JP7296711B2 - Lubricating oil composition, mechanical device provided with lubricating oil composition, and method for producing lubricating oil composition - Google Patents

Description

The present invention relates to a lubricating oil composition, a mechanical device comprising the lubricating oil composition, and a method for producing the lubricating oil composition.

In recent years, there has been a strong demand for reducing carbon dioxide from the viewpoint of protecting the global environment. Fuel-saving vehicles include hybrid vehicles and electric vehicles, and these vehicles are expected to spread rapidly in the future. Hybrid vehicles and electric vehicles are equipped with electric motors, generators, inverters, storage batteries, etc., and run using the power of the electric motors.
Existing automatic transmission fluids (hereinafter ATF) and continuously variable transmission fluids (hereinafter CVTF) are mainly used to cool electric motors and generators in such hybrid vehicles and electric vehicles. In addition, since some hybrid vehicles and electric vehicles have gear reduction gears, lubricating oil compositions are required to have both cooling properties and lubricating properties.

Therefore, at least one acidic phosphorus-based compound selected from the group consisting of a base oil, a neutral phosphorus-based compound, an acidic phosphoric ester amine salt having a predetermined structure and an acidic phosphite having a predetermined structure, and a sulfur-based A lubricating oil composition containing a compound has been proposed (Patent Document 1: WO11/080970).

WO11/080970

However, in the lubricating oil composition described in Patent Document 1, although the volume resistivity, wear resistance and solubility between metals are improved, wear resistance, seizure resistance and low friction at a higher level There is a demand for a lubricating oil composition that satisfies all of There is also a demand for a lubricating oil composition with even higher cooling performance.

Therefore, the inventors of the present invention solved the problem of the present invention by further blending an organic molybdenum compound into a lubricating oil composition containing a base oil, a neutral phosphorus compound, an acidic phosphorus compound and a sulfur compound. Resolved.

The present invention includes inventions of the following aspects.
[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 an organomolybdenum compound (E).
[2]
A mechanical device comprising the lubricating oil composition according to [1].
[3]
Lubricating oil composition comprising a step of mixing a lubricating base oil (A), a neutral phosphorus compound (B), an acidic phosphorus compound (C), a sulfur compound (D) and an organic molybdenum compound (E) Production method.

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

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail. It should be noted that the present invention is not limited to the following embodiments, and can be arbitrarily modified without departing from the gist of the present invention. All documents and publications mentioned herein are hereby incorporated by reference in their entirety for any 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 an organic molybdenum compound (E). .
Total content of lubricating base oil (A), neutral phosphorus compound (B), acidic phosphorus compound (C), sulfur compound (D) and organic molybdenum compound (E) in the lubricating oil composition of the present invention The amount is preferably 70% by mass or more, more preferably 80% by mass or more, still more preferably 85% by mass or more, and even more preferably 90% by mass or more, based on the total amount of the composition.
Each component contained in the lubricating oil composition will be described in detail below.

[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 has lubricating properties, and may be mineral oil or synthetic oil. There are no particular restrictions on the types of these base oils, and any of mineral oils and synthetic oils conventionally used as base oils for lubricating oils for automotive transmissions can be appropriately selected and used.
As the mineral oil, for example, the lubricating oil fraction obtained by vacuum distillation of the atmospheric residue obtained by atmospheric distillation of crude oil is subjected to solvent deasphalting, solvent extraction, hydrocracking, solvent dewaxing, catalytic deasphalting. Refined mineral oil or wax refined by one or more treatments such as wax and hydrorefining, and GTL WAX (gas-to-liquid wax) produced from natural gas by the Fischer-Tropsch process or the like are isomerized. and mineral oil (GTL) produced by Of these, refined mineral oil treated by hydrorefining and mineral oil (GTL) produced by isomerizing GTL WAX are preferable from the viewpoint of %C _P and viscosity index, which will be described later.
Synthetic oils include, for example, polybutene; poly-α-olefins such as α-olefin homopolymers and α-olefin copolymers (e.g., ethylene-α-olefin copolymers); polyol esters, dibasic acid esters, phosphorus Various esters such as acid esters; various ethers such as polyphenyl ether; polyglycol; alkylbenzene; alkylnaphthalene, and the like. Among these synthetic oils, poly-α-olefins and esters are preferred. These synthetic oils may be used alone or in combination of two or more.
In addition, the base oil may contain one kind of mineral oil or two or more kinds thereof. As the base oil, one type of synthetic oil may be used, or two or more types may be used in combination. Additionally, the base oil may comprise one or more mineral oils and one or more synthetic oils.

The base oil is the main component of the lubricating oil composition, and the content of the base oil is usually based on the total amount of the composition, preferably 65 to 98% by mass, more preferably 70 to 97% by mass, more preferably 75 to 96% by mass.

The flash point of the lubricating base oil (A) is not limited, but it is preferable to use a base oil with a high flash point, since the resulting lubricating oil composition tends to have a high flash point. Specifically, the flash point of the lubricating base oil (A) is preferably 172°C or higher, more preferably 174°C or higher, and particularly preferably 176°C or higher. When the lubricating base oil (A) contains a plurality of mineral oils or synthetic oils, etc., it is not necessary that all of these mineral oils or synthetic oils have a flash point of 172 ° C. or higher, and lubrication obtained by mixing them A flash point of 172° C. or higher is sufficient for the volatile base oil (A).
In this specification, the flash point is based on JIS-K-2265-4, C.I. O. It means the value measured by C method.

The viscosity of the base oil is not particularly limited and varies depending on the application of the lubricating oil composition, but the kinematic viscosity at a temperature of 100° C. is preferably 21 to 30 mm ² /s, more preferably 21.5 to 15 mm ² /s. , more preferably 2 to 10 mm ² /s. If the kinematic viscosity at 100° C. is 2 mm ² /s or more, the evaporation loss is small, and if it is 30 mm ² /s or less, the power loss due to viscous resistance is small and the effect of improving fuel efficiency is obtained.
The kinematic viscosity of the base oil at 40° C. is not particularly limited, but is preferably 5 to 65 mm ² /s, more preferably 8 to 40 mm ² /s, still more preferably 10 to 25 mm ² /s. If the kinematic viscosity at 40° C. is 5 mm ² /s or more, the evaporation loss is small, and if it is 65 mm ² /s or less, the power loss due to viscous resistance is small and the effect of improving fuel efficiency is obtained.
As used herein, the “kinematic viscosity at 100° C.” and the “kinematic viscosity at 40° C.” can be measured according to JIS-K-2283:2000. When the lubricating base oil (A) contains two or more types of oils, the "kinematic viscosity at 100°C" and the "kinematic viscosity at 40°C" mean the kinematic viscosity of the entire mixed base oil.
Furthermore, the viscosity index of the base oil is not particularly limited, but is preferably 70 or higher, more preferably 80 or higher, and even more preferably 90 or higher. A base oil having a viscosity index of 70 or more has a small change in viscosity due to a change in temperature. When the viscosity index of the base oil is in this range, the viscosity characteristics of the lubricating oil composition can be easily improved, and the effect of improving fuel efficiency can be obtained. As used herein, the "viscosity index" can be calculated by a method conforming to JIS-K-2283:2000.

The aromatic content (% _{CA )} and sulfur content determined by ring analysis of the base oil are not particularly limited. is preferably used. Here, % C _A by ring analysis indicates the ratio (percentage) of the aromatic content calculated by the ring analysis ndM method measured according to ASTM D 3238. The base oil having a % _CA of 3.0 or less and a sulfur content of 10 ppm by mass or less has good oxidation stability, and provides a lubricating oil composition that can suppress an increase in acid value and sludge formation. can do. A more preferable % _CA is 1.0 or less, and a further preferable % _CA is 0.5 or less. A more preferable sulfur content is 7 mass ppm or less, and a further preferable sulfur content is 5 mass ppm or less.

The paraffin content (% C _P ) of the base oil by ring analysis is not particularly limited, but is preferably 70 or more, more preferably 75 or more, and even more preferably 79 or more. By setting the % _CP to 70 or more, the oxidation stability of the base oil is improved. Although the upper limit is not particularly limited, it is 98 or less, for example. Here, % C _P by ring analysis indicates the ratio (percentage) of paraffin content calculated by the ring analysis ndM method measured according to ASTM D 3238.

The NOACK evaporation amount of the base oil is not particularly limited, but is preferably 15.0% by mass or less, more preferably 14.0% by mass or less, and more preferably 13.0% by mass or less. NOACK evaporation can be measured according to ASTM D 5800 (250° C., 1 hour).

[Neutral phosphorus compound (B)]
The neutral phosphorus compound (B) is added for the purpose of improving wear resistance between metals. The wear resistance between metals cannot be improved unless the neutral phosphorus compound (B) is used.
The neutral phosphorus-based compound (B) is not particularly limited as long as it is a neutral compound containing a phosphorus atom, but preferably a compound represented by the following general formula (2) or (3) is used.

In the general formulas (2) and (3), the hydrocarbon groups of R ⁵ , R ⁶ and R ⁷ are each independently an aryl group having 6 to 30 carbon atoms, an alkyl group having 1 to 30 carbon atoms or a carbon an alkenyl group having 2 to 30 carbon atoms, preferably an aryl group having 8 to 28 carbon atoms, an alkyl group having 2 to 28 carbon atoms or an alkenyl group having 4 to 28 carbon atoms, more preferably an aryl group having 10 to 26 carbon atoms , an alkyl group having 4 to 26 carbon atoms or an alkenyl group having 6 to 26 carbon atoms, particularly preferably an aryl group having 12 to 24 carbon atoms, an alkyl group having 6 to 24 carbon atoms or an alkenyl group having 6 to 24 carbon atoms. . R ⁵ , R ⁶ and R ⁷ may be the same or different.

Examples of the neutral phosphorus compound (B) include aromatic neutral phosphorus compounds such as tricresyl phosphate, triphenyl phosphate, trixylenyl phosphate, tricresylphenyl phosphate, tricresyl thiophosphate, and triphenylthiophosphate. Acid ester; Aliphatic neutral phosphate such as tributyl phosphate, tri-2-ethylhexyl phosphate, tributoxy phosphate, tributyl thiophosphate; triphenyl phosphite, tricresyl phosphite, trisnonylphenyl phosphite, diphenyl mono- Aromatic neutral phosphites such as 2-ethylhexylphosphite, diphenylmonotridecylphosphite, torcreylthiophosphite, triphenylthiophosphite; tributylphosphite, trioctylphosphite, trisdecylphosphite, tris Aliphatic neutral phosphites such as tridecylphosphite, trioleylphosphite, tributylthiophosphite, trioctylthiophosphite and the like. Among these neutral phosphorus compounds, aromatic neutral phosphates, aliphatic neutral phosphates, and the like are preferably used from the viewpoint of abrasion resistance between metals. Moreover, these neutral phosphorus-based compounds may be used alone, or two or more of them may be used in combination.

The content of the neutral phosphorus compound (B) in the lubricating oil composition is preferably 2.5% by mass or less based on the total amount of the composition, and is 0.12% by mass or more and 2.5% by mass or less. more preferably 0.25% by mass or more and 1.3% by mass or less is particularly preferable. When the content of the phosphorus compound (B) is 0.12% by mass or more based on the total amount of the composition, the wear resistance between metals in the lubricating oil composition can be further improved. Further, when the content of the neutral phosphorus compound (B) is 2.5% by mass or less based on the total amount of the composition, the solubility of the neutral phosphorus compound (B) in the base oil can be improved. .
In addition, the content of the neutral phosphorus compound (B) in terms of phosphorus atoms is preferably 2000 ppm by mass or less, preferably 100 ppm by mass or more and 2000 ppm by mass or less, based on the total amount of the composition. It is more preferably 200 mass ppm or more and particularly preferably 1000 mass ppm or less. When the content of the neutral phosphorus compound (B) in terms of phosphorus atoms is 2000 ppm by mass or less based on the total amount of the composition, the solubility of the neutral phosphorus compound (B) in the base oil can be improved. . When the content of the neutral phosphorus compound (B) in terms of phosphorus atoms is 100 ppm by mass or more based on the total amount of the composition, the wear resistance between metals in the lubricating oil composition can be further improved.
In this specification, the content of phosphorus atoms means the value measured according to JPI-5S-38-92.

[Acidic phosphorus compound (C)]
The acidic phosphorus compound (C) is added for the purpose of improving seizure resistance. If the acidic phosphorus-based compound (C) is not used, it may not be possible to improve the seizure resistance.
The acidic phosphorus-based compound (C) is not particularly limited as long as it is an acidic compound containing a phosphorus atom. ) is at least one acidic phosphorus-based compound selected from the group consisting of acidic phosphites represented by

In general formulas (4) and (5) above, R ⁸ and R ⁹ represent hydrogen or a hydrocarbon group having 8 to 30 carbon atoms. Also, R ⁸ and R ⁹ may be the same or different. Furthermore, at least one of R ⁸ and R ⁹ is a hydrocarbon group having 8 to 30 carbon atoms, preferably both are hydrocarbon groups having 8 to 30 carbon atoms, more preferably 10 to 28 carbon atoms. , particularly preferably 12-26. When the number of carbon atoms in the hydrocarbon group is 8 or more, the oxidation stability of the lubricating oil composition is improved. is sufficient. Furthermore, examples of hydrocarbon groups for R ⁸ and R ⁹ include alkyl groups, alkenyl groups, aryl groups, alkylaryl groups, and arylalkyl groups.

Examples of the acidic phosphoric acid ester represented by the general formula (4) and its amine salt include aliphatic acidic phosphoric acid esters such as di-2-ethylhexyl acid phosphate, dilauryl acid phosphate, and dioleyl acid phosphate; diphenyl Aromatic acid phosphates such as acid phosphate and dicresyl acid phosphate; sulfur-containing acid phosphates such as S-octylthioethyl acid phosphate and S-dodecylthioethyl acid phosphate; These acidic phosphates and amine salts thereof may be used alone, or two or more of them may be used in combination.

Examples of the acidic phosphite and its amine salt represented by the general formula (5) include dibutyl hydrogen phosphite, di-2-ethylhexyl hydrogen phosphite, dilauryl hydrogen phosphite, dioleyl hydrogen phosphite, and the like. aromatic acidic phosphites such as diphenyl hydrogen phosphite and dicresyl hydrogen phosphite; sulfur-containing esters such as S-octylthioethyl hydrogen phosphite and S-dodecylthioethyl hydrogen phosphite Acidic phosphites and the like can be mentioned. Also, the lubricating oil composition may contain these acid phosphites as their amine salts. These acidic phosphites and their amine salts may be used alone or in combination of two or more.

In the lubricating oil composition, the content of the acidic phosphorus compound (C) is preferably 0.8% by mass or less based on the total amount of the composition, and is 0.1% by mass or more and 0.8% by mass or less. more preferably 0.1% by mass or more and 0.5% by mass or less is particularly preferable. 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. Moreover, 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 seizure resistance between metals in the lubricating oil composition can be further improved.
In addition, the content of the acidic phosphorus compound (C) in terms of phosphorus atoms is preferably 400 mass ppm or less, more preferably 50 mass ppm or more and 400 mass ppm or less based on the total amount of the composition. , 50 mass ppm or more and 250 mass ppm or less. When the content of the acidic phosphorus compound (C) in terms of phosphorus atoms is 400 ppm by mass or less based on the total amount of the composition, the volume resistivity of the lubricating oil composition can be made sufficient. In addition, when the content of the acidic phosphorus compound (C) in terms of phosphorus atoms is 50 mass ppm or more based on the total amount of the composition, the wear resistance between metals in the lubricating oil composition can be further improved. .

[Sulfur compound (D)]
The sulfur 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 compound (D) is not particularly limited as long as it contains a sulfur atom. As the sulfur-based compound (D), known compounds can be used, and specific examples include thiadiazole-based compounds, polysulfide-based compounds, thiocarbamate-based compounds, sulfurized fat-and-oil compounds, and sulfurized olefin-based compounds. . Among these sulfur-based compounds, thiadiazole-based compounds and polysulfide-based compounds are preferred from the viewpoint of metal seizure resistance and abrasion resistance between metals. These sulfur compounds may be used alone or in combination of two or more.

As the thiadiazole-based compound, known compounds can be used as appropriate, and examples thereof include those represented by the following general formula (6).

In general formula (6), R ¹⁰ and R ¹¹ each independently represent an alkyl group having 1 to 30 carbon atoms, preferably an alkyl group having 6 to 20 carbon atoms, more preferably an alkyl group having 8 to 18 carbon atoms. is the base. Also, the alkyl group may be linear or branched. Also, R ¹⁰ and R ¹¹ may be the same or different. Furthermore, X1 and X2 each independently represent an integer of 1 to 3 and represent the number of sulfur atoms, and those having two sulfur atoms are preferred.
Examples of the thiadiazole compound represented by the general formula (6) include 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 is preferred, 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 and 2,5-bis(1,1,3,3-tetramethylbutyldithio)-1,3,4-thiadiazole are more preferred, 2,5-bis(1,1,3,3-tetramethylbutyldithio)-1,3,4-thiadiazole is particularly preferred.

As the polysulfide-based compound, known compounds can be used as appropriate, and examples thereof include those represented by the following general formula (7).
R ¹² -(S) _Y -R ¹³ (7)
In the general formula (7), R ¹² and R ¹³ each independently represent an alkyl group having 1 to 24 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an alkylaryl group having 7 to 20 carbon atoms. The number of carbon atoms in the alkyl group is preferably 3 or more and 20 or less, more preferably 6 or more and 16 or less. The number of carbon atoms in the aryl group is preferably 6 or more and 20 or less, more preferably 6 or more and 16 or less. The alkylaryl group preferably has 8 or more and 20 or less, more preferably 9 or more and 18 or less. Also, R ¹² and R ¹³ may be the same or different.
In addition, Y represents the number of sulfur atoms, and considering wear resistance, fatigue life, availability, corrosion, etc., 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. An integer of 2 or more and 6 or less is more preferable.
Examples of groups represented by R ¹² and R ¹³ include aryl groups such as phenyl, naphthyl, benzyl, tolyl, and xyl groups; methyl, ethyl, propyl, butyl, pentyl, hexyl, Alkyl groups such as a heptyl group, an octyl group, a nonyl group, a decyl group, a dodecyl group, a cyclohexyl group, and a cyclooctyl group can be mentioned. These groups may be linear or branched. Moreover, these groups may be used alone or in combination of two or more.
Among the polysulfide compounds represented by the general formula (7), dibenzyl polysulfide, di-tert-nonyl polysulfide, didodecyl polysulfide, di-tert-butyl polysulfide, dioctyl polysulfide, diphenyl polysulfide, dicyclohexyl polysulfide and the like are more preferred. , and these disulfides are particularly preferred.

In the lubricating oil composition, the content of the sulfur compound (D) is preferably 0.3% by mass or less based on the total amount of the composition, and is 0.03% by mass or more and 0.3% by mass or less. More preferably, it is 0.03% by mass or more and 0.15% by mass or less is particularly preferable. It can be expected that the volume resistivity of the lubricating oil composition can be maintained when the content of the sulfur-based compound (D) is 0.3% by mass or less based on the total amount of the composition. 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 seizure resistance between metals in the lubricating oil composition can be further improved.
In addition, the content of the sulfur-based compound (D) in terms of sulfur atoms is preferably 1000 mass ppm or less based on the total amount of the composition, more preferably 125 mass ppm or more and 1000 mass ppm or less, Furthermore, from the viewpoint of achieving both volume resistivity and anti-seizure properties of the lubricating oil composition, it is particularly preferable that the content is 125 ppm by mass or more and 500 ppm by mass or less. It can be expected that the volume resistivity of the lubricating oil composition can be maintained when the content of the sulfur-based compound (D) in terms of sulfur atoms is 1000 ppm by mass or less based on the total amount of the composition. When the content of the sulfur-based compound (D) in terms of sulfur atoms is 125 ppm 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.
In this specification, the sulfur content means a value measured according to JIS K2541-6.

[Organomolybdenum compound (E)]
The lubricating oil composition further contains an organic molybdenum compound (E) in addition to the lubricating base oil (A), the neutral phosphorus compound (B), the acidic phosphorus compound (C) and the sulfur compound (D). It is characterized by Thereby, the lubricating oil composition can achieve low friction properties in addition to anti-seizure properties and anti-wear properties. If the organic molybdenum compound (E) is not used, it may not be possible to achieve low friction.

As the molybdenum-based friction modifier (E), any organic compound having a molybdenum atom can be used, but an organic compound represented by formula (1) is preferred.

In formula (1), R ¹ to R ⁴ are each independently a hydrocarbon group having 4 to 18 carbon atoms, preferably an alkyl group having 4 to 18 carbon atoms, an alkenyl group having 4 to 18 carbon atoms, a carbon It is a cycloalkyl group having 4 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, an alkylaryl group having 7 to 18 carbon atoms or an arylalkyl group having 7 to 18 carbon atoms.
Hydrocarbon groups for R ¹ to R ⁴ include, for example, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, Alkyl groups having 5 to 18 carbon atoms such as heptadecyl and octadecyl groups; Alkenyl groups having 5 to 18 carbon atoms such as octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl and pentadecenyl groups; Cycloalkyl groups having 5 to 18 carbon atoms such as cyclohexyl group, dimethylcyclohexyl group, ethylcyclohexyl group, methylcyclohexylmethyl group, cyclohexylethyl group, propylcyclohexyl group, butylcyclohexyl group, heptylcyclohexyl group; phenyl group, naphthyl group, anthracenyl aryl groups having 6 to 18 carbon atoms such as radicals, biphenyl groups and terphenyl groups; alkylaryl groups such as tolyl groups, dimethylphenyl groups, butylphenyl groups, nonylphenyl groups, methylbenzyl groups and dimethylnaphthyl groups; phenylmethyl groups arylalkyl groups having 7 to 18 carbon atoms such as phenylethyl group and diphenylmethyl group.

In formula (1), X ¹ to X ⁴ are each independently an oxygen atom or a sulfur atom. Further, from the viewpoint of improving the solubility in the lubricating base oil (A), the molar ratio [sulfur atom/oxygen atom] of the sulfur atom and the oxygen atom in X ¹ to X ⁴ is 1/3 to 3/1. is preferred, and 1.5/2.5 to 3/1 is more preferred.

In the lubricating oil composition, the content of the organic molybdenum compound (E) is 0.01% by mass or more and 1.0% by mass or less based on the total amount of the lubricating oil composition from the viewpoint of realizing low friction of the lubricating oil composition. 0.1% by mass or more and 0.9% by mass or less is more preferable, and 0.2% by mass or more and 0.8% by mass or less is particularly preferable.

When the ratio of the content (% by mass) of the sulfur-based compound (D) and the organic molybdenum compound (E) (sulfur-based compound (D) / organic molybdenum compound (E)) is in the range of 1 to 10, the lubricating oil This is preferable because it improves the low friction of the composition.
In addition, the ratio of the total content (% by mass) of the acidic phosphorus compound (C) and the sulfur compound (D) to the content (% by mass) of the organic molybdenum compound (E) ((acidic phosphorus compound ( When C) + sulfur compound (D))/organomolybdenum compound (E) is in the range of 0.3 to 1, the wear resistance of the lubricating oil composition is improved, which is preferable.

[Additive]
The lubricating oil composition contains viscosity index improvers, detergent dispersants, antioxidants, metal deactivators, rust preventives, surfactants/demulsifiers, antifoaming agents, and corrosion An inhibitor, an oiliness agent, an acid scavenger, and the like can be appropriately blended and used.

Viscosity index improvers include, for example, non-dispersing polymethacrylates, dispersing polymethacrylates, olefinic copolymers, dispersing olefinic copolymers, and styrene copolymers. The mass average molecular weight of these viscosity index improvers is preferably 5,000 or more and 300,000 or less, for example, for dispersant type and non-disperse type polymethacrylates. Moreover, 800 or more and 100000 or less are preferable in an olefin type copolymer. These may be used individually by 1 type, and may be used in combination of 2 or more type. The amount of the viscosity index improver is not particularly limited, but is preferably 0.5% by mass or more and 15% by mass or less, more preferably 1% by mass or more and 10% by mass or less, based on the total amount of the composition.

As the detergent-dispersant, an ashless-dispersant and a metallic detergent-dispersant can be used.
Examples of ashless dispersants include succinimide compounds, boron-based imide compounds, Mannich-based dispersants, and acid amide-based compounds. These may be used individually by 1 type, and may be used in combination of 2 or more type. The amount of the ashless dispersant to be blended is not particularly limited, but is preferably 0.1% by mass or more and 20% by mass or less based on the total amount of the composition.
Examples of metallic detergent-dispersants 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. mentioned. These may be used individually by 1 type, and may be used in combination of 2 or more type. The amount of the metallic detergent-dispersant compounded is not particularly limited, but is preferably 0.1% by mass or more and 10% by mass or less based on the total amount of the composition.

Examples of antioxidants include amine-based antioxidants, phenol-based antioxidants, and sulfur-based antioxidants. These may be used individually by 1 type, and may be used in combination of 2 or more type. The content of the antioxidant 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.

Pour point depressants include polymethacrylate, ethylene-vinyl acetate copolymer, condensate of chlorinated paraffin and naphthalene, condensate of chlorinated paraffin and phenol, polyalkylstyrene, poly(meth)acrylate, and the like. be done. The mass average molecular weight (Mw) of the pour point depressant is preferably 20,000 to 100,000, more preferably 30,000 to 80,000, and 40,000 to 60,000. is more preferred. Also, the molecular weight distribution (Mw/Mn) is preferably 5 or less, more preferably 3 or less, and even more preferably 2 or less. The content of the pour point depressant may be appropriately determined according to the desired MRV viscosity and the like, and is preferably 0.01% by mass or more and 5% by mass or less, and 0.02% by mass or more and 2% by mass, based on the total amount of the composition. % or less is more preferable.

Metal deactivators include, for example, benzotriazole-based metal deactivators, tolyltriazole-based metal deactivators, thiadiazole-based metal deactivators, and imidazole-based metal deactivators. These may be used individually by 1 type, and may be used in combination of 2 or more type. The amount of the metal deactivator is not particularly limited, but is preferably 0.01% by mass or more and 3% by mass or less, and preferably 0.01% by mass or more and 1% by mass or less, based on the total amount of the composition. more preferred.

Rust inhibitors include, for example, petroleum sulfonates, alkylbenzene sulfonates, dinonylnaphthalene sulfonates, alkenyl succinates, and polyhydric alcohol esters. These may be used individually by 1 type, and may be used in combination of 2 or more type. The amount of the antirust agent is not particularly limited, but is preferably 0.01% by mass or more and 1% by mass or less, and 0.05% by mass or more and 0.5% by mass or less based on the total amount of the composition. is more preferred.

Examples of surfactants/demulsifiers include polyalkylene glycol-based nonionic surfactants. Specific examples include polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, and polyoxyethylene alkylnaphthyl ethers. These may be used individually by 1 type, and may be used in combination of 2 or more type. The amount of the surfactant is not particularly limited, but is preferably 0.01% by mass or more and 3% by mass or less, more preferably 0.01% by mass or more and 1% by mass or less, based on the total amount of the composition. preferable.

Antifoaming agents include, for example, fluorosilicone oils and fluoroalkyl ethers. These may be used individually by 1 type, and may be used in combination of 2 or more type. The amount of the antifoaming agent is not particularly limited, but is preferably 0.005% by mass or more and 0.5% by mass or less, and 0.01% by mass or more and 0.2% by mass or less, based on the total amount of the composition. It is more preferable to have

Examples of corrosion inhibitors include benzotriazole-based corrosion inhibitors, benzimidazole-based corrosion inhibitors, benzothiazole-based corrosion inhibitors, and thiadiazole-based corrosion inhibitors. These may be used individually by 1 type, and may be used in combination of 2 or more type. Although the amount of the corrosion inhibitor to be added is not particularly limited, it is preferably in the range of 0.01% by mass or more and 1% by mass or less based on the total amount of the composition.
Examples of oiliness agents include aliphatic monocarboxylic acids, polymerized fatty acids, hydroxy fatty acids, aliphatic monoalcohols, aliphatic monoamines, aliphatic monocarboxylic acid amides, and partial esters of polyhydric alcohols and aliphatic monocarboxylic acids. be done. These may be used individually by 1 type, and may be used in combination of 2 or more type. The blending amount of the oily agent is not particularly limited, but is preferably in the range of 0.01% by mass or more and 10% by mass or less based on the total amount of the composition.

An epoxy compound can be used as an acid scavenger. Specific examples include phenyl glycidyl ether, alkyl glycidyl ether, alkylene glycol glycidyl ether, cyclohexene oxide, α-olefin oxide, and epoxidized soybean oil. These may be used individually by 1 type, and may be used in combination of 2 or more type. The amount of the acid scavenger to be blended is not particularly limited, but is preferably in the range of 0.005% by mass or more and 5% by mass or less based on the total amount of the composition.

[Properties of lubricating oil composition]
The dynamic viscosity of the lubricating oil composition can be measured by a method conforming to JIS-K-2283:2000.
The kinematic viscosity at 100° C. of the lubricating oil composition is preferably 14.0 mm ² /s or less, more preferably 12.5 mm ² /s, from the viewpoint of improving lubricating performance, viscosity characteristics, and fuel economy. or less, more preferably 10.0 mm ² /s or less, preferably 2.0 mm ² /s or more, more preferably 2.2 mm ² /s or more, still more preferably 2.5 mm ² /s or more is.
The kinematic viscosity at 40° C. of the lubricating oil composition is preferably 80.0 mm ² /s or less, more preferably 70.0 mm ² /s, from the viewpoint of improving lubricating performance, viscosity characteristics, and fuel economy. or less, more preferably 65.0 mm ² /s or less, preferably 5.0 mm ² /s or more, more preferably 7.0 mm ² /s or more, still more preferably 10.0 mm ² /s or more is.

The viscosity index of the lubricating oil composition can be calculated by a method based on JIS-K-2283:2000. The viscosity index (Vscosity Index) of the lubricating oil composition is preferably 90 or more, more preferably 100 or more, and still more preferably 103 or more from the viewpoint of suppressing viscosity changes due to temperature changes and improving fuel efficiency.

[flash point]
Flash point conforms to JIS-K-2265-4, C.I. O. It means the value measured by C method. The flash point of the lubricating oil composition is preferably 172°C or higher, more preferably 174°C or higher, and particularly preferably 176°C or higher.
When the flash point of the lubricating oil composition is 172°C or higher, the ability to cool the mechanical device in which the lubricating oil composition is used can be improved. In order to raise the flash point of the lubricating oil composition, for example, it can be achieved by using an oil having a high flash point for each oil constituting the lubricating base oil (A).

[Use of lubricating oil composition]
The lubricating oil composition of the present invention described above has a flash point within a predetermined range, and exhibits lubricating properties (wear resistance, seizure resistance, low friction). Therefore, it can be preferably applied to mechanical devices such as a device in which a motor and a speed reducer are integrated, for example, a hydraulic device, a stationary transmission, an automobile transmission, and a motor/battery cooling device.

[Method for producing lubricating oil composition]
The method for producing the lubricating oil composition of the present invention is not particularly limited, but a lubricating base oil (A), a neutral phosphorus compound (B), an acidic phosphorus compound (C), a sulfur compound (D) and an organic It is preferable to include a step of mixing the molybdenum compound (E).

[Mechanical equipment]
The lubricating oil composition improves lubricity in mechanical devices and can be used in mechanical devices such as hydraulic systems, stationary transmissions, automotive transmissions or cooling systems for motors and batteries. For example, the lubricating oil composition can be used for motors mounted on hybrid vehicles, electric vehicles, etc., engines mounted on diesel engines or gasoline engines, transmission machines such as automobiles, and the like. In particular, it is preferable to use it for a transmission machine mounted on a hybrid vehicle, an electric vehicle, or the like.

EXAMPLES The present invention will be described in more detail below with reference to Examples, but the present invention is not limited by these Examples.

Properties and performance in Examples and Comparative Examples were measured as follows.
(1) Kinematic Viscosity According to JIS-K-2283:2000, kinematic viscosity at 40° C. and kinematic viscosity at 100° C. were measured using a glass capillary viscometer.
(2) Viscosity Index
It was calculated by a method based on JIS-K-2283:2000.
(3) Flash point According to JIS-K-2265-4, C.I. O.D. Measured by C method.
(4) Abrasion resistance Abrasion resistance was evaluated by a shell four-ball abrasion test. Specifically, according to the method described in ASTM D4172, by measuring the wear scar diameter (unit: mm) under the test conditions of 1800 rpm, 80 ° C., 392 N load, and 30 minutes of test time, Wear resistance between metals was evaluated. It should be noted that the smaller the wear scar diameter, the better the wear resistance between metals.
(5) Seizure resistance According to ASTM D2783-03 (2014), the welding load WL (N) was measured under the conditions of 1800 rpm and room temperature (25°C). The larger this value, the better the seizure resistance.
(6) Friction Property A metal-to-metal friction coefficient was measured by LFW-1 test in accordance with JASO method (high load method) M358:2005. The smaller this value, the better the seizure resistance.

[Examples 1 to 3, Comparative Examples 1 to 4]
Using the following lubricating base oil (A), neutral phosphorus compound (B), acidic phosphorus compound (C), sulfur compound (D), organic molybdenum compound (E), etc., shown in Table 1 A lubricating oil composition was prepared according to the composition. Each component shown in Table 1 constituting the lubricating oil composition is as follows.
[Lubricating base oil (A)]
Mineral oil-1: Mineral oil with a 100° C. kinematic viscosity of 2.4 mm ² /s, a viscosity index of 110 and a flash point of 186° C. Mineral oil-2: A 100° C. kinematic viscosity of 2.4 mm ² /s, a viscosity index of 105, Mineral oil with a flash point of 176° C. Synthetic oil-1: 100° C. Synthetic oil with a kinematic viscosity of 2.4 mm ² /s, a viscosity index of 110 and a flash point of 186° C. [Neutral phosphorus compound (B)]
tricresyl phosphate (TCP) (a compound in which R ⁵ to R ⁷ in the general formula (2) are methylphenyl groups)
[Acidic phosphorus compound (C)]
Dioleyl acid phosphate (acidic phosphate ester in which R ⁸ and R ⁹ in the general formula (4) are oleyl groups)
[Sulfur compound (D)]
2,5-bis(1,1,3,3-tetramethylbutyldithio)-1,3,4-thiadiazole (X1 and X2 in the general formula (6) are 2, R ¹⁰ and R ¹¹ are 1, Thiadiazole compounds that are 1,3,3-tetramethylbutyl groups)
[Organomolybdenum compound (E)]
Molybdenum dithiocarbamate (MoDTC) (a compound in which R ¹ to R ⁴ in formula (1) are each independently 8 or 13 hydrocarbon groups and X ¹ to X ⁴ are oxygen atoms. Molybdenum atom content = 10.0% by mass, sulfur atom content = 11.5% by mass)

Other additives (remainder) contained in the compositions of Examples and Comparative Examples consist of a viscosity index improver, an antioxidant, a detergent dispersant, a pour point depressant, an antifoaming agent and the like.

As shown in Table 1, when comparing Examples 1 to 3 with Comparative Examples 1 to 4, the lubricating base oil (A), the neutral phosphorus compound (B), the acidic phosphorus compound (C), the sulfur compound It was found that the lubricating oil composition containing all of (D) and organomolybdenum compound (E) has excellent performance in terms of wear resistance, seizure resistance and friction.
Further, a comparison between Examples 1 to 3 and Comparative Example 4 revealed that the use of the organic molybdenum compound (E) improved the friction properties of the resulting lubricating oil composition.
In Examples 1 to 3, when a base oil with a high flash point was used as the lubricating base oil (A), the flash point of the lubricating oil composition was increased. In particular, in Examples 1 and 3, since the lubricating base oil (A) had a flash point of 176° C. or higher, the flash point of the obtained lubricating oil composition was also high.

Claims (9)

Integrated motor and speed reducer containing lubricating base oil (A), neutral phosphorus-based compound (B), acidic phosphorus-based compound (C), sulfur-based compound (D) and organic molybdenum compound (E) A lubricating oil composition for use in machinery, wherein the lubricating base oil (A) comprises mineral oil, polybutene, poly-α-olefin, dibasic acid ester, phosphate ester, ether oil, alkylbenzene and alkylnaphthalene. A lubricating oil composition which is one or more selected from the group (excluding lubricating oil compositions having a kinematic viscosity at 100° C. of 5 mm ² /s or more) . 2. The lubricating oil composition according to claim 1, wherein the organic molybdenum compound (E) is a compound represented by the following formula (1).

(In the formula, R ¹ to R ⁴ are each independently a hydrocarbon group having 4 to 18 carbon atoms, and X ¹ to X ⁴ are each independently an oxygen atom or a sulfur atom.) R ¹ to R ⁴ each independently represent an alkyl group having 4 to 18 carbon atoms, an alkenyl group having 4 to 18 carbon atoms, a cycloalkyl group having 4 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, or 7 carbon atoms. 3. The lubricating oil composition of claim 2, which is an alkylaryl group of .about.18 or an arylalkyl group of 7 to 18 carbon atoms. The lubricating oil composition according to any one of claims 1 to 3, wherein the content of the organic molybdenum compound (E) is 0.01% by mass or more and 1.0% by mass or less based on the total amount of the lubricating oil composition. . The lubricating oil composition according to any one of claims 1 to 4, wherein the lubricating base oil (A) has a flash point of 172°C or higher. A lubricating oil composition according to any one of claims 1 to 5, wherein the mechanical device is a hydraulic system, a stationary transmission, an automotive transmission or a cooling system for a motor battery. A mechanical device comprising the lubricating oil composition according to any one of claims 1 to 5. 8. The mechanical device according to claim 7, wherein the mechanical device is a hydraulic system, a fixed transmission, an automobile transmission or a motor battery cooling system. A motor and speed reducer comprising a step of mixing a lubricating base oil (A), a neutral phosphorus-based compound (B), an acidic phosphorus-based compound (C), a sulfur-based compound (D) and an organic molybdenum compound (E) A method for producing a lubricating oil composition used in an integrated mechanical device, wherein the lubricating base oil (A) is mineral oil, polybutene, poly-α-olefin, dibasic acid ester, phosphate ester, ether oil A method for producing a lubricating oil composition (excluding a lubricating oil composition having a kinematic viscosity at 100° C. of 5 mm ² /s or more), which is at least one selected from the group consisting of , alkylbenzene and alkylnaphthalene.