WO2017002969A1

WO2017002969A1 - Lubricant composition, method for reducing friction of internal combustion engine, and method for producing lubricant composition

Info

Publication number: WO2017002969A1
Application number: PCT/JP2016/069709
Authority: WO
Inventors: 啓司大木; 元治石川
Original assignee: 出光興産株式会社
Priority date: 2015-07-01
Filing date: 2016-07-01
Publication date: 2017-01-05
Also published as: CN107683323A; JP6657546B2; JPWO2017002969A1

Abstract

Provided is a lubricant composition which has excellent friction reducing effect, while enabling excellent fuel consumption saving. A lubricant composition which contains (X) a lubricant base oil, (A) a dinuclear organic molybdenum compound represented by general formula (I), (B) a trinuclear organic molybdenum compound represented by general formula (II), and (C) an ashless friction modifier having two or more hydroxyl groups in each molecule, and wherein: the total of the content of the component (A) in terms of molybdenum atoms and the content of the component (B) in terms of molybdenum atoms is 0.012% by mass or more based on the total amount of the lubricant composition; the content of the component (C) is less than 2.0% by mass based on the total amount of the lubricant composition. (In formula (I), each of R¹-R⁴ represents a hydrocarbon group having 4-22 carbon atoms, and the R¹-R⁴ moieties may be the same as or different from each other; and each of X¹-X⁴ represents a sulfur atom or an oxygen atom.) Mo₃S_kE_mL_nA_pQ_z (II) (In formula (II), E represents an oxygen atom or a selenium atom; k represents an integer of 1 or more; m represents 0 or an integer; k + m is 4-10; each L independently represents an anionic ligand having an organic group that contains a carbon atom; the total number of carbon atoms in the organic group in each ligand is 14 or more; the ligands may be the same as or different from each other; n represents an integer of from 1 to 4; A represents an anion other than L; p represents 0 or an integer; Q represents a compound that donates a neutral electron; and z represents an integer of from 0 to 5, and includes a non-stoichiometric amount.)

Description

Lubricating oil composition, friction reducing method for internal combustion engine, and manufacturing method of lubricating oil composition

The present invention relates to a lubricating oil composition, a friction reducing method for an internal combustion engine, and a manufacturing method for the lubricating oil composition.

In recent years, in order to reduce energy loss and carbon dioxide, attention has been focused on improving fuel economy of automobiles.
As measures for improving the fuel efficiency of automobiles, the weight of automobile bodies is being reduced, but lubricating oils are also required to contribute to the fuel efficiency. For this reason, researchers who are involved in the development of lubricating oils are studying to lower the viscosity of lubricating oils and to further improve the friction reduction characteristics of lubricating oils.

In the study of friction reduction characteristics, an organic molybdenum compound such as MoDTC is included in the lubricating oil composition. As a lubricating oil composition containing an organic molybdenum compound, for example, Patent Document 1 proposes.

Japanese Patent Laying-Open No. 2015-010177

The organomolybdenum compound has a higher friction reduction effect than the ashless friction modifier, and is particularly excellent in the friction reduction effect in the boundary lubrication region. For this reason, various engine oils to which an organic molybdenum compound is added have been developed.
However, it is no longer sufficient to simply add an organic molybdenum compound in order to cope with further fuel saving (lower friction).
An object of this invention is to provide the lubricating oil composition excellent in the friction reduction effect and excellent in fuel-saving property.

In order to solve the above problems, it is considered to add an ashless friction modifier to the organic molybdenum compound. However, it has been reported that when an ashless friction modifier is added to an organic molybdenum compound, the friction reducing effect of the organic molybdenum compound is impaired and the friction coefficient increases.
The present inventors have studied a combination of an organomolybdenum compound that was thought to increase the friction coefficient and an ashless friction modifier, a specific organomolybdenum compound, a particular ashless friction modifier, As a result, it has been found that the friction can be drastically reduced and the above-mentioned problems have been solved.

That is, the present invention provides the following lubricating oil composition [1] to [3], a friction reducing method for an internal combustion engine, and a manufacturing method for the lubricating oil composition.
[1] (X) lubricating base oil, (A) a dinuclear organomolybdenum compound represented by the following general formula (I), (B) a trinuclear organomolybdenum compound represented by the following general formula (II), and (C ) An ashless friction modifier having two or more hydroxyl groups in the molecule, and the sum of the content in terms of molybdenum atoms of the component (A) and the content in terms of molybdenum atoms of the component (B) is a lubricating oil. A lubricating oil composition that is 0.012% by mass or more based on the total amount of the composition, and the content of the component (C) is less than 2.0% by mass based on the total amount of the lubricating oil composition.

[In Formula (I), R ¹ to R ⁴ represent a hydrocarbon group having 7 to 22 carbon atoms, and R ¹ to R ⁴ may be the same or different. X ¹ to X ^{4 each} represents a sulfur atom or an oxygen atom. ]
_{_{_{_{Mo 3 S k E m L n}}}} A p Q z (II)
[In formula (II), each E is independently oxygen or selenium. k is an integer of at least 1, m is 0 or an integer, and k + m is 4 to 10. L is independently an anionic ligand having an organic group containing a carbon atom, the total number of carbon atoms of the organic group in each ligand is 14 or more, and each ligand may be the same, May be different. n is an integer of 1 to 4. A is an anion other than L. p is 0 or an integer. Q is a compound which donates a neutral electron independently. z is an integer from 0 to 5 and includes non-stoichiometric values. ]
[2] A method for reducing friction in an internal combustion engine, wherein the lubricating oil composition according to [1] is added to the internal combustion engine.
[3] (X) a lubricating base oil;
(A) a binuclear organomolybdenum compound represented by the above general formula (I);
(B) a trinuclear organomolybdenum compound represented by the above general formula (II);
(C) having a step of mixing with an ashless friction modifier having two or more hydroxyl groups in the molecule;
The sum of the content of the component (A) in terms of molybdenum atoms and the content of the component (B) in terms of molybdenum atoms is 0.012% by mass or more based on the total amount of the lubricating oil composition, and
The manufacturing method of the lubricating oil composition which performs the said mixing process so that content of the said (C) component may be less than 2.0 mass% on the basis of lubricating oil composition whole quantity.

The lubricating oil composition and the friction reducing method for an internal combustion engine of the present invention are excellent in the friction reducing effect and can improve fuel efficiency. In addition, the method for producing a lubricating oil composition of the present invention can produce a lubricating oil composition that has an excellent friction reducing effect and good fuel economy.

Embodiments of the present invention will be described below.
[Lubricating oil composition]
The lubricating oil composition of this embodiment comprises (X) a lubricating base oil, (A) a binuclear organomolybdenum compound represented by the following general formula (I), and (B) a trinuclear organic compound represented by the following general formula (II). An organomolybdenum compound, and (C) an ashless friction modifier having two or more hydroxyl groups in the molecule, the content in terms of molybdenum atom of the component (A), and the content in terms of molybdenum atom of the component (B) The total amount is 0.012% by mass or more based on the total amount of the lubricating oil composition, and the content of the component (C) is less than 2.0% by mass based on the total amount of the lubricating oil composition.

[In Formula (I), R ¹ to R ⁴ represent a hydrocarbon group having 7 to 22 carbon atoms, and R ¹ to R ⁴ may be the same or different. X ¹ to X ^{4 each} represents a sulfur atom or an oxygen atom. ]
_{_{_{_{Mo 3 S k E m L n}}}} A p Q z (II)
[In formula (II), each E is independently oxygen or selenium. k is an integer of at least 1, m is 0 or an integer, and k + m is 4 to 10. L is independently an anionic ligand having an organic group containing a carbon atom, the total number of carbon atoms of the organic group in each ligand is 14 or more, and each ligand may be the same, May be different. n is an integer of 1 to 4. A is an anion other than L. p is 0 or an integer. Q is a compound which donates a neutral electron independently. z is an integer from 0 to 5 and includes non-stoichiometric values. ]

<(X) Lubricating base oil>
The lubricating oil composition of the present embodiment includes (X) a lubricating base oil. Examples of the lubricating base oil of component (X) include mineral oil and / or synthetic oil.
Mineral oils include paraffin-based mineral oils, intermediate-based mineral oils and naphthenic-based mineral oils obtained by ordinary refining methods such as solvent refining and hydrogenation refining; wax produced by the Fischer-Tropsch process (gas-tri-liquid wax) And wax isomerized oil produced by isomerizing wax such as mineral oil-based wax. The mineral oil is preferably classified as Group 3 in the base oil classification of the American Petroleum Institute.
Examples of synthetic oils include hydrocarbon synthetic oils and ether synthetic oils. Examples of the hydrocarbon-based synthetic oil include polybutene, polyisobutylene, 1-octene oligomer, 1-decene oligomer, α-olefin oligomer such as ethylene-propylene copolymer or the hydride thereof, alkylbenzene, alkylnaphthalene and the like. . Examples of ether synthetic oils include polyoxyalkylene glycol and polyphenyl ether.

The component (X) may be a single system using one of the above-described mineral oils and synthetic oils, but is a mixture of two or more mineral oils or a mixture of two or more synthetic oils. A mixed system may be used, such as a mixture of one or more of mineral oil and synthetic oil.

The component (X) preferably has a kinematic viscosity at 100 ° C. of 2.5 to 3.0 mm ² / s and a% C _p by ndM ring analysis of 80% or more.
By setting the 100 ° C. kinematic viscosity of the component (X) to 2.5 mm ² / s or more, it is possible to suppress the friction coefficient from increasing with time due to evaporation of the lubricating oil composition. Moreover, by setting the 100 ° C. kinematic viscosity of the component (X) to 3.0 mm ² / s or less, the high-temperature high-shear viscosity (HTHS viscosity) can be lowered to suppress an increase in the friction coefficient. Further, with the (X) component of the n-d-M ring analysis% C _p of 80% or more, with the friction coefficient by evaporation of the lubricating oil composition can be prevented from increasing with time, HTHS viscosity It is possible to suppress the increase in the friction coefficient.
Accordingly, the component (X) has a kinematic viscosity at 100 ° C. of 2.5 to 3.0 mm ² / s, and% C _p by ndM ring analysis is 80% or more, thereby reducing friction. Excellent effect and good fuel economy.

The 100 ° C. kinematic viscosity of the component (X) is more preferably 2.6 to 3.0 mm ² / s, and further preferably 2.7 to 3.0 mm ² / s.
The% C _p by ndM ring analysis of the component (X) is more preferably 82% or more, and further preferably 82 to 95%.
It is more preferably 2.6 to 3.0 mm ² / s, and further preferably 2.7 to 3.0 mm ² / s.

The content of the component (X) is preferably 60% by mass or more based on the total amount of the lubricating oil composition, more preferably 70 to 95% by mass, and 75% to 90% by mass. Further preferred.

<Organic molybdenum compounds>
The lubricating oil composition of this embodiment includes (A) a binuclear organic molybdenum compound represented by the following general formula (I), and (B) a trinuclear organic molybdenum compound represented by the following general formula (II). In the lubricating oil composition of the present embodiment, the sum of the component (A) in terms of molybdenum atoms and the component (B) in terms of molybdenum atoms is 0.012 based on the total amount of the lubricating oil composition. It is at least mass%.

Usually, when an organic molybdenum compound and an ashless friction reducing agent are used in combination, the friction reducing effect of the organic molybdenum compound is impaired, and the friction coefficient increases.
However, the lubricating oil composition of the present embodiment uses, as the organic molybdenum compound, a binuclear organic molybdenum compound of component (A) and a trinuclear organic molybdenum compound of component (B) in combination, and (A (C) None, which will be described later, by setting the total of the content in terms of molybdenum atoms of the component) and the content in terms of molybdenum atoms of the component (B) to 0.012% by mass or more based on the total amount of the lubricating oil composition. The synergistic action with the ash-based friction reducing agent makes it possible to dramatically reduce the friction coefficient.
On the other hand, when not containing either (A) component or (B) component, even if it uses the (C) ashless friction reducing agent mentioned later, the friction reduction effect of an organic molybdenum compound is impaired, and a friction coefficient is It will increase. Moreover, even if it uses together (A) component and (B) component, when the sum total of content of (A) component and (B) component is less than 0.012 mass%, the organic which becomes the base of a friction reduction effect The absolute amount of molybdenum compound is insufficient and the friction coefficient increases.

The total of the content of the component (A) in terms of molybdenum atom and the content of the component (B) in terms of molybdenum atom is preferably 0.012 to 0.125% by mass based on the total amount of the lubricating oil composition. 0.015 to 0.120% by mass is more preferable, 0.020 to 0.080% by mass is further preferable, and 0.025 to 0.055% by mass is particularly preferable. By making the total content of the component (A) and the component (B) within this range, the friction reduction effect due to the synergistic action with the component (C) described later can be improved, and in a low temperature environment ( White turbidity and precipitation due to the influence of component A) and component (B) can be suppressed.

The content of the component (A) in terms of molybdenum atoms is 0.002 to 0.100% by mass based on the total amount of the lubricating oil composition, and the content in terms of molybdenum atoms of the component (B) is the total amount of lubricating oil composition. The amount is preferably 0.001 to 0.030% by mass.
By setting the content of the component (A) and the component (B) within the above range, the friction reduction effect due to the synergistic action with the component (C) described later can be improved, and in a low temperature environment (A) White turbidity and precipitation due to the influence of the component and the component (B) can be suppressed.
The content of component (A) in terms of molybdenum atoms is more preferably 0.005 to 0.080% by mass, and more preferably 0.010 to 0.050% by mass, based on the total amount of the lubricating oil composition. preferable.
The content of component (B) in terms of molybdenum atoms is more preferably 0.002 to 0.025% by mass, and more preferably 0.005 to 0.020% by mass, based on the total amount of the lubricating oil composition. preferable.
[Content of the component (A) in terms of molybdenum atom / Content of the component (B) in terms of molybdenum atom] is preferably 0.1 to 25.0, and preferably 0.1 to 7.5. More preferably, it is more preferably 1.0 to 5.0, and still more preferably 1.5 to 3.0.

In the general formula (I), R ¹ to R ⁴ each represent a hydrocarbon group having 7 to 22 carbon atoms, and R ¹ to R ⁴ may be the same or different. When the number of carbon atoms of R ¹ to R ⁴ is 6 or less, the oil solubility is poor, and when it is 23 or more, the melting point becomes high, handling becomes worse, and the friction reducing ability is lowered. From the above viewpoint, the number of carbon atoms of R ¹ to R ⁴ is preferably 7 to 18, more preferably 7 to 14, and particularly preferably 8 to 13. The total number of carbon atoms of R ¹ to R ⁴ is preferably 34 to 80, more preferably 36 to 60, and still more preferably 38 to 54.
Examples of the hydrocarbon group for R ¹ to R ⁴ include an alkyl group, an alkenyl group, an alkylaryl group, a cycloalkyl group, and a cycloalkenyl group, and a branched or straight chain alkyl group or alkenyl group is preferable. A chain or straight chain alkyl group is more preferred. Examples of the branched or straight chain alkyl group include n-octyl group, 2-ethylhexyl group, isononyl group, n-decyl group, isodecyl group, dodecyl group, tridecyl group, isotridecyl group and the like.
In addition, from the viewpoint of solubility in base oil, storage stability and friction reducing ability, the binuclear organomolybdenum compound represented by the general formula (I) is an alkyl group in which R ¹ and R ² are the same, R ³ and R It is preferable that ⁴ is the same alkyl group, and the alkyl groups of R ¹ and R ² are different from the alkyl groups of R ³ and R ⁴ .

In the general formula (I), X ¹ to X ⁴ represent a sulfur atom or an oxygen atom, and X ¹ to X ⁴ may be the same or different.
When X ¹ to X ⁴ contain a sulfur atom and an oxygen atom, the ratio of the sulfur atom to the oxygen atom is preferably sulfur atom / oxygen atom = 1/3 to 3/1, more preferably 1/2 to 3/1. More preferably, it is 1.5 / 2.5 to 3/1. By setting the ratio of sulfur atoms to oxygen atoms in X ¹ to X ⁴ within the above range, good performance can be obtained in terms of corrosion resistance and solubility in lubricating base oil.
Further, all of X ¹ to X ⁴ may be sulfur atoms or oxygen atoms.

The (B) component trinuclear organomolybdenum compound is represented by the above general formula (II).
In the general formula (II), each L is independently an anionic ligand having an organic group containing a carbon atom, and the total number of carbon atoms of the organic group in each ligand is 14 or more. Each ligand may be the same or different, but is preferably the same. If the total number of carbon atoms of the organic group in each ligand is 13 or less, the solubility in the base oil will be reduced. The total number of carbon atoms of the organic group in each ligand is preferably 14 to 50, more preferably 16 to 30, and even more preferably 18 to 24.
The anionic ligand is preferably a monoanionic ligand (monovalent anionic ligand).

Each ligand is preferably any one selected from ligands represented by the following general formulas (III-A) to (III-D), for example.

[In the formulas (III-A), (III-B), (III-C) and (III-D), X ³¹ to X ³⁷ and Y are each independently an oxygen atom or a sulfur atom. In the formulas (III-A), (III-B), (III-C) and (III-D), R ³¹ to R ³⁵ are independent organic groups, and R ³¹ to R ³⁵ are the same. It may or may not be. The organic group of R ³¹ to R ³³ has 14 or more carbon atoms. And carbon number of the organic group R ^34, the sum of the carbon number of the organic group for R ³⁵ is 14 or more. ]
The organic group of R ³¹ to R ³³ preferably has 14 to 50 carbon atoms, more preferably 16 to 30 carbon atoms, and still more preferably 18 to 24 carbon atoms. The total of the carbon number of the organic group of R ³⁴ and the carbon number of the organic group of R ³⁵ is preferably 14 to 50, more preferably 16 to 30, and more preferably 18 to 24. Is more preferable. The number of carbon atoms in the organic group of R ^{34 and} the number of carbon atoms in the organic group of R ³⁵ are each preferably 7 to 30, more preferably 7 to 20, and more preferably 8 to 13. Is more preferable.
The organic group of R ^{34 and} the organic group of R ³⁵ may be the same or different, but are preferably different. Moreover, the carbon number of the organic group of R ³⁴ and the carbon number of the organic group of R ³⁵ may be the same or different, but are preferably different.

In the general formula (II), the ligand preferably includes a ligand represented by the above general formula (III-D).
In the general formula (II), it is preferable that all the ligands are the same, and it is more preferable that all the ligands are the ligands represented by the above general formula (III-D).

Preferably, the organic group is a hydrocarbyl group such as an alkyl group, an aryl group, a substituted aryl group, and an ether group. More preferably, each ligand has the same hydrocarbyl group.

The term “hydrocarbyl” refers to a substituent having a carbon atom that is directly bonded to the remainder of the ligand, and within the scope of this embodiment, the property is primarily hydrocarbyl. Such substituents include the following.
1. Hydrocarbon substituents As hydrocarbon substituents, substituted with aliphatic substituents such as alkyl and alkenyl, alicyclic substituents such as cycloalkyl and cycloalkenyl, aromatic groups, aliphatic groups and alicyclic groups An aromatic nucleus, a cyclic group in which the ring is completed via another location in the ligand (ie any two of the indicated substituents may together form an alicyclic group) Can be mentioned.
2. Substituted hydrocarbon substituents Examples of substituted hydrocarbon substituents include those in which the hydrocarbon substituent is substituted with a non-hydrocarbon group that does not change the properties of the hydrocarbyl. Examples of the non-hydrocarbon group include halogen groups such as chloro and fluoro, amino groups, alkoxy groups, mercapto groups, alkyl mercapto groups, nitro groups, nitroso groups, and sulfoxy groups.

Preferred ligands include alkyl xanthates, carboxylates, dialkyldithiocarbamates, and mixtures thereof. Most preferred is a dialkyldithiocarbamate.

In the general formula (II), E (oxygen or selenium) is, for example, capable of substituting sulfur in the core described later. k + m is preferably 4 to 7.
Examples of Q in the general formula (II) include water, amine, alcohol, ether and phosphine. Qs may be the same or different, but are preferably the same. The neutral electron donating compound Q is present to satisfy the empty coordination on the trinuclear molybdenum compound.
Further, the anion of A in the general formula (II) may be a monovalent anion or a divalent anion. Specific examples of A include disulfide, hydroxide, alkoxide, amide and thiocyanate or derivatives thereof.

In one embodiment of general formula (II), k is 4 to 7, n is either 1 or 2, L is a monoanionic ligand, and p is an anion charge based compound in A Is an integer that imparts electrical neutrality to m, and each of m and z is 0.
In a further embodiment of general formula (II), k is 4-7, L is a monoanionic ligand, n is 4, and each of p, m and z is 0.

The trinuclear organomolybdenum compound of the general formula (II) has, for example, a core represented by the following formula (IV-A) or (IV-B). Each core has a net electrical charge of +4. These cores are surrounded by anionic ligands and anions other than the anionic ligands present as needed.

One skilled in the art will select the appropriate anionic ligand (L) and other anions (A) for the formation of the trinuclear molybdenum-sulfur compound, depending on, for example, the sulfur and number of E atoms present in the core. ("E", "L" and "A" represent "E", "L" and "A") in general formula (II)), that is, a sulfur atom, E if present. It will be understood that the total anionic charge constituted by the atom, L and A, if present, must be -4. The trinuclear molybdenum-sulfur compound may also contain cations other than molybdenum, such as (alkyl) ammonium, amine or sodium, if the anionic charge exceeds -4. A preferred embodiment of the anionic ligand (L) and other anions (A) is a configuration having four monoanionic ligands.
Molybdenum-sulfur cores, such as the structures represented by (IV-A) and (IV-B) above, bind to one or more polydentate ligands, ie, molybdenum atoms, to form oligomers. Can be interconnected by a ligand having more than one possible functional group.

The trinuclear organic molybdenum compound can be prepared, for example, by the following methods (1) to (3). The solvent used in (1) to (3) may be, for example, aqueous or organic.
(1) Molybdenum source such as (NH ₄ ) ₂ Mo ₃ S ₁₃ · n (H ₂ O) in a suitable solvent, where n varies between 0 and 2, Is reacted with a suitable ligand source such as tetraalkyl thiuram disulfide.
(2) In an appropriate solvent, a molybdenum source such as (NH ₄ ) ₂ Mo ₃ S ₁₃ .n (H ₂ O), a ligand source such as tetraalkylthiuram disulfide and dialkyldithiocarbamic acid, a cyanide ion, and sulfurous acid It reacts with a sulfur extracting agent such as ions.
(3) Trinuclear molybdenum-sulfur such as [M ′] ₂ [Mo ₃ S ₇ A ₆ ] (where M ′ is a counter ion and A is a halogen such as Cl, Br, or I). The halide salt is reacted with a ligand source such as a dialkyldithiocarbamic acid in a suitable solvent.

The lubricating oil composition of this embodiment may further contain a mononuclear organic molybdenum compound as the organic molybdenum compound as long as the friction reducing effect is not impaired.
In the present embodiment, the (B) trinuclear organomolybdenum compound is preferably a dithiocarbamate compound, such as a trinuclear molybdenum dithiocarbamate. A particularly effective compound is a molybdenum dialkyldithiocarbamate compound represented by the formula Mo ₃ S ₇ ((alkyl) 2dtc) ₄ .

<(C) Ashless friction modifier>
The lubricating oil composition of the present embodiment includes an ashless friction modifier having two or more hydroxyl groups in the molecule as the component (C), and the component (C) is 2.0 based on the total amount of the lubricating oil composition. Contains less than mass%.

As described above, when an organic molybdenum compound and an ashless friction reducing agent are used in combination, the friction reducing effect of the organic molybdenum compound is impaired, and the friction coefficient increases. However, the lubricating oil composition of the present embodiment contains a specific amount of a specific organic molybdenum compound and contains a specific amount of the component (C), so that the friction coefficient can be drastically reduced. .
On the other hand, even if a so-called ashless friction reducing agent is used that does not satisfy the condition of the component (C) (for example, one having one hydroxyl group in the molecule), the friction reducing effect of the organic molybdenum compound is impaired. Increase the coefficient. Moreover, even if it uses (C) component, if content will be 2.0 mass% or more, the friction reduction effect of an organic molybdenum compound will be impaired, and a friction coefficient will start to increase.

The content of the component (C) is preferably 0.1 to 1.5% by mass, more preferably 0.3 to 1.0% by mass based on the total amount of the lubricating oil composition. By making content of (C) component into the said range, the friction reduction effect by a synergistic action with an organic molybdenum compound can be exhibited more, and fuel-saving property can be made more favorable.

Examples of the ashless friction modifier having two or more hydroxyl groups in the component (C) molecule include ester compounds, amine compounds, and amide compounds. Among these, amine compounds and amide compounds are preferable, and among them, amine compounds are preferable. The number of hydroxyl groups in the molecule of component (C) is preferably 2 to 6 and more preferably 2 from the viewpoint of friction reduction effect and solubility in base oil.

(C) As an ester compound which is an example of a component, the thing of the following general formula (V) is mentioned.

In the general formula (V), R ⁵¹ is a hydrocarbon group having 1 to 32 carbon atoms.
The hydrocarbon group of R ⁵¹ preferably has 8 to 32 carbon atoms, more preferably 12 to 24 carbon atoms, and still more preferably 16 to 20 carbon atoms.

Examples of the hydrocarbon group for R ⁵¹ include an alkyl group, an alkenyl group, an alkylaryl group, a cycloalkyl group, and a cycloalkenyl group. Among these, an alkyl group or an alkenyl group is preferable, and an alkenyl group is preferable among them.
^Examples of the alkyl group for R ⁵¹ 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, Examples include pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, henecosyl group, docosyl group, tricosyl group and tetracosyl group, and these may be linear, branched or cyclic .
Examples of the alkenyl group in R ⁵¹ include a vinyl group, a propenyl group, a butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, an octenyl group, a nonenyl group, a decenyl group, an undecenyl group, a dodecenyl group, a tridecenyl group, a tetradecenyl group, and a pentadecenyl group. Group, hexadecenyl group, heptadecenyl group, octadecenyl group, nonadecenyl group, icocenyl group, henicocenyl group, dococenyl group, tricocenyl group, tetracocenyl group, which may be linear, branched or cyclic The position of the double bond is also arbitrary.

R ⁵² to R ⁵⁶ are each a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, and may be the same as or different from each other. All of R ⁵² to R ⁵⁶ are preferably hydrogen atoms.
When R ⁵² to R ⁵⁶ are hydrocarbon groups, the hydrocarbon groups may be saturated or unsaturated, may be aliphatic or aromatic, and may be linear, branched or cyclic.

When the compound represented by the general formula (V) is used as the component (C), a single species in which R ⁵¹ to R ⁵⁶ are all the same may be used, or different types of R ⁵¹ to R ⁵⁶ may be different from each other. things (e.g., those existence of carbon number and double bond of R ⁵¹ are different) may be used as a mixture of two or more.

Examples of the compound represented by the general formula (V) include glycerol fatty acid monoesters such as glycerol monolaurate, glycerol monostearate, glycerol monomysterate, and glycerol monooleate. Of these, glycerin monooleate is preferred.

(C) As an amine compound which is an example of a component, the thing of the following general formula (VI) is mentioned.

In the general formula (VI), R ⁶¹ is a hydrocarbon group having 1 to 32 carbon atoms.
The hydrocarbon group of R ⁶¹ preferably has 8 to 32 carbon atoms, more preferably 10 to 24, and still more preferably 12 to 20.

Examples of the hydrocarbon group for R ⁶¹ include an alkyl group, an alkenyl group, an alkylaryl group, a cycloalkyl group, and a cycloalkenyl group. Among these, an alkyl group or an alkenyl group is preferable.
^Examples of the alkyl group for R ⁶¹ 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, Examples include pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, henecosyl group, docosyl group, tricosyl group and tetracosyl group, and these may be linear, branched or cyclic .
Examples of the alkenyl group in R ⁶¹ include vinyl group, propenyl group, butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, nonenyl group, decenyl group, undecenyl group, dodecenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group. Group, hexadecenyl group, heptadecenyl group, octadecenyl group, nonadecenyl group, icocenyl group, henicocenyl group, dococenyl group, tricocenyl group, tetracocenyl group, which may be linear, branched or cyclic The position of the double bond is also arbitrary.

R ⁶² to R ⁶⁹ are a hydrogen atom, a hydrocarbon group having 1 to 18 carbon atoms, or an oxygen-containing hydrocarbon group containing an ether bond or an ester bond, and may be the same or different from each other. A hydrogen group is preferable, and a hydrogen atom is preferable among them. Further, it is preferable that all of R ⁶² to R ⁶⁹ are hydrogen atoms.

The hydrocarbon group for R ⁶² to R ⁶⁹ may be saturated or unsaturated, may be aliphatic or aromatic, may be linear, branched or cyclic, and is, for example, an aliphatic carbon such as an alkyl group or an alkenyl group. A hydrogen group or an aromatic hydrocarbon group is mentioned. More specifically, methyl group, ethyl group, propyl group, butyl group, butenyl group, hexyl group, hexenyl group, octyl group, octenyl group, 2-ethylhexyl group, nonyl group, decyl group, undecyl group, decenyl group, Dodecyl, dodecenyl, tridecyl, tetradecyl, tetradecenyl, pentadecyl, hexadecyl, hexadecenyl, heptadecyl, octadecyl, octadecenyl, stearyl, isostearyl, oleyl, linole, cyclopentyl, cyclohexyl Group, methylcyclohexyl group, ethylcyclohexyl group, propylcyclohexyl group, dimethylcyclohexyl group, aliphatic hydrocarbon group such as trimethylcyclohexyl group, phenyl group, methylphenyl group, ethylphenyl group, dimethylphenyl group Group, propylphenyl group, trimethylphenyl group, butylphenyl group, an aromatic hydrocarbon group and a naphthyl group.
The hydrocarbon group preferably has 1 to 18 carbon atoms, more preferably 1 to 12 carbon atoms, still more preferably 1 to 4 carbon atoms, and most preferably 2 carbon atoms.

Examples of the oxygen-containing hydrocarbon group containing an ether bond or an ester bond are those having 1 to 18 carbon atoms, such as a methoxymethyl group, an ethoxymethyl group, a propoxymethyl group, an isopropoxymethyl group, an n-butoxymethyl group, t-butoxymethyl group, hexyloxymethyl group, octyloxymethyl group, 2-ethylhexyloxymethyl group, decyloxymethyl group, dodecyloxymethyl group, 2-butyloctyloxymethyl group, tetradecyloxymethyl group, hexadecyloxy group Methyl group, 2-hexyldecyloxymethyl group, allyloxymethyl group, phenoxy group, benzyloxy group, methoxyethyl group, methoxypropyl group, 1,1-bismethoxypropyl group, 1,2-bismethoxypropyl group, ethoxy Propyl group, (2-meth Ciethoxy) propyl group, (1-methyl-2-methoxy) propyl group, acetyloxymethyl group, propanoyloxymethyl group, butanoyloxymethyl group, hexanoyloxymethyl group, octanoyloxymethyl group, 2-ethylhexa Noyloxymethyl group, decanoyloxymethyl group, dodecanoyloxymethyl group, 2-butyloctanoyloxymethyl group, tetradecanoyloxymethyl group, hexadecanoyloxymethyl group, 2-hexyldodecanoyloxymethyl group, benzoyl An oxymethyl group etc. are mentioned.

In the general formula (VI), a and b each represent an integer of 1 to 20.
a + b is preferably 2 to 20, more preferably 2 to 10, still more preferably 2 to 4, and most preferably 2.

When the compound represented by the general formula (VI) is used as the component (C), a single species in which R ⁶¹ to R ⁶⁹ and ab are all the same may be used, or R ⁶¹ to R ⁶⁹ , a to Two or more different types of b different in part (for example, different in the number of carbon atoms of R ⁶¹ and the presence or absence of a double bond) may be used.

Specific compounds of general formula (VI) include octyl diethanolamine, decyl diethanolamine, dodecyl diethanolamine, tetradecyl diethanolamine, hexadecyl diethanolamine, stearyl diethanolamine, oleyl diethanolamine, coconut oil diethanolamine, palm oil diethanolamine, rapeseed oil diethanolamine, beef tallow diethanolamine An amine compound having two 2-hydroxyalkyl groups, such as, polyoxyethylene octylamine, polyoxyethylene decylamine, polyoxyethylene dodecylamine, polyoxyethylene tetradecylamine, polyoxyethylene hexadecylamine, Polyoxyethylene stearylamine, polyoxyethylene oleylamine, polio Has two polyalkylene oxide structures such as polyethylene beef tallow amine, polyoxyethylene palm oil amine, polyoxyethylene palm oil amine, polyoxyethylene laurylamine, polyoxyethylene stearylamine, polyoxyethylene oleylamine, ethylene oxide propylene oxide stearylamine An amine compound; Among these, stearyl diethanolamine and oleyl diethanolamine are preferable.

(C) As an amide compound which is an example of a component, the thing of the following general formula (VII) is mentioned.

The embodiment of R ^{71 in} the general formula (VII) is the same as the embodiment of R ^{61 in} the general formula (VI). Further, the embodiments of R ⁷² to R ⁷⁹ , a and b in the general formula (VII) are the same as the embodiments of R ⁶² to R ⁶⁹ , a and b in the general formula (VI).

Specific compounds of the general formula (VII) include octyl diethanolamide, decyl diethanolamide, dodecyl diethanolamide, tetradecyl diethanolamide, hexadecyl diethanolamide, stearyl diethanolamide, oleyl diethanolamide, coconut oil diethanolamide, palm oil Amide compounds having two 2-hydroxyalkyl groups exemplified by diethanolamide, rapeseed oil diethanolamide, beef tallow diethanolamide, etc .; polyoxyethylene octylamide, polyoxyethylene decylamide, polyoxyethylene dodecylamide, polyoxyethylene Tetradecyl amide, polyoxyethylene hexadecyl amide, polyoxyethylene stearyl amide, polyoxyethylene oleyl amide, polio Two polyalkylene oxide structures such as polyethylene beef tallow amide, polyoxyethylene palm oil amide, polyoxyethylene palm oil amide, polyoxyethylene lauryl amide, polyoxyethylene stearyl amide, polyoxyethylene oleyl amide, ethylene oxide propylene oxide stearyl amide An amide compound. Among these, oleyl diethanolamide is preferable.

In addition, the lubricating oil composition of the present embodiment has [content of component (C) / (content of component (A) in terms of molybdenum atom + content of component (B) in terms of molybdenum atom)] of 3 It is preferably from 0.0 to 50.0, more preferably from 5.0 to 40.0, and even more preferably from 10.0 to 35.0. By setting it as this ratio, the friction reduction effect by the synergistic action of (A) component and (B) component, and (C) component can be exhibited more, and fuel-saving property can be made more favorable.

In the lubricating oil composition of the present embodiment, the total content of the component (A), the component (B) and the component (C) is preferably 80% by mass or more based on the total amount of the lubricating oil composition, 85 The content is more preferably at least mass%, and further preferably at least 87 mass%.
The lubricating oil composition of the present embodiment may contain other ashless friction modifiers as long as the friction reducing effect is not impaired.

<(D) Viscosity index improver>
The lubricating oil composition of this embodiment preferably contains (D) a viscosity index improver in order to further improve fuel economy.

As the viscosity index improver of component (D), a comb polymer is preferably used. The “comb polymer” refers to a polymer having a structure in which the main chain has a number of trident branching points with linear side chains.
As such a comb polymer, for example, a polymer having at least a structural unit derived from a macromonomer having a polymerizable functional group such as a (meth) acryloyl group, an ethenyl group, a vinyl ether group, and an allyl group is preferably exemplified. Here, the structural unit corresponds to a “linear side chain”.
More specifically, various vinyl monomers such as alkyl (meth) acrylates, nitrogen atom-containing systems, halogen element-containing systems, hydroxyl group-containing systems, aliphatic hydrocarbon systems, alicyclic hydrocarbon systems, and aromatic hydrocarbon systems. Preferred is a copolymer having a side chain containing a structural unit derived from a macromonomer having the above polymerizable functional group with respect to a main chain containing a structural unit derived from a monomer.
The number average molecular weight (Mn) of the macromonomer is preferably 200 to 100,000, more preferably 300 to 10,000, and still more preferably 400 to 50,000 or more.
As the viscosity index improver for the component (D), poly (meth) acrylate, olefin copolymer, polyisobutylene, or the like may be used.

The (D) component viscosity index improver preferably has a weight average molecular weight of 300,000 or more and an SSI of 10.0 or less in order to further improve fuel economy and prevent seizure. .

The weight average molecular weight (Mw) of the component (D) is more preferably 300,000 to 500,000, further preferably 350,000 to 420,000.
In the present embodiment, “weight average molecular weight” refers to a molecular weight in terms of polystyrene determined by gel permeation chromatography (GPC) measurement.
In addition, from the viewpoint of improving the fuel saving performance under a low temperature range assuming the engine starting time, the molecular weight distribution (Mw / Mn) of the component (D) is preferably less than 2.0. In addition, as the molecular weight distribution of the component (D) becomes smaller, the fuel saving performance under a low temperature region assuming the time of starting the engine tends to be further improved.
Further, the lower limit of the molecular weight distribution of the component (D) is not particularly limited, but is usually 1.01 or more, preferably 1.05 or more, more preferably 1.10 or more.

The SSI of the component (D) is more preferably 8.0 or less, further preferably 5.0 or less, and particularly preferably less than 2.0. By setting the weight average molecular weight to 420,000 or less, the SSI can be easily set to 10.0 or less.
Here, SSI means the shear stability index (Shear Stability Index), which indicates the ability to resist polymer degradation. Higher SSI indicates that the polymer is more unstable to shear and more susceptible to degradation.

SSI indicates a decrease in viscosity due to shear derived from a polymer, and is calculated by the above formula. In the formula, Kv ₀ is the value of the 100 ° C. kinematic viscosity of the mixture obtained by adding the component (D) to the base oil. Kv ₁ is the value of the 100 ° C. kinematic viscosity after passing the mixture of base oil plus component (D) through a 30 cycle high shear Bosch diesel injector according to the procedure of ASTM D6278. Kv _oil is the value of the 100 ° C. kinematic viscosity of the base oil. As a base oil, a Group II base oil having a kinematic viscosity of 100 ° C. of 5.35 mm ² / s and a viscosity index of 105 is used.

The content of the component (D) is preferably 0.2 to 5.0% by mass, and 0.4 to 3.0% by mass based on the total amount of the lubricating oil composition from the viewpoint of fuel economy. Is more preferable, and 0.8 to 2.5% by mass is even more preferable.
Here, the content of the component (D) means the content of only the resin component of the component (D), and does not include the mass of the diluent oil or the like contained with the component (D), based on the solid content It is.

The monomer constituting the poly (meth) acrylate which is an example of the component (D) is an alkyl (meth) acrylate, preferably an alkyl having a linear alkyl group having 1 to 18 carbon atoms or a branched alkyl group having 3 to 34 carbon atoms. (Meth) acrylate.
(E) As a preferable monomer constituting poly (meth) acrylate, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) ) Acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, tetra (meth) acrylate, hexa (meth) acrylate , Octadecyl (meth) acrylate, and the like. Two or more of these monomers may be used as a copolymer. The alkyl group of these monomers may be linear or branched.
Examples of the alkyl (meth) acrylate having a branched alkyl group having 3 to 34 carbon atoms include isopropyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 3,5,5-trimethylhexyl (meth) acrylate, 2- Butyloctyl (meth) acrylate, 2-hexyldecyl (meth) acrylate, 2-octyldodecyl (meth) acrylate, 2-decyltetradecyl (meth) acrylate, 2-dodecylhexadecyl (meth) acrylate, 2-tetradecyloctadecyl (Meth) acrylate is mentioned.

In the lubricating oil composition of the present embodiment, the total content of the component (A), the component (B), the component (C), and the component (D) is 80% by mass or more based on the total amount of the lubricating oil composition. It is preferably 85% by mass or more, and more preferably 90% by mass or more.

<Optional components>
The lubricating oil composition of the present embodiment contains at least one selected from a pour point depressant, a zinc dialkyldithiophosphate, an antioxidant, a metallic detergent and other ashless detergent as an optional additive component. May be.
The total content of these optional additives is about 0.1 to 15% by mass based on the total amount of the lubricating oil composition.

<Physical properties of lubricating oil composition>
The lubricating oil composition of the present embodiment has a kinematic viscosity, a viscosity index, an HTHS viscosity (high temperature high shear viscosity), a rate of change in kinematic viscosity after a shear test, and NOACK from the viewpoint of reducing friction in a wide temperature range from low temperature to high temperature. The value is preferably in the following range.

The 80 ° C. kinematic viscosity is preferably 5 to 9 mm ² / s, and more preferably 6 to 8 mm ² / s, from the viewpoint of fuel economy. The 120 ° C. kinematic viscosity is preferably 3 to 5 mm ² / s, and more preferably 3.5 to 4.5 mm ² / s, from the viewpoint of securing oil pressure in a high temperature region.
The viscosity index is preferably 250 to 340, and more preferably 270 to 320.
The kinematic viscosity and the viscosity index were measured according to JIS K2283: 2000.

The 80 ° C. HTHS viscosity is preferably 3.7 to 4.6 mPa · s, and more preferably 4.0 to 4.3 mPa · s, from the viewpoint of fuel economy. The 100 ° C. HTHS viscosity is preferably 2.7 to 3.6 mPa · s, more preferably 3.0 to 3.3 mPa · s. The 150 ° C. HTHS viscosity is preferably 1.5 to 2.3 mPa · s, and more preferably 1.7 to 2.0 mPa · s, from the viewpoint of securing an oil film in a high temperature and high shear region.
The HTHS viscosity was measured in accordance with ASTM D4683 and ASTM D6616 using a TBS viscometer (Tapered Bearing Simulator Viscometer), a shear rate of 10 ⁶ / s, a rotation speed (motor) of 3000 rpm, and an interval (interval between the rotor and the stator) of 3 μm. It measured on condition of this.

The rate of change in kinematic viscosity after the shear test, measured according to JPI-5S-29, is preferably 2.00% or less, and more preferably 1.00% or less. More specifically, the rate of change in kinematic viscosity after the shear test can be measured by the method described in the Examples.

The NOACK value at 250 ° C. for 1 hour, measured according to ASTM D5800, is preferably 20 to 50, and more preferably 30 to 40.

<Use of lubricating oil composition>
Although the use of the lubricating oil composition of the present embodiment is not particularly limited, it can be suitably used for various internal combustion engines such as four-wheeled vehicles and two-wheeled vehicles. Examples of the internal combustion engine include a gasoline engine, a diesel engine, an engine using dimethyl ether as a fuel, a gas engine, and the like.

[Method for reducing friction of internal combustion engine]
The friction reducing method for an internal combustion engine according to the present embodiment is to add the above-described lubricating oil composition according to the present embodiment to the internal combustion engine.
According to the friction reducing method for an internal combustion engine of the present embodiment, the friction reducing effect can be dramatically improved by the synergistic action of the component (A), the component (B), and the component (C). Can be good.

[Method for producing lubricating oil composition]
The manufacturing method of the lubricating oil composition of the present embodiment,
(X) a lubricating base oil;
(A) a dinuclear organomolybdenum compound represented by the following general formula (I):
(B) a trinuclear organic molybdenum compound represented by the following general formula (II):
(C) having a step of mixing with an ashless friction modifier having two or more hydroxyl groups in the molecule;
The sum of the content of the component (A) in terms of molybdenum atoms and the content of the component (B) in terms of molybdenum atoms is 0.012% by mass or more based on the total amount of the lubricating oil composition, and
The mixing step is performed so that the content of the component (C) is less than 2.0% by mass based on the total amount of the lubricating oil composition.

According to the manufacturing method of the lubricating oil composition of the present embodiment, the lubricating oil composition capable of dramatically improving the friction reduction effect and improving fuel economy can be easily manufactured. .

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

1. Preparation of Lubricating Oil Compositions of Examples and Comparative Examples Lubricating oil compositions of Examples and Comparative Examples were prepared with the compositions shown in Tables 1 to 6. The following materials were used for the preparation of the lubricating oil composition.
<(X) Component Lubricating Base Oil>
[Lubricant base oil 1]
Group III, 70N hydrorefined base oil, 100 ° C. kinematic viscosity: 2.9 mm ² / S, viscosity index: 121,% C _p by ndM ring analysis: 84.0%
[Lubricant base oil 2]
Group ^II , 70N hydrorefined base oil, 100 ° C. kinematic viscosity: 2.9 mm ² / S, viscosity index: 105,% C _p by ndM ring analysis: 72.5%
[Lube base oil 3]
Group III, 70N hydrorefined base oil, 100 ° C. kinematic viscosity: 3.1 mm ² / S, viscosity index: 123,% C _p by ndM ring analysis: 84.3%
[Lubricant base oil 4]
Group ^II , 60N hydrorefined base oil, 100 ° C. kinematic viscosity: 2.4 mm ² / S, viscosity index: 115,% C _p by ndM ring analysis: 80.8%

<(A) Component Binuclear Organic Molybdenum Compound>
[Organic molybdenum compound 1]
Binuclear organomolybdenum of the general formula (I), wherein R ¹ to R ⁴ each have 8 or 13 carbon atoms, R ¹ to R ⁴ have a total of 42 carbon atoms, and X ¹ to X ⁴ are oxygen atoms Compound. Molybdenum content 10.0 mass%, sulfur content 11.5 mass%.

<(B) component trinuclear organomolybdenum compound>
[Organic molybdenum compound 2]
A trinuclear organomolybdenum compound of general formula (II) having a ligand of general formula (III-D) and having a core of general formula (IV-B). The total number of carbon atoms of R ³⁴ and R ³⁵ in formula (III-D) is 21. In general formula (II), k is 7, L is a monoanionic ligand, n is 4, and each of p, m, and z is 0. Molybdenum content 5.27 mass%.

<Mononuclear organic molybdenum compound>
[Organic molybdenum compound 3]
A mixture of [2,2 ′-(dodecanoylimino) diethanolato] dioxomolybdenum (VI) and [3- (dodecanoyloxy) -1,2-propanediolato] dioxomolybdenum (VI). Molybdenum content 7.9 mass%, nitrogen content 2.8 mass%.
[Organic molybdenum compound 4]
Diisotridecylamine molybdate. Molybdenum content 10.0 mass%.

<Ashless friction modifier of component (C)>
[Ashless friction modifier 1]
Oleyl diethanolamine [Ashless friction modifier 2]
Stearyl diethanolamine [Ashless friction modifier 3]
Oleyl diethanolamide [Ashless friction modifier 4]
Glycerol monooleate

<Other ashless friction modifiers>
[Ashless friction modifier 5]
Stearylamine [Ashless friction modifier 6]
Oleyl alcohol

<Viscosity index improver of component (D)>
[Viscosity index improver 1]
Comb polymer having at least a structural unit derived from a macromonomer having Mn of 500 or more as a resin component (Mw: 370,000, SSI: 0.9, Mw / Mn = less than 2.0)
[Viscosity index improver 2]
Comb polymer having at least a structural unit derived from a macromonomer having Mn of 500 or more as a resin component (Mw: 430,000, SSI: 13.5, Mw / Mn = 2.0 or more)

<Pour point depressant>
Polyalkyl methacrylate (weight average molecular weight: 62,000)
<Additive package>
Package containing zinc dialkyldiliophosphate, antioxidant, metallic detergent, ashless detergent.

2. Measurement and Evaluation The following evaluations were performed on the lubricating oil compositions of Examples and Comparative Examples prepared to the compositions shown in Tables 1 to 6. The results are shown in Tables 1-6.
2-1. Kinematic Viscosity, Viscosity Index, HTHS Viscosity and NOACK Value According to the description in the specification, the kinematic viscosity, viscosity index, HTHS viscosity and NOACK value (250 ° C., 1 hour) of the lubricating oil composition were measured.

2-2. Kinematic viscosity change rate after shear test Based on JIS K2283: 2000, the kinematic viscosity at 100 ° C before the test and after the shear test was measured, and the kinematic viscosity change rate after the shear test was calculated by the following formula. In addition, the shear test was a 30-cycle shear test based on JPI-5S-29 by the Bosch method using a diesel injector.
Change rate of kinematic viscosity after shear test = (([kinematic viscosity before test] − [kinematic viscosity after test]) / [kinematic viscosity before test]) × 100

2-3. Friction coefficient (reciprocating friction test)
Using a TE77 reciprocating friction tester manufactured by Phoenix Tribology, the friction coefficient was measured under the following conditions.
(Test plate)
Material: FC250
Shape: 58mm long x 20mm wide x 4mm thick
(Test cylinder pin)
Material: SUJ-2
Shape: Diameter 6mm x Length 14mm
(Run-in condition)
Stroke 8mm, 20Hz, oil temperature 80 ° C, load 10-200N for 60 minutes (this test condition)
Stroke 8mm, 20Hz, oil temperature 80 ° C, load 80N

2-4. Low temperature stability The lubricating oil compositions of Examples 1 to 5 and Comparative Example 5 were allowed to stand for 5 days in an environment of −5 ° C., and the state of precipitation when returning to room temperature (20 ° C.) was visually confirmed. Low temperature stability was evaluated. “A” indicates that clouding and precipitation were confirmed, “B” indicates that precipitation was not confirmed but clouding was confirmed, and “C” indicates that precipitation was confirmed.

The lubricating oil compositions of Comparative Examples 1 to 4 contain the ashless friction modifier of component (C), but do not contain any one of components (A) and (B). Since the friction coefficient of the lubricating oil compositions of Comparative Examples 1 to 4 is increased with respect to the lubricating oil composition of Example 1, the friction reducing effect by the synergistic action of the organic molybdenum compound and the component (C) It can be confirmed that it is necessary to use the component (A) and the component (B) in combination as an organic molybdenum compound in order to express the above. Further, from the results of Comparative Examples 3 and 4, even when a binuclear or trinuclear organic molybdenum compound and a mononuclear organic molybdenum compound are used in combination, the friction reducing effect due to the synergistic action with the component (C) cannot be exhibited. I can confirm that.

The lubricating oil composition of Comparative Example 5 contains (A) component, (B) component, and (C) component, but has a small sum of contents in terms of molybdenum atoms of (A) component and (B) component It is. Since the friction coefficient of the lubricating oil composition of Comparative Example 5 is increased with respect to the lubricating oil compositions of Examples 1 to 5, a predetermined amount of component (A) is used in order to exhibit a friction reducing effect. And it can confirm that (B) component is required.
Further, from the results of Examples 1 to 5, the lubricating oil composition in which the total content of the component (A) and the component (B) in terms of molybdenum atoms is 0.012% by mass or more is It can be confirmed that the friction reduction effect by the synergistic action can be expressed.
In addition, it can be confirmed that the lubricating oil compositions of Examples 1 to 4 are excellent in low-temperature stability because the organic molybdenum compound does not precipitate even in a low-temperature environment. In particular, the lubricating oil compositions of Examples 1 to 3 did not generate fogging even in a low temperature environment and were extremely excellent in low temperature stability.

The lubricating oil composition of Comparative Example 6 contains the component (A) and the component (B), but does not contain the ashless friction modifier of the component (C). Compared with the lubricating oil composition of Comparative Example 6, the friction coefficient of the lubricating oil composition of Example 1 is dramatically reduced, so that the (A) component and the (B) component are used in combination as the organic molybdenum compound. And by using (C) component, it can confirm that the friction reduction effect by the synergistic action of an organomolybdenum compound and (C) component expresses.
Moreover, although the lubricating oil compositions of Comparative Examples 7 and 8 contain the components (A) and (B) and contain the ashless friction modifier, the ashless friction modifier contains 2 hydroxyl groups. It has no more than one. Since the friction coefficient of the lubricating oil compositions of Comparative Examples 7 and 8 is increased with respect to the lubricating oil composition of Comparative Example 6, the hydroxyl group with respect to the organomolybdenum compound of component (A) and component (B) When an ashless friction modifier that does not have two or more is added, it can be confirmed that the friction reducing effect of the organic molybdenum compound is impaired.

Although the lubricating oil composition of Comparative Example 9 contains the (A) component, the (B) component, and the (C) component, the content of the ashless friction modifier of the (C) component is large. Since the friction coefficient of the lubricating oil composition of Comparative Example 9 is increased with respect to the lubricating oil compositions of Examples 1 and 6 to 8, the content of the ashless friction modifier of component (C) is increased. If it is too much, it can be confirmed that the friction increases conversely.
Further, from the comparison between Examples 1 and 6 to 8 and Comparative Examples 6 and 9, the lubricating oil composition in which the content of the component (C) is less than 2.0% by mass based on the total amount of the lubricating oil composition, It can be confirmed that the friction reducing effect is good. In particular, the lubricating oil compositions of Examples 1, 6 and 7 in which the content of the component (C) is 1.0% by mass or less based on the total amount of the lubricating oil composition are confirmed to have a very good friction reducing effect. it can.

Examples 9 to 11 are obtained by changing the type of the component (C) in Example 1. From the results of Examples 1 and 9 to 11, it can be confirmed that the ashless friction modifier having two or more hydroxyl groups in the molecule exhibits a friction reducing effect regardless of the type. Further, from the comparison between Examples 1 and 9 to 11, among the components (C), the amine-based (Example 1) and the amide-based (Examples 9 and 10) are excellent in friction reduction effect, particularly the amine-based (Example It can be confirmed that the effect of 1) is extremely excellent.

In Example 12, the type of the component (D) in Example 1 is changed. By comparing Example 1 with Example 12, the lubricating oil composition contains a viscosity index improver having a weight average molecular weight of 300,000 or more and an SSI of less than 2.0. While decreasing the viscosity, the rate of change in kinematic viscosity after the shear test can be reduced, and it can be confirmed that fuel economy and seizure can be improved.
In Examples 13 to 15, the type of the component (X) in Example 1 is changed. By comparison between Example 1 and Examples 13 to 15, the lubricating base oil of component (X) has a kinematic viscosity at 100 ° C. of 2.5 to 3.0 mm ² / s, and ndM ring analysis According% C _p in by not less than 80%, while lower HTHS viscosity, it is possible to reduce the NOACK values can be confirmed that the fuel economy can be improved.

In Tables 1 to 6, [mass% Mo] represents the content in terms of molybdenum atoms of the organic molybdenum compound relative to the total amount of the lubricating oil composition.

The lubricating oil composition of this embodiment has a good friction reducing effect and can improve fuel economy. For this reason, the lubricating oil composition of the present embodiment can be suitably used for various internal combustion engines such as four-wheeled vehicles and two-wheeled vehicles. Examples of the internal combustion engine include a gasoline engine, a diesel engine, an engine using dimethyl ether as a fuel, a gas engine, and the like.

Claims

(X) a lubricating base oil,
(A) a dinuclear organomolybdenum compound represented by the following general formula (I):
(B) a trinuclear organic molybdenum compound represented by the following general formula (II), and (C) an ashless friction modifier having two or more hydroxyl groups in the molecule,
The total of the content in terms of molybdenum atoms of the component (A) and the content in terms of molybdenum atoms of the component (B) is 0.012% by mass or more based on the total amount of the lubricating oil composition,
A lubricating oil composition wherein the content of the component (C) is less than 2.0% by mass based on the total amount of the lubricating oil composition.

[In Formula (I), R 1 to R 4 represent a hydrocarbon group having 7 to 22 carbon atoms, and R 1 to R 4 may be the same or different. X 1 to X 4 each represents a sulfur atom or an oxygen atom. ]
Mo 3 S k E m L n A p Q z (II)
[In formula (II), each E is independently oxygen or selenium. k is an integer of at least 1, m is 0 or an integer, and k + m is 4 to 10. L is independently an anionic ligand having an organic group containing a carbon atom, the total number of carbon atoms of the organic group in each ligand is 14 or more, and each ligand may be the same, May be different. n is an integer of 1 to 4. A is an anion other than L. p is 0 or an integer. Q is a compound which donates a neutral electron independently. z is an integer from 0 to 5 and includes non-stoichiometric values. ]
Each ligand of the formula (II) is any one selected from the group of ligands represented by the following general formulas (III-A), (III-B), (III-C) and (III-D) Item 4. The lubricating oil composition according to Item 1.

[In the formulas (III-A), (III-B), (III-C) and (III-D), X 31 to X 37 and Y are each independently an oxygen atom or a sulfur atom. In the formulas (III-A), (III-B), (III-C) and (III-D), R 31 to R 35 are independent organic groups, and R 31 to R 35 are the same. It may or may not be. The organic group of R 31 to R 33 has 14 or more carbon atoms. And carbon number of the organic group R 34, the sum of the carbon number of the organic group for R 35 is 14 or more. ]
The sum of the content of the component (A) in terms of molybdenum atoms and the content of the component (B) in terms of molybdenum atoms is 0.012 to 0.125% by mass based on the total amount of the lubricating oil composition. Item 3. The lubricating oil composition according to Item 1 or 2.
The content in terms of molybdenum atom of the component (A) is 0.002 to 0.100 mass% based on the total amount of the lubricating oil composition, and the content in terms of molybdenum atom of the component (B) is the total amount of the lubricating oil composition The lubricating oil composition according to any one of claims 1 to 3, which is 0.001 to 0.030 mass% on a basis.
The lubricating oil composition according to any one of claims 1 to 4, wherein the content of the component (C) is 0.1 to 1.5% by mass based on the total amount of the lubricating oil composition.
[Content of component (C) / (content of component (A) in terms of molybdenum atom + content of component (B) in terms of molybdenum atom)] is 3.0 to 50.0. Item 6. The lubricating oil composition according to any one of Items 1 to 5.
7. The component (X) has a kinematic viscosity at 100 ° C. of 2.5 to 3.0 mm 2 / s, and% C p by ndM ring analysis is 80% or more. 2. The lubricating oil composition according to item 1.
The lubricating oil composition according to any one of claims 1 to 7, further comprising (D) a viscosity index improver.
The lubricating oil composition according to claim 8, wherein the component (D) has a weight average molecular weight of 300,000 or more and an SSI of 10.0 or less.
The lubricating oil composition according to any one of claims 1 to 9, further comprising at least one selected from a pour point depressant, a zinc dialkyldiliophosphate, an antioxidant, a metallic detergent and an ashless detergent. object.
The lubricating oil composition according to any one of claims 1 to 10, which is used in an internal combustion engine.
A method for reducing the friction of an internal combustion engine, wherein the lubricating oil composition according to any one of claims 1 to 10 is added to the internal combustion engine.
(X) a lubricating base oil;
(A) a dinuclear organomolybdenum compound represented by the following general formula (I):
(B) a trinuclear organic molybdenum compound represented by the following general formula (II):
(C) having a step of mixing with an ashless friction modifier having two or more hydroxyl groups in the molecule;
The sum of the content of the component (A) in terms of molybdenum atoms and the content of the component (B) in terms of molybdenum atoms is 0.012% by mass or more based on the total amount of the lubricating oil composition, and
The manufacturing method of the lubricating oil composition which performs the said mixing process so that content of the said (C) component may be less than 2.0 mass% on the basis of lubricating oil composition whole quantity.

[In Formula (I), R 1 to R 4 represent a hydrocarbon group having 7 to 22 carbon atoms, and R 1 to R 4 may be the same or different. X 1 to X 4 each represents a sulfur atom or an oxygen atom. ]
Mo 3 S k E m L n A p Q z (II)
[In formula (II), each E is independently oxygen or selenium. k is an integer of at least 1, m is 0 or an integer, and k + m is 4 to 10. L is independently an anionic ligand having an organic group containing a carbon atom, the total number of carbon atoms of the organic group in each ligand is 14 or more, and each ligand may be the same, May be different. n is an integer of 1 to 4. A is an anion other than L. p is 0 or an integer. Q is a compound which donates a neutral electron independently. z is an integer from 0 to 5 and includes non-stoichiometric values. ]