US3267033A

US3267033A - Lubricating composition having desirable frictional characteristics

Info

Publication number: US3267033A
Application number: US272848A
Authority: US
Inventors: John W Allen
Original assignee: Lubrizol Corp
Current assignee: Lubrizol Corp
Priority date: 1963-04-15
Filing date: 1963-04-15
Publication date: 1966-08-16
Anticipated expiration: 1983-08-16

Description

United This invention relates to compositions useful as additives in hydrocarbon oils, lubricating compositions, and fuel compositions. In a more particular sense this invention relates to compositions useful as additives in lubricants for internal combustion engines and especially powertransmitting units. The compositions of this invention impant desirable frictional characteristics to lubricants.

Power-transmitting units which employ frictional clutch plates are useful for many purposes. One such use consists of the mechanical clutch type transmissions found in automotive vehicles for transmitting power from the engine to the differential. Recently they have also found use in differentials in automobiles. Units of this type depend upon smooth and firm engagement of clutch plates for eficient transmission of power. To provide smooth operation the units must be lubricated by lubricants possessing suitable frictional properties in addition to the ordinary properties of corrosion resistance, oxidation resistance, detergency, and load carrying properties. Thus, the lubricant must be capable of allowing the clutch plates to slide smoothly into contact and then to become firmly engaged with each other. It must not permit slipping of the engaged plates even when heavy loads are applied to the unit; neither must it permit grabbing of the plate While they are being engaged or disengaged. Failure of the lubricant to satisfy the above frictional requirements will result in interrupted and inefficient transmission of power, which generally manifests itself in the development of a chatter-like noise. If the operation is allowed to continue for an extended period it will result in excessive Wear and premature break-down of the unit in use.

It is accordingly an object of this invention to provide novel compositions of matter.

It is another object of this invention to provide compositions useful as additives in hydrocarbon oils, lubricating compositions, and fuel compositions.

It is another object of this invention to provide lubricatmg compositions.

it is further an object of this invention to provide lubricating compositions adapted especially for use in power transmitting units which employ frictional clutch plates.

It is further an object of this invention to provide lubricating compositions adapted especially for use in automotive differentials.

It is still further an object of this invention to provide lubricating compositions adapted for use in automatic transmissions of automobiles.

These and other objects are attained in accordance with this invention by providing a composition comprising from about 1 to 3 parts by weight of an oil-soluble fatty acid having at least about 12 aliphatic carbon atoms in the fatty radical and from about 1 to 3 parts by weight of a tertiary-aliphatic primary amine salt of a partially esterified phosphoric acid in which the ester radical has from 1 to about 30 aliphatic carbon atoms.

The fatty acids useful in the above composition may contain up to about 30 carbon atoms. They preferably contain from about 16 to 24 carbon atoms. The unsaturated acids are especially useful. They are exemplified by oleic acid, linoleic acid, linolenic acid, behenic acid, etc. Other acids useful in the composition of this invention include for instance, lauric acid, stearic acid,

tates Patent 9,10-dichlorostearic acid, 9-xylylstearic acid, myristic acid, tures of acids such as are obtained from the hydrolysis of tall oil, sperm oil, or other commercial fats. Of these acids, oleic acid appears to be the most effective and therefore is preferred.

As indicated previously, the amin salts of the composition of this invention are those derived from tertiaryaliphatic primary amines having at least about 4 carbon atoms in the alkyl radical. For the most part, they are derived from alkyl amines having less than about 30 carbon atoms in the alkyl radical. Such amines are illustrated by tertiary-butyl amines, tertiary-hexyl amines, 1- met-hyl-l-amino-cyclohexane, tertiary-octyl amine, tertiarydecyl amine, tertiary-dodecyl amine, tertiary-tetradecyl amine, tertiary-hexadecyl amine, tertiary-octadecyl amine, tertiary-tetracosanyl amine, tertiary-octylcosanyl amine, tertiary-hentriacontanyl amine, etc.

The partially esterified phosphoric acids useful in preparing the amine salts of this invention include princi ally the monoand the di-esterified phosphoric acids. They are the acidic esters of phosphoric acids. The ester radical of such acidic ester contains at least one and usually no more than about 30 aliphatic carbon atoms, preferably from about 8 to 24 aliphatic carbon atoms. For the most part, it is derived from an aliphatic hydrocarbon radical such as methyl, ethyl, propyl, iso-octyl, dodecyl, tetradecyl, ootadecyl, docosyl, octacosyl, or a mixture of such radicals. It may contain aromatic hydrocarbon or polar substituents such as phenyl, naphthy-l, chloro, bromo, xylyl, methoxy, ethoxy, phenoxy, keto, or a like substituent. Examples of such substituted ester radicals include those derived from chloroethyl, phenoxyethyl, phenoxyethoxy propyl, heptylphenoxy-tetra(ethoxyl)-propyl, and chlorodecyl radicals.

Specific examples of partially esterified phosphoric acids are: diisopropyl ester of phosphoric acid, mono-dodecyl ester of phosphoric acid, mono-docosyl ester of phos phor-ic acid, cyclohexyl isooctyl ester of phosphoric acid, di(chloropropyl) ester of phosphoric acid, di(heptylphenoxyethyl) ester of phosphoric acid, dicyclohexyl ester of phosphoric acid, di(4-keto-:decyl) ester of phosphoric acid, di-alkyl ester of phosphoric acid in which each alkyl radical is derived from a commercial alcohol mixture containing an average of 13 carbon atoms, and dibehenyl ester of phosphoric acid.

The partially esterified phosphoric acids are most conveniently prepared by the reaction of an alcohol with phosphorus pentoxide.

The molar ratio of the alcohol to phosphorus pentoxide in the reaction should be Within the range from about 1:1 to 4:1, the preferred ratio being about 3:1. The reaction is effected simply by mixing the two reactants at a temperature between about 50 C. and 150 C. In most instances the reaction temperature is below about C. The upper limit of the temperature is the decomposition point of the reaction mixture. The reaction is preferably carried out in the presence of a solvent which facilitates temperature control and mixing of the reactants. The solvent may be any inert fluid substance in which either one or both reactants are soluble or the product is soluble. It is illustrated by an aryl hydrocarbon such as benzene, toluene, or xylene; an aliphatic hydrocarbon such as n-hexane, cyclohexane, or naphtha; or a polar solvent such as diethyl ether carbitol, dibutyl ether dioxane, chlorobenzene, nitrobenzene, carbon tetrachloride or chloroform.

The product of the above reaction is acidic. Its chemical constitution is not precisely known. Evidence indicates, however, that it is a mixture of acidic phosphates consisting predominantly of the monoand the cli-esters of phosphoric acid, the ester radical being derived from the alcohol.

The alcohols preferred for use in preparing the partially esterified phosphoric acids are those having from about 8 to about 30 carbon atoms. Examples of the alcohols are n-octyl alcohol, tertiary-octyl alcohol, n-decyl alcohol, n-dodecyl alcohol, secondary-hexadecyl alcohol, behenyl alcohol, hexacontanyl alcohol, 2-decylcyclohexyl alcohol, etc. The Oxo alcohols, i.e., those prepared by the well-known x0 process are particularly desirable for use in preparing the phosphorus acids. The 0x0 alcohols usually are mixtures of primary alcohols and are most conveniently characterized by the average number of carbon atoms present in a particular mixture. Especially useful are the fatty alcohols obtained by the hydrogenation of fatty esters or acids such as tall oil, coconut oil, sperm oil, etc. The fatty alcohols having an average from about 11 to 24 carbon atoms are preferred.

Another method for preparing the partially esterified phosphoric acids consists of the reaction of a suitable alcohol such as is illustrated above with phosphoric acid at a temperature between about 50 C. and 150 C., preferably between about 80 C. and 120 C. The molar ratio of the alcohol to phosphoric acid to be used in the reaction may range from about 1:1 to 3:1. Still another method for preparing the partially esterified phosphoric acids involves the reaction of a phosphorus halide, phosphorus trichloride, phosphorus tribromide, or phosphorus oxychloride with a suitable alcohol or an epoxide such as ethylene oxide, propylene oxide, 1,2-butene oxide, 1,2- octene oxide, styrene oxide, or cyclohexene oxide. The reaction of phosphorus trichloride or tribromide with an epoxide proceeds to form a halogen-containing intermediate, usually a partially esterified phosphorus halide. The intermediate is readily converted to the cor-responding partially esterified phosphoric acid by reaction with water and oxygen.

The following examples illustrate the methods useful for preparing the amine salts of partially esterified phosphoric acids of this invention.

Example I To a fatty alcohol (6 moles) having an average of 13 carbon atoms and obtained by the hydrogenation of coconut oil there is added at 5080 C. within a period of 2.5 hours, 2 moles of phosphorus pentoxide. The mixture is heated at 80 C. for 3 hours and filtered. The filtrate is the desired partially esterified phosphoric acid having a phosphorus content of 8.5% and an acid number of 216 (phenolphthalein indicator). To 518 grams (2 acid equivalents) of this acidic ester there is added at 35 60 C. a stoichiometrically equivalent amount (i.e., 2 equivalents) of a commercial tertiary-alkyl primary amine vmixture having from 11 to 14 carbon atoms in the alkyl group and an average equivalent weight of 191 (based on nitrogen). The resulting mixture is agitated for 30 minutes. The product is a salt of the amine and the acidic ester having a phosphorus content of 4.7% and a nitrogen content of 3.1

Example 2 A salt is prepared by the procedure of Example 1 except that the partially esterified phosphoric acid is derived from a mixture of equimolar amounts of the alcohol reactant and phosphorus pentoxide.

Example 3 Example 4 A salt is prepared by the procedure of Example 1 except that the amine used is tertiary-octyl primary amine.

4 Example 5 A salt is prepared by the procedure of Example 1 except that the partially esterified phosphoric acid used is derived from a mixture of 2 moles of octacontanyl alcohol and 1 mole of phosphorus pentoxide.

Example 6 A salt is prepared by the procedure of Example 1 except that the partially esterified phosphoric acid used is derived from a mixture of 3 moles of primary-pentyl alcohol and 1 mole of phosphorus pentoxide.

Example 7 A salt is prepared by the procedure of Example 1 except that the partially esterified phosphoric acid used is derived from a mixture of 3 moles of 4-methyl-2- entanol and 1 mole of phosphorus pentoxide.

Example 8 A salt is prepared by the procedure of Example 1 except that the partially esterified phosphoric acid used is derived from a mixture of 3 moles of an alcohol mixture consisting of 35 weight percent of pentyl alcohol and 65 weight percent of isobutyl alcohol and 1 mole of phosphorus pentoxide.

The compositions of this invention, as indicated previously, comprise an oil-soluble fatty acid and an oilsoluble salt, illustrated above, of a tertiary-aliphatic primary amine and a partially esterified phosphoric acid. Such compositions are mixtures of the two indicated components. The relative proportions of the two components in the mixture are within the range of from about 1:3 to about 3:1 by weight. The compositions of this invention are useful as additives in lubricating compositions, especially mineral oil lubricating compositions for use in internal combustion engines, power transmitting units such as gears and differentials in automobiles, tractors, trucks and other automotive equipment.

The lubricating oils in which the compositions of this invention are useful may be of synthetic, animal, vegetable, or mineral origin. Ordinarily, mineral lubricating oils are preferred by reason of their availability, general excellence and low cost. For certain applications oils belonging to one of the other groups may be preferred. For instance, synthetic polyester oils such as didodecyl adipate and dioctyl sebacate are often preferred as jet engine lubricants. Normally, the lubricating oils preferred will be fluid oils ranging in viscosity from about 40 Saybolt Universal seconds at F. to about 200 Saybolt Universal seconds at 210 F.

The particular utility of the compositions of this invention as lubricant additives is predicated on the fact that they impart to the lubricant desirable frictional characteristics as well as other lubricating properties such as load-carrying properties, corrosion inhibiting properties and oxidation resistance.

For use as lubricant additives the compositions of this invention are usually present in a lubricating oil at con centrations ranging from about 0.1 percent to about 5 percent by weight. They may be present in the lubricating compositions at a higher concentration such as 8 percent or 10 percent or even higher. In most applications, however, the compositions of this invention will range from about 0.5 percent to about 3 percent by weight. It will be noted in this regard that the preferred ratio of the fatty acid component to the amine salt component in the additive compositions of this invention is within the range of from about 1:2 to 2:1 by weight although such ratio may be from about 1:3 to about 3:1 by weight.

The compositions of this invention can be incorporated in a lubricating oil simply by adding the components separately to a lubricant base. Alternatively the individual components, i.e., the fatty acid and the amine salt, may be mixed and the resulting mixture is then added to the lubricant base. A preferred method of preparing lubricating compositions containing the additive compositions of this invention involves first preparing a concentrate of the individual components, separately or in admixture, in the lubricant base and then diluting the concentrate with additional amounts of the lubricant base. The concentrate usually contains up to about 80 percent of the lubricant base, more often from about 40 percent to 70 percent of the lubricant base. The lubricant base used in preparing the concentnate usually is the same that is present as the lubricant base in the final lubricating composition.

Other additives may be present in the lubricants containing the compositions of this invention. They include principally detergents of both ashless and ash-containing types, corrosion-inhibiting agents, extreme pressure improving agents, rust-inhibiting agents, pour point depressing agents, viscosity index improving agents, anti-foam agents, oxidation-inhibiting agents, etc. A particularly effective combination of additives for use in lubricants in gear assemblies or differentials consists of the compositions of this invention and a substantially hydrocarbon polysulfide and/ or a neutralized product of an amine with an acid formed by the reaction of a hydroxyalkyl ester of a phosphorodithioic acid with phosphorus pentoxide. Lubricants containing such combination of additives are characterized by non-corrosiveness, improved stability against oxidative and thermal degradation, improved frictional characteristics and the ability to provide effective lubrication in changing operating environment wherein shock load, high speed, and high torque demands are made cyclically or in sequence on the lubricant.

The substantially hydrocarbon polysulfides which are especially useful for this purpose include principally aliphatic, cycloaliphatic, and aromatic disulfides, trisulfides, tetrasulfides, pentasulfide, or higher polysulfides. The term polysulfide as used herein designates compounds in which two substantially hydrocarbon radicals are joined to a group consisting of at least 2 sulfur atoms. Such polysulfides are represented, for the most part, by

any of the structural formulas below.

8 R-S-SAR; R-S-R; R-ISR wherein R" is a substantially hydrocarbon radical such as illustrated previously and n is an integer preferably less than 6. The nature of the linkage between the sulfur atoms is not clearly understood, although it is believed that such linkage may be described by a single covalent bond, a double bond, or a coordinate covalent bond.

Polysulfides preferred for use herein are alkyl polysulfides, cycloalkyl polysulfides, aralkyl polysulfides, aryl polysulfides, alkaryl polysulfides or polysulfides having a mixture of such hydrocarbon radicals. The polysulfides containing at least about 6 carbon atoms per molecule have greater oil solubility and are generally preferred. Specific examples of such polysulfides are diisobutyl trisulfide,

diisopentyl trisulfide,

di-n-butyl tetrasulfide,

dicyclopentyl disulfide,

di-methylcyclohexy tetrasulfide,

di-Z-ethylcyclopentyl disulfide,

dipentyl trisulfide,

beta-pinyl pentasulfide,

dibenzyl trisulfide,

benzyl iso-octyl disulfide,

diphenyl disulfide,

cyclohexyl cyclopentyl trisulfide,

alpha-butyl-beta-naphthyl trisulfide,

bis(polyisobutene (molecular weight of 1000)-substitutedphenyl) disulfide,

di-tolyl disulfide,

di-paraffin wax trisulfide,

6 di-terpenyl disulfide, bis(o,p-diisopropylphenyl) tetrasulfide, didodecyl trisulfide, dibehenyl trisulfide, and isobutyl cyclohexyl tetrasulfide.

Other polysulfides such as polar substituted polysulfides are exemplified by di(p-chlorobenzyl) disulfide, di-(omega-bromopentyl) trisulfide, di(p-butoxyphenyl) disulfide, and di(o-nitro-p-heptylphenyl) disulfide.

The preparation of the polysulfides may be accomplished by any of the various processes which are known and disclosed in the art including, for example, the reaction of a chlorohydrocarbon with an alkali metal polysulfide, the reaction of a mercaptan or a thiophenol with sulfur and/ or sulfur halide, the reaction of saturated and unsaturated hydrocarbons with sulfur and/ or sulfur halide, the reaction of a hydrocarbon monosulfide with sulfur, etc.

The concentration of the polysulfide in a lubricant is usually from about 0.05% to about 10% by weight.

The neutralized product of an amine with an acid formed by the reaction of a hydroxyalkyl ester of a phosphorodithioic acid with phosphorus pentoxide is disclosed in co-pending application Ser. No. 208,553 filed July 9, 1962, now US. Patent No. 3,197,405. Such neutralized product is preferably derived from an amine having from about 4 to about 30 aliphatic carbon atoms such as the tertiary-aliphatic primary amine illustrated previously. Other amines useful in preparing the neutralized product are exemplified by cyclohexyl amine, nbutyl amine, n-dodecyl amine, oleyl amine, N-dodecyl trimethylene amine, tri-decyl amine, menthane diamine, ethylene diamine, tetraethylene pentamine, hexamethylene, tetramine, etc.

The hydroxyalkyl esters of phosphorodithioic acids useful in reaction with phosphorus pentoxide to prepare the acidic intermediate from which the amine neutralized products are obtained are represented by the structural formula R0 S-Alkyl-OH wherein R is a substantially hydrocarbon radical, preferably alkyl radical, having up to about 30 carbon atoms. Specific examples of the hydroxyalkyl esters of phosphorodithioic acids includes principally hydroxy-ethyl dicyclohexylphosphorodithioate, hydroxypropyl dioctylphosphorodithioate, hydroxybutyl ester of n-hexyl isobutyl phosphorodithioic acid, hydroxyoctyl dioctadecylphosphorodithioate and hydroxypropyl ester of a phosphorodithioic acid prepared by the reaction of 1 mole of phosphorus pentasulfide with 4 moles of an alcohol mixture consisting of 65% of isobutyl alcohol and 35% of primary hexyl alcohol. The alkyl group of the hydroxyalkyl radical preferably contains from 2 to 8 carbon atoms. The methods available for the preparation of the hydroxyalkyl esters of phosphorodithioic acids are known in the art. They are also disclosed in copending application Ser. No. 208,553 identified above.

The reaction of the hydroxalkyl ester of phosphorodithioic acid with phosphorus pentoxide to form the acidic intermediate is usually carried out by mixing from about 1 to 5 moles of the ester with each mole of phosphorus pentoxide at a temperature between about 25 C. and 150 0., preferably between about 50 C. and C. The preferred molar ratio of the ester to phosphorus pentoxide is within the range of from about 3:1 to 4:1. The acidic intermediate which results from such reaction is believed to be a mixture of acidic phosphates consisting predominantly of monoor di-esters of phosphoric acid in which the ester radical is the residue obtained by the removal of the hydroxy radical of the hydroxyalkyl ester of phosphorodithioic acids. The precise chemical constitution of the acidic intermediate, however, is not known.

The neutralization of the acidic intermediate with the amine is in most instances exothermc and can be carried out simply by mixing the reactants at ordinary temperatures such as from about C. to about 200 C. The chemical composition of the neutralized product depends to a large extent upon the reaction temperature. Thus at a relatively low temperature such as below about 80 C., the product comprises predominantly a salt of the amine and the acidic intermediate. At a temperature above about 100 C., the product may contain predominantly amides. It Will be noted that the reaction of the acidic intermediate with a tertiary amine results only in a salt.

The concentration of the neutralized product of an amine with the acidic intermediate in a lubricant usually ranges from about 0.05 to about 10% by weight, more often from about 0.5% to Other additives which may be present in the lubricants containing the additives of this invention are illustrated as follows. The detergent additives may be normal or basic metal salts of oil-soluble sulfonic acids, carboxylic acids, or phosphorus acids. They likewise may be ashless detergents such as the copolymer of parts of beta-diethylaminoethyl methacrylate and 90 parts of dodecyl methacrylate or the neutralization product of tetr-aethylene pentamine with an alkenyl succinic anhydride having 75 carbon atoms in the alkenyl group. Oxidation-inhibitors useful in such lubricants include, e.g., basic metal petroleum sulfonates, metal phenates, amines, benzyl thiocyanates, etc. Film strength agents include, e.g., chlorinated paraflin oils containing from to 70% of chlorine, chlorinated eicosane wax containing from 50 to 60% of chlorine, hexachlorodiphenyl ether, polychloro-biphenyl, etc. Oiliness agents include, e.g., methyl oleate, sulfurized sperm oil, sperm oil, corn oil, etc. Pour point depressors include, e.g., Wax-alkylated naphthalene or phenanthrene, copolymer of butyl methacrylate with decyl methacrylate, etc. Foam inhibitors include, e.g., the polymeric di-alkylsilicone, poly-acrylates, etc. Viscosity index improvers include, e.g., polymerized and copolymerized alkyl methacrylates, polymerized butenes, etc.

Still other additives useful in the lubricants of this invention include rust-inhibiting agents such as 3-hydroxyethyl-2-heptadecyl imidazoline, 3-hydroxypropyl-2-octadecyl imidazoline, Z-heptadecyl oxazoline, and Z-pentadecyl oxazoline. Such additives are usually present in the lubricants at concentrations ranging from about 0.001% to about 1%. The presence in the lubricants of a small amount, such as from about 0.001% to about 1%, of a ketone, particularly a methyl ketone, is also advantageous in further improving the frictional properties of the lubricant. The preferred ketones are methyl pentadecyl ketone, methyl heptadecyl ketone, methyldecyl ketone, ethyl pentadecyl ketone, isopropyl octyl ketone, methyl docosyl ketone, and methyl triacontanyl ketone. The ketones for the most part contain one methyl radical and one higher alkyl having from about 8 to 30 carbon atoms.

The following lubricants illustrate the utility of the compositions of this invention as additives in lubricating compositions: (all percentages are by Weight).

Example I Gear lubricant comprising SAE 90 mineral oil containing 2% of oleic acid and 1% of the amine salt of Example 1.

Example II Gear lubricant comprising SAE 80 mineral oil containing 0.5% of 9-chlorostearic acid and 1.5% of the salt of a tertiary docosyl primary amine with dichloroethyl ester of phosphoric acid (obtained by the reaction of 2 moles of ethylene oxide with 1 mole of phosphorus oxychloride to form an intermediate and the hydrolysis of intermediate with water at 0.).

Example III Gear lubricant comprising SAE mineral oil containing 1% of 9,10-dichlorostearic acid and 1% of the salt of tertiary octyl primary amine with a partially esterified phosphoric acid described in Example 5.

Example IV Differential lubricant comprising SAE 90 mineral oil containing 0.8% of 9-xylylstearic acid and 3.5% of the salt of tertiary butyl primary amine and the partially esterified phosphoric acid of Example 1.

Example V Crankcase lubricant comprising SAE 30 mineral oil containing 2% of behenic acid and the salt of 5-chl0ro- 1,1-dimethyloctyl primary amine and the partially esterified phosphoric acide of Example 1.

Example VI Gear lubricant comprising SAE 90 mineral oil containing 0.05% of myristic acid and 2.5% of the amine salt of Example 1.

Example VII Gear lubricant comprising SAE 90 mineral oil containing 1.25% of triacontanoic acid and 0.5% of the amine salt of Example 1.

Example VIII Gear lubricant comprising SAE 90 mineral oil containing 2.5 of octacosanoic acid and 0.1% of the amine salt of Example 1.

Example IX Gear lubricant comprising SAE 90 mineral oil containing 1% of oleic acid and 0.5% of the amine salt of Example 1 and 0.5 of methyl pentadecyl ketone.

Example X Gear lubricant comprising SAE 90 mineral oil containing 1.5% of oleic acid, 0.75% of the amine salt of Example 1 and 3.5% of dibutyl tetrasulfide.

Example XI Gear lubricant comprising SAE 90 mineral oil containing 1.5% of oleic acid, 0.75% of the amine salt of Example 1 and 3.5% of the neutralized product of tertiary tetradecyl primary amine With the acidic intermediate obtained by the reaction at 50-80C. of 1 mole of phosphorus pentoxide and 3 moles of hydroxypropyl dihexyl phosphorodithioate.

Example XII A transmission lubricant comprising SAE 10W-30 mineral oil base containing 1% of oleic acid, 1% of the amine salt of Example 1, 3% of calcium dodecylbenzene sulfonate, 2% of zinc dioctylphosphorodithioate, and 5% of a poly(decyl methacrylate) having a molecular Weight of 25,000 (viscosity index improving agent).

The eificacy of the compositions of this invention as additives in lubricants to improve their frictional properties is shown by the results of a Chevrolet Positraction differential lubricant test. In this test the lubricant is used as the differential lubricant in a 1959 Chevrolet station wagon equipped with a Positraction axle (the socalled locking type). The car is driven on level road and ascending grade of 15.5%. The lubricant is evaluated according to the noise of the differential upon turning at about right angles of the car in both the forward and reverse gears when the lubricant is at about 90100 F. and 180'200 F. The test results are indicated in the table below.

TABLE I Test Results (Noise Level) Test Lubricant (Percent by weight) Level 15.5% Grade Forward Reverse Forward Reverse none (90 F.) none (90 F.)- Light (105 F.) Light (105 F.). SAE 90 Lubncam {none (183 none (183 F.) Medium (183 F.) Meilsil niF- Heavy SAE 90 Gear Lubricant 0.5% of oleic acid {none 90 F.) none (90" F.) none (112 F.) none 112''F.

+ 0.25% of the amine salt of Example 1. none (200 F.) none (200 13.).-. none (195 F.) none (195 F.).

The ability of the compositions of this invention to improve the frictional characteristics of gear lubricants is further illustrated by the following test. In this test, the lubricant is used in the axle of a 1961 Ford sedan equipped with a 390 cubic inch engine and a 2-speed automatic (Fordomatic) transmission. The car is driven on level road and ascending grade of %17%. The lubricant is evaluated according to the noise developed in the axle upon rapid acceleration of the car from zero speed in forward and reverse gears when the lubricant is at a low temperature (about 90120 F.) and a high temperature (about 180190 R). The test results are indicated in the following Table II below.

esterified phosphoric acid is obtained from one mole of phosphorus pentoxide and 3 moles of the alcohol.

4. The composition of claim 2 wherein the alcohol contains about 13 carbon atoms.

5. A composition consisting essentially of (A) oleic acid and (B) a salt of a tertiary alkyl primary amine having from about 11 to 14 carbon atoms and a partially esterified orthophosphoric acid obtained by the reaction of one mole of phosphorus pentoxide with about 3 moles of an alcohol having from about 12 to 18 carbon atoms at a temperature between about 50 C. and 100 C., the weight ratio of the acid of (A) to the salt (B) being from about 1:3 to 3:1.

TABLE 11 Test Result (Noise Level) Test Lubricant (Percent by weight) Level Grade Forward Reverse Forward Reverse $111125?) Gear Lubricant 20% of oleic acid {none (106: F.) none (106: F.) none (119: 1 medium (119 F.). a of the amine salt of Example 1. none (196 F.) light (196 F.) none (198 F.) light (198 F.).

The effectiveness of the compositions of this invention 6. A mineral oil concentrate consisting essentially of to impart load carrying characteristics to lubricants is shown by the results of the Timken OK Load test (ASTM Bulletin No. 181, April 1, 1952). In this test, the load at which the rupture of a lubricant film between the rotating cup and a stationary block and the surface distress (e.g., scoring or abrasion) of the stationary block occur is taken as the measure of the effectiveness of the lubricant. Thus the higher the load, the better the loadcarrying properties of the lubricant. By this test, a SAE 90 gear lubricant containing 2% of oleic acid and 1.65% of the amine salt of Example 1 gives a result of pounds, whereas the SAE 90 mineral base oil gives a result of 5 pounds.

What is claimed is:

1. A composition consisting essentially of (A) an oilsoluble unsaturated fatty acid having from about 12 to about 30 aliphatic carbon atoms and (B) a salt of a tertiary aliphatic primary amine having from about 4 to 30 carbon atoms and a partially esterified orthophosphoric acid in which the ester radical has from 1 to about 30 carbon atoms, the weight ratio of the acid of (A) to the salt of (B) being from about 1:3 to 3:1.

2. A composition consisting essentially of (A) an oilsoluble unsaturated fatty acid having from about 16 to 24 aliphatic carbon atoms and (B) a salt of a tertiary alkyl primary amine having from about 4 to 30 carbon atoms and a partially esterified orthophosphoric acid obtained by the reaction of one mole of a phosphorus pentoxide with from about 1 to 4 moles of an alcohol having from about 8 to 24 carbon atoms at a temperature between about 50 C. and 150 C., the weight ratio of the acid of (A) to the salt of (B) being from about 1:3 to 3:1.

3. The composition of claim 2 wherein the partially from about 40% to of a mineral oil and from about 20% to 60% of the composition of claim 1.

7. A mineral oil concentrate consisting essentially of from about 40% to 80% of a mineral oil and from about 20% to 60% of the composition of claim 5.

8. A lubricating composition comprising a major proportion of a mineral lubricating oil and from about 0.1% to 5% of the composition of claim 1.

9. A lubricating composition comprising a major proportion of a mineral lubricating oil and from about 0.1% to 5% of the composition of claim 5.

10. A lubricating composition comprising a major proportion of a mineral lubricating oil, from about 0.1% to 10% by weight of the composition of claim 1, from about 0.05% to about 10% by weight of a hydrocarbon polysulfide, and from about 0.05 to 1 0% by weight of a neutralized product of an amine with an acid formed by the reaction of a hydroxyalkyl ester of a phosphorodithioic acid with phosphorus pentoxide.

11. A lubricating composition comprising a major proportion of a mineral lubricating oil, from about 0.1% to 10% by weight of the composition of claim 5, from about 0.1% to 10% by Weight of a dialkyl polysulfide having up to about 6 sulfur atoms, and from about 0.1% to 10% by Weight of a neutralized product of an alkyl amine having from about 11 to 14 carbon atoms with an acid formed by the reaction at a temperature between about 50 C. and C. of 1 mole of phosphorus pentoxide with about 3 moles of a hydroxypropyl ester of a dialkyl phosphorodithioic acid having up to about 30 carbon atoms in each alkyl radical.

12. A lubricating composition of claim 11 characterized further in that it contains from about 0.001% to about 1% by weight of a methyl ketone.

(References on following page) References Cited by the Examiner UNITED STATES PATENTS Ralston et a1. 25252 Rosen 25252 Flaxman 25256 Otto 25232.5 Havely et a1. 25232.5

12. Gottshall et a1. 252--32.5 Brornan et a1. 252-33.4 Cantrell et al. 25232.5 Cantrell et a1. 25232.5

DANIEL E. WYMAN, Primary Examiner.

E. W. GOLDSTEIN, P. P. GARVIN,

Assistant Examiners.

Claims

10. A LUBRICATING COMPOSITION COMPRISING A MAJOR PROPORTION OF A MINERAL LUBRICATING OIL, FROM ABOUT 0.1% TO 10% BY WEIGHT OF THE COMPOSITON OF CLAIM 1, FROM ABOUT 0.05% TO ABOUT 10% BY WEIGHT OF A HYDROCABON POLYSULFIDE, AND FROM ABOUT 0.05% TO 10% BY WEIGHT OF A NEUTRALIZED PRODUCT OF AN AMINE WITH AN ACID FORMED BY THE REACTION OF A HYDROXYALKYL ESTER OF A PHOSPHORODITHIOIC ACID WITH PHOSPHORUS PENTOXIDE.