Lubricating oil composition, and method of use and manufacture of lubricating oil composition

Abstract

To provide a lubricating oil composition having excellent rust-preventive properties, although containing a base oil containing a polar substance which has a significant effect of deteriorating rust-preventive properties, and a method for using and manufacturing the same. Furthermore, the problem is solved by providing a lubricating oil composition containing a base oil (A) and a rust-preventive agent (B), wherein the base oil (A) satisfies a specific requirement (α) by gas chromatography, and the rust-preventive agent (B) is one or more selected from a first rust-preventive agent (B1), a second rust-preventive agent (B2), a third rust-preventive agent (B3), and a fourth rust-preventive agent (B4), and satisfies a specific requirement (β).

Description

Technical Field

[0001] This invention relates to lubricating oil compositions, as well as methods of using and manufacturing the lubricating oil compositions. Background Technology

[0002] For lubricating oil compositions used in machinery that may be contaminated with water or water vapor, rust prevention is required to prevent the surfaces of such machinery from rusting.

[0003] For example, in Patent Document 1, a lubricating oil composition with excellent rust-preventing properties was proposed, comprising, based on the total amount of a hydrocarbon oil selected from mineral oils and synthetic oils, 0.008–0.04% by mass of a sarcosine derivative, 0.01–0.07% by mass of an alkenyl succinate, 0.1–3.0% by mass of an amine antioxidant, and 0.1–3.0% by mass of a phenolic antioxidant. In this lubricating oil composition, the sarcosine derivative and alkenyl succinate are added as rust inhibitors.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2017-179197 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] From the viewpoint of diversifying raw material supply, the inventors conducted in-depth research on lubricant compositions for use in machinery that may be contaminated with water or water vapor, using various base oils. The results showed that even when using commonly known succinates alone as rust inhibitors, there were small amounts of base oils whose rust-preventive properties could not be adequately guaranteed.

[0009] The inventors conducted in-depth research to determine the cause. They discovered that the base oil contained polar substances that significantly reduced rust prevention, thus failing to adequately ensure rust protection.

[0010] Furthermore, it was found that even when a rust inhibitor composed of sarcosine derivatives and alkenyl succinates was combined in the base oil as proposed in Patent Document 1, it was still not sufficient to ensure rust prevention.

[0011] From the perspective of diversifying raw material supply, it is desirable to ensure rust prevention even for base oils that exist in small quantities and whose rust prevention cannot be fully guaranteed even when combined with common rust inhibitors.

[0012] Therefore, the objective of this invention is to provide a lubricating oil composition that still exhibits excellent rust prevention properties despite containing a base oil containing a polar substance (which has the effect of significantly reducing rust prevention properties), as well as a method for using and manufacturing the lubricating oil composition.

[0013] Methods for solving problems

[0014] To solve this problem, the inventors conducted repeated and in-depth research. As a result, they discovered parameters for a base oil containing polar substances that significantly reduce rust prevention properties, and also discovered rust inhibitors effective against this base oil and their content. Through further repeated research, they completed this invention.

[0015] That is, the present invention relates to the following [1] to [3].

[0016] [1] A lubricating oil composition comprising a base oil (A) and a rust inhibitor (B), wherein the base oil (A) satisfies the following requirement (α).

[0017] <Requirement (α)>

[0018] Gas chromatograms determined by gas chromatography distillation apparatus according to ASTM D 7500 show peaks in the range of carbon number greater than 11 and less than 23.

[0019] The aforementioned rust inhibitor (B) is selected from one or more of the first rust inhibitor (B1), the second rust inhibitor (B2), the third rust inhibitor (B3), and the fourth rust inhibitor (B4).

[0020] • The aforementioned first rust inhibitor (B1): a combination of succinate (B1-1) and dehydrated sorbitan fatty acid ester (B1-2).

[0021] • The aforementioned second rust inhibitor (B2): Carboxylic acid amide (B2-1)

[0022] • The aforementioned third rust inhibitor (B3): Neutral alkyl phosphate ester (B3-1)

[0023] • The aforementioned fourth rust inhibitor (B4): a combination of fatty acids with 12 or more carbon atoms (B4-1) and primary amines (B4-2);

[0024] Based on the total amount of the aforementioned lubricating oil composition, the contents of the aforementioned first rust inhibitor (B1), the aforementioned second rust inhibitor (B2), the aforementioned third rust inhibitor (B3), and the aforementioned fourth rust inhibitor (B4) satisfy the following requirement (β).

[0025] <Requirement (β)>

[0026] • The aforementioned first rust inhibitor (B1): exceeding 0.02% by mass and less than 0.16% by mass

[0027] • The aforementioned second rust inhibitor (B2): more than 0.05% by mass and less than 0.5% by mass

[0028] • The aforementioned third rust inhibitor (B3): 0.005% by mass or more but less than 0.05% by mass

[0029] • The aforementioned fourth rust inhibitor (B4): more than 0.05% by mass and less than 0.20% by mass.

[0030] [2] Method of use, wherein the lubricating oil composition described in [1] above is used as a turbine oil.

[0031] [3] A method for manufacturing a lubricating oil composition, which includes the step of mixing a base oil (A) and a rust inhibitor (B), wherein,

[0032] The aforementioned base oil (A) meets the following requirement (α),

[0033] <Requirement (α)>

[0034] Gas chromatograms determined by gas chromatography distillation apparatus according to ASTM D 7500 show peaks in the range of carbon number greater than 11 and less than 23.

[0035] The aforementioned rust inhibitor (B) is selected from one or more of the first rust inhibitor (B1), the second rust inhibitor (B2), the third rust inhibitor (B3), and the fourth rust inhibitor (B4).

[0036] • The aforementioned first rust inhibitor (B1): a combination of succinate (B1-1) and dehydrated sorbitan fatty acid ester (B1-2).

[0037] • The aforementioned second rust inhibitor (B2): Carboxylic acid amide (B2-1)

[0038] • The aforementioned third rust inhibitor (B3): Neutral alkyl phosphate ester (B3-1)

[0039] • The aforementioned fourth rust inhibitor (B4): a combination of fatty acids with 12 or more carbon atoms (B4-1) and primary amines (B4-2);

[0040] Based on the total amount of the aforementioned lubricating oil composition, the proportions of the aforementioned first rust inhibitor (B1), the aforementioned second rust inhibitor (B2), the aforementioned third rust inhibitor (B3), and the aforementioned fourth rust inhibitor (B4) satisfy the following requirement (β).

[0041] <Requirement (β)>

[0042] • The aforementioned first rust inhibitor (B1): exceeding 0.02% by mass and less than 0.16% by mass

[0043] • The aforementioned second rust inhibitor (B2): more than 0.05% by mass and less than 0.5% by mass

[0044] • The aforementioned third rust inhibitor (B3): 0.005% by mass or more but less than 0.05% by mass

[0045] • The aforementioned fourth rust inhibitor (B4): more than 0.05% by mass and less than 0.20% by mass.

[0046] Invention Effects

[0047] According to the present invention, a lubricating oil composition that still has excellent rust prevention properties although containing a base oil containing a polar substance (which has the effect of significantly reducing rust prevention) can be provided, as well as a method for using the lubricating oil composition and a method for manufacturing the lubricating oil composition. Attached Figure Description

[0048] Figure 1 Gas chromatograms of base oil (A) that meets requirement (α) and base oil (A') that does not meet requirement (α). Detailed Implementation

[0049] The upper and lower limits of the numerical ranges described in this specification can be combined arbitrarily. For example, in the case where "A~B" and "C~D" are described as numerical ranges, the numerical ranges of "A~D" and "C~B" are also included in the scope of this invention.

[0050] In addition, unless otherwise specified, the numerical range “lower limit to upper limit” described in this specification means above the lower limit and below the upper limit.

[0051] Furthermore, in this specification, the numerical values ​​used in the embodiments are values ​​that can be used as upper or lower limits.

[0052] [The method of the lubricating oil composition of the present invention]

[0053] The lubricating oil composition of the present invention contains a base oil (A) and a rust inhibitor (B).

[0054] The aforementioned base oil (A) meets the following requirement (α).

[0055] <Requirement (α)>

[0056] Gas chromatograms determined by a gas chromatograph distillation apparatus according to ASTM D 7500 show peaks in the range of carbon atoms greater than 11 and less than 23.

[0057] The aforementioned rust inhibitor (B) is selected from one or more of the first rust inhibitor (B1), the second rust inhibitor (B2), the third rust inhibitor (B3), and the fourth rust inhibitor (B4).

[0058] • The aforementioned first rust inhibitor (B1): a combination of succinate (B1-1) and dehydrated sorbitan fatty acid ester (B1-2).

[0059] • The aforementioned second rust inhibitor (B2): Carboxylic acid amide (B2-1)

[0060] • The aforementioned third rust inhibitor (B3): Neutral alkyl phosphate ester (B3-1)

[0061] • The aforementioned fourth rust inhibitor (B4): a combination of fatty acids with 12 or more carbon atoms (B4-1) and primary amines (B4-2);

[0062] Based on the total amount of the aforementioned lubricating oil composition, the contents of the aforementioned first rust inhibitor (B1), the aforementioned second rust inhibitor (B2), the aforementioned third rust inhibitor (B3), and the aforementioned fourth rust inhibitor (B4) satisfy the following requirement (β).

[0063] <Requirement (β)>

[0064] • The aforementioned first rust inhibitor (B1): exceeding 0.02% by mass and less than 0.16% by mass

[0065] • The aforementioned second rust inhibitor (B2): more than 0.05% by mass and less than 0.5% by mass

[0066] • The aforementioned third rust inhibitor (B3): 0.005% by mass or more but less than 0.05% by mass

[0067] • The aforementioned fourth rust inhibitor (B4): more than 0.05% by mass and less than 0.20% by mass.

[0068] In order to solve the above-mentioned problems, the inventors conducted in-depth research and discovered the above-mentioned requirement (α) as a parameter for determining the base oil containing polar substances that significantly reduce rust prevention.

[0069] It should be noted that, during various studies, the inventors confirmed the following (1) and (2). Therefore, it was determined that the substance that significantly reduces the rust prevention properties is a polar substance, and that the polar substance significantly reduces the rust prevention properties of the lubricating oil composition.

[0070] (1) For those that meet the above requirements ( α The base oil was subjected to clay treatment to extract the aforementioned polar substances. These extracted polar substances were then added to a base oil that did not meet the aforementioned requirement (α) to prepare a base oil that met the aforementioned requirement (α). Furthermore, a lubricating oil composition was prepared using this base oil, and its rust-preventive properties were studied. The results confirmed that rust formation was promoted.

[0071] (2) The base oil that meets the above requirement (α) is treated with clay to remove the aforementioned polar substances, thus preparing a base oil that does not meet the above requirement (α). Furthermore, the preparation of lubricating oil compositions using this base oil confirms that rust formation is suppressed.

[0072] Next, in order to ensure excellent rust prevention, the inventors conducted in-depth research on lubricating oil compositions containing base oils that satisfy the above-mentioned requirement (α). The results showed that combinations of succinate and sorbitol fatty acid esters (first rust inhibitor (B1)), carboxylamides (second rust inhibitor (B2)), aliphatic phosphate esters (third rust inhibitor (B3)), or combinations of fatty acids with 12 or more carbon atoms (B4-1) and primary amines (B4-2) (fourth rust inhibitor (B4)) could function as effective rust inhibitors for base oils that satisfy the above-mentioned requirement (β) by adjusting their content. Through further repeated research, the present invention was realized.

[0073] It should be noted that in the following description, “base oil (A)” and “rust inhibitor (B)” will also be referred to as “component (A)” and “component (B)”, respectively.

[0074] In addition, “First Rust Inhibitor (B1)”, “Second Rust Inhibitor (B2)”, “Third Rust Inhibitor (B3)” and “Fourth Rust Inhibitor (B4)” are referred to as “Component (B1)”, “Component (B2)”, “Component (B3)” and “Component (B4)”, respectively.

[0075] The lubricating oil composition of one aspect of the present invention may be free of components other than component (A) and component (B), but preferably further contains one or more additives selected from antioxidant (C), wear-resistant agent (D) and defoamer (E) without impairing the effects of the present invention.

[0076] It should be noted that in the following description, “antioxidant (C)”, “wear-resistant agent (D)” and “defoamer (E)” will also be referred to as “ingredient (C)”, “ingredient (D)” and “ingredient (E)”, respectively.

[0077] In one embodiment of the lubricating oil composition of the present invention, the total content of component (A) and component (B), based on the total amount of the lubricating oil composition, is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. Furthermore, it is preferably less than 100% by mass, more preferably 99.9% by mass or less, and even more preferably 99.5% by mass or less.

[0078] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, it is preferably 80% to less than 100% by mass, more preferably 90% to 99.9% by mass, and even more preferably 95% to 99.5% by mass.

[0079] The components contained in the lubricating oil composition of the present invention will be described in detail below.

[0080] [Base Oil (A)]

[0081] The lubricating oil composition of the present invention contains a base oil (A).

[0082] The base oil (A) meets the following requirement (α).

[0083] <Requirement (α)>

[0084] Gas chromatograms determined by a gas chromatograph distillation apparatus according to ASTM D 7500 show peaks in the range of carbon atoms greater than 11 and less than 23.

[0085] The base oil (A) that meets the above requirement (α) contains a polar substance that significantly reduces rust prevention. In the gas chromatogram, the peak indicating the presence of this polar substance is a peak in the range of carbon atoms exceeding 11 and less than 23 (hereinafter also referred to as "peak 1") (see reference). Figure 1 Base oil (A)).

[0086] It should be noted that if the base oil that meets the above requirement (α) is treated with clay, the first peak disappears. Therefore, the substances belonging to the first peak are polar substances with more than 11 but less than 23 carbon atoms that can be removed by clay treatment.

[0087] It should be noted that, more specifically, the number of carbon atoms in this polar substance can be narrowed down to the range shown below (α1) to (α3). Therefore, the range of carbon atoms present in the first peak can also be narrowed down to the range shown below (α1) to (α3).

[0088] (α1) 12 or more but less than 22 carbon atoms

[0089] (α2) 13 or more but less than 21 carbon atoms

[0090] (α3) The number of carbon atoms is 14 or more and less than 20.

[0091] It should be noted that the above gas chromatograms can be determined using the apparatus and conditions described in the examples described later.

[0092] <Base oil (A) content>

[0093] In one embodiment of the lubricating oil composition of the present invention, the content of base oil (A), based on the total amount of the lubricating oil composition, is preferably 90.0% by mass or more, more preferably 95.0% by mass or more, and even more preferably 97.0% by mass or more. Furthermore, it is preferably 99.5% by mass or less, more preferably 99.2% by mass or less, and even more preferably 99.0% by mass or less.

[0094] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, it is preferably 90.0% to 99.5% by mass, more preferably 95.0% to 99.2% by mass or less, and even more preferably 97.0% to 99.0% by mass.

[0095] (Types of base oil (A))

[0096] As a base oil (A), base oils that meet the above requirements (α) can be used without particular restrictions.

[0097] Examples of base oils (A) that satisfy the above requirement (α) include: atmospheric residue oil obtained by atmospheric distillation of crude oils such as alkane-based crude oil, intermediate crude oil, and cycloalkane-based crude oil; distillate oil obtained by vacuum distillation of the atmospheric residue oil; and hydrocarbon base oils such as mineral oils or waxes (bulk wax, GTL wax, etc.) and isoalkane polymers obtained by treating the distillate oil with one or more of the following refining processes: solvent deasphalting, solvent extraction, hydrogenation refining, solvent dewaxing, catalytic dewaxing, isomerization dewaxing, and vacuum distillation.

[0098] Here, when the base oil (A) is selected from one or more base oils selected from alkane-based mineral oils and hydrocarbon-based oils, as specified in the above requirement (α), when the gas chromatogram is determined using a gas chromatographic distillation apparatus according to ASTM D 7500, a peak (hereinafter also referred to as the "second peak") is also detected in the range of 23 to 50 carbon atoms (refer to...). Figure 1 The second peak is attributed to one or more base oils (the main components of the base oil) selected from alkane mineral oils and hydrocarbon oils.

[0099] Thus, when a second peak is present in the gas chromatogram, the intensity ratio of the aforementioned first peak to the aforementioned second peak in the gas chromatogram [(first peak intensity) / (second peak intensity)] is not particularly limited. From the viewpoint of achieving the effects of the present invention through the rust inhibitor (B) and the aforementioned requirement (β), it is preferably 0.50 or less, more preferably 0.40 or less, and even more preferably 0.35 or less. Furthermore, this intensity ratio can be 0.10 or more, 0.20 or more, or 0.25 or more.

[0100] It should be noted that the number of carbon atoms in the second peak can be more precisely narrowed down to the range shown below as (β1) to (β3).

[0101] (β1) 25 or more but less than 50 carbon atoms

[0102] (β2) 30 or more but less than 45 carbon atoms

[0103] (β3) The number of carbon atoms is 35 or more and 45 or less.

[0104] (Flash point of base oil (A))

[0105] In one aspect of the present invention, from the viewpoint of safety and operability during storage and transportation, the base oil (A) is preferably a high flash point. Specifically, the flash point of the base oil (A) is preferably 250°C or higher. It should be noted that the upper limit of the flash point of the base oil (A) is not particularly limited, and is generally below 400°C.

[0106] In this specification, the flash point of base oil (A) refers to the value determined by the Cleveland open cup method in accordance with JIS K2265-4:2007 (Determination of flash point - Part 4: Cleveland open cup method).

[0107] (Density of base oil (A) at 15°C)

[0108] In one embodiment of the present invention, the density of the base oil (A) at 15°C is preferably 0.9000 g / cm³. 3 The following, or more preferably, is 0.8500 g / cm³ 3 The following, and more preferably, is 0.8300 g / cm³. 3 Below. Furthermore, 0.8000 g / cm³ is preferred. 3 above.

[0109] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, a value of 0.8000 g / cm³ is preferred. 3 ~0.9000g / cm 3 More preferably 0.8000 g / cm³ 3 ~0.8500g / cm 3 A further preferred value is 0.8000 g / cm³. 3 ~0.8300g / cm 3 .

[0110] (Kinetic viscosity and viscosity index of base oil (A) at 100°C)

[0111] In one embodiment of the present invention, the kinematic viscosity of the base oil (A) at 100°C (hereinafter also referred to as "kinematic viscosity at 100°C") is preferably 3.00 mm. 2 / s or higher, more preferably 5.00mm 2 / s or higher, more preferably 7.50mm 2 / s or more. Furthermore, 15.0 mm is preferred. 2 / s or less, more preferably 10.0mm 2 / s or less, more preferably 9.00mm 2 / s or less.

[0112] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, 3.00 mm is preferred. 2 / s~15.0mm 2 / s, more preferably 5.00mm 2 / s~10.0mm 2 / s, further preferably 7.50mm 2 / s~9.00mm 2 / s.

[0113] Furthermore, in one embodiment of the present invention, the viscosity index of the base oil (A) is preferably 100 or higher, more preferably 110 or higher, and even more preferably 120 or higher. It is typically 150 or lower.

[0114] In this specification, the kinematic viscosity and viscosity index of base oil (A) at 100°C are values ​​determined and calculated in accordance with JIS K 2283:2000.

[0115] (Preferred method for base oil (A))

[0116] In one aspect of the present invention, from the viewpoint of excellent viscosity characteristics and ease of preparing high flash point lubricating oil compositions, the base oil (A) preferably satisfies the following requirement (γ) in addition to the above-mentioned requirement (α).

[0117] <The following requirements (γ)>

[0118] • Flash point obtained by the Cleveland open cup method: above 250℃

[0119] Density at 15℃: 0.8300 g / cm³ 3 the following

[0120] Viscosity index: 100 or higher

[0121] Kinematic viscosity at 100℃: 7.50 mm 2 / s or higher and 9.00mm 2 / s or less.

[0122] [Rust Inhibitor (B)]

[0123] The lubricating oil composition of the present invention contains a rust inhibitor (B).

[0124] In the lubricating oil composition of the present invention, the rust inhibitor (B) is selected from one or more of the following: a first rust inhibitor (B1), a second rust inhibitor (B2), a third rust inhibitor (B3), and a fourth rust inhibitor (B4).

[0125] • First rust inhibitor (B1): A combination of succinate (B1-1) and dehydrated sorbitan fatty acid ester (B1-2)

[0126] • Second rust inhibitor (B2): Carboxylic acid amide (B2-1)

[0127] • Third rust inhibitor (B3): Neutral alkyl phosphate ester (B3-1)

[0128] • Fourth rust inhibitor (B4): A combination of fatty acids with more than 12 carbon atoms (B4-1) and primary amines (B4-2).

[0129] In one embodiment of the lubricating oil composition of the present invention, the rust inhibitor (B) is preferably selected from one of the first rust inhibitor (B1), the second rust inhibitor (B2), the third rust inhibitor (B3), and the fourth rust inhibitor (B4).

[0130] Furthermore, in one embodiment of the present invention, from the viewpoint of producing a lubricating oil composition with excellent demulsibility, the rust inhibitor (B) is preferably a first rust inhibitor (B1) or a second rust inhibitor (B2).

[0131] Furthermore, in the lubricating oil composition of the present invention, the contents of the first rust inhibitor (B1), the second rust inhibitor (B2), the third rust inhibitor (B3), and the fourth rust inhibitor (B4), based on the total amount of the lubricating oil composition, satisfy the following requirement (β).

[0132] <Requirement (β)>

[0133] • The aforementioned first rust inhibitor (B1): exceeding 0.02% by mass and less than 0.16% by mass

[0134] • The aforementioned second rust inhibitor (B2): more than 0.05% by mass and less than 0.5% by mass

[0135] • The aforementioned third rust inhibitor (B3): 0.005% by mass or more but less than 0.05% by mass

[0136] • The aforementioned fourth rust inhibitor (B4): more than 0.05% by mass and less than 0.20% by mass.

[0137] The following description, in conjunction with the explanation of requirement (β), details the first rust inhibitor (B1), the second rust inhibitor (B2), the third rust inhibitor (B3), and the fourth rust inhibitor (B4).

[0138] <First Rust Inhibitor (B1)>

[0139] The first rust inhibitor (B1) is a combination of succinate (B1-1) and dehydrated sorbitol fatty acid ester (B1-2).

[0140] (Succinate (B1-1))

[0141] The first rust inhibitor (B1) contains succinate (B1-1).

[0142] Even when used alone, succinate (B1-1) cannot provide sufficient rust protection for base oil (A) that meets the above requirement (α). However, when used in combination with dehydrated sorbitol fatty acid ester (B1-2), it provides excellent rust protection relative to base oil (A) that meets the above requirement (α).

[0143] There are no particular limitations on the succinate (B1-1) as long as it can achieve the effects of the present invention. It can be used alone or in combination of two or more.

[0144] In one embodiment of the present invention, from the viewpoint of more easily achieving the effects of the present invention and from the viewpoint of storage stability, the succinate (B1*1) is preferably an ester of alkenyl succinic acid and a polyol (alkenyl succinic acid polyol ester). Furthermore, the ester is preferably a half-ester.

[0145] The alkenyl succinic acid constituting the alkenyl succinic acid polyol ester is preferably an alkenyl succinic acid having 8 to 28 carbon atoms, more preferably 10 to 24 carbon atoms, and even more preferably 12 to 20 carbon atoms.

[0146] As the polyol constituting the alkenyl succinic acid polyol ester, diols or polyols having about 3 to 20 hydroxyl groups are preferred.

[0147] Examples of diols include ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, undecanediol, and dodecanediol. It should be noted that the aliphatic hydrocarbon groups constituting the diol can be straight-chain or branched.

[0148] Examples of polyols having 3 to 20 hydroxyl groups include: trimethylolethane, trimethylolpropane, trimethylolbutane, trimethylolpentane, trimethylolhexane, trimethylolheptane, di(trimethylolpropane), tri(trimethylolpropane), pentaerythritol, dipentaerythritol, tripentaerythritol, glycerol, polyglycerol (2 to 20 polymers of glycerol), 1,3,5-pentanetriol, sorbitol, dehydrated sorbitol, sorbitol glycerol condensate, calendula alcohol, arabinitol, xylitol, mannitol, etc.; sugars such as xylose, arabinose, ribose, rhamnose, glucose, fructose, galactose, mannose, sorbitol, cellobiose, maltose, isomaltose, trehalose, sucrose, raffinose, gentiotriose, mesotriose, etc.; as well as their partial etherifications and methyl glucosides (glycosides).

[0149] (Sorbitol fatty acid ester (B1-2))

[0150] The first rust inhibitor (B1) contains sorbitol fatty acid ester (B1-2).

[0151] Even when used alone, sorbitol fatty acid esters (B1-2) do not provide sufficient rust protection for base oils (A) that meet the aforementioned requirement (α). However, when used in combination with succinate esters (B1-1), they exhibit excellent rust protection relative to base oils (A) that meet the aforementioned requirement (α).

[0152] There are no particular limitations on the sorbitol fatty acid esters (B1-2) as long as they can achieve the effects of the present invention. One type can be used alone, or two or more types can be used in combination.

[0153] In one aspect of the present invention, from the viewpoint of more easily achieving the effects of the present invention, the sorbitol fatty acid ester (B1-2) is preferably an ester compound of sorbitol and a fatty acid having 12 or more and 30 or fewer carbon atoms.

[0154] Specifically, preferred compounds exemplified as sorbitol fatty acid esters (B1-2) include sorbitol laurate, sorbitol tridecanoate, sorbitol myristate, sorbitol pentadecanoate, sorbitol palmitate, sorbitol heptadecanate, sorbitol stearate, sorbitol oleate, sorbitol nonadecanate, sorbitol arachidate, sorbitol icosanoate, sorbitol icosanoate, sorbitol icosanoate, sorbitol erucate, sorbitol erucate, sorbitol erucate, sorbitol erucate, sorbitol erucate, sorbitol erucate, and sorbitol erucate. The aliphatic hydrocarbon groups of the fatty acids constituting sorbitol fatty acid esters (B1-2) can be linear or branched.

[0155] Here, from the viewpoint of more easily exerting the effects of the present invention, the sorbitol fatty acid ester (B1-2) is preferably an ester compound with fatty acids having 12 or more and 20 or fewer carbon atoms, more preferably an ester compound with fatty acids having 16 or more and 20 or fewer carbon atoms, and even more preferably sorbitol oleate.

[0156] It should be noted that there is no particular limitation on the ester value of the dehydrated sorbitol fatty acid ester, but it is preferred to be 1, 2 or 3.

[0157] (Content of the first rust inhibitor (B1))

[0158] When the lubricating oil composition of the present invention contains a first rust inhibitor (B1), as specified in the above requirement (β), the content of the first rust inhibitor (B1) is more than 0.02% by mass and less than 0.16% by mass based on the total amount of the lubricating oil composition.

[0159] When the content of the first rust inhibitor (B1) is less than 0.02% by mass or more than 0.16% by mass based on the total amount of the lubricating oil composition, it cannot provide sufficient rust prevention for the base oil (A) that meets the above requirement (α).

[0160] In one aspect of the present invention, from the viewpoint of more easily improving rust prevention and producing a lubricating oil composition with superior demulsibility, the content of the first rust inhibitor (B1) specified in the above-mentioned element (β), based on the total amount of the lubricating oil composition, is preferably 0.03% by mass or more, more preferably 0.05% by mass or more, further preferably 0.07% by mass or more, and even more preferably 0.08% by mass or more. Furthermore, it is preferably 0.15% by mass or less, more preferably 0.14% by mass or less, further preferably 0.13% by mass or less, and even more preferably 0.12% by mass or less.

[0161] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, it is preferably 0.03% to 0.15% by mass, more preferably 0.05% to 0.14% by mass or less, further preferably 0.07% to 0.13% by mass, and even more preferably 0.08% to 0.12% by mass.

[0162] (Ratio of succinate (B1-1) to sorbitol fatty acid ester (B1-2))

[0163] In one embodiment of the present invention, from the viewpoint of more easily exerting the effects of the present invention, the content ratio of succinate (B1-1) to dehydrated sorbitol fatty acid ester (B1-2) [(B1-1) / (B1-2)] is preferably 0.1 or more and 5.0 or less by mass.

[0164] Furthermore, from the viewpoint that it is easier to achieve the effects of the present invention, [(B1-1) / (B1-2)] is preferably 0.2 or more, more preferably 0.5 or more, and even more preferably 0.8 or more. In addition, it is preferably 4.0 or less, more preferably 2.0 or less, and even more preferably 1.2 or less.

[0165] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, the range is preferably 0.2 to 4.0, more preferably 0.5 to 2.0, and even more preferably 0.8 to 1.2.

[0166] (Content of succinate (B1-1))

[0167] In one embodiment of the lubricating oil composition of the present invention, from the viewpoint of more easily achieving the effects of the present invention, the content of succinate (B1-1), based on the total amount of the lubricating oil composition, is preferably more than 0.01% by mass, more preferably more than 0.02% by mass, further preferably more than 0.03% by mass, and even more preferably more than 0.04% by mass. Furthermore, it is preferably less than 0.08% by mass, more preferably less than 0.07% by mass, and even more preferably less than 0.06% by mass.

[0168] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, it is preferred to be more than 0.01% by mass to less than 0.08% by mass, more preferably 0.02% by mass to 0.07% by mass, further preferably 0.03% by mass to 0.07% by mass, and even more preferably 0.04% by mass to 0.06% by mass.

[0169] (Content of dehydrated sorbitol fatty acid esters (B1-2))

[0170] In one embodiment of the lubricating oil composition of the present invention, from the viewpoint of more easily achieving the effects of the present invention, the content of dehydrated sorbitol fatty acid ester (B1*2), based on the total amount of the lubricating oil composition, is preferably more than 0.01% by mass, more preferably more than 0.02% by mass, further preferably more than 0.03% by mass, and even more preferably more than 0.04% by mass. Furthermore, it is preferably less than 0.08% by mass, more preferably less than 0.07% by mass, and even more preferably less than 0.06% by mass.

[0171] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, it is preferred to be more than 0.01% by mass to less than 0.08% by mass, more preferably 0.02% by mass to 0.07% by mass, further preferably 0.03% by mass to 0.07% by mass, and even more preferably 0.04% by mass to 0.06% by mass.

[0172] <Second Rust Inhibitor (B2)>

[0173] The second rust inhibitor (B2) is carboxylic acid amide (B2-1).

[0174] (Carboxylic acid amide (B2-1))

[0175] There are no particular limitations on the carboxylic amide (B2-1) as long as it can achieve the effects of the present invention. It can be used alone or in combination of two or more.

[0176] In one embodiment of the present invention, from the viewpoint of more easily achieving the effects of the invention, the carboxylic amide (B2*1) is preferably a carboxylic amide with an acid value of 80 mg KOH / g or less. More preferably, this acid value is 70 mg KOH / g or less, and even more preferably 65 mg KOH / g or less. It should be noted that the lower limit of this acid value is not particularly limited, and is generally 10 mg KOH / g or more.

[0177] It should be noted that the acid value of the carboxylic amide is determined according to JIS K2501:2003, section 5 (indicator titration).

[0178] When specifically exemplifying preferred compounds as carboxylic acid amides (B2-1), examples include carboxylic acid amides obtained by reacting carboxylic acids such as lanolinic acid, caprylic acid, caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, benzolic acid, teicosuccinic acid, palmitoleic acid, oleic acid, linoleic acid, linolenic acid, cod oleic acid, erucic acid, squalene, ricinoleic acid, hydroxystearic acid, alkenyl succinic anhydride, and alkyl succinic anhydride with amines (ammonia).

[0179] As a carboxylic acid, alkenyl succinic anhydride or alkyl succinic anhydride is preferred, and alkenyl succinic anhydride is more preferred. Considering solubility and rust-preventive properties in base oils, the number of carbon atoms in the alkenyl group of the alkenyl succinic anhydride and the number of carbon atoms in the alkyl group of the alkyl succinic anhydride are preferably 11 to 13.

[0180] As the amine, polyalkylene polyamines are preferred. Examples of polyalkylene polyamines include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexadecimaline heptamine, and hexadecimaline octamine. Among these, triethylenetetramine is preferred.

[0181] In addition, carboxylic acid alkanolamides are also suitable as carboxylic acid amides (B2-1). Specific examples of carboxylic acid alkanolamides include lauric acid diethanolamide, oleic acid diethanolamide, stearic acid diethanolamide, oleic acid monoethanolamide, oleic acid monopropanolamide, and oleic acid dipropanolamide.

[0182] (Content of the second rust inhibitor (B2))

[0183] When the lubricating oil composition of the present invention contains a second rust inhibitor (B2), as specified in the above requirement (β), the content of the second rust inhibitor (B2) is more than 0.05% by mass and less than 0.5% by mass based on the total amount of the lubricating oil composition.

[0184] When the content of the second rust inhibitor (B2) is less than 0.05% by mass or more than 0.5% by mass based on the total amount of the lubricating oil composition, it cannot provide sufficient rust prevention for the base oil (A) that meets the above requirement (α).

[0185] In one aspect of the present invention, from the viewpoint of more easily improving rust prevention and producing a lubricating oil composition with superior demulsibility, the content of the second rust inhibitor (B2) specified in the above-mentioned element (β), based on the total amount of the lubricating oil composition, is preferably 0.06% by mass or more, more preferably 0.08% by mass or more, and even more preferably 0.10% by mass or more. Furthermore, it is preferably 0.40% by mass or less, more preferably 0.30% by mass or less, even more preferably 0.25% by mass or less, and even more preferably 0.20% by mass or less.

[0186] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, it is preferably 0.06% to 0.40% by mass, more preferably 0.08% to 0.30% by mass or less, even more preferably 0.08% to 0.25% by mass, and even more preferably 0.10% to 0.20% by mass.

[0187] <Third Rust Inhibitor (B3)>

[0188] The third rust inhibitor (B3) is a neutral alkyl phosphate ester (B3-1).

[0189] (Neutral Alkyl Phosphate (B3-1))

[0190] There are no particular limitations on the neutral alkyl phosphate (B3-1) as long as it can achieve the effect of the present invention. It can be used alone or in combination of two or more.

[0191] As a neutral alkyl phosphate (B3-1), it is preferable to use a compound represented by, for example, the general formula (b3-1) below.

[0192] [Chemistry 1]

[0193]

[0194] In the aforementioned general formula (b3-1), R 1 ~R 3 Each is an alkyl group having 3 to 14 carbon atoms.

[0195] As can be selected as R1 ~R 3 Alkyl groups having 3 to 14 carbon atoms include, for example: propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, etc.

[0196] These alkyl groups can be straight-chain or branched.

[0197] (Content of the third rust inhibitor (B3))

[0198] When the lubricating oil composition of the present invention contains a third rust inhibitor (B3), as specified in the above requirement (β), the content of the third rust inhibitor (B3) is 0.005% by mass or more and less than 0.05% by mass based on the total amount of the lubricating oil composition.

[0199] When the content of the third rust inhibitor (B3) is less than 0.005% by mass or more than 0.05% by mass based on the total amount of the lubricating oil composition, it cannot provide sufficient rust prevention for the base oil (A) that meets the above requirement (α).

[0200] In one aspect of the present invention, from the viewpoint of more easily improving rust prevention and producing a lubricating oil composition with better demulsibility, the content of the third rust inhibitor (B3) specified in the above-mentioned element (β) is preferably 0.006% to 0.04% by mass, more preferably 0.01% to 0.03% by mass or less, and even more preferably 0.01% to 0.02% by mass, based on the total amount of the lubricating oil composition.

[0201] <Fourth Rust Inhibitor (B4)>

[0202] The fourth rust inhibitor (B4) is a combination of fatty acids with more than 12 carbon atoms (B4-1) and primary amines (B4-2).

[0203] (Fatty acids with 12 or more carbon atoms (B4-1))

[0204] The fourth rust inhibitor (B4) contains fatty acids with more than 12 carbon atoms (B4-1).

[0205] Fatty acids with 12 or more carbon atoms (B4-1), even when used alone, cannot provide sufficient rust protection for base oils (A) that meet the above requirement (α). However, when used in combination with primary amines (B4-2), they provide excellent rust protection for base oils (A) that meet the above requirement (α).

[0206] There are no particular limitations on the fatty acids (B4-1) with 12 or more carbon atoms, as long as they can exert the effects of the present invention. One type can be used alone, or two or more types can be used in combination.

[0207] In one aspect of the present invention, from the viewpoint of more easily achieving the effects of the present invention and suppressing the generation of sludge, the fatty acid (B4-1) with 12 or more carbon atoms is preferably a fatty acid with 12 to 20 carbon atoms.

[0208] Examples of such fatty acids include lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, heptadecanoic acid, stearic acid, oleic acid, nonadecanoic acid, arachidic acid, eicosanoic acid, icosanoic acid, behenic acid, erucic acid, tridecanoic acid, and tetradecanoic acid. The aliphatic hydrocarbon groups constituting fatty acids with 12 or more carbon atoms (B4-1) can be either straight-chain or branched.

[0209] (Primary amine (B4-2))

[0210] The fourth rust inhibitor (B4) contains a primary amine (B4-2).

[0211] Even when used alone, primary amines (B4-2) cannot provide sufficient rust protection for base oils (A) that meet the above requirement (α). However, when used in combination with fatty acids (B4-1) that have 12 or more carbon atoms, they provide excellent rust protection for base oils (A) that meet the above requirement (α).

[0212] The primary amine (B4-2) is not particularly limited as long as it can achieve the effects of the present invention. It can be used alone or in combination with two or more.

[0213] In one aspect of the present invention, from the viewpoint of more easily achieving the effects of the present invention and suppressing the generation of sludge, the primary amine (B4-2) is preferably a primary amine having a hydrocarbon group having 3 to 20 carbon atoms, and more preferably a primary amine having a hydrocarbon group having 6 to 12 carbon atoms.

[0214] Examples of preferred hydrocarbon groups include alkyl groups and alkenyl groups.

[0215] Examples of such alkyl groups include hexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl.

[0216] These alkyl groups can be straight-chain or branched.

[0217] In addition, examples of alkenyl groups include hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, and dodecenyl.

[0218] These alkenyl groups can be either straight-chain or branched.

[0219] As primary amines (B4-2), more specific examples include hexylamine, heptenylamine, octylamine, nonylamine, decylamine, undecylamine, dodecylamine, hexenylamine, heptenylamine, octenylamine, nonenylamine, decenylamine, undecenylamine, and dodecenylamine.

[0220] (Content of the fourth rust inhibitor (B4))

[0221] When the lubricating oil composition of the present invention contains a fourth rust inhibitor (B4), as specified in the above requirement (β), the content of the fourth rust inhibitor (B4) is more than 0.05% by mass and less than 0.20% by mass based on the total amount of the lubricating oil composition.

[0222] When the content of the fourth rust inhibitor (B4) is less than 0.05% by mass or more than 0.20% by mass based on the total amount of the lubricating oil composition, it cannot provide sufficient rust prevention for the base oil (A) that meets the above requirement (α).

[0223] In one aspect of the present invention, from the viewpoint of more easily improving rust prevention and producing a lubricating oil composition with superior demulsibility, the content of the fourth rust inhibitor (B4) specified in the above-mentioned element (β), based on the total amount of the lubricating oil composition, is preferably 0.06% by mass or more, more preferably 0.08% by mass or more, and even more preferably 0.10% by mass or more. Furthermore, it is preferably 0.19% by mass or less, more preferably 0.17% by mass or less, and even more preferably 0.15% by mass or less.

[0224] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, it is preferably 0.06% to 0.19% by mass, more preferably 0.08% to 0.17% by mass or less, and even more preferably 0.10% to 0.15% by mass.

[0225] (The ratio of fatty acids with 12 or more carbon atoms (B4-1) to primary amines (B4-2))

[0226] In one embodiment of the lubricating oil composition of the present invention, from the viewpoint of more easily exerting the effects of the present invention, the content ratio of fatty acids (B4-1) with 12 or more carbon atoms to primary amines (B4-2) [(B4-1) / (B4-2)] is preferably 0.03 or more and 3.0 or less by mass.

[0227] Furthermore, from the viewpoint that it is easier to achieve the effects of the present invention, [(B4-1) / (B4-2)] is preferably 0.10 or more, more preferably 0.15 or more, and even more preferably 0.20 or more. In addition, it is preferably 2.0 or less, more preferably 1.0 or less, and even more preferably 0.40 or less.

[0228] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, it is preferably 0.10 to 2.0, more preferably 0.20 to 1.0, and even more preferably 0.20 to 0.40.

[0229] (Content of fatty acids with 12 or more carbon atoms (B4-1))

[0230] In one embodiment of the lubricating oil composition of the present invention, from the viewpoint of more easily exerting the effects of the present invention, the content of fatty acids (B4-1) with 12 or more carbon atoms, based on the total amount of the lubricating oil composition, is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, and even more preferably 0.025% by mass or more. Furthermore, it is preferably 0.05% by mass or less, more preferably 0.04% by mass or less, and even more preferably 0.035% by mass or less.

[0231] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, it is preferably 0.01% to 0.05% by mass, more preferably 0.02% to 0.04% by mass, and even more preferably 0.025% to 0.035% by mass.

[0232] (Primary amine (B4-2) content)

[0233] In one embodiment of the lubricating oil composition of the present invention, from the viewpoint of more easily achieving the effects of the present invention, the content of primary amine (B4-2), based on the total amount of the lubricating oil composition, is preferably 0.05% by mass or more, more preferably 0.07% by mass or more, and even more preferably 0.09% by mass or more. Furthermore, it is preferably 0.19% by mass or less, more preferably 0.15% by mass or less, and even more preferably 0.11% by mass or less.

[0234] The upper and lower limits of these numerical ranges can be combined arbitrarily. Specifically, it is preferably 0.05% to 0.19% by mass, more preferably 0.07% to 0.15% by mass, and even more preferably 0.09% to 0.11% by mass.

[0235] [Rust inhibitor (B') other than rust inhibitor (B)]

[0236] One embodiment of the lubricating oil composition of the present invention may contain a rust inhibitor (B') other than a rust inhibitor (B), but the rust inhibitor (B') cannot provide sufficient rust prevention for the base oil (A) that satisfies the above-mentioned requirement (α). Therefore, the content of the rust inhibitor (B') is preferably low.

[0237] Specifically, based on the total amount of the lubricating oil composition, the content of rust inhibitor (B') is preferably less than 0.01% by mass, more preferably less than 0.008% by mass, even more preferably less than 0.001% by mass, and most preferably free of rust inhibitor (B').

[0238] Examples of rust inhibitors (B') include benzotriazole compounds, acidic phosphates, amine salts of acidic phosphates, phosphites, amine salts of phosphites, hydrogen phosphites, amine salts of hydrogen phosphites, fatty acids with fewer than 12 carbon atoms, and sarcosine derivatives.

[0239] [Antioxidant (C), Wear-resistant agent (D), Defoamer (E)]

[0240] From the viewpoint of improving oxidative stability, the lubricating oil composition of one aspect of the present invention preferably contains an antioxidant (C).

[0241] Furthermore, from the viewpoint of improving wear resistance, the lubricating oil composition of one aspect of the present invention preferably contains a wear-resistant agent (D).

[0242] Furthermore, from the viewpoint of preventing foaming of the lubricating oil composition, one aspect of the present invention preferably contains an antifoaming agent (E).

[0243] That is, the lubricating oil composition of one aspect of the present invention preferably contains one or more additives selected from antioxidants (C), wear-resistant agents (D) and defoamers (E), more preferably contains two or more additives, and even more preferably contains all three additives.

[0244] In one embodiment of the present invention, the total content of components (A) and (B), and one or more additives selected from components (C), (D) and (E), based on the total amount of the lubricating oil composition, is preferably 90% to 100% by mass, more preferably 95% to 100% by mass, and even more preferably 99% to 100% by mass.

[0245] <Antioxidant (C)>

[0246] As an antioxidant (C), any antioxidant that has the effect of inhibiting the oxidation of the lubricating oil composition can be used without particular restrictions.

[0247] In one aspect of the present invention, one or more antioxidants selected from phenolic antioxidants and amine antioxidants may be used. Phenolic antioxidants are preferred.

[0248] (Phenolic antioxidants)

[0249] As a phenolic antioxidant, any compound that does not contain amino groups, has a phenolic structure, and has the effect of inhibiting the oxidation of lubricating oil compositions can be used without particular restrictions.

[0250] Examples of phenolic antioxidants include monocyclic phenolic antioxidants and polycyclic phenolic antioxidants.

[0251] Examples of monocyclic phenolic antioxidants include: 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,4,6-tri-tert-butylphenol, 2,6-di-tert-butyl-4-hydroxymethylphenol, 2,6-di-tert-butylphenol, 2,4-dimethyl-6-tert-butylphenol, 2,6-di-tert-butyl-4-(N,N-dimethylaminomethyl)phenol, 2,6-di-tert-pentyl-4-methylphenol, and n-octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

[0252] Examples of polycyclic phenolic antioxidants include: 4,4'-methylenebis(2,6-di-tert-butylphenol), 4,4'-isopropylidenebis(2,6-di-tert-butylphenol), 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 4,4'-bis(2,6-di-tert-butylphenol), 4,4'-bis(2-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), and 4,4'-butylidenebis(3-methyl-6-tert-butylphenol).

[0253] (Amine-based antioxidants)

[0254] As an amine antioxidant (B), any compound that has at least one hydrogen atom of ammonia (NH3) replaced by a hydrocarbon group and has the effect of inhibiting the oxidation of the lubricating oil composition can be used without particular restrictions.

[0255] Examples of amine-based antioxidants include diphenylamine compounds and naphthylamine compounds.

[0256] Examples of diphenylamine compounds include, for instance, monoalkyl diphenylamine compounds such as monooctyl diphenylamine and monononyl diphenylamine; dialkyl diphenylamine compounds such as 4,4'-dibutyldiphenylamine, 4,4'-dipentyl diphenylamine, 4,4'-dihexyl diphenylamine, 4,4'-diheptyl diphenylamine, 4,4'-dioctyl diphenylamine, and 4,4'-dinonyl diphenylamine; polyalkyl diphenylamine compounds such as tetrabutyl diphenylamine, tetrahexyl diphenylamine, tetraoctyl diphenylamine, and tetranonyl diphenylamine; and 4,4'-bis(α,α-dimethylbenzyl)diphenylamine.

[0257] Examples of naphthylamine compounds include, for example, 1-naphthylamine, phenyl-1-naphthylamine, butylphenyl-1-naphthylamine, pentylphenyl-1-naphthylamine, hexylphenyl-1-naphthylamine, heptylphenyl-1-naphthylamine, octylphenyl-1-naphthylamine, nonylphenyl-1-naphthylamine, decylphenyl-1-naphthylamine, and dodecylphenyl-1-naphthylamine.

[0258] (Content of antioxidant (C))

[0259] In one aspect of the present invention, the content of antioxidant (C) can be appropriately adjusted within a range that enables it to inhibit the oxidation of the lubricating oil composition.

[0260] Specifically, based on the total amount of the lubricating oil composition, the content of antioxidant (C) is preferably 0.3% to 1.0% by mass, more preferably 0.4% to 0.8% by mass, and even more preferably 0.5% to 0.7% by mass.

[0261] <Abrasion-resistant agent (D)>

[0262] As a wear-resistant agent (D), any compound that can improve wear resistance can be used without particular restrictions.

[0263] In one aspect of the invention, the wear-resistant agent (D) can be a neutral aromatic phosphate ester represented by the following general formula (d-1).

[0264] [Chemistry 2]

[0265]

[0266] In the aforementioned general formula (d-1), R 11 ~R 13 Each is independently an alkyl group having 1 to 12 carbon atoms. Examples of such alkyl groups include those listed in the above general formula (b3-1) of neutral alkyl phosphate (B3-1), which can be selected as R. 1 ~R 3 Those alkyl groups that are the same as those can be further exemplified by methyl and ethyl.

[0267] Can be selected as R 11 ~R 13 The alkyl group has 1 to 12 carbon atoms, preferably 1 to 10, more preferably 1 to 8, even more preferably 1 to 6, even more preferably 1 to 3, and even more preferably 1.

[0268] Furthermore, p1 to p3 are each independently an integer from 1 to 5, preferably an integer from 1 to 2, and more preferably 1.

[0269] It should be noted that although the neutral aromatic phosphate esters shown in the above general formula (d-1) have a similar molecular skeleton to the neutral alkyl phosphate esters used as rust inhibitors (B3), they cannot fully exert their rust-preventive properties on the base oil (A) that meets the above requirement (α). That is, both neutral alkyl phosphate esters and neutral aromatic phosphate esters are compounds contained in orthophosphate esters, but in order to fully exert their rust-preventive properties on the base oil that meets the above requirement (α), it is important to use orthophosphate esters with alkyl substituents rather than aromatic groups.

[0270] (Content of wear-resistant agent (D))

[0271] In one aspect of the present invention, the content of the wear-resistant agent (D) can be appropriately adjusted within a range that can improve wear resistance.

[0272] Specifically, based on the total amount of the lubricating oil composition, the content of the wear-resistant agent (D) is preferably 0.1% to 0.7% by mass, more preferably 0.2% to 0.6% by mass, and even more preferably 0.3% to 0.5% by mass.

[0273] <Defoamer (E)>

[0274] As an antifoaming agent (E), compounds that have the effect of inhibiting foaming of the lubricating oil composition can be used without particular restrictions.

[0275] In one aspect of the present invention, examples of defoamers (E) include, for example, silicone-based defoamers, fluorinated defoamers such as fluorosilicone oils and fluoroalkyl ethers, and polyacrylate-based defoamers.

[0276] In one aspect of the present invention, the content of the defoamer (E) as a resin component, based on the total amount of the lubricating oil composition, is preferably 0.0001% to 0.20% by mass, more preferably 0.0005% to 0.10% by mass.

[0277] <Other Lubricating Oil Additives>

[0278] The lubricating oil composition of one aspect of the present invention may contain other lubricating oil additives other than rust inhibitors (B), antioxidants (C), wear-resistant agents (D), and defoamers (E) without impairing the effects of the present invention.

[0279] Other examples of additives for lubricating oils include extreme pressure agents, friction modifiers, and metal passivators.

[0280] These lubricant additives can be used alone or in combination of two or more.

[0281] [Various physical properties of lubricating oil compositions]

[0282] <Kinematic viscosity and viscosity index of lubricating oil composition at 100°C>

[0283] The kinematic viscosity of the lubricating oil composition of one embodiment of the present invention at 100°C is preferably 5.0 mm. 2 / s~10.0mm 2 / s, more preferably 6.0mm 2 / s~9.0mm 2 / s, further preferably 6.4mm 2 / s~8.6mm 2 / s.

[0284] Furthermore, the viscosity index of the lubricating oil composition of one aspect of the present invention is preferably 100 or more, more preferably 110 or more, and even more preferably 120 or more.

[0285] In this specification, the kinematic viscosity and viscosity index of the lubricating oil composition at 100°C are values ​​determined or calculated in accordance with JIS K 2283:2000.

[0286] Flash point of lubricating oil composition

[0287] From the viewpoint of safety and operability during storage and transportation, the lubricating oil composition of one embodiment of the present invention preferably has a flash point of 250°C or higher.

[0288] In this specification, the flash point of the lubricating oil composition refers to the value determined by the Cleveland open cup method in accordance with JIS K2265-4:2007 (Determination of flash point - Part 4: Cleveland open cup method).

[0289] Rust prevention

[0290] The lubricating oil composition of one aspect of the present invention preferably showed no rust formation in the test according to JIS K2510:1998 (B method, artificial seawater method) described in the examples described below.

[0291] <Demulsifying properties>

[0292] In a water separation test according to JIS K2520:2000, as described in the examples below, the time required for separation of the lubricating oil composition of one aspect of the present invention is preferably 20 minutes or less, more preferably 15 minutes or less, and even more preferably 10 minutes or less.

[0293] [Method for manufacturing lubricating oil composition]

[0294] The method for manufacturing the lubricating oil composition of the present invention is not particularly limited.

[0295] For example, one method for manufacturing a lubricating oil composition according to the present invention includes a step of mixing a base oil (A) and a rust inhibitor (B), wherein...

[0296] The aforementioned base oil (A) meets the following requirement (α),

[0297] <Requirement (α)>

[0298] Gas chromatograms determined by a gas chromatograph distillation apparatus according to ASTM D 7500 show peaks in the range of carbon atoms greater than 11 and less than 23.

[0299] The aforementioned rust inhibitor (B) is selected from one or more of the first rust inhibitor (B1), the second rust inhibitor (B2), the third rust inhibitor (B3), and the fourth rust inhibitor (B4).

[0300] • The aforementioned first rust inhibitor (B1): a combination of succinate (B1-1) and dehydrated sorbitan fatty acid ester (B1-2).

[0301] • The aforementioned second rust inhibitor (B2): Carboxylic acid amide (B2-1)

[0302] • The aforementioned third rust inhibitor (B3): Neutral alkyl phosphate ester (B3-1)

[0303] • The aforementioned fourth rust inhibitor (B4): a combination of fatty acids with 12 or more carbon atoms (B4-1) and primary amines (B4-2);

[0304] Based on the total amount of the aforementioned lubricating oil composition, the proportions of the aforementioned first rust inhibitor (B1), the aforementioned second rust inhibitor (B2), the aforementioned third rust inhibitor (B3), and the aforementioned fourth rust inhibitor (B4) satisfy the following requirement (β).

[0305] <Requirement (β)>

[0306] • The aforementioned first rust inhibitor (B1): exceeding 0.02% by mass and less than 0.16% by mass

[0307] • The aforementioned second rust inhibitor (B2): more than 0.05% by mass and less than 0.5% by mass

[0308] • The aforementioned third rust inhibitor (B3): 0.005% by mass or more but less than 0.05% by mass

[0309] • The aforementioned fourth rust inhibitor (B4): more than 0.05% by mass and less than 0.20% by mass.

[0310] There are no particular limitations on the method for mixing the above components; for example, a method that includes a step of adding a rust inhibitor (B) to the base oil (A). When further adding one or more of an antioxidant (C), a wear-resistant agent (D), and a defoamer (E), they can be added simultaneously with the rust inhibitor (B) or separately. The same applies to the formulation of other lubricating oil additives. It should be noted that each component can be added to a diluent oil or the like to prepare a solution (dispersion) before being added. After adding the components, it is preferable to stir them using a known method to achieve uniform dispersion.

[0311] [Uses of Lubricating Oil Compositions]

[0312] One embodiment of the present invention provides a lubricating oil composition that can be suitably used in machinery that may be contaminated with water or water vapor.

[0313] Examples of machines that may contain water or water vapor include steam turbines and other turbine equipment. One embodiment of the lubricating oil composition of this invention can be suitably used as a turbine oil for lubrication of turbine equipment.

[0314] Therefore, according to the lubricating oil composition of the present invention, a method of using the lubricating oil composition in turbine equipment is provided.

[0315] When the lubricating oil composition of one aspect of the present invention is used for steam turbine applications, the antioxidant (C) incorporated in the lubricating oil composition is preferably a phenolic antioxidant, and more preferably a low content of an amine antioxidant. Specifically, based on the total amount of the lubricating oil composition, the content of the amine antioxidant is preferably less than 0.1% by mass, more preferably less than 0.01% by mass, and most preferably free of amine antioxidants.

[0316] [One aspect of the present invention provided]

[0317] According to one aspect of the present invention, the following [1] to [9] are provided.

[0318] [1] A lubricating oil composition comprising a base oil (A) and a rust inhibitor (B), wherein the base oil (A) satisfies the following requirement (α).

[0319] <Requirement (α)>

[0320] Gas chromatograms determined by a gas chromatograph distillation apparatus according to ASTM D 7500 show peaks in the range of carbon atoms greater than 11 and less than 23.

[0321] The aforementioned rust inhibitor (B) is selected from one or more of the first rust inhibitor (B1), the second rust inhibitor (B2), the third rust inhibitor (B3), and the fourth rust inhibitor (B4).

[0322] • The aforementioned first rust inhibitor (B1): a combination of succinate (B1-1) and dehydrated sorbitan fatty acid ester (B1-2).

[0323] • The aforementioned second rust inhibitor (B2): Carboxylic acid amide (B2-1)

[0324] • The aforementioned third rust inhibitor (B3): Neutral alkyl phosphate ester (B3-1)

[0325] • The aforementioned fourth rust inhibitor (B4): a combination of fatty acids with 12 or more carbon atoms (B4-1) and primary amines (B4-2);

[0326] Based on the total amount of the aforementioned lubricating oil composition, the contents of the aforementioned first rust inhibitor (B1), the aforementioned second rust inhibitor (B2), the aforementioned third rust inhibitor (B3), and the aforementioned fourth rust inhibitor (B4) satisfy the following requirement (β).

[0327] <Requirement (β)>

[0328] • The aforementioned first rust inhibitor (B1): exceeding 0.02% by mass and less than 0.16% by mass

[0329] • The aforementioned second rust inhibitor (B2): more than 0.05% by mass and less than 0.5% by mass

[0330] • The aforementioned third rust inhibitor (B3): 0.005% by mass or more but less than 0.05% by mass

[0331] • The aforementioned fourth rust inhibitor (B4): more than 0.05% by mass and less than 0.20% by mass.

[0332] [2] The lubricating oil composition described in [1] above, wherein the aforementioned first rust inhibitor (B1) contains an alkenyl succinic acid polyol ester (B1-1).

[0333] [3] The lubricating oil composition described in [1] or [2] above, wherein the first rust inhibitor (B1) comprises an ester compound of sorbitol and a fatty acid having 12 or more and 30 or fewer carbon atoms.

[0334] [4] The lubricating oil composition described in any one of [1] to [3] above, wherein the acid value of the carboxylic acid amide (B2-1) in the second rust inhibitor (B2) is less than 80 mg KOH / g.

[0335] [5] The lubricating oil composition of any one of [1] to [4] above, wherein the aforementioned base oil (A) further satisfies the following requirement (γ),

[0336] <The following requirements (γ)>

[0337] • Flash point obtained by the Cleveland open cup method: above 250℃

[0338] Density at 15℃: 0.8300 g / cm³ 3 the following

[0339] Viscosity index: 100 or higher

[0340] Kinematic viscosity at 100℃: 7.50 mm 2 / s or higher and 9.00mm 2 / s or less.

[0341] [6] The lubricating oil composition described in any one of [1] to [5] above further contains one or more additives selected from antioxidants (C), wear-resistant agents (D) and defoamers (E).

[0342] [7] The lubricating oil composition described in any one of [1] to [6] above is used as a turbine oil.

[0343] [8] Method of use, wherein the lubricating oil composition described in any one of [1] to [7] above is used as a turbine oil.

[0344] [9] A method for manufacturing a lubricating oil composition, comprising the step of mixing a base oil (A) and a rust inhibitor (B), wherein,

[0345] The aforementioned base oil (A) meets the following requirement (α),

[0346] <Requirement (α)>

[0347] Gas chromatograms determined by a gas chromatograph distillation apparatus according to ASTM D 7500 show peaks in the range of carbon atoms greater than 11 and less than 23.

[0348] The aforementioned rust inhibitor (B) is selected from one or more of the first rust inhibitor (B1), the second rust inhibitor (B2), the third rust inhibitor (B3), and the fourth rust inhibitor (B4).

[0349] • The aforementioned first rust inhibitor (B1): a combination of succinate (B1-1) and dehydrated sorbitan fatty acid ester (B1-2).

[0350] • The aforementioned second rust inhibitor (B2): Carboxylic acid amide (B2-1)

[0351] • The aforementioned third rust inhibitor (B3): Neutral alkyl phosphate ester (B3-1)

[0352] • The aforementioned fourth rust inhibitor (B4): a combination of fatty acids with 12 or more carbon atoms (B4-1) and primary amines (B4-2);

[0353] Based on the total amount of the aforementioned lubricating oil composition, the proportions of the aforementioned first rust inhibitor (B1), the aforementioned second rust inhibitor (B2), the aforementioned third rust inhibitor (B3), and the aforementioned fourth rust inhibitor (B4) satisfy the following requirement (β).

[0354] <Requirement (β)>

[0355] • The aforementioned first rust inhibitor (B1): exceeding 0.02% by mass and less than 0.16% by mass

[0356] • The aforementioned second rust inhibitor (B2): more than 0.05% by mass and less than 0.5% by mass

[0357] • The aforementioned third rust inhibitor (B3): 0.005% by mass or more but less than 0.05% by mass

[0358] • The aforementioned fourth rust inhibitor (B4): more than 0.05% by mass and less than 0.20% by mass.

[0359] Example

[0360] The present invention is illustrated in more detail by way of the following embodiments, but the present invention is not limited to the following embodiments.

[0361] [Methods for determining various physical properties]

[0362] The determination of the properties of the raw materials used in each embodiment and each comparative example, as well as the properties of the lubricating oil compositions in each embodiment and each comparative example, was carried out in accordance with the following procedures.

[0363] (1) Kinematic viscosity and viscosity index

[0364] Measured and calculated according to JIS K2283:2000.

[0365] (2) Flash point

[0366] The flash point was determined by the Cleveland open cup method according to JIS K2265-4:2007 (Determination of flash point - Part 4: Cleveland open cup method).

[0367] (3) Density at 15℃

[0368] Determined in accordance with JIS K 2249-1:2011 (Crude oil and petroleum products - Determination of density - Part 1: Vibration method).

[0369] (4) Acid value

[0370] Determined according to JIS K2501:2003 no.5 (indicator titration method).

[0371] [Examples 1-5, Comparative Examples 1-24, and Reference Example 1]

[0372] The base oils and various additives shown below are thoroughly mixed according to the proportions (mass%) shown in Tables 1 to 7 to prepare lubricating oil compositions.

[0373] Details of the base oils and various additives used in Examples 1-5, Comparative Examples 1-24, and Reference Example 1 are shown below.

[0374] <Base Oil (A)>

[0375] Use base oils with the following physical properties.

[0376] Flash point: 257℃

[0377] Density at 15℃: 0.8254 g / cm³ 3

[0378] Kinematic viscosity at 100℃: 7.527 mm 2 / s

[0379] Viscosity index: 120

[0380] <Base Oil (A')>

[0381] Use mineral oil with the following physical properties.

[0382] Flash point: 256℃

[0383] Density at 15℃: 0.8440 g / cm³ 3

[0384] Kinematic viscosity at 100℃: 7.340 mm 2 / s

[0385] Viscosity index: 118

[0386] <Rust Inhibitor (B)>

[0387] (First Rust Inhibitor (B1))

[0388] "Succinate (B1-1)": Alkenyl succinate polyol ester

[0389] “Sorbitol Fatty Acid Ester (B1-2)”: Sorbitol Monooleate

[0390] (Second rust inhibitor (B2))

[0391] "Carboxylic amide (B2-1)": A carboxylic amide with an acid value of 60 mg KOH / g (a carboxylic amide formed from 3-dodecenyl dihydro-2,5-furandione and triethylenetetramine).

[0392] (Third rust inhibitor (B3))

[0393] "Aliphatic phosphate esters (B3)": Alkyl phosphate esters (12 carbon atoms)

[0394] (Fourth rust inhibitor (B4))

[0395] "Fatty acids with 12 or more carbon atoms (B4-1)": Lauric acid

[0396] "Primary amine (B4-2)": Octylamine

[0397] (Rust Inhibitor (B'))

[0398] "sarcosine derivative" - ​​N-alkylsarcosine

[0399] "Benzotriazole compounds": Dialkylaminomethylbenzotriazole

[0400] "Phosphorus compound 1": A mixture of acidic ammonium phosphates and ammonium phosphites.

[0401] "Phosphorus Compound 2": Dioleate Hydrogen Phosphite

[0402] "Fatric acid with fewer than 12 carbon atoms 1": caprylic acid

[0403] "Fatty acids with fewer than 12 carbon atoms 2": Caprylic acid

[0404] <Antioxidant (C)>

[0405] Phenolic antioxidants

[0406] <Abrasion-resistant agent (D)>

[0407] Trimethyl phosphate

[0408] <Defoamer (E)>

[0409] Organosilicon defoamers

[0410] It should be noted that the content of silicone defoamers listed in Tables 1 to 7 is the content mixed into the diluent oil, and the content of the silicone defoamer resin component is calculated based on the total amount of the lubricating oil composition as 0.001 by mass.

[0411] [evaluate]

[0412] (1) Evaluation of base oils

[0413] For base oil (A) and base oil (A'), gas chromatograms were determined by gas chromatographic distillation under the following determination conditions.

[0414] (Measurement conditions)

[0415] • Measuring apparatus: Gas chromatograph distillation apparatus manufactured by Analytical Controls

[0416] • Gas chromatography specification: ASTM D 7500

[0417] • Column: PAC company's macroporous metal column "Simdis HT / CNS" (column liquid phase: dimethyl polysiloxane, column length 5.0m × column inner diameter 0.53mm × liquid phase film thickness 0.17μm)

[0418] • Carrier gas: Helium (flow rate: 23 mL / min)

[0419] • Injection port temperature: At an initial temperature of 100℃, set the heating rate to 15℃ / min, heat to 430℃, and hold for 22 minutes.

[0420] • Column oven temperature: At an initial temperature of 40℃, set the heating rate to 10℃ / min, heat to 430℃, and hold for 5 minutes.

[0421] Total measurement time: 44 min / sample

[0422] • FID detector temperature: 430℃

[0423] (2) Evaluation of rust prevention

[0424] Using the lubricating oil compositions of Examples 1-5, Comparative Examples 1-24, and Reference Example 1, the rust condition under conditions of 60°C and 24 hours was confirmed according to JIS K2510:1998 (Method B, Artificial Seawater Method). Furthermore, in this example, the case where no rust formation was observed was designated as acceptable "A", and the case where rust formation was observed was designated as unacceptable "F".

[0425] (3) Evaluation of demulsibility

[0426] For the lubricating oil compositions of Examples 1 to 5, a water separation test was conducted in accordance with JIS K2520:2000.

[0427] Specifically, 40 mL of the lubricating oil composition and 40 mL of pure water were added to a test tube, the liquid temperature was maintained at 54°C, and the mixture was stirred at 1,500 revolutions per minute for 5 minutes. The time it took for the generated emulsion to separate into water and oil was then measured.

[0428] The meanings of the evaluation results (abc(d)) for demulsibility in Table 7 are as follows.

[0429] a: Oil layer capacity (unit: mL)

[0430] b: Water volume (unit: mL)

[0431] c: Volume of the emulsion layer (unit: mL)

[0432] d: Time required for separation (in minutes)

[0433] The evaluation results of demulsibility showed that the closer a is to 40 mL, the closer b is to 40 mL, the closer c is to 0 mL, and the shorter d is, the better the demulsibility.

[0434] In “(1) Evaluation of Base Oils”, the gas chromatograms of base oils (A) and (A') obtained by gas chromatography are shown in the figure. Figure 1 .

[0435] In addition, the results of “(2) Evaluation of rust resistance” are shown in Tables 1-6.

[0436] Furthermore, the results of “(3) Evaluation of demulsibility” are shown in Table 7.

[0437] [Table 1]

[0438]

[0439] [Table 2]

[0440]

[0441] [Table 3]

[0442]

[0443] [Table 4]

[0444]

[0445] [Table 5]

[0446]

[0447] [Table 6]

[0448]

[0449] [Table 7]

[0450]

[0451] About Figure 1Examination of the results shown: The relationship between differences in base oils and rust prevention 1>

[0452] Depend on Figure 1 The results shown reveal the following facts.

[0453] The chromatogram of base oil (A) shows a peak (first peak) in the range of carbon atoms exceeding 11 and less than 23, satisfying requirement (α). Therefore, it can be concluded that base oil (A) contains polar substances that significantly reduce rust prevention properties.

[0454] Furthermore, the chromatogram of base oil (A) shows a peak (second peak) in the range of 23 to 50 carbon atoms.

[0455] It should be noted that the intensity ratio of the first peak to the second peak in the gas chromatogram of base oil (A) [(intensity of the first peak) / (intensity of the second peak)] is 0.31.

[0456] In contrast, the chromatogram of base oil (A') does not show any peaks (first peak) in the range of carbon atoms exceeding 11 but less than 23, thus failing to meet the above requirement (α). Therefore, it can be concluded that base oil (A') is essentially free of polar substances that significantly reduce rust prevention properties.

[0457] <Examination of the results shown in Table 1: The relationship between differences in base oils and rust prevention 2>

[0458] The results shown in Table 1 reveal the following facts.

[0459] As with the lubricating oil composition of Reference Example 1, when using a base oil (A') that does not meet the above requirement (α) and is substantially free of polar substances that significantly reduce rust prevention, excellent rust prevention can be ensured by combining it with succinate (B1*1).

[0460] In contrast, it can be seen that, as with the lubricating oil composition of Comparative Example 1, when using a base oil (A) that satisfies the above-mentioned requirement (α) and contains a polar substance that significantly reduces rust prevention, even when succinate (B1-1) is formulated in the same way as in Reference Example 1, rust prevention cannot be adequately ensured.

[0461] Furthermore, it is known that, as with the lubricating oil composition of Comparative Example 24, even when using a combination of previously known rust inhibitors, namely succinate (B1*1) and sarcosine derivative (N-alkylsarcosine), rust prevention cannot be adequately ensured if a base oil (A) is used.

[0462] <Examination of the results shown in Tables 2 and 3: Evaluation results of the rust prevention performance of the first rust inhibitor (B1)>

[0463] The results shown in Tables 2 and 3 reveal the following facts.

[0464] As can be seen from the results shown in Example 1, even when using a base oil (A) that satisfies the above-mentioned requirement (α), a lubricating oil composition with excellent rust prevention can be provided by using a first rust inhibitor (B1) and satisfying the above-mentioned requirement (β).

[0465] In contrast, the results shown in Comparative Examples 1 to 3 indicate that even when succinate (B1-1) is used alone as a rust inhibitor, it is impossible to ensure the rust prevention properties of a lubricating oil composition containing a base oil (A) that satisfies the above-mentioned requirement (α).

[0466] Furthermore, the results shown in Comparative Examples 4 and 5 indicate that even when sorbitol fatty acid ester (B1-2) is used alone as a rust inhibitor, it is impossible to ensure the rust prevention properties of a lubricating oil composition containing a base oil (A) that meets the above requirement (α).

[0467] Furthermore, as shown in Comparative Examples 6 and 7, it can be seen that even when succinate (B1-1) and sorbitol fatty acid ester (B1-2) are used in combination, the rust prevention of a lubricating oil composition containing a base oil (A) that satisfies the above requirement (α) cannot be ensured if the above requirement (β) is not met.

[0468] It should be noted that, as shown in the results of Comparative Examples 8 to 14, the rust prevention properties of lubricating oil compositions containing base oil (A) that meets the above requirement (α) cannot be guaranteed in the cases of combining succinate (B1-1) with benzotriazole compounds and combining dehydrated sorbitol fatty acid ester (B1-2) with benzotriazole compounds.

[0469] <Regarding the results shown in Table 4: Evaluation results of the rust prevention performance of the second rust inhibitor (B2)>

[0470] The results shown in Table 4 reveal the following facts.

[0471] As can be seen from the results shown in Examples 2 and 3, even when using a base oil (A) that satisfies the above-mentioned requirement (α), a lubricating oil composition with excellent rust prevention can be provided by using a second rust inhibitor (B2) and satisfying the above-mentioned requirement (β).

[0472] In contrast, as shown in Comparative Example 15, even when using the second rust inhibitor (B2), if the above requirement (β) is not met, the rust prevention of the lubricating oil composition containing the base oil (A) that meets the above requirement (α) cannot be guaranteed.

[0473] <Examination of the results shown in Table 5: Evaluation results of the rust prevention performance of the third rust inhibitor (B3)>

[0474] The results shown in Table 5 reveal the following facts.

[0475] As shown in Example 4, even when using a base oil (A) that satisfies the above-mentioned requirement (α), a lubricating oil composition with excellent rust prevention can be provided by using a third rust inhibitor (B3) and satisfying the above-mentioned requirement (β).

[0476] In contrast, the results shown in Comparative Examples 16 and 17 indicate that even when using a third rust inhibitor (B3), if the above requirement (β) is not met, the rust prevention properties of the lubricating oil composition containing a base oil (A) that meets the above requirement (α) cannot be guaranteed.

[0477] It should be noted that, as shown in Comparative Examples 18 and 19, the rust prevention properties of lubricating oil compositions containing base oils (A) that satisfy the above requirement (α) cannot be guaranteed when using amine salts of acidic phosphate esters or hydrogen phosphite esters.

[0478] <Examination of the results shown in Table 6: Evaluation results of the rust prevention performance of the fourth rust inhibitor (B4)>

[0479] The results shown in Table 6 reveal the following facts.

[0480] As shown in Example 5, even when using a base oil (A) that satisfies the above-mentioned requirement (α), a lubricating oil composition with excellent rust prevention can be provided by using a fourth rust inhibitor (B4) and satisfying the above-mentioned requirement (β).

[0481] In contrast, as shown in Comparative Example 20, it can be seen that even if fatty acids with 12 or more carbon atoms (B4-1) are used alone as rust inhibitors, it is impossible to ensure the rust prevention of lubricating oil compositions containing base oils (A) that meet the above requirements (α).

[0482] Furthermore, the results shown in Comparative Example 21 indicate that even when primary amine (B4-2) is used alone as a rust inhibitor, it is impossible to ensure the rust prevention properties of a lubricating oil composition containing a base oil (A) that satisfies the above-mentioned requirement (α).

[0483] Furthermore, the results shown in Comparative Examples 22 and 23 indicate that even when using a combination of primary amine (B4-2) and fatty acids with fewer than 12 carbon atoms, it is impossible to ensure the rust prevention properties of a lubricating oil composition containing a base oil (A) that satisfies the above requirement (α).

[0484] <Regarding the results shown in Table 7: Evaluation results of demulsibility>

[0485] The results shown in Table 7 reveal the following facts.

[0486] It can be seen that any of the lubricating oil compositions in Examples 1 to 5 have good demulsification properties.

[0487] Furthermore, it is known that in Examples 1 to 5, the lubricating oil compositions using the first rust inhibitor (B1) or the second rust inhibitor (B2) require a short separation time and exhibit particularly excellent demulsification properties.

Claims

1. A lubricating oil composition comprising base oil A and rust inhibitor B, wherein, The base oil A is selected from one or more base oils from hydrocarbon oils. The base oil A satisfies the following requirement α and the following requirement γ. <Requirement α> The gas chromatogram determined by a gas chromatograph distillation apparatus according to ASTM D 7500 has the first peak in the range of carbon number greater than 11 and less than 23. <Requirement γ> • Flash point obtained by the Cleveland open cup method: above 250℃ • Density at 15℃: 0.8300 g / cm³ 3 the following • Viscosity index: 100 or higher • Kinematic viscosity at 100°C: 7.50 mm 2 / s or higher and 9.00mm 2 / s or less Furthermore, the base oil A, as determined by gas chromatography distillation according to ASTM D 7500, exhibits a second peak in the range of 23 to 50 carbon atoms, and the intensity ratio of the first peak to the second peak, i.e., the ratio of the intensity of the first peak to the intensity of the second peak, is 0.10 to 0.

50. The rust inhibitor B is selected from one or more of the following: first rust inhibitor B1, second rust inhibitor B2, third rust inhibitor B3, and fourth rust inhibitor B4. • First rust inhibitor B1: A combination of succinate B1-1 and dehydrated sorbitol fatty acid ester B1-2 • Second rust inhibitor B2: Carboxylic acid amide B2-1 • The third rust inhibitor B3: Neutral alkyl phosphate B3-1 • The fourth rust inhibitor B4 is a combination of primary amine B4-2 and fatty acid B4-1 with 12 or more carbon atoms; Based on the total amount of the lubricating oil composition, the contents of the first rust inhibitor B1, the second rust inhibitor B2, the third rust inhibitor B3, and the fourth rust inhibitor B4 satisfy the following requirement β. <Requirement β> • First rust inhibitor B1: more than 0.02% by mass and less than 0.16% by mass • Second rust inhibitor B2: more than 0.05% by mass and less than 0.5% by mass • The third rust inhibitor B3: 0.005% by mass or more and less than 0.05% by mass • The fourth rust inhibitor B4: more than 0.05% by mass and less than 0.20% by mass.

2. The lubricating oil composition according to claim 1, wherein, In the first rust inhibitor B1, the succinate B1-1 comprises an alkenyl succinic acid polyol ester.

3. The lubricating oil composition according to claim 1 or 2, wherein, In the first rust inhibitor B1, the sorbitol fatty acid ester B1-2 comprises an ester compound of sorbitol and a fatty acid having 12 or more and 30 or fewer carbon atoms.

4. The lubricating oil composition according to claim 1 or 2, wherein, In the second rust inhibitor B2, the acid value of the carboxylic acid amide B2-1 is below 80 mg KOH / g.

5. The lubricating oil composition according to claim 1 or 2, further comprising one or more additives selected from antioxidant C, wear-resistant agent D, and defoamer E.

6. The lubricating oil composition according to claim 1, wherein, Based on the total amount of the lubricating oil composition, the total content of the base oil A and the rust inhibitor B is 80% by mass to less than 100% by mass.

7. The lubricating oil composition according to claim 1, wherein, The first peak is located in the range of 13 to 21 carbon atoms.

8. The lubricating oil composition according to claim 1, wherein, Based on the total amount of the lubricating oil composition, the content of base oil A is 90.0 to 99.5% by mass.

9. The lubricating oil composition according to claim 1, wherein, The second peak is located in the range of 30 to 45 carbon atoms.

10. The lubricating oil composition according to claim 2, wherein, The alkenyl succinic acid constituting the alkenyl succinic acid polyol ester is an alkenyl succinic acid having an alkenyl group having 10 to 24 carbon atoms.

11. The lubricating oil composition according to claim 2, wherein, The polyol constituting the alkenyl succinic acid polyol ester is a diol or a polyol having 3 to 20 hydroxyl groups.

12. The lubricating oil composition according to claim 1, wherein, The sorbitol fatty acid ester B1-2 is an ester compound of sorbitol and fatty acids with 12 or more but less than 30 carbon atoms.

13. The lubricating oil composition according to claim 1, wherein, The ester valence of the dehydrated sorbitol fatty acid ester B1-2 is 1, 2 or 3.

14. The lubricating oil composition according to claim 1, wherein, When the lubricating oil composition contains a first rust inhibitor B1, the content of the first rust inhibitor B1 is 0.07% to 0.13% by mass based on the total amount of the lubricating oil composition.

15. The lubricating oil composition according to claim 1, wherein, The ratio of succinate B1-1 to sorbitol fatty acid ester B1-2, B1-1 / B1-2, is 0.5 to 2.0 by mass.

16. The lubricating oil composition according to claim 1, wherein, Based on the total amount of the lubricating oil composition, the content of succinate B1-1 is 0.03% to 0.07% by mass.

17. The lubricating oil composition according to claim 1, wherein, Based on the total amount of the lubricating oil composition, the content of the dehydrated sorbitol fatty acid ester B1-2 is 0.03% to 0.07% by mass.

18. The lubricating oil composition according to claim 1, wherein, The carboxylic acid amide B2-1 is a carboxylic acid amide obtained by reacting an alkenyl succinic anhydride or an alkyl succinic anhydride with an amine, wherein the amine is a polyalkylene polyamine.

19. The lubricating oil composition according to claim 1, wherein, When the lubricating oil composition contains the second rust inhibitor B2, the content of the second rust inhibitor B2 is 0.08% to 0.25% by mass based on the total amount of the lubricating oil composition.

20. The lubricating oil composition according to claim 1, wherein, The neutral alkyl phosphate B3-1 is a compound represented by the following general formula (b3-1). In the general formula (b3-1), R 1 ~R 3 Each is an alkyl group having 3 to 14 carbon atoms.

21. The lubricating oil composition according to claim 1, wherein, When the lubricating oil composition contains the third rust inhibitor B3, the content of the third rust inhibitor B3 is 0.01% to 0.03% by mass based on the total amount of the lubricating oil composition.

22. The lubricating oil composition according to claim 1, wherein, The fatty acid B4-1 with 12 or more carbon atoms is selected from lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, heptadecanoic acid, stearic acid, oleic acid, nonadecanoic acid, arachidic acid, eicosanoic acid, dodecanoic acid, behenic acid, erucic acid, tridecanoic acid, and tetradecanoic acid.

23. The lubricating oil composition according to claim 1, wherein, The primary amine B4-2 is selected from autoamine, heptenylamine, octylamine, nonylamine, decylamine, undecylamine, dodecylamine, hexenylamine, heptenylamine, octenylamine, nonenylamine, decenylamine, undecenylamine, and dodecenylamine.

24. The lubricating oil composition according to claim 1, wherein, When the lubricating oil composition contains the fourth rust inhibitor B4, the content of the fourth rust inhibitor B4 is 0.08% to 0.17% by mass based on the total amount of the lubricating oil composition.

25. The lubricating oil composition according to claim 1, wherein, The ratio of fatty acid B4-1 with 12 or more carbon atoms to primary amine B4-2, B4-1 / B4-2, is 0.02 to 1.0 by mass.

26. The lubricating oil composition according to claim 1, wherein, The content of fatty acid B4-1 with 12 or more carbon atoms is 0.02% to 0.04% by mass based on the total amount of the lubricating oil composition.

27. The lubricating oil composition according to claim 1, wherein, The content of the primary amine B4-2 is 0.07% to 0.15% by mass based on the total amount of the lubricating oil composition.

28. The lubricating oil composition according to claim 5, wherein, The antioxidant C is selected from one or more phenolic antioxidants and amine antioxidants.

29. The lubricating oil composition according to claim 5, wherein, Based on the total amount of the lubricating oil composition, the content of antioxidant C is 0.4% to 0.8% by mass.

30. The lubricating oil composition according to claim 5, wherein, The wear-resistant agent D is a neutral aromatic phosphate ester represented by the following general formula (d-1). In the general formula (d-1), R 11 ~R 13 Each is an alkyl group having 1 to 12 carbon atoms, and p1 to p3 are each an integer from 1 to 5.

31. The lubricating oil composition according to claim 5, wherein, Based on the total amount of the lubricating oil composition, the content of the wear-resistant agent D is 0.2% to 0.6% by mass.

32. The lubricating oil composition according to claim 5, wherein, The defoamer E is selected from silicone-based defoamers, fluorinated defoamers, and polyacrylate-based defoamers.

33. The lubricating oil composition according to claim 1, wherein the kinematic viscosity of the lubricating oil composition at 100°C is 5.0 mm. 2 / s~10.0mm 2 / s.

34. The lubricating oil composition according to claim 1, wherein no rust formation was observed in the test according to method B of JIS K2510:1998, artificial seawater method.

35. The lubricating oil composition according to claim 1, wherein the time required for separation in the water separation test according to JIS K2520:2000 is less than 20 minutes.

36. The lubricating oil composition according to claim 5, wherein, The antioxidant C is a phenolic antioxidant, and the content of the amine antioxidant is less than 0.01% by mass based on the total amount of the lubricating oil composition.

37. The lubricating oil composition according to claim 1, wherein, The hydrocarbon oil is an alkane-based mineral oil.

38. The lubricating oil composition according to claim 1 or 2, wherein the lubricating oil composition is used as a turbine oil.

39. A method of using the lubricating oil composition according to any one of claims 1 to 5 as a turbine oil.

40. A method for manufacturing a lubricating oil composition, comprising the step of mixing base oil A and rust inhibitor B, wherein, The base oil A is selected from one or more base oils from hydrocarbon oils. The base oil A satisfies the following requirement α and the following requirement γ. <Requirement α> The gas chromatogram determined by a gas chromatograph distillation apparatus according to ASTM D 7500 has the first peak in the range of carbon number greater than 11 and less than 23. <Requirement γ> • Flash point obtained by the Cleveland open cup method: above 250℃ • Density at 15℃: 0.8300 g / cm³ 3 the following • Viscosity index: 100 or higher • Kinematic viscosity at 100°C: 7.50 mm 2 / s or higher and 9.00mm 2 / s or less Furthermore, the base oil A, as determined by gas chromatography distillation according to ASTM D 7500, exhibits a second peak in the range of 23 to 50 carbon atoms, and the intensity ratio of the first peak to the second peak, i.e., the ratio of the intensity of the first peak to the intensity of the second peak, is 0.10 to 0.

50. The rust inhibitor B is selected from one or more of the following: first rust inhibitor B1, second rust inhibitor B2, third rust inhibitor B3, and fourth rust inhibitor B4. • First rust inhibitor B1: A combination of succinate B1-1 and dehydrated sorbitol fatty acid ester B1-2 • Second rust inhibitor B2: Carboxylic acid amide B2-1 • The third rust inhibitor B3: Neutral alkyl phosphate B3-1 • The fourth rust inhibitor B4 is a combination of primary amine B4-2 and fatty acid B4-1 with 12 or more carbon atoms; Based on the total amount of the lubricating oil composition, the proportions of the first rust inhibitor B1, the second rust inhibitor B2, the third rust inhibitor B3, and the fourth rust inhibitor B4 satisfy the following requirement β. <Requirement β> • First rust inhibitor B1: more than 0.02% by mass and less than 0.16% by mass • Second rust inhibitor B2: more than 0.05% by mass and less than 0.5% by mass • The third rust inhibitor B3: 0.005% by mass or more and less than 0.05% by mass • The fourth rust inhibitor B4: more than 0.05% by mass and less than 0.20% by mass.

41. The method for manufacturing the lubricating oil composition according to claim 40, wherein, The hydrocarbon oil is an alkane-based mineral oil.

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