WO2004003117A1

WO2004003117A1 - Lubricating oil composition

Info

Publication number: WO2004003117A1
Application number: PCT/JP2003/008338
Authority: WO
Inventors: Kazuhiro Yagishita; Akira Yaguchi
Original assignee: Nippon Oil Corporation
Priority date: 2002-06-28
Filing date: 2003-06-30
Publication date: 2004-01-08
Also published as: EP1516910A1; CN1671827A; AU2003241824A1; CN100497560C; EP1516910A4

Abstract

A lubricating oil composition excellent in friction -reducing effect and long-drain performance (leading to a longer period of service) and particularly suitable for internal combustion engines, which comprises a lube base oil, a specific phosphorus compound in an amount of 0.005 to 0.5 % by mass based on the whole of the composition in terms of phosphorus, and at least one additive selected from the group consisting of (C) metallic detergents, (D) ashless dispersants, and (E) antioxidants, and further contains (F) a sulfur-containing organomolybdenum complex and (G) an ashless friction modifier and which satisfies prescribed requirements and has a sulfated ash content not exceeding a specified level.

Description

Description Lubricating oil composition

[Technical field]

The present invention relates to a lubricating oil composition, and more particularly, to a lubricating oil composition having excellent low-friction properties and improved long-drainability, particularly suitable for an internal combustion engine.

[Background technology]

Conventionally, lubricating oil has been used in internal combustion engines, automatic transmissions, and the like in order to facilitate their operation. In particular, lubricating oils for internal combustion engines (engine oils) are required to have high performance as internal combustion engines have higher performance, higher output, and severe operating conditions. For this reason, conventional engine oils contain various additives such as antiwear agents, metallic detergents, ashless dispersants, and antioxidants to meet these required performances. In addition, in fuel-efficient engine oils, the energy loss in the friction area involving the lubricating oil is large, so to reduce friction loss and reduce fuel consumption, organic molybdenum compounds containing sulfur such as molybdenum dicarbamate and molybdenum dithiophosphate are used. Has been used preferably because of its excellent friction reducing effect. In order to exhibit the effect of reducing friction, a technique of forming a molybdenum disulfide film on the sliding surface by using a large amount of a sulfur-containing compound such as zinc dithiophosphate has been generally used. Was. In addition, it is generally known that metal-based detergents such as salicylate-based detergents can exhibit a more effective friction reducing effect by increasing the content thereof. Therefore, low-friction lubricants such as conventional fuel-saving engine oils are known. Studies to reduce the metal content of oil (low ash) and to reduce the sulfur content have not been sufficiently conducted. Sulfur-containing compounds as described above have a remarkable effect of improving oxidative stability, but on the other hand, depletion of organic molybdenum compounds and metal-based detergents due to sulfuric acid generated by their own deterioration and decomposition. It has been found that there is a limit to maintaining the initial low friction performance for a long period of time. That is, the conventional technology has a limit in achieving excellent low friction properties, realizing low ash and low sulfur, and further improving the long drain property more than before. On the other hand, minimize the impact on recent exhaust gas purification catalysts (three-way catalysts, NOx storage reduction catalysts, oxidation catalysts) or exhaust gas aftertreatment devices such as exhaust gas recirculation devices (EGR) and diesel particulate filters (DP F). In order to reduce this, low ash and low sulfur lubricating oils as well as low phosphorus are required.

The present invention has been made in view of the above-mentioned demands, and provides a lubricating oil composition having both low friction properties and long drain properties (oxidation stability, base number maintenance properties, etc.) which is particularly suitable for an internal combustion engine. It is.

[Disclosure of the Invention]

The present inventors have conducted intensive studies on the above-mentioned problems, and as a result, completed the present invention.

That is, the present invention relates to a lubricant base oil comprising (A) a phosphorus compound represented by the general formula (1), a metal salt or an amine salt thereof, a phosphorus compound represented by the general formula (2), At least one phosphorus compound selected from the group consisting of a metal salt or an amine salt of (a) and (B) zinc dithiophosphate, in an amount of 0.005 to 0.5 mass in terms of phosphorus element, based on the total amount of the composition. A lubricating oil composition comprising at least one additive selected from the group consisting of (C) a metal detergent, (D) an ashless dispersant, and (E) an antioxidant. Further, the present invention relates to a lubricating oil composition having any one of the following requirements (I) to (IV).

1 1 3

R-X-P-X-R

(1)

(In the general formula (1), X ¹ , ² and ³ each independently represent an oxygen atom or a sulfur atom, and at least two of them are oxygen atoms, and RR ² and R ³ are And each represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms.) (2)

(In the general formula (2), X ⁴ , X ⁵ , X ⁶ and X ⁷ each independently represent an oxygen atom or a sulfur atom, and at least three of these are oxygen atoms;

Four

R ⁴ , R ⁵ and R ⁶ are each independently a hydrogen atom or a hydrocarbon having 1 to 30 carbon atoms xxpnl

Represents a group. ) 11 5.

^ R 5

Six

(I) As a phosphorus compound, the component (A) is contained as the main component of R, and the sulfated ash content of the composition

6

Is 0.8% by mass or less

(Π) As a phosphorus compound, the component (A) is contained as a main component, and (F) a sulfur-containing organic molybdenum complex is 0.001 in terms of molybdenum element based on the total amount of the composition.

~ 0.2% by mass, and the amount of sulfated ash in the composition is 1.2% by mass or less

(Π) It contains (A) component as a main component as a phosphorus compound, (G) it contains an ashless friction modifier, and the composition has a sulfated ash content of 1.2% by mass or less.

(IV) As a phosphorus compound, the component (B) is contained as a main component, and (G) An ashless friction modifier is contained. And, based on the total amount of the composition, the content of the component (B) is expressed in terms of the elemental phosphorus. 0.05 mass% or less, and the sulfated ash content of the composition is 1.2 mass% or less. In the present invention, the lubricating oil composition described above is brought into contact with a direct-acting type or a roller follower type valve operating mechanism. The present invention also relates to a lubrication method for an internal combustion engine having the valve mechanism. Hereinafter, the present invention will be described in detail.

The lubricating base oil in the lubricating oil composition of the present invention is not particularly limited, and mineral base oils and Z or synthetic base oils used for ordinary lubricating oils can be used.

As a mineral base oil, specifically, the atmospheric residual oil obtained by atmospheric distillation of crude oil is reduced. A lubricating oil fraction obtained by pressure distillation is refined by one or more treatments such as solvent removal, solvent extraction, hydrocracking, solvent dewaxing, hydrorefining, or mineralized wax oil. And base oils produced by a method of isomerizing GTL WAX (gas liquid wax).

The total aromatic content of the mineral base oil is not particularly limited, but is preferably 10% by mass or less, more preferably 6% by mass or less, further preferably 3% by mass or less, and particularly preferably 2% by mass or less. % Or less. If the total aromatic content of the base oil exceeds 15% by mass, the oxidation stability is poor, which is not preferable.

In addition, the above-mentioned total aromatic content means the content of an aromatic fraction (aromatic acid fracaction) measured according to ASTM D2549. Usually, this aromatic fraction contains, in addition to alkylbenzene and alkylnaphthalene, anthracene, phenanthrene, their alkylated compounds, compounds in which four or more benzene rings are condensed, or pyridines, quinolines, phenols, and naphthols And other compounds having heteroaromatics.

The sulfur content in the mineral base oil is not particularly limited, but is preferably 0.05% by mass or less, more preferably 0.01% by mass or less, and 0.005% by mass or less. It is particularly preferred that the content be 5% by mass or less. By reducing the sulfur content of the mineral oil base oil, it has better long drainage properties, and when used as a lubricating oil for internal combustion engines, low sulfur lubrication that can minimize adverse effects on exhaust gas post-treatment equipment An oil composition can be obtained.

Specific examples of the synthetic base oil include polybutene or its hydride; poly- _a- olefin such as 1-octene oligomer and 1-decene oligomer or its hydride; ditridecyl glutarate, and di-ethylethylhexylazir. Diesterols such as polyester, disodecyl adipate, ditridecyl adipate, and di-2-ethylhexyl sepate; neopentinole glycol ester, trimethylol propyl caprylate, trimethylol propaneperargonate, pentaerythritol Examples thereof include polyol esters such as 2-ethylhexanoate and pentaerythritol pelargonate; aromatic synthetic oils such as alkylnaphthalene, alkylbenzene, and aromatic ester, and mixtures thereof. In the present invention, the mineral base oil, the synthetic base oil, or an arbitrary mixture of two or more lubricating oils selected from these can be used. Examples thereof include one or more mineral base oils, one or more synthetic base oils, and a mixed oil of one or more mineral base oils and one or more synthetic base oils.

No particular limitation is imposed kinematic viscosity of the lubricating base oil, kinematic viscosity at its 1 00 ° C is preferably at most 20 m m ² / s, more preferably not more than 1 0 mm ² / s. On the other hand, the kinematic viscosity is preferably at least 1 mm ² / s, more preferably at least 2 mm ² / s. If the kinematic viscosity of the lubricating base oil at 100 ° C exceeds 20 mm ² / s, the low-temperature viscosity characteristics deteriorate, while if the kinematic viscosity is less than lmm ² Zs, the oil film at the lubricating point Insufficient formation results in poor lubricity, and large loss of evaporation of the lubricating base oil is undesirable.

The evaporation loss of the lubricating base oil is preferably 20% by mass or less, more preferably 16% by mass or less, particularly preferably 10% by mass or less, in terms of NOACK evaporation amount. preferable. When the NO ACK evaporation amount of the lubricating base oil exceeds 20% by mass, not only the lubricating oil evaporation loss is large, but also when the lubricating oil is used as a lubricating oil for internal combustion engines, the sulfur compounds and phosphorus compounds in the composition, Alternatively, it is not preferable because the metal component may accumulate in the exhaust gas purification device together with the lubricating base oil, which may adversely affect the exhaust gas purification performance. Note that the NO A CK evaporation amount referred to here, which has been measured according to ASTM D 5800, lubricating oil sample 60 g of 250 ° C, under a reduced pressure of _{20mm H 2 0 (1 96 P} a) The amount of evaporation was measured after holding for one hour.

The viscosity index of the lubricating base oil is not particularly limited, but the value is preferably 80 or more, and more preferably 100 or more, so that excellent viscosity characteristics from low to high temperatures can be obtained. Preferably it is 120 or more. When the viscosity index is less than 80, the low-temperature viscosity characteristics deteriorate, which is not preferable. The component (A) in the lubricating oil composition of the present invention includes a phosphorus compound represented by the general formula (1), a metal salt or an amine salt thereof, a phosphorus compound represented by the general formula (2), At least one phosphorus compound selected from the group consisting of metal salts or amine salts of (Phosphorus-containing wear inhibitor).

(1)

1

In the general formula ^{(1), XIX 1, X} 2及Pi X ³ are each independently an oxygen atom or a sulfur atom, and two at least of these 2 X PI is an oxygen atom, I ¹ ,

X R

R ² and R ³ each independently represent a 23-hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms.

R

Show. Three

X ⁷

4 4 II 6 6

R-X-P-X-R (2)

XR ^{5 In the} general formula (2), X ⁴ , X ⁵ , ⁶ and ⁷ each independently represent an oxygen atom or a sulfur atom, and at least three of these are oxygen atoms; ^4, R ⁵ and R ⁶ are each independently a hydrogen atom or a hydrocarbon group having a carbon number of 1 to 3 0.

Specific examples of the hydrocarbon group having 1 to 30 carbon atoms represented by ¹ to! ^ ⁶ include an alkyl group, a cycloalkyl group, an alkenyl group, an alkyl-substituted cycloalkyl group, an aryl group, and an alkyl-substituted aryl group. And arylalkyl groups.

Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, a pendecyl group, a dodecyl group, a tridecyl group, and a tetradecyl group. And alkyl groups such as a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group (the alkyl groups may be linear or branched).

Examples of the above cycloalkyl group include a cycloalkyl group having 5 to 7 carbon atoms such as a cyclopentyl group, a cyclohexyl group, and a cyclohexyl group. Examples of the above alkylcycloalkyl group include a methylcyclopentyl group, a dimethylcyclopentinole group, a methinoleethynolecyclopentyl group, Clopentyl group, methylcyclohexyl group, dimethylcyclohexyl group, methylethylcyclohexyl group, getylcyclohexyl group, methylcycloheptyl group, dimethylcycloheptyl group, methylethylcycloheptyl group, getylcycloheptyl group, etc. An alkylcycloalkyl group having 6 to 11 carbon atoms (the substitution position of the alkyl group with the cycloalkyl group is also arbitrary).

Examples of the alkenyl group include a butenyl group, a pentyl group, a hexyl group, a hepturyl group, an otaturyl group, a nonenyl group, a decenyl group, a pentadecenyl group, a dodecyl group, a tridecyl group, a tetradecyl group, Alkenyl groups such as pentadecenyl group, hexadecenyl group, heptadecenyl group and octadecenyl group (these alkenyl groups may be linear or branched, and the position of the double bond is arbitrary) Can be mentioned.

Examples of the aryl group include aryl groups such as a phenyl group and a naphthyl group. Examples of the alkylaryl group include, for example, a trinole group, a xylyl group, an ethylphenyl group, a propylphenyl group, a butylphenyl group, a pentylphenyl group, a hexylphenyl group, a heptylphenyl group, an otatinolphenylenol group, An alkylaryl group having 7 to 18 carbon atoms such as a ruphenyl group, a decylphenyl group, a didecylphenyl group, and a dodecylphenyl group (the alkyl group may be linear or branched, and the substitution position of the aryl group) Is also optional).

Examples of the above arylalkyl group include arylalkyl having 7 to 12 carbon atoms such as benzyl group, phenylethyl group, phenylpropyl group, phenylbutynole group, phenylolepentyl group, and phenylhexynole group. Groups (these alkyl groups may be linear or branched).

The hydrocarbon group having 1 to 30 carbon atoms represented by the above scale ¹ to! ^ ⁶ is preferably an alkyl group having 1 to 30 carbon atoms or an aryl group having 6 to 24 carbon atoms, and more preferably. It is preferably an alkyl group having 3 to 18 carbon atoms, more preferably an alkyl group having 4 to 12 carbon atoms. Examples of the phosphorus compound represented by the general formula (1) include the following phosphorus compounds. Phosphorous acid, monothiophosphoric acid; monoester of phosphite having one hydrocarbon group having 1 to 30 carbon atoms; monoester of monothiophosphoric acid; monoester of monophosphorous acid; A phosphite diester having three hydrocarbon groups having 1 to 30 carbon atoms; a phosphite triester having three hydrocarbon groups having 1 to 30 carbon atoms; a monothiophosphorous triester; and a mixture thereof.

In the present invention, it is preferable that all of X i X ³ in the general formula (1) are oxygen atoms. Examples of the phosphorus compound represented by the general formula (2) include the following phosphorus compounds.

Phosphoric acid, monothiophosphoric acid; phosphoric acid monoester and monothiophosphoric acid monoester having one hydrocarbon group having 1 to 30 carbon atoms; phosphoric acid having two hydrocarbon groups having 1 to 30 carbon atoms Diester, monothiophosphoric acid diester; phosphoric acid triester having three hydrocarbon groups having 1 to 30 carbon atoms, monothiophosphoric acid triester; and mixtures thereof.

In the present invention, it is preferable that all of X ^{4 to} X ⁷ in the general formula (2) are oxygen atoms.

As the metal salt or amine salt of the phosphorus compound represented by the general formula (1) or (2), a metal base such as a metal oxide, a metal hydroxide, a metal carbonate, a metal chloride, ammonia, A part or all of the remaining acidic hydrogen was neutralized by the action of a nitrogen compound such as an amine compound having only a hydrocarbon group having 1 to 30 carbon atoms or a hydrocarbon group containing a hydroxyl group in the molecule. Salts may be mentioned.

Specific examples of the metal in the above metal base include lithium metal, lithium, sodium, potassium, cesium and other alkaline metals, calcium, magnesium, barium and other alkaline earth metals, zinc, copper, iron, lead, nickel, and the like. Examples include heavy metals such as silver, manganese, and molybdenum. Of these, alkaline earth metals such as lithium, calcium, and magnesium, and zinc are preferred.

The structure of the metal salt of the phosphorus compound varies depending on the valency of the metal and the number of OH groups or SH groups of the phosphorus compound, and thus the structure is not limited at all. For example, when 1 mo 1 of zinc oxide is reacted with 2 mo 1 of phosphoric acid diester (having one OH group), a compound having the structure represented by the following formula is considered to be obtained as a main component. It is thought that molecules also exist.

Further, for example, when 1 mo 1 of zinc oxide is reacted with monoester of phosphoric acid (2 OH groups) lmo 1, a compound having a structure represented by the following formula is considered to be obtained as a main component. It is considered that a polymerized molecule is also present.

Specific examples of the nitrogen compound include ammonia, monoamine, diamine, and polyamine. More specifically, methylamine, ethylamine, propylamine, butyramine, pentylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, pendecamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, pentadecylamine, pentadecylamine, pentadecylamine Heptadecylamine, octadecylamine, dimethylamine, getylamine, dipropylamine, dibutylamine, dipentinoleamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, didindecylamine, dididylamine, ditridecylamine Noleamine, ditetradecylamine, dipentadecylamine, dihexadecylamine, diheptadecylamine, Alkyl groups having 1 to 30 carbon atoms, such as octadecylamine, methyl / reethylamine, methylpropylamine, methylbutylamine, ethylpropylamine, ethylbutynoleamine, and propylbutylamine. An alkyl group which may be linear or branched); ethyluamine, propenyla! Alkenylamine having an alkenyl group having 2 to 30 carbon atoms (these alkenyl groups may be straight-chain or branched), such as amine, ptenylamine, otaturamine and oleylamine; methanolamine , Ethanolamine, Propanolamine, Butanolamine, Pentanolamine, Hexanolamine, Heptanolamine, Octanolamine, Nonanolamine, Methanolethanolamine, Methanolpropanolamine, Methanolbutanolamine, Ethanol Pronoanolamine Alkanolamines having 1 to 30 carbon atoms such as ethanol butanolamine and propanol butanolamine (these alcohol groups may be straight-chain or branched); Methylenediamine Alkylenediamines having an anolexylene group having 1 to 30 carbon atoms, such as tylenediamine, propylenediamine, and butylenediamine; polyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and pentaethylenehexamine; The above monoamines, diamines, polyamines, etc., such as amine, didecyljetanolamine, dodecyldipronoxanolamine, oleyljetanolenoamine, oleylpropylenediamine, and stearyltetraethylenepentamine, have 8 to 20 carbon atoms. Examples thereof include compounds having an alkyl group or an alkenyl group, and heterocyclic compounds such as N-hydroxylethylolimidazoline; alkylene oxide adducts of these compounds; and mixtures thereof.

Among these nitrogen compounds, those having an alkyl or alkenyl group having 10 to 20 carbon atoms such as decylamine, dodecylamine, dodecyldimethylamine, tridecylamine, heptadecylamine, octadecylamine, oleylamine, and stearylamine. Aliphatic amines (which may be linear or branched) are preferred examples. Among these components (A), salts of zinc or calcium with a phosphite diester having two alkyl groups or aryl groups having 3 to 18 carbon atoms, alkyl groups or aryl groups having 3 to 18 carbon atoms, Preferably, a phosphite triester having three alkyl groups having 6 to 12 carbon atoms, or a monoester of phosphoric acid having one alkyl group having 3 to 18 carbon atoms or one aryl group Salt of ester and zinc or calcium, Al with 3 to 18 carbon atoms A salt of a diester of phosphoric acid having two kill groups or aryl groups with zinc or calcium, or an alkyl or aryl group having 3 to 18 carbon atoms, preferably an alkyl group having 6 to 12 carbon atoms. It is preferably a phosphoric acid triester having three. One or more of these components (A) can be arbitrarily compounded.

In the lubricating oil composition of the present invention, the content of the component (A) is not less than 0.05% by mass, preferably not less than 0.01% by mass, particularly preferably not less than 0.01% by mass in terms of phosphorus element based on the total amount of the composition. Is at least 0.2% by mass, while its content is at most 0.5% by mass, preferably at most 0.2% by mass, more preferably at most 0.1% by mass, still more preferably Is 0.08% by mass or less. When the content of the component (A) is less than 0.05% by mass as a phosphorus element, there is no effect on wear resistance, and the amount is 0.5% by mass. If the ratio exceeds / ₀ , it is not preferable for use in an internal combustion engine because phosphorus may adversely affect the exhaust gas aftertreatment device. When the content of the component (A) is 0.08% by mass or less, particularly 0.05% by mass or less as a phosphorus element, the effect on the exhaust gas aftertreatment device can be significantly reduced. Particularly preferred. Among the above component (A) in the present invention, the compound containing sulfur can also be contained within the range of the above-mentioned phosphorus element amount, but preferably, the content is 0 in terms of sulfur element. 1% by mass or less, more preferably 0.08% by mass or less, and most preferably contains no sulfur-containing compound.

In addition, among the components (A) of the present invention, when a compound that does not dissolve or has low solubility in lubricating oil, for example, zinc dialkyl phosphate which is solid at room temperature is used,

From the viewpoint of improving the solubility of the component (A) in lubricating oil and shortening the production time of the lubricating oil composition, an amine compound, for example, the component (D), the nitrogen compound described above, or the amine compound of the component (E) It is particularly preferable to mix an antioxidant or a mixture thereof with the component (A), and dissolve or react the resulting product or reaction product, and to blend the resulting product as an oil-soluble additive in a lubricating oil composition. Examples of the production of such oil-soluble additives include, for example,

The component (A) and the amine compound are preferably placed in an organic solvent such as hexane, toluene, or decalin at 15 to 150 ° C, preferably 30 to 120 ° C, and particularly preferably 40 to 100 ° C. 10 minutes to 5 hours, preferably 20 minutes to 3 hours, particularly preferably 3 to 90 ° C. It is obtained by mixing and dissolving or reacting for 0 minute to 1 hour and distilling off the solvent by distillation under reduced pressure or the like. The component (B) in the lubricating oil composition of the present invention is zinc dithiophosphate (ZDTP), and specifically, zinc dipropyldithiophosphate, zinc dibutyldithiophosphate, zinc dipentyldithiophosphate, Zinc hexyldithiophosphate, zinc diheptinoresitiophosphate, and zinc dioctyldithiophosphate, etc., having 3 to 18 carbon atoms, preferably 3 to 10 carbon atoms, are linear or branched Primary, secondary or tertiary, preferably primary or secondary) having 6 to 6 carbon atoms such as zinc dialkyldithiophosphate having an alkyl group; zinc diphenyldithiophosphate and zinc ditolyldithiophosphate; 18, preferably di ((alkyl) aryl) zinc dithiophosphate having an aryl group or an alkylaryl group having 6 to 10 carbon atoms, and a mixture thereof.

When the lubricating oil composition of the present invention contains the above-mentioned component (A) as a main component as a phosphorus compound, even if it does not contain the component (B), long-drain performance such as oxidation stability and base number retention can be obtained. A composition which is extremely excellent in high-temperature detergency and further excellent in a friction reducing effect can be obtained. Therefore, when the above-mentioned component (A) is contained as a main component as a phosphorus compound, that is, when the lubricating oil composition of the present invention satisfies any one of the above-mentioned (I) to (II), In order to maintain such an effect, the content of the component (B) is 0.05% by mass or less in terms of a phosphorus element based on the total amount of the composition, and preferably 0.3% by mass. %, More preferably 0.01% by mass or less, and most preferably no component (B).

When (B) zinc dithiophosphate is used as a main component or alone as a phosphorus compound, that is, when the lubricating oil composition of the present invention satisfies the above requirement (IV), its content Is less than 0.05 mass% in terms of phosphorus, based on the total amount of the composition, so that its effect is reduced as compared with the case where component (A) is contained as a main component as a phosphorus compound. A high friction reducing effect can be obtained. The content of the component (B) is preferably from 0.01 to 0.05 mass%. When the content of the component (B) exceeds 0.08% by mass in terms of the phosphorus element based on the total amount of the composition, it is difficult to obtain a sufficient effect. In addition, when the lubricating oil composition of the present invention satisfies the above requirement (IV), it may contain the component (A). The component (C) in the lubricating oil composition of the present invention is a metal-based detergent, for example, an alkali metal sulfonate or an alkaline earth metal sulfonate, an alkaline earth metal phenate or an alkaline earth metal phenate, or an alkaline earth metal phenate. Examples include lithium metal salicylate or alkaline earth metal salicylate, alkali metal phosphonate or alkaline earth metal phosphonate, or a mixture thereof.

More specifically, as the alkali metal or alkaline earth metal sulfonate, for example, an alkyl aromatic compound having a molecular weight of 100 to 150, preferably 200 to 700 is used. Alkali metal salts or alkaline earth metal salts of alkyl aromatic sulfonic acids obtained by the conversion are preferably used, particularly magnesium salts and Z or calcium salts. Specific examples of the alkyl aromatic sulfonic acids include: Examples include so-called petroleum sulfonic acids and synthetic sulfonic acids.

As the petroleum sulfonic acid, generally, a so-called mahoganic acid, which is obtained by sulfonating an alkyl aromatic compound of a lubricating oil fraction of a mineral oil and is by-produced during the production of white oil, is used. Examples of the synthetic sulfonic acid include an alkylbenzene having a linear or branched alkyl group, which is obtained as a by-product from an alkylbenzene production plant used as a raw material for detergents or obtained by alkylating a polyolefin to benzene. Is used as a raw material, and a sulfonated product thereof, or a sulfonated product of dino-naphthalene is used. The sulfonating agent used for sulfonating these alkyl aromatic compounds is not particularly limited, but fuming sulfuric acid or sulfuric acid is usually used.

As the alkali metal or alkaline earth metal phenate, more specifically, an alkylphenol having at least one linear or branched alkyl group having 4 to 30 carbon atoms, preferably 6 to 18 carbon atoms Alkyl phenol sulfide obtained by reacting this alkyl phenol with elemental sulfur or an alkali metal salt or alkoxide of a Manch reaction product of alkyl phenol obtained by reacting this alkyl phenol with formaldehyde Potassium earth metal salts, especially magnesium salts and Z or potassium salts, are preferably used.

As the alkali metal or alkaline earth metal salicylate, more specifically, Alkali metal salts or alkyl earth metal salts of alkyl salicylic acids having at least one linear or branched alkyl group having 4 to 30 carbon atoms, preferably 6 to 18 carbon atoms, particularly magnesium salts And / or calcium salts are preferably used.

Alkali metal or alkaline earth metal sulphonate, alkali metal or alkaline earth metal phenate and alkali metal or alkaline earth metal salicylate include alkyl aromatic sulfonic acid, aryl phenol, alkyl phenol sulfa Mannich reaction products of alkyls and alkylphenols, alkylsalicylic acid, etc., directly react with metal bases such as oxides and hydroxides of alkali metals or alkaline earth metals, or once sodium salt or potassium Not only neutral salts (normal salts) obtained by substituting alkaline earth metal salts with alkaline earth metal salts such as lime salts, but also these neutral salts (normal salts) and excess alkali metal or alkali Earth metal salt or alkaline metal or alkaline earth metal base (water of alkaline metal or alkaline earth metal Or neutral salts in the presence of carbon dioxide or boric acid or borate are converted to alkali metals or alkaline earth metals. And perbasic salts (ultrabasic salts) obtained by reacting with a base such as hydroxide.

These reactions are usually performed in a solvent (aliphatic hydrocarbon solvent such as hexane, aromatic hydrocarbon solvent such as xylene, light lubricating base oil, etc.). Metal-based detergents are usually commercially available diluted with a light lubricating base oil or the like, and are available, but generally have a metal content of 1.0 to 20. wt%, preferably 2.0 to 1 6 mass ^_0/0 is preferable to use those.

In the present invention, the total base number of the component (C) is from 0 to 500 mg KO HZ g, preferably from 20 to 450 mg KOH / g. One or more of sulfonate, phenate, salicylate and the like can be used in combination. The term “total base number” as used herein means the total base number by the perchloric acid method measured in accordance with 7 of JISK 2501 “Testing methods for petroleum products and lubricating oils in Japan”. I do. Further, the component (C) of the present invention is not particularly limited in its metal ratio, and a metal ratio of usually 20 or less can be used. However, from the viewpoint that the friction reducing effect and the long drain property can be further improved, Preferably, the metal ratio is 2.3 or less, more preferably 1.5. Hereinafter, it is more preferable that the metal-based cleaning agent be made of a metal-based detergent having a metal ratio of 2.3 or less, more preferably 1.3 or less. A series of detergents can be used alone or in combination of two or more. Here, the metal ratio is expressed by the valence of the metal element in the metal-based detergent X the content of the metal element (mo 1%) / the content of the soap group (mo 1%). , Potassium, magnesium, and the like, and the soap group means a sulfonic acid group, a salicylic acid group, and the like.

As the component (C) of the present invention, an alkali metal salicylate or an alkaline earth metal salicylate is particularly preferable because it has a large friction reducing effect due to low ash and has excellent long drain properties.

In the lubricating oil composition of the present invention, the upper limit of the compounding amount when the component (C) is contained is not particularly limited as long as the sulfated ash content of the composition is 0.8% by mass or less. Although it can be adjusted by the content of the additive, it is preferably 0.15% by mass, more preferably 0.11% by mass, particularly preferably 0.1% by mass in terms of the metal element based on the total amount of the composition. 0% by mass. The lower limit is usually 0.01% by mass, preferably 0.02% by mass, particularly preferably 0.05% by mass. If the amount of the component (C) is less than 0.01% by mass, long drain performance such as high-temperature detergency, oxidation stability, and base number retention is not easily obtained, which is not preferable. As the ashless dispersant (D) in the lubricating oil composition of the present invention, any ashless dispersant used in lubricating oils can be used, and for example, a straight chain or a branched chain having 40 to 400 carbon atoms. Examples include a nitrogen-containing compound having at least one branched alkyl group or alkenyl group in a molecule or a derivative thereof, and a modified product of alkenyl succinic acid imide. One or two or more arbitrarily selected from these can be blended.

The carbon number of this alkyl group or alkenyl group is 40 to 400, preferably 60 to 350. When the number of carbon atoms in the alkyl group or alkenyl group is less than 40, the solubility of the compound in the lubricating base oil decreases, while when the number of carbon atoms in the alkyl group or alkenyl group exceeds 400, the lubricating oil composition The low-temperature fluidity of the material Each is not preferred. This alkyl group or alkenyl group may be linear or branched, but is preferably, for example, an oligomer of an olefin such as propylene, 1-butene or isobutylene, or a copolymer of ethylene and propylene. Derived branched alkyl groups and branched alkenyl groups are exemplified.

Specific examples of the component (D) include, for example, the following compounds, and one or more compounds selected from these can be used.

(D-1) Succinic imid having at least one alkyl or alkenyl group having 40 to 400 carbon atoms in the molecule, or a derivative thereof

(D-2) Benzylamine having at least one alkyl or alkenyl group having 40 to 400 carbon atoms in the molecule, or a derivative thereof

(D-3) a polyamine having at least one alkyl group or alkenyl group having 40 to 400 carbon atoms in the molecule, or a derivative thereof. As the above (D-1) succinic acid imide, more specifically, Examples include compounds represented by the following general formulas (3) and (4).

In the general formula (3), R ² . Represents an alkyl group or an alkyl group having 40 to 400, preferably 60 to 350 carbon atoms, and h represents an integer of 1 to 5, preferably 2 to 4.

—In the general formula (4), R ²¹ and R ²² are each independently 40 to 4 carbon atoms. And preferably represents 60 to 350 alkyl groups or alkyl groups, and is preferably a polypter group. i represents an integer of 0 to 4, preferably 1 to 3. In addition, succinic acid imid includes a so-called monotype succinic acid imid represented by formula (3) in which succinic anhydride is added to one end of a polyamine, and a formula (in which succinic anhydride is added to both ends of polyamine). And the so-called bis-type succinic acid imid represented by 4). The composition of the present invention may contain any of them or a mixture thereof.

The method for producing these succinic imides is not particularly limited.For example, a compound having an alkyl group or an alkenyl group having 40 to 400 carbon atoms is reacted with maleic anhydride at 100 to 200 ° C. It can be obtained by reacting the resulting alkyl or arcel succinic acid with a polyamine. Specific examples of the polyamine include, for example, ethylene triamine, triethylene tetramine, tetraethylene pentamine, and ethylene hexamine.

More specifically, examples of the above (D-2) benzylamine include compounds represented by the following general formula (5).

(Five)

In the general formula (5), R ^{2 3,} the number 4 0-4 0 0 atoms, preferably an alkyl or alkenyl group having 6 0 to 3 5 0, j is 1 to 5, preferably 2 to 4 Indicates an integer.

The method for producing this benzylamine is not limited at all. For example, a polyolefin such as propylene oligomer, polybutene, and ethylene-α-olefin copolymer is reacted with phenol to form an alkylphenol, and It can be obtained by reacting formaldehyde with a polyamine such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and pentaethylenehexamine by a Mannich reaction.

More specifically, the above (D-3) polyamine is represented by the following general formula (6): The compounds represented can be exemplified.

R ²⁴ -NH- (CH ₂ CH ₂ NH) _k -H (6)

In the general formula (6), R ²⁴ represents an alkyl group or an alkenyl group having 40 to 400 carbon atoms, preferably 60 to 350 carbon atoms, and k represents an integer of 1 to 5, preferably 2 to 4.

The method for producing this polyamine is not limited at all. For example, after chlorinating polyolefin such as propylene oligomer, polybutene, and ethylene- _α -olefin copolymer, ammonia, ethylenediamine, diethylenetol, etc. It can be obtained by reacting a polyamine such as liamine, triethylenetetramine, tetraethylenepentamine, and pentaethylenehexamine. As the derivatives of the nitrogen-containing compound mentioned as an example of the component (D), specifically, for example, a monocarboxylic acid having 1 to 30 carbon atoms (fatty acid, etc.) By reacting a polycarboxylic acid having 2 to 30 carbon atoms such as an acid, trimellitic acid, and pyromellitic acid to neutralize or amidate a part or all of the remaining amino and / or imino groups, A so-called acid-modified compound; a so-called boron-modified compound in which boric acid acts on the above-mentioned nitrogen-containing compound to neutralize or amidate a part or all of the remaining amino and / or imino groups; A sulfur-modified compound obtained by reacting a sulfur-containing compound with a nitrogen-containing compound; and a modified compound obtained by combining the above-mentioned nitrogen-containing compound with two or more kinds of modifications selected from acid modification, hydrogen modification, and sulfur modification. Can be Among these derivatives, the boric acid-modified compound of alkenyl succinic acid imid has excellent heat resistance and antioxidant properties, and is effective in the lubricating oil composition of the present invention to further enhance the base number retention and high-temperature detergency. .

When the component (D) is contained in the lubricating oil composition of the present invention, its content is usually from 0.01 to 20% by mass, preferably from 0.1 to 10% by mass, based on the total amount of the lubricating oil composition. It is expressed in mass%. If the content of the component (D) is less than 0.01% by mass, the effect on high-temperature detergency is small, while if it exceeds 20% by mass, the low-temperature fluidity of the lubricating oil composition is significantly deteriorated. Therefore, each is not preferred. In the lubricating oil composition of the present invention, (ii) a phenolic acid Antioxidants Pamine-based antioxidants, metal-based antioxidants, etc. can be used as long as they are generally used in lubricating oils. By adding the antioxidant, the antioxidant property of the lubricating oil composition can be further enhanced, so that the base number maintenance property and high-temperature detergency can be further enhanced.

Examples of phenolic antioxidants include 4,4, -methylenebis (2,6-di-tert-butynolephenore) and 4,4,1-bis (2,6-di-tert-butinolephenol). ), 4,4, -bis (2-methynole-6-tert-ptinole phenol), 2,2'-methylenebis (4-ethynole 6-tert-butynolephenol), 2,2, methylenebis (4-methyl-6-) tert-butylphenol), 4,4, butylidenebis (3-methyl-6-tert_butylphenol), 4,4, -isopropylidenebis (2,6-zytert-butylphenol), 2,2,1-methylenebis (4-methyl-6-nonylphenol), 2,2,1-isobutylidenebis (4,6-dimethylphenol), 2,2, -methylenebis (4-methynole 6-cyclohexynolephenol), 2, 6— The 1-tert-butyltin 4-enomethyole, 2,6-ditert-butynole 4-ethynole, 2,4-dimethyl-16-tert-butynolepheno, 2,6-di-tert-—dimethinoleamino 1 p-cresonore, 2,6-ditert-butyl-4 (N, N, -dimethylaminomethylphenol), 4,4,4-thiobis (2-methyl-1-6-tert-butynolephenole), 4 , 4, monothiobis (3-methylinole 6-tert-butylphenol), 2'2, -thiobis (4-methinole-6-tert-ptinolephenore), bis (3-methylinole 4-hydroxy-5-tert-butyl) Butynolebenzinole) Sulfide, bis (3,5-di-tert-butyl-4-hydroxylbenzyl) snoresulfide, 2,2, -thiodiethylenebis [31- (3,5-di-tert-butyltinole) One 4-Head Xyphenyl) propionate], tridecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4_hydroxypheno) propionate ], Octyl-3- (3,5-di-tert-butyl-4-hydroxyhydroxyphenyl) propionate, otata-decyl-13- (3,5-di-tert-butyl-4-hydroxyphenyl) pro Pionates and 3-methyl-5-tert-butyl-14-hydroxyphenyl-substituted fatty acid esters can be mentioned as preferred examples. These may be used as a mixture of two or more.

Examples of the amine-based antioxidants include, for example, ebony, phenol-α-naphthylamine, thiol-fueryl-a-naphthylamine, and dianole-kyldiphenylamine. These may be used as a mixture of two or more.

The above phenolic antioxidant and amine antioxidant may be combined and compounded.

When the component (E) is contained in the lubricating oil composition of the present invention, the content thereof is 5% by mass or less, preferably 3% by mass or less, more preferably 2.0% by mass based on the total amount of the lubricating oil composition. 5 mass% or less. If the content exceeds 5% by mass, it is not preferable because sufficient antioxidant properties cannot be obtained in proportion to the compounding amount. On the other hand, the content thereof is preferably 0.1% by mass or more based on the total amount of the lubricating oil composition in order to further enhance the base number maintaining property and the high-temperature detergency during the lubricating oil deterioration process. 1% by mass or more. The lubricating oil composition of the present invention comprises a lubricating base oil containing at least one phosphorus compound selected from the group consisting of the component (A) and the component (B), and the components (C) to (E). A lubricating oil composition comprising at least one additive selected from the group consisting of: and having any one of the following requirements (I) to (IV): .

(I) The component (A) is contained as a main component as a phosphorus compound, and the sulfated ash content of the composition is 0.8% by mass or less.

(Ii) As a phosphorus compound, the component (A) is contained as a main component, and (F) a sulfur-containing organic molybdenum complex is contained in an amount of 0.0001 to 0.2% by mass in terms of molybdenum element, based on the total amount of the composition. And the sulfated ash content of the composition is not more than 1.2% by mass.

(m) As a phosphorus compound, the component (A) is contained as a main component, (G) The ashless friction modifier is contained, and the sulfated ash content of the composition is 1.2% by mass or less. (IV) As a phosphorus compound, the component (B) is contained as a main component, and (G) The ashless friction modifier is contained, and the content of the component (B) is converted to elemental phosphorus based on the total amount of the composition. Not more than 0.05% by mass and the amount of sulfated ash in the composition not more than 1.2% by mass. The requirement (I) is when the component (A) is contained as a main component as a phosphorus compound. It is required that the amount of sulfated ash in the yarn composition is 0.8% by mass or less. The sulfated ash content of the composition is preferably 0.6% by mass or less, more preferably 0.5% by mass or less, and even more preferably 0.4% by mass or less. Here, the values measured by the method specified in 5. “Test methods for sulfated ash” in JISK 2272, ¾; and are mainly due to metal-containing additives. Specific examples of the (F) sulfur-containing organic molybdenum complex in the requirement (ii) include organic molybdenum complexes containing sulfur in the molecule, such as molybdenum dithiophosphate and molybdenum dithiocarbamate.

As the molybdenum dithiophosphate, specifically, for example, a compound represented by the following general formula (6) can be used.

^{(6) In the} formula (6), I ¹¹ , R ¹² , R ¹³ and R ¹⁴ may be the same or different and each have 1 to 30 carbon atoms, preferably 5 to 18 carbon atoms, more preferably An alkyl group of 5 to 12 or 6 to 18 carbon atoms, preferably 10 to 15 carbon atoms

(Alkyl) represents a hydrocarbon group such as an aryl group. Υ ² , Υ ³ and Υ ⁴ each independently represent a sulfur atom or an oxygen atom.

Preferred examples of the alkyl group include ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, pendecyl, dodecyl, tridecyl, tetradecyl, and pentadecyl. Group, hexadeshi And a heptadecyl group, an octadecyl group and the like. These may be a primary alkyl group, a secondary alkyl group or a tertiary alkyl group, and may be linear or branched.

Preferred examples of the (alkyl) aryl group include a phenyl group, a tolyl group, an ethylphenyl group, a propylphenyl group, a butylphenyl group, a pentylphenyl group, a hexylphenyl group, an octylphenyl group, a noerphenyl group, A decylphenyl group, a pendecylphenyl group, a dodecylphenyl group, and the like.The alkyl group may be a primary alkyl group, a secondary alkyl group, or a tertiary alkyl group, or may be a linear or branched alkyl group. May be. Further, these (alkyl) aryl groups include all substituted isomers in which the substitution position of the alkyl group on the aryl group is different.

Specific examples of molybdenum dithiophosphate include molybdenum diethyl dithiophosphate, molybdenum dipropyl dithiophosphate, molybdenum disulfide dibutyl dithiophosphate, molybdenum dipentyl dithiophosphate and molybdenum disulfide. Xyldithiophosphate, molybdenum dioctyl dithiophosphate, molybdenum didecyldithiophosphate, molybdenum disulfide dodecyl dithiophosphate, molybdenum disulfide (butylphenyl) dithiophosphate, molybdenum disulfide (noylphenyl) dithiophosphate, Molybdenum getyl dithiophosphate, oxymolybdenum sulfide propyldithiophosphate, oxymolybdenum dibutyl dithiophosphate, sulfide Molybdenum dipentyl dithiophosphate, oxymolybdenum disulfide hexyl dithiophosphate, oxymolybdenum dioctyl dithiophosphate, oxymolybdenum didecyl dithiophosphate, oxymolybdene didodecyl sulfide Dithiophosphate, oxymolybdenum sulfide (butylphenyl) dithiophosphate, oxymolybdenum sulfide (nonylphenyl) dithiophosphate (Alkyl group may be linear or branched, and alkyl of alkyl alkyl group The bonding position of the group is arbitrary), and mixtures thereof. As these molybdenum dithiophosphates, compounds having a different number of carbon atoms and different or different hydrocarbon groups in one molecule can also be preferably used. As the molybdenum dicarbamate, for example, a compound represented by the following general formula (7) can be used.

In the above formula (7), R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ may be the same or different, and each have 2 to 24 carbon atoms, preferably alkyl having 4 to 13 carbon atoms. And a hydrocarbon group such as a (alkyl) aryl group having 6 to 24 carbon atoms, preferably 10 to 15 carbon atoms. The Υ ^5, Υ ^6, Υ ⁷ and Upsilon ⁸ are each independently represents a sulfur atom or an oxygen atom.

Preferred examples of the alkyl group include ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, pendecyl, dodecyl, tridecyl, tetradecyl, and pentadecyl. Group, hexadecyl group, heptadecyl group, octadecyl group and the like. These may be a primary alkyl group, a secondary alkyl group or a tertiary alkyl group, and may be linear or branched.

Preferred examples of the (alkyl) aryl group include a phenyl group, a tolyl group, an ethyl phenol group, a propynolepheninole group, a butyl phenyl group, a pentyl phenyl group, a hexyl phenyl group, an octyl phenyl group, a nonyl phenyl group and a decynole phenyl group. Groups, such as a phenyl group, a pendecyl phenyl group, and a dodecyl phenyl group, and the alkyl group may be a primary alkyl group, a secondary alkyl group, or a tertiary alkyl group, or may be a linear or branched alkyl group. May be. Further, these (alkyl) aryl groups include all substituted isomers in which the substitution position of the alkyl group on the aryl group is different. In addition, as molybdenum dithiocarbamate other than the above-mentioned structure, dithio or polytrimononuclear molybdenum as disclosed in WO98 / 26030 or WO99 / 3113 may be used. And those having a structure in which a carbamate group is coordinated.

Specific examples of molybdenum dithiocarbamate include molybdenum diethyl dithiocarbamate, molybdenum dipropyl dithiocarbamate, molybdenum dibutyl dithiocarbamate, molybdenum dipentyl dithiocarbamate, and molybdenum dihexyl sulfide. Dithiocarbamate, molybdenum dioctyl sulfide Dithiocarbamate, molybdenum didecyldithiocarbamate, molybdenum sulfide Dendidodecyldithiocarbamate, molybdenum sulfide (butylphenyl) dithiocarbamate, molybdenum sulfide (nonylphenyl) dithiocarbamate, oxymolybdenum decyldithiocarbamate, oxymolybdenum dipropyldithiocarbamate Palmate, oxymolybdenum diptyl dithiocarbamate, oxymolybdenum dipentyl dithiocarbamate, oxymolybdenum disulfide hexyl dithiocarbamate, oxymolybdene dioctyl sulfide Dithiocarbamate, Oxymolybdenum Didecyldithiocarbamate, Oxymolybdenum Didodecyldithiocarbamate, Oxymolybdenum Sulfide (Butylphenyl) Dithiocarbamate, Oxymolybdenum Sulfide (Nonylphenyl) Dithiocarbamate Doo (alkyl group may be and straight-chain or branched, also, the bonding position of alkyl group Arukirufuweniru group is optional), and mixtures of 及 pico these can be exemplified. As these molybdenum dithiocarbamates, compounds having a hydrocarbon group having a different number of carbon atoms and / or structure in one molecule can also be preferably used. Other organic molybdenum complexes containing sulfur include molybdenum compounds (for example, molybdenum oxides such as molybdenum dioxide and molybdenum trioxide, orthomolybdic acid, paramolybdic acid, and molybdenum acid such as (poly) molybdenum sulfide. Metal salts of these molybdic acids, molybdates such as ammonium salts, molybdenum disulfide, molybdenum trisulfide, molybdenum pentasulfide, molybdenum polysulfide, etc., molybdenum sulfide, molybdenum sulfide, metal salts of molybdenum sulfide or amine salts , Molybdenum halides such as molybdenum chloride) and sulfur-containing organic compounds (eg, alkyl (thio) xanthate, thiadiazole, mecaptothiadiazole, thiocarbonate, tetrahydrocarbyl thiuram disulfide, bis (di Chi O) Hydro Cal bilge Chio phosphonate) disulfide, organic (poly) sulfates eyed include complexes like the sulfurized esters) or other organic compounds.

As the component (F) of the present invention, an arbitrary mixture of one or more molybdenum dithiophosphates selected from the above and one or more molybdenum dithiocarbamates or other sulfur-containing molybdenum complexes Mixtures in proportions can also be used as preferred. In requirement (Π), (F) content of the component, the total amount of the composition, of molybdenum terms of element amount, 0. 0 0 1-0. 2 mass ^_0/0, preferably 0. 0 1-0. It is preferably 15% by mass, particularly preferably from 0.02 to 0.1% by mass. When the content of the component (F) exceeds 0.2% by mass, it is difficult to obtain a friction reduction effect commensurate with the content, increase ash and sulfur content, and may deteriorate storage stability. is there.

The sulfated ash content of the composition is 1.2% by mass or less, preferably 1.0% by mass or less, more preferably 0.8% by mass or less, still more preferably 0.6% by mass or less, and particularly preferably 0% by mass or less. Less than 5% by mass.

As the (G) ashless friction modifier in the requirements (II) and (IV), any compound usually used as a friction modifier for lubricating oils can be used. Examples thereof include a hydrocarbon group having 6 to 30 carbon atoms, preferably an alkyl group or an alkenyl group, especially a linear alkyl group or a linear alkenyl group having 6 to 30 carbon atoms in the molecule. Fatty acid esters, amine compounds, etc., which also have one.

As the straight-chain alkyl group or straight-chain alkenyl group having 6 to 30 carbon atoms, specifically, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, a pentadecyl group, a dodecyl group, a tridecyl group, Tetradecyl, pentadecyl, hexadecinole, heptadecyl, octadecyl, nonadecyl, icosyl, henycosinole, docosyl, tricosyl, tetracosyl, pentacosyl, hexacosyl, heptacosyl, octacosyl Alkyl groups such as nonacosyl group and triacontyl group (these alkyl groups may be straight-chain or branched); hexyl group, heptenyl group, otathenyl group, nonenyl group, decenyl group, undecenyl group, dodecenyl group, tridecenyl Group, tetradecenyl group, pentadecenyl , Hexadecene-nore, heptadecenyl, octadecenyl, nonadecenyl, icocinole, henicocynenole, docosynole, tricosynenole, tetracosynenole, pentacosynenole, hexacocynenole, hexacocynenole Alkenyl groups such as octacose-nonyl group, nonacocenyl group and triacontenyl group (these alkenyl groups may be straight-chain or branched, and the position of the double bond is arbitrary); You.

The fatty acid ester may be a straight-chain or branched, preferably straight-chain, having 7 to 31 carbon atoms. Esters of a chain fatty acid with an aliphatic monohydric alcohol or an aliphatic polyhydric alcohol can be exemplified. As the amine compound, a linear or branched, preferably linear aliphatic monoamine having 6 to 30 carbon atoms, a linear or branched, preferably linear aliphatic polyamine, or a fatty acid thereof. Examples thereof include an alkylene oxide adduct of an aromatic amine. In the present invention, fatty acid esters of a fatty acid having 12 to 20 carbon atoms and glycerin / sorbitan, among which glycerin monoester and sorbitan monoester, are preferred, and glycerin monoester of oleic acid is particularly preferred.

In the requirements () and (IV), the content of the (G) ashless friction modifier is not particularly limited, but is usually preferably 0.1% by mass or more, more preferably, based on the lubricating oil composition. 0.2% by mass or more. Further, the content is preferably 1% by mass or less, more preferably 0.8% by mass or less. If the content of the component (G) exceeds 1% by mass, the storage stability may be poor.

In addition, the sulfated ash content of the composition in the requirements (II) and (IV) is 1.2 mass% or less, preferably 1.0 mass% or less, more preferably 0.8 mass% or less, and It is preferably 0.6% by mass or less, more preferably 0.5% by mass, and particularly preferably 0.4% by mass.

In the requirement (IV), the component (B) is contained as a main component or alone as a phosphorus compound, and the component (G) is contained. The content of the component (B) is determined based on the lubricating oil composition based on phosphorus element. The equivalent amount is 0.05% by mass or less, preferably 0.01% to 0.05% by mass, particularly preferably 0.04% to 0.05% by mass. In order to further improve the performance of the lubricating oil composition of the present invention, any additive generally used in lubricating oils can be added according to the purpose. Such additives include, for example, anti-wear agents other than component (A) and component (B), friction modifiers other than component (G), viscosity index improvers, corrosion inhibitors, and anti-oxidants. And additives such as a demulsifier, a metal deactivator, a defoamer, and a colorant.

Examples of the antiwear agent other than the components (A) and (B) include disulfides, olefin sulfides, sulfide oils, dithiophosphoric zinc zinc, and dithiophosphoric acid. And yellow-containing compounds such as dithiocarbamate. Since these sulfur-containing wear inhibitors tend to inhibit the friction reducing effect of the present invention, the content is preferably 0.1% by mass or less, more preferably 0.05% by mass or less, based on the total amount of the composition. More preferably,

Examples of the friction modifier other than the component (G) and the component (E) include a molybdenum amine complex, a molybdenum-succinic imid complex, molybdenum disulfide, a long-chain fatty acid, a long-chain aliphatic alcohol, and a long-chain aliphatic ether. And fatty acid amides. As the viscosity index improver, specifically, a so-called non-dispersion type viscosity index improver such as a polymer or copolymer of one or more monomers selected from various methacrylates or a hydrogenated product thereof is used. Or a so-called dispersion type viscosity index improver obtained by copolymerizing various methacrylate esters containing a nitrogen compound; a non-dispersion type or dispersion type ethylene monoolefin copolymer (propylene as α-olefin, 1-butene; 1-pentene, etc.) or hydrides thereof, polyisobutylene or hydrogenated products thereof, hydrides of styrene-one-gen copolymers, styrene-maleic anhydride copolymers, and polyalkylstyrenes.

The molecular weight of these viscosity index improvers must be selected in consideration of shear stability. Specifically, the number average molecular weight of the viscosity index improver is, for example, usually 5,000 to 1, 0000, 0000, preferably 100 in the case of the dispersion type and the ^ dispersion type polymethalate. When 0,000 to 900,000 is polyisobutylene or a hydride thereof, it is usually 800 to 5,000, preferably 1,000 to 4,000. In the case where 0 is ethylene- _α -olefin copolymer or a hydride thereof, it is usually 800 to 500,000, preferably 3,000 to 200,000.用 is used.

When an ethylene-a-olefin copolymer or a hydride thereof is used among these viscosity index improvers, a lubricating oil composition having particularly excellent shear stability can be obtained. One or more compounds arbitrarily selected from the above viscosity index improvers can be contained in an arbitrary amount. The content of the viscosity index improver is usually 0.1 to 20% by mass based on the lubricating oil composition.

Corrosion inhibitors include, for example, benzotriazoles, Compounds, thiadiazole compounds, and imidazole compounds. Examples of the protective agent include petroleum sulfonate, alkylbenzene sulfonate, dinonylnaphthalene sulfonate, alkenyl succinate, and polyhydric alcohol ester.

Examples of the demulsifier include a polyalkylene glycol-based nonionic surfactant such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, and polyoxyethylene alkyl naphthyl ether.

Examples of the metal deactivator include imidazoline, pyrimidine derivatives, alkylthiadiazole, mercaptobenzothiazole, benzotriazole or derivatives thereof, 1,3,4-thiadiazole polysulfide, 1,3,4-thiadiazolylol 2 , 5_bisdialkyldithiocarbamate, 2— (alkyldithio) benzimidazole, and jS— (o-potoxybenzylthio) propionnitryl.

Examples of the antifoaming agent include silicone, fluorosilicole, and fluoroalkyl ether.

When these additives are contained in the lubricating oil composition of the present invention, the content is 0.005 to 5 for the corrosion inhibitor, the antioxidant, and the demulsifier, based on the total amount of the lubricating oil composition. % By mass, 0.001 to 1% by mass for a metal deactivator, and 0.005 to 1% by mass for an antifoaming agent.

The lubricating oil composition of the present invention has a sulfur content of 0.5% by mass or less, preferably 0.3% by mass or less, depending on the selection of the lubricating base oil, each component and various additives. It is possible to provide a low sulfur lubricating oil composition having excellent low friction properties, more preferably 0.2% by mass or less, even more preferably 0.1% by mass or less, and even more preferably 0.05% by mass or less. In particular, it is also possible to obtain a lubricating oil composition substantially containing no sulfur at 0.01% by mass or less, or even 0.05% by mass or less. The lubricating oil composition of the present invention is not only excellent in friction reducing effect, but also excellent in wear prevention effect, long drain property (oxidation stability, base number maintenance property, etc.) and high-temperature detergency, It can be preferably used as a lubricating oil for internal combustion engines such as gasoline engines, motorcycle engines, diesel engines, gas engines, etc. for motorcycles, automobiles, power generation, ships, etc., and has a low ash content, low sulfur, and low phosphorus. Therefore, it is particularly suitable for an internal combustion engine equipped with an exhaust gas aftertreatment device. In particular, when the valve operating mechanism is a direct drive type or a roller follower type, particularly a roller follower type, the effect of reducing friction is particularly exhibited. In addition, low-sulfur fuels, for example, gasoline, gas oil or kerosene having a sulfur content of 50 mass ppm or less, more preferably 30 mass ppm or less, particularly preferably 10 mass ppm or less, or a sulfur content of 1 mass ppm It is particularly preferably used as a lubricating oil for internal combustion engines, particularly a lubricating oil for gas engines, using the following fuels (LPG, natural gas, hydrogen substantially free of sulfur, dimethyl ether, alcohol, GTL (gas to liquid) fuel, etc.) Can be

Also, lubricating oils that require any of the above-described performances of the present invention, for example, lubricating oils for drive systems of automatic or manual transmissions, grease, wet brake oils, hydraulic oils, turbine oils It can also be suitably used as a lubricating oil such as compressor oil, bearing oil, refrigerating machine oil and the like.

[Best Mode for Carrying Out the Invention]

Hereinafter, the content of the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

(Examples 1-2 Comparative Example 1 and Reference Example 1)

As shown in Table 1, a lubricating oil composition of the present invention (Examples 1-2) and a comparative lubricating oil composition (Reference Example 1 and Comparative Example 1) were prepared.

The following performance evaluation tests were performed on each of the obtained compositions.

(1) Entire engine friction test

Under the following test conditions, a lubricating oil composition shown in Table 1 was subjected to an overall engine friction test, and the lubricating oil composition of Comparative Example 1 was used as a reference oil to measure a torque reduction rate (%). Table 1 shows the evaluation results.

Engine valve train: DOHC, direct hit type Oil temperature: 80, 95 ° C

Engine speed: 750-1500 rpm

(2) Valve train friction test

A valve train friction test was performed on the lubricating oil compositions shown in Table 1 under the following test conditions, and the torque reduction rate (%) with respect to the reference oil (Comparative Example 1) was similarly measured. Table 1 shows the evaluation results.

Engine valve train: OHC, roller follower type

Oil temperature: 80 ° C

Engine speed: 375 ~; l OOO r pm

3) tri (2ethylhexyl) phosphate, phosphorus content: 7.1% by mass, sulfur content: 0% by mass,

4) Alkyl group: secbutyl / sec hexyl group, phosphorus content: 7.2 mass, sulfur content: 15.2 mass%, zinc content: 7.80 / ₀ , sulfated ash content: 11.7 mass%

5) Calcium salicylate detergent, total base number: 120 _mg KOH / g, metal ratio: 1.0, Ca content: 4.0, sulfated ash: 13.6% by mass

6) Calcium salicylate detergent, total base number: 120 mgKOH / g, metal ratio: 2.7, Ca content: 4.0, sulfated ash content: 13.6% by mass

7) Polybutenyl succinate imi number average molecular weight of polybutenyl group: 1300

8) Octyl-3- (3,5-di-tert-butyl-4-hydroxyphenyle) propionate and alkyldiph Xnilamine (1: 1)

9) OCP, weight average molecular weight: 150,000

10) Polyalkylene glycol type As is evident from the results in Table 1, in a direct-drive or roller-follower type engine, the lubricating oil composition of the present invention (Examples 1 and 2) used zinc dithiophosphate. The composition has an extremely superior friction-reducing effect as compared to the composition (Comparative Example 1), and is superior to the composition (Reference Example 1) in which the sulfated ash content of the composition exceeds 0.8% by mass. . In particular, when the phosphoric acid triester is used (Example 2), it can be seen that not only can the ash be reduced, but also the friction reducing effect is remarkable. Further, the composition of Example 1 using the metal-based detergent-1 having a metal ratio of 2.3 or less was obtained by mixing the metal-based detergent-2 (metal ratio: 2.7) in the composition of Reference Example 1. The friction reduction effect is superior to that when the amount is reduced, and it has been confirmed that there is no problem with the wear prevention performance of the valve train. Further, as a result of increasing the amount of the metal-based detergent 11 in the composition of Example 1, the composition in which the sulfated ash content of the composition exceeds 0.8% by mass deteriorates the friction reducing effect and reduces the wear resistance. Inferior results. The lubricating oil composition of the present invention can exert a friction reducing effect even when the valve operating mechanism is an engine other than a direct-acting type or a roller follower type, but the valve operating mechanism is a direct-acting type or a roller follower type. Since the effect of reducing friction is particularly exhibited in the case of an engine, application to such an engine is most preferable.

(Examples 3 to 7 and Comparative Examples 2 to 4)

Lubricating oil compositions of the present invention (Examples 3 to 7) and comparative lubricating oil compositions (Comparative Examples 2 to 4) having the compositions shown in Tables 2 and 3 were respectively prepared. The following performance evaluation tests were performed on each of the obtained compositions.

(3) Overall engine friction test

Under the following test conditions, the entire engine friction test was performed for the lubricating oil compositions shown in Table 2, and the torque reduction rate (%) was measured based on the lubricating oil of Comparative ^! J3. Table 2 shows the evaluation results.

Engine valve train: DOHC, direct hit type

Oil temperature: 80 ° C, 95 ° C

Engine speed: 750-3000 rpm (4) Valve train friction test

A valve train friction test was performed on the lubricating oil compositions shown in Table 3 under the following test conditions, and the torque reduction rate (%) was measured based on the lubricating oil of Comparative Example 4. Table 3 shows the evaluation results.

Engine valve train: OHC, roller follower type

Oil temperature: 80 ° C

Engine speed: 3 75 ~: LOOO r pm

Table 2

Zinc content: 7.80 / ₀ , sulfated ash content: 11.7% by mass

5) Glycerin monoester of oleic acid

6) Calcium salicylate detergent, total base number: 120 mgKOH / _g , calcium content: 4.0 mass ⁰ / o metal ratio: 2.7, sulfated ash content: 13.6 mass%

7) Polybutenyl succinimide, number average molecular weight of polybutenyl group: 1300

8) Octyl-3,3,5-ditertbutyl (4-hydroxyphenyl) propionate and alkyldiphenylamine (11)

9) OCP, weight average molecular weight: 150,000

10) Polyalkylene glycol type Table 3

1) Total aromatic content: 1.2 mass%, sulfur content: 10 mass ppm, kinematic viscosity at 100 ° C: 5.6 mm7s,

Viscosity index: 125, NOACK evaporation: 8% by mass

2) zinc di (n-butyl) phosphate, phosphorus content: 13.2% by mass, sulfur content: 0% by mass, zinc content: 13.0% sulfated ash: 19.5% by mass

4) Alkyl group: sec butyl / sec hexyl group, phosphorus content: 7.2% by mass, sulfur content: 15.2% by mass, zinc content: 7.8 <½, sulfated ash content: 11.7% by mass

5) Glycerin monoester of oleic acid

6) Calcium salicylate detergent, total base number: 120 mgKOH / g, calcium content: 4.0 mass%, metal ratio: 1.0, sulfated ash content: 13.6 mass%

8) Octyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate and alkyldiphenylamine (1: 1)

9) OGP, weight average molecular weight: 150,000

10) Polyalkylene glycol type

As is evident from the results in Table 2, in a direct-drive type engine with a valve operating mechanism, the lubricating oil thread and component (Examples 3 and 4) of the present invention containing the components (A) and (G) The component (B) is used in place of the component (A) in the same amount in terms of the amount of phosphorus element, and shows a very excellent friction reduction effect as compared with the case of the composition not containing the component (G) (Comparative Example 2). . Also, In the case of the composition of Comparative Example 3 in which the component (B) and the component (G) are used in combination, the composition of Comparative Example 2 hardly exhibits a friction reducing effect. Therefore, as shown in Example 3,

It is clear that the combination of components (A) and (G) produces an excellent friction reduction effect for the first time.

Further, as is clear from the results in Table 3, the lubricating oil composition of the present invention containing the components (A) and (G) was used in a roller follower type engine with a valve train (Examples 5 and 6).ぴ 6) Even if component (B) and component (G) are used together, if the content of component (B) is 0.05% by mass or less in terms of phosphorus (Example 7), Compared to the case of using the same amount of component (B) as in Example 7 but not using component (G) (Comparative Example 4), it shows extremely excellent friction reducing effect. In particular, when the phosphoric acid triester was used (Examples 4 and 6), it was found that the friction reducing effect was excellent.

From the comparison between Examples 5 and 6 and Examples 3 and 4 or the comparison between Example 7 and Comparative Example 3, when the sulfated ash content of the composition was 0.8% by mass or less, the metal ratio was 2%. It can be seen that when the following metal-based detergents are used, or when the content of the component (A) and / or the component (B) is reduced, the friction reducing effect is particularly excellent.

Incidentally, the lubricating oil composition of the present invention can exert a friction reducing effect even in the case of an engine other than a direct drive type or a roller follower type with a valve operating mechanism, but the valve operating mechanism is a direct hit type or a roller follower type. Since the effect of reducing friction is particularly exhibited in the case of an engine, it is most preferable to apply to such an engine.

(Examples 8 to 11; 11 and Comparative Examples 5 to 9)

Lubricating oil compositions of the present invention having compositions shown in Table 4 (Examples 8 to 11) and comparative lubricating oil compositions (Comparative Examples 5 to 9) were prepared.

Then, the obtained composition was subjected to a friction test using an OPTimol SRV reciprocating friction tester under the conditions of a load of 400 N, a frequency of 5 OHz, an amplitude of 1.5 mm, and an oil temperature of 80 ° C. The test was performed. Table 4 shows the evaluation results. Table 4

00

As is clear from the results in Table 4, the lubricating oil compositions of the present invention (Examples 8 to 11) show excellent low friction performance. Especially when a metal-based detergent with a metal ratio of 2.3 or less is used

(Examples 8, 9, 11) It can be seen that a more excellent friction reducing effect is exhibited as compared with the case where a metal-based detergent having a metal ratio of more than 2.3 is used (Example 10). Further, instead of the component (A) in the composition of Example 9, zinc di (2-ethylhexyl) monothiophosphate was added in an amount of 0.05 mass in terms of phosphorus element. /. With respect to the lubricating oil composition contained therein, the result of the frictional property test was 0.048, confirming that the lubricating oil composition was also excellent in friction reducing effect. On the other hand, when zinc dithiophosphate was used instead of component (A) (Comparative Examples 5, 6, and 9), and when organic molybdenum complex containing no sulfur was used instead of component (F) (Comparative Example 7). , 8) indicate that the coefficient of friction is high in each case. It has been confirmed that the lubricating oil composition of the present invention is particularly excellent in the friction reducing effect when the valve operating mechanism of the engine is a direct hit type or a roller follower type. Further, the lubricating oil composition of the present invention can suppress the deterioration of the organic molybdenum compound itself because there is no sulfuric acid generation due to the decomposition of zinc dithiophosphate as compared with the case where zinc dithiophosphate is used. In addition to the effect of reducing friction, it also has excellent maintainability, anti-oxidation properties, long drainability such as base number maintenance, and high-temperature cleanliness.

[Industrial applicability]

The lubricating oil composition of the present invention not only exhibits excellent performance in reducing friction but also achieves low sulfur, low ash, and low phosphorus, and also has excellent long drain properties. It is. Therefore, in addition to lubricating oils for internal combustion engines, lubricating oils that require such performance, for example, lubricating oils for drive systems such as automatic or manual transmissions, grease, wet brake oils, hydraulic oils, turbine oils, It can be suitably used as a lubricating oil such as a compressor oil, a bearing oil, and a refrigerator oil.

Claims

The scope of the claims

1. In a lubricating base oil, (A) a phosphorus compound represented by the general formula (1), a metal salt or an amine salt thereof, a phosphorus compound represented by the general formula (2), a metal salt or a metal salt thereof And at least one phosphorus compound selected from the group consisting of a zinc salt and (B) zinc dithiophosphate in an amount of 0.05 to 0.5% by mass in terms of phosphorus element, based on the total amount of the composition. And a lubricating oil composition comprising at least one additive selected from the group consisting of (C) a metal detergent, (D) an ashless dispersant, and (E) an antioxidant, A lubricating oil composition having any one of the requirements selected from (I) to (IV).

1 1 3 3

RXPXR ³

(1)

X ^ R ²

(In the general formula (1), X ¹ , ² and ³ each independently represent an oxygen atom or a sulfur atom, and at least two of these are oxygen atoms, and ¹ , R ² and R ³ Represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms, respectively.)

X

4 4 II 6 6

RXPXR ₍₂₎

XR ⁵ .

(In the general formula ^{(2), X 4, X} 5, X 6 and X ⁷ are each independently indicates SansoHara child or a sulfur atom, and at least three of these is an oxygen atom, RR ⁵ And R ⁶ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms.)

(I) The component (A) is contained as a main component as a phosphorus compound, and the sulfated ash content of the composition is 0.8% by mass or less.-(Π) The component (A) is contained as a main component as a phosphorus compound. , (F) the sulfur-containing organic molybdenum complex is 0.001 in terms of molybdenum element, based on the total amount of the composition. 00.2 mass%, and the composition has a sulfate ash content of 1.2 mass. Not more than

(ΠΙ) As a phosphorus compound, the component (A) is contained as a main component, (G) The ashless friction modifier is contained, and the sulfated ash content of the composition is 1.2% by mass or less.

(IV) As a phosphorus compound, the component (B) is contained as a main component, and (G) An ashless friction modifier is contained. And, based on the total amount of the composition, the content of the component (B) is expressed in terms of the elemental phosphorus. 0.05% by mass or less and the sulfated ash content of the composition is 1.2% by mass or less

2. The component (A) is at least one compound selected from the group consisting of a metal salt of a phosphorus compound represented by the general formula (1) and a metal salt of a phosphorus compound represented by the general formula (2). The lubricating oil composition according to claim 1, wherein

3. In the component (A), X ⁴ , X ⁵ , ⁶ and ⁷ in the general formula (2) are all oxygen atoms, and R ⁴ , R ⁵ and R ⁶ each independently have 1 to 30 carbon atoms. The lubricating oil composition according to claim 1, wherein the lubricating oil composition is at least one compound selected from the group consisting of phosphorus compounds that are hydrocarbon groups.

4. The content of the component (A) is 0.005 to 0.08 mass in terms of phosphorus element based on the total amount of the composition. 2. The lubricating oil composition according to claim 1, wherein the ratio is / ₀ .

5. The method according to claim 1, wherein the content of the component (C) is 0.01 to 0.15% by mass in terms of a metal element, based on the total amount of the composition. Lubricating oil composition.

6. The lubricating oil composition according to claim 1, wherein the component (C) comprises a metal-based detergent adjusted to a metal ratio of 2.3 or less.

7. The lubricating oil composition according to claim 1, wherein the component (C) is an alkali metal salicylate or an alkaline earth metal salicylate.

8. The lubricating oil composition according to claim 1, wherein the component (G) is a fatty acid ester-based friction modifier having a hydrocarbon group having 6 to 30 carbon atoms.

9. The lubricating oil composition according to claim 1, wherein a sulfated ash content of the composition is 0.6% by mass or less.

10. The lubricating oil composition according to claim 1, wherein the content of the sulfur-containing antiwear agent is 0.1% by mass or less in terms of sulfur element based on the total amount of the composition. .

1 1. The total aromatic content of the lubricating base oil is 3% by mass or less and the sulfur content is 0.1%.

The lubricating oil composition _c according to claim 1, wherein the content is not more than 05% by mass.

1 2. A direct-acting or roller-follower-type valve train, which is brought into contact with the lubricating oil composition according to any one of claims 1 to 11 above. Method for lubricating an internal combustion engine.

13. The lubrication method according to claim 12, wherein the internal combustion engine uses a fuel having a sulfur content of 50 mass ppm or less.