JP4976018B2 - Lubricant composition - Google Patents

Description

The present invention relates to a lubricant composition. Specifically, the present invention relates to a lubricant composition containing an ionic liquid.

Conventionally, mineral oils and synthetic lubricating oils (such as ester oils, poly α-olefins, phenyl ether oils, perfluoroalkyl ethers) are often used as base oils used in lubricant compositions.
However, in these lubricant compositions, these base oils evaporate and further decomposed products evaporate, particularly when used under a high temperature atmosphere (for example, 100 to 300 ° C.) or by high temperature due to friction during use. In some cases, the stability of the lubrication effect and the contamination to the surroundings sometimes become problems.
As a countermeasure, there is a method of using a high molecular weight synthetic lubricating oil in order to lower the vapor pressure of the base oil at a high temperature. However, as the molecular weight is increased, the viscosity becomes higher. In the lubricant composition using oil, there is a problem that energy loss due to stirring resistance increases particularly when used at a low temperature.
Accordingly, there is a demand for a lubricant base oil that has low viscosity at low temperatures (for example, −40 to 0 ° C.) and normal temperature, low evaporation at high temperatures, and excellent thermal stability.
Correspondingly, for example, in Patent Document 1, a lubricant composition mainly composed of a saturated aliphatic monocarboxylic acid diester of an aliphatic dihydric alcohol is used, and in Patent Document 2, a low-viscosity ester base oil is used. Lubricant compositions comprising friction modifiers have been proposed.
However, even with the lubricant compositions proposed in these patent documents, the evaporation at a particularly high temperature is not a little, and the stability of the lubricating effect and the contamination to the surroundings sometimes become problems.
Recently, it has also been proposed to use an ionic liquid as a base oil of a semi-solid lubricant composition (Patent Document 3). However, semi-solid lubricant compositions using these ionic liquids have large starting torque and rotational torque at low temperatures (for example, −20 ° C. to 0 ° C.), and liquid lubricants using these ionic liquids The composition had a high viscosity at low temperatures (−10 ° C.), insufficient lubricity at low temperatures, and was highly corrosive to copper plates.
JP 2003-321691 A JP 2004-051719 A JP 2005-154755 A

The object of the present invention is to provide a lubricant composition that has little evaporation at high temperature, low starting torque and low rotational torque at low temperature, low viscosity at low temperature, improved lubricity at low temperature, and low copper plate corrosivity. Is to provide things.

As a result of intensive studies to achieve the object of the present invention, it has been found that the above-mentioned problems can be solved by containing an ionic liquid having a specific cation as a base oil.
That is, the present invention is a lubricant composition containing a lubricating base oil composed of the ionic liquid (A) represented by the general formula (1).

In the formula, R is a monovalent hydrocarbon group having 1 to 36 carbon atoms or a substituted hydrocarbon group, and the substituted hydrocarbon group is a hydroxyl group, a nitro group, a cyano group, a carboxyl group, an alkylamino group, an alkyl ester. Having one or more substituents selected from the group consisting of a group, an alkyl ether group and a halogen atom, the plurality of Rs may be the same or different, and X ⁻ is a counter anion.

The lubricant composition of the present invention has almost no evaporation at high temperature, low starting torque and low rotating torque at low temperature, low viscosity at low temperature, improved lubricity at low temperature, and low copper plate corrosivity. .

The “lubricant composition” in the present invention is a general term for substances used for lubricating the friction surface and improving the lubrication efficiency of the machine. The liquid lubricant composition used in the liquid state and a semi-solid The grease composition used in the form is included.

The “ionic liquid” in the present invention is a salt that is liquid at room temperature called a room temperature molten salt, and is a substance that has been attracting attention as a solvent and battery material for green chemistry by combining various anions and cations. is there.

The ionic liquid (A) in the present invention is represented by the following general formula (1), the cation moiety is a sulfonium cation (a), and the counter anion (b) is an anion in which (A) is liquid at room temperature.

  In the formula, R is a monovalent hydrocarbon group having 1 to 36 carbon atoms or a monovalent substituted hydrocarbon group having 1 to 36 carbon atoms, and the substituted hydrocarbon group is a hydroxyl group, a nitro group, or a cyano group. , A carboxyl group, an alkylamino group, an alkyl ester group, an alkyl ether group, and one or more substituents selected from the group consisting of halogen atoms, and a plurality of R may be the same or different.

Examples of the hydrocarbon group include linear or branched methyl groups, ethyl groups, propyl groups, isopropyl groups, butyl groups, and other aliphatic hydrocarbon groups, and aromatic hydrocarbon groups such as phenyl groups, benzyl groups, and alkylphenyl groups. Is mentioned.
Examples of the substituted hydrocarbon group having a hydroxyl group include a hydroxymethyl group, a 2-hydroxyethyl group, a 4-hydroxybutyl group, and a 2-hydroxyoctyl group.
Examples of the substituted hydrocarbon group having a nitro group include a nitromethyl group and a 2-nitroethyl group.
Examples of the substituted hydrocarbon group having a cyano group include a cyanomethyl group and a 2-cyanoethyl group.
Examples of the substituted hydrocarbon group having a carboxyl group include a carboxymethyl group and a 2-carboxyethyl group.
Examples of the substituted hydrocarbon group having an alkylamino group include a methylaminooctyl group and an ethylaminodecyl group.
Examples of the substituted hydrocarbon group having an alkyl ether group include a methyl ether group and an ethyl ether group.
Examples of the substituted hydrocarbon group having a halogen atom include trifluoromethyl group, 2,2,2-trifluoroethyl group, 3,3,3-trifluoropropyl group, 4,4,4-trifluorobutyl. Group and the like.

R is preferably a hydrocarbon group having no substituent and a halogen atom from the viewpoints of low crystallinity at low temperature, low starting torque and low rotational torque at low temperature, and low kinematic viscosity at low temperature. A substituted hydrocarbon group, more preferably an alkyl group having 1 to 4 carbon atoms. Particularly preferred is an alkyl group having 1 or 2 carbon atoms.

Specific examples of (a) include trimethylsulfonium cation, triethylsulfonium cation, tripropylsulfonium cation, tributylsulfonium cation, tripentylsulfonium cation, monomethyldiethylsulfonium cation, monomethyldipropylsulfonium cation, monomethyldibutylsulfonium cation, monoethyldimethyl. Sulfonium cation, monoethyldipropylsulfonium cation, monoethyldibutylsulfonium cation, monopropyldimethylsulfonium cation, monopropyldiethylsulfonium cation, monopropyldibutylsulfonium cation, monomethylmonoethylmonopropylsulfonium cation, monomethylmonoethylmonobutylsulfonium cation, Mo Phenyldimethylsulfonium cation, monophenyldiethylsulfonium cation, monophenylmonoethylmonomethylsulfonium cation, 2-hydroxyethyldimethylsulfonium cation, 2-nitroethyldimethylsulfonium cation, 2-cyanoethyldimethylsulfonium cation, 2,2,2-trifluoro Examples thereof include ethyldimethylsulfonium cation, 2- (N, Ndimethylamino) ethyldimethylsulfonium cation, 2- (methyl ether) ethyldimethylsulfonium cation, and 2-carboxyethyldimethylsulfonium cation.

As the counter anion (b) constituting the ionic liquid (A) in the present invention, a compound generally known as an anion of the ionic liquid can be used. For example, the following inorganic acid anions (b1) and organic acid anions ( and at least one anion selected from the group consisting of b2).

As the inorganic acid anion (b1), PO ₄ ³⁻ , BO ₃ ³⁻ , SO ₄₂₋ , F ⁻ , PF ₆ −, BF ₄ ⁻ , BF (CF ₃ ) ³⁻ , BF ₂ (CF ₃ ) ²⁻ , BF ₃ (CF ₃ ) ⁻ , B (CF ₃ ) ⁴⁻ , BF ₃ (C ₂ F ₅ ) ⁻ , BF ₃ (C ₃ F ₇ ) ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , ClO ₄ ⁻ , AlF ₄ ⁻ , AlCl ₄ ⁻ , AlF ₃ Cl ⁻ , AlFCl ₃ ⁻ , FeF ₄ ⁻ , FeCl ₄ ⁻ , FeF ₃ Cl ⁻ , FeFCl ₃ ⁻ , TaF ₆ ⁻ , NbF ₆ ⁻ , SiF ₆ ²⁻ , CN ⁻ , SCN ^- , F (HF) ^n- (n is a numerical value of 1 to 4) and the like.

The following are mentioned as an example of an organic acid anion (b2).
In the following examples, organic acids corresponding to anions are described.
(B21) C2-C15 divalent to tetravalent polycarboxylic acid having 2 to 15 carbon atoms:
Aliphatic polycarboxylic acids [saturated polycarboxylic acids (oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, peric acid, azelaic acid, sebacic acid, undencanic acid, dodecanedioic acid, tridecanedioic acid, Tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, methylmalonic acid, ethylmalonic acid, propylmalonic acid, butylmalonic acid, pentylmalonic acid, hexylmalonic acid, dimethylmalonic acid, diethylmalonic acid, methylpropylmalonic acid, methyl Butylmalonic acid, ethylpropylmalonic acid, dipropylmalonic acid, methylsuccinic acid, ethylsuccinic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylsuccinic acid, 2-methylglutaric acid, 3-methylglutaric acid, 3- Methyl-3-ethylglutaric acid, 3,3-diethylglutaric acid, Tilsuccinic acid, 2-methylglutaric acid, 3-methylglutaric acid, 3,3-dimethylglutaric acid, 3-methyladipic acid, etc.), aliphatic unsaturated polycarboxylic acids (maleic acid, fumaric acid, itaconic acid, citraconic acid) ], Aromatic polycarboxylic acid (b211) [phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, etc.], S-containing polycarboxylic acid [thiodibropionic acid, etc.];

C2-C20 oxycarboxylic acid:
Aliphatic oxycarboxylic acid [glycolic acid, lactic acid, lactic butyric acid, castor oil fatty acid, etc.]; aromatic oxycarboxylic acid [salicylic acid, mandelic acid, 4-hydroxybenzoic acid, 1-hydroxy-2-naphthoic acid, 3-hydroxy-2 -Naphthoic acid, 6-hydroxy-2-naphthoic acid, etc.];

C1-C30 monocarboxylic acid:
Aliphatic monocarboxylic acids [saturated monocarboxylic acids (formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, uraric acid, myristic acid, stearic acid, behenic acid, Undencanic acid, etc.), unsaturated monocarboxylic acids (acrylic acid, methacrylic acid, crotonic acid, oleic acid, etc.)]; aromatic monocarboxylic acids [benzoic acid, cinnamic acid, naphthoic acid, toluic acid, ethylbenzoic acid, propyl Benzoic acid, isopropylbenzoic acid, butylbenzoic acid, isobutylbenzoic acid, sec-butylbenzoic acid, tertiarybutylbenzoic acid, hydroxybenzoic acid, ethoxybenzoic acid, propoxybenzoic acid, isopropoxybenzoic acid, butoxybenzoic acid isobutoxybenzoic acid , 2 Butoxybenzoic acid, 3 Butoxybenzoic acid, Aminobenzoic acid Acid, N-methylaminobenzoic acid, N-ethylaminobenzoic acid, N-propylaminobenzoic acid, N-isopropylaminobenzoic acid, N-butylaminobenzoic acid, N-isobutylaminobenzoic acid, N-secondarybutylamino Benzoic acid, N-tert-butylaminobenzoic acid, N, N-dimethylaminobenzoic acid, N, N-diethylaminobenzoic acid, nitrobenzoic acid, fluorobenzoic acid, etc.]

Carboxylic acid represented by the general formula RfCOOH (Rf is a fluoroalkyl group having 1 to 30 carbon atoms):
Trifluoroacetic acid, perfluoropropionic acid, perfluoroisopropionic acid, perfluorobutyric acid, perfluorovaleric acid, perfluorocaproic acid, perfluoropelargonic acid, perfluorocapric acid, perfluoroundecylic acid, perfluorolauric acid, Perfluorotridecanoic acid, perfluorotetradecanoic acid, perfluoron-octanoic acid, perfluorolauric acid, perfluoropalmitic acid and the like;

(B22) alkyl sulfonate (C1-15) benzenesulfonic acid (p-toluenesulfonic acid, nonylbenzenesulfonic acid, dodecylbenzenesulfonic acid etc.), sulfosalicylic acid, methanesulfonic acid, trifluoromethanesulfonic acid, perfluoroethane Such as sulfonic acid.

(B23) Phenol monohydric phenol (including phenols and naphthols) [phenol, alkyl (carbon number 1 to 15) phenols (cresol, xylenol, ethylphenol, n- or isopropylphenol, isododecylphenol, etc.), methoxy Phenols (eugenol, guaiacol, etc.), α-naphthol, β-naphthol, cyclohexylphenol, etc.]; polyhydric phenols (catechol, resorcin, pyrogallol, phloroglucin, bisphenol A, bisphenol F, bisphenol S, etc.).

(B24) Triazole, compound having a tetrazole skeleton 1-H-1,2,4-triazole, 1,2,3-triazole, 1,2,3-benzotriazole, carboxybenzotriazole, 3-mercapto-1,2 , 4-triazole, 1,2,3-triazole-4,5-dicarboxylic acid, 3-mercapto-5-methyl-1,2,4-triazole, 1,2,3,4-tetrazole and the like.

(B25) Other organic acid bistrifluoromethanesulfonimide, bispentafluoroethanesulfonic acid imide, bistrifluoroacetamide, N-trifluoromethanesulfo-trifluoroacetamide, bistrifluoromethylamine, biscyanoimide, tristrifluoromethanesulfomethide Such;

Of the above inorganic acid anions (b1) and organic acid anions (b2), BF ₄ ⁻ , PF ₆ ⁻ , AlF ₄ ⁻ , FeF ₄ ⁻ , trif is preferable from the viewpoint of excellent low viscosity at low temperatures. Fluoroacetic acid, perfluoroethanecarboxylic acid, trifluoromethanesulfonic acid, bistrifluoromethanesulfimide, bistrifluoroacetamide, biscyanoimide, tristrifluoromethanesulfonic acid methide. One kind or two or more kinds of these anions may be used.

The method for producing the ionic liquid (A) in the present invention is not particularly limited. Am. Chem. Soc. , 69, 2269 (1947), US Pat. No. 4,892,944 and the like (a method in which a tertiary amine is quaternized with a carbonate and then acid-exchanged).

In the ionic liquid (A) in the present invention, the equivalent ratio of (a) and (b) is not particularly limited, but from the viewpoint of lubricity and thermal stability, (a) :( b) = 1: 0. The range of 8 to 1: 2 is preferable, and the range of (a) :( b) = 1: 0.95 to 1: 1.05 is more preferable.

The freezing point of the ionic liquid (A) in the present invention is preferably −10 ° C. or lower, more preferably −20 ° C. or lower, from the viewpoint of lubricity at low temperatures.

The lubricant base oil used in the lubricant composition of the present invention may contain an ionic liquid (A) other than (A) as long as the effects of the present invention are not impaired. .

Examples of the cation contained in the ionic liquid other than (A) include cations such as imidazolium, pyridinium, pyrazolium, piperidine, morpholine, piperazine, pyrrole, phosphonium and quaternary ammonium salts. Examples of the anion include the same as those mentioned in (A).

Furthermore, the lubricant base oil used in the lubricant composition of the present invention is a mineral oil or a synthetic lubricant oil that has been conventionally used as a base oil of a lubricant composition, as long as the effects of the present invention are not impaired. It may contain.

Mineral oil refers to oil that is separated, distilled, and refined from natural crude oil, and includes paraffinic, naphthenic, paraffin-naphthene mixed systems, or hydrotreated and solvent refined of these.

Synthetic lubricating oils are chemically synthesized lubricating oils, such as poly-α-olefins, polyisobutylene (polybutene), diesters such as alkyl esters of dicarboxylic acids, polyol esters, phosphate esters, silicate esters, polyesters. Examples thereof include fluorinated compounds such as alkylene glycol, polyphenyl ether, polysilicone, perfluoroalkyl ether, and alkylbenzene.

In the lubricant composition of the present invention, the weight ratio of the ionic liquid (A) and other base oil [ionic liquid other than (A) + mineral oil + synthetic lubricating oil] is usually 10-100 / 0-90. From the viewpoint of viscosity at low temperature and evaporability at high temperature, it is preferably 50 to 100/0 to 50, more preferably 70 to 100/0 to 30, and particularly preferably 100/0.

The lubricant composition of the present invention may be a semi-solid lubricant composition that is semi-solid at 30 ° C., a so-called grease agent, or a liquid lubricant composition that is liquid at 30 ° C. The effect of the ionic liquid (A) can be exhibited.

In the case of a semi-solid lubricant composition, in addition to the base oil, it usually further contains at least one selected from the group consisting of a solid lubricant and a thickener.

Solid lubricants include molybdenum atom-containing compounds (inorganic molybdenum compounds such as molybdenum disulfide, and organic molybdenum compounds such as molybdenum dithiocarbamate, molybdenum dithiophosphate and molybdenum dithiocarbamate), graphite, and fluororesins (polytetrafluoroethylene, etc.) , Melamine cyanuric acid adduct, boron nitride and at least one selected from the group consisting of soft metal particles (such as gold, silver and copper) can be used.
The content of the solid lubricant is not less than an amount effective for making the lubricant composition semi-solid, and is preferably 50% or less (hereinafter,% is not particularly limited) of the entire lubricant composition. % Represents as much as possible), more preferably 5 to 40%.

Further, as the thickener, at least one selected from the group consisting of metal soap, composite metal soap, two or more urea groups, low molecular compounds having two or more urethane groups, and inorganic fine particles can be used.
Examples of the metal soap include aluminum soap, calcium soap, lithium soap, sodium soap and barium soap.
Examples of the composite metal soap include lithium complex soap, calcium complex soap, and aluminum complex soap.
As a low molecular compound having two or more urea groups or two or more urethane groups, a diurea compound represented by the following general formula (2) can be preferably used.
^{R 1 -NHCONH-R 3 -NHCONH-} R 2 (2)
Here, R ³ is an aromatic group having 6 to 15 carbon atoms. R ¹ and R ² are hydrocarbon groups having 6 to 20 carbon atoms.
Examples of inorganic fine particles include carbon black, bentonite, silica (such as hydrophobic silica) and non-metallic inorganic conductive fillers (such as zinc oxide, barium sulfate, aluminum borate, titanium oxide, tin oxide, titanium black and potassium titanate). And may or may not be doped with metal, particularly Sb-doped SnO ₂ .
The metal soap and the composite metal soap are preferably used when a base oil other than the ionic liquid is included as the base oil.

The content of the thickener is not less than an amount effective for making the lubricant composition semi-solid, and preferably 40% or less, more preferably 5 to 35% of the entire lubricant composition. is there.

When both the thickener and the solid lubricant are contained, the total content is preferably 50% or less, more preferably 5 to 40%, of the entire lubricant composition.

In the case of a liquid lubricant composition that is liquid at 30 ° C., the following additives may be contained as required in addition to the base oil.
Additives include viscosity index improvers, pour point depressants, detergents and dispersants.

Examples of the viscosity index improver include polymethacrylate-based and polyolefin-based viscosity index improvers.
Pour point depressants include polymethacrylate and ethylene vinyl acetate pour point depressants.
Examples of the detergent include sulfonate, salicylate, phenate and naphthenate Ca and Mg salts, calcium carbonate, and the like.
Examples of the dispersant include succinimides (bis type, mono type, borate type, Mannich condensation product, etc.).
The content of each of the viscosity index improver, the pour point depressant, the detergent or the dispersant is preferably 20% or less, more preferably 0.1 to 10%, of the entire liquid lubricant composition.

The lubricant composition of the present invention may be semi-solid or liquid, and if necessary, an antioxidant, a friction wear modifier, a friction modifier, an extreme pressure agent, an antifoaming agent, an anti-emulsifier and You may contain the 1 or more types of additive chosen from the group which consists of a corrosion inhibitor.

Antioxidants include phenolic antioxidants, amine antioxidants, zinc thiophosphate, and the like, and the antioxidants may be a mixture of two or more. The addition amount of the antioxidant is usually 5% or less, preferably 0.1 to 3%, based on the total weight of the lubricant composition.
Examples of phenolic antioxidants include 4,4′-methylenebis (2,6-di-tert-butylphenol), 4,4′-bis (2,6-di-tert-butylphenol), 4,4 ′. -Bis (2-methyl-6-tert-butylphenol), 2,2'-methylenebis (4-ethyl-6-tert-butylphenol), 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 4,4′-butylidenebis (3-methyl-6-tert-butylphenol), 4,4′-isopropylidenebis (2,6-di-tert-butylphenol), 2,2′-methylenebis (4-methyl-6) -Nonylphenol), 2,2'-isobutylidenebis (4,6-dimethylphenol), 2,2'-methylenebis (4-methyl-6-cyclohexene) Xylphenol), 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,4-dimethyl-6-tert-butylphenol, 2,6- Di-tert-α-dimethylamino-p-cresol, 2,6-di-tert-butyl-4 (N, N′-dimethylaminomethylphenol), 4,4′-thiobis (2-methyl-6-tert) -Butylphenol), 4,4'-thiobis (3-methyl-6-tert-butylphenol), 2,2'-thiobis (4-methyl-6-tert-butylphenol), bis (3-methyl-4-hydroxy-) 5-tert-butylbenzyl) sulfide, bis (3,5-di-tert-butyl-4-hydroxybenzyl) sulfide, 2,2′-thio-di Ethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], tridecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, pentaerythrityl- Tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, octadecyl-3- ( 3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 3-methyl-5-tert-butyl-4-hydroxyphenyl substituted fatty acid esters and the like.
Examples of amine-based antioxidants include phenyl-α-naphthylamine, alkylphenyl-α-naphthylamine, and dialkyldiphenylamine.

Examples of the friction wear modifier include molybdenum dithiophosphate, molybdenum dithiocarbamate, and zinc dialkyldithiophosphate. The content thereof is usually 5% or less, preferably 0.1 to 3% in the total weight of the lubricant composition. It is.
Friction modifiers include long chain fatty acid systems (such as oleic acid), long chain fatty acid esters (such as oleic acid esters), long chain amine systems (such as oleylamine), and long chain amides (such as oleamide). The content is usually 5% or less, preferably 0.1 to 1%, based on the total weight of the lubricant composition.
Examples of the extreme pressure agent include sulfur phosphorus-based, sulfur-based, phosphorus-based and chlor-based extreme pressure agents, and the content thereof is usually 15% or less, preferably 0.1 to 0.1% based on the total weight of the lubricant composition. 10%.
Examples of the antifoaming agent include silicone oil, metal soap, fatty acid ester, and phosphate ester, and the content thereof is usually 1,000 ppm or less, preferably 10 to 700 ppm in the total weight of the lubricant composition.
Examples of the demulsifier include quaternary ammonium salts, sulfated oils and phosphate esters, and the content thereof is usually 3% or less, preferably 0 to 1%, based on the total weight of the lubricant composition.
Examples of the corrosion inhibitor include benzotriazole and 1,3,4-thiodiazolyl-2,5-bisdialkyldithiocarbamate, and the content thereof is usually 3% or less, preferably 0, based on the total weight of the lubricant composition. ~ 2%.

The total of the antioxidant, friction wear modifier, friction modifier, extreme pressure agent, antifoaming agent, anti-emulsifier and corrosion inhibitor in the semi-solid lubricant composition is in the total weight of the lubricant composition. Preferably it is 20% or less, More preferably, it is 1-15%, Most preferably, it is 1-10%.

The content ratio of the base oil / solid lubricant / thickener / other additives in the semi-solid lubricant composition is usually 50 to 98/0 to 50/0 to 40/0 to 20, preferably at a low temperature. From the viewpoint of the lubricity, it is 50 to 95/5 to 40/5 to 35/0 to 15.

In the liquid lubricating oil composition, the total of the antioxidant, friction wear modifier, friction modifier, extreme pressure agent, antifoaming agent, anti-emulsifier and corrosion inhibitor is preferably in the total weight of the lubricant composition. It is 30% or less, more preferably 3 to 25%, particularly preferably 3 to 15%.

Base oils / other additives (viscosity index improvers, pour point depressants, detergents, dispersants, antioxidants, friction wear modifiers, friction modifiers, extreme pressure agents, dissipators in liquid lubricant compositions The total content of the foaming agent, the demulsifier and the corrosion inhibitor is preferably 70 to 100/0 to 30, more preferably 75 to 97/3 to 25, particularly preferably 85 from the viewpoint of lubricity at low temperatures. ~ 97 / 3-15.

The lubricant composition of the present invention has a low viscosity even at a low temperature and a normal temperature, is excellent in lubricity, and has a low evaporation property even at a high temperature.
Moreover, the lubricant composition of the present invention has a high viscosity index, and is excellent in fluidity at low temperatures, lubricity at high temperatures, and thermal stability.
Furthermore, the lubricant composition of the present invention is less corrosive to a copper plate, and even if the lubricating surface is made of copper or a metal containing copper, the surface corrosion is small.
Further, the lubricant composition of the present invention has low evaporation under high vacuum, and furthermore, since the lubricant composition of the present invention has conductivity, it can exhibit antistatic properties.

[Example]
Examples will be described below, but the present invention is not limited thereto. In addition, the number of parts in Examples and Comparative Examples represents parts by weight unless otherwise specified.

(Semi-solid lubricant composition at 30 ° C.)
Examples 1-8, Comparative Examples 1-3
The following (A1) to (A7), (H1), or (H2) as a base oil, and hydrophobic silica (product name: silophobic: manufactured by Fuji Silysia Chemical Co., Ltd.) as a thickener 3 was mixed and kneaded in a three-stage roll mill to obtain a lubricant composition.

(A1): Monophenyldimethylsulfonium bistrifluoromethanesulfimide (A2): Triethylsulfonium bistrifluoromethanesulfimide (A3): Dimethylmonoethylsulfonium bistrifluoromethanesulfimide (A4): 2,2,2-trifluoroethyl Dimethylsulfonium bistrifluoromethanesulfimide (A5): 2-hydroxyethyldimethylsulfonium bistrifluoromethanesulfimide (A6): 2-nitroethyldimethylsulfonium bistrifluoromethanesulfimide (A7): 2-cyanoethyldimethylsulfonium bistrifluoromethanesulfone Imido (H1): Bis (2ethylhexyl) sebacate (manufactured by Wako Pure Chemical Industries, Ltd.)
(H2): 1-ethyl-3-methylimidazolium trifluoromethanesulfonate

About the obtained lubricant composition, the following physical properties and performance were evaluated by the following methods.
The evaluation results are shown in Tables 1-3.

<Mixed penetration>
Measured according to JIS K222015. The consistency is a numerical value indicating the hardness of the lubricant composition.
<Low temperature torque>
In accordance with JIS K222018, the starting torque and rotational torque at −20 ° C. were measured with a low temperature torque tester. The lower the starting torque at low temperature and the lower the rotating torque, the better the lubricity at low temperature.
"Evaluation criteria for low temperature starting torque"
○: Less than 100 N · cm Δ: 100 N · cm or more and less than 200 N · cm ×: 200 N · cm or more “Evaluation criteria for low-temperature rotational torque”
○: Less than 50 N · cm Δ: 50 N · cm or more and less than 100 N · cm ×: 100 N · cm or more <Copper plate corrosivity>
Measured according to JIS K22209. The evaluation criteria are as follows.
○: There is no green or black discoloration on the copper plate. Δ: There is a slight green or black discoloration on the copper plate. X: There is a clear green or black discoloration on the copper plate.
1 g of the lubricant composition was placed in a petri dish and the change in weight was measured when placed in a high temperature bath at 200 ° C. for 24 hours. Less weight change is better.
“Evaluation criteria for evaporability”
○: Change in weight is less than 1% Δ: Change in weight is 1 or more and less than 2% ×: Change in weight is 2% or more

(Lubricant composition liquid at 30 ° C.)
Examples 9-16, Comparative Examples 3 and 4
(A1) to (A3), (A5) to (A7), (H2), or (H3) below as a base oil, and octyl-3- (3,5-di-) as an antioxidant tert-Butyl-4-hydroxyphenyl) propionate was blended in the number of parts shown in Table 2, and kneaded in a three-stage roll mill to obtain a lubricant composition.
(H3): Mineral oil “YUBASE4” (manufactured by SK Corp.)

About the obtained lubricant composition, the following physical properties and performance were evaluated by the following methods.
The evaluation results are shown in Table 2.

<Lubricity>
Equipment: Optimol SRV tester (Nippon Parkerizing Co., Ltd.)
Ball: 10mm in diameter
Disc: Diameter 24mm x Thickness 7.9mm
Measurement temperature: 30 ° C
Load: 50N Frequency: 50Hz
Amplitude: 2 mm
Measurement time: 30min
"Evaluation criteria for lubricity"
○: Friction coefficient is less than 0.05 Δ: Friction coefficient is 0.05 or more and less than 0.09 ×: Friction coefficient is 0.09 or more <Kinematic viscosity>
The kinematic viscosity at −10 ° C. and + 40 ° C. was measured by the method of JIS K2283. A lower viscosity is superior in that there is less energy loss due to stirring resistance.
"Evaluation criteria for kinematic viscosity at -10 ° C"
○: Less than 500 mm2 / s Δ: 500 or more and less than 2000 mm2 / s ×: 2000 mm2 / s or more “Evaluation criteria of kinematic viscosity at + 40 ° C.”
○: Less than 15 mm2 / s Δ: 15 or more and less than 20 mm2 / s ×: 20 mm2 / s or more <Copper plate corrosivity>
Measured according to JIS K22209. The evaluation criteria are as follows.
○: There is no green or black discoloration on the copper plate. Δ: There is a slight green or black discoloration on the copper plate. X: There is a clear green or black discoloration on the copper plate. <Evaporation (Noack method)>
It was measured by the method of ASTM D5800. Less weight change is better.
“Evaluation criteria for evaporability”
○: Change in weight is less than 1% Δ: Change in weight is 1 or more and less than 2% ×: Change in weight is 2% or more

  The lubricant composition of the present invention can be used as a lubricant composition used in various lubrication apparatuses such as vacuum apparatuses and semiconductor manufacturing apparatuses. Further, since the lubricant composition of the present invention has electrical conductivity, it is suitable for applications requiring antistatic properties such as a lubricant composition for bearings such as hard disks and micromachines, and a lubricant for heat rollers. Yes. Further, since it is less corrosive to copper, it is also suitable as a lubricant composition for a lubricating device using copper or a copper alloy.

Claims (6)

A lubricant composition comprising a lubricating base oil comprising the ionic liquid (A) represented by the general formula (1).
[Wherein, R is a monovalent hydrocarbon group or substituted hydrocarbon group having 1 to 36 carbon atoms in total, and the substituted hydrocarbon group is a hydroxyl group, a nitro group, a cyano group, a carboxyl group, an alkylamino group, an alkyl group. It has one or more substituents selected from the group consisting of an ester group, an alkyl ether group and a halogen atom, and a plurality of R may be the same or different, and X ⁻ represents bistrifluoromethanesulfimide, bispentafluoro It is a counter anion composed of ethanesulfonic acid imide, bistrifluoroacetamide, N-trifluoromethanesulfo-trifluoroacetamide, bistrifluoromethylamine, biscyanoimide or tristrifluoromethanesulfometide . ]   The lubricant composition according to claim 1, further comprising at least one selected from the group consisting of a solid lubricant and a thickener and being semisolid at 30 ° C.   The solid lubricant is at least one selected from the group consisting of a molybdenum atom-containing compound, graphite, fluororesin, melamine cyanuric acid adduct, boron nitride, and soft metal particles, and the thickener is a metal soap or a composite metal soap. 3. The lubricant composition according to claim 2, wherein the lubricant composition is at least one selected from the group consisting of a low molecular compound having two or more urea groups or two or more urethane groups and inorganic fine particles.   The lubricant composition according to claim 1, further comprising at least one lubricating base oil selected from the group consisting of mineral oil, ether oil, ester oil and phosphate ester oil, and is liquid at 30 ° C.   Furthermore, the lubricant composition in any one of Claims 1-4 containing at least 1 sort (s) of antioxidant chosen from the group which consists of a phenolic antioxidant, an amine antioxidant, and zinc thiophosphate.   The lubricant composition according to any one of claims 1 to 5, comprising 10% by weight or more of the ionic liquid (A) in the entire lubricant composition.