JP2005171254A - Power transmission liquid having improved friction characteristics - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmission liquid useful for dropping of a static friction level. <P>SOLUTION: A power transmission liquid composition comprises (a) a major amount of a lubricating viscous oil, (b) an effective amount of a power transmission liquid performance additive package, and (c) a reaction product selected from the group consisting of reaction products of maleic acid or succinic acid or those anhydrides, or a 1-6C alkyl substituted maleic acid or succinic acid, or those anhydrides with a primary aliphatic amine represented by the formula: R-NH<SB>2</SB>(wherein R is a 4-30C hydrocarbyl group), an amount of the reaction product making the static friction reduced. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a power transmission fluid that exhibits a reduced coefficient of static friction.

The present invention is based on the discovery that reaction products of certain maleic acid or succinic acid and / or their anhydrides with primary amines having 4 to 30 carbon atoms are effective in reducing the static friction level of the liquid. Is based.
Reduced friction in mechanical devices is one important aspect that improves their energy efficiency. Friction reduction reduces the amount of energy that can be converted into heat, which in most devices is emitted to the environment and thus loses energy. Accordingly, there is an endless interest in developing chemical compositions that reduce sliding contact friction. In power transmission fluids, it is necessary not only to reduce friction, usually static friction, but also to accurately control the friction level. A further aspect of friction control includes maintaining a desired level of friction, i.e., once the desired level is achieved, the established level is not altered by liquid aging.

  For the purposes of the present invention, power transmission fluid is defined as a lubricant used in contact with gears in connection with the transmission of mechanical energy. Also, in many cases, these devices include wet clutch systems that use friction materials based on cellulose, polyamide (KEVLAR®), carbon fibers or other composite materials. In general, these power transmission devices that may use the liquid of the present invention include automatic transmissions, manual transmissions, continuously variable transmissions, automated manual transmissions. Examples include, but are not limited to, transmissions, dual clutch manual transmissions, transfer cases, axles and differentials used in movable applications. They will also include fixed gears used in industrial applications as well as in industrial transmissions.

SUMMARY OF THE INVENTION According to the present invention, a power transmission fluid composition comprising:
(a) a major amount of lubricating viscous oil;
(b) an effective amount of power transmission fluid performance additive package; and
(c) maleic acid or succinic acid or anhydride thereof, or alkyl-substituted maleic acid or succinic acid having 1 to 6 carbon atoms or anhydride thereof, and a primary aliphatic amine represented by the general formula R-NH ₂ ( The above composition containing the reaction product in an amount that reduces static friction is selected from the group consisting of reaction products with R 4 is a hydrocarbyl group having 4 to 30 carbon atoms.

Preferably, the composition of the present invention is formulated for use as an automatic transmission fluid.
Further aspects of the present invention include power transmission devices, specifically automatic transmission apparatus comprising the liquids of the present invention and methods for lubricating the devices using the liquids of the present invention.
The lubricating oil contemplated for use in the present invention is derived from natural lubricating oil, synthetic lubricating oil, or a mixture of natural and synthetic lubricating oil. Suitable lubricating oils are also produced by hydrocracking (rather than solvent treating) the base stock obtained by isomerization of synthetic and slack waxes, and the aromatic and polar components of crude oil. Base stock. The kinematic viscosity at 100 ° C. of the lubricating oil appears to be about 2 to about 20 mm ² / s (cSt).
Natural lubricating oils include animal oils, vegetable oils (eg, castor oil and lard oil), petroleum oils, mineral oils and oils derived from coal or shale. A preferred natural lubricating oil is mineral oil.

  Mineral oils useful in the present invention include all common mineral oil base stocks. This includes naphthenic or paraffinic oils in chemical structure, and oils refined by conventional techniques using acids, alkalis and clays or other agents such as aluminum chloride, or they are solvent It may also be an extracted oil produced by extraction or treatment with a solvent such as phenol, sulfur dioxide, furfural, dichlorodiethyl ether and the like. They may be hydroprocessing or hydrorefining, dewaxing by cooling or catalytic dewaxing methods, or hydrocracking. Mineral oil may be manufactured from natural crude oil or may be composed of isomerized wax material or other refining process residues.

  A particularly useful class of mineral oils are those that have been severely hydrotreated or hydrocracked. In these processes, the mineral oil is contacted at a very high hydrogen pressure at a high temperature in the presence of a hydrogenation catalyst. Typical processing conditions include a hydrogen pressure type catalyst with a hydrogen pressure of about 3000 pounds per square inch (psi) at a temperature of 300 ° C. to 450 ° C. This process removes sulfur and nitrogen from the lubricating oil and saturates the alkene or aromatic structure in the feedstock. The result is a base oil with very good oxidation resistance and viscosity index. A second advantage of these processes is that the low molecular weight components of the feedstock, such as waxes, can be isomerized from linear to branched structures by providing a final base oil with clearly improved low temperature properties. It is. These hydrotreated base oils are then further dewaxed by a catalyst or conventional means to provide excellent low temperature fluidity. Examples of commercially available lubricant base oils produced by one or more of the above methods include Chevron RLOP, Petro-Canada P65, Petro-Canada P100, SK Corporation-, Yubase 4, Imperial Oil Canada EHC 35, Fortum Nexbase 3060, And Shell XHVI 5.2.

Synthetic lubricating oils include hydrocarbon oils and halo-substituted hydrocarbon oils such as oligomerized, polymerized and interpolymerized olefins [eg, polybutylene, polypropylene, propylene, isobutylene copolymers, chlorinated polyactene, poly (1-hexene]. ), Poly (1-octene), poly (1-decene, etc., and mixtures thereof]; alkylbenzenes [eg, dodecylbenzene, tetradecylbenzene, dinonylbenzene, di (2-ethylhexyl) benzene, etc.]; polyphenyl [ For example, biphenyl, terphenyl, alkylated polyphenyl and the like]; and alkylated diphenyl ether, alkylated diphenyl sulfide and derivatives, analogs and homologues thereof. Preferred oils of this class of synthetic oils are α-olefin oligomers, specifically 1-decene oligomers.
Kinematic viscosity at 100 ° C. of the lubricant base stock is considered to be ^{2.0mm 2 /s(cSt)~20.0mm 2 / s (cSt} ). A preferred mineral oil has a kinematic viscosity of 2 to 6 mm ² / s (cSt) at 100 ° C., and a most preferred mineral oil has a viscosity of 3 to 5 mm ² / s (cSt).

Power Transmission Fluid Performance Additive Package The performance additive package will be determined by the desired end use. In general, power transmission fluid performance packages include antioxidants, antiwear agents, friction modifiers, ashless dispersants, extreme pressure agents, corrosion inhibitors, viscosity modifiers and antifoams. Each of which is present in a customary amount, such as 1-25% by weight, to provide their normal attendant function. The exact amount and presence or absence of individual components will be determined by the intended use. Preferred is a composition that does not contain a polymeric viscosity modifier.

Automotive Gear Oil -The first type of automotive gear oil additive package is believed to contain one or more highly sulfurized hydrocarbons or esters, phosphites or phosphates, corrosion inhibitors, dispersants and antifoam agents. It is done. Examples of commercially available gear oil additive packages are: Lubrizol Corporation's Anglamol 99, Anglamol 6043, Anglamol 6085; Ethyl Corporation's Hitec 320, Hitec 323, Hitec 350 and Hitec 385; Mobilad G-252 available from Exxon Mobil Chemical Company , Mobilad G-251 and Mobilad G-2001.
The second type of automotive gear oil additive package consists of colloidally dispersible potassium triborate particles. This technique is described in US 3,853,772; 3,912,639; 3,912,643 and 4,089,790. An example of a commercially available gear oil package based on this technology is OLOA 9151X from the Oronite division of Chevron Texaco Chemical Company.
Automotive gear oil additive packages typically contain about 1% to about 15% by weight of the final lubricant.

Manual Transmission Fluid —Manual transmission fluid can be formulated directly from a specific additive package or from a vehicle gear oil package with reduced processing speed. In general, manual transmission fluid additive packages include one or more antiwear agents, ashless dispersants, corrosion inhibitors, friction modifiers, antifoam agents, and sometimes viscosity modifiers. Examples of off-the-shelf manual transmission fluid additive packages include Infineum's Infineum T4804, which includes antifoaming agents, antioxidants, rust inhibitors, magnesium sulfonate detergents, seal swellants, and amine phosphates. It includes antiwear additives, borated polyisobutenyl succinimide dispersants and friction modifiers, each present in a customary amount so as to provide the usual attendant functions.
Manual transmission fluid additives generally contain from about 1% to about 10% by weight of the final lubricant.

Automatic transmission fluids -Automatic transmission fluid additive packages generally include ashless dispersants; antiwear agents; antioxidants; corrosion inhibitors; friction modifiers; seal swell agents; Consists of antifoam and sometimes viscosity modifier. Examples of commercially available automatic transmission fluid additives include Lubrizol Corporation Lubrizol 6950; Lubrizol 7900; Lubrizol 9614, Ethyl Corporation Hitec 403; Hitec 420; Hitec 427 and Infineum Infineum T4520, Infineum T4540.
Automatic transmission fluid additives typically contain from about 1 to about 20 weight percent of a final lubricant.
A summary of typical amounts of additives in automatic transmission fluids is as follows:

  A preferred ashless dispersant for use in the automatic transmission fluid (ATF) performance additive package of the present invention is a polyisobutene formed from polyisobutenyl succinic anhydride and an alkylene polyamine such as triethylenetetramine or tetraethylenepentamine. Tenenyl succinimide, the polyisobutenyl substituent is derived from polyisobutene having a number average molecular weight of 700 to 1200 (preferably 900 to 1100). It has been found that the selection of certain dispersants from a wide range of alkenyl succinimides produces liquids with improved frictional properties. The most preferred dispersant of the present invention is one in which the polyisobutene substituent has a molecular weight of about 950 atomic mass units, the basic nitrogen-containing component is polyamine (PAM), and the dispersant is post-treated with a boronating agent. is there.

(式中、Rはヒドロカルビルであり、R₁はヒドロカルビル又は水素であり；好ましくはR又はR₁はチオエーテル(CH₂-S-CH₂)基を含む)。ここに使用する場合、「ヒドロカルビル」は、分子の残基に直接結合する炭素原子を有し、また、本発明の文脈においては主に炭化水素性を有する基を示す。そのような基としては以下のものが挙げられる：(1)炭化水素基；即ち、脂肪族、脂環式(例えば、シクロアルキル又はシクロアルケニル)、芳香族基、アルカリール基等、及び環式基であって、環が分子の他の部位により完成されるもの；(2)置換炭化水素基；即ち、本発明の文脈において非炭化水素基を有する基が、基の炭化水素性を主に変えないもの。当業者は、好適な置換基を認識していると思われる。例としては、ハロ、ヒドロキシ、ニトロ、シアノ、アルコキシ、アシル等が挙げられる；(3)ヘテロ基；即ち、本発明の文脈において、特性において主に炭化水素であるが、炭素原子から構成される他に、鎖又は環に炭素以外の原子を含む基。好適なヘテロ原子は、当業者に自明と思われるが、例えば、窒素、酸素及び硫黄が挙げられる。 Preferred anti-wear additives for use in the ATF performance additive package of the present invention are mono- and di-hydrocarbyl phosphites having the following general structural formula I, where structural formula I is as follows: expressed:

Wherein R is hydrocarbyl and R ₁ is hydrocarbyl or hydrogen; preferably R or R ₁ comprises a thioether (CH ₂ —S—CH ₂ ) group. As used herein, “hydrocarbyl” refers to a group that has a carbon atom directly attached to the residue of the molecule and that is predominantly hydrocarbon in the context of the present invention. Such groups include: (1) hydrocarbon groups; ie, aliphatic, alicyclic (eg, cycloalkyl or cycloalkenyl), aromatic groups, alkaryl groups, etc., and cyclic A group wherein the ring is completed by another part of the molecule; (2) a substituted hydrocarbon group; that is, a group having a non-hydrocarbon group in the context of the present invention is mainly responsible for the hydrocarbon character of the group Things that don't change. Those skilled in the art will recognize suitable substituents. Examples include halo, hydroxy, nitro, cyano, alkoxy, acyl, etc .; (3) hetero groups; ie, in the context of the present invention, which are predominantly hydrocarbons in character but are composed of carbon atoms Other groups containing atoms other than carbon in the chain or ring. Suitable heteroatoms will be apparent to those skilled in the art and include, for example, nitrogen, oxygen and sulfur.

(式中、R₇は、炭素数6〜30のアルキル基であり、zは1〜10である)。
構造式IIの摩擦改質剤を形成するアルケニル無水コハク酸出発材料は、二つのタイプのどちらであってもよい。二つのタイプは、コハク酸成分に対するアルキル側鎖の結合において異なっている。第一のタイプにおいて、アルキル基は、出発オレフィンの第一炭素原子に結合し、従って、そのコハク酸成分に隣接する炭素原子は、第二炭素原子である。第二のタイプにおいて、結合は、出発オレフィンの第二炭素原子により形成され、従ってこれらの材料は、分岐又は異性化された側鎖を有する。従って、コハク酸成分に隣接する炭素原子は、必然的に第三炭素原子である。 A friction modifier that is preferably present in the ATF performance additive package of the present invention is a succinimide compound having the following structural formula II:

(Wherein R ₇ is an alkyl group having 6 to 30 carbon atoms, and z is 1 to 10).
The alkenyl succinic anhydride starting material forming the friction modifier of structural formula II may be either of two types. The two types differ in the attachment of the alkyl side chain to the succinic acid component. In the first type, the alkyl group is attached to the first carbon atom of the starting olefin, so that the carbon atom adjacent to the succinic acid component is the second carbon atom. In the second type, the bond is formed by the second carbon atom of the starting olefin, so these materials have branched or isomerized side chains. Thus, the carbon atom adjacent to the succinic acid component is necessarily a tertiary carbon atom.

(式中、Rは、炭素数3〜27のアルキルである)。 As shown in Structural Formula III, a first type of alkenyl succinic anhydride bonded to a second carbon atom is simply prepared by heating an α-olefin, ie, a terminal unsaturated olefin, with maleic anhydride. Examples of these materials include n-decenyl succinic anhydride, tetradecenyl succinic anhydride, n-octadecenyl succinic anhydride, tetrapropenyl succinic anhydride, and the like.

(Wherein R is alkyl having 3 to 27 carbon atoms).

これらの内部オレフィンは反応混合物に導入することができるか又は、それらを高温で異性化触媒にα-オレフィンを接触させることにより、その場で製造することができる。そのような材料の製造方法は、米国特許第3,382,172号に記載されている。異性化したアルケニル置換無水コハク酸は、以下の構造式IVを有する化合物である： The second type of alkenyl succinic anhydride bonded to a tertiary carbon atom is made from an internally unsaturated olefin and maleic anhydride. An internal olefin is an olefin that is not unsaturated at the end and therefore does not contain the following groups:

These internal olefins can be introduced into the reaction mixture or they can be produced in situ by contacting the α-olefin with an isomerization catalyst at elevated temperatures. A method for producing such a material is described in US Pat. No. 3,382,172. Isomerized alkenyl-substituted succinic anhydride is a compound having the following structural formula IV:

(式中、x及びyは独立した整数であり、その合計は1〜30である)。
好ましい無水コハク酸は、酸性触媒での線状αオレフィンの異性化、その後の無水マレイン酸との反応により製造される。好ましいαオレフィンは、1-オクテン、1-デセン、1-ドデセン、1-テトラデセン、1-ヘキサデセン、1-オクタデセン、1-エイコサン又はこれら材料の混合物である。記載の生成物は、同じ炭素数8〜20の内部オレフィンから製造することができる。本発明の好ましい材料は、1-テトラデセン(x+y=9)、1-ヘキサデセン(x+y=11)及び1-オクタデセン(x+y=13)又はそれらの混合物から製造されるものである。

(Wherein x and y are independent integers, the sum of which is 1-30).
Preferred succinic anhydrides are prepared by isomerization of linear alpha olefins with an acidic catalyst followed by reaction with maleic anhydride. Preferred alpha olefins are 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosane or mixtures of these materials. The products described can be produced from the same internal olefins having 8 to 20 carbon atoms. Preferred materials of the present invention are those made from 1-tetradecene (x + y = 9), 1-hexadecene (x + y = 11) and 1-octadecene (x + y = 13) or mixtures thereof. .

(式中、R₈は、炭素数6〜28のアルキル基であり、Xは、O、S又はCH₂であり、x=1〜6である)。 Preferred succinimide friction modifiers of the present invention are products produced by reaction of isomerized alkenyl succinic anhydrides with diethylenetriamine, triethylenetetramine, tetraethylenepentamine or mixtures thereof. The most preferred product is produced using tetraethylenepentamine. In general, alkenyl succinic anhydride is reacted with the amine in a 2: 1 molar ratio such that both primary amines are converted to succinimides. Sometimes a slight excess of isomerized alkenyl succinic anhydride is used to ensure that all primary amines are reacted. The reaction product is a compound of structural formula II.
Also, ethoxylated amine friction modifiers are useful in the ATF performance additive package of the present invention, which are compounds having the following structural formula VI:

(Wherein R ₈ is an alkyl group having 6 to 28 carbon atoms, X is O, S or CH ₂ , and x = 1 to 6).

Alkoxylated amines are a particularly suitable type of friction modifier for use in the present invention. The total number of carbon atoms in the preferred amine compound is from about 18 to about 30. In a particularly preferred embodiment, this type of friction modifier is characterized by structural formula VI where X represents oxygen, R _{8 has} a total carbon number of 18, and x = 3.
Other useful friction modifiers for the liquids of the present invention are primary amides of long chain carboxylic acids, represented by the structural formula RCONH _{2 where} R is preferably about 12 to 24 carbon atoms. It is an alkenyl or alkyl group, and R is most preferably an alkenyl group having 17 carbon atoms. A preferred primary amide is oleamide. The oleamide is preferably present in an amount of about 0.001 to 0.50 weight percent, most preferably 0.1 weight percent, based on the weight percent of the fully formulated oil composition.

  Another preferred component of the additive system of the present invention is a shear stable viscosity modifier. Viscosity modifiers are oil-soluble polymers that are used to thicken lubricants at high temperatures while producing minimal thickening at low temperatures. Suitable viscosity modifiers include hydrocarbyl polymers and polyesters. Examples of suitable hydrocarbyl polymers include two or more monomers having 2 to 30 carbon atoms, such as homopolymers and copolymers of olefins having 2 to 8 carbon atoms, including both alpha and internal olefins, They may be linear or branched, aliphatic, aromatic, alkyl-aromatic, alicyclic and the like. Often, the viscosity modifier is a copolymer of ethylene and an olefin having 3 to 30 carbon atoms, particularly preferably a copolymer of ethylene and propylene. Use other polymers such as polyisobutylene, homopolymers and copolymers of higher alpha olefins with 6 carbon atoms, polypropylene, styrene, such as hydrogenated polymers and copolymers and terpolymers of eg isoprene and / or butadiene Can do.

Metal detergents that may be used in the ATF performance additive package of the composition of the present invention are one or more of the following acidic substances (or mixtures thereof), oil soluble neutral or overbased alkali metals or alkalis: It may be a salt of an earth metal, preferably calcium or magnesium: (1) sulfonic acid, (2) carboxylic acid, (3) salicylic acid, (4) alkylphenol and (5) sulfurized alkylphenol.
Suitable antioxidants for use in the combination of ATF performance additive package compositions of the present invention include amine type and phenolic antioxidants. Examples of amine-type antioxidants include phenyl alpha naphthylamine, phenyl beta naphthylamine, and bis-alkylated diphenylamines (e.g., p, p'-bis (alkylphenyl) -amines, where the carbon number of the alkyl group is 8-12). Phenolic antioxidants include sterically hindered phenols (e.g., 2,6-di-tert-butylphenol, 4-methyl-2,6-di-tert-butylphenol) and bis-phenols (e.g., 4,4 "-Methylenebis (2,6-di-tert-butylphenol). Another class of useful phenolic antioxidants is cinnamic acid and derivatives of cinnamic esters (eg, 3,5-dimethyl-4- In addition, phosphorus compounds such as ZDDP, or phosphites are commonly added to power transmission fluids as antioxidants.

Suitable corrosion inhibitors for use in the ATF performance additive package of the present invention include zinc dialkyldithiophosphates, phosphosulfurized hydrocarbons, thiadiazoles such as 1,3,4-thiadiazole and those having 2 to 30 carbon atoms. Hydrocarbyl substituted derivatives of the above, benzotriazoles and alkyl substituted benzotriazoles having 1 to 8 carbon atoms such as tolyltriazole and hexylbenzotriazole or their reaction products with monoamines and polyamines.
Suitable seal swell agents for use in the ATF performance additive package of the present invention include aliphatic alcohols having 8 to 13 carbon atoms, such as tridecyl alcohol; and those having 10 to 60 carbon atoms and 2 to 4 bonds. Examples include oil-soluble aliphatic or aromatic hydrocarbon esters such as dihexyl phthalate, and alkoxy sulfolane derivatives such as 3-isodecyloxy-sulfolane.

The composition of the present invention comprises maleic or succinic anhydrides or their diacid equivalents and a general formula R-NH _{2 wherein} R is saturated or unsaturated, substituted or unsubstituted, 4 to 30 hydrocarbyl groups) and is considered to contain 0.01 to 10% by weight of a reaction product formed by reaction with a primary aliphatic amine. Suitable substituted heteroatoms include halogen, nitrogen, silicon, phosphorus, oxygen and sulfur. Preferred R is an alkyl group having 12 to 22 carbon atoms, such as octadecyl. These reaction products consist essentially of cyclic di-imides, although other reaction products may be present. Maleimide is preferred. These imides reduce stiction to the desired low level.

Examples A, B, E, and F illustrate the static friction reducing additive of the present invention. Examples C and D are comparative examples and were evaluated in the following table.
Example A:
A four-necked round bottom flask was equipped with an air-driven stirrer, a water-cooled condenser filter with a Dean-Stark trap, a thermometer and a nitrogen inlet tube. In a flask, 1 mole (98.1 g) of maleic anhydride was placed and heated to melt. One mole (267.5 g) of octadecylamine was introduced into the melt from the addition funnel for 1-2 hours to control the heat of reaction. After the amine addition, the reaction mixture was mixed at 100 ° C. for 1 hour and then swept with nitrogen at 160 ° C. for 2 hours. The mixture was cooled and decanted. Yield: 347g. Elemental analysis of the product: N, 3.96% (theoretical value 4.03%).

Example B:
The procedure of Example A was repeated except that the following materials and amounts were used: 1 mole (114.1 g) methyl succinic anhydride and 1 mole (267.5 g) octadecylamine. Yield: 363g. Elemental analysis of the product: N, 3.83% (theoretical 3.85%).
Example C:
The procedure of Example A was repeated except that the following materials and amounts were used: 1 mol (178.2 g) methyl-5-norbornene-2,3-dicarboxylic anhydride and 1 mol (267.5 g) octadecylamine. Yield: 427g. Elemental analysis of the product: N, 3.30% (theoretical 3.27%).

Example D:
The procedure of Example A was repeated except that the following materials and amounts were used: 1 mole of 1,2-cyclohexane-dicarboxylic anhydride (154.2 g) and 1 mole of octadecylamine (267.5 g). Yield: 403g. Elemental analysis of the product: N, 3.53% (theoretical 3.47%).
Example E:
The method of Example A was repeated except that the following materials and amounts were used: 1 mole maleic anhydride (98.1 g) and 1 mole dodecylamine (185.4 g). Yield: 265g. Elemental analysis of the product: N, 5.46% (theoretical 5.23%).
Example F:
The method of Example A was repeated except that the following materials and amounts were used. 1 mol (100.1 g) of succinic anhydride and 1 mol (185.4 g) of dodecylamine. Yield: 267g. Elemental analysis of the product: FTIR spectroscopy.

In order to demonstrate the effectiveness of the claimed composition in reducing static friction, several test solutions were prepared and the friction was measured with a Low Velocity Friction Apparatus. This technology is described in, for example, `` Friction of Transmission Clutch Materials as Affected by Fluids, Additives and Oxidation '' by Rodgers, JJ and Haviland, ML, Society of Automotive Engineers paper 194A, 1960 and `` Prediction of `` Low Speed Clutch Shudder in Automotive Transmission Using the Low Velocity Friction Apparatus '', Engine Oils and Automotive Lubrication, Marcel Dekker, New York (1992) 732 documents, both of which are included here as references Shall be. The friction data shown in Table 1 was measured at 120 ° C. after slight aging in the test ring.
All liquids contained the same amount of automatic transmission fluid additive package, including ashless dispersants, antioxidants, antiwear agents and viscosity modifiers. The mixture was made with a common mineral oil base solution, ExxonMobil solvent 100 neutral oil.

Table 1 shows the formulation of the test product and the coefficient of static friction at 120 ° C. measured for each mixture. Each product was added to the test oil at a treat rate of 2.0% by weight. Liquid 1 was a blank and it contained no additional friction modifier.
In connection with the blank, the two liquids containing the product of the invention, liquids 2 and 3, clearly showed a reduction in the coefficient of static friction. Two liquids containing a product similar to the claimed product, namely liquids 4 and 5 containing a long chain amine succinimide, did not show a reduction in the coefficient of static friction.

Claims (8)

A power transmission fluid composition comprising:
(a) a large amount of lubricating viscous oil;
(b) an effective amount of a power transmission fluid performance additive package; and
(c) maleic acid or succinic acid or an anhydride thereof, or an alkyl-substituted maleic acid or succinic acid having 1 to 6 carbon atoms or an anhydride thereof, and a primary aliphatic amine represented by the general formula R-NH ₂ ( R is a hydrocarbyl group having 4 to 30 carbon atoms), and the reaction product is selected from the group consisting of a reaction product with an amount that reduces static friction.   The composition of claim 1 wherein the product is derived from maleic acid or anhydride.   The composition according to claim 1, wherein R is alkyl having 12 to 22 carbon atoms.   The composition of claim 1 wherein the reaction product is present at 0.01 to 10 wt%.   The composition of claim 1 wherein the amine is octadecylamine.   The composition of claim 1, wherein the imide is formed from maleic anhydride or methyl succinic anhydride.   A power transmission device comprising the composition of claim 1.   An automatic transmission device containing the composition according to claim 1.