US2690998A - Metal soap grease containing alkaline earth metal phenolate - Google Patents

Description

Patented Oct. 5, 1954 METAL SOAP GREASE CONTAINING ALKA- LINE EARTH .METAL PHENOLATE John P. Dilworth and Charles H. Culnane, Fishkill, N. Y., and Harry V. Ashburn, deceased, late of Beacon, N.Y., byEvelyn L. Ashburn, administratrix, Beacon, N. Y., assignors to The Texas Company, New York, N. Y., a corporation of Delaware No Drawing. Application April 18, 1951, Serial No. 221,742

11 Claims. 1

This invention .relates to alubricating grease composition, and particularly to such a-composition which is inhibited against copper corrosion.

Lithium base lubricating grease compositions have found substantial use in aircraft controls and for other purposes where operation over a wide temperature range, and particularly operation at extremely low temperatures, is encountered. U. S. Patent No. 2,450,221, Ashburn, Barnett and Puryear, is typical of a superior lithium base grease of this type prepared from a lithium soap of a hydroxy fatty acid or the glyceride thereof, such as hydrogenated castor oil, and containing as the major proportion of the liquid lubricating basean oilsoluble high molecular weight high boiling liquid aliphatic dicarboxylic acid ester within the lubricating oil viscosity range and possessing lubricating properties. As disclosed therein, the lithium soap may be formed from a major proportion of the hydroxy fatty acid or glyceride thereof, and a minor proportion of a saturated fatty acid, the grease containinga small excess of free fatty acid. Such 1 tempting to meet this specification, it has been I found that .corrosion inhibitors heretofore employed in greases are ineffective.

One of theprincipal-objects of the present invention is to provide a lubricating grease which satisfactorily meets the copper corrosion test of U. .S. .Army "Specification 2-134.

Another objectof the present invention is to provide a lithium'base grease which retains all the desirable properties of the previously known greases of this type, including shear and texture stability over a wide temperature range and excellent low temperature properties, and at the sion of copper and copper alloys in long time service.

In:accordanee with the present invention, the foregoing objects have beenattained by incorposame time is efiectively inhibited against corrorating in the grease about 0.25 to 5% by weight of an oil-soluble alkaline earth metal salt of an alkyl phenol compound selected from the group consisting of alkyl phenols having a total of 10 to 30 carbon atoms in the alkyl substituents on each benzene nucleus, and the corresponding where R is an alkyl group containing 5 to 30 carbon atoms, n represents the number of alkyl substituents on each benzene nucleus and is generally l or 2 with the proviso that the total .number of carbon atoms of the alkyl substituents on each benzene nucleus is at least 10, and a: is either 1 or 2. The alkaline earth metal salts may be either normal salts wherein the alkaline earth metal completely neutralizes the OH groups .of 2 molecules of the alkyl phenol, producing the compound having the formula where M represents the alkaline earth metal, or

may be the basic salt having the formula OMOH when formed from the alkyl phenol. The corresponding normal alkaline earth metal salt formed from the alkyl phenol sulphide is represented by the formula While the basic salt has the formula OMOH -MOH These various compounds may be prepared in known manner by the alkylation of a phenol or phenol sulfide with a selected olefin or olefin polymer of the proper chain length, namely from to 30 carbon atoms, in the presence of a suitable alkylation catalyst, such as HF, BF3 and the like. The olefin polymer is preferably prepared by polymerizing propylene under pressure, using for example a BF'c.H2O catalyst. Likewise butylene polymer can be used. Depending upon the conditions of the alkylation, the phenol or phenol sulfide may be mono-or dialkylated. Where a lower molecular weight olefin, such as amylene is employed for alkylation, the phenol or phenol sulfide is dialkylated to provide a total of at least carbon atoms in the substituent alkyl groups. Where a high molecular weight olefin is employed, such for example as a propylene polymer fraction having olefins of to 30 carbon atoms in the molecule, the product is generally monoalkylated. In addition to simple phenol, other monohydroxy mononuclear aromatic compounds having the hydroxyl group attached to the ring can be employed as the starting material, such for example as the cresols, xylenols and other alkyl phenols, as well as other corresponding sulfides. In the following description and claims, all of these various alkylated compounds will be referred to as alkyl phenols or alkyl phenol sulfides.

The foregoing alkyl phenols or alkyl phenol sulfides, in solution in a suitable aromatic solvent, such as toluene, are then reacted with the alkaline earth metal compound to produce the corresponding alkaline earth metal salt. Any of the alkaline earth metals, including calcium, barium, strontium and magnesium can be employed, although barium and magnesium are generally preferred. In the manufacture of a magnesium alkyl phenolate, for example, the alkyl phenol in toluene solution may be reacted with magnesium methylate dissolved in excess methyl alcohol at a temperature of about 40-50" C., using slightly less than mol of the magnesium methylate per mol of the alkyl phenol. The temperature is then increased and the methyl alcohol distilled off. The resulting toluene solution of magnesium alkyl phenolate, which is the normal salt represented by Formula No. 2 above, is filtered while hot; and then sufficient mineral lubricating oil, such as a distillate oil having an SUS viscosity at 100 F. of about 300, is added to produce an ultimate to 50% concentrate of the magnesium alkyl phenolate in the lubricating oil. The toluene solvent is then stripped from the lubricating oil concentrate.

In preparing a basic alkaline earth metal salt of the foregoing alkyl phenols or alkyl phenol 4 sulfides, the latter are preferably reacted with a substantial excess of an aqueous solution of a water soluble alkaline earth metal salt. For example, in preparing a basic barium alkyl phenolate, an aqueous solution of barium chloride with the latter in excess of that required for neutralization is added to a lubricating oil solution of the alkyl phenol. The reaction mix is subjected to steaming with agitation for a substantial period of time, such as about 1-4 hours. Following separation of the aqueous phase, the lubricating oil solution of the basic barium alkyl phenolate is washed and then heated to remove residual mixture to obtain a lubricating oil concentrate of the desired additive in about 25-50% concentration. The basic salts may also be prepared by reacting an oil solution of the alkyl phenol or alkyl phenol sulfide with a methanol solution of an excess of barium hydroxide, and then removing the methanol.

Typical compounds prepared'as outlined above and which are useful for purposes of the present invention are barium diamyl phenol monosulfide, barium diamyl phenol disulfide, basic barium cardanolate formed from hydrogenated cardanol, magnesium alkyl phenolate wherein the alkyl group contains from 15 to 30 carbon atoms and is preferably C18 to C25, and similar compounds of the other alkaline earth metals. Instead of preparing the alkyl phenol or alkyl phenol sulfide by alkylation as described above, suitable alkyl phenols containing at least 10 carbon atoms in the alkyl substituents on each benzene nucleus can be used, such as the hydrogenated cardanol as specified above.

The above described alkaline earth metal salts of alkyl phenols or the corresponding alkyl phenol sulfides may be employed in lithium base greases formed from any saturated fatty material, such as the conventional saturated fatty acids or glycerides thereof, to provide copper corrosion inhibition.

Preferably, the lithium base greases formed from hydroxy fatty acids or their corresponding glycerides, such as hydrogenated castor oil, are employed to obtain the improved shear and texture stability. Suitable types of soap-forming hydroxy fatty acids and glycerides thereof are disclosed in said Patent No. 2,450,221. While the soap-forming hydroxy fatty acids or their glycerides may be used as the sole acidic component of the lithium soap, they may be blended or combined with the conventional saturated fatty acids or fats in such proportions that at least 50% of the total acidic component is comprised of the hydroxy fatty acids or glycerides thereof. In

general, any of the recognized fatty acid matethe lithium soap 9, mixture of about 60-80% of hydrogenated castor oil or 12-hydroxy stearic acid, with 40-20% of a saturated fatty acid such as stearic acid. The grease may contain about 10-30% by weight of the lithium soap.

In order to obtain the improved wide temperature range and low temperature properties,

the liquid lubricating .base of the lithium grease composition .isnzpreierably formed-of a majorproportion .of a synthetic ol-eaginous lubricatingcompound or condensation product, many types of which arenow'known in the art. Very satisfactory synthetic lubricants of this character' are represented by .the high molecular weighthigh boiling liquid aliphatic dioarboxylic. acid esters which :are within the lubricating oil viscosity range and possess lubricating prop erties. The compounds within this particular class are the esters of such acids as sebacic, adipi-c, pimelic, aze'laeic, alkenyl :succinic, alky-Imale'ic; etc. The esters thereof are preferably-"the aliphatic esters and particularly the branched chain aliphatic diesters. Specific examples of the preferred oleaginous compounds are di-Z-ethyl hexyl-sebaca'te, di-2-ethyl hexyl azelate, di-Z-ethyl-hexyl adipate, di-secamyl sebacate, di-Z-ethyl hexylalkenyl succinate, di- 2 -lethoxyethyl sebacate, di 2-- ('2' methoxyeth'oxy ethyl sebacate, di-2-(2 -ethyl butoxy) ethyl sebacate, di- 2-'-butoxy ethyl azelate, di-Z- (2." butoxy et-hoxy) ethyl alkenyl succinate, etc.

"lhese oleaginous compounds may 'be used as the: sole-oil component of the grease or they may be'blended witha mineral lubricating oil. "Where a. blend is employed, and'low temperature properties :are required, the mineral lubrieating'oil is preferably a light refined distillate mineral the; lithium hydroxide and dehydration of the resulting .soap are conveniently carried out in the :presence of a portion of the mineral lubricating oil, and the synthetic lubricant together with the additives employed in the grease are then. added following dehydration and as the agitated soap mix cools.

The following examples are given to illustrate the present invention:

EXAMPLE! 1 A lithium base :grease was prepared from a fatty material consisting of about 75% by weight of hydrogenated castor 'oil and 125% by weight of stearic acid. The lubricating base used was" amixtu-re ofabout 75% by weight of di-2-ethyl hexyl azelate with about" 25% by Weight of a paraffinba-se mineral lubricating oil having an SUS viscosity at 100 F of about 100. The method of. preparationinvolved charging a steam heated kettle withthe required amount of..1'0;3 .lithium hydroxide solution together with'a small amount of water, the hydrogenated.

castoroil and .a small proportion oiithe paraffin base-mineral lubricating oil, the latter beinglessthan the amountof hydrogenatedcastor 1 oil and generally about A.; to of thelatter. The kettle contents Wereheld at 17049091. for about c-hours with agitation, and 'then .the stearic acid was added and the temperature maintained with stirring :for another .l-2 hours to complete saponification. Following saponification, a 25% concentrate of an 'octyl :methacrylate ester polymerin a mineral lubricating oil, which is .sold commercially by Rohm and Haas under the name Acryloid. HEhfiOQ. :was.

added in an amount to provide 2% :by weight of :the concentrate in the final grease composition. The feature of adding *methacryla-te ester polymers ofthis type to a lithium base ball and roller bearing grease for the purpose of noisezsuppression in bearings operated at high speeds is disclosed and claimed .in the copending application of Dilworth, Finn and Puryear, SerialxNo. 220,538, filed April ll, 1951, now'Patent No. 2,666,033. The saponified mix was then heated awith'stirring at'290 to 330 Furor about 4 hours toefiect dehydration. The balance of the mineral lubricating oil was then addedwith stirring as the kettle contents cooled down :to aloout280 .F. Thedi-.2-ethyl hexyl azelate was then slowly added withstirring as the mix con tinued to cool to about 220 F. xPhenyl alphanapthylamine in. an amount .of about 0 .5% .by

Weight based 'on the grease was then added as an oxidation inhibitor, and .a small amount .of a dye was introduced. The resulting base rease was drawn at .a temperature below'200 -F.

The resulting base grease .had the following calculated composition:

'Weight percent To different portions of the foregoing base.

grease, various amounts of barium diamylphenol ulfide. which is soldrcommercially by the Enjay Company, Inc. as Paranox '56, were added as shown in samples 2 and 3 in-the following Table I. The said greases were then subjeoted'to'the copper corrosion test of the .2-134 snecifioation with the resultsasshown in the table.

Table I 1 2-134 Cu Corrosion, Test AdditiveWtJPercsnt r r .Rating 1 Copper Grease 1.;BaeeGpeasc.. Grey stain Pink. discol- Fail.

oration. 2. Base Grease -+l% .V'cry slight No change Pass.

fParanox 156. "stain. 3. Base Grease +391, Clean do Do.

'Paranox 56. 4. .-Base Grease +1% Slight Grey do Borderline Paranox 56. stain. to Pass. 5.-Base Grease +07% Clean .do. Pass.

Paranox 56. 6. Base Grease +04% do clo Do.

Earanox 56." 7. 'Base Grease+3.0% do ..do Do.

Paranox 56.

(1), (2 and (3) Free alkali (LiOH) 009%. (4) Freeiatty acid (oleic) 0.23%.

'(5) Free alkali (LiOH) 0.10%. (6) Free alkali (LiOH) 0.08%. (7) Prepared with di-Q-ethyl hexyl sebacatc-Frce fatty acid (oleic) 0.26%

The 2-l34corrosion test ofthe foregoing table Was-run by placing a copper strip in a Norma- Hoffman bomb so as to be partially immersed in the sample of the grease'uncler test, and then maintaining the bomb under oxygen pressure (11'0'pounds per sq. in. initial pressure) at 210 Fafor 20 hours. During that period, no presperiod, both the sample of grease and copper strip are inspected. In addition to the requirement for no pressure drop during the test, there must be no more than a very faint stain on the copper strip and no more than a slight stain on the grease in order to be rated as passing. Slightly inferior products which do not merit a full pass rating are given a rating of borderline to pass where there is no more than a light stain on the grease and no pressure drop; and a rating of borderline to fail where there is a stain on the copper with or without a stain on the grease and no pressure drop. All other results are rated as fail.

Since the foregoing greases of Table I, including the base grease of sample 1 which contained no corrosion inhibitor, all were compounded with about 0.5% by weight of the effective oxidation inhibitor phenyl alphanaphthylamine they all satisfactorily met the requirement for no pressure drop during the test, and this item is not separately listed in the table.

Samples 1-3 inclusive of the foregoing table represent the base grease of Example 1, and the base grease compounded with 1% and 3% respectively of Paranox 56. As will be noted from the calculated composition of the base grease, a calculated excess of 0.2% by weight of lithium hydroxide was employed in preparing this grease; and, as shown by Table I the greases of samples 1-3 analyzed to a free alkali content, calculated as lithium hydroxide, of 0.09%. It is to be noted that the base grease of sample 1 produced a grey stain on the copper strip and a pink discoloration on the grease, and thus failed the test. Samples 2 and 3 containing the Paranox 56 successfully passed this rigorous copper corrosion test. In this connection, and as disclosed in the copending application of George W. Eckert Serial No. 210,096, filed February 8, 1951, now Patent No. 2,610,946, recognized copper corrosion inhibitors which are eifective in other relationships are completely ineffective for purposes of the present invention. It was entirely unexpected that a material, such as an alkaline earth metal salt of an alkyl phenol sulfide, which is recognized as a detergent additive for lubricating oils, such as motor oils, but not as an anti-corrosive, should be effective as a copper corrosion inhibitor in the new environment of a lithium base grease.

In the aforementioned Eckert application, the

use of a different type of copper corrosion in-- hibitor, namely a basic alkaline earth metal sulfonate, in a lithium base grease of this character is disclosed and claimed; and, further, it is pointed out that the grease should be prepared to a calculated excess alkalinity in order for this different type of copper corrosion inhibitor to be uniformly effective in the said 2-134 test. Samples 4-7 of the foregoing Table I show that this requirement of excess alkalinity is obviated by the copper corrosion inhibitors of the present invention. Thus sample 4 represents a grease prepared in accordance with Example 1 above except that a slight excess of stearic acid was used so that the grease analyzed to a free fatty acid content, calculated as oleic, of 0.23% by weight. As shown, 1% of Paranox 56 in this grease gave a borderline to pass rating in the 2-134 copper corrosion test. Sample 7 of Table I represents a grease prepared in accordance with Example 1 above, except that di-Z-ethyl hexyl sebacate was employed as the major portion of the lubricant base instead of the corresponding azelate, and also an excess of stearic acid was again used in the formulation. 3% of Paranox 56 in this particular grease geve a clear pass rating. Samples 5 and 6 of Table I were prepared in accordance with Example 1 above, using a calculated excess of lithium hydroxide of 0.3% and 0.2% respectively. It will be noted that as little as 0.4% by weight of Paranox 56 in this grease gave a pass rating.

EXAMPLE 2 1164 gm. (3 mols). of alkyl phenol averaging C21 alkyl group and 4 liters of dry toluene were charged to a 12 liter 3-neck flask fitted with a stirrer, thermometer, and condenser with a water trap. The materials were heated to toluene reflux temperature and the water present removed by means of the trap. The contents of the flask were cooled to about 40-50 C. and 36.4 gm. (1.5 mols) magnesium added slowly as magnesium methylate dissolved in approximately 1.5 liters of absolute methyl alcohol. The heat was gradually increased to the reflux temperature of methyl alcohol and the alcohol was removed by means of the trap. The temperature was then increased to the boiling point of toluene (230 F.). The solution was filtered through super cel Hy F10 and 3575 gm. 300 Pale Oil were added to the filtrate (sufficient pale oil to produce a 25% concentrate of additive after removing the toluene). The toluene was then removed by distilling in a Claisen-type distillation apparatus using a water aspirator. 4629 gm. of product was obtained. The product was heat treated by heating at 250 F. for 16 hours with stirring.

The foregoing concentrate of magnesium alkyl- 21 phenolate (designated MP-21) was blended into different portions of the base grease of Example 1 above to provide 1% and 3% respectively of the 1VlP-21 on the weight of the grease, and

the resulting grease compositions subjected to the 2-134 copper corrosion test with the satisfactory results shown in they following Table II:

Table II 2-134 Cu Corrosion Test EXAMPLE 3 1128 gm. (4 mols) of hydrogenated cardanol and 2610 gm. of 300 pale oil were charged to a 3-neck 12 liter flask fitted with a stirrer, thermometer, and water trap. The flask was heated to 50 C. to dissolve the cardanol and a mixture of 752 gm. (4 mols plus 10%) of anhydrous barium hydroxide and 4 liters of absolute methanol was added. The temperature was increased slowly up to the boiling point of the alcohol and the alcohol was removed from the flask by means of the trap. The temperature was then increased to C., removing water by means of the trap. The reaction mixture was then allowed to cool, dissolved in benzene and filtered through filter cel. The benzene was removed by distillation and sufficient 300 Pale Oil was added to bring the mixture to 25% concentration of active material. This required about 2610 gm. 5240 gm. of product was obtained.

The foregoingbasicv bari'um cardanolate concentrate was blended into the base=grease of Example 1 above, and the resulting blended grease compositions subjected to the 2-134 copper corrosion testwith thesatisf'actory results asslrown infthe'followingTable'HI:

. Table III 1 2.l34 Cu "Corrosion Tes't Additive" Wt. Percent 1 Rating Copper 2 Grease 1. Base Grease +1% Basic Ba Olean Slight Pink Pass.

Gardanolate.

2. Base Grease +53% Basic Ba do. No Change.... Do.

cardanolate.

In addition to passing the rigorous 2-134 copper corrosion test, the greases of the present invention also satisfactorily pass the different copper corrosion test of Government Specification AN-G-25.

While the additives of the present invention have been specifically described above in connection with lithium base greases because these are representative of the type generally employed for specialty wide temperature range, and particularly low temperature service, it is to be understood that the invention is not limited thereto. Rather, the invention is also applicable to the improvement of the copper corrosion properties of other metal base greases, including those of sodium, calcium, aluminum, barium, and mixed base greases. For example, a grease comprising an oleaginous liquid lubricating base, such as a mineral lubricating oil or a synthetic lubricant base or mixture thereof, thickened to a greaselike consistency with about 10-30% of calcium 12-hydroxy stearate, may have added thereto for copper corrosion inhibition about 0.25-% by weight of a phenolate or phenol sulfide of the type described above. The invention is particularly applicable to various metal base greases wherein the soap-forming fatty material of the metal soap consists of at least 50% by weight of hydroxy fatty acids or the glycerides thereof, such as lz-hydroxy stearic acid and hydrogenated castor oil.

It will be understood that the grease of the present invention may also contain other additives in small proportions which are compatible with the essential ingredients and do not interfere with the desirable properties thereof. Such additional additives include extreme pressure or lubricity agents, such as dibenzyl disulfide and tricresyl phosphate, materials for improving resistance in the salt spray humidity cabinet test, such as sorbitan mono-oleate, and the like.

Obviously many modifications and variations of the invention, as hereinbefore set forth, mayv normally being corrosive to copper, and fromv 0.25 to 5% by weight based on said composition of an oil-soluble alkaline earth metal salt of an alkyl phenol having a total of to 30 carbon atoms in the alkyl substituents on each benzene nucleus, said salt being in sufiicient proportion 1 0 to-eiiabiesaid grea'se composition to pass the-copeorrosicn test (if- U. S.Arfny specification 2 -134 i 2 A lubricating grease composition according toeiaim 1, wherein said salt is'a magnesium alkyl phenol'ate.

3; A lubricating grease composition according to claim 1, wherein said salt is a basicbarium alkyl"pl-ieiiole'ttel 4- A- lubricating grease composition comprising as'tne essential and: at least major proportion ofthe lubricating base an-oil-solubl'e highmolecular weight high-boiling liquid aliphatic dicarboxylic acid'ester within thelubricating viscosity range and possessing lubricating properties, sufncierit lithium soap of soap-forming fatty materialto thicken said'lubric'ant base; said soapforming fatty material consisting of more than 50% by weight of a hydroxy soap-forming fatty material selected from the group consisting of hydroxy fatty acids and hydroxy fatty acid glycerides, said grease normally being corrosive to copper, and from 0.5 to 3% by weight based on said composition of an oil-soluble alkaline earth metal salt of an alkyl phenol having a total of 10 to 30 carbon atoms in the alkyl substituents on each benzene nucleus, said salt being in sufficient proportion to enable said grease composition to pass the copper corrosion test of U. S. Army Specification 2-134.

5. A lubricating grease composition according to claim 4, wherein said salt is magnesium C18 to C25 alkyl phenolate.

6. A lubricating grease composition according to claim 4, wherein said salt is basic barium cardanolate.

7. A lubricating grease composition comprising as the lubricant base a mixture of substantial proportions each of mineral lubricating oil and a branched chain aliphatic diester of a dicarboxylic acid selected from the grou consisting of sebacic, azelaic and adipic acids, with said diester being in major proportion of the said mixture, about 10-30% by Weight based on the composition of lithium soap of a mixture of a major proportion of hydrogenated castor oil and a minor proportion of stearic acid, said grease normally being corrosive to copper, and from 0.5 to 3% by weight based on said composition of an oil soluble alkaline earth metal salt of an alkyl phenol having a total of 10 to 30 carbon atoms in the alkyl substituents on each benzene nucleus, said salt being in sufficient proportion to enable said grease composition to pass the copper corrosion test of U. S. Army Specification 2-134.

8. A lubricating grease composition according to claim 7, wherein said salt is magnesium C18 to C25 alkyl phenolate.

9. A lubricating grease composition according to claim '7, wherein said salt is basic barium cardanolate.

10. A lubricating grease composition consisting essentially of the following constituents in the approximate precentages by weight:

11. A lubricating grease composition comprising as the essential constituents an oleaginous liquid lubricating base as the major constituent, about 10-30% by weight based on said composition of a metal soap of a soap-forming fatty material, said soap-forming fatty material consisting of at least 50% by Weight of a hydroxy fatty material selected from the group consisting of hydroxy fatty acids and the glycerides thereof, said grease normally being corrosive to copper, and from 0.25 to 5% by weight based on said composition of an oil-soluble alkaline earth metal salt of an alkyl phenol having a total of 10 to 30 carbon atoms in the alkyl substituents on each benzene nucleus, said salt being in sufiicient proportion to enable said grease composition to pass the copper corrosion test of U. S. Army Specification 2-134.

* References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Woods June 13, 1944 Mikeska Nov. 7, 1944 McNab Nov. 7, 1944 Fraser Apr. 9, 1946 Morris et a1 Oct. 15, 1946 Ashburn Sept. 28, 1948 Rogers et a1 Oct. 4, 1949 Rogers et a1 Aug. 8, 1950 Hutcheson Sept. 16, 1952

Claims (1)

1. A LUBRICATING GREASE COMPOSITION COMPRISING AS THE ESSENTIAL CONSTITUENTS AN OLEAGINOUS LIQUID LUBRICATING BASE AS THE MAJOR CONSTITUENT, ABOUT 10-30% BY WEIGHT OF A LITHIUM SOAP OF A SATURATED SOAP-FORMING FATTY MATERIAL, SAID GREASE NORMALLY BEING CORROSIVE TO COPPER, AND FROM 0.25 TO 5% BY WEIGHT BASED ON SAID COMPOSITION OF AN OIL-SOLUBLE ALKALINE EARTH METAL SALT OF AN ALKYL PHENOL HAVING A TOTAL OF 10 TO 30 CARBON ATOMS IN THE ALKYL SUBSTITUENTS ON EACH BENZENE NUCLEUS, SAID SALT BEING IN SUFFICIENT PROPORTION TO ENABLE SAID GREASE COMPOSITION TO PASS THE COPPER CORROSION TEST OF U.S. ARMY SPECIFICATION 2-134.