US2846392A - Metal soap-salt complexes and lubricants containing same - Google Patents

Description

United States. Patent f NI ETAL SOAP-SALT COMPLEXES AND LUBRI- CANTS CONTAINING SAME Arnold J. Morway, Clark Township, Union County, and John J. Kolfenbach, North Plainfield, N. J., assignors to Esso Research and Engineering Company, a corporation of Delaware 7 No Drawing. Application October 21, 1953 Serial No. 387,527

10 Claims. (Cl. 252-33.2)

metal soaps and having'an extremely high metal content, and to compositions containing the same.

In brief compass, the invention pertains to compositions containing or consisting of complex compounds consisting of a metal salt of a low molecular weight carboxylic acid and a metal soap of a high molecular weight carboxylic acid, in which the proportion of low molecular weight carboxylic acid is a high multiple of said high molecular weight acid on a mole basis, resulting in an extremely high metal content of the complex compound. The compositions of the invention include novel and improved greases, lubricating oils, gear oils, hydraulic fluids, cutting oils, asphalts, etc.

Soap-salt complexes are well known in the art. These materials which have been used heretofore almost exclusively as thickeners for high temperature greases consist of combinations of metal salts of low molecular. weight carboxylic acids with metal soaps of high molecular weight fatty acids, normally in about equimolecular proportions. The mole ratio of low molecular weight acid to high molecular weight fatty acid in these conventional greases is rather low because of the low thickening elfect of the low molecular weight constituent. Even at mole ratios as low as 3 moles of low molecular Weight acid or less, per mole of high molecular weight fatty acid, the total requirement of soap-salt thickener needed to make greases of satisfactory penetration characteristics is quite high. Mole ratios in excess of 3 on this basis have, therefore, been strongly discouraged by the art concerned with conventional soap-salt complexes.

The present invention is based on the surprising discovery that by drastically increasing the low molecular weight acid content and, with it, the metal content of soap-salt complexes of the type specified, entirely new properties may be built into these complexes, which greatly increase their value as grease thickeners and which extend the scope of their utility to entirely new fields. More specifically, it has been found that complexes of metal salts of low molecular weight carboxylic acids with metal soaps of high molecular weight carboxylic acids, which contain at least 7 moles and up to as much as 40 moles or more, preferably about 8-25 moles, of the low molecular weight acid per mole of the high molecular weight acid, have outstanding loadcarrying, dispersant, detergent and various other beneficial characteristics in addition to thickening properties comparable to those of conventional soap-salt complexes containing substantially lower proportions of low molecular weightcarboxylic acids.

The constitution and chemical structure of the soapsalt complexes of the invention are not fully understood. However, X-ray diifraction spectra obtained from various soap-salt complexes in accordance with the invention, containing an excess of 7moles and up to 45 moles of low molecular weight carboxylic acid for each mole of high molecular weight carboxylic acid, show a pattern definitely inconsistent with that of a physical mixture of the low molecular weight acid salt with the high molecular weight acid soap. More particularly, none of the spectra obtained have patterns coinciding with the known patterns of the X-ray diffraction spectra of the low molecular weight acid salts involved. Also, the X-ray diffraction patterns of complexes composed of the same low molecular acid salt and high molecular weight acid soap, but differing in the mole ratio of low to ,high molecular weight acid employed showed definite differences indicating the existence of different chemical compounds rather than of varying physical mixtures of the same chemical compounds.

In accordance with the present invention, high metal content soap-salt complexes containing the metal salt of at least 7 moles of a low molecular carboxylic acid for each mole of saponified high molecular weight acid are incorporated into a wide variety of liquid and semisolid materials of natural or synthetic origin to improve the utility of these materials. More specific-ally, certain of these high metal content soaps may be compounded with mineral and/or synthetic lubricating oils in greasemaking proportions to produce excellent greases of good high temperature resistance and greatly improved extremepressure characteristics containing about 5-30 wt.

percent of the complex soap. Similar complex soaps- The high molecular weight acids useful for the purposes of the present invention are those having 12-30 carbon atoms and preferably those having 18-22 carbon atoms per molecule. These acids may be derived from saturated or unsaturated naturally occurring or synthetic fatty materials. The fatty acids normally used in the manufacture of conventional greases, particularly the more saturated acids, are preferred. Examples of such acids include stearic, hydroxy stearic, such as 12-hydroxy stearic, di-hydroxy stearic, poly-hydroxy stearic and other saturated hydroxy fatty acids, arachidic, hydrogenated fish oil and tallow acids, etc. However, unsaturated acids, such as oleic, ricinoleic and similar acids may likewise be used.

In some cases, such as in the preparation of extreme pressure greases and detergent oils, it may be desirable to replace a substantial proportion, say, about 25-80 wt. percent, of the high molecular weight fatty acid constituent of the complex by an oil-soluble sulfonate. Sulfonates derived from oil-soluble sulfonic acids having Patented "Aug. 5, I958 3 combining weights in the range of about 350-525 and preferably in the range of about 420-450 may be used for this purpose.

Suitable low molecular weight acids include saturated and unsaturated aliphatic mono-carboxylic acids having about 1-6 carbon atoms, such as formic, acetic, propionic, furoic, acrylic, and similar acids including their hydroxy derivatives, such as lactic acid, etc. Formic and, particularly, acetic acid are preferred.

The choice of the metal component depends to a certain extent on the use for which the complex soap of the invention is contemplated. The alkaline'earth metals, particularly calcium, barium and magnesium are useful for many purposes of the invention. These metals afford greatest advantages when used as thickeners in the manufacture of greases because they permit the production of greases having outstanding load-carrying characteristics and satisfactory structural stability at high temperatures and under mechanical stress even without the use of conventional extreme pressure and stabilizing agents. The alkaline earth metals difier in this respect from the alkali metals. Complex soaps of high alkali metal content, which are analogous to soap-salt complexes of the present invention regarding'type and mole ratio of the acids used, yield greases of poorer structural stability, even when added to the oil dispersant in relatively high proportions.

Other metals useful for the purposes of the invention are the heavy metals of groups I, II and IV of the periodic system, particularly copper, zinc, and lead which may be used either alone or in combination with alkaline earth metals in the preparation of the complex soaps. Copper and zinc give the complex soaps of the invention fungicidal properties while lead increases their load-carrying ability. Cobalt complexes may serve as catalysts in the x0 process or as paint driers. Nickel complexes may be used as hydrogenation catalysts. Chromium complexes may be added to fuel oils to prevent corrosion by sodium salts while manganese complexes have utility as paint driers and corrosion inhibitors.

In general, the metallic elements of the salts as well as, of the soaps may be any one or more of the metals mentioned above, that is, the metal of the salt may be the same as or different from 'the metal of thesoap. However, in most cases, the salt and the soap contain the same metal or combination of metals.

The high metal content soap-salt complexes of. the invention may be prepared by'coneutralization of a mixture of the high and low molecular weight acids with suitable bases, particularly the hydroxide'and/or carbonates of the metals desired. This coneutralization step may be carried out in situ in the liquid menstruum to which the complex soap is to be applied in actual use. For example, the mixed acids may be coneutralized in a portion or all of the lubricating oil forming the dispersant ofai grease to be thickened by the complex soap. Similarly, the coneutralization may be carried out in fuel oil or other dispersant or solvent fluids, the characteristics of which are to be modified by the complex'soap. Coneutralization is particularly desirable in cases in which the soap and salt have the same metal constituent. Usually the coneutralized material is heated to high temperatures of about 450-550 F. or'higher, prior to use to dehydrate the product and to promote formation of the complex. When this heating step. is carried out in a liquid dispersant the. latter should have a boiling point above the heating temperature or the heat treatment should be carried out under pressure.

Instead of using high molecular weight fatty acid proper, esters thereof, particularly the glycerides or other acidogenic materials such as the nitriles, may serve as the starting materials. Naturally occurring animal or vegetable fats and oils are preferred materials of this type. Also, the low molecular weight carboxylic acids may be employed in the form of suitable esters, such as those of glycerine, ethanol, etc., or other acidogneic compounds, such as the nitriles. Conventional conditions conducive to the saponification of these esters followed by dehydration and alcohol removal may be used. Esters of this type may be used as described in the case of coneutralization as well as in the case of separate formation of the soap and salt described below.

The high metal content soap-salt complexes of the invention may also be prepared by separately preforming at least a portion of the high molecular Weight acid soap and/or the low molecular'weight carboxylic acid salt and intimately-mixing the soap with the salt, followed by heating, if necessary. This method is useful particularly when different metals are employed as bases for the soap and salt constituents, respectively.

The use of preformed metal salts may be desirable for other considerations. The production of soap-salt complexes of the type hereinvolved for the manufacture of greases, etc. requires large amounts of low molecular weight carboxylic acids, such as glacial acetic acid. Since these acids are available in large quantities they may be purchased in carload or tank car lots, requiring plant tankage with piping to the kettles and precautions to prevent freezing. Some precautions are also necessary in handling due to the corrosive nature of the acids.

It has been found that by substituting preformed metal salts of the low melecular weight acids, such as calcium acetate for a portion of the free acid employed in the lubricant, a large number of the drawbacks just mentioned may be eliminated. In addition, ,the preformed salts, particularly calcium acetate, in suitable purity are considerably cheaper than those formed in situ by reacting the metal base with the free acid. These advantages may be obtained by replacing about .30-80 wt. percent, preferably at least 50 wt. percent of the free acid with the preformed .metal salt in. formulating the complex for grease manufacture orotherpurposes.

The high metal content soap-salt complexes of theinvention when prepared in a liquid dispersantor solvent solvent extraction of the dispersing medium in a solvent in which the complex is insoluble. Suitable solvents include normal heptane, isopropyl alcohol, acetone, water, etc., the proper choice depending on the solubility characteristics of the liquid menstruum used to disperse the. complex.

The choice of the material to which the high metal content complex soaps of the invention are applied depends, of course, on the use contemplated. For grease manufacture, in accordance with the invention, mineralas well as synthetic lubricating oils'may be used including well-known di-esters, complex esters, hydrocarbon polymers, silicone oils, polyglycol derivatives, etc. Quite generally, these oils should have a viscosity within the range of about 35-200 SSU at- 210 F. and flash points of about 35 0-600 F. A viscosity index of or higher may be' employed, however oils of lower viscosity index, such as below 60 V. I. give better yields. It has also been found that soap-salt complexes containing more than 30'rnoles, e. g. 30-40 moles, of low molecular weight acid for each mole of high molecular weight acid have particular utility for converting synthetic oils of the ester type into excellent greases. Complex soap proportions of about 5-30 wt. percent, preferably about 10-20 wt. percent, based on total grease may be used in preparing the improved greases of the invention.

' As mentioned above, the high metal content soaps of the invention may also serve as dispersant additives and corrosion inhibitors for fuel oils. In this application of the invention particular advantages are secured when adding the complex soap to residual fuel oils of high ash content, specifically those of high vanadium content. When such residual fuels are burned, thevanadium is 2-20 wt. percent, preferably about 5-10 wt. percent, of the'soap -salt complexes of the invention, based on the weight of the total composition. Complex soaps containing magnesium may be employed to prevent corrosion in this corrosion may be inhibited by the addition of alka- 5 gear lubricants. Copper complex metal soaps, if desired line earth metal compounds, particularly compounds of in combination with arsenic, are useful as fungicides in calcium and magnesium to the oil. Addition of these additions of about 2-10 wt. percent to suitable menstrua, metals in the form of the high metal content complex such as paints, leather dressings, solvents, insecticides, soaps of the present invention permits a substantial indispersants', etc. crease in the added metal concentration while still avoid- The invention will be best understood by reference to ing the sedimentation difficulties encountered in the addithe following specific examples which illustrate various tion of conventional alkaline earth metal-type corrosion modifications of the invention. inhibitors. In general, the addition of about ODS-2.5 wt. percent of complex soap is sufficient for this purpose, EXAMPLE I specific preferred proportions depending on the metal content of the complex soap. A number of mineral oil base lubricating greases thick- The detergency and extreme pressure characteristics of ened with calcium soap-salt complexes of Hydrofol acid the complex soaps of the present invention may be uti- (hydrogenated fish oil acids corresponding to commerlized in combination with a wide variety of conventional cial stearic acid in degree of saturation), hydroxy stearic lubricating oils. Relatively large proportions of active acid derived from hydrogenated castor oil and acetic acid metal may thus be introduced into the oil without soluwere prepared as follows: bility problems. Quite generally, the oil should have a The hydrogenated castor oil, the Hydrofol acid and viscosity within the range of 60-2500 SSU at 100 F. hydrated lime and all of the mineral oil were charged and 35-150 SSU at 210 F., a pour point of about +20 to a fire heated kettle equipped with agitating means and to -30 F., and a flash point of about 350-650 F. the mixture was heated to about 130 F. The acetic acid Mineral lubricating oils as well as synthetic oils of the was then added. Heating was continued and the temsynthetic hydrocarbon, hydrocarbon polymer, ester, comperature was raised to 500 F. After reaching 500 F. plex ester, formal, mercaptal, polyaklylene oxide, silicone heating was discontinued and the grease was cooled to or similar types may be used including such specific oils 200 F. While stirring. Thereafter, the grease was hoas di-Z-ethylhexyl sebacate, di-C -Oxo azelate, etc. High mogenized at a high rate of shear in a Gaulin homogenmetal content soap-salt complexes of the alkaline earth izer. The greases so prepared were tested for their strucmetals, particularly of magnesium, calcium and barium tural stability by working, for their load-carrying cahave excellent detergent properties and appreciable loadpacity by the Almen test and for their dropping point. carrying capacity when added in proportions of about The composition of these greases and their properties are 0.5-10 wt. percent, preferably about 1-5 wt. percent, of tabulated below in Table I.

Table l CALCIUM COMPLEX SOAP GREASES N0 1 2 3 4 5 0 7 s 9 1o Composition, Wt. Percent:

' 4. 35 5.00 0. 42 0.10 7.50 9.20 0.00 .70. PhenylaNaphthylamine 0.50 O. 50 0.50 O. 50 0. 50 0. 50 0. 50 .50. Naphthenic Type Mineral oll Distillate s0. 70.05 79.20 77.68 80.50 75.50 73.70 81.40 73.00.

Having a Viscosity of SSU at 210 F. Percent Free Alkali as NaOH 0 0.71 0.50 0.55 0.07 0.30 0.42 0.28 0.42. Mole Ratio, Acetic to High M01. Wt. AcirL. 1:1 2. 5:1 50:1 7. 5:1 10:1 15:1 22. 5:1 40:1. Total Acid Content Acetic and High M01. Wt. 18.2 15. 3 15. 4 l2. 9 15. 5 16. 6 15. 6 15.9. Properties:

ii i Z1 mm'/m 234 153 103 105 103 130 290 nwor e 4 Worked 00 Strokes {Separates i 258 105 144 210 200 198 310 Sets up but seml'fluid and soap. p001. Strum grease-some tion tural stabll- 3; 051550 Dropping Point, F 500+ 500+ 500+ 500+ 500+ 500 500+ Almen Test (Weights Carried) 11 10 10 9 15 15 15 15 15 E5ld ;n;r pin on ton.

the oil. High metal content complexes of lead may be used in proportions of about 0.5-20 Wt. percent, preferably 2-10 wt. percent, to improve the extreme pressure characteristics of the lubricating oils.

The same soap-salt complexes may be added to metal working lubricants, such as cutting oils, drawing colnpounds, forging compounds, etc., of the mineral oil or emulsion type to improve their extreme pressure characteristics. In this case the high metal complex soaps of the invention may replace or supplement additives containing such conventional load-carrying components as sulfur, chlorine, sulfur-chlorides, and phosphorus. Beneficial results are usually secured by the addition of about It will be noted that the complex soaps containing from 7.5 to 20 moles of acetic acid per mole of high molecular weight fatty acid (Nos. 5-8) yielded greases of excellent consistency and dropping point and outstanding load-carrying capacity. Greases containing 5 moles of acetic acid per mole of high molecular weight fatty acid, or less (Nos. 1-4), were far inferior with respect to extreme pressure characteristics at otherwise comparable conditions. Greases containing 30 or more moles of acetic acid per mole of high molecular weight fatty acid (Nos. 9 and 10) had outstanding extreme pressure characteristics. However, these greases were inferior with respect to consistency and structuralstability.

p EXAMPLE II p -A=grease was prepared substantially as described in Example 1 from the following ingredients:

Ingredients: Wt. percent Glacial .acetic acid g 10.0 .Hydrofol Acid 51 5.0 :Hydrated lime 7.3 Naphthenic-type mineral oil distillate having a .viscosity of 55 .SSU at 210 F 77.7

This grease was'rather rough in texture, but became Greme Wt. Percent Ingredients:

Hydroxystearlc Acid.

.Di-hydroxystearic Acid Oil.

Hydrogenated Castor Hydrotnl Acid 51 Glacial Acetic Acid Hydrated Lime.

Phenyl a'Naphthylamiue.

Mineral Oil Distillate Having'a Viscosity of 55'SSU at 210 F Naphthenie-Type Properties:

Appearance Appearance After 1 Month Appearance After 6 Months Penetrations, 77 F. mm./10:

d, 60 Strokes Worke After 6 Months- Excellent uniform when first made Excellent...

Excellent. Exeellent Slightly harder than origin 11 Crust on Grease Very Hard.

smooth and of excellent appearance after Gaulinhomogenization.

Properties:

Mole ratio--acetic:hydrofol acid 9.3:1

Free acidity as oleic acid 0.14

Penetrations, 77 F. mm./ 10:

Unworked 210 Worked 60 strokes 215 Dropping point, "F 500+ Water solubility Insoluble EXAMPLE HI A grease was prepared from the following ingredients as described in Example I, except that the temperature was only raised 'to 450 F. because the grease started to become heavy at 400 F.

Good smooth uniform product;.sorne small specks of undispersed soap.

Appearancebetore homogenization Appearance after Gaulin.homogenization Excellent. Penetrations, 77 F. mm [10- Unworked 176. Worked 60 strok 180. Worked 70,000 strokes 190.

Dro ping point F 500+. lvat er solubility Insoluble.

While excellent grease structures may be obtained according to the present invention with saturated or unsaturated high molecular weight fatty acids, it has been observed that in a short period .of time some of these greases start to harden first forming a crust on the top of the grease exposed to the air and then throughout gradually hardening excessively. It has now been found that when .all or at leastl of the high molecular weight fatty acid consists of hydroxy acids, such as monoan'd/or' di hydroxystearic acids, hardening and crust formation is. prevented. This fact is. illustrated by the following example.

EXAMPLE V Two greases A and B were prepared in commercial scale operation from the following ingredients:

Percent by Weight Hydroiol Acid 51 2. 0 1. 6

Hydrogenated Castor Oil 2.0 1.6

Glacial Acetic Acid 8. 0 6. 4

Hydrated Lime 6. 0 4. 8

Phenyl a Naphthy'lamine 0.5 0. 4 Naphthenic-Type Mineral Oil Distillate Having a Viscosity of 55 SSU at 210 81. 5 85. 2

The greases were prepared by charging the hydrofol acidSl, the hydrogenated castor oil, the hydrated lime and the mineral oil to a fire heated kettle and warming the mixture to F. Then the glacial acetic acid was charged and the mixture was heated to 500 F. This temperature was reached in 4.5 hours. Heating was discontinued and the kettle closed and flooded with CO followed by pressurizing with air to 30 p. s. i. The grease formed was pushed over by the air pressure through a pipe connection to a jacketed cooling kettle.

The temperature of the grease fell to 440 F. during transfer and was further cooled to 250 F. in 1 hour while agitating and passing cooling water through the kettle jacket. Agitation and cooling water were discontinued overnight, the grease further cooling to 174 F. during this period. Aportion of the grease was then homogenized by passing through a Morehouse mill at very close clearance with an outlet temperature of 240 F. The balance of the grease left in the kettle was then diluted to a softer consistency with mineral oil and homogenized with the same mill settings. The milling rate was markedly increased, with an outlet temperature of 180 F.

Wheel Bearing Test, 6 Hours at 220 F Evaporation, percent (50 Hrs. at 210 F.) Separation, percent (50 Hrs. at 210 F.) Copper Corrosion, 24 Hours at 210 F Norma Hofimann Oxidation Test, p. s. i. Drop in 0 Pressure After 100 Hours. AFBMA-NLG/Spiudle Test, H0urs (250 F., 10,000 R. P. M.) 1,800+ 1,800+.

300 F., 10,000 R. P. M.) 334. 4-Bal'lest, Kgs. Load- Pass 252.

Weld 282. Almen Test, Weights Carried 15 15. I Timken Test (33 O. K. Load) Borderllne. Wear Test, 7.5 Kgs., 30 min., at 167 F.,

Scar Diameter, mm 0.26 0.23.

It will be noted that these greases had excellent antiwear, load-carrying and high temperature characteristics combined with outstanding water resistance, consistency and stability.

EXAMPLE VI To isolate the soap-salt complex of the invention, a portion of grease A of Example V was extracted with acetone for about 2 days in a Soxhlet apparatus until all oil was removed. The rafiinate was a brownish plastic amorphous solid which is at least partially soluble in aromatic solvents and substantially insoluble in normal heptane, isopropyl alcohol, acetone and water. The complex decomposes without perceptible melting at temperatures considerably in excess of 500 F.

The invention also permits the preparation of cup greases having excellent water insolubility and utility for services operating at high temperatures well outside of the range of typical cup grease service. In particular, these greases have all of the highly desirable properties of a cup grease, without the limiting property of loss of structure at temperatures above 200 F. These greases in essence consist of equal portions of a typical cup grease and a complex calcium acetate grease of the invention heated together at steam kettle temperatures until anhydrous.

Cup greases have an excellent reputation as water insoluble lubricants of excellent structural stability. Their only deficiency is their inability to satisfactorily lubricate above 200 F. due to loss of structural waterwith resulting soap precipitation. The greases prepared from complex calcium soaps of the invention in which calcium acetate forms a major portion of the complex soap thickener overcome this difliculty. However, these greases normally require high temperatures of manufacture which, in turn, requires expensive equipment.

It has now further been found that excellent greases suitable for high temperature services can be prepared during the regular manufacture of cup greases. In the conventional method the fat and/or fatty acid is saponified with lime while heating to about 300 F. When complete reaction has occurred, the grease is cooled to about 200 F. and water is added and the structure formed. In accordance with this invention an equal portion of a high calcium acetate complex grease is added to the simple soap cup grease at 300 F., and the two products are mixed and heated together for a short period. The resulting product on cooling is an excellent smooth uniform grease. The addition or combination of the dehydrated cup grease and the complex soap grease may be in such proportion as to give a mole ratio of high molecular weight acids to low molecular weight acidsof 1:1 to 1:10.

- l0 p r The following examples further describe this embodiment of the invention.

EXAMPLE VII A conventional cup grease was prepared as described above from the following ingredients:

Ingredients: Wt. percent Animal fat 9.50 Hydrated lime 1.35 Water 0.95 Naphthenic-type mineral oil distillate having a viscosity of 70 SSU at 210 F 87.70 Polybutene tackiness agent 0.50

A high calcium content complex soap thickened grease was prepared substantially as described in Examplel from the following ingredients:

Ingredients: Wt. percent Hydrogenated castor oil 1.6 Hydrofol acid 51 1.6 Acetic acid 6.4 Hydrated lime 4.8

Naphthenic-type mineral oil distillate having a viscosity of 55 SSU at 210 F Phenyl a naphthylamine 0.4

Equal proportions of the two greases were charged to a steam heated kettle and heated while stirring to 300 F. and held at. this temperature for 2 hours until all the water in the cup grease was removed. On cooling an excellent smooth grease was formed.

EXAMPLE VIII In another preparation, the cup grease of Example VII was prepared by charging the fat" and /2 of the mineral oil to the kettle and heating to 130 F. where the lime was added. Heating was continued to 300 F. and held at this temperature until all the fat was saponified. Without cooling, the calcium complex grease of Example VII was added and the two greases cooked together for 2 hours until a firm solid structure formed. Heating was discontinued and the balance of the oil added. The grease was cooled quickly by passing cold water through the kettle jacket. The grease was then drawn, filtered and packaged. Homogenization improved the appearance of the grease.

Properties: Appearance Excellent smooth uniform grease. Dropping point, F 500+. Penetration, 77 F.,

Unworked 285.

Worked, 60 strokes- 300. Worked, 65,000

strokes 320. Wheel bearing test (6 hrs.

at 220 F.) Pass. Leakage None. Water solubility Insoluble in boiling water.

Lubrication life, 10,000

R. P. M., 250 F., Hours 1134. Norma-Hoffmann oxidation test, drop in 0 pressure in hours 3.

In the foregoing two examples the simple calcium soap EXAMPLE 1X A sulfonate-type "grease was prepared from the following ingredients.

Ingredients: Wt. percent =Ca sulfonate (mol. wt. about 1000; 30% concentration of soap in mineraloi'l) 7.0

Hydrofol acid 1 2.0

Glacial acetic acid; 8.0

Hydrated lime 5.7 Naphthenic-type mineral oil distillate having a viscosity of 55 'SSU at 210 F 77.3

The calcium sulfonate, hydrofol acid 51 and of the mineral oil were charged to a grease-making kettle and warmed to 150 F. The acetic acid was then added and followed by a slurry. of the hydrated lime in the balance of the mineral oil. Heating was continued to remove water and the grease was then heated to 460 F. Heating was discontinued. The grease set to a solid product at approximately 450 F. when raising the temperature, having been completely fluid prior to this.

Properties: r

Appearance Smooth uniform grease. Mole ratio-acetic: hydrofol acid 20:1. Penetrations, 77 F., mmJiO:

Unworked 220. Worked, 60 strokes Worked, 1,000 strokes 310. Fluid (semi). After setting minutes after working 1,000 strokes Dropping point, "F 50 Gear lubrication test The portion of the grease in direct contact with the gear is fluidized giving excellent lubrication. The balance of the grease remains solid. Extreme pressure data, Almen test- Carried weights loadslight scratching. Water solubility Insoluble-but will emulsliy.

The above example shows a thixotropic grease in which equal molar proportions of a high molecular weight fatty acid and sulfonic acids were employed. However, the thixotropic nature of the grease can be controlled. When increasing the sulfonate content, the grease tends to fluidize more easily under working stresses. As the fatty acid salt is increased in weight concentration over that of the sulfonate, the structural stability to mechanical working is increased. However, even small amounts of sulfonate have a modifying effect on the grease structure.

Greases made in accordance with the invention which contain metals other than calcium in the soap-salt complex are il'lustrated'by the following examples.

In many cases, mixed metal base soap-salt complex greases may be prepared in accordance with the invention in order to incorporate the desirable characteristics of the individual single metal base complex greases into the final grease while eliminating the deficiencies of the single metal base complex greases involved. For example, greases thickened with complex lime soaps having low mole ratios of low molecular weight to high molecular weight acids are relatively hard and often almost brittle. Complex sodium soap greases, on the other hand, tend to attain a fluid or semi-fluid consistency at relatively low as well as relatively high mole ratios of low to high molecular weight acids. However, when these greases are cornbinedto form a mixed metal base 12 complex grease containing high and low molecular weight acids in the proportions of the invention, an excellent stable grease of desirably soft consistency and excellent water resistance with a suflicient absorption capacity 5 for water to inhibit corrosion is obtained. A grease of this type is illustrated by the following example.

EXAMPLE X An all-calcium complex soap thickened grease A was prepared substantially as described in Example I from the following ingredients:

Wt. percent Ingredients of grease A:

Hydrofol acid 51 3.75 15 Hydrogenated castor oil 3.75 Acetic acid 7.90

Hydrated lime -r 6.42 'Naphthenic-type mineral oil distillate having a viscosity of 55 SSU at 210 F 77.68 Phenyl alpha-naphthylamine 0.50

Properties of grease A:

Free alkalinity as NaOl-l, percent 0.55 Penetrations, 77 F., mm./l0

"Unworked 103 I Worked, 60 strokes 144 Dropping point, F. 500+ I An all-sodium complex soap thickened grease -B was prepared from the following ingredients:

Ingredients of grease B: Wt. percent Acetic acid 12.6 Hydrofol acid 51 4.0 Sodium hydroxide 9.2

Naphthenic-type mineral oil distillate having a viscosity of 55 SSU at 210 F. 74.2

The hydrofol acid, mineral oil and NaOH (as a 40% aqueous solution) were charged to a kettle and warmed to 105 P. Then the acetic acid was added and the grease finished by dehydrating and then heating to 500" F. The grease was cooled while stirring to 200 F. and

Gaulin homogenized.

Properties of grease B:

Free alkalinity as NaOI-I, percent 0.17. Consistency Semi-fluid.

EXAMPLE XI A complex mixed base sodium-calcium grease was prepared by combining of grease A (Example X) with 50 50% of grease B (Example X). This mixed base grease had the following formulation.

Weight percent Formulation:

Acetic acid 10.250 Hydrofol acid 51 3.875 Hydrogenated castor oil 1.875 Hydrated lime 3 .220 Sodium hydroxide 4.600

Naphthenic-type mineral oil distillate having a viscosity of 55 SSU at 210 F 75.940 Phenyl alphanaphthylamine 0.250

The cold greases A and B were mixed together in a conventional grease mixer. An excellent smooth uniform grease was formed.

Properties of mixed metal base grease:

Mole ratioacetic:high molecular Weight p. s. i. drop in 0 pressure .247

Greases having improved anti-corrosion properties suitable for Services in wet hot conditions where acidic waters may be present may contain a mixed calciumzinc complex soap in accordance with the invention. The mixed organic acids, e. g. hydrofol acid 51, hydroxy stearic acid and acetic acid may be coneutralized with a mixture of zinc oxide and calcium hydroxide in situ in the mineral oil to form the grease structure.

In the prior art, calcium soap greases have given excellent service under wet conditions; however, they are prone to cause corrosion of the metal parts since little or no water is absorbed by the grease. These greases also lack high temperature stability due to their low dropping points. Water insolubility and prevention of static corrosion are necessary particularly in canning equipment. In the industry, use .is made of steam-flow can closing equipment. This machine has a number of lubrication requirements including a grease that will lubricate as well as prevent the corrosion of the seam roll bearings. These bearings are subject to an atmosphere of steam (about 200 F.) and to vapors of food, which are acidic in the citrus and tomato industry, and also periodically to washing action of cold water and steam when the canning equipment is washed and sterilized.

A grease capable of meeting these drastic requirements can be prepared from the complex soaps of zinc and cal cium in which acetic acid predominates in the organic portion of the complex dispersed in mineral oil. In addition, these greases have excellent extreme pressure properties. Typical greases of'this type are illustrated by the following examples.

EXAMPLE XII A grease was prepared from the following ingredients.

Ingredients: Weight percent Hydroxy stearic acid 2 All of the ingredients with the exception of the acetic acid were charged to a fire heated grease kettle and warmed While agitating to 130 F. At this temperature the acetic acid was added and the temperature raised to 450 F. Careful heating was continued during the dehydration period. At 450 F. the grease starts to fume copiously and forms a solid heavy structure. Heating was discontinued and stirring continued to 200 F. while cooling. At this temperature, inhibitors such as phenyl alphanaphthylamine may be added or other corrosion preventive additives, such as titanium oxide or magnesium hydroxide. The grease is then homogenized to form an excellent uniform product.

Properties:

Mole ratioacetic:high mol. wt. acids 10:1 Penetrations, 7 F., mm./ l0

Unworked 215 Worked,'60'strokes 245 Worked, 100,000 strokes 290 Dropping point, F 500+ Water solubility, 212 F Nil Humidity cabinet 100% R. H. 120

F., 7 days (1 day at room temperature); steel panels coated with grease No corrosion Almen test, weights carried l5 EXAMPLE XIII Asofter grade of the grease of Example XII was prepared by cutting back the above grease with 39.0%

121* of the same mineral oil, mixing intimately and then Gaulin homogenizing. I i

Ingredients: Weight percent Grease of Example XII 61.0 Mineral oil 39.0

Properties:

Appearance Excellent smooth grease Penetrations, 77 F., mm./10-

Unworked 345 Worked, 60 strokes 354 Dropping point, "F 500+ Almen test, weights carried -Q 15 Other additives that can be employed in place of the zinc oxide include titanium oxide although it is uncertain that the titanium enters the reaction with the acids to form complex soaps. Magnesium hydroxide in combination with calcium hydroxide enters the complex and is an excellent anti-corrosion additive to prevent static corrosion.

The use of a preformed metal salt of a low molecular weight carboxylic acid in the preparation of greases thickened with the soap-salt complexes of the invention is illustrated by the following example.

EXAMPLE XIV Three greases, 1, 2 and 3 were prepared from the materials listed below by mixing theingredients in the proportions indicated in the conventional grease mixer and heating the mixture to about 500 F. In the case of greases l and 3, the free acetic acid was added after the. mixture of the other components had reached a temperature of about F. whereupon heating was continued to 500 F. Thereafter, the greases were cooled to about 250 F. while agitating. Then, the phenyl alpha-naphthylamine was added, the mixture further cooled to about 200 F., homogenized and packaged.

Wt. Percent Grease 1 2 3 Ingredients:

Hydrofol Acid 51 Hydrogenated Castor Oil.. Glacial Acetic Acid Hydrated Lime Calcium Acetate Phenyl a Naphthylamine. Naphthenic Type Mineral Oil Distillate Having a Viscosity of 55 SSU at 210 F. Properties:

Appearance and Structure... Excellent.

Dropping Point, F 500+ Penetrations, 77 F. mm 10 Unworked 220 Worked, 60 Strokes 238 Worked, 75,000 Strokes.- 308 Water Solubility Insoluble.- E. P. Properties Almen Test, Wts. Oarried 15 Shell 4-Ba1l Test:

Pass, Kg 224 Weld, Kg

. Greases having excellent stability both thermally and mechanically and having excellent long lubrication life and inherent load-carrying ability can be prepared employing calcium complex soap-salt thickeners in accordance with the invention. Other alkaline earth metals than calcium can be -employed in forming the complex. However, calcium soap appears to give the preferred structure and ease of manufacture.

' It has now been found'that greases of excellent structure and stability can be prepared from mixed alkaline earthbases when'the alkaline earth metal of higher molecular Weight is employed as the preformed salt of a low molecular weightacid. By using the dry salt, rather than forming'the salt'in situ from the hydroxide, large amounts of water of hydration generally present in the alkaline earth hydroxide are eliminated. This affords a more economical and faster manufacture. Dry calcium hydroxide may be employed to finish the saponification of the high molecular weight acids and the portion of the low molecular weight acid required and not accounted for in the preformed low molecular weight acid salt of the high molecular weight alkaline earth metal. The calcium soap and salt are formed simultaneously in the presence of the preformed higher molecular weigh alkaline earth metal salt.

An example of this embodiment of the invention is given below:

EXAMPLE XV A grease was prepared fromthe following ingredients:

Ingredients: Weight percent Glacial acetic acid 4.00 Hydrofol acid 51 2.00 Hydrogenated castor oil 2.00

v Strontium acetate 7.00 Hydrated lime 3.20 Phenyl a naphthylamine 0.50

Naphthenic-type mineral oil distillate having a viscosity of 55 SSU at 210 F 81.30

All of the ingredients with the exception of the acetic acid and the phenyl oz naphthylamine were charged to a fire heated grease kettle. While mixing, the ingredients were warmed to 135 F. At this temperature the acetic acid was charged and the temperature raised to 500 F. Some small amount of foaming occurred at 220250 F. Heating was discontinued and the grease cooled to 250 F. while agitating. The phenyl oc naphthylamine was then added and the grease further cooled to 200 F.

where it was Gaulin homogenized, filtered and packaged. 7

Properties:

Mole ratioacetic acid:high molecular weight acid 10:1 Percent free alkalinity as NaOI-I 0.25 Dropping point, F 500+ Penetrations, 77 F., mm./10

Unworked 220 Worked, 60 strokes 282 Worked, 100,000 strokes 325 Solubility in boiling water Nil Water washing test, percent loss None Wheel bearing test, 6 hours at 220 F Pass I As pointed out above, other low molecular weight carboxylic acids may be used in place of or together with acetic acid. Attempts to manufacture lubricating greases of good structure employing a complex soap thickener consisting of the calcium soaps of formic and high molecular weight acids (particularly hydroxy acids) in which the calcium formate portion predominates have not been entirely successful. This complex soap, while ,dispersible at elevated temperatures, tends to precipitate out on cooling. Homogenization under high rates of shear redis- 16 perses the precipitated soap in a stable form; the resultant product, however, does not thicken to a solid product. -Greases having excellent structural stabilityand still retaining excellent consistency for dispensingin hand or mechanical centralized lubricating systems can be obtained when mixtures of formic and acetic acids are ernployed in the soap thickener complex. This embodiment of the invention isfurther illustrated by the following examples.

EXAMPLE XVI A grease was prepared from the following ingredients.

Ingredients: Wt. percent Formic acid (98-1007 10.0 Hydroxystearic acid 5.0 Hydrated lime 9.4

Naphthenic-type mineral oil distillate having a viscosity of 55 S. S. U. at 210 F 75.60

The hydroxystearic acid and of the mineral oil were charged to the kettle and warmed to 130 P. Then the formic acid was added, followed immediately by the lime slurried in the balance of the mineral oil. Heating was continued to 500 F. while agitating; then the mixture was allowed to cool. 0n cooling the soap appeared to precipitate. Upon homogenization of the'heterogeneous mass a uniform but fluid product was formed.

EXAMPLE XVII A grease was prepared from the following ingredients:

Ingredients:

Acetic acid 5.00 wt. percent. Formic acid 5.00 wt. percent. Hydrofol acid 51.- 2.50 wt. percent. Hydroxystearic act 2.50 wt. percent. Hydrated lime 8.25 wt. percent. Naphthenic-type mineral oil distillate 76.75 wt. percent.

having a viscosity of 55 SSU at 210 F. Preparation: Similar to that described in Example XVI. Properties:

Mole ratio-low:hlgh mol. wt. acid... 10:1. Appearance Excellent smooth homogeneone product. Penetrations, 77 F.,'mm./10

Unworked 238. Worked, 60 strokes 280. Worked, 100,000 strokes 365. Water solubility Insoluble. Dropping point, F 500+. AFBMA tests:

Excellent lubrication of 204 80F bearing. No tendency to 220 "F become fibrous or throw 250 F out ot'bearing. N o leakage through bearing seals. Almen test, weights carried 15 (Good pin condition).

EXAMPLE XVIII A grease was prepared from'the following'ingredients:

Ingredients: Wt. percent Hydrofol acid 51 4.0 Lactic acid, (employed as v85%Iacid) Hydrated lime Naphthenic-type mineral oil distillate having a viscosity of 55 SSU at 210 F 83.8

The hydrofol acid and of the mineral oil were charged to a fire heated grease kettle and warmed to F. The lactic acid was then charged followed immediately by a slurry of lime dispersed in the balance of the mineral oil. The temperature was then raised to 500 F.

17 and the grease cooled while working to 200 F. It was then homogenized, filtered and packaged.

Worked, 60 strokes-.-

Worked, 65,000 strokes 400. Water solubility Insoluble. Almen test, weights earried 15 (good pin condition). N orma-Hoffmann oxidation test, 235.

hours to p. s. i. dropin 0: pressure.

A. F. B. M. A. Testslubrication-no tendency to throw out of }Excellent bearing or leak through bearing seal. Wheel bearing test, 6 hours at 220 F Pass.

The extreme pressure properties of greases of the type described in Examples I-V may be substantially improved by incorporating lead and other extreme pressure additives into these greases as shown by the following examples.

EXAMPLE XIX A lead containing grease was prepared from the following ingredients.

Ingredients: Wt. percent Glacial acetic acid 8.0 Hydroxy stearic acid 4.0 Hydrated lime 6.0 Lead acetate (CH COO) Pb-3H O 2.0 Naphthenic-type mineral oil distillate having a viscosity of 55 SSU at 210 F 80.0

The hydroxy stearic acid, lime and mineral oil were charged to a fire heated grease kettle and mixing started. When the lime was thoroughly dispersed, heating was initiated and the temperature raised to 130 F. The acetic acid was added followed by the lead acetate as the solid salt. Heating Was continued to 460 F. The grease was then cooled while agitating to 200 F. and ,Gaulin homogenized, 1 pass at 5,000 p. s. i.

Properties:

M oled ratio-aeetic :hydroxy stearic 1O :1.

9.01 Appearance Excellent h o m o g e n e o u s smooth grease. Free alkalinity as N aOH, percent... 0.26. Penetrations, 77F., mm./

Unworked Worked, 60 strokes 840.

Worked 92,000 strokes- 380. Dropping point, F 450+. Almen test, weights carried.. (excellent pin condition). Water solubility Insoluble.

Two complex greases A and B free of lead were prepared substantially as described above from the ingredients given below.

The lead containing grease of this example was compared with greases A and B in extreme pressure tests (Shell 4-Ball E. P. test). The results are tabulated below.

Extreme pressure tests 4-Ball E. P. Tests Lubricants Weld, Kg. Sear Spot Load Diameter,

rrn'n.

285 Weld Leaded Grease 252 No Weld 2. 45 224 No Weld 2. 06 Complex Calcium Soap Grease A (No Pb 252 Weld present). 224 N o Weld 2. 39 Complex Calcium Soap Grease B (N o Pb {252 Weld present). 224 No Weld 2. 25

1 Average diameter of scars of 3 balls.

These data show that the leaded grease carries a high load with less attrition of the contacting surfaces, as compared to the lead-free greases.

As pointed out above, the complex soaps of the invention may also be used in the productionof metal Working lubricants, such as drawing compounds or cutting oils.

A product meeting all of the requirements consists in accordance with the present invention of a complex calcium soap of a high molecular weight carboxylic acid and a low molecular weight acid, e. g. acetic acid, wherein the low molecular weight acid forms up to of the complex. This complex soap may be prepared as shown in the following example.

EXAMPLE H A grease-like composition was prepared from the following ingredients.

Ingredients: Wt. percent Acetic acid 10.00 Hydrofol acid 51 5.00 Hydrated lime 7.30

Naphthenic-type mineral oil distillate having a viscosity of 55 SSU at 210 F 77.70

The acetic acid and the hydrofol acid 51 were blended into of the mineral oil and warmed to F. The lime as a slurry in the balance of the mineral oil was then added and the grease heated to 450-500 F forming a solid grease-like base. lowing properties:

This base had the fol- The above base was then diluted 75% with mineral oil and Gaulin homogenized.

The product was of a semi-fluid swabbable consistency and retained a 500 F. dropping point. An Almen test showed the diluted product to have excellent extrem pressure properties carrying 15 weights.

In cutting oils and metal working fluids of the'prior art, the extreme pressure properties are obtained usually by the addition of sulfur, phosphorus and/or chlorine. These materials may be cooked directly into the oil or reacted with other materials, such as fats to form concentrates, and then blended into the oil. These fluids are generally corrosive, and the greater their load-carrying ability the more corrosive their nature. In accordance with the present invention, non-corrosive cutting oils may be obtained having excellent load-carrying ability.

Mineral oils in which the soap additive of the invention periods of storage. The following example illustrates this fact.

.9 EXAMPLE xxr An additive base was prepared from the following ingredients.

Ingredients: Wt. percent Glacial acetic acid 6.4 Hydrogenated castor oil 1.6 Hydrofol acid 51 1.6 Hydrated lime 4.8

Naphthenic-type mineral oil distillate having I a viscosity of 55 SSU at 210 F. 85.6

The hydrogenated castor oil, the hydrofol acid, the lime and the mineral oil were charged to a fire heated kettle and heated to 130 F., while agitating. The acetic acid was then charged and the temperature raised to 500 F. The mass was then cooled rapidly while stirring in the kettle and passed through a Gaulin homogenizer at 5000 p. s. i. Some properties of the base were:

Properties:

. Mole ratio-acetic:high molecular weight acids :1 Free alkalinity as NaOH, percent 0.25 Penetrations, 77 F., mm./10-- Unworked 280 7 Worked, '60 strokes 328 Dropping point, F 500 This 'additivewas blended into a naphthenic mineral oil distillate having a viscosity of 40 SSU at 210 F. in the following concentrations and homogenized by recycling through a Gaulin homogenizer. Extreme pressure data obtained on Shell 4-ball extreme pressure tests along with Scar diameters are shown below. In addition, tests in which a typical sulfurized fatty material (sulfurized sperm oil 12% sulfur content) was added along with the base additive show that the typical E. 'P. additives are not harmed by the addition of the soap butare greatly improved.

Shell 4-.ball-E. P. tests on metal working oils formed by 140 Pass;

Other alkaline earth metal soaps, such as barium and strontium act similarly to the calcium. Other high molecular-weight acids, such as, branched chain Oxo acids, may be employed in place of or in addition to the fatty acids; and naphthenic or sulfonic acidsmay be added to advantage since they tend tofgive a more soluble product.

Other specialty lubricants which may be prepared in accordance with the present invention include twister ring lubricants. In the twisting of cotton or rayon cord, thread or tire cord, the twister ring and traveler are generally grease lubricated. Petrolatum has been found to have the desirable unique structure and adhesive texture desired for ease of application and adhesiveness to the ring. Petrolatum is of relatively low melting point, and any excess temperature rise during .twistingresultsin the petrolaturn melting and dripping from the ring traveler Wear and early failure.

result in an improved lubricant and more extended and extensive service. In related lubricants and the prior art, Bentones and silicagel have been employed as thickeners and melting point improvers. However, the former is expensive and the latter is abrasive.

The high calcium metal content complex soaps of the present invention, which are relatively inexpensive, have been foundto have excellent utility as a means of increasing the melting point of the petrolatum without materially afiecting the consistency or the texture, structure or color. Dispersion of these complex soaps in the petrolatum requires temperatures in the neighborhood of'450500 R, which tends to darkenthe petrolatum. In accordance with a specific embodiment of'the invention, the complex soap is first formed and dispersed in a mineral-oil at the elevated temperatures required for dispersion. The complex soap concentrate so formed is then blended into the petrolaturn without the addition of heat. To improve dispersion, homogenization may be employed beneficially. The formulation and methodo'f manufacture-are described in the following example.

EXAMPLE XXII Preparation 0) complex high calcium metal content soap concentrate Ingredients: Wt. percent Hydrofol acid 51 5.00 Glacial acetic acid 10.00 Hydrated lime 7.30

Naphthenic-type anineral oil distillate having a a viscosity of 55 SSU at 210 F 77.70

The high molecular weight acid was charged to a steam hea'ted kettlewith of the mineral oil and the mixture warmed to 150 F. The acetic acid was added,

' followed 'by a slurry of the lime in the balance of the mineral oil. Heating was continued to 450 500 P. Then the mixture was worked while cooling to 200 F.

The petrolatum and the complex soap were intimately mixed and then Gaulin homogenized to insure uniformity.

However, homogenization is not necessary for satisfactory lubrication.

Properties of finished twister ring lubricant Mole ratio--acetic:hydrofol acid--. 10:1.

Appearance Excellent uniform adhesive lubricant.

Penetration, 77 F., mm./ 10:

Unworked 300. Worked, 60 strokes 320.

Efiect of varying proportions of complex soap on properties of petrolatum Percent Percent Dropping Blends Calcium Petro- Point, Color Base Conlatum F.

centrate Petrolatum 100 100 White. 1 e 4 10 120 D 0 2-- 20 80 300 Yellow 'Iinge. 3 50 50 400 Faint Yellow.

+500 Yellow.

Acceptable.

It will be seen that the dropping point of petrolatum may be raised to about 400 F. by the addition of suitable amounts of complex soap, without excessive discolorationof the petrolatum.

The following examples illustrate the preparation of.

greases from synthetic lubricating oils in accordance with the invention.

Heretofore, silicone fluids have been diflicult to thicken to solid lubricating grease structures due to incompatability with known soap thickeners. However, novel means of employing soap thickeners have been found such as solvent transfer. Inorganic thickeners have been successful to a limited extent, such as copper phthalocyanine, silica gel, bentone and carbon black. However, none of these products have been found entirely satisfactory.

It has now been found that silicone oil greases having excellent properties can be prepared with the aid of the complex soap-salt thickeners of the invention, which have the advantages of both inorganic and organic type soap thickeners. In addition, the raw materials are inexpensive and most readily available.

The silicone oil greases have excellent high dropping points and good structural stability. They are waterinsoluble and water repellent even at boiling water temperatures. The lack of lubricity of the silicone fluid under loaded conditions is improved markedly by the high metal soap content complex thickener which imparts excellent extreme pressure properties. In contrast, lithium soap and the inorganic thickeners impart no load-carrying properties. These greases, their preparation and properties are described below.

EXAMPLE XFQII A grease was prepared from the following ingredients:

Ingredients: Wt. percent Glacial acetic acid 10.00 Hydrofol acid 51 5.00 Hydrated lime 7.30

Silicone fluid 710 77.70

A methyl phenyl silicone of high phenyl content.

The acetic acid, hydrofol acid and of the silicone fluid were added to a fire heated grease kettle and warmed to 150 F. At this temperature the lime dispersed as a slurry in the balance of the silicone fluid was charged. The mass was further heated to 500 F. to promote complex formation. The anhydrous product when cooled was of excellent grease structure which was further enhanced by Gaulin homogenization. The properties were as The hydrofol acid, hydroxy stearic acid and /a of the ester and the silcone fluid 710 were charged and heated to 150 F. At this temperature the acetic acid was added, followed by the hydrated lime as a slurry in the balance of the ester. The mass was then heated to 450-500 F. and cooled while stirring. The phenyl alpha-naphthylamine was added at 300 F. while cooling and the grease further cooled to 200 F. The grease was of excellent stable structure.

Properties:

Mole ratioacetic: high molecular weight w acids 10:1 Dropping point, F 500+ Penetrations, 77 F., mm./l0

Unworked 295 Worked, 60 strokes 315 Worked, 75,000 strokes 355 Water solubility Insoluble in boiling water EXAMPLE XXV A base grease was prepared from the following ingredients substantially as described in Example XXIV.

Ingredients: Wt. percent Glacial acetic acid 10.00 Hydrofol acid 51 2.50 Hydroxy stearic acid 2.50 Hydrated lime -r 7.30 Di-iso-octyl azelate 77.70

This grease was mixed with an equal quantity of silicone fluid 200 (a methyl phenyl silicone of high methyl content, 10 cs. viscosity at 25 C. grade) without heating. The mixed grease which was soft and very unhomogeneous was then Gaulin homogenized to form an excellent smooth grease having excellent properties.

Properties:

Mole ratioacetic: high molecular weight acids 10:1 Dropping point, F 500+ Penetrations, 77 F., mm./10

Unworked 310 Worked, 60 strokes 325 Water solubility Insoluble in boiling water In the lubrication of the bearings of jet engines, hinges on oven and furnace doors, car wheel bearings entering kilns, and other services where extremely high temperatures are involved, mineral oil lubricants have been found unsatisfactory. The fluid portion of these lubricants is evaporated leaving a soap residue which tends to carbonize, causing bearing failure and, at the least, lack of lubrication. It has been shown heretofore that complex esters having multiple ester linkages, for example: the systems mono-basic acidglycol-dibasic acidglycolmonobasic acid-monohydric alcohol dibasic acid polyglycol-dibasic acidmonohydric alcohol, etc., have exceptional lubricating qualities at elevated temperatures. Complex esters of this type are disclosed in U. S. Patent Nos. 2,575,195; 2,575,196; and others as well as in the copending Smith application, Serial No. 52,429, filed October 1, 1948, now U. S. Patent 2,703,811. It has now been found that solid grease lubricants useful at high temperatures can be prepared from such complex esters employing as a thickening agent the soap-salt complexes of the invention, particularly the alkaline earth metal complexes as such as the complex calcium soap in which.

calcium acetate forms a major portion.

Greases of this type give excellent lubrication in the moderate high temperature range of 300-400 F. In the range of 500 F. and higher, they continue to act as a lubricant where few other materials have been successful. In this range, even the complex or polyesters tend to volatilize. When this occurs with the lubricant of the invention, a residue of calcium soap from the high metal content complex soap thickener remains firmly attached to the lubricated or rubbing surfaces. This extremely stable residual material acts as a lubricant and has been found to have excellent extreme pressure properties. It is postulated that the calcium fluxes with the surface of the metal and prevents welding and acts as a lubricant. An example of a lubricant of this type, with pertinent properties is shown below.

23 EXAMPLE XXVI Ingredients: Wt. percent Hydrofol acid 51 5.0 Glacial acetic acid 10.0 Hydrated lime 7.4 Phenothiazine 1.0

Polyester lubricating oil (monohydric alcoholdibasic acid-polyglycol-dibasic acidmonohydric alcohol; B. P. 446 F. at 0.15 mm.

Hg; viscosity 9O SSU at 210 F., 513 SSU at 100 F 76.6

Properties:

Mole ratio-acetic: hydrofol acid 10:1. Appearance Excellent smooth grease. Dropping point, F 500+. Penetrations, 77 F., mm

Unworked 240. Worked, 60 strokes 260. Worked, 100,000 strokes" 335 Water solubility Insoluble in boiling water. Mufile furnace test:

16 hours 550 F Surface charred. Balance of grease in good condition. 30 minutsn at 700 F Surface charred.

Extreme pressure properties, weights 15.

carried on Almen machine.

Norma-Hofimann oxidation, hours to 375.

p. s. i. in 0: pressure.

A lubricant complying with the requirements for semifiuid gear lubricants can be prepared in accordance with the invention by incorporating into lubricating oil a high metal content soap-salt complex in which the .mole ratio of low molecular weight acid to high molecular weight acid is extremely high, say at least 30:1 and preferably at least 40:1. It has been shown above that when the ratio by weight of the low molecular weight acid to high molecular weight acid is 2:1 a solid grease lubricant is formed at relatively low total thickener concentrations. However, when the amount of low molecular weight acid is increased to a weight ratio of 9 parts of the low molecular weight acid to 1 part of the high molecular weight acid at similar total thickener concentrations, no solid grease structure is formed but F rather a semi-fluid product having excellent extreme pressure properties and structure desired for gear lubrication. This is further illustrated by the following example.

EXAMPLE )QiVH A lubricant was prepared from the following ingredients:

Ingredients: Wt. percent Hydrogenated castor oil 1.00 Acetic acid 9.00 Hydrated lim 6.15

Naphthenic-type mineral oil distillate having a viscosity of 55 SSU at 210 F 83.85

The fat and of the mineral oil were charged to a fire heated kettle and warmed while stirring to 150 F. The acetic acid was added followed by a slurry of hydrated lime in the balance of the mineral oil. Heating was continued to 500 F. Thereafter, the mixture was cooled while stirring to 200 F. On standing there was some indication of settling out of soap. The product was mixed and then homogenized. The resulting product was stable, homogeneous and smooth. After one month storage there was no indication of settling or separation of components.

Properties:

Mole ratio-acetic: high molecular 45:1.

weight acids. Consistency Semi-fluid.

Extreme pressure properties, Almen 15Good pin condition.

test, weights carried.

Heat test, 400 F Grease starts to thin out.

Approaching oil viscosity.

The consistency and stability of this grease is suitable for dispensing from conventional centralized lubrication systems employing spray valves which meter lubricants to sliding surfaces and open gearing.

This invention also permits the production of detergent motor oils. More specifically, it has been found that the new high metal content soap-salt complexes of the invention represent additives capable of imparting detergency characteristics to motor oils. This is particularly true for alkaline earth complex soaps in which a high molecular weight fatty acid, a sulfonic acid and a low molecular weight acid are coneutralized to form the soap. By this method, very high metal content soaps may be incorporated in oil to impart detergency in addition to excellent extreme pressure properties.

In the prior art many materials, particularly alkaline earth soap additives, have been suggested and found to have value as detergents in modern automotive engine oils. However, it has been found that a high metal content is desirable. The present invention provides the means of incorporating such high metal content additives in motor oils as shown in the following examples.

EXAMPLE XXVIII An additive was prepared from the following ingredients:

Ingredients: Wt. percent Calcium sulfonate (30% calcium sulfonate in The calcium sulfonate-mineral oil solution, hydrofol acid 51 and the acetic acid were dissolved in of the mineral oil by heating to 150 F. A slurry of the hydrated lime in the balance of the mineral oil was then added and heating continued until all water was driven 011 and the temperature raised to 450 F. At this temperature the mass solidified. The product was cooled and blended into a heavy duty mineral lubricating oil base in a 5% concentration.

. Wt. percent Above complex soap-mineral oil base 5 Heavy duty mineral lubricating oil base (viscosity 469 SSU at 100 F.; 63.1 SSU at 210 F.; viscosity index The finished lubricating oil of Example XXVIII was homogenized and submitted to viscosity tests and to an additive mineral oil screening test as reported in the table below.

Properties of additives and oil blends of Example XX VIII Properties of additives:

Dropping point, F 500+ Penetration, 77 F., mm./10

Unworked 220 Worked, 60 strokes 300 Properties of oil blends, 5% base in heavy duty mineral base:

As pointed out above, the complex soaps of this invention may be added to residual fuel oils to improve various characteristics of the latter. stable fluid dispersion of a soap of high metal content may serve as an additive to residual fuels to prevent boiler and stack corrosion. For example, a complex soap may be formed by the coneutralization of a monobasic high molecular weight carboxylic acid and a low molecular weight monobasic with an alkaline earth hydroxide or mixture of hydroxides in situ in a mineral oil or residual fuel. The concentrate so obtained may then be diluted to the desired concentration and stabilized by homogenization or milling under relatively high rates of shear. This modification of the invention is illustrated by the following example.

EXAMPLE XXIX A composition suitable for use as a fuel oil additive was prepared from the following ingredients:

Naphthenic-type mineral oil distillate having a viscosity of 55 SSU at 210 F 77.70

The hydrofol acid and /s of the mineral oil were mixed and heated together to about 150 F. The acetic acid and, immediately thereafter, a slurry of the hydrated lime in the balance of the mineral oil were added to the mixture. The temperature was then raised to about 250- 300 F. and the water driven off. The temperature was then further raised to 450-500 F. where the mass became solid. Heating was discontinued and the mass cooled to 200 F. while stirring. The cooled product was of ..smooth unctuous consistency. It contained about 4 wt. percent of calcium and the mole ratio of acetic to hydrofol acid was about 10:1.

The product so prepared was added to a bunker fuel oil containing about 292 parts per million of vanadium to obtain a mixture with a calcium content of about 0.105 wt. percent. The weight ratio of calcium to vanadium in the fuel oil mixture was about 2.75:1. The fuel oil so treated was passed through a Manton-Gaulin homogenizer. The resultant fuel oil was stable, showed no separation on storage for 17 days at 150 F., uniform distribution of the calcium in the fuel oil and no calcium separation upon centrifuging at 115 F. and 1500 R. P. M. for 5 minutes.

The soap-salt complexes of the invention are also capable of improving the water resistance or water repellancy of thin film rust preventives based on asphalts, Waxes or resinous materials forming thin protective films. Rust preventives of this type may contain about 0.5-l0 wt. percent, preferably about 1-5 wt. percent, based on total composition, of a soap-salt complex containing as much as 40 moles and preferably about 7-20 moles of low molecular weight acid for each mole of high molecular weight acid. This embodiment of the invention is illustrated by the following example.

EXAMPLE XXX An oxidized asphalt having a softening point of from 180-200 F. was blended with a concentrated form of the complex calcium soap dispersed in mineral oil by heating and mixing at 300 F. This blend was then cut back to the desired viscosity with an aromatic solvent.

The complex soap concentrate was prepared from the following ingredients:

Ingredients: Wt. percent Glacial acetic acid 8.00 Hydrofol acid 51 4.00 Hydrated lime 6.00

Naphthenic-type mineral oil distillate having a viscosity of 55 SSU at 210 F 82.00 Mole ratio-acetic:hydrofol acid, 10:1.

In particular, a colloidally The hydrofol acid, mineral oil and the lime were blended together and heated to 130 F. The acetic acid was then added and heating continue to 500 F. The mass was then cooled to 200 F. and homogenized. This concentrate may be prepared directly in the asphalt if the mineral oil is undesirable in the finished product for any reason.

Test steel panels were dipped in the cutback blend, dried for 24 hours in air before being submitted to the salt spray test described in detail in the Federal Specification TTP141.b. relating to paints, varnish and lacquers and related materials under Method No. 606.1 January 1949. After 8 days in this salt spray test the panels were removed and inspected. The results are summarized below.

Material Rusting After 8 Days Light, scattered rusting. Some few rust spots. No rusting.

In the preparation of the rust preventive, salt-soap complexes of higher mole ratios (30:1) may be dispersed in the aromatic solvent and then added to the asphalt while diluting to desired viscosity.

The invention is not limited to the specific figures of the foregoing examples. The relative proportions of the constituents of the various products may be varied within the limits indicated in the general portions of the specification. The composition prepared in accordance with the invention may contain various conventional additives, such as inhibitors, dyes, metal deactivators, corrosion preventatives, deodorants, etc., as will be understood by those skilled in the art.

What is claimed is:

1. A method of preparing a soap-salt complex which comprises admixing in an organic liquid dispersant an alkaline earth metal soap of a carboxylic acid containing in the range of 12 to 30 carbon atoms per molecule and calcium acetate, the molar ratio of acetate to soap being in the range of 7:1 to 45: 1, and heating the admixture to a temperature in the range of 450 to 550 F.

2. The method of claim 1 wherein said metal soap is prepared by neutralizing said acid with lime While said acid is in admixture with said calcium acetate.

3. A lubricant comprising a major proportion of a lubricating oil and in the range of 0.5 to 30 wt. percent of a complex prepared at a temperature in the range of 450 to 550 F., said complex consisting of an alkaline earth metal soap of high molecular weight organic acids and calcium acetate, said acids containing at least 20 wt. percent of a carboxylic acid having in the range of 12 to 30 carbon atoms per molecule and the molar ratio of acetate to soap being in the range of 7:1 to 45:1.

4. The lubricant of claim 3 wherein said metal soap consists of carboxylic acid soaps containing in the range of 18 to 22 carbon atoms per molecule, wherein said molar ratio is in the range of 8:1 to 25:1, and wherein said lubricant contains 0.5 to 10 wt. percent of said complex.

5. The lubricant of claim 3 wherein said metal soap contains in the range of 25 to wt. percent of an oilsoluble sulfonate having a combining weight in the range of 350 to 525.

6. The lubricant of claim 3 wherein said lubricating oil has a viscosity in the range of 35 to 200 SSU at 210 F., and a flash point in the range of 350 to 600 F.

7. A lubricating grease comprising a major proportion of a lubricating oil and a minor grease-making proportion of a complex prepared at a temperature in the range of 450 to 550 F., said complex comprising an alkaline earth metal soap of a soap-forming acid having in the range of 12 to 30 carbon atoms per molecule combined 27 with calcium acetate, the molar ratio of acetate to said soap fdrming "acid being in the range of7z1 t'452'1.

8. The lubricating grease'of' claim 7 wherein s'ai dcomplex comprises -in the range of 10 to 20 wt. percent thereof, a'n'd said soap consists of the calcium soaps of hydrogenated castor oil and hydrogenated 'fishoil acids.

9. The lubricating grease of claim 7 wherein said grease-making proportion is in the range of to 30 wt. percent.

10. -'A lubricating grease composition comprising a major proportion of a-mineral lubricating oil andin the range' of 5 to 30'wt. percent, based on total composition, of a grease-forming complex consisting of the calcium soa'p of hy'droxy stearic acid combined with calcium acetate, the-molar ratio-of acetate to hydroxy stearic acid being in the range of 7:1 to 45:1, andsaid complex beingprepared'ata temperature in the range of 450 to 550 F.

References Cited in thefile ot this-patent UNITED STATES PATENTS 243,154 Pickert June 21,1881 1,073,129 Horn Sept. 16, 1913 1,752,309 Rosenbaum Apr. 1, 1930 2,211,921 Brunstrum Aug. 20, 1940 2,262,815 Northum Nov. 18, 1941 2,345,061 Miles -Mar.-28, 1944 "2,417,428 McLennan Mar. 18, 1947 2,417,429 McLennan Mar. 18, 1947 28 2,417,430 McLennan Mar. 18, 1947 2,417,432 'McLennan Mar. 18, 1947 "2,417,433 McLennan Mar. 18, 1947' 2,455,886 Ariente Dec. 7,1948 2,455,892 Fraser Dec. 7, 1948 2,468,098 Morway et a1 Apr. 26, 19.49 2,487,080 Swenson Nov.8, 1949 2,553,422 QHalloran May 15,1951 2,553,423 Shepard May 15, 1951 2,564,561 Carmichael et a1 Aug. 14, 1951 2,573,049 Olson 061.30, 1951 2,575,286 Morway et a1. Nov. 13, 1951 2,583,607 'Sirianni et al. Dec. 3, 1951 2,584,041 Nowak Jan. 29, 1952 2,588,279 'OHallorau Mar.'4, 1952 2,607,735 Sproule et a1. Aug. '19, 1952 2,618,599 King et 'a1. Nov. 18, 1952 2,626,897 Young 1311.27, 1953 2,628,195 Allison et a1. Feb. 10, 1953 2,628,202 Allison et a1. Feb. 10, 1953 FOREIGN 'PATENTS 1,975 Great Britain 1857 OTHER REFERENCES Boner: Lubricating Greases, Reinhold Publishing (10., New York (1954), pages 627 to -629, 631,645.

The Institute Spokesman, vol. 14, No. 12 (March 1951), pages-7-23.

Claims (1)

1. 3. A LUBRICANT COMPRISING A MAJOR PROPORTION OF A LUBRICATILNG OIL AD IN THE RANGE OF 0.5 TO 30 WT. PERCENT OF A COMPLEX PREPARED AT A TEMPERATURE IN THE RANGE OF 450* TO 550*F., SAID COMPLEX CONSISTING OF AN ALKALINE EARTH METAL SOAP OF HIGH MOLECULAR WEIGHT ORGANIC ACIDS AND CALCIUM ACETATE, SAID ACIDS CONTAINING AT LEAST 20 WT. PERCENT OF A CARBOXYLIC ACID HAVING IN THE RANGE OF 12 TO 30 CARBON ATOMS PER MOLECULE AND THE MOLAR RATIO OF ACETATE TO SOAP BEING IN THE RANGE OF 7:1 TO 45:1.