US2208162A - Lubricating composition - Google Patents

Description

Patented July 16, 1940 LUBRICATING COMPOSITION Carl F. Prutton, East Cleveland, Albert K. Smith,

Shaker Heights, and Harry Willoughby, Ohio, assignors,

E. Johnson, by mesne assignments, to The Lubri-Zol Development Corporation, Cleveland, Ohio, a corporation of Delaware No Drawing. Application February 12, 1940, Serial No. 318,624

as Claims. (Cl. 252-48) This application is a continuation in part of our co-pending applications Serial No. 170,501, filed October 22, 1937, Serial No. 300,232, filed October 19, 1939, and Serial Number 744,600 as filed on September 17, 1934.

As disclosed in the patent of Carl F. Prutton No. 2,051,744, granted August 18, 1936, certain desirable improvements in the lubricating properties 'of lubricating oils may be secured by the combination therewith of certain halogenated organic compounds.

The use of sulphur for the purpose of imparting extreme pressure characteristics to lubricating compositions has been known for some time. It has been well recognized that in order for sulphur when used alone to impart extreme pressure characteristics to lubricating compositions it is necessary that such sulphur be present in active or corrosive form. It has been well known that 2 certain organic compounds of sulphur contain sulphur in such stably bound condition that when such compounds were added in minor amounts to a lubricating composition there was no appreciable increase in film strength.

We have discovered that by the combined use in a suitable oil base of certain halogenated organic compounds and organic sulphur compounds we are able to produce a lubricating composition superior in certain respects to those which have 30 been available heretofore. The lubricating composition according to our invention is particularly applicable for use as an extreme pressure lubricant. The term extreme pressure lubrication" is believed to be sufiiciently well known to those familiar in the art that more particular definition thereof in this specification is unnecessary.

It is among the objects of our invention, therefore, to provide a lubricating composition which shall be superior in certain respects to any which has heretofore been available.

Other objects of our invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said invention, then, consists of the meanshereinafter fully described and particularly pointed out in the claims, the following description setting forth in detail one approved combination of ingredients embodying our invention, such disclosed means constituting, however, but one of various forms in which the principle of the invention may be used.

Broadly stated, the improved lubricating compositions of our invention comprise the combination of a major proportion of lubricating oil, an organic halogen and oxygen bearing compound in a minor amount and a relatively inactive organic sulphur compound in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil.

From the foregoing statement of our invention it will be observed that the lubricating compositions which comprise the same may be divided into three components, viz., halogen compound and the sulphur compound. These three components will first be considered separately and directions then given for the manner in which they may be blended in order to achieve the improved results.

The oil base The oil base of our lubricating compositions is a lubricating oil of the type best suited for the particular use for which the ultimate composition is designed. When the lubricating compositions of our invention are designed for the lubrication of automobiles, the oil base will of course preferably consist of a refined mineral lubricating oil of lubricating viscosity for the particular point of application. In other words, a conventional gear oilmay be used for the lubrication of the gears and generally a lighter, more highly refined, oil will be used in the crank case.

This invention is applicable to lubricating compositions in which the base may consist either entirely or in part of synthetic oils, hydrogenated oil, and voltolized oils.

The oil base may also desirably contain other well known constituents such as those which improve the oiliness, pour point, cold test, and oxidation properties, etc., of the oil. In general, compositions of our invention may be employed with any commercially available addition agents for the above defined purposes since they are generally compatible with the same in the amounts usually used.

The halogen compounds The halogen and oxygen bearing organic compounds used should first be oil-soluble to the extent that the required amounts may be incorpo rated in the oil base in a stable form of true solution or colloidal suspension so that there will be no separation on storage, even over periods of considerable length and at reduced temperatures.

The halogen and oxygen bearing organic compounds must be sufficiently non-volatile so that they will not be driven off from the lubricating composition during use. It will generally be found that the halogen compounds should have a vapor pressure less than atmospheric at a temperature of 140 C. and preferably at a'temperature of 170 C.

The halogen and oxygen bearing organic compounds which may be employed as components of the composition may be divided into two broad classes, cyclic or ring compounds and aliphatic the oil base, the

or chain compounds. In general, the ring com- .pounds are more stable and less subject to hydrolysis than are the chain compounds particularly when the halogen is attached to a benzenoid ring structure. Therefore, where moisture and other conditions are encountered which tend to hydrolyze the halogen compounds, the ring compounds are generally preferable. The chain compounds are usually more active than the ring compounds and thus may be employed for the purpose of giving very high extreme pressure characteristics where such is necessary and Where the conditions of use permit the employment of the relatively less stable chain compounds.

The class of oxygen and halogen bearing compounds will be found to be of particular utility in our invention for reasons which may be generally stated as follows: The presence of the oxygen in the same molecule with the halogen tends to increase the tendency of the lubricating composition to be adsorbed on metallic surfaces and to activate the halogen so that the same are made more effective as extreme pressure addition agents. This is particularly true in the case where oxygen is added to the molecule of the relatively stable halogenated carbon ring compounds which might otherwise be so stable as not to be sufiiciently reactive with the bearing surfaces under conditions of extreme pressure. Examples of the various halogen and oxygen bearing organic compounds which may thus be employed as one component of our composition are as follows:

I. Aliphatic, or carbon chain type oxygen-bearing derivatives of:

A. Hydrocarbons of the paraffin series,

. B. Hydrocarbons of the olefine series and C. Hydrocarbons of the acetylene series.

11. Organic ring type Oxygen-bearing derivatives of: A. Carbon ring type compounds ((1) Of the aromatic, or allied type, including oxygen-bearing derivatives of benzene, naphthalene, anthracene, etc., also compounds of the bridged ring type, such as the terpenes, and related compounds.

(b) Of thev class including the cycloparamns, cyclo-olefines. etc. Examples of this class are oxygen-bearing derivatives of the following:

(1) Hydrogenation products of benzene (e. g. cyclohexane, cyclohexene, cyclohexadiene) such as hydrogenated phenol, notably: cyclohexanol, di-hydrophenol, tetra-hydro-phenol.

(2)"Hyd'rogenation products of naphthalene (e. g. decahydronapht h a l e n e, tetrahydronaphthalene, etc.); such as the hydrogenated naphthols.

(3) Naphthenes, such as naphthenic acid, etc.

(0) Of mixed type such as derivatives of irdene, hydrindene, hydranthracene, e 0.

B. Heterocyclic type compounds (a) Of the aromatic or allied type including derivatives of pyridine, quinoline. etc.

(b) Other types such as furain and its derivatives; and derivatives of thiophene, p role, etc.

The oxygen-bearing derivatives of the foregoing compounds may also be classified according to the nature of the attachment of the oxygen to the molecule, viz:

I. Directly attached to one or more carbon atoms as in the case of (1') Ethers and analogous compounds (2') Compounds containing the radicle, such as alcohols and other derivatives of carbinol (including phenols, cresols, naphthols, etc.) (3) Compounds containing the carbonyl radicle, (such as amides, aldehydes, ketones, organic acids, esters and salts of organic acids, thio-acids and esters of thio-acids) (4') Compounds in which oxygen forms a part of the ring structure, e. g. furan and its derivatives, etc.

(5) Compounds with inorganic radicle where the oxygen is directly attached to carbon atom Arsenite- Hypochlorite Phosphite Thiophosphate Thiophosphite p-Hydroxylamines II. indirectly attached through the means of some other atom, i. e., in the form of an inorganic radicle, e. g.: Arsenate Chlorate Chlorite Cyanate a Hydroxylamine Nitrate Nitrite Nitro Nitroso Oxime Perchlorate Phosphate Sulphate Sulphite Sulphinic acid Sulphone Sulphonic acid Sulphoxide Thio-sulphate 2,208,162 3 Aldehydes Ketones Halogenated benzaidehyde Halogenated dipropyl ketone Ketones Halogenated dibutyl ketone Halogenated benzophenone Halogenated phenyl tolyl ketones Halogenated dinaphthyl ketone Halogenated methyl benzophenones Amide and substituted amides Halogenated phenyl amide Halogenated acetanilide Halogenated stearanilide Acids Halogenated phenyl fatty acids, e. g. phenyl acetic acid, phenyl stearic acid Halogenated salicyclic acid Esters Halogenated phenyl acetate Halogenated phenyl carbonate Halogenated ethyl benzoate Halogenated butyl benzoate Halogenated di-ethyl phthalate Halogenated dibutyl phthalate Halogenated esters of phenyl fatty acids, e. g. ethyl and butyl esters of phenyl acetic acid and phenyl stearic acid Halogenated methyl salicylate Halogenated benzyl acetate Salts Halogenated pyridine acetate Halogenated quinoline acetate Halogenated aniline stearate Calcium chlorphenyl stearate Magnesium chlorphenyl stearate Cobalt chlorphenyl stearate Ethers Halogenated dlphenyl ether Halogenated phenyl ethyl ether Halogenated dixenyl ether Halogenated dinaphthyl ether Halogenated alkylated diphenyl ether Non-aromatic oxygen-bearing organic ring compounds Halogenated cyclo-hexanol Halogenated naphthenic acids Halogenated esters of naphthenic acids Halogenated salts of naphthenic acids Oxygen-bearing heterocyclic compounds (1) Halogenated furane and derivatives, e. g. halogenated esters of pyromucic acid (furoates), halogenated furfuryl and hydrofurfuryl esters of fatty acids such as the acetates and stearates.

(2) Halogenated oxygen-bearing derivatives of thiophene and pyrrole, e. g. esters of thiophene carboxylic acids and esters of pyrrole carboxylic acids Chain compounds Alcohols Halogenated octyl alcohol Halogenated decyl alcohol Halogenated lauryl alcohol Halogenated cetyl' alcohol Esters Halogenated methyl stearate Halogenated lauryl acetate Halogenated tri-lauryl phosphate Hydroxy-amines Halogenated tri-ethanol amine- Halogenated tri-butanol amine Ethers Halogenated dibutyl ether Halogenated diamyl ether Halogenated dioctyl ether Halogenated di-amyl ketone Halogenated di-octyl ketone Acids 1 Halogenated propionic acid Halogenated butyric acid Halogenated lauric acid Halogenated oleic acid Halogenated stearic acid Salts Halogenated tri-ethanol-amine stearate Calcium dichlor stearate Complex commercial organic material Halogenatedr Animal and vegetable oils, fats and waxes (and complex derivatives) Oxidized hydrocarbon (e. g. oxidized petroleum or petroleum products) and complex derivaties obtained from such oxidation products (e. g. alox) As a class the halogenated oxygen-bearing compounds are particularly desirable on account of their unusual effectiveness in themselves imparting extreme pressure characteristics and in their unexpected cooperation with the organic sulphur compounds. The following are examples of such preferred compounds:

Halogenated diphen'yl ether Halogenated benzophenone Halogenated methyl benzophenones Halogenated butyl phenyl ketone Halogenated phenyl acetate -Halogenated phenol Halogenated O-phenyl phenol Halogenated cyclo hexanol Halogenated dibutyl phthalate Halogenated methyl salicylate Halogenated lauryl alcohol Halogenated methyl stearate Halogenated di-amyl ether Halogenated oxidized petroleum hydrocarbons Halogenated stearic acid For example of halogen and oxygen bearing organic compounds, reference may be had to our copending application Ser. No. 318,625 filed even date herewith.

It will be observed that among the halogen and oxygen bearing compounds listed for use as the second component of our improved composition also includes compounds which contain sulphur, an example of such being the thioacids and esters of thioacids. It is, therefore, within the contemplation of our invention to utilize a particular sulphur bearing compound which also contains halogen and oxygen as the second constituent in combination with another sulphur compound as the third constituent. In other words, the unexpected cooperation which we have found to exist between halogen and oxygen bearing compound and organic sulphur compounds is present even though the halogen and oxygen compound may also contain sulphur. In the case of an organic-compound containing the three elements, halogen, oxygen, and sulphur, the compound will be most useful as the second component of our composition when the halogen is in a relatively active state, and will be most useful as the third component of our composition when the sulphur is in a relatively more active state as compared with the halogen.

Where the term halogenated" is used, it is not intended that the compound referred to is necessarily formed by direct halogenation. It is intended that this term shall include halogen containing compounds prepared by any other suitable method as for example by a preparation from halogen containing'raw materials, for example in the preparation of chlorphenyl stearic acid, chlorbenzene may be condensed with oleic acid to form chlorphenyl stearic acid.

The organic sulphur compounds As previously indicated, the third component of our composition is sulphur in the form of a relatively inactive organic sulphur compound in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil.

In other words, our invention comprises the combined use of a halogen compound and relatively inactive sulphur to the end that the cooperation between the second and third components of our composition results in the achievement of a film strength in the resultant composition which is due to the cooperation between such second and third components. That is, the organic sulphur compound is of the type or present in amounts such that it, when used alone without the halogen, does not substantially increase the film strength of plain mineral oil but which, when used in conjunction with a halogen compound, is activated by the latter to the production of an unexpected result flowing from the cooperative effect of the second and third components of our composition.

While there is no generally accepted standard machine or test procedure in universal use today for the purpose of determining extreme pressure characteristics of a lubricating composition, nevertheless there are a number of machines which are currently being used with fairly uniform and satisfactory results. The well-known Almen machine was employed in making determinations referred to herein. When in our specification and claims we refer to the fact that the sulphur compound is of the type or present in such amounts as to to not substantially increase the extreme pressure characteristics of a plain mineral oil, we mean such characteristics as would be determined by the use of the Almen machine under the conditions of test prescribed by the manufacturer.

The eilect of sulphur compounds in increasing film strength is enormously enhanced by the presence of halogenand oxygen-containing organic compounds, especially if the relative proportions of such sulphur and halogen compounds are within certain ranges. Sulphur compounds in amounts which have a negligible effect in increasing film strength when used by themselves are very effective when used in combination with the proper proportion of halogenand oxygenbearing organic compounds. Organic sulphides, disulphides, mercaptans, mercaptals, mercaptoles, thioacids, and their esters, dithio-acids,

and their esters, sulphones, sulphoxides, su1- phonic acids, and their esters, sulphinic acids, and their esters, sulphone amides, sulphone chlorides, thio-amides, thio-anilides, organic thiocyanates, organic xanthates etc., (which may or may not contain a ring structure, that is they may be either aliphatic, cycloaliphatic or aromatic) are examples of sulphur compounds which act in this way. Included among the sul- 'phur bearing materials contemplated by our invention are the materials which may be preand complex materials such as esters of fatty acids and particularly unsaturated fatty acid esters, (for example methyl linoleate), also fatty oils such as sperm oil, lard oil and vegetable oil (e. 3. corn 011).

For examples of sulphur bearing materials, reference may be had to our copending application, Ser. No. 318,625 filed even date herewith.

The table below shows the results obtained when solutions in mineral oil of such compounds, alone and with halogen and oxygen containing organic compounds such as chlorinated diphenyl ether, were tested on an Almen lubricant testing machine. The chlorinated diphenyl ether contained a total of about 45% chlorine with about 10% chlorine in the form of addition products, and had been treated with quick-lime at a temperature of about 90 C. The increase in film strength of the oil caused by compounds dissolved in it is shown, and is stated in terms of additional pounds of weight applied to the loading arm of the machine required to cause breakdown, as compared with the oil alone.

Percent of Increase in Percent of diphenyl sulphide chlorinated breakdown diphenyl ether load Percent ofdiphenul disulphide Percent of dibenzgl disulphide l. 5 0 2 l. 5 3 More than 24 3 0 4 3 1. 5 More than 24 Percent of Average in- Pereent of army! mercaptan chlorinated crease in breakdlphenyl ether down load 1. 5 0 0 1. 6 3 More than 24 Percent of dilauryl sulphide 0. 5 0 3 0. 5 4 More than 24 Percent of dibutul disulphide Percent of product of reaction of butylme diamine with CS; 0 4

3 3 3 More than 24 Percent di-methylbenzul sulphide 0. 5 0 3 0. 5 l. 3 More than 24 *This material was an impure product containing about per cent total sulphur and about 3 per cent total chlorine, the latter in nonhydrolizable form. It was prepared by chlorinating boiling xylene until the boiling point reached 200 C. and allowing the chlorinated xylene to react with sodium sulphide in alcoholic solution. The roduct separated as a heavier oily layer and was treated with calcium oxide at 100 C In the specific examples of composition given above, it will be noted that the halogen compound used was the same in each composition in order that such table might show comparative results with the use of different organic sulphur compounds. As previously indicated, the maximum degree of cooperation will generally pared by sulphurizing various organic compoundsbe found to result from the employment of a certain proportional relationship between the halogen compound and the organic sulphur compound. In general, a relatively lesser amount of organic sulphur compound will be employed with the more stable halogen and oxygen bearpurpose of securing the maximum effectiveness from the use of the combination of two such components. Thus, for example, a very satisfactory lubricating composition can be produced by the combined use of 2% of dibenzyl disulphide with 1% of chlorinated stearic acid.

To illustrate the cooperative effect of an oxygen and halogen containing compound with two diiferent types of sulphur compounds reference may be had to thefollowing tests.

A product approximating dichlor stearic acid was prepared by chlorinating a commercial grade of stearic acid to a chlorine content of approximately 20% and then removing the hydrogen chloride and unreacted chlorine from the product. This material is identified in the tables below as BSA. The chlorine content in this material is in relatively active form and the material itself has a tendency to be very readily adsorbed by metallic surfaces. It is, therefore,

itself effective to increase the film strength of the mineral oil when present in only relatively small amounts.

An organic polysulfide was prepared by chlorinating xylene so that its composition approximated methyl benzyl chloride. and then reacting the chlorinated product with sodium polysulfide to replace substantially all of the chlorine with sulfur. This product probably consists, for the most part, of xylyi disulfide and is identifled in the tables below as XDS.

Methyl linoleate was sulfurized, under such conditions as to produce a product containing about 15% of sulfur in firmly bound form. The sulfur content in this product was relatively much less active than the sulfur content in the XDS, as indicated by the fact that it would not darken a copper strip under the same conditions which would cause the XDS to blacken the strip. On the other hand, probably because of the presence in the molecule of the sulfur methyl linoleate has a tendency to be more strongly adsorbed by metallic surfaces. This material is identified in the tables below as SML. I

The table below shows the increase in film strength of a mineral lubricating oil resulting from the addition of the above materials in various proportions. The amount of increase is expressed as the diiference in weight carried on the load-arm of an Almen machine which will just cause failure of the mineral lubricating oil containing the addition agents, and the weight which will cause failure of the mineral oil alone.

Increase in l Percent Percent Almen film- DSA XDS strength, pounds 0. 2 7 l. 0 0 7 0 0. 1 0 1. 0 3 0 2. 0 4 l. 0 0. 5 7 1. 0 l. 0 14 1. 0 2. 0 More than 26 Percent SML 0 0. 5 None 0 l. 0 None 0 2. 0 2 0. 2 0. 5 14 0. 2 1. 0 24 0. 2 2.0 25

Average of two tests.

It will be noted that (a) An unexpectedly high increase in film strength is produced by the combination of BSA and XDS with a relatively small proportion of BSA.

(b) An unexpectedly high increase in film strength is obtained with a combination of BSA and SML with very low percentages of each and with a relatively small proportion of BSA.

This invention, as previously indicated, relates to the discovery that by the use of such a relatively inactive organic sulphur compound, or an organic sulphur compound in such small amounts that, by itself, the extreme pressure characteristics of a plain mineral oil are not substantially increased, will, however, when employed in the same amounts in conjunction with an organic halogen compound, give unexpected film strength improvement. Generally, the halogen bearing organic sulphur compounds are sufiiciently active so that they are satisfactory extreme pressure addition agents when used by themselves. Such halogen bearing organic sulphur compounds, however, may be used in such small amounts that they do not impart any substantial degree of film strength. However, when used in the same amount in conjunction with a separate organic halogen compound, and particularly a halogen and oxygen bearing rganic compound, will be found to give unexpectedly high film strength in such combination. Halogen containing aromatic sulphur compounds, in general, are examples of halogen bearing organic sulphur compounds which act in this way. Specific examples of these are the halogen containing aromatic mercaptans, sulphides, and disulphides, e. g. chlorbenzyl sulphides, chlorbenzyl disulphides, and chlorbenzyl mercaptans.

Following is a list of additional specific examples of organic sulphur compounds which have been found satisfactory for use:

Tallow mercaptan (the reaction product of chicrinated tallow with NaHS) Tri-o-crysyl thiophosphate A Di (di-isobutylene) disulphide Dibutyl sulphide Di-amyl sulphide Di-amyl disulphide Dihydroxy diphenyl disulphide Alkylated hydroxy phenyl disulphides Lauryl thiocyanate Benzyl thiocyanate Benzyl ester of xanthic acid For other specific examples of organic sulphur compounds which may thus be employed as the third component of the composition of our invention, reference may be had to the list of organic sulphur compounds contained in the copending application of Carl F. Prutton, Ser. No. 193,960, filed March 4, 1938.

In order to protect bearings, gears, etc., from very severe overloads, it is sometimes advisable to use a halogen-containing compound which is so active as to be appreciably corrosive under normal conditions. Since chain compounds are generally more corrosive, i. e., more active than ring compounds, they are admirably suited for this purpose. In these circumstances the corrosive effect of such chain compounds and of halogenated organic ring compounds of the addition type for example, may be greatly inhibited by the addition ofcertain other oil-soluble compounds, such as (1) organic bases, aromatic and alkyl amines, triethanolamine, quinoline, etc., (2) organic'phosphates, e. g., tri-butyl phosphate, triphenyl phosphate, tri-cresyl phosphate, etc.

Also certain of the halogen and sulphur compounds referred to above have similar corrosioninhibiting effects, notably, (1) the phosphates of chlorinated ring compounds, e. g. tri-chlorphenyl phosphate, mercaptans and chlor-mercaptans. For other specific examples of corrosion inhibitors reference may be had to copending applications, Ser. Nos. 119, 297,872; 7 297,874; 297,875; and 297,876.

In general, the addition agents which are added to the lubricating oil base should have a vapor pressure less than atmospheric at the temperatures to which the finished product is subjected either during storage or use. For the lubrication of ice machines, one type of addition agent would be suitable which however might be entirely unsuited for the lubrication of internal combustion engines operating at extremely high temper! atures. In general, the addition agents which comprise the second and third components of our composition should have a vapor pressure less than atmospheric at 140 C. and preferably at 170 C.

Percentages and proportions The percentages and proportions within which the three components of our improved lubricating compositions are employed will depend largely upon the purpose for which the lubricating composition is designed and the character of the three components themselves.

The second component of our composition, i. e. the halogen and oxygen bearing compounds will be employed in percentages which are dictated by the results desired and the type of oil base and sulphur compound with which they are combined, etc. For most purposes, the halogen hearing compounds will be employed in percentages less than 20% of the total composition. In most cases, amounts less than 10% will be employed and for certain uses such as for crank case oils in internal combustion engines, amounts less than 5% will usually be employed. In general, the halogen bearing compound will be required to be present in amounts in excess of .02% in order to be effective. The ranges of percentages which may be given therefore for the amount of halogen bearing organic compound which is employed may be given as from about .02%- to about 20%; from about 1% to about and from about .5% to about 5%.

When a separate organic oxygen compound is organic compounds.

employed in combination with a halogen bearing organic compound as the'second component of our composition, such oxygen compound will generally be employed in'amounts from about .10% to about 10%.

The organic'sulphur compounds employed'as the third component of our composition will generally be employed in the range of from about .0l% to about 20%. .For most uses, this range will be from about .1'7% to about 10%, the range of from about .5% to about 5% being usually preferred.

Especially good results are secured when the halogen compound employcd is selected from the general class which contains from about 25% to about 50% of halogen. With this class of halogen compounds optimum results will be secured in high-temperature lubricants by the employment of from one-tenth to 2% of the halogenated compounds.

As above indicated, optimum results are secured by maintaining a certain proportional relationship between-the second and third components depending upon the relative activity of these components. Thus for example, with a relatively very inactive sulphur compound and a relatively very active halogen compound the proportional: relationship would be in the range of from one to two parts of the sulphur compound to one part of the halogen compound. With the sulphur compound relatively more active and the halogen compound of relatively low activity, the proportional relationship wonldbe in the range of one part of the sulphur compound to from two to about ten parts of the halogen compound. In-

termediate ranges which have been successfully employed have been one part of sulphur compound to five parts of halogen compound and one part of sulphur compound to four parts of halogen compound. For the most part good results will be obtained with a proportional relationship of about one part of sulphur compound to three parts of halogen compound.

Throughout the foregoing description of our invention, reference has been made generally to 4 the use of halogen bearing or "halogenated" Of the halogen containing compounds which are thus indicated as useful, it will be understood, of course, that the chlorine containing compounds are usually preferred, largely due to their inherently lower cost and their general superiority over the other halogens. The bromine containing species will generally be found less desirable than the corresponding chlorine compounds, due to higher cost. The iodine containing compounds are, as a class, less desirable than any of the other halogens, because of the high cost and difficulty of preparation. For the most part, the practical advantages which may be achieved by the use of the iodine compounds may be gotten in a more satisfactory manner by the use of the corresponding chlorine compounds.

The fluorinated compounds are again usually less desirable than the chlorinated compounds. However, it is generally true that, with regard to a particularly active chlorine compound, the cor-' responding fiuorinated compound will be more stable and for certain purposes preferable for this reason.

In the light of the foregoing, it will be observed that wherever a particular class or subclass of compounds, or a specific compound. is identified as being halogen containing material, we prefer the use of the corresponding chlorine compound.

In the definition in the foregoing specification of the various materials which may be used as the respective components of our composition, a large number of rather broad classes and sub-classes of organic compounds have been mentioned. Of such broad class, there may be, of course, some few cases where the specific material is unsuited for use in a lubricant, Those skilled in the art will be able to readily appreciate and discard those which, while included along with compounds of greater utility, may, however, be such that they would obviously not be used as a constituent in a lubricating composition in the light I of the teachings of this specification. Generally, the characteristics which render certain specific examples unsatisfactory for use are lack of stability, lack of oil solubility, high volatility, etc. All of the compounds which are suggested for use, therefore, by the present specification are limited to those classes which do have sufiicient stability, sufiicient oil solubility, and a sufiiciently low volatility so that they may be satisfactorily employed in lubricating compositions, always having in mind the particular characteristics of the composition required by the use for which it is designed.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

We therefore particularly point out and distinctly claim as our invention:

l. A lubricating composition comprising a major proportion of mineral oil and a relatively inactive organic sulphur compound in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and a minor amount of a halogen and oxygen bearing organic compound, said compounds being oil soluble within the percentages present in the oil, of sufficiently low volatility and of such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use.

2. A lubricating composition comprising a major proportion of mineral oil and a relatively inactive organic sulphur compound in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and a minor amount of a halogen and oxygen bearing organic ring compound, said compounds being oil soluble within the percentages present in the oil, of sufiiciently low volatility and of such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use.

3. A lubricating composition comprising a major proportion of mineral oil and a relatively inactive organic sulphur compound in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and a minor amount of a halogen and oxygen bearing aliphatic compound, said compounds being oil soluble within the percentages present in the oil, of sufiiciently low volatility and of such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use.

4. A lubricating composition comprising a major proportion of mineral oil and a relatively inactive organic sulphur compound in an amount in which such sulphur compound would not substantially increase the extreme pressure characpound having a vapor pressure less than atmospheric at a temperature of C., said compounds being 011 soluble within the percentages present in the oil, of sufficiently low volatility and of such stability so asnot to be substantially evaporated from or decomposed in the lubricating composition during use.

in lubricating composition comprising a major proportion of mineral oil and a relatively inactive organic sulphur compound in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and .5% to 5% of a halogen and oxygen bearing organic compound having a vapor pressure less than atmospheric at a temperature of C., said compounds being oil soluble within the percentages present in the oil, of suificiently low volatility and of such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use. a

6. A lubricating composition comprising a major proportion of mineral oil and a sulphur bearing organic ring compound in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and a minor amount of a halogen and oxygen bearing organic compound having a vapor pressure less than atmospheric at a temperature of 140 C., said compounds being oil soluble within the percentages present in the oil, of sufiiciently low volatility and of such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use.

'7. A lubricating composition comprising a major proportion of mineral oil and a sulphur bearing aromatic compound in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and a minor amount of a halogen and oxygen bearing organic compound having a vapor pressure less than atmospheric at a temperature of 140 C., said compounds being oil soluble within the percentages present in the oil, of sufilciently low volatility and of such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use.

8. A lubricating composition comprising a major proportion of mineral oil and a sulphur bearing aliphatic compound in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and a minor amount of a halogen and oxygen bearing organic compound having a vapor pressure less than atmospheric at a temperature of 140 C., said compounds being oil soluble within the percentages present in the oil, of sufiiciently low volatility and of such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use.

9. A lubricating composition comprising a major proportion of mineral oil and an organic sulphide in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and a minor amount of a halogen and oxygen bearing organic compound having a vapor pressure less than atmospheric at a temperature of 140 C., said compounds being oil soluble within the percentages present in the oil, of sufl'iciently in the lubricating composition during use.

10. A lubricating composition comprising a major proportion of mineral oil and an aromatic sulphide in an,amount in which such sulphur compound would not'substantially increase the extreme pressure characteristics of a plain mineral oil and a minor amount of a halogen and oxygen bearing organic compound having a vapor pressure less than atmospheric at a temperature of C., said compounds being oil soluble within the percentages present in the oil, of sufliciently low volatility and of such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use.

11. A lubricating composition comprising a major proportion of mineral oil and an aliphatic sulphide in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and a minor amount of a halogen and oxygen bearing organic compound having a vapor pressure less than atmospheric at a temperature of 140 C., said compounds being oil soluble within the percentages present in the oil, of sufliciently low volatility and of such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use.

12. A lubricating composition comprising a major proportion of mineral oil and a sulphurized ester in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and a minor amount of a halogen and oxygen bearing organic compound having a vapor pressure less than atmospheric at a temperature of 140 C., said compounds being oil soluble within the percentages present in the oil, of sufliciently low volatility and of such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use.

13. A lubricating composition comprising a major proportion of mineral oil and an organic polysulphide in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and a minor amount of a halogen and oxygen bearing organic compound having a vapor pressure less than atmospheric at a temperature of 140 C., said compounds being oil soluble within the percentages present in the oil, of sufliciently low volatility and of such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use.

14. A lubricating composition comprising a major proportion of mineral oil and an aromatic polysulphide in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and a minor amount of a halogen and oxygen bearing organic compound having a vapor pressure less than atmospheric at a temperature of 140 C., said compounds being oil soluble within the percentages present in the oil, of sufficiently low volatility and of such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use.

15. A lubricating composition comprising a major proportion of mineral oil and an aliphatic polysulphide in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and a minor amount of a halogen and low volatility and of such stability so as not to be substantially evaporated from or decomposed oxygen bearing organic compound having a vapor pressure' less than atmospheric at a temperature of 140 0., said compounds being oil soluble within the percentages present in the oil; of sufficiently lo'w volatility and or such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use.

16. A lubricating composition comprising a major proportion of mineral oil and a halogen bearing organic sulphur compound in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristl'cs of a plain mineral oil and a minor amount major proportion of mineral oil and a halogen bearing organic sulphide in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain, mineral oil and a minor amount of a halogen and oxygen bearing organic compound having a vapor pressure less than atmospheric at a temperature of 140 C., said compounds being oil soluble within the percentages present in the oil, of sufliciently low volatility and of such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use.

18. A lubricating composition comprising a major proportion of mineral oil and a halogen bearing aromatic sulphide in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and a minor amount of a halogen and oxygen bearing organic compound having a vapor pressure less than atmospheric at a temperature of 140 0., said compounds being oil soluble within the percentages present in the oil, of sufliciently low volatility and of such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use.

19. A lubricating composition comprising a major proportion of mineral oil and a halogen bearing aliphatic sulphide in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and a minor amount of a halogen and oxygen bearing organic compound having a vapor pressure less than atmospheric at a temperature of 140 C., said compounds being oil soluble within the percentages present in the oil, of sufliciently low volatility and of such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use.

20. A lubricating composition comprising a major proportion of mineral oil and a halogen bearing organic polysulphide in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and a minor amount of a halogen and oxygen bearing organic compound having a vapor pressure less than atmospheric at a temperature of 140 C., said compounds being oil soluble within the percentages present in the oil, of sufilciently low volatility and of such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use.

21. A lubricating composition comprising a major proportion of mineral oil and a halogen bearing aromatic polysulphide in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and a minor amount of a halogen and oxygen bearing organic compound having a vapor pressure less than atmospheric at a temperature of 140 C., said compounds being oil soluble within the percentages present in the oil, of sufliciently low volatility and of such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use.

22. A lubricating composition comprising a major proportion of mineral. oil and a halogen bearing aliphatic polysulphide in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and a minor amount of a halogen and oxygen bearing organic compound having a vapor pressure less than atmospheric at a temperature of 140 (1., said compounds being oil soluble within the percentages present in the oil, of sumciently low volatility and of such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use.

23. A lubricating composition comprising a major proportion of mineral oil and an organic disulphide in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and a minor amount of a halogen and oxygen bearing organic compound having a vapor pressure less than atmospheric at a temperature of 140 C., said compounds being oil soluble within the percentages present in the oil, of sufliciently low volatility and of such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use.

24. A lubricating composition comprising a major proportion of mineral oil and an aromatic disulphide in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and a minor amount of a halogen and oxygen bearing organic compound having a vapor pressure less than atmospheric at a temperature of 140 0., said compounds being oil soluble within the percentages present in the oil, of sufiiciently low volatility and of such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use.

25. A lubricating composition comprising a major proportion of mineral oil and a relatively inactive organic sulphur compound in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and a minor amount of a halogen bearing ether having a vapor pressure less than atmospheric at a temperature of 140 0., said compounds being oil soluble within the percentages present in the oil, of sufliciently low volatility and of such stability so as not be substantially evaporated from or decomposed in the lubricating composition during use.

26. A lubricating composition comprising a major proportion of mineral oil and a relatively inactive organic sulphur compound in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and a minor amount of a halogen bearing acid having a vapor pressure less than atmospheric at a temperature of 140 C., said compounds being oil soluble within the percentages present in the oil, of sufliciently low volatility and of such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use.

27. A lubricating composition comprising a major proportion of mineral oil and a relatively inactive organic sulphur compound in an amount in which such sulphur compound would not sub stantially increase the extreme pressure characteristics of a plain mineral oil and a minor amount of a halogen bearing ester having a vapor pressure less than atmospheric at a temperature of 140 0., said compounds being oil soluble within the percentages present in the oil, of suiiiciently low volatility and of such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use.

28. A lubricating composition comprising a major proportion of mineral oil and an aromatic disulphide in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and a minor amount of a halogen bearing ether,- said compounds being oil soluble within the percentages present in the oil, of sufficiently low volatility and of such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use.

29. A lubricating composition comprising a major proportion of mineral oil and an aromatic disulphide in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and a minor amount of a halogen bearing ester, said compounds being oil soluble within the percentages present in the oil, of sufliciently low volatility and of such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use.

30. A lubricating composition comprising a major proportion of mineral oil and an aromatic disulphide in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and a minor amount of a halogen bearing acid, said compounds being oil soluble within the percentages present in the oil, of suificiently low volatility and of such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use. 31. A lubricating composition comprising a major proportion of mineral oil and an organic disulphide containing a radicle of the class consisting of benzyl'and substituted benzyl in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and .1% to 10% of a halogen bearing ether, said compounds being oil soluble within the percentages present in the oil, of sufiieiently low volatility and of such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use.

32. A lubricating composition comprising a major proportion of mineral oil and an organic disulphide containing a radicle of the class consisting of benzyl and substituted benzyl in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and .1% to 10% of a halogen bearing ester, said compounds being oil soluble within the percentages present in the oil, of sufllciently low volatility and such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use.

33. A lubricating composition comprising a major proportion of mineral oil and an organic disulphide containing a radicle of the class consisting of benzyl and substituted benzyl in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and .1% to 10% of a halogen bearing acid, said compounds being oil soluble within the percentages present in the oil, of sufliciently low volatility and of such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use.

34. A lubricating composition comprising a major proportion of mineral oil and dibenzyl disulphide in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and .l% to 10% of a halogen and oxygen bearing organic compound having a vapor pressure less than atmospheric at a temperature of 140 C., said compounds being oil soluble within the percentages present in the oil, of suiiiciently low volatility and or such stability so as not to be substantially evaporated from or decomposed in the lubricating composition during use.

35. A lubricating composition comprising a major proportion of mineral oil and dibenzyl disulphide in an amount in which such sulphur compound would not substantially increase the extreme pressure characteristics of a plain mineral oil and .1% to 10% of a chlorinated diphenyl ether, said compounds being oil soluble within the percentages present in the oil, of sufiiciently low volatility and of such stability so as not to be substantially evaporated from or decomposed in .the lubricating composition during use.-

36. A lubricating composition comprising a- CARL F. PRUT'ION. ALBERT K. SMITH. e HARRY E. JOHNSON.