tire

Abstract

To improve total performance of high mileage, high speed durability, and steering stability.SOLUTION: This tire comprises: a carcass including a carcass code; a belt including a belt code and provided outside the carcass in a tire radial direction; a band including a band code and provided outside the belt in the tire radial direction; and a tread provided outside the band in the tire radial direction. The band code contains a polyethylene terephthalate fiber. When the tread is seen in the tire radial direction in a plan view, an intersection angle which is smaller one of angles between a tire circumferential direction and the longitudinal direction of the belt code is 0-25 degrees. The belt code includes four or more filaments. A radio (Dba / Dbr) of a band code diameter Dba (mm) to a belt code diameter Dbr (mm) satisfies the following expression: 0.5<Dba / Dbr<1.8 (Expression 1).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a tire.

Background Art

[0002] In a passenger car tire, as in Patent Document 1, generally, a band (also called a cap ply) is provided between a tread and a belt from the viewpoint of preventing deformation of the tire due to centrifugal force during high-speed driving.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to improve the overall performance of low fuel consumption, high-speed durability, and handling stability.

Means for Solving the Problems

[0005] The present invention is a carcass including a carcass cord, a belt including a belt cord and provided on the outer side in the tire radial direction of the carcass, a band including a band cord and provided on the outer side in the tire radial direction of the belt, and a tread provided on the outer side in the tire radial direction of the band, wherein the band cord contains polyethylene terephthalate fiber, when the tread is viewed in a plan view in the tire diameter direction, the crossing angle, which is the smaller of the angles formed by the tire circumferential direction and the longitudinal direction of the belt cord, is more than 0 degrees and less than 25 degrees, The belt cord is composed of one or more and four or fewer filaments, the ratio (Dba / Dbr) of the band cord diameter Dba (mm) to the belt cord diameter Dbr (mm) satisfies the following formula (1): Occasionally, The structure of the aforementioned belt cord is one of the following: 1x2 structure, 1x3 structure, 1x4 structure, or 2+2 structure. and the tire is characterized by this. 0.5 < Dba / Dbr < 1.8 (1 formula)

Effect of the Invention

[0006] According to the present invention, it is possible to improve the overall performance of low fuel consumption, high-speed durability, and handling stability.

Brief Description of the Drawings

[0007] [Figure 1] It is a schematic cross-sectional view for explaining a tire according to an embodiment of the present invention.

Mode for Carrying Out the Invention

[0008] [1] Features of the Tire According to the Present Disclosure First, the features of the tire according to the present disclosure will be described.

[0009] 1. Outline The tire according to the present disclosure includes a carcass having a carcass cord, a belt having a belt cord and provided on the outer side in the tire radial direction of the carcass, a band having a band cord and provided on the outer side in the tire radial direction of the belt, and a tread provided on the outer side in the tire radial direction of the band. And the band cord contains polyethylene terephthalate fiber (PET fiber). Further, the belt cord is composed of one or more and four or fewer filaments, and among the angles formed by the tire circumferential direction and the longitudinal direction of the belt cord when the tread is viewed in a plan view in the tire diameter direction, the smaller intersection angle is more than 0 degrees and less than 25 degrees. Furthermore, the ratio (Dba / Dbr) of the band cord diameter Dba (mm) to the belt cord diameter Dbr (mm) satisfies the formula (1). 0.5 < Dba / Dbr < 1.8 (Equation 1) Furthermore, the belt cord structure is one of the following: 1x2 structure, 1x3 structure, 1x4 structure, or 2+2 structure.

[0010] By having these characteristics, as will be described later, it is possible to improve the overall performance of low fuel consumption, high-speed durability, and handling stability.

[0011] In this specification, the "cord diameter" refers to the diameter when the circumscribed circle of the cross-section perpendicular to the cord extending direction is a perfect circle, and in the case of an ellipse or the like, it refers to the equivalent diameter of a perfect circle (the diameter of the perfect circle assumed when the cross-sectional area is the same).

[0012] Also, the band cord diameter (Dba) is a value measured in accordance with the test method specified in JIS L1017:2002 "Test Methods for Chemical Fiber Tire Cords", and the belt cord diameter (Dbr) is a value measured in accordance with the test method specified in JIS G3510:1992 "Test Methods for Steel Tire Cords".

[0013] 2. Mechanism of Effect Manifestation in the Tire According to the Present Disclosure Regarding the mechanism of the above-described effect manifestation in the tire according to the present disclosure, it is considered as follows.

[0014] (1) Band Cord In the tire according to the present invention, a cord containing PET fiber (PET cord) is used for the band cord.

[0015] Since PET fiber has higher rigidity compared to nylon 66 (polyamide synthetic fiber), which has been mainly used for band cords conventionally, by using PET cord for the band cord, it is possible to exhibit the same restraining force even with a smaller cord diameter (even when reducing the cord gauge). As a result, since it is possible to reduce the thickness of the band (prep gauge) and the weight of the band (prep weight), it is considered that the weight of the tire can be reduced, the rolling resistance can be reduced, and the low fuel consumption can be improved.

[0016] In addition, in the above, "a cord containing PET fibers" means that it may be composed not only of PET fibers, but also of PET fibers in combination with other fibers (polyester fibers other than PET fibers, such as polyethylene naphthalate fibers, aramid fibers, etc.).

[0017] In the present invention, it is preferable that the PET fiber is a sustainable material suitable for environmental protection. Examples of sustainable PET fibers (sustainable PET fibers) include PET fibers recycled from plastic waste such as used PET bottles, old items, and waste materials (recycled PET fibers), and PET fibers manufactured from biomass (bio-PET fibers).

[0018] Bands equipped with PET cords can be manufactured by treating the PET cords with an adhesive and then bonding them to a predetermined rubber composition for bands. As adhesives used to bond the PET cords, for example, epoxy compounds such as EX-313 (glycerin polyglycidyl ether, manufactured by Nagase ChemteX Corporation) and RFL (resorcinol-formaldehyde latex) can be used.

[0019] The band cord diameter (Dba) is preferably greater than 0.2 mm, and more preferably greater than 0.4 mm. The upper limit is preferably less than 0.8 mm, and more preferably less than 0.6 mm.

[0020] Furthermore, the band may consist of one or two layers. The band may also be formed across the entire width of the tread, or only at the ends of the tread.

[0021] (2) Belt cord Tires using PET cords with reduced cord diameter in their band cords may have inferior compression fatigue resistance, potentially reducing high-speed durability and handling stability. Furthermore, because PET cords are highly rigid and have a high modulus, the contact patch shape tends to become rounded, leading to a concentration of contact pressure at the shoulder, which can become a point of failure and further reduce high-speed durability and handling stability.

[0022] Therefore, in this invention, the smaller of the angles formed by the circumferential direction of the tire and the longitudinal direction of the belt cord when the tread is viewed in plan in the radial direction of the tire is defined as the "intersection angle," and the "intersection angle," which is theoretically between 0 and 90 degrees, is made smaller to greater than 0 degrees and less than 25 degrees. It is more preferable to be less than 24 degrees, even more preferable to be less than 23 degrees, and even more preferable to be less than 22 degrees.

[0023] By reducing the intersection angle in this way, the tread rigidity can be increased, leading to an increase in restraint force. This is thought to improve responsiveness during driving and enhance handling stability.

[0024] Furthermore, by reducing the intersection angle, the contact shape can be flattened, thus negating the disadvantage that the contact shape tends to become rounded when using the aforementioned PET cord band. It is believed that this will improve high-speed durability through increased restraint force from using PET cord and increased restraint force from reducing the intersection angle.

[0025] In this invention, the intersection angle shall be expressed as an absolute value without a ± sign, in accordance with the definition above, even if the direction of inclination of the belt cord is opposite to the circumferential direction of the tire. Furthermore, if there are, for example, two or more belt layers, each with a different intersection angle, it is sufficient that the intersection angle of at least one belt layer is greater than 0 degrees and less than 25 degrees.

[0026] In this invention, the belt cord is composed of one to four filaments. By reducing the number of filaments in this way, the weight of the tire can be reduced, thereby lowering rolling resistance and improving fuel efficiency.

[0027] The material of the filaments constituting the belt cord is not particularly limited, but it is preferably made of metal, more preferably iron, and especially preferably steel. Furthermore, the structure of the belt cord is preferably one of the following: an untwisted 1x1 structure, a single-twist 1x2 structure, a 1x3 structure, a 1x4 structure, or a layered 2+2 structure.

[0028] (3) Ratio of band cord diameter Dba to belt cord diameter Dbr (Dba / Dbr) The inventors conducted further studies and concluded that when (Dba / Dbr) is appropriately controlled to be greater than 0.5 and less than 1.8, the above-mentioned effects work together to improve overall performance in terms of fuel efficiency, high-speed durability, and handling stability. The lower limit of (Dba / Dbr) is more preferably greater than 0.7, even more preferably greater than 0.9, and even more preferably greater than 1.1. On the other hand, the upper limit is more preferably less than 1.7, even more preferably less than 1.6, and even more preferably less than 1.5.

[0029] [2] More preferred embodiments of the tire relating to the present disclosure The tire relating to this disclosure can achieve even greater effects by adopting the following configurations.

[0030] 1. Content of isoprene-based rubber in the rubber composition forming the tread. In the present invention, it is preferable that the rubber composition for forming the tread (tread rubber composition) contains more than 25 parts by mass of isoprene-based rubber per 100 parts by mass of rubber component.

[0031] By including more than 25 parts by mass of isoprene-based rubber in 100 parts by mass of rubber component, a low-heat-generating tread can be made that reduces heat generation during high-speed driving, thereby reducing rolling resistance and further improving fuel efficiency. In addition, it is possible to suppress the decrease in rigidity (modulus) of the PET cord that occurs in accordance with the rise in tread temperature, thereby improving high-speed durability. It is more preferable to have 30 parts by mass or more, and even more preferable to have 40 parts by mass or more. As an upper limit, for example, it is preferable to have 70 parts by mass or less, and more preferable to have 60 parts by mass or less.

[0032] Specific examples of isoprene-based rubbers include natural rubber (NR), modified natural rubber (modified NR), modified natural rubber (modified NR), and synthetic polyisoprene (isoprene rubber (IR), modified isoprene rubber (modified IR)). Among these, NR is preferred due to its superior strength. For NR, common types used in the tire industry, such as SVR-L, SIR20, RSS#3, and TSR20, can be used.

[0033] 2. Silica content Furthermore, in the present invention, the tread rubber composition preferably contains more than 60 parts by mass of silica as a filler per 100 parts by mass of rubber component. More preferably more than 70 parts by mass, and even more preferably more than 80 parts by mass. As an upper limit, for example, it is preferably less than 150 parts by mass, more preferably less than 130 parts by mass, and even more preferably less than 110 parts by mass.

[0034] Because silica has OH groups on its surface, including a large amount of silica (more than 60 parts by mass per 100 parts by mass of rubber) allows hydrogen bonds to form between silica surfaces and also interact with the rubber. Therefore, it is thought that forces can be easily generated and transmitted within the rubber during driving, and the forces generated during turning can be easily transmitted, thereby further improving handling stability.

[0035] Furthermore, since the OH groups on the surface can capture ozone, it is believed that ozone resistance will be improved, leading to further improvements in high-speed durability.

[0036] 3. Acetone extract content (AE amount) in tread rubber composition Furthermore, in the present invention, the amount of AE in the tread rubber composition is preferably more than 10% by mass, more preferably more than 15% by mass, and even more preferably more than 20% by mass. On the other hand, as an upper limit, for example, it is preferably less than 35% by mass, more preferably less than 30% by mass, and particularly preferably 25% by mass or less.

[0037] The amount of air-exposure (AE) can be considered an indicator of the amount of material that imparts plasticity to the rubber components, such as softeners (plasticizers), in a rubber composition, and can also be considered an indicator of the softness of the rubber composition. Therefore, if the amount of AE in the tread rubber composition is increased to a certain extent, such as more than 10% by mass, the tread blocks will be able to deform more flexibly, ensuring a sufficient contact area with the road surface even at high speeds, suppressing heat generation due to the concentration of contact pressure, and thus further improving high-speed durability.

[0038] The amount of AE can be measured in accordance with JIS K 6229:2015. Specifically, the amount of AE (mass%) can be obtained by immersing a vulcanized rubber test piece cut from the measurement site in acetone for a predetermined time and determining the mass loss rate (%) of the test piece.

[0039] More specifically, the soluble components can be extracted by immersing each vulcanized rubber test piece in acetone for 72 hours at room temperature and atmospheric pressure, measuring the mass of each test piece before and after extraction, and then determining the result using the following formula. AE amount (%) = {(Mass of rubber test piece before extraction - Mass of rubber test piece after extraction)} / (mass of rubber test piece before extraction)} × 100

[0040] The amount of AE can be appropriately changed by altering the blending ratio of plasticizers in the rubber composition.

[0041] The tread described above may consist of only one layer, which is the contact surface layer (cap rubber layer), but it may also consist of two layers, with a base rubber layer inside the cap rubber layer, or it may consist of three layers, or even four or more layers. In this case, the rubber composition for the tread described above is the rubber composition that forms the cap rubber layer, which is the outermost layer on the contact surface side, and it is preferable that it satisfies each of the above parameters.

[0042] In this case, the thickness of the cap rubber layer over the entire tread is preferably 10% or more, more preferably 30% or more, even more preferably 50% or more, and even more preferably 70% or more.

[0043] Here, tread thickness refers to the thickness of the tread on the tire's equatorial plane in the tire's radial cross-section. When the tread is formed from a single rubber composition, it refers to the thickness of that rubber composition. When it is formed from a laminated structure of multiple rubber compositions, it refers to the thickness of the cap rubber layer, which is the outermost layer on the contact surface side. This can be measured by cutting the tire radially and aligning the bead portion with the normal rim width.

[0044] Furthermore, "standard rim" refers to the rim specified for each tire within the standard system that includes the standard on which the tire is based. For example, for JATMA (Japan Automobile Tire Manufacturers Association), it refers to the standard rim for the applicable size listed in the "JATMA YEAR BOOK," for ETRTO (The European Tyre and Rim Technical Organisation), it refers to the "Measuring Rim" listed in the "STANDARDS MANUAL," and for TRA (The Tire and Rim Association, Inc.), it refers to the "Design Rim" listed in the "YEAR BOOK." Refer to JATMA, ETRTO, and TRA in that order, and if an applicable size is available at the time of reference, follow that standard. In the case of tires not specified in the standard, it refers to the rim with the smallest diameter and the narrowest rim width among rims that can be mounted on and can maintain internal pressure, i.e., rims that do not cause air leakage from between the rim and tire.

[0045] [3] Embodiment The present disclosure will be described in detail below based on embodiments.

[0046] 1. Tire according to this embodiment Figure 1 is a schematic cross-sectional view illustrating a tire according to this embodiment. In Figure 1, the vertical direction is the radial direction of the tire, the horizontal direction is the axis of rotation of the tire, and the direction perpendicular to the plane of the paper is the circumferential direction of the tire. In Figure 1, the dashed line CL represents the equatorial plane of the tire. Note that, except for the tread pattern, the shape of this tire is symmetrical with respect to the equatorial plane, so Figure 1 shows 1 / 4 of the entire tire.

[0047] As shown in Figure 1, the tire 1 comprises a tread 2, a pair of sidewalls 3, a pair of chafers 4, a pair of beads 5, an inner liner 6, a carcass 7, a belt 8, a pair of fillers 9, and a band 10. The carcass 7, belt 8, band 10, and tread 2 are arranged from the inside to the outside in the radial direction of the tire. Note that in Figure 1, the tread 2 is made up of a single layer.

[0048] With this configuration, and as mentioned above, using PET cord as the band cord, and using belt cords with one to four filaments, the intersection angle of the belts formed is less than 25 degrees, and by appropriately controlling (Dba / Dbr), it is thought that the overall performance of fuel efficiency, high-speed durability, and handling stability can be improved.

[0049] 2. Rubber composition for treads In this embodiment, the tread rubber composition can be obtained by kneading various compounding materials such as rubber components, fillers (reinforcements), softening agents (oils, resin components, etc.), and anti-aging agents.

[0050] (1) Compounding materials (a) Rubber component As mentioned above, the rubber component preferably contains isoprene-based rubber such as natural rubber (NR), but isoprene-based rubber and diene-based rubber other than isoprene-based rubber may be used in combination. As diene-based rubber other than isoprene-based rubber, it is also preferable to use diene-based rubber such as styrene-butadiene rubber (SBR), butadiene rubber (BR), acrylonitrile-butadiene rubber (NBR), chloroprene rubber (CR), and butyl rubber (IIR), and two types (NR and SBR or NR and BR) may be used in combination, or three types (NR, SBR, and BR) may be used in combination.

[0051] (i) Isoprene rubber As mentioned above, the isoprene-based rubber can be natural rubber (NR) or other isoprene-based rubbers (modified natural rubber (modified NR), modified natural rubber (modified NR), synthetic polyisoprene (isoprene rubber (IR), modified isoprene rubber (modified IR)), etc.). The content of isoprene-based rubber per 100 parts by mass of rubber component is as described above.

[0052] For NR (Nore Rating), common options in the tire industry such as SVR-L, SIR20, RSS#3, and TSR20 can be used.

[0053] Other isoprene-based rubbers besides NR include isoprene rubber (IR), modified NR, modified NR, and modified IR. IR is not particularly limited; for example, IR2200 manufactured by Nippon Zeon Co., Ltd., which is common in the tire industry, can be used. Modified NR includes deproteinized natural rubber (DPNR) and high-purity natural rubber (UPNR). Modified NR includes epoxidized natural rubber (ENR), hydrogenated natural rubber (HNR), and grafted natural rubber. Modified IR includes epoxidized isoprene rubber, hydrogenated isoprene rubber, and grafted isoprene rubber. These may be used individually or in combination of two or more types.

[0054] (b) SBR The weight-average molecular weight of SBR is, for example, more than 100,000 and less than 2,000,000. The styrene content of SBR is preferably more than 5% by mass, more preferably more than 10% by mass, and even more preferably more than 15% by mass. On the other hand, it is preferably less than 40% by mass, more preferably less than 35% by mass, and even more preferably less than 30% by mass. The vinyl content of SBR (amount of 1,2-bonded butadiene units) is preferably more than 5% by mass, more preferably more than 10% by mass, and even more preferably more than 15% by mass. On the other hand, it is preferably less than 70% by mass, more preferably less than 40% by mass, and even more preferably less than 30% by mass. The structural identification of SBR (measurement of styrene content and vinyl content) can be performed, for example, using an instrument from the JNM-ECA series manufactured by JEOL Ltd.

[0055] The SBR is not particularly limited, and for example, emulsion-polymerized styrene-butadiene rubber (E-SBR), solution-polymerized styrene-butadiene rubber (S-SBR), etc., can be used. The SBR may be either unmodified SBR or modified SBR. Furthermore, hydrogenated SBR, in which the butadiene portion of the SBR is hydrogenated, may be used. Hydrogenated SBR may be obtained by subsequently hydrogenating the BR portion of the SBR, or a similar structure may be obtained by copolymerizing styrene, ethylene, and butadiene.

[0056] The modified SBR is preferably an SBR having a functional group that interacts with a filler such as silica. Examples include a terminally modified SBR (terminally modified SBR having the functional group at the terminal) in which at least one end of the SBR is modified with a compound having the functional group (modifying agent), a main chain modified SBR having the functional group in the main chain, a main chain terminally modified SBR having the functional group in both the main chain and the terminal (for example, a main chain terminally modified SBR having the functional group in the main chain and at least one end modified with the modifying agent), and a terminally modified SBR that is modified (coupled) with a polyfunctional compound having two or more epoxy groups in the molecule, and in which hydroxyl groups or epoxy groups are introduced.

[0057] Examples of the above-mentioned functional groups include amino groups, amide groups, silyl groups, alkoxysilyl groups, isocyanate groups, imino groups, imidazole groups, urea groups, ether groups, carbonyl groups, oxycarbonyl groups, mercapto groups, sulfide groups, disulfide groups, sulfonyl groups, sulfinyl groups, thiocarbonyl groups, ammonium groups, imide groups, hydrazo groups, azo groups, diazo groups, carboxyl groups, nitrile groups, pyridyl groups, alkoxy groups, hydroxyl groups, oxy groups, epoxy groups, and the like. These functional groups may also have substituents.

[0058] Furthermore, as modified SBR, for example, SBR modified with a compound (modifying agent) represented by the following formula can be used.

[0059] [ka]

[0060] Note that in the formula, R 1 , R 2 and R 3 R represents, either identical or distinct, an alkyl group, an alkoxy group, a silyloxy group, an acetal group, a carboxyl group (-COOH), a mercapto group (-SH), or a derivative thereof. 4 and R 5 R represents a hydrogen atom or an alkyl group, either identical or different.4 and R 5 may combine to form a ring structure together with the nitrogen atom. n represents an integer.

[0061] As the modified SBR modified by the compound (modifying agent) represented by the above formula, SBR obtained by modifying the polymerization terminal (active terminal) of solution-polymerized styrene-butadiene rubber (S-SBR) with the compound represented by the above formula (modified SBR described in JP-A-2010-111753, etc.) can be used.

[0062] R 1 、R 2 and R 3 An alkoxy group is preferable as (preferably an alkoxy group having 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms). R 4 and R 5 An alkyl group (preferably an alkyl group having 1 to 3 carbon atoms) is preferable. n is preferably 1 to 5, more preferably 2 to 4, and still more preferably 3. Further, when R 4 and R 5 combine to form a ring structure together with the nitrogen atom, a 4- to 8-membered ring is preferable. Note that the alkoxy group includes a cycloalkoxy group (such as a cyclohexyloxy group) and an aryloxy group (such as a phenoxy group and a benzyloxy group).

[0063] Specific examples of the above modifying agent include 2-dimethylaminoethyltrimethoxysilane, 3-dimethylaminopropyltrimethoxysilane, 2-dimethylaminoethyltriethoxysilane, 3-dimethylaminopropyltriethoxysilane, 2-diethylaminoethyltrimethoxysilane, 3-diethylaminopropyltrimethoxysilane, 2-diethylaminoethyltriethoxysilane, 3-diethylaminopropyltriethoxysilane, and the like. These may be used alone or in combination of two or more.

[0064] Furthermore, modified SBR can also be modified using the following compounds (modifying agents): For example, polyglycidyl ethers of polyhydric alcohols such as ethylene glycol diglycidyl ether, glycerin triglycidyl ether, trimethylolethane triglycidyl ether, and trimethylolpropane triglycidyl ether; polyglycidyl ethers of aromatic compounds having two or more phenol groups such as diglycidyl bisphenol A; polyepoxy compounds such as 1,4-diglycidylbenzene, 1,3,5-triglycidylbenzene, and polyepoxylated liquid polybutadiene; epoxy group-containing tertiary amines such as 4,4'-diglycidyl-diphenylmethylamine and 4,4'-diglycidyl-dibenzylmethylamine; diglycidylaniline, N,N'-diglycidyl-4-glycidyloxyaniline, Diglycidylamino compounds such as diglycidyl orthotoluidine, tetraglycidylmetoxylendiamine, tetraglycidylaminodiphenylmethane, tetraglycidyl-p-phenylenediamine, diglycidylaminomethylcyclohexane, and tetraglycidyl-1,3-bisaminomethylcyclohexane; amino group-containing acid chlorides such as bis-(1-methylpropyl)carbamate chloride, 4-morpholine carbonyl chloride, 1-pyrrolidinecarbonyl chloride, N,N-dimethylcarbamate chloride, and N,N-diethylcarbamate chloride; epoxy group-containing silane compounds such as 1,3-bis-(glycidyloxypropyl)-tetramethyldisiloxane and (3-glycidyloxypropyl)-pentamethyldisiloxane;(Trimethylsilyl)[3-(trimethoxysilyl)propyl]sulfide, (Trimethylsilyl)[3-(triethoxysilyl)propyl]sulfide, (Trimethylsilyl)[3-(tributoxysilyl)propyl]sulfide, (Trimethylsilyl)[3-(methyldimethoxysilyl)propyl]sulfide, (Trimethylsilyl)[3-(methyldiethoxysilyl)propyl]sulfide, (Trimethylsilyl)[3-(methyldipropoxysilyl)propyl]sulfide Sulfide group-containing silane compounds such as [sisilyl)propyl]sulfide and (trimethylsilyl)[3-(methyldibutoxysilyl)propyl]sulfide; N-substituted aziridine compounds such as ethyleneimine and propyleneimine; methyltriethoxysilane, N,N-bis(trimethylsilyl)-3-aminopropyltrimethoxysilane, N,N-bis(trimethylsilyl)-3-aminopropyltriethoxysilane, N,N-bis(trimethylsilyl)aminoethyltrimethoxysilane, N,N-bis(trimethylsilyl)aminoethyl Alkoxysilanes such as tiltriethoxysilane; (thio)benzophenone compounds having an amino group and / or a substituted amino group, such as 4-N,N-dimethylaminobenzophenone, 4-N,N-di-t-butylaminobenzophenone, 4-N,N-diphenylaminobenzophenone, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, 4,4'-bis(diphenylamino)benzophenone, and N,N,N',N'-bis-(tetraethylamino)benzophenone; 4-N,N- Benzaldehyde compounds having an amino group and / or a substituted amino group, such as dimethylaminobenzaldehyde, 4-N,N-diphenylaminobenzaldehyde, and 4-N,N-divinylaminobenzaldehyde; N-substituted pyrrolidones such as N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, N-phenyl-2-pyrrolidone, Nt-butyl-2-pyrrolidone, and N-methyl-5-methyl-2-pyrrolidone; N-substituted piperidones such as N-methyl-2-piperidone, N-vinyl-2-piperidone, and N-phenyl-2-piperidone;N-substituted lactams such as N-methyl-ε-caprolactam, N-phenyl-ε-caprolactam, N-methyl-ω-laurylolactam, N-vinyl-ω-laurylolactam, N-methyl-β-propiolactam, and N-phenyl-β-propiolactam; as well as N,N-bis-(2,3-epoxypropoxy)-aniline, 4,4-methylene-bis-(N,N-glycidylaniline), and tris-(2,3-epoxypropyl)-1,3,5-triazine-2,4,6-triones. Examples include N,N-diethylacetamide, N-methylmaleimide, N,N-diethylurea, 1,3-dimethylethyleneurea, 1,3-divinylethyleneurea, 1,3-diethyl-2-imidazolidinone, 1-methyl-3-ethyl-2-imidazolidinone, 4-N,N-dimethylaminoacetophene, 4-N,N-diethylaminoacetophenone, 1,3-bis(diphenylamino)-2-propanone, and 1,7-bis(methylethylamino)-4-heptanone. Modification using the above compounds (modifiers) can be carried out by known methods.

[0065] For example, SBR manufactured and sold by companies such as Sumitomo Chemical Co., Ltd., ENEOS Material Co., Ltd., Asahi Kasei Corporation, and Nippon Zeon Co., Ltd. can be used. SBR may be used alone or in combination of two or more types.

[0066] The SBR content in 100 parts by mass of rubber component is preferably 10 parts by mass or more, more preferably 25 parts by mass or more, and even more preferably 40 parts by mass or more. The upper limit is preferably 70 parts by mass or less, more preferably 60 parts by mass or less, and even more preferably 55 parts by mass or less.

[0067] (H)BR The weight-average molecular weight of BR is, for example, greater than 100,000 and less than 2,000,000. The vinyl content of BR is, for example, greater than 1% by mass and less than 30% by mass. The cis content of BR is, for example, greater than 1% by mass and 98% by mass or less. The trans content of BR is, for example, greater than 1% by mass and less than 60% by mass. The cis content can be measured by infrared absorption spectroscopy.

[0068] The BR is not particularly limited, and can be high-cis content BR (cis content of 90% or more), low-cis content BR, or BR containing syndiotactic polybutadiene crystals. The BR can be either unmodified or modified, and as for modified BR, for example, BR modified with a compound (modifying agent) represented by the following formula can be used.

[0069] [ka]

[0070] Note that in the formula, R 1 , R 2 and R 3 R represents, either identical or distinct, an alkyl group, an alkoxy group, a silyloxy group, an acetal group, a carboxyl group (-COOH), a mercapto group (-SH), or a derivative thereof. 4 and R 5 R represents a hydrogen atom or an alkyl group, either identical or different. 4 and R 5 These atoms may bond to form a ring structure with the nitrogen atom. n represents an integer.

[0071] Modified BR, which has been modified by the compound (modifying agent) represented by the above formula, is an example of BR in which the polymerization end (active end) has been modified by the compound represented by the above formula.

[0072] R 1 , R 2 and R 3 A suitable alkoxy group is used (preferably an alkoxy group having 1 to 8 carbon atoms, more preferably an alkoxy group having 1 to 4 carbon atoms). 4 and R 5 A suitable alkyl group (preferably an alkyl group having 1 to 3 carbon atoms) is used. n is preferably 1 to 5, more preferably 2 to 4, and even more preferably 3. Also, R 4 and R 5When the alkoxy group is bonded to form a ring structure with the nitrogen atom, it is preferably a 4- to 8-membered ring. Note that the alkoxy group also includes cycloalkoxy groups (such as cyclohexyloxy groups) and aryloxy groups (such as phenoxy and benzyloxy groups).

[0073] Specific examples of the above-mentioned denaturing agents include 2-dimethylaminoethyltrimethoxysilane, 3-dimethylaminopropyltrimethoxysilane, 2-dimethylaminoethyltriethoxysilane, 3-dimethylaminopropyltriethoxysilane, 2-diethylaminoethyltrimethoxysilane, 3-diethylaminopropyltrimethoxysilane, 2-diethylaminoethyltriethoxysilane, and 3-diethylaminopropyltriethoxysilane. These may be used individually or in combination of two or more.

[0074] Furthermore, modified BR can also be modified using the following compounds (modifying agents): For example, polyglycidyl ethers of polyhydric alcohols such as ethylene glycol diglycidyl ether, glycerin triglycidyl ether, trimethylolethane triglycidyl ether, and trimethylolpropane triglycidyl ether; polyglycidyl ethers of aromatic compounds having two or more phenol groups such as diglycidyl bisphenol A; polyepoxy compounds such as 1,4-diglycidylbenzene, 1,3,5-triglycidylbenzene, and polyepoxy-modified liquid polybutadiene; epoxy-group-containing tertiary amines such as 4,4'-diglycidyl-diphenylmethylamine and 4,4'-diglycidyl-dibenzylmethylamine; diglycidylaniline, N,N'-diglycidyl-4-glycidyloxyaniline, Diglycidylamino compounds such as diglycidyl orthotoluidine, tetraglycidylmetoxylendiamine, tetraglycidylaminodiphenylmethane, tetraglycidyl-p-phenylenediamine, diglycidylaminomethylcyclohexane, and tetraglycidyl-1,3-bisaminomethylcyclohexane; amino group-containing acid chlorides such as bis-(1-methylpropyl)carbamate chloride, 4-morpholine carbonyl chloride, 1-pyrrolidinecarbonyl chloride, N,N-dimethylcarbamate chloride, and N,N-diethylcarbamate chloride; epoxy group-containing silane compounds such as 1,3-bis-(glycidyloxypropyl)-tetramethyldisiloxane and (3-glycidyloxypropyl)-pentamethyldisiloxane;(Trimethylsilyl)[3-(trimethoxysilyl)propyl]sulfide, (Trimethylsilyl)[3-(triethoxysilyl)propyl]sulfide, (Trimethylsilyl)[3-(tributoxysilyl)propyl]sulfide, (Trimethylsilyl)[3-(methyldimethoxysilyl)propyl]sulfide, (Trimethylsilyl)[3-(methyldiethoxysilyl)propyl]sulfide, (Trimethylsilyl)[3-(methyldipropoxysilyl)propyl]sulfide Sulfide group-containing silane compounds such as [sisilyl)propyl]sulfide and (trimethylsilyl)[3-(methyldibutoxysilyl)propyl]sulfide; N-substituted aziridine compounds such as ethyleneimine and propyleneimine; methyltriethoxysilane, N,N-bis(trimethylsilyl)-3-aminopropyltrimethoxysilane, N,N-bis(trimethylsilyl)-3-aminopropyltriethoxysilane, N,N-bis(trimethylsilyl)aminoethyltrimethoxysilane, N,N-bis(trimethylsilyl)aminoethyl Alkoxysilanes such as tiltriethoxysilane; (thio)benzophenone compounds having an amino group and / or a substituted amino group, such as 4-N,N-dimethylaminobenzophenone, 4-N,N-di-t-butylaminobenzophenone, 4-N,N-diphenylaminobenzophenone, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, 4,4'-bis(diphenylamino)benzophenone, and N,N,N',N'-bis-(tetraethylamino)benzophenone; 4-N,N- Benzaldehyde compounds having an amino group and / or a substituted amino group, such as dimethylaminobenzaldehyde, 4-N,N-diphenylaminobenzaldehyde, and 4-N,N-divinylaminobenzaldehyde; N-substituted pyrrolidones such as N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, N-phenyl-2-pyrrolidone, Nt-butyl-2-pyrrolidone, and N-methyl-5-methyl-2-pyrrolidone; N-substituted piperidones such as N-methyl-2-piperidone, N-vinyl-2-piperidone, and N-phenyl-2-piperidone;N-substituted lactams such as N-methyl-ε-caprolactam, N-phenyl-ε-caprolactam, N-methyl-ω-laurylolactam, N-vinyl-ω-laurylolactam, N-methyl-β-propiolactam, and N-phenyl-β-propiolactam; as well as N,N-bis-(2,3-epoxypropoxy)-aniline, 4,4-methylene-bis-(N,N-glycidylaniline), and tris-(2,3-epoxypropyl)-1,3,5-triazine-2,4,6-triones. Examples include N,N-diethylacetamide, N-methylmaleimide, N,N-diethylurea, 1,3-dimethylethyleneurea, 1,3-divinylethyleneurea, 1,3-diethyl-2-imidazolidinone, 1-methyl-3-ethyl-2-imidazolidinone, 4-N,N-dimethylaminoacetophene, 4-N,N-diethylaminoacetophenone, 1,3-bis(diphenylamino)-2-propanone, and 1,7-bis(methylethylamino)-4-heptanone. Modification using the above compounds (modifying agents) can be carried out by known methods. These modified BRs may be used individually or in combination of two or more.

[0075] For example, BR products from companies such as Ube Industries, Ltd., ENEOS Material Corporation, Asahi Kasei Corporation, and Nippon Zeon Corporation can be used.

[0076] The BR content in 100 parts by mass of rubber component is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less.

[0077] (ii) Other rubber components The rubber composition may also include, if necessary, other rubber components such as nitrile rubber (NBR) or other rubbers (polymers) commonly used in tire manufacturing.

[0078] Furthermore, the raw materials (monomers) for synthetic rubbers such as IR, SBR, and BR mentioned above may be derived from underground resources such as petroleum and natural gas, or they may be recycled from rubber products such as tires or non-rubber products such as polystyrene.

[0079] The monomers obtained by recycling (recycled monomers) are not particularly limited and include recycled polyisoprene, recycled butadiene, recycled aromatic vinyl, etc. Examples of butadiene include 1,2-butadiene and 1,3-butadiene. Examples of aromatic vinyl include styrene, etc. Among these, recycled polyisoprene (recycled isoprene), butadiene (recycled butadiene), and / or recycled styrene (recycled styrene) are preferred as raw materials.

[0080] The method for producing recycled monomer is not particularly limited, and for example, it can be synthesized from recycled naphtha obtained by decomposing rubber products such as tires. Furthermore, the method for producing recycled naphtha is not particularly limited, and for example, rubber products such as tires may be decomposed under high temperature and pressure, decomposed by microwaves, or extracted after mechanical grinding.

[0081] Furthermore, the raw materials (monomers) of synthetic rubbers such as IR, SBR, and BR may be derived from biomass. In this specification, biomass refers to substances derived from natural resources such as plants. Biomass is not particularly limited, but examples include agricultural, forestry, and fishery products, sugars, wood chips, plant residues after obtaining useful components, plant-derived ethanol, and biomass naphtha.

[0082] The biomass-derived monomer (biomass monomer) is not particularly limited and includes biomass-derived butadiene, biomass-derived aromatic vinyl, etc. The butadiene is 1,2-butadiene and 1,3-butadiene. The aromatic vinyl is not particularly limited and includes styrene, etc. The method for producing the biomass monomer is not particularly limited and includes, for example, biological and / or chemical and / or physical transformations of plants and animals. A typical biological transformation is fermentation by microorganisms, and chemical and / or physical transformations include those by catalysts, by high heat, by high pressure, by electromagnetic waves, by critical liquids, and combinations thereof.

[0083] The polymer synthesized from biomass monomer components (biomass polymer) is not particularly limited, and examples include polybutadiene rubber synthesized from biomass-derived butadiene, and aromatic vinyl / butadiene copolymers synthesized from biomass-derived butadiene and / or biomass-derived aromatic vinyl. Examples of the aromatic vinyl / butadiene copolymer include styrene-butadiene rubber synthesized from biomass-derived butadiene and / or biomass-derived styrene.

[0084] Whether the raw materials for a polymer are biomass-derived can be determined by measuring pMC (percent Modern Carbon) in accordance with ASTMD6866-10.

[0085] pMC stands for Modern Standard Reference Carbon. 14 Sample relative to C concentration 14 This is a ratio of C concentrations and is used as an indicator of the biomass ratio of a compound. The significance of this value is described below.

[0086] 1 mole of carbon atoms (6.02 × 10⁻¹⁰) 23 (Each) contains approximately 6.02 × 10¹⁶ atoms, which is about one trillionth of the amount of carbon atoms in a normal atom. 11 individual 14C exists. 14 Carbon dioxide is called a radioactive isotope, and its half-life is 5730 years, decreasing regularly. It takes 226,000 years for all of them to decay. Therefore, in fossil fuels such as coal, oil, and natural gas, which are thought to have been fixed for more than 226,000 years after atmospheric carbon dioxide was taken in by plants, etc., it was initially contained within these materials. 14 All elements of C have decayed. Therefore, in the 21st century, fossil fuels such as coal, oil, and natural gas are no longer viable. 14 It contains absolutely no element C. Therefore, chemical substances produced using these fossil fuels as raw materials also contain C. 14 It contains absolutely no element C.

[0087] on the other hand, 14 C is continuously produced in the Earth's atmospheric environment through nuclear reactions caused by cosmic rays, and its decrease due to radioactive decay balances this process. 14 The amount of C is constant. Therefore, the amount of biomass resource-derived substances currently circulating in the environment 14 As mentioned above, the carbon concentration is approximately 1 × 10¹⁶ of the total carbon atoms. -12 The values ​​are approximately in the range of mol%. Therefore, the difference between these values ​​can be used to calculate the biomass ratio in a given compound.

[0088] this 14 C is typically measured as follows: Using accelerator mass spectrometry based on a tandem accelerator, 13 C concentration ( 13 C / 12 C), 14 C concentration ( 14 C / 12 Perform measurement C). In the measurement, 14 As a modern standard reference for the concentration of C, the amount of cyclic carbon in nature as of 1950 14The C concentration will be used. The specific standard material will be the oxalic acid standard provided by NIST (National Institute of Standards and Technology). The specific radioactivity of carbon in this oxalic acid (per gram of carbon) will be used. 14 The radioactivity intensity of C is separated by carbon isotope, 13 The standard value is obtained by correcting C to a constant value and applying decay correction from 1950 AD to the measurement date. 14 This value is used as the C concentration value (100%). The ratio of this value to the value of the sample actually measured is the pMC value.

[0089] Therefore, if rubber is made from 100% biomass (natural) materials, although there are regional differences, under normal conditions it will often not reach 100, and will show a value of approximately 110 pMC. On the other hand, regarding chemical substances derived from fossil fuels such as petroleum, 14 When the C concentration is measured, it will show a range of approximately 0 pMC (for example, 0.3 pMC). This value corresponds to a biomass ratio of 0% as mentioned above.

[0090] From the above, it is preferable from the viewpoint of environmental protection (sustainability) to use materials such as rubber with a high pMC value, that is, materials such as rubber with a high biomass ratio, in rubber compositions.

[0091] (b) Compounding materials other than rubber components (i) Filling agent The rubber composition preferably contains silica or carbon black as a reinforcing agent, but may also contain other fillers as needed, such as calcium carbonate, talc, alumina, clay, aluminum hydroxide, or mica. When silica is used, it is preferable to use it in combination with a silane coupling agent.

[0092] (i) Silica As mentioned above, silica has OH groups on its surface, and by appropriately blending it in an amount of more than 60 parts by mass per 100 parts by mass of rubber component, it is possible to improve handling stability and high-speed durability.

[0093] The BET specific surface area of ​​silica is considered to be 100 m² from the perspective of obtaining good durability performance. 2 It is preferable that the amount is greater than / g, and 130m 2 It is more preferable if it is greater than / g. On the other hand, 250m 2 It is preferable that the amount be less than / g, and 200m 2 It is more preferable if the value is less than / g. The BET specific surface area mentioned above is the N2SA value measured by the BET method in accordance with ASTM D3037-93.

[0094] The silica used is not particularly limited. For example, silica prepared by the dry method (anhydrous silica) and silica prepared by the wet method (hydrated silica), which are common in the tire industry, can be used. Commercially available products from companies such as Evonik Industries, Rhodia, Tosoh Silica Co., Ltd., Solvay Japan Ltd., and Tokuyama Corporation can be used.

[0095] The raw materials for silica are not particularly limited. For example, they may be mineral-derived raw materials such as quartz, or biologically derived raw materials such as rice husks (e.g., silica made from biomass materials such as rice husks), or silica recycled from silica-containing products may be used. Among these, hydrated silica prepared by a wet process is preferred because it contains a large amount of silanol groups. However, sustainable silica (silica made from biomass materials or silica recycled from silica-containing products) is preferred.

[0096] Silica derived from biomass materials can be obtained, for example, by extracting silicates from rice husk ash obtained by burning rice husks using a sodium hydroxide solution, and then using these silicates to react with sulfuric acid in the same way as conventional wet silica, the precipitate of silicon dioxide is filtered, washed with water, dried, and pulverized.

[0097] The silica recycled from silica-containing products can be, for example, silica recovered from products containing silica such as semiconductors and other electronic components, tires, desiccants, and diatomaceous earth and other filter materials. The recovery method is not particularly limited and can include thermal decomposition and decomposition by electromagnetic waves. Among these, silica recovered from semiconductors and other electronic components or tires is preferred.

[0098] When silica crystallizes, it becomes insoluble in water, and its component, silicic acid, cannot be utilized. By controlling the combustion temperature and combustion time, the crystallization of silica in rice husk ash can be suppressed (see Japanese Patent Publication No. 2009-2594, Akita Prefectural University Web Journal B / 2019, vol.6, pp.216-222, etc.).

[0099] Amorphous silica extracted from rice husks can be commercially available from companies such as Wilmar.

[0100] These silicas may be used individually or in combination of two or more. Furthermore, using biomass silica or recycled silica is preferable from an environmental protection (sustainability) standpoint.

[0101] Furthermore, the particle size (average primary particle size) of silica is preferably greater than 8 nm, more preferably greater than 9 nm, and even more preferably greater than 10 nm, because if it is too small, the processability will be poor. On the other hand, from the viewpoint of ensuring the reinforcing properties of the rubber, it is preferably less than 25 nm, more preferably less than 20 nm, and even more preferably less than 17 nm.

[0102] The average primary particle diameter of silica refers to the average value of measurements taken by observing the smallest particle unit of silica constituting the aggregated structure as a circle, and measuring the absolute maximum length of that smallest particle as the diameter of the circle. This can be determined by observing with a transmission or scanning electron microscope, measuring 400 or more primary silica particles observed within the field of view, and averaging the results.

[0103] Specifically, silica extracted from a rubber composition cut from a tire can be directly observed using an electron microscope or the like. The average primary particle diameter can then be calculated by determining the equal cross-sectional area diameter from the area of ​​each silica particle obtained and then calculating the average value.

[0104] (ii) Silane coupling agent When using silica, it is preferable to use a silane coupling agent in combination to improve the dispersibility of silica and to enhance mechanical properties and moldability through reaction with silica.

[0105] The silane coupling agent is not particularly limited and includes, for example, bis(3-triethoxysilylpropyl)tetrasulfide, bis(2-triethoxysilylethyl)tetrasulfide, bis(4-triethoxysilylbutyl)tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, bis(2-trimethoxysilylethyl)tetrasulfide, bis(2-triethoxysilylethyl)trisulfide, and 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-dimethylthiocarbamoyltetrasulfide, 2-triethoxy Examples include sulfide-based silane coupling agents such as cisilylethyl-N,N-dimethylthiocarbamoyl tetrasulfide and 3-triethoxysilylpropyl methacrylate monosulfide; mercapto-based silane coupling agents such as 3-mercaptopropyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, and NXT and NXT-Z from Momentive; vinyl-based silane coupling agents such as vinyltriethoxysilane and vinyltrimethoxysilane; amino-based silane coupling agents such as 3-aminopropyltriethoxysilane and 3-aminopropyltrimethoxysilane; glycidoxy-based silane coupling agents such as γ-glycidoxypropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane; nitro-based silane coupling agents such as 3-nitropropyltrimethoxysilane and 3-nitropropyltriethoxysilane; and chloro-based silane coupling agents such as 3-chloropropyltrimethoxysilane and 3-chloropropyltriethoxysilane. Among these, silane coupling agents having a thiocarbonyl group, such as NXT mentioned above, are preferred. These may be used alone or in combination of two or more.

[0106] Examples of silane coupling agents that can be used include products from Evonik Industries, Momentive, Shin-Etsu Silicone Co., Ltd., Tokyo Chemical Industry Co., Ltd., Azumax Co., Ltd., and Toray Dow Corning Co., Ltd.

[0107] The silane coupling agent content is preferably more than 3 parts by mass, more preferably 5 parts by mass or more, and even more preferably 7 parts by mass or more, per 100 parts by mass of silica. The upper limit is preferably less than 15 parts by mass, more preferably 12 parts by mass or less, and even more preferably 9 parts by mass or less.

[0108] (iii) Carbon Black Carbon black is preferably used to improve the crack growth resistance, durability, and UV degradation resistance of tires.

[0109] The nitrogen adsorption specific surface area (N2SA) of carbon black is 30m², from the perspective of its reinforcing properties for rubber. 2 It is preferable that it be 50m or more / g 2 It is more preferable that it is 60m or more / g 2 It is even more preferable if it is 1 / g or more. On the other hand, from the viewpoint of exothermic properties, 250m 2 It is preferable that it be less than or equal to / g, and 150m 2 It is more preferable that it be less than or equal to / g, and 120m 2 It is even more preferable if the amount is less than or equal to / g. The specific surface area of ​​nitrogen adsorption of carbon black is measured according to ASTM D4820-93.

[0110] From the viewpoint of rubber rigidity, the dibutyl phthalate (DBP) absorption of carbon black is preferably 50 ml / 100g or more, and more preferably 100 ml / 100g or more. On the other hand, from the viewpoint of rubber deformation flexibility, it is preferably 250 ml / 100g or less, and more preferably 150 ml / 100g or less. The DBP absorption of carbon black is measured according to ASTM D2414-93.

[0111] Carbon black is not particularly limited and can include furnace blacks (furnace carbon blacks) such as SAF, ISAF, HAF, MAF, FEF, SRF, GPF, APF, FF, CF, SCF, and ECF; acetylene black (acetylene carbon black); thermal blacks (thermal carbon blacks) such as FT and MT; and channel blacks (channel carbon blacks) such as EPC, MPC, and CC. Part numbers can include N134, N110, N220, N234, N219, N339, N330, N326, N351, N550, and N762. These can be used individually or in combination of two or more types.

[0112] The raw materials for carbon black may be biomass materials other than mineral oil, such as lignin and vegetable oil, or pyrolysis oil obtained by thermally decomposing rubber products such as waste tires (recycled carbon black). Using these sustainable carbon blacks is preferable from an environmental protection standpoint.

[0113] Furthermore, the method for producing carbon black may be by combustion such as the furnace process, by hydrothermal carbonization (HTC), or by thermal decomposition of methane such as the thermal black process.

[0114] Commercially available products from companies such as Asahi Carbon Co., Ltd., Cabot Japan Co., Ltd., Tokai Carbon Co., Ltd., Mitsubishi Chemical Corporation, Lion Corporation, Nippon Steel Carbon Co., Ltd., and Columbia Carbon Corporation can be used. These can be used individually or in combination of two or more types. The carbon black content is as described above.

[0115] The carbon black content per 100 parts by mass of rubber component is preferably more than 5 parts by mass, more preferably more than 8 parts by mass, and even more preferably more than 10 parts by mass. The upper limit is preferably less than 40 parts by mass, and more preferably less than 35 parts by mass.

[0116] (iv) Other fillers In addition to the carbon black and silica mentioned above, the rubber composition may further contain fillers commonly used in the tire industry, such as graphite, calcium carbonate, talc, alumina, clay, aluminum hydroxide, mica, and magnesium sulfate. The amount of these fillers is, for example, more than 0.1 parts by mass and less than 150 parts by mass per 100 parts by mass of the rubber component.

[0117] (b) Softening agent components In rubber compositions, it is preferable to use a softening agent component as needed, from the viewpoint of imparting plasticity to the rubber component and properly dispersing the powder material during kneading. Here, the term "softening agent component" includes both liquid and solid softening agents at 25°C.

[0118] Examples of softeners include resin components, oils, liquid polymers, and ester-based plasticizers. These softeners may be derived from mineral resources such as petroleum and natural gas, from biomass, or from naphtha recycled from rubber or non-rubber products. In addition, low molecular weight hydrocarbon components obtained by thermal decomposition and extraction of used tires or products containing various components may be used as softeners. Among these, softeners derived from biomass or recycled materials are preferred as sustainable softeners.

[0119] These softening agents may be used individually or in combination of two or more. The content of the softening agent component per 100 parts by mass of rubber component is preferably more than 5 parts by mass, more preferably more than 10 parts by mass, and even more preferably more than 20 parts by mass. As an upper limit, for example, it is preferably less than 70 parts by mass, more preferably less than 60 parts by mass, and even more preferably less than 55 parts by mass. The content of the softening agent component also includes the amount of oil contained in the rubber (oil-applied rubber), etc.

[0120] (i) oil Examples of oils include mineral oil, vegetable oil, and animal oil. Furthermore, from a life cycle assessment perspective, waste oil used in rubber mixers and engines, or refined waste cooking oil used in restaurants, may also be used, and among these, vegetable oil is preferred.

[0121] (i-1) Mineral oil In this specification, mineral oil refers to oil derived from mineral resources such as petroleum and natural gas. Examples of mineral oil include paraffinic oils (mineral oils), naphthenic oils, and aromatic oils.

[0122] Specific examples of mineral oils include MES (Mild Extract Solvated), DAE (Distillate Aromatic Extract), TDAE (Treated Distillate Aromatic Extract), TRAE (Treated Residual Aromatic Extract), and RAE (Residual Aromatic Extract).

[0123] Furthermore, for environmental reasons, oils with a low content of polycyclic aromatic compounds (PCA) can be used. Examples of such low-PCA oils include MES, TDAE, and heavy naphthenic oils.

[0124] Examples of commercially available mineral oils include paraffinic, aromatic, and naphthenic oils. Products from companies such as Idemitsu Kosan Co., Ltd., Sankyo Yuka Kogyo Co., Ltd., ENEOS Corporation, Orisoy Co., Ltd., H&R Co., Ltd., Toyokuni Oil Co., Ltd., Showa Shell Sekiyu K.K., and Fuji Kosan Co., Ltd. can be used. These can be used individually or in combination of two or more types.

[0125] (i-2) Vegetable oil Examples of vegetable oils include linseed oil, rapeseed oil, safflower oil, soybean oil, corn oil, cottonseed oil, rice oil, tall oil, sesame oil, perilla oil, castor oil, tung oil, pine oil, pine tar oil, sunflower oil, coconut oil, palm oil, palm kernel oil, olive oil, camellia oil, jojoba oil, macadamia nut oil, peanut oil, grapeseed oil, and wood wax.

[0126] Furthermore, vegetable oils can also include refined oils (such as salad oil) obtained by refining the above-mentioned oils, transesterified oils obtained by transesterification, hydrogenated oils obtained by hydrogenation, thermally polymerized oils obtained by thermal polymerization, oxidized polymerized oils obtained by oxidation, and waste cooking oils recovered from use as edible oils. Vegetable oils may be liquid or solid at room temperature (25°C). These may be used individually or in combination of two or more types.

[0127] The vegetable oil preferably contains acylglycerol, and more preferably contains triacylglycerol. Acylglycerol refers to a compound in which a hydroxyl group of glycerin is esterified with a fatty acid. The acylglycerol is not particularly limited and may be 1-monoacylglycerol, 2-monoacylglycerol, 1,2-diacylglycerol, 1,3-diacylglycerol, or triacylglycerol. Furthermore, the acylglycerol may be a monomer, a dimer, or a polymer of three or more. Acylglycerols of two or more can be obtained by thermal polymerization, oxidative polymerization, etc. Also, the acylglycerol may be a liquid or a solid at room temperature (25°C).

[0128] There are no particular limitations on the method for determining whether a rubber composition contains acylglycerol, 1 This can be confirmed by 1H-NMR measurement. For example, a rubber composition containing triacylglycerol is immersed in deuterated chloroform at room temperature (25°C) for 24 hours, and after removing the rubber composition, it is measured at room temperature. 1When 1H-NMR is measured and the signal for tetramethylsilane (TMS) is set to 0.00 ppm, signals around 5.26 ppm, 4.28 ppm, and 4.15 ppm are observed. These signals are presumed to originate from hydrogen atoms bonded to carbon atoms adjacent to the oxygen atom of the ester group, thus confirming the presence of acylglycerol. Here, "around" refers to a range of ±0.10 ppm.

[0129] The fatty acids are not particularly limited and may be either unsaturated or saturated fatty acids. Examples of unsaturated fatty acids include monounsaturated fatty acids such as oleic acid, and polyunsaturated fatty acids such as linoleic acid and linolenic acid. Examples of saturated fatty acids include butyric acid and lauric acid.

[0130] In particular, it is desirable that the fatty acid contains fatty acids with few double bonds, i.e., saturated fatty acids or monounsaturated fatty acids, and oleic acid is preferred. As a vegetable oil containing such fatty acids, for example, a vegetable oil containing saturated fatty acids or monounsaturated fatty acids may be used, or a vegetable oil that has been modified by transesterification or other means may be used. Furthermore, in order to produce a vegetable oil containing such fatty acids, plants may be improved by breeding, genetic modification, genome editing, etc.

[0131] As for vegetable oils, commercially available products from companies such as Idemitsu Kosan Co., Ltd., Sankyo Yuka Kogyo Co., Ltd., ENEOS Corporation, Orisoy Co., Ltd., H&R Co., Ltd., Toyokuni Oil Co., Ltd., Fuji Kosan Co., Ltd., and Nisshin Oillio Group Ltd. can be used.

[0132] (ii) Liquid rubber Liquid rubber is a polymer that is in a liquid state at room temperature (25°C) and is a rubber component that can be extracted from vulcanized tires by acetone extraction. Examples of liquid rubber include farnesene polymers, liquid diene polymers, and their hydrogenated derivatives.

[0133] Farnesene polymers are polymers obtained by polymerizing farnesene and have constituent 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).

[0134] The farnesene polymer may be a farnesene homopolymer (farnesene homopolymer) or a farnesene-vinyl monomer copolymer (farnesene-vinyl monomer copolymer).

[0135] 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).

[0136] The liquid diene polymer has a weight-average molecular weight (Mw) on a polystyrene basis, measured by gel permeation chromatography (GPC), for example, 1.0 × 10⁻⁶. 3 Super, 2.0×10 5 It is less than [value]. Here, the Mw of the liquid diene polymer is the polystyrene equivalent value measured by gel permeation chromatography (GPC).

[0137] As for liquid rubber, products from companies such as Kuraray Co., Ltd. and Clay Valley Corporation can be used.

[0138] (iii) Resin components The resin component also functions as a tackifying agent and may be solid or liquid at room temperature. Specific resin components that are preferred include, for example, rosin resins, styrene resins, coumarone resins, terpene resins, C5 resins, C9 resins, C5C9 resins, and acrylic resins, and two or more may be used in combination. These resin components may be modified to contain silica or the like, if necessary. The content of the resin component per 100 parts by mass of the rubber component is preferably 10 parts by mass or more, more preferably 30 parts by mass or more, and even more preferably 50 parts by mass or more.

[0139] Rosin resins are resins whose main component is rosin acid, obtained by processing pine resin. These rosin resins (rosins) can be classified according to whether or not they are modified, and can be classified into unmodified rosin and rosin derivatives. Examples of unmodified rosin include tall rosin (also known as tall oil rosin), gum rosin, wood rosin, disproportionate rosin, polymerized rosin, hydrogenated rosin, and other chemically modified rosins. Rosin derivatives are modified forms of unmodified rosin and include rosin esters, unsaturated carboxylic acid-modified rosins, unsaturated carboxylic acid-modified rosin esters, rosin amide compounds, and rosin amine salts.

[0140] Styrene resins are polymers that use styrene monomers as constituent monomers, and include polymers polymerized with styrene monomers as the main component (50% by mass or more). Specifically, examples include homopolymers obtained by polymerizing 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.) individually, copolymers obtained by copolymerizing two or more styrene monomers, and copolymers of styrene monomers and other monomers that can copolymerize with them.

[0141] Examples of the aforementioned other monomers include acrylonitriles such as acrylonitrile and methacrylonitrile, unsaturated carboxylic acids such as acrylics and methacrylic acid, unsaturated carboxylic acid esters such as methyl acrylate and methyl methacrylate, dienes such as chloroprene and butadiene isoprene, olefins such as 1-butene and 1-pentene; α,β-unsaturated carboxylic acids such as maleic anhydride or their acid anhydrides; and so on.

[0142] Among coumarone-based resins, coumarone-indene resin is preferred. Coumarone-indene resin is a resin that contains coumarone and indene as monomer components that constitute the resin's backbone (main chain). Other monomer components that can be included in the backbone besides coumarone and indene include styrene, α-methylstyrene, methylindene, vinyltoluene, and the like.

[0143] The hydroxyl value (OH value) of coumarone indene resin is, for example, greater than 15 mg KOH / g and less than 150 mg KOH / g. The OH value is expressed in milligrams as the amount of potassium hydroxide required to neutralize the acetic acid bonded to the hydroxyl groups when acetylating 1 g of resin, and is measured by potentiometric titration (JIS K 0070:1992).

[0144] The softening point of coumarone indene resin is, for example, above 30°C and below 160°C. The softening point is determined by measuring the softening point as specified in JIS K 6220-1:2001 using a ring-type softening point measuring device, and it is the temperature at which the sphere descends.

[0145] Examples of terpene resins include polyterpenes, terpene phenols, and aromatically modified terpene resins. Polyterpenes are resins obtained by polymerizing terpene compounds and their hydrogenated products. Terpene compounds are (C5H8) n A hydrocarbon represented by the following composition and its oxygen-containing derivative, a monoterpene (C 10 H 16 ), sesquiterpenes (C 15 H 24 ), diterpene (C 20 H 32These are compounds whose basic skeleton is a terpene, classified as such, and examples include α-pinene, β-pinene, dipentene, limonene, myrcene, allocimene, ocimene, α-phellandrene, α-terpinene, γ-terpinene, terpinolene, 1,8-cineole, 1,4-cineole, α-terpineol, β-terpineol, γ-terpineol, etc.

[0146] Polyterpenes include terpene resins such as α-pinene resin, β-pinene resin, limonene resin, dipentene resin, and β-pinene / limonene resin, which are derived from the terpene compounds mentioned above, as well as hydrogenated terpene resins obtained by hydrogenating these terpene resins. Terpene phenols include resins obtained by copolymerizing the above terpene compounds with phenolic compounds, and resins obtained by hydrogenating these resins. Specifically, resins obtained by condensing the above terpene compounds, phenolic compounds, and formalin are included. Examples of phenolic compounds include phenol, bisphenol A, cresol, and xylenol. Aromatically modified terpene resins include resins obtained by modifying terpene resins with aromatic compounds, and resins obtained by hydrogenating these resins. The aromatic compounds are not particularly limited as long as they are compounds having an aromatic ring, but examples include phenol compounds such as phenol, alkylphenol, alkoxyphenol, and phenol containing an unsaturated hydrocarbon group; naphthol compounds such as naphthol, alkylnaphthol, alkoxynaphthol, and naphthol containing an unsaturated hydrocarbon group; styrene derivatives such as styrene, alkylstyrene, alkoxystyrene, and styrene containing an unsaturated hydrocarbon group; coumarone, indene, and the like.

[0147] "C5 resin" refers to a resin obtained by polymerizing a C5 fraction. Examples of C5 fractions include petroleum fractions with 4 to 5 carbon atoms, such as cyclopentadiene, pentene, pentadiene, and isoprene. Dicyclopentadiene resin (DCPD resin) is preferably used as a C5-based petroleum resin.

[0148] "C9 resin" refers to a resin obtained by polymerizing a C9 fraction, and may be hydrogenated or modified. Examples of C9 fractions include petroleum fractions with 8 to 10 carbon atoms, such as vinyltoluene, alkylstyrene, indene, and methylindene. Specific examples include coumarone indene resin, coumarone resin, indene resin, and aromatic vinyl resins, which are suitably used. As aromatic vinyl resins, α-methylstyrene (AMS resin), a homopolymer of styrene, or a copolymer of α-methylstyrene and styrene is preferred, and a copolymer of α-methylstyrene and styrene is more preferred, due to their economical nature, ease of processing, and excellent heat generation properties. Aromatic vinyl resins that are commercially available from companies such as Kraton and Eastman Chemical can be used.

[0149] "C5C9 resin" refers to a resin obtained by copolymerizing the C5 fraction and the C9 fraction, and may be hydrogenated or modified. Examples of the C5 and C9 fractions include the petroleum fractions mentioned above. As for the C5C9 resin, commercially available products from companies such as Tosoh Corporation and LUHUA can be used.

[0150] While there are no particular limitations on the acrylic resin used, for example, a solvent-free acrylic resin can be used.

[0151] Solvent-free acrylic resins include (meth)acrylic resins (polymers) synthesized by high-temperature continuous polymerization (high-temperature continuous mass polymerization) (methods described in U.S. Patent No. 4,414,370, Japanese Patent Publication No. 59-6207, Japanese Patent Publication No. 5-58005, Japanese Patent Publication No. 1-313522, U.S. Patent No. 5,010,166, Toagosei Research Annual Report TREND2000 No. 3, pp. 42-45, etc.) with minimal use of polymerization initiators, chain transfer agents, organic solvents, etc. as auxiliary raw materials. In this disclosure, (meth)acrylic means methacrylic and acrylic.

[0152] Examples of monomer components constituting the above-mentioned 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.

[0153] Furthermore, as monomer components constituting the above-mentioned acrylic resin, aromatic vinyls such as styrene, α-methylstyrene, vinyltoluene, vinylnaphthalene, divinylbenzene, trivinylbenzene, and divinylnaphthalene may be used along with (meth)acrylic acid and (meth)acrylic acid derivatives.

[0154] The above-mentioned acrylic resin may be a resin composed solely of (meth)acrylic components, or it may be a resin that also contains components other than (meth)acrylic components. Furthermore, the above-mentioned acrylic resin may have hydroxyl groups, carboxyl groups, silanol groups, etc.

[0155] As resin components, products from companies such as Maruzen Petrochemical Co., Ltd., Sumitomo Bakelite Co., Ltd., Yasuhara Chemical Co., Ltd., Tosoh Corporation, Rutgers Chemicals, BASF, Kraton Chemicals, Nippon Paint Chemical Co., Ltd., Nippon Shokubai Co., Ltd., ENEOS Corporation, Arakawa Chemical Industries, Ltd., and Taoka Chemical Industries, Ltd. can be used.

[0156] (H) Wax The rubber composition may contain wax. The wax content is preferably 0.5 parts by mass or more, more preferably 1.0 part by mass or more, and even more preferably 1.5 parts by mass or more, per 100 parts by mass of the rubber component. The upper limit is preferably, for example, 10 parts by mass or less, more preferably 7 parts by mass or less, and even more preferably 4 parts by mass or less.

[0157] The wax used is not particularly limited, and any wax commonly used in the tire industry can be suitably used. Examples include mineral waxes and plant-derived waxes. Mineral waxes refer to waxes derived from mineral resources such as oil and natural gas. Plant-derived waxes refer to waxes derived from natural resources such as plants. Among these, plant-derived waxes are preferred from the standpoint of sustainable materials.

[0158] Examples of plant-derived waxes include rice wax, carnauba wax, and candelilla wax. Examples of mineral-based waxes include paraffin wax, microcrystalline wax, and selected specialty waxes thereof, with paraffin wax being preferred. Stearic acid is not included in the wax.

[0159] As for the wax, commercially available products from companies such as Ouchi Shinko Chemical Industry Co., Ltd., Nippon Seiro Co., Ltd., and Paramelt Co., Ltd. can be used. These waxes may be used individually or in combination of two or more types.

[0160] (ii) Anti-aging agents The rubber composition may contain an anti-aging agent. The amount of the anti-aging agent is preferably more than 1 part by mass per 100 parts by mass of the rubber component, and preferably less than 10 parts by mass as the upper limit.

[0161] While not particularly limited, the following are examples of anti-aging agents: naphthylamine-based anti-aging agents such as phenyl-α-naphthylamine; diphenylamine-based anti-aging agents such as octylated diphenylamine and 4,4'-bis(α,α'-dimethylbenzyl)diphenylamine; N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD), N,N'-bis(1,4-dimethylpentyl)-p-phenylenediamine (77PD), N,N'-diphenyl-p-phenylenediamine (DPPD), and N,N'-ditril-p-phenylenediamine. Examples include p-phenylenediamine-based antioxidants such as amines (DTPD), N-isopropyl-N'-phenyl-p-phenylenediamine (IPPD), and N,N'-di-2-naphthyl-p-phenylenediamine (DNPD); quinoline-based antioxidants such as polymers of 2,2,4-trimethyl-1,2-dihydroquinoline; monophenol-based antioxidants such as 2,6-di-t-butyl-4-methylphenol and styrenated phenol; and bis, tris, and polyphenol-based antioxidants such as tetrakis-[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane. Among these, p-phenylenediamine-based antioxidants and quinoline-based antioxidants are preferred, and polymers of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine and 2,2,4-trimethyl-1,2-dihydroquinoline are more preferred. These may be used individually or in combination of two or more.

[0162] Commercially available products include those from companies such as Seiko Chemical Co., Ltd., Sumitomo Chemical Co., Ltd., Ouchi Shinko Chemical Industry Co., Ltd., and Flexis.

[0163] (e) Processing aids The rubber composition may contain processing aids. Examples of processing aids include metal salts (compounds in which the hydrogen atoms of an acid are replaced by metal ions), fatty acid amides, amide esters, and fatty acid esters. These may be used alone or in combination of two or more. Among these, metal salts and fatty acid amides are preferred, and metal salts are more preferred.

[0164] Examples of metals used in metal salts include alkali metals such as potassium and sodium, and alkaline earth metals such as calcium and barium. Magnesium, zinc, nickel, and molybdenum can also be used. Among these, alkali metals are preferred.

[0165] Acids used in metal salts include fatty acids such as lauric acid, myristic acid, and palmitic acid. Boric acid, carbonic acid, hydrochloric acid, nitric acid, and sulfuric acid can also be used.

[0166] Commercially available processing aids include products from companies such as Kishida Chemical Co., Ltd., Ken-ei Pharmaceutical Co., Ltd., Structol, and Performance Additives.

[0167] The content of the processing aid is preferably 0.5 parts by mass or more, and more preferably 1 part by mass or more, per 100 parts by mass of the rubber component. As an upper limit, for example, it is preferably 6 parts by mass or less, and more preferably 4 parts by mass or less.

[0168] (H) Lubricant (Stearic Acid) The rubber composition may contain a lubricant. Fatty acid derivative-based lubricants such as stearic acid are preferably used. Conventional known stearic acid products can be used; specifically, products from companies such as NOF Corporation, NOF Corporation, Kao Corporation, Fujifilm Wako Pure Chemical Industries Ltd., and Chiba Fatty Acid Co., Ltd. can be used. Furthermore, products such as Structol WB16 manufactured by Structol Corporation can also be used.

[0169] The stearic acid content is preferably more than 0.5 parts by mass per 100 parts by mass of rubber component, and preferably less than 10.0 parts by mass as the upper limit.

[0170] (t) Zinc oxide The rubber composition may contain zinc oxide. The zinc oxide content is preferably more than 0.5 parts by mass per 100 parts by mass of the rubber component, and preferably less than 10 parts by mass as the upper limit. Conventional known zinc oxides can be used, such as products from Mitsui Mining & Smelting Co., Ltd., Toho Zinc Co., Ltd., Hakusui Tech Co., Ltd., Seido Chemical Industry Co., Ltd., and Sakai Chemical Industry Co., Ltd.

[0171] (h) Crosslinking agents and vulcanization accelerators The rubber composition preferably contains a crosslinking agent such as sulfur. The crosslinking agent content is preferably more than 0.1 parts by mass per 100 parts by mass of the rubber component, and preferably less than 10.0 parts by mass as the upper limit. The sulfur content refers to the amount of pure sulfur, and if insoluble sulfur is used, it refers to the content excluding the oil content.

[0172] Examples of sulfur commonly used in the rubber industry include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersible sulfur, and soluble sulfur. These may be used individually or in combination of two or more types.

[0173] For sulfur, products from companies such as Tsurumi Chemical Industries, Karuizawa Sulfur Co., Ltd., Shikoku Chemicals Co., Ltd., Flexis Co., Ltd., Nippon Dry Distillation Co., Ltd., and Hosoi Chemical Industries, Ltd. can be used.

[0174] Other crosslinking agents besides sulfur may be used. Specifically, for example, sulfur-containing vulcanizing agents such as Takkirol V200 from Taoka Chemical Industries, Ltd., DURALINK HTS (1,6-hexamethylene-dithiosulfate sodium dihydrate) from Flexis, and KA9188 (1,6-bis(N,N'-dibenzylthiocarbamoyldithio)hexane: hybrid crosslinking agent) from Lanxess, as well as organic peroxides such as dicumyl peroxide, can be used.

[0175] Furthermore, the rubber composition preferably contains a vulcanization accelerator. The amount of vulcanization accelerator is preferably more than 0.3 parts by mass per 100 parts by mass of the rubber component, and preferably less than 10.0 parts by mass as the upper limit.

[0176] Examples of vulcanization accelerators include thiazole-based vulcanization accelerators such as 2-mercaptobenzothiazole, di-2-benzothiazolyl disulfide, and N-cyclohexyl-2-benzothiadylsulfenamide; 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-benzothiazolesulfenamide, N-oxyethylene-2-benzothiazolesulfenamide, N-oxyethylene-2-benzothiazolesulfenamide, and N,N'-diisopropyl-2-benzothiazolesulfenamide; and guanidine-based vulcanization accelerators such as diphenylguanidine, diortotrilguanidine, and orthotrilbiguanidine. These can be used individually or in combination of two or more.

[0177] (Ri) Others In addition to the components described above, the rubber composition may also contain additives commonly used in the tire industry, such as organic fillers like cellulose fibers and organic peroxides, as needed. The content of these additives is, for example, more than 0.1 parts by mass and less than 50 parts by mass per 100 parts by mass of the rubber component.

[0178] In this disclosure, among the materials described above, various materials containing carbon atoms (for example, rubber, oil, resin, vulcanization accelerator, antioxidant, surfactant, etc.) may be derived from atmospheric carbon dioxide. As a method for obtaining the formulations of this disclosure from carbon dioxide, carbon dioxide may be converted directly, or methane obtained through a methanation process in which methane is synthesized from carbon dioxide may be converted.

[0179] (2) Preparation of rubber composition The rubber composition can be produced by a general method, for example, a manufacturing method that includes a base mixing step in which a rubber component is mixed with a filler such as silica, and a finish mixing step in which the mixture obtained in the base mixing step is mixed with a crosslinking agent.

[0180] Mixing can be carried out using known (closed) mixers such as Banbury mixers, kneaders, and open roll mixers.

[0181] The mixing temperature in the base mixing process is preferably, for example, above 50°C, and preferably below 200°C as the upper limit. The mixing time is preferably, for example, above 30 seconds, and preferably below 30 minutes as the upper limit. In the base mixing process, in addition to the above components, compounding agents conventionally used in the rubber industry, such as softeners such as oils, stearic acid, zinc oxide, antioxidants, waxes, vulcanization accelerators, etc., may be added and mixed as needed.

[0182] In the final mixing step, the mixture obtained in the base mixing step is mixed with the crosslinking agent. The mixing temperature in the final mixing step is preferably above room temperature, and preferably less than 80°C. The mixing time is preferably more than 1 minute, and preferably less than 15 minutes. In the final mixing step, in addition to the above components, a vulcanization accelerator, zinc oxide, etc., may be added and mixed as needed.

[0183] The rubber composition obtained as described above can then be molded into a tread by extruding it into a predetermined shape.

[0184] 3. Tire manufacturing The tire according to this embodiment can be manufactured by conventional methods. First, the rubber composition obtained above is molded into a predetermined shape to produce a tread. Next, it is combined with other rubber components on a tire molding machine to produce an unvulcanized tire.

[0185] Specifically, an inner liner as a component to ensure the airtightness of the tire, a carcass as a component to withstand the load, impact, and air pressure of the tire, and belt members, bands, etc. as components to tightly fasten the carcass and increase the rigidity of the tread are wound around a molding drum, both ends of the carcass are fixed to both side edges, and a bead portion is placed as a component to fix the tire to the rim, and after forming it into a toroid shape, the tread is bonded to the center of the outer circumference and the sidewall is bonded to the radially outward side to form the side portion, thereby producing an unvulcanized tire.

[0186] Subsequently, the unvulcanized tire produced as described above is heated and pressurized in a vulcanizing machine to obtain a tire. The vulcanization process can be carried out by applying known vulcanization methods. The vulcanization temperature is preferably, for example, above 120°C, and preferably below 200°C as the upper limit. The vulcanization time is preferably, for example, above 5 minutes, and preferably below 15 minutes as the upper limit.

[0187] As mentioned earlier, the resulting tire utilizes the combined effects of using PET cord as a band cord and reducing the intersection angle of the belt cord, which is composed of fewer filaments, by appropriately controlling (Dba / Dbr). This allows for an overall improvement in fuel efficiency, high-speed durability, and handling stability.

[0188] Furthermore, the tire relating to this disclosure can be suitably used as a passenger car tire, a large passenger car tire, a large SUV tire, a truck / bus tire, a motorcycle tire, a racing tire, a winter tire such as a studless tire, an all-season tire, a run-flat tire, etc., and is particularly preferred as a passenger car tire. [Examples]

[0189] The following examples (implementations) are considered preferable for implementation, but the scope of the present invention is not limited to these examples.

[0190] We examined a tire (tire size: 215 / 60R16) consisting of a tread molded from the various compound materials listed below, as well as tire components such as bands and belts. The results calculated based on the evaluation methods described later regarding fuel efficiency, high-speed durability, and handling stability are shown at the bottom of Tables 2 and 3.

[0191] 1. Preparation of rubber composition A rubber composition for the tread is prepared using the following compounding materials.

[0192] (1) Compounding materials (a) Rubber component (i) SBR: SBR1502 manufactured by ENEOS Material Co., Ltd. (Styrene content: 23.5% by mass) (b)NR:TSR20 (H) BR: BR150B manufactured by Ube Industries, Ltd. (Cis content 96% by mass)

[0193] (b) Compounding materials other than rubber components (i) Carbon Black: Show Black N220 manufactured by Cabot Japan (N2SA:111m 2 / g) (b) Silica: UltraSil VN3 manufactured by Evonik Industries (N2SA:175m 2 / g) (h) Silane coupling agent: Si266 manufactured by Evonik Industries (Bis(3-triethoxysilylpropyl) disulfide) (ii) Oil: H&R Vivatec 500 (TDAE, aromatic mineral oil) (e) Resin: SYLVARES SA85 manufactured by Arizona Chemical Corporation (α-methylstyrene resin: copolymer of α-methylstyrene and styrene, softening point 85°C) (H) Wax: Ozoace 0355 manufactured by Nippon Seiro Co., Ltd. (T) Anti-aging agent: Antigen 6C manufactured by Sumitomo Chemical Co., Ltd. (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine) (Chi) Stearic acid: NOF Corporation's bead stearic acid "Tsubaki" (R) Zinc oxide: Zinc oxide No. 1 manufactured by Mitsui Mining & Smelting Co., Ltd. (Nu) Sulfur: HK-200-5 (powdered sulfur) manufactured by Hosoi Chemical Industry Co., Ltd. (L) Vulcanization accelerator: Noxella D manufactured by Ouchi Shinko Chemical Industry Co., Ltd. (N,N'-diphenylguanidine)

[0194] (2) Preparation of rubber composition for tread Based on each of the formulations A to C shown in Table 1, the materials other than sulfur and vulcanization accelerator were kneaded for 5 minutes at 150°C using a 1.7L Banbury mixer manufactured by Kobe Steel, Ltd. to obtain a kneaded product.

[0195] Next, sulfur and a vulcanization accelerator are added to the mixture, and it is kneaded using an open roll at 80°C for 5 minutes to obtain tread rubber compositions A to C.

[0196] 2. Molding of tire components (tread, band, belt) (1) Tread molding Next, the rubber composition obtained above is used to form a tread into a predetermined shape.

[0197] (2) Forming the band In parallel, the band cords shown in Tables 2 and 3 are topped with the predetermined rubber composition for bands to form each band.

[0198] (3) Forming of the belt Similarly, each belt is formed by topping each belt cord shown in Tables 2 and 3 with a predetermined belt rubber composition.

[0199] 3. Tire manufacturing Next, the treads, bands, and belts obtained above are bonded together with other tire components to form an unvulcanized tire, which is then press-vulcanized for 10 minutes under conditions of 170°C to produce the test tires for Examples 1 to 5 and Comparative Examples 1 to 6.

[0200] 4. Performance evaluation test (1) Fuel efficiency evaluation Using a rolling resistance tester, the rolling resistance coefficient (RRC) of each test tire is measured when it travels on a drum at a speed of 80 km / h under the following conditions. Rim used: 16×6.5J Internal pressure: 210kPa Load: 4.6kN

[0201] Next, the RRC in Comparative Example 1 is set to 100 and indexed based on the following formula to evaluate fuel efficiency. A higher value indicates lower rolling resistance and superior fuel efficiency. Fuel efficiency evaluation = [(RRC of Comparative Example 1) / (RRC of the test tire)] × 100

[0202] (2) High-speed durability evaluation Each test tire is mounted on a rim (size = 16 x 6.5J), inflated with air to adjust the internal pressure to 210 kPa, and then mounted on a drum running test machine. A high-speed durability test is then conducted in accordance with the method specified in JIS D4230:1998, and the time until the tire is damaged is measured.

[0203] Next, the results in Comparative Example 1 are set to 100 and indexed based on the following formula to serve as an indicator of high-speed durability for evaluation. A higher numerical value indicates a longer time until damage occurs and superior high-speed durability. High-speed durability evaluation = [(Results of test tire) / (Results of comparative example 1)] × 100

[0204] (3) Evaluation of handling stability Each vehicle (a domestically produced FR car with a 2000cc engine) equipped with a test tire on all wheels is driven by one test driver around a dry asphalt test course at a speed of 100 km / h. Then, each of the 20 test drivers subjectively evaluates the handling stability during the drive on a scale of 1 to 5 points (higher numbers indicate better performance) based on characteristics such as steering response, rigidity, and grip, and the total score is calculated.

[0205] Next, the results in Comparative Example 1 are set to 100 and indexed according to the following formula to evaluate handling stability. A higher numerical value indicates better handling stability at high speeds. Handling stability evaluation = [(Results for test tires) / (Results for comparative example 1)] × 100

[0206] (4) Overall performance evaluation Then, (1), (2), and (3) are added together to obtain the overall performance evaluation.

[0207] [Table 1]

[0208] [Table 2]

[0209] [Table 3]

[0210] Although the present disclosure has been described above based on embodiments, the present disclosure is not limited to the embodiments described above. Various modifications can be made to the embodiments described above within the same and equivalent scope as the present disclosure.

[0211] The present invention (1) is, A carcass equipped with a carcass cord, A belt cord is provided, and the belt is provided on the radially outer side of the carcass, A tire comprising a band code and provided with a band on the outer side in the tire radius direction of the belt, and a tread provided on the outer side in the tire radius direction of the band, wherein the band code contains polyethylene terephthalate fibers, when the tread is viewed in a plan view in the tire diameter direction, the crossing angle, which is the smaller of the angles formed by the tire circumferential direction and the longitudinal direction of the belt code, is more than 0 degrees and less than 25 degrees, the belt code is composed of one or more and four or less filaments, the ratio (Dba / Dbr) of the band code diameter Dba (mm) to the belt code diameter Dbr (mm) satisfies the following formula (1): Occasionally, The structure of the aforementioned belt cord is one of the following: 1x2 structure, 1x3 structure, 1x4 structure, or 2+2 structure. characterized in that it is a tire. 0.5 < Dba / Dbr < 1.8 (1)

[0212] The present invention (2) is characterized in that (Dba / Dbr) satisfies the following formula (2), and is the tire according to the present invention (1). 0.9 < Dba / Dbr < 1.7 (2)

[0214] The present invention ( 3 ) is characterized in that the belt code is made of steel, and is the tire according to the present invention (1) or the present invention (2).

[0215] The present invention ( 4 ) is characterized in that the crossing angle is less than 22 degrees, and is the tire according to the present invention (1) or the present invention (2).

[0216] The present invention ( 5 ) is characterized in that the band code diameter is more than 0.2 mm and less than 0.8 mm, and is the tire according to the present invention (1) or the present invention (2).

[0217] The present invention( 6 ) is characterized in that the rubber composition forming the tread contains more than 25 parts by mass of isoprene rubber in 100 parts by mass of the rubber component, and is the tire according to the present invention (1) or the present invention (2).

[0218] The present invention( 7 ) is characterized in that the isoprene rubber is natural rubber, and is the tire according to the present invention( 6 ).

[0219] The present invention( 8 ) is characterized in that the rubber composition forming the tread contains more than 60 parts by mass of silica with respect to 100 parts by mass of the rubber component, and is the tire according to the present invention (1) or the present invention (2).

[0220] The present invention( 9 ) is characterized in that the particle diameter (average primary particle diameter) of the silica is more than 8 nm, and is the tire according to the present invention( 8 ).

[0221] The present invention( 10 ) is characterized in that the acetone extraction amount in the rubber composition forming the tread is more than 10% by mass, and is the tire according to the present invention (1) or the present invention (2).

[0222] The present invention( 11 ) is characterized in that the polyethylene terephthalate fiber is a sustainable polyethylene terephthalate fiber, and is the tire according to the present invention (​​​​​​​​​​​ This invention ( 13 )teeth, The rubber composition forming the tread contains carbon black, The carbon black is characterized by being sustainable carbon black, as described in Invention (1) or Invention (2). These are the tires that are mounted on the vehicle.

[0225] This invention ( 14 )teeth, The tire is characterized in that the rubber composition forming the tread contains vegetable oil, and is the tire according to present invention (1) or present invention (2). [Explanation of symbols]

[0226] 1 tire 2 tread 3 Sidewall 4 Chafers 5 Beads 6. Inner Liner 7 Carcass 8 belts 9 Filler 10 bands CL tire equatorial plane

Claims

1. A carcass equipped with a carcass cord, A belt cord is provided, and the belt is provided on the radially outer side of the carcass, A band cord is provided, and the band is provided on the radially outer side of the belt in the tire direction, A tire comprising a tread provided on the radially outer side of the band, The aforementioned band cord contains polyethylene terephthalate fibers, When the tread is viewed in plan in the radial direction of the tire, the smaller of the angles formed by the circumferential direction of the tire and the longitudinal direction of the belt cord, which is the intersection angle, is greater than 0 degrees and less than 25 degrees. The aforementioned belt cord is composed of one to four filaments. The ratio of the band cord diameter Dba (mm) to the belt cord diameter Dbr (mm) (Dba / Dbr) satisfies the following equation (1): A tire characterized in that the structure of the belt cord is one of a 1x2 structure, a 1x3 structure, a 1x4 structure, or a 2+2 structure. 0.5<Dba / Dbr<1.8 (1 set)

2. The tire according to claim 1, characterized in that the (Dba / Dbr) satisfies the following (2 equations). 0.9<Dba / Dbr<1.7 (2 formulas)

3. The tire according to claim 1 or 2, characterized in that the belt cord is made of steel.

4. The tire according to claim 1 or 2, characterized in that the aforementioned intersection angle is less than 22 degrees.

5. The tire according to claim 1 or 2, characterized in that the band cord diameter is greater than 0.2 mm and less than 0.8 mm.

6. The tire according to claim 1 or 2, characterized in that the rubber composition forming the tread contains more than 25 parts by mass of isoprene-based rubber in 100 parts by mass of rubber component.

7. The tire according to claim 6, characterized in that the isoprene-based rubber is natural rubber.

8. The tire according to claim 1 or 2, characterized in that the rubber composition forming the tread contains more than 60 parts by mass of silica per 100 parts by mass of rubber component.

9. The tire according to claim 8, characterized in that the particle size (average primary particle size) of the silica is greater than 8 nm.

10. The tire according to claim 1 or 2, characterized in that the amount of acetone extracted in the rubber composition forming the tread is more than 10% by mass.

11. The tire according to claim 1 or 2, characterized in that the polyethylene terephthalate fiber is a sustainable polyethylene terephthalate fiber.

12. The tire according to claim 8, characterized in that the silica is sustainable silica.

13. The tire according to claim 1 or 2, characterized in that the rubber composition forming the tread contains carbon black, and the carbon black is sustainable carbon black.

14. The tire according to claim 1 or 2, characterized in that the rubber composition forming the tread contains vegetable oil.

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