JP5030402B2 - Lubricating oil composition - Google Patents

Description

  The present invention relates to a lubricating oil composition suitable for a transmission having a slip control type wet clutch, and more particularly, when a specific salicylate detergent is used, and excellent wear resistance of metal pulleys and metal belts. The present invention relates to a lubricating oil composition for a transmission suitable for a continuously variable transmission having a slip control type wet clutch and a metal belt, particularly a wet start clutch, which has an initial anti-shudder performance and can maintain the anti-shudder performance for a long period of time.

Recent automatic transmissions are desired to be light and small, and the improvement of power transmission capability is pursued as the combined output of the engine increases. Therefore, the lubricating oil used for these is required to have high lubricating performance, that is, performance to prevent wear on the surfaces of bearings, gears and the like. In addition, in the metal belt type continuously variable transmission, the torque transmitted between the metal pulley and the metal belt is increasing with the increase in engine output. A capacity is required, and a performance for preventing wear on the metal surface between the metal pulley and the metal belt is particularly required.
On the other hand, some of these automatic transmissions and continuously variable transmissions have a control (slip lock-up control) that causes a lock-up clutch built in the torque converter to slide at a low speed. Improvements are being made so that engine torque can be efficiently transmitted to the speed change mechanism while absorbing and improving the ride comfort. In addition, some continuously variable transmissions have a wet start clutch, so that the start clutch is slid first and then coupled to perform smooth start from a stopped state, so-called slip control. Has been done. Lubricating oils used in transmissions such as these lock-up clutches and starting clutches that are controlled for slipping are required to have excellent initial shudder prevention performance and performance for maintaining them for a long period of time.

Under these circumstances, in order to maintain the friction characteristics of the lock-up clutch well, to prevent the initial shudder performance and to maintain it for a long period of time, the friction modifier, metal detergent, ashless dispersant, anti-wear agent, etc. are optimized. A transmission oil composition is disclosed (see Patent Documents 1 to 6).
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 Document 4. Is a lubricating oil composition with excellent anti-shudder performance and long anti-shudder life, comprising 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. In Patent Document 5, the anti-shudder life performance of the slip lockup device, in which calcium sulfonate and phosphites, and a sarcosine derivative or a reaction product of a carboxylic acid and an amine are blended, is included. 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. It has excellent oxidation stability for use as well as anti-shudder performance and long-term use. Automatic transmission fluid composition having long-term durability is disclosed to be.

However, according to the study by the present inventors, when a sulfonate detergent is used as a metal detergent, the initial anti-shudder property is still insufficient, and a salicylate detergent, especially a monoalkyl type When salicylate detergents are used, the initial anti-shudder performance is excellent, but wear and elution of metal ions such as iron ions occur frequently in continuously variable transmissions where metal pulleys and metal belts contact under severe conditions. In addition, it has been found that it is difficult to sufficiently maintain the anti-shudder performance even when the friction modifier listed in the above-mentioned patent document is blended.
In Patent Document 7, monoalkyl salicylate detergents inhibit the anti-wear effect of phosphorus additives, so that the use of a specific amide compound improves the valve-system wear prevention performance of an internal combustion engine. Although it is disclosed that it is possible to suppress wear in a transmission having a slip control type wet clutch, particularly a continuously variable transmission in which a metal pulley and a metal belt contact under severe conditions, a shudder unique to the slip control type wet clutch is provided. There is no disclosure or suggestion of a solution to prevent over the long term.
JP 2003-113391 A JP 2001-323292 A JP 2000-355695 A Japanese Patent Application Laid-Open No. 11-50077 Japanese Patent Laid-Open No. 10-306292 Japanese Patent Laid-Open No. 10-25487 JP 2004-67812 A

  In view of the circumstances as described above, the object of the present invention is to have excellent metal pulley and metal belt wear prevention performance and initial shudder prevention performance even when using a monoalkyl type salicylate detergent. Providing a lubricating oil composition suitable for a continuously variable transmission including a slip control wet clutch, a metal pulley, and a metal belt, particularly a continuously variable transmission including a slip control start clutch. It is.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be improved by using a specific salicylate detergent, a specific nitrogen compound and a phosphorus wear inhibitor in combination. It came to complete.

（一般式（１）において、Ｒ^１は、炭素数１〜３０の直鎖状又は分枝状のアルキル基、Ｒ^２は、水素原子又は炭素数１〜２４の直鎖状又は分枝状のアルキル基をそれぞれ示し、ａ及びｂはそれぞれ個別に１、２又は３を示す。）

（一般式（２）において、Ｘ^１、Ｘ^２及びＸ^３は、それぞれ酸素原子を示し、Ｒ^３、Ｒ^４及びＲ^５は、それぞれ水素原子又は炭素数４〜２０のアルキル基を示し、かつそのうちの二つは、炭素数４〜２０のアルキル基を示す。） That is, the present invention provides a lubricating base oil having (A) a monoalkyl salicylic acid metal salt in a composition ratio of 85 to 100 mol% and a dialkyl salicylic acid metal salt in a composition ratio of 0 to 15 mol%, and a 3-alkyl salicylic acid metal salt. An alkylsalicylic acid metal salt and / or a (per) basic salt thereof, (B) a nitrogen compound represented by the general formula (1), and (C) a general formula (2) It is the lubricating oil composition for transmissions which has a slip control type wet clutch characterized by including the phosphorus-type antiwear agent shown.

(In General Formula (1), R ¹ is a linear or branched alkyl group having 1 to 30 carbon atoms, R ² is a hydrogen atom or a linear or branched alkyl group having 1 to 24 carbon atoms. Each represents an alkyl group, and a and b each independently represent 1, 2 or 3.)

(In General Formula (2), X ¹ , X ² and X ³ each represent an oxygen atom, R ³ , R ⁴ and R ⁵ each represent a hydrogen atom or an alkyl group having 4 to 20 carbon atoms, and Two of them represent an alkyl group having 4 to 20 carbon atoms.)

The lubricating oil composition preferably contains a friction modifier, particularly an amine friction modifier and / or a fatty acid friction modifier.
The lubricating oil composition preferably contains calcium sulfonate and / or magnesium sulfonate.
The lubricating oil composition preferably contains a non-boron ashless dispersant and / or a boron ashless dispersant.
Moreover, it is preferable that the said alkyl salicylic acid metal salt is a secondary alkyl type | mold alkyl salicylic acid metal salt.
The lubricating oil composition is preferably for a continuously variable transmission having a metal pulley and a metal belt.
The slip control wet clutch is preferably a slip control start clutch.
The present invention also relates to a continuously variable transmission having a metal pulley and a metal belt, and / or a lubrication method for a slip control type wet clutch, wherein the lubricating oil composition is used.

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, Examples include those refined by performing one or more treatments such as solvent dewaxing, hydrorefining, etc., or base oils produced by a method of isomerizing wax isomerized mineral oil, GTL WAX (Gas Liquid Wax).

  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 , Diisodecyl adipate, ditridecyl adipate, and di-2-ethylhexyl sebacate, etc .; 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 2.5 to ⁶ mm ² / s, particularly preferably. Is preferably adjusted to 3 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 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 further preferably 0.01% by mass or less. It is desirable to be.

  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. The NOACK evaporation amount here means an evaporation amount measured in accordance with CEC L-40-T-87.

As a specific example of the lubricating base oil in the present invention, the kinematic viscosity at 100 ° C. is 1.5 to 3.5 mm ² / s, preferably ² to 3.2 mm ² / s, more preferably 2.5 to 3 mm ^2. / S, the sulfur content is 0.05% by mass or less, preferably 0.01% by mass or less, more preferably 0.005% by mass or less, and the NOACK evaporation is 20 to 80% by mass, preferably 30%. To 65% by mass, more preferably 30 to 55% by mass of base oil, and a kinematic viscosity at 100 ° C. of 3.5 to 6 mm ² / s, preferably 3.8 to 4.5 mm ² / s, more preferably 3 0.9 to 4.3 mm ² / s, sulfur content is 0.05% by mass or less, preferably 0.01% by mass or less, more preferably 0.005% by mass or less, and NOACK evaporation is 5 to 20% by mass. %, Preferably 10 18% by mass, more preferably 12-16% by mass of base oil mixed in a mass ratio of 10:90 to 90:10, preferably 25:75 to 75:25, more preferably 40:60 to 60:40 In addition, it is preferable that the kinematic viscosity, the sulfur content, and the NOACK evaporation amount of the mixed base oil at 100 ° C. are within the above ranges. As a result, it is possible to obtain a composition that can achieve both low-temperature characteristics and lubricating performance suitable as a transmission oil composition.
The mixed base oil further has a kinematic viscosity at 100 ° C. of 6 mm ² / s or more, preferably 10 to 35 mm ² / s, and a sulfur content of 0.05 to 1% by mass, preferably 0.1 to 0. 0.7% by mass, more preferably 0.2-0.6% by mass, and NOACK evaporation is 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less. You may mix 30 mass%.

The component (A) specified in the lubricating oil composition of the present invention has a monoalkyl salicylic acid metal salt constituent ratio of 85 to 100 mol%, a dialkyl salicylic acid metal salt constituent ratio of 0 to 15 mol%, and a 3-alkyl It is the alkyl salicylic acid metal salt and / or its (over) basic salt whose salicylic acid metal salt has a constituent ratio of 40 to 100 mol%.
The monoalkyl salicylic acid metal salt here means an alkyl salicylic acid metal salt having one alkyl group such as a 3-alkyl salicylic acid metal salt, a 4-alkyl salicylic acid metal salt, a 5-alkyl salicylic acid metal salt, and the like. The constituent ratio of the salt is 85 to 100 mol%, preferably 88 to 98 mol%, more preferably 90 to 95 mol% with respect to 100 mol% of the alkylsalicylic acid metal salt, and an alkylsalicylic acid metal salt other than the monoalkylsalicylic acid metal salt, for example, The composition ratio of the dialkyl salicylic acid metal salt is 0 to 15 mol%, preferably 2 to 12 mol%, and more preferably 5 to 10 mol%. Moreover, the structural ratio of 3-alkyl salicylic acid metal salt is 40-100 mol% with respect to 100 mol% of alkyl salicylic acid metal salt, Preferably it is 45-80 mol%, More preferably, it is 50-60 mol%. The total composition ratio of the 4-alkyl salicylic acid metal salt and the 5-alkyl salicylic acid metal salt corresponds to the composition ratio excluding the 3-alkyl salicylic acid metal salt and the dialkyl salicylic acid metal salt with respect to 100 mol% of the alkyl salicylic acid metal salt. And 0 to 60 mol%, preferably 20 to 50 mol%, more preferably 30 to 45 mol%. By containing a small amount of a dialkyl salicylic acid metal salt, it is possible to obtain a composition having both wear prevention properties and low temperature characteristics, and by making the composition ratio of 3-alkyl salicylate 40 mol% or more, the composition of the metal salt of 5-alkyl salicylic acid The ratio can be made relatively low, and the oil solubility can be improved.

In addition, the alkyl group in the alkyl salicylic acid metal salt constituting the component (A) has 10 to 40 carbon atoms, preferably 10 to 19 carbon atoms or 20 to 30 carbon atoms, more preferably 14 to 18 carbon atoms or more carbon atoms. An alkyl group having 20 to 26, particularly preferably an alkyl group having 14 to 18 carbon atoms. Examples of the alkyl group having 10 to 40 carbon atoms include decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, icosyl, heicosyl, docosyl, Examples thereof include alkyl groups having 10 to 40 carbon atoms such as a tricosyl group, a tetracosyl group, a pentacosyl group, a hexacosyl group, a heptacosyl group, an octacosyl group, a nonacosyl group, and a triacontyl group. These alkyl groups may be linear or branched, and may be a primary alkyl group or a secondary alkyl group. In the present invention, a salicylic acid metal salt satisfying the definition of component (A) is used. A secondary alkyl group is particularly preferred because it is easy to obtain.
Examples of the metal in the alkyl salicylic acid metal salt include alkali metals such as sodium and potassium, alkaline earth metals such as calcium and magnesium, and are preferably calcium and magnesium, and particularly preferably calcium.

  (A) component of this invention can be manufactured by a well-known method etc., Although there is no restriction | limiting in particular, For example, 1 mol or more of polymers, such as ethylene, propylene, and butene, or co-polymer with respect to 1 mol of phenol A method of alkylating with a C10-40 olefin such as a coalescence, preferably a linear α-olefin such as an ethylene polymer, and carboxylating with carbon dioxide or the like, or 1 mol or more per 1 mol of salicylic acid Metals such as oxides or hydroxides of alkali metals or alkaline earth metals to olefins, preferably alkylsalicylic acid mainly composed of monoalkylsalicylic acid obtained by the alkylation method using the linear α-olefin React with a base or alkali metal salt such as sodium salt or potassium salt, Further, it can be obtained by replacing an alkali metal salt with an alkaline earth metal salt. Here, the reaction ratio of phenol or salicylic acid and olefin is preferably controlled to, for example, 1: 1 to 1.15 (molar ratio), more preferably 1: 1.05 to 1.1 (molar ratio). The composition ratio of the monoalkyl salicylic acid metal salt and the dialkyl salicylic acid metal salt can be controlled to a desired ratio, and by using a linear α-olefin as the olefin, a 3-alkyl salicylic acid metal salt and a 5-alkyl salicylic acid metal It is particularly preferable because the constituent ratio of the salt and the like can be easily controlled to a desired ratio as in the component (A) specified in the present application, and an alkyl salicylic acid metal salt having a secondary alkyl which is preferable in the present invention can be obtained as a main component. In addition, when a branched olefin is used as the olefin, it is easy to obtain only a 5-alkyl salicylic acid metal salt, but it is oil-soluble by mixing a 3-alkyl salicylic acid metal salt or the like so as to constitute the component (A) of the present application. This is an unfavorable method because the manufacturing process is diversified.

The component (A) of the present invention comprises an alkali metal or alkaline earth gold salicylate (neutral salt) obtained as described above, an excess of alkali metal or alkaline earth metal salt, alkali metal or alkaline earth. In the presence of a basic salt obtained by heating a metal base (a hydroxide or oxide of an alkali metal or alkaline earth metal) in the presence of water, carbon dioxide, boric acid or borate. An overbased salt obtained by reacting a basic salt with a base such as an alkali metal or alkaline earth metal hydroxide is also included.
These reactions are usually carried out in a solvent (an aliphatic hydrocarbon solvent such as hexane, an aromatic hydrocarbon solvent such as xylene, a light lubricating base oil, etc.), and the metal content thereof is 1.0 to It is desirable to use 20% by mass, preferably 2.0 to 16% by mass.

  As the most preferable component (A) specified in the present invention, the composition ratio of the monoalkyl salicylic acid metal salt is 85 to 95 mol%, and the composition ratio of the dialkyl salicylic acid metal salt is 5 to 5 from the viewpoint of excellent initial shudder prevention performance. Alkyl salicylic acid metal salt having a composition ratio of 15 mol%, 3-alkyl salicylic acid metal salt of 50 to 60 mol%, 4-alkyl salicylic acid metal salt and 5-alkyl salicylic acid metal salt of 35 to 45 mol%, and / or its (Over) Basic salt. The alkyl group here is particularly preferably a secondary alkyl group.

  In the present invention, the base number of the component (A) is usually 0 to 500 mgKOH / g, preferably 20 to 450 mgKOH / g, particularly preferably 100 to 300 mgKOH / g, and one or two selected from these These can be used together. The base number referred to here is 7. JIS K2501 “Petroleum products and lubricating oils-Neutralization number test method”. Means the base number measured by the perchloric acid method according to the above.

  In the lubricating oil composition of the present invention, the content of the component (A) is preferably 0 in terms of metal elements, based on the total amount of the lubricating oil composition, from the viewpoint of wear prevention, initial shudder prevention performance, and maintenance performance. 0.005 to 0.5% by mass, preferably 0.01 to 0.2% by mass, more preferably 0.02 to 0.1% by mass, and particularly preferably 0.02 to 0.05% by mass. A smaller amount is better.

The component (B) in the lubricating oil composition of the present invention is a nitrogen compound represented by the general formula (1).

In the general formula (1), R ¹ represents a linear or branched alkyl group having 1 to 30 carbon atoms, preferably 6 to 24 carbon atoms, and more preferably 6 to 12 carbon atoms. R ² represents a hydrogen atom or a linear or branched alkyl group having 1 to 24 carbon atoms, preferably a hydrogen atom or 1 to 12 carbon atoms, and more preferably 6 to 12 carbon atoms. a and b are individually 1, 2 or 3, preferably 1 or 2, and more preferably a and b are both 2.

Specific examples of the linear or branched alkyl group having 1 to 30 carbon atoms represented by R ¹ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, Isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl Group, nonadecyl group, icosyl group, heicosyl group, docosyl group, tricosyl group, tetracosyl group, pentacosyl group, hexacosyl group, heptacosyl group, octacosyl group, nonacosyl group, triaconyl group (these may be linear or branched) Etc. Further, even linear or branched alkyl group having 1 to 24 carbon atoms represented by R ^2, and alkyl groups exemplified above having 1 to 24 carbon atoms in the above R ¹ can be mentioned.

In the nitrogen compound represented by the general formula (1), R ¹ is an alkyl group having 6 to 24 carbon atoms, and R ² is a hydrogen atom, from the viewpoint of further improving the maintenance performance of wear prevention performance and shudder prevention performance. More preferably, it is an alkyl group having 1 to 24 carbon atoms, and a and b are 1 or 2, and R ¹ and R ² are alkyl groups having 6 to 12 carbon atoms, preferably 6 to 10 carbon atoms, Particularly preferred is a case where b and b are both 2.

  As a preferable nitrogen compound represented by the general formula (1), 2,5-bis (alkylthio) -1,3,4-thiadiazole having a linear or branched alkyl group having 6 to 24 carbon atoms, 2,5-bis (alkyldithio) -1,3,4-thiadiazole having a linear or branched alkyl group having 6 to 24 carbon atoms, having a linear or branched alkyl group having 6 to 24 carbon atoms, 2- (alkylthio) -5-mercapto-1,3,4-thiadiazole, 2- (alkyldithio) -5-mercapto-1,3,4 having a straight or branched alkyl group having 6 to 24 carbon atoms -Thiadiazole and mixtures thereof. Among these, 2,5-bis (alkyldithio) -1,3,4-thiadiazole is particularly preferable.

  In the lubricating oil composition of the present invention, the content of the nitrogen compound represented by the general formula (1) is preferably 0.005 to 0.5 mass%, more preferably 0.01 based on the total amount of the composition. It is -0.2 mass%, More preferably, it is 0.02-0.15 mass%, Most preferably, it is 0.03-0.14 mass%. By keeping the content of the nitrogen compound in the above range, it is easy to maintain the wear prevention performance and the anti-shudder performance maintenance performance over a long period of time.

The component (C) in the lubricating oil composition of the present invention is a phosphorus wear inhibitor.
The phosphorus antiwear agent is not particularly limited as long as it contains phosphorus in the molecule, and examples thereof include phosphorus compounds represented by the following general formula (2) or general formula (3) or salts thereof. .

In the general formulas (2) and (3), X ¹ , X ² , X ³ , X ⁴ , X ⁵ and X ⁶ each independently represent an oxygen atom or a sulfur atom. R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms.

Specific examples of the hydrocarbon group having 1 to 30 carbon atoms represented by R ^{3 to} R ⁸ 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.

  As the alkyl group, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, Examples thereof include alkyl groups such as pentadecyl group, hexadecyl group, heptadecyl group and octadecyl group (these alkyl groups may be linear or branched).

  As said cycloalkyl group, C5-C7 cycloalkyl groups, such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, can be mentioned, for example. Examples of the alkylcycloalkyl group include a methylcyclopentyl group, a dimethylcyclopentyl group, a methylethylcyclopentyl group, a diethylcyclopentyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a methylethylcyclohexyl group, a diethylcyclohexyl group, a methylcycloheptyl group, Examples thereof include an alkylcycloalkyl group having 6 to 11 carbon atoms such as a dimethylcycloheptyl group, a methylethylcycloheptyl group, and a diethylcycloheptyl group (the substitution position of the alkyl group with the cycloalkyl group is also arbitrary).

  Examples of the alkenyl group include butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl, heptadecenyl, An alkenyl group such as an octadecenyl group (these alkenyl groups may be linear or branched, and the position of the double bond is also optional).

  As said aryl group, aryl groups, such as a phenyl group and a naphthyl group, can be mentioned, for example. Examples of the alkylaryl group include tolyl group, xylyl group, ethylphenyl group, propylphenyl group, butylphenyl group, pentylphenyl group, hexylphenyl group, heptylphenyl group, octylphenyl group, nonylphenyl group, and decylphenyl. Each alkylaryl group having 7 to 18 carbon atoms such as a group, undecylphenyl group, dodecylphenyl group and the like (the alkyl group may be linear or branched, and the substitution position on the aryl group is arbitrary) be able to.

  Examples of the arylalkyl group include each arylalkyl group having 7 to 12 carbon atoms such as benzyl group, phenylethyl group, phenylpropyl group, phenylbutyl group, phenylpentyl group, and phenylhexyl group. Or may be branched).

The hydrocarbon group having 1 to 30 carbon atoms represented by R ^{3 to} R ⁸ is preferably an alkyl group having 1 to 30 carbon atoms or an aryl group having 6 to 24 carbon atoms, more preferably 4 carbon atoms. An alkyl group having -20 carbon atoms, more preferably an alkyl group having 6-18 carbon atoms.

  Examples of the phosphorus compound represented by the general formula (2) include phosphorous acid, monothiophosphorous acid, dithiophosphorous acid, trithiophosphorous acid; a nitrous acid having one hydrocarbon group having 1 to 30 carbon atoms. Phosphoric acid monoester, monothiophosphorous acid monoester, dithiophosphorous acid monoester, trithiophosphorous acid monoester; phosphorous acid diester having two hydrocarbon groups having 1 to 30 carbon atoms, monothiophosphorous acid diester , Dithiophosphite diester, trithiophosphite diester; phosphite triester having three hydrocarbon groups having 1 to 30 carbon atoms, monothiophosphite triester, dithiophosphite triester, trithiophosphite And acid triesters; and mixtures thereof.

  Examples of the compound represented by the general formula (3) include phosphoric acid, monothiophosphoric acid, dithiophosphoric acid, trithiophosphoric acid, tetrathiophosphoric acid; phosphoric acid monoester having one hydrocarbon group having 1 to 30 carbon atoms, Monothiophosphoric acid monoester, dithiophosphoric acid monoester, trithiophosphoric acid monoester, tetrathiophosphoric acid monoester; phosphoric acid diester having two hydrocarbon groups having 1 to 30 carbon atoms, monothiophosphoric acid diester, dithiophosphoric acid diester, trithiophosphoric acid diester Tetrathiophosphoric acid diesters; phosphoric acid triesters having three hydrocarbon groups having 1 to 30 carbon atoms, monothiophosphoric acid triesters, dithiophosphoric acid triesters, trithiophosphoric acid triesters, tetrathiophosphoric acid triesters; and mixtures thereof Can mention .

In the present invention, among the phosphorus compounds represented by the general formula (2), in the formula (2), one or more of X ¹ , X ² , and X ³ are preferably oxygen atoms, and two or more Is more preferably an oxygen atom, and most preferably all three are oxygen atoms.
Moreover, among the phosphorus compounds represented by the general formula (3), in the formula (3), at least one of X ⁴ , X ⁵ and X ⁶ is preferably an oxygen atom, and two or more are oxygen. More preferably, they are atoms, and most preferably all three are oxygen atoms.

  In addition, as a salt of the phosphorus compound represented by the general formula (2) or (3), the phosphorus compound may be ammonia, a hydrocarbon group having 1 to 18, preferably 1 to 8 carbon atoms, or a hydroxyl group-containing hydrocarbon group. It remains by reacting a nitrogen base such as an amine compound having only a hydrogen atom in the molecule, an alkylene oxide adduct of the amine compound, or a metal base such as a metal oxide, metal hydroxide, metal carbonate, or metal chloride. The salt which neutralized some or all of acidic hydrogen can be mentioned.

  Specific examples of the nitrogen compound include ammonia; monomethylamine, monoethylamine, monopropylamine, monobutylamine, monopentylamine, monohexylamine, monoheptylamine, monooctylamine, monolaurylamine, monostearylamine, Alkyl such as monooleylamine dimethylamine, methylethylamine, diethylamine, methylpropylamine, ethylpropylamine, dipropylamine, methylbutylamine, ethylbutylamine, propylbutylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine or the like Alkenylamine (the alkyl group or alkenyl group may be linear or branched); monomethanolamine, monoethanolamine, monopropylene Noramine, monobutanolamine, monopentanolamine, monohexanolamine, monoheptanolamine, monooctanolamine, monononanolamine, dimethanolamine, methanolethanolamine, diethanolamine, methanolpropanolamine, ethanolpropanolamine, dipropanolamine, Alkanolamines such as methanol butanolamine, ethanolbutanolamine, propanolbutanolamine, dibutanolamine, dipentanolamine, dihexanolamine, diheptanolamine, dioctanolamine (the alkanol group may be linear or branched) ); Addition of alkylene oxides such as ethylene oxide to these alkylamines and alkanolamines; and Mixtures of al can be exemplified.

  Specific examples of the metal in the metal base include alkali metals such as lithium, sodium, potassium and cesium, alkaline earth metals such as calcium, magnesium and barium, zinc, copper, iron, lead, nickel, silver and manganese. And heavy metals such as molybdenum. Among these, alkaline earth metals such as calcium and magnesium and zinc are preferable.

  These (C) components can be arbitrarily blended in one kind or two or more kinds.

  Among the components (C) in the present invention, as a more preferable one, phosphorous acid, phosphoric acid, a phosphorous acid ester having a C 4-20 alkyl group or a C 6-12 (alkyl) aryl group or One or a mixture of two or more selected from phosphoric esters and amine salts in which an alkylamine having an alkyl group having 1 to 18 carbon atoms is allowed to act is preferable. Phosphorous acid, alkyl having 4 to 20 carbon atoms One or a mixture of two or more selected from a phosphite having a group is more preferable, and a phosphite diester having an alkyl group having 4 to 8 carbon atoms is particularly preferable.

  In the lubricating oil composition of the present invention, the content of the component (C) is usually 0.01 to 5% by mass based on the total amount of the composition, but is preferably 0.001 to 0.1% by mass as the phosphorus element concentration. More preferably, it is 0.005-0.08 mass%, More preferably, it is 0.01-0.06 mass%, Most preferably, it is 0.02-0.05 mass%. By making content of (C) component into the said range, while being excellent in abrasion prevention property and initial stage shudder prevention performance, the composition which is easy to maintain shudder prevention performance for a long period can be obtained.

In the lubricating oil composition of the present invention, the mass ratio of the content at the metal element concentration (M) of the component (A) to the content (P) at the phosphorus element concentration of the component (C) on the basis of the total amount of the composition ((M) / (P)) is not particularly limited, but is preferably 0.1 to 250, preferably 0.5 to 50, more preferably 0.8 to 5, and particularly preferably 1 to 3. .
In the lubricating oil composition of the present invention, the mass ratio of the content of the component (B) to the content (P) of the component (C) at the phosphorus element concentration on the basis of the total amount of the composition ((B) / (P) ) Is not particularly limited, but is preferably 0.1 to 250, preferably 0.5 to 50, more preferably 1 to 10, and particularly preferably 1.5 to 5.
(C) By making each mass ratio of the (A) component and the (B) component with respect to the content (P) at the phosphorus element concentration of the component (C) within the above range, the wear resistance and the initial shudder prevention performance are excellent. A composition that can easily maintain anti-shudder performance for a long period of time can be obtained.

  The lubricating oil composition of the present invention has a composition capable of maintaining the anti-shudder performance for a long period of time while being excellent in anti-wear properties and initial anti-shudder performance by using the components (A), (B) and (C) in combination. A known lubricating oil additive can be added for the purpose of further enhancing the performance or for further imparting the performance required as a lubricating oil composition. Additives that can be added include, for example, metallic detergents other than component (A), ashless dispersant, friction modifier, antioxidant, extreme pressure additive, antiwear agent, viscosity index improver, rust inhibitor, corrosion Examples thereof include an inhibitor, a pour point depressant, a rubber swelling agent, an antifoaming agent, and a coloring agent. These can be used alone or in combination of several kinds.

Examples of metallic detergents other than the component (A) include salicylate detergents, sulfonate detergents, and phenate detergents that do not fall under the component (A).
Examples of the salicylate detergent not corresponding to the component (A) include an alkyl salicylic acid metal salt having a composition ratio of a dialkyl salicylic acid metal salt having two alkyl groups having 10 to 40 carbon atoms of 15 mol% or more and / or ( ) Basic salt, dialkyl salicylic acid metal salt having an alkyl group having 1 to 9 carbon atoms and an alkyl group having 10 to 40 carbon atoms and / or (over) basic salt thereof, and the composition ratio of 3-alkyl salicylic acid metal salt is 40 mol. Alkyl salicylic acid metal salt and / or its (over) basic salt, etc., which are less than%. Here, examples of the metal include alkali metals and alkaline earth metals.

Examples of the sulfonate detergent include alkaline earth metal salts of alkyl aromatic sulfonic acids obtained by sulfonated alkyl aromatic compounds having a molecular weight of 100 to 1500, preferably 200 to 700, particularly magnesium salts and the like. Calcium salts are preferably used, and specific examples of the alkyl aromatic sulfonic acid include 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, a raw material is an alkylbenzene having a linear or branched alkyl group, which is obtained as a by-product from an alkylbenzene production plant that is a raw material for detergents or is obtained by alkylating polyolefin with benzene. And a sulfonated one of this, a sulfonated dinonylnaphthalene, or the like. The sulfonating agent for sulfonating these alkyl aromatic compounds is not particularly limited, but usually fuming sulfuric acid or sulfuric acid is used.

  Specifically, the phenate detergent is obtained by reacting sulfur with an alkylphenol having at least one linear or branched alkyl group having 4 to 30 carbon atoms, preferably 6 to 18 carbon atoms. Alkali earth metal salts, particularly magnesium salts and / or calcium salts, of Mannich reaction products of alkylphenols obtained by reacting alkylphenol sulfides or alkylphenols with formaldehyde are preferably used.

  The base number of the metal detergent other than the component (A) is usually 0 to 500 mgKOH / g, preferably 20 to 450 mgKOH / g.

  In the present invention, when a metal detergent other than the component (A) is used, one kind selected from a calcium sulfonate detergent and a magnesium sulfonate detergent having a base number of 0 to 500 mgKOH / g, preferably 100 to 400 mgKOH / g. Or it is particularly preferable to use two or more kinds in combination. By using these sulfonate detergents in combination, it is possible to obtain a composition having an excellent anti-wear effect, anti-shudder property and maintainability in a highly balanced manner.

  In the lubricating oil composition of the present invention, when a metallic detergent other than the component (A) is contained, the content is not particularly limited, but is usually 0.01 to 5% by mass based on the total amount of the composition, preferably Is 0.05 to 1% by mass, particularly preferably 0.1 to 0.5% by mass.

  As the ashless dispersant, any compound usually used as an ashless dispersant for lubricating oil can be used. For example, a nitrogen-containing compound such as succinimide, benzylamine, polyamine, or a derivative or modified product thereof having at least one alkyl group or alkenyl group having 40 to 400 carbon atoms, preferably 60 to 350 carbon atoms in the molecule. Can be mentioned. The alkyl group or alkenyl group having 40 to 400 carbon atoms may be linear or branched. Specifically, preferred examples include olefin oligomers such as propylene, 1-butene and isobutylene, and ethylene and propylene. Examples include branched alkyl groups and branched alkenyl groups derived from co-oligomers. When the carbon number of the alkyl group or alkenyl group is less than 40, the solubility of the compound in the lubricating base oil decreases, whereas when the carbon number of the alkyl group or alkenyl group exceeds 400, the low temperature fluidity of the composition Gets worse.

Examples of the derivative or modified product of the nitrogen-containing compound mentioned as an example of the ashless dispersant include, for example, the nitrogen-containing compounds as described above, monocarboxylic acids having 2 to 30 carbon atoms (fatty acids, etc.), oxalic acid, By reacting a polycarboxylic acid having 2 to 30 carbon atoms such as phthalic acid, trimellitic acid, pyromellitic acid, etc. to neutralize a part or all of the remaining amino group and / or imino group, or amidation, So-called acid-modified compounds; so-called boron-modified compounds in which boric acid is allowed to act on the nitrogen-containing compounds as described above to neutralize or amid some or all of the remaining amino groups and / or imino groups; A so-called phosphorus-modified compound in which phosphoric acid or phosphorous acid is allowed to act on such a nitrogen-containing compound to neutralize or amidate part or all of the remaining amino group and / or imino group; A sulfur-modified compound obtained by allowing a sulfur compound to act on a nitrogen-containing compound as described above; and a nitrogen-containing compound as described above combined with two or more kinds of modifications selected from acid modification, boron modification, phosphorus modification, and sulfur modification Examples include modified compounds.
In the lubricating oil composition of the present invention, one or two or more compounds arbitrarily selected from these can be used in any amount, but the content is usually the total amount of the lubricating oil composition. The reference is 0.1 to 10% by mass.

  The lubricating oil composition of the present invention preferably contains a non-boron ashless dispersant and / or a boron-containing ashless dispersant, and these ashless dispersants are more preferably succinimide ashless dispersants. The content of the non-boron ashless dispersant and / or the boron-containing ashless dispersant is preferably 0.1 to 10% by mass, more preferably 3 to 6% by mass, based on the total amount of the lubricating oil composition. When used in combination, the non-boron ashless dispersant is preferably 10% by mass or less, more preferably 1 to 6% by mass, particularly preferably 2 to 4% by mass, and the boron-containing ashless dispersant is preferably 6%. It is 0.01 mass% or less, More preferably, it is 0.01-4 mass%, Most preferably, it is 0.5-2 mass%. The mass ratio of the content of the boron-containing ashless dispersant to the total content of the non-boron-based ashless dispersant and the boron-containing ashless dispersant is preferably 0.1 to 1, more preferably 0.15 to 0. .5, particularly preferably 0.2 to 0.3. By including a boron-containing ashless dispersant, it is possible to improve the anti-wear property, and by reducing the boron-containing ashless dispersant in a small amount, it is easy to obtain a composition having a well-balanced anti-shudder performance and its maintenance performance and transmission characteristics. Become.

As the friction modifier, any compound usually used as a friction modifier for lubricating oils can be used, but an alkyl group or alkenyl group having 6 to 30 carbon atoms, particularly a linear alkyl group having 6 to 30 carbon atoms. Alternatively, amine-based friction modifiers, imide-based friction modifiers, amide-based friction modifiers, fatty acid-based friction modifiers, and the like that have at least one linear alkenyl group in the molecule.
As the amine-based friction modifier, linear or branched, preferably linear aliphatic monoamine having 6 to 30 carbon atoms, linear or branched, preferably linear aliphatic polyamine, Or, aliphatic amine friction modifiers such as alkylene oxide adducts of these aliphatic amines can be exemplified.
Examples of the imide-based friction modifier include mono- and / or mono- and / or bicyclic hydrocarbon groups having 6 to 30 carbon atoms, preferably 8 to 18 carbon atoms, and preferably having 1 or 2 branched hydrocarbon groups. Or succinic acid such as succinimide-modified compound obtained by reacting bissuccinimide, boric acid, phosphoric acid, carboxylic acid having 1 to 20 carbon atoms or sulfur-containing compound with one or more selected from succinimide. Examples thereof include imide friction modifiers.
Examples of the amide friction modifier include fatty acid amide friction modifiers such as amides of linear or branched, preferably linear fatty acids and ammonia, aliphatic monoamines or aliphatic polyamines having 7 to 31 carbon atoms. Etc. can be illustrated.
Examples of the fatty acid friction modifier include linear or branched, preferably linear fatty acids having 7 to 31 carbon atoms, and fatty acids such as esters of the fatty acids with aliphatic monohydric alcohols or aliphatic polyhydric alcohols. Examples include esters, fatty acid metal salts such as alkaline earth metal salts (magnesium salts, calcium salts, etc.) and zinc salts of the fatty acids.

Of these, the imide friction modifiers described above, especially succinimide friction modifiers, are effective not only for increasing the friction coefficient of wet clutches and improving power transmission efficiency, but also for significantly improving the anti-shudder life. It is.
Of the above-mentioned friction modifiers, aliphatic amine friction modifiers and fatty acid friction modifiers, particularly fatty acid metal salts, can be particularly preferably used in order to significantly improve the initial shudder prevention property. It is particularly preferable to contain these aliphatic amine friction modifiers and / or fatty acid friction modifiers. In the case where an aliphatic amine friction modifier and a fatty acid friction modifier are used in combination, the mass ratio is not particularly limited, but is preferably 1: 5 to 5: 1, more preferably, in terms of excellent transmission characteristics. 1: 3 to 3: 1, particularly preferably 1: 2 to 2: 1.

  In the present invention, one or two or more compounds arbitrarily selected from these friction modifiers can be contained in any amount, but usually the content is based on the lubricating oil composition. It is 0.01-5.0 mass%, Preferably it is 0.03-3.0 mass%.

As the antioxidant, any phenolic compound or amine compound that is generally used in lubricating oils can be used.
Specifically, alkylphenols such as 2-6-di-tert-butyl-4-methylphenol, and bisphenols such as methylene-4,4-bisphenol (2,6-di-tert-butyl-4-methylphenol). , Naphthylamines such as phenyl-α-naphthylamine, dialkyldiphenylamines, (3,5-di-tert-butyl-4-hydroxyphenyl) fatty acid (propionic acid etc.) and mono- or polyhydric alcohols such as methanol, Esters with octadecanol, 1,6 hexadiol, neopentyl glycol, thiodiethylene glycol, triethylene glycol, pentaerythritol, organometallic antioxidants such as phenothiazines, molybdenum, copper, and zinc, and mixtures thereof Can be mentioned.
One or two or more compounds arbitrarily selected from these can be contained in any amount, but usually the content is 0.01 to 5.0 based on the total amount of the lubricating oil composition. % By mass.
In the present invention, it is preferable to use a phenol-based antioxidant and / or an amine-based antioxidant. In particular, the phenol-based antioxidant and the amine-based antioxidant are particularly easy to maintain the anti-shudder performance over a long period of time. It is preferable to use an agent in combination. The mass ratio when the phenolic antioxidant and the amine antioxidant are used in combination is preferably 1: 5 to 10: 1, more preferably 1: 1 to 8: 1, and further preferably 2: 1 to 6: 1.

  As the extreme pressure additive, any compound usually used as an extreme pressure additive for lubricating oil can be used. For example, sulfur compounds such as dithiocarbamates, disulfides, sulfurized olefins, sulfurized fats and oils, etc. Etc. One or two or more compounds arbitrarily selected from these can be contained in any amount, but usually the content is 0.01 to 5.0 based on the total amount of the lubricating oil composition. % By mass.

Specific examples of the viscosity index improver include a so-called non-dispersed viscosity index improver such as a copolymer of one or more monomers selected from various methacrylic esters or a hydrogenated product thereof, or nitrogen. Examples thereof include a so-called dispersion type viscosity index improver obtained by copolymerizing various methacrylic esters containing a compound. Specific examples of other viscosity index improvers include non-dispersed or dispersed ethylene-α-olefin copolymers (the α-olefin can be exemplified by propylene, 1-butene, 1-pentene, etc.) or hydrogen thereof. And polyisobutylene or a hydrogenated product thereof, a styrene-diene hydrogenated copolymer, a styrene-maleic anhydride ester copolymer, and a 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 polyisobutylene or a hydride thereof. Is 800 to 5000, preferably 1000 to 4000. In the case of an ethylene-α-olefin copolymer or a hydride thereof, 800 to 150,000, preferably 3000 to 12000 are preferable.
Further, among these viscosity index improvers, when an ethylene-α-olefin copolymer or a hydride thereof is used, a lubricating oil composition particularly excellent in 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 is usually based on the lubricating oil composition standard. And 0.1 to 20.0% by mass.

Examples of the rust inhibitor include alkenyl succinic acid, alkenyl succinic acid ester, polyhydric alcohol ester, petroleum sulfonate, dinonyl naphthalene sulfonate and the like.
Examples of the corrosion inhibitor include benzotriazole, tolyltriazole, and imidazole compounds.
Examples of the pour point depressant include polymethacrylate polymers that are compatible with the lubricating base oil used.
Examples of rubber swelling agents include aromatic and ester rubber swelling agents.
Examples of the antifoaming agent include silicones such as dimethyl silicone and fluorosilicone.

  The content of these additives is arbitrary, but the content of the corrosion inhibitor is usually 0.005 to 0.2% by mass and the content of the antifoaming agent is 0.0005 to 0.00 based on the total amount of the composition. The content of 01% by mass and other additives is about 0.005 to 10% by mass, respectively.

Kinematic viscosity at 100 ° C. of the lubricating oil composition of the present invention is usually 2 to 25 mm ² / s, preferably 3 to 8 mm ² / s, more preferably 4 to 7 mm ² / s, more preferably 5 to 6 mm ² / s It is.

  The lubricating oil composition of the present invention has an excellent metal pulley and metal belt wear resistance and initial anti-shudder performance, and can maintain the anti-shudder performance for a long period of time. Although it is a lubricating oil composition suitable for a continuously variable transmission having a starting clutch, it is a lubricating oil that requires improved wear prevention or wet clutch properties, specifically, automobiles, construction machinery, agricultural machinery, etc. It is also suitably used as a lubricating oil for transmissions, manual transmissions, and differential gears. 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.

  Monoalkyl type salicylate detergents have excellent initial anti-shudder performance, but not only inhibit the anti-wear effect of phosphorus additives, but also cannot maintain the anti-skid performance of slip-controlled wet clutches for a long period of time. However, by using the component (B) and the component (C) in combination with the component (A) of the present invention, the wear is suppressed in the continuously variable transmission in which the metal pulley and the metal belt contact under severe conditions, and slip control is performed. It becomes possible to prevent a shudder peculiar to a wet type clutch for a long period of time.

  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 1-6 and Comparative Examples 1-3)
Each lubricating oil composition shown in Examples 1 to 6 in Table 1 and each lubricating oil composition shown in Comparative Examples 1 to 3 for comparison were prepared, and the following (1) initial shudder prevention performance and (2) shudder were shown. The preventive maintenance performance and (3) wear prevention performance were evaluated, and the results are also shown in Table 1. The ratio of the base oil is based on the total amount of the base oil, and the amount of each additive is based on the total amount of the composition.

(1) Initial shudder prevention performance Using LVFA, the surface pressure was set to 1.5 MPa, and other conditions were evaluated according to JASO M349-98, and dμ / dV from 2 rpm to 200 rpm was measured. dμ / dV indicates a positive value, and the larger the value, the better the initial anti-shudder performance. If dμ / dV is negative, the anti-shudder property is greatly deteriorated.
(2) Maintainability of anti-shudder performance In a continuously variable transmission in which a metal pulley and a metal belt are contacted under severe conditions, metal wear and elution of iron ions, etc. often occur, especially when the component (A) in the present invention is used. Since it was found that it is difficult to maintain the anti-shudder property, it is assumed that the lubricating oil after long-term use, and each lubricating oil composition was deteriorated at 150 ° C. for 72 hours in accordance with JIS-K2514 as an evaluation oil. Then, 300 mass ppm of organic iron containing iron ions dissolved as iron was prepared. For each evaluation oil, dμ / dV was measured by the same method as in (1). As dμ / dV shows a positive value and the value is larger, the anti-shudder performance in the wet clutch can be maintained for a long time even if the iron content due to the metal pulley and metal belt is eluted in the lubricating oil after long-term use. It is.
(3) Abrasion preventive properties In accordance with ASTM-D4172, the four-ball wear scar diameter was measured. The smaller the wear scar diameter, the better the wear resistance.

  As is apparent from the results in Table 1, when the compositions of Examples 1 to 6 according to the present invention were used, dμ / dV, which is a measure of initial anti-shudder performance, showed a positive value and a large value. The maintenance performance is also remarkable. Further, the wear scar diameter is 0.50 mm or less, and it is understood that the wear prevention performance is excellent. On the other hand, when any of the components (A) to (C) is not used (Comparative Examples 1 to 3), it can be seen that either the initial shudder prevention property or the wear prevention property is significantly inferior.

Claims (2)

In the lubricating base oil, the composition ratio of (A) monoalkyl salicylic acid metal salt is 85 to 100 mol%, the composition ratio of dialkyl salicylic acid metal salt is 0 to 15 mol%, and the composition ratio of 3-alkyl salicylic acid metal salt is 40 Alkyl salicylic acid metal salt and / or its (over) basic salt which is ˜100 mol%, (B) a nitrogen compound represented by the general formula (1) and (C) a phosphorus-based wear represented by the general formula (2) A lubricating oil composition for a transmission having a slip control type wet clutch, comprising an inhibitor.

(In General Formula (1), R ¹ is a linear or branched alkyl group having 1 to 30 carbon atoms, R ² is a hydrogen atom or a linear or branched alkyl group having 1 to 24 carbon atoms. Each represents an alkyl group, and a and b each independently represent 1, 2 or 3.)

(In General Formula (2), X ¹ , X ² and X ³ each represent an oxygen atom, R ³ , R ⁴ and R ⁵ each represent a hydrogen atom or an alkyl group having 4 to 20 carbon atoms, and Two of them represent an alkyl group having 4 to 20 carbon atoms.) The lubricating oil composition according to claim 1, comprising a friction modifier.