阅读说明：本技术 润滑油组合物、润滑油组合物的制造方法和无级变速器 (Lubricating oil composition, method for producing lubricating oil composition, and continuously variable transmission ) 是由 砂川洋二 岩崎猛 于 2019-02-28 设计创作，主要内容包括：提供润滑油组合物、该润滑油组合物的制造方法、和使用了该润滑油组合物的无级变速器,所述润滑油组合物以更高维度兼顾高牵引系数和优异的低温流动性、并且具有高闪点,所述润滑油组合物含有闪点140℃以上的环烷烃系合成油(A)、长叶烯(B)、和规定的单酯系合成油(C)。(Provided are a lubricating oil composition containing a naphthenic synthetic oil (A) having a flash point of 140 ℃ or higher, longifolene (B), and a predetermined monoester synthetic oil (C), a method for producing the lubricating oil composition, and a continuously variable transmission using the lubricating oil composition, wherein the lubricating oil composition has a high traction coefficient and excellent low-temperature fluidity and a high flash point with a higher dimensional factor.)

1. A lubricating oil composition comprising:

a naphthenic synthetic oil (A) having a flash point of 140 ℃ or higher,

Longifolene (B), and

a monoester synthetic oil (C) represented by the following general formula (1),

in the general formula (1), R¹¹And R¹²Each independently represents a branched hydrocarbon group having 3 or more carbon atoms.

2. The lubricating oil composition according to claim 1,

the naphthenic synthetic oil (a) is a synthetic oil having at least one ring selected from a cyclohexane ring, a bicycloheptane ring and a bicyclooctane ring.

3. The lubricating oil composition according to claim 1 or 2,

the naphthenic synthetic oil (A) is a synthetic oil represented by the following general formula (2),

in the general formula (2), R²¹And R²³Each independently represents a hydrocarbyl group, R²²Represents a hydrocarbon group, X₂₁And X₂₂Each independently represents a cyclohexane ring, a bicycloheptane ring or a bicyclooctane ring, p₂₁And p₂₂Each independently represents an integer of 1 to 6 inclusive.

4. The lubricating oil composition according to claim 3,

in the general formula (2), X₂₁And X₂₂Each independently represents a cyclohexane ring, bicyclo [2.2.1]Heptane ring, bicyclo [3.2.1]]Octane rings or bicyclo [2.2.2]Octane ring.

5. The lubricating oil composition according to claim 3 or 4,

in the general formula (2), R²¹And R²³Each independently represents an alkyl or alkenyl group, R²²Represents an alkylene group or an alkenylene group.

6. The lubricating oil composition according to any one of claims 3 to 5,

in the general formula (2), R²¹And R²³Each independently represents an alkyl group having 1 to 4 carbon atoms, R²²Represents an alkylene group having 1 to 4 carbon atoms, p₂₁And p₂₂Each independently represents 1 or 2.

7. The lubricating oil composition according to any one of claims 3 to 5,

in the general formula (2), R²¹And R²³Each independently represents an alkyl group having 1 to 2 carbon atomsRadical, R²²X represents an alkylene group having 1 to 2 carbon atoms₂₁And X₂₂Represents bicyclo [2.2.1]Heptane ring, p₂₁And p₂₂Each independently represents 1 or 2.

8. The lubricating oil composition according to any one of claims 1 to 7,

in the general formula (1), R¹¹And R¹²Each independently represents a branched alkyl or alkenyl group having 4 to 16 carbon atoms.

9. The lubricating oil composition according to any one of claims 1 to 8,

in the general formula (1), R¹¹And R¹²Each independently is a branched alkyl group having a gem-dialkyl structure and having 3 to 16 carbon atoms.

10. The lubricating oil composition according to any one of claims 1 to 9,

the naphthenic synthetic oil (A) is contained in an amount of 20 to 45 mass% based on the total amount of the composition,

the content of longifolene (B) is 15-45% by mass based on the total composition, and

the content of the monoester synthetic oil (C) is 10 mass% or more and 40 mass% or less based on the total amount of the composition.

11. Lubricating oil composition according to any one of claims 1 to 10, having a brookfield viscosity at-40 ℃ of 3000 mPa-s or less, measured according to ASTM D2983-09.

12. The lubricating oil composition according to any one of claims 1 to 11, which is a lubricating oil composition according to JIS K2265-4: the flash point of the 2007 Cleveland open cup method is 130 ℃ or higher.

13. The lubricating oil composition according to any one of claims 1 to 12, which is used for a continuously variable transmission.

14. A process for producing a lubricating oil composition, which comprises blending a naphthenic synthetic oil (A) having a flash point of 140 ℃ or higher, a longifolene (B), and a monoester synthetic oil (C) represented by the following general formula (1),

in the general formula (1), R¹¹And R¹²Each independently represents a branched hydrocarbon group having 3 or more carbon atoms.

15. A continuously variable transmission using a lubricating oil composition containing a naphthenic synthetic oil (A) having a flash point of 140 ℃ or higher, a longifolene (B), and a monoester synthetic oil (C) represented by the following general formula (1),

in the general formula (1), R¹¹And R¹²Each independently represents a branched hydrocarbon group having 3 or more carbon atoms.

Technical Field

The invention relates to a lubricating oil composition, a method for producing the lubricating oil composition, and a continuously variable transmission.

Background

A continuously variable transmission, particularly a traction drive type transmission, is smaller and lighter than a transmission using gears, and is less likely to generate noise because it can be shifted without metal-to-metal contact. Therefore, traction drive type transmissions are being studied for applications mainly in electric vehicles.

A lubricating oil composition used for a traction-drive transmission is required to have a high traction coefficient under high-temperature conditions (for example, about 120 ℃ in the case of automotive applications) from the viewpoint of ensuring a large torque transmission capacity, and also required to have low-temperature fluidity such that the viscosity is low even under low-temperature conditions (for example, about-40 ℃) in order to ensure low-temperature startability in cold regions such as north america and northern europe, but these properties are contradictory properties, and thus it is difficult to achieve a balance therebetween. As a lubricating oil composition having such properties, there have been proposed: a lubricant base oil composition containing a naphthenic synthetic lubricant base oil and a paraffinic synthetic lubricant base oil having a predetermined flash point at a predetermined content, and a lubricant base oil composition further containing a poly- α -olefin (for example, patent document 1).

Disclosure of Invention

Problems to be solved by the invention

However, in recent years, in particular, lubricating oil compositions used for continuously variable transmissions for automobiles, particularly traction-drive transmissions, have been increasingly required to have high traction coefficient, low-temperature fluidity, and other properties, and the lubricating base oil compositions have been unable to cope with these properties. In addition to the requirements for high traction coefficient, low-temperature fluidity, and other properties, a high flash point, for example, a flash point of 130 ℃ or higher is also required from the viewpoint of handling safety.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a lubricating oil composition having a high flash point while achieving a high traction coefficient and excellent low-temperature fluidity with a higher degree of dimensionality, a method for producing the lubricating oil composition, and a continuously variable transmission using the lubricating oil composition.

Means for solving the problems

The present inventors have conducted intensive studies with respect to the above problems, and as a result, have found that the above problems can be solved by the following invention. That is, the present invention provides a lubricating oil composition having the following constitution, a method for producing the lubricating oil composition, and a continuously variable transmission using the lubricating oil composition.

1. A lubricating oil composition comprising: a naphthenic synthetic oil (A) having a flash point of 140 ℃ or higher, a longifolene (B), and a monoester synthetic oil (C) represented by the following general formula (1).

[ solution 1]

(in the general formula (1), R¹¹And R¹²Each independently represents a branched hydrocarbon group having 3 or more carbon atoms. )

2. A process for producing a lubricating oil composition, which comprises blending a naphthenic synthetic oil (A) having a flash point of 140 ℃ or higher, a longifolene (B), and a monoester synthetic oil (C) represented by the general formula (1).

3. A continuously variable transmission using a lubricating oil composition containing a naphthenic synthetic oil (A) having a flash point of 140 ℃ or higher, a longifolene (B), and a monoester synthetic oil (C) represented by the general formula (1).

Effects of the invention

According to the present invention, there are provided a lubricating oil composition having a high traction coefficient and excellent low-temperature fluidity in a higher dimensional balance and a high flash point, a method for producing the lubricating oil composition, and a continuously variable transmission using the lubricating oil composition.

Detailed Description

Hereinafter, embodiments of the present invention (hereinafter, may be simply referred to as "the present embodiment") will be described. In the present specification, the numerical values "above", "below" and "to" relating to the description of the numerical range are numerical values that can be arbitrarily combined.

[ lubricating oil composition ]

The lubricating oil composition of the present embodiment contains a naphthenic synthetic oil (A) having a flash point of 140 ℃ or higher, a longifolene (B), and a monoester synthetic oil (C) represented by the following general formula (1). Hereinafter, each component that the lubricating oil composition of the present embodiment may contain will be specifically described.

[ solution 2]

(in the general formula (1), R¹¹And R¹²Each independently represents a branched hydrocarbon group having 3 or more carbon atoms. )

(naphthenic synthetic oil (A))

The lubricating oil composition of the present embodiment needs to contain a naphthenic synthetic oil (a) (hereinafter, sometimes referred to as "naphthenic synthetic oil (a)") having a flash point of 140 ℃. If the naphthenic synthetic oil (a) is not contained, a high traction coefficient and excellent low-temperature fluidity cannot be achieved at the same time with a higher degree of dimension, and a high flash point cannot be obtained.

In the lubricating oil composition of the present embodiment, the flash point of the naphthenic synthetic oil (a) is required to be 140 ℃. If the flash point is less than 140 ℃, in particular, a high traction coefficient cannot be obtained, and a lubricating oil composition having a high flash point cannot be obtained. In particular, the flash point of the naphthenic synthetic oil (a) is preferably 145 ℃ or higher, more preferably 150 ℃ or higher, and still more preferably 160 ℃ or higher, from the viewpoint of improving the traction coefficient and the flash point, and the upper limit is not particularly limited, but may be about 200 ℃ or lower. In the present specification, the flash point is a value in accordance with JIS K2265-4: 2007 (determination of flash point-No. 4: Cleveland open cup method), and the flash point measured by the Cleveland open cup method.

The naphthenic synthetic oil (a) used in the lubricating oil composition of the present embodiment is not particularly limited as long as it has a flash point of 140 ℃ or higher, but is preferably a synthetic oil having a cyclic structure portion, and more preferably a synthetic oil having at least one ring selected from the group consisting of a cyclohexane ring, a bicycloheptane ring and a bicyclooctane ring, from the viewpoint of improving the traction coefficient and the flash point. Examples of the naphthenic synthetic oil (a) include synthetic oils represented by the following general formula (2).

[ solution 3]

In the general formula (2), R²¹And R²³Each independently represents a hydrocarbyl group, R²²Represents a hydrocarbon group, X₂₁And X₂₂Each independently represents a cyclohexane ring, a bicycloheptane ring or a bicyclooctane ring, p₂₁And p₂₂Each independently represents an integer of 1 to 6 inclusive.

As R²¹And R²³Examples of the hydrocarbon group of (2) include monovalent hydrocarbon groups such as alkyl groups, alkenyl groups, cycloalkyl groups, and aryl groups. Among these monovalent hydrocarbon groups, alkyl groups and alkenyl groups are preferable, and alkyl groups are more preferable, from the viewpoint of improving the traction coefficient and flash point. These monovalent hydrocarbon groups may be linear, branched or cyclic, and may have a substituent such as a halogen atom or a hydroxyl group, or may have a substituent such as an alkyl group when the monovalent hydrocarbon group is a cycloalkyl group or an aryl group.

From the same viewpoint as above, the number of carbons in the monovalent hydrocarbon group is preferably 1 or more, and the upper limit is preferably 12 or less, more preferably 8 or less, further preferably 4 or less, particularly preferably 2 or less, when the monovalent hydrocarbon group is an alkyl group, 2 or more, preferably 3 or more, and the upper limit is preferably 12 or less, more preferably 8 or less, further preferably 4 or less, when the monovalent hydrocarbon group is an alkenyl group.

p₂₁And p₂₂Each independently is an integer of 1 to 6, and from the viewpoint of achieving both a high traction coefficient and excellent low-temperature fluidity with a higher dimension and improving flash point, the upper limit is preferably 4 or less, more preferably 3 or less, and still more preferably 2 or less.

As R²²Examples of the hydrocarbon group of (1) include the group consisting of the above-mentioned R²¹And R²³The monovalent hydrocarbon group (b) is a divalent hydrocarbon group obtained by removing one hydrogen atom, and is preferably an alkylene group or an alkenylene group, and more preferably an alkylene group, from the viewpoint of improving the traction coefficient and the flash point.

In addition, from the viewpoint of achieving both a high traction coefficient and excellent low-temperature fluidity with a higher dimension and also improving flash point, R²²The divalent hydrocarbon group (2) has 1 or more carbon atoms, and the upper limit is preferably 12 or less, more preferably 8 or less, and further preferably 4 or less.

As X₂₁And X₂₂The ring (b) is preferably bicycloheptane ring or bicyclooctane ring, more preferably bicycloheptane ring, from the viewpoint of improving traction coefficient and flash point.

Examples of the bicycloheptane ring include bicyclo [2.2.1] heptane ring, bicyclo [4.1.0] heptane ring and bicyclo [3.2.0] heptane ring, and examples of the bicyclooctane ring include bicyclo [3.2.1] octane ring, bicyclo [2.2.2] octane ring and bicyclo [3.3.0] octane ring. Among them, from the viewpoint of improving the traction coefficient and the flash point, a crosslinked bicyclo ring bonded to both rings while sharing 3 or more carbon atoms is preferable, a bicyclo [2.2.1] heptane ring, a bicyclo [3.2.1] octane ring, and a bicyclo [2.2.2] octane ring are more preferable, and a bicyclo [2.2.1] heptane ring is particularly preferable.

In addition, these ring members may have the above-mentioned R²¹And R²³The monovalent hydrocarbon group may have other substituents such as a hydroxyl group and a halogen atom.

In this embodiment, as aboveAmong the above, R is preferable from the viewpoint of improving traction coefficient and flash point²¹And R²³Each independently is alkyl or alkenyl, and R²²Is a combination of alkylene or alkenylene, more preferably R²¹And R²³Each independently represents an alkyl group having 1 to 4 carbon atoms or R²²Is alkylene having 1 to 4 carbon atoms and p₂₁And p₂₂Each independently is a combination of 1 or 2, further preferably R²¹And R²³Each independently represents an alkyl group having 1 to 4 carbon atoms or R²²Is alkylene with 1 to 4 carbon atoms, X₂₁And X₂₂Is a bicycloheptane ring, and p₂₁And p₂₂Each independently is a combination of 1 or 2, with R being particularly preferred²¹And R²³Each independently represents an alkyl group having 1 to 2 carbon atoms or R²²Is alkylene with 1 to 2 carbon atoms, X₂₁And X₂₂Is bicyclo [2.2.1]Heptane ring, p₂₁And p₂₂Each independently is a combination of 1 or 2.

The content of the naphthenic synthetic oil (a) based on the total amount of the composition is preferably 20 mass% or more, more preferably 25 mass% or more, and further preferably 30 mass% or more from the viewpoint of improving the traction coefficient and the flash point, and the upper limit is preferably 45 mass% or less, more preferably 40 mass% or less, and further preferably 35 mass% or less from the viewpoint of achieving more excellent low-temperature fluidity. In the present embodiment, the naphthenic synthetic oil (a) may be used alone or in combination of two or more, and when two or more are used in combination, the total content of the plurality of naphthenic synthetic oils (a) may fall within the above content range.

(longifolene (B))

The lubricating oil composition of the present embodiment needs to contain longifolene (B). If longifolene (B) is not contained, a high traction coefficient and excellent low-temperature fluidity cannot be obtained, and these properties cannot be simultaneously achieved with a higher dimension.

Longifolene (B) is a compound having a structure of a ring structure in which at least a cycloheptane ring and a bicyclo [2.2.1] heptane ring have 3 carbon atoms in common and a hydrocarbon group bonded via a double bond to one carbon atom forming the ring structure, and more specifically, a compound represented by the following chemical formula (3), (1S, 3aR, 4S, 8aS) -4, 8, 8-trimethyl-9-methylene-decahydro-1, 4-Methanoazulene (Methanoazulene). In the present embodiment, longifolene includes not only the compound represented by chemical formula (3) but also isomers of the compound, and also includes compounds optionally further having a substituent such as a hydrocarbon group including an alkyl group having 1 to 4 carbon atoms, or a halogen atom.

[ solution 4]

In addition, in chemical formula (3), the hydrocarbon group connected via a double bond may be a divalent hydrocarbon group such as an alkenylidene group or a cycloalkylidene group, in addition to an alkylidene group, and an alkylidene group is preferable from the viewpoint of achieving both a high traction coefficient and excellent low-temperature fluidity with a higher dimension, and a carbon number is preferably 1 or more and 4 or less, and a methylene group having a carbon number of 1 is particularly preferable as shown in chemical formula (3). The hydrocarbon group connected via a double bond may have a substituent such as a halogen atom or a hydroxyl group, and when the hydrocarbon group is a cycloalkylidene group, it may further have a substituent such as an alkyl group.

The longifolene (B) is mainly contained in essential oils of pine trees, cypress trees, and the like, and these essential oils are used in the present embodiment, but since the content of longifolene contained in these essential oils is usually 5 to 10 mass%, from the viewpoint of the use effect, it is preferable to use purified longifolene obtained by purification, the content of which is preferably 60 mass% or more, more preferably 70 mass% or more, further preferably 80 mass% or more, and particularly preferably 90 mass% or more. The upper limit of the content of longifolene in purified longifolene is preferably 100 mass% as the content is higher, but is preferably 98 mass% or less from the viewpoint of more efficiently obtaining the effect obtained by using longifolene. In the present embodiment, longifolene obtained by synthesis may be used.

The purified longifolene that can be used in the present embodiment may contain, as components other than longifolene, β -caryophyllene mainly contained in pine, cypress, and the like. Beta-caryophyllene is (1R, 4E, 9S) -4, 11, 11-trimethyl-8-methylene bicyclo [7.2.0] undec-4-ene shown in the following chemical formula. In the present embodiment, components other than longifolene such as β -caryophyllene may be included within a range not to inhibit the effect of the invention, and specifically, components other than longifolene such as β -caryophyllene may be included if the content of longifolene contained in purified longifolene is within the above range.

[ solution 5]

The content of longifolene (B) (longifolene monomer) based on the total amount of the composition is preferably 15 mass% or more, more preferably 20 mass% or more, and still more preferably 25 mass% or more, from the viewpoint of achieving both a high traction coefficient and excellent low-temperature fluidity with a higher dimension, and the upper limit is preferably 40 mass% or less, more preferably 37 mass% or less, and still more preferably 35 mass% or less, from the viewpoint of improving the flash point. In the present embodiment, the longifolene (B) may be the longifolene represented by the chemical formula (3) alone, or a plurality of longifolene isomers and the like may be used in combination, and when a plurality of longifolene isomers and the like are used in combination, the total content of the plurality of longifolene (B) may be within the above content range.

(monoester-based synthetic oil (C) represented by the general formula (1))

The lubricating oil composition of the present embodiment needs to contain a monoester synthetic oil (C) represented by the following general formula (1) (hereinafter, sometimes referred to as "monoester synthetic oil (C)"). If the monoester-based synthetic oil (C) is not contained, a high flash point cannot be obtained, and the lubricating oil composition of the present embodiment has a reduced operational safety and, in particular, a reduced low-temperature fluidity, and thus a high traction coefficient and an excellent low-temperature fluidity cannot be achieved at the same time with a higher degree of dimension.

[ solution 6]

In the general formula (1), R¹¹And R¹²Each independently represents a branched hydrocarbon group having 3 or more carbon atoms.

As R¹¹And R¹²Examples of the branched hydrocarbon group having 3 or more carbon atoms of (b) include the above-mentioned R²¹And R²³The monovalent hydrocarbon group of (a) is a branched group having 3 or more carbon atoms. Among them, a branched alkyl group and an alkenyl group are preferable, and an alkyl group is more preferable, from the viewpoint of satisfying both a high traction coefficient and excellent low-temperature fluidity with a higher dimension. In addition, the carbon number is preferably 4 or more, more preferably 5 or more, and further preferably 6 or more, and the upper limit is preferably 16 or less, more preferably 14 or less, and further preferably 12 or less, from the viewpoint of achieving both a high traction coefficient and excellent low-temperature fluidity with a higher dimension and improving the flash point.

In addition, with respect to R¹¹And R¹²The monovalent hydrocarbon group (b) is preferably a branched group having a geminal dialkyl structure from the viewpoint of achieving both a high traction coefficient and excellent low-temperature fluidity with a higher degree of dimensionality and improving a flash point. In this case, the number of carbons of the alkyl group in the geminal dialkyl structure is preferably 1 or more, the upper limit is preferably 4 or less, more preferably 3 or less, and further preferably 2 or less, and the number of carbons of the 2 alkyl groups may be the same or different. Particularly preferred geminal dialkyl structure is a geminal dimethyl structure in which the alkyl groups in the structure have all 1 carbon atoms.

As R¹¹And R¹²Typical examples of the monovalent hydrocarbon group of (a) include isopropyl group, 1-dimethylethyl group, 2-dimethylpropyl group, 3-dimethylbutyl group, 4, 4-dimethylpentyl group, 5, 5-dimethylhexyl group, 2,4, 4-trimethylpentyl group, 3, 5, 5-trimethylhexyl group, 2,4, 4, 6-pentamethylheptyl group, 2,4, 6, 6-pentamethylheptyl group, 3, 5, 5, 7, 7-pentamethyloctyl group and the like, and among them, 2,4, 4-trimethylpentyl group and 3, 5, 5-trimethylhexyl group are preferable. These monovalent hydrocarbon groups are typical examples and need not necessarily beIn addition, in the present embodiment, the isomers of the hydrocarbon group exemplified above may be provided as R¹¹And R¹²。

The carbon number of the monoester-based synthetic oil (C) is preferably 8 or more, more preferably 12 or more, further preferably 16 or more, and the upper limit is preferably 30 or less, more preferably 25 or less, and further preferably 21 or less, from the viewpoint of achieving both a high traction coefficient and excellent low-temperature fluidity with a higher dimension and also improving the flash point.

The content of the monoester-based synthetic oil (C) based on the total amount of the composition is preferably 10 mass% or more, more preferably 15 mass% or more, further preferably 20 mass% or more, and particularly preferably 25 mass% or more, from the viewpoint of improving excellent low-temperature fluidity and flash point, and the upper limit is preferably 40 mass% or less, more preferably 35 mass% or less, further preferably 30 mass% or less, and particularly preferably 28 mass% or less, from the viewpoint of achieving a higher traction coefficient. In the present embodiment, the above-mentioned monoester-based synthetic oils (C) may be used alone or in combination of two or more, and when two or more are used in combination, the total content of the plurality of monoester-based synthetic oils (C) may fall within the above-mentioned content range.

(other additives)

The lubricating oil composition of the present embodiment contains the above-mentioned naphthenic synthetic oil (a), longifolene (B), and monoester synthetic oil (C), may be composed of the naphthenic synthetic oil (a), longifolene (B), and monoester synthetic oil (C), and may further contain other additives such as a viscosity index improver, a dispersant, an antioxidant, an extreme pressure agent, a metal deactivator, and an antifoaming agent in addition to the naphthenic synthetic oil (a), longifolene (B), and monoester synthetic oil (C). These other additives may be used alone or in combination of two or more.

The total content of these other additives may be appropriately determined as desired, and is not particularly limited, but considering the effect of adding other additives, the total amount of the composition is preferably 0.1 to 20% by mass, more preferably 1 to 15% by mass, and still more preferably 5 to 13% by mass.

Examples of the viscosity index improver include polymethacrylates such as nondispersive polymethacrylate and dispersive polymethacrylate having a mass average molecular weight (Mw) of preferably 500 to 1,000,000, more preferably 5,000 to 800,000; polymers such as olefin copolymers (e.g., ethylene-propylene copolymers) having a mass average molecular weight (Mw) of preferably 800 to 300,000, more preferably 10,000 to 200,000, dispersed olefin copolymers, and styrene copolymers (e.g., styrene-diene copolymers and styrene-isoprene copolymers); and so on.

Examples of the dispersant include ashless dispersants such as boron-free succinimides, boron-containing succinimides, benzylamines, boron-containing benzylamines, succinates, and amides of mono-or dicarboxylic acids represented by fatty acids or succinic acids.

Examples of the antioxidant include amine antioxidants such as a diphenylamine antioxidant and a naphthylamine antioxidant; phenol antioxidants such as monophenol antioxidants, diphenol antioxidants and hindered phenol antioxidants; molybdenum antioxidants such as molybdenum amine complexes obtained by reacting molybdenum trioxide and/or molybdic acid with amine compounds; and so on.

Examples of the extreme pressure agent include sulfur-based extreme pressure agents such as sulfurized fats and oils, thio fatty acids, thioesters, thioolefins, dihydrocarbyl polysulfides, thiadiazole compounds, alkylthiocarbamoyl compounds, and thiocarbamate compounds; phosphorus extreme pressure agents such as phosphoric acid esters, phosphorous acid esters, acidic phosphoric acid esters, acidic phosphorous acid esters, and amine salts thereof; sulfur-phosphorus extreme pressure agents such as zinc dialkylthiocarbamate (Zn-DTC), molybdenum dialkylthiocarbamate (Mo-DTC), zinc dialkyldithiophosphate (Zn-DTP), and molybdenum dialkyldithiophosphate (Mo-DTP); and the like.

Examples of the metal deactivator include benzotriazole compounds, tolyltriazole compounds, thiadiazole compounds, and imidazole compounds, and examples of the defoaming agent include silicone oil, fluorosilicone oil, and fluoroalkyl ether.

(physical Properties of lubricating oil composition)

In relation to the present embodimentThe kinematic viscosity at 40 ℃ of the lubricating oil composition of formula (II) is preferably 3mm from the viewpoints of preventing seizure at high temperatures and ensuring low-temperature fluidity²More than s and 50mm²Less than s, more preferably 5mm²More than s and 30mm²A thickness of 10mm or less, preferably²More than s and 20mm²The ratio of the water to the water is less than s. From the same viewpoint, the kinematic viscosity at 100 ℃ of the lubricating oil composition of the present embodiment is preferably 0.5mm²15mm of more than s²Less than s, more preferably 1mm²More than s and 10mm²A thickness of 1.5mm or less, preferably²5mm of more than s²The ratio of the water to the water is less than s. The viscosity index of the lubricating oil composition of the present embodiment is preferably 75 or more, more preferably 80 or more, and still more preferably 85 or more.

In the present specification, the kinematic viscosity and the viscosity index are based on JIS K2283: 2000. values measured using a glass capillary viscometer.

The brookfield viscosity (BF viscosity) at-40 ℃ of the lubricating oil composition of the present embodiment is preferably 3,000mPa · s or less, more preferably 2,800mPa · s or less, still more preferably 2,600mPa · s or less, and particularly preferably 2,400mPa · s or less. Thus, the lubricating oil composition of the present embodiment has a low brookfield viscosity (BF viscosity) at-40 ℃ and excellent low-temperature fluidity.

In the present specification, the Brookfield viscosity (BF viscosity) at-40 ℃ is measured in accordance with ASTM D2983-09.

The flash point of the lubricating oil composition of the present embodiment is based on JIS K2265-4: 2007. preferably 130 ℃ or higher, more preferably 135 ℃ or higher, and still more preferably 140 ℃ or higher, as measured by the Cleveland open cup method. Thus, the lubricating oil composition of the present embodiment has a high flash point, high flame retardancy, and high safety.

The traction coefficient at 120 ℃ of the lubricating oil composition of the present embodiment is preferably 0.050 or more, more preferably 0.051 or more, and still more preferably 0.052 or more. As described above, the lubricating oil composition of the present embodiment has a high traction coefficient at 120 ℃, and is a lubricating oil composition having a high flash point while achieving a high traction coefficient and excellent low-temperature fluidity with a higher degree of latitude.

In the present specification, the Traction coefficient at 120 ℃ is a value measured using a Traction coefficient measuring instrument (product name: MTM2(Mini Traction Machine2, manufactured by PCS Instruments Co., Ltd.). Here, the measurement conditions of the Traction coefficient at 120 ℃ are as follows.A tank is first heated by a heater to bring the oil temperature to 140 ℃, and the Traction coefficient is measured under conditions of a load of 70N, an average rolling speed of 3.8m/s, and a slip ratio of 5%.

(use of lubricating oil composition)

The lubricating oil composition of the present embodiment can be suitably used for a continuously variable transmission, and can be suitably used for a continuously variable transmission in particular. The continuously variable transmission is of a metal belt type, a chain type, a traction drive type, or the like, but each of the modes requires high transmission efficiency and requires a lubricating oil having a high traction coefficient. In view of this, the lubricating oil composition of the present embodiment can be suitably used for any type of continuously variable transmission, and particularly, can be suitably used for a traction drive type transmission.

Further, the lubricating oil composition of the present embodiment is excellent in traction coefficient, particularly traction coefficient at high temperatures and low-temperature fluidity, and therefore can be suitably used for continuously variable transmission applications in, for example, automobile and aircraft engine generators, and particularly can be suitably used as a fluid for traction-driven transmissions. In addition to the above, the lubricating oil composition of the present embodiment can be suitably used for a continuously variable transmission, a continuously variable transmission and a continuously variable reduction gear in industrial applications such as a drive unit for construction machines and agricultural machines, a speed increaser for wind power generation, and the like.

[ method for producing lubricating oil composition ]

The method for producing a lubricating oil composition of the present embodiment is characterized by blending a naphthenic synthetic oil (a) having a flash point of 140 ℃ or higher, a longifolene (B), and a monoester synthetic oil (C) represented by the following general formula (1).

[ solution 7]

(in the general formula (1), R¹¹And R¹²Each independently represents a branched hydrocarbon group having 3 or more carbon atoms. )

In the method for producing the lubricating oil composition of the present embodiment, the naphthenic synthetic oil (a), longifolene (B), and monoester synthetic oil (C) having a flash point of 140 ℃ or higher are the same as those described as the naphthenic synthetic oil (a), longifolene (B), and monoester synthetic oil (C) contained in the lubricating oil composition of the present embodiment, and the contents of the naphthenic synthetic oil (a), longifolene (B), and monoester synthetic oil (C) are the same as those described as the content of the lubricating oil composition of the present embodiment. In the method for producing the lubricating oil composition of the present embodiment, components other than the naphthenic synthetic oil (a), longifolene (B), and monoester synthetic oil (C), for example, other additives described as components that can be contained in the lubricating oil composition of the present embodiment may be blended.

In the production of the lubricating oil composition, the order of blending the naphthenic synthetic oil (a), the longifolene (B) and the monoester synthetic oil (C) is not particularly limited, and the longifolene (B) and the monoester synthetic oil (C) may be added simultaneously or sequentially to the naphthenic synthetic oil (a), and for example, a product obtained by blending the longifolene (B) and the monoester synthetic oil (C) in advance may be added to the naphthenic synthetic oil (a). In addition, when other additives are blended, various additives used as other additives may be sequentially blended with the naphthenic synthetic oil (a), longifolene (B), and monoester synthetic oil (C), or the various additives may be blended in advance.

[ continuously variable Transmission ]

The continuously variable transmission of the present embodiment is characterized by using a lubricating oil composition containing a naphthenic synthetic oil (a) having a flash point of 140 ℃ or higher, longifolene (B), and a monoester synthetic oil (C) represented by the following general formula (1). The lubricating oil composition used in the continuously variable transmission of the present embodiment is the same as the composition described as the lubricating oil composition of the present embodiment.

[ solution 8]

(in the general formula (1), R¹¹And R¹²Each independently represents a branched hydrocarbon group having 3 or more carbon atoms. )

As the continuously variable transmission, there are a metal belt type, a chain type, a traction drive type, and the like, but in any type of continuously variable transmission, the lubricating oil composition used has a feature of satisfying both a high traction coefficient and excellent low-temperature fluidity with a higher dimension and having a high flash point, and from the viewpoint of more effectively utilizing the feature, a traction drive type continuously variable transmission is preferable.