JP7034921B2 - Lubricating oil composition - Google Patents

Description

The present invention relates to a lubricating oil composition.

Lubricating oil (lubricating oil for a transmission) for transmitting power from an engine to a transmission is used in a transmission such as an automatic transmission oil and a stepless transmission oil. A friction modifier is added to the transmission lubricating oil to adjust its friction characteristics. Examples of the friction modifier include an amine compound having a linear alkyl group or a linear alkenyl group having 12 to 30 carbon atoms, a fatty acid amide, a fatty acid metal salt, a fatty acid having an α-branched structure having 12 or more carbon atoms, and an amine. Reaction products with and the like are known (see Patent Documents 1 to 4 below).

Japanese Unexamined Patent Publication No. 2008-106167 Japanese Unexamined Patent Publication No. 2005-146148 Japanese Unexamined Patent Publication No. 10-219269 JP-A-2007-238524

Lubricating oil for transmissions is required to have a high transmission torque capacity for improving power transmission efficiency and a shudder prevention property for improving ride comfort.

However, the shudder prevention property and the transmission torque capacity are generally in a trade-off relationship, and it is difficult to achieve both of these characteristics by using a conventional transmission lubricating oil. For example, if a conventional lubricant for a transmission having a high transmission torque capacity is used, shadder (abnormal vibration) is likely to occur, and the riding comfort of the automobile may be impaired. On the other hand, if the shudder prevention property of the lubricating oil for a transmission is enhanced, the friction coefficient of a wet clutch in an automatic transmission is lowered, and the friction coefficient between a metal belt or a metal chain and a metal pulley in a continuously variable transmission is lowered. As a result, the transmission loss increases.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a lubricating oil composition capable of achieving both excellent anti-shudder properties and a sufficiently high torque capacity.

In order to solve the above problems, the present invention has a lubricating oil base oil, a first hydrocarbon group containing a linear hydrocarbon chain having 12 or more carbon atoms, and a polar group containing oxygen and / or nitrogen. A first friction modifier, a second hydrocarbon group having 12 or more carbon atoms and no linear hydrocarbon chain having 12 or more carbon atoms, and a polar group containing oxygen and / or nitrogen. Provided is a transmission lubricating oil composition containing the second friction modifier.

According to the above-mentioned lubricating oil composition for a transmission, by combining the first friction modifier and the second friction modifier, a decrease in transmission torque capacity is sufficiently suppressed, and excellent shadder prevention is achieved. Can be achieved.

According to the study of the present inventor, the first friction modifier has excellent anti-shudder properties, but when used alone, the friction coefficient of the friction surface is excessively lowered, and the transmission torque capacity tends to be lowered. There is. On the other hand, the second friction modifier tends not to provide sufficient anti-shudder property when used alone. Therefore, when the first friction modifier and the second friction modifier are used in combination, both the first friction modifier and the second friction modifier are adsorbed on the friction surface, and the first friction modifier is used. It is presumed that the excessive decrease in the friction coefficient seen when the first friction modifier is used alone is suppressed because the function of the first friction modifier is moderately inhibited. It is considered that the combined effect of these friction modifiers makes it possible to achieve both excellent anti-shudder property and high transmission torque capacity, which were difficult to achieve with conventional lubricants for transmissions.

Based on the total amount of the lubricating oil composition, the content of the first friction modifier can be 0.01 to 5% by mass, and the content of the second friction modifier is 0.01 to. It can be 5% by mass.

According to the present invention, there is provided a lubricating oil composition capable of achieving both excellent anti-shudder properties and a sufficiently high torque capacity.

It is a figure which shows the IR measurement data in manufacturing example 1. FIG. It is a figure which shows the IR measurement data in manufacturing example 2. FIG. It is a figure which shows the IR measurement data in manufacturing example 3. FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail.

The lubricating oil composition for a transmission according to the present embodiment contains a lubricating oil base oil, a first friction modifier, and a second friction modifier.

[Lubricating oil base oil]
The lubricating oil base oil used in the present embodiment is not particularly limited, and either mineral oil or synthetic oil can be used. As the mineral oil, various conventionally known mineral oils can be used, and examples thereof include paraffin-based mineral oil, intermediate-based mineral oil, and naphthenic-based mineral oil. Specific examples thereof include light neutral oil, intermediate neutral oil, heavy neutral oil, bright stock and the like obtained by solvent refining or hydrogen refining. Further, GTL base oil obtained by isomerizing wax may be used, and the effect increases as the degree of purification increases.

Similarly, as the synthetic oil, various conventionally known oils can be used. For example, polyα-olefins (including α-olefin copolymers), polybutenes, polyol esters, dibasic acid esters, phosphate esters, polyphenyl ethers, alkylbenzenes, alkylnaphthalene, polyoxyalkylene glycols, neopentyl glycols, silicones. Oil, trimethylol propane, pentaerythritol, hindered ester and the like can be used.

These lubricating oil base oils may be used alone or in combination of two or more, and may be used in combination with mineral oil and synthetic oil.

The kinematic viscosity of the lubricating oil base oil can be appropriately selected according to the application and purpose of the lubricating oil composition. For example, when the lubricating oil composition according to the present embodiment is used as the driving system lubricating oil, the upper limit of the kinematic viscosity of the lubricating oil base oil at 100 ° C. is preferably 30 mm ² / s or less, more preferably 20 mm ² / s. It is s or less, more preferably 10 mm ² / s or less. On the other hand, the lower limit of the kinematic viscosity of the lubricating oil base oil at 100 ° C. is preferably 1 mm ² / s or more, more preferably 2 mm ² / s or more, and further preferably 3 mm ² / s or more. When the kinematic viscosity at 100 ° C. is within the above range, the friction in the sliding portion such as the gear bearing and the clutch of the automatic transmission can be sufficiently reduced, and the low temperature characteristic is also good. On the other hand, when the kinematic viscosity at 100 ° C. exceeds 30 mm ² / s, the fuel consumption tends to deteriorate and the low temperature viscosity tends to be too high. Further, when the kinematic viscosity at 100 ° C. is less than 1 mm ² / s, the lubrication performance is deteriorated such that the amount of wear is increased in the sliding parts such as the gear bearing and the clutch of the automatic transmission, and the lubricity is increased to lubricate. Oil consumption may increase.

Further, the% _CA of the lubricating oil base oil is preferably 20 or less, and more preferably 10 or less, from the viewpoint of low temperature characteristics.

In addition, the viscosity index, NOACK evaporation amount, and the like of the lubricating oil base oil used in the present embodiment can be appropriately set according to the use of the lubricating oil composition.

[First friction modifier]
The first friction modifier used in this embodiment has a first hydrocarbon group containing a linear hydrocarbon chain having 12 or more carbon atoms, and a polar group containing oxygen and / or nitrogen.

The first hydrocarbon group contains a linear hydrocarbon chain having 12 or more carbon atoms. A linear hydrocarbon chain is a structure in which carbon atoms in a hydrocarbon are bonded without branching. The number of carbon atoms of the linear hydrocarbon chain is not particularly limited as long as it is 12 or more, but it is preferably 14 or more carbon atoms, and more preferably 16 or more carbon atoms. The upper limit of the number of carbon atoms in the hydrocarbon chain is not particularly limited, but is preferably 30 or less. Further, the linear hydrocarbon chain may be saturated or unsaturated. Further, the first hydrocarbon group may be, for example, a group composed of a linear hydrocarbon chain having 12 or more carbon atoms, and has a linear hydrocarbon chain having 12 or more carbon atoms and a carbon atom serving as a branch point. It may be a group.

When the first hydrocarbon group is a group consisting of a linear hydrocarbon chain having 12 or more carbon atoms, the linear hydrocarbon chain is preferably saturated. However, when the number of carbon atoms of the linear hydrocarbon chain exceeds 16, the linear hydrocarbon chain is preferably unsaturated from the viewpoint of ensuring solubility in the base oil, and has a structure containing one double bond. It is more preferable to have.

When the first hydrocarbon group is a linear hydrocarbon chain having 12 or more carbon atoms and a group having a carbon atom serving as a branch point, the linear hydrocarbon chain is preferably saturated. As long as it has a linear hydrocarbon chain having 12 or more carbon atoms, the position of the carbon atom serving as a branch point is not particularly limited and may be present at any position. The number of carbon atoms serving as branch points is preferably 2 or less, and more preferably 1.

Examples of the first hydrocarbon group according to the present embodiment include the following formulas (1-a), formula (1-b), formula (2-a), formula (2-b) and the like.

The polar group containing oxygen and / or nitrogen is not particularly limited as long as it is a polar group contained in the friction modifier used in the lubricating oil composition for a transmission, but a specific specific such polar group is used. Examples of the structure include at least one functional group represented by the following formulas (3) to (21).

（式中、＊はそれぞれ独立に第一の炭化水素基に結合する部位を示し、式（６）中、ＸはＮａ、Ｋ、Ｚｎ、Ｃａ、Ｍｇ、Ｂ及びＡｌからなる群より選択される原子を示し、ｈはＸの価数を示し、式（７）中、ＹはＮａ、Ｋ、Ｚｎ、Ｃａ、Ｍｇ、Ｂ及びＡｌからなる群より選択される原子を示し、ｉはＹの価数を示し、式（８）中、ｊ及びｋはそれぞれ独立に１～１０の整数を示し、式（９）中、ｌ及びｍはそれぞれ独立に１～１０の整数を示し、式（１０）中、ｎは０～１０の整数を示し、式（１１）中、ｏは０～１０の整数を示し、式（１２）中、ｐは０～１０の整数を示し、式（１３）中、ｑは０～１０の整数を示す。）

(In the formula, * indicates a site that independently binds to the first hydrocarbon group, and in formula (6), X is selected from the group consisting of Na, K, Zn, Ca, Mg, B and Al. An atom is indicated, h is an valence of X, Y is an atom selected from the group consisting of Na, K, Zn, Ca, Mg, B and Al in the formula (7), and i is a valence of Y. In equation (8), j and k independently indicate integers of 1 to 10, and in equation (9), l and m independently indicate integers of 1 to 10, respectively, and equation (10). In equation (11), o indicates an integer of 0 to 10, p indicates an integer of 0 to 10, and in equation (13), n indicates an integer of 0 to 10. q indicates an integer from 0 to 10.)

In the formulas (8) and (9), j, k, l and m are not particularly limited as long as they are independently integers of 0 to 10, but are preferably integers of 1 to 5, and more preferably 1. It is an integer of 3 to 3, and more preferably 1.

In the formula (10), the formula (11), the formula (12) and the formula (13), n, o, p and q are not particularly limited as long as they are independently integers of 0 to 10, but preferably 1 to 1. It is an integer of 5, and more preferably an integer of 1 to 4.

As the first friction modifier, only those having a single polar group may be used, or those having different polar groups may be used in any combination. From the viewpoint of having sufficient adsorptive power from a low temperature range and imparting more excellent anti-shudder performance to the lubricating oil composition, the first friction modifier is the formula (4), the formula (8), and the formula (9). ), Formula (10), Formula (16), Formula (19) and Formula (20), preferably having at least one functional group represented by the formula (8). It is more preferable to have.

Further, examples of such a first friction modifier include compounds represented by the following formulas (22) to (25). These first friction modifiers may be used alone or in combination of two or more.

（式中、ｎは０～１０の整数を示す。）

(In the formula, n indicates an integer from 0 to 10.)

The first friction modifier may be a commercially available product or may be synthesized by a known method.

In the lubricating oil composition according to the present embodiment, the content of the first friction modifier is not particularly limited, but is preferably 0.01 to 5% by mass, more preferably, based on the total amount of the lubricating oil composition. It is 0.01 to 3% by mass, more preferably 0.01 to 1% by mass. When the content of the first friction modifier is in the above range, it is possible to more effectively impart excellent shudder prevention performance to the lubricating oil composition.

[Second friction modifier]
The second friction modifier used in the present embodiment contains a second hydrocarbon group having 12 or more carbon atoms and no linear hydrocarbon chain having 12 or more carbon atoms, and oxygen and / or nitrogen. Has a polar group containing.

The second hydrocarbon group is a group having 12 or more carbon atoms and does not contain a linear hydrocarbon chain having 12 or more carbon atoms. The second hydrocarbon group is not particularly limited as long as it does not contain a linear hydrocarbon chain having 12 or more carbon atoms, but is preferably 14 or more carbon atoms, and more preferably 16 or more carbon atoms. The upper limit of the carbon number of the second hydrocarbon group is not particularly limited, but is preferably 30 or less. Further, the second hydrocarbon group may be saturated or unsaturated.

The second hydrocarbon group is a group that does not contain a linear hydrocarbon chain having 12 or more carbon atoms, but preferably does not contain a linear hydrocarbon chain having 10 or more carbon atoms, and is a straight chain having 8 or more carbon atoms. It is more preferable that it does not contain a hydrocarbon chain. Further, the second hydrocarbon group preferably has one or more carbon atoms serving as a branch point.

Examples of such a second hydrocarbon group include the following formula (26-a), formula (26-b), formula (27-a), formula (27-b) and the like.

The polar group containing oxygen and / or nitrogen in the second friction modifier is not particularly limited as long as it is a polar group contained in the friction modifier used in the lubricating oil composition for a transmission. Specific examples of such a polar group include at least one functional group represented by the following formulas (28) to (46).

（式中、＊はそれぞれ独立に第二の炭化水素基に結合する部位を示し、式（３１）中、ＸはＮａ、Ｋ、Ｚｎ、Ｃａ、Ｍｇ、Ｂ及びＡｌからなる群より選択される原子を示し、ｈはＸの価数を示し、式（３２）中、ＹはＮａ、Ｋ、Ｚｎ、Ｃａ、Ｍｇ、Ｂ及びＡｌからなる群より選択される原子を示し、ｉはＹの価数を示し、式（３３）中、ｊ及びｋはそれぞれ独立に１～１０の整数を示し、式（３４）中、ｌ及びｍはそれぞれ独立に１～１０の整数を示し、式（３５）中、ｎは０～１０の整数を示し、式（３６）中、ｏは０～１０の整数を示し、式（３７）中、ｐは０～１０の整数を示し、式（３８）中、ｑは０～１０の整数を示す。）

(In the formula, * indicates a site that independently binds to the second hydrocarbon group, and in formula (31), X is selected from the group consisting of Na, K, Zn, Ca, Mg, B and Al. An atom is shown, h is a valence of X, Y is an atom selected from the group consisting of Na, K, Zn, Ca, Mg, B and Al in the formula (32), and i is a valence of Y. In equation (33), j and k independently indicate integers of 1 to 10, and in equation (34), l and m independently indicate integers of 1 to 10, respectively, and equation (35). In equation (36), o indicates an integer of 0 to 10, p indicates an integer of 0 to 10, and in equation (38), n indicates an integer of 0 to 10. q indicates an integer from 0 to 10.)

In the formula (33) and the formula (34), j, k, l and m are not particularly limited as long as they are independently integers of 0 to 10, but are preferably integers of 1 to 5, and more preferably 1. It is an integer of ~ 3, and more preferably 1.

In the formula (35), the formula (36), the formula (37) and the formula (38), n, o, p and q are not particularly limited as long as they are independently integers of 0 to 10, but preferably 1 to 1. It is an integer of 5, and more preferably an integer of 1 to 4.

As the second friction modifier, only those having a single polar group may be used, or those having different polar groups may be used in any combination. From the viewpoint of having sufficient adsorption force in a high temperature range and imparting a higher torque capacity to the lubricating oil composition, the second friction modifier is prepared by the formulas (35), (36) and (37). And at least one functional group represented by the formula (38), and more preferably at least one functional group represented by the formula (35).

Examples of such a second friction modifier include compounds represented by the following formulas (47) and (48). These second friction modifiers can be used alone or in combination of two or more.

（式中、ｎは０～１０の整数を示す。）

(In the formula, n indicates an integer from 0 to 10.)

（式中、ｎは０～１０の整数を示す。）

(In the formula, n indicates an integer from 0 to 10.)

In the lubricating oil composition according to the present embodiment, the content of the second friction modifier is not particularly limited, but is preferably 0.01 to 5% by mass, more preferably, based on the total amount of the lubricating oil composition. It is 0.01 to 3% by mass, more preferably 0.01 to 1% by mass. When the content of the second friction modifier is in the above range, a higher torque capacity can be imparted to the lubricating oil composition.

Further, in the lubricating oil composition according to the present embodiment, the content ratios of the first friction modifier and the second friction modifier are, for example, A for the number of moles of the first friction modifier and the second friction modifier. When the number of moles is B, the molar ratio is preferably A: B = 1:10 to 10: 1, more preferably 1: 5 to 5: 1, and 1: 2 to 2: 1. It is more preferably 1 and particularly preferably 1: 1. When the content ratio of both is within the above range, both excellent shudder prevention performance and sufficiently high torque capacity can be achieved at a higher level.

[Any additive]
The lubricating oil composition according to the present embodiment further contains any additive other than the first friction modifier and the second friction modifier, if necessary, for the purpose of further improving its performance. Can be done.

As the additive, an additive that can be added to the lubricating oil composition for a transmission can be used without particular limitation. Examples of the additive include a viscosity index improver, an ashless dispersant other than the first friction modifier and the second friction modifier, and / or a friction modifier, an anti-wear agent, a metal-based detergent, and a metal inert. Examples thereof include agents, antioxidants, antifoaming agents and the like. These additives may be used alone or in combination of two or more.

Examples of the viscosity index improver include a non-dispersion type or a dispersion type viscosity index improver. Specifically, non-dispersion or dispersion polymethacrylates, non-dispersion or dispersion ethylene-α-olefin copolymers or hydrides thereof, polyisobutylene or hydrides thereof, styrene-diene hydride copolymers, Examples thereof include a styrene-maleic anhydride copolymer, a polymethacrylate-styrene copolymer, a polymethacrylate-olefin copolymer, and a polyalkylstyrene. The weight average molecular weight of these viscosity index improvers is not particularly limited and is usually 10,000 to 1,000,000. The content of the viscosity index improver is also not particularly limited, but is usually 0.5 to 35% by mass based on the total amount of the lubricating oil composition.

Examples of the ashless dispersant and / or the friction modifier other than the first friction modifier and the second friction modifier include amine compounds, imide compounds, fatty acid esters, fatty acid amides, fatty acids, aliphatic alcohols, aliphatic ethers, and molybdenum. Examples thereof include organic molybdenum compounds such as dithiophosphate (MoDTP) and molybdenum dithiocarbamate (MoDTC), graphite, molybdenum disulfide, antimony sulfide, boron compounds, polytetrafluoroethylene and the like. The content of the ashless dispersant and / or the friction modifier is not particularly limited, but is usually 0.1 to 10% by mass based on the total amount of the lubricating oil composition.

As the anti-wear agent, for example, a sulfur-based anti-wear agent, a phosphorus-based anti-wear agent, or the like can be used. Examples of the sulfur-based anti-wear agent include sulfur-containing compounds such as disulfides, polysulfides, sulfurized olefins, sulfurized oils and fats, sulfurized esters, dithiocarbamate, and zinc dithiocarbamate. Examples of the phosphorus-based anti-wear agent include phosphoric acid, monothiophosphate, dithiophosphate, trithiophosphate, tetrathiophosphate, phosphate ester, subphosphate ester, thiophosphate ester and the like. The content of the anti-wear agent is not particularly limited, but is usually 0.01 to 10% by mass based on the total amount of the lubricating oil composition.

Examples of the metal-based detergent include calcium sulfonate, magnesium sulfonate, barium sulfonate, calcium salicylate, magnesium salicylate, calcium phenate, normal salt such as barium phenate, basic salt or hyperbasic salt and the like. Can be mentioned. The content of the metal-based detergent is not particularly limited, but is usually 0.1 to 10% by mass based on the total amount of the lubricating oil composition.

Examples of the metal inactivating agent include imidazoline, pyrimidine, thiadiazole, mercaptobenzothiazole, benzotriazole, and derivatives thereof. The content of the metal deactivating agent is not particularly limited, but is usually 0.01 to 10% by mass based on the total amount of the lubricating oil composition.

Examples of the antioxidant include phenol-based, amine-based, copper-based, molybdenum-based and other antioxidants. Specifically, amine-based antioxidants such as alkylated diphenylamine, phenyl-α-naphthylamine, and alkylated-α-naphthylamine, 2,6-di-t-butyl-4-methylphenol, 4,4'-methylenebis. Examples thereof include hindered phenolic antioxidants such as (2,6-di-t-butylphenol). The content of the antioxidant is not particularly limited, but is usually 0.05 to 5% by mass based on the total amount of the lubricating oil composition.

As the defoaming agent, any compound usually used as a defoaming agent for lubricating oil can be used, and examples thereof include silicones such as dimethyl silicone and fluorosilicone. One or more compounds arbitrarily selected from these can be blended in any amount.

The lubricating oil composition according to the present embodiment is suitable as a lubricating oil composition for transmissions such as automatic transmission oil and continuously variable transmission oil because it can maintain a balance between excellent shudder prevention property and high torque capacity. Is. It can also be used as a lubricating oil for construction machinery and agricultural machinery equipped with a transmission having a wet clutch and a wet brake, a manual transmission, a two-wheeled vehicle gasoline engine, a diesel engine, a gas engine, a shock absorber oil and the like.

Hereinafter, the present invention will be described in more detail based on Examples and Comparative Examples, but the following Examples are not intended to limit the present invention.

[Examples 1 to 9, Comparative Examples 1 to 10]
Lubricating oil compositions having the compositions shown in Tables 1 and 2 were prepared using the base oils and additives shown below. The content ratio of each component in Tables 1 and 2 indicates the content ratio based on the total amount of the lubricating oil composition.

(Base oil)
a1: Hydrodesulfurized mineral oil (40 ° C kinematic viscosity: 19.4 mm ² / s, 100 ° C kinematic viscosity: 4.2 mm ² / s, viscosity index: 125, sulfur content: less than 1 ppm)

ｂ２：下記式（２３）で表される化合物。

ｂ３：下記式（２５）で表され、式中のｎが３である化合物。

(First friction modifier)
b1: A compound represented by the following formula (22).

b2: A compound represented by the following formula (23).

b3: A compound represented by the following formula (25) in which n is 3.

ｃ２：下記式（４８）で表され、式中のｎが３である化合物。

(Second friction modifier)
c1: A compound represented by the following formula (47) in which n is 3.

c2: A compound represented by the following formula (48) in which n is 3.

(Other additives)
d1: Non-dispersive polymethacrylate-based viscosity index improver (weight average molecular weight: 20000)
d2: Non-borated succinimide-based dispersant [bis-type alkenyl succinimide (alkenyl group: polyisobutenyl group of Mw1000, polyamine moiety: tetraethylenepentamine), nitrogen content: 1.3% by mass]
d3: Borylated succinimide-based dispersant [Bis-type alkenyl succinimide (alkenyl group: polyisobutenyl group of Mw1000, polyamine moiety: tetraethylenepentamine), nitrogen content: 1.3% by mass, boron content: 0.3% by mass)
d4: Phosphite ester anti-wear agent (dialkylphosphite)
d5: Over-base type calcium sulfonate-based metal-based detergent (TBN300, calcium content: 12% by mass)
d6: Metal inactivating agent (thiadiazole, sulfur content: 36% by mass)
d7: Hindered phenolic antioxidant d8: Antifoaming agent (polydimethylsiloxane)

Commercially available products were used as the friction modifiers b1 and b2, respectively. Further, the friction modifier b3 and the friction modifiers c1 and c2 were synthesized as follows.

(Manufacturing Example 1: Synthesis of friction modifier (b3))
A flask equipped with a nitrogen introduction tube, a cooler, a Dean-Stark trap, and a stirrer was charged with 178 g of oleic acid, 59 g of tetraethylenepentamine, and 500 ml of xylene. After replacing the inside of the flask with nitrogen while stirring, the reaction was carried out for 20 hours while heating at 160 ° C. and refluxing. Completion of the reaction was confirmed by IR. The IR measurement data is shown in FIG. After completion of the reaction, the solvent was removed by distillation to obtain a friction modifier (b3).
(Manufacturing Example 2: Synthesis of friction modifier (c1))
A friction modifier (c1) was obtained by the same method as in Production Example 1 except that 178 g of isostearic acid was used instead of 178 g of oleic acid. The IR measurement data is shown in FIG.

(Manufacturing Example 3: Synthesis of Friction Modifier (c2))
A friction modifier (c2) was obtained by the same method as in Production Example 1 except that 160 g of 2-hexyldecanoic acid was used instead of 178 g of oleic acid. The IR measurement data is shown in FIG.

[Evaluation test of lubricating oil composition]
(Shadder prevention)
The shudder prevention property of each lubricating oil composition prepared above was calculated according to JASO M349: 2010. Specifically, an approximate formula showing the μ-V characteristics of each lubricating oil composition prepared above at 40 ° C. was obtained, and dμ / dV (dμ / dV (0.3)) at a slip speed of 0.3 m / s was obtained. ) Was asked. Regarding the shudder prevention property, it is judged that the one in which the value of "dμ / dV (0.3)" is positive is excellent in the shudder prevention property.

(Torque capacity)
The torque capacity of the lubricating oil compositions prepared in Examples 1 to 7 and Comparative Examples 1 to 8 was determined by using a low-speed slip test device (LVFA) to determine the μ-V characteristics of the lubricating oil composition at 120 ° C. JASO M349 :. It was calculated in accordance with 2010, and was obtained by calculating the friction coefficient μ at a slip speed of 0.06 m / s in the μ-V characteristic.

The torque capacity of the lubricating oil compositions prepared in Examples 8 to 9 and Comparative Examples 9 to 10 was calculated in accordance with the JASO M358 low load method using a friction and wear tester (LFW-1), and the slip speed. It was obtained by calculating the friction coefficient μ at 0.075 m / s.

The results of the evaluation tests of the lubricating oil compositions of Examples 1 to 9 and Comparative Examples 1 to 10 are shown in Tables 3 and 4.

Claims (2)

Lubricating oil base oil and
A first friction modifier having a first hydrocarbon group and a polar group containing oxygen and / or nitrogen,
A second friction modifier having a second hydrocarbon group and a polar group containing oxygen and / or nitrogen,
The first hydrocarbon group in the first friction modifier is the following general formula (1-a) or (1-b), and the oxygen and / in the first friction modifier. Alternatively, the polar group containing nitrogen is the following formula (4), (8), (9) or (19).
The second hydrocarbon group in the second friction modifier has the following general formulas (26-a), (26-b), (27-a) or (27-b), and the second A lubricating oil composition for a transmission, wherein the polar group containing oxygen and / or nitrogen in the friction modifier is the following formula (35) or (36).

(In formulas (4), (8), (9), and (19), * indicates a site that independently binds to the first hydrocarbon group, and in formula (8), j and k are independently. An integer of 1 to 10 is shown, and in equation (9), l and m independently indicate an integer of 1 to 10).

(In formulas (35) and (36), * indicates a site that independently binds to the second hydrocarbon group, and in formula (35), n represents an integer of 0 to 10, and formula (36). In the middle, o indicates an integer from 0 to 10.) Based on the total amount of the lubricating oil composition, the content of the first friction modifier is 0.01 to 5% by mass, and the content of the second friction modifier is 0.01 to 5% by mass. The lubricating oil composition for a transmission according to claim 1.

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