tire

Abstract

A pneumatic tire (1) comprises: a tread part (2) including land sections (24) delimited by a plurality of main grooves (22) formed in a tread surface (21); an inner liner (7) forming a tire inner surface (7A) on an inner side of the tread part (2); and a mount member (10) that is provided on the tire inner surface (7A) and on which an electric device can be mounted. In the pneumatic tire (1), the acetone extraction amount (AE2) of a rubber composition contained in the inner liner (7) is greater than the acetone extraction amount (AE1) of a rubber composition contained in the mount member (10).

Description

[Technical Field]

[0001] The present disclosure relates to tires mounted on vehicles. [Background technology]

[0002] A tire pressure monitoring system (TPMS) has been proposed in the past for detecting and monitoring the air pressure (tire pressure) of tires mounted on a vehicle (see Patent Document 1). A sensor unit is attached to each tire, and the sensor unit is made up of a sensor that detects tire pressure and a transmitter that transmits the detected tire pressure value. The tire pressure monitoring system monitors changes in tire pressure based on a signal transmitted from the sensor unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2004-155352 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, in order to ensure safe and comfortable vehicle driving, it has become increasingly important to properly detect and manage tire information, such as not only tire pressure but also tire temperature, vibration, and the wear state of the tire tread. One possible way to detect the tire information is to equip the tire with an electrical device, such as a sensor, for detecting the tire information. To accurately obtain the tire information, it is considered desirable for the electrical device to be attached to the inner surface of the tire. However, when the electrical device is attached to the inner surface of the tire, the air permeation resistance of the attachment portion of the electrical device and its surroundings relative to the inner liner that constitutes the inner surface of the tire deteriorates over long-term use of the tire, which may result in a so-called air leak in that portion.

[0005] An object of the present disclosure is to prevent a decrease in the air leak resistance of an inner liner in a tire that is provided with a mounting member to which an electrical device such as a sensor can be attached. [Means for solving the problem]

[0006] A tire according to one aspect of the present disclosure includes a tread portion constituting the tire surface, an inner liner constituting the tire inner surface, and a mounting member provided on the tire inner surface to which an electrical device can be attached. Both a first rubber composition constituting the mounting member and a second rubber composition constituting the inner liner contain a plasticizer. In the tire, an acetone extractable amount AE2 of the second rubber composition is greater than an acetone extractable amount AE1 of the first rubber composition.

[0007] Because the tire is configured in this manner, even if the plasticizer contained in the first rubber composition of the mounting member bleeds due to long-term use, the plasticizer is less likely to transfer to the inner liner, and the mounting portion of the inner liner and its surrounding area can be prevented from softening more than other areas. As a result, a decrease in air permeability resistance due to softening of that area is suppressed, and a decrease in air leak resistance in that area can be prevented. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to prevent a decrease in the air leak resistance of an inner liner in a tire that is provided with a mounting member to which an electrical device such as a sensor can be attached. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a side view of a tire according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a partial cross-sectional view of the tire, showing a cross section taken along the line II-II in FIG. [Figure 3A] FIG. 3A is a schematic diagram showing an example of a mount member attached to the tire. [Figure 3B] FIG. 3B is a schematic diagram showing an example of a mount member attached to the tire. [Figure 4A] FIG. 4A is a schematic diagram showing another example of the mount member attached to the tire. [Figure 4B] FIG. 4B is a schematic diagram showing another example of the mount member attached to the tire. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. Note that the following embodiments are examples that embody the present disclosure and do not limit the technical scope of the present disclosure.

[0011] FIG. 1 is a side view of a pneumatic tire 1 (hereinafter abbreviated as "tire 1") according to an embodiment of the present disclosure, as viewed from the side. FIG. 2 is a cross-sectional view of the tire 1, showing a cross section taken along section II-II in FIG. 1. FIG. 1 partially shows the cross-sectional structure of the equatorial plane CL (see FIG. 2). Here, the up-down direction on the paper in FIGS. 1 and 2 is the radial direction D2 of the tire 1. The left-right direction on the paper in FIG. 2 is the width direction D1 of the tire 1. Arrow D3 shown in FIG. 1 is the circumferential direction of the tire 1. Note that the tire 1 is formed symmetrically in the width direction D1 with respect to the equatorial plane CL1, and therefore FIG. 2 shows a partial cross-sectional view of the tire 1, and other portions are not shown.

[0012] The tire 1 is made primarily of rubber material and is primarily used by being mounted on a vehicle such as an automobile. As shown in FIGS. 1 and 2, the tire 1 is mounted on a rim 30R of a wheel 30. The rim 30R is a standard rim, which will be described later. The tire 1 is a pneumatic tire in which air is filled into the hollow space between the rim 30R and the inner surface 7A of the tire 1. The internal pressure inside the tire 1 is adjusted to a standard internal pressure, which will be described later.

[0013] In this specification, the state in which the internal pressure of the tire 1 mounted on the rim 30R is adjusted to the normal internal pressure and no load is applied to the tire 1 is referred to as the normal state. Figures 1 and 2 show the tire 1 in the normal state mounted on the wheel 30. In this embodiment, unless otherwise specified, the shapes of the tire 1 and each part thereof are the shapes in the normal state, and the dimensions and angles of the tire 1 and each part thereof are measured in the normal state.

[0014] Here, the regular rim is a rim defined in the standard on which the tire 1 is based. Specifically, the regular rim is a "standard rim" in the standard (JATMA standard) defined by JATMA (Japan Automobile Tire Manufacturers Association), a "design rim" in the standard (TRA standard) defined by the US TRA (The Tire and Rim Association), and a "measuring rim" in the standard (ETRTO standard) defined by ETRTO (European Tire Rim Technical Organisation).

[0015] The normal internal pressure is the internal pressure defined in the standard on which the tire 1 is based. Specifically, the normal internal pressure is the "maximum air pressure" in the JATMA standard, the "maximum value" indicated in "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" in the TRA standard, and the "INFLATION PRESSURE" in the ETRTO standard.

[0016] The tire 1 according to this embodiment is preferably used as a radial tire for automobiles. The tire 1 is a pneumatic tire for vehicles, and is not limited to automobiles. It may be a pneumatic tire for use on a wide variety of vehicles, such as passenger cars, large vehicles such as trucks and buses, motorcycles, racing vehicles, industrial vehicles, special vehicles, and load-bearing vehicles such as trailers and dollies. The tire 1 is not limited to radial tires, and is also preferably used as a bias tire. In particular, the tire 1 is preferably used as a tire for passenger cars that are equipped with various electrical devices such as sensors and that require high convenience and low noise during high-speed driving. The passenger car tire is a tire that is mounted on a four-wheeled vehicle and has a maximum load capacity of 1000 kg or less.

[0017] The maximum load capacity is not particularly limited as long as it is 1000 kg or less. However, generally, as the maximum load capacity increases, the tire weight tends to increase, which increases the vibration generated in the tread portion 2 of the tire 1 and increases the noise during running. Therefore, the maximum load capacity is preferably 900 kg or less, more preferably 800 kg or less, and even more preferably 700 kg or less.

[0018] Moreover, from the viewpoint of reducing vibrations in the tread portion 2, the weight of the tire 1 is preferably 20 kg or less, more preferably 15 kg or less, and even more preferably 12 kg or less, 10 kg or less, or 8 kg or less. Note that the tire weight includes the weight of the electrical equipment and the mounting member 10 described below, and also includes the weight of any sealant, sponge, or the like provided in the inner cavity of the tire 1.

[0019] As shown in FIG. 2, the tire 1 includes a tread portion 2, a pair of shoulder portions 3 located at both ends of the tread portion 2 in the width direction D1, a pair of sidewall portions 4 extending from the shoulder portions 3 in a central direction D21 (inward in the radial direction D2) toward the central axis of the tire 1, and a pair of bead portions 5 located at the ends of the sidewall portions 4 on the central direction D21 side.

[0020] Furthermore, the tire 1 includes a carcass 6 extending from the tread portion 2 through the shoulder portion 3 and the sidewall portion 4 to the bead core 5A of the bead portion 5, an inner liner 7 that forms the inner surface 7A of the tire 1, a belt portion 8 and a band portion 9 that are arranged on the inside of the tread portion 2 in the radial direction D2, and a mounting member 10 that is attached to the inner surface 7A of the tire 1 (i.e., the inner surface 7A of the inner liner 7).

[0021] The tread portion 2 is the portion that comes into contact with the road surface when the vehicle is running. The tread portion 2 is made of tread rubber 2A made of a vulcanized rubber composition (vulcanized rubber). The outer surface of the tread portion 2 is a tread surface 21 (an example of a tire surface) that is the surface that comes into contact with the road surface. In this embodiment, the tread surface 21 is a surface that is generally flat in the width direction D1. That is, the tire 1 has the tread portion 2 formed in a flat shape in the width direction D1.

[0022] The rubber composition constituting the tread rubber 2A contains, in addition to the rubber component, fillers (reinforcing agents) such as carbon black and silica, oil, resins such as phenolic resin, processing aids, and additives such as stearic acid, zinc oxide, sulfur, and vulcanization accelerators.

[0023] The rubber component can be a common rubber material, such as isoprene-based rubber, butadiene rubber (BR), styrene-butadiene rubber (SBR), styrene-isoprene rubber, styrene-isoprene-butadiene rubber (SIBR), isoprene-butadiene rubber, acrylonitrile-butadiene rubber (NBR), acrylonitrile-styrene-butadiene rubber, chloroprene rubber (CR), and chlorosulfonated polyethylene. Examples of the isoprene-based rubber include natural rubber (NR), epoxidized natural rubber (ENR), isoprene rubber (IR), modified NR, modified NR, and modified IR. The rubber component can be any one of the rubber materials, or two or more of the rubber materials can be mixed at a predetermined blending ratio.

[0024] A tread pattern is formed on the tread surface 21 to exhibit various tire performance characteristics, such as grip, braking, drainage, and wear suppression. The tread pattern is formed by a plurality of recessed grooves formed on the tread surface 21. The tread surface 21 is formed with a plurality of main grooves 22 (an example of a circumferential groove of the present disclosure) that extend continuously in the circumferential direction D3 (see FIG. 1 ) of the tire 1 as the recessed grooves. Note that a plurality of lug grooves (not shown) that intersect with the main grooves 22, a plurality of sipes that are narrower and shallower than the main grooves 22 and the lug grooves, and the like may also be formed on the tread surface 21. Note that the recessed grooves referred to here refer to grooves with a groove width of more than 2.0 mm and a groove depth of more than 5.0 mm.

[0025] The tread pattern formed on the tread surface 21 may be a so-called rib-type pattern having a plurality of main grooves 22, or a so-called rib-type pattern having main grooves 22 and the lug grooves. However, the tread portion 2 of the tire 1 is not limited to having any of the above patterns formed on the tread surface 21. For example, the tread portion 2 may have a so-called lug-type pattern formed on the tread surface 21, mainly having the lug grooves, or a so-called block-type pattern formed on the tread surface 21, each having independent blocks. The tread pattern may also be asymmetric with respect to the width direction of the contact patch.

[0026] In this embodiment, the tread pattern formed on the tread surface 21 is symmetrical in the width direction D1 with respect to the equatorial plane CL1. Specifically, as shown in FIG. 2, four main grooves 22 are formed on the tread surface 21 along the circumferential direction D3. The four main grooves 22 are arranged at predetermined intervals in the width direction D1 of the tire 1, with two main grooves 22 arranged in each region of the tread surface 21 on the outer side of the equatorial plane CL1 in the width direction D1. Therefore, the tread portion 2 has five land portions 24 divided in the width direction D1 by the four main grooves 22 extending along the circumferential direction D3. Note that this embodiment illustrates a configuration in which four main grooves 22 are formed on the tread surface 21 as shown in FIG. 2, but the present disclosure is not limited to such a configuration. For example, the positions of the main grooves 22 may be asymmetric with respect to the width direction D1. Furthermore, the number of main grooves 22 is not limited to four, and may be less than four or five or more. Also, any one of the main grooves 22 may be provided on the equatorial plane CL1.

[0027] As shown in FIG. 2 , the five land portions 24 include one crown land portion 24A, two middle land portions 24B, and two shoulder land portions 24C. The shoulder land portions 24C are disposed near the shoulder portions 3 and are separated between both side ends of the tread portion 2 in the width direction D1 and the two second main grooves 22B disposed outermost in the width direction D1. The middle land portion 24B is separated between the two first main grooves 22A disposed near the equatorial plane CL1 and the two second main grooves 22B. The crown land portion 24A is disposed in the center of the tread portion 2 of the tire 1 in the width direction D1. In this embodiment, the crown land portion 24A is disposed at a portion of the tread portion 2 that intersects with the equatorial plane CL1. For example, the crown land portions 24A occupy regions of the tread portion 2 that are separated by a predetermined distance in the width direction D1 from the point of intersection with the equatorial plane CL1. The center of this region coincides with the equatorial plane CL1, and the ratio of this region to the contact width of the contact patch of the tread portion 2 is determined within a range of 10 to 50%. For example, the ratio is preferably 30%, and more preferably 20%. The crown land portion 24A is provided in a region of the tread portion 2 that is partitioned between each of the two first main grooves 22A. For example, the crown land portion 24A is a partitioned portion sandwiched between the two first main grooves 22A.

[0028] The crown land portion 24A may extend linearly or zigzag along the circumferential direction D3. The crown land portion 24A may extend obliquely in the circumferential direction D3, or may extend in a curved or arcuate shape. To achieve the above-described shape of the crown land portion 24A, the two first main grooves 22A located on both sides of the crown land portion 24A in the width direction D1 are each formed to extend linearly, zigzag, obliquely, curved, or arcuately along the circumferential direction D3. The crown land portion 24A may have multiple blocks separated in the circumferential direction D3 by lateral grooves or oblique grooves such as lug grooves, or may have multiple semi-blocks separated in the circumferential direction D3 by lateral grooves or oblique grooves such as sipes. The other land portions 24, except for the crown land portion 24A, also extend along the circumferential direction D3 and have the same shape as the crown land portion 24A.

[0029] When the tire 1 is for a passenger car, the groove width of the first main groove 22A is, for example, 4.0% to 7.0% of the width of the tread portion 2. The groove width of the second main groove 22B is, for example, 2.5% to 4.5% of the width of the tread portion 2. The groove depth of the first main groove 22A and the second main groove 22B is, for example, 5 to 10 mm.

[0030] The shoulder portions 3 are portions corresponding to the corners of the tire 1 extending from the tread portion 2 to the sidewall portions 4. The shoulder portions 3 are portions that connect the tread portion 2 and the sidewall portions 4, and are formed in a rounded (curved) shape from the end of the tread portion 2 in the width direction D1 to the upper end of the sidewall portions 4.

[0031] The sidewall portion 4 is made of a vulcanized rubber composition (vulcanized rubber). The sidewall portion 4 is arranged on the outer side of the carcass 6 in the width direction D1. The sidewall portion 4 is connected to an end portion of the tread rubber 2A constituting the tread portion 2 in the width direction D1, and extends along the carcass 6 in the center direction D21. The sidewall portion 4 protects the carcass 6 on the side of the tire 1.

[0032] The carcass 6 is disposed inside the tread 2 and the pair of sidewalls 4, closer to the tread 2 and the sidewalls 4 than the inner liner 7. The carcass 6 is composed of at least one carcass ply. The carcass ply is a cord layer having a large number of carcass cords (not shown) extending in a direction intersecting the equatorial plane CL1 of the tire 1. The carcass ply is formed by covering these carcass cords with a topping rubber made of a predetermined rubber composition (vulcanized rubber). The large number of carcass cords are arranged in a line along the circumferential direction D3 of the tire 1, intersecting the equatorial plane CL1 of the tire 1 at a predetermined angle (for example, an angle set within a range of 70 to 90 degrees). The carcass cords are, for example, cords made of organic fibers such as nylon fibers, polyester fibers, rayon fibers, and aramid fibers (hereinafter referred to as "organic fiber cords").

[0033] The inner liner 7 is provided on the inner side of the carcass 6 and forms an inner surface 7A of the tire 1. The inner liner 7 is made of a rubber composition (vulcanized rubber) that has air barrier properties, and plays a role in maintaining the internal pressure of the tire 1.

[0034] The inner liner 7 is bonded to the inner surface of the carcass 6. The inner liner 7 may be bonded directly to the carcass 6, or may be bonded to an insulation layer disposed radially inward of the carcass 6.

[0035] The rubber composition (second rubber composition) constituting the inner liner 7 contains, in addition to the rubber component, fillers (reinforcing agents) such as carbon black and calcium carbonate, plasticizers such as oils and resins, antioxidants, compatibilizers, stearic acid, zinc oxide, sulfur, coupling agents, vulcanization accelerators, and other additives.

[0036] The rubber component can be a rubber material primarily composed of butyl-based rubber, which has excellent air permeability resistance. Examples of butyl-based rubber include halogenated butyl rubbers (X-IIR) such as butyl rubber (IIR), brominated butyl rubber (BR-IIR), and chlorinated butyl rubber (Cl-IIR), copolymers of isobutylene and p-alkylstyrene, and halides of these copolymers. Halogenated butyl rubber is particularly preferred, with brominated butyl rubber and chlorinated butyl rubber being more preferred, as they can achieve a balanced improvement in sheet processability and air barrier properties. The rubber component can be any one of the butyl-based rubbers, or a mixture of two or more of the rubber materials at a predetermined blending ratio. A viscoelastic material primarily composed of a plastic elastomer with low air permeability can also be used as the rubber composition constituting the inner liner 7.

[0037] As the butyl rubber, it is preferable to use recycled butyl rubber in combination with regular butyl rubber (butyl rubber other than recycled butyl rubber). Recycled butyl rubber usually has a high content of non-halogenated butyl rubber (regular butyl rubber), so by using it in combination with halogenated butyl rubber, good air barrier properties and vulcanization speed can be ensured.

[0038] The total content of butyl rubbers in 100% by mass of the rubber component is 70% by mass or more, preferably 75% by mass or more, and more preferably 80% by mass or more. If it is less than 70% by mass, sufficient air barrier properties may not be obtained. The total content may be 100% by mass, but from the viewpoints of sheet processability and air barrier properties, it is preferably 95% by mass or less, more preferably 90% by mass or less.

[0039] The content of recycled butyl rubber in 100% by mass of the rubber component is preferably 5% by mass or more, more preferably 8% by mass or more. If it is less than 5% by mass, the benefits of using recycled butyl rubber may not be fully obtained. The content is preferably 30% by mass or less, more preferably 25% by mass or less. If it exceeds 30% by mass, sufficient air barrier properties and vulcanization speed may not be ensured.

[0040] The rubber composition constituting the inner liner 7 preferably contains an isoprene-based rubber, since this can improve sheet processability and air barrier properties in a well-balanced manner.

[0041] Examples of the isoprene-based rubber include natural rubber (NR), epoxidized natural rubber (ENR), isoprene rubber (IR), etc. NR and IR are particularly preferred because they can improve sheet processability and air barrier properties in a balanced manner.

[0042] The NR is not particularly limited, and those commonly used in the tire industry can be used, such as SIR20, RSS#3, TSR20, etc. The IR is not particularly limited, and those commonly used in the tire industry can be used.

[0043] The content of isoprene-based rubber in 100% by mass of the rubber component is preferably 5% by mass or more, more preferably 10% by mass or more. If it is less than 5% by mass, a good balance between sheet processability and air barrier properties may not be obtained. The content is preferably 30% by mass or less, more preferably 25% by mass or less. If it exceeds 30% by mass, the vulcanized rubber may not have sufficient air barrier properties.

[0044] In this embodiment, the rubber component of the rubber composition constituting the inner liner 7 may contain other rubber materials in addition to butyl rubber and isoprene rubber. Examples of such diene rubbers include butadiene rubber (BR), styrene butadiene rubber (SBR), ethylene propylene diene rubber (EPDM), styrene isoprene butadiene rubber (SIBR), chloroprene rubber (CR), and acrylonitrile butadiene rubber (NBR). The rubber component of the inner liner 7 may be any one of these rubber materials used alone, or two or more rubber materials may be mixed at a predetermined blending ratio.

[0045] The rubber composition constituting the inner liner 7 preferably contains a filler. Specific fillers include, for example, carbon black, silica, calcium carbonate, talc, alumina, clay, aluminum hydroxide, and mica. Among these, carbon black and calcium carbonate are preferably used as reinforcing agents, and it is preferable to use these in combination.

[0046] The carbon black is not particularly limited, and examples thereof include N134, N110, N220, N234, N219, N339, N330, N326, N351, N550, and N762. These may be used alone or in combination of two or more.

[0047] As the carbon black, for example, products manufactured by Asahi Carbon Co., Ltd., Cabot Japan Co., Ltd., Tokai Carbon Co., Ltd., Mitsubishi Chemical Corporation, Lion Corporation, Shin-Nichika Carbon Co., Ltd., Columbia Carbon Co., Ltd., etc. can be used.

[0048] The amount of the carbon black is preferably 1 part by mass or more, more preferably 3 parts by mass or more, and is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, and even more preferably 10 parts by mass or less, based on 100 parts by mass of the rubber component.

[0049] The rubber composition constituting the inner liner 7 preferably contains a plasticizer (softener). Specific examples of the plasticizer will be described later.

[0050] The rubber composition constituting the inner liner 7 preferably contains an antioxidant. The antioxidant is not particularly limited as long as it is one generally used in the tire industry, and examples thereof include naphthylamine-based antioxidants such as phenyl-α-naphthylamine; diphenylamine-based antioxidants such as octylated diphenylamine and 4,4'-bis(α,α'-dimethylbenzyl)diphenylamine; N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, N,N'-di-2-naphthylamine; Examples of antioxidants include p-phenylenediamine antioxidants such as methyl-p-phenylenediamine; quinoline antioxidants such as polymers of 2,2,4-trimethyl-1,2-dihydroquinoline; monophenol antioxidants such as 2,6-di-t-butyl-4-methylphenol and styrenated phenol; and bis-, tris-, and polyphenol antioxidants such as tetrakis-[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane. These antioxidants may be used alone or in combination of two or more. In particular, p-phenylenediamine antioxidants and quinoline antioxidants are preferred.

[0051] As the antioxidant, for example, products available from Seiko Chemical Co., Ltd., Sumitomo Chemical Co., Ltd., Ouchi Shinko Chemical Industry Co., Ltd., Flexis, etc. can be used.

[0052] The rubber composition constituting the inner liner 7 preferably contains a compatibilizer. The compatibilizer is not particularly limited as long as it is one commonly used in the tire industry, and examples thereof include non-reactive compatibilizers such as styrene-ethylene-butadiene block copolymers, styrene-methyl methacrylate block copolymers, ethylene-styrene graft copolymers, chlorinated polyethylene, mixtures of aromatic hydrocarbon resins and aliphatic hydrocarbon resins, and metal soaps of unsaturated fatty acids, and reactive compatibilizers such as maleic anhydride graft polypropylene, styrene-maleic anhydride copolymers, ethylene-glycidyl methacrylate copolymers, and styrene graft copolymers of ethylene-glycidyl methacrylate copolymers. These may be used alone or in combination of two or more.

[0053] The content of the compatibilizer is preferably 5% by mass or more, more preferably about 5 to 15% by mass, and even more preferably about 5 to 10% by mass, relative to 100% by mass of the rubber component, from the viewpoint of effectively reducing the gas permeability of the rubber composition while suppressing the formation of large voids.

[0054] The stearic acid contained in the rubber composition constituting the inner liner 7 can be any conventionally known product, such as products from NOF Corporation, NOF Corporation, Kao Corporation, Fujifilm Wako Pure Chemical Industries, Ltd., Chiba Fatty Acid Co., Ltd., etc.

[0055] The zinc oxide contained in the rubber composition constituting the inner liner 7 can be any conventionally known material, such as products from Mitsui Mining & Smelting Co., Ltd., Toho Zinc Co., Ltd., Hakusui Tech Co., Ltd., Seido Chemical Industry Co., Ltd., Sakai Chemical Industry Co., Ltd., etc.

[0056] The sulfur contained in the rubber composition constituting the inner liner 7 is not particularly limited as long as it is one commonly used in the tire industry, and examples thereof include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersible sulfur, soluble sulfur, etc. These may be used alone or in combination of two or more.

[0057] As the sulfur, for example, products available from Tsurumi Chemical Industry Co., Ltd., Karuizawa Iso Co., Ltd., Shikoku Chemical Industry Co., Ltd., Flexis Corporation, Nippon Kanzuri Kogyo Co., Ltd., Hosoi Chemical Industry Co., Ltd., etc. can be used.

[0058] The vulcanization accelerator contained in the rubber composition constituting the inner liner 7 is not particularly limited as long as it is one commonly used in the tire industry, and examples thereof include thiazole-based vulcanization accelerators such as 2-mercaptobenzothiazole and di-2-benzothiazolyl disulfide; thiuram-based vulcanization accelerators such as tetramethylthiuram disulfide (TMTD), tetrabenzylthiuram disulfide (TBzTD), and tetrakis(2-ethylhexyl)thiuram disulfide (TOT-N); sulfenamide-based vulcanization accelerators such as N-cyclohexyl-2-benzothiazolylsulfenamide, Nt-butyl-2-benzothiazolylsulfenamide, N-oxyethylene-2-benzothiazolesulfenamide, N-oxyethylene-2-benzothiazolesulfenamide, and N,N'-diisopropyl-2-benzothiazolesulfenamide; and guanidine-based vulcanization accelerators such as diphenylguanidine, di-orthotolylguanidine, and orthotolylbiguanidine. These may be used alone or in combination of two or more. In particular, sulfenamide vulcanization accelerators and thiuram vulcanization accelerators are preferred, and a combined use of a sulfenamide vulcanization accelerator and a thiuram vulcanization accelerator is more preferred.

[0059] As the vulcanization accelerator, for example, products manufactured by Kawaguchi Chemical Co., Ltd., Ouchi Shinko Chemical Co., Ltd., Rhein Chemie AG, etc. can be used.

[0060] In this embodiment, the rubber composition constituting inner liner 7 has a larger acetone extractable amount AE than the rubber composition (first rubber composition) constituting mounting member 10. In other words, the acetone extractable amount AE2 of the rubber composition of inner liner 7 is larger than the acetone extractable amount AE1 of the rubber composition of mounting member 10. The effects of this configuration will be described later.

[0061] The bead portion 5 is a portion that is coupled to the wheel and secures the tire 1 to the rim 30R by internal pressure. The bead portion 5 includes a bead core 5A made of multiple steel bead wires 5C and an apex rubber 5B. The apex rubber 5B is located outward of the bead core 5A in the radial direction D2 and is made of, for example, a rubber composition (vulcanized rubber) having high rigidity. The bead core 5A and the apex rubber 5B are surrounded on their outer sides by the carcass ply of the carcass 6. Specifically, the carcass ply is folded back around the bead core 5A from the inner side to the outer side in the width direction D1 and extends outward in the radial direction D2 from the outer side of the bead portion 5 in the width direction D1. The bead core 5A and the apex rubber 5B are thus arranged in the portion surrounded by the carcass ply.

[0062] The belt portion 8 is a strip-shaped member extending in the circumferential direction D3 of the tire 1. The belt portion 8 is disposed on the inner side of the tread portion 2 in the radial direction D2, and on the outer side of the carcass 6. The belt portion 8 tightens the carcass 6 in the radial direction D2, thereby enhancing the stiffness of the tread portion 2. The belt portion 8 is also a reinforcing layer that reinforces the carcass 6 together with the band portion 9 described below.

[0063] The belt portion 8 is configured by at least one belt ply 8A. In this embodiment, the belt portion 8 has two belt plies 8A. The belt portion 8 extends around the tire 1 in the circumferential direction D3.

[0064] The belt ply 8A has a large number of belt cords (not shown) extending in a direction intersecting the equatorial plane CL1 of the tire 1. The belt ply 8A is formed by covering these belt cords with a topping rubber. The large number of belt cords are arranged so as to be aligned along the circumferential direction D3 of the tire 1, intersecting the equatorial plane CL1 of the tire 1 at a predetermined angle (for example, an angle set in a range of 10 to 35 degrees). In the belt portion 8, each belt ply 8A is arranged so that the belt cords intersect with each other. As the belt cords, for example, steel cords (steel cords) or the organic fiber cords are used.

[0065] The band portion 9 is a belt-shaped member extending in the circumferential direction D3 of the tire 1. The band portion 9 is arranged inside the tread portion 2 in the radial direction D2, and outside the belt portion 8. The band portion 9 has a full band 9A that covers the entire belt portion 8, and a pair of edge bands 9B that are provided at positions corresponding to both ends of the tread portion 2 in the width direction D1. The band portion 9 restrains the movement of the belt portion 8, and serves to prevent the belt portion 8 from lifting up or peeling off due to centrifugal force when the vehicle is running. The band portion 9 also serves as a reinforcing layer that reinforces the carcass 6 together with the belt portion 8 described above.

[0066] 3A and 3B are diagrams showing the configuration of the mount member 10, with FIG. 3A being a perspective view of the mount member 10 and FIG. 3B being a partial cross-sectional view of the mount member 10. In FIG.

[0067] The mount member 10 is used to mount electrical devices such as sensors that detect temperature, vibration, pressure, acceleration, etc., and is fixed to the inner surface 7A of the tire 1, i.e., the inner surface 7A of the inner liner 7. In addition to the sensors, examples of the electrical devices include repeaters that relay wireless communications and transmitters that emit predetermined signals.

[0068] 3A and 3B, the mounting member 10 has a mounting seat 11 fixed to the inner surface 7A and a main body 12 to which the electrical device is detachably attached. The mounting member 10 is formed by integrally forming the mounting seat 11 and the main body 12 using a vulcanized rubber composition (vulcanized rubber). The portion indicated by the dotted line in FIG. 3B indicates the electrical device attached to the mounting member 10.

[0069] Mounting member 10 is made of a different rubber composition from that of inner liner 7. Materials other than the rubber component compounded into the rubber composition of mounting member 10 can be the same as those of the rubber composition of inner liner 7. That is, the rubber composition of mounting member 10 may contain, in addition to the rubber component, fillers (reinforcing agents) such as carbon black, silica, or calcium carbonate, coupling agents, plasticizers such as oils or resins, antioxidants, and additives such as stearic acid, zinc oxide, sulfur, and vulcanization accelerators. Of course, the rubber component of mounting member 10 may be the same as or different from the rubber component of inner liner 7. That is, the rubber component of mounting member 10 may be any one of the rubber materials described above that can be used as the rubber component of inner liner 7, or two or more of the rubber materials may be mixed in a predetermined blending ratio. For example, the rubber component of mounting member 10 may be a different rubber component from that of inner liner 7, such as a rubber component primarily containing butadiene rubber (BR) with a low glass transition temperature Tg and excellent low-temperature properties, and acrylonitrile butadiene rubber (NBR) with excellent mechanical properties. Furthermore, the rubber component of mounting member 10 may further contain other rubber materials, such as diene rubbers such as isoprene rubber, styrene butadiene rubber (SBR), styrene isoprene rubber, styrene isoprene butadiene rubber (SIBR), and chloroprene rubber (CR). Of course, mounting member 10 may be composed of the same rubber component as inner liner 7. For materials common to mounting member 10 and inner liner 7, please refer to the explanation above.

[0070] The rubber component can be a common rubber material, such as isoprene-based rubber, butadiene rubber (BR), styrene-butadiene rubber (SBR), styrene-isoprene rubber, styrene-isoprene-butadiene rubber (SIBR), isoprene-butadiene rubber, acrylonitrile-butadiene rubber (NBR), acrylonitrile-styrene-butadiene rubber, chloroprene rubber (CR), and chlorosulfonated polyethylene. Examples of the isoprene-based rubber include natural rubber (NR), epoxidized natural rubber (ENR), isoprene rubber (IR), modified NR, modified NR, and modified IR. The rubber component can be any one of the rubber materials, or two or more of the rubber materials can be mixed at a predetermined blending ratio.

[0071] When silica and carbon black are used in combination as fillers, the total content thereof is preferably 30% by mass or more and 150% by mass or less based on 100% by mass of the rubber component.

[0072] The ratio of the carbon black content to the silica content is preferably 50% by mass or less, more preferably 25% by mass or less, and more preferably 10% by mass or less. Because carbon black has a higher reinforcing property than silica, if the carbon black content exceeds 50% by mass, the complex modulus of the tread rubber 2A becomes too high, and noise reduction during high-speed driving tends to deteriorate. The ratio of the carbon black content to the silica content is preferably 2% by mass or more, and more preferably 4% by mass or more.

[0073] The rubber composition constituting the mounting member 10 preferably contains silica. Examples of the silica include dry-process silica (silicic anhydride) and wet-process silica (hydrated silica). However, wet-process silica is preferred because it contains a large number of silanol groups. The rubber composition may also contain silica other than the above-mentioned types of silica. These may be used alone or in combination of two or more.

[0074] The content of the silica, relative to 100% by mass of the rubber component, is preferably 10% by mass or more, more preferably 40% by mass or more, even more preferably 60% by mass or more, particularly preferably 70% by mass or more, most preferably 80% by mass or more, and most preferably 90% by mass or more, and is preferably 120% by mass or less, more preferably 115% by mass or less, even more preferably 110% by mass or less, particularly preferably 105% by mass or less, and most preferably 100% by mass or less.

[0075] As the silica, for example, products available from Degussa, Rhodia, Tosoh Silica Co., Ltd., Evonik Japan Co., Ltd., Solvay Japan Co., Ltd., Tokuyama Corporation, etc. can be used.

[0076] The rubber composition that constitutes the mounting member 10 preferably contains a silane coupling agent in addition to silica. The silane coupling agent is not particularly limited, and examples thereof include bis(3-triethoxysilylpropyl)tetrasulfide, bis(2-triethoxysilylethyl)tetrasulfide, bis(4-triethoxysilylbutyl)tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, bis(2-trimethoxysilylethyl)tetrasulfide, bis(2-triethoxysilylethyl)trisulfide, bis(4-trimethoxysilylbutyl)trisulfide, bis(3-triethoxysilylpropyl)disulfide, bis(2-triethoxysilylethyl)disulfide, bis(4-triethoxysilylbutyl)disulfide, bis(3-trimethoxysilylpropyl)disulfide, bis(2-trimethoxysilylethyl)disulfide, bis(4-trimethoxysilylbutyl)disulfide, 3-trimethoxysilylpropyl-N,N-dimethylthiocathanide, Examples include sulfide-based compounds such as rubamoyl tetrasulfide, 2-triethoxysilylethyl-N,N-dimethylthiocarbamoyl tetrasulfide, and 3-triethoxysilylpropyl methacrylate monosulfide; mercapto-based compounds such as 3-mercaptopropyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, and Momentive's NXT and NXT-Z; 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. These compounds may be used alone or in combination of two or more.

[0077] As the silane coupling agent, for example, products available from Degussa, Momentive, Shin-Etsu Silicone Co., Ltd., Tokyo Chemical Industry Co., Ltd., Azumax Co., Ltd., Dow Corning Toray Co., Ltd., etc. can be used.

[0078] The content of the silane coupling agent is, for example, more than 3 mass % and less than 25 mass % relative to 100 mass % of silica.

[0079] The mounting seat 11 is formed, for example, in a disk shape, with an outer diameter larger than that of the main body 12. The main body 12 is formed in a cylindrical shape protruding from one disk surface of the mounting seat 11. An opening 13 that communicates with the interior of the main body 12 is formed in the protruding end surface of the main body 12, and the electrical device is fitted into the main body 12 through this opening 13 and held in place by the elasticity of the rubber. Various methods can be used to mount the mounting seat 11 to the inner surface 7A of the tire 1.

[0080] For example, a mounting method can be applied in which a predetermined surface treatment is applied to the mounting area A1 (mounting surface) on the inner surface 7A to remove the skin of the mounting area A1, and then the mounting seat portion 11 of the mounting member 10 is fixed to the mounting area A1 by welding or bonding with an adhesive. Examples of the surface treatment include polishing the surface of the mounting area A1 on the inner surface 7A with a polishing machine to remove the release agent along with the skin, or irradiating the surface of the mounting area A1 with laser light to remove the skin on the surface of the mounting area A1 together with the release agent.

[0081] More specifically, the surface processing is a process of processing the surface of the mounting area A1 into a uniform surface (e.g., a flat surface) by polishing with a polishing machine or by irradiating with the laser light. This improves the adhesion between the mounting area A1 and the contact surface of the mounting seat 11, thereby improving the mounting strength of the mounting member 10 in the mounting area A1. In addition, since the release agent adhering to the mounting area A1 is also removed, it is possible to prevent a decrease in strength due to the release agent, and the mounting member 10 can be attached to the mounting area A1 more firmly.

[0082] It is preferable to also perform the surface treatment described above on the adhesive surface of the mounting seat 11 by polishing with a polishing machine or irradiating with laser light before attaching the mount member 10. This further improves the adhesion of the adhesive surface of the mounting seat 11 to the attachment area A1, thereby further improving the attachment strength of the mount member 10.

[0083] Other examples of the method for attaching the mounting seat 11 include a method in which the tire 1 is vulcanized without initially applying a release agent to the mounting area A1, and then the mounting seat 11 is fixed to the mounting area A1 by welding or bonding with an adhesive, and a method in which the mounting seat 11 is joined to the inner surface 7A of the tire 1 before vulcanization, and then the tire 1 is vulcanized together with the mounting member 10, thereby fixing the mounting member 10 to the inner surface 7A.

[0084] Here, if the mounting member 10 is not securely attached, there is a concern that the mounting seat 11 of the mounting member 10 may partially peel off during vehicle operation, causing the peeled portion to come into contact with the inner surface 7A of the tire 1 as it rolls, resulting in an unpleasant contact noise. For this reason, the surface treatment is preferably performed by laser light irradiation, which can uniformly and precisely process the surface of the mounting area A1 or the contact surface of the mounting seat 11. Furthermore, laser light irradiation can reduce the step height at the boundary between the treated portion (the surface-treated surface) and the untreated portion (the untreated surface) to 200 μm or less, thereby reducing the amount of surface removal compared to polishing. Whether or not the laser light surface treatment has been performed can be determined by checking whether the step height at the boundary between the treated portion (the surface-treated surface) and the untreated portion (the untreated surface) is 200 μm or less. In other words, if the step at the boundary is 200 μm or less, it can be determined that the surface processing using the laser light has been performed, and if the step at the boundary is more than 200 μm, it can be determined that another surface processing has been performed.

[0085] 2, in this embodiment, the mount member 10 is disposed on the inner surface 7A of the tire 1 at a position corresponding to the center of the tread portion 2 in the width direction D1. In other words, the mount member 10 is disposed on the inner surface 7A of the tire 1 at a position corresponding to the above-mentioned crown land portion 24A. Specifically, the mount member 10 is disposed on the inner surface 7A of the tire 1 in an attachment region A1 (attachment position) corresponding to the above-mentioned crown land portion 24A.

[0086] The mounting region A1 is a region on the inner surface 7A that is bounded by two straight lines L1 that pass through both ends of the crown land portion 24A in the width direction D1 that form the ground contact surface of the crown land portion 24A and are perpendicular to the tread surface profile obtained by virtually connecting the surfaces of the crown land portion 24A. In other words, the mounting region A1 is a region on the back surface (inner surface) of the tread portion 2 that is surrounded by two intersections P1, P1 where two straight lines L1 parallel to the equatorial plane CL1 intersect with the inner surface 7A. Note that the straight lines L1 are straight lines that pass through both ends of the crown land portion 24A in the width direction D1 and are parallel to the equatorial plane CL1. Here, the position corresponding to the crown land portion 24A means a position where the center of the mounting seat portion 11 of the mount member 10 is located within the mounting region A1, and is not limited to a position where the straight line passing through the center of the crown land portion 24A (a straight line included in the equatorial plane CL1) and the center of the mount member 10 coincide with each other.

[0087] The attachment region A1 may correspond to both or either of the two middle land portions 24B. In this case, the attachment region A1 is a region on the inner surface 7A bounded by two straight lines L2 that pass through both ends of the middle land portion 24B in the width direction D1 that form the ground contact surface and are perpendicular to the tread surface profile obtained by virtually connecting the surfaces of the middle land portions 24B. The attachment region A1 may also correspond to both or either of the two shoulder land portions 24C. In this case, the attachment region A1 is a region on the inner surface 7A bounded by a straight line L31 that passes through the end of the ground contact surface of the tread surface 21 in the width direction D1 and is perpendicular to the tread surface profile, and a straight line L32 that passes through the end of the shoulder land portion 24C on the second main groove 22B side and is perpendicular to the tread surface profile.

[0088] In this embodiment, the mount member 10 is provided at a position where the center of the mount member 10 coincides with a straight line (a straight line included in the equatorial plane CL1) passing through the center of the crown land portion 24A. More specifically, the mount member 10 is fixed to the inner surface 7A so that the center of its mounting seat portion 11 coincides with the intersection of the inner surface 7A and a straight line (a straight line included in the equatorial plane CL1) passing through the center of the crown land portion 24A and the center of the tire 1 in the cross-sectional view of FIG. 2. Therefore, the mount member 10 is not provided at a position on the inner surface 7A corresponding to the main groove 22 formed in the tread portion 2. In other words, the mount member 10 is not provided on the back side of the main groove 22 in the tread portion 2.

[0089] Furthermore, it is desirable that the center of the mounting seat 11 is located within an area defined by a line perpendicular to the tread surface profile at a position 50% of the contact width of the contact surface of the tread 2, centered on the equatorial plane CL1. This is because if the center of the mounting seat 11 is located outside of 50% in the width direction D1, the amount of deformation of the tread 2 during rolling will be large, and the vibration noise caused by the mounting member 10 will also be large.

[0090] Here, the tread surface profile is a surface shape that can be obtained by virtually connecting the surfaces of the land portions 24 in the normal state.

[0091] The contact width is the maximum position in the width direction of the contact patch obtained when the tire 1 is pressed against a smooth road surface under the conditions of the normal internal pressure, normal load, and camber angle of 0 degrees.

[0092] The normal load is a load defined in the standard on which the tire 1 is based. Specifically, the normal load is the "maximum load capacity" in the JATMA standard, the "maximum value" indicated in "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" in the TRA standard, and the "LOAD CAPACITY" in the ETRTO standard.

[0093] In this embodiment, a mount member 10 having a mounting seat portion 11 is exemplified, but the mount member 10 may not have the mounting seat portion 11 and may be composed of only the main body portion 12.

[0094] Furthermore, when multiple mount members 10 are attached to the inner surface 7A of the tire 1, the mount members 10 are preferably arranged at equal intervals along the circumferential direction D3 on the inner surface 7A. This makes it possible to maintain an even weight balance in the circumferential direction D3 when multiple mount members 10 are provided.

[0095] The mounting position of the mount member 10 is not limited to the mounting area A1. For example, the mount member 10 may be mounted on the inner surface 7A of the tire 1 at a position corresponding to either one of the two middle land portions 24B. Alternatively, the mount member 10 may be mounted at a position corresponding to both of the two middle land portions 24B.

[0096] Furthermore, when two or more mount members 10 are attached side by side in the width direction D1 on the inner surface 7A, they are preferably attached at positions corresponding to both of the two middle land portions 24B that are equally spaced in the width direction D1 by the equatorial plane CL1 of the tire 1. In this case, if a crown land portion 24A exists on the equatorial plane CL1, each mount member 10 may be attached at a position corresponding to the crown land portion 24A. In this case, the weight balance in the width direction D1 can be kept symmetrical and even around the equatorial plane CL1.

[0097] The mounting member 10 may have any shape as long as it can accommodate an electrical device. For example, it may be formed as shown in FIGS. 4A and 4B. Here, FIGS. 4A and 4B show other configurations of the mounting member 10, with FIG. 4A being a perspective view of the mounting member 10 and FIG. 4B being a partial cross-sectional view of the mounting member 10. The mounting member 10 shown in FIGS. 4A and 4B has an annular circular mounting seat 11A and a cylindrical main body 12A whose inner hole is continuous with an opening 13A of the mounting seat 11A. The other side of the main body 12A is closed. Therefore, when the mounting seat 11A is fixed to the inner surface 7A with the electrical device held inside the main body 12A, the electrical device is sealed off from the outside.

[0098] However, when the mounting member 10 to which the electrical equipment is attached is provided on the inner surface 7A of the tire 1, the air permeability resistance of the attachment portion of the electrical equipment relative to the inner liner 7 and its surroundings may deteriorate over long-term use of the tire 1, and so-called air leaks may occur in those portions.

[0099] In contrast, in this embodiment, inner liner 7 is made of a rubber composition that has a larger acetone extractable amount AE than the rubber composition that constitutes mounting member 10. In other words, the acetone extractable amount AE2 of the rubber composition of inner liner 7 is preferably larger than the acetone extractable amount AE1 of the rubber composition of mounting member 10. In other words, the acetone extractable amount AE2 of the rubber composition of inner liner 7 and the acetone extractable amount AE1 of the rubber composition of mounting member 10 have the relationship ΔA (= AE2 - AE1) > 0.

[0100] The acetone extractables AE of a rubber composition refers to the amount of acetone extractables extracted at room temperature (e.g., 20°C) and normal pressure (1 atmosphere: 1013 hPa) using the acetone extraction method in accordance with JIS K6229. The extracted acetone extractables are primarily plasticizers such as oils that have a softening effect on the rubber composition. The acetone extractables AE are measured by immersing test pieces sampled from the rubber composition of the inner liner 7 and mounting member 10 in acetone for 72 hours to extract the soluble components, and then dividing the mass change of the test piece before and after extraction by the mass of the test piece before extraction, and multiplying the result by 100 to obtain a percentage. Specifically, the acetone extractables AE can be calculated using the following formula: Acetone extractable amount AE = {(mass of test piece before extraction - mass of test piece after extraction) / (mass of test piece before extraction)} x 100

[0101] In this embodiment, as described above, the acetone extractable amount AE2 of inner liner 7 is greater than the acetone extractable amount AE1 of mounting member 10. Therefore, even if a plasticizer contained in the rubber composition of mounting member 10 bleeds due to long-term use of tire 1, it is thought that the plasticizer is less likely to transfer to the rubber composition of inner liner 7. This prevents the portion of inner liner 7 in attachment region A1 of mounting member 10 from softening more than other portions. As a result, a decrease in air permeability resistance due to softening of the attachment portion of mounting member 10 in attachment region A1 is suppressed, and a decrease in air leak resistance in that portion of the inner liner 7 can be prevented.

[0102] In particular, the acetone extractable amount AE2 of the rubber composition of the inner liner 7 is preferably less than 12%, which can improve the air permeability resistance of the inner liner 7. There is no lower limit for the acetone extractable amount AE2 of the rubber composition of the inner liner 7, and the lower the value, the more preferable it is.

[0103] The plasticizer contained in each of the inner liner 7 and the mounting member 10 is not particularly limited, and can be one commonly used in the tire industry, such as a softener that softens the rubber composition. Examples of the plasticizer include oils, resins, liquid polymers, and low-temperature plasticizers. These plasticizers can be used alone or in combination of two or more. Oils and resins are particularly preferred as the plasticizer.

[0104] The oil used as the plasticizer is not particularly limited, and any oil commonly used in the tire industry can be used. Examples of the oil include process oil, vegetable oil, animal oil, and mixtures thereof. In addition, the process oil is preferably used because of its excellent processability.

[0105] Examples of the process oil include paraffin-based process oil (mineral oil), naphthene-based process oil, aromatic process oil (aromatic oil), etc. Mineral oil is particularly preferred.

[0106] Examples of the vegetable oils include castor oil, cottonseed oil, linseed oil, rapeseed oil, soybean oil, palm oil, coconut oil, peanut oil, rosin, pine oil, pine tar, tall oil, corn oil, rice bran oil, safflower oil, sesame oil, olive oil, sunflower oil, palm kernel oil, camellia oil, jojoba oil, macadamia nut oil, and tung oil.

[0107] Examples of the animal fats and oils include oleyl alcohol, fish oil, and beef tallow.

[0108] As the oil, for example, products from Idemitsu Kosan Co., Ltd., Sankyo Yuka Kogyo Co., Ltd., ENEOS Corporation, Orisoi Co., Ltd., H&R Corporation, Toyokuni Oil Mills Co., Ltd., Showa Shell Sekiyu KK, Fuji Kosan Co., Ltd., etc. can be used.

[0109] The resins used as the plasticizer are not particularly limited, and those generally used in the tire industry can be used. Examples of the resins include liquid resins that remain liquid at 25°C and solid resins that remain solid at 25°C.

[0110] The liquid resin is not particularly limited, and examples thereof include liquid aromatic vinyl polymers, coumarone-indene resins, indene resins, terpene resins, rosin resins, and hydrogenated products thereof.

[0111] Examples of liquid aromatic vinyl polymers include resins obtained by polymerizing α-methylstyrene and / or styrene, such as a homopolymer of styrene, a homopolymer of α-methylstyrene, and a copolymer of α-methylstyrene and styrene.

[0112] The liquid coumarone-indene resin is a resin containing coumarone and indene as the main monomer components constituting the resin skeleton (main chain). Here, other monomer components that may be contained in the skeleton besides coumarone and indene include liquid resins such as styrene, α-methylstyrene, methylindene, and vinyltoluene.

[0113] Liquid indene resin is a liquid resin that contains indene as the main monomer component that constitutes the skeleton (main chain) of the resin.

[0114] Liquid terpene resins are resins obtained by polymerizing terpene compounds such as α-pinene, β-pinene, camphor, and dipentene, and liquid terpene resins (terpene phenolic resins, aromatic modified terpene resins, etc.) typified by terpene phenols, which are resins obtained using terpene compounds and phenolic compounds as raw materials.

[0115] Examples of liquid rosin resins include liquid rosin-based resins such as natural rosin, polymerized rosin, modified rosin, ester compounds thereof, and hydrogenated products thereof.

[0116] The solid resin is not particularly limited, and examples thereof include aromatic vinyl polymers, coumarone-indene resins, indene resins, rosin resins, terpene resins, and acrylic resins.

[0117] The liquid polymer used as the plasticizer is not particularly limited, and may be any liquid polymer commonly used in the tire industry, such as liquid SBR, liquid BR, liquid IR, and liquid SIR.

[0118] The low-temperature plasticizer used as the plasticizer is not particularly limited, and those commonly used in the tire industry can be used. Examples of the low-temperature plasticizer include ester-based plasticizers such as dibutyl adipate (DBA), diisobutyl adipate (DIBA), dioctyl adipate (DOA), di-2-ethylhexyl azelate (DOZ), dibutyl sebacate (DBS), diisononyl adipate (DINA), diethyl phthalate (DEP), dioctyl phthalate (DOP), diundecyl phthalate (DUP), dibutyl phthalate (DBP), dioctyl sebacate (DOS), tributyl phosphate (TBP), trioctyl phosphate (TOP), triethyl phosphate (TEP), trimethyl phosphate (TMP), thymidine triphosphate (TTP), tricresyl phosphate (TCP), and trixylenyl phosphate (TXP).

[0119] In this embodiment, the area (mounting area) of the mounting surface of the mounting member 10 in the mounting region A1 of the inner surface 7A of the inner liner 7 is 75 cm 2 It is preferable that the area of the mounting surface of the mounting member 10 (mounting area) is 75 cm or less. 2 By setting the thickness below, it is believed that it is possible to more effectively prevent a decrease in the air leak resistance of the attachment portion of the inner liner 7 to which the mounting member 10 is attached. Furthermore, since the area of the mounting member 10 in contact with the inner liner 7 is reduced, it is believed that the force variation (FV) of the tire 1 can be improved and further that it becomes more difficult for the plasticizer to migrate from the mounting member 10 to the inner liner 7. Note that there is no lower limit for the area of the attachment surface of the mounting member 10, and the smaller this area is, the better.

[0120] The complex modulus E of the rubber composition of the inner liner 7 at 70°C * 2 and the complex modulus E of the rubber composition of the mounting member 10 at 70 ° C. * 2 preferably satisfy the relationship of the following formula (1).

[0121] 0.5 E * 2≦E * 1≦3.0·E * 2···(1)

[0122] In this embodiment, as described above, the complex modulus E of the rubber composition constituting the mounting member 10 at 70°C is * 1 is the complex modulus E * If the complex modulus E is less than 0.5 times, the hardness of the mounting member 10 is too high relative to the inner liner 7, and the air leak resistance at the attachment portion of the mounting member 10 tends to decrease. * 1 is the complex modulus E * If the complex elastic modulus E exceeds 3.0 times, the hardness of the mounting member 10 is too low relative to the inner liner 7, and in this case too, the air leak resistance at the attachment portion of the mounting member 10 tends to decrease. * 1 and the complex modulus E* When 2 satisfies the relationship of the above formula (1), it is expected that the deterioration of the air leak resistance of the attachment portion of the inner liner 7 to which the mount member 10 is attached can be effectively suppressed.

[0123] In addition, the complex elastic modulus E * 1,E * 2 is a measured value obtained by measuring a test piece of the mounting member 10 and the inner liner 7 using a specified viscoelasticity spectrometer (viscoelasticity measuring device), and can be measured, for example, under measurement conditions of a measurement temperature of 70°C, an initial strain of 5%, a dynamic strain of ±1%, a frequency of 10 Hz, and an extension deformation mode.

[0124] Generally, the complex modulus E of a rubber composition * can be adjusted by changing the type and shape of the reinforcing agent, such as carbon black or silica, that is blended. In this embodiment, too, the complex modulus E can be adjusted to satisfy the above formula (1) by appropriately changing the type and blending ratio of each material that constitutes the rubber composition of the inner liner 7 and the mounting member 10, as well as the type and shape of the reinforcing agent. * 1 and E * 2 can be adjusted.

[0125] In this embodiment, since the internal temperature of the tire 1 reaches approximately 70°C when traveling at high speed on a dry road surface, the complex modulus of elasticity E * was used as an index, but the complex elastic modulus E * is not limited to that at 70°C. At any set temperature within the temperature range of 0°C or more and 70°C or less, the complex modulus E * and the complex modulus E of the rubber composition of the mounting member 10 preferably satisfy the relationship of the above formula (1).

[0126] In addition, in the tire 1, the loss tangent tanδ (=E" / E') at 70°C of the rubber composition constituting the inner liner 7 is preferably 0.18 or less. Hereinafter, the loss tangent tanδ of the inner liner 7 at 70°C will be referred to as tanδ·70°C. Furthermore, the loss tangent tanδ·70°C of the rubber composition constituting the inner liner 7 at 70°C is more preferably 0.15 or less.

[0127] When a vehicle travels on a road surface, the internal temperature of the tire 1 rises, increasing the molecular mobility of the rubber composition that constitutes the inner liner 7 and the mounting member 10. In this case, plasticizer that bleeds from the mounting member 10 due to aging is likely to migrate to the inner liner 7. However, by setting the loss tangent tanδ·70°C of the inner liner 7 to 0.18 or less, and more preferably to 0.15 or less, it is possible to reduce the loss modulus E" (viscous term) relative to the storage modulus E' (elastic term) of the rubber composition of the inner liner 7 and thereby reduce viscosity (fluidity). This is thought to reduce the heat buildup of the inner liner 7 and inhibit the migration of plasticizer to the inner liner 7.

[0128] There is no lower limit to the loss tangent tanδ·70°C of the inner liner 7, and the lower the value, the better. The loss tangent tanδ·70°C is a measured value obtained by measuring test pieces of the mounting member 10 and the inner liner 7 using a predetermined viscoelasticity spectrometer (viscoelasticity measuring device), and can be measured, for example, under the following measurement conditions: measurement temperature 70°C, initial strain 10%, dynamic strain ±2.5%, frequency 10 Hz, and extension deformation mode.

[0129] In general, the loss tangent tanδ can be adjusted by changing the type, shape, or amount of the reinforcing agent. It can also be adjusted by changing the amount of plasticizer, such as oil. In this embodiment, too, the loss tangent tanδ·70°C can be adjusted to any desired value by appropriately changing the type and blending ratio of each material constituting the rubber composition of the inner liner 7 and the mounting member 10, as well as the type, shape, and blending amount of the reinforcing agent, and even the blending amount of the plasticizer.

[0130] Although the tire 1 according to the embodiment of the present disclosure has been described above, the present disclosure is not limited to the above-described embodiment. Hereinafter, with reference to Tables 1 and 2, examples of the tire 1 according to the present embodiment will be described along with comparative examples.

[0131] Example Each of the tires of Examples 1 to 6 and Comparative Examples 1 to 5 described below is a pneumatic tire similar to tire 1 described above, and the compounding ratios of the materials constituting the rubber composition of the other parts except for the inner liner 7 and the mounting member 10 are substantially the same.

[0132] Moreover, each of the tires of Examples 1 to 6 and Comparative Examples 1 to 5 is configured in the same manner as the above-described tire 1. That is, the mount member 10 is attached to the attachment region A1 corresponding to the crown land portion 24A on the tire inner surface 7A.

[0133] Table 1 shows the compounding information R1 to R6 of the inner liner 7 and the compounding information R7 to R12 of the mounting member 10 of each of the tires of Examples 1 to 6 and Comparative Examples 1 to 5. Each of the compounding information R1 to R12 includes the compounding ratio and predetermined physical property values of the rubber composition of the corresponding member.

[0134] [Table 1]

[0135] As shown in Table 1, the compounding information R1 to R12 indicates the compounding ratio of a plurality of rubber materials and the compounding ratio of a plurality of additives, and also indicates the physical property values of three physical properties. Here, the compounding ratio indicates the compounding amount of each material (rubber material and additive) in parts by mass. In detail, the compounding ratio of each material indicates the proportion of the compounding amount (parts by mass) of each material when the total parts by mass of one or more types of rubber material (rubber component) is taken as 100. The unit used for the compounding ratio is expressed in phr (per hundred rubber). Furthermore, each physical property shown in Table 1 is the acetone extractable amount AE, the complex modulus of elasticity at 70°C E * , the loss tangent at 70°C is tanδ·70°C.

[0136] Details of the various compounded materials (various compounded materials shown in Table 1) used in the rubber compositions constituting the inner liner 7 and the mounting member 10 are as follows.

[0137] (1) Rubber materials (a) IIR: Chlorobutyl HT1066 manufactured by ExxonMobil (b) BR-IIR: Bromobutyl 2222 manufactured by ExxonMobil (c) SBR: SBR1502 manufactured by JSB

[0138] (2) Additives (a) Reinforcing agent 1 (carbon black): Diablack N220 manufactured by Mitsubishi Chemical Corporation (b) Reinforcing agent 2 (carbon black): STERLING@V manufactured by Cabot Corporation (c) Reinforcing agent 3 (silica): Rhodia's "Zeosil 1115MP" (d) Reinforcing agent 4 (calcium carbonate): Calcium carbonate #200 manufactured by Takehara Chemical Industry Co., Ltd. (e) Plasticizer (mineral oil): Diana Process Oil PA-32 manufactured by Idemitsu Kosan Co., Ltd. (f) Antioxidant 1 (6C): Antigen 6C (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine) manufactured by Sumitomo Chemical Co., Ltd. (g) Antioxidant 2 (RD): Antioxidant TMQ manufactured by Chemi Chemical Co. (h) Compatibilizer: PROMIX 400 manufactured by FLOW POLYMERS (i) Stearic acid: Tsubaki (Tsubaki) manufactured by NOF Corporation (j) Zinc oxide: Two types of zinc oxide manufactured by Mitsui Mining & Smelting Co., Ltd. (k) Sulfur: 5% oil sulfur manufactured by Tsurumi Chemical Industry Co., Ltd. (l) Coupling agent: Momentive's compound silane coupling agent Si266 (m) Vulcanization accelerator 1: Noccela DM-G (mercaptobenzothiazole disulfide) manufactured by Ouchi Shinko Chemical Industry Co., Ltd. (n) Vulcanization accelerator 2: Noccela CZ (N-cyclohexyl-2-benzothiazolyl sulfenamide) manufactured by Ouchi Shinko Chemical Industry Co., Ltd. (o) Vulcanization accelerator 3: Noccela DPG (diphenyl guanidine) manufactured by Ouchi Shinko Chemical Industry Co., Ltd.

[0139] The tires of each example and comparative example were manufactured as follows. First, additives other than sulfur and vulcanization accelerator and rubber materials were blended according to the ratios shown in Table 1 (R1 to R6), and the mixture was kneaded for 4 minutes at a temperature of approximately 130°C using a Banbury mixer. Next, sulfur and vulcanization accelerator were added to the resulting mixture according to the ratios shown in Table 1, and the mixture was kneaded for 4 minutes at a temperature of approximately 80°C using an open roll to obtain an unvulcanized rubber composition. The unvulcanized rubber composition thus obtained was extruded into the shape of the tread portion 2, and then bonded together with an inner liner 7 and other tire components in a tire building machine to form an unvulcanized tire. This was then press-vulcanized for 10 minutes at a temperature of 170°C to produce a test tire (tire size: 205 / 55R16 91V, maximum load capacity: 615 kg).

[0140] The mounting member 10 included in the tires of each example and comparative example was manufactured as follows: First, additives other than sulfur and vulcanization accelerator and rubber materials were blended according to the ratios shown in Table 1 (R7 to R12), and the mixture was kneaded for 4 minutes at a temperature of approximately 130°C using a specified mixer. Next, sulfur and vulcanization accelerator were added to the resulting mixture according to the ratios shown in Table 1, and the mixture was kneaded for 4 minutes at a temperature of approximately 80°C to obtain an unvulcanized rubber composition. The unvulcanized rubber composition thus obtained was extruded into the shape of mounting member 10, and then vulcanized for 10 minutes at a temperature of 170°C to produce mounting member 10.

[0141] The manufactured mounting member 10 was then fixed to the inner surface of the tire of each example and comparative example together with the electrical equipment by the above-mentioned mounting method. The weight of the obtained tire, including the weight of the electrical parts and mounting member 10, was in the range of 7.7 kg ± 0.2 kg.

[0142] The complex elastic modulus E shown in Table 1 * The loss tangent tanδ and the loss tangent tanδ are values measured by the following method for test pieces prepared with the same composition as the rubber composition of the inner liner 7 and test pieces prepared with the same composition as the rubber composition of the mounting member 10. The size of each test piece is 20 mm in long side, 4 mm in width, and 1 mm in thickness. The test piece of the inner liner 7 may be a sample piece of the rubber composition cut out from the test tire. The long side of the test piece is sized to correspond to the circumferential direction D3 of the tire (see FIG. 1), and the thickness is sized to correspond to the thickness direction of the tire. The complex modulus E of each test piece of the inner liner 7 and the mounting member 10 was measured using a viscoelasticity measuring device "IPLEXER (registered trademark)" manufactured by GABO GmbH, Germany. * The complex modulus of elasticity E *The loss tangent tanδ is a value measured in a temperature environment of 70°C under the conditions of an initial strain of 5%, a dynamic strain of ±1%, a frequency of 10 Hz, and an elongation deformation mode. The loss tangent tanδ is a value measured in a temperature environment of 70°C under the conditions of an initial strain of 10%, a dynamic strain of ±2.5%, a frequency of 10 Hz, and an elongation deformation mode. Note that for each measurement value of the same rubber composition, the average value of multiple measurements is calculated and reported.

[0143] Tables 2 and 3 show the composition information (R1 to R12) of the inner liners 7 and mounting members 10 of each of the tires of Examples 1 to 6 and Comparative Examples 1 to 5, the difference ΔA (=AE2-AE1) in the acetone extractable amounts AE of the inner liners 7 and mounting members 10, the attachment area of the mounting members 10, the applicability of the above formula (1), the loss tangent tanδ·70°C, the evaluation values obtained from the air leak test, and the evaluation values obtained from the running test.

[0144] [Table 2]

[0145] [Table 3]

[0146] In Tables 2 and 3, the complex elastic modulus E * 1 satisfies the relationship of the above formula (1), it is evaluated as "Good", and the complex elastic modulus E * The cases where 1 did not satisfy the relationship of the above formula (1) were evaluated as "X". The air leak test was carried out in accordance with ASTM F1112, and the scores for each Example and Comparative Example were calculated. In Tables 2 and 3, the score for Comparative Example 1 was set to 100, and the scores for the other Examples and Comparative Examples were indexed.

[0147] As shown in Tables 2 and 3, in all of Examples 1 to 6, the difference ΔA (= AE2 - AE1) in the acetone extractable amounts was positive (plus), meaning that the acetone extractable amount AE2 of the inner liner 7 was greater than the acetone extractable amount AE1 of the mounting member 10. In contrast, in all of Comparative Examples 1 to 5, the difference ΔA (= AE2 - AE1) in the acetone extractable amounts was negative (minus), meaning that the acetone extractable amount AE2 of the inner liner 7 was smaller than the acetone extractable amount AE1 of the mounting member 10.

[0148] As shown in Table 2, when the acetone extraction amount AE2 of the inner liner 7 is greater than the acetone extraction amount AE1 of the mounting member 10, the decrease in air permeability resistance of the mounting portion of the mounting member 10 in the mounting area A1 of the inner liner 7 is suppressed, and it is expected that the decrease in air leak resistance of that portion of the inner liner 7 can be prevented.

[0149] The embodiments of the present disclosure described above include the following disclosure items (1) to (15).

[0150] The present disclosure (1) provides a tire including a tread portion constituting the tire surface, an inner liner constituting the tire inner surface, and a mounting member provided on the tire inner surface to which an electrical device can be attached. Both a first rubber composition constituting the mounting member and a second rubber composition constituting the inner liner contain a plasticizer. The acetone extractable amount AE2 of the second rubber composition is greater than the acetone extractable amount AE1 of the first rubber composition.

[0151] This configuration makes it difficult for the plasticizer contained in the first rubber composition of the mounting member to bleed out during long-term use, making it possible to prevent the plasticizer from transferring to the inner liner, preventing the mounting member attachment portion and its surrounding area from becoming softer than other portions of the inner liner. As a result, a decrease in air permeability resistance due to softening in this portion is suppressed, and a decrease in air leak resistance in this portion can be prevented.

[0152] The present disclosure (2) is the tire of the present disclosure (1), wherein the acetone extractable amount AE2 of the second rubber composition is less than 12%.

[0153] This can improve the air permeation resistance of the inner liner. Furthermore, by setting the acetone extractable amount AE2 of the second rubber composition to less than 12%, it is possible to improve not only the air permeation resistance of the inner liner but also the air permeation resistance around the attachment portion of the mounting member.

[0154] The present disclosure (3) is a tire according to the present disclosure (1) or (2), wherein the area of the mounting surface of the mounting member on the tire inner surface of the inner liner is 75 cm 2 The following is the result.

[0155] This improves the force variation (FV) of the tire and also makes it difficult for the plasticizer to migrate from the mounting member to the inner liner, so it is preferable that the area where the mounting member comes into contact with the inner liner is small.

[0156] The present disclosure (4) provides a tire according to any one of the present disclosures (1) to (3), wherein the complex modulus E at 70 ° C of the second rubber composition is measured under the measurement conditions of a measurement temperature of 70 ° C, an initial strain of 5%, a dynamic strain of ±1%, a frequency of 10 Hz, and an elongation deformation mode. * 2 and the complex modulus E at 70 ° C of the first rubber composition measured under the measurement conditions * 1 and satisfy the following formula. 0.5 E * 2≦E * 1≦3.0·E * 2

[0157] By limiting the difference in stiffness between the mounting member and the inner liner within the above range, the stiffness difference can be reduced, thereby suppressing cracks, breaks, and ruptures that may occur due to the stiffness difference and making it difficult for plasticizer to migrate from the mounting member to the inner liner.

[0158] The present disclosure (5) is a tire according to any one of the present disclosures (1) to (4), wherein the loss tangent tanδ of the second rubber composition at 70°C measured under measurement conditions of a measurement temperature of 70°C, an initial strain of 10%, a dynamic strain of ±2.5%, a frequency of 10 Hz, and an elongation deformation mode is 0.18 or less.

[0159] This makes it possible to prevent the heat generation of the inner liner from increasing, and as a result, it is possible to suppress the migration of plasticizer from the mounting member to the inner liner.

[0160] The present disclosure (6) is a tire according to any one of the present disclosures (1) to (4), wherein the loss tangent tanδ of the second rubber composition at 70°C measured under measurement conditions of a measurement temperature of 70°C, an initial strain of 10%, a dynamic strain of ±2.5%, a frequency of 10 Hz, and an elongation deformation mode is 0.15 or less.

[0161] This makes it possible to further prevent deterioration of heat generation and further suppress migration of plasticizer from the mounting member to the inner liner.

[0162] The present disclosure (7) is a tire according to any one of the present disclosures (1) to (6), wherein the mount member is disposed on the inner surface of the tire at a position corresponding to the widthwise center of the tread portion.

[0163] The present disclosure (8) is a tire according to the present disclosure (7), wherein the mounting member is arranged on the inner surface of the tire at a position where a straight line passing through the center of the widthwise central part of the tread portion coincides with the center of the mounting member.

[0164] The present disclosure (9) is a tire according to any one of the present disclosures (1) to (8), wherein the tread portion has land portions separated by grooves formed on the tire surface, and the mounting members are arranged at positions on the tire inner surface corresponding to the land portions.

[0165] The present disclosure (10) is a tire according to any one of the present disclosures (1) to (9), wherein the mounting member has a mounting seat portion fixed to the inner surface of the tire and a main body portion to which the electrical device is detachably attached.

[0166] The present disclosure (11) is the tire according to any one of the present disclosures (1) to (10), wherein the mount member is welded to the inner surface of the tire.

[0167] The present disclosure (12) is a tire according to any one of the present disclosures (1) to (11), wherein a plurality of the mounting members are provided on the inner surface of the tire, and the plurality of mounting members are arranged at equal intervals along the circumferential direction of the tire on the inner surface of the tire.

[0168] The present disclosure (13) is the tire according to any one of the present disclosures (1) to (12), wherein the electrical device is a sensor, a wireless communication repeater, or a signal transmitter.

[0169] The present disclosure (14) is a tire for a passenger vehicle according to any one of the present disclosures (1) to (13).

[0170] The present disclosure (15) is a tire according to any one of the present disclosures (1) to (14), which is a pneumatic tire.

Claims

1. a tread portion that constitutes the tire surface; an inner liner that forms the inner surface of the tire; a mounting member provided on the inner surface of the tire and capable of mounting an electrical device, a first rubber composition constituting the mounting member and a second rubber composition constituting the inner liner each contain a plasticizer; The tire, wherein an acetone extractable amount AE2 of the second rubber composition is greater than an acetone extractable amount AE1 of the first rubber composition.

2. The tire according to claim 1 , wherein the acetone extractable amount AE2 of the second rubber composition is less than 12%.

3. The area of the mounting surface of the mount member on the inner surface of the tire of the inner liner is 75 cm ２ 3. A tire according to claim 1 or 2, wherein:

4. The complex modulus E of the second rubber composition at 70 ° C. is measured under the measurement conditions of a measurement temperature of 70 ° C., an initial strain of 5%, a dynamic strain of ±1%, a frequency of 10 Hz, and an elongation deformation mode. ＊ 2, and the complex modulus E at 70 ° C of the first rubber composition measured under the above measurement conditions ＊ 4. The tire according to claim 1, wherein 1 and 2 satisfy the following formula: 0.5・E ＊ 2≦E ＊ 1≦3.0・E ＊ 2

5. 5. The tire according to claim 1, wherein the second rubber composition has a loss tangent tanδ at 70°C of 0.18 or less, measured under measurement conditions of a measurement temperature of 70°C, an initial strain of 10%, a dynamic strain of ±2.5%, a frequency of 10 Hz, and an extension deformation mode.

6. 5. The tire according to claim 1, wherein the second rubber composition has a loss tangent tanδ at 70°C of 0.15 or less, measured under measurement conditions of a measurement temperature of 70°C, an initial strain of 10%, a dynamic strain of ±2.5%, a frequency of 10 Hz, and an extension deformation mode.

7. The tire according to claim 1 , wherein the mount member is disposed on the inner surface of the tire at a position corresponding to a center portion in the width direction of the tread portion.

8. The tire according to claim 7, wherein the mount member is disposed on the tire inner surface at a position where a straight line passing through a center of the widthwise center portion of the tread portion coincides with a center of the mount member.

9. The tread portion has land portions divided by recessed grooves formed on the tire surface, The tire according to claim 1 , wherein the mount member is disposed on the tire inner surface at a position corresponding to the land portion.

10. The tire according to claim 1 , wherein the mount member has a mounting seat portion fixed to the inner surface of the tire, and a main body portion to which the electrical device is detachably attached.

11. The tire according to claim 1 , wherein the mount member is welded to the inner surface of the tire.

12. A plurality of the mount members are provided on the inner surface of the tire, The tire according to claim 1 , wherein the plurality of mount members are arranged on the inner surface of the tire at equal intervals along the circumferential direction of the tire.

13. The tire according to claim 1 , wherein the electrical device is a sensor, a wireless communication repeater, or a signal transmitter.

14. The pneumatic tire according to any one of claims 1 to 13, wherein the tire is a passenger tire.

15. The tire according to any one of claims 1 to 14, wherein the tire is a pneumatic tire.

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