Tire

Abstract

This invention relates to a tire having a tread portion, wherein: a groove is formed in a contact portion on the surface of the tread portion, the groove including an opening facing the surface of the tread portion and a groove bottom, and the groove having a width of less than 2 mm and a depth of less than 20 mm; in a plan view of the surface of the tread portion, the opening intersects with the groove bottom; in a plan view of the surface of the tread portion, the ratio X of the area of ​​the intersection of the opening portion and the groove bottom to the area of ​​the opening portion is less than 95%; the tread portion is formed of a rubber composition comprising rubber components, silica, and carbon black, wherein the ratio Y of the silica content (parts by mass) to the carbon black content (parts by mass) is greater than 50%, and further, X / Y < 1.5; the object of this invention is to further improve late-wear grip performance.

Description

Technical Field

[0001] This invention relates to a tire. Background Technology

[0002] In recent years, there has been a growing demand for improving tire grip performance during tread wear (late-wear grip performance), and various technologies have been proposed to achieve this (e.g., Patent Document 1). However, these technologies are still insufficient and require further improvement. Existing technical documents

[0003] [Patent Literature] [Patent Document 1] JP 2022-19300 A Summary of the Invention

[0004] [The problem the invention aims to solve] In view of the above problems, the present invention aims to further improve the grip performance of tires in the later stages of wear.

[0005] [Solutions for solving the problem] The present invention is; A tire having a tread section, A groove is formed on the contact portion of the surface of the tread portion. The groove has an opening facing the surface of the tread portion and a bottom. The width of the groove is less than 2 mm and the depth is less than 20 mm. When the surface of the tread portion is viewed in a plan view, the opening intersects with the bottom of the groove. When the surface of the tread is viewed from above, the ratio X of the area of ​​the intersection of the opening and the bottom of the groove to the area of ​​the opening is 95% or less. The tread portion is formed of a rubber composition comprising rubber components, silica, and carbon black, wherein the ratio Y of silica content (parts by mass) to carbon black content (parts by mass) is greater than 50%, and X / Y < 1.5.

[0006] [The effects of the invention] According to the present invention, the grip performance of tires in the later stages of wear can be further improved. Attached Figure Description

[0007] [ Figure 1 [A] schematic perspective view and (b) schematic plan view of grooves provided in a tire according to the invention are shown. Detailed Implementation

[0008] [1] Features of the tire according to the present invention First, the features of the tire according to the present invention will be described.

[0009] 1. Overview The tire according to the invention is a tire having a tread, and grooves (hereinafter also referred to as "sipes") with a width of 2 mm or less and a depth of 20 mm or less are formed on the contact portion of the tread surface. These grooves have an opening facing the tread surface and a groove bottom. In these sipes, when the tread surface is viewed from above, the opening intersects with the groove bottom, and when the tread surface is viewed from above, the ratio X of the area of ​​the intersection of the opening and the groove bottom to the area of ​​the opening is 95% or less. Furthermore, the tread is formed of a rubber composition comprising rubber components, silica, and carbon black, and the ratio Y of the silica content (parts by mass) to the carbon black content (parts by mass) is greater than 50%. Additionally, the ratio of X to Y (X / Y) is less than 1.5.

[0010] As will be discussed later, these features enable improved tire grip performance in the later stages of wear.

[0011] 2. The mechanism by which the effect is manifested in the tire according to the present invention The mechanism by which the above-mentioned effects are manifested in the tire according to the present invention is believed to be as follows.

[0012] (1) Shape of the fetal face As described above, in the tire according to the invention, sipes are formed on the contact patch of the tread surface, each sipe having an opening facing the tread surface and a groove bottom. When viewed from above, these sipes are formed in a shape where the opening intersects the groove bottom, i.e., a twisted shape.

[0013] By incorporating these twisted sipes on the tread surface, it is believed that tire wear can be properly controlled, ensuring tread rigidity even in the later stages of wear and improving grip performance in the later stages of wear.

[0014] At this point, if a sufficiently twisted shape is not formed, that is, if the area of ​​the intersection (overlap) between the opening and the bottom of the groove is not small enough, the grip performance in the later stages of wear cannot be sufficiently improved. Therefore, in this invention, when the surface of the tread is observed in a plan view, the area B (mm²) of the intersection between the opening and the bottom of the groove is considered to be... 2 ) relative to the area A (mm²) of the opening 2The ratio X (= B / A) is set to 95% or less. More preferably, the ratio X is 90% or less, even more preferably 80% or less, even more preferably 70% or less, even more preferably 60% or less, and even more preferably 50% or less. As a lower limit, for example, it is preferably 1% or more, more preferably 5% or more, even more preferably 10% or more, even more preferably 20% or more, even more preferably 30% or more, and even more preferably 40% or more.

[0015] (2) Rubber composition for forming the tread area In this invention, the tread portion is formed of a rubber composition comprising rubber components, silica and carbon black, wherein the ratio Y (=Si / CB) of silica content (Si; parts by mass) to carbon black content (CB; parts by mass) is greater than 50%.

[0016] By including reinforcing agents (i.e., carbon black and silica) in the rubber composition, it is believed that tire wear can be properly controlled even in the later stages of wear, ensuring tread rigidity and improving grip performance in the later stages of wear.

[0017] Unlike carbon black, silica contains hydrated water and functional groups on its surface, which capture ozone, improving the ozone resistance of tires, thereby enhancing their durability and ensuring adequate abrasion resistance. Therefore, in this invention, the ratio Y (=Si / CB) of silica content (Si; parts by mass) to carbon black content (CB; parts by mass) is set to be greater than 50%. More preferably, the ratio Y is 70% or more, further preferably 100% or more, further preferably 130% or more, further preferably 160% or more, and further preferably 200% or more. As an upper limit, for example, it is preferably 500% or less, more preferably 460% or less, further preferably 420% or less, further preferably 380% or less, further preferably 340% or less, and further preferably 300% or less.

[0018] (3) X / Y Furthermore, in this invention, the ratio of X to Y (X / Y) is controlled to be less than 1.5. This allows the effects of the sipes and the rubber composition to work together to more appropriately control tire wear, ensuring tread rigidity and improving grip even in the later stages of wear. The ratio X / Y is more preferably 1.4 or less, more preferably 1.2 or less, more preferably 1.0 or less, more preferably 0.8 or less, and more preferably 0.7 or less. As a lower limit, it is preferably 0.01 or more, more preferably 0.03 or more, more preferably 0.10 or more, more preferably 0.15 or more, more preferably 0.20 or more, more preferably 0.25 or more, and more preferably 0.32 or more.

[0019] [2] A more preferred embodiment of the tire according to the present invention The tire according to the present invention can achieve greater effects by adopting the following embodiments.

[0020] 1. Multi-layered tread In the tire according to the invention, the preferred thickness of the tread is 10 mm or more and 20 mm or less. More preferably, it is 12 mm or more and 18 mm or less, and even more preferably, it is 14 mm or more and 16 mm or less.

[0021] The tread can be formed from a single layer of tread rubber, but it can also be made from two layers by setting a base rubber layer inside the tread rubber layer, or it can be made from three or even four or more layers.

[0022] In this case, the thickness of the tread rubber layer across the entire tire tread is preferably 10% or more, more preferably 30% or more, even more preferably 50% or more, and even more preferably 70% or more. This allows sufficient friction to be generated between the tread surface and the road surface even in the later stages of wear, and is considered to further improve grip performance in the later stages of wear.

[0023] The tread thickness mentioned above refers to the thickness of the tread on the equatorial plane of the tire in its 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 laminate of multiple rubber compositions (as described below), it refers to the total thickness of those layers.

[0024] In this invention, the tread portion refers to the component that forms the contact surface of the tire, specifically the portion located radially outward of components containing fibrous materials, such as the tire carcass, belt layer, and belt reinforcement layer. Furthermore, the thickness of the tread portion can be measured by cutting a cross-section of the tire radially and aligning the bead portion with the standard rim width.

[0025] In the above description, "standard rim" refers to a rim defined for each type of tire within a standard system that includes the standard upon which the tire is based. For example, in the case of JATMA (Japan Motor Vehicle Tire Association), it is the standard rim in the applicable size described in the *JATMA YEAR BOOK*; in the case of ETRTO (European Tire and Rim Technology Organization), it is the "Measuring Rim" described in the *STANDARDS MANUAL*; and in the case of TRA (Tire and Rim Association), it is the "Design Rim" described in the *YEAR BOOK*. References are made in the order of JATMA, ETRTO, and TRA, and if an applicable size is available at the time of reference, that standard is followed. In the case of tires not specified in the standard, it refers to a rim that can be assembled and maintain internal pressure, i.e., a rim that does not cause air leakage between the rim and the tire, and has the smallest rim diameter followed by the narrowest rim width.

[0026] 2. Aspect Ratio Aspect ratio is the ratio of a tire's section height to its section width. A lower aspect ratio (lower section height) is generally considered to improve grip. On the other hand, if the aspect ratio becomes too low, it may lead to a decrease in ride comfort.

[0027] Taking these points into consideration, in the tire according to the invention, the aspect ratio is preferably 30% or more and 60% or less, more preferably 40% or more and 50% or less.

[0028] The above aspect ratio (%) can be calculated using the tire's section height Ht (mm), section width Wt (mm), tire outer diameter Dt (mm), and rim diameter R (mm) when the internal pressure is 250 kPa, using the following formula.

[0029] Aspect ratio (%) = (Ht / Wt) × 100 (%) Ht = (Dt -R) / 2 3. Styrene content in SBR In the rubber composition constituting the tread of the tire according to the invention, when styrene-butadiene rubber (SBR) with a low styrene content (by mass) is used as the rubber component, tiny styrene domains can be formed within the rubber matrix, which is believed to further improve late-wear grip performance.

[0030] Specifically, SBR with a styrene content of 25% by mass or less is preferred. More preferably, the styrene content is 20% by mass or less, and even more preferably 15% by mass or less. On the other hand, the lower limit of the styrene content is preferably 4% by mass or more, more preferably 5% by mass or more, and even more preferably 6% by mass or more.

[0031] The term "SBR" with a styrene content of 25% by mass or less indicates that when the rubber composition contains only one type of styrene-containing polymer (SBR), the styrene content is 25% by mass or less. When the rubber composition contains multiple types of styrene-containing polymers (SBR), the styrene content is calculated as the sum of the products of the styrene content (by mass) in each polymer and the mixing amount (by mass) of that polymer in 100 parts by mass of the rubber composition.

[0032] More specifically, when 100 parts by mass of rubber composition contains SBR1 (X1 parts by mass) with S1% styrene and SBR2 (X2 parts by mass) with S2% styrene, the amount of styrene calculated by the formula {(S1×X1) + (S2×X2)} / (X1+X2) is less than 25% by mass.

[0033] In addition, the amount of styrene in the rubber composition after acetone extraction can also be calculated by using solid-state nuclear magnetic resonance (solid-state NMR) or Fourier transform infrared spectrophotometer (FTIR) to determine the amount of styrene contained in the rubber component after acetone extraction.

[0034] 4. Silica particle size As described above, in this invention, the rubber composition forming the tread portion contains silica, and in this case, the particle size (average primary particle size) of the silica is preferably 17 nm or less.

[0035] The average primary particle size can be calculated by directly observing the silica extracted from the rubber composition cut from the tire using an electron microscope (TEM), calculating the equivalent cross-sectional diameter from the area of ​​each silica particle obtained, and then determining the average value.

[0036] 5. Resin component content In this invention, preferably, the rubber composition forming the tread portion comprises a resin component.

[0037] By including resin components in the rubber composition, the adhesive properties of the resin components can maintain grip on the road surface, thereby further improving grip performance in the later stages of wear.

[0038] Examples of preferred resin components include rosin resins, styrene resins, coumarone resins, terpene resins, C5 resins, C9 resins, C5C9 resins, and acrylic resins, as described below. Among these, terpene resins are more preferred.

[0039] [3] Implementation The present invention will now be described in detail based on its implementation methods.

[0040] 1. Groove pattern Figure 1 A schematic perspective view (a) and a schematic plan view (b) are shown illustrating grooves formed in a tire according to the invention. Figure 1 The image shows a sipe pattern in a contact patch area of ​​the tire tread, where 1 is the contact patch, 2 is the opening, and 3 is the bottom of the groove. S is the intersection of the opening and the bottom of the groove.

[0041] like Figure 1 As shown in (a), the groove pattern is twisted from the opening 2 to the bottom 3 of the groove, and when viewed from above, an intersection S is formed where the opening 2 and the bottom 3 of the groove overlap, as shown in (a). Figure 1 As shown in (b).

[0042] Furthermore, as described above, by setting the ratio of the area of ​​the intersection S to the area of ​​the opening 2 to 95% or less, the grip performance in the later stages of wear can be significantly improved.

[0043] 2. Rubber composition In this embodiment, the rubber composition constituting the tread can be obtained by compounding various compounding materials (e.g., rubber components, reinforcing materials, antioxidants, oils, resin materials, and antioxidants).

[0044] (1) Mixing materials (a) Rubber composition There are no particular limitations on the rubber composition. For example, diene rubbers such as natural rubber (NR), styrene-butadiene rubber (SBR), butadiene rubber (BR), isoprene rubber (IR), acrylonitrile-butadiene rubber (NBR), chloroprene rubber (CR), and butyl rubber (IIR) can be used. These can be used alone or in combination of two or more, and in this invention, a combination of SBR and isoprene rubber is preferred.

[0045] (a-1) SBR The weight-average molecular weight of the SBR is, for example, greater than 100,000 and less than 2,000,000. The styrene content of the SBR is preferably greater than 5% by mass, more preferably greater than 10% by mass, and even more preferably greater 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 the SBR (the amount of 1,2-bonded butadiene units) is preferably greater than 5% by mass, more preferably greater than 10% by mass, and even more preferably greater 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 the SBR (measurement of styrene and vinyl content) can be performed, for example, using an instrument from the JNM-ECA series manufactured by Nippon Electronics Corporation.

[0046] There are no particular limitations on SBR; for example, emulsion-polymerized styrene-butadiene rubber (E-SBR) and solution-polymerized styrene-butadiene rubber (S-SBR) can be used. The SBR can be unmodified or modified. Alternatively, hydrogenated SBR, obtained by hydrogenating the butadiene portion of the SBR, can be used. Hydrogenated SBR can be obtained by subsequently hydrogenating the BR portion of the SBR, or by copolymerizing styrene, ethylene, and butadiene to obtain a similar structure.

[0047] The modified SBR can be any SBR having functional groups that interact with fillers such as silica. Examples include: end-modified SBRs, wherein at least one end of the SBR is modified with a compound (modifier) ​​having said functional groups (end-modified SBR with said functional groups at the end); main-chain modified SBRs having said functional groups in the main chain; main-chain end-modified SBRs having said functional groups in the main chain and at least one end (e.g., SBR having said functional groups in the main chain and at least one end modified with said modifier); and end-modified SBRs modified (coupled) with a polyfunctional compound having two or more epoxy groups in the molecule and to which hydroxyl or epoxy groups are introduced.

[0048] Examples of functional groups include amino, amide, silyl, alkoxysilyl, isocyanate, imino, imidazo, urea, ether, carbonyl, oxycarbonyl, mercapto, thioether, dithioether, sulfonyl, sulfinyl, thiocarbonyl, ammonium, imide, hydrazine, azo, diazo, carboxyl, nitrile, pyridinyl, alkoxy, hydroxyl, oxygen, and epoxy groups. These functional groups may have substituents.

[0049] As a modified SBR, for example, an SBR modified with a compound (modifier) ​​represented by the following formula can be used.

[0050] [Chemical Formula 1]

[0051] In the formula, R 1 R 2 and R 3 Same or different, indicating alkyl, alkoxy, silyloxy, acetal, carboxyl (-COOH), mercapto (-SH) or their derivatives. R 4 and R 5 Same or different, indicating hydrogen atoms or alkyl groups. R 4 and R 5 It can combine with nitrogen atoms to form a ring structure. "n" represents an integer.

[0052] As a modified SBR modified with a compound (modifier) ​​represented by the above formula, an SBR whose polymerization end (active end) of solution polymerized styrene-butadiene rubber (S-SBR) has been modified with a compound represented by the above formula (e.g., the modified SBR described in JP-A-2010-111753) can be used.

[0053] R 1 R 2 and R 3 Preferably, it is an alkoxy group (preferably an alkoxy group having 1 to 8 carbon atoms, more preferably an alkoxy group having 1 to 4 carbon atoms). R 4 and R 5 Preferably an alkyl group (preferably an alkyl group having 1 to 3 carbon atoms). "n" is preferably 1 to 5, more preferably 2 to 4, and even more preferably 3. When R 4 and R 5 When combined with a nitrogen atom to form a ring structure, it is preferably a 4- to 8-membered ring. Alkoxy groups also include cycloalkoxy groups (such as cyclohexyloxy) and aryloxy groups (such as phenoxy and benzyloxy).

[0054] Specific examples of modifiers include: 2-dimethylaminoethyltrimethoxysilane, 3-dimethylaminopropyltrimethoxysilane, 2-dimethylaminoethyltriethoxysilane, 3-dimethylaminopropyltriethoxysilane, 2-diethylaminoethyltrimethoxysilane, 3-diethylaminopropyltrimethoxysilane, 2-diethylaminoethyltriethoxysilane, and 3-diethylaminopropyltriethoxysilane. These can be used alone or in combination of two or more.

[0055] As a modified SBR, modified SBRs using the following compounds (modifiers) can also be used. Examples of modifiers include: Polyhydric alcohol polyglycidyl ethers, such as ethylene glycol diglycidyl ether, glycerol triglycidyl ether, trimethylolethane triglycidyl ether and trimethylolpropane triglycidyl ether; Polyglycidyl ethers of aromatic compounds having two or more phenolic groups, such as diglycidylated bisphenol A; Polyepoxides, such as 1,4-diglycidylbenzene, 1,3,5-triglycidylbenzene and polyepoxide-modified liquid polybutadiene; Tertiary amines containing epoxy groups, such as 4,4'-diglycidyl-diphenylmethylamine and 4,4'-diglycidyl-dibenzylmethylamine; Diglycidylamino compounds, such as diglycidylaniline, N,N'-diglycidyl-4-glycidyloxyaniline, diglycidyl-o-toluidine, tetraglycidyl-m-xylyldiamine, tetraglycidylaminodiphenylmethane, tetraglycidyl-p-phenylenediamine, diglycidylaminomethylcyclohexane, and tetraglycidyl-1,3-diaminomethylcyclohexane; Amino-containing acyl chlorides, such as bis-(1-methylpropyl)carbamoyl chloride, 4-morpholine carbamoyl chloride, 1-pyrrolidine carbamoyl chloride, N,N-dimethylcarbamoyl chloride, and N,N-diethylcarbamoyl chloride; Silane compounds containing epoxy groups, such as 1,3-bis-(glycidoxypropyl)-tetramethyldisiloxane and (3-glycidoxypropyl)-pentamethyldisiloxane; Silane compounds containing thioether groups, such as (trimethylsilyl)[3-(trimethoxysilyl)propyl] sulfide, (trimethylsilyl)[3-(triethoxysilyl)propyl] sulfide, (trimethylsilyl)[3-(tripropoxysilyl)propyl] sulfide, (trimethylsilyl)[3-(tributoxysilyl)propyl] sulfide, (trimethylsilyl)[3-(methyldimethoxysilyl)propyl] sulfide, (trimethylsilyl)[3-(methyldiethoxysilyl)propyl] sulfide, (trimethylsilyl)[3-(methyldipropoxysilyl)propyl] sulfide, (trimethylsilyl)[3-(methyldibutoxysilyl)propyl] sulfide; N-substituted aziridine compounds, such as ethyleneimine and propyleneimine; Alkoxysilanes, such as methyltriethoxysilane, N,N-bis(trimethylsilyl)-3-aminopropyltrimethoxysilane, N,N-bis(trimethylsilyl)-3-aminopropyltriethoxysilane, N,N-bis(trimethylsilyl)aminoethyltrimethoxysilane and N,N-bis(trimethylsilyl)aminoethyltriethoxysilane; (Thio)benzophenone compounds having an amino group and / or substituted amino groups, such as 4-N,N-dimethylaminobenzophenone, 4-N,N-di-tert-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; Benzaldehyde compounds having an amino group and / or substituted amino groups, such as 4-N,N-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, N-tert-butyl-2-pyrrolidone and N-methyl-5-methyl-2-pyrrolidone; N-substituted piperidinones, such as N-methyl-2-piperidinone, N-vinyl-2-piperidinone, and N-phenyl-2-piperidinone; and N-substituted lactams, such as N-methyl-ε-caprolactam, N-phenyl-ε-caprolactam, N-methyl-ω-laurolactam, N-vinyl-ω-laurolactam, N-methyl-β-propiolactam and N-phenyl-β-propiolactam; and N,N-bis-(2,3-epoxypropoxy)-aniline, 4,4-methylene-bis-(N,N-glycidylaniline), tri-(2,3-epoxypropyl)-1,3,5-triazine-2,4,6-trione, N,N-diethylacetamide, N-methylmaleimide, N,N-diethylurea, 1,3-dimethylethylurea, 1,3-divinylethylurea, 1,3-diethyl-2-imidazolinone, 1-methyl-3-ethyl-2-imidazolinone, 4-N,N-dimethylaminoacetophenone, 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.

[0056] As an SBR, for example, SBR manufactured and sold by companies such as Sumitomo Chemical Co., Ltd., ENEOS Materials Co., Ltd., Asahi Kasei Corporation, and Zeon Corporation can be used. SBR can be used alone or in combination of two or more types.

[0057] Of 100 parts by weight of the rubber component, the SBR content is preferably 35 parts by weight or more, more preferably 40 parts by weight or more, even more preferably 45 parts by weight or more, and even more preferably 50 parts by weight or more. As an upper limit, for example, it is preferably 65 parts by weight or less, more preferably 60 parts by weight or less, and even more preferably 55 parts by weight or less.

[0058] (a-2) Isoprene rubbers Examples of isoprene rubbers include natural rubber (NR), isoprene rubber (IR), modified NR, modified NR, and modified IR. NR is preferred due to its excellent strength.

[0059] For natural rubber (NR), those commonly used in the tire industry, such as SVR-L, SIR20, RSS#3, and TSR20, can be used. There are no particular restrictions on natural rubber (IR), and those commonly used in the tire industry, such as IR2200 manufactured by Zeon Corporation of Japan, can be used. Examples of modified NR include deproteinized natural rubber (DPNR) and high-purity natural rubber (UPNR). Examples of modified NR include epoxidized natural rubber (ENR), hydrogenated natural rubber (HNR), and grafted natural rubber. Examples of modified IR include epoxidized isoprene rubber, hydrogenated isoprene rubber, and grafted isoprene rubber. These can be used alone or in combination of two or more.

[0060] Of 100 parts by weight of the rubber component, the content of isoprene rubber is preferably 35 parts by weight or more, more preferably 40 parts by weight or more, even more preferably 45 parts by weight or more, and even more preferably 50 parts by weight or more. As an upper limit, for example, it is preferably 65 parts by weight or less, more preferably 60 parts by weight or less, and even more preferably 55 parts by weight or less.

[0061] (a-3) BR The rubber composition may contain BR as needed. 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 less than 98% by mass. 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.

[0062] There are no particular restrictions on the type of BR used; high cis content BR (cis content of 90% or more), low cis content BR, or BR containing isotactic polybutadiene crystals can be used. The BR can be unmodified or modified, and for example, a modified BR can be a BR modified using a compound (modifier) ​​represented by the following formula.

[0063] [Chemical Formula 2]

[0064] In the formula, R 1 R 2 and R 3They may be the same or different, and each represents an alkyl, alkoxy, silyloxy, acetal, carboxyl (-COOH), mercapto (-SH), or a derivative thereof. R 4 and R 5 Same or different, indicating hydrogen atoms or alkyl groups. R 4 and R 5 It can combine with nitrogen atoms to form a ring structure. n represents an integer.

[0065] Examples of modified BRs using compounds (modifiers) represented by the above formula include BRs with polymer ends (active ends) modified by compounds represented by the above formula.

[0066] As R 1 R 2 and R 3 Suitable are alkoxy groups (preferably alkoxy groups having 1 to 8 carbon atoms, more preferably alkoxy groups having 1 to 4 carbon atoms). As R 4 and R 5 Suitable for use is an alkyl group (preferably an alkyl group having 1 to 3 carbon atoms). n is preferably 1 to 5, more preferably 2 to 4, and even more preferably 3. Furthermore, when R... 4 and R 5 When combined to form a ring structure with a nitrogen atom, a 4- to 8-membered ring is preferred. Alkoxy groups also include cycloalkoxy groups (such as cyclohexyloxy) and aryloxy groups (such as phenoxy and benzyloxy).

[0067] Specific examples of the aforementioned modifiers include 2-dimethylaminoethyltrimethoxysilane, 3-dimethylaminopropyltrimethoxysilane, 2-dimethylaminoethyltriethoxysilane, 3-dimethylaminopropyltriethoxysilane, 2-diethylaminoethyltrimethoxysilane, 3-diethylaminopropyltrimethoxysilane, 2-diethylaminoethyltriethoxysilane, and 3-diethylaminopropyltriethoxysilane. These can be used alone or in combination of two or more.

[0068] In addition, modified BR can also be used as a modified BR, modified with the following compounds (modifiers). Examples of modifiers include: Polyhydric alcohol polyglycidyl ethers, such as ethylene glycol diglycidyl ether, glycerol triglycidyl ether, trimethylolethane triglycidyl ether and trimethylolpropane triglycidyl ether; Polyglycidyl ethers of aromatic compounds having two or more phenolic groups, such as diglycidylated bisphenol A; Polyepoxides, such as 1,4-diglycidylbenzene, 1,3,5-triglycidylbenzene and polyepoxide liquid polybutadiene; Tertiary amines containing epoxy groups, such as 4,4'-diglycidyl-diphenylmethylamine and 4,4'-diglycidyl-dibenzylmethylamine; Diglycidylamino compounds, such as diglycidylaniline, N,N'-diglycidyl-4-glycidyloxyaniline, diglycidyl-o-toluidine, tetraglycidyl-m-xylyldiamine, tetraglycidylaminodiphenylmethane, tetraglycidyl-p-phenylenediamine, diglycidylaminomethylcyclohexane, and tetraglycidyl-1,3-diaminomethylcyclohexane; Amino-containing acyl chlorides, such as bis-(1-methylpropyl)carbamoyl chloride, 4-morpholine carbamoyl chloride, 1-pyrrolidine carbamoyl chloride, N,N-dimethylcarbamoyl chloride and N,N-diethylcarbamoyl chloride; Silane compounds containing epoxy groups, such as 1,3-bis-(glycidoxypropyl)-tetramethyldisiloxane and (3-glycidoxypropyl)-pentamethyldisiloxane; Silane compounds containing thioether groups, such as (trimethylsilyl)[3-(trimethoxysilyl)propyl] sulfide, (trimethylsilyl)[3-(triethoxysilyl)propyl] sulfide, (trimethylsilyl)[3-(tripropoxysilyl)propyl] sulfide, (trimethylsilyl)[3-(tributoxysilyl)propyl] sulfide, (trimethylsilyl)[3-(methyldimethoxysilyl)propyl] sulfide, (trimethylsilyl)[3-(methyldiethoxysilyl)propyl] sulfide, (trimethylsilyl)[3-(methyldipropoxysilyl)propyl] sulfide, and (trimethylsilyl)[3-(methyldibutoxysilyl)propyl] sulfide; N-substituted aziridines, such as ethyleneimine and propyleneimine; Alkoxysilanes, such as methyltriethoxysilane, N,N-bis(trimethylsilyl)-3-aminopropyltrimethoxysilane, N,N-bis(trimethylsilyl)-3-aminopropyltriethoxysilane, N,N-bis(trimethylsilyl)aminoethyltrimethoxysilane and N,N-bis(trimethylsilyl)aminoethyltriethoxysilane; (Thio)benzophenone compounds having an amino group and / or substituted amino groups, such as 4-N,N-dimethylaminobenzophenone, 4-N,N-di-tert-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; Benzaldehyde compounds having an amino group and / or substituted amino groups, such as 4-N,N-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, N-tert-butyl-2-pyrrolidone and N-methyl-5-methyl-2-pyrrolidone; N-substituted piperidinones, such as N-methyl-2-piperidinone, N-vinyl-2-piperidinone and N-phenyl-2-piperidinone; N-substituted lactams, such as N-methyl-ε-caprolactam, N-phenyl-ε-caprolactam, N-methyl-ω-laurolactam, N-vinyl-ω-laurolactam, N-methyl-β-propiolactam and N-phenyl-β-propiolactam; and N,N-bis-(2,3-epoxypropoxy)-aniline, 4,4-methylene-bis-(N,N-glycidylaniline), tri-(2,3-epoxypropyl)-1,3,5-triazine-2,4,6-trione, N,N-diethylacetamide, N-methylmaleimide, N,N-diethylurea, 1,3-dimethylethylurea, 1,3-divinylethylurea, 1,3-diethyl-2-imidazolinone, 1-methyl-3-ethyl-2-imidazolinone, 4-N,N-dimethylaminoacetophenone, 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. These modified BRs can be used alone or in combination of two or more.

[0069] As a BR (Brandinger), for example, products manufactured by companies such as Ube Industries, Ltd., ENEOS Materials Co., Ltd., Asahi Kasei Corporation, and Zeon Corporation can be used.

[0070] Of 100 parts by weight of the rubber component, the BR content is preferably 5 parts by weight or more, more preferably 10 parts by weight or more. On the other hand, it is preferably 25 parts by weight or less, more preferably 20 parts by weight or less.

[0071] (a-4) Other rubber components The rubber composition may also include, as needed, rubber (polymer) commonly used in tire manufacturing, such as nitrile rubber (NBR), as other rubber components.

[0072] (b) Compound materials other than rubber components (b-1) Packing The rubber composition contains reinforcing agents such as carbon black and silica as fillers. Besides carbon black and silica, other fillers such as calcium carbonate, talc, alumina, clay, aluminum hydroxide, and mica can also be used. When silica is used, it is preferably used in combination with a silane coupling agent.

[0073] Relative to 100 parts by weight of rubber component, the total content of filler is preferably 40 parts by weight or more, more preferably 50 parts by weight or more, even more preferably 60 parts by weight or more, and even more preferably 90 parts by weight or more. On the other hand, from the viewpoint of dispersibility in the rubber composition, it is preferably 150 parts by weight or less, more preferably 120 parts by weight or less, and even more preferably 100 parts by weight or less.

[0074] (i) Carbon black Carbon black is used to improve tires' resistance to crack growth, durability, and UV cracking.

[0075] From the perspective of reinforcing properties of rubber, the nitrogen adsorption specific surface area (N2SA) of carbon black is preferably 30 m². 2 / g or more, preferably 50 m 2 / g or more, more preferably 60 m 2 / g or more. On the other hand, from the viewpoint of heating performance, it is preferably 250 m 2 / g or less, more preferably 150 m 2 / g Hereinafter, 120 m is further preferred. 2 / g or less. The nitrogen adsorption specific surface area of ​​carbon black was measured according to ASTM D4820-93.

[0076] From the viewpoint of rubber rigidity, the dibutyl phthalate (DBP) absorption of carbon black is preferably 50 ml / 100g or more, more preferably 100 ml / 100g or more. On the other hand, from the viewpoint of adaptability to rubber deformation, it is preferably 250 ml / 100g or less, more preferably 150 ml / 100g or less. The DBP absorption of carbon black was measured according to ASTM D2414-93.

[0077] There are no particular limitations on carbon black, and examples include furnace black (furnace black), such as SAF, ISAF, HAF, MAF, FEF, SRF, GPF, APF, FF, CF, SCF, and ECF; acetylene black; thermal cracking black (thermal cracking black), such as FT and MT; and channel black (channel black), such as EPC, MPC, and CC. These can be used alone or in combination of two or more.

[0078] In addition to carbon black made from mineral oil and other raw materials, biomass-derived carbon black obtained by burning lignin and recycled carbon black obtained by thermal decomposition and refining of carbon black-containing rubber products (such as tires) can also be used as appropriate equivalent substitutes.

[0079] There are no specific limitations on the type of carbon black used; examples include N134, N110, N220, N234, N219, N339, N330, N326, N351, N550, and N762. Commercially available products include those from companies such as Asahi Carbon Co., Ltd., Cabot Japan Co., Ltd., Tokai Carbon Co., Ltd., Mitsubishi Chemical Co., Ltd., Lion Corporation, Shin-Nippon Chemical Carbon Co., Ltd., and Columbia Carbon Co., Ltd. These can be used alone or in combination of two or more.

[0080] Relative to 100 parts by weight of rubber component, the carbon black content is preferably 20 parts by weight or more, more preferably 30 parts by weight or more, and even more preferably 40 parts by weight or more. As an upper limit, for example, it is preferably 80 parts by weight or less, more preferably 70 parts by weight or less, and even more preferably 60 parts by weight or less.

[0081] (ii) Silicon dioxide The hydrated water and surface functional groups contained in silica can capture ozone, thereby improving ozone resistance and thus enhancing tire durability.

[0082] For silica, if the average primary particle size is too small, the processing performance will deteriorate; therefore, silica with a particle size greater than 8 nm is preferred. A particle size of 9 nm or more is more preferred, and 10 nm or more is even more preferred. On the other hand, from the viewpoint of ensuring the reinforcing properties of the rubber and ensuring steering stability on wet surfaces during driving, a particle size of 25 nm or less is preferred, more preferably 20 nm or less, and even more preferably 17 nm or less.

[0083] The average primary particle size of silica refers to the average value of measurements obtained by observing the smallest unit of silica that constitutes the aggregate 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 more than 400 primary silica particles observed in the field of view using a transmission or scanning electron microscope and averaging the results.

[0084] From the perspective of achieving good durability, the BET specific surface area of ​​silica is preferably greater than 100 m². 2 / g, more preferably greater than 130 m 2 / g. On the other hand... Its preferred size is less than 250 m 2 / g, more preferably less than 200 m 2 / g. The BET specific surface area mentioned above is the N2SA value measured by the BET method according to ASTM D3037-93.

[0085] Examples of silica include dry silica (anhydrous silica), wet silica (hydrated silica), and colloidal silica. Wet silica is preferred, as it contains hydrated water and a large number of silanol groups and is capable of effectively capturing ozone. Silica made from hydrated glass or from biomass materials such as rice husks can also be used.

[0086] Products from companies such as Evonik Industries, Rhodia, Tosoh Silicon Chemicals, Solvay Japan, and Tokuyama Corporation can be used as silica.

[0087] Relative to 100 parts by weight of the rubber component, the silica content is preferably 30 parts by weight or more, more preferably 60 parts by weight or more, even more preferably 70 parts by weight or more, and even more preferably 80 parts by weight or more. As an upper limit, from the viewpoint of dispersibility in the rubber composition, it is preferably 120 parts by weight or less, more preferably 110 parts by weight or less, even more preferably 100 parts by weight or less, and even more preferably 90 parts by weight or less.

[0088] (iii) Silane coupling agents When using silica, it is preferable to use silane coupling agents in combination to improve the dispersibility of silica and enhance mechanical properties and formability through reaction with silica.

[0089] There are no particular limitations on silane coupling agents. Examples of silane coupling agents include: Sulfide-based silane coupling agents, such as bis(3-triethoxysilylpropyl)tetrasulfide, bis(2-triethoxysilylethyl)tetrasulfide, bis(4-triethoxysilylbutyl)tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, bis(2-trimethoxysilylethyl)tetrasulfide, bis(2-triethoxysilylethyl)trisulfide, bis(4-trimethoxysilylbutyl)trisulfide, bis(3-triethoxysilylpropyl)disulfide, bis(2-trieth ... 3-Trimethoxysilylpropyl disulfide, bis(4-triethoxysilylbutyl) disulfide, bis(3-trimethoxysilylpropyl) disulfide, bis(2-trimethoxysilylethyl) disulfide, bis(4-trimethoxysilylbutyl) disulfide, 3-trimethoxysilylpropyl-N,N-dimethylthiocarbamoyl tetrasulfide, 2-triethoxysilylethyl-N,N-dimethylthiocarbamoyl tetrasulfide, and 3-triethoxysilylpropyl methacrylate monosulfide; Thiol-based silane coupling agents, such as 3-mercaptopropyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, and NXT and NXT-Z manufactured by Momentive; Vinyl silane coupling agents, such as vinyltriethoxysilane and vinyltrimethoxysilane; Aminosilane coupling agents, such as 3-aminopropyltriethoxysilane and 3-aminopropyltrimethoxysilane; Epoxypropoxysilane coupling agents, such as γ-epoxypropoxypropyltriethoxysilane and γ-epoxypropoxypropyltrimethoxysilane; Nitrosilane coupling agents, such as 3-nitropropyltrimethoxysilane and 3-nitropropyltriethoxysilane; and Chlorinated silane coupling agents, such as 3-chloropropyltrimethoxysilane and 3-chloropropyltriethoxysilane. Preferably, silane coupling agents having a thiocarbonyl group, such as the aforementioned NXT, are used. These can be used alone or in combination of two or more.

[0090] As a silane coupling agent, products available from companies such as Evonik Industries, Momentive, Shin-Etsu Silicones, Tokyo Chemical Industries, Azumax, and Dow Corning Toray Industries, Ltd. can be used.

[0091] The content of silane coupling agent relative to 100 parts by weight of silicon dioxide is preferably, for example, greater than 2 parts by weight, more preferably greater than 3 parts by weight, even more preferably 5 parts by weight or more, and even more preferably 7 parts by weight or more. The upper limit is preferably, for example, less than 15 parts by weight, more preferably 12 parts by weight or less, even more preferably 10 parts by weight or less, and even more preferably 9 parts by weight or less.

[0092] (iv) Other packing materials In addition to the aforementioned carbon black and silica, 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 content of these fillers relative to 100 parts by weight of the rubber component is, for example, greater than 0.1 parts by weight and less than 150 parts by weight.

[0093] (b-2) Plasticizer components In rubber compositions, considering proper dispersion of powdered materials during mixing, it is preferable to use plasticizer components as needed. Here, plasticizer components refer to substances that plasticize the rubber composition, such as processing oils, rubber component filler oils, liquid rubber, and resin components.

[0094] In this case, the content of the plasticizer component is preferably 10 parts by mass or more, more preferably 15 parts by mass or more, even more preferably 20 parts by mass or more, and even more preferably 30 parts by mass or more, relative to 100 parts by mass of the rubber component. As an upper limit, for example, it is preferably 50 parts by mass or less, more preferably 45 parts by mass or less, and even more preferably 40 parts by mass or less.

[0095] It should be noted that the content of plasticizer components includes the amount of oil contained in the rubber (oil-extended rubber), etc.

[0096] (i) Oil Examples of oils include mineral oils, synthetic oils, vegetable oils, animal oils, or mixtures thereof.

[0097] Examples of mineral oils include paraffinic oils, aromatic oils, and naphthenic oils. For example, products obtained from companies such as Idemitsu Kosan Co., Ltd., Sankyo Oil & Chemical Co., Ltd., ENEOS Co., Ltd., Orisoy Co., Ltd., H&R Co., Ltd., Toyokuni Oil Co., Ltd., Showa Shell Oil Co., Ltd., and Fuji Kosan Co., Ltd. can be used alone or in combination of two or more.

[0098] Furthermore, from a life cycle assessment perspective, lubricating oils used in rubber mixers and engines, or waste cooking oils used in restaurants, can be refined for use.

[0099] Examples of vegetable oils include flaxseed oil, rapeseed oil, safflower oil, soybean oil, corn oil, cottonseed oil, rice bran oil, tall oil, sesame oil, perilla oil, castor oil, tung oil, pine oil, pine tar, sunflower seed oil, coconut oil, palm oil, palm kernel oil, olive oil, camellia oil, jojoba oil, macadamia nut oil, peanut oil, grapeseed oil, and wood wax.

[0100] In addition, vegetable oils may also include refined oils (such as salad oils) obtained by refining the aforementioned oils, transesterified oils obtained by transesterification, hydrogenated oils obtained by hydrogenation, thermally polymerized oils obtained by thermal polymerization, oxidatively polymerized oils obtained by oxidation, and waste edible oils recovered from use as edible oils. Vegetable oils may be liquid or solid at room temperature (25°C). They may be used alone or in combination of two or more.

[0101] As a vegetable oil, acylglycerol is preferred, and triacylglycerol is more preferred. Acylglycerol refers to a compound in which the hydroxyl group of glycerol is esterified with a carboxylic acid. Acylglycerol is not particularly limited and can be 1-monoacylglycerol, 2-monoacylglycerol, 1,2-diacylglycerol, 1,3-diacylglycerol, or triacylglycerol. Furthermore, acylglycerol can be a monomer, dimer, or trimer or more. Acylglycerols in dimer or more forms can be obtained through thermal polymerization, oxidative polymerization, etc. In addition, acylglycerol can be liquid or solid at room temperature (25°C).

[0102] There are no particular limitations on the method for confirming whether a rubber composition contains acylglycerol, but it can be done by... 1 H-NMR measurements are used for confirmation. For example, if a rubber composition containing triacylglycerol is immersed in deuterated chloroform at room temperature (25°C) for 24 hours, and after removing the rubber composition, measurements are taken at room temperature... 1 H-NMR, with the tetramethylsilane (TMS) signal set to 0.00 ppm, signals were observed around 5.26 ppm, 4.28 ppm, and 4.15 ppm. Since these signals are presumed to originate from hydrogen atoms bonded to the carbon atom adjacent to the oxygen atom of the ester group, the presence of acylglycerol can be confirmed. Here, "around" refers to a range of ±0.10 ppm.

[0103] There are no particular restrictions on carboxylic acids, and they can 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.

[0104] As vegetable oils, products obtained from companies such as Idemitsu Kosan Co., Ltd., Sankyo Oil & Chemical Co., Ltd., ENEOS Co., Ltd., Orisoy Co., Ltd., H&R Co., Ltd., Toyokuni Oil Co., Ltd., Fuji Kosan Co., Ltd., and Nissin Orisoy Group Co., Ltd. can be used.

[0105] (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 using acetone extraction. Examples of liquid rubber include farnesene polymers, liquid diene polymers, and their hydrogenated derivatives.

[0106] Farnese polymers are polymers obtained by polymerizing farnese and have farnese-based structural units. Farnese includes isomers such as α-farnese ((3E, 7E)-3,7,11-trimethyl-1,3,6,10-dodecathetene) and β-farnese (7,11-dimethyl-3-methylene-1,6,10-dodecathetene).

[0107] Farnese polymers can be homopolymers of farnese (farnese homopolymers) or copolymers of farnese and vinyl monomers (farnese-vinyl monomer copolymers).

[0108] 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).

[0109] The converted weight-average molecular weight (Mw) of polystyrene, measured by gel permeation chromatography (GPC) of liquid diene polymers, is, for example, greater than 1.0 × 10⁻⁶. 3 And less than 2.0 × 10 5 In this context, the Mw of the liquid diene polymer is the polystyrene equivalent measured by gel permeation chromatography (GPC).

[0110] As a liquid rubber, products obtained from companies such as Kuraray Corporation and Clay Valley can be used.

[0111] (iii) Resin composition The resin component also functions as a tackifier and can be solid or liquid at room temperature. Specific examples of resin components include rosin resins, styrene resins, coumarone resins, terpene resins, C5 resins, C9 resins, C5C9 resins, and acrylic resins, and two or more of them can be used in combination. Modifying groups that can react with silica and the like can be provided to these resin components as needed.

[0112] Rosin resins are resins whose main component is rosin acid obtained through the processing of rosin. These rosin resins (rosins) can be classified according to whether they are modified, and can be divided into unmodified rosin (non-modified rosin) and modified rosin (rosin derivatives). Examples of unmodified rosin include tall rosin (also known as tall oil rosin), resin rosin, wood rosin, disproportionated rosin, polymerized rosin, hydrogenated rosin, and other chemically modified rosin. Modified rosin is a modification of unmodified rosin, and examples of such modifications include rosin esters, unsaturated carboxylic acid modified rosin, unsaturated carboxylic acid modified rosin esters, rosin amide compounds, and rosin amine salts.

[0113] Styrene-based resins are polymers that use styrene monomers as constituent monomers. Examples include polymers obtained by polymerizing styrene monomers as the main component (50% by mass or more). Specifically, they include homopolymers obtained by polymerizing styrene monomers alone (styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-methoxystyrene, p-tert-butylstyrene, p-phenylstyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, etc.), copolymers obtained by copolymerizing two or more styrene monomers, and, additionally, copolymers obtained by copolymerizing styrene monomers with other monomers that can be copolymerized with styrene monomers.

[0114] Examples of other monomers include: acrylonitriles, such as acrylonitrile and methacrylonitrile; unsaturated carboxylic acids, such as acrylic acid and methacrylic acid; unsaturated carboxylic acid esters, such as methyl acrylate and methyl methacrylate; dienes, such as chloroprene, butadiene and isoprene; alkenes, such as 1-butene and 1-pentene; and α,β-unsaturated carboxylic acids and their anhydrides, such as maleic anhydride.

[0115] Coumarin-indene resins are preferred as coumarone-based resins. Coumarin-indene resins are resins containing coumarone and indene as monomeric components constituting the resin backbone (main chain). Examples of monomeric components included in the backbone besides coumarone and indene include styrene, α-methylstyrene, methylindene, and vinyltoluene.

[0116] The hydroxyl value (OH value) of coumarone-indene resin is, for example, greater than 15 mgKOH / g and less than 150 mgKOH / g. The OH value is the amount of potassium hydroxide required to neutralize the acetic acid bound to the hydroxyl group when 1 g of resin is acetylated, and is expressed in milligrams. It is a value measured by potentiometric titration (JIS K 0070:1992).

[0117] The softening point of coumarone-indene resin is, for example, above 30°C and below 160°C. The softening point is the temperature at which a ball falls when measured using a ring-and-ball softening point measuring device as defined in JIS K 6220-1:2001.

[0118] Examples of terpene resins include polyterpenes, terpenoids, and aromatic modified terpene resins. Polyterpenes are resins obtained by polymerizing terpene compounds and their hydrides. Terpene compounds are those with the structure (C5H8). n Hydrocarbons or their oxygen-containing derivatives, which are classified as monoterpenes (C 10 H 16 ), sesquiterpenes (C 15 H 24 ), diterpenes (C 20 H 32 Compounds with terpenes as their basic skeleton include α-pinene, β-pinene, dipentene, limonene, myrcene, allociperene, ocimene, α-phellandrene, α-terpinene, γ-terpinene, terpinene oil, 1,8-cineole, 1,4-cineole, α-terpineol, β-terpineol, and γ-terpineol.

[0119] Examples of polyterpenes include terpene resins, such as α-pinene resin, β-pinene resin, limonene resin, dipentene resin, and β-pinene / limonene resin made from the aforementioned terpene compounds; and hydrogenated terpene resins obtained by hydrogenating the aforementioned terpene resins. Examples of terpenoids include resins obtained by copolymerizing the aforementioned terpene compounds with phenolic compounds, and resins obtained by hydrogenating the aforementioned resins. Specifically, resins obtained by condensing the aforementioned terpene compounds, phenolic compounds, and formalin can be cited. Examples of phenolic compounds include phenol, bisphenol A, cresol, and xylenol. Examples of aromatic-modified terpene resins include resins obtained by modifying terpene resins with aromatic compounds, and resins obtained by hydrogenating the aforementioned resins. There are no particular restrictions as long as the aromatic compound is a compound with an aromatic ring. Examples include: phenolic compounds, such as phenol, alkylphenol, alkoxyphenol, and phenol containing an unsaturated hydrocarbon group; naphthols, 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; coumarones; and indene.

[0120] C5 resin refers to resin obtained by polymerizing C5 fractions. Examples of C5 fractions include petroleum fractions having 4 to 5 carbon atoms, such as cyclopentadiene, pentene, pentadiene, and isoprene. Dicyclopentadiene resin (DCPD resin) is preferred as a C5 type petroleum resin.

[0121] C9 resin refers to a resin obtained by polymerizing a C9 fraction, which can be hydrogenated or modified. Examples of C9 fractions include petroleum fractions having 8 to 10 carbon atoms, such as vinyltoluene, alkylstyrene, indene, and methylindene. As specific examples, coumarone-indene resin, coumarone resin, indene resin, and aromatic vinyl resins are preferred. As aromatic vinyl resins, homopolymers of α-methylstyrene or styrene, or copolymers of α-methylstyrene and styrene, are preferred due to their economy, ease of processing, and excellent exothermic properties. Copolymers of α-methylstyrene and styrene are more preferred. As aromatic vinyl resins, for example, those commercially available from companies such as Clayton Corporation and Eastman Chemical Corporation can be used.

[0122] C5C9 resin refers to a resin obtained by copolymerizing C5 and C9 fractions, and can be hydrogenated or modified. Examples of C5 and C9 fractions include the aforementioned petroleum fractions. For example, commercially available C5C9 resins from companies such as Tosoh Corporation and Luhua Corporation can be used.

[0123] There are no particular restrictions on acrylic resins, but for example, solvent-free acrylic resins can be used.

[0124] As a solvent-free acrylic resin, examples include (meth)acrylic resins (polymers) synthesized via high-temperature continuous polymerization (high-temperature continuous bulk polymerization method as described in US Patent No. 4,414,370, Japanese Patent Application Publication No. 59-6207, Japanese Patent Application Publication No. 5-58005, Japanese Patent Application Publication No. 1-313,522, US Patent No. 5,010,166, and the East Asia Synthetic Research Yearbook TREND2000, Issue 3, pp. 42-45). In this disclosure, (meth)acrylic acid means methacrylic acid and acrylic acid.

[0125] Examples of monomeric components that constitute acrylic resins include (meth)acrylic acid and (meth)acrylic acid derivatives, such as (meth)acrylates (alkyl esters, aryl esters, aralkyl esters, etc.), (meth)acrylamide, and (meth)acrylamide derivatives.

[0126] In addition, as a monomeric component constituting acrylic resin, aromatic vinyl compounds (such as styrene, α-methylstyrene, vinyltoluene, vinylnaphthalene, divinylbenzene, trivinylbenzene, divinylnaphthalene, etc.) can be used together with (meth)acrylic acid or (meth)acrylic acid derivatives.

[0127] Acrylic resins can be resins composed solely of (meth)acrylic acid, or resins containing components other than (meth)acrylic acid. Furthermore, acrylic resins may contain hydroxyl, carboxyl, or silanol groups, etc.

[0128] As a resin component, products obtained from Maruzen Petrochemical Co., Ltd., Sumitomo Bakelite Co., Ltd., Yasuhara Chemical Co., Ltd., Tosoh Co., Ltd., Rugers Chemical Co., Ltd., BASF Corporation, Kraton Corporation, Nippon Paint Co., Ltd., Nippon Shokubai Co., Ltd., ENEOS Co., Ltd., Arakawa Chemical Industry Co., Ltd., Taoka Chemical Industry Co., Ltd., etc. can be used.

[0129] (b-3) Lubricant (stearic acid) The rubber composition may contain a lubricant. Fatty acid derivative lubricants, such as stearic acid, are preferred. Conventionally known stearic acid products can be used; specifically, products obtained from companies such as Nippon Oil (NOF) Co., Ltd., Kao Corporation, Fujifilm, Kojun Pharmaceutical Co., Ltd., and Chiba Fatty Acid Co., Ltd. can be used. Alternatively, products such as Structol WB16 manufactured by Structol Corporation can also be used.

[0130] The stearic acid content is preferably greater than 0.5 parts by weight and less than 10.0 parts by weight per 100 parts by weight of rubber component.

[0131] (b-4) Anti-aging agents The rubber composition may contain an antioxidant. The antioxidant content is, for example, greater than 1 part by weight and less than 10 parts by weight relative to 100 parts by weight of the rubber component.

[0132] Examples of antioxidants include: naphthylamine antioxidants, such as phenyl-α-naphthylamine; diphenylamine antioxidants, such as octyl diphenylamine and 4,4'-bis(α,α'-dimethylbenzyl)diphenylamine; p-phenylenediamine antioxidants, such as N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, and N,N'-di-2-naphthyl-p-phenylenediamine; quinoline antioxidants, such as polymers of 2,2,4-trimethyl-1,2-dihydroquinoline; monophenol antioxidants, such as 2,6-di-tert-butyl-4-methylphenol and styreneated phenol; and bisphenol, triphenol, and polyphenol antioxidants, such as tetra-[methylene-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]methane. These can be used alone or in combination of two or more.

[0133] As an anti-aging agent, products from companies such as Seiko Chemical Co., Ltd., Sumitomo Chemical Co., Ltd., Ouchi Shinsei Chemical Co., Ltd., and Flexsys Co., Ltd. can be used.

[0134] (b-5) Zinc oxide The rubber composition may contain zinc oxide. The zinc oxide content, relative to 100 parts by weight of the rubber component, is, for example, greater than 0.5 parts by weight and less than 10 parts by weight. As zinc oxide, conventionally known products can be used, and for example, products from Mitsui Metal Mining Co., Ltd., Toho Co., Ltd., Hakusui Technology Co., Ltd., Seido Chemical Industry Co., Ltd., Sakai Chemical Industry Co., Ltd., etc., can be used.

[0135] (b-6) Wax The rubber composition may contain wax. The wax content is preferably, for example, 0.5 to 20 parts by weight, more preferably 1.0 to 15 parts by weight, and even more preferably 1.5 to 10 parts by weight, relative to 100 parts by weight of the rubber component.

[0136] There are no particular restrictions on the types of waxes used, and examples include: petroleum-based waxes, such as paraffin and microcrystalline waxes; natural waxes, such as plant waxes and animal waxes; and synthetic waxes, such as polymers of ethylene and propylene. These can be used alone or in combination of two or more.

[0137] As a wax, for example, products obtained from companies such as Ouchi Shinshin Chemical Industry Co., Ltd., Nippon Seiwa Co., Ltd., and Seiko Chemical Co., Ltd. can be used.

[0138] (b-7) Crosslinking agents and vulcanization accelerators The rubber composition preferably contains a crosslinking agent such as sulfur. The content of the crosslinking agent is, for example, greater than 0.1 parts by weight and less than 10.0 parts by weight per 100 parts by weight of the rubber component. Sulfur content refers to the amount of pure sulfur, and if insoluble sulfur is used, it is the content excluding oil components.

[0139] Examples of sulfur include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersed sulfur, and soluble sulfur, which are commonly used in the rubber industry. These can be used alone or in combination of two or more.

[0140] For example, products obtained from companies such as Tsurumi Chemical Industry Co., Ltd., Karuizawa Sulfur Co., Ltd., Shikoku Chemical Industry Co., Ltd., Flexsys Co., Ltd., Nippon Inkyu Corporation, and Hosoi Chemical Industry Co., Ltd. can be used as sulfur.

[0141] Crosslinking agents other than sulfur can be used. Specifically, for example, sulfur-containing vulcanizing agents such as Tackyrol V200 manufactured by Taoka Chemical Industry Co., Ltd., DURALINK HTS (1,6-hexamethylene-dithiosulfate sodium dihydrate) manufactured by Flexsys, and KA9188 (1,6-bis(N,N'-dibenzylthiocarbamoyldithio)hexane: a mixed crosslinking agent) manufactured by Lanxess, as well as organic peroxides such as dicumyl peroxide.

[0142] Furthermore, the rubber composition preferably contains a vulcanization accelerator. The content of the vulcanization accelerator is, for example, greater than 0.3 parts by weight and less than 10.0 parts by weight per 100 parts by weight of the rubber component.

[0143] Examples of vulcanization accelerators include: thiazole vulcanization accelerators, such as 2-mercaptobenzothiazole, di-2-benzothiazole disulfide, and N-cyclohexyl-2-benzothiazole sulfenamide; thiuram vulcanization accelerators, such as tetramethylthiuram disulfide (TMTD), tetrabenzylthiuram disulfide (TBzTD), and tetra(2-ethylhexyl)thiuram disulfide (TOT-N); sulfenamide vulcanization accelerators, such as N-cyclohexyl-2-benzothiazole sulfenamide, N-tert-butyl-2-benzothiazole sulfenamide, N-oxoethylene-2-benzothiazole sulfenamide, and N,N'-diisopropyl-2-benzothiazole sulfenamide; and guanidine vulcanization accelerators, such as diphenylguanidine, di-o-tolylguanidine, and o-tolyl biguanide. These can be used alone or in combination of two or more.

[0144] (b-8) Other In addition to the components mentioned 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 relative to 100 parts by weight of the rubber component is, for example, greater than 0.1 parts by weight and less than 50 parts by weight.

[0145] (2) Preparation of rubber composition Rubber compositions can be manufactured by conventional methods, such as a basic mixing step that involves blending rubber components with fillers such as carbon black, and a final mixing step that involves blending the mixture obtained in the basic mixing step with a crosslinking agent.

[0146] Known (closed) mixing machines such as Banbury internal mixers, kneaders, or open roller mills can be used for mixing.

[0147] The mixing temperature in the basic mixing step is, for example, above 50°C and below 200°C, and the mixing time is, for example, longer than 30 seconds and shorter than 30 minutes. In addition to the above-mentioned components, compounding agents commonly used in the rubber industry, such as plasticizers like oils, zinc oxide, antioxidants, waxes, vulcanization accelerators, etc., may be added and mixed as needed in the basic mixing step.

[0148] In the final mixing step, the compound obtained in the basic mixing step is mixed with a crosslinking agent. The mixing temperature in the final mixing step is, for example, above room temperature and below 80°C, and the mixing time is, for example, longer than 1 minute and shorter than 15 minutes. In addition to the above components, vulcanization accelerators, zinc oxide, etc., may be added and mixed appropriately as needed in the final mixing step.

[0149] The rubber composition obtained as described above can then be shaped into a tire tread by extruding it into a predetermined shape.

[0150] 1. Tire manufacturing The tire according to this embodiment can be manufactured using conventional methods. First, the rubber composition obtained above is shaped into a predetermined shape to create the tread. Next, it is combined with other rubber components on a tire forming machine to manufacture an uncured tire.

[0151] Specifically, on a forming drum, the inner liner (ensuring tire airtightness), the tire carcass (bearing loads, impacts, and inflation pressure), and the belt component (for strongly tightening the tire carcass to increase tread rigidity) are wound, and the two ends of the tire carcass are fixed to the side edges. A bead portion (for securing the tire to the rim) is arranged and formed into a ring. Then, the tread is bonded to the center of the outer periphery, and the sidewall is bonded radially outward to form the sidewall, thereby manufacturing an uncured tire.

[0152] The uncured tires thus manufactured are then heated and pressurized in a vulcanizing machine to obtain a tire. The vulcanization step can be carried out by applying known vulcanization methods. The vulcanization temperature is, for example, above 120°C and below 200°C, and the vulcanization time is, for example, longer than 5 minutes and shorter than 15 minutes.

[0153] As described above, the tire obtained in this manner, through the combination of the effect of forming a sipes pattern with appropriate twist and the effect of a rubber composition manufactured with an appropriate silica / carbon black ratio, more effectively controls tire wear. This ensures tread rigidity even in the later stages of wear, thereby improving grip performance in the later stages of wear.

[0154] The tires according to the present invention can be suitably used as tires for passenger cars, large passenger cars, large SUVs, trucks / buses, motorcycles, racing tires, studless anti-skid tires (winter tires), all-season tires, run-flat tires, etc., and are particularly preferred as tires for passenger cars.

[0155] [Example] The following embodiments (implementations) are considered preferred embodiments, but the scope of the invention is not limited to these embodiments.

[0156] Table 1 shows the results calculated based on the grip performance evaluation method in the later stages of wear, assuming that the tire (tire size: 175 / 60R18) is composed of a tread formed from various compound materials listed below and other rubber components.

[0157] 1. Preparation of rubber compositions Rubber compositions for tire treads are prepared using the following compounding materials.

[0158] (1) Mixing materials (a) Rubber composition (a-1) NR: TSR20 (a-2) SBR: HPR840 (S-SBR) manufactured by ENEOS Materials Co., Ltd. (Styrene content: 10% by mass, Vinyl content: 42% by mass)

[0159] (b) Compound materials other than rubber components (b-1) Carbon black: Dia Black N220 (N2SA: 115 m) manufactured by Mitsubishi Chemical Corporation 2 / g) (b-2) Silica: UltraSil VN3 manufactured by Evonik Industries (N2SA: 175 m) 2 / g, average primary particle size: 17 nm) (b-3) Silane coupling agent: NXT manufactured by Momentive. (3-Octaylthiopropyltriethoxysilane) (b-4) Oil: A / OMIX processing oil manufactured by Sankyo Oil Chemical Co., Ltd. (b-5) Resin: YS Resin PX850 manufactured by Yasuhara Chemical Co., Ltd. (Softening point 85°C, β-pinene resin (terpene resin)) (b-6) Wax: Ozoace 0355 manufactured by Nippon Fine Wax Co., Ltd. (b-7) Antioxidant-1: Nocrac 6C manufactured by Ouchi Shinsei Chemical Co., Ltd. (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine) (b-8) Antioxidant-2: Nocrac RD (poly(2,2,4-trimethyl-1,2-dihydroquinoline)) manufactured by Ouchi Shinsei Chemical Co., Ltd. (b-9) Stearic acid: Stearic acid beads "Tsubaki" manufactured by Nippon Oil Co., Ltd. (b-10) Zinc oxide: Zinc oxide No. 2 manufactured by Mitsui Metals & Minerals Co., Ltd. (b-11) Sulfur: Powdered sulfur manufactured by Karuizawa Sulfur Co., Ltd. (b-12) Accelerator-1: Nocceler CZ-G (CBS) (N-cyclohexyl-2-benzothiazolyl sulfenamide) manufactured by Ouchi Shinsei Chemical Co., Ltd. (b-13) Accelerator-2: Nocceler D (DPG) (1,3-diphenylguanidine) manufactured by Ouchi Shinsei Chemical Co., Ltd.

[0160] (2) Preparation of rubber composition for tire tread Based on the formula shown in Table 1, the materials, excluding sulfur and vulcanization accelerator, were mixed for 5 minutes at 150°C using a 1.7L Banbury internal mixer manufactured by Kobe Steel Corporation to obtain a compound.

[0161] Next, sulfur and vulcanization accelerator are added to the obtained compound, and the mixture is kneaded for 5 minutes at 80°C using an open roller mill to obtain various rubber compositions for tire tread.

[0162] 2. Tread forming Next, using the rubber composition obtained above, a tread with a predetermined shape is formed, in which a twisted sipe pattern is formed, such that the width is less than 2 mm and the depth is less than 20 mm, and the area ratio X of the intersection between the opening and the bottom of the groove is less than 95%.

[0163] 3. Tire manufacturing Next, the tread obtained above is bonded together with other tire components to form an uncured tire. The uncured tire is then pressurized at 170°C for 10 minutes to produce the test tires of Examples 1 to 4 and Comparative Examples 1 to 4.

[0164] 4. Performance evaluation test (grip performance evaluation in the later stages of wear) All test tires were installed on all wheels of the vehicle (a domestically produced FF vehicle with a 2000cc engine), inflated to an internal pressure of 230 kPa, and driven for 30,000 km. Afterward, the vehicle was driven on a test track with dry asphalt pavement, and lap time was measured.

[0165] In addition, as a reference example, a tire manufactured by replacing all of the SBR in the formulation of Comparative Example 3 with NR was used, and the lap time was measured in the same manner.

[0166] Then, using the lap time of the reference tire as a benchmark, the reduction in lap time achieved by each test tire was calculated.

[0167] Next, the reduction in lap time in Comparative Example 1 was set to 100, and the index was calculated based on the following formula to evaluate the grip performance in the later stages of wear. A higher value indicates better grip performance in the later stages of wear.

[0168] Grip performance in the later stages of wear = [(Results of tire testing) / (Results of Comparative Example 1)] × 100 [Table 1]

[0169] Although the present invention has been described above based on embodiments, the present invention is not limited to the above embodiments. Various modifications can be made to the above embodiments within the same and equivalent scope as the present invention.

[0170] The present invention (1) is, A tire having a tread section, A groove is formed on the contact portion of the surface of the tread portion. The groove has an opening facing the surface of the tread portion and a bottom. The width of the groove is less than 2 mm and the depth is less than 20 mm. When the surface of the tread portion is viewed in a plan view, the opening intersects with the bottom of the groove. When the surface of the tread is viewed from above, the ratio X of the area of ​​the intersection of the opening and the bottom of the groove to the area of ​​the opening is 95% or less. The tread portion is formed of a rubber composition comprising rubber components, silica, and carbon black, wherein the ratio Y of silica content (parts by mass) to carbon black content (parts by mass) is greater than 50%, and X / Y < 1.5.

[0171] The present invention (2) is, According to the tire of the present invention (1), the ratio X is 80% or less.

[0172] The present invention (3) is, According to the tire of the present invention (2), the ratio X is 60% or less.

[0173] The present invention (4) is, According to any combination of (1) to (3) of the present invention, the ratio X is 1% or more.

[0174] The present invention (5) is, According to any combination of (1) to (4) of the present invention, the tire wherein the ratio Y is 100% or more.

[0175] The present invention (6) is, According to the tire of the present invention (5), the ratio Y is 200% or more.

[0176] The present invention (7) is, According to any combination of (1) to (6) of the present invention, the ratio Y is 380% or less.

[0177] The present invention (8) is, According to any combination of (1) to (7) of the present invention, the tire wherein the X / Y ratio is 1.2 or less.

[0178] The present invention (9) is, According to the tire of the present invention (8), the X / Y ratio is 0.8 or less.

[0179] The present invention (10) is, According to any combination of (1) to (9) of the present invention, the tire wherein the X / Y ratio is 0.03 or more.

[0180] The present invention (11) is, According to any combination of (1) to (10) of the present invention, the thickness of the tread portion is more than 10 mm and less than 20 mm.

[0181] The present invention (12) is, According to any combination of (1) to (11) of the present invention, the tread is formed by multiple layers with the tread rubber layer as the outermost layer.

[0182] The present invention (13) is, According to the tire of the present invention (12), the thickness of the tread rubber layer on the entire tread surface is 10% or more.

[0183] The present invention (14) is, According to the tire of the present invention (13), the thickness of the tread rubber layer is 70% or more over the entire tread surface.

[0184] The present invention (15) is, According to any combination of (1) to (14) of the present invention, the tire has an aspect ratio of 30% or more and 60% or less.

[0185] The present invention (16) is, According to any combination of (1) to (15) of the present invention, wherein the rubber composition comprises styrene-butadiene rubber (SBR) with a styrene content of less than 25% by mass.

[0186] The present invention (17) is, According to the tire of the present invention (16), the content of styrene-butadiene rubber (SBR) in 100 parts by mass of the rubber component is 40 parts by mass or more.

[0187] The present invention (18) is, According to any combination of (1) to (17) of the present invention, the tire contains at least 40 parts by mass of isoprene rubber in 100 parts by mass of the rubber component.

[0188] The present invention (19) is, According to any combination of (1) to (18) of the present invention, the particle size of the silica is less than 17 nm.

[0189] The present invention (20) is, According to any combination of (1) to (19) of the present invention, the rubber composition comprises at least one resin component selected from rosin resins, styrene resins, coumarone resins, terpene resins, C5 resins, C9 resins, C5C9 resins and acrylic resins.

[0190] [Explanation of reference numerals in the attached figures] 1: Grounding part; 2: Opening; 3: Bottom of the trench; S: Intersection.

Claims

1. A tire having a tread portion, A groove is formed on the contact portion of the surface of the tread portion. The groove has an opening facing the surface of the tread portion and a bottom. The width of the groove is less than 2 mm and the depth is less than 20 mm. When the surface of the tread portion is viewed in a plan view, the opening intersects with the bottom of the groove. When the surface of the tread is viewed from above, the ratio X of the area of ​​the intersection of the opening and the bottom of the groove to the area of ​​the opening is 95% or less. The tread portion is formed of a rubber composition comprising rubber components, silica, and carbon black, wherein, The ratio Y of silica content (parts by mass) to carbon black content (parts by mass) is greater than 50%, and X / Y < 1.

5.

2. The tire according to claim 1, wherein, The ratio X is below 80%.

3. The tire according to claim 2, wherein, The ratio X is below 60%.

4. The tire according to any one of claims 1 to 3, wherein, The ratio X is 1% or higher.

5. The tire according to any one of claims 1 to 4, wherein, The ratio Y is 100% or higher.

6. The tire according to claim 5, wherein, The ratio Y is above 200%.

7. The tire according to any one of claims 1 to 6, wherein, The ratio Y is below 380%.

8. The tire according to any one of claims 1 to 7, wherein, The X / Y ratio is 1.2 or less.

9. The tire according to claim 8, wherein, The X / Y ratio is below 0.

8.

10. The tire according to any one of claims 1 to 9, wherein, The X / Y ratio is 0.03 or higher.

11. The tire according to any one of claims 1 to 10, wherein, The thickness of the tread portion is more than 10 mm and less than 20 mm.

12. The tire according to any one of claims 1 to 11, wherein, The tread surface is formed by multiple layers, with the driving tread rubber layer as the outermost layer.

13. The tire according to claim 12, wherein, The thickness of the driving tread rubber layer on the entire tread surface is more than 10%.

14. The tire according to claim 13, wherein, The thickness of the driving tread rubber layer is more than 70% across the entire tread surface.

15. The tire according to any one of claims 1 to 14, wherein, The aspect ratio of the tire is above 30% and below 60%.

16. The tire according to any one of claims 1 to 15, wherein, The rubber composition comprises styrene-butadiene rubber (SBR) with a styrene content of less than 25% by mass.

17. The tire according to claim 16, wherein, Of the 100 parts by weight of the rubber component, the content of styrene-butadiene rubber (SBR) is 40 parts by weight or more.

18. The tire according to any one of claims 1 to 17, wherein, Of the 100 parts by mass of the rubber component, the content of isoprene rubber is 40 parts by mass or more.

19. The tire according to any one of claims 1 to 18, wherein, The silicon dioxide has a particle size of less than 17 nm.

20. The tire according to any one of claims 1 to 19, wherein, The rubber composition comprises at least one resin component selected from rosin resins, styrene resins, coumarone resins, terpene resins, C5 resins, C9 resins, C5C9 resins, and acrylic resins.

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