JP2003041283A - Lubricating oil composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubricating oil composition which excels in fuel consumption saving performance at middle and high temperatures and, in addition, excels in wet clutch friction properties. SOLUTION: The lubrication oil composition comprises a base oil and, based on the total weight of the composition, (A) 0.003-0.1 mass%, in terms of Mo element, organomolybdenum compound, (B) 0.08-0.3 mass%, in terms of N element, boron-containing succinimide and/or boron-free succinimide at a mass ratio of component (B) in terms of N element to component (A) in terms of Mo element of >=1.6, (C) 0.01-0.16 mass%, in terms of an alkaline earth metal, alkaline earth metal-based cleaning agent, (D) 0.01-0.1 mass%, in terms of zinc element, zinc dithiophosphate, (E) <=0.1 mass%, in terms of phosphorus element, phosphoric (phosphorous) esters and, simultaneously, with a sulfate ash in the composition of <=1 mass%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating oil composition, and more particularly to a lubricating oil composition having excellent fuel economy at medium to high temperatures.
The present invention relates to a lubricating oil composition which has excellent friction characteristics of a wet clutch, and is preferably used for a four-cycle engine for motorcycles.

[0002]

2. Description of the Related Art In recent years, from the viewpoint of environmental problems, in particular, reduction of carbon dioxide emission, saving fuel consumption of automobiles is one of the important issues. Therefore, weight reduction of automobiles, improvement of combustion and low friction of engine are required. And development and improvement of drive system devices are being studied. For example, in order to reduce the friction of the engine, improvement of the valve train structure, reduction of the number of piston rings, reduction of the surface roughness of the sliding member, and other improvements from the material side, as well as the development of lean burn engines and direct fuel injection engines, Fuel-saving engine oil is being applied. In the drive system device,
Not only does it reduce friction from the material side of manual transmissions and automatic transmissions, but also has excellent power transmission performance such as automatic transmissions with slip lock-up clutches and continuously variable transmissions such as metal belt type or toroidal type. New technologies have been developed to improve fuel efficiency. Furthermore, recently, there has been a demand for a transmission fluid that has low fuel consumption due to low viscosity and low friction, and proper friction characteristics that are excellent in power transmission performance such as a wet clutch and a metal belt.

In addition to the engine, a lubricating oil used in a four-cycle engine for a motorcycle, in which a transmission and a power transmission portion (wet clutch) of the transmission are housed in one crankcase, the engine oil and the transmission oil are Although it is necessary to meet the performance requirements of both, similar to the above, the demand for fuel saving performance is increasing. And the above-mentioned engine, drive unit, and 4-cycle engine for motorcycles are made smaller and lighter,
Higher output has been further promoted, and the heat load on the lubricating oils used for these has become higher than ever. Therefore, not only medium temperature of about 80 ° C but also fuel saving performance at high temperature is important. There is a tendency. In particular, a four-cycle engine for a motorcycle has a wider engine speed range and a higher regular speed than a four-wheeled engine, and the engine oil temperature fluctuates greatly from a low temperature to a high temperature depending on running conditions. There is a demand for engine oil that has stable fuel economy performance.

On the other hand, in gasoline vehicles, especially diesel vehicles or motorcycles these days, for purification of exhaust gas,
EGR devices, exhaust gas purification devices such as three-way catalysts, oxidation catalysts, and particulate filters (DPF) are beginning to be installed. To maintain the performance of these exhaust gas treatment devices, the reduction of sulfur in gasoline and diesel fuel is being promoted. Has been. In addition to this, further reduction of ash and reduction of phosphorus in engine oils are being studied for the same purpose as described above. To reduce the ash and phosphorus of engine oil, reduce the amount of metallic detergent used, reduce the amount of zinc dithiophosphate added as an excellent antioxidant and antiwear agent, or However, there is a possibility that the performance of conventional engine oil may be impaired, and reduction of ash and reduction of phosphorus are extremely difficult problems.

As a fuel-saving engine oil, for example, Japanese Patent Application Laid-Open No. 8-302378 discloses a specific lubricant (alkaline earth metal salicylate-based detergent, a specific additive for a specific lubricating base oil).
An engine oil composition containing a specific amount of molybdenum dithiocarbamate-based friction reducing agent) has been proposed. Further, in JP-A-2000-087070, a specific base oil contains a specific additive (metal-based detergent, friction modifier, etc.) to reduce oil consumption, and engine speed is 30.
A 4-cycle engine oil composition for motorcycles has been proposed which has excellent fuel economy performance over a range of 00-13000 rpm. However, when these fuel-saving engine oils are directly applied to a four-cycle engine for motorcycles, not only the slippage of the wet clutch is significant and the power transmission capability of the clutch is poor, but also the shifting feeling is deteriorated, the friction material is heated and burned. It has been a common sense of those skilled in the art that it is extremely difficult to satisfy both the fuel consumption saving and the slip prevention of the wet clutch because there is a concern that abrasion, breakage, etc. may occur. Therefore, such a fuel-saving engine oil is limited to the application to a special motorcycle with a clutch slip countermeasure, and is a widely-used motorcycle that has excellent fuel economy at medium to high temperatures and excellent friction characteristics of a wet clutch. There was a long-awaited need for four-cycle engine oil. Incidentally, it has been conventionally known that when a transmission fluid contains an organic molybdenum compound, the static friction characteristics in a wet clutch are extremely deteriorated. Therefore, a fuel-saving lubricating oil composition containing an organic molybdenum is used for a drive system device. It does not exist in practice.

[0006]

DISCLOSURE OF THE INVENTION The inventors of the present invention have disclosed the above-mentioned JP-A-8-302378 and JP-A-2000-0870.
In a conventional fuel-saving engine oil containing an organic molybdenum compound and an alkaline earth metal salicylate as shown in Examples of JP-A-70, an alkali for the purpose of developing a lubricating oil composition for an engine equipped with an exhaust gas purifying device is used. The fuel-saving performance and the frictional characteristics of the wet clutch in the case of reducing the ash content by reducing the content of earth metal salicylate were investigated. As a result, it has been found that the friction characteristics at medium to high temperatures, which have become important due to the increase in heat load in recent years, tend to deteriorate (fuel efficiency performance deteriorates), and that the friction characteristics of wet clutches are extremely likely to deteriorate. did. At the same time, it was also found that the conventional fuel-saving engine oil described above is not satisfactory in fuel-saving property at high temperature.

Further, the inventors of the present invention can achieve both the fuel saving performance and the wet clutch anti-slip performance, and the JASO T903
A 4-cycle engine oil composition for motorcycles, which is determined to be MA class (no clutch slippage) according to the performance classification specified by -98, has already been applied for a patent (Japanese Patent Application 2000-0.
No. 28919). However, it was found that there is room for further improvement in static friction characteristics, which is an index of acceleration response at the time of starting or immediately after shifting. Also, for low ash type (low sulfated ash content type) compositions in which the content of metallic detergents is reduced, and in addition to this, low ash and low phosphorus type compositions in which the content of zinc dithiophosphate is reduced It turned out that there is room for further study.

Therefore, an object of the present invention is to provide a fuel-saving lubricating oil composition containing an organic molybdenum compound, which is excellent in fuel saving over a medium temperature to a high temperature due to an increase in heat load even when the amount of the metallic detergent is reduced. It is to provide a lubricating oil composition having performance. Further, an object of the present invention is to reduce the amount of sulfated ash and the amount of phosphorus element in the composition in a fuel-saving lubricating oil composition containing an organic molybdenum compound, and to a vehicle equipped with an exhaust gas purifying device as described above. It is to provide a lubricating oil composition that is preferably used. A further object of the present invention is to provide a fuel-saving lubricating oil composition containing an organic molybdenum compound, which has excellent fuel economy at medium to high temperatures, and is a wet clutch that is an index of acceleration responsiveness at the time of starting or immediately after shifting. To provide a lubricating oil composition having improved static friction characteristics. Furthermore, the subject of this invention is the fuel-saving type lubricating oil composition containing an organic molybdenum compound, improving the fuel-saving performance from low temperature to high temperature, and in the performance classification of JASO T903-98 regulation, it is M.
It is to provide a lubricating oil composition having improved friction characteristics of a wet clutch that is A (judged to have no clutch slip). Further, the object of the present invention is to improve the friction characteristics to the same extent as the friction characteristics of a wet clutch in a four-cycle engine oil for a motorcycle that does not contain an organic molybdenum compound (has no fuel saving performance), and from low temperature to high temperature. It is an object of the present invention to provide a lubricating oil composition suitable for a four-cycle engine for a two-wheeled vehicle, which has excellent fuel economy performance.

[0009]

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that (A) an organic molybdenum compound and (B) a succinimide-based compound are added to a lubricating base oil. Ash dispersant, (C) alkaline earth metal-based detergent,
The inventors have found that the above problems can be solved by containing (D) zinc dithiophosphate and (E) phosphate ester antiwear agent in specific amounts and in specific proportions, respectively, and have completed the present invention.

According to the present invention, a base oil comprising a mineral oil and / or a synthetic oil is added in an amount of 0.003 to 0.1% by mass of an organic molybdenum compound (A) in terms of molybdenum element, based on the total amount of the composition, and (B). The boron-containing succinimide and / or the boron-free succinimide is 0.0 in terms of nitrogen element.
8 to 0.3 mass%, and a mass ratio of the nitrogen element conversion amount of the (B) component to the molybdenum element conversion amount of the (A) component is 1.6 or more, and (C) an alkaline earth metal-based detergent. 0.01 to 0.16 mass% in terms of alkaline earth metal element, and (D) zinc dithiophosphate in terms of zinc element of 0.0
1 to 0.1% by mass, (E) at least one selected from phosphoric acid esters, phosphite esters and salts thereof, each containing 0.1% by mass or less in terms of phosphorus element, Moreover, the sulfated ash content in the composition is 1 based on the total amount of the composition.
The lubricating oil composition is characterized in that it is contained by mass% or less.

In the lubricating oil composition of the present invention, the component (A) is preferably molybdenum dithiocarbamate. In the lubricating oil composition of the present invention, the component (B) comprises a boron-containing succinimide and a boron-free mono- and / or bissuccinimide,
In addition, the content of the boron-containing succinimide is preferably 0.005 to 0.2% by mass in terms of the amount of boron based on the total amount of the composition. In the lubricating oil composition of the present invention, the component (C) is preferably 0.01 to 0.07% by mass in terms of the total amount of the composition and calculated as an alkaline earth metal element. In the lubricating oil composition of the present invention, the content of the component (D) is 0.01 to 0.
It is preferably 06% by mass. In the lubricating oil composition of the present invention, the amount of sulfated ash in the composition is preferably 0.7% by mass or less based on the total amount of the composition. In the lubricating oil composition of the present invention, the phosphorus element content in the composition is preferably 0.08 mass% or less based on the total amount of the composition.
The lubricating oil composition of the present invention is preferably used as engine oil for vehicles equipped with an exhaust gas purification device. The lubricating oil composition of the present invention is preferably used as a 4-cycle engine oil for motorcycles.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The lubricating oil composition of the present invention having improved friction characteristics will be described below. The lubricating base oil in the present invention is not particularly limited, and any mineral oil or synthetic oil can be used as long as it is usually used as a base oil for engine oil compositions. As the mineral oil-based base oil, a lubricating oil fraction obtained by distilling crude oil under atmospheric pressure and vacuum distillation is used for solvent degassing, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid. Examples include paraffin-based and naphthene-based lubricating base oils that have been refined by appropriately combining washing and purification treatments such as clay treatment.

As the synthetic base oil, poly-α-olefins (for example, polybutene, 1-octene oligomer, 1-decene oligomer, ethylene-propylene oligomer, etc.) or its hydride, isobutene oligomer or its hydride, isoparaffin. , Alkylbenzene, alkylnaphthalene, diesters (eg,
Dibutyl maleate, ditridecyl glutarate, di-
2-ethylhexyl adipate, diisodecyl adipate, ditridecyl adipate, di-2-ethylhexyl sebacate, etc., copolymers of α-olefins and diesters, polyol esters (eg, trimethylolpropane caprylate, trimethylolpropane pelargonate) , Pentaerythritol-2-ethylhexanoate, pentaerythritol pelargonate, etc.), dialkyldiphenyl ether, polyphenyl ether and the like.

As the lubricating base oil in the present invention, the above-mentioned mineral base oil or synthetic base oil can be used alone, and two or more kinds of mineral oil base oils or two or more kinds of synthetic base oils can be used. It may be a mixture, or a mixture of a mineral oil base oil and a synthetic oil base oil. And the mixing ratio of two or more kinds of base oil in the above mixture is
You can choose arbitrarily. The aromatic content of the lubricating base oil in the invention is not particularly limited, but is preferably 15% by mass or less, more preferably 10% by mass or less, and 5% by mass or less, 2% by mass. The above is particularly preferable. Aromatic content here is ASTM D25
Aromatic fraction (aromatics fracti
on) means the content.

The lubricant base oil in the present invention is not particularly limited to its viscosity, the lower limit of the kinematic viscosity at 100 ° C. is preferably from ^{2 mm} 2 / s, even more preferably at ^{3 mm} 2 / s .. On the other hand, the upper limit of the kinematic viscosity at 100 ° C. is preferably 10 mm ² / s, more preferably 8 mm ² / s. By setting the kinematic viscosity of the lubricating base oil at 100 ° C. to 2 mm ² / s or more,
It is possible to obtain a lubricating oil composition capable of forming a sufficient oil film, excellent in lubricity, and having a smaller evaporation loss of the base oil under high temperature conditions, that is, a smaller oil consumption amount. On the other hand, the kinematic viscosity at 100 ° C. is 10 mm ² / s
Since the fluid resistance is reduced by the following, it becomes possible to obtain a lubricating oil composition having a smaller frictional resistance at a lubrication point, that is, an excellent fuel saving performance.

The viscosity index of the lubricating base oil of the present invention is not particularly limited, but is preferably 80 or more, more preferably 100 or more, and the lubricating base oil has a viscosity index of 120 or more. Is more preferably contained in an amount of 15% by mass or more, and particularly preferably a lubricating base oil having a viscosity index of 120 or more. By setting the viscosity index to 80 or more, it becomes possible to obtain a lubricating oil composition which is excellent in fuel economy and has a smaller evaporation loss of the base oil under high temperature conditions. The NOACK evaporation amount of the lubricating base oil of the invention is preferably 20% by mass or less, more preferably 16% by mass or less, and particularly preferably 10% by mass or less. By setting the NOACK evaporation amount of the lubricating base oil to 20% by mass or less, the evaporation loss of the lubricating oil under high temperature conditions is smaller, and the adverse effects due to the accumulation on the exhaust gas purifying device, the piston, and the combustion chamber can be avoided. It is possible to obtain an oil composition. Note that the NOACK evaporation amount here is C
According to EC L-40-T-87, 250 ° C, -2
It means an evaporation amount when 60 g of a lubricating oil sample was evaporated under the condition of 0 mmH ₂ O and 1 hour.

The component (A) in the lubricating oil composition of the present invention is an organic molybdenum compound, the component (B) is a boron-containing succinimide and / or a boron-free succinimide, and the component (C) is It is an alkaline earth metal-based detergent, the component (D) is zinc dithiophosphate, and the component (E) is a phosphoric acid ester, a phosphorous acid ester and / or their salts (hereinafter collectively referred to as (Also referred to as (sub) phosphoric acid ester compound).

The components (A), (B) and (C) are as follows:
The component, the component (D), and the component (E) will be described in detail in order. Examples of the component (A) include molybdenum dithiocarbamate and molybdenum dithiophosphate. Specific examples of molybdenum dithiocarbamate include compounds represented by the following general formula (1). Specific examples of molybdenum dithiophosphate include compounds represented by the following general formula (2).

[0019]

[Chemical 1]

In the general formula (1), R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrocarbon group having 1 to 24 carbon atoms, and a and b are a = 0 to 4; It shows an integer in which b = 0 to 4 and a + b = 4.

[0021]

[Chemical 2]

In the general formula (2), R ⁵ , R ⁶ , R ⁷ and R ⁸ each independently represent a hydrocarbon group having 1 to 24 carbon atoms, and c and d are c = 0 to 4; It shows an integer where d = 0 to 4 and c + d = 4.

Carbonized with 1 to 24 carbon atoms represented by R ¹ , R ² , R ³ and R ^{4 of} the general formula (1) and R ⁵ , R ⁶ , R ⁷ and R ⁸ of the general formula (2). Preferred examples of the hydrogen group are a straight-chain or branched alkyl group having 1 to 24 carbon atoms, a cycloalkyl group having 5 to 13 carbon atoms or a straight-chain or branched alkylcycloalkyl group, and Carbon number 3-24
And a linear or branched alkenyl group, an aryl group having 6 to 18 carbon atoms, a linear or branched alkylaryl group, an arylalkyl group having 7 to 19 carbon atoms, and the like. The alkyl group or alkenyl group may be primary, secondary, or tertiary.

The above R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷
Specific examples of the alkyl group represented by R ⁸ and R ⁸ are methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, and
Octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, henicosyl group, docosyl group, tricosyl group and tetracosyl group. And other alkyl groups (these alkyl groups may be linear or branched)
Can be mentioned.

The above R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷
Specific examples of the cycloalkyl group and the alkylcycloalkyl group represented by R ⁸ and R ⁸ are, respectively, a cycloalkyl group such as a cyclopentyl group, a cyclohexyl group and a cycloheptyl group; a methylcyclopentyl group and a dimethylcyclopentyl group. Group, ethylcyclopentyl group, propylcyclopentyl group, ethylmethylcyclopentyl group, trimethylcyclopentyl group, diethylcyclopentyl group, ethyldimethylcyclopentyl group, propylmethylcyclopentyl group, propylethylcyclopentyl group, dipropylcyclopentyl group, propylethylmethylcyclopentyl group, methyl Cyclohexyl group,
Dimethylcyclohexyl group, ethylcyclohexyl group,
Propylcyclohexyl group, ethylmethylcyclohexyl group, trimethylcyclohexyl group, diethylcyclohexyl group, ethyldimethylcyclohexyl group, propylmethylcyclohexyl group, propylethylcyclohexyl group, dipropylcyclohexyl group, propylethylmethylcyclohexyl group, methylcycloheptyl group, dimethylcyclohexyl group Heptyl group, ethylcycloheptyl group, propylcycloheptyl group, ethylmethylcycloheptyl group, trimethylcycloheptyl group, diethylcycloheptyl group, ethyldimethylcycloheptyl group, propylmethylcycloheptyl group, propylethylcycloheptyl group, dipropylcyclo Alkylcycloalkyl groups such as heptyl group and propylethylmethylcycloheptyl group (these alkyl groups are In chain may be branched, and point of attachment to the cycloalkyl group of the alkyl group is optional) can be exemplified.

The above R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷
Specific examples of the alkenyl group represented by R ⁸ and R ⁸ are:
Decenyl group, undecenyl group, dodecenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group, hexadecenyl group, heptadecenyl group, octadecenyl group such as oleyl group, nonadecenyl group, icosenyl group, henicosenyl group, docosenyl group, tricosenyl group, tetracosenyl group, etc. An alkenyl group (these alkenyl groups may be linear or branched, and the position of the double bond is arbitrary) may be mentioned.

The above R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷
Examples of the aryl group and the alkylaryl group represented by R ⁸ and R ⁸ are individually an aryl group such as a phenyl group and a naphthyl group; a tolyl group, a xylyl group, an ethylphenyl group, a propylphenyl group, and an ethylmethylphenyl group. Group, trimethylphenyl group, butylphenyl group, propylmethylphenyl group, diethylphenyl group, ethyldimethylphenyl group, tetramethylphenyl group, pentylphenyl group, hexylphenyl group, heptylphenyl group,
Alkylaryl groups such as octylphenyl group, nonylphenyl group, decylphenyl group, undecylphenyl group, dodecylphenyl group (these alkyl groups may be linear or branched, and the bonding of alkyl group to aryl group) The position is also arbitrary).

The above R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷
And examples of the arylalkyl group represented by R ⁸ include:
Arylalkyl groups such as benzyl group, methylbenzyl group, dimethylbenzyl group, phenethyl group, methylphenethyl group, dimethylphenethyl group, etc. The bonding position to the group is also optional).

The above R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷
And R ⁸ are each independently a linear or branched alkyl group having 1 to 18 carbon atoms, or 6 carbon atoms.
Particularly preferred is an aryl group of -18 or a linear or branched alkylaryl group.

A particularly preferred diamine as the component (A) of the present invention.
As molybdenum thiocarbamate, specifically,
In general formula (1), R¹, R², R³And R^FourBut that's it
Butyl group, pentyl group, hexyl group, hepti
Group, octyl group, nonyl group, decyl group, undecyl group
Groups, dodecyl groups, and tridecyl groups (these alkyls
The group may be linear or branched), and a = 4,
Molybde dialkyldithiocarbamate with b = 0
R in the general formula (1)¹, R², R³And R^FourBut,
Butyl group, pentyl group, hexyl group,
Heptyl group, octyl group, nonyl group, decyl group, unde
Syl, dodecyl, and tridecyl groups (these
The kill group may be linear or branched), and a =
0, b = 4 dialkyldithiocarbamic acid sulfide
Ribden; in the general formula (1), R ¹, R², R³as well as
R^Four, Respectively, butyl group, pentyl group, hex
Syl group, heptyl group, octyl group, nonyl group, decyl group
Group, undecyl group, dodecyl group, and tridecyl group (
These alkyl groups may be linear or branched)
And a = 1 to 3, b = 1 to 3 and a + b = 4.
Alkyl dithiocarbamate molybdenum oxysulfide; average
Molybdenum dialkyldithiocarbamate, dial
Molybdenum sulfide and dialkyl
Selected from molybdenum oxysulfide dithiocarbamate
Examples include mixtures of two or more kinds of compounds that are used at any mixing ratio.
it can. Furthermore, these compounds are different in one molecule.
Compounds with different carbon numbers and different structure alkyl
May be.

Particularly preferable molybdenum dithiophosphate represented by the general formula (2) is, specifically, R ⁵ , R ⁶ and
R ⁷ and R ⁸ are each independently a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group,
Decyl group, undecyl group, dodecyl group, and tridecyl group (these alkyl groups may be linear or branched)
And molybdenum dialkyldithiophosphate having c = 4 and d = 0; in the general formula (2), R ⁵ , R ⁶ , and R
⁷ and R ⁸ are each independently a butyl group, a pentyl group,
A hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, and a tridecyl group (these alkyl groups may be linear or branched), and c = 0, d = Molybdenum sulfide dialkyldithiophosphate that is 4; in the general formula (2), R ⁵ , R ⁶ ,
R ⁷ and R ⁸ are each independently a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group,
Decyl group, undecyl group, dodecyl group, and tridecyl group (these alkyl groups may be linear or branched)
And molybdenum dialkyldithiophosphate oxysulfide having c = 1 to 3, d = 1 to 3 and c + d = 4; Examples thereof include a mixture of two or more kinds of compounds described above at an arbitrary mixing ratio. Furthermore, these compounds may be compounds having different numbers of carbon atoms or alkyl having different structures in one molecule.

Examples of the organic molybdenum compound in the lubricating oil composition of the present invention include, in addition to the above, basic nitrogen compounds such as succinimide, acidic molybdenum compounds such as molybdenum trioxide, hydrogen sulfide and phosphorus pentasulfide. An organic molybdenum complex which is a reaction product with a sulfur compound and the like are also mentioned as preferable examples. In the lubricating oil composition of the present invention, the lower limit of the content of the (A) organomolybdenum compound is
0.003 in molybdenum element equivalent based on the total amount of the composition
It is mass%, preferably 0.01 mass%. On the other hand, the upper limit of the content is 0.1% by mass in terms of molybdenum element, based on the total amount of the composition, and preferably 0.1.
It is 08% by mass, particularly preferably 0.06% by mass. When the content of the organic molybdenum compound (A) is less than the above lower limit value, a remarkable fuel saving effect cannot be obtained, while
When the content of the organic molybdenum compound (A) exceeds the above upper limit, the fuel saving effect corresponding to the content cannot be improved, and the friction characteristics in the wet clutch are deteriorated, which are not preferable. . In the lubricating oil composition of the present invention, molybdenum dithiophosphate and molybdenum dithiocarbamate are preferably used, but the synergistic effect with other components improves the fuel saving performance from low temperature to high temperature, and the friction characteristics in the wet clutch. It is particularly preferable to use molybdenum dithiocarbamate because it can remarkably improve

The component (B) is a boron-containing succinimide and / or a boron-free succinimide.
Examples of boron-free succinimides include monosuccinimides represented by the following general formula (3), bissuccinimides represented by the general formula (4), and those modified with an oxygen-containing organic compound. It can be illustrated.

[0034]

[Chemical 3]

In the general formula (3) or (4), R ¹⁰ ,
R ¹¹ and R ¹² each independently represent a polybutenyl group, and n represents an integer of 2 to 7.

The polybutenyl group represented by R ¹⁰ , R ¹¹ and R ¹² preferably has a number average molecular weight of 700 or more, more preferably 900 or more.
The number average molecular weight of the polybutenyl group is preferably 3500 or less, more preferably 1500 or less. By setting the number average molecular weight to 700 or more, detergency,
It becomes possible to obtain a lubricating oil composition that is more excellent in dispersibility. On the other hand, by setting the number average molecular weight to 3500 or less, it becomes possible to obtain a lubricating oil composition that is more excellent in low temperature fluidity. From the viewpoint of excellent sludge suppressing effect, the lower limit of n is 2 and preferably 3, while the upper limit of n is 7 and preferably 6. Here, the polybutenyl group can be obtained from polybutene (polyisobutene) obtained by polymerizing a mixture of 1-butene and isobutene or high-purity isobutene with a catalyst such as aluminum chloride or boron fluoride. Those having a vinylidene structure are usually contained in an amount of 5 to 100 mol%. Further, as this polybutene (polyisobutene), it is also possible to use a substance in which a trace amount of residual fluorine and chlorine due to the catalyst in the production process is removed by an appropriate treatment method, and therefore, these fluorine and The content of halogen elements such as chlorine is preferably 50 mass ppm or less, more preferably 10 mass ppm or less, further preferably 5 mass ppm or less, and particularly preferably 1 mass pp.
Those having a size of m or less can also be used.

The method for producing the succinimide represented by the general formula (3) or (4) is not particularly limited. For example, polybutene obtained by chlorinating the above polybutene, preferably polybutene from which chlorine and fluorine are sufficiently removed, is mixed with maleic anhydride to 100 to 2
Polybutenyl succinic acid obtained by reacting at 00 ° C.,
A method of reacting with a polyamine such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, or pentaethylenehexamine can be used. When producing bissuccinimide,
The polybutenyl succinic acid may be reacted in a double amount (molar ratio) of the polyamine. When producing monosuccinimide, the polybutenyl succinic acid and the polyamine may be reacted in an equal amount (molar ratio). Good.

The succinimide containing no boron is, for example, a compound represented by the general formula (3) or (4), which is obtained by reacting an oxygen-containing organic compound with an amino group and / or an imino group. It may be a compound which is partially or wholly neutralized or amidated. Specific examples of the oxygen-containing organic compound include, for example, formic acid, acetic acid, glycolic acid,
Propionic acid, lactic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecylic acid, lauric acid, tridecanoic acid, myristic acid,
C1-C30 monocarboxylic acids such as pentadecanoic acid, palmitic acid, margaric acid, stearic acid, stearic acid, oleic acid, nonadecanoic acid and eicosanoic acid; oxalic acid, phthalic acid, trimellitic acid, pyromellitic acid and other carbon atoms 2 ~ 3
Examples thereof include a polycarboxylic acid of 0 or an anhydride thereof, or an ester compound; an alkylene oxide having 2 to 6 carbon atoms; and a hydroxy (poly) oxyalkylene carbonate. By causing such an oxygen-containing organic compound to act, for example, when a part or all of the amino group or imino group in the compound of the general formula (3) or (4) becomes a structure represented by the following general formula (5). Presumed.

[0039]

[Chemical 4]

Here, R ¹³ is a hydrogen atom, an alkyl group having 1 to 24 carbon atoms, an alkenyl group, an alkoxy group, or --O--.
(R ¹⁴ O) _m H represents a hydroxy (poly) oxyalkylene group, R ¹⁴ represents an alkylene group having 1 to 4 carbon atoms, and m represents an integer of 1 to 5.

The boron-containing succinimide is obtained by reacting the compound of the general formula (3) or (4) with a boron compound. Examples of the boron compound include boric acid, borate salts, and borate esters. Specific examples of boric acid include orthoboric acid, metaboric acid, and tetraboric acid. Examples of the borate include alkali metal salts of boric acid, alkaline earth metal salts, ammonium salts, and the like, and more specifically, for example, lithium metaborate, lithium tetraborate, lithium pentaborate, perborate. Lithium borate such as lithium; sodium metaborate, sodium diborate, sodium tetraborate, sodium pentaborate, sodium hexaborate, sodium octaborate and other sodium borate; potassium metaborate, potassium tetraborate, Potassium borate such as potassium pentaborate, potassium hexaborate and potassium octaborate; calcium borate such as calcium metaborate, calcium diborate, tricalcium tetraborate, pentacalcium tetraborate and calcium hexaborate ; Magnesium metaborate, magnesium diborate, trimagnesium tetraborate, pentaborate penta Neshiumu, magnesium borate and magnesium hexaborate acid; and ammonium metaborate, ammonium tetraborate, ammonium pentaborate and ammonium borate such as ammonium eight borate. Examples of the borate ester include esters of boric acid and an aliphatic alcohol preferably having 1 to 6 carbon atoms, and more specifically, for example, monomethyl borate, dimethyl borate, trimethyl borate, and borate. Acid monoethyl, diethyl borate, triethyl borate, monopropyl borate, dipropyl borate, tripropyl borate, monobutyl borate, dibutyl borate,
Examples include tributyl borate and the like.

The boron-containing succinimide used in the present invention is not particularly limited in the mass ratio (B / N ratio) of the amount of boron and the amount of nitrogen, but the lower limit value is 0.2, preferably 0. 3, more preferably 0.5, while its upper limit is 1.2, preferably 1, and more preferably 0.9. When the B / N ratio is less than the above lower limit, the effect of the present invention is small, while when the B / N ratio exceeds the above upper limit,
It is not preferable because it is inferior in oxidative stability.

In the present invention, the boron-containing succinimide and the boron-free mono- or bis-succinimide can be used alone as the component (B), but the friction characteristics in the wet clutch can be further improved. Therefore, it is preferable to use the boron-containing succinimide alone or to use the boron-containing succinimide and the boron-free mono- and / or bissuccinimide in combination. When the boron-containing succinimide and the boron-free succinimide are used in combination, the preferable mixture ratio (mass ratio) is 100: 0 to 20: 8 for the former: the latter.
It is 0, more preferably 90:10 to 40:60, and particularly preferably 70:30 to 45:55.

The content of the component (B) in the present invention is a nitrogen element conversion amount based on the total amount of the composition, and the lower limit value thereof is 0.
08% by mass, preferably 0.09% by mass, while
The upper limit is 0.3% by mass, preferably 0.2% by mass. When the content of the component (B) is less than the above lower limit value in terms of nitrogen element based on the total amount of the composition, the fuel efficiency at medium and high temperatures and the frictional characteristics in the wet clutch are not sufficiently improved. If the content is the total amount of the composition, in terms of nitrogen element equivalent, and exceeds the above upper limit, fuel economy,
It is not preferable because the low temperature viscosity characteristics are deteriorated and the anti-emulsification property is deteriorated. For the same reason, the lower limit of the content of the boron-containing succinimide is 0.005% by mass in terms of boron element based on the total amount of the composition, and preferably 0.1%.
The content is 01% by mass, more preferably 0.02% by mass. On the other hand, the upper limit is 0.2% by mass, preferably 0.1% by mass, more preferably 0.08% by mass, and particularly preferably 0.05% by mass in terms of boron element based on the total amount of the composition. . When the content of the boron-containing succinimide exceeds the above upper limit, there is a concern that the exhaust gas purifying apparatus may be affected along with the above reason, which is not preferable.

In the lubricating oil composition of the present invention, the lower limit value of the mass ratio of the nitrogen element equivalent amount of the component (B) to the molybdenum element equivalent amount of the component (A) is 1.6, and the lower limit value is 1.8. Is preferable, and 2.1 is particularly preferable. On the other hand, the upper limit value of the mass ratio is 100, preferably 10, more preferably 5, and particularly preferably 4. If the mass ratio is less than the above lower limit, the fuel economy performance is particularly poor at high temperatures, and the friction characteristics in the wet clutch cannot be sufficiently improved. On the other hand, if the mass ratio exceeds the above upper limit, sufficient fuel economy performance is obtained. This is not preferable because it cannot be done.

The alkaline earth metal-based detergent as the component (C) will be described in detail. The component (C) includes an alkaline earth metal sulfonate, an alkaline earth metal phenate and an alkaline earth metal salicylate. In the present invention, one or more alkaline earth metal-based detergents selected from the group consisting of these can be used.

As the alkaline earth metal sulfonate,
Alkaline earth metal salts of alkylaromatic sulfonic acids obtained by sulfonation of alkylaromatic compounds having a molecular weight of 300 to 1500, preferably 400 to 700, particularly magnesium salts and / or calcium salts, and calcium salts are preferred. Used. Specific examples of the alkyl aromatic sulfonic acid 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, or the like. Further, as the synthetic sulfonic acid, for example, a by-product from an alkylbenzene manufacturing plant which is a raw material of a detergent or an olefin having 2 to 12 carbon atoms (ethylene, propylene, etc.)
A sulfonated alkylbenzene having a linear or branched alkyl group, which is obtained by alkylating the above oligomer to benzene, or a sulfonated alkylnaphthalene such as dinonylnaphthalene is used. The sulfonating agent for sulfonating these alkyl aromatic compounds is not particularly limited, but fuming sulfuric acid or sulfuric anhydride is usually used. In the present invention, among these alkaline earth metal sulfonates,
Petroleum-based ones have the effect of particularly improving fuel economy at medium and high temperatures and static friction characteristics in wet clutches, and synthetic ones are particularly effective at improving fuel economy at high temperatures, dynamic friction characteristics and braking time characteristics. Therefore, it can be used as needed.

Examples of the alkaline earth metal phenates include alkylphenols, alkylphenol sulfides, alkaline earth metal salts of Mannich reaction products of alkylphenols, particularly magnesium salts and calcium salts. Specifically, the following general formulas (6) to (8)
Can be mentioned.

[0049]

[Chemical 5]

[0050]

[Chemical 6]

[0051]

[Chemical 7]

In the above general formulas (6), (7) and (8), R ²¹ , R ²² , R ²³ , R ²⁴ , R ²⁵ and R ²⁶ may be the same or different and each has a carbon number. 4-
30 preferably linear or branched alkyl groups of 6 to 18, M ¹ , M ² and M ³ each represent an alkaline earth metal, preferably calcium or magnesium, x
Indicates 1 or 2.

The above R ²¹ , R ²² , R ²³ , R ²⁴ , R ²⁵ and R
Specific examples of the alkyl group represented by ²⁶ include butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, and tetradecyl group. Group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, henicosyl group, docosyl group, tricosyl group, tetracosyl group, pentacosyl group, hexacosyl group, heptacosyl group, octacosyl group, nonacosyl group, and triacontyl group Etc. These may be linear or branched. These may also be primary alkyl groups, secondary alkyl groups or tertiary alkyl groups. In the present invention, these alkaline earth metal phenates can be preferably used because they can improve fuel economy at low to high temperatures and friction characteristics in a wet clutch.

As the alkaline earth metal salicylate,
For example, the alkaline earth metal salts of alkylsalicylic acid, especially the magnesium and calcium salts. Specific examples include compounds represented by the following general formula (9).

[0055]

[Chemical 8]

In the general formula (9), R ²⁷ has 4 to 4 carbon atoms.
30, preferably 6-18 linear or branched alkyl groups, M ⁴ represents an alkaline earth metal, preferably calcium or magnesium. Specific examples of the alkyl group represented by R ²⁷ include butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, Pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group,
Examples thereof include a henicosyl group, a docosyl group, a tricosyl group, a tetracosyl group, a pentacosyl group, a hexacosyl group, a heptacosyl group, an octacosyl group, a nonacosyl group, and a triacontyl group, which may be linear or branched. These may also be primary alkyl groups, secondary alkyl groups or tertiary alkyl groups. In the present invention, the fuel economy from low temperature to high temperature and the frictional characteristics of the wet clutch can be remarkably improved, and therefore, it can be preferably used.

Alkaline earth metal sulfonates, alkaline earth metal phenates and alkaline earth metal salicylates may be prepared by directly adding magnesium or magnesium directly to the above alkyl aromatic sulfonic acid, alkylphenol, alkylphenol sulfide, Mannich reaction product of alkylphenol, or alkylsalicylic acid. And / or reacting with alkaline earth metal bases such as alkaline earth metal oxides and hydroxides of calcium, or once replacing with alkaline earth metal salts such as sodium salts and potassium salts. Neutral (normal salt) alkaline earth metal sulfonates, neutral (normal salt) alkaline earth metal phenates and neutral (normal salt) alkaline earth metal salicylates obtained by
Alternatively, it can be obtained by heating a neutral alkaline earth metal sulfonate, a neutral alkaline earth metal phenate, a neutral alkaline earth metal salicylate, and an excess of an alkaline earth metal salt or an alkaline earth metal base in the presence of water. Of basic alkaline earth metal sulfonates, basic alkaline earth metal phenates and basic alkaline earth metal salicylates; further of neutral alkaline earth metal sulfonates, neutral alkaline earth metal phenates and neutral alkaline earth metal salicylates An overbased (superbasic) alkaline earth metal sulfonate obtained by reacting a hydroxide of an alkaline earth metal with carbon dioxide or boric acid in the presence of
Also included are overbased (ultrabasic) alkaline earth metal phenates and overbased (ultrabasic) alkaline earth metal salicylates.

In the present invention, the above neutral alkaline earth metal salt, basic alkaline earth metal salt, overbased (ultrabasic) alkaline earth metal salt, a mixture thereof and the like can be used. Alkaline earth metal detergents are usually
It is marketed in a state diluted with light lubricating base oil etc.,
It is also available, but generally has a metal content of 1.
0 to 20% by mass, preferably 2.0 to 16% by mass is used. The total base number of the alkaline earth metal-based detergent used in the present invention is arbitrary, but usually the total base number is 500 mgK.
OH / g or less, preferably 150 to 450 mg KOH /
It is g. The total base number is JIS K2501 (199
7) of "Petroleum products and lubricating oils-Neutralization number test method" of 2).
Means the total base number measured by the perchloric acid method in accordance with

The content of the alkaline earth metal-based detergent (C) in the present invention is 0.01% by mass as the lower limit of the alkaline earth metal element conversion amount based on the total amount of the composition.
Preferably 0.02% by mass, more preferably 0.04
It is% by mass. On the other hand, the upper limit is 0.16% by mass, which makes it possible to reduce ash, but 0.13% by mass
Is preferable, 0.12 mass% is more preferable, and 0.07 mass% is particularly preferable. When the content of the component (C) specified above is less than the lower limit value described above, the fuel economy performance at medium and high temperatures and the friction characteristics of the wet clutch are deteriorated, while when the content exceeds 0.16 mass%, Although the friction characteristics of the wet clutch are improved, low ash oil cannot be used, and there is a concern of accumulation in the exhaust gas purifying device or the combustion chamber, which is not preferable.

As the zinc dithiophosphate as the component (D),
Specifically, compounds represented by the following general formula (10) can be exemplified.

[0061]

[Chemical 9]

In the general formula (10), R ³¹ , R ³² , R
³³ and R ³⁴ each independently represent a hydrocarbon group having 1 to 24 carbon atoms.

The hydrocarbon group having 1 to 24 carbon atoms represented by R ³¹ , R ³² , R ³³ and R ³⁴ is represented by the above general formula (1).
Has the same meaning as the example of the hydrocarbon group having 1 to 24 carbon atoms represented by R ¹ , R ² , R ³ and R ⁴ , and the preferred examples are also the same. As the particularly preferred compound represented by the general formula (10), specifically, zinc dimethyldithiophosphate, zinc diethyldithiophosphate, zinc dipropyldithiophosphate, zinc dibutyldithiophosphate, zinc dipentyldithiophosphate, zinc dihexyldithiophosphate can be mentioned. , Zinc diheptyldithiophosphate, zinc dioctyldithiophosphate, zinc dinonyldithiophosphate, zinc didecyldithiophosphate, zinc diundecyldithiophosphate, zinc didodecyldithiophosphate, zinc ditridecyldithiophosphate, zinc ditetradecyldithiophosphate, di Zinc dialkyldithiophosphates such as zinc pentadecyldithiophosphate, zinc dihexadecyldithiophosphate, zinc diheptadecyldithiophosphate, zinc dioctadecyldithiophosphate (these alkyl groups may be linear or branched); diphe Rujichiorin acid zinc;
Zinc ditolyldithiophosphate, zinc dixylyldithiophosphate, zinc diethylphenyldithiophosphate, zinc dipropylphenyldithiophosphate, zinc dibutylphenyldithiophosphate, zinc dipentylphenyldithiophosphate, zinc dihexylphenyldithiophosphate, zinc diheptylphenyldithiophosphate, Zinc dialkylphenyldithiophosphates such as zinc dioctylphenyldithiophosphate, zinc dinonylphenyldithiophosphate, zinc didecylphenyldithiophosphate, zinc diundecylphenyldithiophosphate, zinc didodecylphenyldithiophosphate (even if these alkyl groups are linear It may be branched, and the bonding position of the alkyl group to the phenyl group is arbitrary) and a mixture of two or more compounds selected from these at an arbitrary mixing ratio. Furthermore, these zinc dialkyldithiophosphates and zinc dialkylphenyldithiophosphates are
It may be a compound having an alkyl having a different carbon number or a different structure in the molecule. In the present invention, the component (D) is preferably a mixture of zinc dithiophosphate having a primary alkyl group (primary ZDTP) and zinc dithiophosphate having a secondary alkyl group (secondary ZDTP). The mixing ratio (mass ratio) of the former: latter is preferably 5:95 to 50:50, more preferably 10:90 to 40:60. By setting the mixing ratio within the above-mentioned preferred range, not only the effect of the present invention can be obtained, but also a composition excellent in antiwear performance can be obtained.

The upper limit of the content of (D) zinc dithiophosphate in the lubricating oil composition of the present invention is based on the total amount of the composition,
It is 0.1 mass% in terms of zinc element equivalent, preferably 0.1.
It is 08% by mass, more preferably 0.06% by mass.
On the other hand, the lower limit of the content of zinc dithiophosphate is 0.01% by mass, preferably 0.02% by mass, in terms of zinc element, based on the total amount of the composition. When the content of the zinc dithiophosphate is the total amount of the composition and exceeds the upper limit in terms of the amount of zinc element, the influence of phosphorus or zinc on the exhaust gas purifying device is feared, and the fuel saving performance at high temperature and the wet clutch When the lower limit of the content is less than 0.01% by mass, the antiwear performance may be inferior, and the sulfur source in the composition may decrease, Since the amount of molybdenum disulfide generated on the moving surface is reduced, the fuel economy performance may be inferior. In the present invention, when the content of the component (D) is 0.01 to 0.06 mass% in terms of zinc element conversion, excellent fuel economy performance from low temperature to high temperature is achieved, and particularly the frictional characteristics of the wet clutch are improved. It can be improved significantly.

The (phosphite) ester compound as the component (E) will be described in detail. Examples of the (sub) phosphoric acid ester compound that is the component (D) of the present invention include phosphoric acid monoesters, phosphoric acid diesters, phosphoric acid triesters, phosphorous acid monoesters, and phosphorous acid diesters. , Phosphorous acid triesters, thiophosphoric acid esters, dithiophosphoric acid esters, trithiophosphoric acid esters, thiophosphorous acid esters, dithiophosphorous acid esters, trithiophosphorous acid esters and salts thereof be able to. The compounds listed here usually have 2 carbon atoms.
To 30, preferably a hydrocarbon group having 3 to 20 carbon atoms.

Specific examples of the hydrocarbon group having 2 to 30 carbon atoms include an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group and an arylalkyl group (which may have a substituent). Can be mentioned. Examples of the alkyl group include ethyl group, propyl group, butyl group, pentyl group, hexyl group, 2-ethylhexyl group,
Heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group,
Mention may be made of pentadecyl group, hexadecyl group, heptadecyl group and 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. Examples of the alkyl-substituted cycloalkyl group include a methylcyclopentyl group, a dimethylcyclopentyl group, a methylethylcyclopentyl group, a diethylcyclopentyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a methylethylcyclohexyl group, a diethylcyclohexyl group, a methylcycloheptyl group, and dimethyl. Examples thereof include an alkyl-substituted cycloalkyl group having 6 to 11 carbon atoms such as a cycloheptyl group, a methylethylcycloheptyl group and a diethylcycloheptyl group (the substitution position of the alkyl group to the cycloalkyl group is also optional).

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

Examples of the aryl group include aryl groups such as phenyl group and naphthyl group.
Examples of the alkyl-substituted aryl group include tolyl group, xylyl group, ethylphenyl group, propylphenyl group, butylphenyl group, pentylphenyl group, hexylphenyl group, heptylphenyl group, octylphenyl group, nonylphenyl group, decyl group. 7 to 18 carbon atoms such as phenyl group, undecylphenyl group and dodecylphenyl group
And each alkyl-substituted aryl group (the alkyl group may be linear or branched, and the position of substitution with the aryl group is arbitrary). Examples of the arylalkyl group include arylbenzyl 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 are linear groups However, it may be branched).

Specific examples of preferred compounds as the component (E) include the following. Monopropyl phosphate, monobutyl phosphate, monopentyl phosphate, monohexyl phosphate,
Phosphoric acid monoalkyl esters such as monopeptyl phosphate and monooctyl phosphate (the alkyl group may be linear or branched); monophenyl phosphate,
Mono (alkyl) phosphates such as monocresyl phosphate
Aryl ester; phosphoric acid dialkyl ester such as dipropyl phosphate, dibutyl phosphate, dipentyl phosphate, dihexyl phosphate, dipeptyl phosphate, dioctyl phosphate (the alkyl group may be linear or branched); diphenyl phosphate, dicresyl phosphate Di (alkyl) phosphates, etc.
Aryl ester; phosphoric acid trialkyl ester such as tripropyl phosphate, tributyl phosphate, tripentyl phosphate, trihexyl phosphate, tripeptyl phosphate, trioctyl phosphate (the alkyl group may be linear or branched); triphenyl Phosphoric acid tri (alkyl) aryl esters such as phosphate and tricresyl phosphate;

Monoalkyl phosphite esters such as monopropyl phosphite, monobutyl phosphite, monopentyl phosphite, monohexyl phosphite, monopeptyl phosphite, monooctyl phosphite (alkaline groups may be linear It may be branched); monophenyl phosphite, monocresyl phosphite and other phosphorous acid mono (alkyl) aryl esters; dipropyl phosphite, dibutyl phosphite, dipentyl phosphite, dihexyl phosphite, dipeptyl phosphite , Dioctyl phosphite and other phosphite dialkyl esters (the alkyl group may be linear or branched); diphenyl phosphite, dicresyl phosphite and other phosphite di (alkyl) aryl esters; tripropyl phosphite ,bird Trialkyl phosphite such as tylphosphite, tripentylphosphite, trihexylphosphite, tripeptylphosphite, trioctylphosphite (the alkyl group may be linear or branched); triphenylphosphite Phosphite tri (alkyl) aryl esters such as phyto, tricresyl phosphite; and mixtures thereof.

Specific examples of the salts of the (phosphite) esters described above include phosphoric acid monoesters, phosphoric acid diesters, phosphoric acid triesters, phosphorous acid monoesters, phosphorous acid diesters, or phosphorous acid. To the acid triester,
A salt obtained by causing a nitrogen-containing compound such as an amine compound containing only ammonia or a hydrocarbon group having 1 to 20 carbon atoms or a hydroxyl group-containing hydrocarbon group in a molecule to act to neutralize a part or all of the remaining acidic hydrogen. Examples thereof include divalent metal salts such as zinc and iron.

As the nitrogen-containing compound, specifically,
The following can be mentioned. Ammonia; monomethylamine, monoethylamine, monopropylamine,
Monobutylamine, monopentylamine, monohexylamine, monoheptylamine, monooctylamine, dimethylamine, methylethylamine, diethylamine,
Alkylamines such as methylpropylamine, ethylpropylamine, dipropylamine, methylbutylamine, ethylbutylamine, propylbutylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine and dioctylamine (Alkyl groups may be linear or branched May be in the form); monomethanolamine, monoethanolamine, monopropanolamine, monobutanolamine, monopentanolamine, monohexanolamine, monoheptanolamine, monooctanolamine, monononanolamine, dimethanolamine, methanolethanolamine , Diethanolamine, methanol propanolamine, ethanol propanolamine, dipropanolamine, methanol butanolamine, ethanol Alkanolamines such as butanolamine, propanolbutanolamine, dibutanolamine, dipentanolamine, dihexanolamine, diheptanolamine and dioctanolamine (alkanol groups may be linear or branched); and these blend.

These (E) components are of one type or of two types.
It is possible to arbitrarily mix more than one kind. In the present invention, the component (E) includes phosphoric acid monoesters, phosphoric acid diesters, phosphorous acid monoesters, phosphorous acid diesters, thiophosphoric acid esters, thiophosphorous acid esters and salts thereof. It is preferably at least one selected from the group consisting of, and more preferably at least one selected from the group consisting of (phosphite) monoesters, (phosphite) diesters, and salts thereof.
Further, the number of carbon atoms of the hydrocarbon group constituting these is preferably 4 to 20, and more preferably 6 to 18.

The component (E) in the lubricating oil composition of the present invention can obtain the effects of the present invention even if it is not contained, and further phosphorus reduction can be achieved. At, the engine speed is low (for example, 1,000 rpm) and high (for example, 10,
It has been confirmed that the component (E) exerts a further fuel saving effect when it is more than 000 rpm).
In such a case, it is preferable to contain the component (E). A preferable lower limit value of the component (E) is 0.005 mass% as a phosphorus element conversion amount based on the total amount of the composition,
More preferably, it is 0.01% by mass. On the other hand, (E)
The upper limit of the content of the component is 0.1% by mass as the phosphorus element conversion amount based on the total amount of the composition, preferably 0.08% by mass, and more preferably 0.04% by mass.
If the content of the component (E) exceeds the above upper limit value, not only the effect commensurate with the content cannot be obtained, but also low phosphorus cannot be obtained, which is not preferable.

The lubricating oil composition of the present invention is excellent in fuel saving performance (low friction performance) and friction characteristics of a wet clutch, but in order to further improve the performance, a known lubricating oil additive is added. It can be added to the composition of the invention. Examples of such additives include friction modifiers other than the component (A) of the present invention, ashless dispersants other than the component (B) of the present invention, metallic detergents other than the component (C) of the present invention, Extreme pressure additives other than component (D) or component (E), antiwear agents, antioxidants, rust inhibitors, corrosion inhibitors, viscosity index improvers, pour point depressants, rubber swelling agents, defoaming agents and coloring Examples thereof include agents. These can be used alone or in combination of several kinds.

Examples of friction modifiers other than the component (A) of the present invention include aliphatic alcohols, fatty acids, fatty acid metal salts, fatty acid esters, aliphatic amines, aliphatic amine salts,
Aliphatic amides and the like can be used. Although these friction modifiers are slightly inferior in fuel saving performance to organic molybdenum compounds,
When used in place of the organomolybdenum compound of the present invention,
Alternatively, even when used in combination, a composition having excellent fuel economy performance and friction characteristics in a wet clutch can be obtained.

As the ashless dispersant other than the component (B) of the present invention, for example, benzylamine, alkyl polyamine,
It is possible to use polybutene amine or modified products thereof with boron compounds or sulfur compounds, alkenyl succinic acid esters and the like.

As the metallic detergent other than the component (C) of the present invention, alkali metal sulfonates, phenates,
Salicylates, alkali metal-based or alkaline earth metal-based naphthenates and the like can be used alone or in combination of two or more in the composition of the present invention. Examples of the alkali metal include sodium and potassium.

As the extreme pressure additive and antiwear agent other than the component (D) or the component (E) of the present invention, for example, a sulfur compound can be used. Examples of sulfur compounds include disulfides, sulfurized olefins, and sulfurized oils and fats.

As the antioxidant, any of those generally used in lubricating oils such as phenol compounds and amine compounds can be used. For example, 2,
Alkylphenols such as 6-di-tert-butyl-4-methylphenol, methylene-4,4-bis (2,2)
6-di-tert-butyl-4-methylphenol) and other bisphenols, phenyl-α-naphthylamine and other naphthylamines, dialkyldiphenylamines,
Phenothiazines and the like can be used.

As the rust inhibitor, for example, alkenyl succinic acid, alkenyl succinic acid ester, polyhydric alcohol ester, petroleum sulfonate, dinonylnaphthalene sulfonate and the like can be used.

As the corrosion inhibitor, for example, benzotriazole-based, thiadiazole-based, imidazole-based compounds and the like can be used.

As the viscosity index improver, a non-dispersion type viscosity index improver or a dispersion type viscosity index improver can be used. Specifically, the non-dispersion type or dispersion type polymethacrylate or olefin copolymer, or polyisobutene is used. , Polystyrene, ethylene-propylene copolymer, styrene-
Diene copolymers and hydrides thereof can be used. These weight average molecular weights are generally 5,000 to 1,000.
Although it is 50,000, in order to further improve fuel economy performance,
Weight average molecular weight of 100,000 to 1,000,000
It is desirable to use the above viscosity index improvers of 0, preferably 200,000 to 900,000, particularly preferably 400,000 to 800,000. When the lubricating oil composition of the present invention is used in a four-cycle engine for two-wheeled vehicles, it is particularly preferable to use a styrene-diene copolymer or its hydride because it is necessary to enhance shear stability.

Examples of the pour point depressant include polymethacrylate type polymers compatible with the lubricating base oil used, alkylated aromatic compounds, fumarate-vinyl acetate copolymers, ethylene-vinyl acetate copolymers and the like. Can be used.

As the defoaming agent, for example, silicone compounds such as dimethyl silicone and fluorosilicone can be used.

The amount of these additives added is arbitrary,
Usually, the content of the antifoaming agent is 0.0005 based on the total amount of the composition.
0.01 mass%, the content of the viscosity index improver is 0.05
.About.20 mass%, the content of the corrosion inhibitor is 0.005 to 0.
The content of 2% by mass and other additives is 0.0
It is about 5 to 10% by mass.

The lubricating oil composition of the present invention has not only excellent fuel economy at medium to high temperatures and frictional characteristics of a wet clutch, but also excellent performances such as wear prevention performance, high temperature oxidation stability and cleanability. In addition, the four-cycle engine oil standard for JASO motorcycles (JASO T 903-
98), and has sufficient performance to meet the above requirements.
One of the regulations requires that the amount of sulfated ash of the composition is 1.2% by mass or less based on the total amount of the composition.
The composition of the present invention can be a low ash type lubricating oil having a sulfated ash content of 1.0% by mass or less, further 0.8% by mass or less, and particularly 0.7% by mass or less. Further, it is possible to provide a composition having excellent fuel economy performance at medium and high temperatures and having extremely improved friction characteristics in a wet clutch. Here, the sulfated ash content means a sulfated ash content measured in accordance with JIS K2272, that is, an ash content obtained by adding sulfuric acid to a carbonization residue produced by burning a sample to obtain a constant weight. Further, the lubricating oil composition of the present invention has a phosphorus element content of 0.12% by mass or less based on the total amount of the composition, but by adjusting other constituent components, 0.1% by mass or less, and further 0.0
It can be 8% by mass or less, particularly 0.07% by mass or less, and when the component (E) is not contained, the phosphorus element content can be reduced to 0.05% by mass or less, and the fuel saving performance and It is also possible to obtain a composition having excellent friction characteristics in a wet clutch. When used in a 4-cycle engine for motorcycles, as described in the section of (E) component,
It is preferable to contain the component (E) because it is possible to exhibit further fuel saving performance in an actual vehicle. The low ash type and low phosphorus type lubricating oil composition of the present invention can have an extremely small influence on the exhaust gas purifying device, and is an exhaust gas purifying device such as a three-way catalyst, an oxidation catalyst, an EGR device, and a DPF. It can be advantageously used for vehicles equipped with.

The lubricating oil composition of the present invention preferably has a kinematic viscosity at 100 ° C. of 5.6 mm ² / s or more, more preferably 9.3 mm ² / s or more. On the other hand, the kinematic viscosity at 100 ° C. is preferably 21.9 mm ² / s or less, more preferably 16.3 mm ²
/ S or less, particularly preferably 12.5 mm ² / s or less. By setting the kinematic viscosity of the lubricating oil composition in the above range, it becomes possible to impart high fuel efficiency performance.

The lubricating oil composition of the present invention is used for internal combustion engines such as gasoline engines, diesel engines and gas engines, especially for internal combustion engines equipped with an exhaust gas aftertreatment device, for drive system devices having a wet clutch, and for motorcycles. Although it is suitable for a cycle engine, it can also be used as a lubricating oil that requires fuel economy or a lubricating oil that requires a friction adjusting function, such as a shock absorber.

[0091]

EXAMPLES The contents of the present invention will be described more specifically below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[Examples 1 to 14] and [Comparative Examples 1 and 2] According to the compositions shown in Table 2, the lubricating oil compositions of the present invention (Examples 1 to 14) and comparative lubricating oil compositions (Comparative Examples 1, 2)
Was prepared. The compositions of Examples 1 to 14 are compositions in which the amount of sulfated ash is reduced, and a boron-containing succinimide and a boron-free succinimide are arbitrarily combined. Moreover, the composition of Comparative Example 1 is a conventional alkaline earth metal salicylate fuel-saving engine oil having excellent fuel economy performance, and the composition of Comparative Example 2 is the alkaline earth metal salicylate of the composition of Comparative Example 1. It is a composition in which the amount of sulfated ash is reduced to 0.6% by mass or less by reducing the content of. These compositions were subjected to the SRV friction test and the wet clutch friction characteristic test shown below, and were carried out at 80 ° C to 120 ° C.
The fuel economy performance and the frictional characteristics of the wet clutch were evaluated. The evaluation results are also shown in Table 2.

[SRV Friction Test] The SRV friction tester is generally used for evaluating the fuel saving performance of engine oil compositions, and it is known that the lower the friction coefficient, the better the fuel saving performance. In the present invention, a load of 400 N,
Frequency 50Hz, amplitude 1.5mm, oil temperature 80-120 ℃
The test was performed under the condition (every 10 ° C.), and the friction coefficient at that time was measured.

[Clutch friction characteristic test] JASO 4-cycle engine oil standard for motorcycles (JASO T 903-
98) specifies performance classifications regarding clutch friction characteristics in addition to physicochemical properties suitable as a four-cycle engine oil for motorcycles. That is, JASO T 904
The dynamic friction coefficient, the static friction coefficient and the braking time are measured according to the test conditions based on -98, and the dynamic friction characteristic index, the static friction characteristic index and the braking time index are obtained by the following calculation method. Then, these indexes are calculated according to Table 1 below to MA or MB.
Performance classification. Compositions classified as MA have been shown to have excellent performance in dynamic coefficient of friction, coefficient of static friction and braking time. On the other hand, the composition classified as MB shows that any of the above indexes is lower than the standard, and the wet clutch anti-slip performance may be poor.

[0095]

[Table 1]

Calculation method (eg dynamic friction characteristic index) Dynamic friction characteristic index = 1 + (μd (s) −μd (B)) / (μd (A)
−μd (B)) μd (s): Dynamic friction coefficient of sample oil μd (A): Dynamic friction coefficient of JAFRE-A (high friction characteristic standard oil) μd (B): JAFRE-B (low friction with friction modifier) Characteristic standard oil)
The dynamic friction coefficient and the static friction characteristic index and the braking time index are also calculated by the same calculation method.

[0097]

[Table 2]

From the results shown in Table 2, the composition of Comparative Example 1 contained calcium salicylate in a calcium content of 0.
It is a conventional engine oil containing 18% by mass and excellent in fuel saving performance. Although it has excellent fuel saving performance at 80 ° C, it has been found to be inferior in fuel saving performance at 100 ° C or more. As the frictional characteristics of the clutch, the static frictional characteristic index is extremely low, and there is a particularly high possibility that clutch slippage will occur at the time of starting or shifting. Further, Comparative Example 2 in which the calcium salicylate of the composition of Comparative Example 1 was reduced and the amount of sulfated ash of the composition was 0.6% by mass.
The composition of No. 1 has worse fuel saving performance at medium to high temperatures (80 to 120 ° C.) than that of the composition of Comparative Example 1, and has a low static friction characteristic index in the friction characteristics of the wet clutch, which means that the composition at the time of starting or shifting. It can be seen that the time characteristics are inferior, the dynamic friction characteristic index and the braking time index are deteriorated, and the power transmission performance is also inferior.

From the results shown in Table 2, the B / N ratio is 0.2 to
Compositions containing a boron-containing succinimide of 0.9 and a monotype boron-free succinimide and having a sulfated ash content similar to or similar to Comparative Example 2, or further reduced (Examples 1 to 1 It can be seen that in 9), the fuel economy performance at medium to high temperatures is improved and the friction characteristics in the wet clutch are also improved as compared with Comparative Example 2. In particular, a composition containing calcium salicylate (Example 1)
It can be seen that in comparison with the conventional fuel-saving engine oil (Comparative Example 1) and the composition having the same amount of sulfated ash (Comparative Example 2), the fuel-saving performance over a medium temperature to a high temperature is significantly improved. It can be seen that the compositions containing calcium sulfonate and / or calcium phenate (Examples 2 to 9) have improved fuel economy performance, especially at high temperatures, and have extremely improved static friction characteristic index, especially in wet clutches. .
Among these, petroleum-based calcium sulfonates and B / N derived from sulfonates of mineral oil-based alkyl aromatics.
It was found that the composition containing the boron-containing succinimide having a high ratio of 0.5 to 0.9 (Examples 4, 8, and 9) was particularly effective in improving the static friction property index, and the composition of the ethylene oligomer was alkyl. It can be seen that the composition containing the modified calcium sulfonate (Example 6) is effective in increasing the fuel economy at high temperature, the dynamic friction characteristic index and the braking time index. When a boron-containing succinimide and a monosuccinimide having a low B / N ratio of 0.2 to 0.5 are used in combination, it is preferable to use the petroleum-based calcium sulfonate, which is based on the total amount of the composition. Further reduced to 0.07 mass% in terms of alkaline earth metal element conversion,
The composition in which the amount of sulfated ash in the composition was reduced to 0.5% by mass or less (Example 5) was not only excellent in fuel saving performance in medium to high temperatures, but also was classified as MA in performance classification in the JASO 4-cycle engine oil standard for motorcycles. It can be seen that the result is that the wet clutch has excellent anti-slip properties.

Compositions containing boron-containing succinimide having a B / N ratio of 0.5 to 0.9 and bis-type boron-free succinimide (Examples 10 to 14)
Is also a composition excellent in fuel saving performance over medium to high temperatures and in friction characteristics of a wet clutch, but particularly in compositions containing calcium sulfonate alkylated with ethylene oligomer (Examples 11 to 13) It can be seen that it corresponds to the MA class in the performance classification in the JASO 4-cycle engine oil standard for motorcycles and has excellent slip prevention of the wet clutch. Further, when the component (D) is reduced to a zinc element concentration conversion amount of 0.06 mass% or less and the phosphorus element conversion amount of the composition is 0.1 mass% or less (Example 1
2) The fuel economy performance is improved especially at high temperatures. More surprisingly, MoDTC was contained in place of MoDTP, and the phosphorus element content in the composition total amount basis was 0.0.
When it is reduced to 7% by mass or less (Example 13), a standard oil containing no organic molybdenum compound (the JATRE-
A: It can be seen that each friction characteristic index in the wet clutch was improved to the same level as 2.0), and the composition was extremely improved in clutch slip prevention performance.

Furthermore, when the calcium sulfonate of the composition of Example 13 was replaced with calcium salicylate, the fuel saving performance over a medium temperature to a high temperature was extremely stable and excellent, and in terms of performance classification in the JASO 4-cycle engine oil standard for motorcycles. It can be seen that the composition corresponds to MA class and is excellent in the slip prevention property of the wet clutch. Although not shown in Table 2, Examples 12, 13 and 1
The composition of No. 4 has SRV friction coefficients of 0.038 to 0.042 and 0.040 to 0.0 even at 50 to 70 ° C.
42 and 0.37 to 0.38, which are extremely low, and the compositions of Comparative Examples 1 and 2 (0.0
38-0.041 and 0.040-0.042), and it has confirmed that it has fuel-saving performance equivalent to or more than. In addition, the lubricating oil compositions of Examples 1 to 14 have anti-wear performance,
It can be provided as a product excellent in high-temperature oxidation stability and cleanliness.

[0102]

The lubricating oil composition of the present invention has excellent fuel economy from medium to high temperatures, or from low to high temperatures, and excellent friction characteristics of wet clutches. In particular, the above excellent performance can be maintained even when the amount of sulfated ash and the content of phosphorus element are reduced. Therefore, the lubricating oil composition of the present invention is a lubricating oil for internal combustion engines, a lubricating oil for transmissions having a wet clutch, and a four-cycle engine for two-wheeled vehicles, which are required to have the above-mentioned fuel economy with the increase of heat load in recent years. It can be suitably used as a lubricating oil and an engine lubricating oil for vehicles equipped with an exhaust gas purifying device.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C10M 135/18 C10M 135/18 137/02 137/02 137/04 137/04 137/10 137/10 A Z 139/00 139/00 A 159/22 159/22 159/24 159/24 // C10N 10:04 C10N 10:04 10:12 10:12 30:00 30:00 Z 30:04 30:04 30 : 06 30:06 40:04 40:04 40:25 40:25 F-term (reference) 4H104 BB05C BB24C BF03C BG06C BG10C BH02C BH03C BH06C BH07C BJ05C DA02A DB06C DB07C EA21Z EB02 FA02 FA06 LA02 LA03 LA20 PA03 PA41

Claims (9)

[Claims] 1. A base oil comprising mineral oil and / or synthetic oil,
Based on the total amount of the composition, 0.003 to 0.1% by mass of the (A) organomolybdenum compound in terms of molybdenum element, (B)
A boron-containing succinimide and / or a boron-free succinimide in a nitrogen element conversion amount of 0.08 to 0.3.
In mass%, the mass ratio of the nitrogen element equivalent of the component (B) to the molybdenum element equivalent of the component (A) is 1.
6 or more, 0.01 to 0.16 mass% of the alkaline earth metal-based detergent (C) in terms of alkaline earth metal element, (D)
0.01 to 0.1 of zinc dithiophosphate in terms of zinc element
% Of (E) phosphoric acid ester, phosphorous acid ester and at least one selected from these salts, each of which is contained in an amount of 0.1 mass% or less in terms of phosphorus element, and A lubricating oil composition having a sulfated ash content of 1% by mass or less based on the total amount of the composition. 2. The lubricating oil composition according to claim 1, wherein the component (A) is molybdenum dithiocarbamate. 3. The component (B) comprises a boron-containing succinimide and a boron-free mono- and / or bissuccinimide, and the content of the boron-containing succinimide is boron based on the total amount of the composition. The element conversion amount is 0.
It is 005-0.2 mass%, The lubricating oil composition of Claim 1 or 2 characterized by the above-mentioned. 4. The component (C), based on the total amount of the composition,
The lubricating oil composition according to any one of claims 1 to 3, which is 0.01 to 0.07 mass% in terms of an alkaline earth metal element. 5. The content of the component (D) is 0.01 to 0.06 mass% in terms of zinc element based on the total amount of the composition, and the content is preferably 0.01 to 0.06 mass%. The lubricating oil composition according to the item. 6. The composition according to claim 1, wherein the amount of sulfated ash in the composition is 0.7% by mass or less based on the total amount of the composition.
6. The lubricating oil composition according to any one of items 1 to 5. 7. The lubricating oil composition according to claim 1, wherein the phosphorus element content of the composition is 0.08% by mass or less based on the total amount of the composition. .. 8. The lubricating oil composition according to claim 1, wherein the lubricating oil composition is engine oil for vehicles equipped with an exhaust gas purifying device. 9. The lubricating oil composition according to claim 1, wherein the lubricating oil composition is a four-cycle engine oil for motorcycles.