tire

Abstract

To provide a tire comprising magnetic particles and exhibiting superior abrasion resistance.SOLUTION: A tire comprises a tire member made from a rubber composition comprising a rubber component, magnetic particles, and a saccharide, wherein a product of the ash content Ash (mass%) of the rubber composition, the acetone extract amount AE (mass%) of the rubber composition, and the thickness T (mm) of the tire member (Ash×AE×T) exceeds 400.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a tire. [Background technology]

[0002] Tires have been proposed that contain magnetic particles and that can vary their rigidity by applying a magnetic field (see Patent Document 1, etc.). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-034737 Summary of the Invention [Problem to be solved by the invention]

[0004] However, magnetic particles generally do not mix well with rubber, and there is a concern that they may deteriorate the wear resistance.

[0005] The present invention aims to solve the above problems and to provide a tire containing magnetic particles that has good wear resistance. [Means for solving the problem]

[0006] The present invention relates to a tire having tire components made of a rubber composition containing a rubber component, magnetic particles, and sugars, wherein the product (Ash × AE × T) of the ash content Ash (mass%) of the rubber composition, the acetone extractable amount AE (mass%) of the rubber composition, and the thickness T (mm) of the tire component exceeds 400. [Effects of the Invention]

[0007] The present invention provides a tire having tire components made of a rubber composition containing a rubber component, magnetic particles, and sugars, characterized in that the product (Ash × AE × T) of the ash content Ash (mass%) of the rubber composition, the acetone extractable amount AE (mass%) of the rubber composition, and the thickness T (mm) of the tire components exceeds 400.Therefore, a tire with good wear resistance can be provided despite the inclusion of magnetic particles. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view showing a portion of a pneumatic tire. [Figure 2] FIG. 2 is an enlarged cross-sectional view showing the vicinity of the tread of the tire of FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0009] The tire has a tire component made of a rubber composition containing a rubber component, magnetic particles, and sugars, and is characterized in that the product (Ash × AE × T) of the ash content Ash (mass%) of the rubber composition, the acetone extractable amount AE (mass%) of the rubber composition, and the thickness T (mm) of the tire component exceeds 400.

[0010] The mechanism by which the above-mentioned effects are obtained is not clear, but is presumed to be as follows. Magnetic particles have poor dispersibility in rubber, making it difficult to disperse uniformly, which is thought to lead to a decrease in rubber strength. Therefore, by adding sugars, it is thought that they can interact with the magnetic particles and promote uniform dispersion in the rubber. Furthermore, by increasing the product of the ash content of the rubber composition, the acetone extractable amount of the rubber composition, and the thickness T of the tire component, it is believed that localized collection of magnetic particles can be prevented, and the stress generated in the tire component can be absorbed by the entire rubber, thereby dispersing the stress. For the reasons stated above, it is possible to disperse the magnetic particles uniformly and create a state in which stress can be absorbed by the entire rubber, and therefore it is believed that even rubber compositions containing magnetic particles can have good wear resistance.

[0011] In this way, the tire described above solves the problem (objective) of providing a tire with good wear resistance by satisfying "Ash x AE x T > 400" in a tire having tire components made of a rubber composition containing a rubber component, magnetic particles, and sugars. In other words, the parameter "Ash x AE x T > 400" does not define the problem (objective); the object of the present application is to provide a tire with good wear resistance despite the incorporation of magnetic particles, and a configuration that satisfies this parameter is used as a means to achieve this.

[0012] Regarding the tire, first, the rubber composition constituting the tire components will be described.

[0013] The rubber composition includes a rubber component. In this specification, the rubber component is a component that contributes to crosslinking, and generally refers to a polymer component that is a polymer with a weight-average molecular weight (Mw) of 10,000 or more and is not extracted with acetone. The rubber component is in a solid state at 25°C.

[0014] The weight average molecular weight of the rubber component is preferably 50,000 or more, more preferably 150,000 or more, even more preferably 200,000 or more, and particularly preferably 270,000 or more, and is preferably 2,000,000 or less, more preferably 1,500,000 or less, and even more preferably 1,000,000 or less. Within the above ranges, the effect tends to be more favorable.

[0015] In this specification, the weight average molecular weight (Mw) and number average molecular weight (Mn) can be determined in terms of standard polystyrene based on measurements obtained using a gel permeation chromatograph (GPC) (GPC-8000 series, manufactured by Tosoh Corporation; detector: differential refractometer; column: TSKGEL SUPERMULTIPORE HZ-M, manufactured by Tosoh Corporation).

[0016] The rubber component may be either an unmodified rubber or a modified rubber. Examples of modified rubbers include rubbers having functional groups that interact with fillers such as silica. Examples include terminal-modified rubbers (terminal-modified rubbers having the functional groups at the terminals) in which at least one terminal of the rubber has been modified with a compound (modifier) ​​having the functional group, main-chain-modified rubbers having the functional groups in the main chain, main-chain-terminal-modified rubbers having the functional groups in the main chain and at the terminals (for example, main-chain-terminal-modified rubbers having the functional groups in the main chain and at least one terminal modified with the modifier), and terminal-modified rubbers modified (coupled) with a polyfunctional compound having two or more epoxy groups in the molecule and having hydroxyl groups or epoxy groups introduced therein.

[0017] Examples of the functional group include an amino group, an amide group, a silyl group, an alkoxysilyl group, an isocyanate group, an imino group, an imidazole group, a urea group, an ether group, a carbonyl group, an oxycarbonyl group, a mercapto group, a sulfide group, a disulfide group, a sulfonyl group, a sulfinyl group, a thiocarbonyl group, an ammonium group, an imido group, a hydrazo group, an azo group, a diazo group, a carboxyl group, a nitrile group, a pyridyl group, an alkoxy group, a hydroxyl group, an oxy group, and an epoxy group. These functional groups may have a substituent. Among these, an amino group (preferably an amino group in which a hydrogen atom of the amino group is substituted with an alkyl group having 1 to 6 carbon atoms), an alkoxy group (preferably an alkoxy group having 1 to 6 carbon atoms), and an alkoxysilyl group (preferably an alkoxysilyl group having 1 to 6 carbon atoms) are preferred.

[0018] Examples of the rubber component include isoprene rubber, butadiene rubber (BR), styrene butadiene rubber (SBR), styrene isoprene butadiene rubber (SIBR), ethylene propylene diene rubber (EPDM), chloroprene rubber (CR), and acrylonitrile butadiene rubber (NBR). Other examples include butyl rubber and fluororubber. These may be used alone or in combination of two or more. Among these, from the viewpoint of obtaining better effects, it is preferable to contain at least one of isoprene-based rubber, butadiene rubber, and styrene-butadiene rubber, it is more preferable to contain at least one of butadiene rubber and styrene-butadiene rubber, and it is even more preferable to contain butadiene rubber and styrene-butadiene rubber.

[0019] The rubber component may be modified or hydrogenated, or may be an extended rubber extended with oil, resin, liquid rubber component, or the like.

[0020] Examples of isoprene-based rubbers include natural rubber (NR), isoprene rubber (IR), modified NR, modified NR, and modified IR. NRs such as SIR20, RSS#3, and TSR20 are commonly used in the rubber industry. IRs are not particularly limited, and examples of IRs such as IR2200 are commonly used in the rubber industry. Modified NRs include deproteinized natural rubber (DPNR) and high-purity natural rubber. Modified NRs include epoxidized natural rubber (ENR), hydrogenated natural rubber (HNR), and grafted natural rubber. Modified IRs include epoxidized isoprene rubber, hydrogenated isoprene rubber, and grafted isoprene rubber. These may be used alone or in combination of two or more.

[0021] The BR is not particularly limited, and examples thereof include high-cis BR with a high cis content, BR containing syndiotactic polybutadiene crystals, and BR synthesized using a rare earth catalyst (rare earth BR). These may be used alone or in combination of two or more. Of these, the BR preferably contains high-cis BR with a cis content of 90% by mass or more. The cis content is more preferably 95% by mass or more. The cis content can be measured by infrared absorption spectroscopy.

[0022] The cis content of BR means the cis content of the BR when there is one type of BR, and means the average cis content when there are multiple types of BR. The average cis content of BR can be calculated by {Σ(content of each BR × cis content of each BR)} / total content of all BRs. For example, when 100% by mass of the rubber component contains 20% by mass of BR with a cis content of 90% by mass and 10% by mass of BR with a cis content of 40% by mass, the average cis content of BR is 73.3% by mass (=(20×90+10×40) / (20+10)).

[0023] Both unmodified and modified BR can be used. Modified BR includes modified BR with the same functional groups as modified rubber. Hydrogenated butadiene polymer (hydrogenated BR) can also be used.

[0024] As the BR, for example, products from Ube Industries, Ltd., JSR Corporation, Asahi Kasei Corporation, Nippon Zeon Corporation, etc. can be used.

[0025] The SBR is not particularly limited, and examples thereof include emulsion-polymerized styrene-butadiene rubber (E-SBR), solution-polymerized styrene-butadiene rubber (S-SBR), etc. These may be used alone or in combination of two or more.

[0026] The styrene content of the SBR is preferably 5% by mass or more, more preferably 20% by mass or more, and even more preferably 24% by mass or more. The styrene content is preferably 60% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less. Within the above range, the effect tends to be more favorable. In this specification, the amount of styrene is 1 It can be measured by H-NMR measurement.

[0027] The styrene content of SBR means the styrene content of the SBR when there is one type of SBR, and means the average styrene content when there are multiple types of SBR. The average styrene amount of SBR can be calculated by {Σ(content of each SBR × styrene amount of each SBR)} / total content of all SBRs. For example, when 100% by mass of the rubber component contains 85% by mass of SBR with a styrene amount of 40% by mass and 5% by mass of SBR with a styrene amount of 25% by mass, the average styrene amount of the SBR is 39.2% by mass (=(85×40+5×25) / (85+5)).

[0028] The vinyl content of the SBR is preferably 3% by mass or more, more preferably 10% by mass or more, and even more preferably 17% by mass or more. When the vinyl content is within the above range, preferably 60% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less, the effect tends to be more favorable. In this specification, the vinyl content (amount of 1,2-bonded butadiene units) can be measured by infrared absorption spectroscopy.

[0029] The vinyl content of SBR (amount of 1,2-bonded butadiene units) is the proportion of vinyl bonds (unit: mass%) when the total mass of the butadiene parts in the SBR is taken as 100, and is calculated as vinyl content [mass%] + cis content [mass%] + trans content [mass%] = 100 [mass%]. When there is one type of SBR, it means the vinyl content of that SBR, and when there are multiple types, it means the average vinyl content. The average vinyl content of SBR can be calculated by Σ{content of each SBR × (100 [mass%] - styrene content of each SBR [mass%]) × vinyl content of each SBR [mass%]} / Σ{content of each SBR × (100 [mass%] - styrene content of each SBR [mass%])}. For example, in 100 parts by mass of the rubber component, 75 parts by mass of SBR with a styrene content of 40% by mass and a vinyl content of 30% by mass, 25 parts by mass of styrene and 10 parts by mass of vinyl are used. In the case where 15 parts by mass of SBR with a vinyl content of 20% by mass is used and the remaining 10 parts by mass are other than SBR, the average vinyl content of the SBR is 28% by mass (= {75 × (100 [% by mass] - 40 [% by mass]) × 30 [% by mass] + 15 × (100 [% by mass] - 25 [% by mass]) × 20 [% by mass])} / {75 × (100 [% by mass] - 40 [% by mass]) + 15 × (100 [% by mass] - 25 [% by mass])}.

[0030] Both unmodified and modified SBR can be used. Modified SBR includes modified SBR with the same functional groups as modified rubber. Hydrogenated styrene-butadiene copolymer (hydrogenated SBR) can also be used as SBR.

[0031] As the SBR, for example, SBR manufactured and sold by Sumitomo Chemical Co., Ltd., JSR Corporation, Asahi Kasei Corporation, Nippon Zeon Co., Ltd., etc. can be used. SBR synthesized by a known method can also be used.

[0032] The raw materials (monomers) for synthetic rubbers such as IR, SBR, and BR may be derived from underground resources such as petroleum and natural gas, or may be recycled from rubber products such as tires or non-rubber products such as polystyrene. Monomers obtained by recycling (recycled monomers) are not particularly limited, and examples include recycled polyisoprene, recycled butadiene, and recycled aromatic vinyls. Examples of butadienes include 1,2-butadiene and 1,3-butadiene. Examples of aromatic vinyls include, but are not limited to, styrene. Among these, recycled polyisoprene (recycled isoprene), recycled butadiene (recycled butadiene), and / or recycled styrene (recycled styrene) are preferably used as raw materials.

[0033] The method for producing the recycled monomer is not particularly limited, and examples thereof include synthesis from recycled naphtha obtained by decomposing rubber products such as tires. The method for producing recycled naphtha is also not particularly limited, and examples thereof include decomposing rubber products such as tires under high temperature and pressure, decomposing with microwaves, or mechanically crushing and then extracting.

[0034] Furthermore, the raw materials (monomers) of synthetic rubbers such as IR, SBR, and BR may be derived from biomass. In this specification, biomass refers to materials derived from natural resources such as plants. Examples of biomass include, but are not limited to, agricultural, forestry, and fishery products, sugar, wood chips, plant residues after useful components have been extracted, plant-derived ethanol, and biomass naphtha.

[0035] Monomers derived from biomass (biomass monomers) are not particularly limited and include biomass-derived butadiene and biomass-derived aromatic vinyl. Examples of butadienes include 1,2-butadiene and 1,3-butadiene. Examples of aromatic vinyls include, but are not limited to, styrene. The method for producing biomass monomers is not particularly limited and includes, for example, biological and / or chemical and / or physical conversion of animals and plants. A representative example of biological conversion is fermentation by microorganisms, and examples of chemical and / or physical conversion include catalytic conversion, high heat conversion, high pressure conversion, electromagnetic wave conversion, critical fluid conversion, and combinations thereof.

[0036] The polymer synthesized from a biomass monomer component (biomass polymer) is not particularly limited, and examples thereof include polybutadiene rubber synthesized from biomass-derived butadiene, and aromatic vinyl / butadiene copolymer synthesized from biomass-derived butadiene and / or biomass-derived aromatic vinyl. Examples of the aromatic vinyl / butadiene copolymer include styrene-butadiene rubber synthesized from biomass-derived butadiene and / or biomass-derived styrene.

[0037] Whether the raw material for a polymer is derived from biomass can be determined by the pMC (percent modern carbon) measured in accordance with ASTM D6866-10.

[0038] pMC is the modern standard reference 14 of sample against C concentration 14 This is the ratio of C concentrations and is a value used as an index of the biomass ratio of a compound. The significance of this value is explained below.

[0039] 1 mole of carbon atoms (6.02 × 10 23 ) contains approximately 6.02 × 10 atoms, which is about one trillionth of the number of ordinary carbon atoms. 11 pieces 14C exists. 14 C is called a radioactive isotope, and its half-life is 5,730 years, and it decreases regularly. It takes 226,000 years for all of it to decay. Therefore, in fossil fuels such as coal, oil, and natural gas, which are thought to have been absorbed and fixed by plants and other organisms more than 226,000 years ago, C was also included in these when it was first fixed. 14 All C elements have decayed. Therefore, in the 21st century, fossil fuels such as coal, oil, and natural gas contain 14 Therefore, chemicals produced from these fossil fuels do not contain any C element. 14 It does not contain any C element.

[0040] on the other hand, 14 C is produced continuously by nuclear reactions in the atmosphere caused by cosmic rays, and this balances with the decrease due to radioactive decay. In the Earth's atmospheric environment, 14 Therefore, the amount of carbon derived from biomass resources currently circulating in the environment is constant. 14 As mentioned above, the C concentration is approximately 1 × 10 -12 The value is approximately mol %. Therefore, the biomass ratio of a certain compound can be calculated by using the difference between these values.

[0041] this 14 C is typically measured using accelerator mass spectrometry based on a tandem accelerator. 13 C concentration ( 13 C / 12 C). 14 C concentration ( 14 C / 12 C) is measured. 14 The modern standard reference for the C concentration is the carbon circulating in nature as of 1950. 14The specific standard substance used is the oxalic acid standard provided by NIST (National Institute of Standards and Technology). The specific activity of carbon in this oxalic acid (per gram of carbon) is 14 The radioactivity of C is separated into carbon isotopes, 13 The standard value is the value corrected for decay from 1950 to the measurement date. 14 This is used as the C concentration value (100%). The ratio of this value to the value of the actually measured sample is the pMC value.

[0042] Therefore, if rubber is made from 100% biomass-derived materials, although there are regional differences, under normal circumstances, it will usually not reach 100, and will show a value of approximately 110 pMC. On the other hand, for chemical substances derived from petroleum and other fossil fuels, 14 When the carbon concentration is measured, it will show a value of about 0 pMC (for example, 0.3 pMC), which corresponds to the biomass ratio of 0% mentioned above.

[0043] From the above, it is preferable in terms of environmental protection to use a material such as rubber having a high pMC value, that is, a material such as rubber having a high biomass ratio, in a rubber composition.

[0044] When the rubber composition contains an isoprene-based rubber, the content of the isoprene-based rubber in 100% by mass of the rubber component is preferably 5% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, and is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less. When the content is within the above range, better effects tend to be obtained.

[0045] When the rubber composition contains BR, the BR content in 100% by mass of the rubber component is preferably 5% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, and is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less. Within the above ranges, the effects tend to be more favorably obtained.

[0046] When the rubber composition contains SBR, the content of SBR in 100% by mass of the rubber component is preferably 20% by mass or more, more preferably 60% by mass or more, and even more preferably 80% by mass or more, and is preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less. When the content is within the above range, better effects tend to be obtained.

[0047] The rubber composition contains magnetic particles.

[0048] In this specification, magnetic particles refer to particles made of a magnetic material. A magnetic material is a substance that can be magnetized, and typically refers to a ferromagnetic material. Examples of magnetic materials include soft magnetic materials and hard magnetic materials. In this specification, a "soft magnetic material" is a material that has the property of being magnetized by an external magnetic field and then losing its magnetism when the external magnetic field is reduced to zero. In this specification, a "hard magnetic material" is a material that has the property of remaining magnetized after being magnetized by an external magnetic field even when the external magnetic field is removed to zero.

[0049] Examples of the above magnetic materials include iron (Fe), compounds containing iron element, cobalt (Co), compounds containing cobalt element, nickel (Ni), compounds containing nickel element, aluminum (Al), compounds containing aluminum element, chromium (Cr), compounds containing chromium element, molybdenum (Mo), compounds containing molybdenum element, titanium (Ti), compounds containing titanium, and zirconium (Zr), compounds containing zirconium, etc. Also, iron alloys such as iron nitride, Fe-Ni alloy, Fe-Co alloy, Fe-Cr alloy, Fe-Si alloy, Fe-Al alloy, Fe-Cr-Si alloy, Fe-Cr-Al alloy, Fe-Si-Al alloy, and ferrite-based materials such as Mg-Zn ferrite, Mn-Zn ferrite, Mn-Mg ferrite, Cu-Zn ferrite, Mg-Mn-Sr ferrite, Ni-Zn ferrite, etc. can be mentioned. These can be used alone or in combination of two or more kinds. Among them, from the viewpoint of obtaining the above effects, iron or a compound containing iron element is preferable, and a compound containing iron element is particularly preferable. As the compound containing iron element, carbonyl iron (carbonyl iron powder) is preferable. Carbonyl iron is a material obtained by vaporizing and decomposing carbonyl iron (Fe(CO)5) to remove CO.

[0050] The D50 (median particle size) of the above magnetic particles is preferably 0.1 μm or more and preferably 10 μm or less. When within the above range, the effect tends to be obtained more favorably.

[0051] In this specification, D50 (median particle size) is the particle size at the integrated mass value of 50% of the particle size distribution curve obtained by measuring the particle size distribution using the laser diffraction method. Specifically, it is the value obtained by the following measurement method. <Measurement of D50 (Median Particle Size, Median Diameter)> Using SALD-2000J type manufactured by Shimadzu Corporation, a particle size distribution curve is obtained by the laser diffraction method (the measurement operation is as follows), and the particle size (D50 (μm)) at the integrated mass value of 50% of the particle size distribution curve is measured. (Measurement Operation) The magnetic particles are dispersed in a mixture of a dispersion solvent (toluene) and a dispersant (a 10% by weight solution of sodium di-2-ethylhexyl sulfosuccinate in toluene) at room temperature, and the resulting dispersion is stirred for 5 minutes while being irradiated with ultrasonic waves to obtain a test solution. The test solution is transferred to a batch cell and measured after 1 minute (refractive index: 1.70-0.20i).

[0052] In the rubber composition, the content of the magnetic particles is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and even more preferably 10 parts by mass or more, per 100 parts by mass of the rubber component, and is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, and even more preferably 20 parts by mass or less. Within the above ranges, the effect tends to be better obtained.

[0053] The rubber composition contains a sugar.

[0054] As used herein, sugars refer to monosaccharides, disaccharides, polysaccharides, or sugar alcohols.

[0055] As used herein, polysaccharides refer to substances in which three or more molecules of monosaccharides or sugar alcohols are bound together.

[0056] Examples of the monosaccharides include mannitol, glucose, fructose, and galactose. Examples of the disaccharides include maltose, sucrose, and trehalose. Examples of the polysaccharides include starch, cellulose, chitin, chitosan, hemicellulose, pectin, pullulan, agar, alginic acid, carrageenan, dextrin, trehalose, guar gum, xanthan gum, gum arabic, and fucoidan. Examples of the sugar alcohol include tetritols having four carbon atoms, such as threitol and erythritol; pentitols having five carbon atoms, such as arabinitol and xylitol; and hexitols having six carbon atoms, such as iditol, galactitol, mannitol, and sorbitol. These may be used alone or in combination of two or more. Among them, from the viewpoint of obtaining the above-mentioned effects, at least one sugar selected from the group consisting of monosaccharides, disaccharides and polysaccharides is preferred, and polysaccharides are more preferred.Among them, carrageenan, cellulose, fucoidan and alginic acids are preferred, and carrageenan is more preferred as the polysaccharide.

[0057] In the rubber composition, the amount of the saccharide per 100 parts by mass of the rubber component is preferably at least 5 parts by mass, more preferably at least 10 parts by mass, and even more preferably at least 15 parts by mass, and is preferably at most 60 parts by mass, more preferably at most 40 parts by mass, and even more preferably at most 30 parts by mass. Within the above ranges, the effect tends to be more favorably obtained.

[0058] The rubber composition preferably contains a filler. The filler is not particularly limited, and materials known in the rubber field can be used, such as inorganic fillers such as carbon black, silica, calcium carbonate, talc, alumina, clay, aluminum hydroxide, aluminum oxide, and mica, biochar, and poorly dispersible fillers. Among these, carbon black and silica are preferred, and silica is more preferred, from the viewpoint of obtaining better effects. These may be used alone or in combination of two or more.

[0059] The carbon black that can be used in the rubber composition is not particularly limited, and examples thereof include N134, N110, N220, N234, N219, N339, N330, N326, N351, N550, and N762. The raw material for carbon black may be a biomass material such as lignin or vegetable oil. Furthermore, carbon black may be produced by combustion, such as in a furnace, by hydrothermal carbonization (HTC), or by thermal decomposition of methane, such as in a thermal black process. Commercially available carbon blacks include those from Asahi Carbon Co., Ltd., Cabot Japan Co., Ltd., Tokai Carbon Co., Ltd., Mitsubishi Chemical Corporation, Lion Corporation, Nippon Steel Carbon Co., Ltd., and Columbia Carbon Co., Ltd. These may be used alone or in combination.

[0060] The nitrogen adsorption specific surface area (N2SA) of the above carbon black is 30m 2 / g or more is preferable, and 50m 2 / g or more is more preferable, and 70m 2 / g or more is more preferable. 2 / g or less is preferable, and 150m 2 / g or less is more preferable, and 130m 2 / g or less is more preferable, and 120m 2 Within the above range, the effect tends to be better. The nitrogen adsorption specific surface area of ​​carbon black can be determined by Method A of JIS K6217.

[0061] When the rubber composition contains carbon black, the amount of carbon black is preferably 5 parts by mass or more, more preferably 30 parts by mass or more, and even more preferably 50 parts by mass or more, per 100 parts by mass of the rubber component, and is preferably 150 parts by mass or less, more preferably 100 parts by mass or less, and even more preferably 90 parts by mass or less. When the amount is within the above range, better effects tend to be obtained.

[0062] The silica that can be used in the rubber composition is not particularly limited, and can be, for example, silica prepared by a dry process (anhydrous silica) or silica prepared by a wet process (hydrated silica), which are commonly used in the tire industry. The raw material for the silica is not particularly limited, and can be, for example, a mineral-derived raw material such as quartz, a biological raw material such as rice husk (for example, silica made from a biomass material such as rice husk), or silica recycled from a silica-containing product. Among these, hydrated silica prepared by a wet process is preferred because it contains a large number of silanol groups. These silicas can be used alone or in combination of two or more types.

[0063] Silica made from biomass materials can be obtained, for example, by extracting silicate from rice husk ash obtained by burning rice husks using a sodium hydroxide solution, and then reacting the silicate with sulfuric acid in the same manner as conventional wet-process silica to produce a silicon dioxide precipitate, which is then filtered, washed with water, dried, and pulverized.

[0064] Silica recycled from silica-containing products can be, for example, silica recovered from products containing silica, such as electronic components such as semiconductors, tires, desiccants, and filtering materials such as diatomaceous earth. The recovery method is not particularly limited, and examples include thermal decomposition and decomposition by electromagnetic waves. Among these, silica recovered from electronic components such as semiconductors or tires is preferred.

[0065] When silica crystallizes, it becomes insoluble in water, and its component, silicic acid, cannot be utilized. By controlling the combustion temperature and duration, it is possible to suppress the crystallization of silica in rice husk ash (see, for example, JP 2009-2594 A and Akita Prefectural University Web Journal B / 2019, vol. 6, pp. 216-222).

[0066] Amorphous silica extracted from rice husks may be commercially available from Wilmar Co., Ltd., etc.

[0067] When the rubber composition contains silica, the content of silica is, per 100 parts by mass of the rubber component, preferably 5 parts by mass or more, more preferably 40 parts by mass or more, even more preferably 55 parts by mass or more, particularly preferably 65 parts by mass or more, and is preferably 180 parts by mass or less, more preferably 150 parts by mass or less, even more preferably 120 parts by mass or less, particularly preferably 100 parts by mass or less. Within the above ranges, the effect tends to be more favorably obtained.

[0068] The mechanism by which greater effects are obtained by including more than a certain amount of silica is not clear, but it is believed that the more silica there is, the greater the reinforcing effect, resulting in better abrasion resistance.

[0069] The nitrogen adsorption specific surface area (N2SA) of the silica is preferably 50 m 2 / g or more, more preferably 70m 2 / g or more, more preferably 80m 2 The upper limit of the N2SA of silica is not particularly limited, but is preferably 350 m 2 / g or less, more preferably 300m 2 / g or less, more preferably 250m 2 Within the above range, there is a tendency for the effect to be better obtained. In this specification, the N2SA of silica is a value measured by the BET method in accordance with ASTM D3037-93.

[0070] Examples of the hardly dispersible filler include microfibrillated plant fibers, short fiber cellulose, gel compounds, etc. Among these, microfibrillated plant fibers are preferred.

[0071] The microfibrillated plant fiber is preferably cellulose microfibrils, as they provide good reinforcing properties. The cellulose microfibrils are not particularly limited as long as they are derived from natural products, and examples include those derived from resource biomass such as fruits, grains, and root vegetables; wood, bamboo, hemp, jute, and kenaf; pulp, paper, and cloth obtained from these raw materials; waste biomass such as agricultural waste, food waste, and sewage sludge; unused biomass such as rice straw, wheat straw, and thinned wood; and cellulose produced by sea squirts, acetic acid bacteria, and the like. These microfibrillated plant fibers may be used alone or in combination of two or more.

[0072] In this specification, cellulose microfibrils typically refer to cellulose fibers having an average fiber diameter of 10 μm or less, more typically cellulose fibers having a microstructure formed by the aggregation of cellulose molecules and an average fiber diameter of 500 nm or less. Typical cellulose microfibrils are formed, for example, as an aggregate of cellulose fibers having the above-mentioned average fiber diameter.

[0073] When the rubber composition contains a hardly-dispersible filler, the content of the hardly-dispersible filler is preferably 1 part by mass or more, more preferably 3 parts by mass or more, and even more preferably 5 parts by mass or more, per 100 parts by mass of the rubber component. The upper limit of the content is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 20 parts by mass or less, and particularly preferably 10 parts by mass or less. Within the above range, the effect tends to be more favorably obtained.

[0074] In the rubber composition, the content of the filler (total amount of carbon black, silica, etc.) is preferably 5 parts by mass or more, more preferably 30 parts by mass or more, and even more preferably 50 parts by mass or more, per 100 parts by mass of the rubber component, and is preferably 150 parts by mass or less, more preferably 100 parts by mass or less, and even more preferably 90 parts by mass or less. Within the above ranges, the effect tends to be more favorably obtained.

[0075] In the rubber composition, the total amount of silica and carbon black is preferably 80 parts by mass or less, more preferably 75 parts by mass or less, per 100 parts by mass of the rubber component. The total amount is 20 parts by mass or more, more preferably 30 parts by mass or more, and even more preferably 40 parts by mass or more. Within the above range, the effect tends to be more favorable. The rubber composition may contain either silica or carbon black, or may contain both silica and carbon black.

[0076] When the rubber composition contains silica, it is preferable that the rubber composition further contains a silane coupling agent. The silane coupling agent is not particularly limited, and those known in the rubber field can be used, for example, bis(3-triethoxysilylpropyl)tetrasulfide, bis(2-triethoxysilylethyl)tetrasulfide, bis(4-triethoxysilylbutyl)tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, bis(2-trimethoxysilylethyl)tetrasulfide, bis(2-triethoxysilylethyl)trisulfide, bis(4-trimethoxysilylbutyl)trisulfide, bis(3-triethoxysilylpropyl)disulfide, bis(2-triethoxysilylethyl)disulfide, bis(4-triethoxysilylbutyl)disulfide, bis(3-trimethoxysilylpropyl)disulfide, bis(2-trimethoxysilylethyl)disulfide, bis(4-trimethoxysilylbutyl)disulfide, 3-trimethoxysilylpropyl-N, Examples include sulfide-based compounds such as N-dimethylthiocarbamoyl tetrasulfide, 2-triethoxysilylethyl-N,N-dimethylthiocarbamoyl tetrasulfide, and 3-triethoxysilylpropyl methacrylate monosulfide; mercapto-based compounds such as 3-mercaptopropyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, and NXT and NXT-Z manufactured by Momentive; vinyl-based compounds such as vinyltriethoxysilane and vinyltrimethoxysilane; amino-based compounds such as 3-aminopropyltriethoxysilane and 3-aminopropyltrimethoxysilane; glycidoxy-based compounds such as γ-glycidoxypropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane; nitro-based compounds such as 3-nitropropyltrimethoxysilane and 3-nitropropyltriethoxysilane; and chloro-based compounds such as 3-chloropropyltrimethoxysilane and 3-chloropropyltriethoxysilane. Commercially available products include those from Degussa, Momentive, Shin-Etsu Silicones Co., Ltd., Tokyo Chemical Industry Co., Ltd., Azumax Co., Ltd., and Dow Corning Toray Co., Ltd. These may be used alone or in combination of two or more.

[0077] In the rubber composition, the content of the silane coupling agent is preferably 0.1 parts by mass or more, more preferably 3 parts by mass or more, even more preferably 5 parts by mass or more, and particularly preferably 7 parts by mass or more, relative to 100 parts by mass of silica. The upper limit of the content is preferably 50 parts by mass or less, more preferably 20 parts by mass or less, even more preferably 15 parts by mass or less, and particularly preferably 10 parts by mass or less. Within the above range, the effect tends to be more favorably obtained.

[0078] The rubber composition may contain a plasticizer. In this specification, the term "plasticizer" refers to a material that imparts plasticity to a rubber component, and includes both plasticizers that are liquid at 25°C and plasticizers that are solid at 25°C. Examples of plasticizers include resin components, oils, liquid polymers, and ester-based plasticizers. These plasticizers may be derived from mineral resources such as petroleum and natural gas, biomass-derived plasticizers, or naphtha recycled from rubber and non-rubber products. Low-molecular-weight hydrocarbon components obtained by pyrolysis and extraction of used tires or products containing various components may also be used as plasticizers. These plasticizers may be used alone or in combination.

[0079] Specific examples of the plasticizer include oils, liquid polymers, resins, etc. These may be used alone or in combination of two or more.

[0080] Examples of oils include mineral oil, vegetable oil, animal oil, etc. From the viewpoint of life cycle assessment, waste oils used in rubber mixers or engines, or refined waste cooking oils used in restaurants may also be used.

[0081] As used herein, mineral oil refers to oil derived from mineral resources such as petroleum and natural gas. Examples of mineral oil include paraffinic oil (mineral oil), naphthenic oil, and aromatic oil. Specific examples of mineral oil include mild extract solvated (MES), distillate aromatic extract (DAE), treated distillate aromatic extract (TDAE), treated residual aromatic extract (TRAE), and residual aromatic extract (RAE). Furthermore, as an environmental measure, oils with a low content of polycyclic aromatic compounds (PCA) can also be used. Examples of low PCA oils include MES, TDAE, and heavy naphthenic oil.

[0082] As used herein, examples of vegetable oils include linseed oil, rapeseed oil, safflower oil, soybean oil, corn oil, cottonseed oil, rice oil, tall oil, sesame oil, perilla oil, castor oil, tung oil, pine oil, pine tar oil, sunflower oil, coconut oil, palm oil, palm kernel oil, olive oil, camellia oil, jojoba oil, macadamia nut oil, peanut oil, grapeseed oil, and Japan wax. Further examples of vegetable oils include refined oils (such as salad oil) obtained by refining the above-mentioned oils, interesterified oils obtained by interesterifying the above-mentioned oils, hardened oils obtained by hydrogenating the above-mentioned oils, thermally polymerized oils obtained by thermally polymerizing the above-mentioned oils, oxidatively polymerized oils obtained by oxidizing the above-mentioned oils, and waste edible oils recovered from edible oils and the like. Vegetable oils may be liquid or solid at 25°C. These vegetable oils may be used alone or in combination of two or more.

[0083] The vegetable oil according to this embodiment preferably contains acylglycerol, and more preferably triacylglycerol. In this specification, acylglycerol refers to a compound in which a hydroxyl group of glycerin is esterified with a fatty acid. The acylglycerol is not particularly limited and may be 1-monoacylglycerol, 2-monoacylglycerol, 1,2-diacylglycerol, 1,3-diacylglycerol, or triacylglycerol. Furthermore, the acylglycerol may be a monomer, a dimer, or a polymer (trimer or higher). Dimer or higher acylglycerols can be obtained by thermal polymerization, oxidative polymerization, or the like. The acylglycerol may be liquid or solid at 25°C.

[0084] The method for confirming whether the rubber composition contains the acylglycerol is not particularly limited, but may be any of the following: 1 For example, a rubber composition containing triacylglycerol is immersed in deuterated chloroform at 25°C for 24 hours, and after removing the rubber composition, the 1 When H-NMR was measured, signals were observed around 5.26 ppm, 4.28 ppm, and 4.15 ppm when the signal of tetramethylsilane (TMS) was set at 0.00 ppm. These signals are presumed to be signals derived from hydrogen atoms bonded to carbon atoms adjacent to the oxygen atoms of the ester group. In this paragraph, "around" refers to a range of ±0.10 ppm.

[0085] The fatty acid is not particularly limited and may be either an unsaturated fatty acid or a saturated fatty acid. Examples of unsaturated fatty acids include monounsaturated fatty acids such as oleic acid, and polyunsaturated fatty acids such as linoleic acid and linolenic acid. Examples of saturated fatty acids include butyric acid and lauric acid.

[0086] Among these, it is desirable that the fatty acid contains a fatty acid with few double bonds, i.e., a saturated fatty acid or a monounsaturated fatty acid, and oleic acid is preferred. As a vegetable oil containing such a fatty acid, for example, vegetable oil containing a saturated fatty acid or a monounsaturated fatty acid may be used, or vegetable oil modified by ester exchange or the like may be used. Furthermore, in order to produce vegetable oil containing such a fatty acid, plants may be improved by breeding, genetic modification, genome editing, or the like.

[0087] As the oil, for example, commercially available oils from Idemitsu Kosan Co., Ltd., Sankyo Yuka Kogyo Co., Ltd., ENEOS Corporation, Orisoi Co., Ltd., H&R Corporation, Toyokuni Oil Mills Co., Ltd., Fuji Kosan Co., Ltd., Nisshin Oillio Group Co., Ltd., etc. can be used.

[0088] Examples of the liquid polymer (polymer that is liquid at 25°C) include liquid diene-based polymers (liquid rubber) and liquid farnesene-based polymers that are liquid at 25°C. Examples of liquid rubber include liquid styrene-butadiene copolymers (liquid SBR), liquid butadiene polymers (liquid BR), liquid isoprene polymers (liquid IR), liquid styrene-isoprene copolymers (liquid SIR), liquid styrene-butadiene-styrene block copolymers (liquid SBS block polymers), and liquid styrene-isoprene-styrene block copolymers (liquid SIS block polymers). The terminals or main chains of these may be modified with polar groups. Hydrogenated versions of these may also be used. Among these, it is preferable to contain a liquid diene polymer that is liquid at 25°C, from the viewpoint of obtaining a better effect.

[0089] Although the mechanism by which the inclusion of a liquid diene-based polymer that is liquid at 25°C provides a greater effect is unclear, it is believed that the liquid diene-based polymer effectively disperses the magnetic particles, thereby providing good wear resistance.

[0090] The liquid diene polymer has a weight average molecular weight (Mw) of 1.0×10 in terms of polystyrene as measured by gel permeation chromatography (GPC). 3 ~5.0×10 4 Preferably, it is 3.0 × 10 3 ~1.5×10 4 The lower or upper limit of Mw of the liquid diene polymer may be 4,500 or 8,500. In this specification, the Mw of the liquid diene polymer is a polystyrene-equivalent value measured by gel permeation chromatography (GPC).

[0091] As the liquid diene polymer, for example, products available from Clay Valley, Sartomer, Kuraray Co., Ltd., etc. can be used.

[0092] The resin may be a resin commonly used in tire compounds, and may be liquid or solid at 25°C. Examples include aromatic vinyl polymers, coumarone-indene resins, coumarone resins, indene resins, phenolic resins, rosin resins, petroleum resins, terpene resins, and acrylic resins. The resin may also be a hydrogenated resin (hydrogenated resin). These may be used alone or in combination of two or more. The resin itself may also be a copolymer of monomer components derived from multiple sources. Among these, aromatic vinyl polymers, petroleum resins, terpene resins, and hydrogenated resins thereof are preferred.

[0093] When a resin that is solid at 25° C. is used, the softening point of the resin is preferably 50° C. or higher, more preferably 55° C. or higher, even more preferably 60° C. or higher, and particularly preferably 85° C. or higher. Also, the softening point is preferably 160° C. or lower, more preferably 150° C. or lower, even more preferably 140° C. or lower, and particularly preferably 100° C. or lower. Within the above range, better effects tend to be obtained. When the resin is liquid at 25°C, the softening point is preferably 20°C or lower, more preferably 10°C or lower, and even more preferably 0°C or lower. In the case of hydrogenated resins, it is desirable that the softening point is the same as above. The softening point of the resin is the temperature at which the ball drops when the softening point specified in JIS K6220-1:2001 is measured using a ring and ball softening point tester.

[0094] The aromatic vinyl polymer is a polymer containing an aromatic vinyl monomer as a constituent unit. For example, it may be a resin obtained by polymerizing α-methylstyrene and / or styrene, and specifically may be a homopolymer of styrene (styrene resin), a homopolymer of α-methylstyrene (α-methylstyrene resin), a copolymer of α-methylstyrene and styrene, or a copolymer of styrene and another monomer.

[0095] The coumarone-indene resin is a resin containing coumarone and indene as the main monomer components constituting the resin skeleton (main chain). Other monomer components contained in the skeleton besides coumarone and indene include styrene, α-methylstyrene, methylindene, vinyltoluene, etc.

[0096] The coumarone resin is a resin containing coumarone as a main monomer component constituting the skeleton (main chain) of the resin.

[0097] The indene resin is a resin containing indene as a main monomer component constituting the skeleton (main chain) of the resin.

[0098] The phenolic resin may be a known polymer obtained by reacting phenol with an aldehyde such as formaldehyde, acetaldehyde, or furfural in the presence of an acid or alkali catalyst. Of these, those obtained by reacting with an acid catalyst (such as novolac phenolic resin) are preferred.

[0099] Examples of the rosin resin include rosin-based resins such as natural rosin, polymerized rosin, modified rosin, ester compounds thereof, and hydrogenated products thereof.

[0100] Examples of the petroleum resin include C5 resin, C9 resin, C5 / C9 resin, dicyclopentadiene (DCPD) resin, C9 / DCPD resin, and hydrogenated versions of these. Of these, DCPD resin, hydrogenated DCPD resin, C9 / DCPD resin, and C9 / hydrogenated DCPD resin are preferred.

[0101] The terpene resin is a polymer containing terpene as a structural unit. Examples include polyterpene resins obtained by polymerizing terpene compounds and aromatic-modified terpene resins obtained by polymerizing terpene compounds and aromatic compounds. Examples of aromatic-modified terpene resins include terpene phenol resins made from terpene compounds and phenolic compounds, terpene styrene resins made from terpene compounds and styrene compounds, and terpene phenol styrene resins made from terpene compounds, phenolic compounds, and styrene compounds. Examples of terpene compounds include α-pinene and β-pinene, phenolic compounds include phenol and bisphenol A, and aromatic compounds include styrene compounds (styrene, α-methylstyrene, etc.). Among these, aromatic-modified terpene resins are preferred.

[0102] The acrylic resin is a polymer containing an acrylic monomer as a constituent unit. For example, a styrene-acrylic resin having a carboxyl group and obtained by copolymerizing an aromatic vinyl monomer component with an acrylic monomer component can be used. Among them, a solvent-free carboxyl-containing styrene-acrylic resin can be preferably used.

[0103] Examples of the resins that can be used include products from Maruzen Petrochemical Co., Ltd., Sumitomo Bakelite Co., Ltd., Yasuhara Chemical Co., Ltd., Tosoh Corporation, Rutgers Chemicals, BASF, Arizona Chemical Company, ExxonMobil, KRATON, Nitto Chemical Co., Ltd., Nippon Shokubai Co., Ltd., ENEOS Corporation, Arakawa Chemical Industries, Ltd., and Taoka Chemical Co., Ltd.

[0104] From the viewpoint of sustainability, it is desirable to use the above-mentioned plant-derived plasticizers such as plant-derived oils and farnesene-based polymers as the plasticizer.

[0105] Farnesene polymers are polymers obtained by polymerizing farnesene and contain structural units based on farnesene. Farnesene has isomers such as α-farnesene ((3E,7E)-3,7,11-trimethyl-1,3,6,10-dodecatetraene) and β-farnesene (7,11-dimethyl-3-methylene-1,6,10-dodecatriene), but (E)-β-farnesene, which has the following structure, is preferred. [ka]

[0106] The farnesene polymer may be a homopolymer of farnesene (farnesene homopolymer) or a copolymer of farnesene and a vinyl monomer (farnesene-vinyl monomer copolymer). These may be used alone or in combination of two or more. Among these, a copolymer of farnesene and a vinyl monomer is preferred.

[0107] Examples of vinyl monomers include aromatic vinyl compounds such as styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, α-methylstyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, 4-tert-butylstyrene, 5-tert-butyl-2-methylstyrene, vinylethylbenzene, divinylbenzene, trivinylbenzene, divinylnaphthalene, tert-butoxystyrene, vinylbenzyldimethylamine, (4-vinylbenzyl)dimethylaminoethyl ether, N,N-dimethylaminoethylstyrene, N,N-dimethylaminomethylstyrene, 2-ethylstyrene, 3-ethylstyrene, 4-ethylstyrene, 2-tert-butylstyrene, 3-tert-butylstyrene, 4-tert-butylstyrene, vinylxylene, vinylnaphthalene, vinyltoluene, vinylpyridine, diphenylethylene, and tertiary amino group-containing diphenylethylene, as well as conjugated diene compounds such as butadiene and isoprene. These may be used alone or in combination of two or more. Among these, butadiene is preferred. That is, the farnesene-vinyl monomer copolymer is preferably a copolymer of farnesene and butadiene (farnesene-butadiene copolymer).

[0108] In the farnesene-vinyl monomer copolymer, the copolymerization ratio by mass of farnesene to vinyl monomer (farnesene / vinyl monomer) is preferably 40 / 60 to 90 / 10.

[0109] The farnesene polymer preferably has a weight average molecular weight (Mw) of 3,000 or more and 300,000 or less. The Mw of the farnesene polymer is preferably 8,000 or more, more preferably 10,000 or more, and is preferably 100,000 or less, more preferably 60,000 or less, and even more preferably 50,000 or less. Within the above ranges, the effects tend to be more favorably obtained.

[0110] The farnesene-based polymer may be either a liquid or solid at 25° C. Among these, a liquid farnesene-based polymer that is a liquid at 25° C. is preferred.

[0111] In the rubber composition, the content of the plasticizer (total amount of plasticizer) is preferably 30 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less, per 100 parts by mass of the rubber component, and may be 0 part by mass. When the content is within the above range, better effects tend to be obtained. The plasticizer content includes the amount of oil and resin contained in the oil-extended rubber and resin-extended rubber.

[0112] In the rubber composition, the content of the solid plasticizer in a solid state at 25° C. is preferably 30 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less, per 100 parts by mass of the rubber component, and may be 0 part by mass. When the content is within the above range, better effects tend to be obtained.

[0113] In the rubber composition, the content of the resin in a solid state at 25° C. is preferably 30 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less, per 100 parts by mass of the rubber component, and may be 0 part by mass. When the content is within the above range, better effects tend to be obtained.

[0114] In the rubber composition, the content of the liquid plasticizer in a liquid state at 25° C. is preferably 30 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less, per 100 parts by mass of the rubber component, and may be 0 part by mass. When the content is within the above range, better effects tend to be obtained. The content of the liquid plasticizer mentioned above includes the amount of oil contained in the oil-extended rubber and the amount of liquid resin in the resin-extended rubber extended with the liquid resin.

[0115] In the rubber composition, the content of oil per 100 parts by mass of the rubber component is preferably 30 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less, and may be 0 part by mass. When the content is within the above range, better effects tend to be obtained. The oil content includes the amount of oil contained in the oil-extended rubber.

[0116] The rubber composition may further contain vulcanized rubber particles. The vulcanized rubber particles are particles made of vulcanized rubber, and specifically, rubber powder as specified in JIS K 6316:2017 can be used. From the standpoint of environmental considerations and cost, recycled rubber powder produced from crushed waste tires is preferred. These may be used alone or in combination of two or more types.

[0117] The vulcanized rubber particles are not particularly limited, and may be unmodified vulcanized rubber particles or modified vulcanized rubber particles.

[0118] As commercially available vulcanized rubber particles, for example, products from Lehigh Corporation, Muraoka Rubber Industries Co., Ltd., etc. can be used.

[0119] In the rubber composition, the content of the vulcanized rubber particles is preferably 5 parts by mass or more, more preferably 7 parts by mass or more, and even more preferably 10 parts by mass or more, per 100 parts by mass of the rubber component, and is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less. Within the above ranges, the effect tends to be better obtained.

[0120] The rubber composition preferably contains an antioxidant from the viewpoints of crack resistance, ozone resistance, and the like.

[0121] The antioxidant is not particularly limited, and examples thereof include naphthylamine-based antioxidants such as phenyl-α-naphthylamine; diphenylamine-based antioxidants such as octylated diphenylamine and 4,4'-bis(α,α'-dimethylbenzyl)diphenylamine; N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD), N,N'-bis(1,4-dimethylpentyl)-p-phenylenediamine (77PD), N,N'-diphenyl-p-phenylenediamine (DPPD), and N,N'-ditolyl-p-phenylenediamine. p-phenylenediamine antioxidants such as N-isopropyl-N'-phenyl-p-phenylenediamine (DTPD), N-isopropyl-N'-phenyl-p-phenylenediamine (IPPD), and N,N'-di-2-naphthyl-p-phenylenediamine (DNPD); quinoline antioxidants such as 2,2,4-trimethyl-1,2-dihydroquinoline polymers; monophenol antioxidants such as 2,6-di-t-butyl-4-methylphenol and styrenated phenol; and bis-, tris-, and polyphenol antioxidants such as tetrakis-[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane. Among these, p-phenylenediamine-based antioxidants and quinoline-based antioxidants are preferred, and polymers of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine and 2,2,4-trimethyl-1,2-dihydroquinoline are more preferred. Commercially available products that can be used include those from Seiko Chemical Co., Ltd., Sumitomo Chemical Co., Ltd., Ouchi Shinko Chemical Industry Co., Ltd., Flexis, etc.

[0122] In the rubber composition, the content of the antioxidant is preferably 0.2 parts by mass or more, more preferably 2.0 parts by mass or more, and even more preferably 3.4 parts by mass or more, per 100 parts by mass of the rubber component, and is preferably 10.0 parts by mass or less, more preferably 6.0 parts by mass or less.

[0123] The rubber composition preferably contains stearic acid. In the rubber composition for a side member, the content of stearic acid per 100 parts by mass of the rubber component is preferably 0.5 parts by mass or more, more preferably 1.5 parts by mass or more, and even more preferably 2.0 parts by mass or more, and is preferably 10 parts by mass or less, and more preferably 5 parts by mass or less.

[0124] As the stearic acid, conventionally known products can be used, for example, products available from NOF Corporation, Kao Corporation, Fujifilm Wako Pure Chemical Industries, Ltd., Chiba Fatty Acid Co., Ltd., etc.

[0125] The rubber composition preferably contains zinc oxide. In the rubber composition, the content of zinc oxide is preferably 0.5 parts by mass or more, more preferably 1.5 parts by mass or more, and even more preferably 2.0 parts by mass or more, per 100 parts by mass of the rubber component, and is preferably 6.0 parts by mass or less, and more preferably 4.0 parts by mass or less.

[0126] As the zinc oxide, conventionally known products can be used, for example, products from Mitsui Mining & Smelting Co., Ltd., Toho Zinc Co., Ltd., Hakusui Tech Co., Ltd., Seido Chemical Industry Co., Ltd., Sakai Chemical Industry Co., Ltd., etc. can be used.

[0127] The rubber composition may contain wax. In the rubber composition, the wax content is preferably 0.5 parts by mass or more, more preferably 1.6 parts by mass or more, and preferably 8.0 parts by mass or less, more preferably 5.0 parts by mass or less, per 100 parts by mass of the rubber component.

[0128] The wax is not particularly limited, and any wax commonly used in the tire industry can be suitably used. Examples include mineral waxes and plant-derived waxes. Mineral waxes refer to waxes derived from mineral resources such as oil and natural gas. Plant-derived waxes refer to waxes derived from natural resources such as plants. Among these, mineral waxes are preferred. Examples of plant-derived waxes include rice wax, carnauba wax, and candelilla wax. Examples of mineral waxes include paraffin wax, microcrystalline wax, and selected special waxes thereof, with paraffin wax being preferred. The wax according to this embodiment does not contain stearic acid. Waxes that can be used include those commercially available from, for example, Ouchi Shinko Chemical Industry Co., Ltd., Nippon Seiro Co., Ltd., Paramelt Co., Ltd., etc. These waxes may be used alone or in combination of two or more.

[0129] It is preferable to compound sulfur as a crosslinking agent in the rubber composition, in order to form appropriate crosslinked chains in polymer chains and impart good performance.

[0130] In the rubber composition, the sulfur content is 1.0 part by mass or more, preferably 1.5 parts by mass or more, and more preferably 2.0 parts by mass or more, per 100 parts by mass of the rubber component. The sulfur content is preferably 7.0 parts by mass or less, more preferably 5.0 parts by mass or less, and even more preferably 4.0 parts by mass or less. Within the above range, the effect tends to be more favorably obtained.

[0131] Examples of sulfur include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersible sulfur, soluble sulfur, etc., which are commonly used in the rubber industry. Commercially available products include those from Tsurumi Chemical Industry Co., Ltd., Karuizawa Sulfur Co., Ltd., Shikoku Chemical Industry Co., Ltd., Flexis Corporation, Nippon Kanzuri Kogyo Co., Ltd., Hosoi Chemical Industry Co., Ltd., etc. These may be used alone or in combination of two or more.

[0132] The rubber composition preferably contains a vulcanization accelerator. In the rubber composition, the content of the vulcanization accelerator is not particularly limited and may be freely determined according to the desired vulcanization rate and crosslink density, but is preferably 0.5 parts by mass or more, more preferably 0.8 parts by mass or more, and even more preferably 1.0 part by mass or more, per 100 parts by mass of the rubber component. The upper limit is preferably 8.0 parts by mass or less, more preferably 6.0 parts by mass or less, and even more preferably 5.0 parts by mass or less.

[0133] The type of vulcanization accelerator is not particularly limited, and commonly used ones can be used. Examples of the vulcanization accelerator include benzothiazole-based vulcanization accelerators such as 2-mercaptobenzothiazole, di-2-benzothiazolyl disulfide, and N-cyclohexyl-2-benzothiazyl sulfenamide; thiuram-based vulcanization accelerators such as tetramethylthiuram disulfide (TMTD), tetrabenzylthiuram disulfide (TBzTD), and tetrakis(2-ethylhexyl)thiuram disulfide (TOT-N); sulfenamide-based vulcanization accelerators such as N-cyclohexyl-2-benzothiazole sulfenamide, Nt-butyl-2-benzothiazolyl sulfenamide, N-oxyethylene-2-benzothiazole sulfenamide, and N,N'-diisopropyl-2-benzothiazole sulfenamide; and guanidine-based vulcanization accelerators such as diphenylguanidine, di-orthotolylguanidine, and orthotolylbiguanidine. These may be used alone or in combination of two or more. Among these, sulfenamide-based, guanidine-based and benzothiazole-based vulcanization accelerators are preferred.

[0134] In addition to the above components, the rubber composition may also contain compounding agents generally used in the tire industry, such as a mold release agent, as appropriate.

[0135] In this specification, various materials containing carbon atoms (e.g., rubber, oil, resin, vulcanization accelerator, antioxidant, surfactant, etc.) may be derived from atmospheric carbon dioxide. As a method for obtaining the above-mentioned compound from carbon dioxide, carbon dioxide may be directly converted, or methane obtained through a methanation process in which methane is synthesized from carbon dioxide may be converted.

[0136] The rubber composition is prepared by kneading the components using a rubber kneading device such as an open roll or a Banbury mixer, followed by vulcanization, to obtain a vulcanized rubber composition.

[0137] As for kneading conditions, in the base kneading step in which additives other than the vulcanizing agent and vulcanization accelerator are kneaded, the kneading temperature is preferably 50°C or higher, more preferably 80°C or higher, and preferably 200°C or lower, more preferably 190°C or lower. The kneading time is preferably 30 seconds or higher, more preferably 1 minute or lower, and preferably 30 minutes or lower. In the finish kneading step in which the vulcanizing agent and vulcanization accelerator are kneaded, the kneading temperature is preferably 10°C or higher, and preferably 100°C or lower, more preferably 80°C or lower. The composition kneaded with the vulcanizing agent and vulcanization accelerator is usually subjected to a vulcanization treatment such as press vulcanization. The vulcanization temperature is preferably 120°C or higher, more preferably 140°C or higher, and preferably 200°C or lower, more preferably 180°C or lower.

[0138] The rubber composition is used in tire components. The tire component is not particularly limited, and may be any tire component such as a cap tread, a sidewall, a base tread, a bead apex, a clinch apex, an inner liner, an undertread, a breaker topping, a bright topping, etc. Among these, the present invention is preferably applied to a cap tread.

[0139] The tire is manufactured by a conventional method using the rubber composition. That is, the composition, to which various additives are optionally added, is extruded in an unvulcanized state to match the shape of the tire components, molded in a conventional manner on a tire building machine, and laminated together with other tire components to form an unvulcanized tire, which is then heated and pressurized in a vulcanizer to manufacture the tire.

[0140] The tire is not particularly limited, and examples thereof include pneumatic tires, solid tires, airless tires, etc. Among these, pneumatic tires are preferred.

[0141] The above-mentioned tires are suitable for use as passenger car tires, large passenger car tires, large SUV tires, truck and bus tires, motorcycle tires, racing tires, winter tires (studless tires, snow tires, studded tires), all-season tires, run-flat tires, aircraft tires, mining tires, electric vehicle tires, etc.

[0142] The tire includes a tire component made of a rubber composition containing the rubber component, the magnetic particles, and the sugars, and the product (Ash × AE × T) of the ash content Ash (mass%) of the rubber composition, the acetone extractable amount AE (mass%) of the rubber composition, and the thickness T (mm) of the tire component exceeds 400. The Ash×AE×T is preferably greater than 500, more preferably greater than 800, even more preferably greater than 1000, and particularly preferably greater than 1200. There is no particular upper limit to the Ash×AE×T, but it is preferably less than 3000, more preferably less than 2500, and even more preferably less than 2000. Within the above range, better effects tend to be obtained.

[0143] The lower limit of the ash content (% by mass) is preferably more than 30% by mass, more preferably more than 33% by mass, and even more preferably more than 35% by mass. The upper limit is preferably less than 50% by mass, more preferably less than 40% by mass, and even more preferably less than 38% by mass. Within the above ranges, better effects tend to be obtained.

[0144] The lower limit of the acetone extractable amount AE (mass%) is preferably more than 2.0 mass%, more preferably more than 4.0 mass%, and even more preferably more than 6.0 mass%. The upper limit is preferably less than 30.0 mass%, more preferably less than 20.0 mass%, and even more preferably less than 10.0 mass%. Within the above range, better effects tend to be obtained.

[0145] The lower limit of the thickness T (mm) of the tire component is preferably 1.0 mm or more, more preferably 3.0 mm or more, and even more preferably 5.0 mm or more. The upper limit is preferably 50.0 mm or less, more preferably 30.0 mm or less, even more preferably 10.0 mm or less, and particularly preferably 8.0 mm or less. Within the above ranges, the effects tend to be favorably obtained.

[0146] When the rubber composition is used for a cap tread, the lower limit of the thickness (mm) of the cap tread is preferably 1.0 mm or more, more preferably 3.0 mm or more, and even more preferably 5.0 mm or more. The upper limit is preferably 20.0 mm or less, more preferably 10.0 mm or less, and even more preferably 8.0 mm or less. Within the above ranges, the effect tends to be preferably obtained.

[0147] In this specification, Ash and AE of the rubber composition are physical property values ​​of the rubber composition after vulcanization. The Ash and AE of the rubber composition are values ​​measured by the following method. (Ash content Ash) Acetone extraction is performed on a test piece cut out from the tire component of the tire by the method for measuring acetone extractable amount in accordance with JIS K 6229:2015. For the sample after acetone extraction, the organic matter was pyrolyzed and vaporized by heating in nitrogen (from room temperature to 750°C) in accordance with JIS K6226-1:2003, and the weight loss (mass) was measured. Based on the measurement results, the ash content (mass%) was calculated using the following formula. Ash content (mass%) = (mass of test piece after heating / mass of test piece before heating) x 100 (Acetone extractables AE) A test piece cut out from the tire component of the tire is subjected to measurement of the amount of substance extracted by acetone contained in the test piece in accordance with the method for measuring acetone extractable amount in accordance with JIS K 6229:2015. Acetone extractable amount (mass%) = (mass of test piece before extraction - mass of test piece after extraction) / mass of test piece before extraction × 100

[0148] Methods known to those skilled in the art can be used to adjust Ash and AE. For example, Ash tends to increase as the amount of components that do not burn by oxidative combustion, such as silica, in the rubber composition increases. AE tends to increase as the amount of softeners, such as oil, in the rubber composition increases.

[0149] In this specification, the thickness T of a tire component is the maximum dimension among the thicknesses of the tire component at each point on the surface of the tire component, and the thickness of the tire component at each point is measured along a normal to the surface of the tire component at that point.

[0150] In this specification, dimensions such as thickness are measured under normal conditions. "Normal conditions" refers to a tire mounted on a normal rim, inflated to the normal internal pressure, and unloaded. Here, "normal rim" refers to a rim specified for each tire by the standard system, including the standard on which the tire is based. For example, in the case of JATMA (Japan Automobile Tire Manufacturers Association), this refers to the standard rim for the applicable size listed in the "JATMA Year Book." In the case of ETRTO (The European Tire and Rim Technical Organization), this refers to the "Measuring Rim" listed in the "Standards Manual." In the case of TRA (The Tire and Rim Association, Inc.), this refers to the "Design Rim" listed in the "Year Book." JATMA, ETRTO, and TRA are referenced in this order, and if an applicable size is available at the time of reference, these standards are followed. For tires not specified by a standard, this refers to a rim that can be mounted on a rim and can maintain internal pressure, i.e., the rim with the smallest rim diameter and the next narrowest rim width, among rims that can prevent air leakage between the rim and tire. Additionally, "normal internal pressure" refers to the air pressure specified for each tire by each standard in the standard system, including the standard on which the tire is based. For JATMA, it refers to "maximum air pressure," for ETRTO, it refers to "INFLATION PRESSURE," and for TRA, it refers to the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES." Refer to JATMA, ETRTO, and TRA in that order, and follow the standard if there is an applicable size at the time of reference. In the case of a tire not specified in the standard, it refers to the normal internal pressure (250 KPa or more) of another tire size (specified in the standard) that is specified using the normal rim as the standard rim. Note that if multiple normal internal pressures of 250 KPa or more are listed, it refers to the smallest value among them.

[0151] The tire has a tire component made of a rubber composition containing the rubber component, the magnetic particles, and the sugars, and it is desirable that the product ((Sc / Mc)×T) of the ratio of the sugar content Sc (parts by mass) per 100 parts by mass of the rubber component of the rubber composition to the magnetic particle content Mc (parts by mass) per 100 parts by mass of the rubber component of the rubber composition and the thickness T (mm) of the tire component exceeds 5.0. The above (Sc / Mc)×T) preferably exceeds 6.0, more preferably exceeds 7.0, and even more preferably exceeds 7.2. There are no particular limitations on the upper limit of the above (Sc / Mc)×T), but it is preferably less than 12.0, more preferably less than 9.0, and even more preferably less than 7.8. Within the above range, better effects tend to be obtained.

[0152] The mechanism by which greater effectiveness is achieved by adjusting (Sc / Mc) x T to a value greater than the specified value is not clear, but it is thought that good wear resistance is achieved by the dispersion effect of the magnetic particles obtained by blending a specified amount of sugar with respect to the amount of magnetic particles.

[0153] The tire includes a tire component made of a rubber composition containing the rubber component, the magnetic particles, and the sugars, and it is desirable that the ratio (Ash / T) of the ash content Ash (mass%) of the rubber composition to the thickness T (mm) of the tire component is less than 8.1. The Ash / T is preferably less than 8.0, more preferably less than 7.9, and even more preferably less than 7.8. The lower limit of the Ash / T is not particularly limited, but is preferably greater than 3.0, more preferably greater than 5.0, and even more preferably greater than 5.5. Within the above range, the effect tends to be better.

[0154] The mechanism by which adjusting Ash / T to less than a specified value provides better results is not clear, but it is thought that by reducing the amount of ash per thickness of the tire component, the dispersion effect of the magnetic particles by the sugars is effectively obtained, resulting in good wear resistance.

[0155] The tire includes a tire member made of a rubber composition containing the rubber component, the magnetic particles, and the sugars, and it is desirable that the ratio (AE / T) of the acetone extractable amount AE (mass%) of the rubber composition to the thickness T (mm) of the tire member exceeds 0.50. The AE / T ratio is preferably greater than 0.80, more preferably greater than 1.10, and even more preferably greater than 1.30. There are no particular limitations on the upper limit of the AE / T ratio, but it is preferably less than 2.00, more preferably less than 1.70, and even more preferably less than 1.50. Within the above range, better effects tend to be obtained.

[0156] The mechanism by which greater effects are obtained by adjusting the AE / T ratio to a value greater than a specified value is not clear, but it is thought that increasing the amount of acetone extracted per thickness of the tire component results in flexibility, which in turn results in good wear resistance.

[0157] An example of a tire will be described below with reference to the drawings, but the tire is not limited to this configuration.

[0158] 1, the up-down direction is the radial direction of the tire 2, the left-right direction is the axial direction of the tire 2, and the direction perpendicular to the paper surface is the circumferential direction of the tire 2. The tire 2 is symmetrical. The tread 4 has a single-layer structure.

[0159] In the tire 2 of Fig. 1, the tread 4 is made of the above rubber composition. That is, the tread 4 is made of a rubber composition containing a rubber component, magnetic particles, and a sugar.

[0160] Although FIG. 1 shows an example of a single-layer structure tread 4, a two-layer structure tread consisting of a cap tread and a base tread, or a tread having a structure of three or more layers may also be used.

[0161] In the tire 2, each sidewall 6 extends substantially radially inward from an end of the tread 4. A radially outer portion of each sidewall 6 is joined to the tread 4. A radially inner portion of each sidewall 6 is joined to a clinch 10. The sidewall 6 can prevent damage to the carcass 14.

[0162] 1 is located between the tread 4 and the sidewall 6. The wing 8 is joined to each of the tread 4 and the sidewall 6.

[0163] Each clinch 10 is located approximately radially inward of the sidewall 6 and has at least one or more portions that come into contact with the rim.

[0164] The carcass 14 includes a carcass ply 36. In the tire 2, the carcass 14 is made up of one carcass ply 36, but may be made up of two or more carcass plies.

[0165] In the tire 2, the carcass ply 36 is laid between the bead cores 32 on both sides and extends along the tread 4 and the sidewall 6. The carcass ply 36 is folded back from the inside to the outside in the axial direction around each bead core 32. This folding back forms a main portion 36a and a pair of folded-back portions 36b in the carcass ply 36. That is, the carcass ply 36 includes the main portion 36a and the pair of folded-back portions 36b.

[0166] Each bead core 32 includes a bead apex 34 extending radially outward from the bead core 32. The bead core 32 is preferably ring-shaped and includes a wound, non-stretchable wire. The bead apex 34 tapers radially outward.

[0167] Although not shown, the carcass ply 36 preferably comprises a large number of parallel cords and a topping rubber. The absolute value of the angle that each cord forms with respect to the equatorial plane CL is preferably 75° to 90°. In other words, the carcass 14 preferably has a radial structure.

[0168] The belt layer 16 in FIG. 1 is located radially inward of the tread 4. The belt layer 16 is laminated with the carcass 14. The belt layer 16 reinforces the carcass 14. In the tire 2 in FIG. 1, the belt layer 16 is made up of an inner layer 38 and an outer layer 40. As is clear from FIG. 1, it is desirable that the width of the inner layer 38 is slightly larger than the width of the outer layer 40 in the axial direction. In this tire 2, the axial width of the belt layer 16 is preferably 0.6 times or more and 0.9 times or less the cross-sectional width of the tire 2.

[0169] Each of the inner layer 38 and the outer layer 40 preferably comprises a number of parallel-arranged single steel cords (steel monofilaments) and a topping rubber (coating rubber). In other words, the belt layer 16 includes a number of parallel-arranged steel monofilaments.

[0170] 1 is located radially outside the belt layer 16. In the axial direction, the band 18 has a width equal to the width of the belt layer 16. The band 18 may also have a width greater than the width of the belt layer 16.

[0171] Although not shown, the band 18 is preferably made of a cord and a topping rubber. The cord is wound spirally. This band 18 has a so-called jointless structure. The cord extends substantially in the circumferential direction. The angle of the cord with respect to the circumferential direction is preferably 5° or less, and more preferably 2° or less. The cord restrains the belt layer 16, thereby suppressing lifting of the belt layer 16.

[0172] 1 constitute a reinforcing layer. The reinforcing layer may be constituted by the belt layer 16 alone.

[0173] FIG. 2 is an enlarged view of the vicinity of the tread 4 in FIG. The tire in FIG. 2 is a tire 2 having a groove 26 on the tire equatorial plane (CL).

[0174] FIG. 2 is an enlarged cross-sectional view showing the vicinity of the tread 4 in FIG. In the tire 2 of Fig. 1, the thickness T of the tread 4 is the maximum dimension among the thicknesses of the tread at each point on the surface of the tread 4, and is indicated by T in the example of Fig. 2. The tire 2 satisfies the relationship that the product (Ash × AE × T) of the ash content Ash (mass %) of the rubber composition constituting the tread 4, the acetone extractable amount AE (mass %) of the rubber composition, and the tread thickness T (mm) exceeds 400.

[0175] The inner liner 20 is located inside the carcass 14. The inner liner 20 is bonded to the inner surface of the carcass 14. A typical base rubber of the inner liner 20 is butyl rubber or halogenated butyl rubber. The inner liner 20 maintains the internal pressure of the tire 2.

[0176] Each chafer 22 is located near a bead 12. In this embodiment, the chafer 22 is preferably made of a cloth with rubber impregnated into the cloth. The chafer 22 may be integral with the clinch 10.

[0177] In this tire 2, the tread 4 has main grooves 42 as the grooves 26. As shown in FIG. 1 , a plurality of main grooves 42, specifically three main grooves 42, are formed in the tread 4. These main grooves 42 are spaced apart in the axial direction. The three main grooves 42 formed in the tread 4 form four ribs 44 extending in the circumferential direction. In other words, the spaces between the ribs 44 constitute the main grooves 42.

[0178] Each main groove 42 extends in the circumferential direction. The main grooves 42 are continuous and uninterrupted in the circumferential direction. The main grooves 42 facilitate the drainage of water present between the road surface and the tire 2, for example, in rainy weather. This allows the tire 2 to maintain sufficient contact with the road surface even when the road surface is wet.

[0179] 2D shows the groove depth of the main groove 42 formed in the tread 4 in the circumferential direction.

[0180] In the tire 2, the ash content Ash (mass%) of the rubber composition constituting the tread 4, the acetone extractable amount AE (mass%) of the rubber composition, and the tread thickness T (mm), the ash content Ash (mass%) of the rubber composition, the sugar content Sc per 100 parts by mass of the rubber component of the rubber composition, the magnetic particle content Mc (parts by mass) per 100 parts by mass of the rubber component of the rubber composition, and the silica content (parts by mass) per 100 parts by mass of the rubber component of the rubber composition are desirably within the above-mentioned ranges, and Ash × AE × T, (Sc / Mc) × T, Ash / T, and AE / T are desirably within the above-mentioned ranges. [Example]

[0181] Below, examples (embodiments) that are considered preferable for implementation will be shown, but the scope of the present invention is not limited to the examples.

[0182] The various chemicals used in tire manufacturing are summarized below. If necessary, the chemicals may be refined according to standard methods. SBR: HPR850 manufactured by JSR Corporation (styrene content: 27.5% by mass, vinyl content: 59% by mass) BR: BR150B (cis content: 97% by mass) manufactured by Ube Industries, Ltd. Magnetic particles: HY1 (carbonyl iron powder, D50: 5.5 μm) manufactured by MC Corporation Sugars: Carrageenan manufactured by Tokyo Chemical Industry Co., Ltd. Carbon black: Show Black N220 (N2SA: 111m) manufactured by Cabot Japan Co., Ltd. 2 / g) Silica: Ultrasil VN3 (Evonik, N2SA175m 2 / g) Silane coupling agent: Si266 (bis(3-triethoxysilylpropyl) disulfide) manufactured by Evonik Oil: Idemitsu Kosan Co., Ltd. Diana Process NH-70S (aromatic process oil) Liquid styrene-butadiene copolymer: RICON 100 manufactured by Clay Valley (styrene content 23% by mass, butadiene content 77% by mass, Mw: 4500) Zinc oxide: Zinc oxide No. 1 manufactured by Mitsui Mining & Smelting Co., Ltd. Stearic acid: NOF Corporation's "Tsubaki" stearic acid Sulfur: Powdered sulfur (Tsurumi Chemical Industry Co., Ltd.) Vulcanization accelerator 1: Noccelaer D (N,N'-diphenylguanidine) manufactured by Ouchi Shinko Chemical Industry Co., Ltd. Vulcanization accelerator 2: Noccela CZ (N-cyclohexyl-2-benzothiazolyl sulfenamide) manufactured by Ouchi Shinko Chemical Industry Co., Ltd.

[0183] <Production of Test Tire 1> According to the formulation shown in Table 1, materials other than sulfur and vulcanization accelerator are kneaded for 5 minutes at 150°C using a 1.7L Banbury mixer manufactured by Kobe Steel, Ltd. to obtain a kneaded mixture. Sulfur and a vulcanization accelerator are added to the kneaded mixture, and the mixture is kneaded for 5 minutes at 80°C using an open roll to obtain an uncrosslinked rubber composition. The uncrosslinked rubber composition is molded into the shape of a cap tread, and is laminated together with other tire components on a tire building machine to form an unvulcanized tire, which is then vulcanized at 170°C for 10 minutes to produce test tire 1 (size 195 / 65R15, passenger car tire).

[0184] <Production of Test Tire 2> According to the formulation shown in Table 2, materials other than sulfur and vulcanization accelerator are kneaded for 5 minutes at 150°C using a 1.7L Banbury mixer manufactured by Kobe Steel, Ltd. to obtain a kneaded mixture. Sulfur and a vulcanization accelerator are added to the kneaded mixture, and the mixture is kneaded for 5 minutes at 80°C using an open roll to obtain an uncrosslinked rubber composition. The uncrosslinked rubber composition is molded into the shape of a cap tread, and is laminated together with other tire components on a tire building machine to form an unvulcanized tire, which is then vulcanized at 170°C for 10 minutes to produce test tire 2 (size 205 / 55R16, passenger car tire).

[0185] Tables 1 and 2 show the results of calculations based on the following evaluation method, assuming test tires 1 and 2 obtained from compositions whose formulations and specifications were changed according to Tables 1 and 2. The reference comparative example is as follows. Table 1: Comparative Examples 1-3 Table 2: Comparative Examples 2-3

[0186] <Ash content (Ash)> Test specimens cut from the treads of each test tire 1 and 2 are subjected to acetone extraction in accordance with JIS K 6229:2015. Then, in accordance with JIS K6226-1:2003, the organic matter is pyrolyzed and vaporized by heating in nitrogen (from room temperature to 750°C) to measure the weight loss (mass), and the ash content (mass%) is calculated based on the measurement results using the following formula. Specifically, the ash content (%) is determined by thermogravimetry using the following method. The thermogravimetric measurement was performed using a TA Instruments TGA Q500. The measurement conditions were as follows: the specimen was heated to 750°C in an Ar atmosphere at a rate of 70°C / min, then air was introduced and the specimen was maintained at the same temperature for an additional 5 minutes to decompose. The ash content (%) was then calculated by multiplying the mass of the specimen after heating by the mass of the specimen before heating.

[0187] <Acetone extractables (AE)> Test specimens cut out from the treads of the test tires 1 and 2 are subjected to the acetone extractable amount measurement method in accordance with JIS K 6229:2015, and the amount of substances contained in the test specimens that can be extracted by acetone is measured. Acetone extractable amount (mass%) = (mass of test piece before extraction - mass of test piece after extraction) / mass of test piece before extraction × 100

[0188] <Wear resistance> Using a drum testing machine, the test tire is mounted on a standard rim, pressurized to the standard internal pressure, and run at a speed of 80 km / h under a load (26.72 kN x 2.5). The amount of wear after a specified distance is measured. The result is expressed as an index, with the reference comparative example being 100. The higher the value, the better the wear resistance.

[0189] [Table 1]

[0190] [Table 2]

[0191] The present invention (1) is a tire having tire components made of a rubber composition containing a rubber component, magnetic particles, and sugars, characterized in that the product (Ash × AE × T) of the ash content Ash (mass%) of the rubber composition, the acetone extractable amount AE (mass%) of the rubber composition, and the thickness T (mm) of the tire component exceeds 400.

[0192] The present invention (2) is the tire according to the present invention (1), in which Ash×AE×T exceeds 800.

[0193] The present invention (3) is the tire according to the present invention (1), in which Ash×AE×T exceeds 1,000.

[0194] The present invention (4) is a tire in any combination with any of the present inventions (1) to (3), wherein the rubber composition contains 40 parts by mass or more of silica per 100 parts by mass of the rubber component.

[0195] The present invention (5) is a tire in any combination with any of the present inventions (1) to (4), wherein the rubber composition contains a liquid diene polymer that is liquid at 25°C.

[0196] The present invention (6) is a tire in any combination with any of the present inventions (1) to (5), in which the product ((Sc / Mc)×T) of the ratio of the sugar content Sc (parts by mass) to 100 parts by mass of the rubber component of the rubber composition and the magnetic particle content Mc (parts by mass) to 100 parts by mass of the rubber component of the rubber composition, and the thickness T (mm) of the tire component exceeds 5.0.

[0197] The present invention (7) is a tire in any combination with any of the present inventions (1) to (6), in which the ratio (Ash / T) of the ash content Ash (mass%) of the rubber composition to the thickness T (mm) of the tire component is less than 8.1.

[0198] The present invention (8) is a tire in any combination with any of the present inventions (1) to (7), wherein the rubber component contains at least one selected from the group consisting of butadiene rubber and styrene-butadiene rubber.

[0199] The present invention (9) is a tire in any combination with any of the present inventions (1) to (8), in which the rubber component contains butadiene rubber and styrene-butadiene rubber.

[0200] The present invention (10) is a tire in any combination with any of the present inventions (1) to (9), in which the saccharide is a polysaccharide.

[0201] The present invention (11) is a tire in any combination with any of the present inventions (1) to (10), wherein the rubber composition has a total amount of silica and carbon black of 80 parts by mass or less per 100 parts by mass of the rubber component.

[0202] The present invention (12) is a tire in any combination with any of the present inventions (1) to (11), in which the ratio (AE / T) of the acetone extractable amount AE (mass%) of the rubber composition to the thickness T (mm) of the tire component exceeds 0.50.

[0203] The present invention (13) is a tire for an electric vehicle, which is an optional combination with any of the present inventions (1) to (12). [Explanation of symbols]

[0204] 2 tires 4 Tread 6 Sidewall 8 Wing 10 Clinch 12 beads 14 Carcass 16 Belt Layer 18 bands 20 Inner liner 22 Chafer 24 Tread surface 26 Groove 32 bead core 34 Bead Apex 36 Carcass ply 36a Main part 36b Folded part 38 Inner layer 40 outer layer 42 Main groove 44 Ribs CL Tire equatorial plane T tread thickness D: Main groove depth of the circumferential main groove formed on the tread

Claims

1. A tire including a tire component made of a rubber composition including a rubber component, magnetic particles, and a sugar, A tire characterized in that the product (Ash × AE × T) of the ash content Ash (mass%) of the rubber composition, the acetone extractable amount AE (mass%) of the rubber composition, and the thickness T (mm) of the tire component exceeds 400.

2. 2. The tire of claim 1, wherein Ash x AEX x T is greater than 800.

3. 2. The tire of claim 1, wherein Ash x AEX x T is greater than 1,000.

4. The tire according to claim 1 or 2, wherein the rubber composition contains 40 parts by mass or more of silica per 100 parts by mass of the rubber component.

5. The tire according to claim 1 or 2, wherein the rubber composition contains a liquid diene-based polymer that is liquid at 25°C.

6. 3. The tire according to claim 1, wherein the product ((Sc / Mc)×T) of the ratio of the sugar content Sc (parts by mass) per 100 parts by mass of the rubber component of the rubber composition to the magnetic particle content Mc (parts by mass) per 100 parts by mass of the rubber component of the rubber composition and the thickness T (mm) of the tire component exceeds 5.

0.

7. The tire according to claim 1 or 2, wherein a ratio (Ash / T) of an ash content Ash (mass %) of the rubber composition to a thickness T (mm) of the tire component is less than 8.

1.

8. The tire according to claim 1 or 2, wherein the rubber component contains at least one rubber selected from the group consisting of butadiene rubber and styrene-butadiene rubber.

9. The tire according to claim 1 or 2, wherein the rubber component comprises butadiene rubber and styrene-butadiene rubber.

10. 3. The tire according to claim 1, wherein the saccharide is a polysaccharide.

11. The tire according to claim 1 or 2, wherein the rubber composition contains 80 parts by mass or less of silica and carbon black in total relative to 100 parts by mass of the rubber component.

12. The tire according to claim 1 or 2, wherein a ratio (AE / T) of an acetone extractable amount AE (mass%) of the rubber composition to a thickness T (mm) of the tire member exceeds 0.

50.

13. The tire according to claim 1 or 2, which is a tire for an electric vehicle.

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