Grease composition

Abstract

The objective is to provide a grease composition that has good initial sliding properties. [Solution] A grease composition comprising a base grease containing a base oil and a thickener, and a solid lubricant, wherein the solid lubricant includes a first solid lubricant having a median diameter of 15 μm or more and 50 μm or less, and the content of the solid lubricant is 30% by mass or more and 50% by mass or less with respect to the total amount of the grease composition.

Description

[Technical Field]

[0001] The present invention relates to a grease composition, a sliding device, and a method for using the grease composition. [Background technology]

[0002] It is known that a grease composition is applied to the surface of a sliding device having a sliding surface in order to improve its sliding properties.

[0003] For example, Patent Document 1 discloses a lubricant surface treatment agent characterized by containing at least one of a perfluoroalkyl group-containing compound having a perfluoroalkyl group, or a fluoropolyether-containing compound. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2018-065962 [Overview of the project] [Problems that the invention aims to solve]

[0005] Patent Document 1 describes a lubricant surface treatment agent that enhances foreign matter removal and lubricity. However, from the viewpoint of protecting sliding devices by preventing wear and maintaining their performance, it is preferable to have a low coefficient of friction immediately after sliding begins. The lubricant surface treatment agent in Patent Document 1 has room for further improvement from this viewpoint.

[0006] This invention has been made in view of the above-mentioned problems, and aims to provide a grease composition that can reduce the coefficient of friction immediately after sliding begins, that is, has good initial sliding properties. [Means for solving the problem]

[0007] As a result of diligent research to achieve the above objectives, the present inventors have found that the above problems can be solved by using a grease composition comprising a base grease containing a base oil and a thickener, and a solid lubricant, wherein the solid lubricant comprises a first solid lubricant having a median diameter of 15 μm or more and 50 μm or less, and the content of the solid lubricant is 30% by mass or more and 50% by mass or less of the total amount of the grease composition, and have completed the present invention.

[0008] In other words, the present invention includes the following embodiments. [1] A grease composition comprising a base grease containing a base oil and a thickener, and a solid lubricant, The solid lubricant includes a first solid lubricant having a median diameter of 15 μm or more and 50 μm or less. The content of the solid lubricant is 30% by mass or more and 50% by mass or less, relative to the total amount of the grease composition. Grease composition. [2] The first solid lubricant described above contains polyethylene, The grease composition described in [1]. [3] The solid lubricant includes a second solid lubricant having a median diameter of less than 15 μm. The grease composition described in [1] or [2]. [4] The second solid lubricant comprises one or more selected from the group consisting of melamine cyanurate, polytetrafluoroethylene, talc, graphite, graphite fluoride, molybdenum disulfide, lithium stearate, calcium stearate, aluminum stearate, calcium carbonate, mica, antimony sulfide, tungsten disulfide, boron nitride, and copper. The grease composition described in [3]. [5] Contains an oily agent, The oily agent includes a compound having a polar group. A grease composition as described in any of [1] to [4]. [6] The oiliness agent contains a compound having one or more hydroxyl groups and a saturated or unsaturated hydrocarbon group with 10 or more carbon atoms, which may be substituted or unsubstituted. The grease composition according to [5]. [7] The compound is an ester. The grease composition according to [6]. [8] The ester contains a fatty acid ester. The grease composition according to [7]. [9] The fatty acid ester contains an ester represented by the following formula (1). The grease composition according to [8].

Chemical formula

[10] The fatty acid ester contains an ester represented by the following formula (2). The grease composition according to [8] or [9].

Chemical formula

[11] The fatty acid ester contains an ester represented by the following formula (3). The grease composition according to any one of [8] to

[10] .

Chemical formula

[12] The fatty acid ester includes an ester represented by the following formula (4) and / or an ester represented by the following formula (5). A grease composition as described in any of [8] to

[11] . [ka] [ka] (In the formula, R7, R8, R9, and R 10 Each of these is independently a substituted or unsubstituted monovalent saturated or unsaturated hydrocarbon group having 10 or more carbon atoms.

[13] R7 is a decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, decenyl group, undecenyl group, dodecenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group, hexadecenyl group, heptadecenyl group, octadecenyl group, nonadecenyl group, or icosenyl group. R8, R9, and R 10 However, each is independently a decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, decenyl group, undecenyl group, dodecenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group, hexadecenyl group, heptadecenyl group, octadecenyl group, nonadecenyl group, or icosenyl group. The grease composition described in

[12] .

[14] The content of the oily agent is 0.1% by mass or more and 10.0% by mass or less, relative to the total amount of the grease composition. A grease composition as described in any of [5] to

[13] .

[15] Used to improve the lubrication of the gear parts of the door lock mechanism, window regulator, seat rail, sunroof, suspension, brake, or steering system. A grease composition as described in any of [1] to

[14] .

[16] A sliding device comprising a grease composition according to any one of [1] to

[15] , a base material, and a member that slides on the base material, The grease composition is sandwiched between the base material and the member, and in the portion where the member slides on the base material, Sliding device.

[17] Both the base material and the member are hydrophilic. The sliding device described in

[16] .

[18] containing dust, The sliding device described in

[16] or

[17] .

[19] The grease composition is present in a sealed space surrounded by at least the base material and the member. A sliding device as described in any of

[16] to

[18] .

[20] A grease composition described in any of [1] to

[15] is used in an environment containing dust. Method of using a grease composition. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a grease composition that can reduce the coefficient of friction immediately after sliding begins, that is, one that has good initial sliding properties. [Modes for carrying out the invention]

[0010] The following describes in detail an embodiment of the present invention (hereinafter referred to as "this embodiment"), but the present invention is not limited thereto, and various modifications are possible without departing from its spirit.

[0011] 1. Grease composition The grease composition of this embodiment is a grease composition comprising a base grease containing a base oil and a thickener, and a solid lubricant, wherein the solid lubricant includes a first solid lubricant having a median diameter of 15 μm or more and 50 μm or less, and the content of the solid lubricant is 30% by mass or more and 50% by mass or less of the total amount of the grease composition.

[0012] Conventionally, in sliding devices, a grease composition is sometimes applied to the sliding surface to improve its sliding performance. However, until the grease composition is evenly distributed and settled on the sliding surface, the coefficient of friction on the sliding surface tends to be high. During this time, the sliding surface is subjected to stress, and in some cases, scratches or defects may occur on the sliding surface, potentially negatively affecting its sliding performance.

[0013] Therefore, in order to protect the sliding device and maintain its performance, it is preferable to reduce the coefficient of friction on the sliding surface from the initial stage of sliding. Furthermore, it is preferable to reduce the coefficient of friction on the sliding surface from the initial stage of sliding even when a large load is applied. From this viewpoint, the grease composition of this embodiment contains a first solid lubricant having a median diameter of 15 μm or more and 50 μm or less, and the content of the solid lubricant in the grease composition is 30% by mass or more and 50% by mass or less of the total amount of the grease composition.

[0014] Solid lubricants are added to grease compositions to improve lubricity on sliding surfaces. Here, solid lubricants tend to reduce the coefficient of friction on sliding surfaces even before the grease composition has evenly spread and settled on the sliding surface, and this tendency is even stronger for solid lubricants with a median diameter within the above range. In other words, initial sliding performance is improved by using solid lubricants, and initial sliding performance tends to be further improved by using solid lubricants with a median diameter of 15 μm to 50 μm. This is thought to be because solid lubricants with a median diameter within the above range can more effectively suppress direct contact between the base material and the component, even before the grease composition has evenly spread and settled on the sliding surface where the base material, such as a rail, and the component, such as a resin shoe, slide against each other.

[0015] Furthermore, when the solid lubricant content is within the above range, initial sliding performance tends to be further improved. Specifically, when the solid lubricant content is 30% by mass or more of the total amount of the grease composition, direct contact between the base material and the component during initial sliding can be further suppressed. Also, when the solid lubricant content is 50% by mass or less of the total amount of the grease composition, hardening of the grease composition can be suppressed, and the increase in resistance and friction coefficient during sliding can be suppressed. As a result, initial sliding performance tends to be further improved.

[0016] The solid lubricant content is preferably 32.5% by mass or more and 47.5% by mass or less, and more preferably 35.0% by mass or more and 45.0% by mass or less, relative to the total amount of the grease composition. When the solid lubricant content is within the above range, initial sliding properties tend to be further improved.

[0017] The median diameter (D50) is the particle diameter corresponding to a 50% cumulative degree in the particle size distribution measured by laser diffraction and scattering. It is defined as a particle diameter such that the number of particles with a diameter larger than the median diameter is equal to the number of particles with a diameter smaller than the median diameter.

[0018] The components of the grease composition of this embodiment will be described in detail below.

[0019] 1.1. Base grease The base grease of this embodiment comprises a base oil and a thickener.

[0020] The base grease content is preferably 10.0% to 70.0% by mass, more preferably 15.0% to 67.5% by mass, and even more preferably 20.0% to 65.0% by mass, relative to the total amount of the grease composition. Having the base grease content within this range tends to reduce the coefficient of friction after the grease composition has spread to the sliding surface of the sliding device. In other words, it tends to improve lubricity.

[0021] 1.1.1. Base oil The base oil is not particularly limited, but examples include mineral oil refined from crude oil, animal and vegetable oils obtained by extracting fats from animals and vegetables, synthetic oils synthesized using chemical reactions, and semi-synthetic oils obtained by mixing mineral oil and / or animal and vegetable oils with synthetic oils. These base oils may be used individually or in combination of two or more.

[0022] Examples of mineral oils include, but are not limited to, paraffinic oils, naphthenic oils, and paraffin-naphthenic mixed oils.

[0023] Examples of animal and vegetable oils include castor oil, lard, olive oil, peanut oil, corn oil, soybean oil, and linseed oil.

[0024] Synthetic oils are not particularly limited, but examples include poly-α-olefin oils, polyalkylene glycol oils, hydrocarbon oils, ester oils, ether oils, silicone oils, alkylnaphthalene oils, and perfluoroalkyl polyether oils.

[0025] While impurities cannot be completely removed from mineral oils and animal / vegetable oils, synthetic oils can be completely free of impurities. Furthermore, synthetic oils are easier to adjust to suitable physical properties for use, making them preferable as base oils. Among synthetic oils, poly-alpha-olefin oils are particularly preferred.

[0026] The base oil content is preferably 50% to 99% by mass, more preferably 60% to 99% by mass, and even more preferably 70% to 99% by mass, relative to the total amount of base grease. Lubrication tends to be improved when the base oil content is within the above range.

[0027] The base oil content is preferably 35% to 80% by mass, more preferably 40% to 75% by mass, and even more preferably 45% to 70% by mass, relative to the total amount of the grease composition. Lubricity tends to be improved when the base oil content is within the above range.

[0028] 1.1.2. Thickeners Thickeners in base greases make the base oil semi-solid, that is, they increase the viscosity. In addition, by changing the type of thickener, properties such as heat resistance, water resistance, and shear stability can be imparted to the grease composition. Furthermore, the hardness of the base grease can be adjusted by adjusting the amount of thickener relative to the base oil. For example, reducing the amount of thickener, or conversely, increasing the amount of base oil, tends to decrease the hardness of the base grease.

[0029] The thickener is not particularly limited, but examples include soap-based thickeners such as metallic soaps and complex metallic soaps such as lithium soap, and non-soap-based thickeners such as bentone, silica gel, and urea compounds such as diurea and triurea. Among these, non-soap-based thickeners are preferred, and urea compounds are more preferred. Using urea compounds as a thickener tends to further reduce the coefficient of friction. These thickeners may be used individually or in combination of two or more.

[0030] The thickener content is preferably 1% to 50% by mass, more preferably 5% to 40% by mass, and even more preferably 10% to 30% by mass, relative to the total amount of base grease. When the thickener content is within the above range, the base oil hardens appropriately to a semi-solid state, allowing the grease composition to remain on the sliding surface even after repeated sliding of the sliding device over a long period. Therefore, the lubricity of the sliding device can be maintained even after repeated sliding over a long period. In other words, the lubrication durability tends to improve.

[0031] The thickening agent content is preferably 1.0% to 10.0% by mass, more preferably 1.5% to 8.0% by mass, and even more preferably 2.0% to 6.0% by mass, relative to the total amount of the grease composition. When the thickening agent content is within the above range, the lubrication durability tends to improve.

[0032] 1.1.3. Additives The base grease may contain other additives in addition to the base oil and thickener. Such additives are not particularly limited, but examples include friction modifiers, viscosity index improvers, detergent dispersants, pour point depressants, rust inhibitors, and defoamers. Other additives are selected as appropriate according to the desired physical properties. Furthermore, these other additives may be used individually or in combination of two or more.

[0033] 1.2. Solid Lubricants The solid lubricant of this embodiment may include a first solid lubricant having a median diameter of 15 μm or more and 50 μm or less, and a second solid lubricant having a median diameter of less than 15 μm. The first solid lubricant and the second solid lubricant will be described in detail below.

[0034] 1.2.1. First Solid Lubricant The first solid lubricant is not particularly limited as long as it is in the form of solid parts with a median diameter within the above range, but may include, for example, layered inorganic compounds such as molybdenum disulfide, tungsten disulfide, graphite, graphite fluoride, boron nitride, mica, and talc; non-layered inorganic compounds such as lead oxide, calcium fluoride, and silicon dioxide; soft metals such as gold, silver, tin, lead, and copper; and organic compounds such as polytetrafluoroethylene, tetrafluoroethylene, polyethylene, perfluoroalkyl vinyl ether copolymer, phthalocyanine, melamine cyanurate, and amino acid compounds. Among these, it is preferable to include organic compounds, and more preferable to include polyethylene. As polyethylene, ultra-high molecular weight polyethylene (UHPE) with a weight-average molecular weight of 1 million to 7 million is preferred. The inclusion of the above-mentioned first solid lubricant tends to further improve initial sliding properties. The first solid lubricant may be used alone or in combination of two or more types.

[0035] The weight-average molecular weight is not particularly limited, but can be determined, for example, by gel permeation chromatography (GPC).

[0036] The median diameter of the first solid lubricant is preferably 20 μm to 45 μm, and more preferably 25 μm to 40 μm. When the median diameter of the first solid lubricant is within the above range, the initial sliding properties tend to be further improved.

[0037] The content of the first solid lubricant is preferably 5.0% by mass or more and 25.0% by mass or less, more preferably 7.5% by mass or more and 20.0% by mass or less, and even more preferably 10.0% by mass or more and 17.5% by mass or less, relative to the total amount of solid lubricant. When the content of the first solid lubricant is within the above range, the initial sliding properties tend to be further improved.

[0038] The content of the first solid lubricant is preferably 1.0% by mass or more and 15.0% by mass or less, more preferably 2.0% by mass or more and 12.5% ​​by mass or less, and even more preferably 3.0% by mass or more and 10.0% by mass or less, relative to the total amount of the grease composition. When the content of the first solid lubricant is within the above range, the initial sliding properties tend to be further improved.

[0039] 1.2.2. Second Solid Lubricant The grease composition of this embodiment may also contain a second solid lubricant having a median diameter of less than 15 μm. The median diameter of the second solid lubricant is smaller than that of the first solid lubricant, and even after repeated sliding over a long period of time, the grease composition containing the second solid lubricant tends to remain on the sliding surface, thereby improving lubrication durability.

[0040] The second solid lubricant is not particularly limited as long as it is in the form of solid parts with a median diameter within the above range, but may include, for example, inorganic compounds such as molybdenum disulfide, tungsten disulfide, graphite, graphite, graphite fluoride, boron nitride, mica, talc, lead oxide, calcium fluoride, calcium carbonate, antimony sulfide, silicon dioxide, gold, silver, tin, lead, and copper; and organic compounds such as polytetrafluoroethylene (PTFE), tetrafluoroethylene, polyethylene, perfluoroalkyl vinyl ether copolymer, phthalocyanine, melamine cyanurate (MCA), amino acid compounds, lithium stearate, calcium stearate, and aluminum stearate. Among these, it is preferable to include one or more selected from the group consisting of melamine cyanurate, polytetrafluoroethylene, talc, graphite, graphite fluoride, molybdenum disulfide, lithium stearate, calcium stearate, aluminum stearate, calcium carbonate, mica, antimony sulfide, tungsten disulfide, boron nitride, and copper; more preferably to include one or more selected from the group consisting of MCA, PTFE, and talc; and even more preferably to include MCA and PTFE. The second solid lubricant may be used alone or in combination of two or more.

[0041] MCA and talc have a layered structure, and it is believed that the friction coefficient can be reduced by the cleavage of this layered structure on the sliding surface. PTFE has a smooth molecular surface due to its small surface irregularities. In other words, PTFE has a slippery molecular structure, and it is believed that including PTFE can reduce the friction coefficient. Therefore, the lubricity can be improved by including one or more second solid lubricants selected from the group consisting of MCA, PTFE, and talc in the grease composition.

[0042] The median diameter of the second solid lubricant is preferably 1.0 μm or more and less than 15.0 μm, more preferably 1.0 μm or more and 12.5 μm or less, and even more preferably 1.0 μm or more and 10.0 μm or less. When the median diameter of the second solid lubricant is within the above range, the lubricity tends to be further improved.

[0043] When the second solid lubricant contains MCA, the MCA content is preferably 5.0% to 40.0% by mass, more preferably 6.0% to 37.5% by mass, 7.0% to 35.0% by mass, and even more preferably 8.0% to 35.0% by mass, relative to the total amount of the grease composition. Lubricity tends to be further improved when the MCA content is within the above range.

[0044] When the second solid lubricant contains MCA, the MCA content is preferably 5.0% by mass or more and 90.0% by mass or less, more preferably 7.5% by mass or more and 87.5% by mass or less, and even more preferably 10.0% by mass or more and 85.0% by mass or less, relative to the total amount of solid lubricant. When the MCA content is within the above range, the lubricity tends to be further improved.

[0045] When the second solid lubricant contains MCA, the MCA content is preferably 15.0% by mass or more and 95.0% by mass or less, more preferably 17.5% by mass or more and 95.0% by mass or less, even more preferably 20.0% by mass or more and 95.0% by mass or less, and even more preferably 22.5% by mass or more and 95.0% by mass or less, based on the total amount of the second solid lubricant. When the MCA content is within the above range, the lubricity tends to be further improved.

[0046] When the second solid lubricant contains PTFE, the PTFE content is preferably 0.5% to 10.0% by mass, more preferably 1.0% to 7.5% by mass, and even more preferably 2.0% to 5.0% by mass, relative to the total amount of the grease composition. A PTFE content within the above range tends to improve lubricity.

[0047] When the second solid lubricant contains PTFE, the PTFE content is preferably 1.0% to 20.0% by mass, more preferably 2.0% to 15.0% by mass, and even more preferably 3.0% to 10.0% by mass, relative to the total amount of solid lubricant. A PTFE content within the above range tends to improve lubricity.

[0048] When the second solid lubricant contains PTFE, the PTFE content is preferably 2.0% by mass or more and 20.0% by mass or less, more preferably 3.0% by mass or more and 15.0% by mass or less, and even more preferably 4.0% by mass or more and 10.0% by mass or less, relative to the total amount of the second solid lubricant. When the PTFE content is within the above range, the lubricity tends to be further improved.

[0049] When the second solid lubricant contains talc, the talc content is preferably 3.0% to 30.0% by mass, more preferably 5.0% to 27.5% by mass, and even more preferably 10.0% to 27.5% by mass, relative to the total amount of the grease composition. A talc content within the above range tends to improve lubricity.

[0050] When the second solid lubricant contains talc, the talc content is preferably 40.0% by mass or more and 70.0% by mass or less, and more preferably 45.0% by mass or more and 65.0% by mass or less, relative to the total amount of solid lubricant. A talc content within this range tends to improve lubricity.

[0051] When the second solid lubricant contains talc, the talc content is preferably 50.0% by mass or more and 80.0% by mass or less, and more preferably 55.0% by mass or more and 75.0% by mass or less, relative to the total amount of the second solid lubricant. A talc content within this range tends to improve lubricity.

[0052] The content of the second solid lubricant is preferably 20.0% by mass or more and 45.0% by mass or less, more preferably 25.0% by mass or more and 42.5% by mass or less, and even more preferably 30.0% by mass or more and 40.0% by mass or less, relative to the total amount of the grease composition. When the content of the second solid lubricant is within the above range, the lubrication durability tends to be further improved.

[0053] The content of the second solid lubricant is preferably 50.0% by mass or more and 95.0% by mass or less, more preferably 60.0% by mass or more and 92.5% by mass or less, and even more preferably 70.0% by mass or more and 90.0% by mass or less, relative to the total amount of solid lubricant. When the content of the second solid lubricant is within the above range, the lubrication durability tends to improve further.

[0054] The total amount of the first solid lubricant and the second solid lubricant is preferably 32.5% by mass or more and 47.5% by mass or less, and more preferably 35.0% by mass or more and 45.0% by mass or less, relative to the total amount of the grease composition. When the total amount of the first solid lubricant and the second solid lubricant is within the above range, initial sliding properties and lubrication durability tend to improve.

[0055] The total amount of the first solid lubricant and the second solid lubricant is preferably 75% to 100% by mass, 80% to 100% by mass, 90% to 100% by mass, or 95% to 100% by mass, relative to the total amount of solid lubricant. Alternatively, the solid lubricant may consist substantially of the first solid lubricant and the second solid lubricant, or consist solely of the first solid lubricant and the second solid lubricant. When the total amount of the first solid lubricant and the second solid lubricant is within the above range, initial sliding properties and lubrication durability tend to improve.

[0056] In the grease composition, the ratio of the content of the second solid lubricant to the content of the first solid lubricant (content of the second solid lubricant / content of the first solid lubricant) is preferably 2.0 to 10.0 by mass, more preferably 3.0 to 9.5, and even more preferably 4.0 to 9.0. When this ratio is within the above range, initial sliding properties and lubrication durability tend to be further improved.

[0057] 1.3. Oily agents The grease composition of this embodiment preferably contains an oily agent. The oily agent is not particularly limited, but examples include higher fatty acids such as coconut palm fatty acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, and glycerin; higher alcohols such as oleyl alcohol, octyl alcohol, decyl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, behenyl alcohol, and 2-octyldodecanol; coconutamine (coconut alkylamine), caprylamine (octylamine), laurylamine, stearylamine, oleylamine, dimethylcoconutamine, dimethyloctylamine, dimethyldecylamine, dimethyllaurylamine, dimethylmyristylamine, dimethyl Amines such as palmitylamine, dimethylstearylamine, dimethylbehenylamine, didecylmonomethylamine, trioctylamine, propylenediamine, coconutamine acetate, stearylamine acetate, cetylamine, and octadecylamine; cetyl 2-ethylhexanoate, fatty acid methyl, methyl laurate, isopropyl myristate, isopropyl palmitate, 2-ethylhexyl palmitate, octyldodecyl myristate, methyl stearate, butyl stearate, 2-ethylhexyl stearate, isotridecyl stearate, methyl oleate, myristyl myristate, stearyl stearate, isobutyl oleate, dinormal alkyl phthalates (C8, C10 n-DOP), di-2-ethylhexyl phthalate (DOP), diisononyl phthalate (DINP), didecyl phthalate (n-DDP), dialkyl phthalate (C10-C12), ditridecyl phthalate (DTDP), trin-alkyl trimellitate (C8,C10), Tri-2-ethylhexyl trimellitate, Triisodecyl trimellitate, Diisobutyl adipate (DIBA), Diisodecyl adipate (DIDA), Adipate esters, Sorbitan monolaurate, Sorbitan monostearate, Sorbitan tristearate, Sorbitan monooleate, Sorbitan trioleate, Sorbitan sesquioleate, Sorbitan monopalmitate, Polyoxyethylene (6) Sorbitan monolaurate, Polyoxyethylene (20) Sorbitan Tan monolaurate, polyoxyethylene(20) sorbitan monopalmitate, monostearate (20) polyoxyethylene sorbitan, polyoxyethylene(20) sorbitan monostearate, polyoxyethylene(20) sorbitan tristearate, polyoxyethylene(6) sorbitan monooleate, polyoxyethylene(20) sorbitan monooleate, polyoxyethylene(20) sorbitan trioleate, polyoxyethylene(30) sorbitol tetraoleate Examples of esters include polyoxyethylene (40) sorbitol tetraoleate, polyoxyethylene (60) sorbitol tetraoleate, polyethylene glycol monolaurate, polyethylene glycol monostearate, polyethylene glycol monooleate, polyethylene glycol distearate, ethylene glycol distearate, propylene glycol monostearate, polyoxyethylene bisphenol A laurate, pentaerythritol monooleate, pentaerythritol monostearate, pentaerythritol tetrapalmitate, monoglyceride stearate, monoglyceride oleate, mono-diglyceride stearate, monoglyceride succinate stearate, triglyceride 2-ethylhexanoate, monoglyceride behenic acid, mono-diglyceride caprylic acid, triglyceride caprylic acid, fatty acid (C8, C10, C12) triglycerides, lauryl methacrylate, and special hindered esters. Oily agents may be used individually or in combination of two or more types.

[0058] Furthermore, it is preferable that the oily agent contains a compound having a polar group. The polar groups of such compounds are easily adsorbed onto the sliding surface of a sliding device. Therefore, grease compositions containing such compounds tend to remain on the sliding surface even after repeated sliding, improving lubrication durability and lubricity. The compound having a polar group may be used alone or in combination of two or more.

[0059] Furthermore, the polar groups of the compound interact not only with the base material but also with the surface of dust mixed into the sliding device, causing the oily agent containing the compound to adsorb to the dust surface. As a result, a film of the oily agent containing the compound is formed on the dust surface. Because this film is soft, the attacking power of the dust tends to be reduced. Also, if the polarity of the functional group of the compound opposite to the dust is weak, the dust on which a film of the oily agent containing the compound has formed is more easily dispersed in the grease composition. As a result, the dust is less likely to aggregate in the sliding device, and the attacking power of the dust tends to be further reduced. When the attacking power of the dust is reduced, the components of the sliding device and the base material are less likely to be damaged, and as a result, the lubricity tends to improve. In this embodiment, the attacking power of dust refers to the property of dust to scratch or dent the surface of the base material when it comes into contact with it. For example, if the dust becomes harder or larger, the attacking power of the dust increases.

[0060] The polar groups are not particularly limited, but examples include hydroxyl groups, nitro groups, amino groups, carboxyl groups, fluoromethyl groups, and chloromethyl groups.

[0061] The oily agent preferably contains a compound having one or more hydroxyl groups. Such compounds interact with the base material and / or components of the sliding device on the sliding surface, such as by forming hydrogen bonds. Therefore, grease compositions containing such compounds tend to remain on the sliding surface even after repeated sliding, resulting in improved lubrication durability and lubricity.

[0062] Furthermore, from the viewpoint of improving the affinity between the components of the grease composition, such as the base grease, and the oily agent, it is preferable that the oily agent contains a compound having a saturated or unsaturated hydrocarbon group with 10 or more carbon atoms, whether substituted or unsubstituted. Alternatively, it is preferable that the oily agent contains a compound having one or more hydroxyl groups and a saturated or unsaturated hydrocarbon group with 10 or more carbon atoms, whether substituted or unsubstituted. Using such an oily agent tends to further improve lubrication durability and lubricity.

[0063] The number of carbon atoms in the saturated or unsaturated hydrocarbon groups with 10 or more carbon atoms, whether substituted or unsubstituted, of the compounds contained in the oily agent is preferably between 10 and 25, between 11 and 24, between 12 and 23, between 13 and 22, between 14 and 21, and between 15 and 20. Because the number of carbon atoms is within the above range, the oily agent containing the compound tends to exist stably in the grease composition without agglomerating. Furthermore, if dust is present in the sliding device, a film of the oily agent containing the compound forms on the surface of the dust, which is easily dispersed in the grease composition, further reducing the dust's attacking power.

[0064] The compounds contained in the lubricant are preferably esters. Examples of esters include fatty acid esters, sulfonic acid esters, sulfate esters, nitrate esters, carbonate esters, and phosphate esters, with fatty acid esters being more preferred among these. Using such lubricants tends to improve lubrication durability and lubricity.

[0065] As fatty acid esters, compounds represented by formula (1) below are preferred, fatty acid esters represented by formula (2) below are preferred, fatty acid esters represented by formula (6) below are preferred, fatty acid esters represented by formula (7) below are preferred, fatty acid esters represented by formula (3) below are preferred, fatty acid esters represented by formula (4) below are preferred, and fatty acid esters represented by formula (5) below are preferred. Using such fatty acid esters tends to further improve lubrication durability and lubricity.

[0066] [ka]

[0067] In the formula, R1 is a substituted or unsubstituted monovalent saturated or unsaturated hydrocarbon group having 10 or more carbon atoms, and R2 is a monovalent cyclic or chain hydrocarbon group having 1 to 10 carbon atoms, having one or more hydroxyl groups, which may have an ether bond, and may have substituents other than hydroxyl groups. Also, n is a natural number from 1 to 3.

[0068] [ka]

[0069] In the formula, R3 is a substituted or unsubstituted monovalent saturated or unsaturated hydrocarbon group having 10 or more carbon atoms, and R4 is a monovalent cyclic or chain hydrocarbon group having 4 to 8 carbon atoms, having one or more hydroxyl groups, which may have an ether bond, and which may have substituents other than hydroxyl groups. Also, n is a natural number from 1 to 3.

[0070] [ka]

[0071] In the formula, R 11 R is a substituted or unsubstituted monovalent saturated or unsaturated hydrocarbon group having 10 or more carbon atoms, and 12 n is a monovalent cyclic or chain-like hydrocarbon group having 4 to 8 carbon atoms, possessing one or more hydroxyl groups, having an ether bond, and potentially having substituents other than hydroxyl groups. Furthermore, n is a natural number from 1 to 3.

[0072] [ka]

[0073] In the formula, R13 is a monovalent saturated or unsaturated hydrocarbon group with 10 or more carbon atoms, which may be substituted or unsubstituted, and R 14 is a monovalent cyclic hydrocarbon group with 4 to 8 carbon atoms, having one or more hydroxyl groups, may have an ether bond, and may have substituents other than hydroxyl groups. Further, n is a natural number from 1 to 3.

[0074] [Chemical formula]

[0075] In the formula, R5 is a monovalent saturated or unsaturated hydrocarbon group with 10 or more carbon atoms, which may be substituted or unsubstituted, and R6 is a monovalent cyclic hydrocarbon group with 4 to 8 carbon atoms, having one or more hydroxyl groups, having an ether bond, and may have substituents other than hydroxyl groups. Further, n is a natural number from 1 to 3.

[0076] [Chemical formula]

[0077] In the formula, R7 is a monovalent saturated or unsaturated hydrocarbon group with 10 or more carbon atoms, which may be substituted or unsubstituted.

[0078] [Chemical formula]

[0079] In the formula, R8, R9, and R 10 are each independently a monovalent saturated or unsaturated hydrocarbon group with 10 or more carbon atoms, which may be substituted or unsubstituted.

[0080] R2, R4, R6, R 12 and R 14Regarding substituents other than hydroxyl groups, there are no particular limitations, but examples include, independently, alkyl groups such as methyl, ethyl, and propyl groups; alkenyl groups such as ethenyl, propenyl, and butenyl groups; alkynyl groups such as ethynyl, propynyl, and butynyl groups; monovalent sulfur-containing groups such as mercapto, thio, and thioxo groups; halogeno groups such as fluoro, chloro, and bromo groups; monovalent oxygen-containing groups such as aldehyde, carbonyl, carboxy, and sulfo groups; and monovalent nitrogen-containing groups such as nitro and amino groups.

[0081] In the above equations (1) to (9), R1, R3, R5, R7 to R 11 , R 13 Preferably, the number of carbon atoms is independently 10 or more, 10 to 25, 11 to 24, 12 to 23, 13 to 22, 14 to 21, and 15 to 20. Having the number of carbon atoms within these ranges tends to allow the oily agent to exist stably in the grease composition without aggregation. Furthermore, if dust is present in the sliding device, a film of the oily agent forms on the surface of the dust, which is easily dispersed in the grease composition, further reducing the dust's attacking power.

[0082] In the above equations (1) to (9), R1, R3, R5, R7 to R 11 , R 13 Each of these can independently have substituents or not. If substituents are present, the substituents are not particularly limited, but examples include alkyl groups such as methyl, ethyl, and propyl groups; alkenyl groups such as ethenyl, propenyl, and butenyl groups; alkynyl groups such as ethynyl, propynyl, and butynyl groups; monovalent sulfur-containing groups such as mercapto, thio, and thioxo groups; and monovalent halogeno groups such as fluoro, chloro, and bromo groups.

[0083] In the above equations (1) to (9), R1, R3, R5, R7 to R 11 , R 13The group is preferably a decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, decenyl group, undecenyl group, dodecenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group, hexadecenyl group, heptadecenyl group, octadecenyl group, nonadecenyl group, or icosenyl group.

[0084] In the compound represented by formula (4), R7 is preferably a decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, decenyl group, undecenyl group, dodecenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group, hexadecenyl group, heptadecenyl group, octadecenyl group, nonadecenyl group, or icocenyl group; more preferably an undecyl group, pentadecyl group, heptadecyl group, or heptadecenyl group; and even more preferably a heptadecenyl group.

[0085] In the compound represented by formula (5), R8, R9, and R 10 Preferably, each of these groups is independently a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, an icosyl group, a decenyl group, an undecenyl group, a dodecenyl group, a tridecenyl group, a tetradecenyl group, a pentadecenyl group, a hexadecenyl group, a heptadecenyl group, an octadecenyl group, a nonadecenyl group, or an icosenyl group, and more preferably an undecyl group, a pentadecyl group, a heptadecyl group, or a heptadecenyl group. Also, R8, R9, and R 10 It is even more preferable that all of them are heptadecenyl groups.

[0086] In this embodiment, sorbitan monooleate refers to a mixture of esters obtained by mixing sorbitan and oleic acid in a molar ratio of 1:1, and includes compounds in formula (4) where R7 is a heptadecenyl group. Also, sorbitan trioleate refers to a mixture of esters obtained by mixing sorbitan and oleic acid in a molar ratio of 1:3, and in formula (5), R8, R9, and R 10 These all include compounds that have a heptadecenyl group.

[0087] The HLB value of the oily agent in this embodiment is preferably 2.0 to 10.0, more preferably 2.2 to 8.0, even more preferably 2.4 to 6.0, and even more preferably 2.6 to 5.0. When the HLB value is within the above range, lubricity and lubrication durability tend to be further improved. In addition, when dust is present in the sliding device, the attack of dust tends to be further reduced.

[0088] HLB stands for Hydrophile-lipophile balance, and it is an indicator of the balance between hydrophilic and lipophilic groups within a molecule. The above HLB values ​​were calculated using the Griffin method.

[0089] The oily agent content in this embodiment is preferably 0.1% to 10.0% by mass, more preferably 1.0% to 8.0% by mass, and even more preferably 1.0% to 5.0% by mass, relative to the total amount of the grease composition. When the oily agent content is within the above range, the lubricity and lubrication durability tend to be further improved. In addition, when dust is present in the sliding device, the attack of dust tends to be further reduced.

[0090] 1.4. Other Additives The grease composition may further contain other additives in addition to the components described above. These other additives are not particularly limited, but examples include UV absorbers, friction modifiers, viscosity index improvers, detergent dispersants, pour point depressants, rust inhibitors, and defoamers. The other additives are selected appropriately according to the desired physical properties. Furthermore, these other additives may be used individually or in combination of two or more.

[0091] 2. Method for producing a grease composition The method for producing the grease composition of this embodiment is not particularly limited, but for example, it may include a step of mixing the above components. Alternatively, it may include a step of pre-mixing some of the above components and then adding and mixing the remaining components. Specifically, a base oil composition may be prepared by mixing a portion of the base oil with a thickener, and then the base oil composition, the remaining base oil, and the other components may be mixed. In this case, the base grease includes the base oil composition and the remaining base oil. The base oil composition may be prepared or a commercially available one may be used.

[0092] 3. Sliding device The grease composition of this embodiment is suitably used in sliding devices. The sliding device comprises at least a base material and a component, the component sliding on the base material. The base material and the component are in a sliding relationship, for example, a rail and a slider that moves a large distance on the rail.

[0093] Preferably, the grease composition present in the sliding device is sandwiched between the base material and the component, and is in contact with the base material and the component at the portion where the component slides on the base material. This arrangement of the grease composition tends to improve initial sliding properties and lubrication durability.

[0094] It is preferable that the grease composition present in the sliding device resides within a sealed space surrounded by at least the base material and the component. The presence of the grease composition within this sealed space prevents leakage of the grease composition outside the sliding device, thus reducing initial sliding performance, and also prevents contamination of parts outside the sliding device by the grease composition. Furthermore, while conventional grease compositions would experience deterioration of lubricity and lubrication durability due to dust contamination when dust enters the grease composition within the sealed space (as described later), the grease composition of this embodiment maintains excellent lubricity and lubrication durability regardless of the presence or absence of dust.

[0095] The sliding devices are not particularly limited, but examples include door lock mechanisms, window regulators, seat rails, sunroofs, suspensions, brakes, or gear parts of steering systems. For the aforementioned sliding devices that are frequently exposed to the outside world, there is a high possibility that dust, as described later, will be mixed into the grease composition in the sealed space surrounded by the base material and the component. However, by using the grease composition of this embodiment, excellent lubricity and lubrication durability can be maintained even in the presence of dust. Furthermore, the aforementioned sliding devices tend to be subjected to large loads when the component slides on the base material. In this regard, the grease composition of this embodiment can maintain excellent initial sliding properties even when large loads are applied.

[0096] 3.1. Base material A sliding device in which the grease composition of this embodiment is preferably used has a base material as its structure.

[0097] The base material is not particularly limited, but examples include synthetic resins such as phenolic resin, melamine resin, teflon resin, alkyd resin, epoxy resin, polyester resin, polyurethane resin, polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl acetate resin, polyurethane resin, polylactic acid resin, Teflon resin, acrylonitrile butadiene styrene resin, acrylonitrile styrene resin, acrylic resin, polyvinyl chloride resin, polyamide resin, glass fiber reinforced polyamide resin, polyacetal resin, polycarbonate resin, and modified polyphenylene ether resin, as well as inorganic materials such as aluminum, magnesium, iron, copper, tin, zinc, lead and their alloys, and glass.

[0098] The base material may be hydrophilic or hydrophobic, but it is preferably hydrophilic, and more preferably has hydroxyl groups on its surface. When the base material is hydrophilic, the base material surface interacts with the polar groups of the oily agent contained in the grease composition, allowing the grease composition to adhere to the base material even after sliding, which tends to improve lubricity and lubrication durability. Furthermore, when the oily agent has hydroxyl groups, the presence of hydroxyl groups on the base material surface allows the base material surface and the hydroxyl groups of the oily agent contained in the grease composition to interact through hydrogen bonding, which further improves the adhesion of the grease composition to the base material surface after sliding, and tends to further improve lubricity and lubrication durability.

[0099] Hydrophilicity and hydrophobicity are specifically evaluated by the contact angle with water. In this embodiment, substances with a contact angle with water of 0 to 90° are hydrophilic, and substances with a contact angle with water greater than 90° are hydrophobic.

[0100] The hydrophilic material is not particularly limited, but may be, for example, a hydrophilic resin, metal, or alloy, or a hydrophobic material coated with a hydrophilic film. Examples of hydrophilic resins include polyamide resins. Polyamide resins are preferred because they interact with the oily agent of this embodiment, such as through hydrogen bonding, via amide bonds. Examples of metals include aluminum. Aluminum tends to have hydroxyl groups on its surface due to water present in the environment, and in this case, it readily interacts with the oily agent of this embodiment, such as through hydrogen bonding, making it preferable.

[0101] The surface of the base material may be treated to introduce functional groups that interact with the oily agent of this embodiment, such as hydrogen bonding. The surface treatment method is not particularly limited, but examples include corona treatment and plasma treatment.

[0102] 3.2. Components A sliding device in which the grease composition of this embodiment is preferably used has components as its structure. The material of the components is not particularly limited, but for example, it can be the same as that exemplified in the base material.

[0103] The component may be hydrophilic or hydrophobic, but it is preferable that it be hydrophilic, and even more preferable that it has hydroxyl groups on its surface. When the component is hydrophilic, the polar groups of the oily agent contained in the grease composition interact with the component surface, allowing the grease composition to adhere to the component even after sliding, which tends to improve lubricity and lubrication durability. Furthermore, when the oily agent has hydroxyl groups, the presence of hydroxyl groups on the component surface allows the hydroxyl groups of the oily agent contained in the grease composition to interact with the component surface through hydrogen bonding, which tends to further improve the adhesion of the grease composition to the component surface after sliding, resulting in improved lubricity and lubrication durability.

[0104] The hydrophilic material is not particularly limited, but may be, for example, a hydrophilic resin, metal, or alloy, or a hydrophobic material coated with a hydrophilic film. Examples of hydrophilic resins include polyamide resins. Polyamide resins are preferred because they interact with the oily agent of this embodiment, such as through hydrogen bonding, via amide bonds. Examples of metals include aluminum. Aluminum tends to have hydroxyl groups on its surface due to water present in the environment, and in that case, it is more likely to interact with the oily agent of this embodiment, such as through hydrogen bonding, making it preferable.

[0105] The surface of the component may be treated to introduce functional groups that interact with the oily agent according to this embodiment, such as hydrogen bonding. The surface treatment method is not particularly limited, but examples include corona treatment and plasma treatment.

[0106] The base material and the component may be made of the same material or different materials.

[0107] 3.3.Dust At least a portion of the grease composition is sandwiched between the base material and the component, and the portion of the component that slides on the base material and contacts the base material and the component may contain dust. The grease composition of this embodiment tends to reduce the attack of dust, so even if dust is mixed into the grease composition, high lubricity can be maintained. Furthermore, dust may be mixed into the grease composition that exists in a sealed space surrounded at least by the base material and the component. When a conventional grease composition containing dust is placed in a sealed space surrounded at least by the base material and the component, and the component is slid on the base material, the dust tends to remain in the sealed space, and the lubricity tends to decrease. However, since the grease composition of this embodiment can reduce the attack of dust, even when the grease composition of this embodiment containing dust is placed in a sealed space surrounded at least by the base material and the component, and the component is slid on the base material, the attack of the dust remaining in the sealed space decreases, and high lubricity can be maintained.

[0108] 4. Method of using the grease composition The grease composition of this embodiment is preferably used in a dusty environment, and more preferably in a dusty environment within a sealed space surrounded by a base material and components. The grease composition of this embodiment is suitably used, for example, to improve the lubrication of gear parts of door lock mechanisms, window regulators, seat rails, sunroofs, suspensions, brakes, or steering systems. [Examples]

[0109] The present invention will be described in more detail below using examples and comparative examples. The present invention is not limited in any way by the following examples. Unless otherwise specified, each operation was carried out at room temperature (25°C) and 1 atmosphere.

[0110] 1. Preparation of grease composition Each component was placed in a mixing tank to obtain the composition shown in Table 1, and the mixture was stirred at room temperature to obtain the grease compositions used in each example and comparative example. Unless otherwise specified, the numerical values ​​of each component shown in the table represent mass percent.

[0111] Each component listed in Table 1 represents the following: Base oil composition 1: A mixture of 90.0% by mass of poly-α-olefin oil and 10.0% by mass of diurea (Note that the content in base oil composition 1 is the value when the total amount of base oil composition 1 is considered to be 100% by mass.) Base oil composition 2: A mixture of 90.0% by mass of poly-α-olefin oil and 10.0% by mass of lithium soap (Note that the content in base oil composition 2 is the value when the total amount of base oil composition 2 is considered to be 100% by mass.) Base oil: Poly-alpha-olefin oil, kinematic viscosity measured at 100°C: 6 mm² 2 / s UHPE: Ultra-high molecular weight polyethylene (weight-average molecular weight: 2.00 × 10⁻⁶) 6 ), density 0.94g / cm 3 Melting point 136℃, median diameter 30μm PTFE: Polytetrafluoroethylene, density 2.15 g / cm³ 3 Melting point 310°C or higher, median diameter 3 μm MCA: Melamine cyanurate, density 1.72 g / cm³ 3 Melting point 350°C or higher, median diameter 3 μm Talc: Density 2.70 g / cm³ 3 800℃, median diameter 12μm Oily agent 1: Sorbitan monooleate Oily agent 2: Sorbitan triolate UV absorbers: Benzotriazole-based UV absorbers Organic molybdenum

[0112] [Table 1]

[0113] 2. Evaluation Method 2.1. Evaluation of the coefficient of friction An aluminum plate (100 mm wide, 70 mm long, 1 mm thick) was prepared as the base material, and a cylindrical (2 mm or 10 mm in diameter, 25 mm in height) glass fiber reinforced resin was prepared as the component, containing 30% by mass of glass fiber and 70% by mass of polyamide resin relative to the total mass of the component. The grease composition of each example and comparative example was applied to the entire surface of the base material to a thickness of 200 μm. Mixed dust was added to the grease composition at a ratio of 2% by mass relative to the total amount of the grease composition. The mixed dust was obtained by mixing dust A (type 1), dust B (type 2), and dust C (type 7) in a mass ratio of A:B:C = 2:1:1. Types 1, 2, and 3 are names according to JIS Z8901:2006. Subsequently, the coefficient of friction was measured when the component was slid on the base material using a reciprocating sliding test machine (Shinto Kagaku Co., Ltd., HEIDON-14DR (product name)). The conditions for sliding the component on the base material were as follows: the temperature during sliding was 25°C, the load applied to the component was 3 or 4.5 kgf, the sliding speed of the component was 600 mm / min, and the stroke width of the component was 20 mm in the lateral direction of the base material.

[0114] When the coefficient of friction is low during the initial stages of sliding, it can be said that the initial sliding performance is good. For example, if the average value of the coefficient of friction during the first to fifth sliding cycles is low, it can be said that the initial sliding performance is good.

[0115] Good lubrication can be indicated when the coefficient of friction is low after the grease composition has sufficiently settled within the sliding device. For example, good lubrication can be indicated when the coefficient of friction is low after 150 sliding cycles.

[0116] A low coefficient of friction after repeated sliding over a long period indicates good lubrication durability. For example, a low coefficient of friction after 300 sliding cycles indicates good lubrication durability.

[0117] Table 1 shows the measurement results of the friction coefficient for each example and comparative example grease composition.

[0118] Examples 1, 5, and 7-11, which contain an oily agent, were found to suppress the increase in the coefficient of friction at the 150th and 300th sliding cycles compared to Example 6, which does not contain an oily agent.

[0119] Furthermore, in Examples 5 and 6, we measured whether or not abnormal noise occurred during sliding. As a result, in Example 6, abnormal noise, which is thought to be caused by the stick-slip phenomenon, occurred after 500 sliding cycles, but no such noise occurred in Example 5. In other words, it is thought that the inclusion of an oily agent suppressed the stick-slip phenomenon and improved lubrication durability.

Claims

1. A grease composition comprising a base grease containing a base oil and a thickener, and a solid lubricant, The solid lubricant includes a first solid lubricant having a median diameter of 15 μm or more and 50 μm or less. The content of the solid lubricant is 30% by mass or more and 50% by mass or less, relative to the total amount of the grease composition. Grease composition.

2. The first solid lubricant in the 1st term contains polyethylene, The grease composition according to claim 1.

3. The solid lubricant includes a second solid lubricant having a median diameter of less than 15 μm. The grease composition according to claim 1.

4. The second solid lubricant comprises one or more selected from the group consisting of melamine cyanurate, polytetrafluoroethylene, talc, graphite, graphite fluoride, molybdenum disulfide, lithium stearate, calcium stearate, aluminum stearate, calcium carbonate, mica, antimony sulfide, tungsten disulfide, boron nitride, and copper. The grease composition according to claim 3.

5. Contains an oily agent, The oily agent includes a compound having a polar group. The grease composition according to claim 1.

6. The oily agent comprises a compound having one or more hydroxyl groups and a saturated or unsaturated hydrocarbon group having 10 or more carbon atoms, which is substituted or unsubstituted. The grease composition according to claim 5.

7. The aforementioned compound is an ester. The grease composition according to claim 6.

8. The ester includes fatty acid esters. The grease composition according to claim 7.

9. The aforementioned fatty acid ester includes an ester represented by the following formula (1): The grease composition according to claim 8. 【Chemistry 1】 (In the formula, R 1 R is a substituted or unsubstituted monovalent saturated or unsaturated hydrocarbon group having 10 or more carbon atoms, 2 (This refers to a monovalent cyclic or chain-like hydrocarbon group having 1 to 10 carbon atoms, having one or more hydroxyl groups, which may have an ether bond, and which may have substituents other than hydroxyl groups. Also, n is a natural number from 1 to 3.)

10. The aforementioned fatty acid ester includes an ester represented by the following formula (2): The grease composition according to claim 8. 【Chemistry 2】 (In the formula, R 3 R is a substituted or unsubstituted monovalent saturated or unsaturated hydrocarbon group having 10 or more carbon atoms, 4 (This refers to a monovalent cyclic or chain-like hydrocarbon group having 4 to 8 carbon atoms, having one or more hydroxyl groups, which may have an ether bond, and which may have substituents other than hydroxyl groups. Also, n is a natural number from 1 to 3.)

11. The aforementioned fatty acid ester includes an ester represented by the following formula (3): The grease composition according to claim 8. 【Transformation 3】 (In the formula, R 5 R is a substituted or unsubstituted monovalent saturated or unsaturated hydrocarbon group having 10 or more carbon atoms, 6 (This refers to a monovalent cyclic hydrocarbon group having 4 to 8 carbon atoms, possessing one or more hydroxyl groups, having an ether bond, and potentially having substituents other than hydroxyl groups. Furthermore, n is a natural number from 1 to 3.)

12. The fatty acid ester includes an ester represented by the following formula (4) and / or an ester represented by the following formula (5). The grease composition according to claim 8. 【Chemistry 4】 【Transformation 5】 (wherein, R 7 , R 8 , R 9 , and R 10 are each independently a substituted or unsubstituted monovalent saturated or unsaturated hydrocarbon group having 10 or more carbon atoms.)

13. R 7 However, it is a decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, decenyl group, undecenyl group, dodecenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group, hexadecenyl group, heptadecenyl group, octadecenyl group, nonadecenyl group, or icosenyl group. R 8 , R 9 , and R 10 However, each is independently a decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, decenyl group, undecenyl group, dodecenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group, hexadecenyl group, heptadecenyl group, octadecenyl group, nonadecenyl group, or icosenyl group. The grease composition according to claim 12.

14. The content of the oily agent is 0.1% by mass or more and 10.0% by mass or less, relative to the total amount of the grease composition. The grease composition according to claim 5.

15. Used to improve the lubrication of the gear parts of the door lock mechanism, window regulator, seat rail, sunroof, suspension, brake, or steering system. The grease composition according to claim 1.

16. A sliding device comprising a grease composition according to any one of claims 1 to 15, a base material, and a member that slides on the base material, The grease composition is sandwiched between the base material and the member, and in the portion where the member slides on the base material, Sliding device.

17. Both the base material and the member are hydrophilic. The sliding device according to claim 16.

18. containing dust, The sliding device according to claim 16.

19. The grease composition is present in a sealed space surrounded by at least the base material and the member. The sliding device according to claim 16.

20. The grease composition according to any one of claims 1 to 15 is used in an environment containing dust. Method of using a grease composition.

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