Lubricating oil composition

Abstract

To provide a lubricating oil composition which exhibits excellent friction reducing effect, while having excellent high-temperature detergency, oxidation stability, and copper corrosion resistance, by combining a plurality of molybdenum-based friction modifiers. Also, this problem is solved by forming a lubricating oil composition containing a base oil (A), a molybdenum-based friction modifier (B), a metal-based detergent (C), and an ashless dispersant (D), wherein the aforementioned molybdenum-based friction modifier (B) contains two or more selected from a di-nuclear molybdenum dithiocarbamate (B1), a tri-nuclear molybdenum dithiocarbamate (B2), and a molybdenum amine complex (B3), the aforementioned metal-based detergent (C) contains a sulfur atom, the aforementioned ashless dispersant (D) contains a nitrogen atom, the acid value derived from the aforementioned di-nuclear molybdenum dithiocarbamate (B1) and tri-nuclear molybdenum dithiocarbamate (B2) is less than 0.04 mgKOH / g, the ratio [(C S ) / (D N )] of the sulfur component (C S ) derived from the aforementioned metal-based detergent (C) to the nitrogen component (D N ) derived from the aforementioned ashless dispersant (D) is 0.30 to 0.85 in mass ratio, and the phosphorus content is more than 0.04 mass% and less than 0.10 mass% based on the total amount of the aforementioned lubricating oil composition.

Description

Technical Field

[0001] This invention relates to lubricating oil compositions. Background Technology

[0002] In recent years, there has been a demand for further improvements in fuel efficiency in lubricating oil compositions used in internal combustion engines such as gasoline engines. Therefore, while promoting the reduction of lubricating oil compositions, research on molybdenum-based friction modifiers is also underway, aiming to achieve greater friction reduction.

[0003] As a molybdenum-based friction modifier, for example, known dinuclear molybdenum dithiocarbamate and trinuclear molybdenum dithiocarbamate (see, for example, Patent Document 1).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: International Publication No. 2017 / 002969 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] In recent years, there has been a demand for further improvements in friction reduction. Therefore, the use of a combination of various molybdenum-based friction modifiers has been considered to further enhance friction reduction.

[0009] However, through diligent research, the inventors have found that combining multiple molybdenum-based friction modifiers to further enhance friction reduction deteriorates the high-temperature detergency and oxidative stability of the lubricating oil composition. Furthermore, the copper corrosion resistance of the lubricating oil composition also deteriorates. There is concern that lubricating oil compositions with poor copper corrosion resistance may experience accelerated deterioration due to copper dissolution into the oil caused by corrosion of copper components used in internal combustion engines such as engines.

[0010] The present invention was made in view of the above-mentioned problems, and its subject is to provide a lubricating oil composition that, by combining a variety of molybdenum-based friction modifiers, can exert excellent friction reduction effect, while also exhibiting excellent high-temperature detergency, oxidation stability, and copper corrosion resistance.

[0011] It should be noted that in this specification, "copper corrosion resistance" means that even when copper components are corroded, it is difficult for copper to dissolve into the oil.

[0012] Solution for solving the problem

[0013] In order to solve the above-mentioned problems, the inventors conducted a great deal of research and found the following [1] structure.

[0014] That is, the present invention relates to the following [1] to [4].

[0015] [1] A lubricating oil composition comprising a base oil (A), a molybdenum-based friction modifier (B), a metallic detergent (C), and an ashless dispersant (D), wherein,

[0016] The aforementioned molybdenum-based friction modifier (B) comprises two or more selected from dinuclear molybdenum dithiocarbamate (B1), trinuclear molybdenum dithiocarbamate (B2), and molybdenum amine complex (B3).

[0017] The aforementioned metal-based detergent (C) contains sulfur atoms.

[0018] The aforementioned ashless dispersant (D) contains nitrogen atoms.

[0019] The acid values ​​of the aforementioned dinuclear molybdenum dithiocarbamate (B1) and trinuclear molybdenum dithiocarbamate (B2) are less than 0.04 mg KOH / g.

[0020] The sulfur component (C) originating from the aforementioned metal-based detergent (C) S ), and nitrogen components (D) derived from the aforementioned ashless dispersant (D). N The content ratio of ) [(C S ) / (D N The mass ratio is 0.30 to 0.85.

[0021] The phosphorus content, based on the total amount of the aforementioned lubricating oil composition, is greater than 0.04% by mass and less than 0.10% by mass.

[0022] [2] An internal combustion engine comprising the lubricating oil composition according to [1] above.

[0023] [3] A lubrication method for an internal combustion engine, wherein a lubricating oil composition according to [1] above is used.

[0024] [4] A method for manufacturing a lubricating oil composition, comprising a step of mixing a base oil (A), a molybdenum-based friction modifier (B), a metal-based detergent (C), and an ashless dispersant (D).

[0025] The aforementioned molybdenum-based friction modifier (B) comprises two or more selected from dinuclear molybdenum dithiocarbamate (B1), trinuclear molybdenum dithiocarbamate (B2), and molybdenum amine complex (B3).

[0026] The aforementioned metal-based detergent (C) contains sulfur atoms.

[0027] The aforementioned ashless dispersant (D) contains nitrogen atoms.

[0028] The acid values ​​of the aforementioned dinuclear molybdenum dithiocarbamate (B1) and trinuclear molybdenum dithiocarbamate (B2) are less than 0.04 mg KOH / g.

[0029] Adjusting the sulfur content (C) derived from the aforementioned metal-based detergent (C) S ), and nitrogen components (D) derived from the aforementioned ashless dispersant (D). N The content ratio of ) [(C S ) / (D N This makes it 0.30 to 0.85 by mass ratio.

[0030] Adjust the phosphorus content to be greater than 0.04% by mass and less than 0.10% by mass based on the total amount of the lubricating oil composition.

[0031] Invention Effects

[0032] According to the present invention, by combining a variety of molybdenum-based friction modifiers, a lubricating oil composition can be provided that exhibits excellent friction reduction, high-temperature detergency, oxidation stability, and resistance to copper corrosion. Detailed Implementation

[0033] The upper and lower limits of the numerical ranges described in this specification can be combined arbitrarily. For example, when the numerical ranges are described as "A~B" and "C~D", the numerical ranges of "A~D" and "C~B" are also included in the scope of this invention.

[0034] In addition, unless otherwise stated, the numerical range “lower limit to upper limit” described in this specification refers to the value above the lower limit and below the upper limit.

[0035] Furthermore, in this specification, the numerical values ​​in the embodiments are values ​​that can be used as upper or lower limits.

[0036] [Method of Lubricating Oil Composition]

[0037] The lubricating oil composition of this embodiment contains a base oil (A), a molybdenum-based friction modifier (B), a metal-based detergent (C), and an ashless dispersant (D).

[0038] The molybdenum-based friction modifier (B) contains two or more selected from the following: dinuclear molybdenum dithiocarbamate (B1), trinuclear molybdenum dithiocarbamate (B2), and molybdenum amine complex (B3).

[0039] Metallic detergents (C) contain sulfur atoms.

[0040] Ash-free dispersants (D) contain nitrogen atoms.

[0041] The acid values ​​of molybdenum dithiocarbamate derived from the binuclear molybdenum dithiocarbamate (B1) and the triuclear molybdenum dithiocarbamate (B2) are less than 0.04 mg KOH / g.

[0042] Sulfur component (C) derived from metal-based detergents (C) S ), and nitrogen components (D) derived from ashless dispersant (D) N The content ratio of ) [(C S ) / (D N The mass ratio is 0.30 to 0.85.

[0043] Furthermore, the phosphorus content, based on the total amount of the lubricating oil composition, is greater than 0.04% by mass and less than 0.10% by mass.

[0044] The inventors have conducted extensive research to further enhance the friction-reducing effect by combining various molybdenum-based friction modifiers. As a result, it has been found that while combining multiple molybdenum-based friction modifiers improves the friction-reducing effect, it sometimes results in poor oxidation stability, high-temperature detergency, and copper corrosion resistance. In other words, it is difficult to comprehensively improve oxidation stability, high-temperature detergency, and copper corrosion resistance when using multiple molybdenum-based friction modifiers in combination.

[0045] Therefore, in order to create a lubricating oil composition that can improve oxidation stability, high-temperature detergency, and copper corrosion resistance even when multiple molybdenum-based friction modifiers are used in combination, the inventors have made efforts in two aspects: research on molybdenum-based friction modifiers and research on the balance of additives mixed in the lubricating oil composition.

[0046] As a result, the above-mentioned problems can be solved by using specific molybdenum-based friction modifiers in combination, adjusting the acid value of the molybdenum-based friction modifiers to a specific range, adjusting the ratio of sulfur components from metal-based detergents to nitrogen components from ashless detergents to a specific range, and adjusting the phosphorus content of the lubricating oil composition to a specific range.

[0047] The mechanism by which this invention achieves its effect is not yet clear, but it is speculated that the combination of specific molybdenum-based friction modifiers, metal-based detergents, ashless dispersants, and phosphorus components in the lubricating oil composition interacts to eliminate the problems that arise when using multiple molybdenum-based friction modifiers in combination.

[0048] It should be noted that in the following description, “base oil (A)”, “molybdenum-based friction modifier (B)”, “metal-based detergent (C)”, and “ashless dispersant (D)” will also be referred to as “component (A)”, “component (B)”, “component (C)”, and “component (D)”, respectively.

[0049] In the lubricating oil composition of this embodiment, the total content of components (A) to (D) is preferably 70% by mass or more, more preferably 75% by mass or more, and even more preferably 80% by mass or more, based on the total amount of the lubricating oil composition.

[0050] It should be noted that in the lubricating oil composition of this embodiment, the upper limit of the total content of components (A) to (D) can be adjusted by the relationship with lubricating oil additives other than components (A) to (D), and is generally less than 100% by mass, preferably 99% by mass or less, and more preferably 98% by mass or less.

[0051] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, it is preferably 70% to less than 100% by mass, more preferably 75% to 99% by mass, and even more preferably 80% to 98% by mass.

[0052] The components contained in the lubricating oil composition of this embodiment will be described in detail below.

[0053] <Base Oil (A)>

[0054] The lubricating oil composition of this embodiment contains a base oil (A). As the base oil (A), one or more selected from mineral oils and synthetic oils conventionally used as base oils for lubricating oils can be used without particular limitation.

[0055] Examples of mineral oils include atmospheric residue obtained by atmospheric distillation of crude oils such as paraffinic crude oil, intermediate crude oil, and naphthenic crude oil; distillate obtained by vacuum distillation of the aforementioned atmospheric residue; and mineral oil obtained by refining the aforementioned distillate through one or more of the following processes: solvent deasphalting, solvent extraction, hydrogenation processing, hydrogenation cracking, high-level hydrogenation cracking, solvent dewaxing, catalytic dewaxing, and hydrogenation isomerization dewaxing.

[0056] Examples of synthetic oils include, for example, α-olefin homopolymers, α-olefin copolymers (e.g., α-olefin copolymers with 8 to 14 carbon atoms such as ethylene-α-olefin copolymers), polyα-olefins; isoparaffins; various esters such as polyol esters and diesters; various ethers such as polyphenylene ethers; polyalkylene glycols; alkylbenzenes; alkylnaphthalenes; and GTL base oils obtained by isomerization of waxes produced from natural gas using the Fischer-Tropsch process or similar methods (GTL waxes, Gas To Liquids Wax).

[0057] The base oil (A) used in this embodiment is preferably a mineral oil classified as Group II or Group III of the API (American Petroleum Institute) base oil category.

[0058] The base oil (A) can be used alone, selected from one type of mineral oil, or in combination with two or more types of mineral oil. Alternatively, it can be used alone, selected from one type of synthetic oil, or in combination with two or more types of synthetic oil. Furthermore, it can be used in combination with one or more types of mineral oil and one or more types of synthetic oil.

[0059] For the kinematic viscosity and viscosity index of the base oil (A), the upper limit is preferably set to the following range from the viewpoint of achieving good fuel economy and the lower limit is set from the viewpoint of reducing the loss of the lubricating oil composition due to evaporation and ensuring oil film retention.

[0060] The preferred kinematic viscosity of base oil (A) at 100°C is 2.0 mm. 2 / s~6.0mm 2 / s, more preferably 2.5mm 2 / s~5.5mm 2 / s, further preferably 3.0mm 2 / s~5.0mm 2 / s.

[0061] The viscosity index of the base oil (A) is preferably 80 or higher, more preferably 90 or higher, and even more preferably 100 or higher.

[0062] In this specification, the kinematic viscosity and viscosity index at 100°C are values ​​measured or calculated according to JIS K2283:2000.

[0063] It should be noted that when the base oil (A) is a blended base oil containing two or more base oils, it is preferable that the kinematic viscosity and viscosity index of the blended base oil are within the above-mentioned range.

[0064] In the lubricating oil composition of this embodiment, the content of base oil (A) is not particularly limited. From the viewpoint of facilitating the volatilization of the effects of the present invention, it is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more, based on the total amount of the lubricating oil composition. Furthermore, it is preferably 97% by mass or less, more preferably 96% by mass or less, and even more preferably 95% by mass or less. The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, it is preferably 60% by mass to less than 97% by mass, more preferably 70% by mass to 96% by mass, and even more preferably 80% by mass to 95% by mass.

[0065] <Molybdenum-based friction modifier (B)>

[0066] The lubricating oil composition of this embodiment contains a molybdenum-based friction modifier (B).

[0067] The molybdenum-based friction modifier (B) contains two or more selected from the following: dinuclear molybdenum dithiocarbamate (B1), trinuclear molybdenum dithiocarbamate (B2), and molybdenum amine complex (B3).

[0068] Thus, by using multiple combinations of molybdenum-based friction modifiers, the friction-reducing effect is enhanced. It should be noted that, according to the experiments conducted by the inventors, this friction-reducing effect is confirmed to be effective both at high temperatures and at low temperatures of around 30°C.

[0069] It should be noted that molybdenum-based friction modifiers (B) may include other molybdenum-based friction modifiers besides dinuclear molybdenum dithiocarbamate (B1), trinuclear molybdenum dithiocarbamate (B2), and molybdenum amine complex (B3). Examples of other molybdenum-based friction modifiers include molybdenum dithiophosphate (MoDTP).

[0070] Here, from the viewpoint of easily exerting the effects of the present invention, the total content of two or more of the molybdenum-based friction modifier (B) selected from dinuclear molybdenum dithiocarbamate (B1), trinuclear molybdenum dithiocarbamate (B2), and molybdenum amine complex (B3) is preferably 50% to 100% by mass, more preferably 60% to 100% by mass, further preferably 70% to 100% by mass, even more preferably 80% to 100% by mass, and even more preferably 90% to 100% by mass, based on the total amount of molybdenum-based friction modifier (B).

[0071] The following provides a detailed description of the binuclear molybdenum dithiocarbamate (B1), the triuclear molybdenum dithiocarbamate (B2), and the molybdenum amine complex (B3).

[0072] (Dinuclear molybdenum dithiocarbamate (B1))

[0073] Examples of dinuclear molybdenum dithiocarbamate include compounds represented by the following general formula (b1-1) and compounds represented by the following general formula (b1-2).

[0074] [Chemistry 1]

[0075]

[0076] In the above general formulas (b1-1) and (b1-2), R 11 ~R 14 Each group represents a hydrocarbon group independently; they can be the same as or different from each other.

[0077] X 11 ~X 18Each atom can independently represent an oxygen atom or a sulfur atom; they can be the same as or different from each other. In the general formula (b1-1) above, X... 11 ~X 18 At least two of them are sulfur atoms.

[0078] Optional R 11 ~R 14 The number of carbon atoms in the hydrocarbon group is preferably 6 to 22.

[0079] R can be selected as an option in the above general formulas (b1-1) and (b1-2). 11 ~R 14 Examples of the hydrocarbon group include alkyl, alkenyl, cycloalkyl, aryl, alkylaryl, arylalkyl, etc.

[0080] Examples of such alkyl groups include hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecanyl, octadecyl, etc.

[0081] Examples of this alkenyl group include hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl, and pentadecenyl.

[0082] Examples of cyclohexyl groups include cyclohexyl, dimethylcyclohexyl, ethylcyclohexyl, methylcyclohexylmethyl, cyclohexylethyl, propylcyclohexyl, butylcyclohexyl, and heptylcyclohexyl.

[0083] Examples of this aryl group include phenyl, naphthyl, anthracene, biphenyl, terphenyl, etc.

[0084] Examples of alkylaryl groups include tolyl, dimethylphenyl, butylphenyl, nonylphenyl, and dimethylnaphthyl.

[0085] Examples of aryl alkyl groups include methylbenzyl, phenylmethyl, phenylethyl, and diphenylmethyl.

[0086] Preferably, it is molybdenum dialkyl dithiocarbamate (B1a) (hereinafter also referred to as "compound (B1a)") represented by the following general formula (b1-3).

[0087] [Chemistry 2]

[0088]

[0089] In the aforementioned general formula (b1-3), R 1 R 2 R 3 and R 4Each substituent group (α) represents a short-chain substituent group of an aliphatic hydrocarbon group with 4 to 12 carbon atoms, or a long-chain substituent group (β) represents an aliphatic hydrocarbon group with 13 to 22 carbon atoms. In the aforementioned compound (B1a), the molar ratio [(α) / (β)] of the aforementioned short-chain substituent group (α) to the aforementioned long-chain substituent group (β) in all molecules is 0.10 to 2.0. Furthermore, in the aforementioned general formula (b1-3), X... 1 X 2 X 3 and X 4 Each can be used to represent an oxygen atom or a sulfur atom independently.

[0090] Examples of aliphatic hydrocarbon groups with 4 to 12 carbon atoms that can be used as short-chain substituents (α) include alkyl groups with 4 to 12 carbon atoms and alkenyl groups with 4 to 12 carbon atoms.

[0091] Specifically, examples include butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, and dodecenyl. They can be linear or branched.

[0092] It should be noted that, from the viewpoint of maximizing the effects of the present invention, the number of carbon atoms of the aliphatic hydrocarbon group selected as the short-chain substituent group (α) is preferably 5 to 11, more preferably 6 to 10, and even more preferably 7 to 9.

[0093] Examples of aliphatic hydrocarbon groups with 13 to 22 carbon atoms that can be used as long-chain substituents (β) include alkyl groups with 13 to 22 carbon atoms and alkenyl groups with 13 to 22 carbon atoms.

[0094] Specifically, examples include tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecanyl, octadecyl, nonadecanyl, eicosyl, dodecyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl, heptadecanyl, octadecenyl, oleyl, nonadecanyl, eicosyl, dodecenyl, and dodecenyl. They can be linear or branched.

[0095] It should be noted that, from the viewpoint of maximizing the effects of the present invention, the number of carbon atoms of the aliphatic hydrocarbon group selected as the long-chain substituent group (β) is preferably 13 to 20, more preferably 13 to 16, and even more preferably 13 to 14.

[0096] Here, the compound (B1a) represented by the aforementioned general formula (b1-3) preferably has a molar ratio [(α) / (β)] of 0.10 to 2.0 for the short-chain substituent group (α) to the long-chain substituent group (β) in its entire molecule. If the molar ratio [(α) / (β)] is 0.10 or higher, the effect of compound (B1a) on copper corrosion resistance is reduced, and the friction reduction effect is easily improved. In addition, if the molar ratio [(α) / (β)] is 2.0 or lower, it is easier to ensure low-temperature storage stability.

[0097] Here, from the viewpoint of minimizing the impact on copper corrosion resistance and making it easier to improve the friction reduction effect, the molar ratio [(α) / (β)] is more preferably 0.15 or more, and even more preferably 0.20 or more.

[0098] Furthermore, from the viewpoint of more easily ensuring low-temperature storage stability, the molar ratio [(α) / (β)] is more preferably 1.2 or less, further preferably 1.0 or less, even more preferably 0.80 or less, even more preferably 0.60 or less, and even more preferably 0.50 or less.

[0099] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, the range is preferably 0.15 to 1.2, more preferably 0.20 to 1.0, even more preferably 0.20 to 0.80, even more preferably 0.20 to 0.60, and even more preferably 0.20 to 0.50.

[0100] Here, short-chain substituents (α) and long-chain substituents (β) may or may not coexist in the same molecule. That is, the average value of the molar ratio [(α) / (β)] of short-chain substituents (α) to long-chain substituents (β) in all molecules of the compound (B1a) shown in the aforementioned general formula (b1-3) only needs to be in the range of 0.10 to 1.2.

[0101] Therefore, in compound (B1a), in the aforementioned general formula (b1-3), R 1 R 2 R 3 and R 4 Molecules consisting entirely of short-chain substituents (α) (B1a-1) can coexist, R 1 R 2 R 3 and R 4 Molecules consisting entirely of long-chain substituents (β) (B1a-2) can coexist, R 1 R 2 R 3 and R 4Molecules consisting of a portion of short-chain substituents (α) and the remainder of long-chain substituents (β) (B1a-3) can coexist.

[0102] (Trinuclear molybdenum dithiocarbamate (B2))

[0103] Examples of trinuclear molybdenum dithiocarbamate include compounds represented by the following general formula (b2).

[0104] Mo3S k E m L n A p Q z (b2)

[0105] In the aforementioned general formula (b2), k is an integer of 1 or higher, m is an integer of 0 or higher, k+m is an integer of 4 to 10, preferably an integer of 4 to 7. n is an integer of 1 to 4, p is an integer of 0 or higher, and z is an integer of 0 to 5, including non-stoichiometric values.

[0106] E is either an oxygen atom or a selenium atom, for example, in a substance in which sulfur can be substituted in the nucleus described below.

[0107] Each L is an anionic ligand with an organic group containing carbon atoms, and the total number of carbon atoms in the organic group of each ligand is 14 or more. The ligands may be the same or different.

[0108] A is an anion other than L, each of which is independent.

[0109] Q is an independent, neutral compound that supplies electrons, existing to satisfy empty coordination on the trinuclear molybdenum compound.

[0110] The total number of carbon atoms in the organic group of the anionic ligand represented by L is preferably 14 to 50, more preferably 16 to 30, and even more preferably 18 to 24.

[0111] L is preferably a monoanionic ligand that is a monovalent anionic ligand, and more preferably a ligand shown in the following general formulas (i) to (iv).

[0112] It should be noted that, in the aforementioned general formula (b2), the ligand that can be selected as L is preferably the ligand shown in the following general formula (iv).

[0113] Furthermore, in the aforementioned general formula (b2), the anionic ligands selected as L are preferably all the same, and more preferably all are the ligands shown in the following general formula (iv).

[0114] [Chemistry 3]

[0115]

[0116] In the aforementioned general formulas (i) to (iv), X 31 ~X 37 , and Y are either oxygen atoms or sulfur atoms, and they can be the same or different from each other.

[0117] In the aforementioned general formulas (i) to (iv), R 31 ~R 35 Each is an independent organic group, and they can be the same as or different from each other.

[0118] It should be noted that R can be selected. 31 R 32 and R 33 The number of carbon atoms in each of the organic groups is preferably 14 to 50, more preferably 16 to 30, and even more preferably 18 to 24.

[0119] R in optional form (iv) 34 and R 35 The total number of carbon atoms in the two organic groups is preferably 14 to 50, more preferably 16 to 30, and even more preferably 18 to 24.

[0120] Optional R 34 and R 35 The number of carbon atoms in each of the organic groups is preferably 7 to 30, more preferably 7 to 20, and even more preferably 8 to 13.

[0121] It should be noted that R 34 Organic groups, and R 35 The organic groups can be the same or different, but are preferably different. Additionally, R... 34 The number of carbon atoms in the organic groups and R 35 The number of carbon atoms in the organic groups can be the same or different, but it is preferred that they are different.

[0122] As an optional R 31 ~R 35 Organic groups, such as alkyl, aryl, substituted aryl, and ether groups, are examples of hydrocarbon groups.

[0123] It should be noted that the term "hydrocarbon group" refers to a substituent having a carbon atom directly bonded to the residue of the ligand, and within the scope of this embodiment, its characteristics are primarily hydrocarbon groups. Examples of such substituents include the following groups.

[0124] 1. Hydrocarbon substituents

[0125] Examples of hydrocarbon substituents include aliphatic substituents such as alkyl and alkenyl groups, alicyclic substituents such as cycloalkyl and cycloalkenyl groups, aromatic groups, aromatic nuclei replaced by aliphatic and alicyclic groups, and cyclic groups whose rings are closed through another site in the ligand (i.e., any two of the substituents shown can be used together to form an alicyclic group).

[0126] 2. Substituted hydrocarbon substituents

[0127] Examples of substituents for hydrocarbons include groups obtained by replacing the aforementioned hydrocarbon substituents with non-hydrocarbon groups that do not alter the properties of the hydrocarbon group. Examples of non-hydrocarbon groups include, in particular, halogen groups such as chlorine and fluorine, amino groups, alkoxy groups, mercapto groups, alkyl mercapto groups, nitro groups, nitroso groups, and sulfonyloxy groups.

[0128] In the aforementioned general formula (b2), the anionic ligand that can be selected as L is preferably a ligand derived from alkyl xanthates, carboxylates, dialkyl dithiocarbamates, and mixtures thereof, and more preferably a ligand derived from dialkyl dithiocarbamates.

[0129] In the aforementioned general formula (b2), the anion that can be selected as A can be a monovalent anion or a divalent anion. Examples of anions that can be selected as A include disulfides, hydroxides, alkoxides, ammonides, and thiocyanates or their derivatives.

[0130] In the aforementioned general formula (b2), Q can be represented by water, amines, alcohols, ethers, and phosphine, etc. Q can be the same or different, but the same is preferred.

[0131] As a trinuclear molybdenum dithiocarbamate, it is preferably a compound in the aforementioned general formula (b2) where k is an integer of 4 to 7, n is 1 or 2, L is a monoanionic ligand, p is an integer that imparts electroneutrality to the compound based on the anionic charge in A, and m and z are each 0. More preferably, it is a compound where k is an integer of 4 to 7, L is a monoanionic ligand, n is 4, and p, m and z are each 0.

[0132] Furthermore, as a trinuclear molybdenum dithiocarbamate, a compound having, for example, a nucleus as shown in formula (IV-A) or (IV-B) is preferred. Each nucleus has a net electrical charge of +4. These nuclei are surrounded by anionic ligands and, if necessary, anions other than the anionic ligands.

[0133] [Chemistry 4]

[0134]

[0135] In the formation of trinuclear molybdenum-sulfur compounds, depending on, for example, the number of sulfur and E atoms present in the nucleus, it is necessary to select appropriate anionic ligands (L) and other anions (A), that is, the total anionic charge of the sulfur atom, the E atom in the presence of the present, L and A in the presence of the present must be -4.

[0136] Furthermore, when the anionic charge of the trinuclear molybdenum-sulfur compound is greater than -4, it may contain cations other than molybdenum, such as (alkyl)ammonium, amine, or sodium. A preferred embodiment of the anionic ligand (L) and other anions (A) is a configuration having four monoanionic ligands.

[0137] Molybdenum-sulfur nuclei, such as the structures shown in (IV-A) and (IV-B) above, can be interconnected through one or more polydentate ligands, i.e. ligands having more than one functional group bonded to a molybdenum atom that can form an oligomer.

[0138] The molybdenum content in the trinuclear molybdenum dithiocarbamate (B2), based on the total amount of trinuclear molybdenum dithiocarbamate (B2), is preferably 2.0% by mass or more, more preferably 4.0% by mass or more, and even more preferably 5.0% by mass or more. Furthermore, it is preferably 9.0% by mass or less, more preferably 7.0% by mass or less, and even more preferably 6.0% by mass or less.

[0139] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, it is preferably 2.0% to 9.0% by mass, more preferably 4.0% to 7.0% by mass, and even more preferably 5.0% to 6.0% by mass.

[0140] (Molybdenum amine complex (B3))

[0141] Examples of molybdenum-amine complexes (B3) include those formed by reacting molybdenum trioxide (a hexavalent molybdenum compound) and / or molybdic acid with amine compounds.

[0142] Examples of preferred amine compounds include alkylamines and dialkylamines.

[0143] There are no particular limitations on alkylamines and dialkylamines that react with hexavalent molybdenum compounds; examples include alkylamines and dialkylamines with alkyl groups having 1 to 30 carbon atoms.

[0144] The molybdenum content in the molybdenum amine complex (B3), based on the total amount of the molybdenum amine complex (B3), is preferably 4.0% by mass or more, more preferably 6.0% by mass or more, and even more preferably 7.0% by mass or more. Furthermore, it is preferably 12.0% by mass or less, more preferably 10.0% by mass or less, and even more preferably 9.0% by mass or less.

[0145] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, it is preferably 4.0% to 12.0% by mass, more preferably 6.0% to 10.0% by mass, and even more preferably 7.0% to 9.0% by mass.

[0146] (Content of molybdenum-based friction modifier (B))

[0147] In the lubricating oil composition of this embodiment, the content of the molybdenum-based friction modifier (B), from the viewpoint of improving friction reduction, is preferably 0.30% by mass or more, more preferably 0.50% by mass or more, and even more preferably 0.70% by mass or more, based on the total amount of the lubricating oil composition. Furthermore, it is preferably 3.0% by mass or less, more preferably 2.0% by mass or less, and even more preferably 1.0% by mass or less.

[0148] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, it is preferably 0.30% to 3.0% by mass, more preferably 0.50% to 2.0% by mass, and even more preferably 0.70% to 1.0% by mass.

[0149] In the lubricating oil composition of this embodiment, from the viewpoint of improving friction reduction effect, the molybdenum content derived from the molybdenum-based friction modifier (B) is preferably 0.05% by mass or more, more preferably 0.06% by mass or more, and even more preferably 0.07% by mass or more, based on the total amount of the lubricating oil composition.

[0150] Furthermore, from the viewpoint of reducing sulfuric acid ash, the content of molybdenum atoms derived from the molybdenum-based friction modifier (B) is preferably 0.12% by mass or less, more preferably 0.11% by mass or less, and even more preferably 0.10% by mass or less, based on the total amount of the lubricating oil composition.

[0151] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, it is preferably 0.05% to 0.12% by mass, more preferably 0.06% to 0.11% by mass, and even more preferably 0.07% to 0.10% by mass.

[0152] (The ratio of the content of dinuclear molybdenum dithiocarbamate (B1) to trinuclear molybdenum dithiocarbamate (B2))

[0153] In this embodiment, the ratio of the content of the dinuclear molybdenum dithiocarbamate (B1) to the trinuclear molybdenum dithiocarbamate (B2) [(B1) / (B2)] is preferably 0.1 to 10 by mass from the viewpoint of improving friction reduction, more preferably 0.5 to 7.0, and even more preferably 1.0 to 5.0.

[0154] (The ratio of the content of the dinuclear molybdenum dithiocarbamate (B1) to the molybdenum amine complex (B3))

[0155] In this embodiment, the ratio of the dinuclear molybdenum dithiocarbamate to the molybdenum amine complex [(B1) / (B3)] is preferably 0.1 to 10 by mass, more preferably 1.0 to 8.0, and even more preferably 2.0 to 6.0, from the viewpoint of improving friction reduction.

[0156] (Acid values ​​derived from dinuclear molybdenum dithiocarbamate (B1) and trinuclear molybdenum dithiocarbamate (B2))

[0157] The lubricating oil composition of this embodiment requires an acid value of less than 0.04 mg KOH / g derived from dinuclear molybdenum dithiocarbamate (B1) and trinuclear molybdenum dithiocarbamate (B2).

[0158] If the acid value is above 0.04 mg KOH / g, there is concern about the deterioration of the high-temperature detergency, oxidation stability, and copper corrosion resistance of the lubricating oil composition.

[0159] From the viewpoint of making it easier to improve the oxidative stability, high-temperature detergency, and copper corrosion resistance of the lubricating oil composition, the acid value is preferably below 0.03 mg KOH / g.

[0160] It should be noted that, in this specification, the acid values ​​of molybdenum dithiocarbamate (B1) and molybdenum dithiocarbamate (B2) derived from the dinuclear group are values ​​determined according to JIS K2501:2003 (potential difference titration method).

[0161] (Preferred method for molybdenum-based friction modifier (B))

[0162] The molybdenum-based friction modifier (B) contains two or more selected from the following: dinuclear molybdenum dithiocarbamate (B1), trinuclear molybdenum dithiocarbamate (B2), and molybdenum amine complex (B3).

[0163] Therefore, the combination of molybdenum-based friction modifiers (B) includes any of the following (1) to (4).

[0164] (1) Combination of dinuclear molybdenum dithiocarbamate (B1) and trinuclear molybdenum dithiocarbamate (B2)

[0165] (2) Combination of molybdenum dinuclear dithiocarbamate (B1) and molybdenum amine complex (B3)

[0166] (3) Combination of trinuclear molybdenum dithiocarbamate (B2) and molybdenum amine complex (B3)

[0167] (4) A combination of a dinuclear molybdenum dithiocarbamate (B1), a trinuclear molybdenum dithiocarbamate (B2), and a molybdenum amine complex (B3).

[0168] Of these combinations, from the viewpoint of easily achieving the effects of the invention, the combination of (1), (2), or (4) containing molybdenum dinuclear dithiocarbamate (B1) is preferred.

[0169] <Metallic Detergent (C)>

[0170] The lubricating oil composition of this embodiment contains a metal-based detergent (C). Furthermore, in this embodiment, the metal-based detergent (C) contains sulfur atoms.

[0171] When the lubricating oil composition does not contain a metallic detergent (C), high-temperature detergency cannot be adequately ensured.

[0172] As a metal-based detergent (C), examples include organic acid metal salt compounds containing metal atoms and sulfur atoms selected from alkali metals and alkaline earth metals.

[0173] It should be noted that in this specification, "alkali metals" refers to lithium, sodium, potassium, rubidium, and cesium.

[0174] In addition, in this specification, "alkaline earth metals" refers to beryllium, magnesium, calcium, strontium, and barium.

[0175] From the viewpoint of improving high-temperature cleaning performance, the metal atoms contained in the metal-based detergent (C) are preferably sodium, calcium, magnesium, or barium, and more preferably calcium or magnesium.

[0176] That is, as a metal-based detergent (C), it preferably contains one or more detergents selected from sodium-based detergents, calcium-based detergents, magnesium-based detergents, and barium-based detergents, and more preferably contains one or more detergents selected from calcium-based detergents and magnesium-based detergents.

[0177] Here, metal-based detergents (C) containing sulfur atoms can be listed as, for example, metal sulfonates and metal phenolates, with metal sulfonates being preferred.

[0178] As a metal sulfonate, the compound represented by the following general formula (c-1) is preferred. Additionally, as a metal phenolate, the compound represented by the following general formula (c-2) is preferred.

[0179] [Chemistry 5]

[0180]

[0181] In the above general formulas (c-1) to (c-2), M is a metal atom selected from alkali metals and alkaline earth metals, preferably sodium, calcium, magnesium, or barium, and more preferably calcium or magnesium.

[0182] M E It is an alkaline earth metal, preferably calcium, magnesium, or barium, and more preferably calcium or magnesium.

[0183] q is the valence of M, which is 1 or 2. R c1 and R c2 Each is independently a hydrocarbon group consisting of 1 to 18 hydrogen atoms or carbon atoms.

[0184] S represents a sulfur atom.

[0185] r is an integer greater than or equal to 1, preferably an integer between 1 and 3.

[0186] As an optional R c1 and R c2 Examples of hydrocarbon groups include alkyl groups with 1 to 18 carbon atoms, alkenyl groups with 1 to 18 carbon atoms, cycloalkyl groups with 3 to 18 cyclic carbon atoms, aryl groups with 6 to 18 cyclic carbon atoms, alkylaryl groups with 7 to 18 carbon atoms, and arylalkyl groups with 7 to 18 carbon atoms.

[0187] They can be used individually or in combination of two or more.

[0188] From the viewpoint of making it easier to improve high-temperature detergency and from the viewpoint of solubility in base oil (A), it is preferable to be selected from one or more of calcium sulfonate, calcium phenolate, magnesium sulfonate, and magnesium phenolate, and more preferably from one or more of calcium sulfonate and magnesium sulfonate.

[0189] It should be noted that in the following description, calcium-based detergents containing sulfur atoms will also be referred to as "calcium-based detergents (C1)". In addition, magnesium-based detergents containing sulfur atoms will also be referred to as "magnesium-based detergents (C2)".

[0190] The metal-based detergent (C) can be any of a neutral salt, an alkaline salt, a superalkaline salt, or a mixture thereof. From the viewpoint of easily adjusting the initial base value to a specified value or higher, and from the viewpoint of more easily improving the maintenance of base value, an alkaline salt or a superalkaline salt is preferred, and a superalkaline salt is more preferred.

[0191] It should be noted that in this specification, metal-based detergents with an alkalinity of less than 50 mg KOH / g are defined as "neutral", metal-based detergents with an alkalinity of 50 mg KOH / g or more but less than 150 mg KOH / g are defined as "alkaline", and metal-based detergents with an alkalinity of 150 mg KOH / g or more are defined as "overly alkaline".

[0192] When using an alkaline substance as a metal-based detergent (C), the alkalinity of the metal-based detergent (C) is preferably 200 mg KOH / g or more and 500 mg KOH / g or less, more preferably 250 mg KOH / g or more and 450 mg KOH / g or less.

[0193] In this specification, the alkalinity of the metal-based detergent (B) refers to the value determined by potentiometric titration (alkalinity-perchloric acid method) according to JIS K2501:2003, section 9.

[0194] In this embodiment, when the metal-based detergent (C) includes a calcium-based detergent (C1), the alkalinity of the calcium-based detergent (C1) is preferably 200 mg KOH / g or more and 500 mg KOH / g or less, more preferably 250 mg KOH / g or more and 450 mg KOH / g or less, and even more preferably 250 mg KOH / g or more and 400 mg KOH / g or less.

[0195] When the metal-based detergent (C) includes a calcium-based detergent (C1), the calcium-based detergent (C1) is preferably selected from one or more of calcium sulfonate and calcium phenolate, and more preferably calcium sulfonate.

[0196] In this embodiment, when the metal-based detergent (C) includes a magnesium-based detergent (C2), the alkalinity of the magnesium-based detergent is preferably 200 mg KOH / g or more and 500 mg KOH / g or less, more preferably 250 mg KOH / g or more and 500 mg KOH / g or less, and even more preferably 300 mg KOH / g or more and 450 mg KOH / g or less.

[0197] When the metal-based detergent (C) includes a magnesium-based detergent (C2), the magnesium-based detergent (C2) is preferably selected from one or more magnesium sulfonate and magnesium phenolate, and more preferably magnesium sulfonate.

[0198] In the lubricating oil composition of this embodiment, the content of the metal-based detergent (C) is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 0.8% by mass, based on the total amount of the lubricating oil composition, from the viewpoint of facilitating the volatilization of the effects of the present invention. In addition, it is preferably 5.0% by mass or less, more preferably 4.0% by mass or less, and even more preferably 3.0% by mass or less.

[0199] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, it is preferably 0.1% to 5.0% by mass, more preferably 0.5% to 4.0% by mass, and even more preferably 0.8% to 3.0% by mass.

[0200] It should be noted that the metallic detergent (C) can be used alone or in combination with two or more. When using two or more, the appropriate total concentration is the same as described above.

[0201] In the lubricating oil composition of this embodiment, when the metal-based detergent (C) includes a calcium-based detergent (C1), the calcium content of the calcium-based detergent (C1) is preferably 0.10% by mass or more, more preferably 0.11% by mass or more, based on the total amount of the lubricating oil composition, from the viewpoint that it is easier to improve the high-temperature detergency.

[0202] Furthermore, from the viewpoint of reducing sulfuric acid ash and preventing LSPI (abnormal combustion), the calcium content of the calcium-based detergent (C1) is preferably 0.20% by mass or less, more preferably 0.15% by mass or less, and even more preferably 0.13% by mass or less, based on the total amount of the lubricating oil composition.

[0203] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, it is preferably 0.10% to 0.20% by mass, more preferably 0.10% to 0.15% by mass, and even more preferably 0.11% to 0.13% by mass.

[0204] In the lubricating oil composition of this embodiment, when the metal-based detergent (C) includes a magnesium-based detergent (C2), the magnesium content of the magnesium-based detergent (C2) is preferably 0.03% by mass or more, more preferably 0.04% by mass or more, and even more preferably 0.05% by mass or more, based on the total amount of the lubricating oil composition, from the viewpoint that it is easier to improve the high-temperature detergency.

[0205] Furthermore, from the viewpoint of reducing sulfuric acid ash and preventing LSPI (abnormal combustion), the magnesium content of the magnesium-based detergent (C2) is preferably 0.08% by mass or less, more preferably 0.07% by mass or less, and even more preferably 0.06% by mass or less, based on the total amount of the lubricating oil composition.

[0206] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, it is preferably 0.03% to 0.07% by mass, more preferably 0.04% to 0.06% by mass.

[0207] In the metal-based detergent (C), the content of one or more metal-based detergents selected from calcium-based detergents (C1) and magnesium-based detergents (C2), based on the total amount of metal-based detergents (C), is preferably 50% to 100% by mass, more preferably 60% to 100% by mass, even more preferably 70% to 100% by mass, even more preferably 80% to 100% by mass, and even more preferably 90% to 100% by mass.

[0208] <Ashless Dispersant (D)>

[0209] The lubricating oil composition of this embodiment contains an ashless dispersant (D). Furthermore, in this embodiment, the ashless dispersant (D) contains nitrogen atoms.

[0210] When a lubricating oil composition does not contain an ashless dispersant (D), high-temperature detergency cannot be adequately ensured.

[0211] As an ashless dispersant (D), examples include succinic monoimide selected from alkenyl succinic monoimide and alkyl succinic monoimide; boron-modified succinic monoimide; succinic diimide selected from alkenyl succinic diimide and alkyl succinic diimide; and boron-modified succinic diimide.

[0212] Preferably, it is selected from one or more of succinate monoimide (non-boron modified) and succinate diimide (non-boron modified), more preferably succinate monoimide (non-boron modified).

[0213] Ashless dispersants (D) can be used alone or in combination of two or more.

[0214] Compounds represented by the following general formula (d1) can be listed as alkenyl succinic acid monoimides or alkyl succinic acid monoimides. Additionally, compounds represented by the following general formula (d2) can be listed as alkenyl succinic acid diimides or alkyl succinic acid diimides.

[0215] [Chemistry 6]

[0216]

[0217] In general formulas (d1) and (d2), R d3 R d5 and R d6 It is alkenyl or alkyl, and the mass-average molecular weight (Mw) is preferably 500 to 3000, more preferably 1000 to 3000.

[0218] If R d3 R d5 and R d6If the mass-average molecular weight is above 500, it will have good solubility in base oil (A). Additionally, if R... d3 R d5 and R d6 If the mass-average molecular weight is below 3000, the effects of this invention can be more easily achieved. d5 and R d6 They can be the same or different.

[0219] R d4 R d7 and R d8 They are alkylene groups with 2 to 5 carbon atoms, R d7 and R d8 They can be the same or different.

[0220] n1 represents an integer from 1 to 10, and n2 represents 0 or an integer from 1 to 10.

[0221] Here, n1 is preferably 2 to 5, more preferably 2 to 4. If n1 is 2 or more, the effects of the present invention can be more easily achieved. If n1 is 5 or less, the solubility in the base oil (A) becomes even better.

[0222] Furthermore, n2 is preferably 1 to 6, more preferably 2 to 6. If n2 is 1 or more, the effects of the present invention can be more easily achieved. If n2 is 6 or less, the solubility in the base oil (A) becomes even better.

[0223] As an optional R d3 R d5 and R d6 The alkenyl group can be exemplified by, for example, polybutenyl, polyisobutylene, and ethylene-propylene copolymers, with polybutenyl or polyisobutylene being preferred examples. Polybutenyl is suitable for use as a substance obtained by polymerizing a mixture of 1-butene and isobutylene or high-purity isobutylene.

[0224] As an optional R d3 R d5 and R d6 Alkyl groups, for example, hydrogenated substances such as polybutenyl, polyisobutylene, ethylene-propylene copolymer, etc., are preferred examples, with hydrogenated substances of polybutenyl or polyisobutylene being preferred examples.

[0225] The aforementioned alkenyl succinic anhydride or alkyl succinic anhydride can generally be manufactured by reacting an alkenyl succinic anhydride obtained by reacting a polyolefin with maleic anhydride, or an alkyl succinic anhydride obtained by hydrogenating the polyolefin with a polyamine. Monoimides or diimides can be manufactured by changing the ratio of alkenyl succinic anhydride or alkyl succinic anhydride to polyamine.

[0226] The aforementioned alkenyl succinicotinamide or alkyl succinicotinamide can be boron-modified. This boron-modified material can be manufactured, for example, by reacting boron-free alkenyl succinicotinamide or alkyl succinicotinamide, or alkenyl succinicotinamide or alkyl succinicotinamide, with a boron compound. Preferably, the boron-modified material is an alkenyl succinicotinamide or alkyl succinicotinamide.

[0227] As the olefin monomer for forming polyolefins, one or more α-olefins selected from those having 2 to 8 carbon atoms can be used, and a mixture of isobutylene and 1-butene can be used appropriately.

[0228] On the other hand, examples of polyamines include monodiamines such as ethylenediamine, propylenediamine, butanediamine, and pentanediamine; polyalkylene polyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, di(methylethylene)triamine, dibutyltriamine, tributyltriamine, tributyltetramine, and pentapentylhexamine; and piperazine derivatives such as aminoethylpiperazine.

[0229] Polyamines can be used alone or in combination of two or more.

[0230] Examples of boron compounds include boric acid, borate, and borate esters.

[0231] Examples of boric acids include orthoboric acid, metaboric acid, and paraboric acid.

[0232] Examples of borates include ammonium metaborate, ammonium tetraborate, ammonium pentaborate, and ammonium octaborate.

[0233] Examples of borate esters include monomethyl borate, dimethyl borate, trimethyl borate, monoethyl borate, diethyl borate, triethyl borate, monopropyl borate, dipropyl borate, tripropyl borate, monobutyl borate, dibutyl borate, and tributyl borate.

[0234] In the lubricating oil composition of this embodiment, from the viewpoint of facilitating the volatilization of the effects of the present invention, the content of nitrogen atoms derived from the ashless dispersant is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, and even more preferably 0.03% by mass or more, based on the total amount of the lubricating oil composition. Furthermore, it is preferably 0.10% by mass or less, more preferably 0.08% by mass or less, and even more preferably 0.07% by mass or less.

[0235] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, it is preferably 0.01% to 0.10% by mass, more preferably 0.02% to 0.08% by mass, and even more preferably 0.03% to 0.07% by mass.

[0236] <Sulfur component (C) derived from metal-based detergent (C) S ), and nitrogen components (D) derived from ashless dispersant (D) N The content ratio of ) is >

[0237] The lubricating oil composition of this embodiment requires a sulfur component (C) derived from the metal-based detergent (C). S ), and nitrogen components (D) derived from ashless dispersant (D) N The content ratio of ) [(C S ) / (D N The mass ratio is 0.30 to 0.85.

[0238] If [(C S ) / (D N If the concentration of [(C)] is less than 0.30, a lubricating oil composition with poor oxidation stability and high-temperature detergency is formed. Additionally, if [(C)] is less than 0.30, a lubricating oil composition with poor oxidation stability and high-temperature detergency is formed. S ) / (D N If the concentration exceeds 0.85, it forms a lubricating oil composition with poor resistance to copper corrosion and poor high-temperature detergency.

[0239] Here, from the viewpoint of making it easier to improve oxidation stability, high-temperature detergency, and copper corrosion resistance, [(C S ) / (D N The value is preferably 0.32 or higher, more preferably 0.34 or higher, and even more preferably 0.35 or higher. Furthermore, it is preferably 0.83 or lower, more preferably 0.81 or lower, and even more preferably 0.79 or lower.

[0240] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, the range is preferably 0.32 to 0.83, more preferably 0.34 to 0.81, and even more preferably 0.35 to 0.79.

[0241] <Metal Inertizer (E)>

[0242] From the viewpoint of making it easier to improve resistance to copper corrosion, the lubricating oil composition of this embodiment preferably contains a metal inertizer (E).

[0243] Examples of metal inerts (E) include benzotriazole compounds, methylbenzotriazole compounds, thiadiazole compounds, imidazole compounds, and pyrimidine compounds.

[0244] They can be used individually or in combination of two or more.

[0245] In this embodiment, the lubricating oil composition preferably contains benzotriazole compounds from the viewpoint of improving copper corrosion resistance.

[0246] As a benzotriazole compound, one or more benzotriazole compounds selected from those previously used as metal inert agents can be used without particular restriction.

[0247] Here, in this embodiment, from the viewpoint of improving copper corrosion resistance, the benzotriazole compound preferably includes the benzotriazole compound (E1) represented by the following general formula (e1).

[0248] [Chemistry 7]

[0249]

[0250] In the aforementioned general formula (e1), R e1 It is an alkyl group having 1 to 4 carbon atoms. The alkyl group can be straight-chain or branched. Here, from the viewpoint of improving copper corrosion resistance, the alkyl group preferably has 1 to 3 carbon atoms, more preferably 1 to 2, and even more preferably 1.

[0251] In the aforementioned general formula (e1), p is an integer from 0 to 4. e1 When there are multiple R (i.e., when p is an integer from 2 to 4), multiple R e1 The components can be the same or different. Here, from the viewpoint of improving copper corrosion resistance, p is preferably 0 to 3, more preferably 0 to 2, and even more preferably 1.

[0252] In the aforementioned general formula (e1), R e2 It is methylene or ethylene. Here, from the viewpoint of improving copper corrosion resistance, R e2 The preferred component is methylene.

[0253] In the aforementioned general formula (e1), R e3 and R e4 Each alkyl group is independently composed of hydrogen atoms or 1 to 18 carbon atoms. The alkyl group can be straight-chain or branched, preferably branched. Furthermore, the alkyl group preferably has 2 to 14 carbon atoms, more preferably 4 to 12, and even more preferably 6 to 10.

[0254] When the metal inert agent (E) contains a benzotriazole compound (E1), the content of the benzotriazole compound (E1) is preferably 50% to 100% by mass, more preferably 60% to 100% by mass, further preferably 70% to 100% by mass, even more preferably 80% to 100% by mass, and even more preferably 90% to 100% by mass, based on the total amount of the metal inert agent (E).

[0255] In the lubricating oil composition of this embodiment, the content of the metal inert agent (E) is preferably 0.03% by mass or less, more preferably 0.02% by mass or less, and even more preferably 0.015% by mass or less, based on the total amount of the lubricating oil composition, from the viewpoint of further improving the friction-reducing effect.

[0256] Furthermore, from the viewpoint of making it easier to improve copper corrosion resistance, the content of benzotriazole compounds is preferably 0.003% by mass or more, and more preferably 0.005% by mass or more.

[0257] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, it is preferably 0.003% to 0.03% by mass, more preferably 0.005% to 0.02% by mass, and even more preferably 0.005% to 0.015% by mass.

[0258] <Other Ingredients>

[0259] The lubricating oil composition of this embodiment may contain other components besides those described above, as needed, without impairing the effects of the present invention.

[0260] Other additives include wear-resistant agents, antioxidants, viscosity index improvers, pour point depressants, extreme pressure agents, rust inhibitors, defoamers, deemulsifiers, friction modifiers other than molybdenum-based friction modifiers (B), and metal-based detergents other than metal-based detergents (C').

[0261] They can be used individually or in combination of two or more.

[0262] (Abrasion resistant agent)

[0263] Examples of wear-resistant agents include zinc-containing compounds such as zinc dialkyl dithiophosphate (ZnDTP) and zinc phosphate; sulfur-containing compounds such as disulfides, sulfurized olefins, sulfurized oils, sulfurized esters, thiocarbonates, thiocarbamates, and polysulfides; phosphorus-containing compounds such as phosphites, phosphates, phosphonates, and their amine or metal salts; and wear-resistant agents containing sulfur and phosphorus such as thiophosphites, thiophosphates, thiophosphonates, and their amine or metal salts.

[0264] They can be used individually or in combination of two or more.

[0265] Here, as a wear-resistant agent, a wear-resistant agent containing phosphorus atoms is preferred (hereinafter also referred to as "phosphorus-based wear-resistant agent"). Furthermore, as a phosphorus-based wear-resistant agent, zinc dialkyl dithiophosphate (ZnDTP) is preferred.

[0266] As zinc dialkyl dithiophosphate (ZnDTP), compounds represented by the following general formula (f-1) are preferred.

[0267] [Chemistry 8]

[0268]

[0269] In the general formula (f-1), R f1 ~R f4 Each can be represented independently as a hydrocarbon group. As long as it is a monovalent hydrocarbon group, there are no particular restrictions. For example, from the viewpoint of improving oxidation stability, alkyl, alkenyl, cycloalkyl, aryl, etc. are preferred, and alkyl is more preferred.

[0270] R f1 ~R f4 The alkyl and alkenyl groups can be either linear or branched.

[0271] Furthermore, from the viewpoint of further improving oxidative stability, as R f1 ~R f4 The number of carbon atoms in the hydrocarbon group is preferably 1 or more, more preferably 2 or more, and even more preferably 3 or more, with an upper limit of 24 or less, more preferably 18 or less, and even more preferably 12 or less. When the monovalent hydrocarbon is an alkenyl group, it is preferably 2 or more, more preferably 3 or more, with an upper limit of 24 or less, more preferably 18 or less, and even more preferably 12 or less.

[0272] R f1 ~R f4 The cycloalkyl and aryl groups can be polycyclic groups such as naphthylalkyl (decalyl) and naphthyl. As R f1 ~R f4 The number of carbon atoms in the hydrocarbon group is preferably 5 or more when the monovalent hydrocarbon is a cycloalkyl group, and preferably 20 or less as an upper limit. When the monovalent hydrocarbon is an aryl group, the number of carbon atoms is preferably 6 or more, and preferably 20 or less as an upper limit.

[0273] In addition, a monovalent hydrocarbon group can be partially replaced by groups containing oxygen atoms and / or nitrogen atoms, such as hydroxyl, carboxyl, amino, amide, nitro, and cyano groups, and can also be partially replaced by nitrogen atoms, oxygen atoms, halogen atoms, etc. When the monovalent hydrocarbon group is cycloalkyl or aryl, it can further have substituents such as alkyl or alkenyl groups.

[0274] When the lubricating oil composition of this embodiment contains a phosphorus-based wear-resistant agent, the phosphorus content derived from the phosphorus-based wear-resistant agent, based on the total amount of the lubricating oil composition, is preferably greater than 0.04% by mass and less than 0.10% by mass, more preferably 0.05% to 0.09% by mass, and even more preferably 0.06% to 0.08% by mass.

[0275] (Antioxidants)

[0276] Examples of antioxidants include amine antioxidants and phenolic antioxidants.

[0277] Examples of amine-based antioxidants include diphenylamine, alkylated diphenylamine having 3 to 20 carbon atoms, and naphthylamine, phenyl-α-naphthylamine, substituted phenyl-α-naphthylamine having 3 to 20 carbon atoms, and substituted phenyl-β-naphthylamine having 3 to 20 carbon atoms.

[0278] Examples of phenolic antioxidants include monophenolic antioxidants such as 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, isooctyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate; diphenolic antioxidants such as 4,4'-methylenebis(2,6-di-tert-butylphenol) and 2,2'-methylenebis(4-ethyl-6-tert-butylphenol); and hindered phenolic antioxidants.

[0279] They can be used individually or in combination of two or more.

[0280] (Viscosity index improver)

[0281] Examples of viscosity index improvers include non-dispersed poly(meth)acrylates, dispersed poly(meth)acrylates, comb polymers, star polymers, olefin copolymers (e.g., ethylene-propylene copolymers), dispersed olefin copolymers, and styrene copolymers (e.g., styrene-diene copolymers, styrene-isoprene copolymers).

[0282] The mass-average molecular weight (Mw) of the viscosity index improver is preferably 100,000 to 1,000,000, more preferably 200,000 to 800,000, and even more preferably 250,000 to 750,000.

[0283] The molecular weight distribution (Mw / Mn) of the viscosity index improver is preferably 5.00 or less, more preferably 4.00 or less, even more preferably 3.00 or less, and usually 1.01 or more.

[0284] Viscosity index improvers can be used alone or in combination of two or more.

[0285] (Pour point depressant)

[0286] Examples of pour point depressants include ethylene-vinyl acetate copolymers, condensates of chlorinated paraffin and naphthalene, condensates of chlorinated paraffin and phenol, polymethacrylates (PMA-based; poly(meth)acrylate alkyl esters, etc.), polyvinyl acetate, polybutene, polyalkylstyrene, etc., with polymethacrylates being the preferred choice.

[0287] They can be used individually or in combination of two or more.

[0288] (Extreme pressure agent)

[0289] Examples of extreme pressure agents include sulfur-based extreme pressure agents such as sulfides, sulfoxides, sulfones, and thiophosphonates; halogen-based extreme pressure agents such as chlorinated hydrocarbons; and organometallic extreme pressure agents. Furthermore, compounds that function as extreme pressure agents can also be used in the aforementioned wear-resistant agents.

[0290] They can be used individually or in combination of two or more.

[0291] (Rust inhibitor)

[0292] Examples of rust inhibitors include fatty acids, alkenyl succinate half-esters, fatty acid soaps, alkyl sulfonates, polyol fatty acid esters, fatty acid amines, oxidized paraffins, and alkyl polyoxyethylene ethers.

[0293] They can be used individually or in combination of two or more.

[0294] (Defoamer)

[0295] Examples of defoamers include silicone oils such as dimethylpolysiloxane, fluorosilicone oils, and fluoroalkyl ethers.

[0296] They can be used individually or in combination of two or more.

[0297] (Demulsifier)

[0298] Examples of demulsifiers include anionic surfactants such as castor oil sulfate salts and petroleum sulfonates; cationic surfactants such as quaternary ammonium salts and imidazoline derivatives; polyalkylene glycol-based nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, and polyoxyethylene alkylnaphthalene ethers; esters of polyoxyethylene polyethylene glycol and its dicarboxylic acid; and alkylphenol-formaldehyde condensates, etc.

[0299] They can be used individually or in combination of two or more.

[0300] (Friction modifiers other than molybdenum-based friction modifiers (B))

[0301] The lubricating oil composition of this embodiment may contain friction modifiers other than molybdenum-based friction modifiers (B).

[0302] Friction modifiers other than molybdenum-based friction modifiers (B) include, for example, ashless friction modifiers such as aliphatic amines, fatty acid esters, fatty acid amides, fatty acids, aliphatic alcohols, and aliphatic ethers; oils, amines, amides, sulfides, phosphate esters, phosphites, and phosphate ester amine salts.

[0303] They can be used individually or in combination of two or more.

[0304] (Metallic detergents (C') other than metallic detergents (C))

[0305] The lubricating oil composition of this embodiment may contain a metal-based detergent (C') other than a metal-based detergent (C).

[0306] As a metal-based detergent (C'), examples include organic acid metal salt compounds containing metal atoms selected from alkali metals and alkaline earth metals and free of sulfur atoms.

[0307] Examples of such compounds include metal salicylates.

[0308] Metal-based detergents (C') can be used alone or in combination of two or more.

[0309] (Content of other ingredients)

[0310] The content of the aforementioned other components can be appropriately adjusted within the range that does not impair the effect of the present invention. The content of each of these other components is based on the total amount of the lubricating oil composition and is typically 0.001% to 15% by mass, preferably 0.005% to 10% by mass.

[0311] It should be noted that, in this specification, considering factors such as processability and solubility in base oil (A), the additives mentioned above as other components can be mixed with other components in the form of a solution obtained by diluting and dissolving a portion of the aforementioned base oil (A). In this case, the aforementioned content of the additives mentioned above as other components in this specification refers to the content calculated after removing the effective components of the diluent oil (resin component conversion).

[0312] It should be noted that the lubricating oil composition of this embodiment can reduce friction in a temperature range of 30°C even without the addition of an ashless friction modifier.

[0313] Therefore, the content of ashless friction modifier in the lubricating oil composition of this embodiment can be low. Specifically, the content of ashless friction modifier, based on the total amount of the lubricating oil composition, is preferably less than 0.1% by mass, more preferably less than 0.01% by mass, and even more preferably does not contain ashless friction modifier.

[0314] [Physical properties of lubricating oil compositions, etc.]

[0315] <Kinematic viscosity, viscosity index>

[0316] From the viewpoint of improving fuel efficiency, the kinematic viscosity of the lubricating oil composition involved in this embodiment is preferably 12.5 mm at 100°C. 2 / s or less, preferably 9.3mm 2 / s or less, further preferably 9.0mm 2 / s or less.

[0317] Furthermore, from the viewpoint of easily suppressing evaporation loss of the lubricating oil composition, 5.0 mm is preferred. 2 / s or higher, preferably 6.1mm 2 / s or higher, further preferably 6.9mm 2 / s or more.

[0318] For the lubricating oil composition involved in this embodiment, the viscosity index is preferably 150 or more, more preferably 200 or more, and even more preferably 220 or more.

[0319] <HTHS viscosity at 150℃>

[0320] From the viewpoint of oil film retention, the HTHS viscosity (high-temperature high-shear viscosity) of the lubricating oil composition according to this embodiment is preferably 1.7 mPa·s or more, more preferably 2.0 mPa·s or more, and even more preferably 2.3 mPa·s or more. Furthermore, from the viewpoint of improving fuel efficiency, the HTHS viscosity of the lubricating oil composition according to this embodiment is preferably less than 2.9 mPa·s, more preferably 2.6 mPa·s or less.

[0321] In this specification, the HTHS viscosity of the lubricating oil composition at 150°C is based on ASTM D4683, using a TBS tapered bearing simulator viscometer, at a temperature of 150°C, expressed as a 10-fold viscosity. 6 The measured value of the shear rate per second.

[0322] <CCS viscosity at -35℃>

[0323] From the viewpoint of obtaining good low-temperature viscosity characteristics, the CCS viscosity of the lubricating oil composition of this embodiment is preferably 6200 mPa·s or less at -35°C, and more preferably 6000 mPa·s or less.

[0324] In this specification, the CCS viscosity of the lubricating oil composition at -35°C is a value determined according to JIS K2010:1993.

[0325] <Various Atomic Contents>

[0326] The various atomic contents of the lubricating oil composition of this embodiment are described below.

[0327] It should be noted that the molybdenum, boron, calcium, magnesium, phosphorus, and sulfur content of the lubricating oil composition in this specification are values ​​determined according to JIS-5S-38-03.

[0328] In addition, the nitrogen content of the lubricating oil composition is determined by chemiluminescence method according to JIS K2609:1998.

[0329] (Sulfur content)

[0330] The lubricating oil composition of this embodiment preferably has a sulfur content of 0.35% by mass or less based on the total amount of the lubricating oil composition.

[0331] When the sulfur content is less than 0.35% by mass based on the total amount of the lubricating oil composition, the lubricating oil composition is more likely to have good resistance to copper corrosion and oxidation stability.

[0332] The sulfur content of the lubricating oil composition can be adjusted by adjusting the content of sulfur-containing additives such as molybdenum-based friction modifiers (B) and metal-based detergents (C).

[0333] From the viewpoint of more easily improving copper corrosion resistance and oxidation stability, the sulfur content in the lubricating oil composition is preferably 0.33% by mass or less, more preferably 0.31% by mass or less, and even more preferably 0.30% by mass or less. Additionally, it is preferably 0.25% by mass or more.

[0334] (Phosphorus content)

[0335] The lubricating oil composition of this embodiment requires a phosphorus content of more than 0.04% by mass and less than 0.10% by mass based on the total amount of the lubricating oil composition.

[0336] When the phosphorus content of a lubricating oil composition is less than 0.04% by mass, the oxidative stability of the lubricating oil composition is not good. Furthermore, when the phosphorus content of a lubricating oil composition is 0.10% by mass or more, the high-temperature detergency is not good.

[0337] The phosphorus content of the lubricating oil composition can be adjusted by adjusting the content of phosphorus-containing additives such as phosphorus-based wear-resistant agents (preferably zinc dialkyl dithiophosphate (ZnDTP)).

[0338] Here, from the viewpoint of facilitating the volatilization of the effects of the present invention, the phosphorus content in the lubricating oil composition is preferably 0.05% by mass or more, more preferably 0.06% by mass or more. Furthermore, it is preferably 0.09% by mass or less, more preferably 0.08% by mass or less.

[0339] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, it is preferably 0.05% to 0.09% by mass, more preferably 0.06% to 0.08% by mass.

[0340] (Molybdenum content)

[0341] In the lubricating oil composition of this embodiment, from the viewpoint of improving friction reduction, the molybdenum content is preferably 0.05% by mass or more, more preferably 0.06% by mass or more, and even more preferably 0.07% by mass or more, based on the total amount of the lubricating oil composition.

[0342] Furthermore, from the viewpoint of reducing sulfuric acid ash content, the molybdenum atom content is preferably 0.12% by mass or less, more preferably 0.11% by mass or less, and even more preferably 0.10% by mass or less, based on the total amount of the lubricating oil composition.

[0343] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, it is preferably 0.05% to 0.12% by mass, more preferably 0.06% to 0.11% by mass, and even more preferably 0.07% to 0.10% by mass.

[0344] (Calcium content)

[0345] In the lubricating oil composition of this embodiment, the calcium content is preferably 0.10% by mass or more, more preferably 0.11% by mass or more, based on the total amount of the lubricating oil composition, from the viewpoint of making it easier to improve high-temperature detergency.

[0346] Furthermore, from the viewpoint of reducing sulfuric acid ash and preventing LSPI (abnormal combustion), the calcium content, based on the total amount of the lubricating oil composition, is preferably 0.20% by mass or less, more preferably 0.15% by mass or less, and even more preferably 0.13% by mass or less.

[0347] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, it is preferably 0.10% to 0.20% by mass, more preferably 0.10% to 0.15% by mass, and even more preferably 0.11% to 0.13% by mass.

[0348] (Magnesium content)

[0349] In the lubricating oil composition of this embodiment, the magnesium content is preferably 0.03% by mass or more, more preferably 0.04% by mass or more, based on the total amount of the lubricating oil composition, from the viewpoint that it is easier to improve high-temperature detergency.

[0350] Furthermore, from the viewpoint of reducing sulfuric acid ash and preventing LSPI (abnormal combustion), the magnesium content is preferably 0.07% by mass or less, more preferably 0.06% by mass or less, based on the total amount of the lubricating oil composition.

[0351] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, it is preferably 0.03% to 0.07% by mass, more preferably 0.04% to 0.06% by mass.

[0352] (Nitrogen content)

[0353] In the lubricating oil composition of this embodiment, from the viewpoint of making it easier to improve high-temperature detergency and dispersibility, the nitrogen content, based on the total amount of the lubricating oil composition, is preferably 0.03% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.08% by mass or more. Furthermore, it is preferably 0.20% by mass or less, more preferably 0.18% by mass or less, and even more preferably 0.15% by mass or less.

[0354] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, it is preferably 0.03% to 0.20% by mass, more preferably 0.05% to 0.18% by mass, and even more preferably 0.08% to 0.15% by mass.

[0355] (Boron content)

[0356] In the lubricating oil composition of this embodiment, from the viewpoint of making it easier to improve high-temperature detergency and dispersibility, the boron content is preferably 0.0010% to 0.10% by mass, more preferably 0.0030% to 0.080% by mass, and even more preferably 0.0050% to 0.050% by mass, based on the total amount of the lubricating oil composition.

[0357] <Acid value increase rate after ISOT test>

[0358] The acid value increase rate of the lubricating oil composition of this embodiment after performing an ISOT test (165.5°C, 72 hours) using the method described in the examples below is preferably 55% or less, more preferably 40% or less, and even more preferably 30% or less.

[0359] <Increase in base value after ISOT test>

[0360] For the lubricating oil composition of this embodiment, the base number reduction rate after ISOT test (165.5°C, 72 hours) performed using the method described in the examples below is preferably 35% or less, more preferably 30% or less, and even more preferably 25% or less.

[0361] <Copper dissolution after ISOT test>

[0362] For the lubricating oil composition of this embodiment, the amount of copper leaching after an ISOT test (165.5°C, 72 hours) performed using the method described in the examples below is preferably 130 ppm by mass or less, more preferably 100 ppm by mass or less, and even more preferably 80 ppm by mass or less.

[0363] <Scoring in Heat Pipe Testing>

[0364] For the lubricating oil composition of this embodiment, the score in the heat pipe test (280°C) performed using the method described in the examples described later is preferably 6.0 or higher, more preferably 6.5 or higher.

[0365] [Method for manufacturing lubricating oil composition]

[0366] The method for manufacturing the lubricating oil composition in this embodiment is not particularly limited.

[0367] For example, the method for manufacturing the lubricating oil composition of this embodiment includes a step of mixing a base oil (A), a molybdenum-based friction modifier (B), a metal-based detergent (C), and an ashless dispersant (D).

[0368] The aforementioned molybdenum-based friction modifier (B) comprises two or more selected from dinuclear molybdenum dithiocarbamate (B1), trinuclear molybdenum dithiocarbamate (B2), and molybdenum amine complex (B3).

[0369] The aforementioned metal-based detergent (C) contains sulfur atoms.

[0370] The aforementioned ashless dispersant (D) contains nitrogen atoms.

[0371] The acid values ​​of the aforementioned dinuclear molybdenum dithiocarbamate (B1) and trinuclear molybdenum dithiocarbamate (B2) are less than 0.04 mg KOH / g.

[0372] Furthermore, adjustments are made to reduce the sulfur content (C) derived from the aforementioned metal-based detergent (C). S ), and nitrogen components (D) derived from the aforementioned ashless dispersant (D). N The content ratio of ) [(C S ) / (D N The ratio is adjusted to be 0.30 to 0.85 by mass so that the phosphorus content, based on the total amount of the lubricating oil composition, is greater than 0.04% by mass and less than 0.10% by mass.

[0373] The manufacturing method may further include, as needed, a process of compounding one or more of the other ingredients.

[0374] There are no particular limitations on the method of mixing the components. For example, one method can be used to mix the components (components (B), (C), and (D), and further selected from other components) in a base oil (A). Alternatively, the components can be mixed after being prepared into a solution (dispersion) by adding diluent oil or the like. Preferably, after mixing the components, they are stirred using a known method to ensure uniform dispersion.

[0375] [Uses of Lubricating Oil Compositions]

[0376] The lubricating oil composition of this embodiment exhibits excellent friction reduction properties, while also demonstrating excellent high-temperature detergency, oxidation stability, and resistance to copper corrosion.

[0377] Therefore, the lubricating oil composition of this embodiment is preferably used in an internal combustion engine, more preferably in an automotive engine, and even more preferably in a gasoline engine.

[0378] Furthermore, the lubricating oil composition of this embodiment exhibits excellent friction-reducing properties even at temperatures up to 30°C. Therefore, it is also suitable for use in engines of automobiles equipped with hybrid powertrains and engines of automobiles equipped with idle stop mechanisms.

[0379] Therefore, the lubricating oil composition of this embodiment provides the following (1) to (5).

[0380] (1) A method of using the lubricating oil composition of this embodiment in an internal combustion engine.

[0381] (2) A method of using the lubricating oil composition of this embodiment in an automobile engine.

[0382] (3) A method of using the lubricating oil composition of this embodiment in a gasoline engine.

[0383] (4) A method of using the lubricating oil composition of this embodiment in the engine of a car equipped with a hybrid power system.

[0384] (5) A method of using the lubricating oil composition of this embodiment in the engine of a car equipped with an idle stop mechanism.

[0385] [Lubrication methods using lubricating oil compositions]

[0386] As described in the application of the lubricating oil composition, the lubricating oil composition of this embodiment is preferably used in internal combustion engines, more preferably in automobile engines, and even more preferably in gasoline engines. Furthermore, the lubricating oil composition of this embodiment exhibits excellent friction-reducing properties even at temperatures up to 30°C. Therefore, it is also suitable for use in engines of automobiles equipped with hybrid powertrains and engines of automobiles equipped with idle stop mechanisms.

[0387] Therefore, the lubricating oil composition of this embodiment provides the following (6) to (10).

[0388] (6) A lubrication method for an internal combustion engine, which uses the lubricating oil composition of this embodiment.

[0389] (7) A lubrication method for an automobile engine, which uses the lubricating oil composition of this embodiment.

[0390] (8) A lubrication method for a gasoline engine, which uses the lubricating oil composition of this embodiment.

[0391] (9) A lubrication method for the engine of a car equipped with a hybrid power system, which uses the lubricating oil composition of this embodiment.

[0392] (10) A lubrication method for an engine of a car equipped with an idle stop mechanism, wherein the lubricating oil composition of this embodiment is used.

[0393] [Internal combustion engine containing a lubricating oil composition]

[0394] As other embodiments, internal combustion engines comprising the lubricating oil composition of this embodiment can be listed, and internal combustion engines (engines) comprising the lubricating oil composition of this embodiment as engine oil are preferred examples. Examples of such internal combustion engines include, for instance, automobile engines, and preferably, gasoline engines. Furthermore, engines of automobiles equipped with hybrid powertrains and engines of automobiles equipped with idle stop mechanisms are also preferred examples.

[0395] [One aspect of the present invention provided]

[0396] According to one aspect of the present invention, the following [1] to

[15] may be provided.

[0397] [1] A lubricating oil composition comprising a base oil (A), a molybdenum-based friction modifier (B), a metallic detergent (C), and an ashless dispersant (D), wherein,

[0398] The aforementioned molybdenum-based friction modifier (B) comprises two or more selected from dinuclear molybdenum dithiocarbamate (B1), trinuclear molybdenum dithiocarbamate (B2), and molybdenum amine complex (B3).

[0399] The aforementioned metal-based detergent (C) contains sulfur atoms.

[0400] The aforementioned ashless dispersant (D) contains nitrogen atoms.

[0401] The acid values ​​of the aforementioned dinuclear molybdenum dithiocarbamate (B1) and trinuclear molybdenum dithiocarbamate (B2) are less than 0.04 mg KOH / g.

[0402] The sulfur component (C) originating from the aforementioned metal-based detergent (C) S ), and nitrogen components (D) derived from the aforementioned ashless dispersant (D). N The content ratio of ) [(C S ) / (D N The mass ratio is 0.30 to 0.85.

[0403] The phosphorus content, based on the total amount of the aforementioned lubricating oil composition, is greater than 0.04% by mass and less than 0.10% by mass.

[0404] [2] According to the lubricating oil composition described in [1] above, the sulfur content is less than 0.35% by mass based on the total amount of the aforementioned lubricating oil composition.

[0405] [3] According to the lubricating oil composition described in [1] or [2] above, the phosphorus content is 0.06% to 0.08% by mass based on the total amount of the aforementioned lubricating oil composition.

[0406] [4] The lubricating oil composition according to any one of [1] to [3] above, wherein the molybdenum content is 0.05% to 0.12% by mass based on the total amount of the aforementioned lubricating oil composition.

[0407] [5] The lubricating oil composition according to any one of [1] to [4] above, wherein the aforementioned metal detergent (C) comprises one or more selected from calcium detergent (C1) and magnesium detergent (C2).

[0408] [6] According to the lubricating oil composition described in [5] above, wherein the aforementioned metal-based detergent (C) comprises the aforementioned calcium-based detergent (C1),

[0409] The calcium content is 0.10% to 0.20% by mass, based on the total amount of the lubricating oil composition.

[0410] [7] According to the lubricating oil composition described in [5] above, wherein the aforementioned metal-based detergent (C) comprises the aforementioned magnesium-based detergent (C2),

[0411] The magnesium content is 0.03% to 0.07% by mass, based on the total amount of the lubricating oil composition.

[0412] [8] According to the lubricating oil composition described in [5] above, wherein the aforementioned metal-based detergent (C) comprises the aforementioned calcium-based detergent (C1) and the aforementioned magnesium-based detergent (C2),

[0413] The calcium content, based on the total amount of the lubricating oil composition, is 0.10% to 0.20% by mass.

[0414] The magnesium content is 0.03% to 0.07% by mass, based on the total amount of the lubricating oil composition.

[0415] [9] The lubricating oil composition according to any one of [1] to [8] above, wherein the aforementioned dinuclear molybdenum dithiocarbamate (B1) is a compound represented by the following general formula (b1-3),

[0416] [Chemistry 9]

[0417]

[0418] In the aforementioned general formula (b1-3), R 1 R 2 R 3 and R 4 Each of the above-mentioned compounds (B1) independently represents a short-chain substituent group (α) representing an aliphatic hydrocarbon group with 4 to 12 carbon atoms or a long-chain substituent group (β) representing an aliphatic hydrocarbon group with 13 to 22 carbon atoms, wherein the molar ratio of the aforementioned short-chain substituent group (α) to the aforementioned long-chain substituent group (β) in all molecules of the aforementioned compound (B1) is 0.10 to 1.2. Furthermore, in the aforementioned general formula (b1-3), X1, X2, X3, and X4 independently represent an oxygen atom or a sulfur atom.

[0419]

[10] The lubricating oil composition according to any one of [1] to [9] above, wherein it further comprises a metal inert agent (E).

[0420]

[11] The lubricating oil composition according to any one of [1] to

[10] above, wherein the content of the ashless friction modifier is less than 0.1% by mass based on the total amount of the aforementioned lubricating oil composition.

[0421]

[12] The lubricating oil composition according to any one of [1] to

[11] above is used in an internal combustion engine.

[0422]

[13] An internal combustion engine comprising any one of the lubricating oil compositions described in any one of [1] to

[11] above.

[0423]

[14] A lubrication method for an internal combustion engine, wherein the lubricating oil composition described in any one of [1] to

[11] above is used.

[0424]

[15] A method for manufacturing a lubricating oil composition, comprising a step of mixing a base oil (A), a molybdenum-based friction modifier (B), a metal-based detergent (C), and an ashless dispersant (D).

[0425] The aforementioned molybdenum-based friction modifier (B) comprises two or more selected from dinuclear molybdenum dithiocarbamate (B1), trinuclear molybdenum dithiocarbamate (B2), and molybdenum amine complex (B3).

[0426] The aforementioned metal-based detergent (C) contains sulfur atoms.

[0427] The aforementioned ashless dispersant (D) contains nitrogen atoms.

[0428] The acid values ​​of the aforementioned dinuclear molybdenum dithiocarbamate (B1) and trinuclear molybdenum dithiocarbamate (B2) are less than 0.04 mg KOH / g.

[0429] Adjusting the sulfur content (C) derived from the aforementioned metal-based detergent (C) S ), and nitrogen components (D) derived from the aforementioned ashless dispersant (D). N The content ratio of ) [(C S ) / (D N This makes it 0.30 to 0.85 by mass ratio.

[0430] Adjust the phosphorus content to be greater than 0.04% by mass and less than 0.10% by mass based on the total amount of the lubricating oil composition.

[0431] Example

[0432] The present invention will be specifically described through the following embodiments, but the present invention is not limited to the following embodiments.

[0433] [Methods for determining various physical properties]

[0434] The determination of the properties of the raw materials used in each embodiment and each comparative example, as well as the properties of the lubricating oil compositions in each embodiment and each comparative example, was carried out in accordance with the points shown below.

[0435] (1) Kinematic viscosity, viscosity index

[0436] The kinematic viscosity at 40°C, the kinematic viscosity at 100°C, and the viscosity index of the base oil and lubricating oil composition are determined or calculated according to JIS K 2283:2000.

[0437] (2) CCS viscosity at -35℃

[0438] The CCS viscosity of the lubricating oil composition at -35°C was determined according to JIS K2010:1993.

[0439] (3) HTHS viscosity at 150℃

[0440] The HTHS viscosity of the lubricating oil composition at 150°C was determined according to ASTM D4683, using a TBS tapered bearing simulator viscometer, at 150°C, with a viscosity of 10... 6 The shear rate was measured at / s.

[0441] (4) Acid value of the lubricating oil composition

[0442] The acid value of the lubricating oil composition was determined according to JIS K2501:2003 (potential difference titration method).

[0443] (5) Alkali value of the lubricating oil composition

[0444] The base value of the lubricating oil composition was determined according to section 9 of JIS K2501:2003 using potentiometric titration (base value perchloric acid method).

[0445] (6) Molybdenum content, boron content, calcium content, magnesium content, phosphorus content, and sulfur content

[0446] The molybdenum, boron, calcium, magnesium, phosphorus, and sulfur content of the lubricating oil composition were determined according to JIS-5S-38-03.

[0447] (7) Nitrogen content

[0448] The nitrogen content of the lubricating oil composition was determined by chemiluminescence method according to JIS K2609:1998.

[0449] (8) Alkali value of metal-based detergents

[0450] The alkalinity of metal-based detergents is determined according to section 9 of JIS K2501:2003 using potentiometric titration (alkalinity-perchloric acid method).

[0451] (9) Acid values ​​derived from dinuclear molybdenum dithiocarbamate (B1) and trinuclear molybdenum dithiocarbamate (B2).

[0452] The acid values ​​of molybdenum dithiocarbamate (B1) and molybdenum dithiocarbamate (B2) derived from the dinuclear group were determined according to JIS K2501:2003 (potential difference titration).

[0453] In detail, the acid values ​​of molybdenum dithiocarbamate (B1) derived from the dinuclear group and molybdenum dithiocarbamate (B2) derived from the trinuclear group were determined according to JIS K2501:2003 (potential difference titration method), and the acid values ​​were calculated taking into account their respective contents.

[0454] (10) Mass-average molecular weight (Mw), molecular weight distribution (Mw / Mn)

[0455] One TSK Guardcolumn SuperHZ-L column and two TSK SuperMultipore HZ-M columns were installed sequentially from the upstream side on a Waters 1515 Isocratic HPLC pump and a 2414 differential refractive index (RI) detector. The results were obtained under the following conditions: measurement temperature: 40℃, mobile phase: tetrahydrofuran, flow rate: 0.35 mL / min, and sample concentration: 1.0 mg / mL. The results were obtained by conversion to standard polystyrene.

[0456] [Examples 1-6, Comparative Examples 1-7]

[0457] The following components are added in the amounts shown in Table 1 and mixed thoroughly to obtain a lubricating oil composition.

[0458] The details of each component used in Examples 1-6 and Comparative Examples 1-7 are shown below.

[0459] <Base Oil (A)>

[0460] Mineral oil

[0461] API classification: Group III, kinematic viscosity at 100°C: 4.3 mm 2 Viscosity index: 123 / s

[0462] <Molybdenum-based friction modifier (B)>

[0463] • "Dinuclear molybdenum dithiocarbamate (B1)-1"

[0464] Dinuclear molybdenum dithiocarbamate (B1)-1 (hereinafter also referred to as "dinuclear MoDTC(B1)-1") is a compound of general formula (b1-3) that substantially lacks a short-chain substituent group (α), is substantially formed by a long-chain substituent group (β), and the aliphatic hydrocarbon group of the long-chain substituent group (β) has 13 carbon atoms. In general formula (b1-3), X1 X 2 X 3 and X 4 It is a sulfur atom.

[0465] • "Dinuclear molybdenum dithiocarbamate (B1)-2"

[0466] Dinuclear molybdenum dithiocarbamate (B1)-2 (hereinafter also referred to as "dinonuclear MoDTC(B1)-2") is a compound in general formula (b1-3) in which the aliphatic hydrocarbon group of the short-chain substituent group (α) has 8 carbon atoms and the aliphatic hydrocarbon group of the long-chain substituent group (β) has 13 carbon atoms. In general formula (b1-3), X 1 X 2 X 3 and X 4 The molar ratio of short-chain substituents (α) to long-chain substituents (β) in all MoDTC-1 molecules is 1.0 [(α) / (β)].

[0467] • "Trinuclear molybdenum dithiocarbamate (B2)"

[0468] As a trinuclear molybdenum dithiocarbamate (B2) (hereinafter also referred to as "trinuclear MoDTC(B2)"), trinuclear molybdenum dithiocarbamate with a molybdenum atom content of 5.3% by mass was used.

[0469] • "Molybdenum amine complex (B3)"

[0470] Dialkylamine molybdate (molybdenum content: 7.9% by mass) was used as the molybdenum-amine complex (B3).

[0471] It should be noted that in Examples 3-5 and Comparative Examples 4-7, the molar ratio of short-chain substituents (α) to long-chain substituents (β) in all molecules of the dinuclear MoDTC(B1)-1 and dinuclear MoDTC(B1)-2 [(α) / (β)] is 0.48.

[0472] In addition, in Comparative Example 3, the molar ratio of short-chain substituents (α) to long-chain substituents (β) in all molecules of dinuclear MoDTC(B1)-1 and dinuclear MoDTC(B1)-2 [(α) / (β)] was 0.31.

[0473] <Metallic Detergent (C)>

[0474] Calcium sulfonate

[0475] Alkalinity: 300 mg KOH / g, Calcium content: 11.7% by mass

[0476] Magnesium Sulfonate 1

[0477] Alkali value: 400 mg KOH / g, Magnesium content: 9.5% by mass

[0478] Magnesium Sulfonate 2

[0479] Alkali value: 400 mg KOH / g, Magnesium content: 9.7% by mass

[0480] <Metallic Detergent (C')>

[0481] Calcium salicylate

[0482] Alkali value: 230 mg KOH / g, Calcium content: 8.0% by mass

[0483] <Ashless Dispersant (D)>

[0484] "Non-boron modified polybutene succinic monoimide 1"

[0485] Nitrogen content: 1.4% by mass

[0486] "Non-boron modified polybutene succinic monoimide 2"

[0487] Nitrogen content: 1.0% by mass

[0488] "Boron-modified polybutene-succinic acid diimide 1"

[0489] Boron content: 2.2% by mass, Nitrogen content: 1.2% by mass

[0490] "Boron-modified polybutene-succinic acid diimide 2"

[0491] Boron content: 1.4% by mass, Nitrogen content: 1.3% by mass

[0492] <Metal Inertizer (E)>

[0493] As a metal inert agent, a benzotriazole compound, namely 1-[N,N-bis(2-ethylhexyl)aminomethyl]-4-methyl-1H-benzotriazole, was used.

[0494] [Chemistry 10]

[0495]

[0496] 1-[N,N-bis(2-ethylhexyl)aminomethyl]-4-methyl-1H-benzotriazole is in general formula (e1), R e1 Methyl, p=1, R e2 Methylene, R e3 and R e4 It is a compound of 2-ethylhexyl.

[0497] <Other Additives>

[0498] (Viscosity index improver)

[0499] Non-dispersed polymethyl methacrylate

[0500] Mass-average molecular weight (Mw): 400,000; Molecular weight distribution (Mw / Mn): 1.7

[0501] "Styrene-isoprene copolymer"

[0502] Mass-average molecular weight (Mw): 600,000; Molecular weight distribution (Mw / Mn): 1.1

[0503] (Zinc dialkyl thiophosphate (ZnDTP))

[0504] Phosphorus content: 6.7% by mass, Zinc content: 7.4% by mass

[0505] (other)

[0506] • Amine-based antioxidants (diphenylamine)

[0507] ·Phenolic antioxidants

[0508] Pour point depressant

[0509] • Ash-free friction modifier (glyceryl monooleate)

[0510] [Evaluation Method]

[0511] The following tests were performed to evaluate oxidation stability, high-temperature detergency, copper corrosion resistance, and reduction in the coefficient of friction.

[0512] <ISOT Test>

[0513] Copper and iron sheets were added as catalysts to the test oil (the prepared lubricating oil composition), and the ISOT test according to JISK 2514-1:2013 was performed to force the test oil to deteriorate. The test temperature was set at 165.5°C. For the test oil 72 hours after the start of the ISOT test, the acid value and base value were measured.

[0514] Furthermore, the increase rate (AN) of the acid value of the lubricating oil composition after the ISOT test relative to the acid value of the lubricating oil composition before the ISOT test is calculated using the following formula (I). i (Hereinafter referred to as "acid value increase rate (AN)") i )”).

[0515] (AN i )=[(AN n )-(AN0)] / (AN0)×100…(I)

[0516] In equation (I) above, AN nAN0 represents the acid value of the lubricating oil composition after ISOT testing, while AN0 represents the acid value of the lubricating oil composition before ISOT testing.

[0517] The higher the rate of increase in acid value (AN) i The smaller the lubricating oil composition, the better it can be said to be a lubricating oil composition with excellent oxidation stability.

[0518] In this embodiment, the rate of increase in acid value (AN) is used. i A lubricating oil composition containing less than 55% is considered qualified.

[0519] In addition, the reduction rate (TBN) of the base number of the lubricating oil composition after the ISOT test relative to the base number of the lubricating oil composition before the ISOT test is calculated according to the following formula (II). d (Hereinafter referred to simply as "basic number reduction rate (TBN)") d )”).

[0520] (TBN d )=[(TBN0)-(TBN n )] / (TBN0)X100…(II)

[0521] In equation (II) above, TBN n TBN0 represents the base number of the lubricating oil composition after ISOT testing, while TBN0 represents the base number of the lubricating oil composition before ISOT testing.

[0522] The higher the rate of reduction in basalt number (TBN) d The smaller the lubricating oil composition, the better it can be said to be a lubricating oil composition with excellent high-temperature detergency.

[0523] In this embodiment, the reduction rate of basalt number (TBN) is used. d A lubricating oil composition containing less than 35% is considered qualified.

[0524] <Evaluation of Copper Dissolution after ISOT Test>

[0525] The copper concentration of the test oil subjected to the forced deterioration of the above ISOT test was determined according to JPI-5S-44-11, and this concentration was set as the amount of copper leaching after the ISOT test.

[0526] The less copper leaching occurs after the ISOT test, the better the lubricating oil composition can be considered to have excellent resistance to copper corrosion.

[0527] In this embodiment, a lubricating oil composition with a copper leaching amount of less than 130 ppm by mass after ISOT testing is considered qualified.

[0528] <Heat Pipe Experiment>

[0529] For the test oil (the prepared lubricating oil composition), the heat pipe test was carried out at a test temperature of 280°C according to JPI-5S-55-99.

[0530] The post-test scoring was based on JPI-5S-55-99, evaluating the paint adhering to the test tube in 11 stages from 0 points (black) to 10 points (colorless).

[0531] The higher the score, the less debris there is and the better the cleanliness.

[0532] In this embodiment, lubricating oil compositions with a score of 5.5 or higher are considered qualified.

[0533] <SRV Trial>

[0534] The coefficient of friction was determined using an SRV testing machine (Optimol) under the following conditions when the prepared lubricating oil composition was used.

[0535] • Cylinder: AISI52100

[0536] • Plate: AISI52100

[0537] • Frequency: 50Hz

[0538] • Amplitude: 1.5mm

[0539] • Load: 400N

[0540] Temperature: 30℃

[0541] • Test duration: 20 minutes (friction coefficient is the average of the last minute)

[0542] Furthermore, by dividing the difference between the friction coefficient of each lubricating oil composition and the friction coefficient of the lubricating oil composition of Comparative Example 1 by the friction coefficient of the lubricating oil composition of Comparative Example 1, the reduction rate (%) of the friction coefficient based on the friction coefficient of Comparative Example 1 is calculated for the friction coefficient of each lubricating oil composition.

[0543] The greater the rate of reduction in the coefficient of friction in Comparative Example 1, the better the effect of reducing the coefficient of friction.

[0544] In this embodiment, a lubricating oil composition with a friction coefficient reduction rate of 10% or more based on Comparative Example 1 is considered qualified.

[0545] The results are shown in Table 1.

[0546] [Table 1]

[0547]

[0548] First, in the results shown in Table 1, if Comparative Example 1, which contains only one molybdenum-based friction modifier (B), is compared with Comparative Examples 2 to 7, which contain multiple molybdenum-based friction modifiers (B), the coefficient of friction is reduced in Comparative Examples 2 to 7, which contain multiple molybdenum-based friction modifiers (B). On the other hand, it can be seen that at least one of the following is worse: oxidation stability, high-temperature cleaning properties, and copper corrosion resistance.

[0549] Furthermore, the results shown in Table 1 reveal the following information.

[0550] It can be seen that the lubricating oil compositions of Examples 1 to 6 containing multiple molybdenum-based friction modifiers (B) have a lower coefficient of friction than Comparative Example 1 which contains only one molybdenum-based friction modifier (B). Furthermore, they also exhibit superior oxidation stability, high-temperature detergency, and copper corrosion resistance.

[0551] In contrast, it can be seen that if the lubricating oil compositions of Comparative Examples 2 and 3 have an acid value of 0.04 mg KOH / g or higher derived from dinuclear molybdenum dithiocarbamate and trinuclear molybdenum dithiocarbamate, then at least one of the following effects—reducing the coefficient of friction, improving oxidation stability, improving high-temperature detergency, and improving copper corrosion resistance—cannot be achieved.

[0552] It can be seen that, as in the lubricating oil composition of Comparative Example 4, the sulfur component (C) originating from the metal-based detergent (C) S ), and nitrogen components (D) derived from ashless dispersant (D) N The content ratio of ) [(C S ) / (D N If the value is less than 0.30, the oxidation stability and high-temperature detergency are poor.

[0553] It can be seen that, as in the lubricating oil composition of Comparative Example 5, the sulfur component (C) originating from the metal-based detergent (C) S ), and nitrogen components (D) derived from ashless dispersant (D) N The content ratio of ) [(C S ) / (D N If the value exceeds 0.85, the high-temperature cleaning ability and resistance to copper corrosion will be poor.

[0554] It can be seen that if the phosphorus content is less than 0.04% by mass based on the total amount of the lubricating oil composition, as in Comparative Example 6, the oxidation stability is poor.

[0555] It can be seen that if the phosphorus content is 0.10% by mass or more based on the total amount of the lubricating oil composition, as in Comparative Example 7, the high-temperature detergency is poor.

Claims

1. A lubricating oil composition comprising a base oil (A), a molybdenum-based friction modifier (B), a metallic detergent (C), and an ashless dispersant (D), wherein, The aforementioned molybdenum-based friction modifier (B) contains two or more selected from dinuclear molybdenum dithiocarbamate (B1), trinuclear molybdenum dithiocarbamate (B2), and molybdenum amine complex (B3). The aforementioned metal-based detergent (C) contains sulfur atoms. The aforementioned ashless dispersant (D) contains nitrogen atoms. The acid values ​​of the aforementioned dinuclear molybdenum dithiocarbamate (B1) and trinuclear molybdenum dithiocarbamate (B2) are less than 0.04 mg KOH / g. The sulfur component (C) originating from the aforementioned metal-based detergent (C) S ), and the nitrogen component (D) derived from the aforementioned ashless dispersant (D). N The content ratio of ) (C) S ) / (D N (by mass ratio) 0.30–0.85 The phosphorus content, based on the total amount of the aforementioned lubricating oil composition, is greater than 0.04% by mass and less than 0.10% by mass.

2. The lubricating oil composition according to claim 1, wherein, The sulfur content is less than 0.35% by mass, based on the total amount of the aforementioned lubricating oil composition.

3. The lubricating oil composition according to claim 1 or 2, wherein, The phosphorus content is 0.06% to 0.08% by mass based on the total amount of the aforementioned lubricating oil composition.

4. The lubricating oil composition according to claim 1 or 2, wherein, The molybdenum content is 0.05% to 0.12% by mass, based on the total amount of the aforementioned lubricating oil composition.

5. The lubricating oil composition according to claim 1 or 2, wherein, The aforementioned metal-based detergent (C) includes one or more selected from calcium-based detergent (C1) and magnesium-based detergent (C2).

6. The lubricating oil composition according to claim 5, wherein, The aforementioned metal-based detergent (C) includes the aforementioned calcium-based detergent (C1). The calcium content is 0.10% to 0.20% by mass based on the total amount of the aforementioned lubricating oil composition.

7. The lubricating oil composition according to claim 5, wherein, The aforementioned metal-based detergent (C) includes the aforementioned magnesium-based detergent (C2). The magnesium content is 0.03% to 0.07% by mass based on the total amount of the aforementioned lubricating oil composition.

8. The lubricating oil composition according to claim 5, wherein, The aforementioned metal-based detergent (C) includes the aforementioned calcium-based detergent (C1) and the aforementioned magnesium-based detergent (C2). The calcium content, based on the total amount of the aforementioned lubricating oil composition, is 0.10% to 0.20% by mass. The magnesium content is 0.03% to 0.07% by mass based on the total amount of the aforementioned lubricating oil composition.

9. The lubricating oil composition according to claim 1 or 2, wherein, The aforementioned dinuclear molybdenum dithiocarbamate (B1) is a compound (B1a) represented by the following general formula (b1-3). In the aforementioned general formula (b1-3), R 1 R 2 R 3 and R 4 Each of the above-mentioned compounds (B1a) independently represents either a short-chain substituent group (α) representing an aliphatic hydrocarbon group with 4 to 12 carbon atoms or a long-chain substituent group (β) representing an aliphatic hydrocarbon group with 13 to 22 carbon atoms. The molar ratio (α) / (β) of the aforementioned short-chain substituent group (α) to the aforementioned long-chain substituent group (β) in all molecules of the aforementioned compound (B1a) is 0.10 to 2.

0. Furthermore, in the aforementioned general formula (b1-3), X... 1 X 2 X 3 and X 4 Each can be used independently to represent an oxygen atom or a sulfur atom.

10. The lubricating oil composition according to claim 1 or 2, wherein, It also contains a metal inert agent (E).

11. The lubricating oil composition according to claim 1 or 2, wherein, The content of the ashless friction modifier is less than 0.1% by mass based on the total amount of the aforementioned lubricating oil composition.

12. The lubricating oil composition according to claim 1, wherein, The total content of the aforementioned base oil (A), molybdenum-based friction modifier (B), metal-based detergent (C) and ashless dispersant (D) is 80% to 98% by mass, based on the total amount of the aforementioned lubricating oil composition.

13. The lubricating oil composition according to claim 1, wherein, The aforementioned base oil (A) has a kinematic viscosity of 2.0 mm at 100°C. 2 / s~6.0mm 2 / s.

14. The lubricating oil composition according to claim 1, wherein, The viscosity index of the aforementioned base oil (A) is above 100.

15. The lubricating oil composition according to claim 1, wherein, The content of the aforementioned base oil (A) is 80-95% by mass, based on the total amount of the aforementioned lubricating oil composition.

16. The lubricating oil composition according to claim 1, wherein, The total content of two or more of the molybdenum-based friction modifiers (B) selected from dinuclear molybdenum dithiocarbamate (B1), trinuclear molybdenum dithiocarbamate (B2) and molybdenum amine complex (B3) is 70% to 100% by mass, based on the total amount of the molybdenum-based friction modifiers (B).

17. The lubricating oil composition according to claim 1, wherein, The total content of two or more of the molybdenum-based friction modifiers (B) selected from dinuclear molybdenum dithiocarbamate (B1), trinuclear molybdenum dithiocarbamate (B2) and molybdenum amine complex (B3) is 90% to 100% by mass, based on the total amount of the molybdenum-based friction modifiers (B).

18. The lubricating oil composition according to claim 1, wherein, The aforementioned dinuclear molybdenum dithiocarbamate (B1) is a compound represented by the following general formula (b1-1) or a compound represented by the following general formula (b1-2). In the above general formulas (b1-1) and (b1-2), R 11 ~R 14 Each group represents a hydrocarbon group independently; they may be the same as or different from each other. X 11 ~X 18 Let X represent oxygen or sulfur atoms independently, and they may be the same or different from each other. In the above general formula (b1-1), X... 11 ~X 18 At least two of them are sulfur atoms.

19. The lubricating oil composition according to claim 9, wherein, In the aforementioned general formula (b1-3), the aliphatic hydrocarbon group selected as the short-chain substituent group (α) has 7 to 9 carbon atoms, and the aliphatic hydrocarbon group selected as the long-chain substituent group (β) has 13 to 14 carbon atoms.

20. The lubricating oil composition according to claim 9, wherein, The molar ratio (α) / (β) of the short-chain substituent group (α) to the long-chain substituent group (β) in the aforementioned general formula (b1-3) is 0.15 to 1.

2.

21. The lubricating oil composition according to claim 1, wherein, The aforementioned trinuclear molybdenum dithiocarbamate (B2) is a compound represented by the following general formula (b2). In the aforementioned general formula (b2), k is an integer greater than or equal to 1, m is an integer greater than or equal to 0, k+m is an integer from 4 to 10, n is an integer from 1 to 4, p is an integer greater than or equal to 0, and z is an integer from 0 to 5. Each E is an oxygen atom or a selenium atom. Each ligand (L) is an anionic ligand with an organic group containing carbon atoms. The total number of carbon atoms in the organic group of each ligand is 14 or more. The ligands may be the same or different. A is an anion other than L, each of which is independent. Q is an independent neutral compound that donates electrons.

22. The lubricating oil composition according to claim 1, wherein, The molybdenum content in the aforementioned molybdenum amine complex (B3), based on the total amount of the aforementioned molybdenum amine complex (B3), is 4.0% to 12.0% by mass.

23. The lubricating oil composition according to claim 1, wherein, The content of molybdenum atoms derived from the aforementioned molybdenum-based friction modifier (B) is 0.05% to 0.12% by mass, based on the total amount of the aforementioned lubricating oil composition.

24. The lubricating oil composition according to claim 1, wherein, The mass ratio of the aforementioned dinuclear molybdenum dithiocarbamate (B1) to trinuclear molybdenum dithiocarbamate (B2) (B1) / (B2) is 0.5 to 7.

0.

25. The lubricating oil composition according to claim 1, wherein, The mass ratio of the aforementioned dinuclear molybdenum dithiocarbamate (B1) to molybdenum amine complex (B3) (B1) / (B3) is 1.0 to 8.

0.

26. The lubricating oil composition according to claim 1, wherein, The acid values ​​of the aforementioned dinuclear molybdenum dithiocarbamate (B1) and trinuclear molybdenum dithiocarbamate (B2) are below 0.03 mg KOH / g.

27. The lubricating oil composition according to claim 1, wherein, The aforementioned combination of molybdenum-based friction modifier (B) is any of the following (1) to (4) combinations. (1) A combination of dinuclear molybdenum dithiocarbamate (B1) and trinuclear molybdenum dithiocarbamate (B2); (2) A combination of a dinuclear molybdenum dithiocarbamate (B1) and a molybdenum amine complex (B3); (3) A combination of trinuclear molybdenum dithiocarbamate (B2) and molybdenum amine complex (B3); (4) A combination of dinuclear molybdenum dithiocarbamate (B1), trinuclear molybdenum dithiocarbamate (B2), and molybdenum amine complex (B3).

28. The lubricating oil composition according to claim 5, wherein, The aforementioned calcium-based detergent (C1) has an alkalinity of 250 mg KOH / g or higher and 450 mg KOH / g or lower.

29. The lubricating oil composition according to claim 5, wherein, The aforementioned calcium-based detergent (C1) is selected from one or more of calcium sulfonate and calcium phenolate. The calcium phenolate is a compound represented by the following general formula (c-2). In the above general formula (c-2), M E For calcium, R c1 and R c2 Each is independently a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms. S represents a sulfur atom. r is an integer greater than or equal to 1.

30. The lubricating oil composition according to claim 5, wherein, The aforementioned magnesium-based detergent (C2) has an alkalinity of 250 mg KOH / g or higher and 500 mg KOH / g or lower.

31. The lubricating oil composition according to claim 5, wherein, The aforementioned magnesium-based detergent (C2) is selected from one or more of magnesium sulfonate and magnesium phenolate. The magnesium phenolate is a compound represented by the following general formula (c-2). In the above general formula (c-2), M E It is magnesium. R c1 and R c2 Each is independently a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms. S represents a sulfur atom. r is an integer greater than or equal to 1.

32. The lubricating oil composition according to claim 1, wherein, The aforementioned ashless dispersant (D) is selected from one or more compounds selected from monoimide succinate, boron-modified monoimide succinate, diimide succinate, and boron-modified diimide succinate.

33. The lubricating oil composition according to claim 1, wherein, The nitrogen content derived from the aforementioned ashless dispersant (D) is 0.01% to 0.10% by mass, based on the total amount of the aforementioned lubricating oil composition.

34. The lubricating oil composition according to claim 1, wherein, The sulfur component (C) originating from the aforementioned metal-based detergent (C) S ), and the nitrogen component (D) derived from the aforementioned ashless dispersant (D). N The content ratio of ) (C) S ) / (D N The values ​​range from 0.34 to 0.

81.

35. The lubricating oil composition according to claim 10, wherein, The aforementioned metal inert agent (E) is selected from benzotriazole compounds, methylbenzotriazole compounds, thiadiazole compounds, imidazole compounds, and pyrimidine compounds.

36. The lubricating oil composition according to claim 10, wherein, The content of the aforementioned metal inert agent (E) is 0.005% to 0.02% by mass, based on the total amount of the aforementioned lubricating oil composition.

37. The lubricating oil composition according to claim 1 or 2, used in an internal combustion engine.

38. An internal combustion engine comprising the lubricating oil composition according to any one of claims 1 to 11.

39. Lubrication methods for internal combustion engines, among which, Use the lubricating oil composition according to any one of claims 1 to 11.

40. A method for manufacturing a lubricating oil composition, wherein, This includes the process of mixing base oil (A), molybdenum-based friction modifier (B), metallic detergent (C), and ashless dispersant (D). The aforementioned molybdenum-based friction modifier (B) contains two or more selected from dinuclear molybdenum dithiocarbamate (B1), trinuclear molybdenum dithiocarbamate (B2), and molybdenum amine complex (B3). The aforementioned metal-based detergent (C) contains sulfur atoms. The aforementioned ashless dispersant (D) contains nitrogen atoms. The acid values ​​of the aforementioned dinuclear molybdenum dithiocarbamate (B1) and trinuclear molybdenum dithiocarbamate (B2) are less than 0.04 mg KOH / g. Adjusting the sulfur content (C) derived from the aforementioned metal-based detergent (C) S ), and the nitrogen component (D) derived from the aforementioned ashless dispersant (D). N The content ratio of ) (C) S ) / (D N This makes its mass ratio between 0.30 and 0.

85. Adjust the phosphorus content to be greater than 0.04% by mass and less than 0.10% by mass based on the total amount of the lubricating oil composition.

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