阅读说明：本技术 润滑油组合物、具备润滑油组合物的机械装置和润滑油组合物的制造方法 (Lubricating oil composition, mechanical device provided with lubricating oil composition, and method for producing lubricating oil composition ) 是由 成田惠一 于 2019-01-09 设计创作，主要内容包括：一种润滑油组合物，其包含润滑性基础油(A)、中性磷系化合物(B)、酸性磷系化合物(C)、硫系化合物(D)和仲胺化合物(E)，且闪点为172℃以上。(A lubricating oil composition which comprises a lubricating base oil (A), a neutral phosphorus compound (B), an acidic phosphorus compound (C), a sulfur compound (D) and a secondary amine compound (E) and has a flash point of 172 ℃ or higher.)

1. A lubricating oil composition comprising a lubricating base oil (A), a neutral phosphorus compound (B), an acidic phosphorus compound (C), a sulfur compound (D), and a secondary amine compound (E), wherein the lubricating oil composition has a flash point of 172 ℃ or higher.

2. The lubricating oil composition according to claim 1,

the secondary amine compound (E) is a compound represented by the following formula (1),

in the formula (1), R¹And R²Each independently represents an optionally substituted alkyl group having 1 to 18 carbon atoms or an optionally substituted alkenyl group having 2 to 18 carbon atoms.

3. The lubricating oil composition according to claim 2,

R¹and R²Each independently is a group represented by the following formula (2),

-(CH₂)n-OH (2)

wherein n is an integer of 1 to 8.

4. The lubricating oil composition according to any one of claims 1 to 3,

the content of the secondary amine compound (E) is 0.01 mass% or more and 0.5 mass% or less based on the total amount of the lubricating oil composition.

5. The lubricating oil composition according to any one of claims 1 to 4,

the lubricating base oil (A) has a flash point of 172 ℃ or higher.

6. The lubricating oil composition according to any one of claims 1 to 5, which is a lubricating oil composition for mechanical devices.

7. The lubricating oil composition according to claim 6,

the mechanical device is a hydraulic device, a fixed transmission, an automotive transmission, or a cooling device for a motor battery.

8. A mechanical device comprising the lubricating oil composition according to any one of claims 1 to 5.

9. The mechanical arrangement of claim 8,

the mechanical device is a hydraulic device, a fixed transmission, an automotive transmission, or a cooling device for a motor battery.

10. A method for producing a lubricating oil composition, which comprises a step of mixing a lubricating base oil (A), a neutral phosphorus compound (B), an acidic phosphorus compound (C), a sulfur compound (D) and a secondary amine compound (E),

the flash point of the lubricating oil composition is above 172 ℃.

Technical Field

The present invention relates to a lubricating oil composition, a machine device provided with the lubricating oil composition, and a method for producing the lubricating oil composition.

Background

In recent years, reduction of carbon dioxide has been strongly required from the viewpoint of global environmental protection, and therefore, in the field of automobiles, development of fuel saving technology has been strongly promoted. Vehicles that save fuel consumption are, for example, hybrid vehicles and electric vehicles, and these vehicles are expected to rapidly spread in the future. A hybrid vehicle or an electric vehicle includes an electric motor, a generator, an inverter, a battery, and the like, and travels by the force of the electric motor.

For cooling the electric motor and the generator in such a hybrid vehicle and an electric vehicle, a conventional Automatic Transmission Fluid (hereinafter referred to as ATF) and a continuously variable Transmission Fluid (hereinafter referred to as CVTF) are mainly used. In addition, since hybrid vehicles and electric vehicles are also provided with a gear reducer, both cooling performance and lubricating performance are required for the lubricating oil composition.

Therefore, a lubricating oil composition has been proposed which comprises a base oil, a neutral phosphorus compound, at least one acidic phosphorus compound selected from acidic amine phosphate esters having a predetermined structure and acidic phosphite esters having a predetermined structure, and a sulfur compound (patent document 1: WO 11/080970).

Disclosure of Invention

Problems to be solved by the invention

However, in the lubricating oil composition described in patent document 1, although the volume resistivity, the intermetallic wear resistance and the solubility are improved, a lubricating oil composition satisfying all of the higher-level wear resistance, seizure resistance and low friction property has been demanded. In addition, a lubricating oil composition having high cooling performance has also been demanded.

Means for solving the problems

Therefore, the present inventors have solved the problem of the present invention by further blending a secondary amine compound in a lubricating oil composition containing a base oil, a neutral phosphorus compound, an acidic phosphorus compound and a sulfur compound.

The present invention includes the following inventions.

[1] A lubricating oil composition comprising a lubricating base oil (A), a neutral phosphorus compound (B), an acidic phosphorus compound (C), a sulfur compound (D), and a secondary amine compound (E), wherein the lubricating oil composition has a flash point of 172 ℃ or higher.

[2] The lubricating oil composition according to [1], wherein the secondary amine compound (E) is a compound represented by the following formula (1).

[ solution 1]

(in the formula, R¹And R²Each independently represents an optionally substituted alkyl group having 1 to 18 carbon atoms or an optionally substituted alkenyl group having 2 to 18 carbon atoms. )

[3] The lubricating oil composition according to [2], wherein,

R¹and R²Each independently is a group represented by the following formula (2).

-(CH₂)n-OH (2)

(wherein n is an integer of 1 to 8.)

[4] A mechanical device comprising the lubricating oil composition according to any one of [1] to [3 ].

[5] A method for producing a lubricating oil composition, which comprises a step of mixing a lubricating base oil (A), a neutral phosphorus compound (B), an acidic phosphorus compound (C), a sulfur compound (D), and a secondary amine compound (E), wherein the lubricating oil composition has a flash point of 172 ℃ or higher.

Effects of the invention

The lubricating oil composition according to one embodiment of the present invention exhibits excellent properties in all of wear resistance, seizure resistance, and low friction properties. In addition, the lubricating oil composition according to one embodiment of the present invention has excellent cooling performance.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail. The present invention is not limited to the following embodiments, and can be implemented by being arbitrarily modified within a range not departing from the gist thereof. All documents and publications mentioned in the present specification are incorporated herein by reference in their entirety, regardless of the purpose.

The lubricating oil composition of the present invention comprises a lubricating base oil (a), a neutral phosphorus compound (B), an acidic phosphorus compound (C), a sulfur compound (D), and a secondary amine compound (E). Hereinafter, each component contained in the lubricating oil composition will be described in detail.

[ lubricating base oil (A) ]

The lubricating base oil (a) (hereinafter, also simply referred to as "base oil") contained in the lubricating oil composition is not particularly limited as long as it is an oil having lubricity, and may be a mineral oil or a synthetic oil. The type of these lubricant base oils is not particularly limited, and any base oil can be appropriately selected from mineral oils and synthetic oils conventionally used as base oils for lubricants for automobile transmissions.

Examples of the mineral oil include: subjecting crude oil to atmospheric distillation to obtain atmospheric residue, subjecting the obtained atmospheric residue to vacuum distillation to obtain lubricating oil fraction, and subjecting the obtained lubricating oil fraction to solvent deasphalting, solvent extraction, hydrocracking, solvent dewaxing, contact dewaxing, and hydrogenationMineral oil obtained by refining by 1 or more of refining and the like, mineral oil produced by isomerizing WAX, GTL WAX (Gas To Liquids WAX), and the like. Among them, from% C described later_PFrom the viewpoint of viscosity index, a mineral oil treated by hydrorefining or a mineral oil produced by isomerizing GTLWAX is preferable.

Examples of the synthetic oil include polybutene, poly α -olefin such as α -olefin homopolymer and α -olefin copolymer (e.g., ethylene- α -olefin copolymer), various esters such as polyol ester, dibasic acid ester and phosphoric acid ester, various ethers such as polyphenyl ether, polyglycol, alkylbenzene and alkylnaphthalene, among which poly α -olefin and ester are preferable, and these synthetic oils may be used alone or in combination of 2 or more.

The base oil may contain 1 kind of mineral oil, or may contain 2 or more kinds of mineral oils. Further, 1 kind of synthetic oil may be used as the base oil, or 2 or more kinds of synthetic oils may be used in combination. The base oil may contain 1 or more kinds of mineral oils and 1 or more kinds of synthetic oils.

The base oil is a main component of the lubricating oil composition, and the content of the base oil is preferably 65 to 97% by mass, more preferably 70 to 96% by mass, and still more preferably 75 to 95% by mass, based on the total amount of the composition.

The flash point of the lubricating base oil (a) is not particularly limited, but it is preferable to use a lubricating base oil having a high flash point because the flash point of the resulting lubricating oil composition tends to be high. Specifically, the lubricating base oil (A) preferably has a flash point of 172 ℃ or higher, more preferably 174 ℃ or higher, and particularly preferably 176 ℃ or higher. When the lubricating base oil (a) contains a plurality of mineral oils, synthetic oils, or the like, it is not necessary that all of the mineral oils, synthetic oils, or the like have a flash point of 172 ℃ or higher, and the lubricating base oil (a) obtained by mixing them may have a flash point of 172 ℃ or higher.

The viscosity of the base oil is not particularly limited, and varies depending on the use of the lubricating oil composition, but the kinematic viscosity at a temperature of 100 ℃ is not particularly limitedThe preferred degree is 2-30 mm²(ii) s, more preferably 2 to 15mm²(ii) s, more preferably 2 to 10mm²And s. If the kinematic viscosity at 100 ℃ is 2mm²When the concentration is more than or equal to 30mm, the evaporation loss is small²When the viscosity resistance is less than s, the power loss due to the viscous resistance is small, and the effect of improving the fuel consumption can be obtained.

The kinematic viscosity of the base oil at 40 ℃ is not particularly limited, but is preferably 5 to 65mm²(ii) s, more preferably 8 to 40mm²(ii) s, more preferably 10 to 25mm²And s. If the kinematic viscosity at 40 ℃ is 5mm²When the concentration is 65mm or more, the evaporation loss is small²When the viscosity resistance is less than s, the power loss due to the viscous resistance is small, and the effect of improving the fuel consumption can be obtained.

In the present specification, "kinematic viscosity at 100 ℃ and" kinematic viscosity at 40 ℃ "can be determined by methods based on JIS-K-2283: 2000, respectively. When the lubricating base oil (a) contains 2 or more oils, "kinematic viscosity at 100 ℃ and" kinematic viscosity at 40 ℃ "refer to the kinematic viscosity of the entire mixed base oil.

The viscosity index of the base oil is not particularly limited, but is preferably 70 or more, more preferably 80 or more, and further preferably 90 or more. The base oil having a viscosity index of 70 or more has a small change in viscosity due to a change in temperature. By setting the viscosity index of the base oil in this range, the viscosity characteristics of the lubricating oil composition can be easily improved, and the effect of improving the oil consumption can be obtained. In the present specification, the "viscosity index" can be determined by a method based on JIS-K-2283: 2000, respectively.

Aromatic component (% C) of base oil based on ring analysis_A) The content of sulfur and sulfur components is not particularly limited, but% C is preferably used_A3.0 or less and a sulfur content of 10 mass ppm or less. Here,% C based on Ring analysis_AThe ratio (percentage) of the aromatic component is calculated by a ring analysis n-D-M method measured in accordance with ASTM D3238. The% C_AA base oil having a sulfur content of 10 ppm by mass or less and 3.0 or less can provide a base oil having good oxidation propertiesStability, and inhibition of increase in acid value and formation of residue. More preferably% C_AIs 1.0 or less, and more preferably 0.5 or less. The sulfur content is more preferably 7 mass ppm or less, and still more preferably 5 mass ppm or less.

Paraffin composition (% C) based on ring analysis of base oils_P) The amount is not particularly limited, but is preferably 70 or more, more preferably 75 or more, and still more preferably 79 or more. By bringing the% C_PThe oxidation stability of the base oil becomes good at 70 or more. The upper limit is not particularly limited, but is, for example, 98 or less. Here,% C based on Ring analysis_PThe paraffin component ratio (percentage) is calculated by a ring analysis n-D-M method measured in accordance with ASTM D3238.

The NOACK evaporation amount of the base oil is not particularly limited, but is preferably 15.0 mass% or less, more preferably 14.0 mass% or less, and still more preferably 13.0 mass% or less. The NOACK evaporation can be measured according to ASTM D5800 (250 ℃ C., 1 hour).

[ neutral phosphorus Compound (B) ]

The neutral phosphorus compound (B) is added for the purpose of improving the intermetallic wear resistance. If the neutral phosphorus compound (B) is not used, the intermetallic wear resistance cannot be improved.

The neutral phosphorus-based compound (B) is not particularly limited as long as it is neutral and contains a phosphorus atom, but a compound represented by the following general formula (3) or (4) is preferably used.

[ solution 2]

In the above general formulae (3) and (4), R is³、R⁴And R⁵The hydrocarbon group (C) may be an aryl group having 6 to 30 carbon atoms, an alkyl group having 1 to 30 carbon atoms or an alkenyl group having 2 to 30 carbon atoms, and preferably an aryl group having 8 to 28 carbon atoms or an alkyl group having 2 to 28 carbon atomsThe aryl group has 4 to 28 carbon atoms, preferably an aryl group having 10 to 26 carbon atoms, an alkyl group having 4 to 26 carbon atoms, and an alkenyl group having 6 to 26 carbon atoms, and particularly preferably an aryl group having 12 to 24 carbon atoms, an alkyl group having 6 to 24 carbon atoms, and an alkenyl group having 6 to 24 carbon atoms. R³、R⁴And R⁵May be the same or different.

Examples of the neutral phosphorus-based compound (B) include: aromatic neutral phosphate esters such as tricresyl phosphate, triphenyl phosphate, trixylenyl phosphate, tritolylphenyl phosphate, tricresyl thiophosphate, and triphenyl thiophosphate; aliphatic neutral phosphoric acid esters such as tributyl phosphate, tri (2-ethylhexyl) phosphate, tributyl phosphate, and tributyl thiophosphate; aromatic neutral phosphites such as triphenyl phosphite, tricresyl phosphite, trisnonylphenyl phosphite, diphenylmono-2-ethylhexyl phosphite, diphenylmonotridecyl phosphite, tricresyl thiophosphite, and triphenyl thiophosphite; aliphatic neutral phosphites such as tributyl phosphite, trioctyl phosphite, tridecyl phosphite, tris (tridecyl) phosphite, triolefinyl phosphite, tributyl thiophosphite, and trioctyl thiophosphite. Among these neutral phosphorus compounds, aromatic neutral phosphate esters, aliphatic neutral phosphate esters, and the like are preferably used from the viewpoint of the intermetallic wear resistance. These neutral phosphorus compounds may be used alone or in combination of 2 or more.

The content of the neutral phosphorus compound (B) in the lubricating oil composition is preferably 2.5% by mass or less, more preferably 0.12% by mass or more and 2.5% by mass or less, and particularly preferably 0.25% by mass or more and 1.3% by mass or less, based on the total amount of the composition. When the content of the phosphorus-based compound (B) is 0.12% by mass or more based on the total amount of the composition, the intermetallic wear resistance in the lubricating oil composition can be further improved. When the content of the neutral phosphorus-based compound (B) is 2.5% by mass or less based on the total amount of the composition, the solubility of the neutral phosphorus-based compound (B) in the lubricant base oil can be improved. The amount of phosphorus derived from the neutral phosphorus compound (B) is preferably 2000 mass ppm or less, more preferably 100 mass ppm or more and 2000 mass ppm or less, and particularly preferably 200 mass ppm or more and 1000 mass ppm or less, in terms of the amount of phosphorus calculated based on the total amount of the composition. When the content of the neutral phosphorus compound (B) is 2000 mass ppm or less in terms of phosphorus amount based on the total amount of the composition, the solubility of the neutral phosphorus compound (B) in the lubricant base oil can be improved. If the content of the neutral phosphorus compound (B) is 100 mass ppm or more in terms of phosphorus when the total amount of the composition is taken as a reference, the intermetallic wear resistance in the lubricating oil composition can be further improved. Here, the phosphorus content was measured in accordance with JPI-5S-38-92.

[ acid phosphorus-based Compound (C) ]

The acidic phosphorus compound (C) is added for the purpose of improving the seizure resistance. If the acidic phosphorus compound (C) is not used, the seizure resistance may not be improved.

The acidic phosphorus-based compound (C) is not particularly limited as long as it is acidic and contains a phosphorus atom, but is preferably at least one acidic phosphorus-based compound selected from the group consisting of an acidic phosphate represented by the following general formula (5) and an acidic phosphite represented by the following general formula (6).

[ solution 3]

In the above general formula (5) and the above general formula (6), R⁶And R⁷Represents hydrogen or a C8-30 hydrocarbon group. In addition, R⁶And R⁷May be the same or different. In addition, R⁶And R⁷At least one of the alkyl groups is a C8-30 alkyl group, preferably both alkyl groups are C8-30 alkyl groups, more preferably 10-28 alkyl groups, and particularly preferably 12-26 alkyl groups. By making the carbon number of the hydrocarbon group be 8 or more, the oxidation stability of the lubricating oil composition is improvedOn the other hand, when the number of carbon atoms in the hydrocarbon group is 30 or less, the intermetallic wear resistance becomes sufficient. In addition, as R⁶And R⁷Examples of the hydrocarbon group in (3) include an alkyl group, an alkenyl group, an aryl group, an alkylaryl group, and an arylalkyl group.

Examples of the acidic phosphate ester represented by the general formula (5) and amine salts thereof include aliphatic acidic phosphate esters such as acidic di-2-ethylhexyl phosphate, acidic dilauryl phosphate, and acidic dioleyl phosphate; aromatic acidic phosphates such as acidic diphenyl phosphate and acidic ditolyl phosphate; sulfur-containing acidic phosphate esters such as S-octylthioethyl acid phosphate and S-dodecylthioethyl acid phosphate, and the like. These acidic phosphoric acid esters and amine salts thereof may be used alone, or 2 or more of them may be used in combination.

Examples of the acid phosphite represented by the above general formula (6) and amine salts thereof include aliphatic acid phosphites such as dibutyl hydrogen phosphite, di-2-ethylhexyl hydrogen phosphite, dilauryl hydrogen phosphite, and dioleyl hydrogen phosphite; aromatic acid phosphites such as diphenyl hydrogen phosphite and ditolyl hydrogen phosphite; sulfur-containing acidic phosphites such as S-octylthioethyl hydrogen phosphite and S-dodecylthioethyl hydrogen phosphite. In addition, these acidic phosphites may be contained in the lubricating oil composition in the form of an amine salt thereof. These acidic phosphites and their amine salts may be used alone or in combination of 2 or more.

The content of the acidic phosphorus compound (C) in the lubricating oil composition is preferably 0.8% by mass or less, more preferably 0.1% by mass or more and 0.8% by mass or less, and particularly preferably 0.1% by mass or more and 0.5% by mass or less, based on the total amount of the composition. When the content of the acidic phosphorus compound (C) is 0.8% by mass or less based on the total amount of the composition, the volume resistivity of the lubricating oil composition can be made sufficient. Further, when the content of the acidic phosphorus compound (C) is 0.1% by mass or more based on the total amount of the composition, the intermetallic wear resistance in the lubricating oil composition can be further improved. The amount of phosphorus derived from the acidic phosphorus compound (C) is preferably 400 mass ppm or less, more preferably 50 mass ppm or more and 400 mass ppm or less, and particularly preferably 50 mass ppm or more and 250 mass ppm or less, in terms of the amount of phosphorus calculated on the basis of the total amount of the composition. If the amount of phosphorus derived from the acidic phosphorus compound (C) is 400 ppm by mass or less in terms of the amount of phosphorus when the total amount of the composition is taken as a reference, the volume resistivity of the lubricating oil composition can be made sufficient. Further, if the amount of phosphorus derived from the acidic phosphorus compound (C) is 50 mass ppm or more in terms of the amount of phosphorus based on the total amount of the composition, the intermetallic wear resistance of the lubricating oil composition can be further improved. Here, the phosphorus content was measured in accordance with JPI-5S-38-92.

[ Sulfur-based Compound (D) ]

The sulfur-based compound (D) is added for the purpose of improving seizure resistance. If the sulfur-based compound (D) is not used, the seizure resistance may not be improved.

The sulfur-based compound (D) is not particularly limited as long as it is a compound containing a sulfur atom. As the sulfur-based compound (D), known compounds can be used, and specific examples thereof include thiadiazole-based compounds, polysulfide-based compounds, thiourethane-based compounds, thiogrease-based compounds, and thioolefin-based compounds. Among these sulfur-based compounds, thiadiazole-based compounds and polysulfide-based compounds are preferable from the viewpoint of the seizure resistance of metals and the wear resistance between metals. These sulfur compounds may be used alone, or 2 or more kinds may be used in combination.

As the thiadiazole compound, known compounds can be suitably used, and examples thereof include compounds represented by the following general formula (7).

[ solution 4]

In the above general formula (7), R⁹And R¹⁰Each represents an alkyl group having 1 to 30 carbon atoms, preferably an alkyl group having 6 to 20 carbon atoms, and more preferably an alkyl group having 8 to 18 carbon atoms. The alkyl group may be linear or branched. In addition, R⁹And R¹⁰May be the same or different. X1 and X2 each represent an integer of 1 to 3 and the number of sulfur atoms, and it is preferable to use a compound having a sulfur number of 2. The thiadiazole compound represented by the general formula (7) is preferably 2, 5-bis (n-hexyldithio) -1, 3, 4-thiadiazole, 2, 5-bis (n-octyldithio) -1, 3, 4-thiadiazole, 2, 5-bis (n-nonyldithio) -1, 3, 4-thiadiazole, 2, 5-bis (1, 1, 3, 3-tetramethylbutyldithio) -1, 3, 4-thiadiazole, 3, 5-bis (n-hexyldithio) -1, 2, 4-thiadiazole, 3, 6-bis (n-octyldithio) -1, 2, 4-thiadiazole, 3, 5-bis (n-nonyldithio) -1, 2, 4-thiadiazole, 3, 5-bis (1, 1, 3, 3-tetramethylbutyldithio) -1, 2, 4-thiadiazole, 4, 5-bis (n-octyldithio) -1, 2, 3-thiadiazole, 4, 5-bis (n-nonyldithio) -1, 2, 3-thiadiazole, and 4, 5-bis (1, 1, 3, 3-tetramethylbutyldithio) -1, 2, 3-thiadiazole, more preferably 2, 5-bis (n-hexyldithio) -1, 3, 4-thiadiazole, 2, 5-bis (n-octyldithio) -1, 3, 4-thiadiazole, 2, 5-bis (n-nonyldithio) -1, 3, 4-thiadiazole, 2, 5-bis (1, 1, 3, 3-tetramethylbutyldithio) -1, 3, 4-thiadiazole, particularly preferably 2, 5-bis (1, 1, 3, 3-tetramethylbutyldithio) -1, 3, 4-thiadiazole.

As the polysulfide-based compound, known compounds can be suitably used, and examples thereof include compounds represented by the following general formula (8).

R¹¹-(S)_Y-R¹²…(8)

In the above general formula (8), R¹¹And R¹²Each represents an alkyl group having 1 to 24 carbon atoms, an aryl group having 3 to 20 carbon atoms, or an alkylaryl group having 7 to 20 carbon atoms, and the alkyl group is preferably 3 or more and 20 or less, more preferably 6 or more and 16 or less. The aryl group is preferably a group of 4 to 20 inclusive, more preferably 6 to 16 inclusive. The alkylaryl group is preferably a group of 8 to 20 inclusive, and more preferably a group of 9 to 18 inclusive. In addition, R¹¹And R¹²May be the same or different. Y represents the number of sulfur atoms, considering the resistanceAbrasion resistance, fatigue life, acquisition ease, corrosion, and the like, Y is preferably an integer of 2 or more and 8 or less, more preferably an integer of 2 or more and 7 or less, and further preferably an integer of 2 or more and 6 or less. As R¹¹And R¹²Examples of the group include aryl groups such as phenyl, naphthyl, benzyl, tolyl, and xylyl; and alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, cyclohexyl, and cyclooctyl. These groups may be linear or branched. These groups may be used alone or in combination of 2 or more. Among the polysulfide-based compounds represented by the above general formula (6), dibenzyl polysulfide, di-tert-nonyl polysulfide, di-dodecyl polysulfide, di-tert-butyl polysulfide, dioctyl polysulfide, diphenyl polysulfide, dicyclohexyl polysulfide and the like are more preferable, and their disulfides are particularly preferable.

The content of the sulfur-based compound (D) in the lubricating oil composition is preferably 0.3% by mass or less, more preferably 0.03% by mass or more and 0.3% by mass or less, and particularly preferably 0.03% by mass or more and 0.15% by mass or less, based on the total amount of the composition. When the content of the sulfur-based compound (D) is 0.3% by mass or less based on the total amount of the composition, the volume resistivity of the lubricating oil composition can be expected to be maintained. When the content of the sulfur-based compound (D) is 0.03% by mass or more based on the total amount of the composition, the intermetallic seizure resistance in the lubricating oil composition can be further improved. The amount of sulfur derived from the sulfur-based compound (D) is preferably 1000 mass ppm or less, more preferably 125 mass ppm or more and 1000 mass ppm or less, and particularly preferably 125 mass ppm or more and 500 mass ppm or less, from the viewpoint of satisfying both the volume resistivity and seizure resistance of the lubricating oil composition. If the amount of sulfur derived from the sulfur-based compound (D) is 1000 mass ppm or less in terms of the amount of sulfur based on the total amount of the composition, the volume resistivity of the lubricating oil composition can be expected to be maintained. If the amount of sulfur derived from the sulfur-based compound (D) is 125 mass ppm or more in terms of the amount of sulfur based on the total amount of the composition, the intermetallic seizure resistance in the lubricating oil composition can be further improved. Here, the sulfur content was measured according to JIS K2501.

[ Secondary amine Compound (E) ]

The lubricating oil composition is characterized by containing a lubricating base oil (A), a neutral phosphorus compound (B), an acidic phosphorus compound (C), a sulfur compound (D), and a secondary amine compound (E). Thus, the lubricating oil composition can realize seizure resistance and wear resistance, and can realize low friction properties. If the secondary amine compound (E) is not used, low friction properties may not be achieved.

The secondary amine compound (E) contained in the lubricating oil composition is not particularly limited as long as it is a compound having a secondary amine structure. The secondary amine compound (E) preferably has the structure of formula (1). R in the formula (1)¹And R²Each independently represents an alkyl group having 1 to 18 carbon atoms which may be substituted or an alkenyl group having 2 to 18 carbon atoms which may be substituted, preferably an alkyl group having 1 to 14 carbon atoms which may be substituted or an alkenyl group having 2 to 14 carbon atoms which may be substituted, more preferably an alkyl group having 1 to 8 carbon atoms which may be substituted or an alkenyl group having 2 to 8 carbon atoms which may be substituted, and particularly preferably an alkyl group having 1 to 4 carbon atoms which may be substituted or an alkenyl group having 2 to 4 carbon atoms which may be substituted. These alkyl groups and alkenyl groups may be linear or branched. Examples of the substituent that the alkyl group and the alkenyl group may have include a hydroxyl group, an ester group, a carboxyl group, an amide group, an alkynyl group, a trimethylsilyl group, a trimethylsilylethynyl group, an aryl group, an amino group, a phosphoryl group, a thio group, a carbonyl group, a nitro group, a sulfo group, an imino group, a halogenated group, an alkoxy group, a halogen atom (for example, fluorine, chlorine, bromine, iodine) or a silyl group, and the hydroxyl group, the ester group, the carboxyl group, the amide group, the aryl group and the amino group are preferable, the hydroxyl group is more preferable, and the hydroxyl group is particularly. The number of substituents may be 1 or more, preferably 1 to 4, at the position where substitution can occur. When the number of substituents is 2 or more, the substituents may be the same or different from each other.

In addition, R in the formula (1)¹And R²A group represented by the formula (2) is preferred. In the formula (2), n is an integer of 1 to 8, preferably an integer of 1 to 6, and more preferably an integer of 1 to 3.

The content of the secondary amine compound (E) in the lubricating oil composition is preferably 0.01 mass% or more and 0.5 mass% or less, more preferably 0.03 mass% or more and 0.4 mass% or less, and particularly preferably 0.07 mass% or more and 0.3 mass% or less, based on the total amount of the lubricating oil composition, from the viewpoint of achieving low friction of the lubricating oil composition.

[ additives ]

The lubricating oil composition may be used by appropriately blending a viscosity index improver, a dispersant, an antioxidant, a metal deactivator, a rust inhibitor, a surfactant/demulsifier, an antifoaming agent, an anticorrosive agent, an oiliness agent, an acid scavenger, and the like, within a range not to impair the effects of the present invention.

Examples of the viscosity index improver include non-dispersible polymethacrylate, olefin copolymers, dispersible olefin copolymers, styrene copolymers, and the like. The mass average molecular weight of these viscosity index improvers is preferably 5000 to 300000, for example, in the case of a dispersion-type polymethacrylate and a non-dispersion-type polymethacrylate. The olefin copolymer is preferably 800 or more and 100000 or less. These can be used alone in 1 kind, also can be combined with more than 2 kinds. The amount of the viscosity index improver to be blended is not particularly limited, but is preferably 0.5% by mass or more and 15% by mass or less, and more preferably 1% by mass or more and 10% by mass or less, based on the total amount of the composition.

As the clean dispersant, an ashless dispersant or a metal sulfate dispersant can be used.

Examples of the ashless dispersant include a succinimide compound, a boron imide compound, a mannich (マンニツヒ) -based dispersant, and an acid amide-based compound. These can be used alone in 1 kind, also can be combined with more than 2 kinds. The blending amount of the ashless dispersant is not particularly limited, but is preferably 0.1 mass% or more and 20 mass% or less based on the total amount of the composition.

Examples of the metal based cleaning dispersant include alkali metal sulfonates, alkali metal phenates, alkali metal salicylates, alkali metal naphthenates, alkaline earth metal sulfonates, alkaline earth metal phenates, alkaline earth metal salicylates, and alkaline earth metal naphthenates. These can be used alone in 1 kind, also can be combined with more than 2 kinds. The amount of the metal sulfate dispersant is not particularly limited, but is preferably 0.1 mass% or more and 10 mass% or less based on the total amount of the composition.

Examples of the antioxidant include amine-based antioxidants, phenol-based antioxidants, and sulfur-based antioxidants. These can be used alone in 1 kind, also can be combined with more than 2 kinds. The amount of the antioxidant to be blended is not particularly limited, but is preferably 0.05% by mass or more and 7% by mass or less based on the total amount of the composition.

Examples of the pour point depressant include polymethacrylates, ethylene-vinyl acetate copolymers, condensates of chloroalkanes and naphthalenes, condensates of chloroalkanes and phenols, polyalkylstyrenes, and poly (meth) acrylates. The mass average molecular weight (Mw) of the pour point depressant is preferably 20000 to 100000, more preferably 30000 to 80000, and still more preferably 40000 to 60000. The molecular weight distribution (Mw/Mn) is preferably 5 or less, more preferably 3 or less, and still more preferably 2 or less. The content of the pour point depressant may be determined as appropriate depending on the desired MRV viscosity or the like, and is preferably 0.01 mass% or more and 5 mass% or less, and more preferably 0.02 mass% or more and 2 mass% or less, based on the total amount of the composition.

Examples of the metal deactivators include benzotriazole-based metal deactivators, tolyltriazole-based metal deactivators, thiadiazole-based metal deactivators, and imidazole-based metal deactivators. These can be used alone in 1 kind, also can be combined with more than 2 kinds. The amount of the metal deactivator is not particularly limited, but is preferably 0.01 mass% or more and 3 mass% or less, and more preferably 0.01 mass% or more and 1 mass% or less, based on the total amount of the composition.

Examples of the rust inhibitor include petroleum sulfonate, alkylbenzene sulfonate, dinonylnaphthalene sulfonate, alkenyl succinate, and polyol ester. These can be used alone in 1 kind, also can be combined with more than 2 kinds. The amount of the rust inhibitor to be blended is not particularly limited, but is preferably 0.01 mass% or more and 1 mass% or less, and more preferably 0.05 mass% or more and 0.5 mass% or less, based on the total amount of the composition.

Examples of the surfactant/demulsifier include polyalkylene glycol-based nonionic surfactants. Specific examples thereof include polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether and polyoxyethylene alkyl naphthyl ether. These can be used alone in 1 kind, also can be combined with more than 2 kinds. The amount of the surfactant to be blended is not particularly limited, but is preferably 0.01 mass% or more and 3 mass% or less, and more preferably 0.01 mass% or more and 1 mass% or less, based on the total amount of the composition.

Examples of the defoaming agent include fluorosilicone oil and fluoroalkyl ether. These can be used alone in 1 kind, also can be combined with more than 2 kinds. The amount of the defoaming agent is not particularly limited, but is preferably 0.005 mass% or more and 0.5 mass% or less, and more preferably 0.01 mass% or more and 0.2 mass% or less, based on the total amount of the composition.

Examples of the anticorrosive include benzotriazole anticorrosive, benzimidazole anticorrosive, benzothiazole anticorrosive, and thiadiazole anticorrosive. These can be used alone in 1 kind, also can be combined with more than 2 kinds. The amount of the anticorrosive agent to be added is not particularly limited, but is preferably in the range of 0.01 mass% to 1 mass% based on the total amount of the composition.

Examples of the oily agent include aliphatic monocarboxylic acids, polymerized fatty acids, hydroxy fatty acids, aliphatic monoalcohols, aliphatic monoamines, aliphatic monocarboxamides, and partial esters of polyhydric alcohols and aliphatic monocarboxylic acids. These can be used alone in 1 kind, also can be combined with more than 2 kinds. The amount of the oily agent to be blended is not particularly limited, but is preferably in the range of 0.01 mass% to 10 mass% based on the total amount of the composition.

Specifically, there may be used 1 kind or more of phenyl glycidyl ether, alkyl glycidyl ether, alkylene glycol glycidyl ether, cyclohexene oxide, α -olefin oxide, and epoxidized soybean oil, and the amount of the acid scavenger is not particularly limited, but is preferably in the range of 0.005 mass% or more and 5 mass% or less based on the total amount of the composition.

[ Properties of lubricating oil composition, etc. ]

The kinematic viscosity of the lubricating oil composition can be determined by the following method based on JIS-K-2283: 2000, respectively.

The kinematic viscosity at 100 ℃ of the lubricating oil composition is preferably 14.0mm from the viewpoint of improving the lubricating performance, viscosity characteristics and fuel economy²Less than s, more preferably 12.5mm²A thickness of 10.0mm or less is more preferable²A value of not more than s, preferably 2.0mm²(ii) at least s, more preferably 2.2mm²At least s, more preferably 2.5mm²More than s.

The kinematic viscosity at 40 ℃ of the lubricating oil composition is preferably 80.0mm from the viewpoint of improving the lubricating performance, viscosity characteristics and fuel economy²Less than s, more preferably 70.0mm²A thickness of 65.0mm or less is more preferable²A thickness of 5.0mm or less is preferred²(ii) at least s, more preferably 7.0mm²At least s, more preferably 10.0mm²More than s.

The viscosity index of the lubricating oil composition can be determined by using a viscosity index based on JIS-K-2283: 2000, respectively. The viscosity Index (Vscosity Index) of the lubricating oil composition can suppress a change in viscosity due to a change in temperature, and is preferably 90 or more, more preferably 100 or more, and even more preferably 103 or more, from the viewpoint of improving the fuel economy.

[ flash Point ]

If the flash point of the lubricating oil composition is less than 172 ℃, the ability to cool a machine using the lubricating oil composition may be reduced. In order to increase the flash point of the lubricating oil composition, for example, it can be achieved by using oils having high flash points as the respective oils constituting the lubricating base oil (a).

The flash point of the lubricating oil composition is 172 ℃ or higher, preferably 174 ℃ or higher, and more preferably 176 ℃ or higher.

[ uses of lubricating oil compositions ]

The lubricating oil composition of the present invention has a flash point within a predetermined range and can exhibit lubricity (wear resistance, seizure resistance, and low friction). Therefore, the present invention is preferably applied to mechanical devices such as hydraulic devices, fixed transmissions, automobile transmissions, and cooling devices for electric motor batteries.

[ method for producing lubricating oil composition ]

The method for producing the lubricating oil composition of the present invention is not particularly limited. The lubricating base oil (a), the neutral phosphorus compound (B), the acidic phosphorus compound (C), the sulfur compound (D), and the secondary amine compound (E) may be blended by any method, and the mode is not limited.

[ mechanical means ]

The lubricating oil composition can improve the lubricity of mechanical devices and can be used for mechanical devices such as hydraulic devices, fixed transmissions, automobile transmissions, and cooling devices for electric motor batteries. For example, the lubricating oil composition can be used for an electric motor mounted on a hybrid vehicle, an electric vehicle, or the like, an engine mounted on a diesel engine or a gasoline engine, a transmission machine such as an automobile, or the like. Particularly, the present invention is preferably used for a transmission machine mounted on a hybrid vehicle, an electric vehicle, or the like.