Additive, method for producing additive, additive-containing lubricant, and method for producing additive-containing lubricant.

Abstract

An object of the present disclosure is to provide an additive that can be produced at a relatively low cost and that can effectively improve the sliding properties of movable members. An additive according to one embodiment of the present disclosure is an additive to be added to a lubricating oil, and has granules containing soluble silicic acid as a main component.

Description

[Technical field]

[0001] The present disclosure relates to additives and methods for making the additives. [Background technology]

[0002] Lubricating oils are sometimes used to allow parts to slide smoothly against each other. Some lubricating oils, such as grease, have a relatively high viscosity and are applied to the outer surface of a movable part such as a cylinder rod to reduce sliding resistance, while other lubricating oils, such as engine oil, have a relatively low viscosity and are injected into an apparatus (engine) to flow and reduce the sliding resistance of the movable parts in the apparatus. Additives may be added to such lubricating oils to improve lubricity (JP Patent Publication No. 2018-053021). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-053021 A Summary of the Invention [Problem to be solved by the invention]

[0004] The engine oil additive of Patent Document 1 realizes low friction by including specific components such as nano-onion-like carbon. Since the manufacturing cost of nano-onion-like carbon is relatively high, it may be difficult to provide the additive at a low cost. From the viewpoint of protecting the global environment, fuel efficiency improvement by improving the sliding properties of engine oil is desired, and there is a demand for additives that are cheaper and easier to use. In addition, for greases that are directly applied to the outer surfaces of movable parts, there is a demand for additives that can easily improve sliding properties at a low cost from the viewpoint of improving the operating efficiency of the equipment having the movable parts.

[0005] In view of the above circumstances, an object of the present disclosure is to provide an additive that can be produced at a relatively low cost and can effectively improve the sliding properties of movable members. [Means for solving the problem]

[0006] An additive according to one embodiment of the present disclosure that solves the above problems is an additive to be added to a lubricating oil, and has granules containing soluble silicic acid as a main component. Effect of the Invention

[0007] The additive of the present disclosure can be produced at a relatively low cost and can effectively improve the sliding properties of movable parts. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] [Description of the embodiments of the present disclosure] First, the embodiments of the present disclosure will be listed and described.

[0009] (1) An additive according to one embodiment of the present disclosure is an additive to be added to a lubricating oil and has granules containing soluble silicic acid as a main component.

[0010] Since the additive has granules mainly composed of soluble silicic acid, it can improve the lubricity (sliding property of members) of the lubricating oil to which the additive is added, and can effectively reduce friction. In addition, since soluble silicic acid is abundant in nature, it is easily available and can be produced at low cost. Note that the main component means the component whose content ratio is the largest among all components, for example, the component whose content ratio is 50 mass% or more.

[0011] (2) In the above (1), the granules may further contain potassium oxide, which can further improve the lubricity.

[0012] (3) In the above (1) or (2), the granules may further contain calcium oxide, which can further improve the lubricity.

[0013] (4) In any of (1) to (3) above, the granular material may have an average particle size of 12 μm or less. By making the average particle size of the granular material 12 μm or less, the lubricity can be improved. The average particle size means the 50% volume cumulative standard (D50 value) measured by a laser scattering particle size distribution device.

[0014] (5) An additive according to one embodiment of the present disclosure is an additive to be added to a lubricating oil, and includes a fired product obtained by firing a plant shell.

[0015] Many plant shells contain silicon, so a calcined product containing soluble silicic acid can be easily obtained by calcining the plant shells. The additive contains a calcined product obtained by calcining the plant shells, so the lubricity can be effectively improved. The plant shells are easily available, so the additive can be produced at low cost.

[0016] (6) A method for producing an additive according to one embodiment of the present disclosure is a method for producing an additive to be added to a lubricating oil, the method including the steps of calcining plant shells and pulverizing the calcined shells.

[0017] Many plant shells contain silicon, so by calcining the shells, it is easy to obtain a calcined product containing soluble silicic acid. By pulverizing the calcined product, it is possible to homogenize the shape (particle size). Therefore, the manufacturing method of the additive can obtain an additive that can effectively improve the lubricity of lubricating oil at low cost.

[0018] (7) In the above (6), the husk may be rice husk, which has a high silicon content, making it easy to obtain a burned product containing a sufficient amount of soluble silicic acid.

[0019] [Details of the embodiment of the present disclosure] An example of an embodiment of the present disclosure will be described in detail below.

[0020] <Additives> The additive is an additive to be added to a lubricating oil, and has a granular body mainly composed of soluble silicic acid. The lubricating oil is not particularly limited as long as it forms a film between a moving part and a non-moving part on which the moving part is disposed or another moving part to improve the sliding property, and may be, for example, engine oil used in an internal combustion engine of a transport device such as an automobile, or transmission oil used in a transmission, or grease applied to the outer surface of a sliding part or enclosed in a seal of a seal bearing.

[0021] The additive may be added after the lubricating oil is manufactured, or during the manufacture of the lubricating oil, i.e., the additive may be added to the lubricating oil before use, or the lubricating oil to which the additive has been added may be prepared and used.

[0022] The lower limit of the ratio of the content of soluble silicic acid contained in the granules is preferably 50% by mass. The lower limit of the ratio may be 55% by mass, 60% by mass, or 70% by mass. The upper limit of the ratio is not particularly limited, and may be 100% by mass or 99% by mass. By containing soluble silicic acid in the above range in the granules, the lubricity of the lubricating oil containing the additive can be improved.

[0023] The reason why the lubricity is improved by adding an additive containing soluble silicic acid to a lubricating oil is unclear, but it is believed that the granular material is crushed by the sliding of the members, and the surface roughness (unevenness) of the sliding surface is filled and flattened, thereby improving the lubricity (slidability). It is also believed that the inclusion of soluble silicic acid makes the lubricant more likely to have a porous structure, and that the retention of the lubricating oil promotes the thickening effect of the lubricating oil. It is also believed that the soluble silicic acid is absorbed into the lubricating oil as silicon ions, causing a chemical reaction in the lubricating oil, improving the fluidity of the lubricating oil.

[0024] The lower limit of the ratio of the silicon element content to the total elements of the granular material as determined by quantitative analysis using a fluorescent X-ray device may be 60 mass%, 70 mass%, 80 mass%, or 85 mass%. The upper limit of the ratio is not particularly limited and may be 99 mass%.

[0025] The raw material of the granular material is not particularly limited as long as it contains soluble silicic acid, but it is preferable to use waste materials, such as combustion ash generated at thermal power plants, slag generated at steel mills, and dust ash, which are made by burning plants, and particularly, plant shells are preferable. That is, as another embodiment, the additive may contain a burned product of a plant shell. The plant shell is not particularly limited, but rice husks, which have a high silicon content, are preferable.

[0026] The lower limit of the temperature for firing the plant shells is preferably 200° C., more preferably 300° C. The upper limit of the temperature is not particularly limited and may be 1000° C., 800° C., or 600° C. By setting the temperature for firing the plant shells within the above range, the ease of obtaining soluble silicic acid can be improved.

[0027] The granules may further contain potassium oxide (K2O). The additive contains potassium oxide, which can further improve the lubricity of the lubricating oil. The upper limit of the potassium oxide content of the additive may be 5.0 mass%, 4.0 mass%, or 3.5 mass%.

[0028] The granules may further contain calcium oxide (CaO). The additive contains calcium oxide, which can further improve the lubricity of the lubricating oil. The upper limit of the calcium oxide content of the additive may be 2.5 mass%, 2.0 mass%, or 1.5 mass%.

[0029] The granular material may contain other components such as diphosphorus pentoxide (P2O5), manganese monoxide (MnO), magnesium oxide (MgO), iron oxide (Fe2O3), sulfur trioxide (SO3), and aluminum oxide (Al2O3). The upper limit of the ratio of the content of each component is preferably 0.5 mass% for diphosphorus pentoxide, 0.5 mass% for manganese monoxide, 0.3 mass% for magnesium oxide, 0.2 mass% for iron oxide, 0.3 mass% for sulfur trioxide, and 0.15 mass% for aluminum oxide.

[0030] The average particle size of the granules is preferably 12 μm or less. The upper limit of the average particle size of the granules may be 10.0 μm or 8.0 μm. The lower limit of the average particle size is not particularly limited and may be 0.5 μm or 1.0 μm. By setting the average particle size within the above range, the dispersibility of the granules in the lubricating oil is improved, and the lubricity of the lubricating oil can be improved.

[0031] The additive may further include talc granules. That is, the additive may include granules (first granules) mainly composed of soluble silicic acid and talc granules (second granules). Talc is a soft mineral, and it is believed that the additive containing talc more effectively fills in and flattens the surface roughness of the sliding surface, thereby improving the lubricity.

[0032] The upper limit of the talc content ratio in the additive may be 70% by mass or 60% by mass. The lower limit of the talc content ratio is not particularly limited and may be 10% by mass, 20% by mass, 30% by mass, or 40% by mass. The additive may have the first granular body and the second granular body in a mass ratio of 1:1.

[0033] The upper limit of the average particle size of the talc may be 12.0 μm, 10.0 μm, or 8.0 μm. The lower limit of the average particle size is not particularly limited and may be 0.5 μm or 1.0 μm. The average particle size of the talc (second granular material) is preferably approximately the same as that of the first granular material. By setting the average particle size within the above range, the dispersibility of the talc (second granular material) in the lubricating oil can be made equivalent to that of the first granular material, thereby improving the lubricity.

[0034] The amount of the additive to be added to the lubricating oil is not particularly limited, and may be appropriately determined depending on the properties, use conditions, and purpose of the lubricating oil. Specifically, for example, the lower limit of the amount of the additive to be added to 1.0 L of lubricating oil may be 0.1 g, 0.2 g, or 0.3 g. The upper limit of the amount of the additive to be added to 1.0 L of lubricating oil is not particularly limited, and may be 3.0 g, 2.0 g, or 1.5 g.

[0035] <Additive manufacturing method> The method for producing the additive includes a step of calcining the shells of a plant and a step of pulverizing the calcined shells.

[0036] The shells of the above plants used in the firing step often contain silicon, so that a fired product containing soluble silicic acid can be easily obtained by firing. The shells of the above plants are preferably rice husks, which have a high silicon content. The firing method is not particularly limited, and a known firing furnace or the like may be used.

[0037] The means for pulverizing the burned shells (burned product) is not particularly limited, and may be a known grind mill, rotary cutter, etc. In the above-mentioned pulverizing step, it is preferable to mix talc with the burned plant shells and pulverize them together.

[0038] [Other embodiments] The above-mentioned embodiment does not limit the configuration of the present invention. Therefore, the above-mentioned embodiment may omit, replace or add components of each part of the above-mentioned embodiment based on the description in this specification and common technical knowledge, and it should be construed that all of these are within the scope of the present invention.

[0039] The potassium oxide, calcium oxide, other components, and talc are not essential components of the additive. That is, the content of potassium oxide, calcium oxide, and other components in the granules may be 0% by mass, and the content of talc in the additive may also be 0% by mass. In addition to the above-mentioned components, the additive may contain inevitable impurities. The ratio of the total content of the inevitable impurities is preferably less than 1% by mass. EXAMPLES

[0040] The present disclosure will be further described below with reference to examples, but the present disclosure is not limited to these examples.

[0041] The rice husks were burned to obtain a burned product. The soluble silica content of this burned product was measured using the Fertilizer Testing Method (2023) 4.4.1.b-2017, and was found to be 56.7% by mass. A portion of the burned product was taken out and divided into two (Test Example 1 and Test Example 2), and the contained elements and their contents were analyzed using an X-ray fluorescence analyzer. The results are shown in Table 1.

[0042] [Table 1]

[0043] Furthermore, the compositions and contents of Test Examples 1 and 2 were investigated. The results are shown in Table 2. In the table, "-" means that the measurement was not possible.

[0044] [Table 2]

[0045] The remainder of the calcined product was put into a grinding mill, and the same mass of talc was further added and pulverized to an average particle size of 120 μm or less. The pulverized calcined product and the talc were added as additives to the engine oil of test vehicle 1 and test vehicle 2. The amount of the additive added was 15.8 g for test vehicle 1 and 9.0 g for test vehicle 2. The fuel consumption rate (fuel economy) was calculated for two weeks before and two weeks after the additive was added. The results are shown in Table 3. Test vehicle 1: Route bus, diesel engine, 5190cc displacement Test vehicle 2: Microbus Gasoline engine Displacement 2693cc

[0046] [Table 3]

[0047] From Table 3, it can be seen that adding the above additives to the engine oil improved fuel efficiency by 13.9% in test vehicle 1 and 15.2% in test vehicle 2. The drivers took turns driving, with four drivers driving test vehicle 1 and five drivers driving test vehicle 2, but there was no change in the strength of the engine brake. No changes were noticed in the engine sound and vibration in test vehicle 1, but it was said that the engine sound and vibration had been reduced in test vehicle 2. This is thought to be because test vehicle 2 has its engine mounted at the front of the vehicle (under the driver), making it easy to grasp changes in engine sound and vibration, whereas test vehicle 1 has its engine mounted at the rear of the vehicle, making it difficult to grasp changes in engine sound and vibration.

[0048] In another test, when the additive was added to the engine oil of a small heavy machine (such as a shovel) where the driver (operator) is located close to the engine, no improvement in fuel economy was confirmed, but a reduction in engine noise and vibration was clearly confirmed.With the cooperation of several people, the additive was added to the engine oil of a private passenger car (four-wheeled vehicle), and a 10% or more improvement in fuel economy and a reduction in engine noise and vibration were confirmed in all cases. [Industrial Applicability]

[0049] The additive of the present disclosure can improve the lubricity of a lubricating oil, and is therefore suitable for use in equipment, devices, and the like in which a lubricating oil is used.

Claims

1. A granular additive for addition to a lubricating oil for an internal combustion engine, comprising: The present invention includes a calcined product of plant shells and talc, The baked product is 70% by mass or more of silicic acid; Calcium oxide of 1.03% by mass or more and 2.5% by mass or less; having The average particle size of each of the fired product and the talc is 1.0 μm or more and 12.0 μm or less, The additive has a talc content of 30% by mass or more.

2. The additive according to claim 1 , wherein the calcined product further comprises potassium oxide.

3. An additive-containing lubricating oil containing a lubricating oil for internal combustion engines and the additive of claim 1 in an amount of 0.1 g or more and 3.0 g or less per 1 L of the lubricating oil.

4. 1. A method for producing an additive for addition to a lubricating oil, comprising the steps of: Calcining the plant shells; mixing the fired shells with talc and grinding the mixture; Equipped with The calcined shell has 70% by weight or more of silicic acid and 1.03% by weight or more and 2.5% by weight or less of calcium oxide, The average particle size of the pulverized mixture is 1.0 μm or more and 12.0 μm or less, The method for producing an additive, wherein the content of the talc in the mixture is 30 mass% or more.

5. The method for producing an additive according to claim 4, wherein said husk is rice husk.

6. A process for producing an additive according to claim 4 or 5, comprising the step of adding the additive obtained by the process for producing an additive according to claim 4 or 5 to a lubricating oil for an internal combustion engine, A method for producing an additive-containing lubricant, comprising the step of adding 0.1 g or more and 3.0 g or less of the additive per 1 L of the lubricant.

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