TIRES

Abstract

[Object] An object of the present invention is to improve overall performance of low fuel consumption and durability characteristics. [Solution] A tire is provided which comprises a belt layer containing a belt cord coated with a rubber composition, wherein the belt cord is a steel cord of a filament, the rubber composition contains less than 0.15 parts by mass of cobalt with respect to 100 parts by mass of a rubber component, and a diameter D (mm) of the belt cord, a complex elastic modulus E* (MPa) of the rubber composition measured under conditions of a temperature of 70°C, an initial elongation of 5%, a dynamic elongation of ±1%, a frequency of 10 Hz, and a deformation mode of elongation, and a cobalt amount C (parts by mass) in the rubber composition with respect to 100 parts by mass of the rubber component satisfy the following expression: D / E* < 0,1 × C + 0,05.

Description

Technical field

[0001] The present invention relates to a tire. State of the art

[0002] PTL 1 discloses a tire including a carcass, a belt, and a band. Citation listPatent literature

[0003] [PTL 1] Japanese Unexamined Patent Publication No. 2005-239069 Summary of the inventionTechnical problem

[0004] An object of the present invention is to improve overall performance of low fuel consumption and durability characteristics. Solution to the problem

[0005] According to one embodiment of the present invention, there is provided a tire comprising: a belt layer containing a belt cord coated with a rubber composition, where the belt cord is made of a filament, the rubber composition contains less than 0.15 parts by mass of cobalt with respect to 100 parts by mass of a rubber component, and a diameter D (mm) of the belt cord, a complex elastic modulus E* (MPa) of the rubber composition measured under conditions of a temperature of 70 °C, an initial strain of 5%, a dynamic strain of ±1%, a frequency of 10 Hz, and a deformation mode of elongation, and a cobalt amount C (parts by mass) in the rubber composition with respect to 100 parts by mass of the rubber component satisfy the following expression: D / E*<0.1×C+0.05. Advantageous effects of the invention

[0006] According to the present invention, it is possible to improve the overall performance of low fuel consumption and durability characteristics. Brief description of the drawings Fig. 1 is a schematic cross-sectional view for explanatory description of a structure of a tire according to an embodiment of the present invention. Fig. 2 is a schematic view for an explanatory description of measurement of bending stiffness. Description of Embodiments[1] Properties of tires according to the present invention

[0007] First, characteristics of a tire according to the present invention will be described. 1. Overview

[0008] A tire according to the present invention is a tire including a belt layer configured to have a belt cord (hereinafter also simply referred to as a "cord") coated with a rubber composition. The belt cord is composed of a filament, and the rubber composition contains less than 0.15 parts by mass of cobalt with respect to 100 parts by mass of the rubber component. In addition, a diameter D (mm) of the belt cord, a complex elastic modulus E* (MPa) of the rubber composition measured under conditions of a temperature of 70°C, an initial elongation of 5%, a dynamic elongation of ±1%, a frequency of 10 Hz, and a deformation mode of elongation, and a cobalt amount C (parts by mass) in the rubber composition with respect to 100 parts by mass of the rubber component satisfy the following expression: D / E*<0.1×C+0.05.

[0009] Since these properties are provided, it is possible to improve the overall performance of low fuel consumption and durability properties, as described later.

[0010] It should be noted that the complex elastic modulus E* described above can be measured, for example, by using a viscoelasticity measuring device such as “EPLEXOR (registered trademark)” manufactured by GABO Co., Ltd. 2. Mechanism for showing effect in tires according to the present invention

[0011] A mechanism for exhibiting the above-described effect in the tire according to the present invention is assumed as follows.

[0012] As a means for achieving low fuel consumption of the tire, it is effective to reduce a loss tangent (tanδ) of a rubber member for a tire such as a belt layer.

[0013] However, in order to improve the adhesiveness to the belt cord, a rubber composition of a belt ply constituting a belt layer usually contains cobalt as an impurity, and thus there is a concern that the loss tangent (tanδ) may increase.

[0014] Therefore, in order to reduce the loss tangent (tanδ), it is conceivable to reduce the cobalt content in the rubber composition. However, in this case, although low fuel consumption can be achieved, the adhesion between the cord and the rubber is reduced. Therefore, BEL (belt edge looseness), loosening, or the like, in which the cord and rubber peel off, occurs at an end portion, and there are concerns that tire durability will deteriorate.

[0015] Therefore, increasing the gauge (thickness) of the belt layer is conceivable to address the deterioration in durability. However, there are concerns that increasing the gauge may reduce the low fuel consumption characteristics.

[0016] In the present invention, the belt cord is composed of a filament. Since the belt cord is composed of a filament, the cord diameter can be reduced. Therefore, it is possible to ensure a sufficient rubber thickness (upper cord gauge) without increasing the gauge, and it is possible to suppress the occurrence of BEL, loosening, or the like.

[0017] Furthermore, since the cord with a small cord diameter can reduce the contact area with the rubber, even if the cobalt content in the rubber composition is reduced to less than 0.15 parts by mass relative to 100 parts by mass of the rubber component, the adhesion between the cord and the rubber can be sufficiently ensured. Furthermore, reducing the cobalt content reduces the loss tangent (tanδ), which makes it possible to improve the low fuel consumption characteristics.

[0018] Here, the filament constituting the belt cord preferably has a cross-sectional shape having a circular shape; however, the cross-sectional shape thereof may be an elliptical shape. Furthermore, the filament may be corrugated, and it may be a filament that has undergone a plating treatment. Furthermore, it may be untwisted, it may be simply twisted (1 × 4), or it may be layer-twisted (2 + 2). Note that in the embodiment described later, a filament having a circular cross-sectional shape in a untwisted state (1 × 1 structure) is used without being corrugated.

[0019] The belt cord is preferably a metal cord, more preferably an iron cord and most preferably a steel cord.

[0020] Furthermore, in the above description, the "cord diameter" of the belt cord can be measured in accordance with a test method specified in JIS G 3510:1992 "Testing Methods for Steel Tire Cords." Furthermore, the term "cord diameter" refers to a diameter in a case where a circumscribed circle of a cross section perpendicular to an extending direction of the cord is a perfect circle, and it refers to an equivalent circle diameter in a case of an ellipse or the like (a diameter of a circle in a case where a circle with the same cross-sectional area is assumed).

[0021] Further, in the present invention, a diameter D (mm) of the belt cord, a complex elastic modulus E* (MPa) of the rubber composition measured under conditions of a temperature of 70 °C, an initial elongation of 5%, a dynamic elongation of ±1%, a frequency of 10 Hz, and a deformation mode of elongation, and a cobalt amount C (parts by mass) in the rubber composition with respect to 100 parts by mass of the rubber component satisfy the following expression: D / E*<0.1×C+0.05.

[0022] In the present invention, the above expression indicates that the complex elastic modulus E* of the rubber composition is sufficiently large relative to the cord diameter. As described above, by increasing the complex elastic modulus E* of the rubber composition, the movement of a cord end is sufficiently suppressed. Therefore, it is possible to suppress the occurrence of BEL, loosening, or the like.

[0023] It should be noted that the number of belt layers is not limited to one layer and may be two or more layers. However, in this case, it is sufficient that at least one belt layer satisfies D / E* < 0.1 × C + 0.05 described above, and it is further preferable that all belt layers satisfy D / E* < 0.1 × C + 0.05.

[0024] In the present invention, since the diameter of the belt cord and the amount of cobalt in the rubber composition are appropriately controlled and D / E* < 0.1 × C + 0.05 is also satisfied, the respective effects described above cooperate to exhibit synergy. Therefore, it is considered possible to improve the overall performance of low fuel consumption properties and durability. Moreover, the difference (D / E* - 0.1 × C) between D / E* and 0.1 × C is more preferably 0.043 or less, even more preferably 0.039 or less, even more preferably 0.038 or less, even more preferably 0.036 or less, and still more preferably 0.033 or less.

[0025] Note that the amount of cobalt in the rubber composition is more preferably 0.14 parts by mass or less, even more preferably less than 0.10 parts by mass, even more preferably 0.07 parts by mass or less, even more preferably less than 0.05 parts by mass, even more preferably 0.01 parts by mass or less, even more preferably less than 0.01 parts by mass, and even more preferably less than 0.005 parts by mass, with respect to 100 parts by mass of the rubber component. Moreover, the lower limit thereof is not particularly limited, and it may be 0 parts by mass (not included). [2] Further preferred aspect of tires according to the present invention

[0026] The tire according to the present invention can achieve a greater effect by utilizing the following aspect. 1. Ends of cord and surface

[0027] In the present invention, a product (E × S) of the number E (cords) of cord ends (the number of cords per 50 mm in width in a tire width direction) in the belt layer (belt ply) and a surface S (mm 2 / mm) per unit length (1 mm) is preferably more than 40 (E × S > 40). In a case where (E × S) is increased to be greater than 40, the portion restricted by the rubber at the belt layer (belt ply) is increased. Therefore, the adhesive force between the rubber and the cord can be further sufficiently exhibited, and the movement of the cord can be sufficiently suppressed. Therefore, it is considered that the occurrence of BEL, loosening, or the like can be further suppressed, and the durability can be further improved. Note that the ends described above can be measured, for example, in accordance with a method specified in JIS L 1017:2002 "Test methods for chemical fiber tire cords."

[0028] Furthermore, (E × S) is more preferably 44 or more, even more preferably 50 or more, even more preferably 57 or more, even more preferably 60 or more, and even more preferably 66 or more. 2. Bending stiffness and ends of cord

[0029] In the present invention, it is preferable that the product (E × B) of cord ends and a bending rigidity B (g-cm) at the belt layer (belt ply) be more than 600 (E × B > 600). The movement of the cord can be sufficiently suppressed by increasing (E × B) to be greater than 600. Therefore, it is believed that the occurrence of BEL, loosening, or the like can be further suppressed, and durability can be further improved.

[0030] Note that (E × B) is more preferably more than 750, even more preferably 788 or more, even more preferably 824 or more, even more preferably more than 1000, even more preferably 1394 or more, even more preferably more than 2000, and even more preferably 2221 or more. The upper limit thereof is not particularly limited; however, it is preferably less than 5000, for example.

[0031] The bending stiffness of the belt cord described above can be measured, for example, by using a stiffness testing machine (e.g., 150-D type) manufactured by TABER Industries (USA) in accordance with the following procedure. First, both ends of a belt cord with a length of 145 mm are attached to clamps of a stiffness testing machine, and as shown in Fig. 2, a bending angle of +15 degrees and a bending angle of -15 degrees are applied to a belt cord 10. Then, an average value of the bending moment at +15 degrees and the bending moment at -15 degrees is defined as a bending stiffness value (g-cm). 3. Carbon black contained in rubber composition

[0032] In the present invention, it is preferred that the rubber composition contains carbon black having a BET specific surface area of 45 m 2 / g or more such that the amount of carbon black is 5 parts by mass or more and 70 parts by mass or less with respect to 100 parts by mass of the rubber component.

[0033] This makes it possible to increase the complex elastic modulus E* of the rubber composition. Therefore, it is believed that the occurrence of BEL, loosening, or the like can be further suppressed and durability can be further improved.

[0034] It should be noted that the content of the carbon black with respect to 100 parts by mass of the rubber component is more preferably 30 parts by mass or more and 60 parts by mass or less.

[0035] The BET specific surface area described above is a value of a specific nitrogen adsorption surface area (N2SA) measured by the BET method in accordance with ASTM D3037-93. [3] Embodiments

[0036] Hereinafter, the present invention will be specifically described based on the embodiments. 1. Tires according to the present embodiment

[0037] Fig. 1 is a schematic cross-sectional view for explanatory description of a structure of a tire according to the present embodiment, and shows a tire meridian cross section including a rotational axis of the tire in a normal state.

[0038] Here, the term “normal condition” refers to a condition in which the tire has undergone rim mounting on a normal rim, normal internal pressure has been applied, and there is no additional load.

[0039] It should be noted that the term "normal rim" is a rim defined for each tire by a standard in a standards system that includes the standard on which the tire is based. For example, in a case of The Japan Automobile Tire Manufacturers Association (JATMA), it refers to a standard rim with respect to the applicable size described in "JATMA YEAR BOOK", in a case of The European Tire and Rim Technical Organization (ETRTO), it refers to "Measuring Rim" described in "STANDARDS MANUAL", or in a case of The Tire and Rim Association (TRA), it refers to "Design Rim" described in "YEAR BOOK". Here, JATMA, ETRTO, and TRA are referred to in that order, following a standard with respect to an applicable size in a case where there is an applicable size in a case of reference.In addition, the normal rim refers to a rim that, in a case where the tire is not defined in the standard, is capable of subjecting a tire to rim mounting while maintaining an internal pressure, that is, a rim with the smallest rim diameter and then a rim with the narrowest rim width among rims that do not cause air leakage between a rim and a tire.

[0040] In addition, the term "normal internal pressure" refers to air pressure defined for each tire by each standard in a standards system that includes the standard on which the tire is based, and it refers to "the maximum air pressure" in a case of JATMA, "INFLATION PRESSURE" in a case of ETRTO, or to the maximum value described in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" in a case of TRA. Here, JATMA, ETRTO, and TRA are referred to in that order, following a standard with respect to an applicable size in a case where there is an applicable size in a case of reference.In the case of a tire not defined in the standard, the normal internal pressure refers to a normal internal pressure (which is 250 kPa or more) with respect to a different tire size (defined in the standard) described for the normal rim described above as a standard rim. Note that in a case where multiple normal internal pressures of 250 kPa or more are described, reference is made to the minimum value below.

[0041] As in Fig. 1, a tire 1 includes a carcass 6 extending from a tread portion 2 through a sidewall portion 3 to a bead core 5 of a bead portion 4, and a belt layer 7 disposed outside the carcass 6 in a tire radial direction and inside the tread portion 2. Note that C indicates a center line.

[0042] The carcass 6 is made up of at least one carcass ply 6A (one in Fig. 1) and is locked by folding the periphery of the bead core 5 of the bead portion 4 from the tread portion 2 through the sidewall portion 3 from the inside to the outside. It is in Fig. 1, 6a is an inner main body portion of the carcass ply 6A, 6b is an outer folded portion, and, for example, a bead tapex rubber 8 extending from the bead core 5 outward in the tire radial direction is disposed between the inner main body portion 6a and the outer folded portion 6b.

[0043] The belt layer 7 is configured to arrange at least one belt ply obtained by coating an arrangement body in which a steel cord of a filament is arranged to have predetermined ends with a coating rubber, and in Fig. 1, the belt layer 7 is composed of two belt plies of a first belt ply 7A located on the inside of the tire in the tire radial direction and a second belt ply 7B located on the outside of the first belt ply 7A. Note that three or more belt plies may be used.

[0044] By using such a belt layer 7 as described above, it is possible to improve the overall performance of low fuel consumption characteristics and durability. 2. Rubber composition forming the belt layer

[0045] In the present embodiment, the rubber composition constituting the belt layer can be obtained from a rubber component and other blending materials described below. (1) Mixed material(a) Rubber component

[0046] In the present embodiment, the rubber component is not particularly limited, and a rubber (polymer) commonly used in the production of tires can be used, wherein the rubber (polymer) is a diene-based rubber such as an isoprene-based rubber, a butadiene rubber (BR), a styrene-butadiene rubber (SBR), or a nitrile rubber (NBR), a butyl-based rubber such as butyl rubber, or the like. Among them, an isoprene-based rubber is preferable, and it is preferable to use NR in view of the fact that the cis structure of polyisoprene is almost 100% and the tensile strength is superior to that of other rubber components. Note that BR and SBR can be used together as needed. (a-1) Isoprene-based rubber

[0047] The content (total content) of the isoprene-based rubber in 100 parts by mass of the rubber component is preferably 80 parts by mass or more, more preferably 90 parts by mass or more, and even more preferably 100 parts by mass.

[0048] Examples of the isoprene-based rubber include natural rubber (NR), isoprene rubber (IR), reformulated NR, modified NR and modified IR, with NR being preferred from the viewpoint of excellent strength.

[0049] As the NR, it is possible to use those commonly used in the tire industry, such as SIR20, RSS#3, and TSR20. The IR is not particularly limited, and it is possible to use those commonly used in the tire industry, such as IR 2200. Examples of reformulated NR include deproteinized natural rubber (DPNR) and high-purity natural rubber (UPNR). Examples of modified NR include epoxidized natural rubber (ENR), hydrogenated natural rubber (HNR), and grafted natural rubber. Examples of modified IR include epoxidized isoprene rubber, hydrogenated isoprene rubber, and grafted isoprene rubber. These can be used alone, or two or more types of them can be used in combination. (a-2) Another rubber component

[0050] Furthermore, as another rubber component, rubber (a polymer) commonly used in tire manufacturing, such as butadiene rubber (BR), styrene-butadiene rubber (SBR), or nitrile rubber (NBR), may be included as needed. Note that the content (total content) of these rubber components in 100 parts by mass of the rubber component is preferably 20 parts by mass or less, and more preferably 10 parts by mass or less. (b) Mixed material other than rubber component (b-1) Filler

[0051] In the present embodiment, it is preferable that the rubber composition contains a filler. Examples of the specific filler include carbon black, silica, graphite, calcium carbonate, talc, alumina, clay, aluminum hydroxide, and mica, and among them, carbon black can be preferably used as a reinforcing agent. (i) Soot

[0052] Carbon black is not particularly limited, and examples thereof include furnace black (Furnace Black) such as SAF, ISAF, HAF, MAF, FEF, SRF, GPF, APF, FF, CF, SCF, and ECF; acetylene black (Acetylene Black); thermal black (Thermal Black) such as FT and MT; and channel black (Channel Black) such as EPC, MPC, and CC. One type of these may be used alone, or two or more types of them may be used in combination.

[0053] As described above, the BET specific surface area of the carbon black is preferably 45 m 2 / g or more. Furthermore, the content of the carbon black is preferably 5 parts by mass or more and 70 parts by mass or less, and more preferably 30 parts by mass or more and 60 parts by mass or less, with respect to 100 parts by mass of the rubber component.

[0054] The specific carbon black is not particularly limited, and examples thereof include N134, N110, N220, N234, N219, N339, N330, N326, N351, N550, and N762. As a commercially available product thereof, it is possible to use a product manufactured by, for example, ASAHI CARBON CO., LTD., Cabot Japan KK, TOKAI CARBON CO., LTD., Mitsubishi Chemical Corporation, Lion Specialty Chemicals Co., Ltd., NSCC Carbon Co., Ltd., or Columbia Carbon. These can be used alone, or two or more types of them can be used in combination. (iv) Another filler

[0055] In addition to the carbon black described above, the rubber composition may further contain, as needed, a filler commonly used in the tire industry, such as silica, graphite, calcium carbonate, talc, alumina, clay, aluminum hydroxide, or mica. The contents thereof are, for example, more than 0.1 part by mass and less than 200 parts by mass with respect to 100 parts by mass of the rubber component. Note that in a case where silica is used, the silica is preferably used in combination with a silane coupling agent. (b-2) Curable resin component

[0056] The rubber composition preferably contains a phenolic resin and / or a melamine resin as a curable resin component. This improves the adhesion to the steel cord and allows for easy generation of a large reaction force between the rubber and the steel cord without significantly deteriorating the exothermicity and elongation at the time of fracture.

[0057] Specific examples of the phenolic resin include PR12686 (cashew nut oil modified phenolic resin) manufactured by Sumitomo Bakelite Co., Ltd., and specific examples of the melamine resin include SUMIKANOL 507AP (modified etherified methylol melamine resin) manufactured by Taoka Chemical Co., Ltd.

[0058] The content of the curable resin component is preferably 1 part by mass or more, and more preferably 2 parts by mass or more, relative to 100 parts by mass of the rubber component, from the viewpoint of sufficiently improving the complex elastic modulus and maintaining a large reaction force during deformation. On the other hand, from the viewpoint of maintaining the fracture strength, it is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and even more preferably 5 parts by mass or less.

[0059] It should be noted that in a case where the melamine resin is used, it is preferable that a methylene donor be also included as a curing agent. Examples of the methylene donor include hexamethylenetetramine (HMT), hexamethoxymethylolmelamine (HMMM), and hexamethylolmelamine pentamethyl ether (HMMPME), for example, an amount of 5 parts by mass or more and about 15 parts by mass or less with respect to 100 parts by mass of the curable resin component is preferably included. In a case where the amount is too small, there is a risk that a sufficient complex elastic modulus may not be obtained. On the other hand, in a case where the amount is too large, there is a concern that the viscosity of the rubber may increase and the process efficiency may deteriorate.

[0060] As a specific methylene donor, it is possible to use, for example, SUMIKANOL 507 manufactured by Taoka Chemical Co., Ltd. (b-3) Softening agent component

[0061] The rubber composition may contain an oil (including an extender oil), a liquid rubber, and a resin as a component (softener) that softens the rubber. Note that the softener component is a component that can be extracted from vulcanized rubber with acetone. The total content of the softener component is preferably more than 1 part by mass, and more preferably 2 parts by mass or more, with respect to 100 parts by mass of the rubber component. On the other hand, the amount thereof is preferably less than 20 parts by mass, and more preferably less than 10 parts by mass. Note that the content of the oil also includes the amount of oil contained in rubber (oil-extended rubber). (i) Oil

[0062] Examples of the oil include a process oil, a vegetable oil, an animal oil, or a mixture thereof. For example, a paraffin-based process oil, an aromatic-based process oil, or a naphthene-based process oil can be used as the process oil. Specific examples of the process oil include mild extract solvate (MES), distillate aromatic extract (DAE), treated distillate aromatic extract (TDAE), treated residual aromatic extract (TRAE), and residual aromatic extract (RAE). Note that these can be used alone, or two or more types can be used in combination.

[0063] As the specific process oil, it is possible to use a product manufactured by, for example, Idemitsu Kosan Co., Ltd., SANKYO YUKA KOGYO KK, ENEOS Corporation, Olisoy, H&R Group, HOKOKU CORPORATION, Showa Shell Sekiyu KK or Fuji Kosan Company, Ltd.

[0064] Examples of vegetable oil include linseed oil, rapeseed oil, safflower oil, soybean oil, corn oil, cottonseed oil, rice bran oil, tall oil, sesame oil, wild sesame oil, castor oil, tung oil, pine oil, pine tar oil, sunflower oil, coconut oil, palm oil, palm kernel oil, olive oil, camellia oil, jojoba oil, macadamia nut oil, peanut oil, grapeseed oil, and Japanese wax. These can be used alone, or two or more types can be used in combination.

[0065] As the specific vegetable oil, it is possible to use those commercially available from, for example, Idemitsu Kosan Co., Ltd., SANKYO YUKA KOGYO KK, ENEOS Corporation, Olisoy, H&R Group, HOKOKU CORPORATION, Fuji Kosan Company, Ltd. and Nisshin OilliO Group, Ltd. (ii) Liquid rubber

[0066] The liquid rubber exemplified as the plasticizer is a polymer in a liquid state at normal temperature (25°C), and it is a rubber component that can be extracted from a vulcanized tire by extraction with acetone. Examples of liquid rubber include a farnesene-based polymer, a liquid diene-based polymer, and a hydrogenated substance thereof.

[0067] Farnesene-based polymer is a polymer obtained by polymerizing farnesene and has a farnesene-based constitutional unit. Farnesene isomers include 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).

[0068] The farnesene-based polymer may be a homopolymer of farnesene (a farnesene homopolymer) or a copolymer of farnesene and a vinyl monomer (a farnesene-vinyl monomer copolymer).

[0069] Examples of the liquid diene-based polymer include a liquid styrene-butadiene copolymer (liquid SBR), a liquid butadiene polymer (liquid BR), a liquid isoprene polymer (liquid IR), and a liquid styrene-isoprene copolymer (liquid SIR).

[0070] For the diene-based liquid polymer, the polystyrene equivalent weight-average molecular weight (Mw) measured by gel permeation chromatography (GPC) is, for example, more than 1.0 × 10 3 and less than 2.0 × 10 5 . It should be noted in the present specification that Mw of the liquid diene-based polymer is a polystyrene equivalent value measured by gel permeation chromatography (GPC).

[0071] As the specific liquid rubber, it is possible to use a product manufactured by Kuraray Co., Ltd. or Cray Valley, for example. (iii) Resin component

[0072] The resin component also functions as an adhesion-promoting component and can be a solid or liquid at normal temperature. Specific examples of the resin component include resins such as a rosin-based resin, a styrene-based resin, a coumarone-based resin, a terpene-based resin, a C5 resin, a C9 resin, a C5C9 resin, and an acrylic resin, and two or more types of these can be used in combination.

[0073] Rosin-based resin is a resin containing rosin acid as a main component, which is obtained by processing pine resin. Rosin-based resin (colophony) can be classified according to the presence or absence of modification, and can be classified into unmodified rosin (unmodified rosin) and rosin-modified product (rosin derivative). Examples of unmodified rosin include tall rosin (also known as tall oil rosin), balsam rosin, wood rosin, disproportionate rosin, polymerized rosin, hydrogenated rosin, and other chemically modified rosins.The rosin-modified product is a modified product of the unmodified rosin, examples of which include rosin esters, unsaturated carboxylic acid-modified rosin, unsaturated carboxylic acid-modified rosin esters, amide compounds of rosin, and amine salts of rosin.

[0074] The styrene-based resin is a polymer using a styrene-based monomer as a constituent monomer, and examples thereof include a polymer obtained by conducting polymerization using the styrene-based monomer as a main component (50 mass% or more). Specific examples thereof include a homopolymer obtained by subjecting each of styrene-based monomers (styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-methoxystyrene, p-tert-butylstyrene, p-phenylstyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene and the like) to homopolymerization, and a copolymer obtained by copolymerizing two or more styrene-based monomers, as well as a copolymer of a styrene-based monomer and another monomer capable of copolymerizing with the styrene-based monomer.

[0075] Examples of the other monomer include acrylonitriles such as acrylonitrile and methacrylonitrile; unsaturated carboxylic acids such as acrylic and methacrylic acid; unsaturated carboxylic acid esters such as methyl acrylate and methyl methacrylate; dienes such as chloroprene, butadiene and isoprene; olefins such as 1-butene and 1-pentene; and α,β-unsaturated carboxylic acids such as maleic anhydride or acid anhydrides thereof.

[0076] Among coumarone-based resins, a coumarone-indene resin is preferred. The coumarone-indene resin is a resin containing coumarone and indene as monomer components that form the skeleton (main chain) of the resin. Examples of the monomer component other than coumarone and indene that is contained in the skeleton include styrene, α-methylstyrene, methylindene, and vinyltoluene.

[0077] For example, the content of the coumarone-indene resin is more than 1.0 part by mass and less than 50.0 parts by mass with respect to 100 parts by mass of the rubber component.

[0078] For example, the hydroxyl group (OH) value of coumarone-indene resin is more than 15 mgKOH / g and less than 150 mgKOH / g. Note that the OH value is a value obtained by expressing the amount of potassium hydroxide required to neutralize the acetic acid bonded to the hydroxyl group in milligrams in a case where 1 g of the resin is acetylated, and it is a value measured according to a potentiometric method (JIS K 0070: 1992).

[0079] For example, the softening point of coumarone-indene resin is higher than 30 °C and lower than 160 °C. It should be noted that the softening point is a temperature at which a ball falls in a case where the softening point specified in JIS K 6220-1: 2001 is measured with a ring-and-ball type softening point measuring device.

[0080] Examples of the terpene-based resin include polyterpene, terpene phenol, and an aromatic-modified terpene resin. Polyterpene is a resin obtained by polymerizing a terpene compound and a hydrogenated substance thereof. The terpene compound is a hydrocarbon having a composition of (C5H8)n and an oxygen-containing derivative thereof, and is a compound having, as a basic skeleton, a terpene converted into a monoterpene (C 10 H 16 ), a sesquiterpene (C 15 H 24 ) or a diterpene (C 20 H 32). Examples of these include α-pinene, β-pinene, dipentene, limonene, myrcene, alloocimene, osimene, α-phellandrene, α-terpinene, γ-terpinene, terpinolene, 1,8-cineole, 1,4-cineole, α-terpineol, β-terpineol, and γ-terpineol.

[0081] Examples of the polyterpene also include terpene resins such as an α-pinene resin, a β-pinene resin, a limonene resin, a dipentene resin, and a β-pinene / limonene resin, for which the above-described terpene compounds are respectively used as raw materials, and hydrogenated terpene resins obtained by subjecting the terpene resins to a hydrogenation treatment. Examples of the terpene phenol include a resin obtained by copolymerizing the above-described terpene compound and a phenol-based compound, and a resin obtained by subjecting the resin to a hydrogenation treatment. Specific examples thereof include a resin obtained by condensing the above-described terpene compound, a phenol-based compound, and formalin. Note that examples of the phenol-based compound include phenol, bisphenol A, cresol, and xylenol.Examples of the aromatic-modified terpene resin include a resin obtained by modifying a terpene resin with an aromatic compound and a resin obtained by subjecting the resin to hydrogenation treatment. Note that the aromatic compound is not particularly limited as long as it is a compound having an aromatic ring. However, examples thereof include a phenol compound such as phenol, an alkylphenol, an alkoxyphenol, or an unsaturated hydrocarbon group-containing phenol; a naphthol compound such as naphthol, an alkylnaphthol, an alkoxynaphthol, or an unsaturated hydrocarbon group-containing naphthol; a styrene derivative such as styrene, an alkylstyrene, an alkoxystyrene, and an unsaturated hydrocarbon group-containing styrene; and coumarone and indene.

[0082] The term "C5 resin" refers to a resin obtained by polymerizing a C5 fraction. Examples of the C5 fraction include petroleum fractions equivalent to those containing 4 to 5 carbon atoms, such as cyclopentadiene, pentene, pentadiene, and isoprene. A dicyclopentadiene resin (DCPD resin) is suitably used as the C5-based petroleum resin.

[0083] The term "C9 resin" refers to a resin obtained by polymerizing a C9 fraction, and it may be a resin obtained by hydrogenating or modifying the resulting resin. Examples of the C9 fraction include petroleum fractions equivalent to those having 8 to 10 carbon atoms, such as vinyltoluene, alkylstyrene, indene, and methylindene. As a specific example thereof, a coumarone-indene resin, a coumarone resin, an indene resin, and an aromatic vinyl-based resin are suitably used. The aromatic vinyl-based resin is preferably a homopolymer of α-methylstyrene or styrene, or a copolymer of α-methylstyrene and styrene, and more preferably a copolymer of α-methylstyrene and styrene, because it is economical, easy to process, and excellent in exothermicity.As the aromatic vinyl-based resin, it is possible to use those commercially available from, for example, Kraton Corporation and Eastman Chemical Company.

[0084] The term "C5C9 resin" refers to a resin obtained by copolymerizing the C5 fraction and the C9 fraction, and may be a resin obtained by hydrogenating or modifying the resulting resin. Examples of the C5 fraction and the C9 fraction include the petroleum fraction described above. As the C5C9 resin, it is possible to use those commercially available from, for example, Tosoh Corporation and Shandong Luhua Group Co., Ltd.

[0085] There are no particular restrictions on the acrylic resin, but a solvent-free acrylic resin can be used, for example.

[0086] Examples of the solvent-free acrylic resin include a (meth)acrylic resin (polymer) synthesized according to a high-temperature continuous polymerization method (high-temperature continuous bulk polymerization method) (the method described in U.S. Patent No. 4,414,370, Japanese Unexamined Patent Publication No. S59-6207, Japanese Examined Patent Publication No. H5-58005, Japanese Unexamined Patent Publication No. H1-313522, U.S. Patent No. 5,010,166, TOAGOSEI Annual Research Report, TREND 2000 No. 3, pp. 42-45, or the like) without using, as far as possible, a polymerization initiator, a chain transfer agent, an organic solvent, and the like, which are auxiliary raw materials. It should be noted that in the present invention, (meth)acrylic means methacrylic and acrylic.

[0087] Examples of the monomer component constituting the acrylic resin include (meth)acrylic acid, a (meth)acrylic acid ester (alkyl ester, aryl ester, aralkyl ester or the like), (meth)acrylamide and a (meth)acrylic acid derivative such as a (meth)acrylamide derivative.

[0088] In addition, as the monomer component constituting the acrylic resin, an aromatic vinyl such as styrene, α-methylstyrene, vinyltoluene, vinylnaphthalene, divinylbenzene, trivinylbenzene or divinylnaphthalene can be used together with (meth)acrylic acid or a (meth)acrylic acid derivative.

[0089] The acrylic resin may be a resin composed solely of a (meth)acrylic component, or it may be a resin that also contains a component other than the (meth)acrylic component as a component thereof. Furthermore, the acrylic resin may contain a hydroxyl group, a carboxyl group, a silanol group, or the like.

[0090] As the specific resin component, it is possible to use a product manufactured by, for example, Maruzen Petrochemical CO., LTD., Sumitomo Bakelite Co., Ltd., Yasuhara Chemical Co., Ltd., Tosoh Corporation, Rutgers Chemicals AG, BASF SE, Arizona Chemical, NITTO CHEMICAL CO., LTD., Nippon Shokubai Co., Ltd., ENEOS Corporation, Arakawa Chemical Industries, Ltd. or Taoka Chemical Co., Ltd. (b-4) Cobalt

[0091] In the present invention, the rubber composition contains cobalt as described above. This makes it possible to improve the adhesion between the cord and the rubber.

[0092] Examples of the compound containing cobalt include organic acid cobalt. Specific examples of the organic acid cobalt salt include cobalt stearate, cobalt naphthenate, cobalt neodecanoate, cobalt neodecanoate borate, and cobalt tabietate. As a commercially available product thereof, a product from DIC Corporation or the like can be used. One type of these can be used alone, or two or more types of them can be used in combination. Among the above, cobalt stearate is preferred.

[0093] It should be noted that as a chemical other than the organic acid cobalt described above, a chemical obtained by appropriately replacing the cobalt element with an element having an ionization tendency between zinc and copper can be used. Examples of such a metal element include iron, nickel, tin, antimony, and bismuth.

[0094] In the present invention, these cobalt-containing compounds are appropriately selected and blended so that the amount of cobalt is less than 0.15 parts by mass with respect to 100 parts by mass of the rubber component. Note that, as described above, the amount of cobalt is more preferably less than 0.10 parts by mass, even more preferably less than 0.05 parts by mass, even more preferably less than 0.05 parts by mass, even more preferably less than 0.01 parts by mass, and even more preferably less than 0.005 parts by mass.

[0095] It should be noted that, if necessary, an aliphatic (thiosulfate) sodium salt derivative, such as hexamethylene 1,6-bis(thiosulfate) sodium dihydrate, may be included together with the cobalt organic acid.

[0096] The aliphatic (thiosulfate) sodium salt derivative contains a sulfur atom. Therefore, it also functions as a crosslinking agent, which makes it possible to balance the initial adhesion / heat-resistant adhesion / water-resistant adhesion of the rubber composition to the steel monofilament cord, and also makes it possible to improve the adhesion to the steel monofilament cord.

[0097] Specific examples of the aliphatic (thiosulfate) sodium salt derivative include Duralink HTS (hexamethylene 1,6-bis(thiosulfate) sodium dihydrate) manufactured by FLEXSYS. (b-5) Antioxidants

[0098] It is preferable that the rubber composition contains an antioxidant. The content of the antioxidant is, for example, more than 0.5 parts by mass and less than 10 parts by mass with respect to 100 parts by mass of the rubber component, and more preferably 1 part by mass or more.

[0099] Examples of the antioxidant include a naphthylamine-based antioxidant such as phenyl-α-naphthylamine; a diphenylamine-based antioxidant such as octylated diphenylamine or 4,4'-bis(α,α'-dimethylbenzyl)diphenylamine; a p-phenylenediamine-based antioxidant such as N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, or N,N'-di-2-naphthyl-p-phenylenediamine; a quinoline-based antioxidant such as a polymer of 2,2,4-trimethyl-1,2-dihydroquinoline; a monophenol-based antioxidant such as 2,6-di-t-butyl-4-methylphenol or styrenated phenol; and a bis-, tris-, or polyphenol-based antioxidant, such as tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane. These can be used alone, or two or more types can be used in combination.

[0100] It should be noted that it is possible to use, as the specific antioxidant, a product manufactured by, for example, Seiko Chemical Co., Ltd., Sumitomo Chemical Co., Ltd., OUCHI SHINKO CHEMICAL INDUSTRIAL CO., LTD. or FLEXSYS. (b-6) Zinc oxide

[0101] The rubber composition may contain zinc oxide. The content of zinc oxide is preferably 15 parts by mass or less, and more preferably 10 parts by mass or less, relative to 100 parts by mass of the rubber component.

[0102] It should be noted that, as the zinc oxide, it is possible to use those publicly known in the art, and it is possible to use a product manufactured by, for example, Mitsui Mining & Smelting Co., Ltd., Toho Zinc Co., Ltd., Hakusui Tech Co., Ltd., Shodo Chemical Industry Co., Ltd. or Sakai Chemical Industry Co., Ltd. (b-7) Crosslinking agents and vulcanization accelerators

[0103] The rubber composition preferably contains a crosslinking agent such as sulfur. Examples of sulfur include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersible sulfur, and soluble sulfur, which are commonly used in the rubber industry. These can be used alone, or two or more types can be used in combination.

[0104] The content of sulfur is preferably 8 parts by mass or less, and more preferably 6 parts by mass or less with respect to 100 parts by mass of the rubber component.

[0105] It should be noted that as the sulfur, it is possible to use a product manufactured by, for example, Tsurumi Chemical Industry Co., Ltd., Karuizawa Sulfur Co., Ltd., SHIKOKU CHEMICALS CORPORATION, FLEXSYS, Nippon Inui Kogyo Co., Ltd. or NIPPON KANRYU INDUSTRY CO., LTD.

[0106] Examples of the crosslinking agent other than sulfur include a vulcanizing agent containing a sulfur atom such as TACKIROL V200 manufactured by Taoka Chemical Co., Ltd. or KA9188 (1,6-bis(N,N'-dibenzylthiocarbamoyldithio)hexane) manufactured by Lanxess AG, and an organic peroxide such as dicumyl peroxide.

[0107] The rubber composition preferably contains a vulcanization accelerator. The content of the vulcanization accelerator is, for example, more than 0.3 parts by mass and less than 10.0 parts by mass relative to 100 parts by mass of the rubber component.

[0108] Examples of the vulcanization accelerator include thiazole-based vulcanization accelerators such as 2-mercaptobenzothiazole, di-2-benzothiazolyl disulfide, and N-cyclohexyl-2-benzothiazylsulfenamide; 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-benzothiazolesulfenamide, Nt-butyl-2-benzothiazolylsulfenamide, N-oxyethylene-2-benzothiazolesulfenamide, N-oxyethylene-2-benzothiazolesulfenamide, and N,N'-diisopropyl-2-benzothiazolesulfenamide; and guanidine-based vulcanization accelerators such as diphenylguanidine, diortho-tolylguanidine, and ortho-tolylbiguanidine. These can be used alone, or two or more types can be used in combination. (b-8) Other

[0109] In addition to the components, the rubber composition may be further blended with additives commonly used in the tire industry, such as a metal salt of a fatty acid, a metal salt of a carboxylic acid, an organic peroxide, and a reversion inhibitor (vulcanization reversion), as required. (c) Use of sustainable material in each rubber composition

[0110] In the tire according to the present invention, even in the case of producing each of the other tire elements of the belt layer described above, a predetermined rubber composition is used. However, considering the recent strong demand for environmental protection, it is preferable to use a sustainable material as a material constituting these rubber compositions. (c-1) Rubber material

[0111] For example, as a raw material (monomer) of a synthetic rubber such as SBR or BR, instead of a petroleum-derived material, a material recycled from a rubber product such as a tire or a non-rubber product such as polystyrene may be used.

[0112] The monomer obtained by recycling (recycled monomer) is not particularly limited, and examples thereof include butadiene derived from recycling and aromatic vinyl derived from recycling. Examples of butadiene include 1,2-butadiene and 1,3-butadiene. Furthermore, aromatic vinyl is not particularly limited, and examples thereof include styrene. Among them, it is preferable to use butadiene (recycled butadiene) and / or styrene (recycled styrene) derived from recycling as a raw material.

[0113] A production method for the recycled monomer is not particularly limited, and an example thereof includes a method in which the recycled monomer is synthesized from recycled naphtha obtained by decomposing a rubber product such as a tire. Furthermore, a production method for the recycled naphtha is not particularly limited, and for example, a rubber product such as a tire may be decomposed under high temperature and pressure, may be decomposed using a microwave oven, or may be extracted after mechanical crushing.

[0114] Furthermore, the raw material (monomer) of the synthetic rubber such as SBR or BR may be a raw material derived from biomass. The biomass-derived monomer (biomass monomer) is not particularly limited, and examples thereof include a biomass-derived butadiene and a biomass-derived aromatic vinyl compound. Examples of the butadiene include 1,2-butadiene and 1,3-butadiene. The aromatic vinyl is not particularly limited, and examples thereof include styrene. Furthermore, a production method for the biomass monomer is not particularly limited, and examples thereof include those obtained by biological and / or chemical and / or physical conversion of animals and plants.Fermentation by microorganisms is typical for biological conversion, and chemical and / or physical conversion includes catalyst conversion, high-temperature conversion, high-pressure conversion, electromagnetic wave conversion, critical fluid conversion, and a combination thereof. Examples of biomass sources of these monomers include sugar, wood, plant residues after capture of useful components, plant-derived ethanol, and biomass naphtha.

[0115] A polymer synthesized from the biomass monomer component (biomass polymer) is not particularly limited, and examples thereof include polybutadiene rubber synthesized from biomass-derived butadiene, and an aromatic vinyl-butadiene copolymer synthesized from biomass-derived butadiene and / or biomass-derived aromatic vinyl. Examples of the aromatic vinyl-butadiene copolymer include a styrene-butadiene rubber synthesized from biomass-derived butadiene and / or biomass-derived styrene.

[0116] It should be noted that whether the polymer raw material is derived from biomass or not can be determined by pMC (Percent Modern Carbon) measured in accordance with D6866-10.

[0117] The pMC is a ratio of a 14 C concentration of a sample to a 14C concentration of the modern standard reference carbon (modern standard reference), and this value is used as an index indicating the biomass content of the compound (rubber). The meaning of this value is described below.

[0118] In one mole of carbon atoms (6.02 × 10 23 atoms) are about 6.02 × 10 11 Atoms of 14 C, which is about one trillionth of the total number of carbon atoms. 14 C is referred to as a radioisotope, has a half-life of 5,730 years, and its amount decreases regularly. It takes 226,000 thousand years for its complete decay. Therefore, for fossil fuels such as coal, petroleum, and natural gas, where possibly 226,000 thousand years or more have passed since carbon dioxide and the like in the air were incorporated into plants and the like and then fixed, all 14C elements initially contained in them decay. Therefore, fossil fuels such as coal, petroleum and natural gas do not contain any 11 C elements. Therefore, the chemical substances produced from these fossil fuels as raw materials do not contain any 14 C elements.

[0119] On the other hand, 14 C is constantly produced by the nuclear reaction of cosmic rays in the air, the production of 14 C is balanced with a decrease due to radioactive decay, and thus the amount of 14 C is a constant amount in the Earth's atmospheric environment. As a result, the 14 C concentration of the substance derived from biomass resources that is under substance circulation in the current environment, a value of approximately 1 × 10 -12Mol% or so with respect to the total S atoms, as described above. Consequently, the rate (biomass fraction) of the compound derived from a natural resource (a compound derived from a biomass resource) in a specific compound (rubber) can be calculated by using the difference between these values.

[0120] This 14 C is generally measured as follows. The accelerator mass spectrometry method using a tandem accelerator is used to 13 C concentration ( 13 C / 12 C}) and a 14 C concentration ( 14 C / 12 C) to measure. During the measurement, the 14 C concentration in the circulating carbon in the natural world in 1950 as the modern standard reference, which serves as the reference for the concentration of 14C. An oxalic acid standard substance provided by the National Institute of Standards and Technology (NIST) is used as a specific standard substance. The specific radioactivity of carbon in oxalic acid (the radioactivity intensity of 14 C per 1 g of carbon) is separated for each carbon isotope, for 13 C is corrected to a constant value and subjected to an attenuation correction from 1950 to the measurement date, resulting in a value that is considered to be the value (100%) of the standard 14 C concentration is to be used. The ratio of this value to the value of the actually measured sample is the pMC value.

[0121] As a result, in a case where the rubber is made of 100% biomass-derived substance (natural basis), although there is a regional difference or the like, and thus the rubber has a value of approximately 110 pMC (currently, the rubber in the normal state often does not reach 100). On the other hand, in a case where the 14 When the C concentration of a chemical derived from a fossil fuel, such as petroleum, is measured, the chemical is approximately 0 pMC (e.g., 0.3 pMC). This value corresponds to 0% of the biomass fraction described above.

[0122] From the above, it is suitable to use in the rubber composition a material such as rubber with a high pMC value, that is, a material such as rubber with a high biomass content in terms of environmental protection.

[0123] In addition, it is also preferable to use vulcanized rubber particles as the rubber material.

[0124] Vulcanized rubber particles are particles containing vulcanized rubber as a material. Specifically, rubber powder or the like specified in JIS K 6316:2017 can be used. From the viewpoint of environmental and cost considerations, reclaimed rubber powder made from a powder product of a scrap tire or the like is preferred. One type can be used alone, or two or more types can be used in combination.

[0125] The vulcanized rubber particles are not particularly limited and may be unmodified vulcanized rubber particles or may be modified vulcanized rubber particles.

[0126] As a commercially available product of the vulcanized rubber particles, for example, a product of Lehigh Technologies, Inc., MURAOKA RUBBER RECLAIMING Co., Ltd. or the like can be used. (c-2) Silicon dioxide

[0127] The rubber composition generally contains silica as a reinforcing filler. However, it is also preferred to use sustainable silica instead of a mineral-derived raw material, such as quartz.

[0128] The silica is not particularly limited, and it is possible to use those commonly used in the tire industry, for example, silica (anhydrous silica) produced by a dry-type method and silica (hydrous silica) produced by a wet-type method. The raw material of silica is not particularly limited. For example, it may be a mineral-derived raw material such as quartz, or it may be a biologically derived raw material such as rice husk (for example, silica obtained by using a biomass material such as rice husk as a raw material). Recycled silica from a product containing silica can also be used.Among the above, hydrous silica produced by a wet-type method is preferred because the number of silanol groups is large. This silica can be used alone, or two or more of them can be used in combination.

[0129] Silica obtained by using a biomass material as a raw material can be obtained, for example, by extracting a silicate from rice husk ash obtained by burning rice husks, using a sodium hydroxide solution, and then filtering, washing, drying, and crushing a precipitate of silica produced by reacting the silicate with sulfuric acid in the same manner as in the case of the wet-type silica in the prior art.

[0130] For the silica recycled from a product containing silica, silica recovered from a product containing silica, for example, an electronic component such as a semiconductor, or a filter material such as a tire, a desiccant, or diatomaceous earth, can be used. Furthermore, a method for performing recovery is not particularly limited, and examples thereof include thermal decomposition, electromagnetic wave decomposition, and the like. Among the above, silica recovered from an electronic component such as a semiconductor or from a tire is preferable.

[0131] In a case where silicon dioxide is crystallized, it is not dissolved in water, and the component of silicon dioxide, i.e., silicic acid, cannot be used. By controlling the combustion temperature and combustion time, it is possible to suppress the crystallization of silicon dioxide in rice husk ash (see Japanese Unexamined Patent Publication No. 2009-2594, Akita Prefectural University Web Journal B / 2019, vol. 6, pp. 216-222, and the like).

[0132] For the amorphous silica extracted from rice husks, amorphous silica commercially available from Wilmar International Limited and the like can be used. (c-3) Soot

[0133] In addition, it is also common for the rubber composition to contain carbon black as a reinforcing filler, and it is also preferable to use a sustainable carbon black as such a carbon black.

[0134] The carbon black is not particularly limited, and examples thereof include N134, N110, N220, N234, N219, N339, N330, N326, N351, N550, and N762. The raw material of the carbon black may be a biomass material such as lignin or vegetable oil, or may be a thermally decomposed oil obtained by subjecting a scrap tire to thermal decomposition. Furthermore, a production method for the carbon black may be a combustion production method such as a furnace process, a hydrothermal carbonization (HTC) production method, or a methane thermal decomposition production method by a thermal carbon black process, or the like. As a commercially available product thereof, it is possible to use a product manufactured by ASAHI CARBON CO., LTD., Cabot Japan KK, TOKAI CARBON CO., LTD., Mitsubishi Chemical Corporation, Lion Specialty Chemicals Co., Ltd., NIPPON STEEL Chemical & Material Co., Ltd., or Columbia Carbon. These can be used alone, or two or more types can be used in combination. (c-4) Oil

[0135] Examples of the oil commonly used as the softening agent include a process oil, a vegetable oil, and an animal oil. Examples of the process oil include a paraffin-based process oil (mineral oil), a naphthene-based process oil, and an aromatic process oil. Specific examples of the process oil include mild extract solvate (MES), distillate aromatic extract (DAE), treated distillate aromatic extract (TDAE), treated residual aromatic extract (TRAE), and residual aromatic extract (RAE). In addition, a process oil with a low polycyclic aromatic compound (PCA) content can also be used for environmental measures. Examples of the low PCA process oil include MES, TDAE, and a heavy naphthene-based oil.In addition, from the point of view of life cycle assessment, a waste oil used in a rubber mixer or an engine or an oil obtained by refining a waste cooking oil used in a restaurant can be used.

[0136] In addition, specific examples of vegetable oil include linseed oil, rapeseed oil, safflower oil, soybean oil, corn oil, cottonseed oil, rice bran oil, tall oil, sesame oil, wild sesame oil, castor oil, tung oil, pine oil, pine tar oil, sunflower oil, coconut oil, palm oil, palm kernel oil, olive oil, camellia oil, jojoba oil, macadamia nut oil, peanut oil, grapeseed oil and Japanese wax.Further, examples of the vegetable oil also include vegetable oils such as a refined oil (salad oil or the like) obtained by refining the above-described oil, an ester-exchange oil obtained by subjecting the above-described oil to ester exchange, a hardened oil obtained by hydrogenating the above-described oil, a thermally polymerized oil obtained by subjecting the above-described oil to thermal polymerization, an oxidatively polymerized oil obtained by subjecting the above-described oil to oxidation, and a used edible oil obtained by reclaiming the oil used as edible oil. Note that the vegetable oil may be a liquid or a solid at normal temperature (25°C).

[0137] The vegetable oil preferably contains acylglycerol, and more preferably contains triacylglycerol. Here, the acylglycerol refers to a compound obtained by subjecting a hydroxy group of glycerin and a fatty acid to an ester bond. The acylglycerol is not particularly limited, and it may be 1-monoacylglycerol, may be 2-monoacylglycerol, may be 1,2-diacylglycerol, may be 1,3-diacylglycerol, or may be triacylglycerol. Further, the acylglycerol may be a monomer, may be a dimer, or may be a multimer that is a trimer or more. Note that an acylglycerol that is a dimer or more can be obtained by thermal polymerization, oxidative polymerization, or the like. Furthermore, the acylglycerol may be a liquid or a solid at normal temperature (25°C).

[0138] A method of checking whether the acylglycerol is contained in the rubber composition or not is not particularly limited; however, the check may be carried out by 1 H-NMR measurement can be performed. For example, in a case where a rubber composition mixed with triacylglycerol is immersed in heavy chloroform for 24 hours at normal temperature (25 °C), the rubber composition is removed, 1 When H NMR is subsequently measured at room temperature and a signal from tetramethylsilane (TMS) is set at 0.00 ppm, signals of approximately 5.26 ppm, approximately 4.28 ppm, and approximately 4.15 ppm are observed. These signals are believed to be signals derived from a hydrogen atom bonded to a carbon atom adjacent to the oxygen atom of the ester group. Note that the term "approximately" in this paragraph is a range of ±0.10 ppm.

[0139] The fatty acid is not particularly limited and can be an unsaturated fatty acid or a saturated fatty acid. Examples of unsaturated fatty acids include monovalent unsaturated fatty acids such as oleic acid and polyvalent unsaturated fatty acids such as linoleic acid or linolenic acid. Furthermore, examples of saturated fatty acids include butyric acid and lauric acid.

[0140] Among them, it is desirable that the fatty acid contains a fatty acid having a small number of double bonds, that is, a saturated fatty acid or a monovalent unsaturated fatty acid, and oleic acid is preferred. As the vegetable oil containing such a fatty acid, for example, a vegetable oil containing a saturated fatty acid or a monovalent unsaturated fatty acid can be used, or a vegetable oil subjected to modification such as ester exchange can be used. Furthermore, a plant for producing a vegetable oil containing such a fatty acid can be improved by breeding, genetic recombination, genome editing, or the like.

[0141] As the vegetable oil, it is possible to use those commercially available from, for example, Idemitsu Kosan Co., Ltd., SANKYO YUKA KOGYO KK, ENEOS Corporation, Olisoy, H&R Group, HOKOKU CORPORATION, Fuji Kosan Company, Ltd. and Nisshin OilliO Group, Ltd. (c-5) softening agent other than oil

[0142] In addition to the oil described above, the rubber composition also contains a liquid (liquid-like) softener at normal temperature (25°C) or a solid softener at normal temperature (25°C) as a softener that imparts plasticity to the rubber component. Examples of such a softener include a resin component, a liquid polymer, and an ester-based plasticizer. The softener may be a softener derived from petroleum, a softener derived from biomass, or a softener derived from naphtha recycled from rubber products or non-rubber products (sustainable softener).In addition, a low-molecular-weight hydrocarbon component obtained by thermal decomposition and extraction of a scrap tire or used product containing various components can be used as a softening agent. These softening agents can be used alone, or two or more types can be used in combination. (c-6) Wax

[0143] The rubber composition generally contains wax, and the wax is not particularly limited. Any wax commonly used in the tire industry can be suitably used. Examples of the wax include a petroleum-based wax, a mineral-based wax, a synthetic wax, and a plant-derived wax. Among the above, a petroleum-based wax or a plant-derived wax is preferable, and a petroleum-based wax is more preferable. Examples of the plant-derived wax include a rice wax, a carnauba wax, and a candelilla wax. Examples of the petroleum-based wax include a paraffin wax, a microcrystalline wax, and a carefully selected special wax thereof, and a paraffin wax is preferable. As the wax, a wax commercially available from, for example, OUCHI SHINKO CHEMICAL INDUSTRIAL CO., LTD., NIPPON SEIRO Co., Ltd., or Paramelt BV can be used.These waxes can be used alone, or two or more of them can be used in combination. (c-7) Antioxidant

[0144] The rubber composition generally contains an antioxidant. The antioxidant is not particularly limited, and examples thereof include a naphthylamine-based antioxidant such as phenyl-α-naphthylamine; a diphenylamine-based antioxidant such as octylated diphenylamine or 4,4'-bis(α,α'-dimethylbenzyl)diphenylamine; a p-phenylenediamine-based antioxidant such as N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD), N,N'-bis(1,4-dimethylpentyl)-p-phenylenediamine (77PD), N,N'-diphenyl-p-phenylenediamine (DPPD), N,N'-ditolyl-p-phenylenediamine (DTPD), N-isopropyl-N'-phenyl-p-phenylenediamine (IPPD), or N,N'-di-2-naphthyl-p-phenylenediamine (DNPD); a quinoline-based antioxidant such as a polymer of 2,2,4-trimethyl-1,2-dihydroquinoline;a monophenol-based antioxidant such as 2,6-di-t-butyl-4-methylphenol or styrenated phenol; a bis-, tris-, or polyphenol-based antioxidant such as tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane. Among the above, a p-phenylenediamine-based antioxidant or a quinoline-based antioxidant is preferable, and a polymer of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine and 2,2,4-trimethyl-1,2-dihydroquinoline is more preferable. As a commercially available product thereof, it is possible to use a product manufactured by, for example, Seiko Chemical Co., Ltd., Sumitomo Chemical Co., Ltd., OUCHI SHINKO CHEMICAL INDUSTRIAL CO., LTD. or FLEXSYS.;

[0145] It should be noted that various materials (e.g., a rubber, oil, a resin, a vulcanization accelerator, an antioxidant, and a surfactant) containing a carbon atom can be derived from carbon dioxide in the air. Regarding a method for obtaining a mixture according to the present invention from carbon dioxide, carbon dioxide can be subjected to direct conversion, or methane obtained by a methanation process of synthesizing methane from carbon dioxide can be converted. (2) Production of rubber composition

[0146] The rubber composition is produced according to a general method, for example, a production method including a basic kneading process of kneading a rubber component and a filler such as carbon black, and a final kneading process of kneading the kneaded product obtained in the basic kneading process and a crosslinking agent.

[0147] Kneading can be carried out using a publicly known kneader (of the closed type), such as a Banbury mixer, a kneader or an open roller.

[0148] In the basic kneading process, a kneading temperature is, for example, higher than 50°C and lower than 200°C, and a kneading time is, for example, more than 30 seconds and less than 30 minutes. In the basic kneading process, a mixing agent commonly used in the rubber industry, for example, a softening agent such as oil, zinc oxide, an antioxidant, a wax, or a vulcanization accelerator, can be appropriately added and kneaded in addition to the above-described components as needed.

[0149] In the final kneading process, the kneaded product obtained in the initial kneading process and a crosslinking agent are kneaded. In the final kneading process, a kneading temperature is, for example, higher than room temperature and lower than 80°C, and a kneading time is, for example, more than 1 minute and less than 15 minutes. In the final kneading process, in addition to the components described above, a vulcanization accelerator, zinc oxide, or the like can be appropriately added and kneaded as needed.

[0150] In this case, the complex elastic modulus E* can be appropriately adjusted by adjusting the blending amount of each of the blended materials described above. The complex elastic modulus E* can be increased, for example, by increasing the content of a filler such as carbon black or silica, reducing the particle diameter of the filler, reducing the content of a softening component such as oil and resin, or increasing the content of sulfur and an accelerator. Conversely, the complex elastic modulus E* can be reduced, for example, by reducing the content of a filler such as carbon black, increasing the content of a softening component such as oil and resin, or reducing the content of sulfur and an accelerator. 3. Production of belt layer

[0151] The belt layer (belt ply) can be prepared by covering both surfaces of the cord (a steel cord composed of a filament) arranged in parallel to have predetermined intervals with the rubber composition obtained above.

[0152] Note that it is preferable to form a coating layer by applying an adhesive composition to the surface of the cord before covering the rubber composition. By causing the coating layer to function as an adhesive layer, the rubber composition and the cord can be sufficiently bonded to each other.

[0153] The adhesive composition is preferably an adhesive composition containing a polybenzoxazine compound containing units represented by the following (Chem. 1) to (Chem. 4) because excellent adhesiveness is exhibited with respect to both the rubber composition and the cord.

[0154] It should be noted that in (Chem. 1) and (Chem. 2) described above, X1 is a hydrocarbon selected from an aliphatic hydrocarbon, an alicyclic hydrocarbon, or an aromatic hydrocarbon, and a combination thereof, and it may have any heteroatom of S, O, N, or P and a structure in which these heteroatoms are continuously connected. Furthermore, X2 may have an (S)n structure in which n (1 to 8) pieces of S atoms are connected, and it may have a hydrocarbon selected from an aliphatic hydrocarbon, an alicyclic hydrocarbon, or an aromatic hydrocarbon, and any one of S, O, N, or P, and / or a combination thereof. Furthermore, in (Chem. 3) and (Chem.4) X1 is a hydrocarbon selected from an aliphatic hydrocarbon, an alicyclic hydrocarbon or an aromatic hydrocarbon and a combination thereof, and it has an (S)n structure in which n (1 to 8) pieces of S atoms are bonded.

[0155] The adhesive composition described above can be produced, for example, by using a publicly known method described in US 2020 / 0290402 (PCT Japanese Translation Patent Publication No. 2019-507805) or the like, and an adhesive layer can be formed by applying a coating liquid of the obtained adhesive composition to the surface of the cord and by drying and then thermally crosslinking the coating liquid on the surface of the cord. 4. Manufacturing of tires

[0156] The tire according to the present embodiment can be produced as an unvulcanized tire by molding the belt layer (belt ply) obtained above together with other tire elements on a tire molding machine by a typical method.

[0157] Specifically, an inner liner as a member for ensuring the airtightness retention property of the tire, a carcass as a member that withstands the load, impact, and inflation air pressure applied to the tire, and a belt layer or the like as a member that tightly clamps the carcass and increases the rigidity of the tread are wound on a forming drum. A bead portion as a member for fixing the tire to the rim while attaching both ends of the carcass to edge portions on both sides is arranged to be formed into a toroidal shape. Then, the tread is bonded to a center part of an outer circumference, and the sidewall is bonded to an outer side in the radial direction to form a side part, thereby producing an unvulcanized tire.

[0158] It should be noted in the present embodiment that the belt layer may be composed of multiple layers of belt plies from the viewpoint of increasing the restraining force exerted on the tread during running and easily suppressing the growth of the outer diameter as described above. In this case, an average distance D (mm) between the cords of belt plies to each other in the tread portion in the tire after vulcanization is preferably 0.6 mm or less, more preferably 0.45 mm or less, still more preferably 0.4 mm or less, still more preferably 0.35 mm or less, still more preferably 0.3 mm or less, and even more preferably 0.28 mm or less.Furthermore, it is preferable that an angle of the cord formed between straight lines parallel to each other in a tire circumferential direction of the tire in the tread portion is 10° or more and 35° or less, and the cords of the adjacent belt plies are arranged so as to intersect each other.

[0159] It should be noted that the cord angle is an angle of the cord with respect to the circumferential direction of the tire in a state where the tire is not inflated, and the cord angle can be checked by peeling the tread portion of the tire from the outside in the radial direction.

[0160] Thereafter, the unvulcanized tire produced as described above is subjected to heating and pressurization in a vulcanizing machine to obtain a tire. The vulcanization process can be performed by applying a publicly known vulcanizing agent. A vulcanization temperature is, for example, higher than 120°C and lower than 200°C, and a vulcanization time is, for example, more than 5 minutes and less than 15 minutes.

[0161] In the tire obtained as described above, since the belt cord diameter and the cobalt content in the rubber composition are appropriately controlled and D / E* < 0.1 × C + 0.05 is also satisfied, the respective effects interact, thereby exhibiting synergy. Therefore, it is possible to improve the overall performance of low fuel consumption and durability.

[0162] Furthermore, the tire according to the present invention can be suitably used as a tire for a passenger car, a tire for a large passenger car, a tire for a large SUV, a tire for a small truck, or the like. [Examples]

[0163] Hereinafter, examples (Examples) considered preferable in carrying out the present embodiment are shown; however, the scope of the present invention is not limited to these Examples.

[0164] Tires with a Fig. 1 shown configuration (tyre size: 195 / 65R15) are used in the Fig. 1 shown configuration, and the tires with the in Fig.1 (tire size: 195 / 65R15) are examined, wherein the tires are substantially the same except for the belt layer of each specification shown in Table 1, and the results of low fuel consumption characteristics and durability calculated based on the evaluation method described later are shown together in the lower parts of Table 1. In each example, since a filament having a cross-sectional shape of a perfect circle is made into a belt cord without being twisted and curled, the filament diameter D of each example is identical to the cord diameter. 1. Production of rubber composition

[0165] First, a rubber composition that forms a belt layer is produced. (1) Mixed material (a) Rubber component No.: RSS3 (b) Mixed material other than rubber component (b-1) Carbon Black-1: Show Black N660, manufactured by Cabot Japan KK (specific BET surface area: 35 m 2 / g, (average particle diameter: 40 nm) (b-2) Carbon Black-2: Show Black N326, manufactured by Cabot Japan KK (specific BET surface area: 78 m 2 / g, (average particle diameter: 30 nm) (b-3) Oil: Diana Process AH-24 (aroma oil), manufactured by Idemitsu Kosan Co., Ltd. (b-4) Cobalt organic acid: COST-F, manufactured by DIC Corporation (Cobalt stearate, cobalt content: 9.5% by mass) (b-5) Antioxidant: ANTAGE RD, manufactured by Kawaguchi Chemical Industry Co., Ltd. (2,2,4-trimethyl-1,2-dihydroquinoline) (b-6) Zinc oxide: Zinc oxide No. 1, manufactured by Mitsui Mining & Smelting Co., Ltd. (b-7) Sulfur: Powdered sulfur manufactured by Tsurumi Chemical Industry Co., Ltd. (b-8) Vulcanization accelerator: NOCCELER DZ, manufactured by OUCHI SHINKO CHEMICAL INDUSTRIAL CO., LTD. (N,N-Dicyclohexyl-2-benzothiazolylsulfenamide) (2) Production of rubber composition

[0166] A kneaded product is obtained by kneading materials other than sulfur and a vulcanization accelerator for 5 minutes under a condition of 150 °C using a Banbury mixer according to each blending amount shown in Table 1. Note that each blending amount is given in parts by mass.

[0167] Next, sulfur and a vulcanization accelerator are added to the kneaded product obtained above, and kneading is carried out for 5 minutes under a condition of 80 °C using an open roll to obtain a rubber composition. 2. Manufacturing of tires

[0168] First, belt plies are produced by coating both surfaces of a steel cord having the specification shown in Table 1 with the same amount of the rubber composition obtained above, and two sheets thereof are laminated to form a belt ply.

[0169] Thereafter, the tire is bonded with other tire members to form an unvulcanized tire, and the unvulcanized tire is subjected to press vulcanization for 10 minutes under the condition of 170 °C to manufacture each of test tires (Example 1 to Example 8 and Comparative Example 1 to Comparative Example 4) shown in Table 1. 3. Calculation of parameters

[0170] A rubber test piece for measuring viscoelasticity with a length of 40 mm, a width of 4 mm, and a thickness of 1 mm is produced for the rubber composition, and a complex elastic modulus E* is measured using an EPLEXOR series manufactured by GABO Co., Ltd. under conditions of a temperature of 70 °C, an initial strain of 5%, a dynamic strain of ±1%, a frequency of 10 Hz, and a deformation mode of elongation.

[0171] Then, each of the parameters shown in Table 1 (D / E* - 0.1 × C, E × S and E × B) is calculated. 4. Performance evaluation(1) Evaluation of low fuel consumption characteristics

[0172] Using a rolling resistance testing machine, a rolling resistance coefficient (RRC) is measured in a case where each test tire is subjected to running on a drum at a speed of 80 km / h under the following conditions. Rim to be used: 15 × 6 J Internal pressure: 210 kPa Load: 4.35 kN

[0173] Next, the result for Comparative Example 1 is set to 100, and the evaluation of low fuel consumption characteristics is performed by indexing based on the following expression. It indicates that the larger the numerical value, the better the low fuel consumption characteristics. Evaluation of low fuel consumption properties = [(Result of Comparative Example 1) / (Result of test tires)] × 100 (2) Assessment of durability

[0174] Each test tire is installed on a rim (size = 15 × 6J), the tire is inflated with air, the internal pressure is adjusted to 230 kPa, the tire is mounted on a drum test machine, a vertical load of 5.88 kN is applied, and the speed is increased by 10 km / h stepwise from 210 km / h to measure a time until the tire is damaged.

[0175] Next, the result for Comparative Example 1 is set to 100, indexing is performed based on the following expression to obtain a durability index, and then evaluation is performed. It indicates that the larger the numerical value, the longer the time it takes for the tire to be damaged and the better the durability. Durability Evaluation = [(Result of Test Tire) / (Result of Comparative Example 1)] × 100 (3) Assessment of overall performance

[0176] The low fuel consumption characteristics rating and the durability rating are added to perform the overall performance rating.

[0177] The present invention has been described above based on the embodiments. However, the present invention is not limited to the above-described embodiments. Various modifications can be made to the above-described embodiments within the same and similar ranges as those of the present invention.

[0178] The present invention (1) is a tire characterized by comprising: a belt layer containing a belt cord coated with a rubber composition, where the belt cord is made of a filament, the rubber composition contains less than 0.15 parts by mass of cobalt with respect to 100 parts by mass of a rubber component, and a diameter D (mm) of the belt cord, a complex elastic modulus E* (MPa) of the rubber composition measured under conditions of a temperature of 70 °C, an initial strain of 5%, a dynamic strain of ±1%, a frequency of 10 Hz, and a deformation mode of elongation, and a cobalt amount C (parts by mass) in the rubber composition with respect to 100 parts by mass of the rubber component satisfy the following expression: D / E*<0.1×C+0.05.

[0179] The present invention (2) is the tire according to the present invention (1), which is characterized in that the amount of cobalt in the rubber composition is less than 0.10 parts by mass with respect to 100 parts by mass of the rubber component.

[0180] The present invention (3) is the tire according to the present invention (2), which is characterized in that the amount of cobalt in the rubber composition is less than 0.05 parts by mass with respect to 100 parts by mass of the rubber component.

[0181] The present invention (4) is the tire according to the present invention (3), which is characterized in that the amount of cobalt in the rubber composition is less than 0.01 part by mass with respect to 100 parts by mass of the rubber component.

[0182] The present invention (5) is the tire according to the present invention (4), which is characterized in that the amount of cobalt in the rubber composition is less than 0.005 parts by mass with respect to 100 parts by mass of the rubber component.

[0183] The present invention (6) is the tire according to any combination of the present inventions (1) to (5), which is characterized in that in a tire width direction the belt cords have the number E (cords) of cords per 50 mm in width and a surface S (mm 2 / mm) per unit length (1 mm) satisfy the following expression: E×S>40.

[0184] The present invention (7) is the tire according to any combination of the present inventions (1) to (5), which is characterized in that in a tire width direction of the belt cords, the number E (cords) of cords per 50 mm in width and a bending stiffness B (g-cm) satisfy the following expression: E×W>600.

[0185] The present invention (8) is the tire according to any combination of the present inventions (1) to (5), which is characterized in that a carbon black with a specific BET surface area of 45 m 2 / g or more is contained in the rubber composition so that an amount of the carbon black is 5 parts by mass or more and 70 parts by mass or less with respect to 100 parts by mass of the rubber component. List of reference symbols 1 tire 2 Tread section 3 side wall section 4 bead section 5 Bead core 6 Carcass 6A carcass ply 6a inner main body section 6b outer folded section 7th belt layer 7A first belt layer 7B second belt layer 8 Bead Apex rubber 10 belt cord C Centerline QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2005-239069

[0003] US 4414370

[0086] JP 59-6207

[0086] JP 5-58005

[0086] JP 1-313522

[0086] US 5010166

[0086] JP 2009-2594

[0131] US 2020 / 0290402

[0155] JP 2019-507805

[0155] Cited non-patent literature

[0000] JIS G 3510:1992

[0020] TOAGOSEI Annual Research Report, TREND 2000 No. 3, pp. 42-45

[0086] JIS K 6316:2017

[0124] Akita Prefectural University Web Journal B / 2019, vol. 6, pp. 216-222

[0131]

Claims

[1] Tires, comprising: a belt layer containing a belt cord coated with a rubber composition, where the belt cord is made of a filament, the rubber composition contains less than 0.15 parts by mass of cobalt with respect to 100 parts by mass of a rubber component, and a diameter D (mm) of the belt cord, a complex elastic modulus E* (MPa) of the rubber composition measured under conditions of a temperature of 70 °C, an initial strain of 5%, a dynamic strain of ±1%, a frequency of 10 Hz, and a deformation mode of elongation, and a cobalt amount C (parts by mass) in the rubber composition with respect to 100 parts by mass of the rubber component satisfy the following expression: D / E*<0.1×C+0.

05. [2] The tire according to claim 1, wherein the amount of cobalt in the rubber composition is less than 0.10 parts by mass with respect to 100 parts by mass of the rubber component. [3] The tire according to claim 2, wherein the amount of cobalt in the rubber composition is less than 0.05 parts by mass with respect to 100 parts by mass of the rubber component. [4] The tire according to claim 3, wherein the amount of cobalt in the rubber composition is less than 0.01 part by mass with respect to 100 parts by mass of the rubber component. [5] The tire according to claim 4, wherein the amount of cobalt in the rubber composition is less than 0.005 parts by mass with respect to 100 parts by mass of the rubber component. [6] A tire according to any one of claims 1 to 5, wherein in a tire width direction, the belt cords have the number E (cords) of cords per 50 mm in width and a surface area S (mm 2 / mm) per unit length (1 mm) satisfy the following expression: E×S>40. [7] A tire according to any one of claims 1 to 5, wherein in a tire width direction of the belt cords, the number E (cords) of cords per 50 mm in width and a bending rigidity B (g-cm) satisfy the following expression: E×W>600. [8] Tire according to one of claims 1 to 5, wherein a carbon black having a BET specific surface area of 45 m 2 / g or more is contained in the rubber composition so that an amount of the carbon black is 5 parts by mass or more and 70 parts by mass or less with respect to 100 parts by mass of the rubber component.

Images