JP2003138285A - Automotive transmission oil composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automotive transmission oil composition which can enhance the coefficient of intermetallic friction and hence can achieve a high transfer torque capacity. SOLUTION: This automotive transmission oil composition is prepared by compounding a lube base oil with (A) an oil-soluble metal salt perbasified with a specific alkaline earth metal borate and (B) a sulfur-containing extreme pressure additive.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automotive transmission oil composition, and more particularly to an automotive transmission oil composition that can be advantageously used in an automatic transmission, particularly a metal belt type continuously variable transmission.

[0002]

2. Description of the Related Art A metal belt type continuously variable transmission has come into the limelight in recent years as an automobile transmission because of its small energy loss due to gear shifting. This type of transmission has a mechanism in which torque is transmitted by friction between a metal belt and a metal pulley, and a gear is changed by changing a radius ratio of the pulleys. Therefore, it is extremely important that the lubricating oil used in the metal belt type continuously variable transmission has a performance capable of further increasing the friction coefficient between the metal belt and the metal pulley. Further, the lubricating oil used in the metal belt type continuously variable transmission has a performance as a lubricating oil for a gear that takes out torque and a bearing that supports them, and a performance as a hydraulic control medium for determining a gear ratio, that is, Performance as hydraulic oil is also required. When the continuously variable transmission is provided with a forward / reverse switching wet clutch and a lockup system for a torque converter, the performance of controlling the frictional characteristics of the wet clutch is required in addition to the above performance. As described above, since various performances are required for the metal belt type continuously variable transmission lubricating oil, an automatic transmission fluid (ATF) is generally used for a vehicle equipped with an engine having a low engine torque of 1800 cc or less. It has been. However, when ATF is used as a lubricating oil for a metal belt type continuously variable transmission, it has excellent performance as a hydraulic fluid and a function of controlling the frictional characteristics of a wet clutch, but the metal-to-metal friction between the belt and the pulley is great. Since the coefficient is not sufficient, it has hitherto been difficult to mount a metal belt type continuously variable transmission on a vehicle equipped with an engine of 2000 cc or more.
In particular, the quietness and fuel efficiency of the metal belt type continuously variable transmission are superior to those of a higher displacement engine such as 2500 cc or 3000.
Since the effect is exhibited in a vehicle equipped with an engine of cc or more, it is very important to develop a lubricating oil having a higher friction coefficient between metals and capable of transmitting a larger torque. Therefore, the present invention has been made in view of such circumstances, and an object thereof is to increase a friction coefficient between metals and thereby obtain a larger transmission torque capacity. It is to provide things.

[0003]

Means for Solving the Problems As a result of intensive studies for solving the above-mentioned problems, the present inventors have found that an oil-soluble metal salt overbased with a specific alkaline earth metal borate and a specific electrode It has been found that a transmission oil composition for automobiles that can further increase the coefficient of friction between metals can be obtained by using it together with a pressure additive, and completed the present invention.

That is, the present invention relates to a lubricating base oil,
(A) The oil-soluble metal salt overbased with the alkaline earth metal borate is 0.0 in terms of elemental boron based on the total amount of the composition.
A transmission oil composition for an automobile, characterized in that 01 to 0.3% by mass and (B) a sulfur-containing extreme pressure additive are blended.

In the automotive transmission oil composition of the present invention, the oil-soluble metal salt in the component (A) is preferably an alkaline earth metal sulfonate and / or salicylate. Further, the alkaline earth metal borate in the component (A) is preferably calcium borate and / or magnesium borate. In the automotive transmission oil composition of the present invention, the component (B) is thiophosphorous acid, dithiophosphorous acid, trithiophosphorous acid, thiophosphoric acid, dithiophosphoric acid, trithiophosphoric acid and monosubstituted esters thereof, and two of them. It is preferably at least one compound selected from the group consisting of substituted esters, trisubstituted esters thereof, and salts thereof. Further, the component (B) is blended in an amount of 0.005 to 0.3% by mass as a sulfur element amount and / or 0.005 to 0.1% by mass as a phosphorus element amount, based on the total amount of the composition. preferable. The automobile transmission oil composition of the present invention preferably further contains (C) an ashless dispersant. The transmission oil composition for automobiles of the present invention further comprises (D) a metallic detergent,
It is preferable to contain at least one additive selected from (E) friction modifier, (F) antioxidant, and (G) viscosity index improver. The automotive transmission oil composition of the present invention is preferably for an automatic transmission and / or for a continuously variable transmission. The automotive transmission oil composition of the present invention is preferably for a metal belt type continuously variable transmission.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION As the lubricating base oil in the automotive transmission oil composition of the present invention, any mineral oil and / or synthetic oil used as a base oil for ordinary lubricating oil can be used. As the mineral oil, specifically, for example, a lubricating oil fraction obtained by distilling crude oil under atmospheric pressure and vacuum distillation, solvent removal,
Oils and normal oils such as paraffin-based and naphthene-based oils that have been refined by one or a combination of refining treatments such as solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid washing, and clay treatment Paraffin can be used.
Further, those produced by an advanced hydrocracking process capable of further reducing aromatic content and sulfur content and a method of isomerizing GTL Wax (gas to liquid wax) are preferably used. You can

The synthetic oil is not particularly limited, and examples thereof include poly-α-olefins (eg, 1-octene oligomer, 1-decene oligomer, ethylene-propylene oligomer, etc.) or hydrides thereof, isobutene oligomers or hydrogen thereof. Compound, isoparaffin, alkylbenzene, alkylnaphthalene, diester (eg, ditridecylglutarate, di2-ethylhexyl adipate, diisodecyl adipate, ditridecyl adipate, di2-ethylhexyl sebacate, etc.), polyol ester (eg, trimethylolpropane caprylate) , Trimethylolpropane pelargonate, pentaerythritol 2-ethylhexanoate, pentaerythritol pelargonate, etc.), polyoxyalkylene glycol, dialkyl Phenyl ether, and polyphenyl ether and the like. The kinematic viscosity of the lubricating base oil is not particularly limited, kinematic viscosity at normal 100 ° C. is 1 to 20 mm ² / s, preferably 2 to 10 mm ² /
s.

The component (A) in the automotive transmission oil composition of the present invention is an oil-soluble metal salt that has been overbased with an alkaline earth metal borate. (A) The oil-soluble metal salt overbased with the alkaline earth metal borate is, for example, an alkaline earth metal sulfonate,
Obtained by reacting an oil-soluble metal salt such as an alkaline earth metal salicylate, an alkaline earth metal phenate, and an alkaline earth metal phosphonate, an alkaline earth metal hydroxide or oxide, and boric acid or boric anhydride. .

As the alkaline earth metal sulfonate,
More specifically, an alkaline earth metal salt of an alkyl aromatic sulfonic acid obtained by sulfonation of an alkyl aromatic compound having a molecular weight of 100 to 1500, preferably 200 to 700 is preferably used. Specific examples thereof include so-called petroleum sulfonic acid and synthetic sulfonic acid.

As the petroleum sulfonic acid, generally used is one obtained by sulfonation of an alkyl aromatic compound of a lubricating oil fraction of mineral oil, so-called mahogany acid produced as a by-product during the production of white oil, and the like. Further, as the synthetic sulfonic acid, for example, by-produced from an alkylbenzene production plant which is a raw material of a detergent or obtained by alkylating a polyolefin into benzene, an alkylbenzene having a linear or branched alkyl group is used as a raw material. A sulfonated product thereof, or a sulfonated product of dinonylnaphthalene is used. The sulfonating agent for sulfonating these alkyl aromatic compounds is not particularly limited, but fuming sulfuric acid or sulfuric acid is usually used.

Alkaline earth metal salicylates include
More specifically, it has 4 to 30 carbon atoms, preferably 6 to 18 carbon atoms.
Alkaline earth metal salts of alkylsalicylic acid having at least one linear or branched alkyl group are preferably used.

More specifically, the alkaline earth metal phenate has from 4 to 30 carbon atoms, preferably from 6 carbon atoms.
Alkylphenol sulfide obtained by reacting sulfur with an alkylphenol having at least one linear or branched alkyl group of 18 or alkaline earth metal of Mannich reaction product of alkylphenol obtained by reacting this alkylphenol with formaldehyde Salt is preferably used. Examples of the alkaline earth metal as used herein include magnesium, calcium, barium and the like, but calcium and / or magnesium are preferably used. In the present invention, it is preferable to use an alkaline earth metal sulfonate and / or an alkaline earth metal salicylate as the oil-soluble metal salt from the viewpoint of friction characteristics.

Although the method for producing the component (A) is arbitrary,
The component (A) is, for example, the above oil-soluble metal salt, alkaline earth metal hydroxide or oxide, and borate or boric anhydride in water, alcohols such as methanol, ethanol, propanol and butanol, and benzene and toluene. 20-200 ℃ in the presence of diluting solvent such as xylene
After 2 to 8 hours, the mixture is heated to 100 to 200 ° C. to remove water and, if necessary, alcohol and diluting solvent. These reaction conditions are appropriately selected depending on the raw materials, the amount of the reaction product, and the like. The details of the manufacturing method are described in, for example, JP-A-60-11.
6688, 61-204298, and JP-A-3-68695. As the component (A), the reaction is carried out in the presence of carbon dioxide gas, or an oil-soluble metal salt containing an alkaline earth metal carbonate is used as the reaction raw material to partially contain the alkaline earth metal carbonate. However, in the present invention, those containing no alkaline earth metal carbonate are particularly preferable. The component (A) of the present invention preferably has an average particle size of 0.1 μm or less,
It is particularly preferable that the thickness is 01 to 0.05 μm. Also,
The total base number of the component (A) is preferably 100 mgKOH / g or more, more preferably 150 to 300 mgKOH / g, and 150 to 220 mgKOH / g.
Particularly preferably g. The total base number referred to here is 7. K2501 "Petroleum products and lubricants-Neutralization number test method". Means the total base number measured by the perchloric acid method in accordance with Further, in the present invention,
As the component (A), the alkaline earth metal content is 1.0 to
It is desirable to use those having a content of 20% by mass, preferably 2.0 to 16% by mass, and a boron content of 0.1 to 20% by mass, preferably 0.5 to 10% by mass.

The content of the component (A) in the automotive transmission oil composition of the present invention is 0.001 mass% or more, preferably 0.0, as the amount of boron element based on the total amount of the composition.
It is at least 03 mass%. On the other hand, the content of the component (A) is
It is 0.3 mass% or less, preferably 0.1 mass% or less, and particularly preferably 0.05 mass% or less. (A)
When the content of the components is less than 0.001% by mass,
If a large transmission torque capacity cannot be obtained and the content exceeds 0.3% by mass, the effect commensurate with the content cannot be obtained, which is not preferable.

The component (B) in the automotive transmission oil composition of the present invention is a sulfur-containing extreme pressure additive, specifically, (B-1) a thiophosphorous acid compound, a thiophosphoric acid compound, etc. Sulfur- and phosphorus-containing compounds, (B-2) thiazole compounds, thiadiazole compounds, dithiocarbamate compounds, dihydrocarbyl polysulfide compounds, and sulfur-containing compounds such as sulfurized ester compounds.

Examples of the sulfur- and phosphorus-containing compound (B-1) include compounds represented by the following general formula (1) or (2) and salts thereof.

[0017]

[Chemical 1]

In the general formula (1), X ¹ , X ² , and X
³ is at least one sulfur atom and the other is an oxygen atom. R ¹ , R ² and R ³ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms.

[0019]

[Chemical 2]

In the general formula (2), X ⁴ , X ⁵ and X ⁶
Each independently represents an oxygen atom or a sulfur atom.
R ⁴ , R ⁵ and R ⁶ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms.

Specific examples of the hydrocarbon group having 1 to 30 carbon atoms represented by R ^{1 to} R ⁶ include an alkyl group, a cycloalkyl group, an alkenyl group, an alkyl-substituted cycloalkyl group, an aryl group and an alkyl group. Substituted aryl groups and arylalkyl groups can be mentioned. Examples of the alkyl group include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group. Base,
Examples thereof include alkyl groups such as a hexadecyl group, a heptadecyl group, and an octadecyl group (these alkyl groups may be linear or branched). Examples of the cycloalkyl group include cycloalkyl groups having 5 to 7 carbon atoms such as cyclopentyl group, cyclohexyl group and cycloheptyl group. The alkylcycloalkyl group may be, for example, a methylcyclopentyl group,
Dimethyl cyclopentyl group, methyl ethyl cyclopentyl group, diethyl cyclopentyl group, methyl cyclohexyl group, dimethyl cyclohexyl group, methyl ethyl cyclohexyl group, diethyl cyclohexyl group, methyl cycloheptyl group, dimethyl cycloheptyl group, methyl ethyl cycloheptyl group, diethyl cycloheptyl group And other alkylcycloalkyl groups having 6 to 11 carbon atoms (the position of substitution of the alkyl group with the cycloalkyl group is also arbitrary).

Examples of the alkenyl group include butenyl group, pentenyl group, hexenyl group, heptenyl group,
Alkenyl groups such as octenyl group, nonenyl group, decenyl group, undecenyl group, dodecenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group, hexadecenyl group, heptadecenyl group, octadecenyl group (these alkenyl groups may be linear or branched. Also, the position of the double bond is arbitrary).

Examples of the aryl group include aryl groups such as phenyl group and naphthyl group. Examples of the alkylaryl group include tolyl group, xylyl group, ethylphenyl group, propylphenyl group, butylphenyl group, pentylphenyl group, hexylphenyl group, heptylphenyl group, octylphenyl group, nonylphenyl group, decylphenyl group. Group, undecylphenyl group, dodecylphenyl group and the like having 7 to 18 carbon atoms
Alkylaryl group of (Alkyl group may be linear or branched, and the position of substitution to the aryl group is arbitrary)
Can be mentioned. Examples of the arylalkyl group include arylalkyl groups having 7 to 12 carbon atoms such as benzyl group, phenylethyl group, phenylpropyl group, phenylbutyl group, phenylpentyl group and phenylhexyl group (these alkyl groups may be straight chain). It may be branched)
Can be mentioned.

The hydrocarbon group having 1 to 30 carbon atoms represented by R ^{1 to} R ⁶ is preferably an alkyl group having 1 to 30 carbon atoms or an aryl group having 6 to 24 carbon atoms, and more preferably It is an alkyl group having 4 to 20 carbon atoms, and more preferably an alkyl group having 6 to 18 carbon atoms.

As the compound represented by the general formula (1),
For example, the following sulfur- and phosphorus-containing compounds may be mentioned. Thiophosphorous acid; thiophosphite such as monopropylthiophosphite, monobutylthiophosphite, monopentylthiophosphite, monohexylthiophosphite, monopeptylthiophosphite, monooctylthiophosphite, monolaurylthiophosphite Phosphoric acid monoalkyl ester (alkyl group may be linear or branched);
Thiophosphorous acid mono ((alkyl) aryl) esters such as monophenylthiophosphite and monocresylthiophosphite; dipropylthiophosphite, dibutylthiophosphite, dipentylthiophosphite, dihexylthiophosphite, dipeptylthio Dialkyl thiophosphites such as phosphite, dioctylthiophosphite and dilaurylthiophosphite (alkyl groups may be linear or branched); diphenylthiophosphite, dicresylthiophosphite and other thiophosphites Acid di ((alkyl) aryl) ester; tripropylthiophosphite, tributylthiophosphite, tripentylthiophosphite, trihexylthiophosphite, tripeptylthiophosphite, trioctylthiophosphite, Thiophosphorous acid trialkyl esters such as lauryl thiophosphite (the alkyl group may be linear or branched); Triphenyl phosphite tri ((alkyl) such as triphenylthiophosphite, tricresylthiophosphite, etc. Aryl) ester;

Dithiophosphorous acid; monopropyldithiophosphite, monobutyldithiophosphite, monopentyldithiophosphite, monohexyldithiophosphite, monopeptyldithiophosphite, monooctyldithiophosphite, monolauryldithiophosphite. And other dithiophosphorous acid monoalkyl esters (the alkyl groups may be linear or branched); monophenyldithiophosphite, monocresyldithiophosphite and other dithiophosphite mono ((alkyl) aryl) esters ; Dithiolysines such as dipropyldithiophosphite, dibutyldithiophosphite, dipentyldithiophosphite, dihexyldithiophosphite, dipeptyldithiophosphite, dioctyldithiophosphite, dilauryldithiophosphite Acid dialkyl ester (the alkyl group may be linear or branched); dithiophosphorous acid di ((alkyl) aryl) ester such as diphenyldithiophosphite, dicresyldithiophosphite; tripropyldithiophosphite, tributyl Dithiophosphite, tripentyldithiophosphite, trihexyldithiophosphite, tripeptyldithiophosphite,
Dithiophosphite trialkyl esters such as trioctyldithiophosphite and trilauryldithiophosphite (alkyl groups may be linear or branched); Dithios such as triphenyldithiophosphite and tricresyldithiophosphite Tris ((alkyl) aryl) phosphite
Ester; trithiophosphorous acid; monopropyltrithiophosphite, monobutyltrithiophosphite, monopentyltrithiophosphite, monohexyltrithiophosphite, monopeptyltrithiophosphite, monooctyltrithiophosphite, monolauryltrithiophosphite, etc. Trithiophosphite monoalkyl ester (alkyl group may be linear or branched); trithiophosphite mono ((alkyl) aryl) ester such as monophenyltrithiophosphite or monocresyltrithiophosphite;

Dialkyl esters of trithiophosphites such as dipropyltrithiophosphite, dibutyltrithiophosphite, dipentyltrithiophosphite, dihexyltrithiophosphite, dipeptyltrithiophosphite, dioctyltrithiophosphite, dilauryltrithiophosphite ( The alkyl group may be linear or branched); trithiophosphite di ((alkyl) aryl) esters such as diphenyltrithiophosphite and dicresyltrithiophosphite; tripropyltrithiophosphite, tributyltrithiophosphite,
Trithiophosphite trialkyl esters such as tripentyl trithiophosphite, trihexyl trithiophosphite, tripeptyl trithiophosphite, trioctyl trithiophosphite, trilauryl trithiophosphite (Alkyl groups may be linear or branched. May be used); trithiophosphite tri ((alkyl) aryl) esters such as triphenyltrithiophosphite, tricresyltrithiophosphite; and mixtures thereof.

In the present invention, X in the above general formula (1) is used.
It is preferable that two or more of ^{1 to} X ³ are sulfur atoms.

As the compound represented by the general formula (2),
For example, the following sulfur- and phosphorus-containing compounds may be mentioned. Thiophosphoric acid; monopropyl thiophosphate, monobutyl thiophosphate, monopentyl thiophosphate,
Monoalkyl esters of thiophosphoric acid such as monohexyl thiophosphate, monopeptyl thiophosphate, monooctyl thiophosphate, monolauryl thiophosphate (the alkyl group may be linear or branched); monophenyl thiophosphate, monocresyl thiophosphate Thiophosphoric acid mono ((alkyl) aryl) esters such as; dipropyl thiophosphates, dibutyl thiophosphates, dipentyl thiophosphates, dihexyl thiophosphates, dipeptyl thiophosphates, dioctyl thiophosphates, dilauryl thiophosphates, etc. thiophosphoric acid dialkyl esters ( The alkyl group may be linear or branched); di ((alkyl) aryl) thiophosphate such as diphenylthiophosphate, dicresylthiophosphate, etc. Ter; thiophosphoric acid trialkyl ester such as tripropyl thiophosphate, tributyl thiophosphate, tripentyl thiophosphate, trihexyl thiophosphate, tripeptyl thiophosphate, trioctyl thiophosphate, trilauryl thiophosphate (Alkyl group is linear It may be branched); thiophosphoric acid tri ((alkyl) aryl) esters such as triphenylthiophosphate, tricresylthiophosphate, etc .;

Dithiophosphoric acid; monoalkyl dithiophosphates such as monopropyldithiophosphate, monobutyldithiophosphate, monopentyldithiophosphate, monohexyldithiophosphate, monopeptyldithiophosphate, monooctyldithiophosphate, monolauryldithiophosphate, etc. The group may be linear or branched); dithiophosphoric acid mono ((alkyl) aryl) esters such as monophenyldithiophosphate, monocresyldithiophosphate; dipropyldithiophosphate, dibutyldithiophosphate,
Dithiophosphoric acid dialkyl esters such as dipentyldithiophosphate, dihexyldithiophosphate, dipeptyldithiophosphate, dioctyldithiophosphate, dilauryldithiophosphate (the alkyl group may be linear or branched); diphenyldithiophosphate, dicresyldithio Dithiophosphoric acid di ((alkyl) aryl) esters such as phosphates; tripropyldithiophosphates, tributyldithiophosphates, tripentyldithiophosphates, trihexyldithiophosphates, tripeptyldithiophosphates, trioctyldithiophosphates, trilauryldithiophosphates, etc. Dithiophosphoric acid trialkyl ester (alkyl group may be linear or branched); triphenyldithiophosphate, Dithiophosphoric acid such as cresyl dithiophosphate tri ((alkyl) aryl) ester;

Trithiophosphoric acid; trithiolines such as monopropyltrithiophosphate, monobutyltrithiophosphate, monopentyltrithiophosphate, monohexyltrithiophosphate, monopeptyltrithiophosphate, monooctyltrithiophosphate and monolauryltrithiophosphate. Acid monoalkyl ester (the alkyl group may be linear or branched); monophenyltrithiophosphate, monocresyltrithiophosphate and other dithiophosphoric acid mono ((alkyl) aryl) esters; dipropyltrithiophosphate, dibutyl Trithiophosphate, dipentyltrithiophosphate, dihexyltrithiophosphate, dipeptyltrithiophosphate, dioctyltrithiophosphate, dilauryltri Dithiophosphoric acid dialkyl ester such as ophosphate (the alkyl group may be linear or branched); Trithiophosphoric acid di ((alkyl) aryl) ester such as diphenyltrithiophosphate, dicresyltrithiophosphate; tripropyltrithio Trithiophosphoric acid trialkyl ester such as phosphate, tributyltrithiophosphate, tripentyltrithiophosphate, trihexyltrithiophosphate, tripeptyltrithiophosphate, trioctyltrithiophosphate, trilauryltrithiophosphate (alkyl group is linear Or branched)); trithiophosphoric acid tri ((alkyl) aryl) esters such as triphenyltrithiophosphate, tricresyltrithiophosphate and the like;

Tetrathiophosphoric acid; monopropyltetrathiophosphate, monobutyltetrathiophosphate,
Monoalkyl esters of tetrathiophosphoric acid such as monopentyltetrathiophosphate, monohexyltetrathiophosphate, monopeptyltetrathiophosphate, monooctyltetrathiophosphate, monolauryltetrathiophosphate (whether the alkyl group is linear or branched) Good); monophenyltetrathiophosphate, monocresyltetrathiophosphate, etc. dithiophosphoric acid mono ((alkyl) aryl) ester; dipropyltetrathiophosphate, dibutyltetrathiophosphate,
Dithiophosphoric acid dialkyl ester such as dipentyltetrathiophosphate, dihexyltetrathiophosphate, dipeptyltetrathiophosphate, dioctyltetrathiophosphate, dilauryltetrathiophosphate (the alkyl group may be linear or branched); diphenyltetra Tetrathiophosphoric acid di ((alkyl) aryl) esters such as thiophosphate and dicresyltetrathiophosphate; tripropyltetrathiophosphate, tributyltetrathiophosphate, tripentyltetrathiophosphate, trihexyltetrathiophosphate, tripeptyltetrathio Tetrathiophosphoric acid trialkyl ester (alkyl group) such as phosphate, trioctyltetrathiophosphate, trilauryltetrathiophosphate, etc. Linear or branched in form); triphenyl thiophosphate, Tetorachiorin acid tri ((alkyl) aryl such as tricresyl tetra thiophosphate) ester; and mixtures thereof.

In the present invention, X in the above general formula (2) is used.
1 to 3 of ^{4 to} X ⁶ are preferably sulfur atoms, and more preferably 1 or 2 are sulfur atoms.

As the salt of the sulfur- and phosphorus-containing compound represented by the general formula (1) or (2), ammonia, a hydrocarbon group having 1 to 8 carbon atoms or a hydroxyl group can be added to the sulfur- and phosphorus-containing compound. By reacting a nitrogen compound such as an amine compound having only a contained hydrocarbon group in the molecule, a salt obtained by neutralizing a part or all of the remaining acidic hydrogen, or the above sulfur and phosphorus containing compound and titanium, calcium, magnesium, Examples thereof include salts with zinc, sodium, potassium and the like, such as zinc dialkyldithiophosphate and zinc dialkylthiophosphate. As the nitrogen compound,
Specifically, ammonia; monomethylamine, monoethylamine, monopropylamine, monobutylamine, monopentylamine, monohexylamine, monoheptylamine, monooctylamine, dimethylamine, methylethylamine, diethylamine, methylpropylamine, ethylpropyl. Alkylamines such as amines, dipropylamine, methylbutylamine, ethylbutylamine, propylbutylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine (alkyl groups may be linear or branched); mono Methanolamine, monoethanolamine,
Monopropanolamine, monobutanolamine, monopentanolamine, monohexanolamine, monoheptanolamine, monooctanolamine, monononanolamine, dimethanolamine, methanol ethanolamine, diethanolamine, methanol propanolamine, ethanol propanolamine, dipropanol Amine, methanol butanol amine, ethanol butanol amine, propanol butanol amine,
Examples thereof include alkanolamines such as dibutanolamine, dipentanolamine, dihexanolamine, diheptanolamine, and dioctanolamine (alkanol groups may be linear or branched); and mixtures thereof.

Among the sulfur-containing compounds (B-2), as the thiazole compound, compounds represented by the following general formulas (3) and (4) are preferably used.

[0036]

[Chemical 3]

In the above general formulas (3) and (4), R
¹⁰ and R ¹¹ each represent a hydrogen atom, a hydrocarbon group having 1 to 30 carbon atoms, R ¹² represents an alkyl group having 1 to 4 carbon atoms, e, f and g each independently represent an integer of 0 to 3. Represent

Among these, the benzothiazole compound represented by the above general formula (4) is particularly preferable. here,
As the hydrocarbon group having 1 to 30 carbon atoms represented by R ¹⁰ and R ¹¹ in the general formulas (3) and (4), the above (B-
It has the same meaning as the group represented by R ^{1 to} R ⁶ in the general formula (1) or (2) of 1).

Of the (B-2) sulfur-containing compounds,
As the thiadiazole compound, a 1,3,4-thiadiazole compound represented by the following general formula (5), a 1,2,4-thiadiazole compound represented by the general formula (6),
And a 1,4,5-thiadiazole compound represented by the general formula (7).

[0040]

[Chemical 4]

In the above general formulas (5) to (7),
R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ may be the same or different and each is a hydrogen atom or a carbon number of 1 to 30.
Of the above hydrocarbon group, and h, i, j, k, l and m each independently represent an integer of 0-8.

In the above general formulas (5) to (7), R ¹³
The hydrocarbon group having 1 to 30 carbon atoms represented by R ¹⁸ to R ¹⁸ has the same meaning as the group represented by R ^{1 to} R ⁶ in the general formula (1) or (2) of the above (B-1). .

Of the (B-2) sulfur-containing compounds,
Although any dithiocarbamate can be used as the dithiocarbamate compound, preferred examples include compounds represented by the following general formulas (8) and (9).

[0044]

[Chemical 5]

In the general formulas (8) and (9), R ¹⁹
, R ²⁰ , R ²¹ , R ²² , R ²³ and R ²⁴ each independently represent a hydrocarbon group having 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms, and R ²⁵ is a hydrogen atom or 1 to 30 carbon atoms, Preferably, it represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, n represents an integer of 0 to 4, and o represents an integer of 0 to 6. The hydrocarbon group having 1 to 30 carbon atoms represented by R ^{19 to} R ²⁴ is a group represented by R ^{1 to} R ⁶ in the general formula (1) or (2) of the above (B-1). Are synonymous.

Of the (B-2) sulfur-containing compounds,
The dihydrocarbyl polysulfide compound is a sulfur-based compound generally called polysulfide or sulfurized olefin, and is specifically represented by the following general formula (10). _{^{R 26 -S p -R 27 (10}} )

In the general formula (10), R ²⁶ and R ²⁷ are each independently a straight chain or branched alkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, and 7 to 7 carbon atoms.
Represents an alkylaryl group having 20 or an arylalkyl group having 7 to 20 carbon atoms, and p is 2 to 6, preferably 2 to
Represents an integer of 5.

Specific examples of the alkyl group represented by R ²⁶ and R ²⁷ include n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group,
tert-butyl group, straight-chain or branched pentyl group, straight-chain or branched hexyl group, straight-chain or branched heptyl group, straight-chain or branched octyl group, straight-chain or branched nonyl group, straight-chain or branched Decyl group, straight chain or branched undecyl group, straight chain or branched dodecyl group, straight chain or branched tridecyl group, straight chain or branched tetradecyl group, straight chain or branched pentadecyl group, straight chain or branched hexadecyl group , A straight-chain or branched heptadecyl group, a straight-chain or branched octadecyl group, a straight-chain or branched nonadecyl group, a straight-chain or branched icosyl group.

Specific examples of the aryl group represented by R ²⁶ and R ²⁷ include a phenyl group and a naphthyl group. Specific examples of the alkylaryl group represented by R ²⁶ and R ²⁷ include a tolyl group (including all structural isomers), an ethylphenyl group (including all structural isomers), a straight chain or a branched chain. A branched propylphenyl group (including all structural isomers), a linear or branched butylphenyl group (including all structural isomers), a linear or branched pentylphenyl group (including all structural isomers), Linear or branched hexylphenyl group (including all structural isomers), linear or branched heptylphenyl group (including all structural isomers), linear or branched octylphenyl group (all structural isomers) ,), A straight-chain or branched nonylphenyl group (including all structural isomers), a straight-chain or branched decylphenyl group (including all structural isomers), a straight-chain or branched undecylphenyl group ( Including all structural isomers), direct Or branched dodecylphenyl group (including all structural isomers), xylyl group (including all structural isomers), ethylmethylphenyl group (including all structural isomers), diethylphenyl group (all structural isomers) Body), di (linear or branched) propylphenyl group (including all structural isomers), di (linear or branched) butylphenyl group (including all structural isomers), methylnaphthyl group (Including all structural isomers),
Ethylnaphthyl group (including all structural isomers), linear or branched propylnaphthyl group (including all structural isomers), linear or branched butylnaphthyl group (including all structural isomers), dimethyl Naphthyl group (including all structural isomers), ethylmethylnaphthyl group (including all structural isomers), diethylnaphthyl group (including all structural isomers), di (linear or branched) propylnaphthyl group (Including all structural isomers), di (linear or branched) butylnaphthyl group (including all structural isomers) and the like can be mentioned.

Specific examples of the arylalkyl group represented by R ²⁶ and R ²⁷ include a benzyl group, a phenylethyl group (including all isomers) and a phenylpropyl group (including all isomers). And so on.

R ²⁶ and R ²⁷ are respectively an alkyl group having 3 to 18 carbon atoms, an aryl group having 6 to 8 carbon atoms, and an alkylaryl group having 7 to 8 carbon atoms, which are derived from propylene, 1-butene or isobutylene. , Or carbon number 7 ~
It is preferably an arylalkyl group of 8.

Specifically, examples of the alkyl group include an isopropyl group, a branched hexyl group derived from a propylene dimer (including all branched isomers), and a propylene trimer. Branched nonyl group (including all branched isomers), branched dodecyl group derived from propylene tetramer (including all branched isomers), derived from propylene pentamer Branched pentadecyl group (including all branched isomers), branched octadecyl group derived from propylene hexamer (including all branched isomers), sec-butyl group, tert -Butyl group, 1
-A branched octyl group derived from butene dimer (including all branched isomers), a branched octyl group derived from isobutylene dimer (including all branched isomers) , A branched dodecyl group derived from a 1-butene trimer (including all branched isomers), a branched dodecyl group derived from an isobutylene trimer (including all branched isomers) ), A branched hexadecyl group derived from 1-butene tetramer (including all branched isomers), a branched hexadecyl group derived from isobutylene tetramer (all branched isomers) (Including the body). Examples of the aryl group include a phenyl group. Examples of the alkylaryl group include a tolyl group (including all structural isomers), an ethylphenyl group (including all structural isomers), a xylyl group (including all structural isomers), and the like. . Examples of the arylalkyl group include a benzyl group and a phenethyl group (including all isomers).

Further, the above R ²⁶ and R ²⁷ each independently have a carbon number of 3 to 3 derived from ethylene or propylene from the viewpoint that a higher transmission torque capacity can be obtained.
A branched alkyl group having 18 carbon atoms is more preferable, and a branched alkyl group having 6 to 15 carbon atoms derived from ethylene or propylene is particularly preferable.

As the dihydrocarbyl polysulfide compound, any sulfur content can be used. However, from the viewpoint that a larger transmission torque capacity can be obtained, the sulfur content is usually 10 to 55% by mass, It is preferable to use one having a content of 20 to 50% by mass.

Of the (B-2) sulfur-containing compounds,
Specific examples of the sulfurized ester compound include animal and vegetable fats and oils such as beef tallow, lard, fish fat, rapeseed oil and soybean oil; unsaturated fatty acids (oleic acid, linoleic acid or fatty acids extracted from the above animal and vegetable fats and oils). Unsaturated fatty acid ester obtained by reacting (including) with various alcohols; and those obtained by sulfurizing a mixture thereof or the like by an arbitrary method.

As the sulfurized ester compound, any sulfur content can be used, but from the viewpoint that a larger transmission torque capacity can be obtained, the sulfur content is usually 2 to 40% by mass, preferably It is preferable to use the one of 5 to 35 mass%.

In the automotive transmission oil composition of the present invention, these (B) components may be used alone or in admixture of two or more. When the component (B) is used as a lubricating oil for an automatic transmission, not only a large transmission torque capacity can be obtained, but also optimized friction characteristics in a wet clutch can be provided at the same time. . In the automobile transmission oil composition of the present invention, the content of the component (B) is 0.
005 mass% or more, preferably 0.008 mass%
Above, on the other hand, the content is 0.1 mass% or less, preferably 0.08 mass% or less. When the content of the component (B) is less than 0.005 mass% as a phosphorus element, a large transmission torque capacity cannot be obtained,
When the content exceeds 0.1% by mass, a large transmission torque capacity commensurate with the content cannot be obtained, which is not preferable.

In the case of (B-2) sulfur-containing compound,
Its content is 0.1% as the amount of elemental sulfur based on the total amount of the composition.
005 mass% or more, preferably 0.008 mass%
Above, on the other hand, the content is 0.3 mass% or less, preferably 0.2 mass% or less. When the content of the component (B) is less than 0.005 mass% as the amount of elemental sulfur, a large transmission torque capacity cannot be obtained,
If the amount exceeds 0.3% by mass, a large transmission torque capacity cannot be obtained, which is not preferable.

The automotive transmission oil composition of the present invention comprises:
By using the components (A) and (B) together, a sufficient torque transmission capacity can be achieved. However, in order to achieve a higher torque transmission capacity, it is preferable to further use (C) an ashless dispersant. .

As the ashless dispersant (C), any compound commonly used as an ashless dispersant for lubricating oils can be used. For example, at least an alkyl group or alkenyl group having 40 to 400 carbon atoms in the molecule can be used. Examples thereof include a nitrogen-containing compound having one or a derivative thereof, a modified alkenylsuccinimide, and the like. The alkyl group or alkenyl group may be linear or branched, but as a preferable example, specifically, it is derived from an olefin oligomer such as propylene, 1-butene, or isobutylene, or an ethylene / propylene co-oligomer. And branched alkenyl groups and the like. The carbon number of this alkyl group or alkenyl group is 40 to 400, preferably 60 to 400.
350. When the alkyl group or alkenyl group has less than 40 carbon atoms, the solubility of the compound in the lubricating base oil decreases, while when the alkyl group or alkenyl group has more than 400 carbon atoms, the transmission oil composition for automobiles Since the low temperature fluidity of is deteriorated, it is not preferable.

Specific examples of such nitrogen-containing compounds include polybutenyl succinimide, polybutenylamine, polybutenylbenzylamine and the like. Specific examples of the derivative of the nitrogen-containing compound include, for example, the above-mentioned nitrogen-containing compounds such as monocarboxylic acids (fatty acids) having 2 to 30 carbon atoms, oxalic acid, phthalic acid, trimellitic acid, pyromellitic acid and the like. A polycarboxylic acid having 2 to 30 carbon atoms is allowed to act to neutralize a part or all of the remaining amino groups and / or imino groups, or is amidated, a so-called acid-modified compound; A so-called boron-modified compound obtained by reacting an acid to neutralize a part or all of the remaining amino group and / or imino group or amidated; a sulfur-modified compound obtained by causing a sulfur compound to act on the above-mentioned nitrogen-containing compound. And a modified compound obtained by combining the above-mentioned nitrogen-containing compound with two or more modifications selected from acid modification, boron modification, and sulfur modification.

The automotive transmission oil composition of the present invention may contain one kind or two or more kinds of compounds arbitrarily selected from the above-mentioned (C) ashless dispersant, in an arbitrary amount. Usually, its content is 0.1 to 10% by mass, preferably 0.5 to 8% by mass, based on the total amount of the lubricating oil composition. If the content of the ashless dispersant (C) is less than 0.1% by mass, a synergistic effect with the components (A) and (B) cannot be expected, while the content of the ashless dispersant (C) is When it exceeds 10% by mass, no further synergistic effect with the components (A) and (B) is observed.

The transmission oil composition for automobiles of the present invention comprises:
By having (A) an oil-soluble metal salt overbased with an alkaline earth metal borate and (B) an extreme pressure additive further containing (C) an ashless dispersant, a higher torque transmission capacity can be obtained. A lubricating oil composition can be obtained, and if necessary, (D) a metallic detergent, (E) a friction modifier,
It is preferable to include at least one additive selected from (F) antioxidant and (G) viscosity index improver.

As the (D) metal-based detergent, any compound other than the (A) component usually used as a metal-based detergent for lubricating oil, for example, an alkali metal such as sodium or potassium or an alkali such as calcium or magnesium is used. Sulfonates, phenates, salicylates, naphthenates, etc. of earth metals can be used alone or in combination of two or more, but in order to achieve a high torque transmission capacity, calcium or magnesium sulfonates, phenates are used as metal-based detergents. It is desirable to use the salicylates alone or in combination of two or more. The details of the alkaline earth metal sulfonate, the alkaline earth metal salicylate and the alkaline earth metal phenate are as described in the section of the oil-soluble metal salt in the component (A), but the component (D) is Alkyl aromatic sulfonic acid, alkyl salicylic acid, alkylphenol, alkylphenol sulfide, Mannich reaction products of alkylphenol, etc., directly with alkaline earth metal bases such as oxides and hydroxides of magnesium and / or calcium alkaline earth metals. Not only neutral salts (normal salts) obtained by reacting or once replaced with alkaline earth metal salts such as alkali metal salts such as sodium salts and potassium salts, and further these neutral salts (normal salts) )
In the presence of carbon dioxide and basic salts obtained by heating excess alkaline earth metal salt or alkaline earth metal base (hydroxide or oxide of alkaline earth metal) in the presence of water. Overbased salt (ultrabasic salt) obtained by reacting a neutral salt (normal salt) with an alkaline earth metal base
Is also included.

Incidentally, these reactions are usually carried out in a solvent (aliphatic hydrocarbon solvent such as hexane, aromatic hydrocarbon solvent such as xylene, light lubricating base oil, etc.). The total base number of the (D) metallic detergent is not particularly limited, and is 0 to 500.
Although it is possible to use mgKOH / g, it can be arbitrarily selected according to the required performance of the lubricating oil, but in order to secure a high torque transmission capacity, its total base number is 10
It is preferably 0 mgKOH / g or more, more preferably 150 mgKOH / g or more, and particularly preferably 20.
0 mgKOH / g or more, while its total base number is
It is preferably 400 mgKOH / g or less, more preferably 350 mgKOH / g or less, and particularly preferably 300 mgKOH / g or less. The total base number is defined in JIS K2501 "Petroleum products and lubricants-Neutralization number test method". Means the total base number measured by the perchloric acid method in accordance with

The (D) metallic detergent is usually marketed in a state diluted with a light lubricating base oil or the like, and
Available, but generally has a metal content of 1.0
It is desirable to use -20 to 20% by mass, preferably 2.0 to 16% by mass.

In the automotive transmission oil composition of the present invention, 1 selected from the above (D) metallic detergents
One kind or two or more kinds of compounds can be contained in any amount, but the content is usually 0.01 to 10% by mass, preferably 0.
It is 0.05 to 5% by mass, more preferably 0.1 to 1.
It is 5% by mass.

As the friction modifier (E), any compound usually used as a friction modifier for lubricating oil can be used. For example, an alkyl group or an alkenyl group having 6 to 30 carbon atoms can be used in the molecule. An imide compound, an amine compound, a fatty acid ester, a fatty acid amide, which has at least one
And fatty acid metal salts. As the imide compound, a succinimide having a linear or branched alkyl group or alkenyl group having 6 to 30, preferably 8 to 24, and particularly preferably 10 to 20 carbon atoms, and its boric acid, phosphoric acid, Examples thereof include acid-modified compounds with carboxylic acid, sulfuric acid and the like. As the amine compound, a linear or branched, preferably linear aliphatic monoamine having 6 to 30 carbon atoms, a linear or branched, preferably linear aliphatic polyamine, or these fatty acids Examples thereof include alkylene oxide adducts of group amines. Examples of the fatty acid ester include esters of straight-chain or branched, preferably straight-chain fatty acids having 7 to 31 carbon atoms with an aliphatic monohydric alcohol or an aliphatic polyhydric alcohol. Examples of the fatty acid amide include a straight-chain or branched, preferably straight-chain fatty acid having 7 to 31 carbon atoms and an amide of an aliphatic monoamine or an aliphatic polyamine. Examples of the fatty acid metal salt include alkaline earth metal salts (magnesium salt, calcium salt, etc.) and zinc salt of a linear or branched, preferably linear, fatty acid having 7 to 31 carbon atoms. The automotive transmission oil composition of the present invention includes the above friction modifier (E).
One or two or more kinds of compounds arbitrarily selected from the above can be contained in an arbitrary amount, but the content is usually 0.01-based on the transmission oil composition for automobiles.
It is 5.0% by mass, preferably 0.03 to 3.0% by mass.

As the antioxidant (F), any of those generally used in lubricating oils such as phenol compounds and amine compounds can be used. Specifically, 2,
Alkylphenols such as 6-di-tert-butyl-4-methylphenol; 4,4-methylenebis (2,6-
Bisphenols such as di-tert-butylphenol); naphthylamines such as phenyl-α-naphthylamine; dialkyldiphenylamines; zinc dialkyldithiophosphates such as zinc di-2-ethylhexyldithiophosphate; and (3,5-di-tert -Butyl-4-hydroxyphenyl) fatty acid (for example, propionic acid) and a monohydric or polyhydric alcohol (for example, methanol, octadecanol, 1,6-hexadiol, neopentyl glycol, thiodiethylene glycol, triethylene glycol, And pentaerythritol, etc.) and the like. The automotive transmission oil composition of the present invention may contain one kind or two or more kinds of compounds arbitrarily selected from the above-mentioned antioxidant (F) in an arbitrary amount, but the content thereof is usually included. The amount is 0.01 to 5.0 mass% based on the total amount of the transmission oil composition for automobiles.

The (G) viscosity index improver is specifically one or two selected from various methacrylic acid esters.
Examples include so-called non-dispersion type viscosity index improvers such as copolymers of one or more monomers or hydrogenated products thereof, or so-called dispersion type viscosity index improvers obtained by copolymerizing various methacrylic acid esters further containing a nitrogen compound. . Specific examples of other viscosity index improvers include non-dispersion type or dispersion type ethylene-α-olefin copolymers (as α-olefins, propylene, 1-butene, 1-pentene, etc.) or hydrides thereof. , Polyisobutylene or hydrogenated products thereof, styrene-diene copolymers or hydrogenated products thereof, styrene-maleic anhydride copolymers and polyalkylstyrenes.

The molecular weight of the viscosity index improver (G) is not particularly limited, but it is necessary to select it in consideration of shear stability. Specifically, the number average molecular weight of the viscosity index improver is, for example, in the case of dispersion type and non-dispersion type polymethacrylate, 5,000 to 150,000, preferably 5,000 to 35,000. In the case of isobutylene or its hydride, ethylene-α is 800 to 5,000, preferably 1,000 to 4,000.
800 for olefin copolymers or their hydrides
˜150,000, preferably 3,000 to 12,000
0 is preferable. When an ethylene-α-olefin copolymer or a hydride thereof is used among the above-mentioned (G) viscosity index improvers, a transmission oil composition for automobiles having particularly excellent shear stability can be obtained. The automotive transmission fluid composition of the present invention may contain one or more compounds arbitrarily selected from the above-mentioned (G) viscosity index improvers in an arbitrary amount. The content is 0.1 to 40 mass% based on the total amount of the transmission oil composition for automobiles.

For the purpose of further improving the performance of the automotive transmission oil composition of the present invention, for example, (H) a titanium compound, a silicon compound, or a boron compound, which has a function of increasing the intermetallic friction coefficient, Alternatively, further known lubricating oil additives can be added. Known additives that can be added include, for example, (I) antiwear agent, (J)
Rust inhibitor, (K) corrosion inhibitor, (L) pour point depressant,
(M) rubber swelling agent, (N) defoaming agent, (O) colorant and the like. These compounds can be used alone or in combination of several kinds.

(H) Titanium compounds, silicon compounds, boron compounds, and other compounds having a function of increasing friction coefficient between metals, examples of the titanium compound include organic orthotitanates having a hydrocarbon group having 1 to 30 carbon atoms, organic compounds. Examples thereof include a titanate / polyamine condensate, an organic titanate / polyol condensate, and titanium phosphate.
Examples of the silicon compound include organic orthosilicates having a hydrocarbon group having 1 to 30 carbon atoms, organic orthosilicate / polyamine condensates, organic orthosilicate / polyol condensates, and the like. Examples of the boron compound include an organic borate having a hydrocarbon group having 1 to 30 carbon atoms, an organic borate / polyamine condensate, an organic borate / polyol condensate, an organic borate / phosphite adduct, and an organic mercaptoalkyl borate. Can be mentioned. The titanium compound, silicon compound, and boron compound may be used alone or in combination of two or more in each compound. Further, a titanium compound, a silicon compound or a boron compound may be used in an appropriate combination. The content in the case of adding these compounds (the total content in the case of using a plurality of compounds in combination) is preferably 0.01 to 10% by mass, more preferably the total amount of the lubricating oil composition. Is 0.02 to 5% by mass, and particularly preferably 0.05 to 3% by mass. A lubricating oil composition containing these compounds is disclosed in Japanese Patent Application No. 2001-27533.
Nos. 27534 and 27535 have the disclosures thereof.

Examples of the antiwear agent (I) include phosphoric acid, phosphoric acid monoesters, phosphoric acid diesters, phosphoric acid triesters, phosphorous acid, phosphorous acid monoesters and phosphorous acid diesters. , Phosphite triesters,
Alternatively, (phosphite), (phosphite) monoesters, metal salts or amine salts of (phosphite) diesters, and mixtures thereof may be mentioned. Of the antiwear agents listed here, those without phosphoric acid usually have 2 to 2 carbon atoms.
It is a compound containing 30, preferably 3 to 20 hydrocarbon groups. When the antiwear agent is contained, its content is preferably 0.005 to 0.2 mass% as a phosphorus element based on the total amount of the automotive transmission oil composition. If the phosphorus element content is less than 0.005% by mass, there is no effect on the wear resistance, and if it exceeds 0.2% by mass, the oxidation stability deteriorates, which is not preferable.

Examples of the rust inhibitor (J) include alkenyl succinic acid, alkenyl succinic acid ester, polyhydric alcohol ester, petroleum sulfonate, and dinonylnaphthalene sulfonate. As the corrosion inhibitor (K), for example, any compound usually used as a corrosion inhibitor for lubricating oils can be used, and examples thereof include benzotriazole-based, tolyltriazole-based, thiadiazole-based and imidazole-based compounds. Is mentioned. Examples of the (L) pour point depressant include polymethacrylate-based polymers compatible with the lubricating base oil used. Examples of the rubber swelling agent (M) include aromatic compounds and sulfur compounds. Examples of the (N) defoaming agent include silicones such as dimethyl silicone and fluorosilicone.

In the present invention, the content of these additives is arbitrary, but when these additives are contained, the rust inhibitor, corrosion inhibitor, pour point depressant, The content of the rubber swelling agent is 0.005 to 3% by mass, and the content of the defoaming agent is about 0.0005 to 0.01% by mass.

The automotive transmission oil composition of the present invention comprises 10
Kinematic viscosity at 0 ° C is 4 to 30 mm ²Be / s
Preferably, more preferably 5 to 25 mm²/ S
It

The automotive transmission oil composition of the present invention can be preferably used for an automatic transmission and / or a continuously variable transmission. In particular, it can be suitably used for a metal belt type continuously variable transmission. Further, it can be suitably used for an automatic transmission having a normal wet clutch, a manual transmission and the like.

[0079]

The present invention will be described in more detail with reference to the following examples and comparative examples, but the present invention is not limited to these examples.

(Examples 1 to 7) and (Comparative Examples 1 to 10)
Using a hydrorefined mineral oil as a base oil, the automotive transmission oil composition of the present invention having the composition shown in each example of Table 1 (Example 1
.About.7), and comparative automotive transmission fluid compositions (Comparative Examples 1-10) having the compositions shown in the respective examples of Table 2 were prepared. ASTM for each composition prepared
The LFW-1 friction test was performed under the following conditions in accordance with the test conditions specified in D2714, and the friction coefficient was obtained from the friction force measured under each sliding speed. The results are shown in Tables 1 and 2. (Test conditions) Ring: Falex S-10 Test Ring (SAE 4620 Steel) Block: Falex H-60 Test Bloc
k (SAE 01 Steel) Test oil temperature: 110 ° C. Test load: 250 lb Sliding speed: 25 cm / s

[0081]

[Table 1]

[0082]

[Table 2]

As is clear from the results of Tables 1 and 2,
The automotive transmission fluid composition of the present invention comprising (A) an oil-soluble metal salt overbased with an alkaline earth metal borate, and (B) a sulfur-containing extreme pressure additive is (A) component, Alternatively, compositions not containing any one of the components (B) (Comparative Examples 1 to 4) and compositions having a content of the component (A) outside the range specified in the present invention (Comparative Examples 5 and 6) , (A)
Compositions containing oil-soluble metal salts overbased only with alkaline earth metal carbonates instead of the components (Comparative Examples 7 to 9),
Further, the intermetallic friction coefficient, which is an index of the transmission torque capacity, can be further increased as compared with the composition (Comparative Example 10) in which a phosphorus compound containing no sulfur is added instead of the component (B).

[0084]

By using the automotive transmission oil composition of the present invention, the coefficient of friction between metals can be increased.
Therefore, if the transmission oil composition for automobiles of the present invention is used, a sufficient transmission torque capacity can be secured, so that it can be applied to a vehicle equipped with an engine having a higher displacement than that of the present situation, particularly, a vehicle equipped with an engine of 2500 cc or more, As a result, it becomes possible to further improve the quietness and fuel economy of the vehicle equipped with the metal belt type continuously variable transmission.

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Claims (9)

[Claims] 1. A lubricating base oil comprising 0.001 to 0.3% by mass of (A) an oil-soluble metal salt obtained by overbasing with an alkaline earth metal borate as a boron element based on the total amount of the composition. And (B) a sulfur-containing extreme pressure additive, which is incorporated into a transmission oil composition for an automobile. 2. The automobile transmission oil composition according to claim 1, wherein the oil-soluble metal salt in the component (A) is an alkaline earth metal sulfonate and / or salicylate. 3. The alkaline earth metal borate in the component (A) is calcium borate and / or magnesium borate.
The transmission oil composition for automobiles according to 1. 4. The component (B) is thiophosphorous acid, dithiophosphorous acid, trithiophosphorous acid, thiophosphoric acid, dithiophosphoric acid, trithiophosphoric acid and their mono-substituted esters, their di-substituted esters and their tri-phosphoric acids. The automotive transmission oil composition according to any one of claims 1 to 3, which is at least one compound selected from the group consisting of substituted esters and salts thereof. 5. The component (B) is blended in an amount of 0.005 to 0.3% by mass as a sulfur element amount and / or 0.005 to 0.1% by mass as a phosphorus element amount based on the total amount of the composition. The automotive transmission fluid composition according to any one of claims 1 to 4, wherein 6. The automobile transmission oil composition according to claim 1, further comprising (C) an ashless dispersant. 7. Further, at least one additive selected from the group consisting of (D) metallic detergent, (E) friction modifier, (F) antioxidant and (G) viscosity index improver is contained. The transmission oil composition for automobiles according to any one of claims 1 to 6, characterized in that: 8. The automotive transmission oil composition according to any one of claims 1 to 7, which is used for an automatic transmission and / or a continuously variable transmission. 9. The automotive transmission oil composition according to claim 8, which is for a metal belt type continuously variable transmission.