Tire and static elimination method of tire

Abstract

To provide a tire capable of efficiently suppressing a charged state and improving cruising performance of a vehicle body.SOLUTION: By using dispersion liquid containing, a tire surfaces 21, metallic nanoparticles (Ag (silver) nanoparticles 22) having at least diameters equal to or smaller than 100 nm, the metallic nanoparticles 22 are adhered to the tire surfaces 21. As a result, it is possible to efficiently prevent the tire from becoming a charged state and to improve cruising performance of a vehicle body.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a tire used on a vehicle or the like and a method for eliminating static electricity from the tire, and more particularly to a tire that exhibits a static elimination effect and a method for eliminating static electricity from the tire. [Background technology]

[0002] Generally, the electrical resistance of a tire is 10 5 ~10 10 Its resistance is around Ω, making it an insulator that does not easily conduct electricity. However, tires contain a variety of materials (conductive materials such as carbon black) mixed in to reinforce the rubber, and it is known that the tire becomes charged when it repeatedly comes into contact with, separates from, and rubs against the road surface while the vehicle is running. In addition, the surface of the vehicle also becomes charged with static electricity due to friction with the air containing fine particles while it is running.

[0003] It has long been known that static electricity generated on the vehicle body affects air resistance, resulting in poor driving performance, and that static electricity generated on the tires affects tire rolling resistance, resulting in adverse effects on fuel economy and driving stability.

[0004] To prevent static electricity from building up on the vehicle body, an aluminum tape tune is known, which improves driving performance by applying tape containing aluminum, a type of metallic substance, directly to the vehicle body (see, for example, Non-Patent Document 1).

[0005] Also, for example, a method for neutralizing static electricity from a tire has been disclosed that includes a neutralization slit that is charged with a polarity opposite to the electrical polarity of the tire that is charged when the tire rotates on the road surface (see, for example, Patent Document 1).Furthermore, a rubber member has also been disclosed in which a plurality of micro recesses are present on the surface of the rubber member, nanomaterials are disposed on the inner surfaces of the micro recesses, and the average coverage of the inner surfaces of the micro recesses is 10% or more (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-276737 [Patent Document 2] Japanese Patent Application Publication No. 2018-21109 [Non-patent literature]

[0007] [Non-Patent Document 1] "What is Aluminum Tape Tune? How to use it and its effects!" [Retrieved April 8, 2024], Internet<URL:https: / / matome.response.jp / articles / 4924> Summary of the Invention [Problem to be solved by the invention]

[0008] However, as disclosed in Patent Document 1, providing a static elimination feature directly on a tire poses the problem of requiring very expensive and large-scale equipment and many processes in the tire manufacturing process, which increases the effort and manufacturing costs.

[0009] Furthermore, this type of static elimination method of forming a static elimination structure on the tire surface cannot be used as a direct static elimination measure for tires after they have been purchased.

[0010] Furthermore, the tire shown in Patent Document 2 is not intended to improve static elimination performance, but rather to reduce the contact resistance between the tire and the road surface, and the adhesion area of ​​nanomaterials to the tire must exceed at least 10%.

[0011] In recent years, silica-blended rubber has been used to reinforce rubber, but because silica has high electrical resistance, there is a problem in that static electricity generated on the vehicle body due to air resistance cannot be effectively discharged to the ground through the tires.

[0012] In other words, the technology to efficiently prevent tires from becoming charged and to effectively discharge static electricity generated on the vehicle body to the ground, thereby improving the vehicle's driving performance, is still in its infancy, and there is no doubt that there is room for improvement.

[0013] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a tire that efficiently prevents the tire from becoming charged, thereby improving the vehicle's cruising performance. [Means for solving the problem]

[0014] In order to achieve the above object, the tire of the present invention has a ground contact surface to which metal nanoparticles contained in a dispersion containing metal nanoparticles with diameters at least on the nano-level are attached, and the dispersion is characterized in that the dispersion is composed of isopropyl alcohol (IPA), metal nanoparticles, and water, and the metal nanoparticles are blended in the dispersion in a range of 0.001 to 1 wt%.

[0015] In this tire, it is preferable that the diameter of the metal nanoparticles is 100 nm or less, and that the metal nanoparticles are made of Ag (silver), Au (gold), Pt (platinum), or a mixture of these.

[0016] In this tire, the metal nanoparticles are preferably attached so as to occupy less than 10% of the area of ​​the tire's contact patch.

[0017] In this tire, the blending ratio of the dispersion is preferably 4 wt % IPA, 0.1 wt % metal nanoparticles, and 95.9 wt % water.

[0018] In order to achieve the above object, the tire according to the present invention is characterized in that it has metal nanoparticles with diameters on the nanometer level in at least a part of the contact surface.

[0019] In this tire, it is preferable that the diameter of the metal nanoparticles is 100 nm or less, and that the metal nanoparticles are made of Ag (silver), Au (gold), Pt (platinum), or a mixture of these.

[0020] In this tire, the metal nanoparticles are preferably attached so as to occupy less than 10% of the area of ​​the tire's contact patch.

[0021] In order to achieve the above object, the tire according to the present invention is characterized in that the ratio of metal nanoparticle components to the volume of the rubber component used in the tire is 0.001 to less than 10 vol%, the diameter of the metal nanoparticles is 100 nm or less, and the metal nanoparticles are Ag (silver), Au (gold), Pt (platinum), or a mixture of these.

[0022] In order to achieve the above object, the present invention provides a method for neutralizing static electricity from a tire, which includes a step of applying metal nanoparticles contained in a dispersion containing metal nanoparticles with diameters at least on the nanometer level to the surface of the tire, wherein the dispersion is composed of isopropyl alcohol (IPA), metal nanoparticles, and water, and the metal nanoparticles are blended in the dispersion in an amount ranging from 0.001 to 1 wt%.

[0023] In this tire static elimination method, it is preferable that the metal nanoparticles have a diameter of 100 nm or less, and are made of Ag (silver), Au (gold), Pt (platinum), or a mixture of these.

[0024] In this method for neutralizing static electricity from a tire, the dispersion preferably contains 4 wt % IPA, 0.1 wt % metal nanoparticles, and 95.9 wt % water. [Effects of the Invention]

[0025] The tire according to the present invention has a ground contact surface to which metal nanoparticles, contained in a dispersion containing metal nanoparticles with diameters at least on the nanometer level, are attached, the dispersion being a dispersion composed of isopropyl alcohol (IPA), metal nanoparticles, and water, and the metal nanoparticles are blended in the dispersion in an amount of 0.001 to 1 wt%. With this configuration, the tire according to the present invention can improve the cruising performance of a vehicle body without requiring large-scale equipment or multiple processes. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a flowchart showing steps of a static elimination method for a tire according to an embodiment of the present invention. [Figure 2] 3(a) and 3(b) are schematic diagrams of the coating process of the tire. [Figure 3] FIG. 2 is a diagram showing the cover of a commissioned test report on the running performance of the tire. [Figure 4] FIG. 2 is a diagram showing various conditions during the commissioned test. DETAILED DESCRIPTION OF THE INVENTION

[0027] (Embodiment) A tire and a tire static elimination method according to an embodiment of the present invention will be described with reference to Figures 1 to 4. The dispersion used in the present invention is not limited to tires for vehicles such as automobiles and bicycles, but can be applied to various materials that require improvement in the surface resistance performance.

[0028] The tire according to the present embodiment is formed by using a dispersion containing metal nanoparticles having a diameter (average diameter) of at least nanometer order, and the metal nanoparticles are attached to the surface of the tire. Here, the nanometer order preferably refers to nanoparticles having a diameter of 100 nm or less.

[0029] When metal nanoparticles adhere to a tire, their malleability and ductility allow them to deform according to the unevenness of the tire surface and adhere to the surface. Furthermore, if the diameter of the metal nanoparticles is 100 nm or less, once they adhere to the tire surface, they can remain attached to the tire surface until the tire rubber wears out. It is also possible to use a component that effectively bonds the metal nanoparticles to the sulfur components of the tire, or to use a binder that acts as an adhesive layer between the metal nanoparticles and the tire.

[0030] The metal nanoparticles are preferably Ag (silver) nanoparticles due to their electrical conductivity, heat resistance, strength, lightness, and cost. However, they are not limited to these, and other metal nanoparticles such as Au (gold), Pt (platinum), and Al (aluminum), which are resistant to oxidation, or corrosion-resistant alloys such as stainless steel, can also be used. Furthermore, these nanoparticles can also be used in combination.

[0031] The tires to which the dispersion is applied are primarily fuel-efficient tires (eco-tires) and other tires that use a rubber composition that has good rolling resistance, little friction loss, and high abrasion resistance, but the dispersion is not limited to these and can be applied to tires in general.

[0032] The dispersion liquid is a solvent composed of, for example, isopropyl alcohol (IPA), Ag (silver) nanoparticles, and water, and the Ag (silver) nanoparticles are preferably blended in this solvent in a range of 0.001 to 1 wt % because this range allows the area occupied by the Ag (silver) nanoparticles on the tire surface to be less than 10% (more preferably about 0.1%).

[0033] Furthermore, as the blending ratio of Ag (silver) nanoparticles increases, the Ag (silver) nanoparticles tend to aggregate, and the above range is preferable for uniform coating on the tire surface. Furthermore, the solvent in the Ag (silver) nanoparticle solvent is not limited to isopropyl alcohol (IPA), and a solvent that has low viscosity and is volatile at room temperature so as to easily spread on the tire surface when sprayed onto the tire surface, such as ethanol, is preferable.

[0034] The solvent containing Ag (silver) nanoparticles can be, for example, "Ag-1000-Water-IPA," manufactured and sold by Hamamatsu Nanotechnology, an affiliate of the applicant. This solvent containing Ag (silver) nanoparticles is composed of isopropyl alcohol (IPA), Ag (silver) nanoparticles, and water, with a blend ratio of 4 wt% IPA, 0.1 wt% Ag (silver) nanoparticles, and 95.9 wt% water, and is harmless to the human body.

[0035] The Ag (silver) nanoparticles are ultrafine particles with a diameter of 5 to 20 nm (preferably 100 nm or less), and adhere to the tire surface contours. The Ag nanoparticles exert a static elimination effect, suppressing the rise in potential on the tire surface due to frictional charging while the tire is running. As a result, they reduce the peeling resistance when the tire leaves the road surface, leading to reduced rolling resistance.

[0036] Next, the procedure for the static elimination method for a tire according to this embodiment will be described with reference to Fig. 1. First, the surface of an unused tire or a used tire is washed to remove oil stains and dust adhering to the tire surface (S11), leaving the tire surface bare.

[0037] Next, an Ag (silver) nanoparticle solvent containing Ag (silver) nanoparticles is applied to the tire surface to form an Ag (silver) nanoparticle film on the tire surface (Ag (silver) nanoparticle film formation step (S12)). To form a Ag (silver) nanoparticle film on the tire surface, the Ag (silver) nanoparticle solvent (nano dispersion) is applied to the tire surface as a fine spray using a spray gun or an air compressor. The solution then dries quickly upon contact with air, thanks to the isopropyl alcohol used, completing the application of Ag (silver) nanoparticles to the tire surface.

[0038] Alternatively, a film may be formed on the tire surface by applying an appropriate amount of the dispersion with a brush or by atomizing using ultrasonic waves. When using an apparatus, a dip coating method or a spin coating method may also be used.

[0039] Furthermore, in order to prevent unevenness in the coating of Ag (silver) nanoparticles formed on the tire surface, it is also possible to use, for example, the applicant's thin film formation method using an electrostatic application method (Japanese Patent Application No. 2013-211366).

[0040] Next, the coating process of the tire surface according to this embodiment will be described with reference to Fig. 2. As shown in Fig. 2(a), a great number of irregularities are actually formed on the tire surface 21. The presence of these irregularities contributes to the rolling resistance performance and grip performance of the tire.

[0041] 2(b), a thin layer of the dispersion liquid described above is sprayed onto the tire surface 21, and the solvent dries, forming a coating of uniformly dispersed Ag (silver) nanoparticles 22 on the tire surface 21. At this time, because the Ag (silver) nanoparticles 22 are metal, their malleability and ductility allow them to deform in accordance with the unevenness of the tire surface even during running, allowing them to adhere to the surface. Furthermore, because the size of the Ag (silver) nanoparticles 22 is 100 nm or less, once they are adhered to the tire surface 21, they tend to maintain that state.

[0042] Furthermore, when the tire becomes charged by rolling on the road surface or when the surface of the vehicle body becomes charged, the static electricity can be efficiently discharged to the ground via Ag (silver) nanoparticles 22, which are conductive materials attached to the tire surface. As a result, it is possible to appropriately prevent static electricity generated on the vehicle body from affecting air resistance and deteriorating driving performance, and static electricity generated in the tire from adversely affecting the rolling resistance of the tire.

[0043] In this case, the key is to attach the metal nanoparticles so that their occupancy area (coverage rate) is less than 10%. In other words, as long as they are effective in eliminating static electricity from the tire, it will be effective enough if the metal nanoparticles occupy less than 10% of the tire's contact surface. However, even if the metal nanoparticles' adhesion area on the tire's contact surface is 1% or less (for example, about 0.1%) in order to achieve the static elimination effect, tire charging can be suppressed and fuel efficiency can be improved.

[0044] <Comparative test> Next, a comparative test was conducted between an example using a tire coated with metal nanoparticles according to the present embodiment and an uncoated tire. The following comparative test was conducted to determine whether the use of a tire coated with metal nanoparticles according to the present embodiment has an effect of improving cruising distance compared to a conventional example. The comparative test was commissioned to the Japan Automobile Research Institute, a general incorporated foundation, and was conducted on December 26, 2023, as shown in the commissioned test report in Figure 3.

[0045] The test location was the Shirosato Test Center / Test Promotion Group of the Japan Automobile Research Institute (JAR), with the test date set to December 26, 2023. The coated tires were sprayed with the aforementioned Ag-1000-Water-IPA onto the tire contact surface.

[0046] As shown in 401 of FIG. 4, the test vehicle has the name, model, and chassis number of Nissan Leaf (registered trademark) ZAA ZEO-000646.

[0047] As shown in 402 of Figure 4, the weight conditions and tire information are as follows: actual vehicle gross weight 1610.2 kg (front axle: 913.9 kg, rear axle: 696.3 kg, one person in the driver's seat + speedometer installed), tire size and brand 205 / 55R16 YOKOHAMA iceGUARD iG50PLUS (studless), tire manufacturing year / week and tire pressure all wheels: 2019 / 43rd week, all wheels: 250 kPa.

[0048] The test equipment is shown in Figure 4, 403, and includes a portable vehicle weighing scale (1 ton) manufactured by Kyowa Denki HS1001NX4E8, a speed and stopping distance measuring device manufactured by GVS Speed ​​and Distance Meter BIOS System VGVS-SP5Ci, a meteorological observation device with a fixed A station ANEOS wind direction and speed meter: WS-BN6S, a thermometer manufactured by TS-301C-2, a hygrometer manufactured by HS-501, a barometer manufactured by PTB21004C3N, a tire pressure gauge manufactured by Asahi Sangyo MTS-5, a road surface temperature gauge manufactured by Surface Thermometer 1-110KI FT3700, and a charger manufactured by CHAdeMO and Nissan NSQC-44-A-1.

[0049] As shown in 404 of Figure 4, the test conditions were as follows: the test road surface was an outer perimeter road, an asphalt road surface, and dry conditions; the road surface temperature was, without coating, start: 1.6°C, end: 1.0°C; with coating, start: 0.6°C, end: -0.7°C; the weather was, without coating, start: sunny, end: sunny; with coating, start: sunny, end: sunny; the wind direction and wind speed were, without coating, start: west-northwest·1.0m / s, end: west-northwest·0.4m / s; with coating, start: west 1.2m / s; End: North-northeast 0.7m / s. Without coating, the temperature and humidity were 1.0℃ and 75.5% at the start and -0.6℃ and 78.2% at the end. With coating, the temperature and humidity were 0.5℃ and 86.1% at the start and -0.4℃ and 88.5% at the end. Without coating, the air pressure was 1001.9hPa at the start and 1001.8hPa at the end. With coating, the air pressure was 1001.5hPa at the start and 1002.2hPa at the end.

[0050] -Range measurement The test records for the Examples and Comparative Examples were measured and are summarized in Table 1 below.

[0051] [Table 1]

[0052] As shown in Table 1, without the coating, the driving time was 2,607.2 seconds, the average vehicle speed was 59.66 km / h, and the driving distance was 43,208.07 m. On the other hand, with the coating, the driving time was 3,016.3 seconds, the average vehicle speed was 59.74 km / h, and the driving distance was 50,061.84 m. As such, the vehicle's cruising range was approximately 43 km in the comparative example, but was dramatically extended to approximately 50 km in the example using tires coated with Ag (silver) nanoparticles. The results of this comparative test showed that tires according to the present embodiment can dramatically improve driving performance compared to conventional tires.

[0053] As described above, the tire according to this embodiment has nano-sized metal nanoparticles in at least a portion of the tire's contact patch. The diameter of the metal nanoparticles is 100 nm or less, and the metal nanoparticles are Ag (silver), Au (gold), Pt (platinum), or a mixture of these. The metal nanoparticles are attached to the tire, occupying less than 10% of the tire's contact patch. This configuration effectively prevents the tire from becoming charged, and effectively discharges static electricity generated on the vehicle body to the ground, thereby improving the vehicle's driving range, without requiring large-scale equipment or multiple processes.

[0054] When Ag (silver) nanoparticles are coated on the tire's contact surface, the malleability and ductility of the metal molecules allow them to deform and adhere to the tire's surface in response to unevenness. This then exerts a static elimination effect, suppressing the rise in the tire's surface potential due to frictional charging while the tire is in motion. As a result, the separation resistance when the tire leaves the road surface is reduced, resulting in a reduction in rolling resistance.

[0055] (Embodiment 2) A second embodiment of a tire according to the present invention will be described below. The tire according to the second embodiment uses a rubber product in which the metal nanoparticles described in the first embodiment are mixed with a rubber component at a predetermined ratio. For example, the metal nanoparticle component is added at a ratio of 0.001 to less than 10 vol% relative to the volume of the rubber component used in the tire. The rubber component may be, for example, a commonly used rubber component such as natural rubber or general-purpose synthetic rubber, e.g., styrene-butadiene rubber, polybutadiene rubber, or polyisoprene rubber. Other necessary fillers may also be added during tire manufacturing. Even in this case, charging performance can be improved compared to conventional tires, and driving range can be improved at the same time.

[0056] The present invention is not limited to the configuration of the above-described embodiment, and various modifications are possible within the scope of the invention. For example, the dispersion liquid can be used on the surface of rubber members other than tires. Needless to say, other processes can be added if the same effects are achieved. [Explanation of symbols]

[0057] 21 Tire surface 22 Metal nanoparticles

Claims

1. a contact surface to which metal nanoparticles having a diameter at least on the nanometer level are attached, the metal nanoparticles being contained in a dispersion liquid containing the metal nanoparticles; The tire is characterized in that the dispersion is a dispersion composed of isopropyl alcohol (IPA), metal nanoparticles, and water, and the metal nanoparticles are blended in the dispersion in a range of 0.001 to 1 wt%.

2. The diameter of the metal nanoparticles is 100 nm or less, 2. The tire according to claim 1, wherein the metal nanoparticles are made of Ag (silver), Au (gold), Pt (platinum), or a mixture thereof.

3. 3. The tire of claim 2, wherein the metal nanoparticles are deposited over an area of ​​less than 10% of the tire's tread area.

4. 4. The tire according to claim 3, wherein the dispersion contains 4 wt% IPA, 0.1 wt% metal nanoparticles, and 95.9 wt% water.

5. A tire characterized by having metal nanoparticles with nano-level diameters in at least a portion of the contact surface.

6. The diameter of the metal nanoparticles is 100 nm or less, 6. The tire according to claim 5, wherein the metal nanoparticles are made of Ag (silver), Au (gold), Pt (platinum), or a mixture thereof.

7. 7. The tire of claim 6, wherein the metal nanoparticles are attached to the tire in an area that occupies less than 10% of the tire's tread area.

8. The metal nanoparticle component is 0.001 to less than 10 vol% relative to the volume of the rubber component used in the tire, The diameter of the metal nanoparticles is 100 nm or less, The tire is characterized in that the metal nanoparticles are made of Ag (silver), Au (gold), Pt (platinum), or a mixture thereof.

9. A method for neutralizing static electricity from a tire, comprising: a step of applying metal nanoparticles contained in a dispersion containing metal nanoparticles having a diameter at least on the nano-level to a surface of the tire, The method for neutralizing static electricity from a tire is characterized in that the dispersion is a dispersion composed of isopropyl alcohol (IPA), metal nanoparticles, and water, and the metal nanoparticles are blended in the dispersion in a range of 0.001 to 1 wt%.

10. The diameter of the metal nanoparticles is 100 nm or less, 10. The tire static elimination method according to claim 9, wherein the metal nanoparticles are made of Ag (silver), Au (gold), Pt (platinum), or a mixture thereof.

11. 11. The method for neutralizing static electricity from a tire according to claim 10, wherein the dispersion liquid has a blending ratio of 4 wt% IPA, 0.1 wt% metal nanoparticles, and 95.9 wt% water.

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