US2898297A

US2898297A - Grease composition and method of preparation thereof

Info

Publication number: US2898297A
Application number: US783158A
Authority: US
Inventors: John E Schott
Original assignee: Socony Mobil Oil Co Inc
Current assignee: ExxonMobil Oil Corp
Priority date: 1958-12-29
Filing date: 1958-12-29
Publication date: 1959-08-04
Anticipated expiration: 1976-08-04

Description

Un St te Pam-Q {F GREASE COMPOSITION AND METHOD. or I PREPARATION THEREOF John E. Schott, New York, -N.Y., assignor to Socony Mobil Oil Company, Inc., a corporation of New York No Drawing. Application December- 29, 1958 Serial No. 783,158

19 Claims. Cl. 252-46) I r 2,898,297 Patented A g- It has now been found that a grease characterized by all of the foregoing desirable properties can be prepared from certain soaps and salts of the following acids, interrelated as shown below: g I I Wt. Per- Acld No. otOarbon cent of Atoms Total Acid Low Molecular Weightl- 10-50 Intermediate Molecular W 7-12 5-50 Hlgh Molecular Weight 13-22 or more. 6-40 Coconut Oil Acids 6- 26-60 It is to be understood that the coconut oil acids generally' constitute about 86 to about 89% by weight of coconut oil.

.' The foregoing percentage ranges are applicable broad- 1y to the grease compositions of this invention." With blends of oils having a viscosity of about 70seconds (S.U.V.) at 210 F., and a V1. between 0 and 60, the

optimum percentage range is the following:

effectiveness when subjected to severe operating condi tions, and particularly when subjected to high temperature operations. In lubricating machine parts, for example, it is essential that a grease retain its useful form; failure to do so results in a high consumption of the grease and frequent servicing. In general, available greases suffer from a marked tendency to change in character when used over a wide range of temperature, notably at high temperatures of the order of 250350 F. and higher. Some conventional greases are characterized by excessive softening when exposed to such high temperature operations, thereby being expelled too rapidly from the area being lubricated to provide eflicientjpbrication.

The action of waterwhether salt or fresh watermay cause the grease to thin out into a liquidwhich leaks out from the lubricated surfaces." This is a prime consideration inasmuch as grease-lubricated machine parts are encountered in port installations, on deck of navy and marine vessels, in steel rolling mills, in water pumps of all kinds, in mining machinery, in oil-well} drilling equipment, etc. high operating temperatures develop, such that even lime base greases, which are highly resistant to water, become unstable. While a number of modifying agents have been incorporated in various grease types 'to improve their In many of such instances, relatively stability, such modifying agents have generally beeri'relatively expensive and some have depreciated one or more other desirable characteristics of the grease.

On the other hand, many ofthe'past and presentday greases have failed to provide resistance to corrosion in humid air ofthe machine parts which the greases should protect. Such greases have generally been hygroscopic in character and, as a result, harden appreciably. In this respect, they have proven inadequate.

Present day demands for greases have also given rise to the need for greases characterized by excellent extreme pressure character, oxidation stability and long bearing performance life. -While some success has been realized in providing greases withextreme pressure characteristics, for example, the greases so characterized have fallen far short of having satisfactory oxidation stability or good bearing performance. Corresp ondingly there has been success in the development of greases having a high degree of oxidation stability; but, here again,- the same grease will generally'have an undesirably low extreme pressure value.

Acid: I Wt. percent of total acid Low molecular weight 28 Intermediate molecular weight 17 High molecular weight 14 1 "Coconut oil acids 41 ,That .this relationship is critical is revealed by the fact that when an insufficient quantity of a low molecular weight acid, such as acetic acid, is used, the grease made therewith .is semi-fluid and has an undesirably low drop-- ping point. correspondingly, an excessive amount of an acid such as acetic produces a soap structure which is diflicult, if not impossible, to disperse in a stable state in the oil vehicle. A similar influence is seen in the use of too' little, or an excess of an intermediate molecular weight acid, such as caprylic. An insufl'icient quantity of caprylic acid generally causes 'the product to harden excessively in storage; and an excess of caprylic acid causes the product to bleed excessively in storage. An improper balance is realized, too, when an insufficiency or excess of high molecular weight acid, such as stearic is used. Too little stearic acid results in a product of excessive fluidity in oilbl eeding instorage and poor worked stability; and an excess of stearic acid is responsible for undesirable changes in storage, lowered dropping point, and poor response to water contamination. ,7 Typical of'the low molecular weight acids contemplated herein are: aCGilC PIOPiOHiC, butyric, valeric, and caproic, Of these, acetic is particularly desirable because it provides outstanding products. f 7 Typical of intermediate molecular weight acidsare: heptanoic, caprylic,pelargonic, capric, lauric; monohydroxy substituted acids such as alpha-hydroxy decanoic, mixed unsubstituted C C C having 'a methyl side chain, such acids being obtained by the Oxo process. Caprylic, capric and pelargonic are particularly advantag'eous of such acids.

Illustrative of the high molecular weight monoca'rboxylic acids of the invention are: saturated aliphatic acids such as myristic, palmitic, stearic, etc.; mono unsaturated aliphatic acids such as oleic; mono hydroxy substituted acids such as 12-hydroxy stearic ,acid. Prefe'rred are the unsubstituted saturated acids, particularly stearic and palmitic' acids. i

It is to be understood, of course, that more thanone acid of a given type can be used so long as the balance recited above is maintained. g As i ndioateid above, another component of the greases of this-invention going to make up the desired soaps, is coconut oil. This oil contains glycerides, a large proportion of the fatty acids of which have from about 3 12 to about 14 carbon atoms per molecule. As is well known in the art, however, coconut oil also contains other glycerides the acids of which have as few as about 6-10 carbon atoms per molecule and other acids which have as many as about 18 carbon atoms-per molecule. In addition to the said acids, there is the equivalent of about 11 to about 14% by weight of glycerine in coconut oil. A typical coconut oil used herein has the following characteristics:

Total 100.0

As shown hereinafter, greases of superior quality are obtained when either coconut oil or comparable quantitiese of glycerine and coconut oil fatty acids, are used. However, greases formed from coconut oil according to this invention, are exceptionable with respect to oxidation stability and, for this reason, coconut oil is particularly preferred.

In addition to coconut oil, and its saponification products coconut oil fatty acids and glycerine, other nut or kernel oils in which the fatty acids are predominantly in the C -C range are considered suitable for use in preparing the greases of this invention. Typical of such oils are palm kernel oil and babassu kernel oil. The distribution of acids present in such oils is given below, weight percent being shown:

Capr

Caprylic Palm kernel and babassu kernel oils contain approximately the same percent by weight of glycerine as coconut oil. The kernel oils can be used in place of or together with coconut oil. Here too, it is contemplated that the kernel oils be used or that compararble quantities of glycerine and the kernel fatty acids be used.

The metal component of the salts and soaps formed from the foregoing acids, in the preparation of the greases of this invention, is primarily calcium. However, as much as about to about 15 %--on a chemical equivalent basis-of the calcium used may be replaced by barium such that the finished grease will contain a mixture of calcium and barium soaps. The corresponding metal oxides, metal hydroxides and metal carbonates can be reacted with the aforesaid acids in order to provide the desired salts and soaps.

In addtion to the salts and soaps described above, the greases contemplated herein contain a lead compound. A lead compound or compounds are formed in situ by means of reaction between the said acids and leadr ever, it is also contemplated herein, that a lead compound of any one or more of the acids of the character recited above can be incorporated into the grease rather than being formed in situ.

Another component of the greases of this invention is a chlorine-containing, sulfur-containing, chlorine-andsulfur-containing, phosphoruscontaining, phosphorusand-chlorine-containing, phosphorus-and-sulfur-containing, or phosphorus-and sulfur-and-chlorine-containing organic compoundiknown in the art as an extreme pressure agent. Among such compounds are the following, which are particularly effective and as such are preferred:

Methyl dichlorostearate Chlorinated sperm oil one example of which is Alpha- Chlor 33 Sulfurized sperm oil Sulfurized lard oil- Aryl, alkyl and alkyl-aryl phosphates typical of which is tricresyl phosphate Alpha-Chlor 33" is a chlorinated sperm oil. It is sold by the Carlisle Chemical Works under the trade name Alpha-Chlor 33 and is described by its properties in the following manner:

Chlorine, percent by weight 33.

Lbs/gal. at 60 F. 9.6.

Pour point, F. 5.

Flash point None.

Viscosity, 210 F., SSU 200.

Solubility Completely soluble in most petroleum oils, partially soluble in solvent refined oils.

The mineral oil component of the greases of this invention can vary considerably in character. In general, such oils are characterized by a viscosity (S.U.V.) greater than about 40 seconds at F., preferably from about 60 to about 6,000 seconds at 100 F. It has been'found, however, that the character of mineral oil used materially influences the character of the grease composition. A blend of a solvent-refined naphthenic oil having a' viscosity of 500 seconds at 100 F., and a viscosity index of 60, when blended with a naphthenic bright stock having a viscosity of -140 seconds at 210 R, such that the final blend has a viscosity at 210 F. of about 70, has proven to be particularly desirable.

In place of all or part of the mineral oil component, other oils of lubricating viscosity can also be used, such oils including synthetic vehicles comprising esters of dibasic acids. Typical of such synthetic oils are: di-(2- ethyl hexyl) sebacate, dibutyl phthalate, di-(Z-ethyl hexyl) adipate. Other suitable synthetic oils are esters of poly alcohols and'monocarboxylic acids, such as polyethylene glycol di-(Z-ethyl hexoate).

The oil component or vehicle, and the components mentioned herein above, are usedin the grease compositions in the proportions (percent by weight of the finished grease composition) as indicated in the following tabulation:

It has been found that greases of outstanding character are realized when a novel technique or procedure is followed. It appears that the order of these steps is critical in' nature, since departure from the said order results in a less advantageous product. By way of illustration, a batch of grease 'is formed in the manner described in Example 1 below.

Mineral oil solvent refined naphthenic oil,

60 V.I., 500 sec., S.U.S. at 100 F. 56 lbs.

Lime flour 9 lbs. 7 oz. Acetic acid 8 lbs. 5 oz. Water 4 lbs. Caprylic acid. 5 lbs. Coconut oil 12 lbs. 11 oz. Hydrogenated tallow fatty acids 4lbs. 3 oz. Litharge 3 lbs.

The agitator of the Stratco contactor is in motion at all times during the addition of the aforesaid materials. The contents of the contactor are heated to about 345 F. by means of the hot oil circulating system forming a part of the Stratco contactor. Approximately one hour is required to heat the contents from the initial temperature of 250 F. to about 345 F. The pressure within the contactor reaches a value of about 100 lbs/sq. in. under such conditions. Heat is discontinued and the contents are transferred (blown over) into a preheated steam kettle which is of the open paddle kettle type.

The course of reaction is determined by withdrawing a sample of the soap from the contactor. In a typical preparation, the alkalinity of the contents, determined as percent by weight CaO, is between about 0.5 and about 0.7%. (Determined in accordance with ASTM Method Dl28-47, modified by using a 50-50 mixture of water and alcohol.) When the alkalinity value is within this range the contents are dehydrated.

When the materials from the contactor are transferred to the open paddle kettle, the temperature thereof drops to about 300 F. as a result of moisture loss and as a result of the influence of atmospheric temperature; The materials now in the open kettle are heated and paddled for about 1 /2 hours at 300 to 320 F. Thereupon, 44 lbs. of the oil described above and 30 lbs. of a naphthenic bright stock having a viscosity of 130-140 seconds (S.U.S.) at 210 F. and a V.I. of less than 0, are added. Heating of the open kettle is discontinued and the contents thereof are recycled through a high pressure homogenizer as described in Armstrong Patent 2,704,363, at about 3,000 lbs. per sq. in. until the temperature drops to about 180 F. When the temperature is about 190 F., a quantity (5 lbs. 3 oz.) of Alpha-Chlor 33 is added. The worked penetration is adjusted to about 290-300 by adding a mineral oil blend to the product. The mineral oil blend comprises an 80-20 mixture of the initial oil and of the naphthenic bright stock, respectively, described above. This will generally call for from 0 to about lbs. of oil blend in order that the penetration value be realized. The product is then filled in packages through the homogenizer at 3,000 lbs. per sq. in. at 180 F.

Typical results of pilot plant batches, such as the batch described hereinbefore, are given below in the following tabulation:

holes -2 Oxidation stability, 1b. drop in hours, ASTM Bomb at 210F- l0#/200 hrs. with no oxidation inhibitor. Oxidation stability, lb. drop in hours, ASTM Bomb at 210 F 4#/500 hrs. with 0.5%

i Ionol.

Penetration 290/390...

Separability in percent, 100' hrs.,

' 7.5#/sq. in. pressure at 77.F .4.9. Bleeding, in percent, 50 hrs-at 210 F., MIL-G-3278 3.5. Dropping point, F .500 plus. Salt spray, M]L-G10924.. 100 hours plus. Performance life in loaded Navy I tester at 257 F. 15.00 hrs. without oxi I dation inhibitor. Performance life in loaded Navy tester at 257 F 3500 hrs. with, 0.5

I I I 1 Ionol. Apparent viscosity at F.... 860. I Apparent viscosity at 0 F-. 3300.

Several unusual features are shown in the aforesaid tabulation of data. It is to be noted that an extreme pressure value as high as 45 pounds, together with'excellent oxidation stability and'long bearing performance life, is a relationship not hitherto realized in the prepare. tion of greases. High extreme pressure values have been obtained in the past but a grease so characterized has not had satisfactory oxidationstability or bearing performance life at elevated temperatures such as 200 F. and above. I

Similarly, excellent oxidation stability or bearingperformance life have been realized yet the extreme pres-.

. sure value has been lacking or so low as to be negligible.

Here, for the first time, all three features are together in excellent balance. I 7

Results obtained with other typical greases of this invention are shown in Table I below. In the greases shown here, extreme pressure agents other than Alpha- Chlor 33 were used in the grease, containing the latter, defined hereinabove.

I Table I Timken ASTM Motormatic Extreme Pressure Agent, Percent OK Penetra- Worker Test,

by Wt. Load, tions 5,000XP9D8! Lbs.- tratlon Methyl dichlorstearate, 2.6 35 208/212 255 Methyl dichlorstearate, 5.2 40 235/238 346 Sulfurized lard oil, 5.0 45 224/244 277 Tricresyl phosphate, 2.6 -4--. 40 207/226 289 The nature of present invention is illustrated further by the following examples, wherein products were formed with either barium or sodium substituted for calcium in the grease described by Example 1. Com parison is then set out in Table ll of the calcium grease and the products formed with barium and with sodium.

EXAMPLE 2 The materials usedare the following: Mineral oil, solvent refined, 500 S.U.S. I 4

F 20 pounds. Barium hydroxide octahydrate 20 pounds. Acetic acid 4 pounds 2% oz. Caprylic acid 2 pounds 8 oz. Coconut oil 6 pounds. Hydrogenated tallow fatty acids 2 pounds 1 oz. Litharge 1 pound 8 oz.

. EXAMPLE 3 .The Stratco contactor'was preheated to 220 F. and

the following materials were charged thereto in the order in which they are listed below:

Mineraloil, solvent, refined, naphthenic, 60 V.I., '500 secs. S.U.S. at

100 F 56 pounds. Sodium hydroxide 10 pounds. Acetic acid 8 pounds oz. Water 4 pounds. Caprylic acid 5 pounds. Coconut-ohm... 12 pounds 11 oz. Hydrogenated tallow fatty aeids -4 pounds 3 oz. Litharge 3 pounds.

' As in Example 2, the charge was heated to 345 F. One hour and 15 minutes were required to heat the charge from 220 F. to 345 F. A pressure of 100 psi. developed in the contactor. The reaction mixture was blown over into a 120 pound drum, and was then transferred to a hot steam kettle. The mixture from theStratco'was soft and mushy. The alkalinity was determinedto be 0.90 percent by weight of sodium hydroxide; this was determined by ASTM Method D128-47, modified as indicated above.

The reaction mixture was heated in the steam kettle for 1 /3 hours, when a temperature of 320 F. was reached. Heating of the kettle was continued for 1 /2 hours. Fifty pounds of grease was removed from the kettle. Twenty-two pounds of the same oil as used in the charge, was added to the balance of the reaction mixture remaining in the steam kettle. Heating of the steam kettle was discontinued. The contents of the steam kettle were then homogenized at 3000 p.s.i. in a Manton Gaulin unit. The homogenized product was cooled from 320 F. to 180 F. during a 1 /2 hour period. Alpha-Chlor 33, 2 pounds and 6 ounces, were then added to the cooled product. The unworked and worked penetrations of the product were in excess of 420.

Comparison of the products formed in Examples 1, 2 and 3 are shown in Table II, following.

Table II Example No 1 2 3 Type ofSoep Ca1cium Barium Sodium. Acetic Acid, wt. percent" 4.67 4.67 4.67. Caprylic Acid, wt. per- 2.81 2.81 2.81.

cent. Coconut Oil, wt. percent; 7.14 7.14 7.14. Hydrogenated Tallow 2.36 2.36 2.36.

Fatty Acid, wt. percent. Litharge,wt.percent -1.69; 1.69 1.69. Mineral Oil Balance Balance Balance. Metal Component Calcium Barium Sodium. CaleiumIonEquivalentL- 2.95 2.95 2.95. Type of Product- Buttery Semi-Fluid Semi-Fluid. Pen etrlgtim, Unworked/ 2901300.. 420+/420+ 420+/420+.

or e 1 2.05 equals 5.47 weight percent of own).

40 X5A7-a95 As shown by Examples 1 through. 3 calcium is useful in forming excellent greases of the character contemplated herein, whereas. barium and sodium can not be used in place of calcium. Although a complete substitution' can not be made, a minor proportion. of calcium can be replaced bybarium. This is demonstrated by Example 4 following. 1 r

' EXAMPLE 4 A grease was formed from the following materials:

. p Wt. percent Mineral oil, identifiedin Example 1 56.75. Naphthenic bright'stock in Example 1 18.70 Lime 4.45 Barium hydr 0.50 Litharge 1.50 Acetic aci 4.16 Caprylic acid 2.5 Coconut oil 634 Hydrogenated tallow fattyacids 2.5 Alpha-Chlor 33 2.6

The procedure used in preparing this grease involved charging a Stratco contactor with the components listed, except for the naphthenic bright stock and Alpha-Chlor 33 and one-half of the mineral oil. The charge was heated and maintained at 320-330 F. for two hours at a pressure of 40-45 p.s.i. Pressure was then reduced to atmospheric. The charge was heated at 320-330 F. for an additional 2 hours, during which time the remaining one-half of the mineral oil was added thereto. Heating of the contactor was discontinued. The naphthenic bright stock was added. The resulting mixture was cooled to 170 F. Alpha-Chlor 33 was added. The product was then homogenized thru a Charlotte mill, having a clearance of 0.002 inch. The product had an alkalinity of 0.27% CaO (determined as identified above). The grease so formed had the following characteristics:

Peneration, worked/unworked 294/312 ASTM Motormatic worker test after 5000 strokes with A" 354 As revealed by the foregoing properties, a satisfactory grease is formed by replacing some of the calcium component with barium. However, when as much as twenty percent (chemical equivalent basis) of the lime used was substituted by barium hydroxide octahydrate, a semi-fluid product was obtained.

Comparison has also been made of the calcium grease described in Example 1, above, in which coconut oil was used, with a grease prepared with comparable quantities of glycerine and coconut oil fatty acids. The latter grease is described in Example 5 below.

EXAMPLE 5 The following charge was added to a Stratco contractor, which had been preheated to 250 F.:

Mineral oil, solvent refined naphthenic,

developed in the contactor. The reaction mixture was blown over into a pound drum and was then transferred to a hot steam kettle. The mixture was firm. After the mixture had been paddled in the kettle for 15 minutes, a sample was taken for an alkalinity determination; the mixture had an alkalinity of 0.15% CaO (alkalinity determined as indicated above). Half of the mixture was removed from the kettle.

The mixture remaining in the kettle was then heated to 320 F. duringa 1% hour period. Additional'minernl oil (the same as charged), 22 pounds, was added to the mixture. Then, 15 pounds of another mineral oil was added; this was a naphthenic bright stock having a-viscosity of 130-140 seconds (S.U.S.) at 210 F. Heating of the kettle was discontinued. The resulting mixture was paddled and then was passed through a' Manton Gaulin unit (operating at 3000 p.s.i.) from 320 *F. to 180 F. over a 1 /2 hour period. At this stage, 2 pounds and 10 ounces of Alpha-Chlor 33 was added. I The mixture so formed was paddled for a 4 hour, and 10 pounds of an oil blend was added. The oil blend comprised the solvent refined oil and the naphthenic bright stock identified above. The resulting product was paddled for 4 hour. A 10 pound sample was taken at this stage; it was identified as sample 1. To the remainder ofthe product wasadded 0.5 percent by weight of Ionol (2-6- ditertiary butyl-4-methylphenol). The resulting product was paddled for hour and a sample (sample 2 was drawn out through the Manton Gaulin unit.

Data for the products of Examples 1 and 5 are shown in Table III following. A

Table III Example No 1 5 Coconut Oil Yes. Coconut Oil Fatty Acids Yes. Glycerine- Yes. Properties:

Penetration, Worked 300 288. Timken OK Load, lbs 45 45. Oxidation Stability, lb. drop in hours,

ASTM Bomb 210 F.-

no oxidation inhibitor #/200 hrs 10#/126 hrs. with 0.5% oxidation inhibitor 4#/500 hrs.-- loft/286 hrs.

1 Ionol.

EXAMPLE 6 (a) A grease was prepared by the procedure given in Example 1, from the following materials:

Percent by weight Mineral oil 7 58.23 Naphthenic bright stock 19.20 Lime flour 4.87 Acetic acid 4.16 Caprylic acid 2.50 Coconut oil 6.34 Hydrogenated tallow fatty cids 2.10 Alpha-Chlor 33 2.60

1 Same as described in Example 1, above.

(b) A grease differing principally from that described as 6(a) in the incorporation of 1.5 percent by weight of litharge and in the omission of Alpha-Chlor 33, was prepared as described in Example 1.

(c) A grease differing principally from that described in 6(a) in the incorporation of 1.5 percent of litharge. This grease also contained 2.6 percent of Alpha-Chlor 33.

Comparison of the greases of Example 6 is provided in Table IV, wherein all values are expressed in percent by 7 weight unless otherwise indicated.

6 1 Table IV 5 Example N o b- UI m m z i s e 1 as mum H re cn o oous oa 'io 1 Same as in Example Data shown inTable IV reveal the surprising and unexpected results obtained by using lead and an extreme pressure additive together inthe grease compositions of this invention.

As indicated by the illustrative examples shown herein, the greases of this invention have an excellent combination of desirable properties. Thegreases have long bearing life even under heavy and shock loads because of extreme pressure and anti-wear properties. They have outstanding resistance to rust and corrosion, and resist water Wash-out in service. Because of their outstanding oxidation stability, they will lubricate for hundreds of hours at 300 F. and for thousands of hours at 250 F. Dropping points of greater than 500 F. indicate one reason for their remaining in place when subjected to high temperature operations. They are suitable for all types of lubricated surfaces, including anti-friction and plain bearings, cams, slides and the like. They are readily handled in dispensing and application equipment, as for centralized lubricating systems and pressure gun application.

The greases of this invention are suitable for a wide range of industrial application. Some, for example, are suitable for multi-purpose automotive greases, serving as chassis, wheelbearing, water-pump grease lubricant. Others are multi-purpose industrial greases sewing as plain-bearing and anti-friction greases for normally loaded and heavily loaded equipment. In general, then, greases contemplated herein range from types suitable as textile machinery lubricants, to solid block type greases used in lubrication of machinery in steel mills, paper mills, cement mills, etc.

It is to be understood that the greases of this invention can also contain other characterizing materials and fillers. In particular, it has been found that certain antioxidants enhance the storage and shelf stability of the grease compositions. Outstanding among such materials is 2-6-ditertiary-butyl-4-methylphenol. Other such materials which may be used herein are: phenothiazine, diphenyl p-phenylene diamine, hexyl gallate, 4-tertiary butyl catechol, phenyl beta-naphthylamine, 2-4-ditertiary butyl p-cresol, tritertiary amyl phenyl phosphite together with a small amount of dicyclohexyl amine, polymerized trimethyl dihydroquinoline (Agerite resin of R. T. Vanderbilt Company), and mixtures of mono and diheptyl diphenylamines (Agerite Stalite of R. T. Vanderbilt Comp y)- I claim:

1. A grease composition, comprising: an oil of lubricating viscosity and a mixture (A) of alkaline earth metal soaps and salts therewith, the alkaline earth metals being selected from the group consisting of calcium and a mixture (B) of calcium and barium, not more than about fifteen percent of barium on a chemical equivalent basis being associated in said mixture (B) with calcium in said soaps and salts, the mixture (A) of said soaps and salts being present in a grease forming quantity, and the metal salts of said mixture (A) being salts of a low molecular weight unsubstituted saturated monocarboxylic acid (I) having from one to six carbon atoms per molecule, and

#11 the metal soaps of said mixture (A) being soaps of different acids with said acid (I) as shown in the following tabulation:

-Weight Acid No. of Oar- Percent of hen Atoms Total Acids (1) Low Molecular Weight 1-6 10-50 (11) Intermediate Molccular'Weight 7-12 -50 (III) High Molecular'Weight.-..; at least 13 5-40 (IV) Oil Acids 8-18 25-60 -by weight of an extreme pressure agent containing at least one of the elements selected from the group consisting of chlorine, sulfur and phosphorus.

2. A grease as defined by claim 1 wherein the oil is a mineral oil.

3. A grease as defined by claim 1 wherein the alkaline earth metal is calcium.

4. A grease as defined by claim 1 wherein the low molecular weight acid (I) is acetic acid.

5. A grease as defined by claim 1 wherein the intermediate molecular weight acid (H) is caprylic acid.

6. A grease as defined by claim 1 wherein the high molecular weight acid (III) is stearic acid.

7. Agrease as defined by claim 1 wherein the oil acids are coconut oil fatty acids.

. 8. A grease as defined by claim 1 wherein the oil acids are provided in the form of coconut oil.

9. A grease as defined by claim 1 wherein the extreme pressure agent is methyl dichlorstearate.

10. A grease as defined by claim 1 wherein the extreme pressure agent is a chlorinated sperm oil containing about thirty-three percent by weight of chlorine.

11. A grease composition comprising: (a) from about fifty to about ninety-eight percent by weight of an oil lubricating viscosity; (b) from about one to about forty percent by weight of a mixture of calcium salts and soaps of acids interrelated as shown below:

(c) from about 0.5 to about 5 percent by weight (expressed as PhD) of a lead soap of at least one of said acids (I) through (IV); and (d) from about one to about ten percent by weight of an extreme pressure agent containing at 'least one of the elements selected from the group consisting of chlorine, sulfur and phosphorus.

: 12. A grease as defined by claim 11 wherein the coconut oil'acids are provided in the form of coconut oil.

13. A grease as defined by claim 11 wherein the oil is a mineral oil.

14.The method of preparing a grease composition, comprising: (a) charging to a reaction vessel in the order named and heating together at a temperature from about 250 F. to about 350 R: an oil of lubricating viscosity; a calcium compound selected from the group consisting of an oxide, a hydroxide and a carbonate; a low molecular weight unsubstituted monocarboxylic acid (I) having from one to six carbon atoms per molecule; a minor quantity of water; an intermediate molecular weight monocarboxylic acid containing from seven to twelve carbon atoms per molecule and selected from the group consisting of an unsubstituted, a monohydroxy-substituted and a methyl-substituted saturated aliphatic acid; coconut oil acids; a high molecular weight aliphatic monocarboxylic acid containing at least thirteen carbon atoms per molecule and selected from the group consisting of an unsubstituted acid, a monohydroxy-substituted acid and a monounsaturated acid; and litharge; (b) dehydrating the mixture formed in (a), at a temperature from about 300 F. to about 350 F. at atmospheric pressure; (c) incorporating into the resultant product of (b), at a temperature below about 300 R, an extreme pressure agent containing at least one of the elements selected from the group consisting of chlorine, sulfur and phosphorus; (d) the proportions of said materials being as defined in claim 3.

15. The method of preparing a grease composition, comprising: (a) charging to a reaction vessel in the order named and heating together at a temperature from about 250 F. to about 350 F.: a mineral oil, lime flour, aceticacid, a minor quantity of water, caprylic acid, coconut oil, stearic acid and litharge; (b) dehydrating the mixture formed in (a), at a temperature from about 300 F. to about 350 F. at atmospheric pressure; (0) incorporating into the resultant product of (b), at a temperature belowabout 300 R, an extreme pressure agent containing at least one of the elements selected from the group consisting of chlorine, sulfur and phosphorus; (d) the proportions of said materials being as defined in claim 3.

16. The method of claim 15 wherein step (a) is conducted at a pressure up to about 200 pounds per square inch.

17. The method of claim 15 wherein additional mineral oil is added to the resultant product of (b) before step (c).

18. The method of claim 15 wherein the grease formed in (c) is homogenized.

19. The method of claim 15 wherein an antioxidant is added in step (0).

References Cited in the file of this patent UNITED STATES PATENTS 2,229,042 Brunstrum et al. Ian. 21, 1941 2,319,405 Ittner Mar. 18, 1943 2,457,586 McGrogan Dec. 28, 1948 2,583,394, Schott et al Ian. 22, 1952 2,704,363 Armstrong Mar. 15, 1955 2,846,392 Morway et al. Aug. 5, 1958 2,863,847 Morway Dec. 9, 1958 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 2,898,297 August 4, 1959 John E. Schott It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should readas corrected below.

Column 4, lines 6'7, 68, and 69, in the table, under the heading "Preferred Range" for read 2-5 0,2 g 0243.6

WIDE- colum 8, line 34, for "Peneration" read me Penetration -=-=o igned and sealed this 9th day of February 196m ROBERT C. WATSON Commissioner of Patents KARL 1-1., AXLINE Attesting Oflicer

Claims

1. A GREASE COMPOSITION, COMPRISING: AN OIL OF LUBIRCATING VISCOSITY AND A MIXTURE (A) OF ALKALINE EARTH METAL SOAPS AND SALTS THEREWITH, THE ALKALINE EARTH METALS BEING SELECTED FROM THE GROUP CONSISTING OF CALCIUM AND A MIXTURE (B) OF CALCIUM AND BARIUM, NOT MORE THAN ABOUT FIFTEEN PERCENT OF BARIUM ON A CHEMICAL EQUIVALENT BASIS BEING ASSOCIATED IN SAID MIXTURE (B) WITH CALCIUM IN SAID SOAPS AND SALTS, THE MIXTURE (A) OF SAID SOAPS AND SALTS BEING PRESENT IN A GREASE FORMING QUANTITY, AND THE METALS SALTS OF SAID MIXTURE (A) BEING SALTS OF A LOW MOLECULAR WEIGHT UNSUBSTITUTED SATURATED MONOCARBOXYLIC ACID (1) HAIVNG FROM ONE TO SIX CARBON ATOMS PER MOLECULE, AND THE METAL SOAPS OF SAID MIXTURE (A) BEING SOAP OF DIFFERENT ACIDS WITH SAID ACID (1) AS SHOWN IN THE FOLLOWING TABULATION: