JP2017088550A - Organomolybdenum compound, lubricant composition and grease composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organomolybdenum compound that has high thermal stability and can be used for a long time even at a high temperature.SOLUTION: The present invention provides an organomolybdenum compound represented by the following general formula (1) (where R-Rare a C1-C8 alkyl group or a C7-C13 aralkyl group, X-Xare an oxygen atom or a sulfur atom, where, at least one of R-Ris a C7-C13 aralkyl group).SELECTED DRAWING: None

Description

  The present invention relates to novel organomolybdenum compounds, lubricating oil compositions and grease compositions.

Organic molybdenum compounds have excellent lubricity and wear resistance, and among them, molybdenum dialkyldithiocarbamate compounds are widely used in lubricating oil and grease applications because of their low corrosiveness to metals. Known examples of the alkyl group of the molybdenum dialkyldithiocarbamate compound include a butyl group, an octyl group, a dodecyl group, and a tridecyl group (see, for example, Patent Documents 1 and 2).
However, conventional molybdenum dialkyldithiocarbamate compounds cannot be said to have sufficient heat resistance, and molybdenum dialkyldithiocarbamate compounds gradually decompose when used at high temperatures for long periods of time, resulting in a gradual decrease in lubricity and wear resistance. There was a problem to do.

JP-A-62-081396 JP 2004-002872 A

  Accordingly, an object of the present invention is to provide an organomolybdenum compound that has high thermal stability and can be used for a long time even at high temperatures.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that an organic molybdenum compound having high heat resistance can be obtained by introducing an aralkyl group, thereby completing the present invention. The headline and the present invention were completed. That is, the present invention is an organic molybdenum compound represented by the following general formula (1).

(Wherein R ^{1 to} R ⁴ represent an alkyl group having 1 to 8 carbon atoms or an aralkyl group having 7 to 13 carbon atoms, and X ^{1 to} X ⁴ represent an oxygen atom or a sulfur atom, provided that R ^{1 to} R ^At least one of ⁴ is an aralkyl group having 7 to 13 carbon atoms.)

  According to the present invention, an organomolybdenum compound that has high thermal stability and can be used for a long time even at high temperatures can be provided.

1 is a ¹ H-NMR spectrum of an organomolybdenum compound of Example 1. 3 is a ¹³ C-NMR spectrum of the organomolybdenum compound of Example 1. ^{1 is} a ¹ H-NMR spectrum of dibenzylamine. It is a ¹³ C-NMR spectrum of dibenzylamine. 2 is a ¹ H-NMR spectrum of an organomolybdenum compound of Example 2. ^{1 is} a ¹ H-NMR spectrum of N-methyl-N-benzylamine.

  The organomolybdenum compound of the present invention is represented by the following general formula (1).

In General Formula (1), R ^{1 to} R ⁴ represent an alkyl group having 1 to 8 carbon atoms or an aralkyl group having 7 to 13 carbon atoms. However, at least one of R ^{1 to} R ⁴ is an aralkyl group having 7 to 13 carbon atoms. Examples of the alkyl group having 1 to 8 carbon atoms include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, isopropyl group, isobutyl group, secondary butyl group, t- Examples thereof include a butyl group, isopentyl group, secondary pentyl group, t-pentyl group, secondary hexyl group, secondary heptyl group, secondary octyl group, and 2-ethylhexyl group.

  Examples of the aralkyl group having 7 to 13 carbon atoms include benzyl group, phenethyl group, cumyl group, hydrocinnamyl group, benzhydryl group, methylbenzyl group, t-butylbenzyl group and the like.

R ^{1 to} R ⁴ are preferably an alkyl group having 1 to 4 carbon atoms and an aralkyl group having 7 to 8 carbon atoms, more preferably a methyl group and a benzyl group, and most preferably a benzyl group because heat resistance is enhanced. . At least one of R ^{1 to} R ⁴ is an aralkyl group having 7 to 13 carbon atoms, but at least one of R ¹ and R ² is an aralkyl group having 7 to 13 carbon atoms, and R ³ and R ⁴ Of these, at least one is preferably an aralkyl group having 7 to 13 carbon atoms. Particularly preferred combinations are when R ^{1 to} R ⁴ are all benzyl groups, and when R ¹ and R ³ are methyl groups and R ² and R ⁴ are benzyl groups.

In the general formula ^(1), X 1 ~X ⁴ represents an oxygen atom or a sulfur atom. Since it is excellent in lubricity, it is preferable that 2 to 3 of X ^{1 to} X ⁴ are sulfur atoms and the rest are oxygen atoms.

  When manufacturing the organomolybdenum compound represented by the general formula (1), a known method may be used. For example, after reducing molybdenum by adding a reducing agent to an aqueous solution or suspension of a hexavalent molybdenum compound such as molybdenum trioxide, an alkali metal of molybdate and an alkali hydrosulfide or an alkali sulfide, It can be produced by adding a secondary amine represented by the general formula (2) or (3) and carbon disulfide and reacting them.

^(Wherein, R 1 to R ⁴ are as in formula (1) synonymous.)

  Examples of the alkali metal salt of molybdic acid include sodium molybdate, potassium molybdate, and molybdate heteropolyacid. Examples of the alkali hydrosulfide include sodium sulfide, potassium sulfide, and ammonium sulfide.

  Examples of the alkali hydrosulfide include sodium hydrosulfide and potassium hydrosulfide. Examples of the alkali sulfide include sodium sulfide, potassium sulfide and ammonium sulfide. Among these, alkali sulfide is preferable and sodium sulfide is more preferable because of good reactivity and good industrial availability. These aqueous solutions such as potassium sulfide and ammonium sulfide, and alkali sulfide aqueous solutions obtained by introducing a sulfide gas into an alkali hydroxide aqueous solution can also be used. Since the organomolybdenum compound of the present invention can be produced with good yield, the amount of alkali hydrosulfide or alkali sulfide used is preferably 1 to 2 moles relative to 1 mole of molybdenum of the hexavalent molybdenum compound, and 1.2 to 1 More preferred is 8 moles.

  Examples of the reducing agent include hydrides such as hydrogen iodide, hydrogen sulfide, and sodium borohydride; sodium sulfite, sodium dithionate, sodium dithionite (hydrosulfide), sodium bisulfite, sodium pyrosulfite, thio Low oxygen acid salts such as sodium sulfate; sulfur compounds such as sodium sulfide, polysodium sulfide, ammonium sulfide; low valence states such as iron (II), tin (II), titanium (III), chromium (II) Specific metal salts; aldehydes such as formaldehyde and acetaldehyde, hydrazine, borane, diborane, formic acid, oxalic acid, ascorbic acid and the like. In view of good reactivity and easy industrial availability, alkali metal salts of lower oxygen acids are preferred, and sodium sulfite and sodium hydrogen sulfite are more preferred. Since the organomolybdenum compound of the present invention can be produced with good yield, the amount of the reducing agent used is preferably 0.05 to 2 mol, preferably 0.1 to 1 mol, relative to 1 mol of molybdenum in the hexavalent molybdenum compound. Further preferred.

  Since the organomolybdenum compound of the present invention can be produced with good yield, the secondary amine and carbon disulfide are preferably used in the same number of moles, and the amount of secondary amine and carbon disulfide used is that of the hexavalent molybdenum compound. It is preferable that it is 0.9-2 mol with respect to 1 mol of molybdenum, respectively, and it is still more preferable that it is 1-1.5 mol.

  Since the organomolybdenum compound of the present invention can be produced with good yield, the reaction temperature after adding the secondary amine and carbon disulfide is preferably 20 to 110 ° C, more preferably 60 to 100 ° C, and the reaction time is 2 ~ 15 hours. After completion of the reaction, the reaction solution is neutralized with sulfuric acid or the like, and the product is separated to obtain the organomolybdenum compound of the present invention.

In addition, when a diaralkylamine or N-alkyl-N-aralkylamine is used in combination with a dialkylamine as a secondary amine, R ^{1 to} R ^{4 in} the general formula (1) are all alkyl groups. Although compounds are by-produced, such compounds may or may not be separated when used as a lubricating additive.

  The conventional molybdenum dialkyldithiocarbamate compound is excellent in friction reduction and wear resistance, but the organic molybdenum compound of the present invention is excellent in thermal stability and oxidation resistance in addition to friction reduction and wear resistance. It is useful as a lubricating additive.

  Applications in which the organomolybdenum compound of the present invention can be used as a lubricant additive include, for example, engine oil, gear oil, turbine oil, hydraulic oil, flame retardant hydraulic fluid, refrigerator oil, compressor oil, vacuum pump oil, and bearing oil. , Insulating oil, sliding surface oil, rock drill oil, metal working oil, plastic working oil, heat treatment oil and other lubricating oils; bearing grease, gear grease, gear grease, joint grease, bearing grease, etc. Etc. Since the organomolybdenum compound of the present invention has high crystallinity and low solubility in mineral oil and hydrocarbon synthetic oil, it is preferably used for grease. When the organomolybdenum compound of the present invention is added to a base oil to form a lubricating oil composition, the 50% particle size of the particles of the organomolybdenum compound of the present invention is 30 to 450 nm in order to improve dispersion stability. It is preferable to grind and disperse until.

  The method for producing the lubricating oil composition in which the particles of the organic molybdenum compound described above are dispersed in the base oil is not particularly limited, and the organic molybdenum compound may be finely pulverized and then dispersed in the base oil. You may grind | pulverize after adding an organic molybdenum compound. Since a dispersion having good dispersion stability and a small particle size of 50% can be obtained, it is preferable to add a particulate organic molybdenum compound to the base oil and then finely pulverize it. Preferable pulverizers for producing the lubricating oil composition of the present invention include a roller mill, a hammer mill, a rotating mill, a vibration mill, a planetary mill, an attritor, a bead mill and the like. Since the dispersion stability is good and a dispersion having a small particle size of 50% is obtained, the organic molybdenum compound is added to the base oil, and the particles of the organic molybdenum compound measured by a laser diffraction light scattering method using a bead mill are used. It is preferable to grind and disperse until the 50% particle diameter becomes 30 to 450 nm. When the organic molybdenum compound is added to the base oil and finely pulverized, the pulverization is facilitated. Therefore, the organic molybdenum compound is preferably pulverized at a temperature at least 10 ° C. lower than the melting point of the organic molybdenum compound.

  When using a bead mill to disperse the organic molybdenum compound in the base oil, it is preferable to use an organic molybdenum compound that has been coarsely pulverized in advance to a particle size of 50% of about 100 to 1000 μm. The diameter of the beads in the bead mill is preferably 0.3 mm or less, and more preferably 0.1 mm or less, because a dispersion having a small particle diameter can be obtained. The material of the beads may be any of metal, glass, ceramics, resin, etc., but ceramics are preferred because they are less contaminated with impurities and excellent in dispersion efficiency.

  When the organic molybdenum compound is dispersed in the base oil, it is preferable to add as much organic molybdenum compound as possible to the base oil and disperse it, and then dilute with the base oil so as to achieve the target concentration. However, if the amount of the organomolybdenum compound is excessive, the viscosity is increased and pulverization becomes insufficient. Therefore, in the roller mill and the hammer mill, the organomolybdenum compound is preferably 10 per 100 parts by mass of the base oil. -180 parts by mass, more preferably 20-150 parts by mass, and in the rotating mill, vibration mill, planetary mill, attritor, and bead mill, the organomolybdenum compound is preferably used in an amount of 1-40 with respect to 100 parts by mass of the base oil. Part by mass, more preferably 1.5 to 30 parts by mass is added.

  Examples of the base oil used in the lubricating oil composition of the present invention include paraffinic mineral oil, naphthenic mineral oil, or hydrorefining, solvent removal, solvent extraction, solvent dewaxing, hydrodewaxing, contact Mineral oil such as refined mineral oil such as dewaxing, hydrocracking, alkali distillation, sulfuric acid washing, clay treatment, etc .; poly-α-olefin, ethylene-α-olefin copolymer, polybutene, GTL (Gas to liquids) Hydrocarbon synthetic oils such as base oils, alkylbenzenes and alkylnaphthalenes; ether synthetic oils such as polyphenyl ethers, alkyl-substituted diphenyl ethers and polyalkylene glycols; polyol esters, dibasic acid esters, hindered esters, monoesters, etc. Ester synthetic oils; phosphate ester synthetic oils, polysiloxane synthetic oils, Hydrocarbon type synthetic oils. These base oils may be used singly, or a mixture of two or more thereof. As the base oil when used in the lubricating oil, mineral oil and hydrocarbon-based synthetic oil are preferred because the lubricity improvement effect of the organomolybdenum compound is likely to occur, and paraffin-based refined mineral oil, poly-α-olefin, More preferred is GTL base oil.

The viscosity of the base oil is preferably higher from the viewpoint of the dispersion stability of the organomolybdenum compound, but if it is too high, it may be difficult to disperse the organomolybdenum compound. preferably the kinematic viscosity of ℃ is 1~800mm ² / s, more preferably in a 3~250mm ² / s, and most preferably 8~80mm ² / s.

  When the amount of the organomolybdenum compound of the present invention added to the lubricating oil composition is too small, sufficient friction reduction and wear resistance cannot be obtained, and when it is too large, an improvement in performance commensurate with the amount added can be obtained. Not only may there be an adverse effect on the physical properties of the lubricating oil. The addition amount of the organic molybdenum compound of the present invention is preferably 0.05 to 4% by mass, more preferably 0.1 to 1% by mass, and 0.2 to 0.7% by mass with respect to the lubricating oil composition. Most preferred.

  Examples of the base oil when the organomolybdenum compound of the present invention is added to the base oil to form a grease composition include the base oils exemplified in the case of the lubricating oil composition. As the base oil used in the grease composition, mineral oil and hydrocarbon-based synthetic oil are preferable because the lubricity improvement effect of the organomolybdenum compound is likely to be obtained. Paraffin-based refined mineral oil, poly-α-olefin, GTL Base oil is more preferred.

  The grease composition of the present invention may further contain a thickener. Examples of the thickener include soap-based or complex soap-based thickeners, organic non-soap thickeners, inorganic non-soap thickeners, and the like. In addition, a grease that includes a base oil and a thickener and does not contain other additives may be referred to as a base grease.

  Examples of the soap thickener include lauric acid, myristic acid, palmitic acid, stearic acid, 12-hydroxystearic acid, arachidic acid, behenic acid, zomarinic acid, oleic acid, linoleic acid, linolenic acid, ricinoleic acid and the like. A soap in which a higher fatty acid is reacted with a base such as lithium, sodium, potassium, aluminum, barium, calcium, and the above fatty acid and base are further reacted with acetic acid, benzoic acid, sebacic acid, azelaic acid, phosphoric acid, boric acid, etc. And complex soap thickeners.

  Examples of organic non-soap thickeners include terephthalate thickeners, urea thickeners, fluorine based polytetrafluoroethylene, fluorinated ethylene-propylene copolymers, and the like. System thickeners are preferred. Examples of the urea thickener include, for example, a monourea compound obtained by reacting monoisocyanate and monoamine, a diurea compound obtained by reacting diisocyanate and monoamine, a urea urethane compound obtained by reacting diisocyanate, monoamine and monool, and diisocyanate. Examples include tetraurea compounds obtained by reacting diamine and monoisocyanate.

  If the amount of the organomolybdenum compound of the present invention added to the grease composition is too small, sufficient friction reduction and wear resistance cannot be obtained, and if it is too large, an improvement in performance commensurate with the amount added cannot be obtained. In addition, the physical properties of the grease composition may be adversely affected. The addition amount of the organic molybdenum compound of the present invention is preferably 0.1 to 10% by mass, more preferably 0.2 to 7% by mass, and most preferably 0.3 to 5% by mass with respect to the grease composition.

  When the organomolybdenum compound of the present invention is added to a base oil to obtain a lubricating oil composition or a grease composition, a known lubricating oil additive may be used in combination as necessary. Lubricating additives include amine antioxidants, phenolic antioxidants, phosphorus antioxidants, sulfur antioxidants, and other antioxidants; calcium, magnesium, barium and other sulfonates, phenates, salicylates, phosphates And detergents such as these overbased salts; oiliness improvers such as higher alcohols, higher fatty acids, higher fatty acid glycerin esters, higher fatty acid amides, higher alkyl amines; dispersants such as alkenyl succinimides; Extreme pressure agents such as phosphate ester, zinc dialkyldithiophosphate (ZnDTP), zinc dialkyldithiocarbamate; other organic molybdenum such as dialkyldithiocarbamate, dialkyldithiophosphate, molybdenum long chain amine salt, molybdenum alkenyl succinimide complex Compound; viscosity Index improvers, pour point depressants, rust inhibitors, corrosion inhibitors, antifoaming agents and the like. These lubricating oil additives may be blended with the organomolybdenum compound of the present invention to form a lubricating oil additive composition, and then used in lubricating oils and greases.

  Hereinafter, the present invention will be described more specifically with reference to examples. In the following examples, “%” is based on mass unless otherwise specified. For mass spectrometry, MALDI-TOFMS (Bruker Daltonics, model: ultraXtreme) was used (matrix: 2,5-dihydroxybenzoic acid, ionizing agent: sodium trifluoroacetate). In MALDI-TOFMS analysis using sodium trifluoroacetate as an ionizing agent, molybdenum compounds are detected as monovalent ions with sodium, but since molybdenum has many stable isotopes, many peaks are detected. The

[Example 1]
In a glass reactor, 500 ml of water and 144 g (1 mol) of molybdenum trioxide powder are suspended, and 221 g (1.5 mol) of a 38% by weight aqueous solution of sodium hydrosulfide is added to the suspension while stirring in a sealed state. The reaction was allowed for 30 minutes. Next, 260 g of toluene was added, and 146 g (1.2 mol) of a 30% by mass hydrochloric acid aqueous solution was added. In addition, the mixture was stirred at room temperature for 30 minutes, further heated to 100 ° C., and stirred for 4 hours to be reacted. The reaction product was present as a cake in a toluene-water emulsion. 86 g of toluene was added to this to make a slurry, which was then filtered, washed sequentially with 300 g of toluene and 300 g of water and dried to obtain a powdery organic molybdenum compound A1 of the present invention with a yield of 93%. . A1 is a compound in which R ^{1 to} R ⁴ are benzyl groups, X ^{1 to} X ² are sulfur atoms, and X ^{3 to} X ⁴ are oxygen atoms in the general formula (1).
Elemental analysis value: Molybdenum content 22.6% (theoretical value 23.0%)
Sulfur content 24.4% (theoretical value 23.1%)
Mass spectrometry: many peaks around 855 (theoretical value 855.85)
Melting point: 258 ° C
1 and 2 show the ¹ H-NMR spectrum and ¹³ C-NMR spectrum of the molybdenum compound A1, respectively. 3 and 4 show the ¹ H-NMR spectrum and ¹³ C-NMR spectrum of the starting material dibenzylamine, respectively.

[Example 2]
The same operation as in Example 1 was carried out except that dibenzylamine (1.1 mol) was changed to N-methyl-N-benzylamine (1.1 mol) in Example 1, and the yield was 91%. A powdery organic molybdenum compound A2 of the present invention was obtained. A2 is a compound in which R ¹ and R ³ are methyl groups, R ² and R ⁴ are benzyl groups, X ^{1 to} X ² are sulfur atoms, and X ^{3 to} X ⁴ are oxygen atoms in the general formula (1).
Elemental analysis value: Molybdenum content 29.8% (theoretical value 28.2%)
Sulfur content 33.0% (theoretical value 28.3%)
Mass spectrometry: many peaks around 703 (theoretical value 703.64)
Melting point: 270 ° C
FIG. 5 shows a ¹ H-NMR spectrum of molybdenum compound A2. FIG. 6 shows the ¹ H-NMR spectrum of the starting material N-methyl-N-benzylamine.

(Preparation of lubricating oil composition)
25 parts by mass of organomolybdenum compound A1 or A2 is added to 100 parts by mass of paraffin-based refined mineral oil, and laser diffraction light scattering is performed at a liquid temperature of 25 ° C. using a bead mill (product name: UAM-015). After pulverizing until the 50% particle diameter measured using a method particle size distribution meter (manufactured by Shimadzu Corporation, model: SALD-2200) is 100 nm or less, and dispersing in paraffin-based refined mineral oil, What was added so that the content of Mo might become 700 ppm was used as the lubricating oil composition of Examples 3-4. The 50% particle diameter of the particles of the organomolybdenum compound A1 dispersed in the lubricating oil composition of Example 3 measured using a laser diffraction light scattering particle size distribution analyzer is 87 nm. The lubricating oil composition of Example 4 The 50% particle diameter of the particles of the organomolybdenum compound A2 dispersed in the product, measured using a laser diffraction light scattering particle size distribution analyzer, was 80 nm. Moreover, what added the comparative organic molybdenum compound B1 or B2 to the commercially available engine oil so that the content of Mo might be 700 ppm was used as the lubricating oil composition of Comparative Examples 1-2.

The comparative organomolybdenum compounds B1 and B2, the paraffinic refined mineral oil, and the commercially available engine oil used here are as follows.
Comparative organomolybdenum compound B1: In general formula (1), R ^{1 to} R ⁴ are isotridecyl groups, X ^{1 to} X ² are sulfur atoms, and X ^{3 to} X ⁴ are oxygen atoms Comparative organomolybdenum compound B2: An organomolybdenum compound in which R ⁵ is a 2-ethylhexyl group in the following general formula (4)

Paraffin-based refined mineral oil: 40 ° C. kinematic viscosity 19.5 mm ² / s, 100 ° C. kinematic viscosity 4.24 mm ² / s)
Commercial engine oil: Toyota Motor Corporation, product name: Toyota Castle SN 0W-20

  About these lubricating oil compositions, thermal stability was evaluated by measuring a friction coefficient and the residual amount of an organic molybdenum compound by the following method. In Comparative Example 3, commercially available engine oil was used as it was.

<Evaluation of thermal stability>
〔Coefficient of friction〕
200 mL of the sample was placed in a 300 mL glass graduated cylinder, placed in a constant temperature bath at 140 ° C., and oxidized by blowing air at a flow rate of 50 mL / min into the sample. The coefficient of friction of the samples before, 1 day, 3 days and 6 days before the test was measured as follows. The results are shown in Table 1.
Tester used: SRV measurement tester (manufactured by Optimol, model: type3)
Evaluation condition ・ Measure the coefficient of friction under the line contact condition of the cylinder on plate.
・ Load: 200N
・ Temperature: 80 ℃
・ Measurement time: 15 minutes ・ Amplitude: 1 mm
・ Upper cylinder: φ15 × 22mm (Material SUJ-2)
・ Lower plate: φ24 × 6.85mm (Material SUJ-2)
Evaluation method: Evaluated by the average value of the friction coefficient for 10 to 15 minutes.
[Residual amount of organomolybdenum compound]
200 mL of the sample was placed in a 300 mL glass graduated cylinder, placed in a constant temperature bath at 140 ° C., and oxidized by blowing air at a flow rate of 50 mL / min into the sample. Before the test, the content of the organomolybdenum compound in the sample after 1 day, 3 days and 6 days was quantified by liquid chromatography. The ratio of the content after the test (after 1 day, 3 days, and 6 days) with respect to the content before the test was calculated in 100 minutes. The results are shown in Table 2.

[Preparation of grease composition]
Base grease (thickening) using the above-mentioned paraffinic refined mineral oil as base oil and diphenylmethane-4,4'-diisocyanate / cyclohexylamine / octadecylamine reacted at a mass ratio of 9/6/4 Addition and mixing of secondary alkyl ZnDTP and organic molybdenum compounds A1 to A2 and B1 to 2 so that the content is 2500 ppm by mass in terms of molbudene. The grease compositions of Examples 5-6 and Comparative Examples 4-5 were prepared. Further, Comparative Example 6 was prepared by adding and mixing 1% by mass of secondary alkyl ZnDTP to the base grease and containing no organic molybdenum compound. The organic molybdenum compounds B1 and B2 are uniformly dissolved in the base grease, but the organic molybdenum compounds A1 and A2 are not dissolved in the base grease. Therefore, after coarsely pulverizing with a mortar, a sieve having an opening of 500 μm is used. The one that passed through the sieve was used.

These grease compositions were evaluated for thermal stability by measuring the coefficient of friction before and after the sealed heating test by the following method.
<Evaluation of thermal stability>
[Sealed heating test]
Test method: Using an oxidation stability tester of JIS K2220 (grease), fill the grease composition in the same way as JIS K2220, fill and seal air at 25 ° C in atmospheric pressure, and then heat to 140 ° C. Let stand for 240 hours.
〔Coefficient of friction〕
The friction coefficient of the sample before and after the hermetic heating test was measured according to the following. The results are shown in Table 3.
Tester used: SRV measurement tester (manufactured by Optimol, model: type3)
Evaluation condition ・ Measure the coefficient of friction under the line contact condition of the cylinder on plate.
・ Load: 200N
・ Temperature: 80 ℃
・ Measurement time: 15 minutes ・ Amplitude: 1 mm
・ Upper cylinder: φ15 × 22mm (Material SUJ-2)
・ Lower plate: φ24 × 6.85mm (Material SUJ-2)
Evaluation method: Evaluated by the average value of the friction coefficient for 10 to 15 minutes.

  As apparent from the test results of the lubricating oil composition, the lubricating oil composition containing the organomolybdenum compound of the present invention can maintain a low coefficient of friction over a long period of time even at high temperatures. This is because the organomolybdenum compound of the present invention is difficult to decompose even at high temperatures. Further, the grease composition test results show that the grease composition containing the organomolybdenum compound of the present invention can maintain a low coefficient of friction over a long period of time even at high temperatures.

Claims (4)

An organic molybdenum compound represented by the following general formula (1).

(Wherein R ^{1 to} R ⁴ represent an alkyl group having 1 to 8 carbon atoms or an aralkyl group having 7 to 13 carbon atoms, and X ^{1 to} X ⁴ represent an oxygen atom or a sulfur atom, provided that R ^{1 to} R ^At least one of ⁴ is an aralkyl group having 7 to 13 carbon atoms.) ^{2. At} least one of R ¹ and R ^{2 in} the general formula (1) is an aralkyl group having 7 to 13 carbon atoms, and at least one of R ³ and R ⁴ is an aralkyl group having 7 to 13 carbon atoms. The organomolybdenum compound described in 1.   A lubricating oil composition in which the particles of the organomolybdenum compound according to claim 1 or 2 are dispersed in a base oil, and the 50% particle size of the particles of the organomolybdenum compound measured by a laser diffraction light scattering method is 30 to 30. A lubricating oil composition that is 450 nm.   A grease composition containing the organomolybdenum compound according to claim 1.

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