WO2015141026A1

WO2015141026A1 - Lubricating oil composition

Info

Publication number: WO2015141026A1
Application number: PCT/JP2014/073002
Authority: WO
Inventors: 義隆真鍋
Original assignee: Ｊｘ日鉱日石エネルギー株式会社
Priority date: 2014-03-20
Filing date: 2014-09-02
Publication date: 2015-09-24
Also published as: JP6259511B2; JPWO2015141026A1; CN106103672A; US20170190996A1

Abstract

As a continuously variable transmission oil with a high metal-to-metal friction coefficient and favorable fatigue resistance and seize resistance, a lubricating oil composition for a metal belt-type continuously variable transmission is provided, the lubricating oil composition being characterized in that a lubricating base oil: contains (A) 0.01-0.03 mass% by alkaline earth metal weight of an overbased alkaline earth metal sulfonate with a base number by a perchloric acid method of 300-500 mg KOH/g, (B) 0.005-0.015 mass% by alkaline earth metal weight of a low basic alkaline earth metal sulfonate with a base number by a perchloric acid method of 0-40 mg KOH/g, and (C) 0.02-0.06 mass% by phosphorus weight of a sulfur-containing phosphite ester; and is blended so that the ratio ([M]/[P]) of the content ([M]) by alkaline earth metal weight of the (B) low basic alkaline earth metal sulfonate to the content ([P]) by phosphorus weight of the (C) sulfur-containing phosphite ester is at least 0.15.

Description

Lubricating oil composition

The present invention relates to a lubricating oil composition, and more particularly to a lubricating oil composition for a metal belt type continuously variable transmission.

Recent automatic transmissions and continuously variable transmissions are desired to be lighter and smaller, and with the increase in the output of the combined engine, improvement in power transmission capability is being pursued. The purpose of reducing the weight and size is to improve the fuel consumption of a vehicle to be mounted.
In particular, in the case of a metal belt type continuously variable transmission, if the friction coefficient between the belt and the pulley can be improved, the size can be reduced, so that the lubricating oil used there has a characteristic of maintaining a high coefficient of friction between metals. Things are preferred.
Furthermore, the fuel consumption reduction by these lubricating oil is also calculated | required. Specifically, it contributes to the improvement of fuel consumption by reducing the agitation resistance by lowering the viscosity of the lubricating oil and reducing the power loss by reducing the viscous resistance during idling of the wet clutch pack or at the time of fluid lubrication.

Conventional transmission fluids maintain good friction characteristics of lock-up clutches and maintain anti-shudder performance for a long period of time, or μ-V characteristics between belt and pulley (change in friction coefficient with changes in slip speed) In order to prevent the generation of scratch noise by making a positive slope, a transmission oil composition in which a friction modifier, a metallic detergent, an ashless dispersant, an antiwear agent and the like are optimized has been proposed (for example, And Patent Documents 1 to 9).

For example, Patent Document 1 includes a specific calcium salicylate and SP-based extreme pressure agent, a specific amount of a specific succinimide and a boron-containing ashless dispersant, excellent anti-shudder life, and excellent fatigue life. A lubricating oil composition for a transmission having performance has a high intermetal friction coefficient, in which an organic acid metal salt having a specific structure, an antiwear agent, and a boron-containing succinimide are blended as essential components in Patent Document 2. Is a lubricant composition for continuously variable transmissions that achieves both anti-shudder properties and slip control mechanisms. Patent Document 3 contains calcium salicylate, phosphorus-based antiwear agent, friction modifier, and dispersion type viscosity index improver. A lubricating oil composition for a continuously variable transmission that is compatible with a high coefficient of friction between metals and anti-shudder for a slip control mechanism and can be used for a long period of time is disclosed in Patent Literature Contains a dithiocarbamate compound, a condensate of a branched chain fatty acid having 8 to 30 carbon atoms and an amine, and an amine-based antioxidant, and has an excellent anti-shudder performance and a long anti-shudder life. The composition of Patent Document 5 has anti-shudder performance for a slip lock-up device containing calcium sulfonate and phosphites, and also a sarcosine derivative or a reaction product of a carboxylic acid and an amine. An automatic transmission oil composition having a long life performance with respect to a belt-type CVT device is disclosed in Patent Document 6, which includes a specific amount of a specific alkaline earth metal sulfonate and an automatic transmission with a slip control mechanism. Excellent oxidation stability for machine, anti-shudder performance and long-term use Automatic transmission fluid composition having long-term durability to be sustained is disclosed. Patent Document 7 discloses an automatic transmission oil having excellent anti-suddering properties and a constant transmission torque capacity, which includes calcium salicylate and magnesium salicylate, specific friction modifiers, and specific amounts of boric acid-modified succinimide. Document 8 discloses a continuously variable transmission oil having good wear resistance and a high transmission torque capacity containing specific amounts of overbased calcium sulfonate and orthophosphate phosphates, and Patent Document 9 discloses a low base number. The friction coefficient between metals in a metal belt includes a specific amount of one or more alkaline earth metal sulfonates or phenates, imide compounds, and phosphorus compounds, including both alkaline earth metal salts and high base number alkaline earth metal salts. A lubricating oil composition that is high and has a long anti-shudder life is disclosed.

JP 2003-113391 A JP 2001-323292 A JP 2000-355695 A Japanese Patent Laid-Open No. 11-50077 JP-A-10-306292 Japanese Patent Laid-Open No. 10-25487 JP 2000-63869 A JP 2008-222904 A JP 2001-288488 A

However, when the viscosity is further reduced, the oil film in the lubrication part becomes thinner. In particular, when a lubricating oil having a high intermetallic friction coefficient is used, fatigue resistance is deteriorated and seizure is likely to occur. Therefore, by maintaining a high coefficient of friction between metals, while maintaining the transmission torque capacity, it is excellent in fatigue prevention and seizure resistance even when the viscosity is lowered, and is particularly suitable as a metal belt type continuously variable transmission oil. It is to provide a composition.

As a result of intensive studies to solve the above problems, the present inventors have found that a lubricating oil composition containing a specific amount of an alkaline earth metal sulfonate having a specific base number and a phosphorus-based additive having a specific structure is The present inventors have found that the problem can be improved and have completed the present invention.

That is, the present invention relates to (A) an overbased alkaline earth metal sulfonate having a perchloric acid method base number of 300 to 500 mgKOH / g in an amount of 0.01 to 0.03 mass in terms of alkaline earth metal. %, (B) low basic alkaline earth metal sulfonate having a perchloric acid method base number of 0 to 40 mg KOH / g, 0.005 to 0.015 mass% in terms of alkaline earth metal, and (C) the following structure: The sulfur-containing phosphite represented by the formula (I) is contained in an amount of 0.02 to 0.06% by mass, and (B) the alkaline earth metal amount of the low basic alkaline earth metal sulfonate is The ratio ([M] / [P]) of the content ([M]) and the content ([P]) as the phosphorus content of the (C) sulfur-containing phosphite is 0.15 or more. Metal belt type characterized by being A continuously variable transmission lubricating oil composition.

(In the formula (I), R represents a hydrocarbyl group having 4 to 20 carbon atoms containing sulfur, and R ¹ represents a hydrogen atom, a hydrocarbyl group having 4 to 20 carbon atoms or a hydrocarbyl group having 4 to 20 carbon atoms containing sulfur. )

In the lubricating oil composition for continuously variable transmission, the present invention may further include (D) a phosphorous acid ester and / or a normal phosphoric acid ester containing a phosphorus amount and a phosphorus amount in the lubricating oil composition of 0.08% by mass. A lubricating oil composition for a continuously variable transmission, characterized by being blended to the following range.

In the lubricating oil composition for continuously variable transmissions, the present invention further includes a friction modifier, a metallic detergent, a viscosity index improver, a pour point depressant, an antioxidant, a corrosion inhibitor, and an antifoaming agent. A lubricating oil composition for a continuously variable transmission, comprising at least one selected from the group consisting of:

The lubricating oil composition of the present invention is a lubricating oil composition that is particularly suitable as a metal belt type continuously variable transmission oil that can maintain a high coefficient of friction between metals, has excellent anti-fatigue properties, and has improved performance to prevent seizure. .
The lubricating oil composition of the present invention is also excellent in performance as a transmission oil other than the above, and is used for automatic transmissions such as automobiles, construction machines, and agricultural machines, manual transmissions, and differential gears. Also preferably used. In addition, it can be suitably used for industrial gear oils, automobiles such as motorcycles and automobiles, gasoline engines for power generation and marine use, diesel engines, lubricating oils for gas engines, turbine oils, compressor oils, etc. it can.

The present invention is described in detail below.
There is no restriction | limiting in particular as lubricating base oil in the lubricating oil composition of this invention, Mineral base oil and synthetic base oil which are used for normal lubricating oil can be used.

Specifically, as the mineral base oil, the lubricating oil fraction obtained by subjecting the crude oil to atmospheric distillation obtained under reduced pressure is subjected to solvent removal, solvent extraction, hydrocracking, Refined by one or more treatments such as hydroisomerization, solvent dewaxing, hydrorefining, etc., or base oil produced by isomerizing wax isomerized mineral oil, GTLＴWAX (gas-tuly wax) Can be illustrated.

As the mineral oil base oil in the present invention, a hydrocracked mineral oil base oil is preferable. Further, a wax isomerized isoparaffin base oil obtained by isomerizing a raw material containing 50% by mass or more of a wax such as petroleum-based or Fischer-Tropsch synthetic oil is more preferably used. These can be used alone or in any mixture, but it is preferable to use a wax isomerized base oil alone.

Specific examples of synthetic base oils include polybutene or hydrides thereof; poly-α-olefins such as 1-octene oligomers and 1-decene oligomers or hydrides thereof; ditridecyl glutarate, di-2-ethylhexyl adipate Diesters such as diisodecyl adipate, ditridecyl adipate, and di-2-ethylhexyl sebacate; neopentyl glycol ester, trimethylolpropane caprylate, trimethylolpropane pelargonate, pentaerythritol-2-ethylhexanoate, and pentaerythritol Examples thereof include polyol esters such as pelargonate; aromatic synthetic oils such as alkyl naphthalene, alkyl benzene, and aromatic esters, or mixtures thereof.

As the lubricating base oil in the present invention, the above mineral base oil, the above synthetic base oil, or an arbitrary mixture of two or more selected from these can be used. Examples thereof include one or more mineral base oils, one or more synthetic base oils, a mixed oil of one or more mineral base oils and one or more synthetic base oils, and the like.

The kinematic viscosity of the lubricating base oil used in the present invention is not particularly limited, but the kinematic viscosity at 100 ° C. is preferably 2 to 8 mm ² / s, more preferably 2 to 6 mm ² / s, and particularly preferably 2 It is desirable to adjust to ˜4.5 mm ² / s. When the kinematic viscosity at 100 ° C. of the lubricating base oil exceeds 8 mm ² / s, the low-temperature viscosity characteristic deteriorates. On the other hand, when the kinematic viscosity is less than 2 mm ² / s, an oil film is formed at the lubrication point. Insufficient lubrication results in poor lubricity and increases the evaporation loss of the lubricating base oil, which is not preferable.

The viscosity index of the lubricating base oil is not particularly limited, but is preferably 100 or more, more preferably 120 or more, further preferably 130 or more, particularly preferably 140 or more, usually 200 or less, preferably 160 or less. By setting the viscosity index to 100 or more, it is possible to obtain a composition exhibiting favorable viscosity characteristics from a low temperature to a high temperature. On the other hand, if the viscosity index is too high, the viscosity at low temperatures tends to increase, which is not preferable.

In order to improve the low temperature viscosity characteristics and viscosity index of the lubricating oil composition, a low viscosity base oil having a viscosity index of 115 or more and a kinematic viscosity at 100 ° C. of 2 mm ² / s or more and less than 3.5 mm ² / s; Two or more types of viscosity index of 115 or more selected from relatively high viscosity base oils having a viscosity index of 125 or more and a kinematic viscosity at 100 ° C. of 3.5 mm ² / s or more and 4.5 mm ² / s or less. A combination of base oils is preferred. In particular, the viscosity index can be improved by mixing, whereby the block field viscosity at −40 ° C. can be made 10000 mPa · s or less.

The viscosity index of the low viscosity base oil is preferably 120 or more, and more preferably 125 or more. The viscosity index of the base oil having a relatively high viscosity is preferably 130 or more, and more preferably 135 or more. Thereby, the block field viscosity at −40 ° C. can be made 8000 mPa · s or less.

Further, the sulfur content of the lubricating base oil used in the present invention is not particularly limited, but is preferably 0.1% by mass or less, more preferably 0.05% by mass or less, and 0.01% by mass. % Or less, more preferably 0.005% by mass or less, and most preferably substantially 0. A composition superior in oxidation stability can be obtained by reducing the sulfur content of the lubricating base oil.

The evaporation loss amount of the lubricating base oil is not particularly limited, but the NOACK evaporation amount is preferably adjusted to 10 to 50% by mass, more preferably 20 to 40% by mass, and particularly preferably 22 to 35% by mass. It is desirable that By using a lubricating base oil having a NOACK evaporation amount adjusted to the above range, both low temperature characteristics and wear resistance can be achieved. Here, the NOACK evaporation amount means an evaporation amount measured according to CEC L-40-T-87.

The lubricating oil composition of the present invention contains, as component (A), an overbased alkaline earth metal sulfonate having a perchloric acid base number of 300 to 500 mgKOH / g.
More specifically, the overbased alkaline earth metal sulfonate of the component (A) in the present invention is an alkyl aromatic obtained by sulfonating an alkyl aromatic compound having a molecular weight of 100 to 1500, preferably 200 to 700, for example. A group sulfonic acid is directly reacted with an alkaline earth metal base such as magnesium or / or calcium alkaline earth metal oxide or hydroxide, or once as an alkali metal salt such as sodium salt or potassium salt. An excess of an alkaline earth metal salt or an alkaline earth metal base (an alkaline earth metal hydroxide or oxide) is added to a neutral salt (normal salt) obtained by substituting it with an alkaline earth metal salt. In the presence of a basic salt obtained by heating in the presence of carbon dioxide, carbon dioxide and / or boron compounds such as boric acid and borate An overbased salt (superbasic salt) obtained by reacting a neutral salt (normal salt) with an alkaline earth metal base is also included. These reactions are usually performed in a solvent (an aliphatic hydrocarbon solvent such as hexane, an aromatic hydrocarbon solvent such as xylene, a light lubricant base oil, or the like).

The alkyl aromatic sulfonic acid mentioned here specifically includes so-called petroleum sulfonic acid and synthetic sulfonic acid. As the petroleum sulfonic acid, those obtained by sulfonating an alkyl aromatic compound of a lubricating oil fraction of mineral oil or so-called mahoganic acid which is produced as a by-product when white oil is produced is used. As the synthetic sulfonic acid, for example, an alkylbenzene having a linear or branched alkyl group obtained as a by-product from an alkylbenzene production plant that is a raw material for detergents or by alkylating polyolefin with benzene is used as a raw material. , Sulfonated ones thereof, sulfonated ones of dinonylnaphthalene, and the like are used. The sulfonating agent for sulfonating these alkyl aromatic compounds is not particularly limited, but usually fuming sulfuric acid or sulfuric acid is used.

Alkaline earth metal sulfonates such as those described above are usually commercially available in a state diluted with a light lubricating base oil or the like, and are available, but generally the metal content is 1.0 to It is desirable to use 20% by mass, preferably 2.0 to 16% by mass.

Further, these components (A) in the present invention are preferably added in an amount of 0.01 to 0.03% by mass in terms of the amount of alkaline earth metal from the viewpoint of improving the coefficient of friction between metals and seizure resistance. Is 0.02 to 0.03% by mass. If it is less than 0.01% by mass, the oxidation stability is lowered, which is not preferable. If it exceeds 0.03% by mass, seizure resistance is lowered, which is not preferable.

The lubricating oil composition of the present invention contains, as component (B), a low basic alkaline earth metal sulfonate having a perchloric acid base number of 0 to 40 mg KOH / g.
In the present invention, the blending amount of the component (B) is 0.005 to 0.015% by mass in terms of alkaline earth metal, from the viewpoint of improvement of the intermetal friction coefficient, fatigue resistance and seizure resistance, Is 0.005 to 0.010 mass%. If it is less than 0.005% by mass, the anti-fatigue property decreases, which is not preferable. If it exceeds 0.015% by mass, seizure resistance is lowered, which is not preferable.

In addition, as the alkaline earth metal in the component (A) and the component (B), calcium and magnesium are preferable, and calcium is particularly preferable.

The lubricating oil composition of the present invention contains a sulfur-containing phosphite represented by the structural formula (I) as the component (C).
The sulfur-containing phosphite of component (C) in the present invention is a mono- or di-hydrocarbyl phosphite represented by the following structural formula (I).

Here, R is a hydrocarbyl group having 4 to 20 carbon atoms containing sulfur, and R ¹ is a hydrogen atom, a hydrocarbyl group having 4 to 20 carbon atoms, or a hydrocarbyl group having 4 to 20 carbon atoms containing sulfur.
Examples of the hydrocarbyl group containing sulfur include a hydrocarbyl group containing a thioether bond (—CH ₂ —S—CH ₂ —) in the main chain or branched chain.

Examples of the hydrocarbyl group include an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an aryl group, an alkylaryl group, and an arylalkyl group. Further, it may contain a substituent such as halogen, hydroxy group, nitro group, cyano group, alkoxy group.
The hydrocarbyl group is preferably an alkyl group, cycloalkyl group or aryl group having 4 to 20, preferably 6 to 18, and most preferably 8 to 16 carbon atoms. Specific examples include butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, octadecyl, cyclohexyl and phenyl.

The hydrocarbyl group having 4 to 20 carbon atoms containing sulfur includes a hydrocarbyl group containing a thioether bond (—CH ₂ —S—CH ₂ —) in the main chain or branched chain of the hydrocarbyl group having 4 to 20 carbon atoms. Are preferable, and examples thereof include a group represented by the following formula (II).
— (CH ₂ ) _m —S— (CH ₂ ) _n —CH ₃ (II)
Here, m is 1 to 18, preferably 2 to 12, more preferably 2 to 6, n is 2 to 18, preferably 4 to 16, more preferably 6 to 14, and m + n is 3 to 19 And preferably 5 to 17, more preferably 7 to 15.
Specific examples of the hydrocarbyl group having 4 to 20 carbon atoms including sulfur include, for example, — (CH ₂ ) ₂ —S— (CH ₂ ) ₆ —CH ₃ , — (CH ₂ ) ₂ —S— (CH ₂ ) ₇ —CH ₃ , — (CH ₂ ) ₂ —S— (CH ₂ ) ₈ —CH ₃ , — (CH ₂ ) ₂ —S— (CH ₂ ) ₉ —CH ₃ , — (CH ₂ ) ₂ —S— ( CH ₂ ) ₁₀ —CH ₃ , — (CH ₂ ) ₂ —S— (CH ₂ ) ₁₁ —CH ₃ , — (CH ₂ ) ₂ —S— (CH ₂ ) ₁₂ —CH _3, — (CH ₂ ) ₃ —S— (CH ₂ ) ₆ —CH ₃ , — (CH ₂ ) ₃ —S— (CH ₂ ) ₇ —CH ₃ , — (CH ₂ ) ₃ —S— (CH ₂ ) ₈ —CH ₃ , — ( CH ₂ ) ₃ —S— (CH ₂ ) ₉ —CH ₃ , — (CH ₂ ) ₃ —S— (CH ₂ ) ₁₀ —CH ₃ , — (CH ₂ ) ₃ —S— (CH ₂ ) ₁₁ —CH ₃ , — (CH ₂ ) ₃ —S— (CH ₂ ) ₁₂ —CH _3, — (CH ₂ ) ₄ —S— (CH ₂ ) ₆ —CH ₃ , — (CH ₂ ) ₄ —S— (CH ₂ ) ₇ —CH ₃ , — (CH ₂ ) ₄ —S— (CH ₂ ) ₈ —CH ₃ , — (CH ₂ ) ₄ —S— (CH ₂ ) ₉ —CH ₃ , — (CH ₂ ) ₄ —S— (CH ₂ ) ₁₀ —CH ₃ , — (CH ₂ ) ₄ —S— (CH ₂ ) ₁₁ —CH ₃ , — (CH ₂ ) ₄ —S— (CH ₂ ) ₁₂ —CH _{3 and the} like can be exemplified.
Among these, — (CH ₂ ) ₂ —S— (CH ₂ ) ₈ —CH ₃ (3-thiaundecyl), — (CH ₂ ) ₂ —S— (CH ₂ ) ₁₂ —CH ₃ (3-thiapentadecyl) Is particularly preferred.

The component (C) in the present invention is preferably 0.02 to 0.06% by mass in terms of phosphorus amount from the viewpoint of improvement in the coefficient of friction between metals, fatigue resistance and seizure resistance. Is 0.03 to 0.05 mass%. If it is less than 0.02% by mass, the anti-fatigue property decreases, which is not preferable. If it exceeds 0.06% by mass, the friction coefficient between metals decreases, which is not preferable.

In the lubricating oil composition of the present invention, the content ([M]) of (B) the low basic alkaline earth metal sulfonate as described above and the phosphorus content of (C) the sulfur-containing phosphite described above. The content ([P]) as the ratio ([M] / [P]) needs to be 0.15 or more, preferably 0.20 or more, more preferably 0.25 or more, particularly preferably It is 0.30 or more. When [M] / [P] is less than 0.15, the μ-V characteristic between the belt and the pulley is deteriorated, and the scratch noise prevention performance is deteriorated. On the other hand, the upper limit of [M] / [P] is 0.75, preferably 0.70 or less, more preferably 0.65 or less, and still more preferably 0.60 or less.

The lubricating oil composition of the present invention preferably contains a phosphite and / or a normal phosphate as component (D).
The phosphite and / or orthophosphate is not particularly limited, and examples thereof include phosphoric acid monoesters, phosphoric diesters, phosphoric triesters, phosphites having a hydrocarbon group having 1 to 30 carbon atoms. Examples thereof include phosphoric acid monoesters, phosphorous acid diesters, and phosphorous acid triesters. Further, salts of these esters with amines or alkanolamines, metal salts such as zinc salts, and the like can also be used.

Specific examples of the orthophosphate ester include, for example, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, tris (isopropylphenyl) phosphate, tris (t-butylphenyl) ) Phosphate, tributyl phosphate, tripentyl phosphate, trihexyl phosphate, triheptyl phosphate, trioctyl phosphate, trinonyl phosphate, tridecyl phosphate, triundecyl phosphate, tridodecyl phosphate, tritridecyl phosphate, tritetradecyl phosphate, tripenta Decyl phosphate, trihexadecyl phosphate, triheptadecyl phosphate, trioctadecyl Phosphates, such as the trio Rail phosphate and the like.
Specific examples of phosphites include monoalkyl phosphites such as monopropyl phosphite, monobutyl phosphite, monopentyl phosphite, monohexyl phosphite, monopeptyl phosphite, monooctyl phosphite (Alkyl group may be linear or branched); Phosphorous acid mono (alkyl) aryl ester such as monophenyl phosphite, monocresyl phosphite; dipropyl phosphite, dibutyl phosphite, dipentyl phosphite, Dialkyl phosphites such as dihexyl phosphite, dipeptyl phosphite, dioctyl phosphite (alkyl groups may be linear or branched); diphosphites such as diphenyl phosphite and dicresyl phosphite ( Alkyl) aryl ester Trialkyl phosphites such as tripropyl phosphite, tributyl phosphite, tripentyl phosphite, trihexyl phosphite, tripeptyl phosphite, trioctyl phosphite (the alkyl group may be linear or branched); Good); tri (alkyl) aryl phosphites such as triphenyl phosphite and tricresyl phosphite; and mixtures thereof.

In the present invention, the blending amount of the component (D) is such that the amount of phosphorus in the lubricating oil composition is 0.08% by mass or less from the viewpoint of improvement in the coefficient of friction between metals, fatigue resistance and seizure resistance. Preferably, it is the range of 0.06 mass% or less. Exceeding 0.08% by mass is not preferable because fatigue resistance decreases.

In the lubricating oil composition of the present invention, a friction modifier and / or a metallic detergent may be added alone or in combination of several kinds. By blending these into the lubricating oil composition of the present invention, a better lubricating oil composition for a belt type continuously variable transmission equipped with a wet friction clutch can be obtained.

As the friction modifier that can be used in combination with the lubricating oil composition of the present invention, any compound that is usually used as a friction modifier for lubricating oils can be used, for example, an alkyl group or alkenyl group having 6 to 30 carbon atoms. Examples thereof include amine compounds, fatty acid amides, fatty acid metal salts, and the like (in particular, alkyl groups or alkenyl groups having 6 to 30 carbon atoms having at least one linear alkyl group or linear alkenyl group in the molecule).

Among the amine compounds described above, succinimide and the like which are a reaction product with polyamine are also included. These include those modified with boron compounds and phosphorus compounds.
Examples of the amine compound include linear or branched, preferably linear aliphatic monoamines having 6 to 30 carbon atoms, linear or branched, preferably linear aliphatic polyamines, these aliphatic Examples include alkylene oxide adducts of amines, salts of these amine compounds with phosphate esters or phosphites, or boric acid modified products of (phosphite) phosphate salts of these amine compounds.

Also, alkylene oxide adducts of amine compounds; salts of these amine compounds with phosphoric acid esters (eg, di2-ethylhexyl phosphoric acid ester) and phosphites (eg, di-2-ethylhexyl phosphorous acid ester); A boric acid modified product of a (phosphite) phosphate salt of an amine compound; or a mixture thereof is particularly preferably used.

Examples of the fatty acid amide include amides of linear or branched, preferably linear fatty acids having 7 to 31 carbon atoms and aliphatic monoamines or aliphatic polyamines. More specifically, for example, , Lauric acid amide, lauric acid diethanolamide, lauric acid monopropanolamide, myristic acid amide, myristic acid diethanolamide, myristic acid monopropanolamide, palmitic acid amide, palmitic acid diethanolamide, palmitic acid monopropanolamide, stearic acid amide, Stearic acid diethanolamide, stearic acid monopropanolamide, oleic acid amide, oleic acid diethanolamide, oleic acid monopropanolamide, coconut oil fatty acid amide, coconut oil fatty acid diethanolamide, coconut oil fatty acid mono Ropanoruamido, synthetic mixed fatty amides having 12 to 13 carbon atoms, synthetic mixed fatty acid diethanolamide having 12 to 13 carbon atoms, synthetic mixed fatty acid mono-propanol amide having 12 to 13 carbon atoms, and mixtures thereof are particularly preferred.

Examples of the fatty acid metal salt include an alkaline earth metal salt (magnesium salt, calcium salt, etc.) or zinc salt of a linear or branched, preferably linear fatty acid having 7 to 31 carbon atoms, More specifically, for example, calcium laurate, calcium myristate, calcium palmitate, calcium stearate, calcium oleate, coconut oil fatty acid calcium, synthetic mixed fatty acid calcium having 12 to 13 carbon atoms, zinc laurate, zinc myristate, Zinc palmitate, zinc stearate, zinc oleate, coconut oil fatty acid zinc, synthetic mixed fatty acid zinc having 12 to 13 carbon atoms, and mixtures thereof are particularly preferably used.

In the present invention, one kind or two or more kinds of compounds arbitrarily selected from these friction modifiers can be contained in any amount, but usually the content thereof is a lubricating oil composition. The total amount is preferably 0.01 to 5% by mass, more preferably 0.03 to 3% by mass.

Examples of metal detergents that can be used in the lubricating oil composition of the present invention include alkali metal sulfonates or alkaline earth metal sulfonates other than the components (A) and (B), alkali metal phenates or alkaline earth metal phenates, and Examples thereof include alkali metal salicylates and alkaline earth metal salicylates. Among these, alkaline earth metal detergents can be preferably used.
In the present invention, when the metal detergent is blended, the blending amount is preferably 0.01% by mass and 0.1% by mass or more based on the total amount of the composition from the viewpoint of rust prevention. More preferably, it is more preferably 0.15% by mass or more. Further, from the viewpoint of thermal stability and antioxidant life, it is preferably 2% by mass or less, more preferably 1.5% by mass or less, and more preferably 1% by mass or less, based on the total amount of the composition. More preferred is 0.8% by mass or less.

In the lubricating oil composition of the present invention, a known lubricating oil additive such as an ashless dispersant, a viscosity index improver, an antioxidant, a corrosion inhibitor, an antifoaming agent, a colorant, etc. is used for the purpose of further enhancing the performance. Can be blended alone or in combination of several kinds.

As the ashless dispersant that can be used in combination with the lubricating oil composition of the present invention, any compound that is usually used as an ashless dispersant for lubricating oil can be used. For example, it has 40 to 400 carbon atoms, preferably 60 carbon atoms. A nitrogen-containing compound having at least one alkyl group or alkenyl group having 350 to 350 in the molecule, a bis-type or mono-type succinimide having an alkenyl group having 40 to 400 carbon atoms, preferably 60 to 350 carbon atoms, and these Examples of the above-mentioned compounds include modified products in which boric acid, phosphoric acid, carboxylic acid or derivatives thereof, and sulfur compounds are allowed to act, and one or two or more compounds arbitrarily selected from these Can be used together.

The alkyl group or alkenyl group herein may be linear or branched, but specific examples include olefin oligomers such as propylene, 1-butene and isobutylene and ethylene / propylene copolymers. Examples include branched alkyl groups and branched alkenyl groups derived from oligomers. Polybutenyl groups obtained by polymerizing a butene mixture or high-purity isobutylene with an aluminum chloride catalyst or a boron fluoride catalyst, etc. It is preferable that the halogen compound is removed, and particularly, a compound from which a halogen compound has been removed is particularly preferable.

When the carbon number of these alkyl groups or alkenyl groups is less than 40, the clean dispersion performance is poor. On the other hand, when the carbon number of the alkyl groups or alkenyl groups exceeds 400, the low-temperature fluidity of the lubricating oil composition deteriorates. Therefore, it is not preferable respectively. The content of these compounds is arbitrary, but is preferably 0.1 to 10% by mass, more preferably 1 to 8% by mass based on the total amount of the lubricating oil composition. In the present invention, the ashless dispersant to be used in combination further improves the speed change characteristics, so that a succinimide having a polybutenyl group having a weight average molecular weight of 700 to 3,500, preferably 900 to 2,000, and / or these It is particularly preferable to blend a boric acid modifying compound. Moreover, it is preferable to mix boric acid-modified succinimide with the ashless dispersant, and further to compound boric acid-modified succinimide as one component in order to improve the peeling prevention property of the wet clutch. preferable.

Specific examples of the viscosity index improver that can be used in combination with the lubricating oil composition of the present invention include so-called copolymers of one or more monomers selected from various methacrylic acid esters or hydrogenated products thereof. Examples thereof include a non-dispersed viscosity index improver, or a so-called dispersed viscosity index improver obtained by copolymerizing various methacrylic esters containing a nitrogen compound. Specific examples of other viscosity index improvers include non-dispersed or dispersed ethylene-α-olefin copolymers (the α-olefins include propylene, 1-butene, 1-pentene, etc.) and hydrogen thereof. Compound, polyisobutylene and hydrogenated product thereof, styrene-diene hydrogenated copolymer, styrene-maleic anhydride ester copolymer, and polyalkylstyrene.

The molecular weight of these viscosity index improvers needs to be selected in consideration of shear stability. Specifically, the number average molecular weight of the viscosity index improver is, for example, 5,000 to 150,000, preferably 5,000 to 35,000 in the case of dispersed and non-dispersed polymethacrylates. In the case of isobutylene or a hydride thereof, those of 800 to 5,000, preferably 1,000 to 4,000, and in the case of an ethylene-α-olefin copolymer or a hydride thereof, 800 to 15,000, preferably Those of 3,000 to 12,000 are desirable. Of these viscosity index improvers, when an ethylene-α-olefin copolymer or a hydride thereof is used, a lubricating oil composition having particularly excellent shear stability can be obtained. In the present invention, one or two or more compounds arbitrarily selected from these viscosity index improvers can be contained in any amount, but the content thereof is usually a lubricating oil composition. The content is preferably 0.1 to 40% by mass.

As the antioxidant that can be used in combination with the lubricating oil composition of the present invention, any antioxidant that is generally used in lubricating oils such as phenolic compounds and amine-based compounds can be used. Alkylphenols such as 2,6-di-tert-butyl-4-methylphenol, bisphenols such as 4,4′-methylenebis (2,6-di-tert-butylphenol), and naphthylamines such as phenyl-α-naphthylamine Dialkyldiphenylamines, zinc dialkyldithiophosphates such as zinc di-2-ethylhexyldithiophosphate, (3,5-di-tert-butyl-4-hydroxyphenyl) fatty acid (propionic acid, etc.) and mono- or polyvalent Alcohols such as methanol, octadecanol, 1,6-hexanediol, neopentylglycol Lumpur, thiodiethylene glycol, triethylene glycol, esters of pentaerythritol and the like. One or two or more kinds of antioxidants arbitrarily selected from these can be contained in any amount, and the content is usually 0.01 to 5 based on the total amount of the lubricating oil composition. It is desirable that the amount be 0.0 mass%.

As the corrosion inhibitor that can be used in combination with the lubricating oil composition of the present invention, any compound that is usually used as a corrosion inhibitor for lubricating oils can be used, for example, triazoles such as benzotriazole and tolyltriazole, Examples include thiadiazole and imidazole compounds. One or two or more compounds arbitrarily selected from these can be contained in any amount, and the content is usually 0.01 to 3.0 based on the total amount of the lubricating oil composition. It is desirable that it is mass%.

As an antifoaming agent that can be used in combination with the lubricating oil composition of the present invention, any compound that is usually used as an antifoaming agent for lubricating oils can be used. For example, silicones such as dimethyl silicone and fluorosilicone can be used. Can be mentioned. One or two or more compounds arbitrarily selected from these can be contained in any amount, but the content is usually 0.001 to 0.05 based on the total amount of the lubricating oil composition. It is desirable that it is mass%.

The colorant that can be used in combination with the lubricating oil composition for transmission of the present invention is optional and can contain any amount, but the content is usually 0.001 based on the total amount of the lubricating oil composition. It is desirable that the content be ˜1.0% by mass.

Hereinafter, the contents 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 1 to 10 and Comparative Examples 1 to 11)
Each lubricating oil composition shown in the Examples and Comparative Examples in Table 1 was prepared, the tests shown below were performed, and the evaluation results are also shown in Table 1. In Table 1, the amount of each additive added is based on the total amount of the composition.

(1) Initial seizure load (LNSL) by the high-speed four-ball test method based on ASTM D2783
(2) Wear scar diameter according to high-speed four-ball test method conforming to ASTM D4172 (3) Seizure load according to Falex seizure test method conforming to ASTM D3233 (4) Friction between metals according to LFW-1 test conforming to JASO M358: 2005 coefficient

The footnotes in Table 1 are as follows.
1) Kinematic viscosity at 100 ° C .: 3.0 mm ² / s, viscosity index 109, S amount 0.1% by mass or less 2) Base number 300 mgKOH / g, Ca amount 11.6% by mass
3) Base number 500 mgKOH / g, Ca amount 18.0 mass%
4) Base number 80 mgKOH / g, Ca amount 4.5% by mass
5) Base number 20 mgKOH / g, Ca amount 2.4 mass%
6) Base number 170 mgKOH / g, Ca content 6.3% by mass
7) Base number 250 mgKOH / g, Ca amount 9.3 mass%
8) 3-thiopentyl hydrogen phosphite 9) Dibutyl hydrogen phosphite 10) Tricridyl phosphate 11) Butyl acid phosphate 12) Ashless dispersant, antioxidant, viscosity index improver, friction modifier, sealant , Metal deactivator 13) Four-ball fatigue test (IP300): rotation speed 3000 rpm, temperature 120 ° C., surface pressure 3.9 GPa
14) Block-on-ring test (LFW-1): load 400N, sliding speed 0.05m / s, temperature 80 ° C
15) Pin / V-block seizure test: 290 rpm, temperature 80 ° C
16) Base number of hydrochloric acid method after 72 hours at 165.5 ° C. 17) Block-on-ring test (LFW-1): load 90 N, sliding speed 0 to 0.2 m / s, temperature 60 ° C. If the friction coefficient ratio (μ2 / μ20) at a sliding speed of 0.02 m / s and 0.2 m / s is 1 or less, especially less than 1, μ-V has a positive gradient, and therefore has excellent scratch noise prevention properties. It was judged.

As can be seen from Table 1, Comparative Example 4 in which the compounding amount of (A) overbased alkaline earth metal sulfonate is less than 0.01% by mass of calcium has a lower ISOT residual base number than the Examples, Oxidation stability tends to be poor, and Comparative Example 9 exceeding 0.03% by mass has a lower seizure load than the Examples and tends to lower seizure resistance. Comparative Examples 7 and 8 containing an overbased alkaline earth metal salicylate or an overbased alkaline earth metal phenate tend to have a short fatigue prevention life and poor fatigue prevention properties as compared to the Examples.
(B) Comparative Examples 3 and 5 in which the blending amount of the low basic alkaline earth metal sulfonate is less than 0.005 mass% in terms of calcium amount have a short fatigue prevention life and a tendency to have poor fatigue prevention properties as compared with Examples. Comparative Example 6 exceeding 0.015% by mass has a lower seizure load than the Examples, and the seizure resistance tends to decrease.
(C) Comparative Example 2 in which the compounding amount of the sulfur-containing phosphite is less than 0.02% by mass in phosphorus tends to have a short fatigue prevention life and poor fatigue prevention properties compared to the Examples. Comparative Examples 1 and 11 exceeding 0.06% by mass have a lower coefficient of friction between metals than the Examples, and affect the transmission torque capacity.
(B) The content ([P]) of the low basic alkaline earth metal sulfonate as phosphorus and the content ([M]) of (C) the sulfur-containing phosphite as metals Even when the ratio is within the specified range, the comparative example 10 in which the ratio ([M] / [P]) is less than 0.15 has a negative μ-V gradient in the block-on-ring test compared to the example, and the belt- It tends to be inferior in the scratch noise prevention property of the pulley.

Claims

(A) An overbased alkaline earth metal sulfonate with a perchloric acid method base number of 300 to 500 mg KOH / g is added to the lubricating base oil in an amount of 0.01 to 0.03% by mass of alkaline earth metal, (B) Low basic alkaline earth metal sulfonate having a perchloric acid method base number of 0 to 40 mg KOH / g in an amount of alkaline earth metal of 0.005 to 0.015% by mass, and (C) in the following structural formula (I) The sulfur-containing phosphite ester shown is contained in an amount of 0.02 to 0.06% by mass of phosphorus, and the content of the (B) low basic alkaline earth metal sulfonate as an alkaline earth metal amount ([M ]) And the content ([P]) of the sulfur-containing phosphite ester (C) as a phosphorus amount ([M] / [P]) is 0.15 or more. Metal belt type continuously variable transmission lubrication Composition.

(In the formula (I), R represents a hydrocarbyl group having 4 to 20 carbon atoms containing sulfur, and R 1 represents a hydrogen atom, a hydrocarbyl group having 4 to 20 carbon atoms or a hydrocarbyl group having 4 to 20 carbon atoms containing sulfur. )
Further, (D) the phosphorous acid ester and / or the normal phosphoric acid ester is mixed in such a manner that the amount of phosphorus in the lubricating oil composition is in the range of 0.08% by mass or less. A lubricating oil composition for continuously variable transmissions according to 1.
Furthermore, it contains at least one selected from the group consisting of a friction modifier, a metallic detergent, a viscosity index improver, a pour point depressant, an antioxidant, a corrosion inhibitor, and an antifoaming agent. The lubricating oil composition for a continuously variable transmission according to claim 1 or 2.