US2223127A - Lubricant - Google Patents

Description

Patented Nov. 26, 1940 PATENT OFFICE LUBRICANT Carl F. Prutton, Cleveland Heights, Ohio, assignor to The Lubrl-Zol Corporation, Wicklifl'e, Ohio, a corporation of Ohio No Drawing. Application December l2, 1938, Serial No. 245,226

25 Claims. ((1 252-39) This invention relates, as indicated, to lubricating compositions and more particularly to lubricating compositions which are predominantly hydrocarbon oil, the properties of which affect- 5 ing its use for particular purposes are improved by the addition of materials which are particularly effective in rendering the lubricants suitable ior use under conditions of extreme stress as imposed by high temperatures, high loads, etc.

In my co-pending applications, Ser. Nos.

737,070, filed July 26, 1934, and 216,153, filed June 27, 1938, I have disclosed a broad class of lubricating compositions of general utility, particularly in the field of use where extreme pressures are encountered.

My present invention relates to the discovery that a certain class of such materials is particularly suitable for use in lubricants subjected to conditions of extreme stress such as those involved in the lubrication of heavily loaded gears, and in the lubrication of internal combustion engines operating under severe service conditions; for example, those encountered by internal combustion engines particularly of the aviation and Diesel types.

It is the principal object of my invention, therefore, to provide a lubricating composition which is especially suited for the purposes described.

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

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

Broadly stated, this invention comprises the provision of a lubricating composition for the purposes specified, characterized by the fact that the same contains a lubricating oil, preferably of the hydrocarbon type, as a major constituent with the properties or such composition affecting its use as a lubricant, especially under the conditions specified, by the incorporation therein 50 of a minor amount, based on the amount of lubricating oil present, of a stable, oil-soluble salt of an aromatic acid.

More especially, my invention comprises the discovery that salts of aromatic acids of the type 55 which may be produced by condensing an aromatic compound with a long-chain fatty acid, are particularly suited for use.

The lubricating oil which may be employed as the-base for my composition is preferably a hydrocarbon lubricating oil, whether naturally occurring or synthetic, and including hydrogenated oils. The base oil is preferably a refined mineral lubricating oil of the character which will not readily decompose under conditions of extreme stress such as high pressures and high temperatures. The mineral oil base may have incorporated therein such constituents as are usually employed for the purpose of improving its pour-point, etc., as well as constituents which are added to prevent oxidation and sludging. In general, the commercially available materials for this purpose will be found entirely compatible with the, addition agent which characterizes the compositions of my invention.

As above indicated, the addition agents which characterize the compositions comprising my invention may be broadly defined as salts of arcmatic acids of the type which may beproduced by condensing an aromatic compound with a long-chain fatty acid.

For certain purposes, the addition agent may advantageously contain an element of the type represented by: the halogens; sulphur, selenium and tellurium; phosphorus and arsenic. When maximum stability is desired, the halogen is preferably attached to a benzenoid ring such as the aromatic nucleus of the compound.

Specific examples of salts which, as above indicated, are disclosed in my previously identified earlier applications and which are representative 5 of those which are useful in preparing the compounded lubricants of my invention are:

Aluminum phenyl mercapto stearate Aluminum phenyl stearate 40 Calcium phenyl mercapto stearate Calcium phenyl stearate Sodium phenyl mercapto stearate Sodium phenyl stearate Zinc phenyl stearate 45 and halogen derivatives of the above such as:

As above indicated, the aromatic acids used in the preparation of these salts are of the type which may be produced by condensing an aromatic compound with a long-chain fatty acid. When the addition agent contains a halogen, it may be conveniently prepared by condensing a halogenated aromatic compound with a longchain fatty acid.

The condensation reaction by which the arcmatic acids referred to may be formed may be of the type in which the fatty acid is unsaturated, that is, contains at least one pair of multiplebonded carbon atoms such as the following groups:

-CH=CH and CsC- or of the type in which the fatty acid has been halogenated: that is, contains a halogen substituent. In either case, the condensation reaction is carried on in the presence of a catalyst of the type represented by anhydrous aluminum chloride, anhydrous ferric chloride and the addi tion products formed in the reaction of such anhydrous chlorides with oleflnes, such as ethylene.

For further definition of the catalyst which may be employed, reference may be had to my aforesaid co-pending application Sqrial No. 216,153, page 4, lines 8 to inclusive.

While the addition agents contemplated for use in my compounded lubricants may be prepared by forming a salt of an aromatic acid produced by the condensation reactions described, it is also possible, in certain'cases, to produce such addition agents by reacting a salt of a longchain fatty acid with an aromatic compound in one of the following ways:

1. A salt of a long-chain unsaturated fatty acid may be condensed with an aromatic compound in the presence of a catalyst, for example: the condensation of aluminum oleate with chlorbenzene in the presence of anhydrous aluminum chloride.

2. A salt of a halogenated long-chain fatty acid may be condensed with a halogenated aromatic compound by means of an alkali metal in accordance with the Wurtz-Flttig reaction, for example: the condensation of zinc chlor stearate with ortho-di-chlorbenzene with metallic sodium.

3. A salt of a halogenated long-chain fatty acid may be reacted with a metallic aromatic compound, such as sodium phenyl, sodium phenate and the like.

The long-chain fatty acid which may be employed in the preparation of the aromatic acids, the salts of which are used as addition agents in my compounded lubricants, may contain substituent groups, such as those listed in my copending application, Serial No. 216,153, in Table No. 1 on page 6.

The aromatic compounds suitable for use in a condensation reaction in the preparation of these materials in addition to the hydrocarbon aromatic compounds include oxygen-substituted aromatic hydrocarbons, as well as aromatic compounds containing other substituent groups, such as those listed in application Serial No. 216,153 in Table No. 5, on pages 11 to 14.

The following is a list of suitable aromatic compounds which may be employed as constituents in the preparation of the aromatic acids, the salts of which are used as addition agents in my compounded lubricants:

Benzene Toluene Xyienes Ethylbenzenes Naphthalene Methyl naphthalenes Ethyl naphthalenes Anthracene Retene Diphenyl Benzophenone Anthraquinone Diphenylether Salicylic acid Triphenyl phosphate Triphenyl phosphite Iricresyl phosphate Phenyl cyclohexane Diphenyl ether Chlor-naphthalenes Chlor-benzenes Chlor-diphenyls Chlor-diphenyl ethers Chlor-benzophenones Benzonitrile Methyl salicyiate Methyl chlorsalicylates Retene oil Among the suitable fatty acids which may be employed as constituents in the preparation of the aromatic acids, the salts of which are employed as constituents in my compounded lubricants, are the following:

Long-chain unsaturated fatty acids, such as:

Oleic acid Elaidic acid Linoleic acid Linolenic acid Elaeostearic acid Stearolic acid Ricinoleic acid Any of the above acids which have been halogenated.

Halogenated long-chain saturated fatty acids,

such as:

Chlorinated lauric acid Chlorinated palmitic acid Chlorinated stearic acid Chlorinated mercapto oleic acids Chlorinated mercapto stearic acids Chlorinated hydroxy stearic acids Chlorinated thio-stearic acids The various salts contemplated for use in the compounded lubricants of my invention are the ammonium, substituted ammonium, potassium, sodium, calcium, barium, strontium, magnesium, aluminum, zinc and lead salts of the aromatic acids above identified.

In view of the particular uses for which my compounded lubricants are intended, it is apparent that of the salts included in the foregoing enumeration of the addition agents which may be employed, those which are readily oil-soluble are the ones preferred for use. When these compounded oils are designed for use under conditions where high temperatures are usually encountered, the addition agents should be stable at elevated temperatures. For use in crankcase lubricants for internal combustion engines, they when the lubricating composition is exposed to temperatures up to 250 1".

The addition agents which are to be selected from the class described should be such that they are relatively non-corrosive with respect to the metallic surfaces with which they come in contact during use. Certain of the named addition agents may be found to be detrimentally corrosive to ertain sensitive bearing metals, in which case an appropriate corrosion inhibitor may be employed in conjunction therewith in the composition.

A lubricating composition prepared in accordance with my invention and which is predominantly hydrocarbon oil may contain from an effective amount to 20% of thesalt addition agent above identified. In general, it will be found that.

an amount as low as .l% will often be quite effective and that amounts in excess of 10% are seldom necessary. A preferredrange of concentrations for the salt in the oilis from .5% to about 2%.

It is also within the contemplation of this invention to provide the addition agents in the form of a concentrate in a suitable oil, said oil containing rather high percentages of the addition agents. Such concentrates may be employed for further blending with a lubricating oil in the proportions desired for the particular conditions of use.

While mineral oil, generally, is the principal ingredient of the lubricant, it is not essential that it be the only ingredient other than the addition agent, provided that there be no additional ingredient which is incompatible with such addition agent. It is within the contemplation of this invention to include, if necessary or desirable, such other addition agents as are commonly added to improve the viscosity index or cold test of the lubricants; and a lubricating composition according to this invention which also has a separate film-strength or oiliness increasing agent has been found to be especially effective.

When used in conjunction with a hydrocarbon lubricating oil, it is obvious that, generally, only such amounts of the addition agent may be in-.

cluded as are soluble in the specified amount of oil. By the term soluble", as herein used, it is intended to indicate the ability to form not only true solutions but also any form of substantially permanently homogeneous composition when incorporated in mineral oil. With most of the compounds there is usually little difllculty, especially if the incorporation is effected in the manner described in Cornell Patent No. 2,042,880, and since quite small percentages often give remarkably improved results, it is seldom of extreme importance that the addition agents be oil-soluble in all proportions. Also, certain compounds are of value as gelling or bodying agents when used in amounts greater than are strictly soluble.

The addition agents above enumerated for use in my compounded lubricants include certain ones which may be found to at least partially decompose under conditions of extreme stress such as the very high temperature encountered in certain classes of use, while others are quite stable even under such extreme conditions.

The use for which the lubricant is designed therefore determines the particular type of addition agent to be selected. A certain amount of decomposition, which proceeds at a relatively slow rate, is usually not harmful. Care should be exercised, however, to select for a particular set of operating conditions, an addition agent which in the oil base used, will not decompose under such operating conditions except at a low rate.

By the term stable as used herein in describing the addition agents is meant the characteristic of the addition agents which enables them to resist decomposition in the oil under the condition of use for which the lubricating composition is designed.

The lubricating compositions of this invention may be prepared by first preparing the salt and then dissolving the salt in the oil base, or they may be prepared by reacting the acid in solution in all or a portion of the oil with a suitable basic compound in order to form the desired salt directly in solution in oil. In the latter case, it is frequently desirable to remove the water formed by the reaction, or which may have been added with the basic compound, by some means such as by heating at atmospheric or sub-atmospheric pressure.

In case the salt to be used is water-insoluble, an alternative procedure is as follows:

An aqueous, solution of a water-soluble salt of the acid is first prepared, for example by dissolving the acid in an aqueous solution of caustic soda or caustic potash. The aqueous salt solution is then emulsified with oil and a water-soluble salt containing the cation of the desired salt is added to the mixture. The desired salt is thus precipitated from the aqueous medium and subsequently or simultaneously dissolved by the oil medium. Separation of the aqueous and oil layers is then effected for'example by settling or centrifuging. Subsequent water-washing of the oil solution to remove traces of inorganic salts may be desirable, and removal of moisture may also be required.

This application is a. continuation-in-part of my aforesaid co-pending applications Serial Numbers 737,070 and 216,153, the latter being in turn a continuation in part of Patent No. 2,121,825 dated June 28, 1938, based on an application Serial No. 760,038, filed December 31, 1934.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the materials employed, provided the ingredients stated by any of the following claims or the equivalent of such stated ingredients be employed.

I therefore particularly point out and distinctly claim as my invention:

1. A lubricating composition containing as a principal lubricating constituent a major amount of mineral lubricating oil with the properties of such composition affecting its use as a lubricant improved by incorporating therein a minor amount, based on the amount of mineral oil, of a stable, oil-soluble salt of an aromatic acid of the type which may be produced by condensing an aromatic compound with a long chain fatty acid.

2. A lubricating composition containing as a principal lubricating constituent a major amount of mineral lubricating oil with the properties of such composition affecting its use as a lubricant improved by incorporating therein a minor amount, based on the amount of mineral oil, of a principal lubricating constituent a major amount 4 of mineral lubricating oil with the properties of such composition aifecting its use as a lubricant improved by incorporating therein a minor amount, based on the amount of mineral oil, 01' a stable,'oil-soluble salt of an aromatic acid oi the type which may be produced by condensing a halogenated aromatic compound with a long chain unsaturated acid.

4. A lubricating composition containing as a principal lubricating constituent a major amount of mineral lubricating oil with the properties of such composition affecting its use as a lubricant improved by incorporating therein a minor amount, based on the amount of mineral oil, of

- a stable, oil-soluble salt of an aromatic acid of the type which may be produced by condensing an aromatic compound with oleic acid.

5. A lubricating composition containing as a principal lubricating constituent a major amount of mineral lubricating oil with the properties of such composition affecting its use as a lubricant improved by incorporating therein a minor amount, based on the amount of mineral oil, of a stable, oil-soluble salt of an aromatic acid of the type which may be produced by condensing a halogenated aromatic compound with oleic acid.

6. A lubricating composition containing as a principal lubricating constituent a major amount of mineral lubricating oil with the properties of such composition aflecting its use as a lubricant improved by incorporating therein a minor amount, based on the amount of mineral oil, of a stable, oil-soluble salt of an aromatic acid 0! the type which may be produced by condensing a halogenated aromatic compound of the type in which the halogen is attached to a benzenoid ring with oleic acid.

7. A lubricating composition containing as a principal lubricating constituent a major amount of mineral lubricating oil with the properties of such composition aifecting its use as a lubricant improved by incorporating therein a minor amount, based on the amount of mineral oil, of

a stable, oil-soluble salt of an aromatic acid oi the type which may be produced by condensing an aromatic compound with a mercapto fatty acid.

8. A lubricating composition containing as a principal lubricating constituent a major amount of mineral lubricating oil with the properties of such composition affecting its use as a lubricant improved by incorporating therein a minor amount, based on the amount of mineral oil, of a stable, oil-soluble salt of an aromatic mercapto stearic acid.

9. A lubricating composition containing as a principal lubricating constituent a major amount of mineral lubricating oil with the properties of such composition aifecting its use as a lubricant improved by incorporating therein a minor 'amount, based on the amount of mineral oil, of

a stable. oil-soluble salt of a halogen derivative of phenyl mercapto stearic acid.

10. A lubricating composition containing as a principal lubricating constituent a major amount of mineral lubricating oil with the properties of such composition affecting its use as a lubricant improved by incorporating therein a minor amount, based on the amount of mineral oil, of a stable, oil-soluble halogen derivative of calcium phenyl stearate.

11. A lubricating composition containing as a principal lubricating constituent a major amount of mineral lubricating oil with the properties of such composition airecting its use as a lubricant improved by incorporating therein from about 0.10% to about based on the amount or mineral oil, of a stable, oil-soluble metallic salt of an aromatic acid of the type which may be produced by condensing an aromatic compound with a long chain fatty acid.

12. A lubricating composition containing as a principal lubricating constituent a major amount of mineral lubricating oil with the properties of such composition afiecting its use as a lubricant improved by incorporating therein from about 10 0.50% to about 2%, based on the amount of mineral oil, of a stable, oil-solublemetallic salt or an aromatic acid of the type which may be produced by condensing an. aromatic compound with a long chain fatty acid, which salt is 01' the type in which the metal is in the divalent form.

13. A lubricating composition containing as a principal lubricating constituent a major amount of mineral lubricating oil with the properties 01' such composition affecting its use as a lubricant improved by incorporating therein a minor amount, based on the amount of mineral oil, of a stable, oil-soluble salt of an aromatic acid of the type which may be produced by condensing a halogen bearing aromatic compound with a long chain fatty acid,

l4. A lubricating composition containing as a principal lubricating constituent a major amount or mineral lubricating oil with the properties of such composition ailecting its use as a lubricant improved by incorporating therein from about 0.10% to about 10%, based on the amount of mineral oil, of a stable, oil-soluble salt of an aromatic acid of the type which may be produced by condensing an aromatic compound with a halogen bearing long chain fatty acid.

15. A lubricating composition containing as a principal lubricating constituent a major amount of mineral lubricating oil with the properties of such composition aflecting its. use as a lubricant improved "by incorporating therein from about 0.50% to-about 2%, based on the amount of mineral ,oil, of a stable, oil-soluble salt or an aromatic acid of the type which may be produced by condensing an aromatic compound with a halogen bearing long chain unsaturated acid.

16. A lubricating composition containing as a principal lubricating constituent a major amount of mineral lubricating oil with the'propertles of such composition afl'ecting its use as a lubricant improved by incorporating therein from about 0.10% to about 10%, based on the amount of mineral oil, of a. stable, oil-soluble salt of an aromatic acid of the type which may be produced by condensing a halogen bearing aromatic compound with a halogen bearing long chain fatty acid. 1

1'7. A lubricating composition containing as a principal lubricating constituent a major amount of mineral lubricating oil with the properties of such composition affecting its use as a lubricant improved by incorporating therein a minor amount, based on the amount of mineral oil, of a stable, oil-soluble salt of a substituted phenyl stearic acid.

18. A lubricating composition containing as a principal lubricating constituent a major amount oi mineral lubricating oil with the properties 01' such composition affecting its use as a lubricant improved by incorporating therein a minor amount, based on the amount of mineral oil, of a stable, oil-soluble salt of a halogen bearing derivative of phenyl stearic acid.

19. A lubricating composition containing as a principal lubricating constituent a major amount or mineral lubricating oil with the properties of such composition aflecting its use as a lubricant improved by incorporating therein a minor amount, based on the amount of mineral oil, of a stable, oil-soluble salt of chlor phenyl stearic acid.

20. A lubricating composition containing as a principal lubricating constituent a major amount of mineral lubricating oil with the properties of such composition aiiecting its use as a lubricant improved by incorporating therein a minor amount, based on the amount oi mineral oil, of calcium chlor phenyl stearate.

21. A lubricating composition containing as a principal lubricating constituent a major amount of mineral lubricating oil with the properties of such composition aflecting its use as a lubricant improved by incorporating therein a minor amount, based on the amount oi mineral oil, of aluminum chlor phenyl stearate.

22. A lubricating composition containing as a principal lubricating constituent a major amount of mineral lubricating oil with the properties of such composition aflecting its use'as a lubricant improved by incorporating therein a minor amount, based on the amount oi mineral oil, oi a stable, oil-soluble salt of an aromatic acid of the type which may be produced by condensing an aromatic compound with a mercapto fatty acid.

23. A lubricating composition containing as a principal lubricating constituent a major amount of mineral lubricating oil with the properties or .such composition aflecting its use as a lubricant improved by incorporating therein a minor amount, based on the amount oi mineral oil, or a stable, oil soluble salt oi a phenyl mercapto' stearic acid.

24. A lubricating composition containing as a principal lubricating constituent a major amount of mineral lubricating oil with the properties of such composition affecting its use as a lubricant improved by incorporating therein a minor amount. based on the amount or mineral oil, of a stable, oil-soluble salt or chlor phenyl mercapto stearlc acid.

25. A lubricating composition containing as a principal lubricating constituent a major amount of mineral lubricating oil with the properties of such composition aflecting its use as a lubricant improved by incorporating therein a minor amount, based on the amount of mineral oil, or calcium chlor phenyl mercapto stearate.