Lubricating base oil

Abstract

There is a demand for a new lubricating oil composition having properties (for example, insulating properties, a friction reducing effect, and rubber swelling resistance) suitable for lubrication according to various mechanisms incorporated in a device.SOLUTION: The lubricant base oil contains at least one ester compound (A) selected from diesters (A1) having 24 or more carbon atoms and triesters (A2) having 24 or more carbon atoms, and at least one base oil (B) selected from mineral oils and synthetic oils other than the components (A).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a lubricating base oil and a lubricating oil composition comprising the lubricating base oil. [Background technology]

[0002] Engines, transmissions, reducers, compressors, hydraulic systems, and other devices are all equipped with torque converters, It has mechanisms such as a hydraulic clutch, a gear bearing mechanism, an oil pump, and a hydraulic control mechanism. In the construction, lubricating oil compositions are used, and lubricating oil compositions that can meet various requirements are available. It is being developed.

[0003] For example, Patent Document 1 discloses an automobile transmission oil composition suitable for use in vehicles equipped with electric motors. The components include a base oil, a hydrocarbon group-containing zinc dithiophosphate, a triaryl phosphate, and a tri a phosphorus compound selected from the group consisting of aryl thiophosphates and mixtures thereof; Contains a specified amount and has a volume resistivity of 1 x 10 at 80°C 7 Automatically adjusted to Ω·m or more A transmission fluid composition for automobiles is disclosed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2002-097017 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, lubricating oil compositions used in various devices such as electric motors contain insulating At the same time, depending on the type of device, properties such as friction reduction effect and rubber swelling resistance are required. In other words, the lubricating properties (e.g., lubrication characteristics) suitable for various mechanisms incorporated in the device may be required. Therefore, there is a demand for new lubricating oil compositions that have the following properties: insulation, friction reduction, and resistance to rubber swelling. are. [Means for solving the problem]

[0006] The present invention relates to a method for producing a polymerizable composition comprising at least one ester selected from diesters and triesters having a predetermined number of carbon atoms. a ester compound and at least one base oil ( B), and lubricating oil compositions comprising the lubricating base oil. Specifically, the present invention provides the following [1] to

[12] . [1] Diesters (A1) having 24 or more carbon atoms and triesters (A2) having 24 or more carbon atoms At least one ester compound (A) selected from the following: and at least one base oil (B) selected from mineral oils and synthetic oils other than ester-based synthetic oils. Contains lubricating base oils. [2] The density of the lubricating base oil at 15 ° C is 0.850 g / cm 3 Less than the above [ 1] The lubricating base oil according to claim 1. [3] The content of component (A) is 1 to 90 mass% based on the total amount of the lubricating base oil. The lubricating base oil according to [1] or [2]. [4] The compound according to any one of the above [1] to [3], wherein the component (A1) has 26 or more carbon atoms. Lubricating base oil. [5] The component (A1) contains a compound (A11) represented by the following general formula (a1-1): The lubricating base oil according to any one of [1] to [4] above. [ka] (In the above formula, R 1 and R 2are each independently a monovalent chain hydrocarbon group, and A 1 is a divalent hydrocarbon group having 5 or more carbon atoms. [6] The above component (A2) contains a compound (A21) represented by the following general formula (a2-1): The lubricating base oil according to any one of [1] to [5] above. [ka] (In the above formula, R 3 , R 4 and R 5 are each independently a monovalent chain hydrocarbon group, , A 2 is a trivalent hydrocarbon group having 5 or more carbon atoms. [7] Any one of the above [1] to [6], wherein the component (A) contains at least the component (A1). Item 1. The lubricating base oil according to item 1. [8] Any one of the above [1] to [6], wherein the component (A) contains at least the component (A2). Item 1. The lubricating base oil according to item 1. [9] A lubricating oil composition comprising the lubricating base oil according to any one of [1] to [8] above.

[10] In addition, pour point depressants, viscosity index improvers, antioxidants, extreme pressure agents, metallic detergents, One or more selected from ashless dispersants, metal deactivators, corrosion inhibitors, rust inhibitors, and antifoaming agents The lubricating oil composition according to [9] above, containing the lubricating oil additive.

[11] The content of fatty acid amide is 1 based on the total amount (100 mass%) of the lubricating oil composition. The lubricating oil composition according to [9] or

[10] above, wherein the total amount of hydroxybenzoates is less than 0.0 mass%.

[12] Immerse the test nitrile rubber in the lubricating oil composition and measure the lubricating oil composition in accordance with JIS K6258. The volume change rate of the test nitrile rubber measured under the conditions of 100°C for 144 hours was The lubricating oil composition according to any one of the above [9] to

[11] , wherein the content of hydroxybenzoates is less than 10%. [Effects of the Invention]

[0007] The lubricating base oil of a preferred embodiment of the present invention has properties suitable for various mechanisms incorporated in the device. In a more preferred embodiment, the lubricating base oil has insulating properties and friction-reducing properties. Thus, it is possible to prepare a lubricating oil composition having a well-balanced improvement in the properties of rubber swelling resistance and rubber lubricant performance. DETAILED DESCRIPTION OF THE INVENTION

[0008] Regarding the numerical ranges described in this specification, the upper and lower limits can be combined in any combination. For example, the numerical range is preferably 30 to 100, more preferably 40 to 100. If "80" is listed, the range "30-80" or "40-100" is also The numerical ranges described in this specification are included in the numerical ranges. It is preferably 30 or more, more preferably 40 or more, and is preferably 100 or less, more preferably If it says "is 80 or less," it should be in the range of "30 to 80" or "40 to 100." and ranges are also included in the numerical ranges described herein. In addition, as a numerical range described in this specification, for example, "60 to 100" This means that the range is "60 or more and 100 or less."

[0009] In this specification, kinematic viscosity and viscosity index are based on JIS K2283:2000. It means a measured or calculated value.

[0010] [Configuration of lubricating base oil] The lubricating base oil of one embodiment of the present invention comprises a diester (A1) having 24 or more carbon atoms and a diester (A2) having 24 or more carbon atoms. At least one ester compound (A) selected from the above triesters (A2) and a mineral and (B) at least one base oil selected from the group consisting of synthetic oils other than ester-based synthetic oils. .

[0011] In recent years, electric vehicles and hybrid vehicles have been packaging the transmission and electric motor. There is a demand for smaller and lighter vehicles by using a system that integrates a transmission and an electric motor. The lubricating oil composition to be used has insulating properties as an electric motor oil and friction reduction properties as a transmission. In addition to effectiveness, properties such as resistance to rubber swelling are also required. However, general transmission fluids have the problem of poor insulating properties. On the other hand, lubricating oil compositions containing ester-based synthetic oils as base oils may have good insulating properties. However, the problem is that they generally have poor resistance to rubber swelling. There are many cases like this. To address this problem, the lubricating base oil of one embodiment of the present invention contains the above-mentioned ester compound (A ) and base oil (B), it provides a balance of insulation properties, friction reduction effects, and rubber swelling resistance. The lubricating base oil can be used to prepare lubricating oil compositions with improved performance.

[0012] The lubricating base oil of one embodiment of the present invention may contain component (A) within a range that does not impair the effects of the present invention. and (B) may contain other base oils. Such other base oils include, for example, ester-based synthetic oils that do not fall under the category of component (A). Specifically, monoesters, diesters having 23 or less carbon atoms, and diesters having 37 or less carbon atoms are included. Examples include triesters and polyesters having four or more ester bonds.

[0013] In one embodiment of the lubricating base oil of the present invention, the characteristics of insulating property, friction reducing effect, and rubber swelling resistance are From the viewpoint of providing a lubricating base oil that can be used to prepare a lubricating oil composition having well-balanced improved properties, The total content of (A) and (B) is preferably based on the total amount (100% by mass) of the lubricating base oil. or 92 to 100 mass%, more preferably 95 to 100 mass%, and even more preferably 97 to 100 mass%. 100% by mass, even more preferably 99 to 100% by mass, particularly preferably 100% by mass be. Components (A) and (B) contained in the lubricating base oil of one embodiment of the present invention will be described in detail below. .

[0014] <Component (A): Ester compound> The lubricating base oil of one embodiment of the present invention comprises a diester (A1) having 24 or more carbon atoms and a diester (A2) having 24 or more carbon atoms. At least one ester compound (A) selected from the above triesters (A2) . As the component (A), a diester (A1) or triester (A2) having such a specific carbon number is preferably used. A2) reduces friction without the need for friction modifiers, which can cause a decrease in insulation. It is possible to prepare a lubricating oil base oil from which a lubricating oil composition having excellent friction-reducing effects can be prepared. By using a lubricating base oil containing component (A) in the presence of the above-mentioned component (B), it is possible to obtain excellent insulating properties. A lubricating oil composition can be prepared.

[0015] In the lubricating base oil of one embodiment of the present invention, the content of component (A) is (100 mass%), it is possible to prepare a lubricating oil composition having improved insulating properties and friction reducing effects. From the viewpoint of obtaining a lubricating base oil, the content of the hydroxybenzoate is preferably 1 mass % or more, more preferably 3 mass % or more. More preferably 5% by mass or more, more preferably 7% by mass or more, and even more preferably 10% by mass More preferably, 12% by mass or more, even more preferably, 15% by mass or more, and even more preferably, The content of component (B) is preferably 17% by mass or more, and particularly preferably 20% by mass or more. and a lubricating base oil capable of preparing a lubricating oil composition having excellent insulating properties and rubber swelling resistance. From this viewpoint, it is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less. 0% by mass or less, more preferably 60% by mass or less, even more preferably 55% by mass or less, Preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less. % or less, and particularly preferably 35% or less by mass.

[0016] The component (A) used in one embodiment of the present invention has a structure containing at least one component (A1). It may be composed of at least one component (A2), and may be composed of at least Even if the composition contains at least one component (A1) and at least one component (A2) in combination, good.

[0017] In one embodiment of the present invention, component (A) is a combination of component (A1) and component (A2). The content ratio of component (A1) to component (A2) [(A1) / (A2)] is 1 / (A2) by mass. 99 or more, 5 / 95 or more, 10 / 90 or more, 15 / 85 or more, 20 / 80 or more, 25 / 7 5 or more, 30 / 70 or more, 35 / 65 or more, 40 / 60 or more, or 45 / 55 or more Also, 99 / 1 or less, 95 / 5 or less, 90 / 10 or less, 85 / 15 or less, 80 / 20 or less, 75 / 25 or less, 70 / 30 or less, 65 / 35 or less, or 60 / 40 or less That's fine.

[0018] The number of carbon atoms in component (A1) is determined to improve the insulating properties and friction reducing effect and to prevent a decrease in rubber swelling resistance. From the viewpoint of obtaining a lubricating base oil from which a lubricating oil composition having a low viscosity can be prepared, the preferred range is 24 or more. or 26 or more, more preferably 27 or more, and even more preferably 28 or more, and Below, 75 or below, 70 or below, 65 or below, 60 or below, 55 or below, 50 or below, 45 or below, 40 It may be 37 or less, or 35 or less.

[0019] The number of carbon atoms in component (A2) is determined to improve the insulating properties and friction reducing effect and to prevent the rubber swelling resistance from decreasing. From the viewpoint of obtaining a lubricating base oil from which a lubricating oil composition having a low viscosity can be prepared, the preferred range is 24 or more. or 30 or more, more preferably 38 or more, more preferably 40 or more, more preferably 4 4 or more, more preferably 48 or more, even more preferably 50 or more, even more preferably 54 or more, It is more preferably 58 or more, particularly preferably 60 or more, and is also 100 or less, 95 or less. It may be 90 or less, 85 or less, 80 or less, 75 or less, or 70 or less.

[0020] [Specific composition of component (A1)] The component (A1) used in one embodiment of the present invention is a compound represented by the following general formula (a1-1): A11) is preferably included. [ka] In the above general formula (a1-1), R 1 and R 2 are each independently a monovalent chain hydrocarbon A group 1 is a divalent hydrocarbon group having 5 or more carbon atoms.

[0021] R 1 and R 2 The monovalent chain hydrocarbon group may be an alkyl group or an alkene group. The nyl group is preferred. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group (n-propyl group), and , isopropyl group), butyl group (n-butyl group, s-butyl group, t-butyl group, isobutyl group ethyl group), pentyl group, hexyl group, heptyl group, octyl group, 2-ethylhexyl group, 1 -methylheptyl group, nonyl group, 1-methyloctyl group, 1,1-dimethylheptyl group, Decyl group, 1-methylheptyl group, undecyl group, 1-methyldecyl group, dodecyl group, 1 -methylundecyl group, tridecyl group, 1-methyldodecyl group, tetradecyl group, 1-methyl ethyltridecyl group, pentadecyl group, 1-methyltetradecyl group, hexadecyl group, 1- Methylpentadecyl group, heptadecyl group, 1-methylhexadecyl group, octadecyl group, Straight-chain alkyl groups such as 1-methylheptadecyl, nonadecyl, and 1-methyloctadecyl groups or branched alkyl groups. Examples of the alkenyl group include an ethenyl group, a propenyl group, a butenyl group, and a pentyl group. nyl group, hexenyl group, heptenyl group, octenyl group, methylheptenyl group, nonyl group, Methyloctenyl group, decenyl group, methylnonyl group, undecenyl group, methyldecenyl group , dodecenyl group, methylundecenyl group, tridecenyl group, methyldodecenyl group, tetra Decenyl group, methyltridecenyl group, pentadecenyl group, methyltetradecenyl group, hexadecenyl group a pentadecenyl group, a heptadecenyl group, a methylhexadecenyl group, Octadecenyl group, methylheptadecenyl group, nonadecenyl group, methyloctadecenyl group and the like, and also includes straight chain or branched chain alkenyl groups such as —(CH2) m1 -C H=CH-(CH2) m2 A group represented by —CH3 (wherein m1 and m2 are independently In other words, m1 and m2 are integers of 0 or greater, and m1+m2 are integers of 1 or greater.

[0022] R 1 and R2 The number of carbon atoms in the monovalent chain hydrocarbon group can be selected as A lubricating oil composition that can improve friction-reducing effect and suppress deterioration of rubber swelling resistance is provided. From the viewpoint of the oil base oil, it is preferably 3 or more, more preferably 4 or more, and even more preferably 5 or more. More preferably, it is 6 or more, particularly preferably 7 or more, and also preferably 30 or more. or less, more preferably 25 or less, even more preferably 20 or less, and even more preferably 16 or less, Particularly preferably, it is 12 or less.

[0023] A 1 Examples of the divalent hydrocarbon group that can be selected as cycloalkylene groups, cycloalkenylene groups, arylene groups, and The divalent group may be a group having one or more carbon atoms. The total number of carbon atoms in the combination of the above groups may be 5 or more. The alkylene group may be a straight-chain alkylene group or a branched-chain alkylene group. Specifically, the following groups (i) to (iii) can be mentioned. (i):-(CH2) n - (where n is an integer of 1 or more). (ii):-(CH2) p1 -CH(CH3)-(CH2) q1 - (wherein , p1 and q1 are each independently an integer of 0 or greater). (iii):-(CH2) p2 -C(CH3)2-(CH2) q2 - (only a group represented by and p2 and q2 are each independently an integer of 0 or greater. The alkenylene group may be a linear alkenylene group, or a branched alkenylene group. Specifically, it may be a vinylene group, a methylvinylene group, or an n-propenylene group. , isopropenylene group, n-butenylene group, isobutenylene group, methylbutenylene group, ethylene ethylbutenylene group, n-pentenylene group, isopentylene group, methylpentenylene group, ethylene Tylpentenylene group, n-hexenylene group, isohexenylene group, methylhexenylene group , ethylhexenylene group, n-heptenylene group, isoheptenylene group, methylheptenylene octenylene group, ethylheptenylene group, n-octenylene group, isooctenylene group, methyloctenylene group Examples thereof include an octenylene group and an ethyloctenylene group. Examples of the cycloalkylene group include a cyclopentylene group and a cyclohexylene group. , a cyclopentylene group, a cyclooctylene group, and the like. Examples of the cycloalkenylene group include a cyclopentenylene group and a cyclohexenylene group. Examples of the cyclopentenylene group include a cyclopentenylene group and a cyclooctenylene group. Examples of the arylene group include a phenylene group, a naphthylene group, and an anthracenylene group. groups, etc.

[0024] Among these, the insulation and friction reduction effects have been improved, and the deterioration of rubber swelling resistance has been suppressed. From the viewpoint of being a lubricating base oil from which a lubricating oil composition can be prepared, 1 The bivalent The hydrocarbon group is preferably an alkylene group or an alkenylene group, and It is more preferable that the lubricating oil composition is prepared in such a manner that the decrease in rubber swelling resistance is more suppressed. From the viewpoint of obtaining a lubricating base oil that can be manufactured, -(CH2) n - (where n is 5 or less) or more (preferably 6 or more, more preferably 7 or more, even more preferably 8 or more, still more preferably It is more preferable that the number is an integer of 9 or more, and particularly preferably 10 or more.

[0025] A 1 The number of carbon atoms of the divalent hydrocarbon group can be selected as The present invention aims to provide a lubricating base oil capable of preparing a lubricating oil composition having improved rubber swelling resistance and suppressing the decrease in rubber swelling resistance. From this viewpoint, the number is 5 or more, preferably 6 or more, more preferably 7 or more, and even more preferably 8. More preferably, it is 9 or more, and particularly preferably 10 or more. 0 or less, more preferably 24 or less, even more preferably 20 or less, and even more preferably 16 or less More preferably, it is 14 or less.

[0026] In the lubricating base oil of one embodiment of the present invention, the content of compound (A11) in component (A1) is based on the total amount (100% by mass) of component (A1) contained in the lubricating base oil, preferably 70 to 100% by mass, more preferably 80 to 100% by mass, and even more preferably 90 to 100% by mass % by mass, even more preferably 95 to 100% by mass, and particularly preferably 98 to 100% by mass. be.

[0027] [Specific composition of component (A2)] The component (A2) used in one embodiment of the present invention is a compound represented by the following general formula (a2-1): A21) is preferably included. [ka] In the above general formula (a2-1), R 3 , R 4 and R 5 are each independently a monovalent chain carbon A hydrogen hydride group, 2 is a trivalent hydrocarbon group having 5 or more carbon atoms.

[0028] R3 , R 4 and R 5 The monovalent chain hydrocarbon group may be selected from an alkyl group or An alkenyl group is preferred, and R 1 and R 2 The options available are: The alkyl group and the alkenyl group are the same as those mentioned above.

[0029] R 3 , R 4 and R 5 The number of carbon atoms in the monovalent chain hydrocarbon group can be selected as It is possible to prepare a lubricating oil composition that has improved lubricating properties and friction-reducing effects and suppresses a decrease in rubber swelling resistance. From the viewpoint of providing a lubricating base oil, the saturation ratio is preferably 3 or more, more preferably 5 or more, and even more preferably 1 or more. is 7 or more, more preferably 9 or more, even more preferably 11 or more, and particularly preferably 13 or more and preferably 40 or less, more preferably 35 or less, and even more preferably 30 or less. It is preferably 25 or less, even more preferably 22 or less.

[0030] A 2 The trivalent hydrocarbon group that can be selected as the trivalent hydrocarbon group is, for example, a group represented by the above-mentioned general formula ( A in a1-1) 1 and removing one more hydrogen atom from a divalent hydrocarbon group which may be selected as and trivalent groups represented by the formula: Among these, a group represented by the following general formula (a2-1-1) is preferred. [ka]

[0031] In the above general formula (a2-1-1), * indicates the bonding position. x1, x2, and x3 are each independently an integer of 0 or more, preferably 0 to 1 An integer of 5, more preferably an integer of 0 to 10, more preferably an integer of 0 to 8, and even more preferably is an integer of 1 to 6, more preferably an integer of 1 to 4, even more preferably an integer of 1 to 3, particularly An integer of 1 to 2 is preferred. R 7 is an alkyl group, and R 1 and R 2 can be selected as Examples of the alkyl group include the same alkyl groups as those mentioned above. R 7 The number of carbon atoms of the alkyl group that can be selected as Preferably, the number is 1 to 10, more preferably 1 to 8, even more preferably 1 to 6, and even more preferably 1 to 8 4, and particularly preferably 2 to 3.

[0032] In the lubricating base oil of one embodiment of the present invention, the content of compound (A21) in component (A2) is based on the total amount (100% by mass) of component (A2) contained in the lubricating base oil, preferably 70 to 100% by mass, more preferably 80 to 100% by mass, and even more preferably 90 to 100% by mass % by mass, even more preferably 95 to 100% by mass, and particularly preferably 98 to 100% by mass. be.

[0033] <Component (B): Base oil> In one embodiment of the present invention, the lubricating base oil is selected from mineral oils and synthetic oils other than ester-based synthetic oils. It comprises at least one base oil (B). By including component (B) together with component (A), which is a factor in reducing rubber swelling resistance, While maintaining the friction reduction effect of A), the combined use of components (A) and (B) provides insulation properties. The present invention provides a lubricating oil composition that improves the rubber swelling resistance and suppresses the decrease in rubber swelling resistance caused by component (A). The lubricating base oil can be produced as a lubricating base oil.

[0034] In the lubricating base oil of one embodiment of the present invention, the content of component (B) is (100% by mass) of a lubricating oil composition that is excellent in insulating properties and rubber swelling resistance. From the viewpoint of lubricating base oil, the content is preferably 10% by mass or more, more preferably 20% by mass or more, More preferably, it is 30% by mass or more, more preferably, 40% by mass or more, and even more preferably, it is 45% by mass or more. % by mass or more, more preferably 50% by mass or more, even more preferably 55% by mass or more, and even more preferably The content of component (A) is preferably 60% by mass or more, and particularly preferably 65% ​​by mass or more. The present invention aims to provide a lubricating base oil capable of preparing a lubricating oil composition having improved friction-reducing effect by ensuring the amount of the lubricating base oil. From this viewpoint, it is preferably 99% by mass or less, more preferably 97% by mass or less, and even more preferably 95% by mass or less. % by mass or less, more preferably 93% by mass or less, even more preferably 90% by mass or less, and even more preferably or 88% by mass or less, more preferably 85% by mass or less, and even more preferably 83% by mass or less It is particularly preferably 80% by mass or less.

[0035] Examples of the mineral oil used in one embodiment of the present invention include paraffinic crude oil, intermediate crude oil, and naphthalene crude oil. Atmospheric residue obtained by atmospheric distillation of crude oil such as fumes; distillate obtained by solvent deasphalting, solvent extraction, hydrocracking, solvent dewaxing, catalytic Refined oil obtained by one or more refining processes such as catalytic dewaxing and hydrorefining (hydrocracking) ;etc.

[0036] Examples of synthetic oils other than ester-based synthetic oils that can be used in one embodiment of the present invention include α-olefins. olefin homopolymer, or α-olefin copolymer (e.g., ethylene-α-olefin copolymer) Polyα-olefins such as α-olefin copolymers having 8 to 14 carbon atoms; isopara Fin; Polyalkylene glycol; Ether oil such as polyphenyl ether; Alkyl Benzene; alkylnaphthalenes; produced from natural gas by the Fischer-Tropsch process It is obtained by isomerizing the wax (GTL wax (Gas To Liquids Wax)) Examples include synthetic oil (GTL).

[0037] In one embodiment of the present invention, component (B) is a group of API (American Petroleum Institute) base oils. At least one selected from mineral oils classified into Group 2 and Group 3, and synthetic oils It is preferred that it contains

[0038] [Properties of lubricating base oil] The kinematic viscosity at 100°C of the lubricating base oil of one embodiment of the present invention is 1.0 mm 2 / s or more, 1.2mm 2 / s or more, 1.5mm 2 / s or more, 1.7mm 2 / s or more, 2.0mm 2 / s or more, 2 .2mm 2 / s or more, or 2.5 mm 2 / s or more, and 10 mm 2 / s or later Bottom, 9.0mm 2 / s or less, 8.0mm 2 / s or less, 7.0mm 2 / s or less, 6.0mm 2 / s or less, 5.0mm 2 / s or less, 4.5mm 2 / s or less, 4.2mm 2 / s or less, 4 .0mm 2 / s or less, 3.8mm 2 / s or less, or 3.5 mm 2 / s or less may be used.

[0039] The viscosity index of the lubricating base oil of one embodiment of the present invention is 70 or more, 80 or more, 85 or more, or 90 or more. , 95 or more, 100 or more, 105 or more, 110 or more, or 115 or more.

[0040] The lubricating base oil of one embodiment of the present invention preferably has a density at 15°C of 0.850 g / cm 3 less than, More preferably 0.848 g / cm 3 or less, more preferably 0.847 g / cm 3 below, Even more preferably 0.846 g / cm 3 and 0.845 g / cm 3 Below Bottom, 0.844g / cm 3 Below, 0.843g / cm 3 Below, 0.842g / cm 3 below , or 0.841 g / cm 3 It may be less than 0.600 g / cm 3 Above, 0. 650g / cm 3 More than 0.700g / cm 3 More than 0.750g / cm 3 Over 0.8 00g / cm 3 More than 0.810g / cm 3 More than 0.820g / cm 3 Greater than or equal to 0. 825g / cm 3 It may be more than that.

[0041] [Constitution of lubricating oil composition] A lubricating oil composition according to one embodiment of the present invention contains the lubricating base oil according to one embodiment of the present invention described above. The lubricating oil composition of one embodiment of the present invention may further contain lubricating oil additives, specifically Pour point depressants, viscosity index improvers, antioxidants, extreme pressure agents, metallic detergents, ashless dispersants one or more lubricating oil additives selected from the group consisting of metal deactivators, corrosion inhibitors, rust inhibitors, and antifoaming agents; Additives may also be included. These lubricating oil additives may be used alone or in combination of two or more. stomach.

[0042] The content of each of these lubricating oil additives is within a range that does not impair the effects of the present invention. Although it can be appropriately adjusted, each of the components is based on the total amount (100 mass%) of the lubricating oil composition. The amount of each additive is usually 0.001 to 15 mass %, preferably 0.005 to 10 mass %. %, and more preferably 0.01 to 5 mass %.

[0043] In the lubricating oil composition of one embodiment of the present invention, the content of the lubricating base oil of one embodiment of the present invention is preferably 50% by mass or more, more preferably 50% by mass or more, based on the total amount (100% by mass) of the lubricating oil composition. Preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more. % by mass or more, and particularly preferably 90% by mass or more.

[0044] <Pour point depressants> Examples of pour point depressants that can be used in one embodiment of the present invention include ethylene-vinyl acetate copolymers. Condensation products of chlorinated paraffins and naphthalene, Condensation products of chlorinated paraffins and phenol Examples of the polymerizable compound include polymethacrylates, polyalkylstyrenes, and the like. These pour point depressants may be used alone or in combination of two or more.

[0045] <Viscosity index improver> Examples of viscosity index improvers used in one embodiment of the present invention include non-dispersant polymethacrylates. acrylate, dispersed polymethacrylate, olefin copolymer (e.g., ethylene-propylene copolymer) copolymers), dispersion-type olefin copolymers, styrene copolymers (e.g., styrene- Examples of polymers include diene copolymers, styrene-isoprene copolymers, etc. These viscosity index improvers may be used alone or in combination of two or more. The viscosity index improver used in one embodiment of the present invention has a weight average molecular weight (Mw) of 5.00 0 or more, 7,000 or more, 10,000 or more, 15,000 or more, or 20,000 or more It may also be 1,000,000 or less, 700,000 or less, 500,000 or less Under, 300,000 or less, 200,000 or less, 100,000 or less, or 50,000 The following may also be used.

[0046] <Antioxidants> Examples of antioxidants used in one embodiment of the present invention include alkylated diphenylamines, Amine antioxidants such as phenylnaphthylamine and alkylated phenylnaphthylamine; 2,6-di-t-butylphenol, 4,4'-methylenebis(2,6-di-t-butyl) Phenol), Isooctyl-3-(3,5-di-t-butyl-4-hydroxyphenyl ) propionate, n-octadecyl-3-(3,5-di-t-butyl-4-hydroxy phenolic antioxidants such as phenyl)propionate; These antioxidants may be used alone or in combination of two or more. In the lubricating oil composition of one embodiment of the present invention, the antioxidant is an amine-based antioxidant and a phenol-based antioxidant. It is preferable to use a phenol-based antioxidant in combination.

[0047] <Extreme pressure agent (anti-wear agent)> Examples of extreme pressure agents (antiwear agents) used in one embodiment of the present invention include zinc dithiophosphate. Sulfur-containing compounds; phosphites, phosphates, phosphonates, and Phosphorus-containing compounds such as amine salts or metal salts thereof; thiophosphites, thiophosphates sulfur and thiophosphonates such as esters, thiophosphonates, and their amine salts or metal salts; Phosphorus-containing compounds These extreme pressure agents may be used alone or in combination of two or more.

[0048] <Metallic detergents> The metal-based detergent used in one embodiment of the present invention includes metal sulfonates, metal salicylates, and the like. and metal salts such as metal phenates. As the metal atom, a metal atom selected from alkali metals and alkaline earth metals is preferred, and sodium More preferred are zinc, calcium, magnesium, or barium, with calcium being even more preferred. stomach. These metallic detergents may be used alone or in combination of two or more.

[0049] In the lubricating oil composition of one embodiment of the present invention, the metal-based detergent is calcium sulfonate, It may contain one or more selected from calcium salicylate and calcium phenate. It is preferable to include calcium sulfonate. The calcium sulfonate content is determined based on the metal detergent content in the lubricating oil composition. Based on the total amount (100% by mass), the amount is preferably 50 to 100% by mass, more preferably 60 to 1 00 mass%, more preferably 70 to 100 mass%, and even more preferably 80 to 100 mass% %.

[0050] The base number of the metallic detergent is preferably 0 to 600 mgKOH / g. However, in the lubricating oil composition of one embodiment of the present invention, the metallic detergent has a base number of 100m Preferably, the detergent is an overbased metallic detergent with an acidity of gKOH / g or more. The base number of the overbased metallic detergent is preferably 100 mgKOH / g or more. Preferably, it is 150 to 500 mg KOH / g, more preferably 200 to 450 mg KOH / g. do. In this specification, the "base number" refers to the base number of petroleum products as defined in JIS K2501:2003 and the base number measured by the perchloric acid method in accordance with 7. of "Lubricating Oils - Neutralization Number Test Method" means.

[0051] <Ashless dispersant> The ashless dispersant used in one embodiment of the present invention is, for example, a boron-free alkenyl dispersant. boron-free succinimides such as succinimides, boron-containing alkenyl succinimides, etc. boron-containing succinimides, benzylamines, boron-containing benzylamines, succinimides esters of succinic acid, fatty acids or mono- or dicarboxylic acid amides represented by succinic acid etc. These ashless dispersants may be used alone or in combination of two or more.

[0052] <Metal deactivator> The metal deactivator used in one embodiment of the present invention is, for example, a benzotriazole-based compound. compounds, tolyltriazole compounds, imidazole compounds, thiadiazole compounds, imidine compounds and the like. These metal deactivators may be used alone or in combination of two or more.

[0053] <Corrosion inhibitor> Examples of the corrosion inhibitor used in one embodiment of the present invention include amine compounds, alkanols, and the like. Examples of the compound include amine compounds, amide compounds, and carboxylic acid compounds. These corrosion inhibitors may be used alone or in combination of two or more.

[0054] <Rust inhibitor> Examples of the rust inhibitor used in one embodiment of the present invention include fatty acids, half alkenyl succinates, Esters, fatty acid soaps, alkyl sulfonates, polyhydric alcohol fatty acid esters, fats Examples include fatty acid amines, oxidized paraffins, and alkyl polyoxyethylene ethers. These rust inhibitors may be used alone or in combination of two or more.

[0055] <Antifoaming agent> Examples of the antifoaming agent used in one embodiment of the present invention include silicone oil and fluorosilicone. oil and fluoroalkyl ether. These antifoaming agents may be used alone or in combination of two or more.

[0056] <Fatty acid amide> The lubricating oil composition of one embodiment of the present invention uses a lubricating base oil containing components (A) and (B). Therefore, it has an excellent friction reducing effect and does not need to contain an aliphatic amide. In addition, since aliphatic amides are a factor that reduces the insulating properties of the lubricating oil composition, their inclusion The smaller the amount, the more preferable, and it is more preferable that the amount is substantially zero. In the lubricating oil composition of one embodiment of the present invention, the content of the fatty amide is Based on the total amount (100% by mass), it is preferably less than 1.0% by mass, more preferably 0.5% by mass. It is preferably less than 0.1% by mass, more preferably less than 0.1% by mass.

[0057] In this specification, the term "substantially free of aliphatic amides" means that, based on a specific purpose, This provision excludes the case where an aliphatic amide is contained as an impurity of another component. It does not exclude cases where mido is unavoidably included and is unintentionally included. do not have. In addition, when the embodiment of "substantially not containing aliphatic amide" is also taken into consideration, the content of aliphatic amide The amount is more preferably 0.01 mass % based on the total amount (100 mass %) of the lubricating oil composition. less than 0.001% by mass, and even more preferably less than 0.0001% by mass It is particularly preferably less than 0.00001% by mass.

[0058] Examples of the aliphatic amide include a reaction product of an aliphatic carboxylic acid and an aliphatic amine. can be. Examples of aliphatic carboxylic acids include palmitic acid, isopalmitic acid, and stearic acid. , Isostearic Acid, Behenic Acid, Lignoceric Acid, Cetironic Acid, Heptacosanoic Acid, Montana Examples of such acids include carboxylic acid, melissic acid, lacteric acid, cetoleic acid, and erucic acid. Examples of aliphatic amines include ammonia, ethylenediamine, and diethylenetriamine. Triamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine Min et al.

[0059] [Properties and characteristics of lubricating oil composition] The kinematic viscosity at 100°C of the lubricating oil composition of one embodiment of the present invention is adjusted appropriately depending on the application, and is 1. 0mm 2 / s or more, 1.5mm 2 / s or more, 2.0mm 2 / s or more, 2.2mm 2 / s or later Top, 2.5mm 2 / s or more, 2.7mm 2 / s or more, or 3.0 mm 2 / s or more Well, also 10mm 2 / s or less, 9.0mm 2 / s or less, 8.0mm 2 / s or less, 7. 0mm 2 / s or less, 6.0mm 2 / s or less, 5.0mm 2 / s or less, 4.5mm 2 / s or later Bottom, 4.2mm 2 / s or less, 4.0mm 2 / s or less, 3.8mm 2 / s or less, or 3.5 mm 2 / s or less may be used.

[0060] The viscosity index of the lubricating oil composition of one embodiment of the present invention is 70 or more, 80 or more, 85 or more, 90 or more. Above, 95 or above, 100 or above, 105 or above, 110 or above, 115 or above, 120 or above, 125 It may be 130 or more.

[0061] The lubricating oil composition of one embodiment of the present invention was measured at a temperature of 8 The volume resistivity measured under the conditions of 0°C, applied voltage 250V, and measurement time 1 minute is preferably 1.4×10 7 More than Ω·m, preferably 1.5×10 7 Ω·m or more, more preferably 1 .6×10 7 Ω·m or more, and even more preferably 1.7×10 7 Ω·m or more. The volume resistivity value means a value measured by the method described in the examples below.

[0062] The lubricating oil composition according to one embodiment of the present invention was measured for its gold content in accordance with the method described in the Examples below. The intermetallic friction coefficient is preferably less than 0.160, more preferably 0.158 or less, and even more preferably or 0.157 or less, even more preferably 0.155 or less, particularly preferably 0.153 The following is the result.

[0063] A test nitrile rubber was immersed in the lubricating oil composition according to one embodiment of the present invention, and the test was carried out according to JIS K6258 The volume change rate of test nitrile rubber measured under conditions of 100°C for 144 hours in accordance with is preferably 10% or less, more preferably 8% or less, even more preferably 7% or less, and even more preferably It is preferably 5% or less, and particularly preferably 4% or less. The volume change rate of the test nitrile rubber is a value measured by the method described in the examples below. means.

[0064] [Uses of lubricating oil composition] The lubricating oil composition of a preferred embodiment of the present invention has properties suitable for various mechanisms incorporated in devices. It has excellent insulation properties, friction reduction effects, and resistance to rubber swelling. Taking these characteristics into consideration, the lubricating oil composition of one embodiment of the present invention is suitable for use in, for example, electric drive units. These are incorporated into various devices such as engines, transmissions, reducers, compressors, and hydraulic systems. For mechanisms such as oil converters, wet clutches, gear bearing mechanisms, oil pumps, and hydraulic control mechanisms It can be used suitably for lubrication in the following cases. It also has excellent cooling and insulating properties. It can also be suitably used for cooling and insulating motors and batteries. Furthermore, the lubricating oil composition of a preferred embodiment of the present invention has excellent resistance to rubber swelling, and therefore, It can also be suitably used in the parts that come into contact with the ring or gasket. [Example]

[0065] Next, the present invention will be described in more detail with reference to examples. However, the present invention will not be limited to these examples. The methods for measuring or calculating various properties are as follows, but are not limited to these.

[0066] (1)Kinematic viscosity, viscosity index Measurements and calculations were made in accordance with JIS K2283:2000. (2) Density Measurement was carried out in accordance with JIS K2249.

[0067] Examples 1 to 7, Comparative Examples 1 to 4 Lubricating base oils were prepared by blending the types and amounts of base oils shown in Table 1. The kinematic viscosity at 100°C, viscosity index, and density at 15°C were measured or calculated, and the results are shown in Table 1. The value shown is as follows. Then, lubricating oil additives of the types and amounts shown in Table 1 were added to prepare lubricating oil compositions. Ta. The base oil components and lubricating oil additives used in the preparation of the lubricating base oil and lubricating oil composition were as follows: That's right.

[0068] <Ester-based synthetic oil> "C28 diester": bis(2-ethylhexyl) dodecanedioate, a compound of the following general formula (a1 -i) is a diester having 28 carbon atoms. "C26 diester": bis(2-ethylhexyl) sebacate, a diester of the following general formula (a1- ii) A diester having 26 carbon atoms. "C22 diester": bis(2-ethylhexyl) adipate, a carboxylic acid ester of the following general formula (a1- A diester having 22 carbon atoms represented by iii). [ka]

[0069] "C60 triester": Trimethylolpropane (oleic acid) triester, A triester having 60 carbon atoms represented by general formula (a2-i). "C30·C36 triester": Trimethylolpropane (caprylic acid·capric acid) ) triester, a triester having 30 carbon atoms represented by the general formula (a2-iia) and the A mixture with a triester having 36 carbon atoms represented by general formula (a2-iib). [ka]

[0070] <Base oils other than ester-based synthetic oils> "60N mineral oil": Paraffinic mineral oil belonging to Group II of the API base oil category, 10 0℃ kinematic viscosity=2.3mm 2 / s, viscosity index=106. "100N mineral oil": Paraffinic mineral oil belonging to Group III of the API base oil category, 100℃ kinematic viscosity=4.2mm 2 / s, viscosity index=125. "PAO(1)": Poly-α-olefin synthetic oil, kinematic viscosity at 100°C = 1.8 mm 2 / s . "PAO(2)": Poly-α-olefin synthetic oil, kinematic viscosity at 100°C = 3.9 mm 2 / s , viscosity index=120.

[0071] <Lubricant additives> - "Pour point depressant": Polymethacrylate (PMA)-based pour point depressant. "Additive mixture": Phosphite ester, phenolic antioxidant, amine antioxidant , thiadiazole, calcium sulfonate, boron-modified polybutenyl succinimide, An additive mixture consisting of a corrosion inhibitor and a silicone-based defoamer. "Fatty acid amide": reaction product of tetraethylenepentamine and isostearic acid.

[0072] The kinematic viscosity at 100°C and viscosity index of the prepared lubricating oil composition were measured or calculated. The following tests (1) to (3) were carried out. The results are shown in Table 1.

[0073] (1) Insulation test In accordance with JIS C2101, measurement temperature: 80°C, applied voltage: 250V, measurement time: 1 minute The volume resistivity of the sample oil was measured under the test conditions. The higher the volume resistivity value, It can be said that this lubricating oil composition has excellent insulating properties. x10 7 Lubricating oil compositions with a resistance exceeding Ω·m were determined to have good insulating properties.

[0074] (2) Friction reduction effect test Using a reciprocating friction tester (SRV reciprocating friction tester manufactured by Optimar), the following tests were carried out. The friction coefficient was measured by the procedure. The test piece was a disk (diameter 24 mm, thickness 7.9 mm, material: SUJ-2). A few drops of the lubricating oil composition to be measured were placed on the disc, and a ball (10 mm in diameter) was used. A ball (material: SUJ-2) was set on top of the disk. In this state, the temperature was 100°C, the load was 75N (1.7GPa), the speed was 0.16m / s, and the amplitude was 1m. The coefficient of friction was determined under the conditions of 50 Hz and 50°C. The smaller the value of the friction coefficient, the more effective the lubricating oil composition is in reducing friction. In this example, a lubricating oil composition having a friction coefficient of less than 0.160 has a friction reducing effect. It was determined that the composition had good lubricating properties.

[0075] (3) Rubber swelling resistance test A rubber immersion test was conducted in accordance with JIS K6258. Nitrile rubber for testing (product name "A727" manufactured by NOK Corporation) was immersed in the lubricating base oil at a temperature The test was carried out under the conditions of 100°C temperature and 144 hours of immersion. The volume of the test piece was measured, and the volume change rate was calculated using the following formula. ·[Volume change rate (%)] = ([Volume of test piece after test] - [Volume of test piece before test]) / [Volume of test piece before test] x 100 The higher the volume resistivity value, the more excellent the resistance to rubber swelling of the lubricating oil composition. In this example, the lubricating oil composition with a volume change rate of 10% or less has a high resistance to rubber swelling. It was determined to be a good lubricating composition.

[0076] [Table 1]

[0077] As can be seen from Table 1, the lubricating oil compositions of Examples 1 to 7 exhibited excellent insulating properties, friction reducing effects, and rubber swelling resistance. All of the characteristics were well balanced and excellent. On the other hand, the lubricating oil compositions of Comparative Examples 1 to 4 have excellent insulating properties, friction reducing effects, and rubber swelling resistance. At least one species performed poorly.

Claims

1. A diester (A1) having 24 or more carbon atoms and a triester (A2) having 24 or more carbon atoms At least one selected ester compound (A), and at least one base oil (B) selected from mineral oils and synthetic oils other than ester-based synthetic oils. Contains lubricating base oils.

2. The density of the lubricating base oil at 15 ° C. is 0.850 g / cm ３ less than The lubricating base oil described above.

3. The content of component (A) is 1 to 90 mass% based on the total amount of the lubricating base oil.

3. The lubricating base oil according to claim 1 or 2.

4. The lubricating oil according to any one of claims 1 to 3, wherein the component (A1) has 26 or more carbon atoms. Base oil.

5. The component (A1) contains a compound (A11) represented by the following general formula (a1-1):

5. The lubricating base oil according to any one of 1 to 4. 【Chemistry 1】 (In the above formula, R １ and R ２ are each independently a monovalent chain hydrocarbon group, １ is a divalent hydrocarbon group having 5 or more carbon atoms.

6. The component (A2) includes a compound (A21) represented by the following general formula (a2-1):

6. The lubricating base oil according to any one of 1 to 5. 【Chemistry 2】 (In the above formula, R ３ , R ４ and R ５ are each independently a monovalent chain hydrocarbon group, , A ２ is a trivalent hydrocarbon group having 5 or more carbon atoms.

7. 7. The composition according to claim 1, wherein the component (A) comprises at least the component (A1). Lubricant base oil.

8. 7. The composition according to claim 1, wherein the component (A) comprises at least the component (A2). Lubricant base oil.

9. A lubricating oil composition comprising the lubricating base oil of any one of claims 1 to 8.

10. In addition, pour point depressants, viscosity index improvers, antioxidants, extreme pressure agents, metal detergents, ashless One or more lubricants selected from dispersants, metal deactivators, corrosion inhibitors, rust inhibitors, and antifoaming agents The lubricating oil composition of claim 9, comprising an oil additive.

11. The content of fatty acid amide is 1.0 mass % based on the total amount (100 mass %) of the lubricating oil composition.

11. The lubricating oil composition of claim 9 or 10, wherein the amount of hydroxybenzoates is less than 1% by weight.

12. A test nitrile rubber was immersed in the lubricating oil composition and subjected to 1 The volume change rate of the test nitrile rubber measured under the conditions of 100°C for 144 hours was 10%. The lubricating oil composition of any one of claims 9 to 11, wherein the total mass of the lubricating oil composition is less than 1000 kJ / g.

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