Lubricating oil composition, metalworking fluid, and metalworking method

Abstract

To provide a lubricating oil composition having improved extreme pressure performance.SOLUTION: The lubricating oil composition contains a lubricating base oil, a sulfur-containing compound and a metal soap. The lubricant composition according to claim 1, wherein the metallic soaps are one or more selected from the group consisting of aliphatic acid metallic salts represented by the following general formula (2-1), aliphatic acid borate metallic salts represented by the following general formula (2-2), and amine ligand metallic complex compounds of the aliphatic acid metallic salts and amine compounds (M21 and M22 are each independently Li, Na, K, Mg, Ba, Bi, Cu, Pb, Zn, Zr or Co). ).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a lubricating oil composition, a metalworking oil and a metalworking method. [Background technology]

[0002] In metal processing, lubricating oil compositions are used to ensure smooth metal processing. The lubricating oil compositions are generally compositions in which additives such as extreme pressure agents, oiliness improvers, antioxidants, rust inhibitors, and antifoaming agents are added to a lubricating base oil such as mineral oil.

[0003] When a chlorine-based extreme pressure agent is used as the extreme pressure agent, the chlorine-based extreme pressure agent has various problems such as environmental pollution due to the generation of dioxins during incineration and concerns about carcinogenicity. In order to solve such problems, non-chlorine-based extreme pressure agents such as sulfur-based extreme pressure agents have been proposed (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2020 / 158205 Summary of the Invention [Problem to be solved by the invention]

[0005] Sulfur-based extreme pressure agents are used as non-chlorine-based extreme pressure agents, but in recent years, there has been a demand for further improvements in extreme pressure performance to meet demands for increased hardness of metal materials and more efficient processing.

[0006] The problem to be solved by the present invention is to provide a lubricating oil composition having improved extreme pressure performance. Another problem to be solved by the present invention is to provide a metalworking oil having improved extreme pressure performance and a metalworking method using the metalworking oil. [Means for solving the problem]

[0007] As a result of intensive research to solve the above problems, the present inventors have found that excellent extreme pressure performance can be obtained by combining a sulfur compound having a specific structure with a metal soap having a specific structure, and have completed the present invention.

[0008] That is, the present invention relates to the following lubricating oil compositions, etc. 1. A lubricating oil composition comprising a lubricating base oil, a sulfur-containing compound, and a metal soap, The sulfur-containing compound is a compound represented by the following general formula (1): The lubricating oil composition, wherein the metal soap is at least one selected from the group consisting of a fatty acid metal salt represented by the following general formula (2-1), a fatty acid metal borate represented by the following general formula (2-2), and an amine ligand metal complex compound of the fatty acid metal salt and an amine compound: [ka] (In the general formulas (1), (2-1) and (2-2), R 11 and R 12 are each independently an alkyl group having 2 to 24 carbon atoms or an unsaturated hydrocarbon group having 2 to 24 carbon atoms and one or more carbon-carbon unsaturated bonds, x is an integer ranging from 1 to 8; R 21 and R 22 are each independently an alkyl group having 1 to 12 carbon atoms, n is an integer ranging from 1 to 4, M 21 and M 22 are each independently lithium, sodium, potassium, magnesium, barium, bismuth, copper, lead, zinc, zirconium, or cobalt. 2. The lubricating oil composition according to 1, wherein the sulfur-containing compound is a compound represented by the following general formula (1-1) and / or a compound represented by the following general formula (1-2): [ka] (In the general formulas (1-1) and (1-2), R 13 and R 14 are each independently an alkyl group having 1 to 22 carbon atoms or an unsaturated hydrocarbon group having 2 to 22 carbon atoms and one or more carbon-carbon unsaturated bonds, R 15 and R 16 are each independently an alkyl group having 1 to 21 carbon atoms or an unsaturated hydrocarbon group having 2 to 21 carbon atoms and one or more carbon-carbon unsaturated bonds, x is an integer ranging from 1 to 8. 3.M 21 and M 22 are each independently barium, bismuth, lead or potassium. 4.R 21 and R 22 and each independently represent an alkyl group having 3 to 9 carbon atoms. 5. The lubricating oil composition according to any one of 1 to 4, wherein the sulfur-containing compound is contained in an amount of 0.1 to 20 parts by mass per 100 parts by mass of the lubricating base oil. 6. The lubricating oil composition according to any one of 1 to 5, which contains the metal soap in an amount of 0.1 to 20 parts by mass per 100 parts by mass of the lubricating base oil. 7. The lubricating oil composition according to any one of 1 to 6, wherein the sulfur atoms derived from the sulfur-containing compound are contained in the range of 0.01 to 20 mass %. 8. The lubricating oil composition according to any one of 1 to 7, containing 0.01 to 10 mass % of metal atoms derived from the metal soap. 9. A metal working oil containing the lubricating oil composition according to any one of 1 to 8. A metalworking method using the metalworking oil described in 10.9. [Effects of the Invention]

[0009] The present invention can provide a lubricating oil composition with improved extreme pressure performance. The present invention provides a metalworking oil with improved extreme pressure performance and a metalworking method using the metalworking oil. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the present invention will be described below. The present invention is not limited to the following embodiment, and can be implemented by making appropriate modifications within the scope that does not impair the effects of the present invention. The compounds in this specification may be derived from fossil resources or biological resources.

[0011] [Lubricating oil composition] The lubricating oil composition of the present invention contains a lubricating base oil, a sulfur-containing compound having a (poly)sulfide structure, and a specific metal soap. In the lubricating oil composition of the present invention, the sulfur-containing compound functions as an extreme pressure agent. Here, an "extreme pressure agent" is an additive that suppresses wear due to friction between metals, and it is believed that the (poly)sulfide compound suppresses wear by sulfurizing the metal surface and forming a lubricating film (tribofilm) made of metal sulfide. In the present invention, it is presumed that the inclusion of a specific metal soap promotes the decomposition of the sulfur-containing compound and the accompanying generation of sulfur radicals, thereby promoting the formation of the tribofilm. Each component contained in the lubricating oil composition of the present invention will now be described.

[0012] (sulfur-containing compounds) The sulfur-containing compound contained in the lubricating oil composition of the present invention is a sulfur-containing compound having a (poly)sulfide structure represented by the following general formula (1). Hereinafter, the sulfur-containing compound contained in the lubricating oil composition of the present invention may be referred to as the "(poly)sulfide compound of the present invention."

[0013] [ka] (In the general formula (1), R 11 and R 12are each independently an alkyl group having 2 to 24 carbon atoms or an unsaturated hydrocarbon group having 2 to 24 carbon atoms and one or more carbon-carbon unsaturated bonds, x is an integer ranging from 1 to 8.

[0014] x is an integer ranging from 1 to 8, and preferably an integer ranging from 1 to 6.

[0015] R 11 and R 12 The alkyl group having 2 to 24 carbon atoms is preferably an alkyl group having 2 to 18 carbon atoms, and more preferably an alkyl group having 2 to 12 carbon atoms.

[0016] R 11 and R 12 The "unsaturated hydrocarbon group having 2 to 24 carbon atoms and one or more carbon-carbon unsaturated bonds" is an alkyl group having one or more carbon-carbon unsaturated bonds, such as an alkenyl group. The unsaturated hydrocarbon group is preferably an unsaturated hydrocarbon group having 2 to 18 carbon atoms, and more preferably an unsaturated hydrocarbon group having 2 to 12 carbon atoms.

[0017] R 11 and R 12 The chain structure of the alkyl group and unsaturated hydrocarbon group is not particularly limited, and may be a straight chain or a branched chain.

[0018] The sulfur-containing compound represented by the general formula (1) is preferably a compound represented by the following general formula (1-1) and / or a compound represented by the following general formula (1-2).

[0019] [ka] (In the general formulas (1-1) and (1-2), R 13 and R 14 are each independently an alkyl group having 1 to 22 carbon atoms or an unsaturated hydrocarbon group having 2 to 22 carbon atoms and one or more carbon-carbon unsaturated bonds, R 15 and R 16 are each independently an alkyl group having 1 to 21 carbon atoms or an unsaturated hydrocarbon group having 2 to 21 carbon atoms and one or more carbon-carbon unsaturated bonds, x is an integer ranging from 1 to 12.

[0020] The (poly)sulfide compound of the present invention has R bonded to the (poly)sulfide structure. 11 and R 12 They are generally classified by the number of carbon atoms in the carbon chain (alkyl group, alkenyl group), and R 11 and R 12 A compound in which all of the carbon chains are linear is usually called a primary (poly)sulfide, a compound represented by the general formula (1-1) is usually called a secondary (poly)sulfide, and a compound represented by the general formula (1-2) is usually called a tertiary (poly)sulfide.

[0021] Specific examples of primary polysulfides include diethyl polysulfide, di-n-butyl polysulfide, di-n-hexyl polysulfide, di-n-octyl polysulfide, di-n-nonyl polysulfide, di-n-dodecyl polysulfide, and di-n-octadecyl polysulfide.

[0022] Examples of secondary polysulfides include bishexen-2-yl polysulfide, bisoctan-2-yl polysulfide, bisdecen-2-yl polysulfide, and bisdodecen-2-yl polysulfide, with bisdecen-2-yl polysulfide being preferred.

[0023] Examples of tertiary polysulfides include bis-2-methylethane-2-yl polysulfide, bis-2-methylpentan-2-yl polysulfide, bis-2-methylhexan-2-yl polysulfide, bis-2-methylheptan-2-yl polysulfide, bis-2-methylnonan-2-yl polysulfide, bis-2-methylundecen-2-yl polysulfide, and bis-2,4,4-trimethylpentan-2-yl polysulfide, and preferably bis-2,4,4-trimethylpentan-2-yl polysulfide.

[0024] Examples of specific structures of polysulfides are shown below:

[0025] [ka] (x1 is an integer between 11 and 16)

[0026] The sulfur content in the (poly)sulfide compound is, for example, in the range of 10 to 60 mass%, preferably in the range of 20 to 60 mass%, more preferably in the range of 25 to 60 mass%, and even more preferably in the range of 29.5 to 50 mass%. The sulfur content in the (poly)sulfide compound is confirmed by the method described in the examples.

[0027] The kinematic viscosity of the (poly)sulfide compound is, for example, 5 to 1,000 mm based on the kinematic viscosity at 40°C. 2 / s, preferably 10 to 500 mm 2 / s, and more preferably 10 to 200 mm 2 / s range.

[0028] The lubricating oil composition of the present invention may contain one type of (poly)sulfide compound, or two or more types.

[0029] The content of the (poly)sulfide compound of the present invention in the lubricating oil composition of the present invention is, for example, in the range of 0.1 to 50 parts by mass per 100 parts by mass of the lubricating base oil, preferably in the range of 0.1 to 20 parts by mass per 100 parts by mass of the lubricating base oil, more preferably in the range of 1 to 10 parts by mass per 100 parts by mass of the lubricating base oil, and even more preferably in the range of 1 to 5 parts by mass per 100 parts by mass of the lubricating base oil.

[0030] The content of sulfur atoms derived from the (poly)sulfide compound of the present invention in the lubricating oil composition of the present invention is, for example, in the range of 0.01 to 20 mass%, preferably in the range of 0.04 to 8 mass%, and more preferably in the range of 0.4 to 4 mass%.

[0031] The (poly)sulfide compound of the present invention can be produced by known methods, for example, by sulfurizing an olefin or by crosslinking a mercaptan with sulfur.

[0032] (metal soap) The metal soap contained in the lubricating oil composition of the present invention (hereinafter sometimes referred to as "the metal soap of the present invention") is one or more selected from the group consisting of fatty acid metal salts, fatty acid metal borate salts, aluminum chelate compounds, and amine ligand metal complex compounds.

[0033] The fatty acid metal salt, which is the metallic soap of the present invention, is a compound represented by the following general formula (2-1).

[0034] [ka] (In the general formula (2-1), R 21 is an alkyl group having 1 to 12 carbon atoms, n is an integer ranging from 1 to 4, M 21 is lithium, sodium, potassium, magnesium, barium, bismuth, copper, lead, zinc, zirconium, or cobalt.

[0035] In the general formula (2-1), when n is an integer of 2 or more, a plurality of R 21 may be the same as or different from each other.

[0036] R 21 The alkyl group having 1 to 12 carbon atoms in R may be a linear alkyl group, a branched alkyl group, or may contain an alicyclic structure. 1 The alkyl group having 1 to 12 carbon atoms is preferably an alkyl group having 1 to 9 carbon atoms, and more preferably an alkyl group having 3 to 9 carbon atoms. R 21 is an alkyl group having 1 to 9 carbon atoms, this is preferred because the metal soap does not excessively increase the viscosity of the lubricating oil composition.

[0037] R 21 The alkyl group having 1 to 12 carbon atoms is used in the production of fatty acid metal salts. 21 It corresponds to a carboxylic acid residue obtained by removing the carboxyl group (COOH) from a carboxylic acid represented by COOH, and is preferably an acrylic acid residue, a methacrylic acid residue, a butyric acid residue, a pentanoic acid residue, an octylic acid residue (2-ethylhexanoic acid residue), an isononanoic acid residue, a neodecanoic acid residue, or a naphthenic acid residue.

[0038] M 21 is lithium, sodium, potassium, magnesium, barium, bismuth, copper, lead, zinc, zirconium or cobalt, preferably barium, bismuth, lead or potassium, more preferably barium, bismuth or potassium. M 21 When the metal is one of these metals, the lubricating oil composition can ensure high transparency. The transparency of the lubricating oil composition can reduce the cleaning load on the workpiece after processing when the lubricating oil composition is used as a metalworking oil, and can also make oil contamination on the machine tool, its building, and floor less noticeable. Furthermore, it is easy to determine whether or not the metalworking oil has changed over time, such as by oxidation.

[0039] n1 is M 21is a value determined by the metal atoms in 21 If is lithium, n1 is 1, and M 21 If is cobalt, n1 is 2.

[0040] When a fatty acid metal salt is used as the metal soap, one type of fatty acid metal salt may be used alone, or two or more types of fatty acid metal salts having different structures may be used.

[0041] The fatty acid metal salt, which is a metal soap, can be produced by a known method, and a commercially available product may also be used. Commercially available metallic soaps such as fatty acid metal salts include, for example, the OCTOATE series (manufactured by DIC Corporation).

[0042] (Fatty acid metal borate) The metallic soap of the present invention, a fatty acid metal borate, is a compound represented by the following general formula (2-2).

[0043] [ka] (In the general formula (2-2), R 22 is an alkyl group having 1 to 12 carbon atoms, M 22 are each independently lithium, sodium, potassium, magnesium, barium, bismuth, copper, lead, zinc, zirconium, or cobalt.

[0044] In the general formula (2-2), a plurality of R 22 may be the same or different. 22 may be the same as or different from each other.

[0045] R 22 The alkyl group having 1 to 12 carbon atoms in R may be a linear alkyl group, a branched alkyl group, or may contain an alicyclic structure. 22The alkyl group having 1 to 12 carbon atoms is preferably an alkyl group having 1 to 9 carbon atoms, and more preferably an alkyl group having 3 to 9 carbon atoms.

[0046] R 22 The alkyl group having 1 to 12 carbon atoms is R 22 It corresponds to a carboxylic acid residue obtained by removing the carboxyl group (COOH) from a carboxylic acid represented by COOH, and is preferably an acrylic acid residue, a methacrylic acid residue, a butyric acid residue, a pentanoic acid residue, an octylic acid residue (2-ethylhexanoic acid residue), an isononanoic acid residue, a neodecanoic acid residue, or a naphthenic acid residue.

[0047] M 22 is lithium, sodium, potassium, magnesium, barium, bismuth, copper, lead, zinc, zirconium or cobalt, preferably barium, bismuth, lead or potassium, more preferably barium, bismuth or potassium. M 22 When is one of these metals, the lubricating oil composition can be guaranteed to have high transparency.

[0048] When a fatty acid metal borate is used as the metal soap, one type of fatty acid metal borate may be used alone, or two or more types of fatty acid metal borate salts having mutually different structures may be used.

[0049] The metal soap fatty acid metal borate can be produced by a known method, or a commercially available product may be used. Examples of commercially available metal soap fatty acid metal borate products include the DICNATE series (manufactured by DIC Corporation).

[0050] (Amine Ligand Metal Complex Compounds) The amine ligand metal complex compound, which is the metallic soap of the present invention, is a compound in which a fatty acid metal salt and an amine compound form a complex through a coordinate bond.

[0051] As the fatty acid metal salt that forms the amine ligand metal complex compound, the same fatty acid metal salts as those explained as the metal soap of the present invention can be used.

[0052] Examples of amine compounds that form amine ligand metal complex compounds include N-methylmorpholine, pyridine, 1,8-diazabicyclo[5.4.0]undecene-7 (DBU), 1,5-diazabicyclo[4.3.0]nonene-5 (DBN), 1,4-diazabicyclo[2.2.2]octane (DABCO), 4-dimethylaminoamine (DMAP), dicyandiamide (DICY), tri-n-butylamine, dimethylbenzylamine, butylamine, 1,2-propanediamine, 1,2-cyclohexanediamine, octylamine, monoethanolamine, diethanolamine, triethanolamine, 2-[[(2-dimethylamino)ethyl]methylamino]ethanol, 2,2'-[propane-1,2-diylbis(azanylylidenemethanylylidene)]diphenol, imidazole, 1-methylamino Examples of the silane include imidazole, 2-methylimidazole, 4-methylimidazole, 2,4-dimethylimidazole, 1,4-diethylimidazole, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(N-phenyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropylmethyldimethoxysilane, tetramethylammonium hydroxide, 8-quinolinol, 5-chloro-8-quinolinol, 2,2'-bipyridyl and derivatives thereof, 2,2'-[propane-1,2-diylbis(azanylylidenemethanylylidene)]diphenol and derivatives thereof, and 2,2'-methylenebis[6-(2h-benzotriazol-2-yl)-4-tert-octylphenol]. These amine compounds may be used alone or in combination of two or more.

[0053] The amine compound is preferably one or more selected from 2-[[(2-dimethylamino)ethyl]methylamino]ethanol, 1,2-propanediamine, 1,2-cyclohexanediamine, monoethanolamine, diethanolamine, triethanolamine, imidazole, 1-methylimidazole, 2-methylimidazole, 4-methylimidazole, 2,4-dimethylimidazole, 1,4-diethylimidazole, 8-quinolinol, 5-chloro-8-quinolinol, 2,2′-bipyridyl and its derivatives, and 2,2′-[propane-1,2-diylbis(azanylylidenemethanylylidene)]diphenol and its derivatives.

[0054] In the amine ligand metal complex compound, the ratio (molar ratio) of the fatty acid metal salt to the amine compound is, for example, in the range of 0.1 to 12 mol, preferably 0.3 to 10 mol, and more preferably 0.5 to 10 mol, of the amine compound per 1 mol of the metal atom of the fatty acid metal salt.

[0055] The amine ligand metal complex compound, which is a metal soap, can be produced by a known method, and commercially available products may also be used. Commercially available amine ligand metal complex compounds include, for example, the DICNATE series (manufactured by DIC Corporation).

[0056] In the lubricating oil composition of the present invention, the content of the metal soap of the present invention is, for example, in the range of 0.1 to 50 parts by mass, preferably 0.1 to 20 parts by mass, more preferably 1 to 10 parts by mass, and even more preferably 1 to 5 parts by mass, per 100 parts by mass of the lubricating base oil.

[0057] The content of metal atoms derived from the metal soap of the present invention in the lubricating oil composition of the present invention is, for example, in the range of 0.01 to 10 mass%, preferably in the range of 0.02 to 4 mass%, and more preferably in the range of 0.2 to 2 mass%.

[0058] The content of the metal soap in the lubricating oil composition of the present invention is, for example, in the range of 0.01 to 10, preferably 0.1 to 5, and more preferably 1 to 3, as the mass ratio (sulfur atom / metal atom) of metal atoms derived from the metal soap to sulfur atoms contained in the sulfur-containing compound of the present invention. When preparing the lubricating oil composition, it is advisable to adjust the amount of metal soap added so that the content of metal atoms derived from the metal soap falls within the above range.

[0059] (Lubricant base oil) The lubricating base oil for the lubricating oil composition of the present invention may be appropriately selected depending on the intended use and conditions, and may be selected from mineral base oils, chemically synthesized base oils, and mixtures thereof.

[0060] Examples of mineral base oils include paraffinic crude oil, naphthenic crude oil, intermediate crude oil, and aromatic crude oil. In addition, distillate oils obtained by atmospheric distillation of these crude oils and distillate oils obtained by vacuum distillation of the atmospheric distillation residues of these crude oils can also be used. Further, refined oils obtained by refining these crude oils (solvent refined oils, hydrogenated refined oils, dewaxed oils, clay-treated oils, etc.) can also be used.

[0061] Examples of chemically synthesized base oils include poly-α-olefins, polyisobutylene (polybutene), monoesters, diesters, polyol esters, silicate esters, polyalkylene glycols, polyphenyl ethers, silicones, fluorinated compounds, alkylbenzenes, GTL base oils, etc. Among these, poly-α-olefins, polyisobutylene (polybutene), diesters, and polyol esters can be used for general purposes.

[0062] Examples of the poly-α-olefin include polymers or oligomers of 1-hexene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-tetradecene, and the like, as well as hydrogenated products of the polymers and oligomers.

[0063] Examples of the diesters include diesters of dibasic acids such as glutaric acid, adipic acid, azelaic acid, sebacic acid, and dodecanedioic acid with alcohols such as 2-ethylhexanol, octanol, decanol, dodecanol, and tridecanol.

[0064] Examples of the polyol ester include esters of polyols such as neopentyl glycol, trimethylolethane, trimethylolpropane, pentaerythritol, dipentaerythritol, and tripentaerythritol with fatty acids such as caproic acid, caprylic acid, lauric acid, capric acid, myristic acid, palmitic acid, stearic acid, and oleic acid.

[0065] The lubricating base oil may be used alone or in combination of two or more.

[0066] The lubricating base oil is preferably a base oil containing a mineral base oil and / or a chemically synthetic base oil, and more preferably one or more base oils selected from the group consisting of paraffin-based highly refined mineral oils, poly-α-olefin-based chemically synthetic base oils, and GTL-based chemically synthetic base oils.

[0067] The viscosity of the lubricating base oil is not particularly limited, but from the viewpoint of the low temperature stability and friction reducing properties of the lubricating oil composition, the kinematic viscosity at 100°C is preferably 0.8 to 8.0 mmHg, for example. 2 / s, preferably 1.0 to 7.0 mm 2 / s, and more preferably 1.2 to 6.0 mm 2 / s range. The kinematic viscosity is a value obtained by measurement according to the method described in JIS K 2283.

[0068] The content of the lubricating base oil in the lubricating oil composition of the present invention is not particularly limited and can be appropriately adjusted, for example, within the range of 20 to 98 mass % based on the total amount of the lubricating oil composition of the present invention.

[0069] (Other ingredients) The lubricating oil composition of the present invention may contain the (poly)sulfide compound of the present invention, the metal soap of the present invention, and a lubricating base oil, and may also contain other components. As such other components, known additives for lubricating oil compositions can be used, such as extreme pressure agents, antiwear agents, oiliness agents, antioxidants, rust inhibitors, metal deactivators, demulsifiers, and antifoaming agents other than the (poly)sulfide compound of the present invention.

[0070] (Extreme Pressure Agents Other Than the (Poly)sulfide Compound of the Present Invention) Examples of extreme pressure agents other than the (poly)sulfide compounds of the present invention include sulfurized fats and oils, sulfurized esters, sulfurized fatty acids, sulfur-containing organic molybdenum compounds, and sulfur-containing organic zinc compounds.

[0071] Examples of sulfurized fats and oils include sulfides of unsaturated animal and vegetable fats and oils such as lard, beef tallow, fish oil, rapeseed oil, palm oil, canola oil, coconut oil, corn oil, cottonseed oil, olive oil, palm oil, peanut oil, sunflower oil, soybean oil, safflower oil, rice oil, palm oil, sesame oil, linseed oil, grapeseed oil, and recovered vegetable oil. Specific examples of sulfurized fats and oils include sulfurized lard, sulfurized rapeseed oil, sulfurized castor oil, sulfurized soybean oil, sulfurized fish oil, and sulfurized whale oil.

[0072] The weight average molecular weight of the sulfurized oil or fat is, for example, in the range of 1,000 to 100,000, preferably in the range of 1,000 to 50,000, more preferably in the range of 1,000 to 15,000, and even more preferably in the range of 1,500 to 15,000.

[0073] The sulfur content of the sulfurized oil or fat is, for example, in the range of 2 to 30 mass %, and preferably in the range of 5 to 20 mass %.

[0074] The viscosity of sulfurized oils and fats is, for example, 100 to 5,000 mm, based on the kinematic viscosity at 40°C. 2 / s, preferably in the range of 200 to 3,000 mm 2 / s, and more preferably 500 to 2,000 mm 2 / s range.

[0075] Examples of sulfurized esters include alkyl esters having 1 to 12 carbon atoms of sulfurized fatty acids having 8 to 22 carbon atoms, and specific examples include sulfurized fatty acid methyl esters.

[0076] Sulfurized fatty acids include sulfides of unsaturated fatty acids such as ministoleic acid, palmitoleic acid, sapienic acid, oleic acid, elaidic acid, vaccenic acid, gadoleic acid, eicosenoic acid, erucic acid, nervonic acid, linoleic acid, eicosadienoic acid, docosadienoic acid, linolenic acid, pinolenic acid, eleostearic acid, mead acid, dihomo-γ-linolenic acid, eicosatrienoic acid, stearidonic acid, arachidonic acid, eicosatetraenoic acid, adrenic acid, bosseopentaenoic acid, osbondo acid, sardine acid, tetracosapentaenoic acid, docosahexaenoic acid, herring acid, beef tallow fatty acid, and palm kernel fatty acid.

[0077] The lubricating oil composition of the present invention preferably does not contain the above-mentioned sulfurized fats and oils, sulfurized esters, or sulfurized fatty acids.

[0078] The sulfur-containing organomolybdenum compound is preferably a compound represented by the following general formula (5-1) or (5-2).

[0079] [ka] (In the general formulas (5-1) and (5-2), R 51 , R 52 , R 53 and R 54 are each independently an alkyl group having 3 to 18 carbon atoms, X 1 , X 2 , X 3 and X 4 are each independently an oxygen atom or a sulfur atom.

[0080] R 51 , R 52, R 53 and R 54 The alkyl group having 3 to 18 carbon atoms may be a linear or branched alkyl group, and may contain an alicyclic structure.

[0081] R 51 , R 52 , R 53 and R 54 The alkyl group having 3 to 18 carbon atoms is preferably an alkyl group having 8 to 14 carbon atoms, and more preferably a straight-chain alkyl group such as an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, an n-dodecyl group, an n-tridecyl group, or an n-tetradecyl group, a secondary octyl group, an isooctyl group, a secondary nonyl group, an isononyl group, a secondary decyl group, an isodecyl group, a secondary undecyl group, an isoundecyl group, a secondary dodecyl group, an isododecyl group, a secondary tridecyl group, an isotridecyl group, a secondary tetradecyl group, or an isotetradecyl group.

[0082] X 1 , X 2 , X 3 and X 4 is preferably X 1 ~X 4 Two or three of the X are sulfur atoms and the rest are oxygen atoms, more preferably 1 ~X 4 two of which are sulfur atoms and the remaining are oxygen atoms, and more preferably X 1 and X 2 is a sulfur atom, and X 3 and X 4 is an oxygen atom.

[0083] The sulfur-containing organic molybdenum compounds may be used alone or in combination of two or more.

[0084] The sulfur-containing organo-molybdenum compound can be produced by a known method, or a commercially available product such as ADEKA SAKURA-LUBE (manufactured by ADEKA Corporation) may be used.

[0085] The sulfur-containing organozinc compound is preferably a compound represented by the following general formula (6).

[0086] [ka] (In the general formula (6), R 61 , R 62 , R 63 and R 64 are each independently a hydrocarbon group having 1 to 20 carbon atoms.

[0087] R 61 , R 62 , R 63 and R 64 Examples of the hydrocarbon group having 1 to 20 carbon atoms include an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, and an aromatic hydrocarbon group having 6 to 20 carbon atoms. The alkyl group having 1 to 20 carbon atoms may be straight-chain or branched, and may contain an alicyclic ring. The alkenyl group having 2 to 20 carbon atoms may be straight-chain or branched.

[0088] R 61 , R 62 , R 63 and R 64 The hydrocarbon group having 1 to 20 carbon atoms is preferably a hydrocarbon group having 3 to 14 carbon atoms, more preferably a hydrocarbon group having 3 to 10 carbon atoms, and even more preferably an alkyl group having 3 to 8 carbon atoms.

[0089] The content of the sulfur-containing organozinc compound in the lubricating oil composition of the present invention is, for example, in the range of 50 to 1,000 ppm by mass, preferably 100 to 800 ppm by mass, and more preferably 100 to 500 ppm by mass, of zinc atoms derived from the sulfur-containing organozinc compound relative to the total amount of the lubricating oil composition of the present invention.

[0090] The sulfur-containing organozinc compound can be produced by a known method, or a commercially available product may be used.

[0091] (anti-wear agent) Examples of the anti-wear agent include phosphorus-based anti-wear agents such as phosphate ester-based anti-wear agents, acidic phosphate ester-based anti-wear agents, phosphite ester-based anti-wear agents, acidic phosphite esters, and amine salts thereof.

[0092] (oil-based agent) Examples of oily agents include saturated and unsaturated aliphatic monocarboxylic acids such as stearic acid and oleic acid; polymerized fatty acids such as dimer acid and hydrogenated dimer acid; hydroxy fatty acids such as ricinoleic acid and 12-hydroxystearic acid; saturated and unsaturated aliphatic monoalcohols such as lauryl alcohol and oleyl alcohol; saturated and unsaturated aliphatic monoamines such as stearylamine and oleylamine; saturated and unsaturated aliphatic monocarboxylic acid amides such as lauric acid amide and oleic acid amide; and partial esters of polyhydric alcohols such as glycerin and sorbitol with saturated or unsaturated aliphatic monocarboxylic acids.

[0093] The content of the oiliness improver in the lubricating oil composition of the present invention is not particularly limited and can be adjusted appropriately depending on the intended use, etc., but can be contained, for example, in the range of 0.01 to 10 mass % relative to the total amount of the lubricating oil composition.

[0094] (antioxidant) Examples of the antioxidant include phenolic antioxidants such as 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, and 2,2′-methylenebis(4-methyl-6-tert-butylphenol); amine-based antioxidants such as alkylated diphenylamine, alkylated-α-naphthylamine, phenyl-α-naphthylamine, and N,N′-diphenyl-p-phenylenediamine; and sulfur-based antioxidants such as 2,6-di-tert-butyl-4-[4,6-bis(octylthio)-1,3,5-triazin-2-ylamino]phenol and dilaurylthiodipropionate.

[0095] The content of the antioxidant in the lubricating oil composition of the present invention is not particularly limited and can be adjusted appropriately depending on the intended use, etc., but can be contained, for example, in the range of 0.01 to 5 mass % relative to the total amount of the lubricating oil composition.

[0096] (rust inhibitor) Examples of rust inhibitors include alkyl or alkenyl succinic acid derivatives such as dodecenyl succinic acid half ester, octadecenyl succinic anhydride, and dodecenyl succinamide; polyhydric alcohol partial esters such as sorbitan monooleate, glycerin monooleate, and pentaerythritol monooleate; metal sulfonates such as Ca-petroleum sulfonate, Ca-alkylbenzene sulfonate, Ba-alkylbenzene sulfonate, Mg-alkylbenzene sulfonate, Na-alkylbenzene sulfonate, Zn-alkylbenzene sulfonate, and Ca-alkylnaphthalene sulfonate; amines such as rosin amine and N-oleyl sarcosine; and dialkyl phosphite amine salts.

[0097] The content of the rust inhibitor in the lubricating oil composition of the present invention is not particularly limited and can be adjusted appropriately depending on the intended use, etc., but can be contained, for example, in the range of 0.01 to 10 mass % relative to the total amount of the lubricating oil composition.

[0098] (metal deactivator) Examples of metal deactivators include N,N'-salicylidene-1,2-propanediamine, alizarin, tetraalkylthiuram disulfide, benzotriazole, benzimidazole, 2-alkyldithiobenzimidazole, 2-alkyldithiobenzothiazole, 2-(N,N-dialkylthiocarbamoyl)benzothiazole, 2,5-bis(alkyldithio)-1,3,4-thiadiazole, and 2,5-bis(N,N-dialkylthiocarbamoyl)-1,3,4-thiadiazole.

[0099] The content of the metal deactivator in the lubricating oil composition of the present invention is not particularly limited and can be adjusted appropriately depending on the intended use, etc., but can be contained, for example, in the range of 0.005 to 5 mass% relative to the total amount of the lubricating oil composition.

[0100] (Demulsifier) Examples of the demulsifier include surfactants such as anionic surfactants, cationic surfactants, and nonionic surfactants.

[0101] The content of the demulsifier in the lubricating oil composition of the present invention is not particularly limited and can be adjusted appropriately depending on the intended use, etc., but can be contained, for example, in the range of 0.0001 to 0.5 mass% relative to the total amount of the lubricating oil composition.

[0102] (Antifoaming agent) Examples of the defoaming agent include silicone-based defoaming agents such as silicone oil, fluorinated silicone-based defoaming agents such as fluorosilicone oil, and polyacrylate-based defoaming agents.

[0103] The content of the antifoaming agent in the lubricating oil composition of the present invention is not particularly limited and can be adjusted appropriately depending on the intended use, etc., but can be contained, for example, in the range of 0.0001 to 0.5 mass% relative to the total amount of the lubricating oil composition.

[0104] (carbonate) Alkali metal carbonates such as lithium carbonate, sodium carbonate, and potassium carbonate, and alkaline earth carbonates such as magnesium carbonate, calcium carbonate, and barium carbonate may denature (overbase) the metal soap of the present invention. Therefore, the lubricating oil composition of the present invention preferably does not contain alkali metal carbonates or alkaline earth carbonates.

[0105] The uses of the lubricating oil composition of the present invention are not particularly limited, and it can be used, for example, as an automotive lubricating oil used in drive system devices such as internal combustion engines, automatic transmissions, shock absorbers, and power steering, as well as gears; a metal working oil used in metal working such as cutting, grinding, and plastic working; and a hydraulic oil, which is a power transmission fluid used for power transmission, force control, buffering, and other operations in hydraulic systems such as hydraulic equipment and devices.

[0106] (Grease composition) By further adding a known thickener to the lubricating oil composition of the present invention, it is possible to make it into a solid or semi-solid grease composition. Examples of the thickener include metal soaps other than the metal soap of the present invention (metal soaps of fatty acids with long carbon chains such as metal isostearate and metal oleate), urea compounds, bentonite, silica gel, etc. [Example]

[0107] The present invention will be specifically described below with reference to examples and comparative examples. The present invention is not limited to the following examples.

[0108] Examples 1-13 and Comparative Examples 1-30 Sulfur-containing compounds, metal soaps, other extreme pressure agents and lubricating base oil (mineral oil (ISO VG150, kinematic viscosity (40°C) = 150 mm) shown in Table 1-6 2 Each of the components was weighed into a 2 L glass beaker in the amounts shown in Table 1-6. The components were then heated on a hot plate at 50°C and mixed by stirring at 350 rpm for 30 minutes using a Three-One motor equipped with a SUS anchor-type stirring blade to prepare a lubricating oil composition.

[0109] The components of the lubricating oil compositions used in the examples are as follows:

[0110] [ka]

[0111] [ka] (x2 is an integer ranging from 1 to 3. The sulfur content of sulfurized oil / fat A is 11.3% by mass, the sulfur content of sulfurized oil / fat B is 14.5% by mass, the sulfur content of sulfurized oil / fat C is 11.4% by mass, and the sulfur content of sulfurized oil / fat D is 11.4% by mass. Although sulfurized oils / fat C and D have the same sulfur content, the composition of the vegetable oils contained therein differs from that of sulfurized oil / fat D.

[0112] [ka] (x3 is an integer ranging from 1 to 3. The sulfur content of sulfurized ester A is 11.6% by mass, and the sulfur content of sulfurized ester B is 11.4% by mass.

[0113] [ka] (x4 is an integer ranging from 1 to 3. The sulfur content of sulfurized fatty acid A is 11.5% by mass, and the sulfur content of sulfurized fatty acid B is 10.6% by mass.

[0114] The lubricating oil compositions prepared were evaluated as follows, and the results are shown in Tables 1-6. (Sulfur concentration) The sulfur content of the sulfur-containing compound was measured in accordance with JIS K2541-7:2023, and the sulfur concentration in the lubricating oil composition was calculated based on the obtained value.

[0115] (Sulfur / metal mass ratio) The sulfur content of the sulfur-containing compound was measured in accordance with JIS K2541-7:2023, and the sulfur / metal mass ratio was calculated by dividing this by the amount of metal derived from the metal soap.

[0116] (Extreme pressure performance (fusion load)) The weld load of the lubricating oil composition was evaluated in accordance with ASTM D-2783. Specifically, the weld load of the lubricating oil composition was evaluated under the following conditions. A higher value of this weld load indicates better extreme pressure performance of the lubricating oil composition. Vertical shaft rotation speed: 1770 rpm Test steel ball: 1 / 2 inch for ball bearings (SUJ2) Welding load measurement time: 10 seconds

[0117] [Table 1]

[0118] [Table 2]

[0119] [Table 3]

[0120] [Table 4]

[0121] [Table 5]

[0122] [Table 6] (In the table, the sulfur content of sulfurized isobutylene is 45% by mass. The molybdenum dithiocarbamate used was "Sacralbu 525" manufactured by ADEKA Corporation. The molybdenum dithiophosphate used was "Sacralbu 300" manufactured by ADEKA Corporation. The zinc dithiophosphate used was "LZ1371" manufactured by Lubrizol.

[0123] High extreme pressure performance was obtained in the lubricating oil compositions containing both the sulfur-containing compound of the present invention and the metal soap of the present invention in Examples 1-6 of Table 1, whereas sufficient extreme pressure performance was not obtained in the lubricating oil compositions not containing the sulfur-containing compound of the present invention in Table 2 and the lubricating oil compositions not containing the metal soap of the present invention in Table 3. In other words, the results in Tables 1-3 show that high extreme pressure performance can be obtained by combining the sulfur-containing compound of the present invention and the metal soap of the present invention.

[0124] In Examples 7-13 in Table 4, high extreme pressure performance was obtained by using the metal soap of the present invention, whereas in Comparative Examples 20-24 in Table 5, a metal soap containing a different metal species from the metal soap of the present invention was used, and sufficient extreme pressure performance was not obtained. This shows that it is not enough to simply use a metal soap, but the type of metal is also important.

[0125] In Table 6, metal organic compounds such as molybdenum dithiocarbamate are used, but the extreme pressure performance is significantly reduced when an organometallic compound is used in combination. This shows that not just any organometallic compound can be used in combination with a sulfur-containing compound.

Claims

1. A lubricating oil composition comprising a lubricating base oil, a sulfur-containing compound, and a metal soap, The sulfur-containing compound is a compound represented by the following general formula (1): The lubricating oil composition, wherein the metal soap is at least one selected from the group consisting of a fatty acid metal salt represented by the following general formula (2-1), a fatty acid metal borate represented by the following general formula (2-2), and an amine ligand metal complex compound of the fatty acid metal salt and an amine compound: 【Chemistry 1】 (In the general formulas (1), (2-1) and (2-2), R １１ and R １２ are each independently an alkyl group having 2 to 24 carbon atoms or an unsaturated hydrocarbon group having 2 to 24 carbon atoms and one or more carbon-carbon unsaturated bonds, x is an integer ranging from 1 to 8; R ２１ and R ２２ are each independently an alkyl group having 1 to 12 carbon atoms, n is an integer ranging from 1 to 4; M ２１ and M ２２ are each independently lithium, sodium, potassium, magnesium, barium, bismuth, copper, lead, zinc, zirconium, or cobalt.

2. The lubricating oil composition according to claim 1, wherein the sulfur-containing compound is a compound represented by the following general formula (1-1) and / or a compound represented by the following general formula (1-2): 【Chemistry 2】 (In the general formulas (1-1) and (1-2), R １３ and R １４ are each independently an alkyl group having 1 to 22 carbon atoms or an unsaturated hydrocarbon group having 2 to 22 carbon atoms and one or more carbon-carbon unsaturated bonds, R １５ and R １６ are each independently an alkyl group having 1 to 21 carbon atoms or an unsaturated hydrocarbon group having 2 to 21 carbon atoms and one or more carbon-carbon unsaturated bonds, x is an integer ranging from 1 to 8.

3. M ２１ and M ２２ 2. The lubricating oil composition of claim 1, wherein each of is independently barium, bismuth, lead, or potassium.

4. R ２１ and R ２２ The lubricating oil composition according to claim 1, wherein each of the groups independently represents an alkyl group having 3 to 9 carbon atoms.

5. 2. The lubricating oil composition according to claim 1, wherein the sulfur-containing compound is contained in an amount of 0.1 to 20 parts by mass per 100 parts by mass of the lubricating base oil.

6. 2. The lubricating oil composition according to claim 1, wherein the metal soap is contained in an amount ranging from 0.1 to 20 parts by mass per 100 parts by mass of the lubricating base oil.

7. 2. The lubricating oil composition according to claim 1, wherein the sulfur atoms derived from the sulfur-containing compound are contained in an amount ranging from 0.01 to 20 mass %.

8. 2. The lubricating oil composition according to claim 1, wherein the metal atoms derived from the metal soap are contained in an amount ranging from 0.01 to 10% by mass.

9. A metal working oil containing the lubricating oil composition according to any one of claims 1 to 8.

10. A metalworking method using the metalworking oil according to claim 9.

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