Lubricant and method for applying lubricant

Abstract

To provide a lubricant capable of exhibiting excellent wear resistance on a sliding surface.SOLUTION: A lubricant contains at least one of a Class 1 petroleum oil and a Class 2 petroleum oil, a base oil, and fine cellulose particles, wherein the content of the fine cellulose particles is 0.1 to 4.5 wt.%.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a lubricant and a method for applying a lubricant. [Background technology]

[0002] BACKGROUND ART Conventionally, in machines having parts (sliding parts) that slide against each other while rubbing against each other, lubricants are used to reduce wear and friction on the sliding surfaces.

[0003] As such a lubricant, Patent Document 1 describes a lubricating oil composition comprising a base oil consisting of at least one of a synthetic hydrocarbon oil and an ester-based synthetic oil, a solid lubricant such as graphite, molybdenum disulfide or melamine cyanurate, and a lithium-based soap, a lithium-based complex soap, or a urea-based compound. This lubricating oil composition is said to be able to maintain the solid lubricant dispersed in the base oil in a good dispersed state for a long period of time without impairing the fluidity, load-bearing capacity, or wear characteristics of the lubricant.

[0004] In Patent Document 2, the kinematic viscosity at 40°C is 10mm 2 / s or more 60mm 2 The document describes a lubricating grease composition containing a base oil having a viscosity of 1 / s or less, a thickener containing at least one soap selected from the group consisting of metal soaps and metal complex soaps, and a solid lubricant containing porous polyamide particles. Such a lubricating grease composition is said to be able to increase the static friction coefficient between sliding members and to be excellent in start-up performance, durability, and low-temperature performance. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-246499 [Patent Document 2] International Publication No. 2020 / 129587 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the techniques of Patent Documents 1 and 2 do not provide sufficient wear resistance on the sliding surfaces, and further improvement in wear resistance is required.

[0007] The present invention has been made in view of the above circumstances, and has an object to provide a lubricant that can exhibit excellent wear resistance on sliding surfaces. [Means for solving the problem]

[0008] As a result of extensive research to solve the above problems, the present inventors have found that the above problems can be solved by the following configuration, and have completed the present invention through further research based on this finding.

[0009] A lubricant according to one embodiment of the present invention contains at least one of first and second petroleum products, a base oil, and cellulose fine particles, with the cellulose fine particle content being 0.1 to 4.5 wt %. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a lubricant that can exhibit excellent wear resistance on sliding surfaces. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view of a chain to which a lubricant is applied in this embodiment. [Figure 2] FIG. 2 is a diagram showing the results of the wear resistance test for the lubricants of Examples 1 and 2 and Comparative Examples 1 and 2. [Figure 3] FIG. 3 is a graph showing the results of the wear resistance test for the lubricants of Example 3 and Comparative Example 3. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these.

[0013] <Lubricant> The lubricant in this embodiment contains at least one of first and second petroleum products, a base oil, and cellulose fine particles, and the content of the cellulose fine particles is 0.1 to 4.5 wt %. With this configuration, it is possible to provide a lubricant that can exhibit excellent wear resistance on sliding surfaces.

[0014] The lubricant contains at least one of the first petroleum product and the second petroleum product, and cellulose fine particles, thereby maintaining the viscosity of the lubricant at an appropriate level. This allows the lubricant to penetrate the sliding surface well. As a result, the sliding surface can exhibit excellent wear resistance. The lubricant may contain both the first petroleum product and the second petroleum product, or may contain either the first petroleum product or the second petroleum product (either the first petroleum product or the second petroleum product).

[0015] When the content of the cellulose microparticles is 0.1 wt% or more relative to 100 wt% of the lubricant, the cellulose microparticles are easily dispersed uniformly in the lubricant, thereby achieving excellent wear resistance on the sliding surface.When the content of the cellulose microparticles is 4.5 wt% or less relative to 100 wt% of the lubricant, the viscosity of the lubricant is easily maintained at an appropriate level, thereby improving the penetration of the lubricant into the sliding surface and achieving excellent wear resistance on the sliding surface.

[0016] Each component contained in the lubricant of this embodiment will be specifically described below.

[0017] [Cellulose fine particles] The median diameter of the particle size distribution of the cellulose microparticles in this embodiment is preferably 1 to 100 μm. When the median diameter is within the above range, the viscosity of the lubricant can be easily maintained at an appropriate level, and the lubricant can penetrate the sliding surface well. As a result, excellent wear resistance can be more reliably obtained on the sliding surface.

[0018] The median diameter is more preferably 1 to 50 μm, and even more preferably 1.5 to 30 μm.

[0019] The median diameter (particle diameter at which the cumulative volume-based frequency reaches 50%) is determined using a laser diffraction / diffusion particle size distribution analyzer (Horiba, Ltd., instrument name: LA960). Specifically, cellulose microparticles are adjusted with ion-exchange water to a final concentration of 0.5% by mass, processed in a Waring blender (Waring, instrument name: 7012S) at 3400 rpm for 5 minutes, and then subjected to ultrasonic dispersion treatment for 1 minute before measurement, followed by particle size distribution measurement. The half-value width is the width obtained by taking half the maximum frequency of the mountain-shaped peak obtained in particle size distribution measurement. The particle size measurement range is 0.1 to 500 μm.

[0020] The method for producing cellulose fine particles in this embodiment is not particularly limited, and the cellulose fine particles can be produced from a cellulose raw material by various production methods.

[0021] Examples of the cellulose raw material that can be used include pulps such as wood pulp produced from wood and cotton linter pulp obtained from cotton, as well as papers.

[0022] Examples of methods for producing the cellulose microparticles include a method of producing the desired cellulose by mechanical defibration. Specifically, the desired cellulose microparticles can be obtained by cutting the cellulose raw material to a predetermined length using a beater or refiner, and then fibrillating or pulverizing (mechanical pulverization) using a high-pressure homogenizer, grinder, impact pulverizer, bead mill, or the like. Alternatively, the desired cellulose microparticles can be obtained by chemically treating the cellulose raw material to make it easier to pulverize, and then pulverizing it by mechanical defibration.

[0023] The cellulose microparticles in this embodiment are preferably mechanically defibrated cellulose microparticles produced by mechanical defibration. Cellulose microparticles produced by mechanical defibration are not chemically modified during pulverization, and only an aqueous medium is used as the medium, so they have the advantage of being free of compounds that are likely to have an adverse effect on the particles and are chemically and thermally stable.

[0024] [First petroleum] The first petroleum product in this embodiment is a liquid having a flash point of less than 21°C at 1 atmosphere. From the viewpoint of improving abrasion resistance, the first petroleum product preferably contains at least one selected from isohexane, n-hexane, toluene, ethyl acetate, and n-heptane. One type of the first petroleum product may be used alone, or two or more types may be used.

[0025] [Second petroleum] The second petroleum product in this embodiment is a liquid having a flash point of 21°C or higher and lower than 70°C at 1 atmosphere. From the viewpoint of improving abrasion resistance, the second petroleum product preferably contains at least one selected from xylene, mineral spirits, and chlorobenzene. One type of the second petroleum product may be used alone, or two or more types may be used.

[0026] [Base oil] The base oil in this embodiment is not particularly limited, and may be, for example, a mineral base oil (mineral oil) and / or a synthetic base oil, which are commonly used as base oils. The base oil preferably contains at least one of a mineral oil and a synthetic base oil. This configuration has the advantage of more reliably achieving excellent wear resistance on the sliding surface.

[0027] The mineral oil is not particularly limited, but may be, for example, one refined by an appropriate combination of vacuum distillation, solvent deasphalting, solvent extraction, hydrocracking, solvent dewaxing, sulfuric acid washing, clay refining, and hydrorefining. As the mineral oil, it is preferable to use paraffinic mineral oil, intermediate base mineral oil, naphthenic mineral oil, etc. The mineral oil may be used alone or in combination of two or more types.

[0028] The synthetic base oil is not particularly limited, but it is preferable to use, for example, a hydrocarbon base oil (hydrocarbon oil), an aromatic base oil, an ester base oil, an ether base oil, a fatty acid ester base oil, etc. The synthetic base oil may be used alone or in combination of two or more.

[0029] The hydrocarbon base oil is not particularly limited, but examples thereof include normal paraffin, isoparaffin, polybutene, polyisobutylene, 1-decene oligomer, polyalphaolefin (PAO), etc. The hydrocarbon base oil may be used alone or in combination of two or more.

[0030] The base oil preferably contains at least one of a mineral oil and a hydrocarbon oil, which has the advantage of more reliably providing excellent wear resistance on the sliding surface and also improving penetration.

[0031] [others] In addition to the above components, the lubricant in this embodiment may contain various additives that are commonly added to lubricants, as long as the effects of the present invention are not impaired. The lubricant may also contain, for example, a propellant, a thickener, etc.

[0032] [Content] The content of the cellulose fine particles in this embodiment is 0.1 to 4.5% by weight relative to 100% by weight of the lubricant, preferably 0.5 to 4.0% by weight, and more preferably 1.0 to 3.0% by weight, relative to 100% by weight of the lubricant.

[0033] When the lubricant contains a first petroleum product, the content of the first petroleum product is preferably 10 to 60 wt % relative to 100 wt % of the lubricant. This configuration more reliably achieves excellent wear resistance on the sliding surface. The content of the first petroleum product is more preferably 10 to 50 wt %, and even more preferably 15 to 40 wt %, relative to 100 wt % of the lubricant.

[0034] When the lubricant contains a second petroleum product, the content of the second petroleum product is preferably 10 to 50 wt % relative to 100 wt % of the lubricant. This configuration more reliably achieves excellent wear resistance on the sliding surface. The content of the second petroleum product is more preferably 15 to 40 wt % relative to 100 wt % of the lubricant.

[0035] The content of the base oil is preferably 10 to 60% by weight based on 100% by weight of the lubricant. With this configuration, excellent wear resistance can be more reliably obtained on the sliding surface. The content of the base oil is more preferably 15 to 50% by weight, and even more preferably 20 to 40% by weight based on 100% by weight of the lubricant.

[0036] In this embodiment, the ratio of the total weight of the first petroleum product and the second petroleum product to the weight of the base oil (total weight of the first petroleum product and the second petroleum product / weight of the base oil) is preferably 0.1 to 6.0.

[0037] When the lubricant contains a propellant, the content of the base oil relative to 100% by weight of the lubricant is preferably 20 to 80% by weight, and the content of the propellant relative to 100% by weight of the lubricant is preferably 30 to 70% by weight.When the lubricant does not contain a propellant, the content of the base oil relative to 100% by weight of the lubricant is preferably 35 to 60% by weight.

[0038] When the lubricant in this embodiment contains a propellant, the ratio of the weight of the propellant to the total weight of the cellulose microparticles, the first and second petroleum products, and the base oil (weight of propellant / total weight of the cellulose microparticles, the first and second petroleum products, and the base oil) is preferably 0.4 to 2.5.

[0039] <Lubricant manufacturing method> The lubricant in this embodiment can be produced by uniformly mixing at least one of the first petroleum product and the second petroleum product, the base oil, the cellulose fine particles, and, if necessary, other components. The mixing can be carried out using, for example, a known or commercially available device such as a mixer or kneader.

[0040] <Lubricant applications> The lubricant in this embodiment can be used by being applied to any target such as sliding parts of various mechanical parts that constitute automobiles, motorcycles, machinery, electrical and electronic equipment, and the like.

[0041] The lubricant can be preferably applied to roller chains, and more preferably to motorcycle drive chains and bicycle chains. Specifically, in roller chains, motorcycle drive chains, and bicycle chains, the chain elongates primarily due to wear between the chain pins and bushings, and when this elongation exceeds a certain limit, the chain no longer meshes smoothly with the sprocket. Because the lubricant in this embodiment has excellent wear resistance on sliding surfaces, applying the lubricant to the sliding portions of, for example, a roller chain, motorcycle drive chain, or bicycle chain can suppress wear between the chain pins and bushings.

[0042] <How to apply lubricant> The method for applying the lubricant in this embodiment to any target (sliding part) is not particularly limited, and known methods such as spray application and brush application can be used. However, since the lubricant can be easily applied uniformly, it is suitable for use in a spray application method.

[0043] The method of applying the lubricant by spraying in this embodiment will be specifically described below.

[0044] When the lubricant of this embodiment is applied by spraying, it is preferable that the lubricant further contains a propellant in addition to at least one of the first petroleum product and the second petroleum product, the cellulose fine particles, and the base oil.The lubricant containing these components is preferably placed in any spray container such as a general aerosol spray, and sprayed onto any target (sliding part) to be applied.

[0045] The propellant is not particularly limited as long as it can be used as a spray when used together with at least one of the first and second petroleum products, the cellulose microparticles, and the base oil, and may be in either a gaseous or liquid state. Examples of the propellant include liquefied petroleum gas (LPG) containing propane, butane, isobutane, etc. as a main component, dimethyl ether (DME), isopentane, nitrogen gas, and carbon dioxide gas. The propellant may be used alone or in combination of two or more types.

[0046] Of these, it is preferable to use LPG as the propellant from the viewpoint of cost.

[0047] The lubricant may be used in a spray container such as a so-called "atomizer" without containing a propellant.

[0048] As described above, this specification discloses various aspects of the technology, but the main technologies among them are summarized below.

[0049] The lubricant in a first embodiment contains at least one of a first petroleum product and a second petroleum product, a base oil, and cellulose fine particles, and the content of the cellulose fine particles is 0.1 to 4.5 wt %.

[0050] In a second embodiment of the lubricant, the cellulose fine particles in the lubricant of the first embodiment have a median diameter of 1 to 100 μm.

[0051] A third aspect of the lubricant is the lubricant of the first or second aspect, wherein the first petroleum includes at least one selected from isohexane, n-hexane, toluene, ethyl acetate, and n-heptane.

[0052] A fourth aspect of the lubricant is the lubricant of any one of the first to third aspects, wherein the second petroleum product includes at least one selected from xylene, mineral spirits, and chlorobenzene.

[0053] A fifth aspect of the lubricant is the lubricant of any one of the first to fourth aspects, wherein the base oil comprises at least one of a mineral oil and a synthetic base oil.

[0054] The lubricant according to a sixth aspect is the lubricant according to any one of the first to fifth aspects, which is used for roller chains.

[0055] In a seventh aspect, the lubricant application method is such that the lubricant in any one of the first to sixth aspects is applied by spraying.

[0056] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples in any way. [Example]

[0057] [Example 1] A lubricant containing cellulose microfibers (product number "F25", manufactured by Sugino Machine Co., Ltd., median diameter 7 μm) (cellulose microparticles), isohexane (first petroleum product), paraffinic mineral oil (base oil) as mineral oil, and LPG (propellant) was prepared. Specifically, the cellulose microfibers were blended at 1 wt % relative to 100 wt % of the lubricant. Furthermore, isohexane was blended at 24 wt % relative to 100 wt % of the lubricant. Paraffinic mineral oil was blended at 25 wt % relative to 100 wt % of the lubricant. Furthermore, the ratio of the weight of LPG to the total weight of the cellulose microfibers, isohexane, and paraffinic mineral oil (LPG / cellulose microfibers, isohexane, and paraffinic mineral oil) was 1. In this way, the lubricant in Example 1 was obtained.

[0058] [Example 2] The lubricant in Example 2 was obtained in the same manner as in Example 1, except that the content of cellulose microfiber was 3 wt % relative to 100 wt % of the lubricant, and isohexane was blended so as to be 22 wt % relative to 100 wt % of the lubricant.

[0059] [Example 3] The lubricant in Example 3 was obtained in the same manner as in Example 1, except that isohexane was not used and instead mineral spirits (secondary petroleum products) was blended in an amount of 24 wt % relative to 100 wt % of the lubricant.

[0060] [Comparative Example 1] A lubricant in Comparative Example 1 was obtained in the same manner as in Example 1, except that cellulose microfibers were not used and isohexane was blended in an amount of 25% by weight relative to 100% by weight of the lubricant.

[0061] Comparative Example 2 The lubricant in Comparative Example 2 was obtained in the same manner as in Example 1, except that the content of cellulose microfiber was 5% by weight relative to 100% by weight of the lubricant, and isohexane was blended in an amount of 20% by weight relative to 100% by weight of the lubricant.

[0062] Comparative Example 3 The lubricant in Comparative Example 3 was obtained in the same manner as in Example 1, except that cellulose microfiber was not used, isohexane was not used and instead mineral spirits (secondary petroleum products) was blended at 25 wt% relative to 100 wt% of the lubricant, and mineral oil was not used and instead polybutene was blended as a hydrocarbon oil at 25 wt% relative to 100 wt% of the lubricant.

[0063] The blending ratios of the cellulose microparticles, second petroleum products, first petroleum products, base oil, and propellant in the lubricants of Examples 1 to 3 and Comparative Examples 1 to 3 are shown in Table 1. The numerical values of the composition of each component in Table 1 are in "% by weight."

[0064] [Table 1]

[0065] [Wear resistance test] The lubricants of Examples 1 to 3 and Comparative Examples 1 to 3 obtained as described above were evaluated for wear resistance according to the following method.

[0066] First, the chain to be used in the wear resistance test was degreased. Specifically, the chain (product number "DID50", manufactured by Daido Kogyo Co., Ltd.) was immersed in cleaning solution and degreased in an ultrasonic cleaner for 10 minutes. Next, the chain was turned upside down and degreased for 10 minutes. After that, excess cleaning solution was blown off with an air blower. Finally, it was dried in a constant temperature bath at 40°C for 12 to 15 hours and then washed with acetone.

[0067] Next, the lubricant was filled into a spray container (aerosol can), and the lubricant was applied to the chain. Specifically, the lubricant (chain lube) in the aerosol can was first shaken approximately 100 times before application. Then, the nozzle tip of the aerosol can was held approximately 2-3 mm away from the chain, and the lubricant was applied to the chain. A more specific application method is explained using Figure 1. Figure 1 is a cross-sectional view of a chain 1 equipped with rollers 2, bushings 3, pins 4, inner plates 5, and outer plates 6. The chain 1 was placed on a workbench with the side showing the rollers 2 facing up, and the lubricant was applied from both sides between the pins 4 and bushings 3, then between bushings 3 and rollers 2, then turned upside down and the lubricant was applied from both sides between the pins 4 and bushings 3, and finally between bushings 3 and rollers 2. After application, the chain was dried at room temperature for one hour while horizontally and floating above the floor.

[0068] The chains were lubricated, measured, and then joined together to form a loop. The joint parts used were the same pins and outer plates as the main chain.

[0069] A looped chain was attached to two sprockets (number of teeth: Dr15T x Dn43T). A load of 1.5kN (3kN total on both sides) was applied in the opposite direction from the center of one sprocket to the other (constant one-sided tension). The chain had approximately 30mm of slack. In this state, the sprockets were rotated at 2000 rpm, and the chain elongation was measured at intervals of 7 hours or 15 hours. Note that no lubrication was performed during the measurements. The elongation was measured by measuring the initial length of the chain before the test and the length of the chain at specified intervals, and expressed as a percentage of the chain's elongation compared to its initial length before the test.

[0070] The results of the abrasion resistance test are shown in Figures 2 and 3. In Figures 2 and 3, the vertical axis represents elongation (%) and the horizontal axis represents time (hr).

[0071] [Consideration] 2, it was found that when the lubricants of Examples 1 and 2, which contained an appropriate amount of cellulose microparticles, were used, chain elongation was suppressed and wear resistance on the sliding surface was excellent. On the other hand, when the lubricant of Comparative Example 1, which did not contain cellulose microparticles, was used, the chain elongation rate was higher than in Examples 1 and 3, resulting in poor wear resistance on the sliding surface. Furthermore, the lubricant of Comparative Example 2, which contained cellulose microparticles but more than 4.5 wt %, also had poor wear resistance on the sliding surface compared to Examples 1 and 2.

[0072] 3, the lubricant of Example 3 containing an appropriate amount of cellulose fine particles was found to have excellent wear resistance, while the lubricant of Comparative Example 3 containing no cellulose fine particles was found to have inferior wear resistance on the sliding surface compared to Example 3. [Explanation of symbols]

[0073] 1 Chain 2. Laura 3 bushes 4-pin 5 Inner plate 6 outer plate

Claims

1. The oil composition includes at least one of a first petroleum product and a second petroleum product, a base oil, and cellulose fine particles, The lubricant contains the cellulose fine particles in an amount of 0.1 to 4.5% by weight.

2. 2. The lubricant according to claim 1, wherein the cellulose fine particles have a median diameter of 1 to 100 μm.

3. 2. The lubricant of claim 1, wherein the first petroleum oil comprises at least one selected from isohexane, n-hexane, toluene, ethyl acetate, and n-heptane.

4. 10. The lubricant of claim 1, wherein the second petroleum product comprises at least one selected from xylene, mineral spirits, and chlorobenzene.

5. 10. The lubricant of claim 1, wherein the base oil comprises at least one of a mineral oil and a synthetic base oil.

6. The lubricant of claim 1 for use in roller chains.

7. A method for applying a lubricant, comprising applying the lubricant according to any one of claims 1 to 6 by spraying.

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