US2417429A - Complex basic soap greases - Google Patents

Description

Patented Mar. 18, 1947 2,417,429 COMPLEX BASIC SOAP GREASES Lester W. McLennan,

El Cerrito, Calif., assignor to Union Oil Company of California, Los Angeles, Calif., a corporation of California No Drawing. Application April 16, 1945, Serial No. 588,719

This invention relates to lubricating compositions containing complex basic soaps and has special reference to greases containing these soaps. This application is a continuation-in-part of my copending application Serial No, 473,217 filed January 22, 1943.

The object of the invention is to obtain all the benefits in such lubricants and greases as are peculiar to complex basic soaps. Complex basic soaps produce stable greases which have excellent melting point and penetration characteristics, do not require hydration, have exceptional resistance to deterioration by the action of heat and by the action of moisture including boiling water and have unusual thickening effects on lubricating oils even at relatively low concentrations. An especially important fact is that stable greases are formed with high viscosity oils of both parafiinic and naphthenic types. Another object of this invention is to provide processes for the manufacture of complex basic soap lubricants.

By the term complex basic soap as used in this application it is meant to include products in which at least two metals are present and in which the ratio of equivalents of combined metals to equivalents of saponified high molecular weight organic acids is greater than 1.1:1 and preferably is greater than about 1.2:1; Depending upon the particular saponifiable material and upon the characteristics of the mineral oil employed it is preferred that this ratio be between about 12:1 and 2:1 but it may be as high as 3:1 or even as high as 4:1. Further, even though the ratio of equivalents of combined metals to equivaents of saponified high molecular weight organic acids is greater than 1:1, the complex basic soaps of this invention are substantially neutral or substantially free from'readily titratable excess alkalinity at least beyond a relatively small amount.

By the term nor application it is meant to include those products which result when one equivalent of a metal hydroxide vor a mixture of metal hydroxides or other basically reacting metal compounds is reacted with one equivalent of a saponifiable material to form a soap, said soap being the normal metal salt of the high molecular weight organic acid present as such or derivable by saponification from the saponifiable material.

I be different from the mal soap as used in this 23 Claims. (01. 252-36) Examples of saponifiable materials containing high molecular weight organic acids present as such ,or readily derivable therefrom by saponiflcation include fats such as tallow, lard oil, hog fat, horse fat, etc., high molecular weight organic acids such as stearic acid, oleic acid, the high molecular weight acids resulting from the oxidation of petroleum fractions (for example, paraffin wax and mineral oil), rosin and related products, high molecular weight naphthenic acids, sulfonic acids, etc., and saponifiable waxes such as beeswax, sperm oil, degras, etc.

One of the metals employed in the formation of the complex basic soaps of the present invention must be polyvalent and is preferably selected from the alkaline earth metals, barium, calcium, strontium, and magnesium. However, aluminum, beryllium, zinc, cadmium, boron, tin, zirconium, cerium, vanadium, antimony. bismuth, arsenic, copper, molybdenum, germanium, columbium, chromium, selenium, tellurium, tungsten, manganese, iron, cobalt, or nickel may be used as the polyvalent metal. The second metal must first and is preferably an alkali metal, namely, lithium, sodium, potassium, or cesium, or an alkaline earth metal, namely, barium, calcium, strontium, or magnesium although the other metals listed above may also be used. It is not meant to indicate that the complex basic soaps of this invention are limited to the use of two metals, as three or. even more metals can be employed but in any event at least one of the metals must be polyvalent.

The present invention resides in lubricating compositions, especially greases, which contain complex basic soaps which are substantially neutral or substantially free from readily titratable excess alkalinity. While the invention may be extended to freely fluid lubricants, such as Diesel engine lubricating oils containing small proportions of complex basic soaps, it includes more particularly the use of such complex basic soaps in proportions to thicken lubricating oils appreciably for the purpose of producing liquid greases .or solid greases of varying consistencies. More particularly, the invention resides in mineral oil lubricants containing thickening proportions of complex basic soaps where the ratio of equivalents of combined metals to equivalents of saponified high molecular weight organic acids is plex basic soaps to produce lubricants employing I high viscosity mineral oils, e. g., 50 or '70 S. A. E. grade or even bright stocks as well as lower viscosity mineral oils, e. g., 20 or 30 S. A. E. grade. For some purposes'it has even been found desirable toincorporate as much as 25% or even more of asphalt in the complex basic soap greases of this invention. Good lubricants may also be produced from the very low viscosity bottoms fraction obtained by fractionating heavy alkylates obtained from alkylation processes in the man-'.

ufacture of motor and aviation fuels from certain stocks where said bottoms have a viscosity in the order of that of spray oils or even lower.

In connection with the present complex basic soaps it has been found that under appropriate conditions it is possible to react one equivalent weight of a saponifiable material (as determined byits saponification number) with more than about 1.1 and up to about twice the equivalent weight (or even up to a ratio of 4 as above indicated) of a mixture of basically reacting metal compoundsysuch as for example strontium hydrate and calcium hydroxide, to produce a material which is substantially neutral or substantially free from readily titratable excess alkalinity. Although it is within the scope of the present invention to react directly one equivalent of a saponlfiable material with more than one equivalent of a mixture of the basically reacting compounds of two or more metals, it is preferred to prepare the complex basic soaps by first forming a normal soap by reacting one equivalent of a saponifiable material withjone equivalent of a basically reacting metal compound, for example strontium hydrate. Subsequently. the desired number of equivalents of a basically reacting compound of another metal, such as for example one equivalent of calcium hydroxide, is then added and the mixture heated until the product is substant ally neutral or substantially free from readily titratable excess alkalinity. In either case, the resultant material is a complex basic soap of the present invention. The latter can be formed in the presence of oil to produce a grease or fluid lubricant direct y or the com lex basic soap can be formed in the absence of oil and later compounded with oil to form the desired lubricant.

Altho gh I do not wis to b limited by t e theories advanced herein. he pet reaction whi h appears to occur and which results in the formation of the im roved greases forming the subject of this invention is the oxidation of a port on of the s ponifiable mater al and reaction of the basically reacting metal compounds with the remaining saponifiable material and the acidic products formed. It is l kely that regardless of i the particular procedure used, the initial reaction which occurs in the formation of a normal 1 soap by the saponification of the saponifiable material with an equivalent quantity of a basically reacting metal compound. Subsequently a portion of the normal soap is oxidized by oxygen and 5 the excess basically reacting metal compound I present, and added either prior to or after the formation of the normal soap, combines with the acidic materials formed.

The character of the oxidation reaction which occurs is probably influenced by the presence of the excess basically reacting metal compound or compounds and possibly by the presence of a polar solvent such as water or glycerine. In this connection evidence has been obtained indicatin .that in the presence of a polar solvent such as results when one equivalent of a fat, saponifiable wax, or high molecular weight saponifiable or ganic acid is reacted with about 1.1 or more equivalents of basically reacting metal compounds under the conditions as disclosed in the present invention and illustrated in the subsequent examples, is carbon dioxide present in the final product as metal carbonate. In addition, appreciable amounts of acetic acid and relatively smaller amounts 'of other low molecular weight carboxylic acids, such as formic acid, propionic acid, oxalic acid, etc., also appear to be formed and are present in the final product as the corresponding metal salts. Under some conditions of oxidation coming within the scope-of the present invention, metal carbonate may be the principal salt formed and may be preferred for certain combinations of mineral oil and saponifiable materials. I have also discovered that many of the desirable properties of the complex basic soap greases formed, for example. by reacting one equivalent of calcium hydroxide with one equivalent of a saponii'iable material in'the presence of oil and subsequently reacting the normal calcium soap with one equivalent of strontium hydroxide to give a substantially neutral complex basic soap grease, can be obtained by mixing one mol of the normal calcium soap of the same saponifiable material with lubricating oil and subsequently adding one mol of an aqueous solution of strontium acetate and then heating to an elevated temperature to eiTect dehydration and dispersion in the lubricating oil. Also, greases even more closely resembling those obtained by reacting one equivalent of calcium hydroxide with one equivalent of a saponifiable material in the presence of oil and subsequently reactingthe normal calcium soap with one equivalent of strontium hydroxide to give a substantially neutral com--. plex basic soap grease have been produced by combining one mol of the normal calcium soap of the same saponifiable material with 0.5 mol of strontium acetate and 0.5 mol of strontium carbonate and dispersing the resultant product in lubricating oil.

I have also discovered that complex'bas'c soap greases can be formed not only by the addition of a, normal metal soap and the acetate salt of a different metal to a lubricating oil or a normal metal soa along with the acetate and carbonate salt of adifierent metal to lubricating oil, but also by compounding a normal metal soap, or a mixture of normal metal soaps lubricating oil, and a variety of salts of other different metals.

Metal salts which are useful for the foregoing purposes include preferably the simple reaction products resulting from the combination of one equivalent of a metal oxide or metal hydroxide with one equivalent of a mineral acid or of an organic acid of relatively low molecular weight. However, I may also employ acidic or basic salts in which one equivalent of metal oxide or metal hydroxide has been reacted with more or less than one equivalent of a mineral acid or acid anhydride such as sulfuric acid, hydrochloric acid, orthophosphoric acid, pyrophosphoric acid, sulfurous acid, carbonic acid, boric acid, thiosulfuric acid, etc., S02, S03, C02, etc. I may also employ metal salts of organic acids of relatively lowmolecular weight which are relatively insoluble in lubricating oil. As examples may be cited the metal salts of monocarboxylic and polycarboxylic acids containing less than about 7 carbon atoms per molecule, such as formic, acetic, propionic, valeric, oxalic, malonic, succinic, etc., acids, the low molecular weight alkyl and aryl sufonic acids, the low molecular weight carboxylic acids, such as glyceric, glycollic, thioglycollic, etc.

In the case of greases coming within the scope of the present invention, I prefer to employ a complex of a normal metal soap with a carbonate of a metal different from that contained in the metal soap or with a monocarboxylic acid salt of a metal different from that in the .metal soap, said acid having less than about 7 carbon atoms, or a mixture of any two or more of such complexes, either as such or in admixture with a normal metal soap. In the case of greases to be used under acidic conditions, such as are en countered in the canning industry, it may be desirable to employ a complex of a normal metal soap with a metal oxide or metal hydroxide in conjunction with the preferred complexes listed above. It is also within the scope of my invention to incorporate an alkaline-type filler, such as zinc oxide in the finished grease in order to overcome the effects of any acid liquors with which the greases may come in contact. In accordance with the present invention of using as lubricants complex basic soaps compounded in mineral oil, I prefer to employ more than 0.1 equivalent and preferablymore than 0.2 equivalent and desirably between 0.3 and 0.9 equivalent and as high as 2.0 equivalents or, even as much as 3.0 equivalents of a metal salt in conjunction with one equivalent of a normal soap of a different metal as the basic complex soap to be compounded with mineral oil to form the complex basic soap lubricants of the present invention. the above that the ratios of the different metals will be of the same magnitude, i. e., between limits of 0.1 and 3.0 equivalents of one metal to one equivalent of a different metal.

It is not meant to intimate that any given metal salt is the full equivalent of any other metal salt for modifying the characteristics of a dispersion of a normal metal soap in lubricating oil. In fact, the complexes of various metal salts with a given normal metal soap vary over a wide range as regards their respective solubilities in a given mineral lubricating oil. For example, I have found that of the various complex basic calcium soap greases coming within the scope of the present invention, those produced by reacting 0.1 or more equivalents of either strontium acetate or lithium acetate with one equivalent of normal 1, calcium soap dispersed in mineral oil, possess unusual and highly desirable properties not exhibited by combinations of normal calcium soap with other metal salts.

It has also been noted that even though the final grease is to be substantially anhydrous, a

It follows from product of improved characteristics can often be obtained by adding a small amount of water, for

. sequently increasing the temperature to efiect substantially complete dehydration. The grease may be at a temperature of about 210 F. or less when such water additions are made, although temperatures as high as 230 F. or even as high as 300 F. or-higher may be used, and subsequent dehydration has been accomplished by heating to temperatures in the neighborhood of 250 F. or

higher when necessary. With certain saponification reagents the greases produced by the pro-,

cesses of the present invention have a granular appearance, but by employing the hydrationdehyration technic, products of smooth buttery texture are obtained often accompanied by an increase in consistency and melting point. Further improvements in grease texture can likewise usually be obtained by working the grease at temperatures below about 200 F. and preferably below about F. prior to final packaging.

Normally in reacting a saponifiable material with an excess of basically reacting metal compounds the extent of the oxidation reaction is controlled so as to produce a final grease which is substantially neutral or free from readily titratable excess alkalinity, that is, one having a free acid or free alkali content less than about the equivalent of 5.0 mg. KOH per gram of soap present. In other words, the oxidation is so controlled that it results in the formation of at least about 0.1 equivalent of acidic oxidation products and preferablyabout 0.2 to 1.0 equivalent of acidic oxidation products or even as high as about i soaps in lubricants of this invention be substantially neutral, they may contain a small amount of free acidity or alkalinity. The finished grease may have a free alkali content calculated as metal hydroxide as high as about 05% by weight of grease or a free acid content equivalent to about 2.0 mg. KOH per gram of grease. A grease having a free acid content may be obtained by either continuing the oxidation to produce an excess of acidic reaction products over that required to neutralize the free basically reacting material or the oxidation reaction can be stopped at an earlier stage, such as while free basically reacting material is still present, and fatty acid or other acidic materials added in sufficient quantity to give a grease of the desired free acid content. In order to obtain a free alkali content the oxidationcan be stopped at an intermediate point or it can be continued to produce a substantially neutral or even acidic soap and the desired excess of basically reacting compound then added.

Usually the hydration-dehydration technique to produce a. final substantially anhydrous grease is most effective on a slightly acidic complex basic soap grease. Subsequently the greasecan be adjusted to the desired acidity or alkalinity by the 7 glycerine.

the complex from the normal metal salt.

may be. In a similar manner complex basic soap greases prepared by compounding normal metal soap with a. salt of a different metal can be ren-. dered acidic or alkaline asdesired by adding fatty acids or other acidic materials or metal hydroxide or other basically reacting metal compounds, as the case may be. s

Free alkalinity is measured in accordanc with A. S. T. 'M. method of test No. D-l28-40, section 18, except that titration is conducted in the cold and the titration is made directly with standard HCl solution rather than by adding an-excess of HCl solution and then back titrating with alcoholic potassium hydroxide solution. Free acidity is measured in accordance with A. S. T. M. meth-' d of test No. D-128 -40, section 20. Briefly, the methods of test employed are as follows:

A IOgram sample'of the'grease is weighed to the nearest tenth of a gram into a 250 'ml.;. Erlenmeyer flask. To the flask is then added 75 ml. of petroleum ether and 50 ml. of 95% alcohol containing phenolphthalein indicator, the alcohol' having been previously made neutral as indicated by the phenolphthalein indicator. The flask is stoppered and shaken vigorously in the lowed to settle and free alkali or free acid,'-as

observed by the color of the alcoholic layer, is titrated carefully in the cold to the phenolphthalein end point with 0.5. normal H0] or alcoholic KOH, as required. Free alkalinity is calculated in terms of metal hydroxide; free acidity in terms of oleic acid or acetic acid. Free alkalinity and free acidity may also be expressed in terms of equivalent mg. of KOH per'gram" of oxygen-containing gas. Further, preferably, the

1 reaction should be conducted in the presence of a polar, solvent such as, for example, water or If desired, a' portion or all of the j mineral oil can be blended with the saponifiable material and reaction with the basically reacting metal compounds subsequently conducted. Un'der' these conditions the mineral oilappears to serve essentially only as an inert diluent. On the some conditions smaller quantities, such as about Further, it appears that preferably this polar solvent should be water, although under some conditions the oxidation and complex formation proceeds more readily in the presence of a mixture of water and glycerine, water and glycol, or with some hydroxy or polyhydroxy organic compound, such as ethyl alcohol, dlethylene glycol, etc. Preferably the proportion of polar solvent present should be in the range of 0.5% to 4.0% by weight of the reacting mass, but under 0.1% and higher quantities, such as about 10% .25 cold until the grease has completely disintegrated I andno lumps remain. The solution is then alcan be used. As an indication of the desirability of having at least a small percentage of a polar solvent present. I have observed in the case of certain anhydrous normal metal soaps thatwhen mixed with anhydrous metal hydroxides and heated in the presence of oxygen at a temperature of 350 F. to 500 F. for three hours and the mixture subsequently analysed, little or no reaction had occurred and substantially all ofthe metal hydroxide could be recovered unchanged. Further, if the same mixtures containing an added 0.5% of water were heated in a closed kettle under the same conditions but with oxygen exeluded, little or no reaction was observed to take place. However, when the same mixtures containing 0.5% of added water were heated for three hours in contact with air or oxygen and at a temperature of 350 F. to 500 F., the resulting products contained normal metal soap along with metal carbonate and the metal salts of organic acidic oxidation products. and a corresponding amount of the metal hydroxide had disappeared.

One of the preferred methods of forming complex basic soap lubricants from a normal metal soap, a metal salt, and mineral oil is to dissolve the normal metal soap in all or only a portion of the mineral oil to be used and subsequently add a solution or a dispersion of the desired metal salt in a polar solvent, intimately mix and then other hand, the saponifiable material can be reis to be formed by reacting a normal metal soap solvent present in order to effect formation of acted with the basically reacting metal compounds in the absence of mineral oil thereby forming a concentrate which can be subsequently compounded with mineral oil to form a grease. When 3 a complex basic soap or complex basic'soap grease metal soap and As indicated hereinabove, in order for the desired oxidation reaction and normal metal soap Imetal salt complex formation to proceed within the preferred temperature range it is usually desirable that at least a small percentage of a polar solvent, in the neighborhood of at least about j 0.1% by weight of the reacting mass, be present.

while continuing the mixing boil off or evaporate all or a portion of the polar solvent. Additional oil can be added during or after the removal of the polar solvent, if desired. The normal metal soap can'be preformed or it can be made in the presence or absence of the mineral oil by reacting a saponifiable material with a basically reacting metal compound, such a a metal oxide, or metal hydroxide by methods known to those skilled in the art.

Another preferred method of forming a complex basic soap lubricant from a normal metal scan. a metal salt, and mineral oil is to dissolve the desired normal metal soap in mineral oil or form the normal metal soap from the desired saponifiable material and a basically reacting metal compound such as a metal oxide or metal hydroxide in the presence of all or a part of the desired mineral oil. Subsequently, a complex is formed between the normal metal soap and a metal oxide or metal hydroxide, added 1 an amount equivalent to the amount of salt which it is desired to complex with the normal metal soap, in the manner described in the preceding paragraph, except thatthe polar solvent need not be removed. Finally the acid,of the desired salt in an amount equivalent to'the added metal oxide or metal hydroxide is introduced and all or a part of the polar solvent, then removed by heatin g to a temperature within the range of about 200 F. to 600 F. Additional mineral oil can be added at any or all stages of the compounding as will be obvious to one skilled in the art.

As a special case of the preferred method described in the preceding paragraph, the desired saponifiable material can be reacted with anmetal,

complex. After the saponification has been completed the acid of the desired metal salt can be added in quantity just suflicient to neutralize the excess metal oxide or metal hydroxide present. It is also possible under thisspecial case to mix the desired saponifiable material with the acid whose metal salt is desired in the complex and then add an amount of a mixture of metal oxides or metal hydroxides or otherbasieally reacting metal compounds sufficient to finally eifect the saponification, form the salt and produce the complex. If it is desired to produce a final product having a free alkali or free acid content the desired acidity or alkalinity can be introduced at any of several stages as will be obvious to one skilled in the art.

It is of particular interest to note that the greases constituting the subject of this invention can usually be produced as substantially anhydrous products having, a stable grease structure. However, under some conditions and in order to obtain certain specific characteristics it may be desirable to produce greases containing small amounts of water, for example less than about 1.0% and preferably less than about 0.5%. It will be obvious to one skilled in the art that this amount of water can be incorporated at any of several stages in the process of making the grease. For example, if the grease has less than the desired amount of water, the required additional water can be added and worked into the grease at a temperature of 200 F. or less prior to drawing. On the other hand, if desired, an excess of water can be added to the grease before or after all of the oil has been incorporated or even during addition of oil and when the temperature. is in the neighborhood of 210 F. or less or even at more elevated temperatures such as 220 F. to 300 F. and the excess water subsequently re- I .moved by increasing the temperature of the grease if necessary and then coolingafter the desired water content has been reached.

The formation of the complex basic soap greases of thisinvention generally requires high temperatures, preferably in the region of about 400? F. to 550 F., although they can be formed over a wider temperature range such as about 250 F. to

about 75% may be desirable for certain special combinations and applications.

Complex basic soaps may also be used in relatively small proportions to produce liquid greases and fluid lubricants, such as lubricating. oils for internal combustion engines, especially Diesel engines. The soap concentrations' in such'applications are usually below about 5% and are normally in the range of 0.2% to about 2.0%. However, by a proper choice of saponifiable material, metal salt, and mineral oil, it is possible to pro duce' a'fiuid lubricant containing as high as' 10% by weight of complex basic soap or'even higher.

Materials other than complex basic soaps may also be added to the lubricating compositions of this invention, such as water, alcohols, and other solvents, anti-oxidants, fillers, etc., as desired.

An especially hard grease, for example, was prepared by the incorporation of an oil containing about 40% of asphalt instead of the usual lubricating oil. Additions of petrolatum and solvent extracts from lubricating oil stocks have been.

helpful in some instances.

In addition to using both light and heavy mineral lubricating oils to make complex basic soap lubricants, I may also employ the light lubricating-type oil which is recovered as heavy bottoms from the distillation of residuals obtained alkylate.

600 F. In forming normal metal soaps and com,-

plex basic soaps by reacting a saponiflable material with basically reacting metal compounds, the bases are added preferably-as metal hydroxides although in some instances metal oxides, metal carbonates, etc., may be'employed. The bases may be added as a powder, small granules, or as an aqueous or oil slurry, as desired. Either normal orv complex basic soap formation is preferably carried out in the presence of part of the lubricating oil to be used in the finished grease, although inert low-boiling solvents may be used under pressure and subsequently evaporated to leave a pure soap residue. The powder can then be dispersed in a mineral oil and a complex basic in modern alkylation processes employed in making alkylate'd motor fuels from some stocks. In some such processes the mentioned residuals are recovered in fairly large proportions. About 80% thereof is then distilledofi to be used for various purposes, thereby leaving about 20% of the'heavy alkylated bottoms mentioned. This 20% fraction may be further cut to yield lighter and heavier fractions. These fractions have viscosities in the order of that of spray oil and of very light lubricating oil, e. g., S. A. E. 10. In view of the properties of the complex basic soaps hereof, such heavy alkylated bottoms may be used as the lubricating fraction, especially where a' light oil is desirable for a given fluid or greaselike product having a low pour point. The described bottoms may, for example, be recovered from the sulfuric acid alkylation process de-' scribed in th Refiner for September, 1941, vol. 20, page 3'78. Suitable bottoms. are obtained, for example, after recovery of the motorfuel Some stocks yield larger amounts of such alkylate bottoms than others. These bottoms may in turn be fractionated for the present purpose.

The following examples will serve as illustrations of the present invention:

Example I equivalents=2.5l) and themixture was heated until saponifica-tion was. substantially complete. Then 450 grams of barium hydrate (Ba(O-H )2 content=53%; equivalents=2.79) and 620 g. of

' the same lubricating oil were added slowlyand the mixture heated with agitationuntil substantially all the water had been evaporated and the free alkalinity of the 'mixture calculated as Ba(OI-I)z amounted to 0.3%. Since the total weight of the product at this point was about 3276 g., 0.3% of free alkalinity amounted to about g. of Ba(OH) 2 1 dehydration were substantially complete.

11 or0.12 equivalents. whereas the excess of basic equivalents 2.51+2.79 5.3o) over acid equivalents 2.'l2+o.2a=a.oo) in the charge was 2.30, or nearly times as great.

The abovecomplex basic soap concentrate was diluted with about 3580 g. of a naphthen'ic-type S. A. E. 30 lubricating oil to give a substantially anhydrous grease containing about 17 by weight of soap. This product had a melting point ofabout 250 F., and A. S. T. M. worked penetra- I The ratio 01' equivalents of combined metals to tion at 77 F. of about 345,'contained about 0.1%

of free alkalinity, calculated as Ba(OH) z, and exhibited good water resistance.

The ratio of equivalents of combined metals (sodium-i-barium) to equivalents of saponifled high molecular weight organic acids in the complex basic soap was determined by analysis to be about 1.85. This ratio is slightly higher than that calculated on the basis of the ingredients charged (5.30/3.00=1.77) due to the oxidation of a small amount of the 'saponifiable material. These data indicate that since the amount of oxidation of saponiflable material is relatively small, the ratio of equivalents of combined-metals to equivalents of saponified high molecular weight organic acids in the product can be approximated from the amounts of ingredients used to form the complex basic soap.

A grease of similar characteristics was produced by reacting 2.72 equivalents of tallow and 0.28 equivalent of sperm oil with 2.51 equivalents of NaOH in the presence of oil as described above, subsequently adding 2.79 equivalents of barium hydrate and' 2.29 equivalents of acetic acid, and finally dehydrating and grading with oil to give a final product of about 17% by weight complex basic soap content. I

Example II 1 Approximately 860 g. of aluminum stearate same tallow as used in Example 111 was mixed (2.94 equivalents of aluminum and 2.00 equiv alents of stearic acid) and 2000 g. of a naphthenic-tyDe S. A. E. 30 lubricating oil were mixed and heated to 300 F. Subsequently 474 .g. of

barium hydrate'(Ba(OH)z content=54%; equivalents=2.99 was added slowly with stirring and heating continued. The excess alkalinity gradually disappeared and a neutral product was obtained in about 6 hours. The temperature v was then decreased to about 200 F. and 0.05% of water added to improve the body and smoothness of the grease. This product contained about of soap and had a ratio of equivalents of combined metals toequivalents of saponified high molecular weight acids of about 3.0.

Example III Approximately 850 g. of tallow (saponification 1 number=193; equivalents=2.92). and 144.2 g. of an aqueous lithium hydroxide solution (LiOH content=5 4.85%; equivalents=3.30) and 1500 g. of a naphthenic-type S. A. E. 20 lubricating oil 1 were mixed and heated until saponiflcation and Subsequently 438g. of barium hydrate (Ba(0H)z content=53.6%; equivalents=2.74) was added to equivalents of saponified high molecular weight organic acids was about 2.1 and the soap content was approximately 23% by weight. The resultant substantially anhydrous grease had a- Ubbelohde' melting point of 285 F. and an A. S. T. M. worked penetration at 77 F. 'of 290.

A grease of similar properties was obtained'by following the same procedure as outlined above except that 3.0 equivalents of propionic acid was added alongwith the barium hydrate followed by heating to 350 F. for only suflicient'time to eifect substantially complete dehydration.

Example IV V Approximately 0.293 gram-equivalents of the with 0.250 gram-equivalents of sodium hydroxide, added as a 46.8% aqueous solution'and 200 grams of S. A. E. 20 naphthenic-type lubricating oil. This mixture was heated until saponification and dehydration had taken place. Then 0.293 gram equivalents of magnesium hydroxide was added and heating continued at a temperature of approximately 500 F. until all the excess alkalinity had disappeared. Finally, 30 grams of S. -A. E. 30 and 280 grams lubricating oils were added as the mixture cooled.

The resulting product contained a small amount.

of free acidity equivalent to a neutralization number of 4.0 mg. of KOH per gram of sample. The grease contained about 15% of soap and had a ratio of equivalents of combined metals to equivalents of saponified high molecular weight organic acids of about 2.1. I The grease had a Ubbelohde melting point of 390 F., and A. S. T. M. penetration of 435, a dark green color, avery smooth texture and was very stable.

Example V Approximately 50 grams of a conventional cup grease, containing 9 grams of calcium tallow soap (0.03 equivalents), was mixed with 3.5 gramsof strontium acetate (0.034 equivalents) dissolved.

decomposition by water, had an A. S. T. M. pene-,

T. M. dropping tration at 77 F. of 300, an A. S.

point in excess of 450 F., and was substantially neutral.

the above mixture and the temperature maintained at about 350 F. until the per cent of free 1 base calculated as Ba(OH) 2 was reduced to 0.13%.

1 Then 387 g. of S. A. E. 20 naphthentic type lubrieating oil and 3213 g. of S. A E. 30 naphthenictype lubricating oil were incorporated in the above I concentrate to obtain a grease containing only A grease of similar properties was prepared by mixing 50 grams or the samecup grease with 4.5 grams of strontium hydroxide octahydrate (0.034 equivalents), subsequently heating to a temperature of 450 maintaining at this temperature until the material was substantially neutral and finally cooling to room temperature and working.

The foregoing description of my invention is notto be taken as limiting my invention but only as illustrative thereof since many variations may be made by those skilledin the art without departing from the scope or the following claims.

I claim:

1. A lubricating composition comprising min- 1 eral oil and a metal soap complex, said soap complex having atoms of at least two different metals, at least one of which is polyvalent, and containing a ratio of equivalents of metals to equiv alents of saponified high molecular weight orof- S. A. E. 20 naphthenic-type 13 ganic acids between'about 1.1 and 4 and being substantially free from readily titratable excess alkalinity, in which the ratio of equivalents of the different metals is between 0.1 and 3.0.

2. A lubricating composition comprising mineral oil and a metal soap complex, said soap complex having atoms of at least two different metals, at least one of which is polyvalent, and containing a ratio of equivalents of metals to equivalents of saponified high molecular weight organic acids between about 1.1 and 4 and being substantially free from readily titratable excess alkalinity, said composition being substantially anhydrous, in which the ratio of equivalents of the different metals is between 0.1 and 3.0.

3. A lubricating composition according to claim 1, in which the ratio of equivalents of metals to equivalents of saponified high molecular weight organic acids is between about 1.3 and 1.9.

4. A lubricating composition according to claim 1, in which the soap complex comprises a normal metal soap and a metal salt of a mineral acid in which the ratio of equivalents Of metal salt to equivalents of normal metal soap is greater than about 0.1.

5. A lubricating composition according to claim 1, in which the soap complex comprises a normal metal soap and a metal salt of a low molecular weight organic acid and in which the ratio of equivalents of metal salt to equivalents of normal metal soap is greater than about 0.1.

6. A lubricating composition according to claim 1, in which the soap complex comprises a normal metal soap and a metal salt of a mineral acid in which the ratio of equivalents of metal salt to equivalents of normal metal soap is between about 0.2 and 2.0.

7. A lubricating composition according to claim 1, in which the soap complex-comprises a normal metal soap and a metal salt of a low molecular weight organic acid and in which the ratio of equivalents of metal salt to equivalents of normal metal soap is between about 0.2 and 2.0.

8. A lubricating composition according to claim 1, in which the soap complex is made by reacting in excess of one equivalent of a basically reacting metal compound with one equivalent of a saponifiable material.

9. A lubricating composition according to claim 1, in which the soap complex is made by reacting normal metal soap and a metal salt of mineral acid.

10. A lubricating composition according to claim 1, in which the soap complex is made by reacting normal metal soap and a metal salt of a low molecular weight organic acid.

11. A lubricating composition according to claim 1, in which the soap complex is made by reacting normal metal soap, basically reacting metal compound and a mineral acid, the amount of mineral acid being sufficient to neutralize said basically reacting metal compound.

12. A lubricating composition according to claim 1, in which the soap complex is made by reacting normal metal soap, basically reacting metal compound and a low molecular weight organic acid, the amount of said acid being sufficient to neutralize said basically reacting metal compound.

13. A lubricating composition according to claim 1, in which one of the metals is an alkaline earth metal and the remaining metals are from the class consisting of alkaline earth metals and alkali metals.

14. A lubricating composition according to claim 1, in which one ofthe metals is an-alkaline earth metal and one of the metals is an alkali metal.

15. A lubricatin claim 1,- wherein said two different metals are barium and aluminum.

10. A lubricating composition claim 1, wherein said two different metals are barium and sodium.

17. A lubricating composition according to claim 1, wherein said two different metals are magnesium and sodium.

18. A lubricating composition comprisingmineral oil and a minor proportion of a metal soap complex containing at least two different metals, at least one of which is polyvalent, said soap complex-being produced by reacting substantially equal equivalents of basically reacting metal compounds and saponifiable high molecular weight organic acids to substantially complete saponifi cation and then reacting the soap product with an appreciable additional quantity of a basically reacting compound of another metal in the presence of oxygen at temperatures between approximately 300 F. and 600 F. until the product is substantially free from readily titratable excess alkalinity, said soap complex having a ratio of equivalents of metals to. saponifiable high molecular weight organic acids in excess of about 1.1,

in which the ratio of equivalents of the different metals is between 0.1 and 3.0.

19. A lubricating composition comprising mineral oil and a metal soap complex prepared by reacting at least 1.2 equivalents of basically reacting compounds of at least two different metals, at least one of which is polyvalent, with one equivalent 0f saponifiable high molecular weight organic acids at temperatures between about 400 F. and 550 F. in the presence of oxygen until the product is substantially free from readily titratable excess alkalinity, in which the ratio of equivalents of the different metals is between 0.1 and 3.0.

20. A lubricating composition as in claim 19, in which the soap complex is prepared by reacting said basically reacting metal compounds and said high molecular weight organic acid in the presence of mineral oil.

21. A lubricating composition comprising mineral oil and a soap complex containing at least 1.2 equivalents of metals to one equivalent of saponified high molecular weight organic acids, said soap complex being prepared by reacting an aluminum soap with an appreciable portion of a basically reacting compound of an alkaline earth metal at temperatures between about 300 F. and I 600 F. in the presence of oxygen until the soap product is substantially free from readily titratable excess alkalinity, in which the ratio of equivalents of the different metals is between 0.1 and 22. A lubricating composition according to claim 21, in which said aluminum soap is aluminum stearate and said alkaline earth metal is barium.

23. A method of preparing lubricants comprising reacting a saponifiable material with an approximately equal chemical equivalent of a basically reacting metal compound in the presence of mineral oil under saponifying conditions until saponification is complete and then reacting the soap product with an additional quantity of a basically reacting compound of a different metal at temperatures between about 400 F. and 550 F. in the presence of oxygen to yield a soap com- .composition according to.

according to plex which is substantially free from readily titratable excess alkalinity, which contains at least two different metals, at least one of which is polyvalent and which contains a ratio of equivalents of metals to equivalents of saponified material of r at least 1.1, cooling the final reaction mixture and adding additional mineral oil, in which the ratio of equivalents of the different metals is between 0.1 and 3.0.

LESTER W. MCLENNAN. REFERENCES CITED The following references are of record in the file 01' this patent:

asimao OTHER REFERENCES McLennan, Methods of Compounding Barium Greases, Their Properties, Uses and Future, Ar-

ticle in National Petroleum News, Apr. pages 3-234, R-236, R-238 and R9239.