tire

Abstract

We provide tires that can improve the durability of the tire's sidewall. [Solution] The present invention is a tire having a sidewall and / or clinch, Butyl rubber, a cyclic amine having a double bond in the ring, and 24M4 dibutyl phthalate with an oil absorption capacity of 170 cm³ (24M4 DBP oil absorption capacity). 3 A rubber composition containing 100g or more of carbon black is used in the sidewall and / or clinch. Furthermore, this relates to a tire having bead reinforcement rubber.

Description

[Technical Field]

[0001] This invention relates to tires. [Background technology]

[0002] It is known that by providing bead reinforcing rubber, excessive outward tilting of the folded portion in the tire axial direction is suppressed, thereby providing excellent durability (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-163942 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] As a result of diligent research by the inventors, it was found that because electric vehicles carry a greater load than conventional automobiles, when using tires for electric vehicles, better durability, particularly better durability of the tire's sidewall, is required. The present invention aims to solve the aforementioned problems and provide a tire that can improve the durability of the tire's sidewall. [Means for solving the problem]

[0005] The present invention relates to a tire having a sidewall and / or clinch, comprising a butyl rubber, a cyclic amine having a double bond in the ring, and 24M4 dibutylphthalate with an oil absorption capacity (24M4DBP oil absorption capacity) of 170 cm². 3 The present invention relates to a tire having a rubber composition containing 100g or more of carbon black used in the sidewall and / or clinch, and further having bead reinforcement rubber. [Effects of the Invention]

[0006] The present invention relates to a tire having a sidewall and / or clinch, comprising a butyl rubber, a cyclic amine having a double bond in the ring, and 24M4 dibutylphthalate with an oil absorption capacity (24M4DBP oil absorption capacity) of 170 cm². 3 The tire has a rubber composition containing 100g or more of carbon black used in the sidewall and / or clinch, and furthermore, it has bead-reinforced rubber, resulting in good durability of the tire's sidewall. [Brief explanation of the drawing]

[0007] [Figure 1] This is a meridian cross-sectional view of a pneumatic tire according to one embodiment of the present invention. [Figure 2] This is an enlarged view of the sidewall and bead sections of Figure 1. [Modes for carrying out the invention]

[0008] The tire of this disclosure is a tire having a sidewall and / or clinch, comprising a butyl rubber, a cyclic amine having a double bond in the ring, and 24M4 dibutyl phthalate with an oil absorption capacity (24M4DBP oil absorption capacity) of 170 cm 3 The tire has a rubber composition containing 100g or more of carbon black used in the sidewall and / or clinch, and further has bead reinforcement rubber.

[0009] The reason why the aforementioned effect is obtained with the aforementioned tires is presumed to be as follows. By using cyclic amines with double bonds in the ring, along with butyl rubber, it is possible to create materials with ionic crosslinking, and by utilizing their reversibility, fatigue fracture resistance, including resistance to flexural crack growth, can be improved. On the other hand, this material also has the characteristic that its fatigue fracture resistance deteriorates as its hardness increases. This is a problem when applying it to electric vehicle tires, where heavy loads are immense and increased rigidity of each component is required, making it a challenge to improve the balance between rigidity and fatigue fracture resistance. In addition to butyl rubber and cyclic amines having double bonds in the ring, this disclosure also includes a 24M4DBP oil absorption capacity of 170 cm³. 3 By using carbon black of high structure (100g or more), a new, strong, reversible bond can be formed between the π electrons on the carbon black surface and the cations of cyclic amines having double bonds in the ring, thereby enabling the creation of rubber with improved hardness while maintaining fatigue fracture resistance. This material is applied to the sidewall and / or clinch to improve the rigidity and fatigue fracture resistance of the sidewall and / or clinch area. For the outer parts near the bead (tire surface area) that cannot be covered by the sidewall and / or clinch, rigidity is further ensured by introducing bead reinforcing rubber. This improves the durability of the tire's sidewall, making it suitable for use as a tire for electric vehicles.

[0010] The rubber composition contains rubber components. Here, the rubber component is a component that contributes to crosslinking, and generally, it is a polymer with a weight-average molecular weight (Mw) of 10,000 or more that is not extracted by acetone. The rubber component is in a solid state at room temperature (25°C).

[0011] The weight-average molecular weight of the rubber component is preferably 50,000 or more, more preferably 150,000 or more, even more preferably 250,000 or more, and also preferably 2,000,000 or less, more preferably 1,500,000 or less, and even more preferably 1,000,000 or less. Within this range, a better effect tends to be obtained.

[0012] In this specification, the weight-average molecular weight (Mw) can be determined by converting the measured values ​​obtained by gel permeation chromatography (GPC) (GPC-8000 series manufactured by Tosoh Corporation, detector: differential refractometer, column: TSKGEL SUPERMULTIPORE HZ-M manufactured by Tosoh Corporation) to standard polystyrene equivalents.

[0013] The aforementioned rubber composition contains butyl rubber as a rubber component. Examples of butyl rubbers include butyl rubber, chlorinated butyl rubber (Cl-IIR), brominated butyl rubber (Br-IIR), and fluorinated butyl rubber (F-IIR), which are all halogenated butyl rubbers. Commercially available butyl rubbers include Exprobutyl and chlorobutyl HT1068 from ExxonMobil. These may be used individually or in combination of two or more types. Among these, halogenated butyl rubber is preferred, and brominated butyl rubber is more preferred, because it provides better durability to the tire sidewalls.

[0014] Butyl rubber may be oil-stretched rubber, resin-stretched rubber, or other plasticizer-stretched rubber. These may be used individually or in combination of two or more types. The plasticizer content in these stretchable rubbers is not particularly limited, but is usually around 5 to 50 parts by mass per 100 parts by mass of rubber solids. The oil used in oil-stretchable rubbers and the resin used in resin-stretchable rubbers are the same as those described later. Other plasticizers include liquid polymers, which will be described later.

[0015] Butyl rubber may have functional groups that interact with fillers such as silica introduced through modification. Examples of the functional groups include silicon-containing groups (-SiR3 (where R is the same or different and can be hydrogen, a hydroxyl group, a hydrocarbon group, an alkoxy group, etc.), amino groups, amide groups, isocyanate groups, imino groups, imidazole groups, urea groups, ether groups, carbonyl groups, oxycarbonyl groups, mercapto groups, sulfide groups, disulfide groups, sulfonyl groups, sulfinyl groups, thiocarbonyl groups, ammonium groups, imide groups, hydrazo groups, azo groups, diazo groups, carboxyl groups, nitrile groups, pyridyl groups, alkoxy groups, hydroxyl groups, oxy groups, epoxy groups, etc. These functional groups may have substituents. Among these, silicon-containing groups are preferred, and -SiR3 (where R is the same or different and can be hydrogen, a hydroxyl group, a hydrocarbon group (preferably a hydrocarbon group having 1 to 6 carbon atoms (more preferably an alkyl group having 1 to 6 carbon atoms)) or an alkoxy group (preferably an alkoxy group having 1 to 6 carbon atoms)), with at least one of R being a hydroxyl group) is more preferred.

[0016] Specific examples of compounds (modifiers) that introduce the aforementioned functional groups include 2-dimethylaminoethyltrimethoxysilane, 3-dimethylaminopropyltrimethoxysilane, 2-dimethylaminoethyltriethoxysilane, 3-dimethylaminopropyltriethoxysilane, 2-diethylaminoethyltrimethoxysilane, 3-diethylaminopropyltrimethoxysilane, 2-diethylaminoethyltriethoxysilane, and 3-diethylaminopropyltriethoxysilane.

[0017] In the rubber composition, the content of butyl rubber in 100% by mass of the rubber component is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and particularly preferably 20% by mass or more. The upper limit is preferably 80% by mass or less, more preferably 60% by mass or less, and even more preferably 40% by mass or less. When the content is within the above range, the effect tends to be better obtained.

[0018] The rubber composition may contain other rubber components besides butyl rubber. Examples of other rubbers include isoprene rubber, butadiene rubber (BR), styrene-butadiene rubber (SBR), styrene-isoprene-butadiene rubber (SIBR), ethylene-propylene-diene rubber (EPDM), chloroprene rubber (CR), acrylonitrile-butadiene rubber (NBR), and other diene rubbers. Fluororubber is also an example. These may be used individually or in combination of two or more. In particular, from the viewpoint of obtaining better effects, it is preferable to include isoprene rubber and / or BR, and more preferably to include isoprene rubber and butadiene rubber.

[0019] Examples of isoprene-based rubbers include natural rubber (NR), isoprene rubber (IR), modified NR, modified NR, and modified IR. For NR, common types used in the rubber industry can be used, such as SIR20, RSS#3, and TSR20. For IR, there are no particular limitations; common types used in the rubber industry can be used, such as IR2200. Examples of modified NR include deproteinized natural rubber (DPNR) and high-purity natural rubber (UPNR). Examples of modified NR include epoxidized natural rubber (ENR), hydrogenated natural rubber (HNR), and grafted natural rubber. Examples of modified IR include epoxidized isoprene rubber, hydrogenated isoprene rubber, and grafted isoprene rubber. These may be used individually or in combination of two or more types.

[0020] Isoprene-based rubber may be oil-stretched rubber, resin-stretched rubber, or other plasticizer-stretched rubber. These may be used individually or in combination of two or more types. The plasticizer content in these stretchable rubbers is not particularly limited, but is usually around 5 to 50 parts by mass per 100 parts by mass of rubber solids. The oil used in oil-stretchable rubbers and the resin used in resin-stretchable rubbers are the same as those described later. Other plasticizers include liquid polymers, which will be described later.

[0021] Isoprene-based rubber may have functional groups that interact with fillers such as silica introduced through modification. Examples of the functional groups include silicon-containing groups (-SiR3 (where R is the same or different and can be hydrogen, a hydroxyl group, a hydrocarbon group, an alkoxy group, etc.), amino groups, amide groups, isocyanate groups, imino groups, imidazole groups, urea groups, ether groups, carbonyl groups, oxycarbonyl groups, mercapto groups, sulfide groups, disulfide groups, sulfonyl groups, sulfinyl groups, thiocarbonyl groups, ammonium groups, imide groups, hydrazo groups, azo groups, diazo groups, carboxyl groups, nitrile groups, pyridyl groups, alkoxy groups, hydroxyl groups, oxy groups, epoxy groups, etc. These functional groups may have substituents. Among these, silicon-containing groups are preferred, and -SiR3 (where R is the same or different and can be hydrogen, a hydroxyl group, a hydrocarbon group (preferably a hydrocarbon group having 1 to 6 carbon atoms (more preferably an alkyl group having 1 to 6 carbon atoms)) or an alkoxy group (preferably an alkoxy group having 1 to 6 carbon atoms)), with at least one of R being a hydroxyl group) is more preferred.

[0022] Specific examples of compounds (modifiers) that introduce the aforementioned functional groups include 2-dimethylaminoethyltrimethoxysilane, 3-dimethylaminopropyltrimethoxysilane, 2-dimethylaminoethyltriethoxysilane, 3-dimethylaminopropyltriethoxysilane, 2-diethylaminoethyltrimethoxysilane, 3-diethylaminopropyltrimethoxysilane, 2-diethylaminoethyltriethoxysilane, and 3-diethylaminopropyltriethoxysilane.

[0023] When the rubber composition contains isoprene-based rubber, the content of isoprene-based rubber in 100% by mass of the rubber component in the rubber composition is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and particularly preferably 20% by mass or more. The upper limit is preferably 80% by mass or less, more preferably 60% by mass or less, and even more preferably 40% by mass or less. When the content is within the above range, the effect tends to be better obtained.

[0024] The BR is not particularly limited, and can be any BR that is common in the tire industry, such as BR1220 from Nippon Zeon Co., Ltd., BR150B from Ube Industries, Ltd., BR1280 from LG Chem, BR containing 1,2-syndiotactic polybutadiene crystals (SPB) such as VCR412 and VCR617 from Ube Industries, Ltd., or butadiene rubber synthesized using a rare earth element catalyst (rare earth BR). These may be used individually or in combination of two or more. In particular, it is preferable that the BR 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.

[0025] The cis amount of BR mentioned above refers to the cis amount of a single type of BR if there is only one type, and to the average cis amount if there are multiple types. The average cis content of BR can be calculated using the formula {Σ(content of each BR × cis content of each BR)} / total BR content. For example, if 20% of BR has a cis content of 90% and 10% has a cis content of 40% out of 100% of rubber components, the average cis content of BR is 73.3% (=(20 × 90 + 10 × 40) / (20 + 10)).

[0026] While known rare earth element catalysts can be used for the synthesis of rare earth BRs, lanthanum series rare earth element compounds are preferred, and neodymium-containing compounds (Nd-based catalysts) are more preferred.

[0027] BR may be oil-stretched rubber, resin-stretched rubber, or other plasticizer-stretched rubber. These may be used individually or in combination of two or more types. The plasticizer content in these stretchable rubbers is not particularly limited, but is usually around 5 to 50 parts by mass per 100 parts by mass of rubber solids. The oil used in oil-stretchable rubbers and the resin used in resin-stretchable rubbers are the same as those described later. Other plasticizers include liquid polymers, which will be described later.

[0028] BR may have functional groups that interact with packing materials such as silica introduced through modification. Examples of the functional groups include silicon-containing groups (-SiR3 (where R is the same or different and can be hydrogen, a hydroxyl group, a hydrocarbon group, an alkoxy group, etc.), amino groups, amide groups, isocyanate groups, imino groups, imidazole groups, urea groups, ether groups, carbonyl groups, oxycarbonyl groups, mercapto groups, sulfide groups, disulfide groups, sulfonyl groups, sulfinyl groups, thiocarbonyl groups, ammonium groups, imide groups, hydrazo groups, azo groups, diazo groups, carboxyl groups, nitrile groups, pyridyl groups, alkoxy groups, hydroxyl groups, oxy groups, epoxy groups, etc. These functional groups may have substituents. Among these, silicon-containing groups are preferred, and -SiR3 (where R is the same or different and can be hydrogen, a hydroxyl group, a hydrocarbon group (preferably a hydrocarbon group having 1 to 6 carbon atoms (more preferably an alkyl group having 1 to 6 carbon atoms)) or an alkoxy group (preferably an alkoxy group having 1 to 6 carbon atoms)), with at least one of R being a hydroxyl group) is more preferred.

[0029] Specific examples of compounds (modifiers) that introduce the aforementioned functional groups include 2-dimethylaminoethyltrimethoxysilane, 3-dimethylaminopropyltrimethoxysilane, 2-dimethylaminoethyltriethoxysilane, 3-dimethylaminopropyltriethoxysilane, 2-diethylaminoethyltrimethoxysilane, 3-diethylaminopropyltrimethoxysilane, 2-diethylaminoethyltriethoxysilane, and 3-diethylaminopropyltriethoxysilane.

[0030] For BR, hydrogenated BR, which has hydrogen added to it, can also be used. When BR is hydrogenated BR, there are no particular limitations on the hydrogenation method or reaction conditions; hydrogenation can be carried out using known methods and conditions. Typically, this is done at 20-150°C, under a hydrogen pressure of 0.1-10 MPa, and in the presence of a hydrogenation catalyst. Other manufacturing methods and conditions are also not particularly limited; for example, the contents described in International Publication No. 2016 / 039005 can be applied. Furthermore, hydrogenated BR has the same structure as a copolymer of ethylene and butadiene as a result of hydrogen being added to the butadiene portion of BR. Therefore, in this specification, hydrogenated BR includes not only hydrogenated BR but also copolymers of ethylene and butadiene.

[0031] The hydrogenation rate of hydrogenated BR is preferably 65 mol% or more, more preferably 70 mol% or more, even more preferably 80 mol% or more, with the total butadiene units before hydrogenation being 100 mol%, and also preferably 95 mol% or less, more preferably 92 mol% or less, and even more preferably 90 mol% or less. When the rate is within the above range, a better effect tends to be obtained. The hydrogenation rate is 1 It can be calculated from the spectral reduction rate of the unsaturated bond region of the spectrum obtained by measuring 1H-NMR.

[0032] 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 10% by mass or more, even more preferably 20% by mass or more, and particularly preferably 30% by mass or more. The upper limit is preferably 80% by mass or less, more preferably 60% by mass or less, and even more preferably 50% by mass or less. Within this range, the effect tends to be better obtained.

[0033] The SBR is not particularly limited; for example, emulsion-polymerized styrene-butadiene rubber (E-SBR), solution-polymerized styrene-butadiene rubber (S-SBR), etc., can be used. These may be used individually or in combination of two or more types.

[0034] The styrene content of SBR is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and particularly preferably 20% by mass or more. The styrene content 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, the effect tends to be better obtained. In this specification, the styrene content of SBR is as follows: 1It is calculated by 1H-NMR measurement.

[0035] The vinyl content of SBR is preferably 10 mol% or more, more preferably 20 mol% or more, and even more preferably 30 mol% or more. The vinyl content is preferably 90 mol% or less, more preferably 80 mol% or less, and even more preferably 70 mol% or less. When the content is within the above range, a better effect tends to be obtained. In this specification, the vinyl content (amount of 1,2-bonded butadiene units) of SBR can be measured by infrared absorption spectroscopy.

[0036] The styrene content of SBR mentioned above refers to the styrene content of a single type of SBR if that type is used, and to the average styrene content if there are multiple types of SBR. The average styrene content of SBR can be calculated using the formula {Σ(content of each SBR × styrene content of each SBR)} / total content of all SBR. For example, if 85% of the rubber component is SBR with a styrene content of 40% by mass and 5% is SBR with a styrene content of 25% by mass, the average styrene content of the SBR is 39.2% by mass (=(85 × 40 + 5 × 25) / (85 + 5)).

[0037] Furthermore, the vinyl content of SBR mentioned above is the ratio of vinyl bonds when the total mass of the butadiene portion in the SBR is set to 100 (unit: mass%), and is calculated as: vinyl content [mass%] + cis content [mass%] + trans content [mass%] = 100 [mass%]. If there is only one type of SBR, it refers to the vinyl content of that SBR; if there are multiple types, it refers to the average vinyl content. The average vinyl content of SBR can be calculated using the formula: 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, if 100 parts by mass of rubber component, 75 parts by mass of SBR contain 40% styrene and 30% vinyl, and 25% styrene, If 15 parts by mass of SBR have a vinyl content of 20% by mass, and the remaining 10 parts by mass are other than SBR, the average vinyl content of SBR is 28% by mass (= {75 × (100 [mass%] - 40 [mass%]) × 30 [mass%] + 15 × (100 [mass%] - 25 [mass%]) × 20 [mass%])} / {75 × (100 [mass%] - 40 [mass%]) + 15 × (100 [mass%] - 25 [mass%])}.

[0038] The glass transition temperature (Tg) of SBR is preferably -20°C or lower, more preferably -40°C or lower, and more preferably -80°C or higher, more preferably -60°C or higher. Within this range, the effect tends to be better. The glass transition temperature of SBR was measured in accordance with JIS-K7121:2012 using a differential scanning calorimeter (Q200) manufactured by T.A. Instruments Japan, under a heating rate of 10°C / min.

[0039] Hydrogenated SBRs, which have hydrogen added to them, can also be used as SBRs. When SBR is hydrogenated SBR, there are no particular limitations on the hydrogenation method or reaction conditions; hydrogenation can be carried out using known methods and conditions. Typically, this is done at 20-150°C, under a hydrogen pressure of 0.1-10 MPa, and in the presence of a hydrogenation catalyst. Other manufacturing methods and conditions are also not particularly limited; for example, the contents described in International Publication No. 2016 / 039005 can be applied. Furthermore, hydrogenated SBR has the same structure as a copolymer of ethylene, butadiene, and styrene as a result of hydrogen being added to the butadiene portion of SBR. Therefore, in this specification, hydrogenated SBR includes not only hydrogenated butadiene-styrene copolymers (SBR) but also copolymers of ethylene, butadiene, and styrene.

[0040] The hydrogenation rate of hydrogenated SBR is preferably 65 mol% or more, more preferably 70 mol% or more, and even more preferably 75 mol% or more, with the total butadiene units before hydrogenation being 100 mol%, and also preferably 99 mol% or less, more preferably 97 mol% or less, and even more preferably 95 mol% or less. When the rate is within the above range, a better effect tends to be obtained. The hydrogenation rate is 1 It can be calculated from the spectral reduction rate of the unsaturated bond region of the spectrum obtained by measuring 1H-NMR.

[0041] SBR may be oil-stretched rubber, resin-stretched rubber, or other plasticizer-stretched rubber. These may be used individually or in combination of two or more types. The plasticizer content in these stretchable rubbers is not particularly limited, but is usually around 5 to 50 parts by mass per 100 parts by mass of rubber solids. The oil used in oil-stretchable rubbers and the resin used in resin-stretchable rubbers are the same as those described later. Other plasticizers include liquid polymers, which will be described later.

[0042] SBR may have functional groups that interact with fillers such as silica introduced through modification. Examples of the functional groups include silicon-containing groups (-SiR3 (where R is the same or different and can be hydrogen, a hydroxyl group, a hydrocarbon group, an alkoxy group, etc.), amino groups, amide groups, isocyanate groups, imino groups, imidazole groups, urea groups, ether groups, carbonyl groups, oxycarbonyl groups, mercapto groups, sulfide groups, disulfide groups, sulfonyl groups, sulfinyl groups, thiocarbonyl groups, ammonium groups, imide groups, hydrazo groups, azo groups, diazo groups, carboxyl groups, nitrile groups, pyridyl groups, alkoxy groups, hydroxyl groups, oxy groups, epoxy groups, etc. These functional groups may have substituents. Among these, silicon-containing groups are preferred, and -SiR3 (where R is the same or different and can be hydrogen, a hydroxyl group, a hydrocarbon group (preferably a hydrocarbon group having 1 to 6 carbon atoms (more preferably an alkyl group having 1 to 6 carbon atoms)) or an alkoxy group (preferably an alkoxy group having 1 to 6 carbon atoms)), with at least one of R being a hydroxyl group) is more preferred.

[0043] Specific examples of compounds (modifiers) that introduce the aforementioned functional groups include 2-dimethylaminoethyltrimethoxysilane, 3-dimethylaminopropyltrimethoxysilane, 2-dimethylaminoethyltriethoxysilane, 3-dimethylaminopropyltriethoxysilane, 2-diethylaminoethyltrimethoxysilane, 3-diethylaminopropyltrimethoxysilane, 2-diethylaminoethyltriethoxysilane, and 3-diethylaminopropyltriethoxysilane.

[0044] For example, SBR manufactured and sold by companies such as Sumitomo Chemical Co., Ltd., JSR Corporation, Asahi Kasei Corporation, and Nippon Zeon Co., Ltd. can be used.

[0045] When the rubber composition contains SBR, the SBR content in 100% by mass of the rubber component is preferably 3% by mass or more, more preferably 5% by mass or more, and even more preferably 7% by mass or more. The upper limit is preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 15% by mass or less, and particularly preferably 10% by mass or less.

[0046] Rubber components other than butyl rubber, isoprene rubber, BR, and SBR may be oil-stretched rubber, resin-stretched rubber, or other plasticizer-stretched rubber. These may be used individually or in combination of two or more. The plasticizer content in these stretchable rubbers is not particularly limited, but is usually around 5 to 50 parts by mass per 100 parts by mass of rubber solids. The oil used in oil-stretchable rubbers and the resin used in resin-stretchable rubbers are the same as those described later. Other plasticizers include liquid polymers, which will be described later.

[0047] Rubber components other than butyl rubber, isoprene rubber, BR, and SBR may have functional groups that interact with fillers such as silica introduced through modification. Examples of the functional groups include silicon-containing groups (-SiR3 (where R is the same or different and can be hydrogen, a hydroxyl group, a hydrocarbon group, an alkoxy group, etc.), amino groups, amide groups, isocyanate groups, imino groups, imidazole groups, urea groups, ether groups, carbonyl groups, oxycarbonyl groups, mercapto groups, sulfide groups, disulfide groups, sulfonyl groups, sulfinyl groups, thiocarbonyl groups, ammonium groups, imide groups, hydrazo groups, azo groups, diazo groups, carboxyl groups, nitrile groups, pyridyl groups, alkoxy groups, hydroxyl groups, oxy groups, epoxy groups, etc. These functional groups may have substituents. Among these, silicon-containing groups are preferred, and -SiR3 (where R is the same or different and can be hydrogen, a hydroxyl group, a hydrocarbon group (preferably a hydrocarbon group having 1 to 6 carbon atoms (more preferably an alkyl group having 1 to 6 carbon atoms)) or an alkoxy group (preferably an alkoxy group having 1 to 6 carbon atoms)), with at least one of R being a hydroxyl group) is more preferred.

[0048] Specific examples of compounds (modifiers) that introduce the aforementioned functional groups include 2-dimethylaminoethyltrimethoxysilane, 3-dimethylaminopropyltrimethoxysilane, 2-dimethylaminoethyltriethoxysilane, 3-dimethylaminopropyltriethoxysilane, 2-diethylaminoethyltrimethoxysilane, 3-diethylaminopropyltrimethoxysilane, 2-diethylaminoethyltriethoxysilane, and 3-diethylaminopropyltriethoxysilane.

[0049] 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 they may be recycled from rubber products such as tires or non-rubber products such as polystyrene. The monomers obtained by recycling (recycled monomers) are not particularly limited, but examples include recycled polyisoprene, recycled butadiene, and recycled aromatic vinyl. Examples of butadiene include 1,2-butadiene and 1,3-butadiene. Examples of aromatic vinyl include styrene, but are not particularly limited. In particular, it is preferable to use recycled polyisoprene (recycled isoprene), recycled butadiene (recycled butadiene), and / or recycled styrene (recycled styrene) as raw materials.

[0050] The method for producing recycled monomer is not particularly limited, and for example, it can be synthesized from recycled naphtha obtained by decomposing rubber products such as tires. Furthermore, the method for producing recycled naphtha is not particularly limited, and for example, rubber products such as tires may be decomposed under high temperature and pressure, decomposed by microwaves, or extracted after mechanical grinding.

[0051] 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 substances derived from natural resources such as plants. Biomass is not particularly limited, but examples include agricultural, forestry, and fishery products, sugars, wood chips, plant residues after obtaining useful components, plant-derived ethanol, and biomass naphtha.

[0052] The biomass-derived monomer (biomass monomer) is not particularly limited and includes biomass-derived butadiene and biomass-derived aromatic vinyl. The butadiene is 1,2-butadiene and 1,3-butadiene. The aromatic vinyl is not particularly limited and includes styrene. Furthermore, the method for producing the biomass monomer is not particularly limited and includes, for example, biological and / or chemical and / or physical conversion of plants and animals. A typical biological conversion is fermentation by microorganisms, while chemical and / or physical conversions include those by catalysts, high heat, high pressure, electromagnetic waves, critical liquids, and combinations thereof.

[0053] The polymer synthesized from biomass monomer components (biomass polymer) is not particularly limited, and examples include polybutadiene rubber synthesized from biomass-derived butadiene, and aromatic vinyl / butadiene copolymers 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.

[0054] Whether the raw materials for a polymer are biomass-derived can be determined by measuring pMC (percent Modern Carbon) in accordance with ASTMD6866-10.

[0055] pMC stands for Modern Standard Reference Carbon. 14 Sample relative to C concentration14 It is the ratio of C concentration and is a value used as an index indicating the biomass ratio of a compound. The significance of this value is described below. In 1 mole (6.02×10 23 atoms) of carbon atoms, there are approximately 6.02×10 11 atoms of 14 C, which is about one trillionth of ordinary carbon atoms. 14 C is called a radioactive isotope, and its half-life is 5730 years and it decreases regularly. It takes 226,000 years for all of these to decay. Therefore, after carbon dioxide in the atmosphere, etc. is taken up and fixed by plants, etc., in fossil fuels such as coal, oil, and natural gas, where it is considered that more than 226,000 years have passed, all of the 14 C element that was also contained in them at the time of fixation has decayed. Therefore, at present in the 21st century, fossil fuels such as coal, oil, and natural gas do not contain any 14 C element. Therefore, chemical substances produced from these fossil fuels also do not contain any 14 C element.

[0056] On the other hand, 14 C is constantly generated by nuclear reactions of cosmic rays in the atmosphere, and the decrease due to radioactive decay is balanced. In the atmospheric environment of the earth, the amount of 14 C is constant. Therefore, the 14 C concentration of substances derived from biomass resources that are circulating in the current environment is about 1×10 -12 mol% with respect to the entire C atoms as described above. Therefore, the biomass ratio of a certain compound can be calculated using the difference between these values.

[0057] This 14 C is generally measured as follows. Using accelerator mass spectrometry based on a tandem accelerator, 13 the C concentration ( 13 C / 12 C), 14 the C concentration ( 14 C / 12 C) is measured. In the measurement, 14As a modern standard reference for the concentration of C, the amount of cyclic carbon in nature as of 1950 14 The C concentration will be used. The specific standard material will be the oxalic acid standard provided by NIST (National Institute of Standards and Technology). The specific radioactivity of carbon in this oxalic acid (per gram of carbon) will be used. 14 The radioactivity intensity of C is separated by carbon isotope, 13 The standard value is obtained by correcting C to a constant value and applying decay correction from 1950 AD to the measurement date. 14 This value is used as the C concentration value (100%). The ratio of this value to the value of the sample actually measured is the pMC value.

[0058] Therefore, if the rubber is made from 100% biomass-derived materials, although there are regional differences, under normal conditions it will often not reach 100, and will show a value of approximately 110 pMC. On the other hand, regarding chemical substances derived from fossil fuels such as petroleum, 14 When the C concentration is measured, it will show a value of approximately 0 pMC (for example, 0.3 pMC). This value corresponds to a biomass ratio of 0% as mentioned above.

[0059] Based on the above, using materials such as rubber with a high pMC value, that is, materials such as rubber with a high biomass ratio, in rubber compositions is preferable from an environmental protection standpoint.

[0060] (Filler) The aforementioned rubber composition contains 24M4 dibutyl phthalate as a filler, with an oil absorption capacity (24M4DBP oil absorption capacity) of 170 cm². 3 Contains 100g or more of carbon black. This carbon black may be used alone or in combination of two or more types. The oil absorption capacity of the aforementioned carbon black is 170 cm³. 3 / 100g or more, preferably 200cm 3 / 100g or more, preferably 250cm 3 / 100g or more, more preferably 300cm 3 / 100g or more, especially preferably 350cm 3 / 100g or more, most preferably 400cm 3 / 100g or more, more preferably 420cm 3 The amount is 100g or more, and there is no particular upper limit, but preferably 1000cm 3 / 100g or less, more preferably 800cm 3 / 100g or less, more preferably 600cm 3 / 100g or less, particularly preferably 500cm 3 It is less than 100g. Within this range, better effects tend to be obtained. The 24M4DBP oil absorption amount of carbon black is measured according to ASTM D3493-91 (Standard Test Method for Carbon Black-n-Dibuty 1 Phthalate Absorption Number of Compressed Sample).

[0061] 24M4DBP oil absorption is 170cm 3 As for carbon black with a concentration of 100g or more, there are no particular limitations as long as the 24M4DBP oil absorption capacity is 170ml / 100g or more. GPF, FEF, HAF, ISAF, SAF, etc., can be used individually or in combination of two or more types. Commercially available products include those from Orion Engineered Carbons, etc.

[0062] The aforementioned 24M4DBP oil absorption capacity is 170 cm³. 3 The nitrogen adsorption specific surface area (N2SA) of carbon black of 100g or more is preferably 200m². 2 / g or more, comfortably within 300m 2 / g or more, more preferably 400m 2 / g or more, particularly preferably 500m 2 / g or more, most preferably 600m 2 / g or more, more preferably 700m 2 / g or more, and most preferably 800m 2 / g or more, most preferably 900m 2 It is 1500m or more / g, preferably 1500m 2 / g or less, more preferably 1200m 2 / g or less, more preferably 1100m 2 It is less than or equal to / g. When it is within the aforementioned range, a better effect tends to be obtained. Note that the N2SA value of carbon black is measured in accordance with JIS K6217-2:2001.

[0063] The aforementioned 24M4DBP oil absorption capacity is 170 cm³. 3 The amount of dibutyl phthalate (DBP) absorbed by 100g or more of carbon black is preferably 200cm³. 3 / 100g or more, preferably 300cm 3 / 100g or more, more preferably 400cm 3 The amount is 100g or more, and there is no particular upper limit, but preferably 600cm 3 / 100g or less, more preferably 500cm 3 / 100g or less, more preferably 450cm 3 It is less than 100g. Within this range, better effects tend to be obtained. The DBP oil absorption capacity of carbon black is measured in accordance with JIS K6217-4:2001.

[0064] In the aforementioned rubber composition, the oil absorption capacity of 24M4DBP is 170 cm 3 The carbon black content of 100g or more is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, and even more preferably 8 parts by mass or more, per 100 parts by mass of rubber component. The upper limit of the content is preferably less than 40 parts by mass, more preferably 30 parts by mass or less, and even more preferably 20 parts by mass or less. When the content is within the above range, the effect tends to be better obtained.

[0065] The aforementioned rubber composition contains 24M4 dibutyl phthalate as a filler, with an oil absorption capacity (24M4DBP oil absorption capacity) of 170 cm². 3 / Carbon black other than 100g (24M4DBP oil absorption capacity is 170cm) 3 It may contain less than 100g of carbon black. While not particularly limited, usable carbon blacks include N134, N110, N220, N234, N219, N339, N330, N326, N351, N550, and N762. The raw materials for carbon black may be biomass materials such as lignin and vegetable oil, or pyrolysis oil obtained by thermal decomposition of waste tires. The manufacturing method for carbon black may be combustion, such as the furnace method, hydrothermal carbonization (HTC), or thermal decomposition of methane by the thermal black method. Commercially available products include those from Asahi Carbon Co., Ltd., Cabot Japan Co., Ltd., Tokai Carbon Co., Ltd., Mitsubishi Chemical Corporation, Lion Corporation, Shin-Nippon Chemical Carbon Co., Ltd., and Columbia Carbon Corporation. These may be used individually or in combination of two or more types.

[0066] In the aforementioned rubber composition, the amount of 24M4DBP oil absorbed in 100% by mass of the total carbon black content is 170 cm³. 3 The carbon black content per 100g or more is preferably 60% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, particularly preferably 95% by mass or more, and may also be 100% by mass.

[0067] Other fillers that can be used besides carbon black are not particularly limited and materials known in the rubber field can be used, such as inorganic fillers such as silica, layered silicate minerals, calcium carbonate, talc, alumina, clay, aluminum hydroxide, aluminum oxide, and mica; biochar; and poorly dispersible fillers. These may be used individually or in combination of two or more.

[0068] The silica used is not particularly limited, and common types used in the tire industry can be used, such as silica prepared by a dry process (anhydrous silica) or silica prepared by a wet process (hydrated silica). The raw material for silica is not particularly limited, and may be a mineral-derived raw material such as quartz, or a biological-derived raw material such as rice husks (for example, silica made from biomass materials such as rice husks), or silica recycled from silica-containing products may be used. Among these, hydrated silica prepared by a wet process is preferred because it contains a large number of silanol groups. These silicas may be used individually or in combination of two or more types. Commercially available products from companies such as Evonik, Tosoh Silica Co., Ltd., Solvay Japan Ltd., and Tokuyama Corporation can be used.

[0069] Silica derived from biomass materials can be obtained, for example, by extracting silicates from rice husk ash obtained by burning rice husks using a sodium hydroxide solution, and then using these silicates to react with sulfuric acid in the same way as conventional wet silica, the precipitate of silicon dioxide is filtered, washed with water, dried, and pulverized.

[0070] The silica recycled from silica-containing products can be, for example, silica recovered from products containing silica such as semiconductors and other electronic components, tires, desiccants, and diatomaceous earth and other filter materials. The recovery method is not particularly limited and can include thermal decomposition and decomposition by electromagnetic waves. Among these, silica recovered from semiconductors and other electronic components or tires is preferred.

[0071] When silica crystallizes, it becomes insoluble in water, and its component, silicic acid, cannot be utilized. By controlling the combustion temperature and combustion time, the crystallization of silica in rice husk ash can be suppressed (see Japanese Patent Publication No. 2009-2594, Akita Prefectural University Web Journal B / 2019, vol.6, pp.216-222, etc.).

[0072] Amorphous silica extracted from rice husks can be commercially available from companies such as Wilmar.

[0073] The average particle size of silica is preferably 24 nm or less, more preferably 20 nm or less, even more preferably 18 nm or less, preferably 6 nm or more, more preferably 9 nm or more, and even more preferably 12 nm or more. Within this range, a better effect tends to be obtained.

[0074] In this specification, the method for measuring the average particle size of silica is transmission electron microscopy (TEM) observation. Specifically, silica particles are photographed with a transmission electron microscope, and if the particle shape is spherical, the diameter of the sphere is defined as the particle size; if it is needle-shaped or rod-shaped, the shorter axis is defined as the particle size; if it is irregularly shaped, the average particle size from the center is defined as the particle size; and the average particle size of 100 fine particles is defined as the average particle size.

[0075] If the rubber composition contains silica, the silica content is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, and preferably 30 parts by mass or less, and more preferably 20 parts by mass or less, per 100 parts by mass of the rubber component. Within this range, a better effect tends to be obtained.

[0076] Examples of poorly dispersible fillers include microfibrillated plant fibers, short fibrous cellulose, and gel-like compounds. Among these, microfibrillated plant fibers are preferred.

[0077] As the microfibrillated plant fiber, cellulose microfibrils are preferred in that they provide good reinforcing properties. The cellulose microfibrils are not particularly limited as long as they are derived from natural products, and examples include resource biomass such as fruits, grains, and root vegetables; wood, bamboo, hemp, jute, and kenaf; pulp, paper, cloth, agricultural residues, food waste, and sewage sludge obtained from these raw materials; unused biomass such as rice straw, wheat straw, and thinned wood; and cellulose produced by sea squirts, acetic acid bacteria, etc. One type of these microfibrillated plant fiber may be used, or two or more types may be used in combination.

[0078] In this specification, cellulose microfibrils typically refer to cellulose fibers having an average fiber diameter of 10 μm or less, and more typically, cellulose fibers having a microstructure with an average fiber diameter of 500 nm or less, formed by an aggregate of cellulose molecules. Typical cellulose microfibrils are formed, for example, as aggregates of cellulose fibers having the average fiber diameter described above.

[0079] If the rubber composition contains a poorly dispersible filler, the content of the poorly 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 less than 40 parts by mass, 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. When the content is within the above range, the effect tends to be better obtained.

[0080] The rubber composition has a total filler content of preferably 3 parts by mass or more, more preferably 5 parts by mass or more, and even more preferably 8 parts by mass or more, per 100 parts by mass of the rubber component. The upper limit of the content is preferably less than 40 parts by mass, more preferably 30 parts by mass or less, and even more preferably 20 parts by mass or less. When the content is within the above range, a better effect tends to be obtained.

[0081] When the total filler content is below a predetermined level, particularly below 40 parts by mass, the mechanism by which this effect is obtained is not clear. However, it is thought that a lower total filler content is less likely to inhibit the self-healing properties of the rubber composition after vulcanization, resulting in higher self-healing properties. Therefore, it is thought that the overall performance of hardness and crack growth resistance is further improved, and the durability of the tire sidewall is further enhanced.

[0082] In the aforementioned rubber composition, the amount of 24M4DBP oil absorbed in 100% by mass of the total filler content is 170 cm³. 3The carbon black content per 100g or more is preferably 60% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, particularly preferably 95% by mass or more, and may also be 100% by mass.

[0083] (Other combination drugs) The rubber composition contains a cyclic amine having a double bond in the ring. The cyclic amine having a double bond in the ring may be used alone or in combination of two or more types. In this specification, a cyclic amine having a double bond in the ring means a compound having at least one double bond in the ring structure of a cyclic amine.

[0084] In the rubber composition, the content of cyclic amines having a double bond in the ring (total amount of cyclic amines having a double bond in the ring) is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, even more preferably 0.5 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, and also preferably 15.0 parts by mass or less, more preferably 10.0 parts by mass or less, and even more preferably 6.0 parts by mass or less. When the content is within the above range, the effect tends to be better obtained.

[0085] The cyclic amine having a double bond within the ring is not particularly limited as long as it achieves the aforementioned effects. For example, the ring can be a 3-membered, 4-membered, 5-membered, or 6-membered ring, and among these, a 5-membered or 6-membered ring is preferred from the viewpoint of obtaining better effects. A 5-membered ring is more preferable. It may also have heteroatoms other than nitrogen atoms.

[0086] Among the cyclic amines having a double bond in the ring, imidazole compounds and pyridine compounds can be suitably used, with imidazole compounds being particularly preferred.

[0087] The imidazole compound is a compound having an imidazole ring, and among these, the compound represented by the following formula (I) is preferred.

[0088] [Chemical formula]

[0089] In the above formula (I), R 1 , R 2 , R 3 , R 4 represents, independently of each other, a hydrogen atom or a hydrocarbon group. R 3 , R 4 may combine with each other to form a ring structure.

[0090] R 1 , R 2 , R 3 , R 4 Examples of the hydrocarbon group of R

[0091] include, for example, an alkyl group having 1 to 20 carbon atoms (preferably 2 to 12 carbon atoms, more preferably 4 to 9 carbon atoms), a cycloalkyl group having 5 to 24 carbon atoms (preferably 5 to 8 carbon atoms), an aryl group having 6 to 30 carbon atoms (preferably 6 to 24 carbon atoms), and an aralkyl group having 7 to 25 carbon atoms (preferably 7 to 13 carbon atoms). 4 , R 5 When R 4 , R 5 combine to form a ring structure, examples of the ring structure formed by R

[0092] with the carbon atoms of the imidazole ring include, for example, an aromatic ring, a heterocyclic ring, and an aliphatic ring having 5 to 12 carbon atoms. 1 , R 2 , R 3 , R 4 From the viewpoint of obtaining better effects, at least one of R 1 , R 2 , R 3 , R 4 is preferably an alkyl group, and more preferably, one of R 1 is an alkyl group and the other three are hydrogen atoms, and even more preferably, R 2 , R 3 , R 4 are hydrogen atoms. In addition, R 1 If the alkyl group has a small number of carbon atoms, the ionic bond between the imidazole compound and the high-structure carbon black becomes stronger, and the hardness tends to increase. If the number of carbon atoms is large, the ionic bond between the imidazole compound and the high-structure carbon black becomes weaker and is more likely to come off, so it tends to be easier to release force during bending.

[0093] Specific examples of the imidazole compound include imidazole, 1-nonylimidazole, 1-butylimidazole, 1-propylimidazole, 1-ethylimidazole, 1-methylimidazole, 1,2-dimethylimidazole, 1-decyl-2-methylimidazole, 1-benzyl-2-methylimidazole, and the like. These may be used alone or in combination of two or more. Among them, 1-nonylimidazole, 1-butylimidazole, 1-propylimidazole, 1-ethylimidazole, and 1-methylimidazole are preferred, 1-nonylimidazole and 1-butylimidazole are more preferred, and 1-nonylimidazole is even more preferred.

[0094] The pyridine compound is a compound having a pyridine ring, and among them, the compound represented by the following formula (II) is preferred.

[0095]

Chemical formula

[0096] In the formula (II), R 11 ~R 15 are the same or different and represent a hydrogen atom or a monovalent organic group. R 11 ~R 15 may be bonded to each other or may form a ring structure.

[0097] In the formula (II), R 11 ~R 15If it is a monovalent organic group, the monovalent organic group may be an aryl group, heterocyclic group, alkyl group, alkenyl group, alkynyl group, alkoxy group, aryloxy group, arylalkoxy group, silyl group, hydroxy group, amino group, halogen atom, carboxyl group, thiol group, epoxy group, acyl group, oligoaryl group, monovalent oligoheterocyclic group, alkylthio group, arylthio group, arylalkyl group, arylalkoxy group, arylalkylthio group, azo group, staniyl group, phosphino group, silyloxy group, aryloxycarb Examples include nyl groups, alkoxycarbonyl groups, carbamoyl groups, arylcarbonyl groups, alkylcarbonyl groups, arylsulfonyl groups, alkylsulfonyl groups, arylsulfinyl groups, alkylsulfinyl groups, formyl groups, cyano groups, nitro groups, arylsulfonyloxy groups, alkylsulfonyloxy groups, alkylsulfonate groups, arylsulfonate groups, arylalkylsulfonate groups, boryl groups, sulfonium methyl groups, phosphonium methyl groups, phosphonate methyl groups, arylsulfonate groups, aldehyde groups, acetonitrile groups, etc. Note that R 11 ~R 15 If the monovalent organic group has substituents, it may have one substituent or two or more substituents.

[0098] The aforementioned R 11 ~R 15When a monovalent organic group has substituents, the substituents include halogen atoms such as fluorine, chlorine, bromine, and iodine; haloalkyl groups such as methyl chloride, methyl bromide, methyl iodide, fluoromethyl, difluoromethyl, and trifluoromethyl; linear or branched alkyl groups having 1 to 20 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, and tert-butyl; cyclic alkyl groups having 5 to 7 carbon atoms such as cyclopentyl, cyclohexyl, and cycloheptyl; methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, tert-butoxy, and pentyl groups. Examples include linear or branched alkoxy groups having 1 to 20 carbon atoms, such as xy group, hexyloxy group, heptyloxy group, and octyloxy group; hydroxyl group; thiol group; nitro group; cyano group; amino group; azo group; acyl group; alkenyl groups having 2 to 20 carbon atoms, such as vinyl group, 1-propenyl group, allyl group, butenyl group, and styryl group; alkynyl groups having 2 to 20 carbon atoms, such as ethynyl group, 1-propynyl group, propargyl group, and phenylacetylyl group; alkenyloxy groups such as vinyloxy group and allyloxy group; alkynyloxy groups such as ethynyloxy group and phenylacetyloxy group; and aryloxy groups such as phenoxy group, naphthoxy group, biphenyloxy group, and pyrenyloxy group. These groups may also be bonded to each other at any point to form a ring.

[0099] Specific examples of the aforementioned pyridine compounds include pyridine, 2-methylpyridine, 3-methylpyridine, 4-methylpyridine, and 4-dimethylaminopyridine. These may be used individually or in combination of two or more. Among these, 2-methylpyridine, 3-methylpyridine, 4-methylpyridine, and 4-dimethylaminopyridine are preferred from the viewpoint of basicity, and 4-dimethylaminopyridine is more preferred. Using a pyridine compound with strong basicity tends to strengthen the ionic bond between the pyridine compound and the high-structure carbon black, thereby increasing the hardness.

[0100] The rubber composition may contain a silane coupling agent. The silane coupling agent is not particularly limited and includes, 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 Examples include sulfide-based compounds such as ropyl-N,N-dimethylthiocarbamoyl tetrasulfide, 2-triethoxysilylethyl-N,N-dimethylthiocarbamoyl tetrasulfide, and 3-triethoxysilylpropyl methacrylate monosulfide; mercapto-based compounds such as 3-mercaptopropyltrimethoxysilane and 2-mercaptoethyltriethoxysilane; 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. Among these, mercapto-based compounds are preferred. Commercially available products include those from companies such as Degussa, Momentive, Shin-Etsu Silicone Co., Ltd., Tokyo Chemical Industry Co., Ltd., Azumax Co., Ltd., and Toray Dow Corning Co., Ltd. These can be used individually or in combination of two or more types.

[0101] In addition to compounds containing a mercapto group, compounds in which the mercapto group is protected by a protecting group (for example, compounds represented by the following formula (S1)) can also be used as mercapto-silane coupling agents.

[0102] Particularly suitable mercapto-silane coupling agents include compounds represented by the following formula (S1), compounds represented by the following formula (1), and silane coupling agents comprising a bonding unit A shown in the following formula (2) and a bonding unit B shown in the following formula (3). [ka] (In the formula, R 1001 -Cl, -Br, -OR 1006 -O(O=)CR 1006 , -ON=CR 1006 R 1007 , -NR 1006 R 1007 and -(OSiR 1006 R 1007 ) h (OSiR 1006 R 1007 R 1008 A monovalent group (R) selected from ) 1006 , R 1007 and R 1008 They may be the same or different, and each is a hydrogen atom or a monovalent hydrocarbon group with 1 to 18 carbon atoms, and the average value of h is 1 to 4. 1002 is R 1001 , hydrogen atom or monovalent hydrocarbon group having 1 to 18 carbon atoms, R 1003 is -[O(R 1009 O) j ]-group(R 1009 is an alkylene group with 1 to 18 carbon atoms, and j is an integer from 1 to 4. ), R 1004 R is a divalent hydrocarbon group having 1 to 18 carbon atoms. 1005 (where represents a monovalent hydrocarbon group with 1 to 18 carbon atoms, and x, y, and z are numbers that satisfy the relationships x + y + 2z = 3, 0 ≤ x ≤ 3, 0 ≤ y ≤ 2, and 0 ≤ z ≤ 1.)

[0103] [ka] In equation (1) above, R 101 , R 102 , and R 103 Each of these is independently an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or -O-(R 111 -O) z -R 112 (z R 111 Each of these is independently a divalent hydrocarbon group having 1 to 30 carbon atoms; R 112 R is a group represented as an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, or an aralkyl group having 7 to 30 carbon atoms; z represents an integer from 1 to 30; R 104 This represents alkylenes with 1 to 6 carbon atoms.

[0104] [ka] [ka] In equations (2) and (3) above, x represents an integer greater than or equal to 0; y represents an integer greater than or equal to 1; R 201 R represents a C1-C30 alkyl, C2-C30 alkenyl, or C2-C30 alkynyl atom which may be substituted with a hydrogen atom, a halogen atom, a hydroxyl or carboxyl atom; 202 R represents alkylene with 1 to 30 carbon atoms, alkenylene with 2 to 30 carbon atoms, or alkynylene with 2 to 30 carbon atoms; 201 and R 202 They may form a ring structure.

[0105] In equation (S1), R 1005 , R 1006 , R 1007 and R 1008 Each of these is preferably independently selected from the group consisting of linear, cyclic, or branched alkyl groups, alkenyl groups, aryl groups, and aralkyl groups having 1 to 18 carbon atoms. 1002If is a monovalent hydrocarbon group having 1 to 18 carbon atoms, it is preferably a group selected from the group consisting of linear, cyclic, or branched alkyl groups, alkenyl groups, aryl groups, and aralkyl groups. 1009 The alkylene group is preferably linear, cyclic, or branched, and is particularly preferred to be linear. 1004 Examples of these include alkylene groups having 1 to 18 carbon atoms, alkenylene groups having 2 to 18 carbon atoms, cycloalkylene groups having 5 to 18 carbon atoms, cycloalkylalkylene groups having 6 to 18 carbon atoms, arylene groups having 6 to 18 carbon atoms, and aralkylene groups having 7 to 18 carbon atoms. The alkylene groups and alkenylene groups may be linear or branched, and the cycloalkylene groups, cycloalkylalkylene groups, arylene groups, and aralkylene groups may have functional groups such as lower alkyl groups on their rings. 1004 Preferably, the alkylene group has 1 to 6 carbon atoms, and in particular, linear alkylene groups such as methylene, ethylene, trimethylene, tetramethylene, pentamethylene, and hexamethylene groups are preferred.

[0106] R in equation (S1) 1002 , R 1005 , R 1006 , R 1007 and R 1008 Specific examples include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, decyl group, dodecyl group, cyclopentyl group, cyclohexyl group, vinyl group, propenyl group, allyl group, hexenyl group, octenyl group, cyclopentenyl group, cyclohexenyl group, phenyl group, tolyl group, xylyl group, naphthyl group, benzyl group, phenethyl group, naphthylmethyl group, and the like. R in equation (S1) 1009 Examples of linear alkylene groups include methylene, ethylene, n-propylene, n-butylene, and hexylene groups, while examples of branched alkylene groups include isopropylene, isobutylene, and 2-methylpropylene groups.

[0107] Specific examples of silane coupling agents represented by formula (S1) include 3-hexanoylthiopropyltriethoxysilane, 3-octanoylthiopropyltriethoxysilane, 3-decanoylthiopropyltriethoxysilane, 3-lauroylthiopropyltriethoxysilane, 2-hexanoylthioethyltriethoxysilane, 2-octanoylthioethyltriethoxysilane, 2-decanoylthioethyltriethoxysilane, 2-lauroylthioethyltriethoxysilane, 3-hexanoylthiopropyltrimethoxysilane, 3-octanoylthiopropyltrimethoxysilane, 3-decanoylthiopropyltrimethoxysilane, 3-lauroylthiopropyltrimethoxysilane, 2-hexanoylthioethyltrimethoxysilane, 2-octanoylthioethyltrimethoxysilane, 2-decanoylthioethyltrimethoxysilane, and 2-lauroylthioethyltrimethoxysilane. These may be used individually or in combination of two or more. Among them, 3-octanoylthiopropyltriethoxysilane is particularly preferred.

[0108] Examples of compounds represented by formula (1) include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, and compounds represented by the following formula (4) (Si363 manufactured by Evonik). Compounds represented by the following formula (4) can be preferably used. These may be used individually or in combination of two or more.

[0109] [ka]

[0110] In a silane coupling agent containing a bonding unit A represented by formula (2) and a bonding unit B represented by formula (3), the content of bonding unit A is preferably 30 mol% or more, more preferably 50 mol% or more, preferably 99 mol% or less, and more preferably 90 mol% or less. The content of bonding unit B is preferably 1 mol% or more, more preferably 5 mol% or more, even more preferably 10 mol% or more, preferably 70 mol% or less, more preferably 65 mol% or less, and even more preferably 55 mol% or less. The total content of bonding units A and B is preferably 95 mol% or more, more preferably 98 mol% or more, and particularly preferably 100 mol%. The content of bonding units A and B includes the amount when bonding units A and B are located at the ends of the silane coupling agent. The form of bonding units A and B when they are located at the ends of the silane coupling agent is not particularly limited, as long as they form units corresponding to the equations (2) and (3) that represent bonding units A and B.

[0111] R in equations (2) and (3) 201 Examples of halogens include chlorine, bromine, and fluorine. Examples of branched or unbranched alkyl groups with 1 to 30 carbon atoms include methyl and ethyl groups. Examples of branched or unbranched alkenyl groups with 2 to 30 carbon atoms include vinyl and 1-propenyl groups. Examples of branched or unbranched alkynyl groups with 2 to 30 carbon atoms include ethynyl and propynyl groups.

[0112] R in equations (2) and (3) 202 Regarding branched or unbranched alkylene groups with 1 to 30 carbon atoms, examples include ethylene and propylene groups. Regarding branched or unbranched alkenylene groups with 2 to 30 carbon atoms, examples include vinylene and 1-propenylene groups. Regarding branched or unbranched alkylene groups with 2 to 30 carbon atoms, examples include ethynylene and propynylene groups.

[0113] In a silane coupling agent containing a bonding unit A represented by formula (2) and a bonding unit B represented by formula (3), the sum of the number of repeats of bonding unit A (x) and the number of repeats of bonding unit B (y), (x+y), is preferably in the range of 3 to 300.

[0114] When the rubber composition contains a silane coupling agent, the content of the silane coupling agent in the rubber composition is preferably 4 parts by mass or more, more preferably 7 parts by mass or more, even more preferably 10 parts by mass or more, and preferably 25 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less, per 100 parts by mass of silica. When the content is within the above range, a better effect tends to be obtained.

[0115] The rubber composition may contain a plasticizer. A plasticizer is a material that imparts plasticity to rubber components, and the concept includes both liquid and solid plasticizers at 25°C. Examples of plasticizers include resins, oils, liquid polymers, and ester-based plasticizers. Among these, oils are preferred. These plasticizers may be derived from mineral resources such as petroleum and natural gas, from biomass, or from naphtha recycled from rubber or non-rubber products. Alternatively, low molecular weight hydrocarbon components obtained by thermal decomposition and extraction of used tires or products containing various components may be used as plasticizers. These plasticizers may be used individually or in combination of two or more.

[0116] Examples of oils include mineral oil, vegetable oil, and animal oil. From a life cycle assessment perspective, waste oil used in rubber mixers and engines, or refined waste cooking oil used in restaurants, may also be used.

[0117] In this specification, mineral oil refers to oil derived from mineral resources such as petroleum and natural gas. Examples of mineral oil include paraffinic oils (mineral oil), naphthenic oils, and aromatic oils. Specific examples of mineral oil include MES (Mild Extract Solvated), DAE (Distillate Aromatic Extract), TDAE (Treated Distillate Aromatic Extract), TRAE (Treated Residual Aromatic Extract), and RAE (Residual Aromatic Extract). Furthermore, for environmental reasons, oils with a low content of polycyclic aromatic compounds (PCA) can be used. Examples of such low-PCA oils include MES, TDAE, and heavy naphthenic oils.

[0118] In this specification, vegetable oils include, for example, 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 wood wax. Furthermore, vegetable oils may also include refined oils (such as salad oil) obtained by refining the above oils, transesterified oils obtained by transesterifying the above oils, hydrogenated oils obtained by hydrogenating the above oils, thermally polymerized oils obtained by thermally polymerizing the above oils, oxidized polymerized oils obtained by oxidizing the above oils, and waste cooking oils recovered from use as edible oils. Note that vegetable oils may be liquid or solid at 25°C. These may be used individually or in combination of two or more types.

[0119] The vegetable oil according to this embodiment preferably contains acylglycerol, and more preferably contains triacylglycerol. In this specification, acylglycerol refers to a compound in which a hydroxyl group of glycerin and a fatty acid are ester-bonded. 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 of three or more. Note that acylglycerols of two or more forms can be obtained by thermal polymerization, oxidative polymerization, etc. Also, the acylglycerol may be a liquid or a solid at 25°C.

[0120] The method for confirming whether the rubber composition contains the acylglycerol is not particularly limited, 1 This can be confirmed by 1H-NMR measurement. For example, a rubber composition containing triacylglycerol is immersed in deuterated chloroform at 25°C for 24 hours, and after removing the rubber composition, it is measured at room temperature. 1 When 1H-NMR was measured and the tetramethylsilane (TMS) signal was set to 0.00 ppm, signals were observed around 5.26 ppm, 4.28 ppm, and 4.15 ppm. These signals are presumed to originate from hydrogen atoms bonded to carbon atoms adjacent to the oxygen atom of the ester group. In this paragraph, "around" refers to a range of ±0.10 ppm.

[0121] The aforementioned fatty acids are not particularly limited and may be either unsaturated or saturated fatty acids. 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.

[0122] In particular, it is desirable that the fatty acid contains fatty acids with few double bonds, i.e., saturated fatty acids or monounsaturated fatty acids, and oleic acid is preferred. As a vegetable oil containing such fatty acids, for example, a vegetable oil containing saturated fatty acids or monounsaturated fatty acids may be used, or a vegetable oil that has been modified by transesterification or other means may be used. Furthermore, in order to produce a vegetable oil containing such fatty acids, plants may be improved by breeding, genetic modification, genome editing, etc.

[0123] As for vegetable oils, commercially available products from companies such as Idemitsu Kosan Co., Ltd., Sankyo Yuka Kogyo Co., Ltd., ENEOS Corporation, Orisoy Co., Ltd., H&R Co., Ltd., Toyokuni Oil Co., Ltd., Fuji Kosan Co., Ltd., and Nisshin Oillio Group Ltd. can be used.

[0124] If the rubber composition contains vegetable oil, the amount of vegetable oil in the rubber composition is preferably 1 to 40 parts by mass per 100 parts by mass of the rubber component.

[0125] Commercially available oils that can be used include those from Idemitsu Kosan Co., Ltd., Sankyo Yuka Kogyo Co., Ltd., ENEOS Corporation, Orisoy Co., Ltd., H&R Co., Ltd., Toyokuni Oil Co., Ltd., Showa Shell Sekiyu K.K., Fuji Kosan Co., Ltd., Nisshin Oillio Group Ltd., and others.

[0126] If the rubber composition contains oil, the oil content in the rubber composition is preferably 3 parts by mass or more, more preferably 7 parts by mass or more, preferably 40 parts by mass or less, more preferably 25 parts by mass or less, and even more preferably 15 parts by mass or less, per 100 parts by mass of the rubber component. When the oil content is within this range, a better effect tends to be obtained.

[0127] The resin is not particularly limited, but resins commonly used in the tire industry can be used, and may be either liquid or solid at room temperature (25°C). Examples of adhesive resins include C5 resins, C9 resins, C5C9 resins, aromatic vinyl resins, dicyclopentadiene resins, coumarone resins, indene resins, terpene resins, rosin resins, and phenolic resins. These resins may be used individually or in combination of two or more.

[0128] 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, when using a resin that is solid at room temperature. Furthermore, it 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 this range, the effect tends to be better obtained. When the resin is liquid at room temperature, the softening point is preferably 20°C or lower, preferably 10°C or lower, and preferably 0°C or lower. In the case of hydrogenated resins, it is desirable that the softening point be the same as described above. The softening point of the aforementioned resin is determined by measuring the softening point specified in JIS K6220-1:2001 using a ring-type softening point measuring device, and the temperature at which the sphere descends is the softening point.

[0129] C5 resins refer to resins obtained by polymerizing C5 fractions, and may be hydrogenated or modified versions of these resins. Examples of C5 fractions include petroleum fractions with 4 to 5 carbon atoms, such as isoprene, pentane, isopentane, neopentane, pentene, and pentadiene. These C5 resins may be used individually or in combination of two or more types.

[0130] C9 resins refer to resins obtained by polymerizing a C9 fraction, and may be obtained by polymerizing the C9 fraction alone, or as copolymers obtained by copolymerizing the C9 fraction with other components. They may also be hydrogenated or modified. Examples of C9 fractions include petroleum fractions with 8 to 10 carbon atoms, such as vinyltoluene, alkylstyrene, coumarone, indene, and methylindene. These C9 resins may be used individually or in combination of two or more types.

[0131] C5C9 resins refer to resins obtained by copolymerizing the C5 fraction and the C9 fraction, and may be hydrogenated or modified versions of these resins. As C5C9 petroleum resins, for example, those commercially available from Tosoh Corporation, LUHUA, etc., can be used. These C5C9 resins may be used individually or in combination of two or more types.

[0132] Aromatic vinyl resins refer to resins containing aromatic vinyl compounds such as styrene, α-methylstyrene, vinyltoluene, and p-chlorostyrene as the most abundant monomer component, and may also be hydrogenated or modified versions of these compounds. For aromatic vinyl resins, α-methylstyrene or a homopolymer of styrene, or a copolymer of α-methylstyrene and styrene is preferred, and a copolymer of α-methylstyrene and styrene is more preferred, due to their economical nature, ease of processing, and excellent heat generation properties. Aromatic vinyl resins that can be used are commercially available from companies such as Kraton, Eastman Chemical Company, and Mitsui Chemicals, Inc. These aromatic vinyl resins may be used individually or in combination of two or more types.

[0133] Dicyclopentadiene resins refer to resins containing cyclopentadiene (CPD) or dicyclopentadiene (DCPD) as monomer components, and may be hydrogenated or modified. Examples of dicyclopentadiene resins include DCPD / C9 resins containing dicyclopentadiene and C9 fraction as monomer components (these DCPD / C9 resins may be hydrogenated or modified), with DCPD / C9 resins containing dicyclopentadiene and styrene as monomer components being preferred, and DCPD / C9 resins containing dicyclopentadiene, styrene, and indene as monomer components being particularly preferred. Dicyclopentadiene resins that are commercially available from companies such as ExxonMobil, ENEOS Corporation, Nippon Zeon Corporation, and Maruzen Petrochemical Co., Ltd. can be used. These dicyclopentadiene resins may be used individually or in combination of two or more types.

[0134] Coumarone-based resins refer to resins containing coumarone as a monomer component, and may be hydrogenated or modified resins. Examples of coumarone resins include coumarone-indene resins containing coumarone and indene as monomer components, and coumarone-indene-styrene resins containing coumarone, indene, and styrene as monomer components. These coumarone-based resins may be used individually or in combination of two or more types.

[0135] Indene resins refer to resins containing indene as a monomer component, and may be hydrogenated or modified resins. Examples of indene resins include coumarone-indene resins containing coumarone and indene as monomer components, and coumarone-indene-styrene resins containing coumarone, indene, and styrene as monomer components. These indene resins may be used individually or in combination of two or more types.

[0136] Terpene resins are resins that contain terpene compounds such as α-pinene, β-pinene, limonene, and dipentene as the most abundant monomer component, and may be hydrogenated or modified versions of these compounds. Specific examples of terpene resins include, for example, polyterpene resins containing only one or more of the aforementioned terpene compounds as monomer components; aromatically modified terpene resins containing the aforementioned terpene compounds and aromatic compounds as monomer components; and terpene-phenol resins containing the aforementioned terpene compounds and phenolic compounds as monomer components. Examples of aromatic compounds that serve as monomer components in aromatically modified terpene resins include styrene, α-methylstyrene, vinyltoluene, and divinyltoluene. Examples of phenolic compounds that serve as monomer components in terpene-phenol resins include phenol, bisphenol A, cresol, and xylenol. These terpene resins may be used individually or in combination of two or more types.

[0137] Rosin-based resins refer to resins containing rosin acid compounds such as abietic acid, neoabietic acid, palastic acid, and isopimal acid, and may be hydrogenated or modified versions of these compounds. Rosin-based resins are not particularly limited, but examples include natural resin rosin and rosin-modified resins obtained by hydrogenation, disproportionation, dimerization, esterification, etc. These rosin-based resins may be used individually or in combination of two or more types.

[0138] Phenolic resins are resins that contain phenol compounds such as phenol and cresol as the most abundant monomer component. Phenolic resins are not particularly limited, but examples include phenol-formaldehyde resins, alkylphenol-formaldehyde resins, alkylphenol-acetylene resins, and oil-modified phenol-formaldehyde resins. These phenolic resins may be used individually or in combination of two or more types.

[0139] The resin may be a modified resin (functionalized resin) into which functional groups have been introduced. Modified resins can be produced by known methods, such as slurry methods and metathesis methods. Specifically, they can be produced, for example, by reacting a polymer that forms the polymer backbone of the modified resin with a functional compound that allows for the introduction of functional groups, using known methods.

[0140] The polymer forming the polymer backbone is not particularly limited and may be, for example, the C5 resin, aromatic resin, or terpene resin mentioned above, or other resins. These may be used alone or in combination of two or more. Among these, aromatic resins are preferred, α-methylstyrene resins are more preferred, and styrene-α-methylstyrene resin (a copolymer of styrene and α-methylstyrene) is even more preferred.

[0141] The functional group is preferably one containing at least one element selected from the group consisting of oxygen, silicon, and nitrogen, and more preferably one containing silicon.

[0142] If the rubber composition contains a modified resin, the amount of the modified resin in the rubber composition is preferably 0.5 to 50 parts by mass per 100 parts by mass of the rubber component.

[0143] Commercially available resins from companies such as Maruzen Petrochemical Co., Ltd., Sumitomo Bakelite Co., Ltd., Yasuhara Chemical Co., Ltd., Tosoh Corporation, Rutgers Chemicals, BASF, Arizona Chemical Company, Nippon Paint Chemical Co., Ltd., Nippon Shokubai Co., Ltd., ENEOS Corporation, Arakawa Chemical Industries, Ltd., and Taoka Chemical Industries, Ltd. can be used.

[0144] If the rubber composition contains a resin, the resin content in the rubber composition is preferably 0.5 to 50 parts by mass per 100 parts by mass of the rubber component.

[0145] Liquid polymers are (co)polymers that are in a liquid state at 25°C, and examples include liquid rubber and liquid resin. Furthermore, the liquid polymer may have undergone modification or hydrogenation treatment. Commercially available products include those from Cray Valley, Kuraray Co., Ltd., etc. These may be used individually or in combination of two or more types.

[0146] The weight-average molecular weight (Mw) of the liquid polymer is less than 120,000, preferably 50,000 or less, more preferably 20,000 or less, even more preferably 8,000 or less, and also preferably 100 or more, more preferably 1,000 or more, and even more preferably 2,000 or more. Within this range, a better effect tends to be obtained. In this specification, liquid polymers are not included in the rubber component.

[0147] As the liquid rubber, at least one diene-based (co)polymer selected from the group consisting of butadiene, isoprene, styrene, farnesene, and their derivatives can be used. Specific examples include liquid diene polymers such as liquid styrene-butadiene copolymer (liquid SBR), liquid butadiene polymer (liquid BR), liquid isoprene polymer (liquid IR), liquid styrene-isoprene copolymer (liquid SIR), liquid farnesene polymer, and liquid farnesene-butadiene copolymer. Among these, branched conjugated diene polymers such as liquid farnesene polymer and liquid farnesene-butadiene copolymer are preferred.

[0148] The liquid rubber may be modified with functional groups that interact with silica, or its terminals and / or main chain may be modified with functional groups containing at least one element selected from the group consisting of oxygen, nitrogen, silicon, and phosphorus. The liquid rubber may also be unhydrogenated or hydrogenated.

[0149] If the rubber composition contains liquid rubber, the amount of liquid rubber in the rubber composition is preferably 1 to 30 parts by mass per 100 parts by mass of the rubber component.

[0150] The liquid resin is a resin that is liquid at 25°C, and any of the above-mentioned types of resins can be used. One type of liquid resin may be used alone, or two or more types of liquid resins may be used in combination.

[0151] If the rubber composition contains a liquid resin, the amount of liquid resin in the rubber composition is preferably 1 to 30 parts by mass per 100 parts by mass of the rubber component.

[0152] If the rubber composition contains a liquid polymer, the amount of liquid polymer in the rubber composition is preferably 1 to 30 parts by mass per 100 parts by mass of the rubber component.

[0153] The ester-based plasticizer is not particularly limited as long as it is a compound having an ester group that is in a liquid state at 25°C, but examples include phthalic acid derivatives, long-chain fatty acid derivatives, phosphoric acid derivatives, sebacic acid derivatives, and adipic acid derivatives. These may be used individually or in combination of two or more. Among these, phosphoric acid derivatives, sebacic acid derivatives, and adipic acid derivatives are preferred, with sebacic acid derivatives being more preferred. The phthalic acid derivative is not particularly limited, but examples include phthalic acid esters such as di-2-ethylhexyl phthalate (DOP) and diisodecyl phthalate (DIDP). The long-chain fatty acid derivative is not particularly limited, but examples include long-chain fatty acid glycerol esters. The phosphate derivative is not particularly limited, but examples include phosphate esters such as tris(2-ethylhexyl) phosphate (TOP) and tributyl phosphate (TBP). The sebaciate derivative is not particularly limited, but examples include sebaciate esters such as di(2-ethylhexyl) sebacate (DOS) and diisooctyl sebacate (DIOS). The adipic acid derivative is not particularly limited, but examples include adipic acid esters such as di(2-ethylhexyl) adipate (DOA) and diisooctyl adipate (DIOA). Among these, phosphate esters, sebacate esters, and adipic esters are preferred, with sebacate esters being more preferred. Furthermore, as for specific compounds, TOP, DOS, and DOA are preferred, with DOS being more preferred. As ester-based plasticizers, products from companies such as Daihachi Chemical Industry Co., Ltd. and Taoka Chemical Industry Co., Ltd. can be used.

[0154] The glass transition temperature (Tg) of the ester-based plasticizer is preferably -110°C or higher, more preferably -100°C or higher, even more preferably -80°C or higher, preferably -20°C or lower, more preferably -40°C or lower, and even more preferably -55°C or lower. The aforementioned effects tend to be more favorably obtained within this range. In this specification, the glass transition temperature of ester-based plasticizers is the value measured using a differential scanning calorimeter (Q200) manufactured by T.A. Instruments Japan Co., Ltd., in accordance with JIS-K7121:2012, under a heating rate of 10°C / min.

[0155] If the rubber composition contains an ester-based plasticizer, the content of the ester-based plasticizer in the rubber composition is preferably 1 to 20 parts by mass per 100 parts by mass of the rubber component.

[0156] If the rubber composition contains a plasticizer, the plasticizer content in the rubber composition is preferably 3 parts by mass or more, more preferably 7 parts by mass or more, preferably 40 parts by mass or less, more preferably 25 parts by mass or less, and even more preferably 15 parts by mass or less, per 100 parts by mass of the rubber component. When the content is within this range, a better effect tends to be obtained. Furthermore, the plasticizer content includes the amount of oil and resin contained in oil-extracted rubber and resin-extracted rubber.

[0157] The aforementioned rubber composition may contain processing aids. Examples of processing aids include metal salts (compounds in which the hydrogen atoms of an acid are replaced by metal ions), fatty acid amides, amide esters, and fatty acid esters. These may be used individually or in combination of two or more.

[0158] Examples of metals used in metal salts include alkali metals such as potassium and sodium, and alkaline earth metals such as calcium and barium. Magnesium, zinc, nickel, and molybdenum can also be used.

[0159] Acids used in metal salts include fatty acids such as lauric acid, myristic acid, and palmitic acid. Boric acid, carbonic acid, hydrochloric acid, nitric acid, and sulfuric acid can also be used.

[0160] Commercially available processing aids include products from companies such as Kishida Chemical Co., Ltd., Ken-ei Pharmaceutical Co., Ltd., Structol, and Performance Additives.

[0161] If the rubber composition contains a processing aid, the amount of the processing aid in the rubber composition is preferably 0.1 to 10 parts by mass per 100 parts by mass of the rubber component.

[0162] The rubber composition may further contain vulcanized rubber particles. 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 viewpoint of environmental considerations and cost, recycled rubber powder produced from crushed waste tires is preferred. These may be used individually or in combination of two or more types.

[0163] The vulcanized rubber particles are not particularly limited and may be either unmodified or modified vulcanized rubber particles.

[0164] Commercially available vulcanized rubber particles can be used, for example, products from Lehigh, Muraoka Rubber Industries, Ltd., and others.

[0165] When the rubber composition contains vulcanized rubber particles, the content of vulcanized rubber particles in the rubber composition is preferably 5 parts by mass or more, more preferably 7 parts by mass or more, even more preferably 10 parts by mass or more, and also 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, per 100 parts by mass of the rubber component. When the content is within the above range, a better effect tends to be obtained.

[0166] The aforementioned rubber composition may contain an anti-aging agent. While not particularly limited, examples of anti-aging agents include naphthylamine-based anti-aging agents such as phenyl-α-naphthylamine; diphenylamine-based anti-aging agents 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'-ditril-p-phenylenediamine. Examples include p-phenylenediamine-based antioxidants such as methyl amine (DTPD), N-isopropyl-N'-phenyl-p-phenylenediamine (IPPD), and N,N'-di-2-naphthyl-p-phenylenediamine (DNPD); quinoline-based antioxidants such as polymers of 2,2,4-trimethyl-1,2-dihydroquinoline; monophenol-based antioxidants such as 2,6-di-t-butyl-4-methylphenol and styrenated phenol; and bis-, tris-, and polyphenol-based 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 include those from companies such as Seiko Chemical Co., Ltd., Sumitomo Chemical Co., Ltd., Ouchi Shinko Chemical Co., Ltd., and Flexis. These may be used individually or in combination of two or more.

[0167] If the rubber composition contains an anti-aging agent, the amount of the anti-aging agent in the rubber composition is preferably 1 to 10 parts by mass per 100 parts by mass of the rubber component.

[0168] The rubber composition may contain wax. 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. The wax can be commercially available from companies such as Ouchi Shinko Chemical Industry Co., Ltd., Nippon Seiro Co., Ltd., and Paramelt Co., Ltd. These waxes may be used individually or in combination of two or more types.

[0169] The wax is preferably obtained as a by-product of Fischer-Tropsch synthesis derived from natural gas. The raw materials for Fischer-Tropsch synthesis may also be recycled methane (such as methane obtained by thermal decomposition of tires) or biomass-derived methane (such as methane obtained from carbon dioxide through a methanation process).

[0170] If the rubber composition contains wax, the amount of wax in the rubber composition is preferably 1 to 10 parts by mass per 100 parts by mass of the rubber component.

[0171] The rubber composition may contain stearic acid. Conventional known stearic acid can be used, and commercially available products from companies such as NOF Corporation, Kao Corporation, Fujifilm Wako Pure Chemical Industries Ltd., and Chiba Fatty Acid Co., Ltd. can be used. These may be used individually or in combination of two or more types.

[0172] When the rubber composition contains stearic acid, the stearic acid content in the rubber composition is preferably 0.3 parts by mass or more, more preferably 0.5 parts by mass or more, and preferably 8 parts by mass or less, more preferably 5 parts by mass or less, per 100 parts by mass of the rubber component. Within this range, a better effect tends to be obtained.

[0173] The rubber composition may contain zinc oxide. Conventional known zinc oxides can be used, and commercially available products from companies such as Mitsui Mining & Smelting Co., Ltd., Toho Zinc Co., Ltd., Hakusui Tech Co., Ltd., Seido Chemical Industry Co., Ltd., and Sakai Chemical Industry Co., Ltd. can be used. These may be used individually or in combination of two or more types.

[0174] When the rubber composition contains zinc oxide, the zinc oxide content in the rubber composition is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and preferably 10 parts by mass or less, more preferably 5 parts by mass or less, per 100 parts by mass of the rubber component. Within this range, a better effect tends to be obtained.

[0175] The aforementioned rubber composition may contain sulfur. Examples of sulfur commonly used as a crosslinking agent in the rubber industry include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersible sulfur, and soluble sulfur. Commercially available products from companies such as Tsurumi Chemical Industries, Karuizawa Sulfur Co., Ltd., Shikoku Chemicals Co., Ltd., Flexis Co., Ltd., Nippon Dry Distillation Co., Ltd., and Hosoi Chemical Industry Co., Ltd. can be used. These may be used individually or in combination of two or more types.

[0176] If the rubber composition contains sulfur, the sulfur content in the rubber composition is preferably 0.5 parts by mass or more, more preferably 1.5 parts by mass or more, and preferably 10 parts by mass or less, more preferably 5 parts by mass or less, per 100 parts by mass of the rubber component. Within this range, a better effect tends to be obtained.

[0177] The rubber composition may contain a vulcanization accelerator. Examples of vulcanization accelerators include benzothiazole-based vulcanization accelerators such as 2-mercaptobenzothiazole and di-2-benzothiazolyl disulfide; thiram-based vulcanization accelerators such as tetramethylthiuram disulfide (TMTD) and tetrakis(2-ethylhexyl)thiuram disulfide (TOT-N); sulfenamide-based vulcanization accelerators such as N-cyclohexyl-2-benzothiadylsulfenamide (CBS), N-tert-butyl-2-benzothiazolylsulfenamide (TBBS), N-oxyethylene-2-benzothiazolesulfenamide, and N,N′-diisopropyl-2-benzothiazolesulfenamide; and guanidine-based vulcanization accelerators such as diphenylguanidine, diortotolylguanidine, and orthotolylbiguanidine. Commercially available products from companies such as Sumitomo Chemical Co., Ltd. and Ouchi Shinko Chemical Co., Ltd. can be used. These may be used individually or in combination of two or more.

[0178] If the rubber composition contains a vulcanization accelerator, the content of the vulcanization accelerator in the rubber composition is preferably 0.3 parts by mass or more, more preferably 0.5 parts by mass or more, preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 2 parts by mass or less, per 100 parts by mass of the rubber component. When the content is within this range, a better effect tends to be obtained.

[0179] In addition to the components mentioned above, the rubber composition may further contain additives commonly used in the tire industry, such as organic peroxides. The content of these additives is preferably 0.1 to 200 parts by mass per 100 parts by mass of the rubber component.

[0180] 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 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.

[0181] The rubber composition can be obtained by, for example, kneading the above-mentioned components using a rubber kneading device such as an open roll or Banbury mixer, and then vulcanizing it, thereby obtaining a vulcanized rubber composition (vulcanized rubber).

[0182] Regarding the mixing conditions, in the base mixing step where additives other than the vulcanizing agent and vulcanization accelerator are mixed, the mixing temperature is usually 50 to 200°C, preferably 80 to 190°C, and the mixing time is usually 30 seconds to 30 minutes, preferably 1 minute to 30 minutes. In the finish mixing step where the vulcanizing agent and vulcanization accelerator are mixed, the mixing temperature is usually 100°C or lower, preferably room temperature to 80°C. Furthermore, the composition mixed with the vulcanizing agent and vulcanization accelerator is usually subjected to a vulcanization treatment such as press vulcanization. The vulcanization temperature is usually 120 to 200°C, preferably 140 to 180°C.

[0183] The tire of this disclosure is manufactured by conventional methods using the rubber composition. Specifically, the composition, which may contain various additives as needed, is extruded to match the shape of various tire components such as sidewalls and / or clinches at an uncrosslinked or unvulcanized stage, molded in conventional methods on a tire molding machine, bonded together with other tire components such as bead reinforcing rubber to form an unvulcanized tire, and then heated and pressurized in a vulcanizing machine to manufacture the tire.

[0184] The aforementioned tires are not particularly limited and include, for example, pneumatic tires, solid tires, and airless tires. Among these, pneumatic tires are preferred.

[0185] The aforementioned tires (pneumatic tires, etc.) can be used for passenger cars; trucks and buses; motorcycles; high-performance tires; winter tires such as studless tires; run-flat tires with side reinforcement layers; tires with sound-absorbing materials such as sponges inside the tire cavity; tires with sealing materials that can be sealed in the event of a puncture inside the tire or inside the tire cavity; tires with electronic components that have electronic components such as sensors and wireless tags inside the tire or inside the tire cavity; electric vehicle tires, etc., and are particularly suitable for electric vehicle tires.

[0186] The size of the aforementioned tires is not particularly limited; for example, the tire width can be selected within the range of 100 to 400 mm, the aspect ratio within the range of 25 to 85%, and the rim diameter within the range of 10 to 25 inches, as appropriate. Specific examples include 105 / 50R16, 115 / 50R17, 125 / 55R20, 135 / 45R21, 145 / 45R21, 155 / 45R18, 165 / 45R22, 175 / 45R23, 185 / 60R20, 195 / 55R14, 205 / 40R16, 215 / 40R16, 225 / 40R17, 235 / 40R17, 245 / 40R16, 255 / 40R17, 265 / 40R17, 275 / 35R18, 285 / 30R19, 295 / 45R20, etc.

[0187] The aforementioned tire preferably satisfies the following relationship between the tire outer diameter Dt and the tire section width Wt.

number

[0188] Examples of tires that can satisfy the above formula include 145 / 60R18, 145 / 60R19, 155 / 55R18, 155 / 55R19, 155 / 70R17, 155 / 70R19, 165 / 55R20, 165 / 55R21, 165 / 60R19, 165 / 65R19, 165 / 70R18, 175 / 55R19, 175 / 55R20, 175 / 55R22, 175 / 60R18, 185 / 55R19, 185 / 60R20, 195 / 50R20, 195 / 55R20, and others.

[0189] Tires that satisfy the above formula are preferably applied to pneumatic tires for electric vehicles. This is because pneumatic tires for electric vehicles that satisfy the above formula tend to be more suitable for solving the problems of this invention.

[0190] The tire disclosed herein has a sidewall and / or clinch, and the rubber composition (butyl rubber, a cyclic amine having a double bond in the ring, and 24M4DBP oil absorption capacity of 170 cm 3 A rubber composition containing 100g or more of carbon black is used in the sidewall and / or clinch. Specifically, the tire of this disclosure has the rubber composition (butyl rubber, a cyclic amine having a double bond in the ring, and a 24M4DBP oil absorption capacity of 170cm 3 The rubber composition (vulcanized rubber) after vulcanization (containing 100g or more of carbon black) is used for the sidewall and / or clinch.

[0191] In this specification, the sidewall is a member arranged on the outside of the case from the shoulder portion to the bead portion, and specifically refers to the member shown in Figure 1 of Japanese Patent Publication No. 2005-280612, Figure 1 of Japanese Patent Publication No. 2000-185529, etc. In this specification, "clinch" refers to a rubber member disposed at the inner end of the sidewall, and is the member shown in Figure 1 of Japanese Patent Application Publication No. 2010-163560, etc.

[0192] It is preferable that the hardness Hs of the sidewall and / or the clinch (vulcanized rubber composition) using the rubber composition exceeds 45, more preferably exceeds 47, and still more preferably exceeds 50. Also, it is preferably less than 70, more preferably less than 65, still more preferably less than 60, and even more preferably less than 55. When within the above range, the effect tends to be obtained more favorably. In this specification, Hs is a value measured in accordance with JIS K6253-3 (2012), and specifically, it is measured by the method described in the examples below.

[0193] When Hs exceeds a certain value, particularly when Hs exceeds 45, the mechanism by which a more pronounced effect is obtained is not clear, but it is considered that the rigidity of the tire itself increases due to the high hardness, resulting in better durability of the side of the tire.

[0194] As a method for adjusting the Hs of the rubber (vulcanized rubber composition), methods known to those skilled in the art can be employed. For example, it can be adjusted by changing the type and blending ratio of the rubber component, or by changing the type and blending amount of the plasticizer and filler.

[0195] The tanδ of the sidewall and / or the clinch (vulcanized rubber composition) using the rubber composition is preferably 0.10 or more, more preferably 0.11 or more, still more preferably 0.12 or more, and preferably 0.20 or less, more preferably 0.19 or less, still more preferably 0.18 or less. When within the above range, the effect tends to be obtained more favorably.

[0196] When tanδ is within the above range, the mechanism by which a more pronounced effect is obtained is not clear, but it is considered that the heat generation of the rubber is suppressed, resulting in better durability of the side of the tire.

[0197] In this specification, the tanδ of rubber (rubber composition after vulcanization) refers to the tanδ at 70°C and is measured in accordance with the provisions of JIS K6394:2007 using a viscoelastic spectrometer (GABO's "Iplexer series") under the conditions of initial strain 10%, dynamic strain 1%, frequency 10Hz, temperature 70°C, and tensile mode. In this measurement, the test specimen (length: 20 mm, width: 4 mm, thickness: 1 mm) is sampled from the sidewall and / or clinch in which the rubber composition is used. However, if only test specimens less than 1 mm thick can be sampled from the sidewall and / or clinch in which the rubber composition is used, the measurement may be performed using such test specimens less than 1 mm thick. In this sampling, the length direction of the test specimen is aligned with the circumferential direction of the tire, and the thickness direction of the test specimen is aligned with the radial direction of the tire. If sampling is not possible from the sidewall and / or clinch in which the rubber composition is used, a test specimen can be sampled from a sheet of cross-linked rubber (rubber sheet) obtained by heating the rubber composition at 150°C for 12 minutes.

[0198] Methods known to those skilled in the art can be used to adjust the tanδ of the rubber (rubber composition after vulcanization) at 70°C. For example, it can be adjusted by changing the type and blending ratio of rubber components, or by changing the type and blending amount of plasticizers and fillers. For example, increasing the isoprene-based rubber content, decreasing the amount of fillers, or decreasing the amount of liquid plasticizer tends to decrease tanδ.

[0199] It is preferable that the tanδ × total filler amount of the sidewall and / or clinch using the rubber composition (the product of tanδ of the sidewall and / or clinch using the rubber composition and the total filler amount) < 3, with the right-hand side of the inequality more preferably 2 and even more preferably 1.8, and it is preferable that the tanδ × total filler amount of the sidewall and / or clinch using the rubber composition > 0.5, with the right-hand side of the inequality more preferably 1 and even more preferably 1.5. When the values ​​are within the above ranges, a better effect tends to be obtained. Here, the total amount of filler refers to the total amount of filler (parts by mass) per 100 parts by mass of rubber component in the rubber composition.

[0200] When the product of the tanδ of the sidewall and / or clinch in which the rubber composition is used and the total amount of filler is less than a predetermined value, particularly less than 3, the mechanism by which a greater effect is obtained is not clear, but it is thought that the durability of the tire sidewall becomes better.

[0201] It is preferable that the hardness Hs of the sidewall and / or clinch using the rubber composition / tanδ of the sidewall and / or clinch using the rubber composition (ratio of the hardness Hs of the sidewall and / or clinch using the rubber composition to the tanδ of the sidewall and / or clinch using the rubber composition) > 200, with the right-hand side of the inequality more preferably 250 and still more preferably 300. It is preferable that the hardness Hs of the sidewall and / or clinch using the rubber composition / tanδ of the sidewall and / or clinch using the rubber composition < 500, with the right-hand side of the inequality more preferably 450 and still more preferably 400. When the values ​​are within the above ranges, the effect tends to be better obtained.

[0202] When the ratio of the hardness Hs of the sidewall and / or clinch using the rubber composition to the tanδ of the sidewall and / or clinch using the rubber composition exceeds a predetermined value, particularly exceeding 200, it is believed that the durability of the tire sidewall will be improved, although the mechanism by which this is more effective is not clear.

[0203] The hardness Hs of the sidewall and / or clinch using the rubber composition × the 24M4DBP oil absorption of the carbon black contained in the rubber composition (product of the hardness Hs of the sidewall and / or clinch using the rubber composition and the 24M4DBP oil absorption of the carbon black contained in the rubber composition) is 7600 cm². 3 It is preferable that the amount be 100g or more, and 10000cm 3It is more preferable that the amount be 100g or more, and 15000cm 3 It is even more preferable that the amount be 100g or more, and 20000cm 3 It is particularly preferable that the amount be 100g or more, and 35000cm 3 It is preferable that the amount be 100g or less, and 30000cm 3 It is more preferable that the amount be 100g or less, and 25000cm 3 It is even more preferable that the amount be 100g or less, and 23000cm 3 It is particularly preferable that the amount be 100g or less. When it is within the aforementioned range, a better effect tends to be obtained. Here, the 24M4DBP oil absorption amount of carbon black refers to the weight-based average value of the 24M4DBP oil absorption amount of all carbon black contained in the rubber composition.

[0204] When the hardness Hs of the sidewall and / or clinch using the rubber composition × the 24M4DBP oil absorption amount of the carbon black contained in the rubber composition) exceeds a predetermined value, particularly exceeding 7600, the mechanism by which a greater effect is obtained is not clear. However, it is thought that increasing the hardness increases rigidity, and by using high-structure carbon black with a large 24M4DBP oil absorption amount, the carbon black interacts more easily with the rubber components, making cracks less likely to occur, and even if they do occur, the self-healing properties of the rubber composition after vulcanization are enhanced. Therefore, it is thought that crack growth resistance is further improved, and the durability of the tire sidewall is further improved.

[0205] The ratio of the 24M4DBP oil absorption amount of the carbon black contained in the rubber composition to the thickness of the sidewall and / or clinch using the rubber composition (the ratio of the 24M4DBP oil absorption amount of the carbon black contained in the rubber composition to the thickness of the sidewall and / or clinch using the rubber composition) is 68 cm². 3 It is preferable that it be (100g·mm) or more, and 100cm 3 It is more preferable that it be (100g·mm) or more, and 150cm 3 It is even more preferable that it be (100g·mm) or more, and 180cm3 It is particularly preferable that the weight is 100g·mm or more, and 350cm 3 It is preferable that the weight is 100g·mm or less, and 300cm 3 It is more preferable that the weight is 100g·mm or less, and 250cm 3 It is even more preferable that the weight is 100g·mm or less, and 220cm 3 It is particularly preferable that the weight is 100g·mm or less. Here, the 24M4DBP oil absorption amount of carbon black refers to the weight-based average of the 24M4DBP oil absorption amount of all carbon black contained in the rubber composition. Furthermore, the thickness of the sidewall and / or clinch in which the rubber composition is used refers to the thickness Tc described later.

[0206] When the ratio (24M4DBP oil absorption amount of carbon black contained in the rubber composition / thickness of the sidewall and / or clinch using the rubber composition) exceeds a predetermined value, particularly 68, the mechanism by which a greater effect is obtained is not clear. However, it is thought that by using high-structure carbon black with a large 24M4DBP oil absorption amount, the interaction between the carbon black and the rubber component is increased, and by reducing the thickness of the rubber material, the contact between the rubber component and the carbon black becomes easier, thereby increasing self-healing properties. Therefore, it is thought that crack growth resistance is further improved, and the durability of the tire sidewall is further improved.

[0207] In the tire, the thickness Tc [mm] of the rubber member (sidewall and / or clinch using the rubber composition) is preferably 0.5 mm or more, more preferably 0.8 mm or more, even more preferably 1.0 mm or more, and even more preferably 1.5 mm or more. It is also preferably 10.0 mm or less, more preferably 7.0 mm or less, even more preferably 5.0 mm or less, and particularly preferably 2.5 mm or less. When the thickness is within this range, a better effect tends to be obtained.

[0208] Although the mechanism by which adjusting the thickness Tc of the rubber component (sidewall and / or clinch using the rubber composition) to a predetermined range yields greater effectiveness is not clear, setting the thickness of the rubber component to a predetermined range ensures rubber strength and crack growth resistance. Therefore, it is believed that crack growth resistance is further improved.

[0209] In this specification, the thickness Tc of a rubber member (sidewall and / or clinch using the rubber composition) refers to the maximum thickness of each rubber member. The thickness at each point on the surface of each rubber member is the straight-line distance measured along the normal to the surface of each rubber member at that point, and the thickness Tc of each rubber member is the maximum thickness at that point. The same definition of Tc applies to members other than sidewalls and clinches.

[0210] In this specification, dimensions such as thickness are measured with the tire bead aligned to the standard rim width. During measurement, the tire is cut in the radial direction, and the bead ends on both sides of the sample are fixed in place, aligned to the standard rim width.

[0211] In this specification, unless otherwise specified, the dimensions of each part of a tire are values ​​measured under normal conditions. In this specification, "normal state" refers to a state in which the tire is mounted on a normal rim (not shown) and filled with the normal internal pressure, without any load.

[0212] If it is not possible to measure the tire with it mounted on a standard rim, the dimensions and angles of each part of the tire in its meridional cross-section are measured by cutting the tire along a plane containing the axis of rotation, and matching the distance between the left and right beads in the tire cross-section to the distance between the beads in a tire mounted on a standard rim.

[0213] A "standard rim" refers to the rim specified for each tire within the tire standard system, including the standard on which the tire is based. For example, for JATMA (Japan Automobile Tire Manufacturers Association), it refers to the "standard rim" for the applicable size listed in the "JATMA YEAR BOOK," for ETRTO (The European Tyre and Rim Technical Organisation), it refers to the "Measuring Rim" listed in the "STANDARDS MANUAL," and for TRA (The Tire and Rim Association, Inc.), it refers to the "Design Rim" listed in the "YEAR BOOK." Refer to JATMA, ETRTO, and TRA in that order, and if an applicable size is available at the time of reference, follow that standard. In the case of tires not specified in the standard, it refers to the rim with the smallest diameter and the narrowest rim width among rims that can be mounted on and can maintain internal pressure, i.e., rims that do not cause air leakage between the rim and tire.

[0214] "Regular internal pressure" refers to the air pressure specified for each tire in the tire standard system, including the standard on which the tire is based. For example, it refers to the "maximum air pressure" for JATMA, "INFLATION PRESSURE" for ETRTO, and the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" for TRA. Similar to "regular rim," refer to JATMA, ETRTO, and TRA in that order and follow the respective standard. For tires not specified in the standard, it refers to the regular internal pressure (but 250kPa or higher) of another tire size (specified in the standard) that uses the aforementioned regular rim as the standard rim. If multiple regular internal pressures of 250kPa or higher are listed, refer to the lowest value among them.

[0215] In the aforementioned tire, it is preferable that the ratio of the tire's weight WT [kg] to the tire's maximum load capacity WL [kg] (WT / WL) is less than 0.0170. (WT / WL) is more preferably less than 0.0160, and even more preferably less than 0.0150. When the lower limit of (WT / WL) is preferably more than 0.0010, more preferably more than 0.0050, and even more preferably more than 0.0100 within the above range, the effect tends to be obtained better.

[0216] In addition, in this specification, the weight WT of the tire is the weight of the tire alone, excluding the weight of the rim. On the other hand, when a member made of sponge or sealant or a sensor member, etc. is provided in the inner cavity of the tire, it is the weight including them. Also, the maximum load capacity (normal load) WL of the tire is the load determined for each tire in the standard system including the standard on which the tire is based. For JATMA, it is the maximum load capacity; for ETRTO, it is "LOAD CAPACITY"; for TRA, it refers to the maximum value described in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES". Similar to the case of the above-mentioned "normal rim" and "normal internal pressure", refer to JATMA, ETRTO, and TRA in this order and follow the standard. For tires not specified in the standard, the normal load WL is obtained by the following calculation. V ={(Dt / 2) 2 -(Dt / 2 - Ht) 2}×π×Wt WL = 0.000011×V + 175 WL: Normal load (kg) V: Virtual volume of the tire (mm 3 ) Dt: Outer diameter of the tire (mm) Ht: Section height of the tire (mm) Wt: Section width of the tire (mm)

[0217] The "section width Wt (mm)" of the tire is the maximum width between the outer surfaces of the sidewalls excluding patterns or characters etc. on the tire side surface in the normal state.

[0218] The "outer diameter Dt (mm)" of the tire refers to the outer diameter of the tire in the normal state.

[0219] The "section height Ht (mm)" of a tire refers to the height in the radial direction of the tire's radial cross-section. When the tire's rim diameter is R (mm), it corresponds to half the difference between the tire's outer diameter Dt and its rim diameter R. In other words, the section height Ht can be calculated using (Dt-R) / 2.

[0220] In the aforementioned tire, the tire cross-sectional width Wt [mm] is preferably 260 mm or less, more preferably 255 mm or less, and even more preferably 250 mm or less. The lower limit is preferably 150 mm or more, more preferably 180 mm or more, and even more preferably 200 mm or more. When it is within the above range, the effect tends to be better obtained.

[0221] The tire of this disclosure further comprises bead reinforcement rubber. In this specification, bead reinforcing rubber refers to a member that has the function of reinforcing the bead portion, and specifically refers to the member shown in Figure 1 of Japanese Patent Application Publication No. 2022-163942, etc.

[0222] The hardness Hs of the bead reinforcing rubber is preferably greater than 45, more preferably greater than 47, and even more preferably greater than 50. Furthermore, it is preferably less than 70, more preferably less than 65, even more preferably less than 60, and even more preferably less than 55. When the hardness is within the above range, a better effect tends to be obtained.

[0223] In the aforementioned tire, the thickness Tc [mm] of the bead reinforcing rubber is preferably 0.5 mm or more, more preferably 0.8 mm or more, even more preferably 1.0 mm or more, and even more preferably 2.0 mm or more, and also preferably 10.0 mm or less, more preferably 7.0 mm or less, even more preferably 6.0 mm or less, and particularly preferably 5.0 mm or less. When the thickness is within the above range, a better effect tends to be obtained.

[0224] An example of the tire of the present invention will be described below with reference to the figures, but the present invention is not limited to this form.

[0225] Figure 1 is a meridian cross-sectional view of a pneumatic tire (hereinafter sometimes simply referred to as "tire") 1 in its normal state, including the tire rotation axis (not shown), which represents one embodiment of the present invention.

[0226] The tire 1 of this embodiment includes a tread portion 2, a pair of sidewall portions 3, 3 extending radially inward from the tread portion 2, and a pair of bead portions 4, 4 connected radially inward from the pair of sidewall portions 3, 3. An annular bead core 5 is embedded in the bead portion 4.

[0227] The tire 1 includes, for example, a tread rubber 2G that forms the tread contact surface 2a of the tread portion 2, a sidewall rubber 3G that forms the outer surface 3a of the sidewall portion 3, and a clinch rubber 4G that forms the outer surface 4a of the bead portion 4. The sidewall rubber 3G and / or clinch rubber 4G contain the rubber composition (butyl rubber, a cyclic amine having a double bond in the ring, and 24M4DBP oil absorption capacity of 170 cm 3 A rubber composition (vulcanized rubber) after vulcanization (containing 100g or more of carbon black) is used.

[0228] In this embodiment, the tire 1 includes a carcass 6 stretched between a pair of bead portions 4, 4 and a belt layer 7 arranged on the tread portion 2.

[0229] The carcass 6 is composed of at least one carcass ply, in this embodiment, a first carcass ply 6A and a second carcass ply 6B superimposed on the first carcass ply 6A. In this embodiment, the first carcass ply 6A is positioned radially inward of the second carcass ply 6B. Alternatively, the first carcass ply 6A may be positioned radially outward of the second carcass ply 6B.

[0230] In this embodiment, each carcass ply 6A and 6B includes a main body portion 6a and a pair of folded portions 6b, 6b, respectively. The main body portion 6a extends from the tread portion 2 through a pair of sidewall portions 3, 3 to the bead core 5 of a pair of bead portions 4, 4. Each folded portion 6b is connected to the main body portion 6a and is folded back around the bead core 5 from the inside to the outside in the tire axial direction. In this embodiment, each folded portion 6b has an outer end 6o in the tire radial direction that terminates at the sidewall portion 3. Furthermore, each folded portion 6b is formed to include, for example, an inner portion 6i that slopes inward in the tire axial direction toward the tire radially outward from the bead core 5, and an outer portion 6e that is connected to the inner portion 6i and slopes outward in the tire axial direction toward the tire radially outward. However, each folded portion 6b is not limited to this configuration.

[0231] Each carcass ply 6A and 6B is formed, for example, by covering a carcass cord (not shown) with topping rubber. In this embodiment, the carcass cord is arranged at an angle of, for example, 75 to 90 degrees with respect to the tire equator C. The carcass cord can be made of metal fiber cords such as steel, or organic fiber cords such as polyester, nylon, rayon, or aramid.

[0232] The belt layer 7 consists of at least one, in this embodiment, two belt plies: an inner belt ply 7A and an outer belt ply 7B, arranged on the inside and outside in the radial direction of the tire. Each belt ply 7A and 7B includes belt cords (not shown) arranged at an angle of 10 to 35° with respect to the tire equator C. The belt plies 7A and 7B are overlapped in a direction in which the belt cords intersect each other. For the belt cords, steel cords are preferred, but highly elastic organic fiber cords such as aramid or rayon can also be used.

[0233] In this embodiment, the inner belt ply 7A is formed to be wider than the outer belt ply 7B. The width Wa of the inner belt ply 7A in the tire axial direction is preferably 80% to 100% of the tread width TW. However, the inner belt ply 7A may be narrower than, for example, the outer belt ply 7B.

[0234] The term "tread width TW" refers to the distance in the tire axial direction between tread ends Te, Te. The term "tread end Te" refers to the outermost contact point in the tire axial direction when the tire 1 in the normal state is subjected to a normal load and contacts a plane with a camber angle of 0 degrees.

[0235] A pair of bead sections 4, 4 are fitted with bead apex rubber 8. Figure 2 is an enlarged view of Figure 1. As shown in Figure 2, the bead apex rubber 8 of this embodiment has a two-layer structure including an apex 11 and a bead reinforcing rubber 12. The apex 11 extends, for example, from the outer surface 5a of the bead core 5 in the tire radial direction outward. The bead reinforcing rubber 12 is positioned, for example, further outward in the tire axial direction than the apex 11.

[0236] Bead reinforcement rubber is a component that has the function of reinforcing the bead portion. In this embodiment, the apex 11 and the bead reinforcement rubber 12 are shown arranged with the carcass 6 in between, but the bead reinforcement rubber 12 may also form a two-layer structure in which the apex 11 and the bead reinforcement rubber 12 are arranged adjacent to each other on the tire axial side of the apex 11. In this case, for example, the apex 11 and the bead reinforcement rubber 12 on the tire axial side are arranged adjacent to each other, and the carcass 6 extends in the tire radial direction on the tire axial side of the bead reinforcement rubber 12. Although not shown, the clinch rubber 4G and the bead reinforcement rubber 12 may also form a two-layer structure in which the clinch rubber 4G and the bead reinforcement rubber 12 are arranged adjacent to each other on the tire axial side of the clinch rubber 4G. When bead reinforcement rubber 12 is present, wear resistance and durability of the tire sidewall are improved.

[0237] The reason for these effects is not entirely clear, but it is presumed to be due to the following mechanism. By providing bead reinforcing rubber such as bead reinforcing rubber 12, excessive outward tilting of the folded portion 6b in the tire axial direction is suppressed, providing excellent durability. As a result, wear resistance is improved, good handling stability is provided, and the durability of the tire sidewall is further improved.

[0238] In this embodiment, the apex 11 is sandwiched between the main body portion 6a and the folded portion 6b of each carcass ply 6A and 6B. In this embodiment, the bead reinforcing rubber 12 is positioned on the tire axial side of each folded portion 6b. Thus, in this embodiment, both carcass ply 6A and 6B extend between the apex 11 and the bead reinforcing rubber 12.

[0239] It is desirable that the outer edge 12e of the bead reinforcement rubber 12 in the tire radial direction be located further outward in the tire radial direction than, for example, the outer edge 11e of the apex 11 in the tire radial direction.

[0240] Preferably, the bead reinforcing rubber 12 is formed to include, for example, a first portion 12A of the bead reinforcing rubber 12 in which the thickness t1 in the tire axial direction gradually increases toward the outside in the tire radial direction, and a second portion 12B of the bead reinforcing rubber 12 that is connected to the first portion 12A and in which the thickness t1 gradually decreases toward the outside in the tire radial direction. In this embodiment, the first portion 12A of the bead reinforcing rubber 12 is in contact with the inner portion 6i of the folded portion 6b. In this embodiment, the second portion 12B of the bead reinforcing rubber 12 is in contact with the outer portion 6e of the folded portion 6b.

[0241] The inner end 12i of the bead reinforcing rubber 12 in the tire radial direction is preferably located radially outward from, for example, the outer surface 5a of the bead core 5. In this embodiment, the inner end 12i of the bead reinforcing rubber 12 is preferably located radially inward from the outer end 11e of the apex 11.

[0242] In this embodiment, the apex 11 is formed with a substantially triangular cross-section, where the thickness t2 in the tire axial direction gradually decreases from the outer surface 5a of the bead core 5 outward in the tire radial direction. It is desirable that the outer end 11e of the apex 11 be positioned near the outer end in the tire radial direction of the inner portion 6i of the folded portion 6b.

[0243] In this embodiment, the outer end of the folded portion 6b of the first carcass ply 6A and the outer end of the folded portion 6b of the second carcass ply 6B are spaced apart, for example, in the radial direction of the tire.

[0244] In this embodiment, the outer end of the first carcass ply 6A and the outer end of the second carcass ply 6B are spaced apart in the radial direction of the tire, with the tire's maximum width position M in between. In this embodiment, the outer end of the second carcass ply 6B is located inward in the tire's radial direction from the tire's maximum width position M.

[0245] As shown in Figure 2, the bead portion 4 of this embodiment is equipped with a chafer rubber 20 for preventing rim slippage and a reinforcing member 21 for increasing the rigidity of the bead portion 4.

[0246] The chafer rubber 20 is preferably formed in the form of a thin sheet, for example, with a thickness of about 0.5 to 1.5 mm. The chafer rubber 20 is preferably formed from a hard rubber with excellent abrasion resistance. The chafer rubber 20 can be formed from rubber alone, but it can also be reinforced by embedding, for example, a canvas cloth or an array of organic fiber cords in the rubber to further enhance its abrasion resistance.

[0247] In this embodiment, the chafer rubber 20 is formed including a base portion 20A, an outer piece portion 20B, and an inner piece portion 20C. In this embodiment, the base portion 20A is in contact with the rim seat surface of the rim (not shown) and extends in the tire axial direction. In this embodiment, the outer piece portion 20B is connected to the outer end of the base portion 20A in the tire axial direction and extends radially outward in the tire direction, and is terminated by being sandwiched between the folded portion 6b and the bead reinforcing rubber 12. In this embodiment, the inner piece portion 20C is connected to the inner end of the base portion 20A in the tire axial direction and extends radially outward along the inner surface of the tire and terminates thereafter.

[0248] In this embodiment, the outer piece 20B is sandwiched between the inner portion 6i and the first portion 12A of the bead reinforcing rubber 12, and terminates radially inward from the outer end 11e of the apex 11. Such an outer piece 20B concentrates the strain during driving near the tire's maximum width position M.

[0249] In this embodiment, the reinforcing member 21 extends outward in the tire radial direction, connected to the apex 11. The reinforcing member 21 is sandwiched, for example, between each main body portion 6a and each folded portion 6b. The outer end 21e of the reinforcing member 21 in the tire radial direction is located inward in the tire radial direction than the outer end 12e of the bead reinforcing rubber 12.

[0250] The reinforcing member 21 is preferably formed with a thickness t4 in the range of 0.5 to 3.0 mm.

[0251] In tire 1, the tread rubber 2G is provided with main grooves 42 as grooves 26. As shown in Figure 1, this tread rubber 2G has multiple main grooves 42, specifically three. These main grooves 42 are spaced apart in the axial direction. The three main grooves 42 on this tread 4 form four ribs that extend in the circumferential direction. Each of the main grooves 42 extends in the circumferential direction. The main grooves 42 are continuous and uninterrupted in the circumferential direction. [Examples]

[0252] The following examples (implementations) are considered preferable for implementation, but the scope of the present invention is not limited to these examples.

[0253] The various chemicals used in the examples and comparative examples are described below.

[0254] (Rubber component) Halide-treated butyl rubber: Bromobutyl rubber 2255 (brominated butyl rubber) manufactured by ExxonMobil. NR:TSR20 BR: BR150B manufactured by Ube Industries, Ltd. (Cystic content: 97% by mass, Vinyl content: 1% by mass)

[0255] (Chemicals other than rubber components) Carbon Black 1: Show Black N220 (24M4DBP) manufactured by Cabot Japan Co., Ltd. (Oil absorption capacity: 98cm³) 3 / 100g, N2SA:115m 2 / g) Carbon Black 2: Printex XE2B (24M4DBP) manufactured by Orion Engineered Carbons (oil absorption capacity: 420cm³) 3 / 100g, N2SA:1000m 2 / g, DBP oil absorption: 420cm 3 (100g) Carbon Black 3: Show Black N550 (N2SA: 42m) manufactured by Cabot Japan Co., Ltd. 2 / g) Stearic acid: Stearic acid "Tsubaki" manufactured by NOF Corporation 1-Butylimidazole: Manufactured by Tokyo Chemical Industry Co., Ltd. 1-Methylimidazole: Manufactured by Tokyo Chemical Industry Co., Ltd. 1-Nonylimidazole: Manufactured by Tokyo Chemical Industry Co., Ltd. 4-Dimethylaminopyridine: Manufactured by Tokyo Chemical Industry Co., Ltd. Oil: Diana Process NH-70S manufactured by Idemitsu Kosan Co., Ltd. Zinc oxide: Zinc oxide manufactured by Mitsui Mining & Smelting Co., Ltd. Sulfur: HK-200-5 (5% oil-containing powdered sulfur) manufactured by Hosoi Chemical Industry Co., Ltd. Vulcanization accelerator: Noxellar CZ (N-cyclohexyl-2-benzothiazolyl sulfenamide) manufactured by Ouchi Shinko Chemical Industry Co., Ltd.

[0256] (Examples and Comparative Examples) According to the formulation shown in Table 1, the materials other than sulfur and vulcanization accelerator were kneaded for 5 minutes at 150°C using a 1.7L Banbury mixer manufactured by Kobe Steel, Ltd. to obtain a mixture. Next, sulfur and vulcanization accelerator were added to the mixture and kneaded for 5 minutes at 80°C using an open roll to obtain an unvulcanized rubber composition. Next, the unvulcanized rubber composition is molded into the shape of the sidewall and clinch, and bonded together with other tire components to form an unvulcanized tire with bead reinforcement rubber. This tire is then press-vulcanized at 150°C for 12 minutes to produce the test tire (size: 175 / 60R18) shown in Figures 1 and 2. The test tires manufactured in this manner were examined, and the results calculated based on the evaluation method described below are shown in Table 1. In Table 1, Hs represents the hardness of the sidewall and clinch, tanδ(70°C) represents the tanδ of the sidewall and clinch at 70°C, tanδ × total filler amount represents (tanδ of the sidewall and clinch at 70°C) × (total filler content per 100 parts by mass of rubber component in the sidewall and clinch), Hs / tanδ represents (hardness of sidewall and clinch) / (tanδ of sidewall and clinch at 70°C), Hs × 24MDBP represents (hardness of sidewall and clinch) × (24M4DBP oil absorption amount of carbon black contained in the sidewall and clinch), rubber thickness [mm] represents the thickness Tc [mm] of the sidewall and clinch, and 24MDBP / rubber thickness represents (24M4DBP oil absorption amount of carbon black contained in the sidewall and clinch) / (thickness Tc [mm] of sidewall and clinch).

[0257] <hs> A test specimen is cut from the sidewall or clinch of a test tire. The hardness Hs of the test specimen is then measured using a Type A durometer in accordance with JIS K6253-3 (2012) "Vulcanized rubber and thermoplastic rubber - Method for determining hardness - Part 3: Durometer hardness". The measurement is performed at 25°C.

[0258] <Viscoelasticity Measurement> In accordance with JIS K6394:2007, the loss tangent (tanδ) is measured using a viscoelastic spectrometer (GABO's "Iplexer series") under the conditions of initial strain 10%, dynamic strain 1%, frequency 10Hz, temperature 70°C, and tensile mode. The test specimen (length: 20mm, width: 4mm, thickness: 1mm) is sampled from the sidewall or clinch of the test tire. When sampling, the length direction of the test specimen is aligned with the circumferential direction of the tire, and the thickness direction of the test specimen is aligned with the radial direction of the tire.

[0259] <Durability of the tire sidewall> Cracks are made in the sidewall of the test tires, running along the circumferential direction of the tire. Each test tire with cracks is mounted on a vehicle and driven on rough roads until the driver notices something unusual. The distance traveled until the driver notices something unusual is expressed as an index, with the distance traveled until the driver notices something unusual in the reference comparison (Comparative Example 1) set to 100. A higher index indicates better durability of the tire's sidewall.

[0260] [Table 1]

[0261] The present invention (1) is a tire having a sidewall and / or clinch, Butyl rubber, a cyclic amine having a double bond in the ring, and 24M4 dibutyl phthalate with an oil absorption capacity of 170 cm³ (24M4 DBP oil absorption capacity). 3 A rubber composition containing 100g or more of carbon black is used in the sidewall and / or clinch. Furthermore, this relates to a tire having bead reinforcement rubber.

[0262] The present invention (2) relates to the tire according to the present invention (1), wherein the hardness of the sidewall and / or clinch using the rubber composition is greater than 45.

[0263] The present invention (3) relates to the tire according to the present invention (1) or (2), wherein the rubber composition has a total filler content of less than 40 parts by mass per 100 parts by mass of rubber component.

[0264] The present invention (4) relates to a tire according to any one of the present inventions (1) to (3), wherein the tanδ × total filler amount of the sidewall and / or clinch using the rubber composition is < 3 (where the total filler amount means the total filler content per 100 parts by mass of rubber component in the rubber composition).

[0265] The present invention (5) relates to a tire according to any one of the present inventions (1) to (4), wherein the total amount of filler in the sidewall and / or clinch using the rubber composition is tanδ × total amount of filler < 2 (where the total amount of filler means the total content of filler per 100 parts by mass of rubber component in the rubber composition).

[0266] The present invention (6) relates to a tire according to any one of the present inventions (1) to (5), wherein the hardness of the sidewall and / or clinch using the rubber composition / tanδ of the sidewall and / or clinch using the rubber composition > 200.

[0267] The present invention (7) relates to a tire according to any one of the present inventions (1) to (6), wherein the tanδ of the sidewall and / or clinch using the rubber composition is 0.10 or more and 0.20 or less.

[0268] The present invention (8) is that the hardness of the sidewall and / or clinch using the rubber composition × the 24M4DBP oil absorption of the carbon black contained in the rubber composition is 7600 cm 3 This invention relates to a tire according to any one of claims (1) to (7) of the present invention, which weighs 100g or more.

[0269] The present invention (9) relates to the 24M4DBP oil absorption amount of carbon black contained in the rubber composition / the thickness of the sidewall and / or clinch in which the rubber composition is used is 68 cm 3 This invention relates to a tire described in any one of claims (1) to (8) of the present invention, having a weight of (100g·mm) or more.

[0270] The present invention (10) relates to a tire according to any one of the present inventions (1) to (9), wherein the rubber composition comprises isoprene rubber and / or butadiene rubber.

[0271] The present invention (11) relates to a tire according to any one of the present inventions (1) to (10), wherein the rubber composition comprises isoprene rubber and butadiene rubber.

[0272] The present invention (12) relates to a tire according to any one of the present inventions (1) to (11), wherein the butyl rubber is halogenated butyl rubber.

[0273] The present invention (13) relates to a tire according to any one of the present inventions (1) to (12), wherein the butyl rubber is brominated butyl rubber.

[0274] The present invention (14) relates to the rubber composition wherein the amount of oil absorbed by 24M4DBP in the total filler content of 100% by mass is 170 cm 3 This invention relates to a tire according to any one of claims (1) to (13) of the present invention, wherein the carbon black content is 60% by mass or more, and the carbon black content is 100g or more.

[0275] The present invention (15) relates to a tire for electric vehicles, as described in any one of the present inventions (1) to (14). [Explanation of Symbols]

[0276] 1 tire 2 Tread section 2a Tread contact surface 2G Tread Rubber 3. Sidewall section 3a Outer surface of sidewall portion 3 3G Sidewall Rubber 4. Bead section 4a Outer surface of bead portion 4 4G Clinch Rubber 5 Bead core 5a Outer surface of the bead core 5 in the radial direction of the tire 6 Carcass 6A 1st Carcass Spry 6B 2nd Carcass Ply 6a Main body 6b Folded section 6o Outer edge in the radial direction of the tire 6i Inner portion that slopes inward in the axial direction of the tire 6e Outer part that slopes outward in the axial direction of the tire 7 Belt layer 7A Inner belt ply 7B Outer belt ply 8 Bead Apex Rubber 11 Apex Legends 11e Apex 11 tire radial outer edge 12 Bead reinforcement rubber 12A First part of bead reinforcement rubber 12 12B Bead reinforcement rubber 12, second part 12e Bead reinforcement rubber 12 Tire radial outer edge 12i Bead reinforcement rubber 12 Tire radial inner edge 20 Chaehwa Gum 20A base 20B Outer piece 20C inner piece 21 Reinforcement member 21e Outer end of reinforcing member 21 in the tire radial direction 26 Groove 42 Main groove C Tire Equator Wa Inner Belt Ply 7A Tire Axial Width TW Tread width Te tread edge M tire maximum width position t1 Bead reinforcement rubber 12 Tire axial thickness T2 Apex 11 tire axial thickness t4 Thickness of reinforcing member 21< / hs>

Claims

1. A tire having a sidewall and / or clinch, Butyl rubber, a cyclic amine having a double bond in the ring, and 24M4 dibutyl phthalate oil absorption (24M4 DBP oil absorption) of 170 cm ３ A rubber composition containing 100g or more of carbon black is used in the sidewall and / or clinch. Furthermore, the tire has bead reinforcement rubber.

2. The tire according to claim 1, wherein the hardness of the sidewall and / or clinch using the rubber composition is greater than 45.

3. The tire according to claim 1 or 2, wherein the rubber composition contains less than 40 parts by mass of filler per 100 parts by mass of rubber component.

4. The tire according to claim 1 or 2, wherein the tanδ × total filler amount of the sidewall and / or clinch using the rubber composition is < 3 (where the total filler amount means the total content of filler per 100 parts by mass of rubber component in the rubber composition).

5. The tire according to claim 1 or 2, wherein the tanδ × total filler amount of the sidewall and / or clinch using the rubber composition is < 2 (where the total filler amount means the total content of filler per 100 parts by mass of rubber component in the rubber composition).

6. The tire according to claim 1 or 2, wherein the hardness of the sidewall and / or clinch using the rubber composition / tanδ of the sidewall and / or clinch using the rubber composition > 200.

7. The tire according to claim 1 or 2, wherein the tanδ of the sidewall and / or clinch using the rubber composition is 0.10 or more and 0.20 or less.

8. The hardness of the sidewall and / or clinch using the rubber composition × the 24M4DBP oil absorption of the carbon black contained in the rubber composition is 7600 cm². ３ A tire according to claim 1 or 2, wherein the weight is 100g or more.

9. The amount of 24M4DBP oil absorbed by the carbon black contained in the rubber composition / the thickness of the sidewall and / or clinch in which the rubber composition is used is 68 cm. ３ A tire according to claim 1 or 2, having a thickness of 100 g / mm or more.

10. The tire according to claim 1 or 2, wherein the rubber composition comprises isoprene rubber and / or butadiene rubber.

11. The tire according to claim 1 or 2, wherein the rubber composition comprises isoprene rubber and butadiene rubber.

12. The tire according to claim 1 or 2, wherein the butyl rubber is halogenated butyl rubber.

13. The tire according to claim 1 or 2, wherein the butyl rubber is brominated butyl rubber.

14. In the aforementioned rubber composition, the amount of 24M4DBP oil absorbed in 100% by mass of the total filler content is 170 cm³. ３ A tire according to claim 1 or 2, wherein the carbon black content is 60% by mass or more, comprising 100g or more of carbon black.

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

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