tire

Abstract

This pneumatic tire (1) comprises: a tread part (2) having land portions (24) divided by a plurality of main grooves (22) formed in a tread surface (21); an inner liner (7) constituting a tire inner surface (7A) on an internal side of the tread part (2); and a mount member (10) which can mount an electrical device provided to the tire inner surface (7A). In the pneumatic tire (1), a complex modulus of elasticity E*1 of a rubber composition constituting the mount member (10) is greater than a complex modulus of elasticity E*2 of a rubber composition constituting the inner liner (7).

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] Japanese Patent Application Laid-Open 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. To detect the tire information, it is considered to equip the tire with an electrical device, such as a sensor, for detecting the tire information. To accurately obtain the tire information, the electrical device is preferably attached to the inner surface of the tire. However, when a vehicle equipped with a tire having the electrical device attached to the inner surface of the tire travels, vibrations transmitted from the road surface to the tire propagate through the tread to the electrical device, causing the electrical device to vibrate inside the tire. Furthermore, each time the tire makes one revolution, the load from the electrical device is periodically applied to the road surface via the tread, thereby applying periodic vibrations to the tread. Both the vibrations transmitted from the tread to the electrical device and the vibrations transmitted from the electrical device to the tread cause noise (e.g., rumble) such as road noise that occurs when the vehicle is traveling. Such vibrations are particularly noticeable when the vehicle is traveling at high speeds.

[0005] An object of the present disclosure is to suppress noise generated when a vehicle is running in a tire that is equipped 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 a tire surface, an inner liner constituting an inner surface of the tire, and a mounting member provided on the inner surface of the tire and capable of mounting an electrical device. In the tire, a complex modulus E at 70°C of a first rubber composition constituting the mounting member is * 1 is the complex modulus E of the second rubber composition constituting the inner liner at 70 ° C. * Greater than 2.

[0007] Because the tire is configured in this manner, the hardness of the inner liner can be made lower than that of the mounting member, and the inner liner can be made a viscoelastic body that is more flexible than the mounting member. As a result, in the tire having electrical equipment attached to the mounting member, vibrations transmitted from the tread to the mounting member and the electrical equipment during vehicle travel are attenuated by the inner liner, and vibrations transmitted from the mounting member and the electrical equipment to the tread are also attenuated by the inner liner. As a result, noise caused by the load of the mounting member and the electrical equipment can be suppressed. [Effects of the Invention]

[0008] According to the present disclosure, in a tire provided with a mount member to which an electrical device such as a sensor can be attached, it is possible to suppress noise (such as rumble and static) that occurs when a vehicle is traveling. [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 (an example of a carcass portion of the present disclosure) 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 inside the radial direction D2 in the tread portion 2, and a mounting member 10 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, additives such as fillers (reinforcing agents) such as carbon black, oil, resins such as phenolic resin, processing aids, stearic acid, zinc oxide, sulfur, and vulcanization accelerators.

[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 well-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 contained in 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 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 silica are preferably used as reinforcing agents, and it is preferable to use these in combination. When silica is used, it is preferably used in combination with a silane coupling agent.

[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). Examples of the plasticizer include resin components, oil, liquid rubber, and ester-based plasticizers. These may be used alone or in combination of two or more. In particular, oil and resin components are preferred as the plasticizer.

[0050] The oil is not particularly limited as long as it is one commonly used in the tire industry, and examples thereof include process oil, vegetable oil, and mixtures thereof. Examples of process oils that can be used include paraffin-based process oil, aromatic process oil, and naphthenic process oil. Examples of 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. These oils may be used alone or in combination of two or more. Process oils are particularly preferred, and aromatic process oils are more preferred.

[0051] 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.

[0052] Furthermore, the rubber composition constituting the inner liner 7 preferably contains a resin component as needed. The resin component may be solid or liquid at room temperature, and specific examples of the resin component include styrene-based resins, coumarone-based resins, terpene-based resins, C5 resins, C9 resins, C5C9 resins, and acrylic resins. These may be used alone or in combination of two or more. The content of the resin component is preferably more than 2% by mass and less than 45% by mass, and more preferably less than 30% by mass, based on 100% by mass of the rubber component.

[0053] The styrene-based resin is a polymer using a styrene-based monomer as a constituent monomer, and examples thereof include polymers obtained by polymerizing a styrene-based monomer as the main component (50% by mass or more).Specific examples include homopolymers obtained by polymerizing each of styrene-based monomers (styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-methoxystyrene, p-tert-butylstyrene, p-phenylstyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, etc.) alone, copolymers obtained by copolymerizing two or more types of styrene-based monomers, and copolymers of a styrene-based monomer and another monomer copolymerizable therewith.

[0054] Examples of the other monomers include acrylonitriles such as acrylonitrile and methacrylonitrile, unsaturated carboxylic acids such as acrylics and methacrylic acid, unsaturated carboxylic acid esters such as methyl acrylate and methyl methacrylate, dienes such as chloroprene and butadiene isoprene, olefins such as 1-butene and 1-pentene, α,β-unsaturated carboxylic acids such as maleic anhydride, and acid anhydrides thereof.

[0055] As the coumarone-based resin, a coumarone-indene resin is preferably used. The coumarone-indene resin is a resin containing coumarone and indene as monomer components constituting the resin skeleton (main chain). Other monomer components contained in the skeleton besides coumarone and indene include styrene, α-methylstyrene, methylindene, vinyltoluene, etc.

[0056] The amount of the coumarone-indene resin per 100 parts by mass of the rubber component is, for example, more than 1.0 part by mass and less than 50.0 parts by mass.

[0057] The hydroxyl value (OH value) of the coumarone-indene resin is, for example, more than 15 mgKOH / g and less than 150 mgKOH / g. The OH value is the amount of potassium hydroxide, expressed in milligrams, required to neutralize acetic acid bonded to hydroxyl groups when acetylating 1 g of the resin, and is a value measured by potentiometric titration (JIS K 0070:1992).

[0058] The softening point of the coumarone-indene resin is, for example, more than 30° C. and less than 160° C. The softening point is the temperature at which the ball drops when the softening point specified in JIS K 6220-1:2001 is measured using a ring and ball softening point tester.

[0059] Terpene resins include polyterpenes, terpene phenols, and aromatic modified terpene resins. Polyterpenes are resins obtained by polymerizing terpene compounds and their hydrogenated products. Terpene compounds are (C5H8) n The hydrocarbons and their oxygen-containing derivatives are represented by the following composition: monoterpenes (C 10 H 16 ), sesquiterpenes (C 15 H 24 ), diterpenes (C 20 H 32 ), and examples thereof include α-pinene, β-pinene, dipentene, limonene, myrcene, alloocimene, ocimene, α-phellandrene, α-terpinene, γ-terpinene, terpinolene, 1,8-cineole, 1,4-cineole, α-terpineol, β-terpineol, and γ-terpineol.

[0060] Examples of polyterpenes include terpene resins such as α-pinene resin, β-pinene resin, limonene resin, dipentene resin, and β-pinene / limonene resin, which are made from the above-mentioned terpene compounds, as well as hydrogenated terpene resins obtained by hydrogenating the terpene resins. Examples of terpene phenols include resins obtained by copolymerizing the above-mentioned terpene compounds with phenolic compounds, and resins obtained by hydrogenating the above-mentioned resins. Specific examples include resins obtained by condensing the above-mentioned terpene compounds, phenolic compounds, and formalin. Examples of phenolic compounds include phenol, bisphenol A, cresol, and xylenol. Examples of aromatic-modified terpene resins include resins obtained by modifying terpene resins with aromatic compounds, and resins obtained by hydrogenating the above-mentioned resins. The aromatic compound is not particularly limited as long as it is a compound having an aromatic ring, and examples thereof include phenolic compounds such as phenol, alkylphenol, alkoxyphenol, and unsaturated hydrocarbon group-containing phenol; naphthol compounds such as naphthol, alkylnaphthol, alkoxynaphthol, and unsaturated hydrocarbon group-containing naphthol; styrene derivatives such as styrene, alkylstyrene, alkoxystyrene, and unsaturated hydrocarbon group-containing styrene; coumarone, indene, and the like.

[0061] "C5 resin" refers to a resin obtained by polymerizing a C5 fraction. Examples of C5 fractions include petroleum fractions having 4 to 5 carbon atoms, such as cyclopentadiene, pentene, pentadiene, and isoprene. Dicyclopentadiene resin (DCPD resin) is preferably used as a C5 petroleum resin.

[0062] "C9 resin" refers to a resin obtained by polymerizing a C9 fraction, and may be a hydrogenated or modified version of the C9 fraction. Examples of C9 fractions include petroleum fractions having 8 to 10 carbon atoms, such as vinyltoluene, alkylstyrene, indene, and methylindene. Specific examples of suitable aromatic vinyl resins include coumarone-indene resins, coumarone resins, indene resins, and aromatic vinyl resins. As aromatic vinyl resins, homopolymers of α-methylstyrene or styrene or copolymers of α-methylstyrene and styrene are preferred, and copolymers of α-methylstyrene and styrene are more preferred, because they are economical, easy to process, and have excellent heat generation properties. As aromatic vinyl resins, commercially available products available from Kraton, Eastman Chemical Company, etc. may be used.

[0063] "C5C9 resin" refers to a resin obtained by copolymerizing the C5 fraction and the C9 fraction, and may be a hydrogenated or modified resin. Examples of the C5 fraction and the C9 fraction include the petroleum fractions mentioned above. As the C5C9 resin, for example, commercially available products from Tosoh Corporation, LUHUA, etc. can be used.

[0064] The acrylic resin is not particularly limited, but for example, a solventless acrylic resin can be used.

[0065] Examples of solvent-free acrylic resins include (meth)acrylic resins (polymers) synthesized by high-temperature continuous polymerization (high-temperature continuous bulk polymerization) (methods described in U.S. Pat. No. 4,414,370, JP-A-59-6207, JP-B-5-58005, JP-A-1-313522, U.S. Pat. No. 5,010,166, and Toa Gosei Kenkyusho TREND 2000 Vol. 3, pp. 42-45, etc.), with minimal use of secondary raw materials such as polymerization initiators, chain transfer agents, and organic solvents. In this disclosure, (meth)acrylic refers to both methacrylic and acrylic.

[0066] Examples of the monomer components constituting the acrylic resin include (meth)acrylic acid, (meth)acrylic acid esters (such as alkyl esters, aryl esters, and aralkyl esters), (meth)acrylamide, and (meth)acrylic acid derivatives such as (meth)acrylamide derivatives.

[0067] In addition, aromatic vinyls such as styrene, α-methylstyrene, vinyltoluene, vinylnaphthalene, divinylbenzene, trivinylbenzene, and divinylnaphthalene may be used together with (meth)acrylic acid or a (meth)acrylic acid derivative as a monomer component constituting the acrylic resin.

[0068] The acrylic resin may be a resin composed only of (meth)acrylic components, or a resin containing components other than (meth)acrylic components as constituent elements, and may have a hydroxyl group, a carboxyl group, a silanol group, or the like.

[0069] As the resin component, for example, products from Maruzen Petrochemical Co., Ltd., Sumitomo Bakelite Co., Ltd., Yasuhara Chemical Co., Ltd., Tosoh Corporation, Rutgers Chemicals, BASF, Arizona Chemical Company, Nitto Chemical Co., Ltd., Nippon Shokubai Co., Ltd., ENEOS Corporation, Arakawa Chemical Industries, Ltd., Taoka Chemical Co., Ltd., etc. can be used.

[0070] The rubber composition constituting the inner liner 7 preferably contains a processing aid. The processing aid is not particularly limited as long as it is one commonly used in the tire industry, and examples thereof include fatty acid metal salts, fatty acid amides, amide esters, silica surfactants, fatty acid esters, mixtures of fatty acid metal salts and amide esters, and mixtures of fatty acid metal salts and fatty acid amides. These may be used alone or in combination of two or more. Of these, fatty acid metal salts, amide esters, and mixtures of fatty acid metal salts and amide esters or fatty acid amides are preferred, and mixtures of fatty acid metal salts and fatty acid amides are particularly preferred.

[0071] The fatty acid constituting the fatty acid metal salt is not particularly limited, but examples thereof include saturated or unsaturated fatty acids (preferably saturated or unsaturated fatty acids having 6 to 28 carbon atoms (more preferably 10 to 25 carbon atoms, and even more preferably 14 to 20 carbon atoms)), such as lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, arachidic acid, behenic acid, and nervonic acid. These may be used alone or in combination of two or more. Of these, saturated fatty acids are preferred, and saturated fatty acids having 14 to 20 carbon atoms are more preferred.

[0072] Examples of metals constituting fatty acid metal salts include alkali metals such as potassium and sodium, alkaline earth metals such as magnesium, calcium and barium, zinc, nickel, molybdenum, etc. Of these, zinc and calcium are preferred, and zinc is more preferred.

[0073] The fatty acid amide may be saturated or unsaturated. Examples of saturated fatty acid amides include N-(1-oxooctadecyl)sarcosine, stearic acid amide, and behenic acid amide. Examples of unsaturated fatty acid amides include oleic acid amide and erucic acid amide.

[0074] A specific example of the mixture of a fatty acid metal salt and a fatty acid amide is WB16 manufactured by Struktol, which is a mixture of fatty acid calcium salt and a fatty acid amide.

[0075] The content of the processing aid per 100 parts by mass of the rubber component is preferably 0.1 part by mass or more, more preferably 0.5 part by mass or more, and even more preferably 1 part by mass or more, and is preferably 10 parts by mass or less, more preferably 5 parts by mass or less.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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 Kanritsu Kogyo Co., Ltd., Hosoi Chemical Industry Co., Ltd., etc. can be used.

[0080] 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.

[0081] 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.

[0082] In this embodiment, the inner liner 7 has a complex modulus of elasticity E at 70° C. that is lower than that of the rubber composition (first rubber composition) that constitutes the mounting member 10. * That is, the complex modulus E at 70° C. of the rubber composition constituting the inner liner 7 is * 2 is the complex modulus E of the rubber composition constituting the mounting member 10 at 70°C. * It is smaller than 1. The effects of this configuration will be described later.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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 within 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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, reinforcing agents such as carbon black and silica, and additives such as antioxidants, vulcanization accelerators, and plasticizers. 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 made of 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. The rubber component of the 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). The mounting member 10 may also be made of the same rubber component as the inner liner 7. For materials common to the inner liner 7, please refer to the above description.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] The mounting member 10 may have elasticity sufficient to hold the electronic device, and the complex modulus of elasticity E at 70°C of the rubber composition of the mounting member 10 is * is preferably, for example, 4.5 MPa.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] Incidentally, when the mount member 10 to which the electrical equipment is attached is provided on the inner surface 7A of the tire 1, vibrations transmitted from the road surface to the tire 1 propagate through the tread portion 2 to the mount member 10 and the electrical equipment during vehicle travel, potentially causing the electrical equipment to vibrate inside the tire 1. Furthermore, the mount member 10 periodically contacts the road surface via the tread portion 2 each time the tire 1 makes one revolution, and the loads of the mount member 10 and the electrical equipment are periodically applied to the road surface via the tread portion 2. This could result in periodic vibrations in the tread portion 2. Vibrations transmitted from the tread portion 2 to the mount member 10 and the electrical equipment, and vibrations transmitted from the mount member 10 and the electrical equipment to the tread portion 2, both cause noise during vehicle travel, and there is concern that these vibration sounds may be perceived as unpleasant noise by vehicle occupants. Such vibrations become more pronounced when the vehicle is traveling at high speeds.

[0113] In contrast, in this embodiment, the temperature inside the tire 1 reaches approximately 70°C when traveling at high speed on a dry road surface, so the mounting member 10 has a complex modulus of elasticity E at 70°C that is higher than that of the rubber composition constituting the inner liner 7. * That is, the rubber composition constituting the mounting member 10 has a large complex modulus of elasticity E *1 is the complex modulus E of the rubber composition constituting the inner liner 7 at 70°C. * 2. In other words, the complex elastic modulus E of the mounting member 10 * 1 and the complex modulus of elasticity E of the inner liner 7 * Between the two, there is an E * 1-E * The relationship is 2>0.

[0114] 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 of the rubber composition constituting the inner liner 7 at 70°C. * 2. For this reason, the inner liner 7 can be made of a viscoelastic material that is more flexible than the mounting member 10. As a result, in the tire 1 having the electrical equipment attached to the mounting member 10, it is thought that vibrations transmitted from the tread portion 2 to the mounting member 10 and the electrical equipment during vehicle travel are damped by the inner liner 7, and vibrations transmitted from the mounting member 10 and the electrical equipment to the tread portion 2 are also damped by the inner liner 7.

[0115] As a result, it is possible to suppress noise caused by the weight of the mount member 10 and the electrical equipment while the vehicle is running. In particular, noise can be effectively suppressed during high-speed running at speeds exceeding 80 km / h. Furthermore, since vibrations caused by the weight of the mount member 10 and the electrical equipment are suppressed, the running stability of the vehicle can be improved.

[0116] 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.

[0117] Here, the complex elastic modulus E of the mounting member 10 at 70°C is* Complex modulus E of 1 and inner liner 7 at 70 ° C * Difference from 2 ΔE * (=E * 1-E * 2) is, 2.5 MPa. If the inner liner 7 becomes too flexible with respect to the mount member 10, the vibration transmitted from the tread portion 2 may not be attenuated by the inner liner 7 but may be amplified instead. In this case, there is a risk that the noise may be aggravated. Furthermore, there is a risk that the mount member 10 and the electrical equipment may break down due to the vibration. For this reason, the difference ΔE * is preferably within a range in which the noise suppression effect can be achieved when the vehicle is running, and specifically, 2.5 It is preferably less than MPa.

[0118] In general, the complex modulus E * 1 and E * 2 can be adjusted by changing the type and amount of rubber components, the type and shape and amount of fillers (reinforcing agents) such as carbon black and silica, and the type and amount of other additives. In this embodiment, too, by appropriately changing the type and amount of each material constituting the rubber compositions of the inner liner 7 and the mounting member 10, as well as the type and shape of the reinforcing agents, E * 1-E * It is possible to satisfy the relationship 2>0.

[0119] In the tire 1 of the present embodiment, the loss tangent tanδ (=E" / E') at 70°C of the rubber composition constituting the inner liner 7 is preferably 0.26 or less. Hereinafter, the loss tangent tanδ of the inner liner 7 at 70°C will be referred to as tanδ·70°C.

[0120] Furthermore, the loss tangent tanδ·70°C at 70°C of the rubber composition constituting the inner liner 7 is more preferably 0.13 or less. There is no lower limit to the loss tangent tanδ·70°C of the inner liner 7, and the lower the value, the more preferable it is.

[0121] 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). For example, the measurement can be performed under the following measurement conditions: 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.

[0122] 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.

[0123] In order to damp vibrations and the like at the inner liner 7, the thickness d (see FIG. 2 ) from the inner surface of the carcass 6 to the inner surface of the inner liner 7 is preferably 0.6 mm or more. If an intervening member such as an insulation layer is provided between the carcass 6 and the inner liner 7, the thickness d is the sum of the thickness of the member and the thickness of the inner liner 7. Furthermore, if no intervening member is provided, the thickness d is the thickness of the inner liner 7. The minimum thickness of the thickness d is 0.6 mm. The thickness d in a typical pneumatic tire can be determined depending on the type of inner liner, the application and type of the pneumatic tire, and other factors. If the thickness d is too thin, sufficient damping cannot be obtained. Therefore, as described above, the thickness d is preferably 0.6 mm or more. There is no upper limit to the thickness d, but it can be set to an upper limit within a generally acceptable range (1.0 mm for passenger cars and 2.0 mm for large vehicles).

[0124] In particular, in this embodiment, as described above, the loss tangent tanδ·70°C of the inner liner 7 is 0.26 or less, and more preferably 0.13 or less. Therefore, the loss modulus E″ (viscosity term) can be made smaller relative to the storage modulus E′ (elastic term) of the rubber composition of the inner liner 7, thereby suppressing heat generation in the inner liner 7. This makes the inner liner 7 less likely to soften, and as a result, vibrations in the inner liner 7 are suppressed, making it less likely that noise will be generated when the vehicle is running. Furthermore, because the inner liner 7 is less likely to soften, it becomes easier to adjust the thickness of the inner liner 7 in a direction that increases its size.

[0125] In addition, since the tire 1 of this embodiment has a configuration in which the inner liner 7 is bonded to the inner surface of the carcass 6, the thickness of the inner liner 7 is set to 0.6 mm or more. However, if, for example, a rubber layer other than the inner surface of the carcass 6 and the inner liner 7 is provided between these, it is preferable to adjust the thickness of each of the other rubber layer and the inner liner 7 so that the thickness from the inner surface of the carcass 6 to the inner surface 7A of the inner liner 7 is 0.6 mm or more.

[0126] Furthermore, it is desirable that the glass transition temperature T1 of the rubber composition constituting the mounting member 10 is lower than the glass transition temperature T2 of the rubber composition constituting the inner liner 7. In other words, the glass transition temperature T1 of the mounting member 10 and the glass transition temperature T2 of the inner liner 7 have the relationship T2-T1>0.

[0127] In the tire 1 of this embodiment, the difference ΔT (=T2-T1) between the glass transition temperature T2 of the inner liner 7 and the glass transition temperature T1 of the mounting member 10 is preferably greater than 0° C. and less than or equal to 20° C., and more preferably, the difference ΔT is greater than or equal to 2° C. and less than or equal to 4° C. For example, if the glass transition temperature T1 of the mounting member 10 is −22° C., then the glass transition temperature T2 of the inner liner 7 is preferably within the range of −20 to −18° C.

[0128] While the glass transition temperature Tg of a typical inner liner is around -60°C, in this embodiment, the glass transition temperature T2 of the inner liner 7 is higher than the normal value (-60°C). Therefore, in this embodiment, the glass transition temperature T1 of the mounting member 10 is lower than the glass transition temperature T2 of the inner liner 7. As a result, when the tire temperature rises to approximately 70°C while the vehicle is running, the inner liner 7 is less likely to soften than the mounting member 10, and vibration in the inner liner 7 is suppressed. This further suppresses noise generated when the tire 1 rotates.

[0129] Generally, the glass transition temperatures T1 and T2 can be adjusted by changing the type and amount of rubber material to be compounded or by changing the reinforcing agent. In this embodiment, too, the glass transition temperatures T1 and T2 can be adjusted to any desired values ​​by changing the amount of the reinforcing agent to be compounded.

[0130] Furthermore, in this embodiment, as described above, the mount member 10 is fixed to the attachment area A1. Therefore, when the tire 1 rotates while the vehicle is running, most of the force generated by the rotation of the tire 1 and the weight of the mount member 10 and electronic components acts on the crown land portion 24A. As a result, noise caused by the load of the mount member 10 and electronic components while the vehicle is running is generated only from the crown land portion 24A, and as a result, the noise caused by the load can be suppressed.

[0131] If the mount member 10 were positioned on the inner surface 7A at a position corresponding to the main groove 22, the load would act on each of the two land portions 24 on either side of the main groove 22 in the width direction D1. In this case, noise caused by the load would be generated from each of the land portions 24 when the vehicle is running, and the sound waves of these noises would combine to produce a higher-pitched humming noise. In contrast, in the tire 1 of this embodiment, the mount member 10 is fixed to the attachment area A1, so no such noise would be generated.

[0132] To effectively suppress the noise, the mount member 10 is preferably positioned within the mounting area A1. However, if the mounting seat 11 is a plate-like member formed into a disk shape and the volume of the mounting seat 11 is sufficiently smaller than that of the main body 12, the impact of the mounting seat 11 on the noise is small. Therefore, in this case, it is sufficient that at least the main body 12 is positioned within the mounting area A1.

[0133] 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 to 3, examples of the tire 1 according to the present embodiment will be described along with comparative examples.

[0134] Example Each of the tires of Examples 1 to 17 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.

[0135] The various compounding materials used in the rubber composition constituting the inner liner 7 and the mounting member 10 are as follows.

[0136] (1) Rubber materials (a) IIR: Bromobutyl 2222 manufactured by ExxonMobil

[0137] (2) Additives (a) Reinforcing agent (carbon black): Diablack N220 manufactured by Mitsubishi Chemical Corporation (b) Oil: Process X-260 manufactured by ENEOS Corporation (c) Resin A1: YS Resin PX1150N manufactured by Yasuhara Chemical Co., Ltd. (d) Resin A2: SYLVATRAXX 4401 (α-methylstyrene resin) manufactured by Arizona Chemical Company (e) Processing aid: PROMIX 400 manufactured by Flow Polymers (f) Stearic acid: Tsubaki (Tsubaki) manufactured by NOF Corporation (g) Zinc oxide: Two types of zinc oxide manufactured by Mitsui Mining & Smelting Co., Ltd. (h) Vulcanization accelerator: Noccela CZ-G (CBS) manufactured by Ouchi Shinko Chemical Industry Co., Ltd.

[0138] Moreover, each of the tires of Examples 1 to 17 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.

[0139] Table 1 shows the compounding information R1 to R15 of the inner liner 7 and the compounding information R21 and R22 of the mounting member 10 of each tire of Examples 1 to 17 and Comparative Examples 1 to 5. Each of the compounding information R1 to R15, R21, and R22 includes the compounding ratio and predetermined physical property values ​​of the rubber composition of the corresponding member.

[0140] [Table 1]

[0141] As shown in Table 1, the compounding information R1 to R15, R21, and R22 indicate the compounding ratios of three types of rubber materials and nine types of additives, and also show the physical property values ​​of five physical properties. Here, the compounding ratios are expressed in parts by mass of the compounded amount of each material (rubber material and additives). In detail, the compounding ratio of each material indicates the proportion of the compounded amount (parts by mass) of each material when the total parts by mass of the rubber component made up of one or more types of rubber material is taken as 100. The unit used for the compounding ratios is phr (per hundred rubber). Furthermore, each physical property shown in Table 1 is expressed as the complex modulus of elasticity E at 70°C. * , loss tangent at 70℃ tanδ·70℃, complex modulus of elasticity E at 0℃ * , loss tangent at 0°C tanδ·0°C, and glass transition temperature Tg.

[0142] 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 R15), 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 kneaded to obtain an unvulcanized rubber composition. The unvulcanized rubber composition thus obtained is stretched and wound around a drum or the like to form a sheet-like member for the inner liner 7. This sheet-like member was attached to a tire building machine as the inner liner 7 and then bonded together with the tread portion 2 and other tire components to form an unvulcanized tire. The unvulcanized tire was 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).

[0143] 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 formulation information R21 or R21 in Table 1, 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 vulcanized for 10 minutes at a temperature of 170°C to produce mounting member 10.

[0144] 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.

[0145] 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 under the conditions of an initial strain of 5%, a dynamic strain of ±1%, a frequency of 10 Hz, and an elongation deformation mode in a temperature environment of 0°C or 70°C. The loss tangent tanδ is a value measured 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 in a temperature environment of 0°C or 70°C. Note that each measurement value for the same rubber composition is calculated and reported as an average value of multiple measurements.

[0146] The glass transition temperatures Tg shown in Table 1 were measured using test pieces with the same rubber composition as the inner liner 7 and the mounting member 10, using the following method. For each test piece of the inner liner 7 and the mounting member 10, the loss tangent tanδ was measured at each temperature within a predetermined temperature range using an Iplexer (registered trademark) viscoelasticity measuring device manufactured by GABO GmbH, Germany, under the following measurement conditions: frequency of 10 Hz, initial strain of 10%, amplitude of ±0.5%, and heating rate of 2°C / min. A temperature distribution curve of the measured loss tangent tanδ was then obtained, with the temperature at the time of measurement as a variable. The peak temperature (the point where the measured loss tangent tanδ was the largest) in the obtained temperature distribution curve was then designated as the glass transition temperature Tg. The measurement temperature range was from -60°C to 40°C.

[0147] Table 2 shows the compounding information of the inner liner 7 and the mounting member 10 of each of the tires in Examples 1 to 6 and Comparative Examples 1 to 5, the complex modulus E * The difference ΔE * (=E * 1-E * 2), the loss tangent tanδ·70°C of the rubber composition of the inner liner 7, the thickness d including the thickness of the inner liner 7, the thickness of the mounting member 10, the difference in glass transition temperatures ΔT (=T2−T1), and an evaluation value for noise when the vehicle is running (hereinafter referred to as the noise evaluation value). In each example and comparative example, the thickness of the mounting member 10 was 6.0 mm.

[0148] [Table 2]

[0149] The noise evaluation values ​​shown in Table 2 were calculated by the following method. Tires of each Example and Comparative Example were mounted on all wheels of a four-wheel vehicle in the normal condition, and the vehicle was driven around a test course at a speed of 100 km / h. The noise felt by the driver inside the vehicle was rated on a 10-point scale from 1 to 10. A similar test was conducted with 10 drivers, and the scores of each driver were added together. The total score for Example 1 was set to 100, and the total scores for the other Examples and Comparative Examples were indexed. The higher the noise evaluation value, the lower the noise felt by the driver while driving at high speed, and the better the result.

[0150] As shown in Table 2, in Example 1, the difference ΔE * is positive, that is, the complex elastic modulus E of the mounting member 10 * 1 is the complex modulus of elasticity E of the inner liner 7 * 2. In contrast, in each of Comparative Examples 1 to 5, the difference ΔE * is negative, that is, the complex elastic modulus E of the mounting member 10 * 1 is the complex modulus of elasticity E of the inner liner 7 * 2. In Example 1, when compared with Comparative Examples 1 to 5, the difference ΔE * Although there are differences in other items as well, the noise evaluation value of Example 1 is higher than the noise evaluation value of any of Comparative Examples 1 to 5. In other words, the tire of Example 1 generates less noise during vehicle running than any of the tires of Comparative Examples 1 to 5. This is because the difference ΔE * is positive, that is, the complex elastic modulus E of the mounting member 10 * 1 is the complex modulus E of the inner liner 7 * It is clear that this is due to the fact that it is larger than 2.

[0151] Moreover, in Example 2, the difference ΔE *is large and the loss tangent tanδ·70°C is small. For this reason, the noise evaluation value of Example 2 is higher than the noise evaluation value of Example 1, and it can be understood that the tire of Example 2 generates less noise during vehicle travel than the tire of Example 1. In both Examples 1 and 2, the difference ΔT is negative, and therefore the glass transition temperature T2 of the inner liner 7 is lower than the glass transition temperature T1 of the mounting member 10.

[0152] Moreover, in Example 3, the difference ΔE * is larger, and the loss tangent tanδ·70°C is smaller. For this reason, the noise evaluation value of Example 3 is higher than the noise evaluation value of Example 2, and it can be understood that the tire of Example 3 generates less noise during vehicle travel than the tire of Example 2. In both Examples 2 and 3, the difference ΔT is negative, and therefore the glass transition temperature T2 of the inner liner 7 is lower than the glass transition temperature T1 of the mounting member 10.

[0153] The only difference between Comparative Example 3 and Comparative Example 4 is the thickness d, and the other configurations and specifications are substantially the same. Comparing Comparative Examples 3 and 4, Comparative Example 4, which has a larger thickness d, has a higher noise evaluation value. From this, it can be understood that a larger thickness d results in a higher damping effect in the inner liner 7 and a higher effect of suppressing noise generated when the vehicle is running.

[0154] Furthermore, comparing Comparative Example 4 and Comparative Example 5, the difference ΔT is significantly different, and the loss tangent tanδ·70°C is slightly different but is almost the same, and the other configurations and specifications are substantially the same. Comparing Comparative Examples 4 and 5, the difference ΔT is positive (plus), and therefore Comparative Example 5 has a higher glass transition temperature T2 of the inner liner 7 than the glass transition temperature T1 of the mounting member 10, resulting in a higher noise evaluation value. From this, it can be understood that a higher glass transition temperature T2 of the inner liner 7 results in a higher damping effect in the inner liner 7 and a higher effect of suppressing noise generated when the vehicle is running.

[0155] Furthermore, Examples 4, 5, and 6 each use a mounting member with different composition information compared to Examples 1, 2, and 3. Specifically, the composition information for the mounting member in Examples 1, 2, and 3 is R21, while the composition information for the mounting member in Examples 4, 5, and 6 is R22. As shown in Table 2, it can be seen that even in Examples 4, 5, and 6, which use a mounting member with composition information R22, noise evaluation values ​​similar to those of Examples 1, 2, and 3 were obtained.

[0156] Table 3 shows the compounding information for each component of the inner liner 7 and the mounting member 10 of each tire of Examples 7 to 17, the complex modulus of elasticity E * The difference ΔE * (=E * 1-E * 2), the loss tangent tanδ·70°C of the inner liner 7, the thickness d, the thickness of the mounting member 10, the difference in glass transition temperatures ΔT (=T2−T1), and an evaluation value for noise when the vehicle is running (hereinafter referred to as the noise evaluation value). In each example, the thickness of the mounting member 10 was 6.0 mm.

[0157] [Table 3]

[0158] The noise evaluation values ​​shown in Table 3 were calculated in the same manner as the noise evaluation values ​​shown in Table 2.

[0159] As shown in Table 3, Example 7 differs from Example 1 only in the thickness d, with the other configurations and specifications being substantially the same. Specifically, the thickness d of Example 7 is 0.6 mm, which is 0.2 mm larger than the thickness d (=0.4 mm) of Example 1. Comparing Example 7 and Example 1, Example 7, which has a larger thickness d, has a higher noise evaluation value than Example 1. From this, it can be understood that a larger thickness d results in a higher damping effect in the inner liner 7 and a higher effect of suppressing noise generated when the vehicle is running.

[0160] Moreover, Example 8 differs from Example 2 only in the thickness d, with the other configurations and specifications being substantially the same. Specifically, the thickness d of Example 8 is 0.6 mm, which is 0.2 mm larger than the thickness d (=0.4 mm) of the inner liner 7 of Example 2. Comparing Example 8 and Example 2, Example 8, which has a larger thickness d, has a higher noise evaluation value than Example 2, and is even higher than the noise evaluation value of Example 7. From this, it can be understood that a larger thickness d results in a higher damping effect in the inner liner 7 and a higher effect of suppressing noise generated when the vehicle is running.

[0161] Moreover, Example 9 differs from Example 3 only in the thickness d, with the other configurations and specifications being substantially the same. Specifically, the thickness d of Example 9 is 0.6 mm, which is 0.2 mm larger than the thickness d (=0.4 mm) of Example 3. Comparing Example 9 and Example 3, Example 9, which has a larger thickness d, has a higher noise evaluation value than Example 3, and is even higher than the noise evaluation value of Example 8. From this, it can be understood that a larger thickness d results in a higher damping effect in the inner liner 7 and a higher effect of suppressing noise generated when the vehicle is running.

[0162] Example 10 differs from Example 1 only in the difference ΔT, with the other configurations and specifications being substantially the same. Specifically, the difference ΔT in Example 10 is +2.0, meaning that the glass transition temperature T2 of the inner liner 7 is 2°C higher than the glass transition temperature T1 of the mounting member 10. In contrast, in Example 1, the difference ΔT is -3.0, meaning that the glass transition temperature T2 of the inner liner 7 is 3°C lower than the glass transition temperature T1 of the mounting member 10. Comparing Example 10 and Example 1, Example 10 has a higher noise evaluation value than Example 1. From this, it can be seen that when the glass transition temperature T2 of the inner liner 7 is higher than the glass transition temperature T1 of the mounting member 10, the damping effect of the inner liner 7 is higher and the effect of suppressing noise generated during vehicle travel is greater.

[0163] Example 11 differs from Example 2 only in the difference ΔT, with the other configurations and specifications being substantially the same. Specifically, the difference ΔT in Example 11 is +3.0, meaning that the glass transition temperature T2 of the inner liner 7 is 3°C higher than the glass transition temperature T1 of the mounting member 10. In contrast, in Example 2, the difference ΔT is -2.0, meaning that the glass transition temperature T2 of the inner liner 7 is 2°C lower than the glass transition temperature T1 of the mounting member 10. Comparing Example 11 and Example 2, Example 11 has a higher noise evaluation value than Example 2, which is even higher than the noise evaluation value of Example 10. From this, it can be seen that when the glass transition temperature T2 of the inner liner 7 is higher than the glass transition temperature T1 of the mounting member 10, the damping effect of the inner liner 7 is higher and the effect of suppressing noise generated during vehicle travel is greater.

[0164] Example 12 differs from Example 3 only in the difference ΔT, with the other configurations and specifications being substantially the same. Specifically, the difference ΔT in Example 12 is +4.0, meaning that the glass transition temperature T2 of the inner liner 7 is 4°C higher than the glass transition temperature T1 of the mounting member 10. In contrast, in Example 3, the difference ΔT is -1.0, meaning that the glass transition temperature T2 of the inner liner 7 is 1°C lower than the glass transition temperature T1 of the mounting member 10. Comparing Example 12 and Example 3, Example 12 has a higher noise evaluation value than Example 3 and is even higher than the noise evaluation value of Example 11. From this, it can be seen that when the glass transition temperature T2 of the inner liner 7 is higher than the glass transition temperature T1 of the mounting member 10, the damping effect of the inner liner 7 is higher and the effect of suppressing noise generated during vehicle travel is greater.

[0165] Example 13 differs from Example 3 only in the difference ΔT, with the other configurations and specifications being substantially the same. Specifically, the difference ΔT in Example 13 is +10.0, i.e., the glass transition temperature T2 of the inner liner 7 is 10°C higher than the glass transition temperature T1 of the mounting member 10. Example 14 differs from Example 3 only in the difference ΔT, with the other configurations and specifications being substantially the same. Specifically, the difference ΔT in Example 14 is +20.0, i.e., the glass transition temperature T2 of the inner liner 7 is 20°C higher than the glass transition temperature T1 of the mounting member 10. Comparing Examples 13 and 14 with Example 3, Examples 13 and 14 have a larger ΔT than Example 3 and the noise evaluation value is also equivalent to Example 9. From this, it can be seen that when the glass transition temperature T2 of the inner liner 7 is higher than the glass transition temperature T1 of the mounting member 10, the damping effect of the inner liner 7 is higher and the noise suppression effect generated during vehicle travel is greater.

[0166] Example 15 differs from Example 14 only in the difference ΔT, with the other configurations and specifications being substantially the same. Specifically, the difference ΔT in Example 15 is +21.0°C, meaning that the glass transition temperature T2 of the inner liner 7 is 21°C higher than the glass transition temperature T1 of the mounting member 10. However, the noise evaluation value of Example 15 is lower than the noise evaluation value of Example 14. From this, it can be seen that if the glass transition temperature T2 of the inner liner 7 becomes too high above the glass transition temperature T1 of the mounting member 10, the effect of suppressing noise generated during vehicle travel will be reduced. Therefore, it is preferable that the difference ΔT be 20°C or less.

[0167] Example 16 is compared with the other examples and each comparative example, and the difference ΔE *The difference between them is that the loss tangent tanδ·70°C is relatively large at +2.0, the loss tangent tanδ·70°C is the smallest at 0.13, the thickness d is 0.6 mm, and the difference ΔT is +4.0, but the other configurations and specifications are substantially the same. Compared with the other examples and comparative examples, Example 16 has the highest noise evaluation value and the greatest effect of suppressing noise generated when the vehicle is running.

[0168] In Example 17, in comparison with Example 16, the difference ΔE * The only difference is that the other configurations and specifications are substantially the same. * is +2.5 MPa, that is, the complex elastic modulus E of the mounting member 10 * 1 is the complex modulus E of the inner liner 7 * 2 is 2.5 MPa larger. However, the noise evaluation value of Example 17 is lower than the noise evaluation value of Example 16. From this, it can be understood that if the inner liner 7 becomes too flexible with respect to the mount member 10, the effect of suppressing noise generated when the vehicle is running decreases. Therefore, the difference ΔE * teeth, 2.5 It is preferably less than MPa.

[0169] The embodiments of the present disclosure described above include the following disclosure items (1) to (15).

[0170] 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 and capable of mounting an electrical device. In the tire, a complex modulus E at 70°C of a first rubber composition constituting the mounting member is * 1 is the complex modulus E of the second rubber composition constituting the inner liner at 70°C, measured under the conditions of a measurement temperature of 70°C, an initial strain of 5%, a dynamic strain of ±1%, a frequency of 10Hz, and an elongation deformation mode. * The complex modulus E2 of the first rubber composition at 70°C is measured under the above-mentioned measurement conditions. * 1 is the complex modulus E of the second rubber composition at 70 ° C.* Greater than 2.

[0171] Because the tire is configured in this manner, the hardness of the inner liner can be made lower than that of the mounting member, and the inner liner can be made a viscoelastic body that is more flexible than the mounting member. As a result, in the tire having electrical equipment attached to the mounting member, vibrations transmitted from the tread to the mounting member and the electrical equipment during vehicle travel are attenuated by the inner liner, and vibrations transmitted from the mounting member and the electrical equipment to the tread are also attenuated by the inner liner. As a result, noise caused by the load of the mounting member and the electrical equipment can be suppressed.

[0172] The present disclosure (2) is a tire according to the present disclosure (1), wherein the complex modulus E of the first rubber composition at 70 ° C. * 1, and the complex modulus E of the second rubber composition at 70 ° C. * The difference between 2 is 2.5 It is less than MPa.

[0173] If the hardness of the inner liner is too low compared to the mounting member, the vibration transmitted from the tread portion is not attenuated by the inner liner but is instead amplified, which may increase the noise generated when the vehicle is running. Also, there is a risk that the electrical equipment attached to the mounting member may break down due to the vibration. For this reason, the complex modulus E * The difference is preferably within a range in which the noise suppression effect can be achieved, specifically, 2.5 It is preferable that it is less than 10 ...

[0174] Disclosure (3) provides the tire of Disclosure (1) or (2), wherein the second rubber composition constituting the inner liner has a loss tangent tanδ of 0.26 or less at 70°C, measured under the following conditions: 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.

[0175] Disclosure (4) provides the tire of Disclosure (1) or (2), wherein the second rubber composition constituting the inner liner has a loss tangent tanδ of 0.13 or less at 70°C, measured under the following measurement conditions: 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.

[0176] The present disclosure (5) is the tire according to any one of the present disclosures (1) to (4), further comprising a carcass portion disposed closer to the tread portion than the inner liner, wherein the thickness from the inner surface of the carcass portion to the inner surface of the inner liner is 0.6 mm or more.

[0177] The present disclosure (6) relates to the tire of any one of the present disclosures (1) to (5), wherein the glass transition temperature T1 of the first rubber composition of the mounting member is a peak temperature corresponding to a peak position in a temperature distribution curve of the loss tangent tanδ of the first rubber composition measured under the measurement conditions of a frequency of 10 Hz, an initial strain of 10%, an amplitude of ±0.5%, and a heating rate of 2°C / min. The glass transition temperature T2 of the second rubber composition of the inner liner is a peak temperature corresponding to a peak position in a temperature distribution curve of the loss tangent tanδ of the second rubber composition measured under the measurement conditions of a frequency of 10 Hz, an initial strain of 10%, an amplitude of ±0.5%, and a heating rate of 2°C / min. The glass transition temperature T1 is lower than the glass transition temperature T2.

[0178] The present disclosure (7) is the tire of the present disclosure (6), wherein the difference between the glass transition temperature T1 and the glass transition temperature T2 is in the range of more than 0°C and not more than 20°C.

[0179] The present disclosure (8) is a tire according to any one of the present disclosures (1) to (7), wherein the mount member is arranged on the inner surface of the tire at a position corresponding to the widthwise center of the tread portion.

[0180] 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.

[0181] 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.

[0182] 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.

[0183] 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.

[0184] 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.

[0185] The present disclosure (14) is a tire according to any one of the present disclosures (1) to (13), which is a tire for a passenger vehicle.

[0186] 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, The complex modulus E at 70°C of the first rubber composition constituting the mounting member * The complex modulus E of the second rubber composition constituting the inner liner at 70°C is measured under the 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 is measured under the above measurement conditions, The complex modulus E of the first rubber composition at 70°C * 1 is the complex modulus E of the second rubber composition at 70°C * greater than 2, A tire in which a difference between the complex modulus E*1 of the first rubber composition at 70°C and the complex modulus E*2 of the second rubber composition at 70°C is less than 2.5 MPa.

2. 2. The tire according to claim 1, wherein the second rubber composition constituting the inner liner has a loss tangent tanδ at 70°C of 0.26 or less, as 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.

3. 2. The tire according to claim 1, wherein the loss tangent tanδ of the second rubber composition constituting the inner liner at 70°C is 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, and is 0.13 or less.

4. The tire further includes a carcass portion disposed closer to the tread portion than the inner liner, The tire according to claim 1 , wherein a thickness from an inner surface of the carcass portion to an inner surface of the inner liner is 0.6 mm or more.

5. A tread portion that constitutes a 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, The complex modulus E*1 at 70°C of the first rubber composition constituting the mounting member is measured 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 elongation deformation mode, and the complex modulus E*2 at 70°C of the second rubber composition constituting the inner liner is measured under the same measurement conditions, The complex modulus E*1 of the first rubber composition at 70°C is greater than the complex modulus E*2 of the second rubber composition at 70°C, the glass transition temperature T1 of the first rubber composition of the mounting member is a peak temperature corresponding to a peak position in a temperature distribution curve of a loss tangent tanδ of the first rubber composition measured under measurement conditions of a frequency of 10 Hz, an initial strain of 10%, an amplitude of ±0.5%, and a temperature rise rate of 2°C / min, the glass transition temperature T2 of the second rubber composition of the inner liner is a peak temperature corresponding to a peak position in a temperature distribution curve of a loss tangent tanδ of the second rubber composition measured under measurement conditions of a frequency of 10 Hz, an initial strain of 10%, an amplitude of ±0.5%, and a temperature rise rate of 2°C / min, A tire in which the glass transition temperature T1 is lower than the glass transition temperature T2.

6. The tire according to claim 5, wherein a difference between the glass transition temperature T1 and the glass transition temperature T2 is in a range of more than 0°C and not more than 20°C.

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 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.

9. 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.

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

11. 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.

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

13. 13. The tire according to any one of claims 1 to 12, wherein the tire is a passenger tire.

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

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