JPH09194869A - Lubricating oil composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a highly antioxidant lubricating oil composition by mixing a base oil with a combination comprising a specified nitrogenous compound and specified sulfur and phosphorus compounds. SOLUTION: This composition comprises a lubricating base oil, 0.1-5 mass %, based on the total weight of the composition (the same shall apply hereinbelow), 3-methyl-5-tert-butyl-4-hydroxyphenyl-substituted fatty acid ester represented by the formula (wherein R<1> is a 1-6C alkylene; and R<2> is a 1-24C alkyl or alkenyl), 0.001-1 mass wt.% nitrogenous compound selected from among thiadiazole, benzotriazole and/or derivatives thereof and 0.1-5 mass % compound selected from among sulfides, phosphites, dithiophosphates and dithiocarbamates.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a lubricating oil composition, and more particularly to a lubricating oil composition having excellent oxidative stability.

[0002]

2. Description of the Related Art Conventionally, as antioxidants for lubricating oil,
2,6-di-tert-butyl-p-cresol (DB
PC) is known to have excellent performance and is frequently used in lubricating oils, especially turbine oils. However, since this 2,6-di-tert-butyl-p-cresol has a relatively low molecular weight as an antioxidant, when it is used for a long time under high temperature conditions such as turbine oil, it scatters due to heat. There is a problem that the content concentration is reduced by evaporation and the antioxidant property is not sustained. Further, JP-A-60-156644 describes that a sterically hindered hydroxyphenylcarboxylic acid ester is useful as a stabilizer for synthetic organic polymers, animal and vegetable oils, hydrocarbons, lubricating oils, etc. In the examples, (3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid ester is disclosed. However, this (3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid ester is 2,6-di-
Compared with tert-butyl-p-cresol, scattering
Although it was excellent in the evaporation prevention property, it was inferior in the antioxidant property and was insufficient in performance as a substitute for 2,6-di-tert-butyl-p-cresol. The present inventors have conducted research to develop an antioxidant for lubricating oil having equivalent or higher performance as an alternative to 2,6-di-tert-butyl-p-cresol, and as a result, hydrogenation A highly refined base oil such as cracked oil or certain specific synthetic oil containing a specific amount of 3-methyl-5-tert-butyl-4-hydroxyphenyl-substituted fatty acid ester, which is very excellent in oxidation. It was found that a lubricating oil composition having preventive properties can be obtained, and a patent application was previously filed (Japanese Patent Application No. 6-
330305).

[0003]

However, in recent years, with the increase in output, downsizing and longer life of equipment, gas turbine oil,
In lubricating oils such as compressor oils and hydraulic oils, where oxidation stability is particularly important at high temperatures, there is a marked tendency to require higher oxidation stability. By the way, the above 3
-Methyl-5-tert-butyl-4-hydroxyphenyl group-substituted fatty acid ester is used as a lubricating oil, a low-refined oil is used as the base oil, or a highly refined oil is used as the base oil. However, when the lubricating oil is used for a long time under relatively mild oxidizing conditions such as low temperature and low oxygen pressure, the existing 2,6-di-tert-butyl-p
It was found that 3-methyl-5-tert-butyl-4-hydroxyphenyl group-substituted fatty acid ester does not necessarily exhibit remarkably excellent performance as compared with phenolic antioxidants such as -cresol. . Then, as a result of further research by the present inventors, 3-methyl-5-tert-butyl-4-hydroxyphenyl group-substituted fatty acid ester, a specific nitrogen-containing compound, a specific sulfur- and / or phosphorus-containing compound It was found that a lubricating oil composition having remarkably excellent antioxidative properties can be obtained by using these three types in combination, and has completed the present invention. And also, when the present inventors have used a specific base oil as the base oil of the lubricating oil composition, it has excellent antioxidant properties even under high temperature, and it can be used for a long time under high temperature conditions. It has also been found that a lubricating oil composition can be obtained in which the antioxidant property does not decrease.

[0004]

A lubricating oil composition according to the present invention comprises: [I] a lubricating base oil, based on the total amount of the composition,
[II] 3-methyl-5- represented by the following general formula (1)
0.1 to 5 mass% of tert-butyl-4-hydroxyphenyl group-substituted fatty acid ester,

Embedded image [In the formula (1), R ¹ represents an alkylene group having 1 to 6 carbon atoms, and R ² represents an alkyl group or alkenyl group having 1 to 24 carbon atoms. [III] 0.001-1 mass% of one or more nitrogen-containing compounds selected from the following (III-1) to (III-3), (III-1) thiadiazole, (III -2) Benzotriazole and / or its derivative (III-3) Benzothiazole and [IV] One or two or more compounds selected from the following (IV-1) to (IV-4) are used. 1 to 5 mass% (IV-1) sulfides, (IV-2) phosphites, (I
V-3) dithiophosphates and (IV-4) dithiocarbamates are blended respectively.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the contents of the present invention will be described in more detail. The lubricating base oil that is the component [I] of the present invention is not particularly limited, and any mineral oil or synthetic oil can be used as long as it is usually used as a lubricating base oil. As the mineral oil-based lubricating base oil, for example, a lubricating oil fraction obtained by distilling crude oil under atmospheric pressure and vacuum distillation, solvent degassing, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrogen Oils such as paraffin-based and naphthene-based oils obtained by appropriately combining chemical purification, purification with sulfuric acid, purification treatment such as clay treatment, and the like can be used. Examples of synthetic lubricating base oils include poly α-olefins (polybutene, 1-octene oligomers, 1-decene oligomers, etc.), alkylbenzenes, alkylnaphthalenes, diesters (ditridecyl glutarate, di-2-ethylhexyl adipate,
Diisodecyl adipate, ditridecyl adipate, di-2-ethylhexyl sebacate, etc., polyester (trimellitic acid ester, etc.), polyol ester (trimethylolpropane caprylate, trimethylolpropane pelargonate, pentaerythritol-2)
-Ethyl hexanoate, pentaerythritol pelargonate, etc.), polyoxyalkylene glycol, dialkyl diphenyl ether, polyphenyl ether and the like can be used. These base oils may be used alone or in combination of two or more kinds at an arbitrary ratio. The lubricating base oil used in the present invention is not particularly limited in its viscosity, but generally has a viscosity of 1 to 100 at 40 ° C.
Those are preferably used for 0 mm ² / s, that of 5~800mm ² / s are more preferably used.

However, when combined with the 3-methyl-5-tert-butyl-4-hydroxyphenyl group-substituted fatty acid ester, which is the component [II] of the present invention, it exhibits excellent antioxidant properties and sludge formation preventive properties. In terms of [I]
Lubricating base oils used as components are the following (I-1) to (I-3)
It is preferable to use one or more base oils selected from the components. (I-1) The kinematic viscosity at 40 ° C. is 5 to 200 mm ² / s,
And a mineral oil having a total aromatic content of 15% by mass or less (I-2) a polymer of an olefin having 2 to 16 carbon atoms or a hydride thereof and having a number average molecular weight of 250 to 4000 (I-3) 1 to 4 alkyl groups having 1 to 40 carbon atoms,
And an alkylbenzene whose alkyl group has a total carbon number of 6 to 40

The component (I-1) has a kinematic viscosity of 5 at 40 ° C.
~200mm a ² / s, and total aromatic content of 15 mass% of mineral oil. The lower limit of kinematic viscosity of component (I-1) at 40 ° C. is 5 mm ² / s, preferably 10 mm ² / s, while the upper limit of kinematic viscosity at 40 ° C. is 200 mm ² / s, It is preferably 100 mm ² / s. If the kinematic viscosity of the component (I-1) at 40 ° C is less than 5 mm ² / s, the oil film may not be formed sufficiently, resulting in poor lubricity. Also, the evaporation loss of the base oil under high temperature conditions is large. Could be. On the other hand, when the kinematic viscosity of the component (I-1) at 40 ° C. exceeds 200 mm ² / s, the fluid resistance increases, and the frictional resistance at the lubricated portion may increase. The upper limit of the total aromatic content of the component (I-1) is 15% by mass, preferably 10% by mass,
It is important that it is more preferably 7% by mass. When the total aromatic content exceeds 15% by mass, the synergistic effect of the (I-1) component and the [II] component may not be obtained so much, and the excellent antioxidant property and sludge generation preventive property may not be exhibited. There is. The lower limit of the total aromatic content of the component (I-1) is not particularly limited, but when the total aromatic content is 0% by mass or more and less than 2% by mass, the lubricating oil composition is in use. The total aromatic content is preferably 2% by mass or more because the solubility of sludge generated in 1 tends to be poor. The total aromatic content referred to in the present invention means ASTM D 254.
9 "Standard Test Method for Separatio"
n of Representative Aromatics and Nonarimatics Frac
tions of High-Boiling Oils by Elution Chromatograp
aromatics (aromatics fracti
on) content, and usually, in this aromatic fraction, alkylbenzene, alkylnaphthalene, anthracene, phenanthrene, and their alkylated products,
Examples include compounds in which four or more benzene rings are fused, or compounds having a heteroaromatic such as pyridines, quinolines, phenols, and naphthols. The method for producing the component (I-1) having the above properties is arbitrary and can be produced by a known method. For example, distillate oil of paraffin-based crude oil and / or mixed base crude oil by atmospheric distillation; vacuum distillation distillate (WVGO) of paraffin-based crude oil and / or mixed base crude oil under atmospheric distillation residue oil;
And / or mild hydrocracking (M
HC) treated oil (HIX); selected from 2
Mixed oil of at least one kind of oil ;, or Deasphalted oil (DAO); Mild hydrocracking (M
HC) treated oil; a mixed oil of two or more kinds of oils selected from among, is used as a raw material oil, and this raw material oil is used as it is, or a lubricating oil fraction recovered from this raw material oil is processed by a conventional refining method. It can be obtained by refining and collecting a lubricating oil fraction. The refining method here is not particularly limited, and any refining method used in the production of the lubricating base oil can be adopted. Usual purification methods include, for example, (1) hydrocracking, hydrofinishing such as hydrofinishing, (2) solvent purification such as furfural solvent extraction, and (3) dewaxing such as solvent dewaxing or catalytic dewaxing. , (4) white clay purification with acid clay or activated clay, (5) chemical (acid / alkali) purification such as sulfuric acid cleaning, caustic soda cleaning, etc. One or more of these may be employed in the present invention in any combination and in any order. In addition, as a reminder, not only the mineral oil obtained by the above-mentioned method but also the mineral oil obtained by other methods has a kinematic viscosity of 5 to 200 mm ^{2 at} 40 ° C. of itself or an arbitrary mixture thereof. Any mineral oil or any mixture thereof can be used as the component (I-1) of the present invention as long as it is / s and the total aromatic content is 15% by mass or less. When the base oil in the lubricating oil composition of the present invention is composed only of mineral oil, the raw material oil selected from the above is recovered as it is or from this raw material oil because of its excellent synergistic effect with the component [II]. The formed lubricating oil fraction is hydrocracked to recover the product as it is, or the lubricating oil fraction is recovered, and then subjected to dewaxing treatment such as solvent dewaxing or contact dewaxing, and then solvent refining. Processing or
After the solvent refining treatment, the component (I-1) produced by performing dewaxing treatment such as solvent dewaxing or catalytic dewaxing is preferably 50 mass% or more, more preferably 70 mass% or more based on the total amount of base oil. It is particularly preferable to contain 80% by mass or more. The conditions for hydrocracking referred to herein are arbitrary, but usually, in the presence of a hydrocracking catalyst, the total pressure is 6 to 25 MPa.
a, temperature 350 ~ 500 ℃, LHSV0.1 ~ 2.0hr
^Under the reaction conditions such as ^-1 , the hydrocracking conditions are adopted so that the decomposition rate is 40% by mass or more. Although any hydrocracking catalyst can be used, usually, for example, molybdenum,
Chrome, tungsten, vanadium, platinum, nickel,
Copper, iron, cobalt, oxides and / or sulfides of these, or mixtures thereof are used. These catalysts may be used as they are, or may be used in a form supported on a carrier such as silica-alumina, activated alumina and zeolite.

The component (I-2) is a polymer and / or copolymer of an olefin having 2 to 16 carbon atoms, or a hydride thereof, and has a number average molecular weight of 250 to 4000. The olefin mentioned here has 2 carbon atoms.
To 16 and preferably C2 to C12 olefins, which may be so-called α-olefins having the double bond at the terminal or so-called internal olefins having the double bond inside. Further, it may be a linear olefin or a branched olefin. Specific examples of such an olefin include ethylene, propylene, 1-butene, 2-butene, isobutene, linear or branched pentene (including α-olefin and internal olefin), and linear olefin. Or branched hexene (including α-olefins and internal olefins), linear or branched heptene (including α-olefins and internal olefins), linear or branched octene (α-olefins) , Including internal olefin), linear or branched nonene (including α-olefin and internal olefin), linear or branched decene (including α-olefin and internal olefin), linear Or branched undecene (α-
Olefin, including internal olefin), linear or branched dodecene (including α-olefin and internal olefin), linear or branched tridecene (including α-olefin and internal olefin), linear Linear or branched tetradecene (including α-olefins and internal olefins), linear or branched pentadecene (including α-olefins and internal olefins), linear or branched hexadecene (α- Olefins, including internal olefins), and mixtures thereof, among others, especially ethylene, propylene, 1-butene, 2-butene, isobutene, 1-octene, 1-decene, 1-dodecene and mixtures thereof. It is preferably used. Of the present invention
The component (I-2) is a polymer of these olefins or a hydride thereof, and the polymer here means not only a homopolymer of one olefin but also a random copolymer of two or more olefins. It also means a copolymer such as a coalesce, an alternating copolymer and a block copolymer. The olefin homopolymer or copolymer usually contains a double bond, but the component (I-2) of the present invention has a double bond from the viewpoint of excellent heat / oxidation stability. It is preferable to use a homopolymer or copolymer obtained by hydrogenating. The method for producing the olefin polymer as the component (I-2) is arbitrary and is not limited in any way, but generally, it is an organic peroxide catalyst such as benzoyl peroxide or the like by an uncatalyzed thermal reaction; aluminum chloride. , Aluminum chloride-polyhydric alcohol system, aluminum chloride-titanium tetrachloride system, aluminum chloride-alkyltin halide system, boron fluoride, etc. Friedel-Crafts type catalyst; organic aluminum chloride-titanium tetrachloride system, organic aluminum-tetrachloride system Ziegler type catalysts such as titanium type; metallocene type catalysts such as aluminoxane-zirconocene type and ionic compound-zirconocene type; known catalyst systems such as aluminum chloride-base type and Lewis acid complex type catalysts such as boron fluoride-base type To homopolymerize or copolymerize the above olefins. And obtained by The method for obtaining the hydride of the olefin polymer is also optional, for example, by hydrogenating the olefin polymer with hydrogen in the presence of a known hydrogenation catalyst to saturate the double bond present in the olefin polymer. can get. Some catalysts can perform olefin polymerization and hydrogenation of double bonds present in the polymer in one step without going through the two-step process of polymerizing the olefin and hydrogenating the obtained polymer. is there. Of the present invention
As the component (I-2), ethylene-propylene copolymer, polybutene (butane-butene (which is a by-product of thermal decomposition of naphtha) (from the viewpoint of excellent heat / oxidation stability, viscosity-temperature characteristics, and low-temperature fluidity). 1-butene, a mixture of 2-butene and isobutene) a copolymer obtained by the polymerization of fractions),
1-octene oligomer, 1-decene oligomer, 1-
Dodecene oligomer, hydrides thereof, and mixtures thereof are more preferably used, and ethylene-propylene copolymer hydride, polybutene hydride, 1-
Octene oligomer hydride, 1-decene oligomer hydride, 1-dodecene oligomer hydride, and mixtures thereof are particularly preferably used. It should be noted that synthetic oils such as ethylene-propylene copolymers, polybutene and poly-α-olefins that are currently commercially available for lubricating base oils are usually those in which their double bonds have already been hydrogenated. In the present invention, these commercially available products can also be preferably used. The lower limit of the number average molecular weight of the component (I-2) is 250, preferably 350, and the upper limit is 40.
00, preferably 1500. Number average molecular weight is 25
If it is less than 0, the oil film may not be sufficiently formed, resulting in poor lubricity, and the evaporation loss of the base oil under high temperature conditions may increase. On the other hand, the number average molecular weight is 400
If it exceeds 0, the fluid resistance increases, which may increase the frictional resistance at the lubrication point. (I-2)
The viscosity of the olefin polymer or its hydride as a component is not particularly limited, but the preferable kinematic viscosity is 5 ° C. at 40 ° C.
200 mm ² / s, more preferably from 10 to 100 mm ² / s.

Component (I-3) of the present invention is an alkylbenzene having 1 to 4 alkyl groups having 1 to 40 carbon atoms, and the total number of carbon atoms of the alkyl groups is 6 to 40.
It has 1 carbon atom because of its excellent oxidative stability and availability.
It is preferable that the alkylbenzene has 1 to 4 alkyl groups having 40 to 40 carbon atoms, and the total number of carbon atoms of the alkyl groups is 12 to 40, and further has 1 to 4 alkyl groups having 1 to 30 carbon atoms. And the total number of carbon atoms in the alkyl group is 15
More preferably, it is an alkylbenzene of 30. When an alkylbenzene in which the total number of carbon atoms in the alkyl group is less than 6 is used, the oil film may not be sufficiently formed, resulting in poor lubricity, and the evaporation loss of the base oil under high temperature conditions may increase. . On the other hand, when alkylbenzene in which the total carbon number of the alkyl group exceeds 40 is used, the fluid resistance increases, and thus the frictional resistance at the lubricated portion may increase. C1-C4 here
The alkyl group of 0 may be linear or branched. Specifically, for example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group,
sec-butyl group, tert-butyl group, linear or branched butyl group, linear or branched pentyl group, linear or branched hexyl group, linear or branched heptyl group, linear or branched A branched octyl group, a straight chain or branched nonyl group, a straight chain or branched decyl group, a straight chain or branched undecyl group, a straight chain or branched dodecyl group, a straight chain or branched tridecyl group, Straight chain or branched tetradecyl group,
Straight-chain or branched pentadecyl group, straight-chain or branched hexadecyl group, straight-chain or branched heptadecyl group, straight-chain or branched octadecyl group, straight-chain or branched nonadecyl group, straight-chain or branched Icosyl group, straight-chain or branched henicosyl group, straight-chain or branched docosyl group, straight-chain or branched tricosyl group, straight-chain or branched tetracosyl group, straight-chain or branched pentacosyl group, direct A chain or branched hexacosyl group, a straight chain or branched heptacosyl group, a straight chain or branched octacosyl group, a straight chain or branched nonacosyl group, a straight chain or branched triacontyl group,
A straight-chain or branched Hentriacontyl group, a straight-chain or branched Dotriacontyl group, a straight-chain or branched tritriacontyl group, a straight-chain or branched tetracontyl group, a straight-chain or branched pentacontyl group, A straight-chain or branched hexacontyl group, a straight-chain or branched heptacontyl group, a straight-chain or branched octacontyl group, a straight-chain or branched nonacontyl group, a straight-chain or branched tetracontyl group, etc. may be mentioned. The alkyl group of alkylbenzene may be linear or branched, but is preferably a branched alkyl group from the viewpoint of viscosity-temperature characteristics and low-temperature fluidity, and is particularly available. From the viewpoint, a branched alkyl group derived from an olefin oligomer such as propylene, butene, and isobutylene is more preferable.
The alkylbenzene as the component (I-3) has 1 alkyl group.
Alkylbenzenes having 1 or 2 alkyl groups, ie, monoalkylbenzenes, dialkylbenzenes, or a mixture thereof, which have an excellent thermal and oxidative stability, are retained by the formula (I- Component 3) most preferred. Needless to say, the alkylbenzene which is the component (I-3) of the present invention has 1 to 4 alkyl groups having 1 to 40 carbon atoms, and the total number of carbon atoms of the alkyl groups is 6 to 4
As long as it is 0, it may be an alkylbenzene having a single structure or a mixture of alkylbenzenes having different structures. The viscosity of the alkylbenzene as the component (I-3) is not particularly limited, but the preferable kinematic viscosity is 5 to 2 at 40 ° C.
00mm ² / s, more preferably from 10 to 100 mm ² / s. The method for producing the alkylbenzene used as the component (I-3) of the present invention is arbitrary and is not limited at all, but generally it can be produced by the synthetic method shown below.
Specific examples of the aromatic compound as a raw material include:
Benzene, toluene, xylene, ethylbenzene, methylethylbenzene, diethylbenzene, a mixture thereof and the like are used. As the alkylating agent,
Specifically, for example, lower mono-olefins such as ethylene, propylene, butene and isobutylene, preferably linear or branched olefins having 6 to 40 carbon atoms obtained by polymerization of propylene; wax, heavy oil, petroleum fraction ,
A linear or branched olefin having 6 to 40 carbon atoms obtained by thermal decomposition of polyethylene, polypropylene, etc .; n-paraffin is separated from petroleum fractions such as kerosene, light oil, etc. The obtained linear olefin having 6 to 40 carbon atoms; and a mixture thereof can be used. As the alkylation catalyst in the alkylation, Friedel-Crafts type catalysts such as aluminum chloride and zinc chloride; acidic catalysts such as sulfuric acid, phosphoric acid, silicotungstic acid, hydrofluoric acid and activated clay;
Known catalysts are used.

In the lubricating oil composition of the present invention, when the above-mentioned (I-2) component and / or (I-3) component is used as the [I] component, use of the lubricating oil composition of the present invention For the purpose of improving the swelling property of a member such as a rubber seal material used in a place, the kinematic viscosity at 40 ° C. is 5 to 200 mm ² / s,
A mineral oil-based base oil, an ester-based base oil, an ether-based base oil, and a mixture thereof, which are preferably 10 to 100 mm ² / s, are used in an amount of less than 40% by mass based on the total amount of the base oil which is the [I] component,
Preferably less than 30% by weight, more preferably 20% by weight
Can be included in an amount less than. The mineral oil base oil used in combination with the component (I-2) and / or the component (I-3) is not limited in its total aromatic content, and paraffin base crude oil or mixed base crude oil may be subjected to atmospheric distillation and vacuum distillation. The lubricating oil fraction thus obtained is subjected to a single refining process such as hydrorefining, solvent refining, dewaxing, clay refining, chemical (acid / alkali) refining, or two or more refining processes including the same or the same refining method. It is possible to use a mineral oil-based base oil such as a paraffin-based or naphthene-based base oil having an arbitrary total aromatic content, which is refined by combining arbitrary refining methods in an arbitrary order. However, in the case of using a mineral oil-based base oil, it is more preferable to use the component (I-1) of the present invention in combination, particularly in view of its excellent synergistic effect with the fatty acid ester of the component (II). Specific examples of the above-mentioned ester base oil used in combination with the component (I-2) and / or the component (I-3) include ditridecyl glutarate, di-2-ethylhexyl adipate, diisodecyl adipate and ditri Decyl adipate, di-3-
Diester oils typified by ethylhexyl sebacate; polyol ester oils typified by trimethylolpropane tricaprylate, trimethylolpropane tripelargonate, pentaerythritol tetra (2-ethylhexanoate), pentaerythritol tetrapelargonate, etc. ; And 2 selected from these
Examples include a mixture of one or more ester base oils. Specific examples of the ether base oil include polyglycol oils represented by polyoxyethylene glycol, polyoxypropylene glycol, polyoxyethyleneoxypropylene glycol, polyoxybutylene glycol, etc .; Examples thereof include alkyl ether compounds and dialkyl ether compounds; diphenyl ether, polyphenylene ether, and a mixture of two or more kinds of ether base oils selected from these.

The component [II] of the present invention is 3-methyl-5-tert-butyl-represented by the following general formula (1).
It is a 4-hydroxyphenyl group-substituted fatty acid ester.

Embedded image In the above formula (1), R ¹ is a linear or branched alkylene group having 1 to 6 carbon atoms, and R ² is 1 to 24 carbon atoms,
A straight-chain or branched alkyl group or alkenyl group is shown, respectively. R ¹ is, for example, a methylene group, a methylmethylene group, an ethylene group (dimethylene group), an ethylmethylene group, a propylene group (methylethylene group), a trimethylene group, a linear or branched butylene group, a linear or branched group. And a straight-chain or branched hexylene group. R ¹ is more preferably an alkylene group having 1 to 2 carbon atoms, specifically, for example, a methylene group, a methylmethylene group, an ethylene group (dimethylene group), etc., since the component [II] can be produced in a small reaction step. preferable. Specific examples of R ² include a methyl group, an ethyl group, an n-propyl group, an isopropyl group,
n-butyl group, isobutyl group, sec-butyl group, te
an rt-butyl group, a linear or branched pentyl group, a linear or branched hexyl group, a linear or branched heptyl group,
Linear or branched octyl group, linear or branched nonyl group, linear or branched decyl group, linear or branched undecyl group, linear or branched dodecyl group, linear or branched A tridecyl group, a linear or branched tetradecyl group,
Straight-chain or branched pentadecyl group, straight-chain or branched hexadecyl group, straight-chain or branched heptadecyl group, straight-chain or branched octadecyl group, straight-chain or branched nonadecyl group, straight-chain or branched An alkyl group such as an icosyl group, a linear or branched henicosyl group, a linear or branched docosyl group, a linear or branched tricosyl group, a linear or branched tetracosyl group; a vinyl group, a propenyl group, Isopropenyl group, straight-chain or branched butenyl group, straight-chain or branched pentenyl group, straight-chain or branched hexenyl group, straight-chain or branched heptenyl group, straight-chain or branched octenyl group, direct Chain or branched nonenyl group, straight chain or branched decenyl group, straight chain or branched undecenyl group, straight chain or branched dodecenyl group, straight chain or branched tridecenyl group, direct Or branched tetradecenyl,
Straight-chain or branched pentadecenyl group, straight-chain or branched hexadecenyl group, straight-chain or branched heptadecenyl group, straight-chain or branched octadecenyl group, straight-chain or branched octadecadienyl group, straight-chain Or a branched nonadecenyl group, a straight-chain or branched icosenyl group, a straight-chain or branched henicosenyl group, a straight-chain or branched docosenyl group, a straight-chain or branched tricosenyl group, a straight-chain or branched tetracosenyl group An alkenyl group such as a group; Considering the solubility of the [II] component with respect to the [I] component, R ² in the general formula (1) has 4 to 18 carbon atoms.
An alkyl group of, for example, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, linear or branched pentyl group, linear or branched hexyl group, linear or branched A branched heptyl group, a straight-chain or branched octyl group, a straight-chain or branched nonyl group, a straight-chain or branched decyl group, a straight-chain or branched undecyl group, a straight-chain or branched dodecyl group, Straight-chain or branched tridecyl group, straight-chain or branched tetradecyl group, straight-chain or branched pentadecyl group, straight-chain or branched hexadecyl group, straight-chain or branched heptadecyl group, straight-chain or branched Is preferably an alkyl group such as octadecyl group, and of these, a linear or branched alkyl group having 6 to 12 carbon atoms is more preferable, and a branched alkyl group having 6 to 12 carbon atoms is preferable. is there Theft is particularly preferred. Preferred 3-methyl-5-tert-butyl-4-hydroxyphenyl group-substituted fatty acid ester as the component [II] is the above (1).
In the formula, R ¹ is an alkylene group having 1 to 2 carbon atoms,
R ² is a fatty acid ester which is a straight chain or branched alkyl group having 6 to 12 carbon atoms, R ¹ is an alkylene group having 1 to 2 carbon atoms, and R ² is branched chain having 6 to 12 carbon atoms. A fatty acid ester which is a linear alkyl group is particularly preferable as the component [II]. As a matter of course, as the component [II] of the present invention, one kind of compound represented by the formula (1) may be used alone, and two or more kinds of compounds included in the formula (1) may be used. You may use the mixture which mixed the compound in arbitrary ratios. A specific description of the compound preferable as the component [II] in the present invention is (3-methyl-5-tert-butyl-
4-hydroxyphenyl) acetic acid n-hexyl, (3-methyl-5-tert-butyl-4-hydroxyphenyl) acetic acid isohexyl, (3-methyl-5-tert-)
Butyl-4-hydroxyphenyl) acetic acid n-heptyl,
(3-Methyl-5-tert-butyl-4-hydroxyphenyl) isoheptyl acetate, (3-methyl-5-te
rt-Butyl-4-hydroxyphenyl) n-octyl acetate, (3-methyl-5-tert-butyl-4-hydroxyphenyl) isooctyl acetate, (3-methyl-5)
-Tert-butyl-4-hydroxyphenyl) acetic acid 2
-Ethylhexyl, (3-methyl-5-tert-butyl-4-hydroxyphenyl) acetic acid n-nonyl, (3-
Methyl-5-tert-butyl-4-hydroxyphenyl) acetic acid isononyl, (3-methyl-5-tert-butyl-4-hydroxyphenyl) acetic acid n-decyl, (3
-Methyl-5-tert-butyl-4-hydroxyphenyl) acetic acid isodecyl, (3-methyl-5-tert-
Butyl-4-hydroxyphenyl) n-undecyl acetate, (3-methyl-5-tert-butyl-4-hydroxyphenyl) isoundecyl acetate, (3-methyl-5)
-Tert-butyl-4-hydroxyphenyl) acetic acid n
-Dodecyl, (3-methyl-5-tert-butyl-4
-Hydroxyphenyl) isododecyl acetate, (3-methyl-5-tert-butyl-4-hydroxyphenyl)
N-hexyl propionate, (3-methyl-5-ter
Isohexyl t-butyl-4-hydroxyphenyl) propionate, (3-methyl-5-tert-butyl-4)
-Hydroxyphenyl) n-heptyl propionate,
(3-Methyl-5-tert-butyl-4-hydroxyphenyl) isoheptyl propionate, (3-methyl-
N-octyl 5-tert-butyl-4-hydroxyphenyl) propionate, (3-methyl-5-tert-
Butyl-4-hydroxyphenyl) isooctyl propionate, 2-ethylhexyl (3-methyl-5-tert-butyl-4-hydroxyphenyl) propionate,
(3-Methyl-5-tert-butyl-4-hydroxyphenyl) n-nonyl propionate, (3-methyl-5
-Tert-Butyl-4-hydroxyphenyl) isononyl propionate, n-decyl (3-methyl-5-tert-butyl-4-hydroxyphenyl) propionate, (3-methyl-5-tert-butyl-4-hydroxy) Phenyl) isodecyl propionate, n-undecyl (3-methyl-5-tert-butyl-4-hydroxyphenyl) propionate, (3-methyl-5-ter
t-Butyl-4-hydroxyphenyl) isoundecyl propionate, (3-methyl-5-tert-butyl-
4-hydroxyphenyl) n-dodecyl propionate,
Examples include isododecyl (3-methyl-5-tert-butyl-4-hydroxyphenyl) propionate, and a mixture thereof. 3 which is the [II] component of the present invention
The method for producing the -methyl-5-tert-butyl-4-hydroxyphenyl group-substituted fatty acid ester is arbitrary and is not particularly limited by the method. For reference, one example thereof is (3-methyl-5-t
To produce ert-butyl-4-hydroxyphenyl) propionic acid ester, 2-methyl-6-tert
-Methyl (3-methyl-5-tert-butyl-4-hydroxyphenyl) propionate can be obtained by reacting butylphenol with methyl acrylate in the presence of a basic catalyst such as sodium metal. In addition, the methyl (3-methyl-5-tert-butyl-4-hydroxyphenyl) propionate and another aliphatic alcohol having 2 to 24 carbon atoms are subjected to transesterification reaction as necessary to give (3- Methyl-5-tert
An esterified product of -butyl-4-hydroxyphenyl) propionic acid and an aliphatic alcohol having 2 to 24 carbon atoms can be easily obtained. The content of the [II] component in the lubricating oil composition of the present invention is based on the total amount of the lubricating oil composition, and the lower limit of the content is 0.1% by mass, preferably 0.2% by mass, while The upper limit of its content is 5.0% by mass,
It is preferably 3.0% by mass. When the content of the [II] component is less than 0.1% by mass based on the total amount of the lubricating oil composition, the effect of improving the oxidative stability by the inclusion of the [II] component is insufficient, while the upper limit is the lubricating oil composition. If the total amount of the substances exceeds 5.0% by mass, the effect of improving the oxidation stability commensurate with the content cannot be obtained, and it is economically disadvantageous, which is not preferable.

The component [III] of the present invention comprises the following (III-1)
One or more nitrogen-containing compounds selected from the group (III-3). (III-1) thiadiazole, (III-2) benzotriazole and / or its derivative (III-3) benzothiazole

The above-mentioned component (III-1) includes a thiadiazole compound represented by the following general formula (2).

Embedded image In the above formula (2), R ³ represents a linear or branched alkyl group having 1 to 30 carbon atoms, preferably 6 to 24 carbon atoms,
R ⁴ is hydrogen or a linear or branched alkyl group having 1 to 30 carbon atoms, preferably hydrogen or 1 to 24 carbon atoms
A linear or branched alkyl group of
And b independently represent the numbers 1-3, preferably 1 or 2. Specific examples of R ³ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a linear or branched pentyl group, and a direct group. Chain or branched hexyl group, straight chain or branched heptyl group, straight chain or branched octyl group, straight chain or branched nonyl group, straight chain or branched decyl group, straight chain or branched chain Undecyl group,
Straight-chain or branched dodecyl group, straight-chain or branched tridecyl group, straight-chain or branched tetradecyl group, straight-chain or branched pentadecyl group, straight-chain or branched hexadecyl group, straight-chain or branched Heptadecyl group, straight-chain or branched octadecyl group, straight-chain or branched nonadecyl group, straight-chain or branched icosyl group, straight-chain or branched henicosyl group, straight-chain or branched docosyl group, direct Chain or branched tricosyl group, straight chain or branched tetracosyl group, straight chain or branched pentacosyl group, straight chain or branched hexacosyl group, straight chain or branched heptacosyl group, straight chain or branched chain Examples thereof include an octacosyl group, a linear or branched nonacosyl group, and a linear or branched triacontyl group. Specific examples of R ⁴ include hydrogen and various alkyl groups having 1 to 30 carbon atoms as exemplified for R ³ above. Among the thiadiazoles represented by the general formula (2), R ³ is a group selected from an alkyl group having 6 to 24 carbon atoms and R ⁴ because of its excellent antioxidant property.
Is hydrogen or a group selected from an alkyl group having 1 to 24 carbon atoms, and a and b are each independently 1 or 2, and thiadiazole is preferable, and R ³ is selected from an alkyl group having 6 to 24 carbon atoms. A thiadiazole in which R ⁴ is hydrogen or a group selected from an alkyl group having 1 to 24 carbon atoms, and a is 1 and 2 and b is 1 is more preferable. A particularly preferable compound as the thiadiazole which is the component (III-1) of the present invention is specifically described as follows. For example, 2,5-bis (linear or branched hexylthio)-
1,3,4-thiadiazole, 2,5-bis (linear or branched heptylthio) -1,3,4-thiadiazole,
2,5-bis (linear or branched octylthio) -1,
3,4-thiadiazole, 2,5-bis (linear or branched nonylthio) -1,3,4-thiadiazole, 2,5
-Bis (linear or branched decylthio) -1,3,4-thiadiazole, 2,5-bis (linear or branched undecylthio) -1,3,4-thiadiazole, 2,5-bis (linear or Branched dodecylthio) -1,3,4-thiadiazole, 2,5-bis (linear or branched tridecylthio) -1,3,4-thiadiazole, 2,5-bis (linear or branched tetradecylthio) -1,3,4-thiadiazole, 2,5-bis (linear or branched pentadecylthio) -1,3,4-thiadiazole, 2,5-bis (linear or branched hexadecylthio) -1,3 , 4-thiadiazole, 2,5-bis (linear or branched heptadecylthio) -1,3,4-thiadiazole, 2,5-bis (linear or branched octadecylthio) -1,3,4-
Thiadiazole, 2,5-bis (linear or branched nonadecylthio) -1,3,4-thiadiazole, 2,5-bis (linear or branched icosylthio) -1,3,4-thiadiazole, 2,5- Bis (linear or branched henicosylthio) -1,3,4-thiadiazole, 2,5-bis (linear or branched docosylthio) -1,3,4-thiadiazole, 2,5-bis (linear or branched) Branched tricosylthio) -1,3,4-thiadiazole, 2,5-bis (linear or branched tetracosylthio) -1,3,4-thiadiazole; 2,5-bis (linear or branched hexyldithio) -1,3,4-thiadiazole, 2,5-bis (linear or branched heptyldithio) -1,3,4-thiadiazole, 2,5-bis (linear or branched octyldithio) -1,3, 4- Thiadiazole, 2,5-bis (linear or branched nonyldithio) -1,3,4-thiadiazole, 2,5-bis (linear or branched Deshirujichio) -
1,3,4-thiadiazole, 2,5-bis (linear or branched undecyldithio) -1,3,4-thiadiazole, 2,5-bis (linear or branched dodecyldithio)-
1,3,4-thiadiazole, 2,5-bis (linear or branched tridecyldithio) -1,3,4-thiadiazole, 2,5-bis (linear or branched tetradecyldithio) -1,3 4-thiadiazole, 2,5-bis (linear or branched pentadecyldithio) -1,3,4-thiadiazole, 2,5-bis (linear or branched hexadecyldithio) -1,3,4- Thiadiazole, 2,5-bis (linear or branched heptadecyldithio) -1,3,4
-Thiadiazole, 2,5-bis (linear or branched octadecyldithio) -1,3,4-thiadiazole, 2,
5-bis (linear or branched nonadecyldithio) -1,
3,4-thiadiazole, 2,5-bis (linear or branched icosyldithio) -1,3,4-thiadiazole,
2,5-bis (linear or branched henicosyldithio)-
1,3,4-thiadiazole, 2,5-bis (linear or branched docosyldithio) -1,3,4-thiadiazole, 2,5-bis (linear or branched tricosyldithio)
-1,3,4-thiadiazole, 2,5-bis (linear or branched tetracosyldithio) -1,3,4-thiadiazole; 2- (linear or branched hexylthio) -5-mercapto-1 , 3,4-thiadiazole, 2- (linear or branched heptylthio) -5-mercapto-1,3,4
-Thiadiazole, 2- (linear or branched octylthio) -5-mercapto-1,3,4-thiadiazole,
2- (linear or branched nonylthio) -5-mercapto-
1,3,4-thiadiazole, 2- (linear or branched decylthio) -5-mercapto-1,3,4-thiadiazole, 2- (linear or branched undecylthio) -5-mercapto-1,3 4-thiadiazole, 2- (linear or branched dodecylthio) -5-mercapto-1,3,4
-Thiadiazole, 2- (linear or branched tridecylthio) -5-mercapto-1,3,4-thiadiazole,
2- (linear or branched tetradecylthio) -5-mercapto-1,3,4-thiadiazole, 2- (linear or branched pentadecylthio) -5-mercapto-1,3,4
-Thiadiazole, 2- (linear or branched hexadecylthio) -5-mercapto-1,3,4-thiadiazole, 2- (linear or branched heptadecylthio) -5-mercapto-1,3,4-thiadiazole, 2 -(Linear or branched octadecylthio) -5-mercapto-1,
3,4-thiadiazole, 2- (linear or branched nonadecylthio) -5-mercapto-1,3,4-thiadiazole, 2- (linear or branched icosylthio) -5-mercapto-1,3,4- Thiadiazole, 2- (linear or branched henicosylthio) -5-mercapto-1,3
4-thiadiazole, 2- (linear or branched docosylthio) -5-mercapto-1,3,4-thiadiazole,
2- (linear or branched tricosylthio) -5-mercapto-1,3,4-thiadiazole, 2- (linear or branched tetracosylthio) -5-mercapto-1,3,4-
Thiadiazole; 2- (linear or branched hexyldithio) -5-mercapto-1,3,4-thiadiazole,
2- (linear or branched heptyldithio) -5-mercapto-1,3,4-thiadiazole, 2- (linear or branched octyldithio) -5-mercapto-1,3,4-thiadiazole, 2- ( Linear or branched nonyldithio)-
5-mercapto-1,3,4-thiadiazole, 2-
(Straight-chain or branched decyldithio) -5-mercapto-
1,3,4-thiadiazole, 2- (linear or branched undecyldithio) -5-mercapto-1,3,4-thiadiazole, 2- (linear or branched dodecyldithio)-
5-mercapto-1,3,4-thiadiazole, 2-
(Linear or branched tridecyldithio) -5-mercapto-1,3,4-thiadiazole, 2- (linear or branched tetradecyldithio) -5-mercapto-1,3,4-
Thiadiazole, 2- (linear or branched pentadecyldithio) -5-mercapto-1,3,4-thiadiazole, 2- (linear or branched hexadecyldithio) -5-
Mercapto-1,3,4-thiadiazole, 2- (linear or branched heptadecyldithio) -5-mercapto-
1,3,4-thiadiazole, 2- (linear or branched octadecyldithio) -5-mercapto-1,3,4-thiadiazole, 2- (linear or branched nonadecyldithio) -5-mercapto-1,3 , 4-thiadiazole,
2- (linear or branched icosyldithio) -5-mercapto-1,3,4-thiadiazole, 2- (linear or branched henicosyldithio) -5-mercapto-1,3,4
-Thiadiazole, 2- (linear or branched docosyldithio) -5-mercapto-1,3,4-thiadiazole,
2- (linear or branched tricosyldithio) -5-mercapto-1,3,4-thiadiazole, 2- (linear or branched tetracosyldithio) -5-mercapto-1,3
4-thiadiazole; and mixtures thereof.

The benzotriazole which is the component (III-2) of the present invention includes compounds represented by the following general formula (3).

Embedded image Further, one of the benzotriazole derivatives which is the component (III-2) of the present invention is an alkylbenzotriazole represented by the following general formula (4).

[Chemical 6] In the above formula (4), R ⁵ represents a linear or branched alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group, and c is 1 to 3, preferably 1 or 2 Shows the number of. Specific examples of R ⁵ include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-
Butyl group, isobutyl group, sec-butyl group, tert
-Butyl group and the like. As the alkylbenzotriazole represented by the general formula (4), it is preferable that R ⁵ is a methyl group or an ethyl group and c is 1 or 2 from the viewpoint of excellent antioxidation property. Examples of preferred alkylbenzotriazoles include methylbenzotriazole (tolyltriazole), dimethylbenzotriazole, ethylbenzotriazole, ethylmethylbenzotriazole, diethylbenzotriazole,
And mixtures thereof. (III of the present invention
Another one of the benzotriazole derivatives usable as the component (-2) is an (alkyl) aminoalkylbenzotriazole represented by the following general formula (5).

Embedded image In the above formula (5), R ⁶ represents a linear or branched alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group, R ⁷ represents a methylene group or an ethylene group, and R ⁸
And R ⁹ are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 18 carbon atoms, preferably 1 to 1 carbon atoms.
12 straight-chain or branched alkyl groups, and d
Indicates a number of 0 to 3, preferably 0 or 1. R
Specific examples of ⁶ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. Further, specific examples of R ⁸ and R ⁹ include a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group,
tert-butyl group, straight-chain or branched pentyl group, straight-chain or branched hexyl group, straight-chain or branched heptyl group, straight-chain or branched octyl group, straight-chain or branched nonyl group, Straight-chain or branched decyl group, straight-chain or branched undecyl group, straight-chain or branched dodecyl group, straight-chain or branched tridecyl group, straight-chain or branched tetradecyl group, straight-chain or branched A pentadecyl group, a linear or branched hexadecyl group, a linear or branched heptadecyl group,
Mention may be made of alkyl groups such as straight-chain or branched octadecyl groups. Among the (alkyl) aminoalkylbenzotriazoles represented by the formula (5), R ⁶ is a methyl group, d is 0 or 1, and R ⁷ is a methylene group, from the viewpoint of being excellent in antioxidant property. It is possible to use dialkylaminoalkylbenzotriazoles, dialkylaminoalkyltolyltriazoles, which are ethylene groups and R ⁸ and R ⁹ are linear or branched alkyl groups having 1 to 12 carbon atoms, and mixtures thereof. preferable. Specific examples of dialkylaminoalkylbenzotriazoles include, for example, dimethylaminomethylbenzotriazole, diethylaminomethylbenzotriazole, di (linear or branched) propylaminomethylbenzotriazole, di (linear or branched) butylamino. Methylbenzotriazole, di (straight or branched)
Pentylaminomethylbenzotriazole, di (linear or branched) hexylaminomethylbenzotriazole,
Di (linear or branched) heptylaminomethylbenzotriazole, di (linear or branched) octylaminomethylbenzotriazole, di (linear or branched) nonylaminomethylbenzotriazole, di (linear or branched) Decylaminomethylbenzotriazole, di (linear or branched) undecylaminomethylbenzotriazole, di (linear or branched) dodecylaminomethylbenzotriazole; dimethylaminoethylbenzotriazole, diethylaminoethylbenzotriazole, di (linear) Or (branched) propylaminoethylbenzotriazole, di (straight or branched) butylaminoethylbenzotriazole, di (straight or branched) pentylaminoethylbenzotriazole, di (straight or branched) hexylaminoethylbenzo bird Zole, di (linear or branched) heptylaminoethylbenzotriazole, di (linear or branched) octylaminoethylbenzotriazole, di (linear or branched) nonylaminoethylbenzotriazole, di (linear or branched) (Branched) decylaminoethylbenzotriazole, di (linear or branched) undecylaminoethylbenzotriazole, di (linear or branched) dodecylaminoethylbenzotriazole; and the like, and dialkylaminoalkyltolyl. Specific examples of triazoles include dimethylaminomethyltolyltriazole, diethylaminomethyltolyltriazole, di (linear or branched) propylaminomethyltolyltriazole, di (linear or branched) butylaminomethyltolyltriazole, di ( straight Or branched)
Pentylaminomethyltolyltriazole, di (linear or branched) hexylaminomethyltolyltriazole,
Di (linear or branched) heptylaminomethyltolyltriazole, di (linear or branched) octylaminomethyltolyltriazole, di (linear or branched) nonylaminomethyltolyltriazole, di (linear or branched) Decylaminomethyltolyltriazole, di (linear or branched) undecylaminomethyltolyltriazole, di (linear or branched) dodecylaminomethyltolyltriazole; dimethylaminoethyltolyltriazole, diethylaminoethyltolyltriazole, di (linear) Or branched) propylaminoethyltolyltriazole, di (linear or branched) butylaminoethyltolyltriazole, di (linear or branched) pentylaminoethyltolyltriazole, di (linear or branched) hexylaminoethyltolyl bird Zole, di (linear or branched) heptylaminoethyltolyltriazole, di (linear or branched) octylaminoethyltolyltriazole, di (linear or branched) nonylaminoethyltolyltriazole, di (linear or branched) Branched) decylaminoethyltolyltriazole, di (linear or branched) undecylaminoethyltolyltriazole, di (linear or branched) dodecylaminoethyltolyltriazole; and the like.

The benzothiazole which is the component (III-3) of the present invention is represented by the following general formula (6).

Embedded image In the above formula (6), R ¹⁰ represents a linear or branched alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group, and R ¹¹ has 1 to 30 carbon atoms, preferably 6 to 24
, A linear or branched alkyl group, and e is a number of 0 to 3, preferably 0 or 1, and f is 1 to
The number 3, preferably 1 or 2, is indicated. Specific examples of R ¹⁰ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. Specific examples of R ¹¹ include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, linear or branched pentyl group. , A straight-chain or branched hexyl group, a straight-chain or branched heptyl group, a straight-chain or branched octyl group, a straight-chain or branched nonyl group, a straight-chain or branched decyl group, a straight-chain or branched Undecyl group of branch,
Straight-chain or branched dodecyl group, straight-chain or branched tridecyl group, straight-chain or branched tetradecyl group, straight-chain or branched pentadecyl group, straight-chain or branched hexadecyl group, straight-chain or branched Heptadecyl group, straight-chain or branched octadecyl group, straight-chain or branched nonadecyl group, straight-chain or branched icosyl group, straight-chain or branched henicosyl group, straight-chain or branched docosyl group, direct Chain or branched tricosyl group, straight chain or branched tetracosyl group, straight chain or branched pentacosyl group, straight chain or branched hexacosyl group, straight chain or branched heptacosyl group, straight chain or branched chain Mention may be made of alkyl groups such as octacosyl groups, straight-chain or branched nonacosyl groups and straight-chain or branched triacontyl groups. As the benzothiazole represented by the formula (6), R ¹⁰ is a methyl group or an ethyl group, and R ¹¹ is a straight-chain or branched-chain group having 6 to 24 carbon atoms, since it is particularly excellent in antioxidant properties. A compound in which e is a number of 0 or 1 and f is a number of 1 or 2 is preferably used. A particularly preferred benzothiazole used for the component (III-3) of the present invention is specifically shown by, for example, 2- (linear or branched hexylthio)
-Benzothiazole, 2- (linear or branched heptylthio) -benzothiazole, 2- (linear or branched octylthio) -benzothiazole, 2- (linear or branched nonylthio) -benzothiazole, 2- (direct Chain or branched decylthio) -benzothiazole, 2-linear or branched undecylthio-benzothiazole, 2- (linear or branched dodecylthio) -benzothiazole, 2- (linear or branched tridecylthio) -benzothiazole, 2-
(Straight chain or branched tetradecylthio) -benzothiazole, 2- (Straight chain or branched pentadecylthio) -benzothiazole, 2-bis (Straight chain or branched hexadecylthio) -benzothiazole, 2- (Straight chain) Or branched heptadecylthio) -benzothiazole, 2- (linear or branched octadecylthio) -benzothiazole, 2- (linear or branched nonadecylthio) -benzothiazole, 2-
(Straight or branched icosylthio) -benzothiazole,
2- (linear or branched henicosylthio) -benzothiazole, 2- (linear or branched docosylthio) -benzothiazole, 2- (linear or branched tricosylthio)-
Benzothiazole, 2- (linear or branched tetracosylthio) -benzothiazole; 2- (linear or branched hexylthio) -methylbenzothiazole, 2- (linear or branched heptylthio) -methylbenzothiazole, 2 −
(Straight or branched octylthio) -methylbenzothiazole, 2- (Straight or branched nonylthio) -methylbenzothiazole, 2- (Straight or branched decylthio) -methylbenzothiazole, 2-Straight or branched Undecylthio-methylbenzothiazole, 2- (linear or branched dodecylthio) -methylbenzothiazole, 2- (linear or branched tridecylthio) -methylbenzothiazole, 2- (linear or branched tetradecylthio) -methyl Benzothiazole, 2- (linear or branched pentadecylthio) -methylbenzothiazole, 2-bis (linear or branched hexadecylthio) -methylbenzothiazole,
2- (linear or branched heptadecylthio) -methylbenzothiazole, 2- (linear or branched octadecylthio) -methylbenzothiazole, 2- (linear or branched nonadecylthio) -methylbenzothiazole, 2- (direct Chain or branched icosylthio) -methylbenzothiazole, 2- (linear or branched henicosylthio) -methylbenzothiazole, 2- (linear or branched docosylthio) -methylbenzothiazole, 2- (linear or branched tricosylthio) ) -Methylbenzothiazole, 2- (linear or branched tetracosylthio) -methylbenzothiazole; 2- (linear or branched hexyldithio) -benzothiazole, 2- (linear or branched heptyldithio)-
Benzothiazole, 2- (linear or branched octyldithio) -benzothiazole, 2- (linear or branched nonyldithio) -benzothiazole, 2- (linear or branched decyldithio) -benzothiazole, 2-linear Or branched undecyldithio-benzothiazole, 2- (linear or branched dodecyldithio) -benzothiazole, 2- (linear or branched tridecyldithio) -benzothiazole,
2- (linear or branched tetradecyldithio) -benzothiazole, 2- (linear or branched pentadecyldithio)
-Benzothiazole, 2-bis (linear or branched hexadecyldithio) -benzothiazole, 2- (linear or branched heptadecyldithio) -benzothiazole, 2-
(Straight-chain or branched octadecyldithio) -benzothiazole, 2- (Straight-chain or branched nonadecyldithio) -benzothiazole, 2- (Straight-chain or branched icosyldithio)
-Benzothiazole, 2- (linear or branched henicosyldithio) -benzothiazole, 2- (linear or branched docosyldithio) -benzothiazole, 2- (linear or branched tricosyldithio) -benzothiazole , 2-
(Linear or branched tetracosyldithio) -benzothiazole; 2- (linear or branched hexyldithio) -methylbenzothiazole, 2- (linear or branched heptyldithio) -methylbenzothiazole, 2- (direct Chain or branched octyldithio) -methylbenzothiazole, 2- (linear or branched nonyldithio) -methylbenzothiazole, 2- (linear or branched decyldithio) -methylbenzothiazole, 2-linear or branched undecyldithio −
Methylbenzothiazole, 2- (linear or branched dodecyldithio) -methylbenzothiazole, 2- (linear or branched tridecyldithio) -methylbenzothiazole,
2- (linear or branched tetradecyldithio) -methylbenzothiazole, 2- (linear or branched pentadecyldithio) -methylbenzothiazole, 2-bis (linear or branched hexadecyldithio) -methylbenzo Thiazole, 2- (linear or branched heptadecyldithio) -methylbenzothiazole, 2- (linear or branched octadecyldithio) -methylbenzothiazole, 2- (linear or branched nonadecyldithio) -methylbenzothiazole,
2- (linear or branched icosyldithio) -methylbenzothiazole, 2- (linear or branched henicosyldithio) -methylbenzothiazole, 2- (linear or branched docosyldithio) -methylbenzothiazole, 2- (Linear or branched tricosyldithio) -methylbenzothiazole, 2- (linear or branched tetracosyldithio) -methylbenzothiazole; and mixtures thereof.

The [III] component of the present invention includes (III-1)
One compound selected from the component (III-3) may be used alone, or a mixture of two or more compounds selected from the component (III-1) at an arbitrary mixing ratio, (III-2) A mixture of two or more compounds selected from the components in any mixing ratio, (III
-3) A mixture of two or more compounds selected from the component may be used in an arbitrary mixing ratio. Furthermore, a mixture of one or more compounds selected from the component (III-1) and one or more compounds selected from the component (III-2) at an arbitrary mixing ratio, (III-
1) a mixture of one or more compounds selected from the component and one or more compounds selected from the component (III-3) in an arbitrary mixing ratio, and one or more compounds selected from the component (III-2) III-
3) a mixture of one or more compounds selected from the components in an arbitrary mixing ratio, one or more compounds selected from the component (III-1) and one or more compounds selected from the component (III-2) ( III-3)
A mixture of one or more compounds selected from the components in any mixing ratio may be used. The lower limit of the content of the [III] component in the lubricating oil composition of the present invention is 0.001% by mass, preferably 0.0
05 mass%, while the upper limit is 1.0 mass%,
It is preferably 0.5% by mass. When the content of the [III] component is less than 0.001% by mass based on the total amount of the lubricating oil composition, the effect of improving the oxidation stability by the inclusion of the [III] component is insufficient, while the upper limit is the lubricating oil composition 1. Based on the total quantity of goods.
If the amount exceeds 0% by mass, the effect of improving the oxidation stability commensurate with the content cannot be obtained, and it is economically disadvantageous, and thus it is not preferable.

The component [IV] of the present invention comprises the following (IV-1) to (I
One or more sulfur- and / or phosphorus-containing compounds selected from V-4). (IV-1) sulfides, (IV-2) phosphites, (I
V-3) Dithiophosphates, (IV-4) Dithiocarbamates

The above-mentioned component (IV-1) includes dihydrocarbyl polysulfide represented by the following general formula (7). _{^{R 12 -S g -R 13 (7}} ) (7) wherein, R ¹² and R ¹³ may be the same or different, each a straight-chain or branched alkyl group having 1 to 22 carbon atoms, carbon Aryl group having 6 to 20 carbon atoms and 7 to
20 is an alkylaryl group or an arylalkyl group having 7 to 20 carbon atoms, and g is 1 to 5, preferably 1 to
2, more preferably 2. Specific examples of R ¹² and R ¹³ include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, straight chain or branched pentyl group, Straight chain or branched hexyl group, cyclohexyl group, straight chain or branched heptyl group, straight chain or branched octyl group (tert-octyl group, etc.), straight chain or branched nonyl group, straight chain or branched decyl group, Straight-chain or branched undecyl group, straight-chain or branched dodecyl group (tert-dodecyl group, etc.), straight-chain or branched tridecyl group, straight-chain or branched tetradecyl group, straight-chain or branched pentadecyl group, straight-chain or Branched hexadecyl group (2-methylpentadecyl group, tert-hexadecyl group, etc.), straight chain or branched heptadecyl group, straight chain or branched octadecyl group, straight chain or Alkyl group such as branched nonadecyl group, straight chain or branched icosyl group, straight chain or branched henicosyl group, straight chain or branched docosyl group; alkenyl group such as propenyl group, butenyl group; phenyl group, naphthyl group (all Aryl groups such as); tolyl group, ethylphenyl group, propylphenyl group, butylphenyl group, pentylphenyl group, hexylphenyl group, heptylphenyl group, octylphenyl group, nonylphenyl group, decylphenyl group, Undecylphenyl group, dodecylphenyl group, xylyl group, ethylmethylphenyl group, diethylphenyl group, dipropylphenyl group, dibutylphenyl group, methylnaphthyl group, ethylnaphthyl group, propylnaphthyl group, butylnaphthyl group, dimethylnaphthyl group, Ethylmethylnaphthyl group, di An alkylaryl group such as a tylnaphthyl group, a dipropylnaphthyl group, a dibutylnaphthyl group (the alkyl portion of these alkylaryl groups may be linear or branched, and the substitution position of the alkyl portion on the aryl group is arbitrary); and Examples thereof include arylalkyl groups such as a benzyl group, a phenethyl group, and a phenylpropyl group (the alkyl portion of these arylalkyl groups may be linear or branched, and the substitution position of the aryl portion is arbitrary). Among those listed as specific examples of R ¹² and R ¹³ , an alkyl group having 3 to 18 carbon atoms derived from propylene or isobutene; an aryl group having 6 to 8 carbon atoms; an alkylaryl group having 7 to 8 carbon atoms; Alternatively, an arylalkyl group having 7 to 8 carbon atoms is preferable. Examples of these groups include an isopropyl group, a branched hexyl group derived from a propylene dimer, a branched nonyl group derived from a propylene trimer,
A branched dodecyl group derived from a propylene tetramer, a branched pentadecyl group derived from a propylene pentamer,
Branched octadecyl group derived from propylene hexamer, tert-butyl group, branched octyl group derived from isobutene dimer, branched dodecyl group derived from isobutene trimer, tetrabutane isobutene group An alkyl group such as a branched hexadecyl group derived from the body (these alkyl groups include all branched isomers); a propenyl group,
Alkenyl group such as butenyl group; alkylaryl group such as phenyl group, tolyl group, ethylphenyl group, xylyl group (the alkyl moiety of these alkylaryl groups may be linear or branched, and the substitution position of the alkyl moiety on the aryl group) Is arbitrary.); And an arylalkyl group such as a benzyl group and a phenylethyl group (the substitution position of the phenyl group is arbitrary). Of these, C3 to C1 derived from propylene or isobutene
Particularly preferred are 8 and especially 6 to 15 alkyl groups. Specific examples of the dihydrocarbyl polysulfide represented by the above formula (7) include dimethylpolysulfide such as dimethylmonosulfide and dimethyldisulfide; diethylpolysulfide such as diethylmonosulfide and diethyldisulfide; di-n-propylmonosulfide and din-propylmonosulfide. di-n-propyl polysulfide such as n-propyl disulfide; diisopropyl monosulfide, diisopropyl polysulfide such as diisopropyl disulfide; di-n-butyl monosulfide,
Di-n-butyl polysulfide such as di-n-butyl disulfide; Diisobutyl polysulfide such as diisobutyl monosulfide and diisobutyl disulfide; Disec-butyl polysulfide such as disec-butyl monosulfide and disec-butyl disulfide; Di tert-butyl monosulfide, diter
Di-tert-butyl polysulfide such as t-butyl disulfide; di (linear or branched pentyl) monosulfide, di (linear or branched pentyl) disulfide such as di (linear or branched pentyl) disulfide; di (Straight or branched hexyl) monosulfide,
Di (linear or branched hexyl) disulfide or other di (linear or branched hexyl) polysulfide; Dicyclohexyl monosulfide, dicyclohexyl disulfide or other dicyclohexyl polysulfide; Di (linear or branched heptyl) monosulfide, di ( Di (linear or branched heptyl) polysulfides such as linear or branched heptyl) disulfide; ditert-octylpolysulfides such as ditert-octylmonosulfide, ditert-octyldisulfide;
Di (linear or branched octyl) monosulfide, di (linear or branched octyl) disulfide, etc., di (linear or branched octyl) polysulfide; di (linear or branched nonyl) monosulfide, di ( Di (linear or branched nonyl) polysulfide such as linear or branched nonyl) disulfide; di (linear or branched decyl) monosulfide, di (direct or branched decyl) disulfide, etc. Chain (branched or branched decyl) polysulfide; di (straight or branched undecyl) monosulfide, di (straight or branched undecyl) disulfide, or other di (straight or branched undecyl) polysulfide;
Di tert-dodecyl monosulfide, di tert-
Di-tert-dodecyl polysulfide such as dodecyl disulfide; di (linear or branched dodecyl) monosulfide, di (linear or branched dodecyl) disulfide such as di (linear or branched dodecyl) polysulfide; di (direct) Di (linear or branched tridecyl) polysulfides such as chain or branched tridecyl) monosulfide, di (linear or branched tridecyl) disulfide;
Di (linear or branched tetradecyl) monosulfide,
Di (linear or branched tetradecyl) disulfide or other di (linear or branched tetradecyl) polysulfide;
Di (linear or branched pentadecyl) monosulfide,
Di (linear or branched pentadecyl) disulfide, such as di (linear or branched pentadecyl) disulfide;
Di2-methylpentadecyl monosulfide, di2-methylpentadecyl disulfide, etc .; di2-methylpentadecyl polysulfide; ditert-hexadecyl monosulfide, ditert-hexadecyl disulfide, etc. Di (linear or branched hexadecyl) monosulfide, di (linear or branched hexadecyl) disulfide, etc. di (linear or branched hexadecyl) polysulfide; di (linear or branched heptadecyl) monosulfide, di Di (linear or branched heptadecyl) polysulfide such as (linear or branched heptadecyl) disulfide; di (linear or branched octadecyl) monosulfide, di (linear or branched octadecyl) disulfide such as di (linear or branched octadecyl) disulfide Straight chain or Branch octadecyl) polysulfide; di- (straight or branched nonadecyl) monosulfide, di (straight or branched nonadecyl) disulfide and di the (linear or branched nonadecyl) polysulfide;
Di (linear or branched icosyl) monosulfide, di (linear or branched icosyl) disulfide, etc. di (linear or branched icosyl) polysulfide; di (linear or branched henicosyl) monosulfide, di ( Di (linear or branched henicosyl) polysulfide such as linear or branched henicosyl) disulfide; Di (directly or branched docosyl) monosulfide, di (direct or branched docosyl) disulfide (Chain or branched docosyl) polysulfide; dipropenyl monosulfide such as dipropenyl monosulfide, dipropenyl disulfide; dibutenyl polysulfide such as dibutenyl monosulfide, dibutenyl disulfide; diphenyl such as diphenyl monosulfide, diphenyl disulfide Risarufaido; dinaphthyl sulfide, dinaphthyl polysulfide such as dinaphthyl distearate disulfide; ditolyl mono sulfide, ditolyl such ditolyl distearate disulfide polysulfides;
Diethylphenyl polysulfide such as diethylphenyl monosulfide, diethylphenyldisulfide; Dipropylphenylpolysulfide such as dipropylphenylmonosulfide, dipropylphenyldisulfide; Dibutylphenylpolysulfide such as dibutylphenylmonosulfide, dibutylphenyldisulfide; Dipentylphenyl Monosulfide,
Dipentylphenyl polysulfide such as dipentylphenyl disulfide; Dihexylphenyl monosulfide such as dihexylphenyl monosulfide, dihexylphenyl disulfide; Diheptylphenyl polysulfide such as diheptylphenyl monosulfide, Diheptylphenyl disulfide; Dioctylphenyl monosulfide, dioctylphenyl Dioctylphenyl polysulfide such as disulfide; Dinonylphenyl polysulfide such as dinonylphenyl monosulfide and dinonylphenyl disulfide; Didecylphenyl polysulfide such as didecylphenyl monosulfide and didecylphenyl disulfide;
Diundecylphenyl monosulfide, diundecylphenyl polysulfide such as diundecylphenyl disulfide; didodecylphenyl monosulfide,
Didodecyl phenyl polysulfide such as didodecyl phenyl disulfide; dixylyl monosulfide,
Dixylylpolysulfides such as dixylyldisulfide; Diethylmethylphenylpolysulfides such as diethylmethylphenylmonosulfide, diethylmethylphenyldisulfide; Di (diethylphenyl) such as di (diethylphenyl) monosulfide, di (diethylphenyl) disulfide Polysulfide; Di (dipropylphenyl) polysulfide such as di (dipropylphenyl) monosulfide, di (dipropylphenyl) disulfide; Di (dibutylphenyl) such as di (dibutylphenyl) monosulfide, di (dibutylphenyl) disulfide ) Polysulfide; dimethylnaphthylpolysulfide such as dimethylnaphthylmonosulfide, dimethylnaphthyldisulfide; diethylnaphthylmonosa Diethylnaphthyl polysulfides such as Fide and diethylnaphthyldisulfide; Dipropylnaphthylpolysulfides such as dipropylnaphthylmonosulfide and dipropylnaphthyldisulfide; Dibutylnaphthylpolysulfides such as dibutylnaphthyldisulfide and dibutylnaphthylpolysulfide; Dibenzylmonosulfide, Examples thereof include dibenzyl polysulfide such as dibenzyl disulfide; diphenethyl polysulfide such as diphenethyl monosulfide and diphenethyl disulfide; diphenylpropyl polysulfide such as diphenylpropyl monosulfide and diphenylpropyl disulfide, and a mixture thereof.

Another compound contained in the sulfides as the component (IV-1) is a diester polysulfide represented by the following general formula (8). R ¹⁴ OCO (CH ₂ ) _h S _j (CH ₂ ) _k COOR ¹⁵ (8) (8) In the formula, R ¹⁴ and R ¹⁵ may be the same or different and each has 2 to 20 carbon atoms, preferably 4 carbon atoms. In the straight-chain or branched alkyl group of -20, h and k may be the same or different, and each is 2-5, preferably 2, and j is 1-2, preferably 2. R ¹⁴ and R
Specific examples of ¹⁵ include ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, straight chain or branched pentyl group, straight chain or branched hexyl group. Group, straight chain or branched heptyl group, straight chain or branched octyl group, straight chain or branched nonyl group, straight chain or branched decyl group, straight chain or branched undecyl group, straight chain or branched dodecyl group, Straight-chain or branched tridecyl group, straight-chain or branched tetradecyl group, straight-chain or branched pentadecyl group, straight-chain or branched hexadecyl group, straight-chain or branched heptadecyl group, straight-chain or branched octadecyl group, straight-chain Alternatively, a branched nonadecyl group, a straight chain or branched icosyl group may be mentioned. Specific examples of the diester polysulfide represented by the formula (8) include:
_{C 4 H 9 OCO (CH 2} ) 2 S (CH 2) 2 COOC 4 H 9, C
₄ H ₉ OCO (CH ₂ ) ₂ S ₂ (CH ₂ ) ₂ COOC ₄ H ₉ , C ₅
H ₁₁ OCO (CH ₂ ) ₂ S (CH ₂ ) ₂ COOC ₅ H ₁₁ , C ₅
H ₁₁ OCO (CH ₂ ) ₂ S ₂ (CH ₂ ) ₂ COOC ₅ H ₁₁ , C
₆ H ₁₃ OCO (CH ₂ ) ₂ S (CH ₂ ) ₂ COOC ₆ H ₁₃ , C
₆ H ₁₃ OCO (CH ₂ ) ₂ S ₂ (CH ₂ ) ₂ COOC ₆ H ₁₃ ,
_{C 7 H 15 OCO (CH 2} ) 2 S (CH 2) 2 COOC 7 H 15,
C ₇ H ₁₅ OCO (CH ₂ ) ₂ S ₂ (CH ₂ ) ₂ COOC
₇ H ₁₅ , C ₈ H ₁₇ OCO (CH ₂ ) ₂ S (CH ₂ ) ₂ COOC
₈ H ₁₇ , C ₈ H ₁₇ OCO (CH ₂ ) ₂ S ₂ (CH ₂ ) ₂ COO
_{C 8 H 17, C 9 H} 19 OCO (CH 2) 2 S (CH 2) 2 COO
C ₉ H ₁₉ , C ₉ H ₁₉ OCO (CH ₂ ) ₂ S ₂ (CH ₂ ) ₂ CO
OC ₉ H ₁₉ , C ₁₀ H ₂₁ OCO (CH ₂ ) ₂ S (CH ₂ ) ₂ C
OOC ₁₀ H ₂₁ , C ₁₀ H ₂₁ OCO (CH ₂ ) ₂ S ₂ (CH ₂ )
₂ COOC ₁₀ H ₂₁ , C ₁₁ H ₂₃ OCO (CH ₂ ) ₂ S (C
H ₂ ) ₂ COOC ₁₁ H ₂₃ , C ₁₁ H ₂₃ OCO (CH ₂ ) ₂ S ₂
(CH ₂ ) ₂ COOC ₁₁ H ₂₃ , C ₁₂ H ₂₅ OCO (CH ₂ ) ₂
S (CH ₂ ) ₂ COOC ₁₂ H ₂₅ , C ₁₂ H ₂₅ OCO (C
H ₂ ) ₂ S ₂ (CH ₂ ) ₂ COOC ₁₂ H ₂₅ , C ₁₃ H ₂₇ OCO
(CH ₂ ) ₂ S (CH ₂ ) ₂ COOC ₁₃ H ₂₇ , C ₁₃ H ₂₇ OC
O (CH ₂ ) ₂ S ₂ (CH ₂ ) ₂ COOC ₁₃ H ₂₇ , C ₁₄ H ₂₉
OCO (CH ₂ ) ₂ S (CH ₂ ) ₂ COOC ₁₄ H ₂₉ , C ₁₄ H
₂₉ OCO (CH ₂ ) ₂ S ₂ (CH ₂ ) ₂ COOC ₁₄ H ₂₉ , C
₁₅ H ₃₁ OCO (CH ₂ ) ₂ S (CH ₂ ) ₂ COOC ₁₅ H ₃₁ ,
C ₁₅ H ₃₁ OCO (CH ₂ ) ₂ S ₂ (CH ₂ ) ₂ COOC ₁₅ H
₃₁ , C ₁₆ H ₃₃ OCO (CH ₂ ) ₂ S (CH ₂ ) ₂ COOC ₁₆
H ₃₃ , C ₁₆ H ₃₃ OCO (CH ₂ ) ₂ S ₂ (CH ₂ ) ₂ COO
C ₁₆ H ₃₃ , C ₁₇ H ₃₅ OCO (CH ₂ ) ₂ S (CH ₂ ) ₂ CO
OC ₁₇ H ₃₅ , C ₁₇ H ₃₅ OCO (CH ₂ ) ₂ S ₂ (CH ₂ ) ₂
COOC ₁₇ H ₃₅ , C ₁₈ H ₃₇ OCO (CH ₂ ) ₂ S (C
H ₂ ) ₂ COOC ₁₈ H ₃₇ , C ₁₈ H ₃₇ OCO (CH ₂ ) ₂ S ₂
(CH ₂ ) ₂ COOC ₁₈ H ₃₇ , C ₁₉ H ₃₉ OCO (CH ₂ ) ₂
S (CH ₂ ) ₂ COOC ₁₉ H ₃₉ , C ₁₉ H ₃₉ OCO (C
H ₂ ) ₂ S ₂ (CH ₂ ) ₂ COOC ₁₉ H ₃₉ , C ₂₀ H ₄₁ OCO
(CH ₂ ) ₂ S (CH ₂ ) ₂ COOC ₂₀ H ₄₁ , C ₂₀ H ₄₁ OC
_{O (CH 2) 2 S 2} (CH 2) 2 COOC 20 H 41 or a mixture thereof.

Still another compound contained in the sulfides as the component (IV-1) is a tetraester tetrasulfide represented by the following general formula (9). (R ¹⁶ SCH ₂ CH ₂ COOCH ₂ ) ₄ C (9) (9) In the formula, R ¹⁶ has 8 to 20 carbon atoms, preferably 12 to
13 represents a linear or branched alkyl group. Specific examples of R ¹⁶ include straight chain or branched octyl group, straight chain or branched nonyl group, straight chain or branched decyl group, straight chain or branched undecyl group, straight chain or branched dodecyl group, straight chain or Branched tridecyl group, straight chain or branched tetradecyl group,
Straight-chain or branched pentadecyl group, straight-chain or branched hexadecyl group, straight-chain or branched heptadecyl group, straight-chain or branched octadecyl group, straight-chain or branched nonadecyl group, straight-chain or branched icosyl group In particular, a straight chain or branched dodecyl group and a straight chain or branched tridecyl group are preferable. Specific examples of the tetraester tetrasulfide represented by the formula (9) include (C ₈ H ₁₇ SCH ₂ CH ₂
COOCH ₂ ) ₄ C, (C ₉ H ₁₉ SCH ₂ CH ₂ COOC
H ₂ ) ₄ C, (C ₁₀ H ₂₁ SCH ₂ CH ₂ COOCH ₂ ) ₄ C,
(C ₁₁ H ₂₃ SCH ₂ CH ₂ COOCH ₂ ) ₄ C, (C ₁₂ H ₂₅
SCH ₂ CH ₂ COOCH ₂ ) ₄ C, (C ₁₃ H ₂₇ SCH ₂ C
H ₂ COOCH ₂ ) ₄ C, (C ₁₄ H ₂₉ SCH ₂ CH ₂ COO
CH ₂ ) ₄ C, (C ₁₅ H ₃₁ SCH ₂ CH ₂ COOCH ₂ )
₄ C, (C ₁₆ H ₃₃ SCH ₂ CH ₂ COOCH ₂ ) ₄ C, (C
₁₇ H ₃₅ SCH ₂ CH ₂ COOCH ₂ ) ₄ C, (C ₁₈ H ₃₇ SC
H ₂ CH ₂ COOCH ₂ ) ₄ C, (C ₁₉ H ₃₉ SCH ₂ CH ₂ C
OOCH ₂ ) ₄ C, (C ₂₀ H ₄₁ SCH ₂ CH ₂ COOC
H ₂ ) ₄ C or mixtures thereof, especially (C _{12
H 25 SCH 2 CH 2 COOCH 2} ) 4 C is preferred.

One of the compounds included in the phosphite which is the component (IV-2) is represented by the following general formula (10). In _{^{(R 17 O) m -P- (}} OR 18) 3-m (10) (10) formula, R ¹⁷ is a linear or branched alkyl group having 4 to 20 carbon atoms, R ¹⁸ is phenyl Group or carbon number 1
An alkylphenyl group having an alkyl group of 20 to m
Indicates 0 to 3. Specific examples of R ¹⁷ include n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, linear or branched pentyl group, linear or branched hexyl group, linear or branched heptyl group, Straight chain or branched octyl group, straight chain or branched nonyl group, straight chain or branched decyl group, straight chain or branched undecyl group, straight chain or branched dodecyl group, straight chain or branched tridecyl group, straight chain Or a branched tetradecyl group, a straight chain or branched pentadecyl group,
A straight-chain or branched hexadecyl group, a straight-chain or branched heptadecyl group, a straight-chain or branched octadecyl group, a straight-chain or branched nonadecyl group, a straight-chain or branched icosyl group can be mentioned, and among them, 2-ethylhexyl is particularly preferable. Octyl groups such as groups and decyl groups are preferred. Specific examples of R ¹⁸ include
Phenyl group, methylphenyl group, dimethylphenyl group,
Ethylphenyl group, diethylphenyl group, n-propylphenyl group, di-n-propylphenyl group, isopropylphenyl group, diisopropylphenyl group, n-butylphenyl group, di-n-butylphenyl group, isobutylphenyl group, diisobutylphenyl group, sec-butylphenyl group, disec-butylphenyl group, tert-butylphenyl group, ditert-butylphenyl group, (straight chain or branched pentyl) phenyl group, di (straight chain or branched pentyl) phenyl group, ( Linear or branched hexyl) phenyl group, di (linear or branched hexyl) phenyl group,
(Straight or branched heptyl) phenyl group, di (straight or branched heptyl) phenyl group, (straight or branched octyl) phenyl group, di (straight or branched octyl) phenyl group, (straight or Branched nonyl) phenyl group, di (straight chain or branched nonyl) phenyl group, (straight chain or branched decyl) phenyl group, di (straight chain or branched decyl) phenyl group, (straight chain or branched undecyl) Phenyl group, di (linear or branched undecyl) phenyl group, (linear or branched dodecyl) phenyl group, di (linear or branched dodecyl) phenyl group, (linear or branched tridecyl) phenyl group, di (Straight or branched tridecyl) phenyl group,
Mention may be made of (straight or branched tetradecyl) phenyl groups, di (straight or branched tetradecyl) phenyl groups, (straight or branched pentadecyl) phenyl groups, di (straight or branched pentadecyl) phenyl groups. it can. (Linear or branched hexadecyl) phenyl group, di (linear or branched hexadecyl) phenyl group, (linear or branched heptadecyl) phenyl group, di (linear or branched heptadecyl) phenyl group, (linear or branched (Branched octadecyl) phenyl group, di (linear or branched octadecyl) phenyl group, (linear or branched nonadecyl) phenyl group, di (linear or branched nonadecyl) phenyl group, (linear or branched icosyl) Examples thereof include a phenyl group and a di (linear or branched icosyl) phenyl group, and among them, a phenyl group, a (linear or branched nonyl) phenyl group, and a di (linear or branched nonyl) phenyl group are preferable. Specific examples of the phosphite represented by the formula (10) include nonylphenyl-bis (dinonylphenyl) phosphite, tris (nonylphenyl) phosphite, 2-ethylhexyl-diphenylphosphite, decyl-diphenylphosphite. , Tridecyl phosphite, triphenyl phosphite or mixtures thereof.

The other compound included in the phosphite which is the component (IV-2) is represented by the following general formula (11). ((R ¹⁹ O) ₂ P (OPh)) ₂ C (CH ₃ ) ₂ (11) (11) In the formula, R ¹⁹ represents a straight-chain or branched alkyl group having 12 to 15 carbon atoms, Ph represents a phenyl group.
Specific examples of R ¹⁹ include a straight chain or branched dodecyl group, a straight chain or branched tridecyl group, a straight chain or branched tetradecyl group, and a straight chain or branched pentadecyl group.
Specific examples of the phosphite represented by the formula (11) include ((C ₁₂ H ₂₅ O) ₂ P (OPh)) ₂ C (CH ₃ ) ₂ ,
((C ₁₃ H ₂₇ O) ₂ P (OPh)) ₂ C (CH ₃ ) ₂ ,
((C ₁₄ H ₂₉ O) ₂ P (OPh)) ₂ C (CH ₃ ) ₂ ,
((C ₁₅ H ₃₁ O) ₂ P (OPh)) ₂ C (CH ₃ ) ₂ or mixtures thereof.

One of the compounds included in the dithiophosphates as the component (IV-3) is zinc dihydrocarbyl dithiophosphate represented by the following general formula (12).

Embedded image In formula (12), R ²⁰ , R ²¹ , R ²² and R ²³ may be the same or different and each have a linear or branched alkyl group having 2 to 18 carbon atoms, preferably 3 to 8 carbon atoms, or An aryl group having 6 to 24 carbon atoms is shown. R ²⁰ , R ²¹ , R ²²
Specific examples of R ²³ and R ²³ include ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s
ec-butyl group, tert-butyl group, straight chain or branched pentyl group, straight chain or branched hexyl group, straight chain or branched heptyl group, straight chain or branched octyl group, straight chain or branched nonyl group, Straight chain or branched decyl group, straight chain or branched undecyl group, straight chain or branched dodecyl group, straight chain or branched tridecyl group, straight chain or branched tetradecyl group,
Alkyl groups such as linear or branched pentadecyl groups, linear or branched hexadecyl groups, linear or branched heptadecyl groups, linear or branched octadecyl groups; and phenyl groups, ethylphenyl groups, propylphenyl groups, isopropylphenyl Group, butylphenyl group, pentylphenyl group, hexylphenyl group, heptylphenyl group, octylphenyl group, 2-ethylhexylphenyl group, nonylphenyl group, decylphenyl group, undecylphenyl group, dodecylphenyl group, tridecylphenyl group, Examples of the aryl group include a tetradecylphenyl group, a pentadecylphenyl group, a hexadecylphenyl group, a heptadecylphenyl group, and an octadecylphenyl group. (1
Specific examples of the zinc dihydrocarbyl dithiophosphate represented by the formula 2) include zinc diethyldithiophosphate, zinc di-n-propyldithiophosphate, zinc diisopropyldithiophosphate, zinc di-n-butyldithiophosphate, zinc diisobutyldithiophosphate, and disec. -Zinc butyldithiophosphate,
Zinc ditert-butyl dithiophosphate, zinc di (linear or branched pentyl) dithiophosphate, zinc di (linear or branched hexyl) dithiophosphate, zinc di (linear or branched heptyl) dithiophosphate, di (direct Chain or branched octyl) zinc dithiophosphate, zinc di (linear or branched nonyl) dithiophosphate, zinc di (linear or branched decyl) dithiophosphate, zinc di (linear or branched undecyl) dithiophosphate, di Zinc (straight or branched dodecyl) dithiophosphate, Zinc di (straight or branched tridecyl) dithiophosphate, Zinc di (straight or branched tetradecyl) dithiophosphate, Zinc di (straight or branched pentadecyl) dithiophosphate Zinc di (linear or branched hexadecyl) dithiophosphate, Zinc di (linear or branched octadecyl) dithiophosphate, diphenyldithio Phosphate zinc, diethyl phenyl zinc dithiophosphate, dipropyl phenyl zinc dithiophosphate, diisopropylphenyl zinc dithiophosphate, dibutyl phenyl zinc dithiophosphate, dipentyl phenyl zinc dithiophosphate, dihexyl phenyl zinc dithiophosphate,
Zinc diheptylphenyldithiophosphate, zinc dioctylphenyldithiophosphate, zinc di2-ethylhexylphenyldithiophosphate, zinc dinonylphenyldithiophosphate, zinc didecylphenyldithiophosphate, zinc diundecylphenyldithiophosphate, zinc didodecylphenyldithiophosphate, Zinc ditridecyl phenyldithiophosphate,
Mention may be made of zinc ditetradecylphenyldithiophosphate, zinc dipentadecylphenyldithiophosphate, zinc dihexadecylphenyldithiophosphate, zinc diheptadecylphenyldithiophosphate, zinc dioctadecylphenyldithiophosphate or mixtures thereof.

Another compound contained in the dithiophosphates as the component (IV-3) is dihydrocarbyl dithiophosphate represented by the following general formula (13).

Embedded image In the formula (10), R ²⁴ , R ²⁵ , R ²⁶ and R ²⁷ may be the same or different and each have a linear or branched alkyl group having 2 to 18 carbon atoms, preferably 3 to 8 carbon atoms, or an aryl group having 6 to 24 carbon atoms, a is S, shows the S-S or S-CH ₂ -S. Specific examples of R ²⁴ , R ²⁵ , R ²⁶ and R ²⁷ include ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, straight chain or branched chain. A branched pentyl group,
Straight chain or branched hexyl group, straight chain or branched heptyl group, straight chain or branched octyl group, straight chain or branched nonyl group, straight chain or branched decyl group, straight chain or branched undecyl group, straight chain Or a branched dodecyl group, a linear or branched tridecyl group, a linear or branched tetradecyl group, a linear or branched pentadecyl group, a linear or branched hexadecyl group,
Alkyl group such as linear or branched heptadecyl group, linear or branched octadecyl group; and phenyl group, ethylphenyl group, propylphenyl group, isopropylphenyl group, butylphenyl group, pentylphenyl group, hexylphenyl group, heptylphenyl group Group, octylphenyl group, 2-ethylhexylphenyl group, nonylphenyl group, decylphenyl group, undecylphenyl group, dodecylphenyl group, tridecylphenyl group, tetradecylphenyl group, pentadecylphenyl group, hexadecylphenyl group, hepta There are aryl groups such as decylphenyl group and octadecylphenyl group.

One of the compounds contained in the dithiocarbamate which is the component (IV-4) is zinc dihydrocarbyl dithiocarbamate represented by the following general formula (14).

Embedded image In the formula (14), R ²⁸ , R ²⁹ , R ³⁰ and R ³¹ may be the same or different and each have a linear or branched alkyl group having 2 to 18 carbon atoms, preferably 3 to 8 carbon atoms, or An aryl group having 6 to 24 carbon atoms is shown. R ²⁸ , R ²⁹ , R ³⁰
And specific examples of R ³¹ include ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s
ec-butyl group, tert-butyl group, straight chain or branched pentyl group, straight chain or branched hexyl group, straight chain or branched heptyl group, straight chain or branched octyl group, straight chain or branched nonyl group, Straight chain or branched decyl group, straight chain or branched undecyl group, straight chain or branched dodecyl group, straight chain or branched tridecyl group, straight chain or branched tetradecyl group,
Alkyl groups such as linear or branched pentadecyl groups, linear or branched hexadecyl groups, linear or branched heptadecyl groups, linear or branched octadecyl groups; and phenyl groups, ethylphenyl groups, propylphenyl groups, isopropylphenyl Group, butylphenyl group, pentylphenyl group, hexylphenyl group, heptylphenyl group, octylphenyl group, 2-ethylhexylphenyl group, nonylphenyl group, decylphenyl group, undecylphenyl group, dodecylphenyl group, tridecylphenyl group, There are aryl groups such as tetradecylphenyl group, pentadecylphenyl group, hexadecylphenyl group, heptadecylphenyl group and octadecylphenyl group. Specific examples of the zinc dihydrocarbyl dithiocarbamate represented by the formula (14) include zinc diethyldithiocarbamate and din.
-Zinc propyldithiocarbamate, zinc diisopropyldithiocarbamate, zinc di-n-butyldithiocarbamate, zinc diisobutyldithiocarbamate, dise
zinc c-butyldithiocarbamate, zinc ditert-butyldithiocarbamate, zinc di (linear or branched pentyl) dithiocarbamate, di (linear or branched hexyl) zinc dithiocarbamate, di (linear or branched heptyl) Zinc dithiocarbamate, Zinc di (linear or branched octyl) dithiocarbamate, Zinc di (linear or branched nonyl) dithiocarbamate, Zinc di (linear or branched decyl) dithiocarbamate, Di (linear or branched) Undecyl) zinc dithiocarbamate, zinc di (linear or branched dodecyl) dithiocarbamate, zinc di (linear or branched tridecyl) dithiocarbamate, zinc di (linear or branched tetradecyl) dithiocarbamate,
Zinc di (linear or branched pentadecyl) dithiocarbamate, Zinc di (linear or branched hexadecyl) dithiocarbamate, Zinc di (linear or branched heptadecyl) dithiocarbamate, Di (linear or branched octadecyl)
Zinc dithiocarbamate, zinc diphenyldithiocarbamate, zinc diethylphenyldithiocarbamate, zinc dipropylphenyldithiocarbamate, zinc diisopropylphenyldithiocarbamate, zinc dibutylphenyldithiocarbamate, zinc dipentylphenyldithiocarbamate, zinc dihexylphenyldithiocarbamate, diheptylphenyldithiocarbamine Zinc acid, zinc dioctylphenyldithiocarbamate, di-2
-Zinc ethylhexylphenyldithiocarbamate, zinc dinonylphenyldithiocarbamate, zinc didecylphenyldithiocarbamate, zinc diundecylphenyldithiocarbamate, zinc didodecylphenyldithiocarbamate, zinc ditridecylphenyldithiocarbamate, zinc ditetradecylphenyldithiocarbamate, Zinc dipentadecylphenyldithiocarbamate,
Mention may be made of zinc dihexadecylphenyldithiocarbamate, zinc diheptadecylphenyldithiocarbamate, zinc dioctadecylphenyldithiocarbamate or mixtures thereof.

Another one of the compounds contained in the dithiocarbamate which is the component (IV-4) is dihydrocarbyl dithiocarbamate represented by the following general formula (15).

Embedded image In the formula (15), R ³² , R ³³ , R ³⁴ and R ³⁵ may be the same or different and each have a linear or branched alkyl group having 2 to 18 carbon atoms, preferably 3 to 8 carbon atoms, or an aryl group having 6 to 24 carbon atoms, B is S, shows the S-S or S-CH ₂ -S. Specific examples of R ³² , R ³³ , R ³⁴ and R ³⁵ include ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, straight chain or A branched pentyl group,
Straight chain or branched hexyl group, straight chain or branched heptyl group, straight chain or branched octyl group, straight chain or branched nonyl group, straight chain or branched decyl group, straight chain or branched undecyl group, straight chain Or a branched dodecyl group, a linear or branched tridecyl group, a linear or branched tetradecyl group, a linear or branched pentadecyl group, a linear or branched hexadecyl group,
Alkyl group such as linear or branched heptadecyl group, linear or branched octadecyl group; and phenyl group, ethylphenyl group, propylphenyl group, isopropylphenyl group, butylphenyl group, pentylphenyl group, hexylphenyl group, heptylphenyl group Group, octylphenyl group, 2-ethylhexylphenyl group, nonylphenyl group, decylphenyl group, undecylphenyl group, dodecylphenyl group, tridecylphenyl group, tetradecylphenyl group, pentadecylphenyl group, hexadecylphenyl group, hepta There are aryl groups such as decylphenyl group and octadecylphenyl group.

The content of the component [IV] in the lubricating oil composition of the present invention is 0.1% by mass, preferably 0.2% by mass, based on the total amount of the lubricating oil composition, while
The upper limit is 5.0% by mass, preferably 2.0% by mass. If the content of the [IV] component is less than 0.1% by mass based on the total amount of the lubricating oil composition, the effect of adding the [IV] component is insufficient, while if it exceeds 5.0% by mass, it is economical. It is not preferable because it is disadvantageous.

The lubricating oil composition of the present invention has an excellent antioxidative effect as it is, but for the purpose of further enhancing its various performances, known lubricating oil additives may be used alone or in combination of several kinds. It can be used in different forms. Specific examples of these known additives include phenol-based, amine-based, sulfur-based, zinc dithiophosphate-based, phenothiazine-based antioxidants; alkenyl succinic acid, alkenyl succinic acid ester, polyhydric alcohol ester, etc. , Petroleum sulfonate, dinonylnaphthalene sulfonate, etc. rust inhibitor; Phosphate ester, sulfurized oil, sulfide, anti-wear agent such as zinc dithiophosphate, extreme pressure agent; Aliphatic alcohol, fatty acid, aliphatic amine, aliphatic amine Friction reducing agents such as salts and fatty acid amides;
Metal-based detergents such as alkaline earth metal sulfonates, alkaline earth metal phenates, alkaline earth metal salicylates, alkaline earth metal phosphonates; ashless dispersants such as succinimides, succinic acid esters and benzylamines; methyl silicone, fluoro Antifoaming agent such as silicone; viscosity index improver such as polymethacrylate, polyisobutylene, olefin copolymer, polystyrene,
Examples include pour point depressants. The amount of these additives added is arbitrary, but normally the content of the defoaming agent is 0.0005 to 1% by weight, and the content of the viscosity index improver is 1 to 30% by weight based on the total amount of the lubricating oil composition. %, The content of metal deactivator is 0.005 to 1% by weight, and the content of other additives is 0.1 to 15% by weight, respectively. The lubricating oil composition of the present invention is particularly preferably used as a turbine oil, but in addition, engine oil such as gasoline engine oil and diesel engine oil; automotive gear oil (automatic transmission oil, manual transmission oil, differential) Oil) and gear oils such as industrial gear oils; hydraulic oils; compressor oils; refrigerating machine oils; cutting oils, plastic working oils (rolling oil, press oil, forging oil, drawing oil, drawing oil, punching oil, etc.), It is also preferably used in various lubricating oils such as metal working oils such as heat treatment oils and electric discharge machining oils; sliding guide surface oils; bearing oils; rust preventive oils; heat carrier oils.

[0029]

EXAMPLES The contents of the present invention will be described more specifically below with reference to Examples and Comparative Examples, but the present invention is not limited to these. Examples 1 to 9 and Comparative Examples 1 to 6 Lubricating oil compositions according to the present invention were prepared according to the compositions shown in Table 1. For comparison, when the [II] component is not used (Comparative Examples 1 and 2), the [III] component is not used (Comparative Examples 3 and 4), and the [IV] component is not used (Comparative Example 5). Regarding 6) and 6), each lubricating oil composition was prepared with the composition shown in Table 2. The components used for the preparation of each lubricating oil composition are as follows. [I] Component A: Solvent-refined paraffinic mineral oil having a kinematic viscosity at 40 ° C. of 32 mm ² / s and a total aromatic content of 25% by mass B: Kinematic viscosity at 40 ° C. of 32 mm ² / s, a total aromatic content 5% by mass of hydrocracked and refined paraffinic mineral oil C: 1-decene oligomer hydride having a number average molecular weight of 480 (kinematic viscosity 31 mm ² / s (@ 40 ° C.)) [II] Component D:

Embedded image E:

Embedded image Component [III] : F: 2-octyldithio-5-mercapto-1,3,4
-Thiadiazole G: benzotriazole H: dioctylaminomethylbenzotriazole I: dioctylaminomethyltolyltriazole J: 2-octyldithio-benzothiazole [IV] component : K: dilauryl thiodipropionate (dilauryl thiodipropionate) L : Diphenyloctyl phosphite (diphenyloctyl phosphite) M: zinc dioctyldithiophosphate N: zinc dipentyldithiocarbamate For each prepared lubricating oil composition, JIS K 25
14 Lubricating oil oxidation stability test (oxidation stability test I) specified in 3.1 and Rotating cylinder type oxidation stability test (oxidation stability test specified in JIS K 25143.3)
II) was performed and the time from the start of the test to the end was measured. In the oxidation stability tests I and II, the test temperature was 150 ° C. In the oxidation stability test I, the test was conducted under air blowing conditions, and in the oxidation stability test II, pure oxygen was added to 6.
The test was carried out by pressurizing and sealing to 3 kgf / cm ² . In the oxidation stability test I, the end point was when the total acid value of the sample oil reached 2 mgKOH / g. Table 1 shows the test results of the lubricating oil compositions of the examples, and Table 2 shows the test results of the lubricating oil compositions of the comparative examples.

[0030]

[Table 1]

[0031]

[Table 2]

As is clear from the comparison between Tables 1 and 2, the compositions of Examples 1 to 9 according to the present invention were tested under two kinds of oxidation tests under different test conditions.
It shows very good oxidative stability. In particular, the compositions of Examples 2 and 3 using the particular base oil as the base oil are superior to the composition of Example 1. On the other hand, [II]
The compositions of Comparative Examples 1 and 2 which did not use any component were significantly inferior in oxidation stability in any oxidation test. In addition, the compositions of Comparative Examples 3 and 4 not using the [III] component and the compositions of Comparative Examples 5 and 6 not using the [IV] component exhibited better oxidative stability than the compositions of Comparative Examples 1 and 2. Although shown, it is inferior in oxidative stability to the compositions of Examples containing all the components [I] to [IV]. As described above, the effect of using the components [I], [II], [III] and [IV] together is clear.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location C10M 129: 76 133: 44 135: 36 135: 20 135: 18 137: 02 137: 10) C10N 20:02 30 : 08 30:10 (72) Inventor Toshio Yoshida 8 Chidori-cho, Naka-ku, Yokohama City Central Research Institute of Japan Petroleum Corporation

Claims (2)

[Claims] 1. [I] a lubricating base oil and, based on the total amount of the composition, [II] 3-methyl-represented by the following general formula (1):
5-tert-butyl-4-hydroxyphenyl group-substituted fatty acid ester, 0.1-5% by mass, [In the formula (1), R ¹ represents an alkylene group having 1 to 6 carbon atoms, and R ² represents an alkyl group or alkenyl group having 1 to 24 carbon atoms. [III] One or more nitrogen-containing compounds selected from the following (III-1) to (III-3), 0.001 to 1 mass%, (III-1) thiadiazole, (III -2) Benzotriazole and / or its derivative (III-3) Benzothiazole and [IV] one or more compounds selected from the following (IV-1) to (IV-4); 1 to 5 mass% (IV-1) sulfides, (IV-2) phosphites, (I
A lubricating oil composition comprising V-3) dithiophosphates and (IV-4) dithiocarbamates. 2. A lubricating base oil of component [I] has the following (I-
The lubricating oil composition according to claim 1, which is one or more lubricating base oils selected from the components 1) to (I-3). (I-1) The kinematic viscosity at 40 ° C. is 5 to 200 mm ² / s,
And a mineral oil having a total aromatic content of 15% by weight or less (I-2) a polymer of an olefin having 2 to 16 carbon atoms or a hydride thereof and having a number average molecular weight of 250 to 4000 (I-3) 1 to 4 alkyl groups having 1 to 40 carbon atoms,
And an alkylbenzene whose alkyl group has a total carbon number of 6 to 40