JPH09183991A - Lubricating oil composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a lubricating oil compsn. which is excellent in oxidation resistance and prevention of sludge formation and has oxidation resistance not degraded even when long used at high temps. by compounding a lube base oil with a specific fatty acid ester and a specific phenol compd. in a specified ratio. SOLUTION: This compsn. is prepd. by compounding a lube base oil with 0.1-5.0 mass % (based on the compsn.; the same applies hereunder) 3-methyl-5- tert-butyl-4-hydroxyphenyl-substd. fatty acid ester represented by formula I (wherein R<1> is 1-6C alkylene; and R<2> is 1-24C alkyl, etc.) and 0.1-5.0 mass % at least one phenol compd. selected from among phenol compds. represented by formulas II and III. In formula II, R<3> is 1-4C alkyl, a group represented by formula IV (wherein R<4> is 1-6C alkylene; and R<5> is 1-24C alkyl), etc. In formula I, R<7> and R<8> are each independently 1-6C alkylene; and X is 1-18C alkylene, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating oil composition, and more particularly to a lubricating oil composition having excellent oxidation stability at high temperatures and sludge formation preventing property.

[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 a lubricating oil having equivalent or higher performance as an alternative to 2,6-di-tert-butyl-p-cresol, and as a result, specific When a specific amount of 3-methyl-5-tert-butyl-4-hydroxyphenyl-substituted fatty acid ester is contained in a base oil composed of a mineral oil having a property and / or a synthetic oil having a specific structure, 2,6- It has the same or higher level of anti-oxidation properties and sludge formation-preventing properties as those containing di-tert-butyl-p-cresol, and that the anti-oxidation properties do not deteriorate even after long-term use under high temperature conditions. It was found that a lubricating oil composition having excellent performance was obtained, and a patent application was previously filed (Japanese Patent Application No. 6-330).
532).

[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 and sludge formation prevention properties.
Therefore, as a result of further studies, the present inventors have found that when a 3-methyl-5-tert-butyl-4-hydroxyphenyl-substituted fatty acid ester and a phenol compound having a specific structure are used in a specific amount, both are independently used. It was found that a lubricating oil composition having higher antioxidative properties and sludge formation-preventing properties can be obtained as compared with the case of using,
The present invention has been completed. An object of the present invention is to provide a lubricating oil composition which has excellent antioxidant properties and sludge generation inhibiting properties, and whose antioxidant properties do not deteriorate even when used under high temperature conditions for a long time.

[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)
tert-butyl-4-hydroxyphenyl group-substituted fatty acid ester is 0.1 to 5.0% by mass,

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] 0.1 to 5.0% by mass of one or more phenol compounds selected from the compounds represented by the following general formula (2) or (3)

[Chemical 6] [In the formula (2), R ³ represents an alkyl group having 1 to 4 carbon atoms, a group represented by the following general formula (a), or a group represented by the following general formula (b). ] (In the formula (a), R ⁴ represents an alkylene group having 1 to 6 carbon atoms, and R ⁵ represents an alkyl group or alkylene group having 1 to 24 carbon atoms)

Embedded image (In the formula (b), R ⁶ represents an alkylene group having 1 to ⁶ carbon atoms)
Is shown. ]

Embedded image [In the formula (3), R ⁷ and R ⁸ each independently represent an alkylene group having 1 to 6 carbon atoms, and X represents an alkylene group having 1 to 18 carbon atoms or a group represented by the following general formula (c). Shown respectively. ^{] -R 9 -S-R 10 -} ( in formula (c), R ⁹ and R ¹⁰ independently represents an alkylene group having 1 to 6 carbon atoms) (c), characterized in that blended.

[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-ethylhexano) Ate, pentaerythritol pelargonate, etc.), polyoxyalkylene glycol, dialkyldiphenyl 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 viscosity of the lubricating base oil used in the present invention is arbitrary, but normally the viscosity at 40 ° C. is 1 to 1000.
those mm ² / s are preferably used, those 5~800mm ² / s are more preferably used.

However, as the lubricating base oil of the component [I], 3-methyl-5-tert- which is the component [II] is particularly preferable.
One or two or more selected from the following components (A) to (C) from the viewpoint of excellent synergistic effect on the antioxidant property and the sludge formation preventive property with the butyl-4-hydroxyphenyl group-substituted fatty acid ester. It is preferred to use a base oil. (A) Mineral oil having a kinematic viscosity at 40 ° C. of 5 to 250 mm ² / s and a total aromatic content of 15% by mass or less (B) A polymer of olefin having 2 to 16 carbon atoms or a hydride thereof And having a number average molecular weight of 250 to 4000 (C) 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

The above component (A) has a kinematic viscosity at 40 ° C. of 5
~200mm a ² / s, and total aromatic content of 15 mass% of mineral oil. The lower limit of kinematic viscosity of component (A) 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, preferably It is 100 mm ² / s. 4 of mineral oil which is (A) ingredient
If the kinematic viscosity at 0 ° C. is less than 5 mm ² / s, the oil film may not be sufficiently formed, resulting in poor lubricity, and the evaporation loss of the base oil may increase under high temperature conditions. on the other hand,
When the kinematic viscosity of the component (A) at 40 ° C. exceeds 200 mm ² / s, the fluid resistance increases, and the frictional resistance at the lubricated portion may increase. The component (A) also has an upper limit of the total aromatic content of 15% by mass, preferably 1
It is important that it is 0% by weight, more preferably 7% by weight. When the total aromatic content exceeds 15% by mass,
There is a possibility that the synergistic effect of the component (A) and the component [II] may not be obtained so much that the excellent antioxidant property and sludge generation preventive property may not be exhibited. The lower limit value of the total aromatic content in the component (A) is not particularly limited, but when the total aromatic content is 0% by mass or more and less than 2% by mass, the total amount of aromatic compounds in the lubricating oil composition is Since the solubility of the generated sludge tends to be poor, the total aromatic content in the component (A) is preferably 2% by mass or more. The term "total aromatic content" as used in the present invention means "Standard Test Method for Separation of Represion" specified in ASTM D 2549.
sentative Aromatics and Nonaromatics Fractions of H
igh-Boiling Oils by Elution Chromatography ”means the aromatics fraction content measured in accordance with“ igh-Boiling Oils by Elution Chromatography ”. Usually, this aromatic fraction contains alkylbenzene, alkylnaphthalene, anthracene, phenanthrene, and These include alkylated compounds, compounds in which four or more benzene rings are condensed, or compounds having a heteroaromatic group such as pyridines, quinolines, phenols and naphthols, etc. Component (A) having the above properties ( Mineral oil) can be produced by any known method, for example, distillate oil obtained by atmospheric distillation of paraffin-based crude oil and / or mixed base-based crude oil; paraffin-based crude oil and / or mixed oil. Distillate oil of vacuum distillation of base oil under atmospheric distillation (WVGO);
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 oil selected from among
Alternatively, it can be obtained by refining the lubricating oil fraction recovered from this raw oil by a conventional refining method. Even mineral oil obtained by a method other than the above,
Moreover, even if it is an arbitrary mixture of the mineral oils, these 40
These can be used as the component (A) of the present invention as long as the kinematic viscosity at 5 ° C is 5 to 200 mm ² / s and the total aromatic content is 15% by mass or less. The refining method for obtaining the component (A) is not particularly limited, and any refining method used in the production of the lubricating base oil can be adopted. For example, (1) hydrocracking, Hydrorefining such as hydrofinishing, (2) Solvent refining such as furfural solvent extraction, (3) Dewaxing such as solvent dewaxing or contact dewaxing, (4) White clay refining with acid clay or activated clay, (5) ) Chemical (acid / alkali) purification such as sulfuric acid cleaning, caustic soda cleaning, or the like can be performed alone, or two or more optional purification methods including the same or the same type of purification method can be performed in any order. When the component (A) is used alone as the base oil in the lubricating oil composition of the present invention, it is particularly preferable to use [II]
In terms of excellent synergistic effect with the fatty acid ester which is a component, the feedstock oil selected from the above ~ or the lubricating oil fraction recovered from this feedstock oil is hydrocracked to leave the product as it is, or from this Collect the lubricating oil fraction, then perform dewaxing treatment such as solvent dewaxing or contact dewaxing, and then carry out solvent refining treatment or after solvent refining treatment, such as solvent dewaxing or contact dewaxing. It is desirable that the mineral oil produced by performing the dewaxing treatment contains 50% by mass or more, more preferably 70% by mass or more, and particularly preferably 80% by mass or more based on the total amount of the component (A). The conditions for hydrocracking referred to here are arbitrary, but usually, in the presence of a hydrocracking catalyst, the total pressure is 6 to 25 MPa, the temperature is 350 to 500 ° C., and the LHSV is 0.1.
Under the reaction conditions such as ˜2.0 hr ⁻¹ , the hydrogenolysis conditions are adopted so that the decomposition rate is 40% by mass or more. Any hydrocracking catalyst may be used, for example, molybdenum, chromium, tungsten, vanadium, platinum, nickel, copper, iron, cobalt, oxides and / or sulfides thereof, or a mixture thereof. It is possible. 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 (B) of the present invention 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 referred to here is an olefin having 2 to 16 carbon atoms, preferably 2 to 12 carbon atoms, and is a so-called α-olefin having a double bond at the terminal, or a so-called internal olefin having the double bond inside. May be 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 (α-
Olefin, including internal olefin), linear or branched heptene (including α-olefin and internal olefin), linear or branched octene (including α-olefin and internal olefin), linear Linear or branched nonene (including α-olefins and internal olefins), linear or branched decene (including α-olefins and internal olefins), 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. The component (B) of the present invention 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 copolymers such as polymers, alternating copolymers and block copolymers. Further, the olefin homopolymer or copolymer usually contains a double bond, but the component (B) of the present invention has a double bond from the viewpoint of excellent heat / oxidation stability. Preference is given to using hydrogenated homopolymers or copolymers. In addition,
The olefin polymer of the component (B) may be produced by any method for producing a hydride, and is not limited in any way. In general, an organic peroxide catalyst such as benzoyl peroxide or a chlorinated compound can be produced by a thermal reaction without a catalyst. Friedel-Crafts type catalysts such as aluminum, aluminum chloride-polyhydric alcohol system, aluminum chloride-titanium tetrachloride system, aluminum chloride-alkyltin halide system, boron fluoride; organic aluminum chloride-titanium tetrachloride system, organic aluminum-4 system Ziegler type catalyst such as titanium chloride type; metallocene type catalyst such as aluminoxane-zirconocene type or ionic compound-zirconocene type; known catalyst such as aluminum chloride-base type or Lewis acid complex type catalyst such as boron fluoride-base type The system is used to homopolymerize or copolymerize the above olefins. Obtained by engaged. Further, a method for obtaining a hydrogenated product of an olefin polymer is also optional, for example, hydrogenating an olefin polymer with hydrogen in the presence of a known hydrogenation catalyst to saturate double bonds existing in the olefin polymer. Obtained by In addition, some catalysts can carry out the olefin polymerization and the hydrogenation of the double bond existing in the polymer in one step without going through the two steps of olefin polymerization and hydrogenation of the obtained polymer. . As the component (B) of the present invention, an ethylene-propylene copolymer, polybutene (butane-butene produced as a by-product during naphtha thermal decomposition) are used because of its excellent heat / oxidation stability, viscosity-temperature characteristics, and low-temperature fluidity. (Mixture of 1-butene, 2-butene and isobutene) Copolymer obtained by polymerization of fraction), 1-octene oligomer, 1-decene oligomer, 1-dodecene oligomer and hydrides thereof, and mixture 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. To be 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 (B) is 250, preferably 350, and the upper limit of the average molecular weight is 400.
It is 0, preferably 1500. Number average molecular weight is 250
If it is less than the above range, the lubricity may be deteriorated because the oil film is not sufficiently formed, and the evaporation loss of the base oil under high temperature conditions may be large. On the other hand, the number average molecular weight is 4000
If it exceeds, the fluid resistance increases, which may increase the frictional resistance at the lubrication point. The viscosity of the olefin polymer of component (B) or its hydride is not particularly limited, but the preferred kinematic viscosity is 5 at 40 ° C.
˜200 mm ² / s, more preferably 10 to 100 mm ² / s.

The component (C) 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. From the viewpoint of excellent stability and availability, it is preferable that the alkylbenzene has 1 to 4 alkyl groups having 1 to 40 carbon atoms, and the total number of carbon atoms of the alkyl groups is 12 to 40, Further, it has 1 to 4 alkyl groups having 1 to 30 carbon atoms, and the total number of carbon atoms of the alkyl groups is 15
More preferably, it is an alkylbenzene of -30. When the total number of carbon atoms in the alkyl group of the alkylbenzene is less than 6, the oil film formation is not sufficient, so that the lubricity may be poor, and the evaporation loss of the base oil under high temperature conditions may be large. On the other hand, when the total number of carbon atoms of the alkyl group exceeds 40, the fluid resistance increases, so that the friction resistance at the lubrication point may increase. Even if the alkyl group having 1 to 40 carbon atoms is linear,
It may be branched. Specifically, for example, a 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, direct A chain or branched hexyl group,
Straight-chain or branched heptyl group, straight-chain or branched octyl group, straight-chain or branched nonyl group, straight-chain or branched decyl group, straight-chain or branched Undecyl group, straight-chain or branched dodecyl group, straight-chain or branched tridecyl group, straight-chain or branched tetradecyl group, straight-chain or branched pentadecyl group, direct 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 -Like or branched pentacosyl groups, straight-chain or branched Sacosyl group, straight-chain or branched heptacosyl group, straight-chain or branched octacosyl group, straight-chain or branched nonacosyl group, straight-chain or branched triacontyl group, straight-chain Or a branched Hentriacontyl group, a linear or branched Dotriacontyl group, a linear or branched tritriacontyl group,
Straight chain or branched tetracontyl group, straight chain or branched pentacontyl group, straight chain or branched hexacontyl group, straight chain or branched heptacontyl group, straight chain or Examples thereof include a branched octacontyl group, a linear or branched nonacontyl group, and a linear or branched tetracontyl group. The alkyl group may be linear or branched, but a branched alkyl group is preferable from the viewpoint of viscosity-temperature characteristics and low temperature fluidity, and particularly from the viewpoint of availability, Branched alkyl groups derived from oligomers of olefins such as propylene, butene, isobutylene are more preferred. The number of alkyl groups in the alkylbenzene of the component (C) is 1 to 4, but the alkylbenzene having one or two alkyl groups is excellent in terms of heat and oxidation stability and availability. Alkylbenzenes, dialkylbenzenes, or mixtures thereof are most preferably used.
Needless to say, as the alkylbenzene as the component (C), not only alkylbenzene having a single structure but also 1 to 4 alkyl groups having 1 to 40 carbon atoms and the total number of carbon atoms of the alkyl groups is 6 A mixture of alkylbenzenes having different structures may be used as long as the alkylbenzenes satisfy the condition of being ~ 40. The viscosity of the alkylbenzene as the component (C) is not particularly limited, but the preferable kinematic viscosity is 5 to 200 mm ² / s at 40 ° C., more preferably 10
~ 100 mm ² / s. The method for producing the alkylbenzene as the component (C) is arbitrary and is not limited at all, but it can be generally produced by the following synthetic method. Specific examples of the aromatic compound as a raw material include benzene, toluene, xylene, ethylbenzene, methylethylbenzene, diethylbenzene, and mixtures thereof. Specific examples of the alkylating agent include lower monoolefins such as ethylene, propylene, butene, and isobutylene, preferably linear or branched olefins having 6 to 40 carbon atoms obtained by polymerization of propylene; A linear or branched olefin having 6 to 40 carbon atoms obtained by thermal decomposition of wax, heavy oil, petroleum fraction, polyethylene, polypropylene, etc .; n-paraffin is separated from petroleum fraction such as kerosene, light oil, etc. A linear olefin having 6 to 40 carbon atoms obtained by olefin conversion of the same with a catalyst; and a mixture thereof can be used. Further, as the alkylation catalyst in the alkylation, there are Friedel-Crafts type catalysts such as aluminum chloride and zinc chloride; sulfuric acid, phosphoric acid,
Known catalysts such as silicotungstic acid, hydrofluoric acid, and acid catalysts such as activated clay are used.

In the lubricating oil composition of the present invention, as the base oil of the component [I], the above-mentioned component (B) alone, the component (C) alone, or the component (B) and the component (C) are combined. When used in a mixture in an arbitrary ratio, it may be added at 40 ° C., if necessary, for the purpose of improving the swelling property of a member such as a rubber seal material used in a place where the lubricating oil composition of the present invention is used. Kinematic viscosity of 5 to 200 mm ² / s, preferably 10 to 100 mm ² / s
Less than 40% by weight, preferably 30% by weight, more preferably 20% by weight, based on the total amount of the component [I], other mineral oil base oils, ester base oils, ether base oils, and mixtures thereof. It is also possible to contain less than this. The mineral oil-based base oil here is not particularly limited in the total aromatic content, and a lubricating oil fraction obtained by atmospheric distillation and vacuum distillation of paraffin base crude oil or mixed base crude oil is hydrorefined. ,
Purification by solvent purification, dewaxing, white clay refining, chemical (acid / alkali) refining, etc. alone or in combination of two or more arbitrary refining methods including the same or the same refining method in any order, A mineral oil base oil such as a paraffin base oil or a naphthene base oil having an arbitrary total aromatic content can be used. However, when a mineral oil-based base oil is used, it is more preferable to use the component (A) of the present invention together, particularly in view of its excellent synergistic effect with the fatty acid ester of the component [II]. In addition, as the ester base oil mentioned here, specifically, for example, ditridecyl glutarate,
Diester oil represented by di-2-ethylhexyl adipate, diisodecyl adipate, ditridecyl adipate, di-3-ethylhexyl sebacate, trimethylolpropane tricaprylate, trimethylolpropane triperargonate, pentaerythritol tetra (2-ethyl) Hexanoate), pentaerythritol tetrapelargonate, and other polyol ester oils, and a mixture of two or more ester base oils selected from these. As the ether base oil, specifically, for example, polyglycol oil represented by polyoxyethylene glycol, polyoxypropylene glycol, polyoxyethyleneoxypropylene glycol, polyoxybutylene glycol, etc. Examples thereof include alkyl ether compounds, dialkyl ether compounds, diphenyl ethers, polyphenylene ethers, and a mixture of two or more ether base oils selected from these.

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

Embedded image In the above 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. The alkylene group having 1 to 6 carbon atoms represented by R ¹ may be linear or branched. 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 has 1 carbon atom because it can be produced in a reaction step in which the fatty acid ester of the component [II] is small.
~ 2 alkylene group, specifically, for example, a methylene group,
A methylmethylene group and an ethylene group (dimethylene group) are more preferable. The alkyl group or alkenyl group having 1 to 24 carbon atoms represented by R ² may be linear or branched. Examples of R ² include a methyl group, an 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, straight-chain Straight 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, linear 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, direct Alkyl group such as chain or branched docosyl group, straight chain or branched tricosyl group, straight chain or branched tetracosyl group; vinyl group, propenyl group, isopropenyl group, straight chain or Branched butenyl group, linear or branched pentenyl group, linear or branched hexenyl group, linear or branched heptenyl group, linear or branched octenyl group , Linear or branched Nyl 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, straight-chain Or a branched tetradecenyl group, a straight-chain or branched pentadecenyl group, a straight-chain or branched hexadecenyl group, a straight-chain or branched heptadecenyl group, a straight-chain or branched octadecenyl group Group, straight-chain or branched octadecadienyl group, straight-chain or branched nonadecenyl group, straight-chain or branched icosenyl group, straight-chain or branched henicosenyl group, direct And an alkenyl group such as a linear or branched docosenyl group, a linear or branched tricosenyl group, or a linear or branched tetracosenyl group. [I
Since the solubility of component I] in the lubricating base oil is excellent,
R ² is an alkyl group having 4 to 18 carbon atoms, specifically, for example, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, linear or branched pentyl group, direct 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 chain 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 An alkyl group such as a linear or branched pentadecyl group, a linear or branched hexadecyl group, a linear or branched heptadecyl group, a linear or branched octadecyl group, and the like. Among them, straight or branched chain having 6 to 12 carbon atoms More preferably alkyl group, carbon number 6
Particularly preferred are -12 branched alkyl groups. Especially [II]
As the component 3-methyl-5-tert-butyl-4-hydroxyphenyl group-substituted fatty acid ester, in the above formula (1), R ¹ is an alkylene group having 1 to ² carbon atoms and R ² is 6 to 6 carbon atoms. A straight-chain or branched alkyl group having 12 carbon atoms is more preferable, and in the formula (1), R ¹ is an alkylene group having 1 to 2 carbon atoms, and R ² is a branched alkyl group having 6 to 12 carbon atoms. Those which are alkyl groups are particularly preferred. As a matter of course, as the [II] component of the present invention, one compound represented by the formula (1) may be used alone, and two compounds represented by the formula (1) are further used. A mixture of the above compounds in an arbitrary mixing ratio may be used. Specific examples of the compound preferable as the component [II] in the present invention include (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. As an example, for example, (3-methyl-5-tert
-Butyl-4-hydroxyphenyl) propionic acid ester can be prepared by reacting 2-methyl-6-tert-butylphenol with methyl acrylate in the presence of a basic catalyst such as sodium metal (3-methyl-4-methylphenylacrylate). Methyl -5-tert-butyl-4-hydroxyphenyl) propionate can be obtained. In addition, this (3-methyl-5-tert-butyl-
By transesterifying methyl 4-hydroxyphenyl) propionate and another aliphatic alcohol having 2 to 24 carbon atoms, (3-methyl-5-tert-butyl-4-hydroxyphenyl) propionic acid and carbon number Two
It is possible to easily obtain an esterified product with an aliphatic alcohol of ~ 24. [II] in the lubricating oil composition of the present invention
The content of the component is based on the total amount of the lubricating oil composition, the lower limit of the content is 0.1% by mass, preferably 0.2% by mass, while the upper limit of the content is 5.0% by mass. %, Preferably 2.0% 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, [II]
The effect of improving the oxidative stability due to the inclusion of the components is not sufficient. On the other hand, when the upper limit value exceeds 5.0 mass% based on the total amount of the lubricating oil composition, the effect of improving the oxidative stability commensurate with the content cannot be obtained. It is economically disadvantageous and therefore not preferable.

The component [III] of the present invention is one or more phenol compounds selected from the compounds represented by the following general formula (2) or (3).

Embedded image [In the formula (2), R ³ represents an alkyl group having 1 to 4 carbon atoms, a group represented by the following general formula (a), or a group represented by the following general formula (b). ] (In the formula (a), R ⁴ represents an alkylene group having 1 to 6 carbon atoms, and R ⁵ represents an alkyl group or alkylene group having 1 to 24 carbon atoms)

Embedded image (In the formula (b), R ⁶ represents an alkylene group having 1 to ⁶ carbon atoms)
Is shown. ]

Embedded image [In the formula (3), R ⁷ and R ⁸ each independently represent an alkylene group having 1 to 6 carbon atoms, and X represents an alkylene group having 1 to 18 carbon atoms or a group represented by the following general formula (c). Shown respectively. ^{] -R 9 -S-R 10 -} (c) ( in formula (c), R ⁹ and R ¹⁰ represents a separate alkylene group having 1 to 6 carbon atoms) in the general formula (2) shows a R ³ Specific examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, and n.
-Propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group and the like can be mentioned, but a methyl group or an ethyl group is preferable from the viewpoint of excellent oxidation stability. Among the phenol compounds represented by the general formula (2), particularly preferable compounds when R ³ is an alkyl group having 1 to 4 carbon atoms are 2,6-di-tert-
Butyl-p-cresol, 2,6-di-tert-butyl-4-ethylphenol and mixtures thereof. When R ³ in the general formula (2) is a group represented by the formula (a), the alkylene group having 1 to 6 carbon atoms represented by R ⁴ in the formula (a) may be a straight chain or branched chain. The alkylene group represented by R ¹ may be any of the various alkylene groups described above. R ⁴ is an alkylene group having 1 to 2 carbon atoms, specifically, for example, a methylene group, a methylmethylene group, an ethylene group (a dimethylene group), in that the compound represented by the general formula (2) can be produced in a small number of reaction steps. And the like are more preferable. On the other hand, the alkyl group or alkenyl group having 1 to 24 carbon atoms represented by R ⁵ in the formula (a) may be linear or branched, and specifically, for example, the alkyl group or alkenyl represented by R ² Examples of the group include those exemplified above. R ⁵ is an alkyl group having 4 to 18 carbon atoms, specifically, for example, n-butyl group, isobutyl group, sec, since the compound represented by the general formula (2) has excellent solubility in the component [I].
-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 a branched tridecyl group, a linear or branched tetradecyl group, a linear or branched pentadecyl group, a linear or branched hexadecyl group, a linear or branched heptadecyl group And alkyl groups such as straight-chain or branched octadecyl groups are preferred, and among them, carbon numbers 6 to 1
A straight chain or branched alkyl group having 2 carbon atoms is more preferable, and a branched alkyl group having 6 to 12 carbon atoms is particularly preferable. In the phenol compound represented by the general formula (2), R ³ is (a)
When the compound represented by the formula is a compound represented by the formula (a), R ⁴ is an alkylene group having 1 to 2 carbon atoms, and R ⁵ is a linear or branched alkyl group having 6 to 12 carbon atoms. It is more preferable that R ^{4 in the} formula (a) has 1 to 2 carbon atoms.
Are particularly preferred, and R ⁵ is a branched alkyl group having 6 to 12 carbon atoms. More specifically, more preferable examples of the compound include (3,5-di-ter
t-Butyl-4-hydroxyphenyl) acetic acid n-hexyl, (3,5-di-tert-butyl-4-hydroxyphenyl) isohexyl acetate, (3,5-di-tert)
-Butyl-4-hydroxyphenyl) acetic acid n-heptyl, (3,5-di-tert-butyl-4-hydroxyphenyl) isoheptyl acetate, (3,5-di-tert)
-Butyl-4-hydroxyphenyl) n-octyl acetate, isooctyl (3,5-di-tert-butyl-4-hydroxyphenyl) acetate, (3,5-di-tert)
-Butyl-4-hydroxyphenyl) acetic acid 2-ethylhexyl, (3,5-di-tert-butyl-4-hydroxyphenyl) acetic acid n-nonyl, (3,5-di-ter)
t-Butyl-4-hydroxyphenyl) isononyl acetate, (3,5-di-tert-butyl-4-hydroxyphenyl) acetic acid n-decyl, (3,5-di-tert-)
Butyl-4-hydroxyphenyl) isodecyl acetate,
(3,5-Di-tert-butyl-4-hydroxyphenyl) acetic acid n-undecyl, (3,5-di-tert-
Butyl-4-hydroxyphenyl) isoundecyl acetate, (3,5-di-tert-butyl-4-hydroxyphenyl) acetic acid n-dodecyl, (3,5-di-tert)
-Butyl-4-hydroxyphenyl) isododecyl acetate, n-hexyl (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, (3,5-di-
tert-Butyl-4-hydroxyphenyl) isohexyl propionate, (3,5-di-tert-butyl-
4-hydroxyphenyl) n-heptyl propionate,
Isoheptyl (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, (3,5-di-te
rt-Butyl-4-hydroxyphenyl) n-octyl propionate, (3,5-di-tert-butyl-4-)
(Hydroxyphenyl) isooctyl propionate,
2-Ethylhexyl (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, n-nonyl (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, (3,5-di) -Tert-butyl-
4-hydroxyphenyl) isononyl propionate,
N-decyl (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, (3,5-di-ter
Isodecyl t-butyl-4-hydroxyphenyl) propionate, n-undecyl (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, (3,5-
5-di-tert-butyl-4-hydroxyphenyl)
Isoundecyl propionate, (3,5-di-tert
-Butyl-4-hydroxyphenyl) propionic acid n-
Dodecyl, isododecyl (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, mixtures thereof and the like. R ³ in the general formula (2)
Is a group represented by the formula (b), R in the formula (b) is
⁶ represents an alkylene group having 1 to ⁶ carbon atoms. The alkylene group may be linear or branched,
Specific examples include various alkylene groups exemplified for R ¹ . R ⁶ is an alkylene group having 1 to 3 carbon atoms, specifically, for example, a methylene group, a methylmethylene group, and ethylene, because the compound of the general formula (2) can be produced in a small number of reaction steps and the raw material thereof is easily available. More preferred are groups (dimethylene group), ethylmethylene group, propylene group (methylethylene group), trimethylene group and the like.
Among the phenol compounds represented by the general formula (2), R ³
Specific examples of preferred compounds in which is a group represented by the formula (b) include, for example, bis (3,5
-Di-tert-butyl-4-hydroxyphenyl) methane, 1,1-bis (3,5-di-tert-butyl-
4-hydroxyphenyl) ethane, 1,2-bis (3,3
5-di-tert-butyl-4-hydroxyphenyl)
Ethane, 1,1-bis (3,5-di-tert-butyl-4-hydroxyphenyl) propane, 1,2-bis (3,5-di-tert-butyl-4-hydroxyphenyl) propane, 1, 3-bis (3,5-di-tert
-Butyl-4-hydroxyphenyl) propane, 2,2
-Bis (3,5-di-tert-butyl-4-hydroxyphenyl) propane, mixtures thereof and the like.

On the other hand, in the above general formula (3), R ⁷
And the alkylene group having 1 to 6 carbon atoms which represents R ⁸ may be linear or branched, and specifically, R
^The various alkylene groups described above for ¹ may be mentioned. R ⁷ and R ⁸ are independently an alkylene group having 1 to 2 carbon atoms, specifically, for example, in that the compound of the general formula (3) can be produced in a small number of reaction steps and the raw materials thereof are easily available. A methylene group, a methylmethylene group, an ethylene group (dimethylene group) and the like are more preferable. Further, in the general formula (3), examples of the alkylene group having 1 to 18 carbon atoms and representing X include methylene group, methylmethylene group, ethylene group (dimethylene group), ethylmethylene group,
Propylene group (methylethylene group), trimethylene group,
Straight chain or branched butylene group, straight chain or branched pentylene group, straight chain or branched hexylene group, straight chain or branched heptylene group, straight chain or branched octylene group, straight chain or branched nonylene group, straight chain Or a branched decylene group, a linear or branched undecylene group, a linear or branched dodecylene group, a linear or branched tridecylene group, a linear or branched tetradecylene group, a linear or branched pentadecylene group, a linear or branched Examples thereof include a branched hexadecylene group, a straight-chain or branched heptadecylene group, and a straight-chain or branched octadecylene group, but from the viewpoint of easy availability of raw materials, separately, an alkylene group having 1 to 6 carbon atoms, specifically, for example, Methylene group, methylmethylene group, ethylene group (dimethylene group), ethylmethylene group, propylene group (methylethylene group), trimethylene group, straight chain or A branched butylene group, a linear or branched pentylene group, a linear or branched hexylene group and the like are more preferable, and an ethylene group (dimethylene group), trimethylene group, linear butylene group (tetramethylene group, linear pentylene group (penta A methylene group), a straight-chain hexylene group (hexamethylene group), and other straight-chain alkylene groups having 2 to 6 carbon atoms are particularly preferable, and among the phenol compounds represented by the general formula (3), X is 1-carbon atoms. As the compound having 18 alkylene groups, preferable compounds are represented by the following formula.

[13] When X in the general formula (3) is a group represented by the formula (c), the alkylene group having 1 to 6 carbon atoms represented by R ⁹ and R ¹⁰ in the formula (c) is a direct group. It may be chain-like or branched, and specific examples thereof include various alkylene groups described above for R ¹ . Since the raw materials for producing the compound of the general formula (3) are easily available, R ⁹ and R
¹⁰ is an alkylene group having 1 to 3 carbon atoms, such as methylene group, methylmethylene group, ethylene group (dimethylene group), ethylmethylene group, propylene group (methylethylene group), trimethylene group, etc. More preferable. Among the phenol compounds represented by the general formula (3), preferable compounds can be represented by the following formula when X is a group represented by the formula (c).

Embedded image Further, as a matter of course, as the component [III] of the present invention, one compound represented by the general formula (2) or (3) may be used alone, and further, the general formula ( A mixture of two or more compounds represented by 2) in any mixing ratio,
A mixture of two or more compounds represented by the general formula (3) at an arbitrary mixing ratio, one or more compounds represented by the general formula (2) and one or more compounds represented by the general formula (3). You may use the mixture etc. of the compound in arbitrary mixing ratios. The content of the [III] 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 the content is 5.0% by mass, preferably 2.0% by mass. [II
When the content of the component [I] is less than 0.1% by mass based on the total amount of the lubricating oil composition, the effect of improving the oxidation stability by the content of the component [III] is insufficient, while the upper limit is the total amount of the lubricating oil composition. If it exceeds 5.0 mass% based on the standard, it is economically disadvantageous because the effect of improving the oxidation stability commensurate with the content cannot be obtained, which is not preferable.

The lubricating oil composition of the present invention is excellent in sustaining effects of antioxidant property and sludge formation preventing property as it is, but a known lubricating oil additive is used alone for the purpose of further enhancing various performances thereof. It can be used in the form of or a combination of several kinds. Specific examples of these known additives include amine-based, sulfur-based, zinc dithiophosphate-based, phenothiazine-based antioxidants; alkenyl succinic acid, alkenyl succinic acid ester, polyhydric alcohol ester, petroleum sulfonate. Rust inhibitors such as dinonylnaphthalene sulfonate; anti-wear agents such as phosphates, sulfurized oils, sulfides, zinc dithiophosphates, extreme pressure agents; aliphatic alcohols, fatty acids, aliphatic amines, aliphatic amine salts, fatty acids Friction reducing agents such as amides; metal-based detergents such as alkaline earth metal sulfonates, alkaline earth metal phenates, alkaline earth metal salicylates, alkaline earth metal phosphonates; succinimides, succinates, benzylamine, etc. Ash dispersant; thiadiazole, zenzotriazo , Metal deactivators, such as benzothiazole or derivatives thereof; methyl silicone, antifoaming agents, such as fluorosilicone, polymethacrylate, polyisobutylene, olefin copolymer viscosity index improvers such as 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.

[0015]

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 4 Lubricating oil compositions according to the present invention were prepared with the compositions shown in Table 1 (Examples 1 to 9). For comparison, the lubricating oil composition was prepared according to the composition shown in Table 1 also when the component [II] was not used (Comparative Examples 1 and 2) and when the component [III] was not used (Comparative Examples 3 and 4). Prepared. The components used in Table 1 are shown below. [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: 2,6-di-tert-butylphenol

Embedded image G:

Embedded image H:

Embedded image I:

Embedded image J:

Embedded image Regarding the lubricating oil compositions of these Examples and Comparative Examples,
The performance evaluation test shown below was performed, and the results are also shown in Table 1. [Oxidation stability test I] A test temperature of 150 according to the lubricating oil oxidation stability test specified in JIS K 2514 3.1.
An oxidation test was carried out at 0 ° C., and the time until the total acid value of the sample oil reached 2 mgKOH / g was measured. [Oxidation stability test II] An oxidation test was performed in accordance with a rotary cylinder type oxidation stability test specified in JIS K 2514 3.3, and the time until the end point was reached was measured. The results are shown in Table 1.

[0016]

[Table 1]

As is clear from the results of the performance evaluation test of Table 1, the compositions of Examples 1 to 9 according to the present invention were extremely excellent in both of two kinds of oxidation stability tests under different test conditions. It shows oxidative stability. In particular, the results of Examples 2 to 9 using a specific base oil as the base oil are superior to the results of Example 1. On the other hand, [I
[I] component not used (Comparative Examples 1 and 2) and [I
When the component [II] is not used (Comparative Examples 3 and 4), the oxidation stability is inferior to the results of the Examples under any of the oxidation stability test conditions.

Embedded image

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[Procedure amendment]

[Submission date] March 25, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Name of invention

[Correction method] Change

[Correction contents]

Lubricating oil composition

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location C10M 107/02 C10M 107/02 141/08 141/08 // (C10M 129/00 129: 76 129: 10 129 : 14) (C10M 141/08 129: 76 135: 26) C10N 20:02 20:04 30:04 30:08 30:10 (72) Inventor Toshio Yoshida 8 Chidoricho, Naka-ku, Yokohama Japan Petroleum Stock Association Central Technology Research Institute

Claims (2)

[Claims] 1. [I] A 3-methyl-5-tert-butyl-4-hydroxyphenyl group represented by the following general formula (1) based on the total amount of the composition based on the lubricating base oil. 0.1 to 5.0% by mass of substituted fatty acid ester, [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] 0.1 to 5.0% by mass of one or more phenol compounds selected from the compounds represented by the following general formula (2) or (3): [In the formula (2), R ³ represents an alkyl group having 1 to 4 carbon atoms, a group represented by the following general formula (a), or a group represented by the following general formula (b). ] (In the formula (a), R ⁴ represents an alkylene group having 1 to 6 carbon atoms, and R ⁵ represents an alkyl group or alkylene group having 1 to 24 carbon atoms) (In the formula (b), R ⁶ represents an alkylene group having 1 to ⁶ carbon atoms)
Is shown. ] [In the formula (3), R ⁷ and R ⁸ each independently represent an alkylene group having 1 to 6 carbon atoms, and X represents an alkylene group having 1 to 18 carbon atoms or a group represented by the following general formula (c). Shown respectively. ^{] -R 9 -S-R 10 -} (c) ((c) wherein, R ⁹ and R ¹⁰ independently represents an alkylene group having 1 to 6 carbon atoms) lubricating oil composition characterized by being blended Stuff. 2. The lubricating base oil according to claim 1, wherein the lubricating base oil of the component (I) is one or more lubricating base oils selected from the following components (A) to (C). Oil composition. (A) a mineral oil having a kinematic viscosity of 5 to 200 mm ² / s at 40 ° C. and a total aromatic content of 15% by weight or less (B) an olefin polymer having 2 to 16 carbon atoms or a hydride thereof. And having a number average molecular weight of 250 to 4000 (C) 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