tire

Abstract

A pneumatic tire (1) comprises a tread portion (2) including a land portion (24) divided by a plurality of main grooves (22) formed in the tread surface (21), and a mounting member (10) which is provided on a tire inner surface (7A) on the inner side of the tread portion (2) and onto which an electric device is mountable. The mounting member (10) is disposed on the tire inner surface (7A) at a position corresponding to the land portion (24). The complex modulus E*1 of the rubber composition forming the mounting member (10) is greater than the complex modulus E*2 of the rubber composition forming the tread portion (2).

Description

[Technical field]

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

[0002] Conventionally, a tire pressure monitoring system (TPMS) has been proposed that detects and monitors the air pressure (tire pressure) of tires mounted on a vehicle (see Patent Document 1). A sensor unit is attached to each tire, which is composed 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] JP 2004-155352 A Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, in order to ensure safe and comfortable running of a vehicle, it is important to appropriately detect and manage tire information, such as not only tire pressure but also tire temperature, vibration, and wear condition of the tire tread portion. In order to detect the tire information, it is considered to provide the tire with an electric device, such as a sensor for detecting the tire information. In order to accurately obtain the tire information, it is desirable that the electric device be attached to the inner surface of the tire. For example, the electric device is fixed to a part of an area of ​​the inner surface of the tire that corresponds to the back surface of the tread portion.

[0005] However, when a vehicle equipped with a tire having the electric device attached to the inner surface of the tire is traveling, the electric device receives contact pressure from the road surface via the tread portion every time the tire makes one revolution. In other words, the electric device receives the contact pressure periodically while the vehicle is traveling. This may cause periodic contact noise from the tire. This contact noise may be a cause of noise (rumble, noise, etc.) such as road noise generated when the vehicle is traveling. In addition, the load of the electric device is periodically applied to the road surface via the tread portion, which may cause vibrations in the tread portion. This vibration may also cause the noise. The contact noise and vibrations are considered to be more noticeable when the vehicle is traveling at high speed.

[0006] An object of the present disclosure is to suppress noise (such as rumble and static) generated when a vehicle is traveling at high speeds in a tire equipped with a mounting member to which an electrical device such as a sensor can be attached. [Means for solving the problem]

[0007] A tire according to one aspect of the present disclosure includes a tread portion having land portions divided by grooves formed on the surface, and a mounting member provided on the inner surface of the tire on the inner side of the tread portion and capable of mounting an electrical device. The mounting member is disposed at an attachment position on the inner surface of the tire corresponding to the land portions. The complex modulus E of a first rubber composition constituting the mounting member is * 1 is the complex modulus E of the second rubber composition constituting the tread portion * Greater than 2.

[0008] Because of this configuration, even in a tire in which electrical equipment is attached to the mounting member, noise caused by the load of the mounting member and the electrical equipment can be suppressed. Effect of the Invention

[0009] According to the present disclosure, in a tire equipped with a mounting member to which an electrical device such as a sensor can be attached, it is possible to suppress noise (such as rumble, static, etc.) generated when a vehicle is traveling at high speeds. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a side view of a tire according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a partial cross-sectional view of the tire taken along the section II-II in FIG. [Figure 3A] FIG. 3A is a schematic diagram showing an example of a mounting member attached to a tire. [Figure 3B] FIG. 3B is a schematic diagram showing an example of a mounting member attached to a tire. [Figure 4A] FIG. 4A is a schematic diagram showing another example of a mounting member attached to a tire. [Figure 4B] FIG. 4B is a schematic diagram showing another example of a mounting member attached to a tire. [Diagram 5] FIG. 5 is a cross-sectional view of a tire according to a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. Note that the following embodiments are examples of the present disclosure and are not intended to limit the technical scope of the present disclosure.

[0012] 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 of the cutting plane II-II in FIG. 1. FIG. 1 partially shows a cross-sectional structure of the equatorial plane CL (see FIG. 2). Here, the up-down direction of the paper in FIG. 1 and FIG. 2 is the radial direction D2 of the tire 1. The left-right direction of the paper in FIG. 2 is the width direction D1 of the tire 1. Also, the 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 parts are not shown.

[0013] The tire 1 is made mainly of rubber material and is primarily used by being mounted on a vehicle such as an automobile. As shown in Figures 1 and 2, the tire 1 is mounted on a rim 30R of a wheel 30. The rim 30R is a regular rim, which will be described later. The tire 1 is filled with air, and the internal pressure is adjusted to a regular internal pressure, which will be described later.

[0014] In this specification, a 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 a normal state. Figures 1 and 2 show the tire 1 in the normal state mounted on a 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.

[0015] 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).

[0016] 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.

[0017] The tire 1 according to the present embodiment is preferably used as a radial tire for automobiles. The tire 1 is a pneumatic tire used for vehicles, and may be a pneumatic tire used for 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 may also be preferably used as bias tires. In particular, the tire 1 is preferably used as a passenger car tire that is equipped with various electrical devices such as sensors and is required to have high convenience and low noise during high-speed driving. The passenger car tire is a tire that is mounted on a four-wheeled automobile and has a maximum load capacity of 1000 kg or less.

[0018] The maximum load capacity is not particularly limited as long as it is 1000 kg or less, but generally, as the maximum load capacity increases, the tire weight tends to increase, the vibration generated in the tread portion 2 of the tire 1 tends to increase, and the noise during running tends to increase, so the maximum load capacity is preferably 900 kg or less, more preferably 800 kg or less, and even more preferably 700 kg or less.

[0019] From the viewpoint of reducing vibrations in the tread portion 2, the tire weight of the tire 1 is preferably 20 kg or less, more preferably 15 kg or less, further preferably 12 kg or less, 10 kg or less, or 8 kg or less. The tire weight includes the weight of the electric device and the mounting member 10 described below, and also includes the weight of a sealant, a sponge, or the like, if any, provided in the inner cavity of the tire 1.

[0020] 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 a 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.

[0021] Furthermore, the tire 1 includes a carcass 6 extending from the tread portion 2 through the shoulder portion 3 and the sidewall portion 4 to the bead core 5A of the bead portion 5, an inner liner 7 that forms the inner surface 7A of the tire 1, a belt portion 8 and a band portion 9 that are arranged on the inside of the tread portion 2 in the radial direction D2, and a mounting member 10 attached to the inner surface 7A of the tire 1.

[0022] The tread portion 2 is a portion that comes into contact with the road surface when the vehicle is traveling. 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 that is a 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.

[0023] The rubber composition (second rubber composition) constituting the tread rubber 2A contains, in addition to the rubber component, additives such as reinforcing agents such as silica and carbon black, oil, resin components, wax, antioxidants, zinc oxide, stearic acid, sulfur, and vulcanization accelerators.

[0024] As the rubber component, a general rubber material can be used, and examples of the rubber material include 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), chlorosulfonated polyethylene, etc. In addition, the rubber component may be any one of the rubber materials alone, or two or more of the rubber materials may be mixed at a predetermined blending ratio. In particular, the rubber component is preferably isoprene-based rubber, BR, or SBR.

[0025] The SBR is not particularly limited, and for example, those commonly used in the tire industry such as emulsion-polymerized SBR (E-SBR), solution-polymerized SBR (S-SBR), etc. These may be used alone or in combination of two or more.

[0026] The styrene amount of SBR is preferably 10 mass% or more, more preferably 15 mass% or more, even more preferably 20 mass% or more, particularly preferably 25 mass% or more, and is preferably 50 mass% or less, more preferably 45 mass% or less, even more preferably 40 mass% or less, particularly preferably 30 mass% or less.

[0027] The SBR may be unmodified or modified. In particular, modified SBR is preferred. By using modified SBR, better fuel economy can be obtained. The modified SBR may be any SBR having a functional group that interacts with a filler such as silica. For example, terminal-modified SBR (terminal-modified SBR having the functional group at the terminal) in which at least one terminal of SBR is modified with a compound (modifier) ​​having the functional group, main-chain-modified SBR having the functional group in the main chain, main-chain-terminal-modified SBR having the functional group in the main chain and at least one terminal (for example, main-chain-terminal-modified SBR having the functional group in the main chain and modified with the modifier at least one terminal), and terminal-modified SBR modified (coupled) with a polyfunctional compound having two or more epoxy groups in the molecule and having a hydroxyl group or an epoxy group introduced therein may be mentioned. These may be used alone or in combination of two or more.

[0028] Examples of the functional group include an amino group, an amide group, a silyl group, an alkoxysilyl group, an isocyanate group, an imino group, an imidazole group, a urea group, an ether group, a carbonyl group, an oxycarbonyl group, a mercapto group, a sulfide group, a disulfide group, a sulfonyl group, a sulfinyl group, a thiocarbonyl group, an ammonium group, an imide group, a hydrazo group, an azo group, a diazo group, a carboxyl group, a nitrile group, a pyridyl group, an alkoxy group, a hydroxyl group, an oxy group, and an epoxy group. These functional groups may have a substituent. Among them, an amino group (preferably an amino group in which a hydrogen atom of an amino group is substituted with an alkyl group having 1 to 6 carbon atoms), an alkoxy group (preferably an alkoxy group having 1 to 6 carbon atoms), an alkoxysilyl group (preferably an alkoxysilyl group having 1 to 6 carbon atoms), and an amide group are preferable.

[0029] As the SBR, for example, SBR manufactured and sold by Sumitomo Chemical Co., Ltd., JSR Corporation, Asahi Kasei Corporation, Zeon Corporation, and the like can be used.

[0030] The content of SBR in 100% by mass of the rubber component is preferably 20% by mass or more, more preferably 50% by mass or more, and is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less. In particular, the content of SBR in 100% by mass of the rubber component is preferably 55% by mass or more.

[0031] The BR is not particularly limited, and any BR commonly used in the tire industry can be used. These may be used alone or in combination of two or more kinds.

[0032] The cis content of BR is preferably 90% by mass or more, more preferably 95% by mass or more, and even more preferably 97% by mass or more. There is no particular upper limit, and it may be 100% by mass.

[0033] The BR may be either unmodified or modified. The modified BR may be the modified BR having the above-mentioned functional groups introduced therein. The preferred embodiments are the same as those of the modified SBR.

[0034] As the BR, for example, products from Ube Industries, Ltd., JSR Corporation, Asahi Kasei Corporation, Zeon Corporation, etc. can be used.

[0035] The BR content in 100% by mass of the rubber component is preferably 10% by mass or more, more preferably 15% by mass or more, and is preferably 80% by mass or less, preferably 50% by mass or less, more preferably 35% by mass or less.

[0036] Examples of isoprene-based rubber include natural rubber (NR), epoxidized natural rubber (ENR), isoprene rubber (IR), modified NR, modified NR, and modified IR. Examples of NR include SIR20, RSS#3, and TSR20, which are common in the tire industry. Examples of IR are not particularly limited, and examples of IR include IR2200, which are common in the tire industry. Examples of modified NR include deproteinized natural rubber (DPNR), high-purity natural rubber (UPNR), and the like. Examples of modified NR include epoxidized natural rubber (ENR), hydrogenated natural rubber (HNR), and grafted natural rubber. Examples of modified IR include epoxidized isoprene rubber, hydrogenated isoprene rubber, and grafted isoprene rubber. These may be used alone or in combination of two or more. NR is particularly preferred.

[0037] The amount of the 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, and is preferably 40% by mass or less, more preferably 30% by mass or less.

[0038] The tread rubber 2A preferably contains a filler. Specific examples of the filler include silica, carbon black, calcium carbonate, talc, alumina, clay, aluminum hydroxide, and mica. Among these, silica and carbon black are preferably used as reinforcing agents, and it is preferable to use these in combination. When silica is used, it is preferable to use it in combination with a silane coupling agent.

[0039] When silica and carbon black are used in combination, the total content thereof is preferably 30% by mass or more and 150% by mass or less based on 100% by mass of the rubber component.

[0040] The ratio of the carbon black content to the silica content is preferably 50% by mass or less, more preferably 25% by mass or less, and more preferably 10% by mass or less. Since carbon black has a higher reinforcing property than silica, if the carbon black content exceeds 50% by mass, the complex modulus of the tread rubber 2A becomes too high, and the low noise property during high-speed driving tends to deteriorate. The ratio of the carbon black content to the silica content is preferably 2% by mass or more, and more preferably 4% by mass or more.

[0041] The rubber composition of the tread rubber 2A preferably contains silica. Examples of the silica include dry process silica (anhydrous silicic acid) and wet process silica (hydrated silicic acid). Wet process silica is preferred because it contains a large number of silanol groups. The rubber composition may contain silica other than the above-mentioned types of silica. These may be used alone or in combination of two or more.

[0042] The content of the silica, relative to 100 parts by mass of the rubber component, is preferably 10 parts by mass or more, more preferably 40 parts by mass or more, even more preferably 50 parts by mass or more, even more preferably 60 parts by mass or more, particularly preferably 70 parts by mass or more, most preferably 80 parts by mass or more, even more preferably 90 parts by mass or more, and is preferably 120 parts by mass or less, more preferably 115 parts by mass or less, even more preferably 110 parts by mass or less, particularly preferably 105 parts by mass or less, and most preferably 100 parts by mass or less.

[0043] As the silica, for example, products available from Degussa, Rhodia, Tosoh Silica, Evonik Japan, Solvay Japan, Tokuyama, etc. can be used.

[0044] The rubber composition of the tread rubber 2A preferably contains a silane coupling agent together with silica. The silane coupling agent is not particularly limited, and examples thereof include bis(3-triethoxysilylpropyl)tetrasulfide, bis(2-triethoxysilylethyl)tetrasulfide, bis(4-triethoxysilylbutyl)tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, bis(2-trimethoxysilylethyl)tetrasulfide, bis(2-triethoxysilylethyl)trisulfide, bis(4-trimethoxysilylbutyl)trisulfide, bis(3-triethoxysilylpropyl)disulfide, bis(2-triethoxysilylethyl)disulfide, bis(4-triethoxysilylbutyl)disulfide, bis(3-trimethoxysilylpropyl)disulfide, bis(2-trimethoxysilylethyl)disulfide, bis(4-trimethoxysilylbutyl)disulfide, 3-trimethoxysilylpropyl-N,N-dimethylthiocarbamoyl silane, and the like. Examples of the silyl silane include sulfide-based silanes such as rubamoyl tetrasulfide, 2-triethoxysilylethyl-N,N-dimethylthiocarbamoyl tetrasulfide, and 3-triethoxysilylpropyl methacrylate monosulfide; mercapto-based silanes such as 3-mercaptopropyl trimethoxysilane, 2-mercaptoethyl triethoxysilane, and NXT and NXT-Z manufactured by Momentive; vinyl-based silanes such as vinyl triethoxysilane and vinyl trimethoxysilane; amino-based silanes such as 3-aminopropyl triethoxysilane and 3-aminopropyl trimethoxysilane; glycidoxy-based silanes such as γ-glycidoxypropyl triethoxysilane and γ-glycidoxypropyl trimethoxysilane; nitro-based silanes such as 3-nitropropyl trimethoxysilane and 3-nitropropyl triethoxysilane; and chloro-based silanes such as 3-chloropropyl trimethoxysilane and 3-chloropropyl triethoxysilane. These may be used alone or in combination of two or more.

[0045] As the silane coupling agent, for example, products available from Degussa, Momentive, Shin-Etsu Silicones, Tokyo Chemical Industry, Azumax, Dow Corning Toray, and the like can be used.

[0046] The content of the silane coupling agent is, for example, more than 3 mass % and less than 25 mass % with respect to 100 mass % of silica.

[0047] The carbon black contained in the rubber composition of the tread rubber 2A 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.

[0048] As the carbon black, for example, products available from Asahi Carbon Co., Ltd., Cabot Japan Co., Ltd., Tokai Carbon Co., Ltd., Mitsubishi Chemical Corporation, Lion Corporation, Shinnikka Carbon Co., Ltd., Columbia Carbon Company, etc. can be used.

[0049] The amount of the carbon black, based on 100 parts by mass of the rubber component, 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 further preferably 10 parts by mass or less.

[0050] The rubber composition of the tread rubber 2A preferably contains a plasticizer (softener). Examples of the plasticizer include a resin component, oil, liquid rubber, and ester-based plasticizer. These may be used alone or in combination of two or more. In particular, the plasticizer is preferably an oil or a resin component.

[0051] The oil is not particularly limited as long as it is commonly used in the tire industry, and examples thereof include process oil, vegetable oil, and mixtures thereof. Examples of process oil include paraffin-based process oil, aromatic process oil, and naphthenic process oil. Examples of vegetable oil 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 oil, safflower oil, sesame oil, olive oil, sunflower oil, palm kernel oil, camellia oil, jojoba oil, macadamia nut oil, and tung oil. These may be used alone or in combination of two or more. Particularly, process oil is preferred, and aromatic process oil is more preferred.

[0052] 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., and the like can be used.

[0053] The liquid rubber mentioned as the softening agent is a polymer that is in a liquid state at room temperature (25° C.) and contains the same monomer as the solid rubber as a constituent element. Examples of the liquid rubber include farnesene-based polymers, liquid diene-based polymers, and hydrogenated products thereof.

[0054] Farnesene polymers are polymers obtained by polymerizing farnesene and contain structural units based on farnesene. Farnesene has isomers such as α-farnesene ((3E,7E)-3,7,11-trimethyl-1,3,6,10-dodecatetraene) and β-farnesene (7,11-dimethyl-3-methylene-1,6,10-dodecatriene).

[0055] The farnesene-based polymer may be a homopolymer of farnesene (farnesene homopolymer) or a copolymer of farnesene and a vinyl monomer (farnesene-vinyl monomer copolymer).

[0056] Examples of liquid diene polymers include liquid styrene-butadiene copolymer (liquid SBR), liquid butadiene polymer (liquid BR), liquid isoprene polymer (liquid IR), and liquid styrene-isoprene copolymer (liquid SIR).

[0057] The liquid diene polymer has a weight average molecular weight (Mw) of, for example, 1.0×10 3 Super, 2.0×10 5 In this specification, the Mw of the liquid diene polymer is a polystyrene-equivalent value measured by gel permeation chromatography (GPC).

[0058] The amount of the liquid rubber (total amount of the liquid farnesene polymer, the liquid diene polymer, etc.) is, for example, more than 1 part by mass and less than 100 parts by mass per 100 parts by mass of the rubber component.

[0059] As the liquid rubber, for example, products of Kuraray Co., Ltd., Cray Valley Co., Ltd., etc. can be used.

[0060] In addition, the rubber composition of the tread rubber 2A preferably contains a resin component as necessary. The resin component may be solid or liquid at room temperature, and specific examples of the resin component include styrene-based resin, coumarone-based resin, terpene-based resin, C5 resin, C9 resin, C5C9 resin, acrylic resin, etc. 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, more preferably less than 30% by mass, based on 100% by mass of the rubber component.

[0061] The styrene resin is a polymer using a styrene monomer as a constituent monomer, and examples thereof include polymers polymerized with a styrene monomer as the main component (50% by mass or more).Specific examples thereof include homopolymers obtained by polymerizing each of the styrene 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 kinds of styrene monomers, and copolymers of a styrene monomer and another monomer that can be copolymerized therewith.

[0062] Examples of the other monomer 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.

[0063] As the coumarone resin, coumarone-indene resin is preferably used. Coumarone-indene resin is a resin containing coumarone and indene as monomer components constituting the skeleton (main chain) of the resin. Other monomer components contained in the skeleton besides coumarone and indene include styrene, α-methylstyrene, methylindene, vinyltoluene, etc.

[0064] 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.

[0065] 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 required to neutralize acetic acid bonded to hydroxyl groups when acetylating 1 g of the resin, expressed in milligrams, and is a value measured by potentiometric titration (JIS K 0070:1992).

[0066] 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.

[0067] Terpene resins include polyterpene, terpene phenol, 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 represented by the composition 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.

[0068] Examples of polyterpenes include terpene resins such as α-pinene resin, β-pinene resin, limonene resin, dipentene resin, and β-pinene / limonene resin 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, and specifically 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, alkylphenols, alkoxyphenols, and phenols containing an unsaturated hydrocarbon group; naphthol compounds such as naphthol, alkylnaphthols, alkoxynaphthols, and naphthols containing an unsaturated hydrocarbon group; styrene derivatives such as styrene, alkylstyrenes, alkoxystyrenes, and styrenes containing an unsaturated hydrocarbon group; coumarone, indene, and the like.

[0069] "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. As a C5 petroleum resin, dicyclopentadiene resin (DCPD resin) is preferably used.

[0070] The term "C9 resin" refers to a resin obtained by polymerizing a C9 fraction, and may be a resin obtained by hydrogenating or modifying the resin. Examples of C9 fractions include petroleum fractions having 8 to 10 carbon atoms, such as vinyltoluene, alkylstyrene, indene, and methylindene. Specific examples of suitable 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, for example, those commercially available from Kraton, Eastman Chemical, etc. can be used.

[0071] The term "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. As the C5C9 resin, for example, those commercially available from Tosoh Corporation, LUHUA, etc. can be used.

[0072] The acrylic resin is not particularly limited, but for example, a solventless acrylic resin can be used.

[0073] Examples of the solvent-free acrylic resin 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 Kenkyuu Nenpo TREND 2000 Vol. 3, p. 42-45, etc.) with minimal use of auxiliary raw materials such as polymerization initiators, chain transfer agents, and organic solvents. In this disclosure, (meth)acrylic means methacryl and acrylic.

[0074] Examples of monomer components constituting the acrylic resin include (meth)acrylic acid, (meth)acrylic acid esters (alkyl esters, aryl esters, aralkyl esters, etc.), (meth)acrylamide, and (meth)acrylic acid derivatives such as (meth)acrylamide derivatives.

[0075] 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.

[0076] The acrylic resin may be a resin composed only of a (meth)acrylic component, or a resin containing components other than the (meth)acrylic component as constituent elements. The acrylic resin may have a hydroxyl group, a carboxyl group, a silanol group, or the like.

[0077] Examples of the resin component that can be used include products from Maruzen Petrochemical Co., Ltd., Sumitomo Bakelite Co., Ltd., Yasuhara Chemical Co., Ltd., Tosoh Corporation, Rutgers Chemicals, BASF, Arizona Chemical Company, Nippon Paint Chemical Co., Ltd., Nippon Shokubai Co., Ltd., JX Energy Corporation, Arakawa Chemical Industries, Ltd., and Taoka Chemical Co., Ltd.

[0078] Examples of the resin component that can be used include products from Maruzen Petrochemical Co., Ltd., Sumitomo Bakelite Co., Ltd., Yasuhara Chemical Co., Ltd., Tosoh Corporation, Rutgers Chemicals, BASF, Arizona Chemical Company, Nippon Paint Chemical Co., Ltd., Nippon Shokubai Co., Ltd., ENEOS Corporation, Arakawa Chemical Industries, Ltd., and Taoka Chemical Co., Ltd.

[0079] The wax contained in the rubber composition of the tread rubber 2A is not particularly limited as long as it is one that is commonly used in the tire industry, and examples thereof include petroleum waxes such as paraffin wax and microcrystalline wax; natural waxes such as vegetable wax and animal wax; and synthetic waxes such as polymers of ethylene and propylene. These may be used alone or in combination of two or more. In particular, petroleum waxes are preferred, and paraffin wax is more preferred.

[0080] As the wax, for example, products available from Ouchi Shinko Chemical Industry Co., Ltd., Nippon Seiro Co., Ltd., Seiko Chemical Co., Ltd., etc. can be used.

[0081] The antioxidant contained in the rubber composition of the tread rubber 2A is not particularly limited as long as it is one that is commonly used in the tire industry, and examples of the antioxidant include naphthylamine-based antioxidants such as phenyl-α-naphthylamine; diphenylamine-based antioxidants such as octylated diphenylamine and 4,4'-bis(α,α'-dimethylbenzyl)diphenylamine; N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, N,N' p-phenylenediamine-based antioxidants such as 1,2-di-2-naphthyl-p-phenylenediamine; quinoline-based antioxidants such as 2,2,4-trimethyl-1,2-dihydroquinoline polymer; monophenol-based antioxidants such as 2,6-di-t-butyl-4-methylphenol and styrenated phenol; and bis-, tris-, and polyphenol-based antioxidants such as tetrakis-[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane. These may be used alone or in combination of two or more. In particular, p-phenylenediamine-based antioxidants and quinoline-based antioxidants are preferred.

[0082] As the antioxidant, for example, products available from Seiko Chemical Co., Ltd., Sumitomo Chemical Co., Ltd., Ouchi Shinko Chemical Industry Co., Ltd., Flexis, etc. can be used.

[0083] The zinc oxide contained in the rubber composition of the tread rubber 2A may be any known zinc oxide, 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.

[0084] The stearic acid contained in the rubber composition of the tread rubber 2A may be any conventionally known stearic acid, such as products from NOF Corporation, NOF Corporation, Kao Corporation, Fujifilm Wako Pure Chemical Industries, Ltd., Chiba Fatty Acid Co., Ltd., etc.

[0085] The sulfur contained in the rubber composition of the tread rubber 2A 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 kinds.

[0086] As the sulfur, for example, products available from Tsurumi Chemical Industry Co., Ltd., Karuizawa Sulfur Co., Ltd., Shikoku Chemical Industry Co., Ltd., Flexis Corporation, Nippon Kanritsu Kogyo Co., Ltd., Hosoi Chemical Industry Co., Ltd., and the like can be used.

[0087] The vulcanization accelerator contained in the rubber composition of the tread rubber 2A is not particularly limited as long as it is one that is widely 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-benzothiazolyl sulfenamide, Nt-butyl-2-benzothiazolyl sulfenamide, N-oxyethylene-2-benzothiazole sulfenamide, N-oxyethylene-2-benzothiazole sulfenamide, and N,N'-diisopropyl-2-benzothiazole sulfenamide; and guanidine-based vulcanization accelerators such as diphenyl guanidine, di-orthotolyl guanidine, and orthotolyl biguanidine. 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 combination of a sulfenamide vulcanization accelerator and a thiuram vulcanization accelerator is more preferred.

[0088] 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.

[0089] A tread pattern is formed on the tread surface 21 to provide various tire performances 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. A plurality of main grooves 22 (an example of a circumferential groove of the present disclosure) extending continuously in the circumferential direction D3 (see FIG. 1) of the tire 1 are formed as the recessed grooves on the tread surface 21. Note that a plurality of lug grooves (not shown) intersecting the main grooves 22, a plurality of sipes narrower and shallower than the main grooves 22 and the lug grooves, and the like may be formed on the tread surface 21. Note that the recessed grooves referred to here refer to grooves having a groove width of more than 2.0 mm and a groove depth of more than 5.0 mm.

[0090] 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 the main grooves 22 and the lug grooves. However, the tread portion 2 of the tire 1 is not limited to one having any of the above patterns formed on the tread surface 21. For example, the tread portion 2 may be one having a so-called lug type pattern mainly having the lug grooves formed on the tread surface 21, or one having a so-called block type pattern having independent blocks formed on the tread surface 21. The tread pattern may be asymmetric with respect to the width direction of the contact surface.

[0091] 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, and two of them are arranged in each of the regions on the tread surface 21 that are outward from 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, in this embodiment, a configuration in which the four main grooves 22 shown in FIG. 2 are formed on the tread surface 21 is illustrated as an example, but the present disclosure is not limited to such a configuration. For example, the positions of the main grooves 22 may be asymmetrical with respect to the width direction D1. In addition, the number of the main grooves 22 is not limited to four, and may be less than four or five or more. Furthermore, any one of the main grooves 22 may be provided on the equatorial plane CL1.

[0092] 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 divided between both side ends in the width direction D1 of the tread portion 2 and two second main grooves 22B disposed on the outermost sides in the width direction D1. The middle land portion 24B is divided between two first main grooves 22A (an example of a circumferential groove of the present disclosure) disposed near the equatorial plane CL1 and two second main grooves 22B. The crown land portion 24A is disposed at a portion intersecting the equatorial plane CL1 in the tread portion 2 of the tire 1 and is divided between the two first main grooves 22A. That is, the crown land portion 24A is divided so as to be sandwiched between the two first main grooves 22A.

[0093] The crown land portion 24A may extend linearly along the circumferential direction D3, or may extend zigzag-like. The crown land portion 24A may extend inclined in the circumferential direction D3, or may extend in a curved or arc-like shape. In order for the crown land portion 24A to have the above-mentioned shape, the two first main grooves 22A located on both sides in the width direction D1 are formed to extend linearly, zigzag-like, inclined, curved, or arc-like along the circumferential direction D3. The crown land portion 24A may have a plurality of blocks divided in the circumferential direction D3 by lateral grooves or inclined grooves such as the lug grooves, or may have a plurality of semi-blocks divided in the circumferential direction D3 by lateral grooves or inclined grooves such as the sipes. The other land portions 24 except the crown land portion 24A also extend along the circumferential direction D3 and are formed in the same shape as the crown land portion 24A.

[0094] When the tire 1 is for a passenger vehicle, 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.

[0095] The shoulder portions 3 correspond to corners of the tire 1 extending from the tread portion 2 to the sidewall portion 4. The shoulder portions 3 connect the tread portion 2 and the sidewall portion 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 portion 4.

[0096] The sidewall portion 4 is made of a vulcanized rubber composition (vulcanized rubber). The sidewall portion 4 is disposed 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 carcass 6 on the side of the tire 1 is protected by the sidewall portion 4.

[0097] The carcass 6 is disposed on the inner side of the tread portion 2 and the pair of sidewall portions 4, and closer to the tread portion 2 and the sidewall portion 4 than the inner liner 7. The carcass 6 is constituted by at least one carcass ply 6A. The carcass ply 6A 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 6A 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 so as to be aligned along the circumferential direction D3 of the tire 1 while 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). As the carcass cord, for example, a cord made of an organic fiber such as nylon fiber, polyester fiber, rayon fiber, or aramid fiber (hereinafter referred to as "organic fiber cord") is used.

[0098] 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) having air barrier properties, and plays a role in maintaining the internal pressure of the tire 1.

[0099] The bead portion 5 is a portion that is coupled to the wheel, and fixes the tire 1 to the rim 30R by internal pressure. The bead portion 5 includes a bead core 5A consisting of a plurality of steel bead wires 5C, and an apex rubber 5B. The apex rubber 5B is located outside 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 the outside by the carcass ply of the carcass 6. Specifically, the carcass ply 6A is folded back around the bead core 5A from the inside to the outside in the width direction D1, and extends from the outside of the width direction D1 of the bead portion 5 to the outside in the radial direction D2. The bead core 5A and the apex rubber 5B are arranged in the portion surrounded by the carcass ply 6A in this manner.

[0100] The belt portion 8 is a belt-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 to enhance the stiffness of the tread portion 2. The belt portion 8 is also a reinforcing layer that reinforces the carcass 6 together with a band portion 9 described later.

[0101] 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.

[0102] 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 lined up along the circumferential direction D3 of the tire 1 while 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, a steel cord (steel cord) or the organic fiber cord is used.

[0103] The band portion 9 is a belt-shaped member extending in the circumferential direction D3 of the tire 1. The band portion 9 is disposed 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 plays a role in preventing the belt portion 8 from lifting up or peeling off due to centrifugal force when the vehicle is running. The band portion 9 is also a reinforcing layer that reinforces the carcass 6 together with the above-mentioned belt portion 8.

[0104] 3A and 3B are diagrams showing the configuration of the mounting member 10, with FIG. 3A being a perspective view of the mounting member 10 and FIG. 3B being a partial cross-sectional view of the mounting member 10. In FIG.

[0105] The mount member 10 is for mounting electrical devices such as sensors for detecting temperature, vibration, pressure, acceleration, etc., and is fixed to the inner surface 7A of the tire 1. In addition to the sensors, examples of the electrical devices include repeaters that relay wireless communications and transmitters that transmit predetermined signals.

[0106] As shown in Figures 3A and 3B, the mount 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 mount member 10 is formed by integrally forming the mounting seat 11 and the main body 12 with a vulcanized rubber composition (vulcanized rubber). The portion indicated by the dotted line in Figure 3B indicates the electrical device attached to the mount member 10.

[0107] The mounting member 10 is made of a rubber composition different from the tread rubber 2A, but the materials blended into the rubber composition can be the same as those of the rubber composition of the tread rubber 2A. In other words, the rubber composition (first rubber composition) constituting the mounting member 10 contains, in addition to the above-mentioned rubber components, reinforcing agents such as silica and carbon black, oil, resin components, wax, antioxidants, zinc oxide, stearic acid, sulfur, vulcanization accelerators, and other additives. Of course, the rubber component may be any one of the rubber materials used alone, or two or more of the rubber materials may be mixed at a predetermined blending ratio.

[0108] The mounting seat 11 is formed, for example, in a disk shape, and its outer diameter is formed to be 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 communicating with the inside is formed in the protruding end surface of the main body 12, and the electrical device is fitted into the inside of the main body 12 from this opening 13 and is held therein by the elasticity of rubber. Various methods can be used to attach the mounting seat 11 to the inner surface 7A of the tire 1.

[0109] For example, a mounting method can be applied in which the mounting area A1 (mounting surface) on the inner surface 7A is subjected to a predetermined surface processing treatment to remove the skin of the mounting area A1, and then the mounting seat portion 11 of the mounting member 10 is welded to the mounting area A1 or adhered with an adhesive to fix it. Examples of the surface processing treatment include a process of polishing the surface of the mounting area A1 on the inner surface 7A with a polishing machine to remove the release agent together with the skin, and a process of 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.

[0110] More specifically, the surface processing is a process for processing the surface of the mounting area A1 into a uniform surface (e.g., a flat surface) by polishing with a polishing machine or irradiating with the laser light. This improves the adhesion between the contact surface of the mounting area A1 and the mounting seat portion 11, and improves 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 caused by the release agent, and the mounting member 10 can be attached to the mounting area A1 more firmly.

[0111] It is preferable to perform the above-mentioned surface treatment by polishing with a polishing machine or irradiating with laser light on the adhesive surface of the mounting seat 11 as well before mounting the mount member 10. This further enhances the adhesion of the adhesive surface of the mounting seat 11 to the mounting area A1, and further improves the mounting strength of the mount member 10.

[0112] Other examples of the mounting method of the mounting seat portion 11 include a mounting method in which the tire 1 is vulcanized without initially applying a release agent to the mounting area A1, and then the mounting seat portion 11 is fixed to the mounting area A1 by welding or bonding with an adhesive, and a mounting method in which the mounting seat portion 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.

[0113] Here, if the mounting member 10 is not fixed sufficiently, the mounting seat 11 of the mounting member 10 may partially peel off during vehicle running, and the peeled part may come into contact with the inner surface 7A as the tire 1 rolls, causing the contact sound to be perceived as an unpleasant noise. For this reason, the surface processing is preferably a processing by irradiation of laser light, which can uniformly process the surface of the mounting area A1 or the contact surface of the mounting seat 11 with high precision. In addition, the processing by irradiation of laser light can reduce the step of the boundary between the treated part (surface-treated surface) and the untreated part (untreated surface) to 200 μm or less, so that the amount of surface removal can be reduced compared to processing by polishing. Whether or not the surface processing by the laser light has been performed can be determined by checking whether or not the step of the boundary between the surface-treated part (surface-treated surface) and the untreated part (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.

[0114] 2, in this embodiment, the mount member 10 is disposed at a position corresponding to the above-mentioned crown land portion 24A on the inner surface 7A of the tire 1. Specifically, the mount member 10 is disposed at an attachment region A1 (attachment position) on the inner surface 7A of the tire 1 corresponding to the above-mentioned crown land portion 24A.

[0115] The mounting area A1 is an area on the inner surface 7A that is divided by two straight lines L1 perpendicular to the tread surface profile obtained by virtually connecting the surfaces of the crown land portion 24A and passing through both ends in the width direction D1 that form the ground contact surface of the crown land portion 24A. In other words, the mounting area A1 is an area 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. The straight lines L1 are straight lines that pass through both ends in the width direction D1 of the crown land portion 24A 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 disposed within the mounting area 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.

[0116] The attachment region A1 may be a region corresponding 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 that is divided by two straight lines L2 that pass through both ends in the width direction D1 that form the ground contact surface of the middle land portion 24B and are perpendicular to the tread surface profile obtained by virtually connecting the surfaces of the middle land portion 24B. The attachment region A1 may be a region corresponding 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 that is divided 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.

[0117] In this embodiment, the mount member 10 is fixed to the inner surface 7A so that the center of the attachment 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. In other words, the mount member 10 is not disposed in 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.

[0118] In addition, it is preferable that the center of the mounting seat portion 11 is within a region 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 portion 2 from the equatorial plane CL1. This is because if the center of the mounting seat portion 11 is in a region outside of 50% in the width direction D1, the amount of deformation of the tread portion 2 during rolling will be large, and the vibration noise caused by the mounting member 10 will also be large.

[0119] 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.

[0120] 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.

[0121] 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.

[0122] Incidentally, when the mount member 10 to which the electric device is attached is provided on the inner surface 7A of the tire 1, the mount member 10 periodically contacts the road surface via the tread portion 2 each time the tire 1 makes one revolution while the vehicle is traveling. In this case, periodic contact noise is generated. Furthermore, the load from the mount member 10 and the electric device is periodically applied to the road surface via the tread portion 2, causing vibrations in the tread portion 2, which in turn generates vibration noise. There is a concern that the periodic contact noise and the vibration noise may be perceived as unpleasant noise (noise, disturbance, etc.) by vehicle occupants.

[0123] In contrast, 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 the electronic components acts on the crown land portion 24A. As a result, it is considered that the unpleasant noise caused by the load of the mount member 10 and the electronic components is generated only from the crown land portion 24A, and as a result, the noise caused by the load can be suppressed.

[0124] If the mounting member 10 is disposed at a position on the inner surface 7A corresponding to the main groove 22, the load acts on each of the two land portions 24 disposed on both sides of the main groove 22 in the width direction D1. In this case, noise caused by the load may be generated from each of the land portions 24, and the sound waves of the noises may be combined to generate a higher-pitched humming noise. In contrast, in the tire 1 of this embodiment, the mounting member 10 is fixed to the attachment area A1, so it is considered that such noise will not be generated.

[0125] In order to effectively suppress the noise, it is preferable that the mount member 10 is disposed within the range of the above-mentioned mounting area A1. However, if the mounting seat portion 11 is a plate-like member formed into a disk shape and the volume of the mounting seat portion 11 is sufficiently smaller than that of the main body portion 12, the influence of the mounting seat portion 11 on the noise is small. Therefore, in this case, it is sufficient that at least the main body portion 12 is disposed within the range of the mounting area A1.

[0126] In this embodiment, the mounting member 10 including the mounting seat portion 11 is exemplified, but the mounting member 10 may not include the mounting seat portion 11 and may be configured only by the main body portion 12. In this case, the center position of the mounting seat portion 11 is the center of the joint surface between the main body portion 12 and the inner surface 7A of the tire 1.

[0127] Furthermore, when multiple mounting members 10 are attached to the inner surface 7A of the tire 1, the mounting 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 mounting members 10 are provided.

[0128] The mounting position of the mounting member 10 is not limited to the mounting area A1. For example, the mounting member 10 may be attached to the inner surface 7A of the tire 1 at a position corresponding to either one of the two middle land portions 24B. The mounting member 10 may also be attached to positions corresponding to both of the two middle land portions 24B.

[0129] Furthermore, when two or more mounting 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, when a crown land portion 24A exists on the equatorial plane CL1, each mounting 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 with respect to the equatorial plane CL1.

[0130] The mount member 10 may have any shape as long as it can accommodate an electric device, and may be formed as shown in FIG. 4A and FIG. 4B. Here, FIG. 4A and FIG. 4B are diagrams showing another configuration of the mount member 10, FIG. 4A is a perspective view of the mount member 10, and FIG. 4B is a partial cross-sectional view of the mount member 10. The mount member 10 shown in FIG. 4A and FIG. 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 electric device held inside the main body 12A, the electric device is sealed from the outside.

[0131] In this embodiment, the maximum thickness d1 (see FIG. 3B) of the mount member 10 is preferably in a range of more than 0.25 times and less than 1.25 times the thickness d2 (see FIG. 2) of the crown land portion 24A in the tread portion 2. That is, the thickness d1 of the mount member 10 and the thickness d2 of the tread portion 2 have the relationship of the following formula (1). The thickness d1 is more preferably more than 0.75 times the thickness d2, even more preferably more than 0.85 times, and particularly preferably more than 0.90 times. Moreover, the thickness d1 is more preferably less than 1.15 times the thickness d2, even more preferably less than 1.10 times, and particularly preferably less than 1.05 times. Here, the thickness d1 of the mount member 10 is the shortest distance from the bottom surface of the mounting seat portion 11 of the mount member 10 to the apex of the main body portion 12. Further, the thickness d2 of the crown land portion 24A is the shortest distance from the tread surface of the tread rubber 2A to the band portion 9 at the center of the crown land portion 24A at the attachment position of the mount member 10.

[0132] 0.25×d2 <d1<1.25×d2 ··· (1)

[0133] When the thickness d1 of the mount member 10 is 0.25 times or less than the thickness d2 of the crown land portion 24A, the load that the mount member 10 and the electrical equipment exert on the road surface during rotation of the tire 1 is small, and therefore, the noise caused by the load is considered to be small. On the other hand, when the thickness d1 of the mount member 10 is 1.25 times or more than the thickness d2 of the crown land portion 24A, the load that the mount member 10 and the electrical equipment exert on the road surface becomes excessive, and even if the mount member 10 is disposed in the attachment region A1, the noise caused by the load can no longer be suppressed. Therefore, it is considered that the noise generated from the tire 1 during vehicle running can be effectively suppressed when the thickness d1 of the mount member 10 and the thickness d2 of the tread portion 2 satisfy the relationship of formula (1).

[0134] The thickness d1 of the mounting member 10 is preferably 15 mm or less, more preferably 12 mm or less, and even more preferably 10 mm or less. If the thickness d1 exceeds 15 mm, it is considered that when the land portion 24 corresponding to the position where the mounting member 10 is attached comes into contact with the road surface, the movement of the tip of the mounting member 10 becomes large, and vibration is likely to occur. In addition, the lower limit of the thickness d1 of the mounting member 10 is not particularly limited, but is preferably 1 mm or more, more preferably 3 mm or more, and even more preferably 6 mm or more.

[0135] Furthermore, the thickness d2 of the land portion 24 corresponding to the position where the mounting member 10 is attached is preferably 5 mm or more, more preferably 6 mm or more, and even more preferably 7 mm or more. If the thickness d2 is less than 5 mm, it is considered that vibrations are easily transmitted from the tread surface 21 to the mounting member 10, and the effect of suppressing noise is reduced. On the other hand, the upper limit of the thickness d2 of the land portion 24 is not particularly limited, but the thickness d1 is preferably 12 mm or less, and more preferably 10 mm or less.

[0136] The complex modulus E of the rubber composition constituting the mounting member 10 at 30°C * 1 is the complex modulus E of the rubber composition constituting the tread rubber 2A at 30 ° C. *It is desirable that the complex elastic modulus E of the mounting member 10 is larger than 2. * 1 and the complex modulus of elasticity E of tread rubber 2A * Between 2, there is E * 1-E * The relationship is 2>0.

[0137] Complex modulus of elasticity E of rubber composition * is known as a parameter that is an index of the viscoelasticity of a rubber composition, and is correlated with the hardness of the rubber composition. * and a rubber composition with a large complex modulus E * In comparison with a rubber composition having a smaller hardness, the former has a larger hardness, while the latter has a smaller hardness than the former and can be said to be a flexible viscoelastic body.

[0138] In this embodiment, as described above, the complex modulus E at 30° C. of the rubber composition constituting the mounting member 10 is * 1 is the complex modulus E of the rubber composition constituting the tread rubber 2A at 30 ° C. * 2. Therefore, the hardness of the mounting member 10 is greater than that of the tread rubber 2A. Because of this relationship, in a tire 1 equipped with the mounting member 10 and the electric device, vibrations caused by the load of the mounting member 10 and the like are less likely to be transmitted from the mounting member 10 to the tread portion 2, and as a result, noise during vehicle running can be more effectively suppressed. In addition, because vibrations caused by the load of the mounting member 10 and the electric device are suppressed, the running stability of the vehicle can also be improved.

[0139] 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 tread rubber 2A using a specified viscoelasticity spectrometer, and can be measured, for example, under measurement conditions of a measurement temperature of 30°C, an initial strain of 5%, a dynamic strain of ±1%, a frequency of 10 Hz, and an elongation deformation mode.

[0140] In general, the complex modulus E * 1 and E *The E2 can be adjusted by changing the type and shape of the reinforcing agent such as carbon black or silica that is blended. It can also be adjusted by changing the type and blending amount of the rubber material, plasticizer such as oil, and vulcanization accelerator. In this embodiment, too, the E2 can be adjusted by appropriately changing the type and blending ratio of each material constituting the rubber composition of the tread rubber 2A and the mounting member 10, as well as the type and shape of the reinforcing agent. * 1-E * It is possible to satisfy the relationship 2>0.

[0141] Complex elastic modulus E of the mounting member 10 * 1 and the complex modulus of elasticity E of tread rubber 2A * Difference from 2 ΔE * (=E * 1-E * 2) is preferably at least 2.0 MPa. If the difference is 2.0 MPa or more, noise generated when the tire 1 is mounted on the vehicle and the vehicle is driven can be further suppressed.

[0142] The complex elastic modulus E of the mounting member 10 * The upper limit of the complex elastic modulus E of the mount member 10 is not particularly limited, but is preferably 15 MPa or less, and more preferably 13 MPa or less. * The lower limit value is not particularly limited, but is preferably 8 MPa or more, more preferably 9 MPa or more, and even more preferably 10 MPa or more.

[0143] The upper limit of the complex elastic modulus E*2 of the tread rubber 2A is not particularly limited, but is preferably 10 MPa or less, more preferably 9 MPa or less, and even more preferably 8 MPa or less. On the other hand, the lower limit of the complex elastic modulus E*2 of the tread rubber 2A is not particularly limited, but is preferably 4 MPa or more, more preferably 5 MPa or more, and even more preferably 6 MPa or more.

[0144] In the tire 1, the loss tangent tan δ at 0°C (hereinafter referred to as tan δ·0°C) of the rubber composition constituting the tread rubber 2A is preferably 0.30 or more, more preferably 0.33 or more, and even more preferably 0.35 or more. There is no upper limit for the loss tangent tan δ·0°C of the tread rubber 2A, and the higher the value, the more preferable it is.

[0145] Further, the loss tangent tanδ at 30°C (hereinafter referred to as tanδ·30°C) of the rubber composition constituting the tread rubber 2A is preferably 0.13 or less, and more preferably 0.10 or less. There is no lower limit for the loss tangent tanδ·30°C of the tread rubber 2A, and the lower the value, the more preferable.

[0146] The loss tangent tanδ·0°C and the loss tangent tanδ·30°C are measured values ​​obtained by measuring test pieces of the mounting member 10 and the tread rubber 2A using a predetermined viscoelasticity spectrometer. The loss tangent tanδ·0°C can be measured, for example, under the following measurement conditions: measurement temperature 0°C, initial strain 10%, dynamic strain ±2.5%, frequency 10Hz, and elongation deformation mode. The loss tangent tanδ·30°C can be measured under the following measurement conditions: measurement temperature 30°C, initial strain 5%, dynamic strain ±1%, frequency 10Hz, and elongation deformation mode.

[0147] In general, the loss tangent tanδ can be adjusted by changing the type and shape of the reinforcing agent or the amount of the reinforcing agent. It can also be adjusted by changing the type and amount of the rubber material, the plasticizer such as oil, and the vulcanization accelerator. In this embodiment, too, the loss tangent tanδ·0°C and the loss tangent tanδ·30°C can be adjusted to any desired value by appropriately changing the type and mixing ratio of each material constituting the rubber composition of the tread rubber 2A and the mounting member 10, as well as the type, shape, and amount of the reinforcing agent, and further the amount of the plasticizer.

[0148] In addition, the glass transition temperature T1 of the rubber composition constituting the mounting member 10 is desirably lower than the glass transition temperature T2 of the rubber composition constituting the tread rubber 2A. In other words, there is a relationship of T1-T2<0 between the glass transition temperature T1 of the mounting member 10 and the glass transition temperature T2 of the tread rubber 2A. For example, the glass transition temperature T1 of the mounting member 10 is -35°C, and in this case, the glass transition temperature T2 of the tread rubber 2A is -30°C. Due to this relationship, the mobility of the polymer of the mounting member 10 is always higher than the mobility of the polymer of the tread rubber 2A. As a result, when the above-mentioned vibration occurs in the mounting member 10 or when vibration is transmitted from the tread portion 2 to the mounting member 10, it becomes possible to absorb the vibration within the mounting member 10, and it is considered that the noise generated from the tire 1 during vehicle running can be further suppressed.

[0149] In general, the glass transition temperatures T1 and T2 can be adjusted by changing the type and amount of the rubber material to be blended, or by changing the type and amount of the plasticizer such as oil. In this embodiment, the glass transition temperatures T1 and T2 can be adjusted to any value by changing the type and amount of the rubber material. The glass transition temperature Tg can be measured by a predetermined viscoelasticity spectrometer using a test piece. For example, a temperature distribution curve of tan δ is measured using an Iplexer series manufactured by GABO under the 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, and the tan δ peak temperature showing the largest tan δ value in the obtained temperature distribution curve can be determined as the glass transition point (Tg).

[0150] 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 FIG. 5 and Tables 1 to 3, examples of the tire 1 according to the present embodiment will be described along with comparative examples.

[0151] Example In each of the tires of Examples 1 to 8 and Comparative Examples 1 to 16 described below, the mixing ratio of each material constituting the rubber composition in the portions other than the tread portion 2 and the mounting member 10 is substantially the same.

[0152] The various compounded materials used in the rubber composition constituting the tread portion 2 and the mounting member 10 are as follows.

[0153] (1) Rubber materials (a) NR:TSR20 (b) SBR: Europrene SOL® C2525 manufactured by Versalis (styrene content: 27% by mass, weight average molecular weight: 6.0 × 10 5 g / mol) (c) BR: UBEPOL-BR150 manufactured by Ube Industries, Ltd. (d) NBR: Nipol DN401LL manufactured by Zeon Corporation

[0154] (2) Additives (a) Reinforcement agent 1 (silica): Ultrasil VN3 (N2SA: 175 ml) manufactured by Evonik Degussa 2 / g) (b) Reinforcing agent 2 (carbon black): Diablack N220 manufactured by Mitsubishi Chemical Corporation (c) Silane coupling agent: Degussa Si266 (bis(3-triethoxysilylpropyl) disulfide) (d) Process oil: Process X-260 manufactured by ENEOS Corporation (d) Mineral oil: Diana Process PA32 (paraffin-based) manufactured by Idemitsu Kosan Co., Ltd. (e) Resin: SYLVATRAXX 4401 (α-methylstyrene resin) manufactured by Arizona Chemical Company (f) Wax: Ozoace 0355 manufactured by Nippon Seiro Co., Ltd. (g) Antioxidant 1: Nocrac 6C (N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine) manufactured by Ouchi Shinko Chemical Industry Co., Ltd. (h) Antioxidant 2: Antage RD (2,2,4-trimethyl-1,2-dihydroquinoline) manufactured by Kawaguchi Chemical Industry Co., Ltd. (i) Zinc oxide: Two types of zinc oxide manufactured by Mitsui Mining & Smelting Co., Ltd. (j) Stearic acid: Tsubaki manufactured by NOF Corporation (k) Sulfur: HK-200-5 (containing 5% oil by mass) manufactured by Hosoi Chemical Co., Ltd. (l) Vulcanization accelerator 1: Noccela CZ-G (CBS) (N-cyclohexyl-2-benzothiazolyl sulfenamide) manufactured by Ouchi Shinko Chemical Industry Co., Ltd. (m) Vulcanization accelerator 2: Noccela DPG (1,3-diphenylguanidine) manufactured by Ouchi Shinko Chemical Industry Co., Ltd.

[0155] Moreover, each of the tires of Examples 1 to 8 and Comparative Examples 9 to 16 is configured similarly to the above-mentioned tire 1. That is, in each tire, the mount member 10 is attached to the attachment region A1 corresponding to the crown land portion 24A on the tire inner surface 7A.

[0156] Moreover, each tire of Comparative Examples 1 to 8 is a tire 1A shown in FIG. 5. FIG. 5 is a diagram showing the configuration of the tire 1A of Comparative Examples 1 to 8, and the same reference numerals are used to indicate parts common to the tire 1. The tire 1A is different from the configuration of the tire 1 described above in that three main grooves 22 are formed on the tread surface 21 of the tread portion 2, and four land portions 24 divided in the width direction D1 by the main grooves 22 are provided in the tread portion 2. The main groove 22C is disposed in the central portion intersecting with the equatorial plane CL1 in the tread surface 21, and the main grooves 22D are disposed at positions spaced apart from the main groove 22C to the outside in the width direction D1. Therefore, the mount member 10 is disposed in the attachment region A2 corresponding to the main groove 22C on the inner surface 7A.

[0157] Table 1 shows compounding information R1 to R6 of the tread portion 2 of each tire of Examples 1 to 8 and Comparative Examples 1 to 16, and compounding information R7 and R8 of the mounting member 10. Each of the compounding information R1 to R8 includes the compounding ratio and predetermined physical property values ​​of the rubber composition of the corresponding member.

[0158] [Table 1]

[0159] As shown in Table 1, the compounding information R1 to R8 shows the compounding ratio of four types of rubber materials and the compounding ratio of 14 types of additives, and also shows the physical property values ​​of four physical properties. Here, the compounding ratio is 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 ratio of the compounded amount (parts by mass) of each material when the total parts by mass of one or more types of rubber materials (rubber components) is taken as 100. The unit used for the compounding ratio is expressed in phr (per hundred rubber). In addition, each physical property shown in Table 1 is loss tangent tanδ·30°C at 30°C, loss tangent tanδ·0°C at 0°C, complex modulus E at 30°C, and the like. * (E * -30℃), and glass transition temperature Tg.

[0160] The tires of each example and each comparative example were manufactured as follows. First, additives other than sulfur and vulcanization accelerator and rubber materials were mixed according to the ratios shown in the compounding information R1 to R6 in Table 1, and the mixture was kneaded for 4 minutes at a temperature of about 130°C using a Banbury mixer. Next, sulfur and vulcanization accelerator were added to the obtained mixture according to the ratios shown in Table 1, and the mixture was kneaded for 4 minutes at a temperature of about 80°C using an open roll to obtain an unvulcanized rubber composition. The unvulcanized rubber composition thus obtained was extrusion molded into the shape of the tread portion 2, and laminated together with other tire components on a tire molding machine to form an unvulcanized tire, which was press-vulcanized for 10 minutes at a temperature of 170°C to manufacture a test tire (tire size: 205 / 55R16 91V, maximum load capacity: 615kg).

[0161] The mounting member 10 included in the tires of each of the examples and comparative examples was manufactured as follows. First, additives other than sulfur and the vulcanization accelerator and rubber materials were mixed according to the ratios shown in the compounding information R7 to R8 in Table 1, and the mixture was kneaded for 4 minutes at a temperature of about 130°C using a specified mixer. Next, sulfur and the 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 about 80°C to obtain an unvulcanized rubber composition. The unvulcanized rubber composition thus obtained was extruded into the shape of the mounting member 10, and vulcanized for 10 minutes at a temperature of 170°C to produce the mounting member 10.

[0162] The manufactured mounting member 10 is then fixed to the inner surface of the tire of each of the examples and comparative examples together with the electrical equipment by the above-mentioned mounting method. Here, in Examples 1 to 7, Comparative Examples 1 to 7, and Comparative Examples 9 to 15, the mounting area of ​​the inner surface 7A of the tire 1 is surface-treated by mechanical polishing, and then the mounting member 10 is attached to the mounting area together with the electrical equipment. In addition, in Example 8 and Comparative Examples 8 and 16, the mounting area of ​​the inner surface 7A of the tire 1 is surface-treated by laser light irradiation, and then the mounting member 10 is attached to the mounting area together with the electrical equipment. The weight of the obtained tire, including the weight of the electrical parts and the mounting member 10, was all within the range of 7.7 kg±0.2 kg.

[0163] In addition, the surface processing using laser light was performed by moving the laser light back and forth multiple times over the mounting area where the mounting member 10 was to be attached, using a moving pitch of 60 μm and a moving speed of 4000 mm / s, to remove the rubber surface together with the release agent so that the removal depth (removal step) was 97 μm.

[0164] The complex elastic modulus E shown in Table 1 *The loss tangent tanδ and glass transition temperature Tg are values ​​measured using a predetermined viscoelasticity spectrometer by cutting test pieces of 20 mm in length, 4 mm in width and 1 mm in thickness from the tread portion 2 and the mounting member 10 of the tire manufactured as described above. The circumferential and longitudinal directions of the sample of the tread portion 2 are the same. In addition, when the same rubber composition was measured, the average values ​​thereof are calculated and described.

[0165] Table 2 shows the compounding information (R1 to R8), thickness (d1, d2), and complex modulus E of each part of the tread portion 2 and the mounting member 10 of the tire of each of Example 1 and Comparative Example 1, Example 2 and Comparative Example 2, Example 3 and Comparative Example 3, Example 4 and Comparative Example 4, Example 5 and Comparative Example 5, Example 6 and Comparative Example 6, Example 7 and Comparative Example 7, and Example 8 and Comparative Example 8. * ·30℃, the loss tangent tanδ·30℃, the loss tangent tanδ·0℃, the glass transition temperature Tg, and the difference ΔE * (=E * 1-E * 2), the thickness ratio (d1 / d2) of each thickness d1, d2, the difference in glass transition temperature ΔT (=T1-T2), the attachment position of the mounting member 10, the method of surface processing of the attachment area of ​​the mounting member 10, and the evaluation value related to noise (hereinafter referred to as the noise evaluation value). As shown in Table 2, in each embodiment and each comparative example, 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 tread portion 2 * Greater than 2.

[0166] Here, the thickness d2 of the tread portion 2 is the thickness of the corresponding land portion 24 when the mounting member 10 is attached to the attachment region A1 corresponding to the land portion 24 of the tread portion 2. Also, when the mounting member 10 corresponds to the main groove 22, that is, when it does not correspond to the land portion 24 of the tread 2, the thickness d2 is the thickness of the land portion 24 to which the center position of the mounting member 10 is closest.

[0167] [Table 2]

[0168] The noise evaluation values ​​shown in Table 2 were calculated by the following method. The tires of each Example and Comparative Example were mounted on all wheels of a four-wheel vehicle in the normal state, and the vehicle was driven around a test course at a speed of 100 km / h. The noise felt by the driver in 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 up. The total score of Example 1 was set to 100, and the total scores of the other Examples and Comparative Examples were indexed. The larger the noise evaluation value, the smaller and better the noise felt by the driver while driving at high speed.

[0169] As shown in Table 2, Example 1 and Comparative Example 1 have different numbers of main grooves in the tread portion 2, and therefore the mounting positions of the mounting members 10 are different. The only difference between Example 1 and Comparative Example 1 is the mounting position of the mounting member 10, and the other configurations and specifications are substantially the same. In this case, it can be understood that Example 1, in which the mounting member 10 is mounted in the mounting region A1 (see FIG. 2), has a higher noise evaluation value than Comparative Example 1, in which the mounting member 10 is mounted in the mounting region A2 (see FIG. 5), that is, the noise generated during high-speed driving is lower. Note that in all of Examples 1 to 8, the mounting member 10 is mounted in the mounting region A1, and in all of the corresponding Comparative Examples 1 to 8, the mounting member 10 is mounted in the mounting region A2, and it can be understood from Table 2 that in all of the Examples and Comparative Examples, Examples 1 to 8 have higher noise evaluation values ​​than the corresponding Comparative Examples 1 to 8.

[0170] In Example 2 and Comparative Example 2, the complex elastic modulus ΔE * Complex elastic modulus ΔE of tread portion 1 and tread portion 2 * The difference ΔE from 2 *is 1.0 higher. There is also a difference in that the loss tangent tanδ·30°C of the tread portion 2 is 0.15, which is 0.05 lower. In this case, the noise evaluation value of Example 2 is 4 points higher than that of Example 1, and the noise evaluation value of Comparative Example 2 is 3 points higher than that of Comparative Example 1. From this, it can be seen that, when other conditions are the same, the complex elastic modulus ΔE * 1 is the complex modulus of elasticity ΔE of the tread portion 2 * 2, i.e., the difference ΔE * It can be understood that the larger the loss tangent tanδ·30°C, the higher the noise evaluation value, that is, the lower the noise generated during high-speed driving. Also, it can be understood that the noise evaluation value is higher when the loss tangent tanδ·30°C of the tread portion 2 is 0.15 rather than 0.20, that is, the lower the noise generated during high-speed driving.

[0171] Example 3 and Comparative Example 3 are different from Example 2 and Comparative Example 2 in that the loss tangent tan δ·0°C of the tread portion 2 is 0.28, which is 0.03 higher. In this case, the noise evaluation value of Example 3 is 6 points higher than that of Example 2, and the noise evaluation value of Comparative Example 3 is 3 points higher than that of Comparative Example 2. From this, it can be understood that, when other conditions are the same, the noise evaluation value is higher when the loss tangent tan δ·0°C of the tread portion 2 is larger, that is, the noise generated during high-speed running is lower.

[0172] Example 4 and Comparative Example 4 are different from Example 3 and Comparative Example 3 in that the loss tangent tan δ·30°C of the tread portion 2 is 0.10, which is 0.05 smaller, and the loss tangent tan δ·0°C of the tread portion 2 is 0.30, which is 0.02 larger. In this case, the noise evaluation value of Example 4 is 4 points higher than that of Example 3, and the noise evaluation value of Comparative Example 4 is 4 points higher than that of Comparative Example 3. From this, it can be understood that, when other conditions are the same, the smaller the loss tangent tan δ·30°C, the higher the noise evaluation value, and the larger the loss tangent tan δ·0°C of the tread portion 2, the higher the noise evaluation value, that is, the lower the noise generated during high-speed running.

[0173] In Example 5 and Comparative Example 5, the difference ΔE * is 1.0 higher, and the loss tangent tanδ·0°C of the tread portion 2 is 0.05 higher. In this case, the noise evaluation value of Example 5 is 6 points higher than that of Example 4, and the noise evaluation value of Comparative Example 5 is 6 points higher than that of Comparative Example 4. From this, when other conditions are the same, the difference ΔE * It can be understood that the larger the loss tangent tan δ·0° C. of the tread portion 2, the higher the noise evaluation value, and the larger the loss tangent tan δ·0° C. of the tread portion 2, the higher the noise evaluation value, that is, the lower the noise generated during high-speed running.

[0174] In Example 6 and Comparative Example 6, the thickness ratio (d1 / d2) between the thickness d1 of the mount member 10 and the thickness d2 of the tread portion 2 is larger than in Example 5 and Comparative Example 5. More specifically, in Example 5 and Comparative Example 5, the thickness d1 is 1.5 times the thickness d2, whereas in Example 6 and Comparative Example 6, the thickness d1 and the thickness d2 are the same. In this case, the noise evaluation value of Example 6 is 4 points higher than that of Example 5, and the noise evaluation value of Comparative Example 6 is 4 points higher than that of Comparative Example 5. From this, it can be understood that, when other conditions are the same, the noise evaluation value is higher when the thickness ratio (d1 / d2) is 1.0 than when the thickness ratio (d1 / d2) is 1.5, that is, the noise generated during high-speed running is lower.

[0175] Example 7 and Comparative Example 7 are different from Example 6 and Comparative Example 6 in that the glass transition temperature T1 of the mounting member 10 is lower than the glass transition temperature T2 of the rubber composition of the tread portion 2, and the difference in glass transition temperatures ΔT (=T1-T2) is -5°C. In this case, the noise evaluation value of Example 7 is 6 points higher than that of Example 6, and the noise evaluation value of Comparative Example 7 is 2 points higher than that of Comparative Example 6. From this, it can be understood that, when other conditions are the same, the noise evaluation value is higher when the glass transition temperature T1 of the mounting member 10 is lower than the glass transition temperature T2 of the rubber composition of the tread portion 2, that is, the noise generated during high-speed driving is lower.

[0176] Example 8 and Comparative Example 8 are different from Example 7 and Comparative Example 7 in that the surface processing method of the attachment region to which the mount member 10 is attached is different. In detail, as described above, the surface processing of Example 7 and Comparative Example 7 is mechanical polishing, while the surface processing of Example 8 and Comparative Example 8 is a method of irradiating the attachment region with laser light. In this case, the noise evaluation value of Example 8 is 5 points higher than that of Example 7, and the noise evaluation value of Comparative Example 8 is 2 points higher than that of Comparative Example 7. From this, it can be understood that the noise evaluation value is higher, that is, the noise generated during high-speed driving is lower, when the surface processing of the attachment region of the mount member 10 is laser light irradiation processing rather than mechanical polishing.

[0177] Table 3 shows the compounding information (R1 to R8), thickness (d1, d2), and complex modulus E of each part of the tread portion 2 and the mounting member 10 of the tire of each of Example 1 and Comparative Example 9, Example 2 and Comparative Example 10, Example 3 and Comparative Example 11, Example 4 and Comparative Example 12, Example 5 and Comparative Example 13, Example 6 and Comparative Example 14, Example 7 and Comparative Example 15, and Example 8 and Comparative Example 16. * ·30℃, the loss tangent tanδ·30℃, the loss tangent tanδ·0℃, the glass transition temperature Tg, and the difference ΔE * (=E * 1-E * 2), the thickness ratio (d1 / d2) of each thickness d1, d2, the difference in glass transition temperature ΔT (=T1-T2), the attachment position of the mounting member 10, the method of surface treatment of the attachment region of the mounting member 10, and the noise evaluation value. As shown in Table 3, the composition information of the mounting members 10 in each of Examples 1 to 8 is different from the composition information of the mounting members 10 in each of Comparative Examples 9 to 16. For this reason, in each of Examples 1 to 8, 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 tread portion 2 * 2. In each of Comparative Examples 9 to 16, 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 tread portion 2 * Less than 2.

[0178] [Table 3]

[0179] The noise evaluation values ​​shown in Table 3 were calculated in the same manner as the noise evaluation values ​​shown in Table 2.

[0180] As shown in Table 3, in both Example 1 and Comparative Example 9, the mounting member 10 is attached to the attachment area A1 (see FIG. 2). On the other hand, 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 tread portion 2 * 2. However, in Comparative Example 9, 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 tread portion 2 * 2. The difference between Example 1 and Comparative Example 8 is that the complex elastic modulus E * The complex elastic modulus E of the tread portion 2 * 2, the other configurations and specifications are substantially the same. In this case, the difference ΔE * In the first embodiment, the difference ΔE * It can be seen that the noise evaluation value is higher than that of Comparative Example 1, in which the difference ΔE * is positive (plus), and the difference ΔE * It can be seen from Table 3 that the noise evaluation value is negative and that in all of Examples 1 to 8, the noise evaluation value is higher than the corresponding Comparative Examples 9 to 16.

[0181] Example 2 and Comparative Example 10 are different from Example 1 and Comparative Example 9 in that the loss tangent tanδ·30°C of the tread portion 2 is 0.15, which is 0.05 smaller than that of Example 1 and Comparative Example 9.* is further increased by 1.0 to +4.0. In this case, the noise evaluation value of Example 2 is 4 points higher than that of Example 1, and the evaluation value of Comparative Example 10 is 2 points higher than that of Comparative Example 9. From this, when other conditions are the same, the difference ΔE * It can be seen that the larger the loss tangent tanδ·30°C, the higher the noise evaluation value, and the smaller the loss tangent tanδ·30°C, the higher the noise evaluation value. In other words, it can be seen that the noise generated during high-speed driving is lower.

[0182] Example 3 and Comparative Example 11 are different from Example 2 and Comparative Example 10 in that the loss tangent tan δ·0°C of the tread portion 2 is 0.28, which is 0.03 higher. In this case, the noise evaluation value of Example 3 is 6 points higher than that of Example 2, and the evaluation value of Comparative Example 11 is 6 points higher than that of Comparative Example 10. From this, it can be understood that, when other conditions are the same, the noise evaluation value is higher when the loss tangent tan δ·0°C is larger, that is, the noise generated during high-speed driving is lower.

[0183] Example 4 and Comparative Example 12 are different from Example 3 and Comparative Example 11 in that the loss tangent tan δ·30°C of the tread portion 2 is 0.10, which is 0.05 smaller, and the loss tangent tan δ·0°C of the tread portion 2 is 0.30, which is 0.02 larger. In this case, the noise evaluation value of Example 4 is 4 points higher than that of Example 3, and the noise evaluation value of Comparative Example 12 is 4 points higher than that of Comparative Example 11. From this, it can be understood that, when other conditions are the same, the smaller the loss tangent tan δ·30°C, the higher the noise evaluation value, and the larger the loss tangent tan δ·0°C of the tread portion 2, the higher the noise evaluation value, that is, the lower the noise generated during high-speed running.

[0184] In Example 5 and Comparative Example 13, the complex elastic modulus E of the mounting member 10 is higher than that of Example 3 and Comparative Example 11. * The complex elastic modulus E of the tread portion 2 * Difference from 2 ΔE * (=E * 1-E *2) is 1.0 higher. In this case, the noise evaluation value of Example 5 is 6 points higher than that of Example 4, and the noise evaluation value of Comparative Example 13 is 4 points higher than that of Comparative Example 12. From this, it can be seen that, when other conditions are the same, the complex elastic modulus E * 1 is the complex modulus of elasticity E of the tread portion 2 * It can be understood that a value greater than 2 indicates a higher noise evaluation value, meaning that the noise generated when driving at high speeds is lower.

[0185] In Example 6 and Comparative Example 14, the thickness ratio (d1 / d2) between the thickness d1 of the mount member 10 and the thickness d2 of the tread portion 2 is larger than in Example 5 and Comparative Example 13. More specifically, in Example 5 and Comparative Example 13, the thickness d1 is 1.5 times the thickness d2, whereas in Example 6 and Comparative Example 14, the thickness d1 and the thickness d2 are the same. In this case, the noise evaluation value of Example 6 is 4 points higher than that of Example 5, and the noise evaluation value of Comparative Example 14 is 6 points higher than that of Comparative Example 13. From this, it can be understood that, when other conditions are the same, the noise evaluation value is higher when the thickness ratio (d1 / d2) is 1.0 than when the thickness ratio (d1 / d2) is 1.5, that is, the noise generated during high-speed running is lower.

[0186] Example 7 and Comparative Example 15 are different from Example 6 and Comparative Example 14 in that the glass transition temperature T1 of the mounting member 10 is lower than the glass transition temperature T2 of the rubber composition of the tread portion 2, and the difference in glass transition temperatures ΔT (=T1-T2) is -5°C. In this case, the noise evaluation value of Example 7 is 6 points higher than that of Example 6, and the noise evaluation value of Comparative Example 15 is 2 points higher than that of Comparative Example 14. From this, it can be understood that, when other conditions are the same, the noise evaluation value is higher when the glass transition temperature T1 of the mounting member 10 is lower than the glass transition temperature T2 of the rubber composition of the tread portion 2, that is, the noise generated during high-speed driving is lower.

[0187] Example 8 and Comparative Example 16 are different from Example 7 and Comparative Example 15 in that the surface treatment methods of the attachment region to which the mount member 10 is attached are different. In detail, as described above, the surface treatment of Example 7 and Comparative Example 15 is mechanical polishing, whereas the surface treatment of Example 8 and Comparative Example 16 is a method of irradiating the attachment region with laser light. In this case, the noise evaluation value of Example 8 is 5 points higher than that of Example 7, and the noise evaluation value of Comparative Example 16 is 2 points higher than that of Comparative Example 15. From this, it can be understood that the noise evaluation value is higher, that is, the noise generated during high-speed driving is lower, when the surface treatment of the attachment region of the mount member 10 is laser light irradiation treatment rather than mechanical polishing.

[0188] The embodiments of the present disclosure described above include the following disclosure items (1) to (12).

[0189] The present disclosure (1) is a tire including a tread portion having land portions divided by grooves formed on the surface, and a mounting member provided on the inner surface of the tire on the inner side of the tread portion and capable of mounting electrical equipment. In the tire of the present disclosure (1), the mounting member is disposed at an attachment position on the inner surface of the tire corresponding to the land portions. The complex modulus E of a first rubber composition constituting the mounting member is * 1 is the complex modulus E of the second rubber composition constituting the tread portion * 2. Because of this configuration, even in a tire in which an electric device is attached to the mounting member, noise caused by the load of the mounting member and the electric device can be suppressed.

[0190] The present disclosure (2) relates to the tire according to the present disclosure (1), wherein the complex modulus E at 30 ° C. of the first rubber composition is * 1 and the complex modulus E of the second rubber composition at 30 ° C. * The difference from 2 is at least 2.0 MPa.

[0191] The present disclosure (3) relates to the tire according to the present disclosure (1) or (2), in which the second rubber composition constituting the tread portion has a loss tangent tan δ at 0° C. of 0.30 or more.

[0192] The present disclosure (4) relates to the tire according to any one of the present disclosures (1) to (3), wherein the second rubber composition constituting the tread portion has a loss tangent tan δ at 30° C. of 0.13 or less.

[0193] The present disclosure (5) relates to the tire according to the present disclosure (4), in which the second rubber composition constituting the tread portion has a loss tangent tan δ at 30° C. of 0.10 or less.

[0194] The present disclosure (6) is a tire according to any one of the present disclosures (1) to (5), wherein a glass transition temperature T1 of the first rubber composition of the mounting member is lower than a glass transition temperature T2 of the second rubber composition of the tread portion.

[0195] The present disclosure (7) is a tire according to any one of the present disclosures (1) to (6), wherein a maximum thickness d1 of the mounting member in a direction perpendicular to the tire inner surface and a thickness d2 of the land portion of the tread portion satisfy the following formula (1). 0.25×d2 <d1<1.25×d2 ··· (1)

[0196] The present disclosure (8) is a tire according to any one of the present disclosures (1) to (7), wherein the groove includes at least two circumferential grooves formed on both sides of the tire equatorial plane and extending along the tire circumferential direction, and the mounting member is arranged on the inner surface of the tire at the attachment position corresponding to the land portion sandwiched between the two circumferential grooves.

[0197] The present disclosure (9) is a tire according to any one of the present disclosures (1) to (8), in which the mounting member is fixed to the mounting position in a state in which the surface of the mounting surface including the mounting position on the tire inner surface and / or the adhesive surface of the mounting member that is adhered to the tire inner surface are removed by a predetermined surface processing treatment. This can improve the mounting strength of the mounting member on the tire inner surface. The mounting member can be fixed by welding, adhesive, or the like.

[0198] The present disclosure (10) is a tire according to the present disclosure (9), wherein the surface treatment is a treatment of irradiating a laser beam. More preferably, the surface treatment is a treatment of irradiating the laser beam to process the attachment surface on the inner surface of the tire or the contact surface of the mounting member into a uniform surface. This improves the adhesion between the attachment surface and the contact surface, and as a result, the attachment strength of the mounting member on the inner surface of the tire can be improved. In addition, the release agent adhering to each surface is also removed, so that the attachment strength can be further improved.

[0199] The present disclosure (11) is a tire according to any one of the present disclosures (1) to (10), comprising two of the mounting members, the mounting members being arranged on the inner surface of the tire at the attachment positions corresponding to two land portions separated in the tire width direction by the tire equatorial plane.

[0200] The present disclosure (12) is a tire for a passenger vehicle, the tire according to any one of the present disclosures (1) to (11). That is, the present disclosure (12) is suitably used for a tire for a passenger vehicle to be mounted on a passenger vehicle.

Claims

1. A tread portion having land portions divided by grooves formed on a surface thereof; a mounting member provided on an inner surface of the tire on an inner side of the tread portion, to which an electrical device can be attached; the mount member is disposed at an attachment position on the inner surface of the tire corresponding to the land portion, The complex elastic modulus E of the first rubber composition constituting the mounting member was measured under the following measurement conditions: measurement temperature 30° C., initial strain 5%, dynamic strain ±1%, frequency 10 Hz, and elongation deformation mode. * 1, and the complex elastic modulus E of the second rubber composition constituting the tread portion * A tire in which, when complex modulus E*1 at 30° C. of the first rubber composition is measured, complex modulus E*2 at 30° C. of the second rubber composition is larger than complex modulus E*2 at 30° C. of the second rubber composition.

2. The complex modulus E of the first rubber composition at 30 ° C. * 1, and the complex modulus E of the second rubber composition at 30 ° C. * 2. The tire according to claim 1, wherein the difference between the first and second values ​​is at least 2.0 MPa or more.

3. A tire as described in claim 1 or 2, wherein when the loss tangent tan δ of the second rubber composition constituting the tread portion at 0°C is measured under measurement conditions of a measurement temperature of 0°C, an initial strain of 10%, a dynamic strain of ±2.5%, a frequency of 10 Hz, and an extension deformation mode, the loss tangent tan δ of the second rubber composition at 0°C is 0.30 or more.

4. A tire as described in any of claims 1 to 3, wherein when the loss tangent tan δ of the second rubber composition constituting the tread portion at 30°C is measured under measurement conditions of a measurement temperature of 30°C, an initial strain of 5%, a dynamic strain of ±1%, a frequency of 10 Hz, and an extension deformation mode, the loss tangent tan δ of the second rubber composition at 30°C is 0.13 or less.

5. The tire according to claim 4, wherein the second rubber composition constituting the tread portion has a loss tangent tan δ at 30° C. of 0.10 or less.

6. The tire according to claim 1 , wherein a glass transition temperature T1 of the first rubber composition of the mounting member is lower than a glass transition temperature T2 of the second rubber composition of the tread portion.

7. The tire according to claim 1 , wherein a maximum thickness d1 of the mount member in a direction perpendicular to the tire inner surface and a thickness d2 of the land portion of the tread portion satisfy the following formula (1): 0.25×d2<d1<1.25×d2... (1)

8. The recessed groove includes at least two circumferential grooves formed on both sides of the tire equatorial plane and extending along the tire circumferential direction, The tire according to claim 1 , wherein the mount member is disposed on the inner surface of the tire at the attachment position corresponding to the land portion sandwiched between the two circumferential grooves.

9. 9. The tire according to claim 1, wherein the mounting member is fixed to the mounting position in a state in which a surface of a mounting surface including the mounting position on the tire inner surface and / or an adhesive surface of the mounting member that is adhered to the tire inner surface have been removed by a predetermined surface processing treatment.

10. The tire according to claim 9 , wherein the surface treatment is a treatment of irradiating with laser light.

11. the tire comprises two or more of the mounting members, The tire according to claim 1 , wherein the mount members are disposed on the inner surface of the tire at the attachment positions corresponding to two land portions separated in the tire width direction by the tire equatorial plane.

12. 12. The tire according to claim 1, wherein the tire is a passenger tire.

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