ninety seconds Saybolt Uni- 'versal viscosity at 210 F., passed the load limit of 30,000 pounds in the Almen pintestA and gave ,l

lmeaanst.

When the above ten per cent blend of mineral ollwassubjectedtoaheattestbymaintainlng the blend at a temperatureof 300 F. for a period of forty-eight hours with and without the presence of metals, it was found to show a high retention of its original extreme pressure lubricant characteristics. When the oil composition was subjected to the above test in the of a copper strip weighing 5.2766 grams, lt.was foimd that the copperwas not at allpittedandhadlost only 0.0180 gram weight. Where a steel 1in origi- Y nally weighing 9.7640 grams was subjected to the same test conditions, the weight lost ums only 0.0002 gram, and the surface showed no pitting and no hard coating, showing only a blackening which could be removed easily by rubbing.

Emmple VIII As av further example illustrating the value of chlornaphtha-alwl trithiocarbonate reaction products for use as extreme pressure ingredients, we have condensed petroleum naphtha-with a commercial pro'duct marketed under the trade name of Fioto. 'lhis material, which was'used in place of the potassimn amyl trlthiocarbonate described in Example VI, is made fromamix'tureofreiinerymercaptansandisa so mixed sodium trlthiocarbonate. The material is predominantly sodium ethyl trithiocarbonate, but the alkyl substituent probably ranges from methyl to amyl. 'I'he synthesis of the chlornaphtha trithiocarbonate prepared from this material followed the same procedure outlined above in Example VI, using 100 parts of chlorinated naphtha and parts of Floto and 200 parts of acetone. 'The iinished product contained 36.4 per cent chlorine and 7.1. per cent sulfur, or more specically such product contained 7.9 per cent of the characterizing trithiocarbonate (divalent CSi) group.

The-lubricating eiiiciency (load-carrying capacity) tests of the oil blended with the chlornaphtha-tnthiocarbonate reaction product obtained' with Floto showed the following results:

Almen pin test load 7? BB1 limit, lbs. l

Concoutration, percent if El...

The corrosion Atest for forty-eight hours at 300 F. showed the following results on steel and copper:

steel Coppe Grana Grams Before 9. w 5.0777 Afin' 9. m 5. 055

1408s l (Lm in nature containing from iive to iifteen carbon atoms. Petroleum naphtha, which contains on the average of about ten carbon atoms, is predominantly comprised of aliphatic hydrocarbons, although it may contain some cyclic compounds, but the term aliphatic material as it is-used herein is intended to include petroleuml naphtha and similar mixed hydrocarbon materials of predominantly aliphatic character. The .characterizing thiocarbonate group (divalent XCSa in which X is either sulfur or oxygen) in'the chlorine-containing reaction, products is preferably derived from an alkali alkyl xanthate (the characterizing xanthate group being OCSz); but, as shown from the foregoing examples, the trithiocarbonate group (divalent CS1) yields products having high load-carrying capacities, which like the xanthate products -do not have the highly corrosive tendencies found in 'sulfur-chlorinecontaining organic compoimds heretofore proposed as extreme pressure ingredients.

In compounding extreme pressure lubricant compositions with the extreme pressure ingredients described above, mineral lubricating oil is preferred as the carrying medium. However, it is our intention to include within the scope of 'this invention other` carrying mediums, such as animal oils, vegetable oils, and light mineral oil distillates, in which these E. P. agents may beY dispersed with substantial permanence either as true solutions or as colloidal suspensions. 'I'he concentration of ingredient used in the suspending or carrying medium may be varied, depending upon the conditions of use, the carrying medium, etc. In general the concentration may be said to range from one per cent to twenty per cent, concentrations of from about ilve per cent to ten per cent being satisfactory for most purposes where the carrying medium is a mineral lubricating oil.

This application is a continuation in part of our copending applications, Serial No. 123,846, led February 3, 1937, and Serial No. 159,872, filed August 19, 1937.

We claim:

1. An extreme pressure lubricant composition comprising a major portion -of mineral lubricating oil and a minor proportion of a product obtained by chemically substituting a part only of the chlorine in a chlorinated aliphatic material with a thiocarbonate group. A

2.' An extreme pressure lubricant composition comprising a major portion of mineral lubricating oil and a minor proportion of a product obtained by chemically substituting a part only of the chlorine in a-ehlorinated aliphatic material with a xanthate group.

3. An extreme pressure lubricant composition comprising a major portion of mineral lubricating oil and a minor proportion of a product obtained by chemically substituting a part only of the chlorine in a chlorinated aliphatic material with a trithiocarbonate group.

4. An extreme pressure lubricant composition comprising a major portion of mineral lubricating oil and a minor proportion of a chlorinated aliphatic hydrocarbon having from about ve to about fifteen carbon atoms in which a part only of the chlorine has been chemically substituted with a thiocarbonate group, said product having a chlorine content oi from about twenty-five per cent to-about forty per cent and a characterlzing-thiocarbonate-group content of from about seven per cent to about twenty-two per 5. An extreme lubricant composition aliphatic hydrocarbon having from about iive to about fifteen carbon atoms in which a part only of the chlorine has been chemically substituted with a trithiocarbonate group, said product having a chlorine content of from about twenty-five per cent to about forty per cent and a. characterizing-trithiocarbonate-group content of from about seven per cent to about seventeen per cent.

7. An extreme pressure lubricant composition comprising a major portion of mineral lubricating oil and a minor proportion of a chlorinated petroleum naphtha in which a part only of the chlorine has been chemically substituted with a thiocarbonate group, said product having a chlorine content of from about twenty-uve per cent to about forty per cent and a characterizing-thiocarbonate-group 'content of `from about seven per cent to about twenty-two per cent.

8. An extreme pressure lubricant composition comprising a major portion of mineral lubricating oil and a minor proportion of a chlorinated petroleum naphtha in which a part only of the chlorine has been chemically substituted with an alkyl xanthate group, said product having a chlorine' content of from about twenty-ve per cent to about forty per cent and a characterizing-xanthate-group content of from about ten per cent to about twenty-two per cent.

9. An extreme pressure lubricant composition comprising amajor portion of mineral lubricating oil and a minor proportion of a chlorinated petroleum naphtha in which a part only of the chlorine has been chemically substituted with an alkyl trithiocarbonate group; said product having a chlorine content of from about twentyacterizing-trithiocarbonate-group ilve per cent'to about forty per cent and a charcontent of from about seven per cent to about seventeen per cent.

10. An extreme pressure lubricant composition comprising a mineral lubricating oil containing` as' an extreme pressure ingredient from one per cent to twenty per cent of a chlorinated petroleum naphtha in which part of the chlorine has been chemically substituted with an alkyl trithiocarbonate group, said extreme pressure ingredient having a chlorine content of from about twenty-live per cent to about forty per cent and a characterizing-trithiocarbonate-group content of from about seven per cent to about seventeen per cent.

11. An extreme pressure lubricant composition comprising a mineral lubricating oil containing as an extreme pressure ingredient from one per cent to twenty per cent of a chlorinated petroleum naphtha in which part of the chlorine has been chemically substituted with an alkyl xanthate group, said extreme pressure ingredient having a chlorine content of from about twentyilve per cent to about forty per cent and a characterizing-xanthate-group content of from about ten per cent to about twenty-two per cent. l

12. An extreme pressure lubricant composition comprising a mineral lubricating oil and a minor proportion of a product obtained by the reaction of chlorinated petroleum naphtha of from about forty per cent to about sixty per cent chlorine content and an alkali alkyl xanthate in the ratio of about fty to seventy parts by weight of the xanthate to about one hundred parts by weight oi the chlorinated naphtha.

13. An extreme pressure lubricant composition comprising a relatively large proportion oi an oil and a minor proportion of extreme pressure ingredient dispersed with substantial permanence in said oil, said extreme pressure ingredient comprising a polychlorinated aliphatic material in which a part only of the chlorine has been replaced with an alkyl thiocarbonate group.

HENRY G. BERGER. ROBERT C. MORAN. FRANCIS M. SEGER.

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