CA1280404C

CA1280404C - Lubricant composition

Info

Publication number: CA1280404C
Application number: CA000533759A
Authority: CA
Inventors: James J. Schwind; Craig D. Tipton
Original assignee: Lubrizol Corp
Current assignee: Lubrizol Corp
Priority date: 1986-04-04
Filing date: 1987-04-03
Publication date: 1991-02-19
Anticipated expiration: 2008-02-19
Also published as: AU7281287A; WO1987005927A3; MX169010B; CN87102960A; IN169147B; WO1987005927A2; ES2004723A6; CN1018843B; ZA872446B

Abstract

ABSTRACT

Manual transmission fluids having excellent static and dynamic frictional characteristics are described herein. The fluids are particularly useful in cold weather operation of the vehicle.

Description

- 2 ~ 1~8~0~

BACKGROUND OF THE INVENTION

1. Field of the Invention This invention relates to a lubricating composition, and, in particular, to manual transmission fluids.

2. Description of the Art Practices Transmission fluids, particularly those for synchro-mesh manual transmissions, have typically been based upon high weight mineral oils, e.g., 80 weight oil, engine oils, differential oils and automatic transmission fluids.
The lighter of these oils, e.g., automatic transmission fluid, thins out too much at the high temperatures reached during summertime driving resulting in objectional gear noise. While the heavier of these oils are acceptable under normal summertime driving conditions, difficulties are often encountered in cold weather conditions. The viscosity of the heavier mineral oils increases substantially in the winter due to low temperatures. The shifting characteristics for the manual transmission are then significantly hindered due to the thickened oil. The hindered operation of the manual transmission requires greater effort to shift the gears. In extreme cases, this has resulted in a broken shifting lever.
A second problem which faces a synchromesh transmission is that of double detent or double bump.
This phenomena results when the static coefficient of friction is too high and the cone and ring cannot engage due to insufficient slippage to allow smooth engaging. A
further problem arises if the dynamic coefficient of friction is too low as clashing is observed. The clashing arises because the relative velocity of the blocker ring and cone assembly does not go to zero before engagement.
Given a resurgence of manual transmissions in an attempt to conserve fuel and in high performance vehicles using manual transmissions, it becomes imperative that the problems of double detent, low dynamic coefficient of 1~80404 friction and high static coefficient of friction be solved. The present invention provides a solution to double detent through the formulation of a manual transmission fluid which exhibits high dynamic friction properties as well as low static friction properties.
Various components of the present invention are known in lubricating fluids. For instance, United States Patent 4,031,023 issued June 21, 1977 to Musser and Koch, discloses the use of viscosity improvers to impart a liquid character to a lubricating composition. Musser et al also discloses synthetic lubricating oils, extreme pressure (EP) agents and dispersants. The term dispersants as utilized by Musser et al include materials which suspend or disperse sludge and which are described as being oil-soluble, and stably dispersible in lubricating compositions.
Heilman et al in United States Patent 3,957,664 issued May 18, 1976, discuss the use of olefin based synthetic lubricants. In particular, internal olefins or mixtures of internal olefins are combined with di-t-butyl-p-cresol to obtain a high temperature lubricant.
Wiley et al in United States Patent 3,944,495 issued March 16, 1976, discuss various di-alkyl dithiophosphates obtained from oxylated long, straight-chain alcohols, acids or mercaptans and the use of such materials in lubricating oils. Wiley et al is concerned with automatic transmission fluids and, in particular, zinc salts which are stated to give anti-corrossion and anti-wear properties to the automatic transmission.
United States Patent 4,119,550 issued October 10, 1978 to Davis and Holden describes sulfurized olefins as lubricant additives. A further disclosure of sulfurized olefins for use in lubricants is found in United States Patent 4,119,549 issued October 10, 1978 to Davis.
Further disclosures of sulfurized olefins for lubricant formulations are found in United States Patent 4,344,854 to Davis et al issued August 17, 1982. Still further disclosures of sulfurized products useful in lubricants are found in Davis, United States Patent 4,191,659 issued March 4, 1980.
The use of calcium alkyl benzene sulfonates and polyolefins in a lubricant is found in United States patent 4,172,855 issued October 30, 1979 to Shubkin et al.
Horodysky, in United States Patent 4,529,528 issued July 16, 1985 describes borated amine-phosphite reaction products which are useful in lubricants and fuels. Horodysky also discloses various olefin polymers which are stated to be useful in synthetic oils.
Howie et al, in United States Patent 4,525,289 issued June 25, 1985, discloses various lubricating formulations utilizing overbased calcium sulfonate and overbased magnesium sulfonate. Trimers of alpha-decene are shown in combination with the sulfonate salts and as well with dispersants, foam inhibitors and amides in Howie et al.
The foregoing references, while generally applicable to lubricating compositions, do not specifically discuss the issue of obtaining good dynamic and static properties in a manual transmission fluid. The present invention deals with obtaining a manual transmission fluid having outstanding static and dynamic frictional properties.
Throughout the specification and claims, percentages and ratios are by weight, temperatures are in degrees Celsius, and pressures are in KPascals over ambient unless otherwise indicated.
A

128~404 SUMMARY OF THE INVENTION

The present invention describes a synthetic lubricant mixture suitable for a manual transmission fluid comprising:
(a) an alkaline earth metal salt selected from the group consisting of sulfonates, phenates, oxylates, carboxylates and mixtures thereof;
(b) a friction modifier selected from the group consisting of fatty phosphites, borated fatty epoxides, borated glycerol monocarboxylates, borated alkoxylated fatty amines and mixtures thereof;
(c) a sulfurized olefin; and (d) a synthetic lubricant.

128q)404 DETAILED DESCRIPTION OF THE INVENTION

The first aspect of the present invention is the alkaline earth metal salt which has been found particularly useful to assist in the frictional properties in the manual transmission fluid compositions. The salt may be a phenate, oxylate, carboxylate or preferably a sulfonate. It has been determined that the preferred salt is a magnesium sulfonate. Calcium salts are adequate for usage alone in the present invention but when used are preferably in combination with the magnesium sulfonate salts. Barium salts may also be used herein.
The sulfonate salts are those having a substantially oleophilic character and which are formed from organic materials. Organic sulfonates are well known materials in the lubricant and detergent arts. The sulfonate compound should contain on average from about 10 to about 40 carbon atoms, preferably from about 12 to about 36 carbon atoms and preferably from about 14 to about 32 carbon atoms on average. Similarily, the phenates, oxylates and carboxylates have a substantially oleophilic character.
While the present invention allows for the carbon atoms to be either aromatic or in a paraffinic configuration, it is highly preferred that alkylated aromatics be employed. While naphthalene based materials may be employed, the aromatic of choice is the benzene moiety.
The most preferred composition is thus a mono-sulfonated alkylated benzene, and is preferably the mono-alkylated benzene. Typically, alkyl benzene fractions are obtained from still bottom sources and are mono- or di-alkylated.
It is believed, in the present invention, that the mono-alkylated aromatics are superior to the di-alkylated aromatics in overall properties. The use of mono-functional (e.g., mono-sulfonated) materials avoids _ -- 7 --128~)404 crosslinking of the molecules with less precipitation of the salt in the transmission.
It is desired that a mixture of mono-alkylated aromatics (benzene) be utilized to obtain the mono-alkylated salt (benzene sulfonate) in the presentinvention. The mixtures wherein a substantial portion of the composition contains polymers of propylene as the source of the alkyl groups assists in the solubility of the salt in the manual transmission fluid.
The amount of the salt utilized in the present invention is typically from about 0.5% to about 8%, preferably from about 0.75% to about 6%, and most preferably from about 1% to about 5% by weight of the total composition. For maximum effectiveness, the salt should be greater than 3% by weight of the composition.
It is also desired that the salt be "overbased". By overbasing, it is meant that a stoichiometric excess of the alkaline earth metal be present over that required to neutralize the anion of the salt. The excess metal from overbasing has the effect of neutralizing acids which may build up in the lubricant. A second advantage is that the overbased salt increases the dynamic coefficient of friction. Typically, the excess alkaline earth metal will be present over that which is required to neutralize the anion at about 10:1 to 30:1, preferably 11:1 to 18:1 on an equivalent basis.
The second required component of the manual trans-mission fluid of the present invention is a friction modifier such as a fatty phosphite. The phosphites are generally of the formula (RO)2PHO. The preferred dialkylated phosphite as shown in the preceding formula is typically present with a mono-alkylated phosphite of the formula (RO)(HO)PHO. Both of these phosphites are concomitantly produced and thus mixture of the mono-phosphite and the di-phosphite is present.
The mixtures of the phosphites are typically such that the weight ratio of the mono-phosphite to the 1~8~)404 di-phosphite is from about 2:1 to about 1:4 by weight. It is, of course, highly desirable that the di-phosphite be present in an excess over the mono-phosphite.
In the above structure of the phosphite, the term "R"
has been referred to as an alkyl group. It is, of course, possible that the alkyl is alkenyl and thus the terms "alkyl" and "alkylated", as used herein, embrace other than saturated alkyl groups within the phosphite. The phosphite utilized herein is thus one having sufficient hydrocarbyl groups to render the phosphite substantially oleophilic and further that the hydrocarbyl groups are preferably substantially unbranched.
It is preferred that the phosphite contain from about 10 to about 24 carbon atoms in each of the fatty radicals described as "R". The inclusion of substantial amounts of the mono-alkylated phosphite require that the radical "R"
contain a larger number of carbon atoms. Preferably, the fatty phosphite contains from about 12 to about 22 carbon atoms in each of the fatty radicals, most preferably from about 16 to about 20 carbon atoms in each of the fatty radicals. It is highly preferred that the fatty phosphite be formed from oleyl groups, thus having 18 carbon atoms in each fatty radical.
Other friction modifiers which are useful herein are borated fatty epoxides, borated glycerol monocarboxylates, and borated alkoxylated fatty amines. Borated fatty epoxides are known from Canadian Patent 1,188,704 issued June 11, 1985 to Davis. The oil-soluble boron-containing compositions of Davis are prepared by reacting at a temperature from about 80C to about 250C, (A) at least one of boric acid or boron trioxide with (B) at least one epoxide having the formula R R C[O]CR R

128~04 - wherein each of Rl, R2, R3 and R4 is hydrogen or an aliphatic radical, or any two thereof together with the epoxy carbon atôm or atoms to which they are attached, form a cyclic radical, said epoxide containing at least 8 carbon atoms.
As will be apparent, the borated fatty epoxides are characterized by the method for their preparation which involves the reaction of two materials. Reagent A may be boron trioxide or any of the various forms of boric acid, including metaboric acid (HBO2), orthoboric acid (H3BO3) and tetraboric acid (H2B4O7). Boric acid, and especially orthoboric acid, is preferred.
Reagent B is at least one epoxide having the above formula and containing at least 8 carbon atoms. In the formula, each of the R values is most often hydrogen or an aliphatic radical with at least one being an aliphatic radical containing at least 6 carbon atoms. The term "aliphatic radical" includes aliphatic hydrocarbon radicals (e.g., hexyl, heptyl, octyl, decyl, dodecyl, tetradecyl, stearyl, hexenyl, oleyl), preferably free from acetylenic unsaturation; substituted aliphatic hydrocarbon radicals including substituents such as hydroxy, nitro, carbalkoxy, alkoxy and alkylthio (especially those containing a lower alkyl radical; i.e., one containing 7 carbon atoms or less); and hetero atom-containing radicals in which the hetero atoms may be, for example, oxygen, nitrogen or sulfur. The aliphatic radicals are preferably alkyl radicals, and more preferably those containing from about 10 to about 20 carbon atoms. Mixtures of epoxides may be used; for example, commercial available C14 16 or C14 18 epoxides and the like, wherein R is a mixture of alkyl radicals having two less carbon atoms than the epoxide. Most desirably, Rl is a straight-chain alkyl radical and especially the tetradecyl radical.
35Further useful epoxides are those in which any two of the R radicals form a cyclic radical, which may be alicyclic or heterocyclic. Examples are n-butylcyclo-~Z8 [)40~

pentene oxide, n-hexylcyclohexene oxide, methylenecyclo-octene oxide and 2-methylene-3-n-hexyltetrahydrofuran oxide.
The borated fatty epoxides may be prepared by merely blending the two reagents and heating them at a temperature from about 80 to about 250C., preferably from about 100 to about 200C., for a period of time sufficient for reaction to take place. If desired, the reaction may be effected in the presence of a substan-tially inert, normally liquid organic diluent such astoluene, xylene, chlorobenzene, dimethylformamide or the like, but the use of such diluents is usually unnecessary.
During the reaction, water is evolved and may be removed by distillation.
The molar ratio of reagent A to reagent B is generally between about 1:0.25 and about 1:4. Ratios between about 1:1 and about 1:3 are preferred, with 1:2 being an especially preferred ratio.
It is frequently advantageous to employ a catalytic amount of an alkaline reagent to facilitate the reaction.
Suitable alkaline reagents include inorganic bases and basic salts such as sodium hydroxide, potassium hydroxide and sodium carbonate; metal alkoxides such as sodium methoxide, potassium t-butoxide and calcium ethoxide;
heterocyclic amines such as piperidine, morpholine and pyridine; and aliphatic amines such as n-butylamine, di-n-hexylamine and tri-n-butylamine. The preferred alkaline reagents are the aliphatic and heterocyclic amines and especially tertiary amines. When the preferred method involving the "heel" is used, the alkaline reagent is typically added to the blend of the "heel" with reagent A.
The molecular structures of the compositions of this invention are not known with certainty. During their preparation, water is evolved in near-stoichiometric amounts for conversion of boric acid to boron trioxide when reagent A is boric acid, and gel permeation 1~8~)4C~d~

chromatography of the composition prepared from boric acid and a C16 alpha-olefin oxide mixture in a 1:2 molar ratio indicates the presence in substantial amounts of three constituents having approximate molecular weights of 400, 600 and 1200.
The borated amines are generally known from European published applications 84 302 342.5 filed April 5, 1984 and 84 307 355.2 filed October 25, 1984, both authored hy Reed Walsh.
The borated amine friction modifiers are conveniently prepared by the reaction of a boron compound selected from the group consisting of boric acid, boron trioxide and boric acid esters of the formula B(OR)3 wherein R is a hydrocarbon-based radical containing from 1 to about 8 carbon atoms and preferably from about 1 to about 4 carbon atoms with an amine selected from the group consisting of hydroxy containing tertiary amines corresponding to the formulae B-(OR )XNR R (A) and B-[(OR )xZ]3 (B) wherein Z is an imidazolene radical, Rl in each formula is a lower alkylene based radical containing from 1 to about 8 carbon atoms, R2 is a radical selected from the group consisting of hydrocarbon based radicals containing from 1 to about 100 carbon atoms and alkoxy radicals of the structure H(oR4)y~ where R is a lower alkylene based radical containing from 1 to about 8 carbon atoms, R and R (pendent from the ethylenic carbon in the 2 position in the imidazolene (Z) radical) are each hydrocarbon based radicals containing from 1 to about 100 carhon atoms, x and y are each an integer ranging from at least 1 to about 50 and the sum of x+y is at most 75. In a preferred embodiment, the amines useful in preparing the organo-borate additive compositions are those tertiary amines corresponding to (A) above wherein R is an alkoxy ~286~4~

radical of the structure H(oR4)V- wherein R is a lower alkylene radical containing from 1 to about 8 carbon atoms and R3 is an aliphatic based hydrocarbon radical containing from about 8 to about 25 carbon atoms, and preferably from about 10 to about 20 carbon atoms and x and y are each an integer ranging from at least 1 to about 25 and wherein the sum of x+y is at most 50, and those tertiary amines containing the imidazoline structure above wherein R1 is a lower alkylene based radical containing from 1 to about 8 carbon atoms, R5 is an aliphatic based hydrocarbon radical, preferably alkyl or alkenyl based radical, containing from about 8 to about 25 carbon atoms and preferably from about 10 to about 20 carbon atoms.
Preferred tertiary amines useful in preparing the multi-functional organo-borate additive compositions are those tertiary amines corresponding to formula (A) above wherein R2 is an alkoxy radical of the structure H(oR4) -, wherein R1 and R4 are individually ethylene or propylene radicals, R3 is an alkyl or an alkenyl based hydrocarbon radical containing from about 10 to about 20 carbon atoms, x and y are each an integer ranging from at least 1 to about 9 and preferably from at least 1 to about 5 and the sum of x+y is at most 10 and preferably at most 5, i.e., the sum of x+y ranges from about 2 to about 10 and preferably from about 2 to about 5 respectively.
As used herein, the term "hydrocarbon-based radical"
denotes a radical having a carbon atom directly attached to the remainder of the molecule and having predominantly hydrocarbon character within the context of this invention. Such radicals include the following:
(1) Hydrocarbon radicals; that is, aliphatic, (e.g., alkyl or alkenyl), alicyclic (e.g., cycloalkyl or cyclo-alkenyl), aromatic, aliphatic- and alicyclic-substituted aromatic, aromatic-substituted aliphatic and alicyclic radicals, and the like, as well as cyclic radicals whereln the ring is completed through another portion of the molecule (that is, any two indicated hydrocarbon radicals, ~ 13 -1~8~)40~

e.g., R2 and R3, may together form an alicyclic radical and such radical may contain heteroatoms such as nitrogen, oxygen and sulfur). Such radicals are known to those skilled in the art; representative examples are examples of such radicals as represented by R2, R3 and R5 in the formulae above include methyl, ethyl, butyl, hexyl, octyl, decyl, dodecyl, tetradecyl, octadecyl, eicosyl, cyclohexyl, phenyl and naphthyl and the like including all isomeric forms of such radicals and when R2 and R3 together form an alicyclic radical, then examples of such radicals include morpholinyl, piperidyl, piperazinyl, phenothiazinyl, pyrrolyl, pyrrolidyl, thiazolidinyl and the like.
(2) Substituted hydrocarbon radicals; that is, radicals containing non-hydrocarbon substituents which, in the context of this invention, do not alter the predomin-antly hydrocarbon character of the radical. Those skilled in the art will be aware of suitable substituents;
representative examples are hydroxy (HO-); alkoxy (RO-);
carbalkoxy (RO2C-); acyl [RC(O)-]; acyloxy (RCO2-);
carboxamide (H2NC(O)-); acylimidazyl; [RC(NR)-]; nitro-(-NO2); and alkylthio(RS-) and halogen atoms (e.g., F, Cl, Br and I).
Hetero radicals; that is, radicals which, while predominantly hydrocarbon, contain atoms other than carbon present in a chain or ring otherwise composed of carbon atoms. Suitable hetero atoms will be apparent to those skilled in the art and include, for example, nitrogen, oxygen and sulfur.
In general, no more than about three substituents or hetero atoms, and preferably no more than one, will be present for each 10 carbon atoms in the hydrocarbon-based radical.
Terms such as "alkyl-based radical," "alkenyl-based radical" and alkylene-based radical" and the like have analogous meanings with respect to alkyl and aryl radicals and the like.

1~86)~0~

Representative examples of the tertiary amine compounds useful in preparing the organo-borate compounds of this invention include monoalkoxylated amines such as dimethylethanolamine, diethylethanolamine, dibutylethanol-amine, diisopropylethanolamine, di(2-ethylhexyl) ethanolamine, phenylethylethanolamine, dibutylisopropanol-amine, dimethylisopropanolamine and the like and poly-alkoxylated amines such as methyldiethanolamine, ethyl-diethanolamine, phenyldiethanolamine, diethyleneglycol mono-N-morpholinoethyl ether, N-(2-hydroxyethyl)thiazoli-dine, 3-morpholinopropyl-(2-hydroxyethyl)cocoamine, N-(2-hydroxy-ethyl)-N-tallow-3-aminomethylpropionate, N-(2-hydroxyethyl)-N-tallow acetamide, 2-oleoylethyl(2-hydroxyethyl) tallowamine, N-[N'-dodecenyl; N'-[2-hydroxy-ethylaminoethyl] thiazole, 2-methoxyethyl-(2-hydroxyethyl) tallowamine, 1-[N-dodecenyl; N-2-hydroxyethyl-aminoethyl]
imidazole, N-[N'-octadecenyl-N'-2-hydroxyethyl-aminoethyl]
phenothiazine, 2-hydroxydicocamine, 2-heptadecenyl-1-(2-hydroxyethylimidazoline, 2-dodecyl-1-(5-hydroxypentyl-imidazoline), 2-(3-cyclohexylpropyl)-1-(2-hydroxyethyl-imidazoline) and the like.
An especially preferred class of tertiary amines useful in preparing the organo-borate compounds of the invention is that constituting the commercial alkoxylated fatty amines known by the trademark "ETHOMEEN" and available from the Armak Company. Representative examples of these ETHOMEEN is ETHOMEEN C/12 (bis[2-hydroxyethyl]
cocoamine); ETHOMEEN C/20(polyoxyethylene[10]cocoamine);
ETHOMEEN S/12(bis[2-hydroxyethyl]soyamine); ETHOMEEN
T/12(bis[2-hydroxyethyl]tallowamine); ETHOMEEN T/15-(polyoxyethylene-[5]tallowamine); ETHOMEEN 0/12(bis[2-hydroxyethyl]oleyl-amine; ETHOMEEN 18/12(bis[2-hydroxy-ethyl]octadecylamine; ETHOMEEN 18/25 (polyoxyethylene-[15]octadecylamine and the like. Of the various ETHOMEEN

~L~8~)~0~

compounds useful in reparing the organo-borate additive compounds of the invention, ETHOMEEN T/12 is most preferred.
If desired, the tertiary amine reactants represented by formulae (A) and tB) above may be reacted first with elemental sulfur to sulfurize any carbon-to-carbon double bond unsaturation which may be present in the hydrocarbon based radicals R2, R3 and R5 when these radicals are, for example, alkenyl radicals (e.g., fatty oil or fatty acid radicals). Generally the sulfurization reaction will be carried out at temperatures ranging from about 100C. to about 250C. and preferably from about 150C. to about 200C. The molar ratio of sulfur to amine can range from about 0.5:1.0 to about 3.0:1.0 and preferably 1.0:1Ø
Although, generally no catalyst is required to promote sulfurization of any carbon-to-carbon double bond unsaturation which may be present in any tertiary amine reactant useful in preparing the organo-borate compositions of this invention, catalysts may be employed, if desired. If such catalysts are employed, preferably such catalysts are tertiary hydrocarbon substituted amines, most preferably, trialkylamines. Representative examples of which include tributylamine, dimethyloctyl-amine, triethylamine and the like.
The organo-borate additive friction modifiers can be prepared by adding the boron reactant, preferably boric acid, to at least one of the above defined tertiary amine reactants, in a suitable reaction vessel, and heating the resulting reaction mixture at a temperature ranging from about 50 to about 300C with continuous stirring. The reaction is continued until by-product water ceases to evolve from the reaction mixture indicating completion of the reaction. The removal of by-product water is facilitated by either blowing an inert gas, such as nitrogen, over the surface of the reaction mixture or by conducting the reaction at reduced pressures. Preferably the reaction between the boron reactant and the tertiary 128q)~0'~

amine will be carried out at temperatures ranging from about 100C to about 250C and most preferably between about 150C and 230C while blowing with nitrogen.
Although normally the amines will be liquid at room temperature, in those instances where the amine reactant is a solid or semi-solid, it will be necessary to heat the amine to above its melting point in order to liquify it prior to the addition of the boron-containing reactant thereto. Those of ordinary skill in the art can readily determine the melting point of the amine either from the general literature or through a simple melting point analysis.
Generally, the amine reactant alone will serve as the solvent for the reaction mixture of the boron containing reactant and amine reactant. However, if desired, an inert normally liquid organic solvent can be used such as mineral oil, naptha, benzene, toluene or xylene can be used as the reaction media. Where the organo-borate additive compound is to be added directly to a lubricating oil, it is generally preferred to conduct the reaction merely using the amine reactant as the sole solvent.
The borated fatty acid esters of glycerol are prepared by borating a fatty acid ester of glycerol with boric acid with removal of the water of reaction.
Preferably, there is sufficient boron present such that each boron will react with from l.S to 2.5 hydroxyl groups present in the reaction mixture.
The reaction may be carried out at a temperature in the range of 60C to 135C, in the absence or presence of any suitable organic solvent such as methanol, benzene, xylenes, toluene, neutral oil and the like.
Fatty acid esters of glycerol can be prepared by a variety of methods well known in the art. Many of these esters, such as glycerol monooleate and glycerol tallowate, are manufactured on a commercial scale. The esters useful are oil-soluble and are preferably prepared from C8 to C22 fatty acid or mixtures thereof such as are -~ - 17 -12~3~40~

found in natural products. The fatty acid may be saturated or unsaturated. Certain compounds found in acids from natural sources may include licanic acid which contains one keto group. Most preferred C8 to C22 fatty acids are those of the formula RCOOH wherein R is alkyl or alkenyl.
The fatty acid monoester of glycerol is preferred, however, mixtures of mono- and diesters may be used.
Preferably any mixture of mono- and diester contains at least 40% of the monoester. Most preferably, mixtures of mono- and diesters of glycerol contain from 40 to 60 percent by weight of the monoester. For example, commercial glycerol monooleate contains a mixture of from 45% to 55% by weight monoester and from 55% to 45%
diester.
Preferred fatty acids are oleic, stearic, isostearic, palmitic, myristic, palmitoleic, linoleic, lauric, linolenic, and eleostearic, and the acids from the natural products tallow, palm oil, olive oil, peanut oil, corn oil, neat's foot oil and the like. A particularly preferred acid is oleic acid. The borated fatty acid esters are conveniently stabilized against hydrolysis by reacting the esters with an alkyl or alkenyl mono- or bis-succinimide.
The amount of the friction modifier employed in the transmission fluids of the present invention is typically from about 0.1% to about 5%, preferably from about 0.25%
to about 4%, and most preferably from about 0.5% to about 3.5% by weight of the total composition.
A sulfurized olefin is included in the present invention as an extreme pressure agent. Extreme pressure agents are materials which retain their character and prevent metal to metal damage, e.g., contact, when gears are engaged and meshed. The sulfurization of olefins is generally known as is evidenced by United States Patent 4,191,659 as previously disclosed.

~28[)~0~

The sulfurized olefins which are useful in the present invention are those materials formed from olefins which been reacted with sulfur. Thus, an olefin is defined as a compound having a double bond connecting two aliphatic carbon atoms. In its broadest sense, the olefin may be defined by the formula R1R2C=CR3R4, wherein each of R , R , R3 and R is hydrogen or an organic radical. In general, the R values in the above formula which are not hydrogen may be satisfied by such groups as -C(R5)3, -COOR , -CON(R )2' -COON(R )4, -COOM, -CN, -C(R5)=C(R )2' -C(R5)=Y

-X, -YR or -Ar.
Each R5 is independently hydrogen, alkyl, alkenyl, aryl, substituted alkyl, substituted alkenyl or substituted aryl, with the proviso that any two R5 groups can be alkylene or substituted alkylene whereby a ring of up to about 12 carbon atoms is formed;
M is one equivalent of a metal cation (preferably Group I or II, e.g., sodium, potassium, magnesium, barium, calcium);
X is halogen (e.g., chloro, bromo, or iodo);
Y is oxygen or divalent sulfur; and Ar is an aryl or substituted aryl radical of up to about 12 carbon atoms.
Any two of R , R , R and R may also together form an alkylene or substituted alkylene group; i.e., the olefinic compound may be alicyclic.
The nature of the substituents in the substituted moieties described above are not normally a critical aspect of the invention and any such substituent is useful so long as it is, or can be made compatible, with lubricating environments and does not interfere under the contemplated reaction conditions. Thus, substituted compounds which are so unstable as to deleteriously decompose under the reaction conditions employed are not )40':~

contemplated. However, certain substituents such as keto or aldehydo can desirably undergo sulfurization. The selection of suitable substituents is within the skill of the art or may be established through routine testing.
Typical of such substituents include any of the above-listed moieties as well as hydroxy, amidine, amino, sulfonyl, sulfinyl, sulfonate, nitro, phosphate, phosphite, alkali metal mercapto and the like.
The olefinic compound is usually one in which each R
value which is not hydrogen is independently alkyl, alkenyl or aryl, or (less often) a corresponding substituted radical. Monoolefinic and diolefinic compounds, particularly the former, are preferred, and especially terminal monoolefinic hydrocarbons; that is, those compounds in which R3 and R4 are hydrogen and R1 and R2 are alkyl or aryl, especially alkyl (that is, the olefin is aliphatic). Olefinic compounds having about 3 to 30 and especially about 3 to 18 (most often less than 9) carbon atoms are particularly desirable.
Isobutene, propylene and their oligomers such as dimers, trimers and tetramers, and mixtures thereof are especially preferred olefinic compounds. Of these compounds, isobutylene and diisobutylene are particularly desirable because of their availability and the particularly desirable because of their availability ana the particularly high sulfur-containing compositions which can be prepared therefrom.
The sulfurization of such compounds is conducted as is known in the art and thus no further discussion of the sulfurized olefin component is given at this point.
The sulfurized olefins useful in the present invention as extreme pressure agents are typically utilized at from about 0.1% to about 5%, preferably from about 0.2S% to about 4% and, most preferably from about 0.5% to about 3.5% by weight of the total composition.

1~8~)40~

Various sulfurized olefins which are useful in the present invention are shown in Table I below:
TABLE
% sulfur 5Olefinic Molar Temp., in Example compound ratiol C. product (a) Isobutene; 1- 1:1:0.5 171 46.9 butene2 (b) l-Octene 1:1.5:0.5 171 34.3 (c) Isobutene; 1- 1:1:0.5 171 44.
octene3 (d) Diisobutene 1:1.5:0.5 171 41.
(e) C16-C18 a-olefin 1:1.5:0.5 171 20.6 (f) Cyclohexene 1:1:0.5 171 31.8 (g) Isobutene; 1- 1:1:0.5 171 39.5 hexene2 (h) Methyl oleate 1:1.5:0.5 171 16.5 (i) a-Methylstyrene 1:1:0.5 171 39.2 (j) Isobutene; 1:1:0.5 171 47.2 butadiene3 (k) Polyisobutene4 1:1.5:0.5 171 2.6 (l) Triisobutene 1:1.5:0.5 171 (m) l-Butene 1:1:0.5 138-171 49.5 (n) Isodecyl acrylate 1:0.5:0.5 171 13.1 (o) Diels-Alder 1:1.5:0.5 171 25.1 adduct of butadiene and butyle acrylate (p) 2-Butene6 1:1:0.5 171 48.9 (q) Turpentine 1:1.5:0.5 171 39.2 Olefinic compound(s):S:H2S.
1:1 molar ratio.
0.9:0.1 molar ratio.
Number average molecular weight of about 1000 a determined by vapor pressure osmometry.
5No separation step.
6Cis and trans isomers.

128~)~0~

The synthetic lubricating oils useful herein include hydrocarbon oils and halosubstituted hydrocarbon oils such as polymerized and interpolymerized olefins (e.g., polybutylenes, polypropylenes, propylene-isobutylene copolymers, chlorinated polybutylenes, etc.); poly(l-hexenes), poly(l-octenes), poly(l-decenes), etc. and mixtures thereof; alkylbenzenes (e.g., dodecylbenzenes, tetradecylbenzenes, dinonylbenzenes, di-(2-ethylhexyl)-benzenes, etc.); polyphenyls (e.g., biphenyls, terphenyls, alkylated polyphenyls, etc.); alkylated diphenyl ethers and alkylated diphenyl sulfides and the derivatives, analogs and homologs thereof and the like.
Alkylene oxide polymers and interpolymers and deriva-tives thereof where the terminal hydroxyl groups have been modified by esterification, etherification, etc., constitute another class of known synthetic lubricating oils that can be used. These are exemplified by the oils prepared through polymerization of ethylene oxide or propylene oxide, the alkyl and aryl ethers of these polyoxyalkylene polymers (e.g., methylpolyisopropylene glycol ether having an average molecular weight of about 1000, diphenyl ether of polyethylene glycol having a molecular weight of about 500-1000, diethyl ether of polypropylene glycol having a molecular weight of about 25 1000-lS00, etc.) or mono- and polycarboxylic esters thereof, for example, the acetic acid esters, mixed C3-C8 fatty acid esters, or the C13Oxo acid diester of tetra-ethylene glycol.
Another suitable class of synthetic lubricating oils that can be used comprises the esters of dicarboxylic acids (e.g., phthalic acid, succinic acid, alkyl succinic acids, alkenyl succinic acids, maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid dimer, malonic acid, alkyl malonic acids, alkenyl malonic acids, etc.) with a variety of alcohols ~2~3~40'~

(e.g., butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoether, propylene glycol, etc.). Specific examples of these esters include dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl phthalate, dieicosyl sebacate, the 2-ethylhexyl diester of linoleic acid dimer, the complex ester formed by reacting one mole of sebacic acid with two moles of tetraethylene glycol and two moles of 2-ethylhexanoic acid and the like.
Esters useful as synthetic oils also include those made from C5 to C12 monocarboxylic acids and polyols and polyol ethers such as neopentyl glycol, trimethylol propane, pentaerythritol, dipentaerythritol, tripent-aerythritol, etc.
Silicon-based oils such as the polyalkyl-~ polyaryl-, polyalkoxy- or polyaryloxy-siloxane oils and silicate oils comprise another useful class of synthetic lubricants (e.g., tetraethyl silicate, tetraisopropyl silicate, tetra-(2-ethylhexyl)silicate, tetra-(4-methyl-hexyl)-silicate, tetra-(p-tert-butylphenyl)silicate, hexyl-(4-methyl-2-pentoxy)disiloxane, poly(methyl)siloxanes, poly(methylphenyl)siloxanes, etc.). Other synthetic lubricating oils include liquid esters of phosphorus-containing acids (e.g., tricresyl phosphate, trioctvl phosphate, diethyl ester of decane phosphonic acid, etc.), polymeric tetrahydrofurans and the like.
Polyolefin oligomers are typically formed by the polymerization reaction of alpha-olefins. Nonalpha-olefins may be oligomerized to give a synthetic oil within the present invention, however, the reactivity and availability of alpha-olefins at low cost dictates their selection as the source of the oligomer.
The polyolefin oligomer synthetic lubricating oils of interest in the present invention include hydrocarbon oils and halo-substituted hydrocarbon oils such as are obtained 1280~04 as the polymerized and interpolymerized olefins, e.g., oligomers, include the polybutylenes, polypropylenes, propylene-isobutylene copolymers, chlorinated poly-butylenes, poly(l-hexenes), poly(1-octenes), poly(1-decenes)-, similar materials and mixtures thereof.
Typically, the oligomer is obtained from a monomer containing from about 6 to 18 carbon atoms, preferably from about 8 carbon atoms to about 12 carbon atoms. Most preferably, the monomer used to form the oligomer is decene, and preferably 1-decene. The nomenclature alpha-olefin is a trivial name and the IUPAC nomenclature of a 1-ene compound may be considered to have the same meaning within the present invention.
While it is not essential that the oligomer be formed from an alpha-olefin, such is desirable. The reason for forming the oligomer from an alpha-olefin is that branching will naturally occur at the points where the olefin monomers are joined together and any additional branching within the backbone of the olefin can provide too high a viscosity of the end oil. It is also desirable that the polymer formed from the alpha olefin be hydrogenated. The hydrogenation is conducted according to known practices. By hydrogenating the polymer free radical attack on the allyic carbons remaining after polymerization is minimized.
The molecular weight of the oligomer is typically averages from about 250 to about 1400, conveniently from about 280 to about 1200 preferably from about 300 to about 1100 and most preferably about 340 to about 520. The choice of molecular weight of the oligomer is largely dependent upon whether a viscosity improver is included within the formulation. That is, the polyolefin oligomer, may require either a thickening or a thinning effect to ensure that the proper lubricating viscosities are maintained under extreme heat and cold conditions.
A further desirable synthetic lubricant is an alkylated aromatic compound. The alkvlated aromatic 1~8~40dS

compounds are particularly beneficial in improving the low temperature flow characteristics. The alkylated aromatics may be referred to, supra, under the discussion of the alkaline earth metal salt. The alkylated aromatics are the same base materials utilized to manufacture the aromatic sulfonate.
The alkylated aromatic compound may be obtained in mixture with the sulfonate due to incomplete sulfonation of the alkylated aromatic. Of course, the alkylated aromatic may be obtained directly. Preferably, the aromatic nucleus of the alkylated aromatic compound is benzene~ A particularly useful synthetic lubricant is a mixture of the alpha olefin oligomer and the alkylated aromatic. Typically, a mixture of the oligomer to the alkylated aromatic will be at a weight ratio of about 8:1 to about 1:8.
The amount of the synthetic lubricant which is employed in the present invention is typically from about 4% to about 98%, with intermediate ranges of about 7% to about 96~, and about 5% to about 95%~ by weight of the composition. The variability in the amount of the synthetic lubricant utilized in the present invention is largely because the synthetic lubricant may be obtained as a separate material with components A through C inclusive being utilized as a concentrate. ~hat is, components A
through C require more specialized processing condition~
than the formation of the synthetic lubricant and thus it is often convenient to ship components A through C for blending with the synthetic lubricant. Where a concentrate is desired, components (A), (B) and (C) are conveniently obtained at from 95% to 50% by weight of the composition and the synthetic lubricant is obtained at 5%
to 50% by weight of the composition.
Several additional components are desirably added to the manual transmission fluids of the present invention.
Viscosity improving materials as previously referred to may be included in the compositions of the present ~28~4 invention. The viscosity index improvers typically include polymerized and copolymerized alkyl methacrylates and mixed esters of styrene-maleic anhydride interpolymers reacted with nitrogen-containing compounds.
Polyisobutylene compounds are also typically used as viscosity index improvers. The amount of viscosity improver which may be typically added to the fully formulated manual transmission fluid composition is about 1% to about 50%, preferably about 10% to about 25% bv weight.
Zinc salts are also added to manual transmission lubricants. Zinc salts are ordinarily utilized as extreme pressure agents such as zinc dithiophosphates. The zinc salts are added at levels measured by weight of the zinc 15 metal at from about 0.02% to about 0.2%, preferably from about 0.04~ to about 0.15% by weight.
Mineral oil such as 100 neutral oil may be included in the present invention. That is, it may be desirable as the mineral oil is less expensive than the oligomer to formulate the composition removing a portion of the oligomer and replacing the same with the mineral oil.
Thus, when mineral oil is utilized in the composition of the present invention, it may be present at from 0.1% to about 75~, preferably from about 0.5~ to about 50% by weight of the total composition.
Additional ingredients which may be included in the manual transmission fluid of the present invention are fatty acid amides which are useful as additional friction modifiers, particularly for reducing the static coefficient of friction. Further useful components herein include seal swell agents such as sulfones and sulfolanes.
Suitable seal swell agents are disclosed in United States Patent 4,029,587 to Koch issued June 14, 1977. A still further useful component in the present invention is a foam suppression agent such as a silicone oil. Any other typical ingredient may be included herein such as pour point depressants, dyes, odorants and the like.

128~40'~

The products of the present invention are obtained as a light orange, nearly clear liquid. Typical prior art manual transmission fluids will turn black after extended useage and a visible inspection is thus not possible. An advantage to the compositions of the present invention is that the products may be visually examined for contamin-ants. Such contaminants may indicate the failure of seals or metal parts within the manual transmission. Thus a particular utility of the products of the present invention in addition to being highly effective in having a high dynamic and a low static coefficient of friction is that they may be visually examined for deterioration of the transmission or contamination of the transmission fluid. The products herein are also of relatively low viscosity at temperatures of -25C and thus shift easily.
The products herein are primarily designed for manual transmission fluids although they may be used, where appropriate, for hydraulic fluids and other functional fluids.
The following are suggested examples of the present invention.

040~

EXAMPLE I

A manual transmission fluid is prepared by combining the following ingredients:

56.5 parts of a poly alpha-olefin based on 1-decene monomer.
parts of a polyisobutylene having an average molecular weight (Mw) of approximately 1700.
15 parts of an alkylated benzene wherein the average alkyl chain is approximately 24 carbon atoms.
1 part of a maleic anhydride-styrene copolymer esterified as a pour point depressant.
lOOppm foam inhibitor which is a polydimethyl siloxane.
1.0 part zinc dithiophosphate 0.75 part dioleylphosphite l part sulfurized olefin based on a mixture of 35 parts C -1 alpha-olefin, 63% soya oil and 2% oleic acid whel~e ~he mixture has a sulfur content of 10% by weight 0.25 part fatty amide 0.3 part seal swell agent.
3.5 part magnesium alkyl benzene sulfonate (overbased) wherein the alkyl contains about 24 carbon atoms on average.
The product herein has a high dynamic coefficient of friction and a low static coefficient of friction. Cold weather viscosity is such that shifting is easily accomplished. The product is a light orange in color.

- 28 ~ ~8~0~

EXAMPLE II

A manual transmission fluid is prepared by combining the following ingredients:

56.5 parts of a poly alpha-olefin based on 1-decene monomer.
parts of a polyisobutylene having an average molecular weight (Mw) of approximately 1700.
15 parts of an alkylated benzene wherein the average alkyl chain is approximately 24 carbon atoms.
1 part of a maleic anhydride-styrene copolymer esterified as a pour point depressant.
lOOppm foam inhibitor which is a polydimethyl siloxane.
l.0 part zinc dithiophosphate 0.5 part borated fatty (Cl6) epoxide 1 part sulfurized olefin of Example I
0.25 part fatty amide 3.5 part magnesium alkyl benzene sulfonate (overbased) wherein the alkyl contains about 24 carbon atoms on average.
The product herein has a high dynamic coefficient of friction and a low static coefficient of friction. Cold weather viscosity is such that shifting is easily accomplished. The product is a light orange in color.

-~ - 29 -121~ 0~

EXAMPLE III

A manual transmission fluid is prepared by combining the following ingredients:

56.5 parts of a poly alpha-olefin based on l-decene monomer.
parts of a polyisobutylene having an average molecular weight (Mw) of approximately 1700.
15 parts of an alkylated benzene wherein the average alkyl chain is approximately 24 carbon atoms.
1 part of a maleic anhydride-styrene copolymer esterified as a pour point depressant.
lOOppm foam inhibitor which is a polydimethyl siloxane.
1.0 part zinc dithiophosphate 0.5 part borated fatty (C16) epoxide 1 part sulfurized olefin based on Example I
0.25 part fatty amide 3.5 parts calcium sulfur coupled alkyl (C12) phenate overbased to 200 total base number.
The product herein has a high dynamic coefficient of friction and a low static coefficient of friction. Cold weather viscosity is such that shifting is easily accomplished. The product is a light orange in color.

EXAMPLE IV

A manual transmission fluid is prepared by combining the following ingredients:

56.5 parts of a poly alpha-olefin based on l-decene monomer.
parts of a polyisobutylene having an average molecular weight (Mw) of approximately 1700.
15 parts of an alkylated benzene wherein the averase alkyl chain is approximately 24 carbon atoms.
1 part of a maleic anhydride-styrene copolymer esterified as a pour point depressant.
lOOppm foam inhibitor which is a polydimethyl siloxane.
1.0 part zinc dithiophosphate 0.75 part dioleylphosphite 1 part sulfurized olefin based on Example I
0.25 part fatty amide 3.5 part calcium alkyl benzene sulfonate (overbased) wherein the alkyl contains about 24 carbon atoms on average.
The product herein has a high dynamic coefficient of friction and a low static coefficient of friction. Cold weather viscosity is such that shifting is easily accomplished. The product is a light orange in color.

)40~

EXAMPLE V
A manual transmission fluid is prepared by combining the following ingredients:
56.5 parts of a poly alpha-olefin based on l-decene S monomer.
20 parts of a polymethyacrylate having an average molecular weight (Mw) of approximately 1700.
15 parts of an alkylated benzene wherein the average alkyl chain is approximately 24 carbon atoms.
1 part of a maleic anhydride-styrene copolymer esterified as a pour point depressant.
lOOppm foam inhibitor which is a polydimethyl siloxane.
1.0 part zinc dithiophosphate 0.75 part dioleylphosphite 1 part sulfurized olefin based on a mixture of 35 parts Cl -1 alpha-olefin, 63% soya oil and 2% oleic acid whe~e ~he mixture has a sulfur content of 10% by weight.
0.25 part fatty amide.
0.3 part seal swell agent.
3.5 part magnesium alkyl benzene sulfonate (overbased) wherein the alkyl contains about 24 carbon atoms on average.
The product herein has a high dynamic coefficient of friction and a low static coefficient of friction. Cold weather viscosity is such that shifting is easily accomplished. The product is a light orange in color.

Claims

1. A synthetic lubricant mixture suitable for a manual transmission fluid comprising:
(a) an alkaline earth metal salt selected from the group consisting of sulfonates, phenates, oxylates, carboxylates and mixtures thereof;
(b) a friction modifier selected from the group consisting of fatty phosphites, borated fatty epoxides, borated glycerol monocarboxylates, borated alkoxylated fatty amines and mixtures thereof;
(c) a sulfurized olefin; and (d) a synthetic lubricant.

2. The lubricant mixture of claim 1 containing a fatty acid amide.

3. The lubricant mixture of claim 1 wherein the synthetic lubricant is selected from the group consisting of hydrocarbon oils, halosubstituted hydrocarbon oils, alkylene oxide polymers and interpolymers, alkylated benzenes, esters of dicarboxylic and polycarboxylic acids, silicone-based oils, silicate based oils, esters of phosphorous containing acids, polymers of tetrahydrofuran and mixtures thereof.

4. The lubricant mixture of claim 1 wherein the friction modifier is a fatty phosphite.

5. The lubricant mixture of claim 1 wherein alkaline earth metal salt is a magnesium salt.

6. The lubricant mixture of claim 3 wherein the hydrocarbon oil is a polyolefin oligomer.

7. The lubricant mixture of claim 4 wherein the fatty phosphite contains about 10 carbon atoms to about 24 carbon atoms in each of the fatty radicals.

8. The lubricant mixture of claim 5 wherein the salt is a magnesium sulfonate salt which contains an average alkyl chain length of about 10 to about 40 carbon atoms.

9. The lubricant mixture of claim 6 wherein the oligomer is obtained from a monomer having about 6 to about 18 carbon atoms.

10. The lubricant mixture of claim 1 wherein the alkaline earth metal salt is overbased.

11. The lubricant mixture of claim 7 wherein the fatty phosphite contains about 12 carbon atoms to about 22 carbon atoms in each of the fatty radicals.

12. The lubricant mixture of claim 9 wherein the oligomer is obtained from a monomer containing about 8 carbon atoms to about 12 carbon atoms.

13. The lubricant mixture of claim 8 wherein the magnesium sulfonate contains an aromatic nucleus.

14. The lubricant mixture of claim 1 wherein the alkaline earth metal salt is a magnesium salt.

15. The lubricant mixture of claim 1 wherein the alkaline earth metal salt is a calcium salt.

16. The lubricant mixture of claim 6 wherein the average molecular weight of the oligomer is about 340 to about 520.

17. The lubricant mixture of claim 1 containing a viscosity improver.

18. The lubricant mixture of claim 1 containing a zinc salt.

19. The lubricant mixture of claim 1 containing mineral oil.

20. The lubricant mixture of claim 1 wherein the synthetic lubricant is an alkylated aromatic.

21. The lubricant mixture of claim 18 wherein the zinc salt is zinc dithiophosphate.

22. The lubricant mixture of claim 13 wherein the aromatic nucleus is a benzene nucleus.

23. The lubricant mixture of claim 1 wherein:
(a) the alkaline earth metal salt is a magnesium sulfonate salt present at about 0.5% to about 8%
by weight;
(b) the friction modifier is a fatty phosphite present at about 0.1% to about 5% by weight;
(c) the sulfurized olefin is present at about 0.1% to about 5% by weight; and (d) the synthetic lubricant is a polyolefin oligomer present at about 4% to about 98% by weight.

24. The lubricant mixture of claim 1 containing a seal swell agent.

25. The lubricant mixture of claim 17 wherein the viscosity improver is a member selected from the group consisting of polyisobutylene and polymethacrylate and mixtures thereof.

26. The lubricant mixture of claim 20 wherein the alkylated aromatic is an alkyl benzene.

27. The lubricant mixture of claim 1 containing a foam suppressor.

28. The lubricant mixture of claim 24 wherein the seal swell agent is an oil soluble sulfone.

29. The lubricant mixture of claim 18 wherein the zinc salt is present at about 0.02% to about 0.2% by weight of the composition as zinc metal.

30. The lubricant mixture of claim 19 wherein the mineral oil is present at about 0.1% to about 75% by weight.

31. The lubricant mixture of claim 20 wherein the synthetic lubricant is a mixture of an alkylated aromatic and a polyolefin oligomer.

32. The lubricant mixture of claim 23 wherein the polyolefin oligomer is present at about 5% to about 95% by weight of the composition.

33. The lubricant mixture of claim 4 wherein the alkyl radicals in the fatty phosphite are substantially free of branching.

34. The lubricant mixture of claim 1 wherein the alkaline earth metal salt is a barium salt.

35. The lubricant mixture of claim 12 wherein the oligomer is obtained from a monomer which is 1-decene.

36. A concentrate containing about 95% to about 50 by weight of a mixture of (a), (b) and (c):
(a) an alkaline earth metal salt selected from the group consisting of sulfonates, phenates, oxylates, carboxylates and mixtures thereof;
(b) a friction modifier selected from the group consisting of fatty phosphites, borated fatty epoxides, borated glycerol monocarboxylates, borated alkoxylated fatty amines and mixtures thereof;
(c) a sulfurized olefin; and (d) from about 5% to about 50% by weight of a synthetic lubricant.