Lubricating oil composition

Abstract

Provided is a lubricating oil composition containing a base oil (A) and a metal-based detergent (B), the content ratio of a heavy component (Hf) having 32 or more carbon atoms in component (A) being 14.0 mass% or more based on the total amount of component (A), the component (B) containing an overbased calcium salicylate (B1) having a base number of 100 mgKOH / g or more, and the content ratio of component (B1) in component (B) being 35.0 mass% or more based on the total amount of component (B).

Description

Technical Field

[0001] The present invention relates to a lubricating oil composition, an internal combustion engine and a method for lubricating an internal combustion engine. Background Art

[0002] Internal combustion engines used in automobiles and the like are being required to be smaller and more powerful, to be more fuel-efficient, and to comply with exhaust gas control, and lubricating oil compositions used in internal combustion engines are being developed to comply with such requirements.

[0003] For example, Patent Document 1 discloses an invention related to a lubricating oil composition containing 14% by mass or more of a fraction having a boiling point of 500 to 550° C. and 5% by mass or more of a fraction having a boiling point exceeding 550° C., with the purpose of providing a lubricating oil composition having a further improved performance in suppressing the formation of compressor deposits.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2016-196595 Summary of the invention

[0007] Problems to be solved by the invention

[0008] However, as a countermeasure to the environment, a supercharger equipped with an EGR system that re-intakes a portion of the exhaust gas and refluxes it has been developed. If the charge pressure of the supercharger equipped with the EGR system is increased, deposits derived from the engine oil are easily generated, which becomes a cause of reducing the efficiency of the supercharger. Furthermore, fuel efficiency is required for internal combustion engines used in automobiles and the like.

[0009] Under such circumstances, a lubricating oil composition is desired which has a high effect of suppressing the formation of deposits, is excellent in fuel saving properties, and can be applied to internal combustion engines regardless of the usage environment.

[0010] Means used to solve problems

[0011] The present inventors have conducted intensive studies and have found that a lubricating oil composition using a base oil having a content ratio of a heavy component (Hf) having a carbon number of 32 or more adjusted to a predetermined range and a metal-based detergent containing overbased calcium salicylate having a predetermined base number at a predetermined ratio can solve the above-mentioned problems. Specifically, the present invention discloses the following aspects.

[0012] [1] A lubricating oil composition comprising a base oil (A) and a metallic detergent (B),

[0013] The content of the heavy component (Hf) having 32 or more carbon atoms in the component (A) is 14.0% by mass or more based on the total amount of the component (A),

[0014] Component (B) contains highly basic calcium salicylate (B1) having a base value of 100 mgKOH / g or more,

[0015] The content of the component (B1) in the component (B) is 35.0% by mass or more based on the total amount of the component (B).

[0016] [2] An internal combustion engine filled with the lubricating oil composition described in [1] above.

[0017] [3] A method for lubricating an internal combustion engine, comprising using the lubricating oil composition described in [1] above for lubricating the internal combustion engine.

[0018] Effects of the Invention

[0019] The lubricating oil composition of one preferred embodiment of the present invention is excellent in deposit suppression effect, detergency, stability, and fuel efficiency regardless of the usage environment. Therefore, the lubricating oil composition of one embodiment of the present invention can be suitably used for lubrication of internal combustion engines, for example. DETAILED DESCRIPTION

[0020] For the numerical ranges described in this specification, the upper limit and the lower limit may be arbitrarily combined. For example, when "preferably 30 to 100, more preferably 40 to 80" is described as a numerical range, the ranges of "30 to 80" and "40 to 100" also fall within the numerical ranges described in this specification.

[0021] In addition, for example, when "preferably 30 or more, more preferably 40 or more, and preferably 100 or less, more preferably 80 or less" is described as a numerical range, the range of "30 to 80" and the range of "40 to 100" also fall within the numerical range described in this specification. In other words, in the provisions of the upper limit and the lower limit described in this specification, the numerical range from the lower limit to the upper limit can be specified by appropriately selecting from the respective options and combining them arbitrarily.

[0022] Furthermore, as a numerical range described in the present specification, for example, the description "60 to 100" means a range of "60 or more (60 or more) and 100 or less (100 or less)".

[0023] Furthermore, various conditions described as preferred embodiments in this specification may be combined in plurality.

[0024] [Composition of lubricating oil composition]

[0025] The lubricating oil composition according to one embodiment of the present invention comprises a specific base oil (A) and a specific metallic detergent (B), and may further contain other components within a range that does not impair the effects of the present invention.

[0026] For example, from the viewpoint of reducing the temperature dependency of viscosity and providing a lubricating oil composition having excellent fuel efficiency, the lubricating oil composition of one embodiment of the present invention may further contain a viscosity index improver (C).

[0027] In the lubricating oil composition of one embodiment of the present invention, the total content of components (A) and (B) is preferably 50% by mass or more, more preferably 60% by mass or more, more preferably 65% ​​by mass or more, further preferably 70% by mass or more, further preferably 75% by mass or more, still further preferably 80% by mass or more, and particularly preferably 83% by mass or more, based on the total amount (100% by mass) of the lubricating oil composition. It may be 100% by mass or less, 99.9% by mass or less, 99.0% by mass or less, 97.0% by mass or less, 95.0% by mass or less, 92.0% by mass or less, or 90.0% by mass or less.

[0028] In the lubricating oil composition of one embodiment of the present invention, the total content of components (A), (B) and (C) is preferably 55 mass% or more, more preferably 60 mass% or more, more preferably 65 mass% or more, further preferably 70 mass% or more, further preferably 75 mass% or more, still further preferably 80 mass% or more, particularly preferably 85 mass% or more, based on the total amount (100 mass%) of the lubricating oil composition, and may be 100 mass% or less, 99.9 mass% or less, 99.0 mass% or less, 97.0 mass% or less, 95.0 mass% or less, 92.0 mass% or less, or 90.0 mass% or less.

[0029] Hereinafter, details of each component contained in the lubricating oil composition according to one embodiment of the present invention will be described.

[0030] <Ingredient (A): Base oil>

[0031] In the lubricating oil composition of one embodiment of the present invention, the base oil used as the component (A) may be one or more selected from mineral oils and synthetic oils.

[0032] Examples of the mineral oil include atmospheric residues obtained by atmospheric distillation of crude oils such as paraffinic crude oil, intermediate crude oil, and cycloparaffinic crude oil; distillates obtained by vacuum distillation of these atmospheric residues; and refined oils obtained by subjecting the distillates to one or more refining treatments such as solvent deasphalting, solvent extraction, hydrocracking, solvent dewaxing, contact dewaxing, and hydrorefining.

[0033] Examples of synthetic oils include poly-α-olefins such as α-olefin homopolymers and α-olefin copolymers (e.g., α-olefin copolymers having 8 to 14 carbon atoms, such as ethylene-α-olefin copolymers); isoparaffins; polyalkylene glycols; ester oils such as polyol esters, dibasic acid esters, and phosphate esters; ether oils such as polyphenyl ethers; alkylbenzenes; alkylnaphthalenes; synthetic oils (GTL) obtained by isomerizing wax produced from natural gas using the Fischer-Tropsch process, etc. (GTL wax (Gas To Liquids WAX)); and the like.

[0034] The base oil (A) used in one embodiment of the present invention satisfies the following condition (I).

[0035] · Condition (I): The content of the heavy component (Hf) having 32 or more carbon atoms in the component (A) is 14.0% by mass or more based on the total amount of the component (A).

[0036] By using a base oil (A) adjusted to satisfy condition (I), a lubricating oil composition can be prepared in which the base oil evaporates easily, the amount of evaporation is suppressed even when used in a high temperature environment and / or a high pressure environment, and the lubricating oil composition has good fluidity. As a result, the lubricating oil composition of one embodiment of the present invention having good fluidity can spread the metallic detergent of component (B) over the lubrication surface, and can effectively suppress the generation of deposits.

[0037] On the other hand, a lubricating oil composition in which the content of the heavy component (Hf) having 32 or more carbon atoms in the component (A) is less than 14.0% by mass tends to fail to sufficiently suppress evaporation under a high temperature environment and / or a high pressure environment, resulting in a decrease in fluidity and an insufficient effect of suppressing the formation of deposits.

[0038] From the viewpoint of obtaining a lubricating oil composition which can maintain good fluidity even when used in a high temperature environment and / or a high pressure environment and has a high effect of suppressing the generation of deposits, the content of the heavy component (Hf) having 32 or more carbon atoms is preferably 15.0 mass% or more, more preferably 16.0 mass% or more, further preferably 17.0 mass% or more, even more preferably 18.0 mass% or more, and particularly preferably 19.0 mass% or more, based on the total amount (100 mass%) of the component (A). From the viewpoint of obtaining a lubricating oil composition having good fuel efficiency, the content is preferably 40.0 mass% or less, more preferably 37.0 mass% or less, more preferably 35.0 mass% or less, more preferably 33.0 mass% or less, further preferably 30.0 mass% or less, further preferably 27.0 mass% or less, further preferably 25.0 mass% or less, and particularly preferably 23.0 mass% or less.

[0039] Furthermore, the base oil (A) used in one embodiment of the present invention preferably further satisfies at least one of the following conditions (IIa) and (IIb), and more preferably further satisfies both of the following conditions (IIa) and (IIb).

[0040] Condition (II): The content ratio of the light component (Lf) having 21 or less carbon atoms to the heavy component (Hf) having 32 or more carbon atoms in the component (A) [(Lf) / (Hf)] is 0.05 or more in terms of mass ratio.

[0041] Condition (III): The content of the light component (Lf) having 21 or less carbon atoms in the component (A) is 1.0% by mass or more based on the total amount of the component (A).

[0042] By using the base oil (A) adjusted so as to satisfy the condition (II) and / or the condition (III), it is possible to obtain a lubricating oil composition having improved fuel efficiency.

[0043] From the viewpoint of obtaining a lubricating oil composition with further improved fuel efficiency, the content ratio [(Lf) / (Hf)] is preferably 0.07 or more, more preferably 0.09 or more, more preferably 0.10 or more, further preferably 0.11 or more, further preferably 0.12 or more, particularly preferably 0.13 or more, and can be 0.15 or more, 0.17 or more, 0.20 or more, 0.23 or more, 0.25 or more, 0.27 or more, or 0.30 or more.

[0044] Furthermore, from the viewpoint of obtaining a lubricating oil composition which can maintain better fluidity even when used in a high temperature environment and / or a high pressure environment and has a higher effect of suppressing the generation of deposits, the content ratio [(Lf) / (Hf)] is preferably 0.80 or less, more preferably 0.70 or less, more preferably 0.60 or less, further preferably 0.55 or less, further preferably 0.50 or less, and particularly preferably 0.48 or less, in terms of mass ratio.

[0045] From the viewpoint of obtaining a lubricating oil composition having further improved fuel efficiency, the content of the light component (Lf) having 21 or less carbon atoms is preferably 1.5% by mass or more, more preferably 1.7% by mass or more, further preferably 2.0% by mass or more, still further preferably 2.3% by mass or more, particularly preferably 2.5% by mass or more, based on the total amount (100% by mass) of the component (A), and can further be 2.7% by mass or more, 3.0% by mass or more, 3.5% by mass or more, 4.0% by mass or more, 4.5% by mass or more, 5.0% by mass or more, 5.5% by mass or more, 6.0% by mass or more, 6.5% by mass or more, or 7.0% by mass or more.

[0046] Furthermore, from the viewpoint of obtaining a lubricating oil composition which can maintain better fluidity even when used in a high temperature environment and / or a high pressure environment and has a higher effect of suppressing the generation of deposits, the content of the light component (Lf) having a carbon number of 21 or less is preferably 25.0 mass% or less, more preferably 20.0 mass% or less, more preferably 17.0 mass% or less, more preferably 15.0 mass% or less, further preferably 12.0 mass% or less, further preferably 10.0 mass% or less, still further preferably 9.5 mass% or less, and particularly preferably 9.0 mass% or less, based on the total amount (100 mass%) of the component (A).

[0047] The content of the middle component (Mf) having 22 or more and 31 or less carbon atoms in the component (A) used in one embodiment of the present invention is preferably 35.0% by mass or more, more preferably 40.0% by mass or more, more preferably 45.0% by mass or more, further preferably 50.0% by mass or more, further preferably 55.0% by mass or more, still further preferably 60.0% by mass or more, particularly preferably 65.0% by mass or more, and is preferably 85% by mass or less, more preferably 83.5% by mass or less, more preferably 81.0% by mass or less, further preferably 80.0% by mass or less, further preferably 79.0% by mass or less, further preferably 78.0% by mass or less, and particularly preferably 77.0% by mass or less.

[0048] It should be noted that in the present specification, the contents of the components of each carbon number constituting component (A), the content ratio of the heavy component (Hf) having 32 or more carbon atoms, the content ratio of the light component (Lf) having 21 or less carbon atoms, and the content ratio of the middle component (Mf) having 22 or more and 31 or more carbon atoms refer to the values ​​measured according to the methods described in the examples.

[0049] The component (A) used in one embodiment of the present invention preferably has a kinematic viscosity at 40° C. of 10 to 120 mm 2 / s, more preferably 15 to 100 mm 2 / s, more preferably 20 to 80 mm 2 / s, more preferably 25 to 70 mm 2 / s, more preferably 30 to 60 mm 2 / s, particularly preferably 35 to 50 mm 2 / s.

[0050] The viscosity index of the component (A) used in one embodiment of the present invention is preferably 80 or more, more preferably 100 or more, further preferably 110 or more, further preferably 120 or more, particularly preferably 130 or more.

[0051] The kinematic viscosity and viscosity index are values ​​measured and calculated in accordance with JIS K2283:2000.

[0052] It should be noted that, in one embodiment of the present invention, when a mixed oil obtained by combining two or more base oils is used as component (A), the kinematic viscosity and viscosity index of the mixed oil are preferably within the above ranges. In addition, the weighted average of the kinematic viscosity and viscosity index calculated from the content ratio of the base oil constituting the mixed oil is preferably within the above ranges.

[0053] In the lubricating oil composition of one embodiment of the present invention, the content of component (A) is preferably 40% by mass or more, more preferably 50% by mass or more, more preferably 60% by mass or more, further preferably 65% ​​by mass or more, further preferably 70% by mass or more, still further preferably 75% by mass or more, particularly preferably 80% by mass or more, based on the total amount (100% by mass) of the lubricating oil composition, and may be 99.9% by mass or less, 99.5% by mass or less, 99.0% by mass or less, 97.0% by mass or less, 95.0% by mass or less, 92.0% by mass or less, or 90.0% by mass or less.

[0054] <Component (B): Metallic Detergent>

[0055] A lubricating oil composition according to one embodiment of the present invention contains a metallic detergent (B) comprising an overbased calcium salicylate (B1) having a base number of 100 mgKOH / g or more.

[0056] In addition, the component (B) and the component (B1) used in one embodiment of the present invention may be used alone or in combination of two or more.

[0057] By containing the overbased calcium salicylate (B1) as the metallic detergent (B), it is possible to obtain a lubricating oil composition having improved detergency and stability in a high temperature environment and excellent fuel saving performance.

[0058] In addition, the component (B) used in one embodiment of the present invention may be used alone or in combination of two or more.

[0059] In the lubricating oil composition of one embodiment of the present invention, from the viewpoint of providing a lubricating oil composition having improved detergency and stability in a high temperature environment and excellent fuel saving performance, the content ratio of the component (B1) in the component (B) is 35.0% by mass or more based on the total amount (100% by mass) of the component (B) contained in the lubricating oil composition.

[0060] A lubricating oil composition containing the component (B1) in an amount of less than 35.0% by mass may be prone to problems in detergency and stability under high temperature environments, and may also suffer from reduced fuel efficiency.

[0061] From the above viewpoints, the content of component (B1) in component (B) is preferably 37.0% by mass or more, more preferably 40.0% by mass or more, based on the total amount (100% by mass) of component (B) contained in the lubricating oil composition. From the viewpoint of obtaining a lubricating oil composition with further excellent fuel efficiency, it is more preferably 45.0% by mass or more, further preferably 50.0% by mass or more, further preferably 55.0% by mass or more, still further preferably 60.0% by mass or more, and particularly preferably 63.0% by mass or more. It may also be 100% by mass or less, 99.0% by mass or less, 98.0% by mass or less, 95.0% by mass or less, 90.0% by mass or less, 85.0% by mass or less, 80.0% by mass or less, 75.0% by mass or less, or 70.0% by mass or less.

[0062] As a component (B1) used in one embodiment of the present invention, a compound represented by the following general formula (b-1) can be mentioned, for example.

[0063] [Chemistry 1]

[0064]

[0065] In the above general formula (b-1), R is a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms.

[0066] Examples of the hydrocarbon group that can be selected as R include alkyl groups having 1 to 18 carbon atoms, alkenyl groups having 1 to 18 carbon atoms, cycloalkyl groups having 3 to 18 ring carbon atoms, aryl groups having 6 to 18 ring carbon atoms, alkylaryl groups having 7 to 18 carbon atoms, and arylalkyl groups having 7 to 18 carbon atoms.

[0067] The component (B1) used in one embodiment of the present invention has high basicity, and therefore has a base value of 100 mgKOH / g or more.

[0068] From the viewpoint of obtaining a lubricating oil composition having further improved detergency and stability in a high temperature environment and also having more excellent fuel saving properties, the base number of component (B1) used in one embodiment of the present invention is preferably 120 mgKOH / g or more, more preferably 150 mgKOH / g or more, more preferably 170 mgKOH / g or more, further preferably 200 mgKOH / g or more, further preferably 220 mgKOH / g or more, still further preferably 250 mgKOH / g or more, and particularly preferably 270 mgKOH / g or more, and may be 600 mgKOH / g or less, 550 mgKOH / g or less, 500 mgKOH / g or less, 450 mgKOH / g or less, or 400 mgKOH / g or less.

[0069] In addition, in this specification, "base number" means the value measured by the perchloric acid method based on "9. Potentiometric titration method (base number·perchloric acid method)" of JIS K2501 "Petroleum products and lubricating oils-Neutralization number test method".

[0070] In the lubricating oil composition of one embodiment of the present invention, from the viewpoint of further improving the detergency and stability in a high temperature environment and further improving the fuel saving performance, the content of the component (B1) in terms of calcium atom is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, more preferably 0.07% by mass or more, further preferably 0.10% by mass or more, still further preferably 0.12% by mass or more, and particularly preferably 0.14% by mass or more, and is preferably 0.80% by mass or less, 0.70% by mass or less, 0.60% by mass or less, 0.50% by mass or less, 0.40% by mass or less, 0.30% by mass or less, 0.25% by mass or less, 0.22% by mass or less, or 0.20% by mass or less, based on the total amount (100% by mass) of the lubricating oil composition.

[0071] In addition, in this specification, the content of calcium atoms (Ca) refers to the value measured according to JPI-5S-38-92.

[0072] In the lubricating oil composition of one embodiment of the present invention, from the viewpoint of further improving the detergency and stability in a high temperature environment and further improving the fuel saving performance, the content of the component (B1) is preferably 0.10 mass% or more, more preferably 0.50 mass% or more, more preferably 0.70 mass% or more, further preferably 1.00 mass% or more, still further preferably 1.20 mass% or more, and particularly preferably 1.40 mass% or more, and is preferably 8.00 mass% or less, 7.00 mass% or less, 6.00 mass% or less, 5.00 mass% or less, 4.00 mass% or less, 3.00 mass% or less, 2.50 mass% or less, 2.20 mass% or less, or 2.00 mass% or less, based on the total amount (100 mass%) of the lubricating oil composition.

[0073] The lubricating oil composition of one embodiment of the present invention may contain, as component (B), another metallic detergent (B2) other than component (B1), or may not contain another metallic detergent (B2) other than component (B1).

[0074] In addition, when containing a component (B2), a component (B2) may be used individually or in combination of 2 or more types.

[0075] As component (B2) used in one embodiment of the present invention, examples include organic acid metal salt compounds containing metal atoms selected from alkali metals and alkaline earth metals, and specifically, metal salicylates containing metal atoms selected from alkali metals and alkaline earth metals (excluding high-based calcium salicylate corresponding to component (B1)), metal phenates, and metal sulfonates.

[0076] The metal atom contained in the metallic detergent is preferably sodium, calcium, magnesium or barium, and more preferably calcium, from the viewpoint of providing a lubricating oil composition having further improved high-temperature detergency.

[0077] In addition, the component (B2) used in one embodiment of the present invention may be any of a neutral salt having a base value of less than 100 mgKOH / g, a high basic salt having a base value of 100 mgKOH / g or more, and a mixture thereof.

[0078] As a base number of the component (B2) used in one embodiment of the present invention, 0 to 600 mgKOH / g is preferable, 10 to 600 mgKOH / g is more preferable, and 20 to 500 mgKOH / g is further more preferable.

[0079] From the viewpoint of obtaining a lubricating oil composition having further improved detergency and stability in a high temperature environment and more excellent fuel saving performance, the component (B) used in the lubricating oil composition of one embodiment of the present invention preferably comprises the component (B1) and a neutral metal sulfonate having a base number of less than 100 mgKOH / g, and more preferably comprises the component (B1) and a neutral calcium sulfonate having a base number of less than 100 mgKOH / g.

[0080] In the lubricating oil composition of one embodiment of the present invention, the content of component (B) in terms of metal atoms is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, more preferably 0.07% by mass or more, further preferably 0.10% by mass or more, still further preferably 0.12% by mass or more, particularly preferably 0.14% by mass or more, and is preferably 1.00% by mass or less, 0.90% by mass or less, 0.80% by mass or less, 0.70% by mass or less, 0.60% by mass or less, 0.50% by mass or less, 0.40% by mass or less, 0.30% by mass or less, 0.25% by mass or less, or 0.20% by mass or less.

[0081] In addition, in this specification, the content of metal atoms refers to the value measured according to JPI-5S-38-92.

[0082] In the lubricating oil composition of one embodiment of the present invention, the content of component (B) is preferably 0.10 mass% or more, more preferably 0.50 mass% or more, more preferably 1.00 mass% or more, further preferably 1.50 mass% or more, still further preferably 1.70 mass% or more, particularly preferably 2.00 mass% or more, based on the total amount (100 mass%) of the lubricating oil composition, and may be 8.00 mass% or less, 7.00 mass% or less, 6.00 mass% or less, 5.00 mass% or less, 4.00 mass% or less, 3.70 mass% or less, 3.50 mass% or less, 3.20 mass% or less, 3.00 mass% or less, 2.70 mass% or less, or 2.50 mass% or less.

[0083] <Component (C): Viscosity Index Improver>

[0084] The lubricating oil composition of one embodiment of the present invention may contain a viscosity index improver as component (C). By containing the viscosity index improver (C), the temperature dependency of the viscosity can be reduced, and a lubricating oil composition having excellent fuel efficiency can be obtained.

[0085] In addition, the component (C) used in one embodiment of the present invention may be used alone or in combination of two or more.

[0086] As component (C) used in one embodiment of the present invention, polymers such as non-dispersed polymethacrylate, dispersed polymethacrylate, olefin copolymers (such as ethylene-propylene copolymers), dispersed olefin copolymers, and styrene copolymers (such as styrene-diene copolymers and styrene-isoprene copolymers) can be listed.

[0087] Component (C) used in one embodiment of the present invention may be a comb polymer having a structure with a plurality of trifurcated branch points from which high molecular weight side chains branch out in the main chain, or a star polymer having a structure in which three or more chain polymers are bonded to one atom such as a carbon atom.

[0088] From the viewpoint of reducing the temperature dependence of the viscosity, making a lubricating oil composition with excellent fuel efficiency, and adjusting the viscosity grade to a lubricating oil composition of 0W-20 based on SAE J300:2015, the component (C) used in one embodiment of the present invention is preferably a combination of a comb polymer and a dispersed polymethacrylate.

[0089] The content ratio of the comb polymer to the dispersed polymethacrylate [comb polymer / dispersed polymethacrylate] is preferably 20 / 80 or more, more preferably 40 / 60 or more, more preferably 55 / 45 or more, further preferably 65 / 35 or more, further preferably 75 / 25 or more, further preferably 80 / 20 or more, particularly preferably 85 / 15 or more, and is preferably 99 / 1 or less, more preferably 98 / 2 or less, further preferably 97 / 3 or less, further preferably 96 / 4 or less, and particularly preferably 95 / 5 or less.

[0090] From the viewpoint of reducing the temperature dependence of the viscosity, making a lubricating oil composition with excellent fuel saving performance, and adjusting the viscosity grade to a lubricating oil composition of 0W-30 based on SAE J300:2015, it is preferred that the component (C) used in one embodiment of the present invention is a combination of a non-dispersible polymethacrylate and a dispersible polymethacrylate.

[0091] The content ratio of the non-dispersed polymethacrylate to the dispersed polymethacrylate [non-dispersed polymethacrylate / dispersed polymethacrylate] is preferably 20 / 80 or more, more preferably 40 / 60 or more, more preferably 55 / 45 or more, further preferably 65 / 35 or more, further preferably 75 / 25 or more, further preferably 80 / 20 or more, particularly preferably 85 / 15 or more, and is preferably 99 / 1 or less, more preferably 98 / 2 or less, further preferably 97 / 3 or less, further preferably 96 / 4 or less, and particularly preferably 95 / 5 or less.

[0092] From the viewpoint of reducing the temperature dependency of the viscosity and obtaining a lubricating oil composition with excellent fuel saving performance, the weight average molecular weight (Mw) of the viscosity index improver used in one embodiment of the present invention is preferably 10,000 or more, more preferably 30,000 or more, more preferably 50,000 or more, further preferably 70,000 or more, further preferably 100,000 or more, further preferably 120,000 or more, and particularly preferably 150,000 or more. Furthermore, it may be 170,000 or more, 200,000 or more, 250,000 or more, or 300,000 or more. From the viewpoint of obtaining a lubricating oil composition capable of suppressing the generation of deposits, it may be 1,000,000 or less, 900,000 or less, 800,000 or less, 700,000 or less, 650,000 or less, 600,000 or less, 550,000 or less, or 500,000 or less.

[0093] In the lubricating oil composition of one embodiment of the present invention, from the viewpoint of reducing the temperature dependency of the viscosity and making a lubricating oil composition excellent in fuel saving performance, the content of the component (C) in terms of resin component is preferably 0.01% by mass or more, more preferably 0.10% by mass or more, more preferably 0.30% by mass or more, more preferably 0.50% by mass or more, further preferably 0.70% by mass or more, further preferably 0.90% by mass or more, still further preferably 1.10% by mass or more, and particularly preferably 1.30% by mass or more, based on the total amount (100% by mass) of the lubricating oil composition.

[0094] From the viewpoint of providing a lubricating oil composition capable of suppressing the generation of deposits, the content of component (C) in terms of resin component is preferably 4.0% by mass or less, more preferably 3.5% by mass or less, more preferably 3.0% by mass or less, further preferably 2.5% by mass or less, still further preferably 2.2% by mass or less, and particularly preferably 2.0% by mass or less, based on the total amount (100% by mass) of the lubricating oil composition.

[0095] It should be noted that, generally, in consideration of the operability and solubility with the component (A), the component (C), the pour point depressant described later, and the defoamer used in one embodiment of the present invention are often sold in the form of a solution dissolved in a diluent oil such as mineral oil or synthetic oil. In this specification, the content of the component (C), the pour point depressant, and the defoamer refers to the content calculated on a solid content basis after removing the diluent oil.

[0096] <Lubricant Additives>

[0097] The lubricating oil composition of one embodiment of the present invention may further contain other lubricating oil additives in addition to the components (B) to (C) as necessary, within a range not impairing the effects of the present invention.

[0098] Examples of such lubricating oil additives include pour point depressants, antioxidants, friction modifiers, anti-wear agents, extreme pressure agents, metal inactivators, ashless dispersants, rust inhibitors, and defoaming agents.

[0099] These lubricating oil additives may be used alone or in combination of two or more.

[0100] The content of each of these lubricating oil additives can be appropriately adjusted within a range that does not impair the effects of the present invention. The content of each additive is usually 0.001 to 15 mass %, preferably 0.005 to 10 mass %, more preferably 0.01 to 5 mass %, based on the total amount (100 mass %) of the lubricating oil composition.

[0101] [Pour Point Depressant]

[0102] The lubricating oil composition of one embodiment of the present invention may further contain a pour point depressant. The pour point depressant may be used alone or in combination of two or more.

[0103] Examples of the pour point depressant used in one embodiment of the present invention include ethylene-vinyl acetate copolymers, condensates of chlorinated paraffins and naphthalene, condensates of chlorinated paraffins and phenol, polymethacrylates, and polyalkylstyrenes.

[0104] The mass average molecular weight (Mw) of the pour point depressant used in one embodiment of the present invention may be 5,000 or more, 7,000 or more, 10,000 or more, 15,000 or more, 20,000 or more, 25,000 or more, 30,000 or more, 35,000 or more, 40,000 or more, 45,000 or more, 50,000 or more, 55,000 or more, or 60,000 or more, and may be 150,000 or less, 120,000 or less, 100,000 or less, 90,000 or less, or 80,000 or less.

[0105] [Antioxidant]

[0106] The lubricating oil composition of one embodiment of the present invention may further contain an antioxidant. The antioxidant may be used alone or in combination of two or more.

[0107] As the antioxidant used in one embodiment of the present invention, there can be listed, for example, amine antioxidants such as alkylated diphenylamine, phenylnaphthylamine, and alkylated phenylnaphthylamine; phenolic antioxidants such as 2,6-di-tert-butylphenol, 4,4'-methylenebis(2,6-di-tert-butylphenol), isooctyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and n-octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate; sulfur antioxidants such as phenothiazine, distearyl sulfide, dilauryl-3,3'-thiodipropionate, and 2-mercaptobenzimidazole.

[0108] [Friction modifiers and anti-wear agents]

[0109] The lubricating oil composition of one embodiment of the present invention may further contain a friction modifier or an anti-wear agent. The friction modifier or the anti-wear agent may be used alone or in combination of two or more.

[0110] As friction modifiers and anti-wear agents used in one embodiment of the present invention, for example, as friction modifiers and anti-wear agents, there can be listed sulfur compounds such as sulfided olefins, dialkyl polysulfides, diaryl alkyl polysulfides, and diaryl polysulfides; phosphorus compounds such as phosphates, thiophosphates, phosphites, alkyl hydrogen phosphites, phosphate amine salts, and phosphite amine salts; organic molybdenum compounds such as molybdenum dithiocarbamate (MoDTC), molybdenum dithiophosphate (MoDTP), and amine salts of molybdic acid; organic zinc compounds such as zinc dithiophosphate (ZnDTP) and zinc dithiocarbamate (ZnDTC); ashless friction modifiers such as amine compounds, fatty acid esters, fatty acid amides, fatty acids, aliphatic alcohols, aliphatic ethers, urea compounds, and hydrazide compounds, etc.

[0111] [Extreme pressure agent]

[0112] The lubricating oil composition of one embodiment of the present invention may further contain an extreme pressure agent. The extreme pressure agent may be used alone or in combination of two or more.

[0113] As the extreme pressure agent used in one embodiment of the present invention, there can be listed, for example, sulfur compounds such as sulfided olefins, dialkyl polysulfides, diaryl alkyl polysulfides, and diaryl polysulfides; phosphorus compounds such as phosphates, thiophosphates, phosphites, alkyl hydrogen phosphites, phosphate amine salts, and phosphite amine salts; and the like.

[0114] [Metal inert agent]

[0115] The lubricating oil composition of one embodiment of the present invention may further contain a metal inactivator. The metal inactivators may be used alone or in combination of two or more.

[0116] Examples of the metal inactivating agent used in one embodiment of the present invention include benzotriazole, triazole derivatives, benzotriazole derivatives, and thiadiazole derivatives.

[0117] [Ashless dispersant]

[0118] From the viewpoint of improving dispersibility, the lubricating oil composition of one embodiment of the present invention may further contain an ashless dispersant. The ashless dispersant may be used alone or in combination of two or more.

[0119] As the ashless dispersant used in one embodiment of the present invention, alkenyl succinimide is preferred, and examples thereof include alkenyl succinic acid bisimide represented by the following general formula (f-1) and alkenyl succinic acid monoimide represented by the following general formula (f-2).

[0120] [Chemistry 2]

[0121]

[0122] In the above general formulas (f-1) and (f-2), R f1 , R f2 and R f3 Each independently is an alkenyl group having a mass average molecular weight (Mw) of 500 to 3000 (preferably 900 to 2500).

[0123] As an optional R f1 , R f2 and R f3 Examples of the alkenyl group include a polybutenyl group, a polyisobutenyl group, and an ethylene-propylene copolymer. Among these, a polybutenyl group or a polyisobutenyl group is preferred.

[0124] A f1 , A f2 and A f3 Each is independently an alkylene group having 2 to 5 carbon atoms.

[0125] x1 is an integer of 0-10, preferably an integer of 1-4, and more preferably 2 or 3.

[0126] x2 is an integer of 1 to 10, preferably an integer of 2 to 5, and more preferably 3 or 4.

[0127] It should be noted that the compound represented by the aforementioned general formula (f-1) or (f-2) may be a modified alkenyl succinimide obtained by reacting with one or more selected from boron compounds, alcohols, aldehydes, ketones, alkylphenols, cyclic carbonates, epoxy compounds and organic acids.

[0128] [Rust inhibitor]

[0129] The lubricating oil composition of one embodiment of the present invention may further contain a rust inhibitor. The rust inhibitor may be used alone or in combination of two or more.

[0130] Examples of the rust inhibitor used in one embodiment of the present invention include fatty acids, alkenyl succinic acid half esters, fatty acid soaps, alkyl sulfonates, polyol fatty acid esters, fatty acid amines, paraffin oxides, and alkyl polyoxyethylene ethers.

[0131] [Defoaming agent]

[0132] The lubricating oil composition of one embodiment of the present invention may further contain a defoaming agent. The defoaming agent may be used alone or in combination of two or more.

[0133] Examples of the defoaming agent used in one embodiment of the present invention include alkyl silicone-based defoaming agents, fluorosilicone-based defoaming agents, and fluoroalkyl ether-based defoaming agents.

[0134] <Method for producing lubricating oil composition>

[0135] The method for producing the lubricating oil composition according to one embodiment of the present invention is not particularly limited, but is preferably a method comprising the step of blending the components (B) and (C) and other lubricating oil additives with the base oil (A) as required from the viewpoint of productivity.

[0136] [Properties of Lubricating Oil Composition]

[0137] From the viewpoint of making the lubricating oil composition more fuel-efficient, the kinematic viscosity of the lubricating oil composition of one embodiment of the present invention at 40° C. is preferably 50.0 mm 2 / s or less, more preferably 47.0 mm 2 / s or less, more preferably 45.0 mm 2 / s or less, and preferably 5.0 mm 2 / s or more, more preferably 10.0 mm 2 / s or more, more preferably 15.0 mm 2 / s or more, more preferably 20.0 mm 2 / s or more, particularly preferably 25.0 mm 2 / s or more.

[0138] From the viewpoint of making the lubricating oil composition more fuel-efficient, the kinematic viscosity of the lubricating oil composition of one embodiment of the present invention at 100° C. is preferably 15.0 mm 2 / s or less, more preferably 13.0 mm 2 / s or less, more preferably 11.0 mm 2 / s or less, and preferably 3.0 mm2 / s or more, more preferably 4.0 mm 2 / s or more, more preferably 5.0 mm 2 / s or more.

[0139] The viscosity index of the lubricating oil composition of one embodiment of the present invention is preferably 130 or more, more preferably 140 or more, more preferably 150 or more, further preferably 160 or more, further preferably 170 or more, particularly preferably 180 or more.

[0140] The viscosity grade of the lubricating oil composition according to one embodiment of the present invention can be 0W-20 to 0W-30 in the classification based on SAE J300:2015.

[0141] When the viscosity grade of the lubricating oil composition according to one embodiment of the present invention is 0W-20 according to SAE J300:2015, the kinematic viscosity of the lubricating oil composition at 40° C. is preferably 40.0 mm / s from the viewpoint of making the lubricating oil composition more fuel-efficient. 2 / s or less, more preferably 37.0 mm 2 / s or less, more preferably 35.0 mm 2 / s or less, and preferably 22.0 mm 2 / s or more, more preferably 25.0 mm 2 / s or more, more preferably 27.0 mm 2 / s or more.

[0142] When the viscosity grade of the lubricating oil composition according to one embodiment of the present invention is 0W-20 according to SAE J300:2015, the kinematic viscosity of the lubricating oil composition at 100° C. is preferably 8.0 mm / s from the viewpoint of making the lubricating oil composition more fuel-efficient. 2 / s or less, more preferably 7.7 mm 2 / s or less, more preferably 7.5 mm 2 / s or less, and preferably 5.5mm 2 / s or more, more preferably 6.0 mm 2 / s or more, more preferably 6.5 mm 2 / s or more.

[0143] When the viscosity grade of the lubricating oil composition according to one embodiment of the present invention is 0W-30 according to SAE J300:2015, the kinematic viscosity of the lubricating oil composition at 40° C. is preferably 45.0 mm / s from the viewpoint of making the lubricating oil composition more fuel-efficient. 2 / s or less, more preferably 44.0 mm 2 / s or less, and preferably 25.0 mm 2 / s or more, more preferably 30.0 mm 2 / s or more, more preferably 35.0 mm 2 / s or more, more preferably 40.0 mm 2 / s or more.

[0144] When the viscosity grade of the lubricating oil composition according to one embodiment of the present invention is 0W-30 according to SAE J300:2015, the kinematic viscosity of the lubricating oil composition at 100° C. is preferably 10.0 mm / s from the viewpoint of making the lubricating oil composition more fuel-efficient. 2 / s or less, more preferably 9.8 mm 2 / s or less, and preferably 6.0 mm 2 / s or more, more preferably 7.0 mm 2 / s or more, more preferably 8.0 mm 2 / s or more, more preferably 9.0 mm 2 / s or more.

[0145] From the viewpoint of improving the oil film retention in a high temperature environment and obtaining a lubricating oil composition excellent in wear resistance, the HTHS viscosity of the lubricating oil composition of one embodiment of the present invention at 150°C is preferably 2.5 mPa·s or more, more preferably 2.6 mPa·s or more. From the viewpoint of achieving good fuel saving in a high temperature environment and obtaining a lubricating oil composition suitable for use in a high pressure environment, the HTHS viscosity is preferably 3.7 mPa·s or less, more preferably 3.5 mPa·s or less, further preferably 3.4 mPa·s or less, still further preferably 3.3 mPa·s or less, and particularly preferably 3.2 mPa·s or less.

[0146] In this specification, the HTHS viscosity at 150°C refers to a value measured at 150°C in accordance with ASTM D4683.

[0147] From the viewpoint of producing a lubricating oil composition that can maintain good fluidity even when used in a high temperature environment and / or a high pressure environment and has a high effect of suppressing the generation of deposits, the lubricating oil composition of one embodiment of the present invention has a residue oil ratio measured and calculated by the method described in the Examples described below, which is preferably 25.0 mass % or more, more preferably 26.0 mass % or more, even more preferably 27.0 mass % or more, and even more preferably 28.0 mass % or more.

[0148] The lubricating oil composition of one embodiment of the present invention has an SRV friction coefficient measured by the method described in the Examples below, preferably 0.08 or less, more preferably 0.07 or less, further preferably 0.06 or less, and further preferably 0.05 or less.

[0149] The lubricating oil composition of one embodiment of the present invention has a score of preferably 7.0 or more, more preferably 7.5 or more, further preferably 8.0 or more, and even more preferably 8.5 or more in a hot pipe test conducted in accordance with JPI-5S-55-99.

[0150] It should be noted that the specific steps and conditions of the heat pipe test are the same as those described in the examples described later.

[0151] [Application of lubricating oil composition]

[0152] The lubricating oil composition of one embodiment of the present invention is excellent in the effect of suppressing deposit generation, detergency and stability, and fuel efficiency regardless of the usage environment.

[0153] Therefore, the lubricating oil composition according to one embodiment of the present invention can be suitably used for lubrication of an internal combustion engine, for example.

[0154] Therefore, the lubricating oil composition of one embodiment of the present invention can be applied to various devices that can exhibit the above-mentioned characteristics, and can be suitably used for lubrication between various components in an internal combustion engine. Moreover, among internal combustion engines, it can be more suitably used for lubrication between various components in a diesel engine. In addition, it can also be suitably used for lubrication between various components in a supercharger having an EGR system that re-intakes a part of the exhaust gas and refluxes it.

[0155] Such internal combustion engines are prone to being in high temperature and / or high pressure environments, which can easily increase the evaporation of the lubricating oil composition, reduce fluidity, and easily generate deposits. In addition, the reduction in detergency and stability and the reduction in fuel efficiency are also likely to become problems.

[0156] In view of these problems, the lubricating oil composition of one embodiment of the present invention has excellent deposit inhibition effect, detergency and stability, and fuel saving regardless of the usage environment, and can therefore be suitably used for lubrication of internal combustion engines that are easily exposed to high temperature environments and / or high pressure environments.

[0157] Furthermore, in consideration of the above-mentioned characteristics of the lubricating oil composition of one embodiment of the present invention, the present invention can also provide the following [I] and [II].

[0158] [I] An internal combustion engine filled with the lubricating oil composition according to one embodiment of the present invention.

[0159] [II] A method for lubricating an internal combustion engine, comprising applying the lubricating oil composition according to one embodiment of the present invention to lubricate an internal combustion engine.

[0160] Examples of the internal combustion engine described in [I] and [II] include a diesel engine and a supercharger equipped with an EGR system for re-inhaling a part of the exhaust gas and recirculating it.

[0161] As described above, the present invention discloses the following aspects.

[0162] [1] A lubricating oil composition comprising a base oil (A) and a metallic detergent (B),

[0163] The content of the heavy component (Hf) having 32 or more carbon atoms in the component (A) is 14.0% by mass or more based on the total amount of the component (A),

[0164] Component (B) contains highly basic calcium salicylate (B1) having a base value of 100 mgKOH / g or more,

[0165] The content of the component (B1) in the component (B) is 35.0% by mass or more based on the total amount of the component (B).

[0166] [2] The lubricating oil composition according to [1] above, wherein the content ratio of the light component (Lf) having 21 or less carbon atoms to the heavy component (Hf) having 32 or more carbon atoms [(Lf) / (Hf)] in the component (A) is 0.05 or more in terms of mass ratio.

[0167] [3] The lubricating oil composition according to [1] or [2] above, wherein the content of the light component (Lf) having 21 or less carbon atoms in the component (A) is 1.0 mass % or more based on the total amount of the component (A).

[0168] [4] The lubricating oil composition according to any one of [1] to [3] above, wherein the content of component (B1) in terms of calcium atom is 0.01 to 0.80% by mass based on the total amount of the lubricating oil composition.

[0169] [5] The lubricating oil composition according to any one of [1] to [4] above, wherein the content of component (B) in terms of metal atoms is 0.01 to 1.00% by mass based on the total amount of the lubricating oil composition.

[0170] [6] The lubricating oil composition according to any one of [1] to [5] above, further comprising a viscosity index improver (C).

[0171] [7] The lubricating oil composition according to any one of [1] to [6] above, wherein the kinematic viscosity of the lubricating oil composition at 40° C. is 50.0 mm 2 / s or less.

[0172] [8] The lubricating oil composition according to any one of [1] to [7] above, wherein the lubricating oil composition has a viscosity index of 130 or more.

[0173] [9] The lubricating oil composition according to any one of [1] to [8] above, wherein the lubricating oil composition has a HTHS viscosity at 150°C of 2.5 mPa·s or more.

[0174]

[10] The lubricating oil composition according to any one of [1] to [9] above, wherein the viscosity grade of the lubricating oil composition is 0W-20 to 0W-30 in the classification based on SAE J300:2015.

[0175]

[11] The lubricating oil composition according to any one of [1] to

[10] above, which is used for a diesel engine.

[0176]

[12] An internal combustion engine filled with the lubricating oil composition according to any one of [1] to

[11] above.

[0177]

[13] The internal combustion engine according to

[12] above, wherein the internal combustion engine is a diesel engine.

[0178]

[14] A method for lubricating an internal combustion engine, comprising using the lubricating oil composition according to any one of [1] to

[11] above for lubricating the internal combustion engine.

[0179]

[15] The internal combustion engine lubrication method according to

[14] above, wherein the internal combustion engine is a diesel engine.

[0180] Example

[0181] Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples at all. It should be noted that the methods for measuring various physical properties are as follows.

[0182] (1) Kinematic viscosity and viscosity index

[0183] The measurement and calculation were performed in accordance with JIS K2283:2000.

[0184] (2) Ring analysis

[0185] The measurement was carried out according to ASTM D-3238 ring analysis (ndM method).

[0186] (3) Content of components of each carbon number that make up the base oil

[0187] Using a gas chromatograph (manufactured by Shimadzu Corporation, product name "GC-2014"), the content of components having different carbon numbers constituting the base oil was calculated by comparing the chromatogram with that of a standard sample under the following measurement conditions.

[0188] Column size: 4mm×3mm×1.5mm (SUS)

[0189] · Column packing agent: SiliconeOV-11.5% · Shinwasorb-S60 / 80

[0190] ·Standard samples: n-hexane, n-paraffin: C8~C36 standard samples

[0191] Gas: Helium, 50mL / min

[0192] (4) Alkalinity (perchloric acid method)

[0193] The measurement was conducted in accordance with "9. Potentiometric titration method (base value / perchloric acid method)" of JIS K2501 "Petroleum products and lubricating oils-Neutralization value test method".

[0194] (5) Calcium atom (Ca) content

[0195] The measurement was carried out according to JPI-5S-38-92.

[0196] (6) Weight average molecular weight (Mw)

[0197] The measurement was performed using a gel permeation chromatography apparatus (manufactured by Agilent, "1260 HPLC") under the following conditions, and the measured value in terms of standard polystyrene was used.

[0198] (Measurement conditions)

[0199] Column: Connect two Shodex LF404 in series.

[0200] Column temperature: 35°C

[0201] ·Developing solvent: Chloroform

[0202] Flow rate: 0.3mL / min

[0203] (7) HTHS viscosity (150℃)

[0204] The measurement was carried out at 150°C in accordance with ASTM D4683.

[0205] Examples 1 to 6, Comparative Examples 1 to 6

[0206] The base oil and various additives were added and mixed in the amounts shown in Tables 1 and 2 to prepare lubricating oil compositions. In Examples 1 to 3 and Comparative Examples 1 to 3 shown in Table 1, the viscosity characteristics of the lubricating oil compositions were adjusted so as to correspond to 0W-20 in the classification based on SAE J300:2015. In addition, in Examples 4 to 6 and Comparative Examples 4 to 6 shown in Table 2, the viscosity characteristics of the lubricating oil compositions were adjusted so as to correspond to 0W-30 in the classification based on SAE J300:2015.

[0207] It should be noted that the details of the components used to prepare the lubricating oil composition are as follows.

[0208] <Ingredient (A): Base oil>

[0209] "Base oil (a-1)": a base oil classified as Group III of the API base oil category, 40°C kinematic viscosity = 7.1 mm 2 / s, viscosity index = 109.

[0210] "Base oil (a-2)": a base oil classified as Group III of the API base oil category, 40°C kinematic viscosity = 18.4 mm 2 / s, viscosity index = 125.

[0211] "Base oil (a-3)": a base oil classified as Group III of the API base oil category, 40°C kinematic viscosity = 32.7 mm 2 / s, viscosity index = 132.

[0212] "Base oil (a-4)": a base oil classified as Group III of the API base oil category, 40°C kinematic viscosity = 43.8 mm 2 / s, viscosity index = 143.

[0213] <Component (B): Metallic Detergent>

[0214] "Overbased calcium salicylate (1)": calcium salicylate with a base value of 356 mgKOH / g, a calcium content of 12.5% ​​by mass, corresponding to component (B1).

[0215] "Overbased calcium salicylate (2)": calcium salicylate with a base value of 228 mgKOH / g, a calcium content of 7.9% by mass, corresponding to component (B1).

[0216] "Neutral calcium salicylate": calcium salicylate with a base value of 67.4 mgKOH / g and a calcium content of 2.32% by mass.

[0217] "Overbased calcium sulfonate": calcium sulfonate having a base number of 305 mgKOH / g, a calcium content of 11.7% by mass.

[0218] "Overbased calcium phenate": calcium phenate with a base value of 152 mgKOH / g, a calcium content of 5.49% by mass.

[0219] "Neutral calcium sulfonate": calcium sulfonate having a base value of 17 mgKOH / g and a calcium content of 2.4% by mass.

[0220] <Component (C): Viscosity Index Improver>

[0221] "PMA": non-dispersed polymethacrylate with Mw = 400,000.

[0222] "Comb-shaped PMA": a polymethacrylate-based comb-shaped polymer having a Mw of 310,000.

[0223] "Dispersed OCP": a dispersed polyolefin copolymer with Mw = 120,000.

[0224] <Other additives>

[0225] “Additive mixture”: an additive mixture comprising antioxidants, ashless dispersants, friction modifiers, defoamers, and metal inertizers.

[0226] The kinematic viscosity at 40° C. and 100° C., the viscosity index, and the HTHS viscosity at 150° C. of the prepared lubricating oil composition were measured or calculated, and the following various measurements and tests were performed. The results are shown in Tables 1 and 2.

[0227] (1) Determination of residual oil rate

[0228] Using the container and constant temperature air bath used in the lubricating oil thermal stability test specified in JIS K2540, 1 g of sample oil was placed in the container, and air was flowed into the constant temperature air bath at a flow rate of 10 L / hr while heating at 200°C for 20 hours, and the residue amount of the heated sample oil was measured. In addition, the residue oil rate was calculated according to the following formula.

[0229] Residue oil rate [%] = Residue amount of sample oil after heating [g] / Mass of sample oil before heating (=1g) × 100

[0230] The higher the residual oil ratio, the better the fluidity of the lubricating oil composition in a high temperature environment and the higher the deposit suppressing effect. In this example, when the residual oil ratio is 25.0% or more, it is judged to be a lubricating oil composition with good fluidity in a high temperature environment and high deposit suppressing effect.

[0231] (2) SRV test

[0232] The friction coefficient of each lubricating oil composition prepared was measured under the following conditions using an SRV tester (manufactured by Optimol). The lower the friction coefficient, the better the effect of reducing friction, and thus it can be said that the lubricating oil composition is excellent in fuel saving. In this example, when the friction coefficient is 0.08 or less, it is judged to be a lubricating oil composition with good fuel saving.

[0233] ·Test piece: (a) disk: SUJ-2 material, (b) cylinder: SUJ-2 material

[0234] Amplitude: 1.5mm

[0235] Frequency: 50Hz

[0236] Load: 400N

[0237] Temperature: 40℃

[0238] (3) Heat pipe test

[0239] The hot pipe test was conducted in accordance with JPI-5S-55-99. Specifically, for a glass tube with an inner diameter of 2 mm, the lubricating oil composition prepared in the examples and comparative examples was continuously circulated into the glass tube at a rate of 0.3 mL / hour and air at a rate of 10 mL / minute for 16 hours while the temperature of the glass tube was maintained at 290°C. After the hot pipe test, the paint attached to the glass tube was compared with the color sample, and the degree of discoloration in the glass tube was scored in 21 stages with a scale of 0.5, with the colorless and transparent case being 10 points and the black case being 0 points. The higher the score, the better the high-temperature detergency and high-temperature stability of the lubricating oil composition. In this embodiment, when the score is 7.0 or more, it is judged to be a lubricating oil composition with good high-temperature detergency.

[0240] [Table 1]

[0241] Table 1

[0242]

[0243] [Table 2]

[0244] Table 2

[0245]

[0246] According to Tables 1 and 2, it can be seen that the lubricating oil compositions prepared in Examples 1 to 6 have excellent fluidity even in a high temperature environment and a high effect of suppressing the generation of deposits. In addition, the viscosity characteristics such as the kinematic viscosity at 40°C are also good, and the friction coefficient measured in the SRV test is low, so the fuel saving performance is also excellent. Furthermore, the score of the hot pipe test is as high as 8.5 or more, and the detergency and stability in a high temperature environment are also good.

[0247] On the other hand, the lubricating oil compositions prepared in Comparative Examples 1 and 4 had poor fluidity in a high temperature environment, and therefore it is considered that the inhibition of deposit generation was insufficient. In addition, the lubricating oil compositions prepared in Comparative Examples 2 and 5 had the same 40°C kinematic viscosity, which was higher than that of the examples in the table, and therefore showed the following results: there were problems in fuel saving, and the scores of the hot pipe test were low, and there were problems in detergency and stability in a high temperature environment. Furthermore, regarding the lubricating oil compositions prepared in Comparative Examples 3 and 6, the following results were shown: the friction coefficient measured in the SRV test was high, there were also problems in fuel saving, the scores of the hot pipe test were low, and there were problems in detergency and stability in a high temperature environment.

Claims

1. A lubricating oil composition comprising a base oil (A) and a metallic detergent (B), The content of the heavy component (Hf) having 32 or more carbon atoms in the component (A) is 14.0% by mass or more based on the total amount of the component (A), Component (B) contains highly basic calcium salicylate (B1) having a base value of 100 mgKOH / g or more, The content of the component (B1) in the component (B) is 35.0% by mass or more based on the total amount of the component (B).

2. The lubricating oil composition according to claim 1, wherein The content ratio [(Lf) / (Hf)] of the light component (Lf) having 21 or less carbon atoms and the heavy component (Hf) having 32 or more carbon atoms in the component (A) is 0.05 or more in terms of mass ratio.

3. The lubricating oil composition according to claim 1 or 2, wherein The content of the light component (Lf) having 21 or less carbon atoms in the component (A) is 1.0% by mass or more based on the total amount of the component (A).

4. The lubricating oil composition according to any one of claims 1 to 3, wherein The content of the component (B1) in terms of calcium atoms is 0.01 to 0.80% by mass based on the total amount of the lubricating oil composition.

5. The lubricating oil composition according to any one of claims 1 to 4, wherein The content of the component (B) in terms of metal atoms is 0.01 to 1.00% by mass based on the total amount of the lubricating oil composition. 6 . The lubricating oil composition according to claim 1 , further comprising a viscosity index improver (C).

7. The lubricating oil composition according to any one of claims 1 to 6, wherein The kinematic viscosity of the lubricating oil composition at 40° C. is 50.0 mm 2 / s or less.

8. The lubricating oil composition according to any one of claims 1 to 7, wherein The lubricating oil composition has a viscosity index of 130 or more.

9. The lubricating oil composition according to any one of claims 1 to 8, wherein The lubricating oil composition has a HTHS viscosity at 150° C. of 2.5 mPa·s or more.

10. The lubricating oil composition according to any one of claims 1 to 9, wherein The viscosity grade of the lubricating oil composition is 0W-20 to 0W-30 in the classification based on SAE J300:2015. 11 . The lubricating oil composition according to claim 1 , which is used in a diesel engine.

12. An internal combustion engine filled with the lubricating oil composition according to any one of claims 1 to 11.

13. The internal combustion engine according to claim 12, wherein: The internal combustion engine is a diesel engine.

14. A method for lubricating an internal combustion engine, wherein: The lubricating oil composition according to any one of claims 1 to 11 is used for lubrication of an internal combustion engine.

15. The internal combustion engine lubrication method according to claim 14, wherein: The internal combustion engine is a diesel engine.

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