JP7029947B2 - Lubricating oil composition - Google Patents

Description

The present invention relates to a lubricating oil composition, for example, a lubricating oil composition for a continuously variable transmission.

In recent years, improving fuel efficiency has become an important issue for automobiles due to global environmental problems, and continuously variable automatic transmissions (hereinafter, "CVT") are more efficient than multi-stage automatic transmissions (hereinafter, also referred to as "AT"). The mounting ratio of "" is increasing. As the CVT, a belt type is generally used for a relatively low torque engine, and a chain type is generally used for a high torque engine.

Belt-type or tune-type CVTs transmit power by friction between the pulley and the belt or between the pulley and the chain. The belt or chain is pressed against the pulley with great force to prevent slipping between them. The space between the pulley and the belt or the pulley and the chain is lubricated with lubricating oil, but since the reduction of the pressing force between them leads to the improvement of fuel efficiency, the friction coefficient between metals should be increased for the lubricating oil for CVT. Is required. In addition, vibration or noise may occur between the pulley and the belt or between the pulley and the chain. Therefore, conventionally, in order to prevent the above-mentioned vibration and noise while increasing the coefficient of friction between metals, a CVT containing a high-basic alkaline earth metal sulfonate, a sulfur-containing phosphorus compound, and an aliphatic primary amine is blended. Lubricants for use are known (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2014-98063

However, in recent years, since the engine has a high output and the torque and the like have become high, in a CVT, particularly a chain type CVT, the lubrication state between the pulley and the chain or between the pulley and the belt has become severe. Therefore, even if the conventional lubricating oil for CVT disclosed in Patent Document 1 is used, the coefficient of friction between metals may not be sufficiently increased. Further, it is becoming difficult to suppress vibration and noise generated between the pulley and the chain or between the pulley and the belt.

The present invention has been made in view of the above problems, and the object of the present invention is to use a pulley and a chain or a pulley while increasing the coefficient of friction between metals even if the lubrication state becomes severe in a CVT or the like. It is an object of the present invention to provide a lubricating oil composition capable of suppressing vibration and noise generated between the belt and the belt.

As a result of diligent studies, the present inventor has found that the above problems can be solved by blending an alkaline earth metal-based detergent, a phosphite ester, and an aliphatic monoamine in a predetermined amount in a base oil, and the following inventions have been made. Was completed. That is, the present invention provides the following lubricating oil composition and a method for producing the lubricating oil composition.
(1) Atomic weight of alkaline earth metal derived from component (A) containing base oil, alkaline earth metal detergent (A), phosphite ester (B), and aliphatic monoamine (C). However, the composition has an atomic weight of 300 mass ppm or more and 600 mass ppm or less based on the total amount of the composition, a phosphorus atomic weight derived from the component (B) of 5 mass ppm or more and 50 mass ppm or less based on the total amount of the composition, and a nitrogen atomic weight derived from the component (C). Lubricating oil composition having a total amount of 50% by mass or more and 200% by mass or less.
(2) At least the alkaline earth metal detergent (A), the phosphite ester (B), and the aliphatic monoamine (C) are added to the base oil, and the atomic weight of the alkaline earth metal derived from the component (A) is composed. 300% by mass or more and 600% by mass or less based on the total amount of the material, (B) the phosphorus atomic weight derived from the component is 5% by mass or more and 50% by mass or less based on the total amount of the composition, and (C) the nitrogen atomic weight derived from the component is the total amount of the composition. A method for producing a lubricating oil composition, which comprises blending the mixture so as to be contained in the lubricating oil composition at an amount of 50% by mass or more and 200% by mass or less to obtain a lubricating oil composition.

Provided is a lubricating oil composition capable of suppressing vibration and noise generated between a pulley and a chain or a pulley and a belt while increasing the coefficient of friction between metals even if the lubrication state becomes severe in a CVT or the like. do.

Hereinafter, the present invention will be described with reference to embodiments.
The lubricating oil composition according to one embodiment of the present invention contains a base oil, an alkaline earth metal-based detergent (A), a phosphite ester (B), and an aliphatic monoamine (C). Hereinafter, each component used in the lubricating oil composition will be described in detail.

(Base oil)
The base oil used in the lubricating oil composition is not particularly limited, and any mineral oil or synthetic oil can be used as long as it can be used for an automatic transmission.
Examples of the mineral oil include paraffin-based mineral oil, intermediate-based mineral oil, naphthenic-based mineral oil, and the like, and specific examples thereof include light neutral oil, medium neutral oil, heavy neutral oil, and bright stock. Further, GTL oil produced by isomerizing GTL WAX (gas to liquid wax) can also be mentioned as mineral oil.
Examples of the synthetic oil include polybutene, polyolefins represented by α-olefin homopolymers and copolymers (for example, ethylene-α-olefin copolymers), polyol esters, dibasic acid esters, phosphoric acid esters and the like. Examples thereof include various esters, various ethers such as polyphenyl ethers and polyoxyalkylene glycols, alkylbenzenes and alkylnaphthalene.
In the lubricating oil composition, one type of the above mineral oil may be used as the base oil, or two or more types may be used in combination. Further, one kind of the above synthetic oil may be used, or two or more kinds may be used in combination. Furthermore, one or more types of mineral oil and one or more types of synthetic oil may be used in combination.

The base oil is not particularly limited, but the kinematic viscosity at 100 ° C. is preferably 0.5 mm ² / s or more and 10 mm ² / s or less, more preferably 1 mm ² / s or more and 7 mm ² / s or less, and 1.5 mm ² / s. More preferably 4 mm ² / s or less. By setting the kinematic viscosity of the base oil within these ranges, it becomes easy to adjust the kinematic viscosity of the lubricating oil composition within the range described later. The viscosity index of the base oil is preferably 80 or more, more preferably 90 or more, and even more preferably 100 or more. By setting the viscosity index of the base oil within these ranges, it becomes easy to adjust the viscosity index of the lubricating oil composition within the range described later.
In this specification, the kinematic viscosity and the viscosity index are measured according to JIS K 2283: 2000.
In the lubricating oil composition, the base oil is preferably contained in an amount of 60% by mass or more, more preferably 65% by mass, based on the total amount of the lubricating oil composition (also simply referred to as “total amount of composition standard” in the present specification). It is contained in an amount of 97% by mass or less, more preferably 70% by mass or more and 95% by mass or less.

(Alkaline earth metal-based detergent (A))
The lubricating oil composition of the present embodiment contains an alkaline earth metal-based detergent (A). By containing the alkaline earth metal-based detergent (A) in the lubricating oil composition, it is possible to increase the coefficient of friction between metals even if the lubricating state becomes severe. Further, the coefficient of friction between metals and the slip velocity characteristic (hereinafter, also referred to as “μ-V characteristic between metals”) are also good. When the μ-V characteristic between metals becomes good in the lubricating oil composition, it becomes possible to reduce the vibration and noise generated between the pulley and the chain or between the pulley and the belt.

Examples of the alkaline earth metal-based cleaning agent (A) include alkaline earth metal sulfonate, alkaline earth metal salicylate, and alkaline earth metal phenate. Here, examples of the alkaline earth metal include magnesium and calcium, and calcium is preferably used. Preferable specific examples of the alkaline earth metal-based detergent (A) include calcium sulphonate and calcium salicylate, and calcium sulphonate is more preferable. The alkaline earth metal-based detergent (A) may be used alone or in combination of two or more.

As the alkaline earth metal-based detergent (A), basic and hyperbasic ones are preferably used, and specifically, the base value is preferably 300 mgKOH / g or more. The base value is more preferably 300 mgKOH / g or more and 500 mgKOH / g or less, and further preferably 350 mgKOH / g or more and 450 mgKOH / g or less. As described above, by increasing the base value of the alkaline earth metal-based cleaning agent (A), it becomes easy to increase the coefficient of friction between metals. The base value was measured according to the perchloric acid method of JIS K-2501: 2003.

(Phosphite ester (B))
The lubricating oil composition further contains a phosphite ester (B) in addition to the above component (A). By containing the phosphite ester (B) in the lubricating oil composition, it is possible to increase the coefficient of friction between metals even if the lubricating state becomes severe. Furthermore, the μ-V characteristics between metals are also improved, and vibration and noise can be reduced as described above.

Specific examples of the phosphite ester (B) include compounds represented by the following formula (I).
(R ¹ O) _a P (OH) _3-a ... (I)
(In the formula (I), R ¹ represents a hydrocarbon group having 12 to 16 carbon atoms, and a represents an integer of 1 to 3. When a is 2 or 3, R ¹ may be the same as each other. And may be different.)

In the formula (I), examples of the hydrocarbon group represented by R ¹ include an alkyl group, an alkenyl group, an aryl group, an aralkyl group and the like, and the hydrocarbon group may be an aliphatic hydrocarbon group such as an alkyl group and an alkenyl group. preferable.
The alkyl group and the alkenyl group may be linear, branched or cyclic, and examples thereof include various dodecyl groups, various tetradecyl groups, various hexadecyl groups, various dodecenyl groups, various tetradecenyl groups and various hexadecenyl groups. And so on. The term "various" as used herein means to include linear chains and all branched chain chains which are structural isomers thereof, and the same applies hereinafter.

As the phosphite ester (B), in the formula (I), a is preferably 2 and R ¹ is an aliphatic hydrocarbon group having 12 to 16 carbon atoms, and a is 2 and a is 2. It is more preferable that the aliphatic hydrocarbon group has 12 to 14 carbon atoms, and it is further preferable that the aliphatic hydrocarbon group is an alkyl group.
Examples of such phosphite ester (B) include dilaurylhydrogenphosphite, dimyristylhydrogenphosphite, dipalmitylhydrogenphosphite, and the like, and among them, dilaurylhydrogenphosphite is preferable.
The phosphite ester (B) may be used alone or in combination of two or more.

(Alphatic monoamine (C))
The lubricating oil composition in the present embodiment contains an aliphatic monoamine (C) in addition to the above components (A) and (B). By containing the aliphatic monoamine (C) in the lubricating oil composition, it is possible to increase the coefficient of friction between metals even if the lubricating state becomes severe. Furthermore, the μ-V characteristics between metals are also improved, and vibration and noise can be reduced as described above.

Specific examples of the aliphatic monoamine (C) include compounds represented by the following formula (II).
NR ² R ³ R ⁴ ... (II)
(In formula (II), R ² represents an aliphatic hydrocarbon group having 12 to 18 carbon atoms, R ³ and R ⁴ represent hydrogen atoms, or an alkyl group having 1 to 4 carbon atoms. R ³ and R ⁴ represent each other. It may be the same or different.)

In the formula (II), examples of the aliphatic hydrocarbon group represented by R ² include an alkyl group and an alkenyl group. The alkyl group and the alkenyl group may be linear, branched or cyclic, and examples thereof include various dodecyl groups, various tetradecyl groups, various hexadecyl groups, various octadecyl groups, various dodecenyl groups and various tetradecenyl groups. , Various hexadecenyl groups, various octadecenyl groups and the like.
Further, in the formula (II), the alkyl groups having 1 to 4 carbon atoms represented by R ³ and R ⁴ are methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group and sec-. Examples thereof include a butyl group and a tert-butyl group.

As the aliphatic monoamine (C), in the formula (II), R ² is an aliphatic hydrocarbon group having 12 to 18 carbon atoms, and R ³ and R ⁴ are hydrogen atoms or an alkyl group having 1 to 2 carbon atoms. Group monoamines are preferable, and among them, primary amines in which R ² is an aliphatic hydrocarbon group having 12 to 18 carbon atoms and R ³ and R ⁴ are hydrogen atoms are more preferable, and the aliphatic hydrocarbon group is an alkenyl group. Is even more preferable.
The aliphatic monoamine (C) may be used alone or in combination of two or more.

As the aliphatic monoamine (C), it is more preferable to use a primary amine as described above, and among them, as a component (C), a primary amine (that is, an amine in which R ³ and R ⁴ are hydrogen atoms) is used. It is preferable to use it alone, but a primary amine and a tertiary amine (that is, an amine in which R ³ and R ⁴ are alkyl groups) may be used in combination.
When used in combination, as described above, the primary amine is an aliphatic hydrocarbon group having 12 to 18 carbon atoms, R ³ and R ^{4 are hydrogen atoms, and the tertiary amine is R 2 .} Is an aliphatic hydrocarbon group having 12 to 18 carbon atoms, and R ³ and R ⁴ are preferably an alkyl group having 1 to 2 carbon atoms.
When the above primary amine and tertiary amine are used in combination, the mass ratio of the nitrogen atomic weight derived from the tertiary amine (tertiary amine / primary amine) to the nitrogen atomic weight derived from the primary amine is preferably 0.15 or more and 6 or less. , 0.25 or more and 4 or less is preferable, and 0.33 or more and 3 or less is more preferable.
Preferable specific examples of the primary amine that can be used as the aliphatic monoamine (C) include laurylamine, myristylamine, palmitylamine, stearylamine, and oleylamine. Examples of the tertiary amine include dimethyllaurylamine, dimethylmyristylamine, dimethylpalmitylamine, dimethylstearylamine, and dimethyloleylamine. Among these, oleylamine is particularly preferable as the aliphatic monoamine (C).

(Contents of components (A) to (C))
The lubricating oil composition has an alkaline earth metal atomic weight derived from the alkaline earth metal detergent (A) of 300% by mass or more and 600% by mass or less based on the total amount of the composition, and a phosphorus atomic weight derived from the phosphite ester (B). The above (A) to (A) to (A) to (A) to (A) to 50 mass ppm or less based on the total amount of the composition and 50 mass ppm or more and 200 mass ppm or less based on the total amount of the composition. C) Contains ingredients.
In the present embodiment, when the alkaline earth metal atomic weight, phosphorus atomic weight, and nitrogen atomic weight derived from (A) to (C) are out of the above ranges, the coefficient of friction between metals becomes high when the lubrication state becomes severe. It becomes difficult to do. Further, it becomes difficult to improve the μ-V characteristics between metals, and it becomes difficult to reduce the vibration and noise generated between the pulley and the chain described above.

The alkaline earth metal atomic weight derived from the component (A) is obtained by measuring the amount of the alkaline earth metal atom in the component (A) by ICP analysis and converting it to the total composition standard. The phosphorus atom content derived from the component (B) is obtained by measuring the phosphorus atom content in the component (B) by ICP analysis and converting it on the basis of the total amount of the composition. Further, the nitrogen atomic weight derived from the component (C) is obtained by measuring the nitrogen atomic weight in the component (C) in accordance with JIS K 2609: 1998 and converting it into the total composition standard.

From the viewpoint of further improving the coefficient of friction between metals and the μ-V characteristics between metals, the atomic weight of the alkaline earth metal derived from the component (A) is preferably 350 mass ppm or more and 575 mass ppm or less based on the total amount of the composition. It is more preferably 400 mass ppm or more and 550 mass ppm or less.
From the same viewpoint, the phosphorus atomic weight derived from the component (B) is preferably 10 mass ppm or more and 40 mass ppm or less, and more preferably 15 mass ppm or more and 30 mass ppm or less, based on the total amount of the composition. .. Similarly, the nitrogen atomic weight derived from the component (C) is preferably 70 mass ppm or more and 160 mass ppm or less, and more preferably 80 mass ppm or more and 140 mass ppm or less, based on the total amount of the composition.

(Viscosity index improver)
The lubricating oil composition preferably contains a viscosity index improver. By containing the viscosity index improver, the lubricating oil composition tends to improve the viscosity index, and for example, the viscosity index can be set to 200 or more as described later.
Examples of the viscosity index improver include polymethacrylate (PMA) -based agents such as polyalkyl methacrylate, ethylene-propylene copolymers, olefin copolymer (OCP) -based agents such as polybutylene, styrene-diene copolymers, and styrene-isoprenes. Examples include a styrene copolymer system such as a copolymer. Among these, the polymethacrylate system is preferable. The viscosity index improver may be either a dispersed type or a non-dispersed type, but a non-dispersed type is preferable.
The weight average molecular weight (Mw) of the viscosity index improver is preferably 30,000 or more and 40,000 or less. The weight average molecular weight refers to the polystyrene-equivalent molecular weight obtained by gel permeation chromatography (GPC) measurement.
The structure of the viscosity index improver may be a straight chain or may have a branched chain. Further, it may be a polymer having a specific structure such as a comb-shaped polymer having a structure having a large number of three-pronged branch points having a large number of side chains in the main chain. By using a comb-shaped polymer, it is possible to improve the viscosity index with a small amount of the viscosity index improver. The viscosity index improver may be contained in an amount that appropriately improves the viscosity index.

(Other additives)
The lubricating oil composition may further contain components (A) to (C) and other additives other than the viscosity index improver, if necessary, as long as the effects of the present invention are not impaired. Examples of other additives include phosphorus compounds other than the above component (B), monoamine compounds other than the component (C), antioxidants, ashless dispersants, sulfur-based extreme pressure agents, and copper inactivating agents. , Anti-rust agents, friction modifiers, antifoaming agents and the like. As these other additives, one kind or two or more kinds may be appropriately selected and used.

Examples of the phosphorus-based compound other than the component (B) include a phosphoric acid ester, an acidic phosphoric acid ester, and an amine salt thereof. Examples of the phosphoric acid ester include trialkyl phosphate and trialkenyl phosphate. Examples of the acidic phosphoric acid ester include monoalkyl acid phosphate, dialkyl acid phosphate, monoalkenyl acid phosphate, dialkenyl acid phosphate and the like. Examples of the alkyl group and the alkenyl group in the phosphoric acid ester and the acidic phosphoric acid ester include those having about 8 to 18 carbon atoms. Examples of the monoamine compound other than the component (C) include aromatic monoamine compounds having one aromatic ring such as phenylamine.

Examples of the antioxidant include amine-based antioxidants other than the above-mentioned monoamine compounds (for example, diphenylamines, phenylnaphthylamines, etc.), phenol-based antioxidants, sulfur-based antioxidants, and the like. The content of the antioxidant is preferably 0.05% by mass or more and 7% by mass or less, and more preferably 0.1% by mass or more and 5% by mass or less based on the total amount of the lubricating oil composition.
Examples of the ashless dispersant include succinimide compounds, borated succinimide compounds, and acid amide compounds. The content of the ashless dispersant is preferably 0.1% by mass or more and 20% by mass or less, and more preferably 0.5% by mass or more and 15% by mass or less based on the total amount of the composition.
Examples of the sulfur-based extreme pressure agent include thiadiazole-based compounds, polysulfide-based compounds, thiocarbamate-based compounds, sulfurized fat-based compounds, and sulfurized olefin-based compounds. The content of the sulfur-based extreme pressure agent is preferably 0.02% by mass or more and 3% by mass or less, and more preferably 0.05% by mass or more and 2% by mass or less based on the total amount of the composition.

Examples of the copper inactivating agent include benzotriazole, benzotriazole derivative, triazole, triazole derivative, imidazole, imidazole derivative, thiadiazole, thiadiazole derivative and the like. The content of the copper inactivating agent is preferably 0.01% by mass or more and 5% by mass or less, and more preferably 0.02% by mass or more and 3% by mass or less based on the total amount of the composition.
Examples of the rust preventive agent include fatty acids, alkenyl succinic acid half esters, fatty acid sucrose, alkyl sulfonates, polyhydric alcohol fatty acid esters, fatty acid amides, oxidized paraffins, and alkyl polyoxyethylene ethers. The content of the rust inhibitor is preferably 0.01% by mass or more and 3% by mass or less, and more preferably 0.02% by mass or more and 2% by mass or less based on the total amount of the composition.

Examples of the friction modifier include carboxylic acids, carboxylic acid esters, fats and oils, carboxylic acid amides, and sarcosine derivatives. The content of the friction modifier is preferably 0.01% by mass or more and 5% by mass or less, and more preferably 0.05% by mass or more and 3% by mass or less based on the total amount of the composition.
Examples of the defoaming agent include silicone-based compounds, fluorinated silicone-based compounds, and ester-based compounds. The content of the defoaming agent is preferably 0.01% by mass or more and 5% by mass or less, and more preferably 0.01% by mass or more and 0.5% by mass or less based on the total amount of the composition.

(Lubricating oil composition)
The lubricating oil composition of the present embodiment preferably has a kinematic viscosity at 100 ° C. of 4 mm ² / s or more and 6 mm ² / s or less and a viscosity index of 210 or more. In the present embodiment, when the viscosity characteristic of the lubricating oil composition is within the above range, the coefficient of friction between metals can be increased, and the μ-V characteristic between metals can be easily improved. In addition, the coefficient of friction between metals can be increased over a wide temperature range, and the μ-V characteristics between metals can be easily improved. Further, by setting the kinematic viscosity at 100 ° C. to be equal to or lower than the above upper limit value, it becomes easy to realize fuel efficiency.
From the viewpoint of further improving the coefficient of friction between metals and the μ-V characteristics between metals, the 100 ° C. kinematic viscosity of the lubricating oil composition is more preferably 4.3 mm ² / s or more and 5.7 mm ² / s or less. More preferably, it is 5 mm ² / s or more and 5.5 mm ² / s or less. The viscosity index of the lubricating oil composition is preferably 215 or more, more preferably 225 or more. The upper limit of the viscosity index is not particularly limited, but is usually about 300 or less.

The lubricating oil composition of the present embodiment is used in a continuously variable transmission such as a manual transmission, a multi-stage automatic transmission (AT), and a continuously variable automatic transmission (CVT), and is particularly continuous. It is suitably used for machines (CVT). Specific examples of the CVT include a chain type CVT and a belt type CVT. The lubricating oil composition is used for lubricating between a pulley and a chain or between a pulley and a belt in a chain type CVT and a belt type CVT. Above all, it is particularly suitable for a chain type CVT.

(Manufacturing method of lubricating oil composition)
In the method for producing a lubricating oil composition according to an embodiment of the present invention, the above-mentioned alkaline earth metal-based detergent (A), phosphite ester (B), and aliphatic monoamine (C) are added to the base oil. It is a method of obtaining a lubricating oil composition by blending at least. In this method, a viscosity index improver may be further added to the base oil. Further, the components (A) to (C) and other additives other than the viscosity index improver may be further added to the base oil. Here, the blending amounts of the components (A) to (C) are the alkaline earth metal atomic weight derived from the component (A), the phosphorus atomic weight derived from the component (B), and the nitrogen derived from the component (C) in the lubricating oil composition. The atomic weight is adjusted to be within the above range. The details of each of these components, the content in the composition, the details of the lubricating oil composition, etc. are as described above, and the description thereof will be omitted.

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

The methods for measuring and evaluating various properties of the lubricating oil composition in this example are as follows.
(1) Kinematic viscosity, viscosity index Measured according to JIS K 2283: 2000.
(2) Friction coefficient between metals Evaluation was made using a block-on-ring tester (manufactured by Farex) based on ASTM D2714. The higher the coefficient of friction between metals, the larger the transmission torque capacity. The evaluation conditions are as follows.
<Breaking condition>
Surface pressure: 0.8 GPa
Oil temperature: 90 ° C
Average slip speed: 0.500m / s
Time: 30 minutes <Measurement conditions>
Surface pressure: 0.8 GPa
Oil temperature: 90 ° C
Average slip speed: 0.500m / s
<Test piece material>
Steel-steel

(3) μ-V characteristics between metals (μ ratio)
The μ ratio was determined and evaluated using a block-on-ring tester (manufactured by Farex) conforming to ASTM D2714. The smaller the μ ratio, the less likely it is that vibration or noise will occur. The evaluation conditions are as follows.
<Breaking condition>
Surface pressure: 0.8 GPa
Oil temperature: 90 ° C
Average slip speed: 0.500m / s
Time: 30 minutes <Measurement conditions>
Surface pressure: 0.8 GPa
Oil temperature: 90 ° C
Average slip speed: 0.025m / s, 0.500m / s
<Test piece material>
Steel-Steel <Calculation method of μ ratio>
μ ratio = (coefficient of friction at 0.025 m / s) / (coefficient of friction at 0.500 m / s)

[Example 1, Comparative Examples 1 to 3]
Lubricating oil compositions of Example 1 and Comparative Examples 1 to 3 were prepared according to the formulations shown in Table 1. The components used in Examples and Comparative Examples are as follows.
Base oil: 70N mineral oil (100 ° C. kinematic viscosity: 2.8 mm ² / s, viscosity index: 100)
Alkaline earth metal detergent (A): Calcium sulfonate phosphite ester with a base value of 400 mgKOH / g (B): Dilaurylhydrogenphosphite aliphatic monoamine (C): Oleylamine Other additives: Imid compounds, Amide compound, amine-based antioxidant, phenol-based antioxidant, polymethacrylate-based viscosity index improver (weight average molecular weight: 35,000)

As described above, the lubricating oil composition of Example 1 contains the components (A) to (C) so that the alkaline earth metal atom weight, the phosphorus atom weight, and the nitrogen atom weight are predetermined amounts, so that the slip speed can be increased. The coefficient of friction between metals could be set to a high value even under conditions of rapid lubrication and harsh lubrication. Further, since the μ-V characteristic between metals is improved, vibration and noise generated between the pulley and the chain or between the pulley and the belt can be reduced. On the other hand, since the lubricating oil compositions of Comparative Examples 1 to 3 do not contain any one of the components (A) to (C), the coefficient of friction between metals is low, and further, μ-between metals. The V characteristic did not improve either.

Claims (10)

It contains a base oil, an alkaline earth metal-based detergent (A), a phosphite ester (B), and an aliphatic monoamine (C).
Further contains a viscosity index improver having a weight average molecular weight (Mw) of 30,000 or more and 40,000 or less.
It does not contain a phosphorus compound other than the phosphite ester (B) and a monoamine compound other than the aliphatic monoamine (C).
(A) The atomic weight of the alkaline earth metal derived from the component is 300 mass ppm or more and 600 mass ppm or less based on the total amount of the composition.
(B) The amount of phosphorus atom derived from the component is 5% by mass or more and 30 % by mass or less based on the total amount of the composition.
(C) A lubricating oil composition having a nitrogen atomic weight derived from the component (C) of 50% by mass or more and 200% by mass or less based on the total amount of the composition. The lubricating oil composition according to claim 1, wherein the 100 ° C. kinematic viscosity is 4 mm ² / s or more and 6 mm ² / s or less, and the viscosity index is 210 or more. The lubricating oil composition according to claim 1 or 2, wherein the phosphite ester (B) is a compound represented by the following formula (I).
(R ¹ O) _a P (OH) _3-a ... (I)
(In the formula (I), R ¹ represents a hydrocarbon group having 12 to 16 carbon atoms, and a represents an integer of 1 to 3. When a is 2 or 3, R ¹ may be the same as each other. And may be different.) The lubricating oil composition according to claim 3, wherein in the formula (I), a is 2 and R ¹ is an aliphatic hydrocarbon group having 12 to 16 carbon atoms. The lubricating oil composition according to any one of claims 1 to 4, wherein the aliphatic monoamine (C) is a compound represented by the following formula (II).
NR ² R ³ R ⁴ ... (II)
(In formula (II), R ² represents an aliphatic hydrocarbon group having 12 to 18 carbon atoms, R ³ and R ⁴ represent hydrogen atoms, or an alkyl group having 1 to 4 carbon atoms. R ³ and R ⁴ represent each other. It may be the same or different.) The lubricating oil composition according to claim 5, wherein in the formula (II), R ² represents an aliphatic hydrocarbon group having 12 to 18 carbon atoms, and R ³ and R ⁴ represent a hydrogen atom or an alkyl group having 1 to 2 carbon atoms. thing. The lubricating oil composition according to any one of claims 1 to 6, wherein the alkaline earth metal-based detergent (A) is at least one selected from the group consisting of calcium sulfonate and calcium salicylate. thing. The lubricating oil composition according to any one of claims 1 to 7, wherein the alkaline earth metal-based detergent (A) has a base value of 300 mgKOH / g or more. The lubricating oil composition according to any one of claims 1 to 8, which is for a continuously variable transmission. At least the alkaline earth metal detergent (A), the phosphite ester (B), and the aliphatic monoamine (C) are added to the base oil, and the atomic weight of the alkaline earth metal derived from the component (A) is based on the total amount of the composition. 300 mass ppm or more and 600 mass ppm or less, the phosphorus atomic weight derived from the component (B) is 5 mass ppm or more and 30 mass ppm or less based on the total amount of the composition, and the nitrogen atomic weight derived from the component (C) is 50 mass ppm based on the total amount of the composition. Blended so as to be contained in the lubricating oil composition of 200% by mass or more and 200% by mass or less.
Further, a viscosity index improver having a weight average molecular weight (Mw) of 30,000 or more and 40,000 or less is blended .
A method for producing a lubricating oil composition, wherein a lubricating oil composition is obtained without blending a phosphorus compound other than the phosphite ester (B) and a monoamine compound other than the aliphatic monoamine (C) .