Tire

Abstract

To improve total performance of high-speed durability and rolling resistance.SOLUTION: A tire comprises: a carcass comprising a carcass cord; a belt which comprises a belt cord and is provided outside the carcass in a tire radial direction; a band which comprises a band cord and is provided outside the belt in the tire radial direction; and a tread provided outside the band in the tire radial direction. The band cord is obtained by twisting one yarn comprising a PET fiber. The tread is formed, by using a rubber composition having an acetone-extractable content of more than 15 mass%, so as to have a thickness of more than 6 mm and rubber hardness (Shore hardness) Hs of more than 60. A product of a diameter (mm) of the band cord and the thickness (mm) of the tread is less than 5.0.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 high-speed durability and rolling resistance.

Means for Solving the Problems

[0005] The present invention is a carcass including carcass cords, a belt including belt cords and provided on the outer side in the tire radial direction of the carcass, a band including band cords 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 cords are formed by twisting one yarn containing polyethylene terephthalate fibers, the tread is formed using a rubber composition having an acetone extract content of more than 15% by mass, a thickness of more than 6 mm, and a rubber hardness (Shore hardness) Hs of more than 60, A tire characterized in that the product of the diameter (mm) of the band cord and the thickness (mm) of the tread is less than 5.0.

Advantages of the Invention

[0006] According to the present invention, it is possible to improve the overall performance of high-speed durability and rolling resistance.

Brief Description of the Drawings

[0007]

Figure 1

Modes for Carrying Out the Invention

[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 present invention includes a carcass provided with a carcass cord, a belt provided with a belt cord and disposed on the outer side in the tire radial direction of the carcass, a band provided with a band cord and disposed on the outer side in the tire radial direction of the belt, and a tread disposed on the outer side in the tire radial direction of the band. The band cord is formed by twisting one yarn containing polyethylene terephthalate (PET) fiber. The tread is formed using a rubber composition (tread rubber composition) having an acetone extract content of more than 15% by mass, a thickness of more than 6 mm, and a rubber hardness (Shore hardness) Hs of more than 60. Further, the product of the diameter (mm) of the band cord and the thickness (mm) of the tread is less than 5.0.

[0010] By having these features, as will be described later, it is possible to improve the overall performance of high-speed durability and rolling resistance.

[0011] 2. Mechanism of Effect Expression in the Tire According to the Present Invention Regarding the mechanism of the above-described effect manifestation in the tire according to the present invention, it is considered as follows.

[0012] (1) Use of PET band In the tire according to the present invention, as the band cord, a single-twist PET band obtained by twisting a single yarn containing PET fiber is used.

[0013] (a) PET band Since the PET band has a higher modulus than nylon 66 (polyamide synthetic fiber) which has been mainly used conventionally, by adopting the PET band as the band cord, the high-speed durability can be further improved.

[0014] (b) Single-twist band However, the PET band is more likely to generate heat compared to nylon 66 (polyamide synthetic fiber), and there is a risk of deterioration of the rolling resistance.

[0015] In the present invention, as the band cord, a single-twist band obtained by twisting a single yarn is adopted to reduce heat generation. That is, since the adoption of the single-twist band can reduce the band cord volume, heat generation can be reduced.

[0016] Also, the adoption of the single-twist band can reduce the tire weight and achieve weight reduction of the tire, so that the rolling resistance can be reduced.

[0017] Note that the cord top gauge of the band is preferably 0.01 mm or more and 0.05 mm or less, and more preferably 0.02 mm or more and 0.04 mm or less. Also, the total gauge of the band is preferably 0.20 mm or more and 0.60 mm or less, and more preferably 0.30 mm or more and 0.50 mm or less.

[0018] (2) Tread However, when a single-twist band is adopted, the compression fatigue resistance deteriorates, and there is a risk of a decrease in high-speed durability.

[0019] (a) Tread thickness In the present invention, the tread is thickened. Specifically, the thickness is more than 6 mm. Thereby, the compression received by the band can be reduced, so that the compression fatigue resistance can be improved and the high-speed durability can be improved. It is more preferably 8 mm or more, and further preferably 10 mm or more. As the upper limit, for example, it is preferably 20 mm or less, more preferably 15 mm or less, and further preferably 12 mm or less.

[0020] Note that the tread may be formed of only one layer of the cap rubber layer, but a base rubber layer may be provided inside the cap rubber layer to form two layers, or may be three layers, or four or more layers. In this case, the rubber composition for the tread described above becomes the rubber composition forming the cap rubber layer.

[0021] In this case, the thickness of the cap rubber layer in the entire tread is preferably 10% or more, more preferably 30% or more, further preferably 50% or more, and further preferably 70% or more.

[0022] In the present invention, the tread thickness refers to the thickness of the tread on the tire equatorial plane in the tire radial cross-section. When the tread is formed of a single rubber composition, it is the thickness of the rubber composition. When it is formed of a laminated structure of a plurality of rubber compositions, it refers to the total thickness of these layers. It can be measured by making the bead portion in a state adapted to the normal rim width in the cross-section cut out in the radial direction of the tire.

[0023] The "normal rim" refers to the rim defined for each tire in a standard system including the standards on which the tire is based. For example, in the case of JATMA (Japan Automobile Tire Association), it refers to the standard rim in the applicable sizes described in the "JATMA YEAR BOOK"; in the case of ETRTO (The European Tyre and Rim Technical Organisation), it refers to the "Measuring Rim" described in the "STANDARDS MANUAL"; and in the case of TRA (The Tire and Rim Association, Inc.), it refers to the "Design Rim" described in the "YEAR BOOK". Refer to JATMA, ETRTO, and TRA in this order, and follow the relevant standards if there are applicable sizes during the reference. In the case of a tire not defined in the standards, it refers to a rim that can be assembled with the tire and can hold the internal pressure, that is, among the rims that do not cause air leakage between the rim and the tire, the one with the smallest rim diameter and then the narrowest rim width.

[0024] (b) Rubber hardness (Shore hardness) Hs If the tread is soft, during high-speed driving, the amount of deformation of the tread increases, and the compression applied to the belt increases, so there is a risk that the high-speed durability deteriorates due to compression fatigue.

[0025] In the present invention, the rubber hardness (Shore hardness) Hs of the tread is set to be more than 60. Thereby, sufficient rigidity can be ensured, and the deformation of the tread during high-speed driving can be suppressed. Therefore, the compression fatigue applied to the belt can be reduced, and the high-speed durability can be improved.

[0026] The above-mentioned rubber hardness (Shore hardness) Hs can be measured using a Type A durometer in accordance with the method specified in JIS K6253-3:2012.

[0027] And the rubber hardness (Shore hardness) Hs is more preferably 65 or more, and even more preferably 70 or more. As the upper limit, for example, it is preferably 85 or less, and more preferably 80 or less.

[0028] (c) Acetone extract In the present invention, the acetone extract (AE) of the tread is more than 15% by mass.

[0029] The acetone extract (AE) can be considered as an index indicating the amount of materials that impart plasticity to the rubber component, such as softeners, in the rubber composition, and can also be considered as an index indicating the softness of the rubber composition. Therefore, when the AE amount of the tread is increased to a certain extent, it is possible to sufficiently secure the contact area with the road surface even during high-speed driving, and it is also possible to suppress heat generation due to the concentration of the contact pressure, thus improving high-speed durability.

[0030] The measurement of the acetone extract (AE) can be carried out in accordance with JIS K 6229:2015. Specifically, the vulcanized rubber test piece cut out from the measurement site is immersed in acetone for a predetermined time, and the mass reduction rate (%) of the test piece is obtained to obtain AE (% by mass).

[0031] More specifically, at normal temperature and normal pressure, each vulcanized rubber test piece is immersed in acetone for 72 hours to extract the soluble components, the mass of each test piece before and after extraction is measured, and it can be obtained by the following formula. Acetone extraction amount (%) = {(mass of the rubber test piece before extraction - mass of the rubber test piece after extraction) / (mass of the rubber test piece before extraction)} × 100

[0032] Also, the above-mentioned acetone extract can be appropriately changed by changing the blending ratio of the plasticizer in the rubber composition.

[0033] Note that the AE amount is more preferably 17% by mass or more. On the other hand, as the upper limit, for example, it is preferably 25% by mass or less, and more preferably 20% by mass or less.

[0034] (3) The product of the diameter (mm) of the band cord and the thickness (mm) of the tread As a result of further studies by the present inventor, when the product of the diameter (mm) of the belt cord and the tread thickness (mm) is less than 5.0, the above-described effects cooperate with each other, and it is considered that the overall performance of high-speed durability and rolling resistance can be improved. In addition, the product of the diameter (mm) of the belt cord and the tread thickness (mm) is more preferably 3.0 or less, and even more preferably 2.5 or less. As the lower limit, for example, it is preferably 1.0 or more, more preferably 1.5 or more, and even more preferably 2.0 or more.

[0035] In the above description, the tread is described as a single layer, but it may be composed of two or more layers. In that case, it is preferable that the outermost layer (cap tread layer) on the ground contact side satisfies the above parameters.

[0036] [2] More preferred embodiments of the tire according to the present invention The tire according to the present invention can obtain a greater effect by adopting the following embodiments.

[0037] 1. Belt cord In the present invention, as the belt cord constituting the belt, a steel cord is preferable, and it is preferably a cord composed of 4 or less filaments from the viewpoint of reducing the weight of the tire. As the lower limit, for example, it is preferably 1 or more. The belt cord can select a twisting method such as single twist (for example, 1×2 structure, etc.) or layer twist (for example, 2+2 structure, etc.) for 1 to 4 filaments, and can also select a non-twisted one (untwisted).

[0038] In addition, the number of cord ends per 50 mm width is preferably 20 or more, and more preferably 30 or more. As the upper limit, for example, it is preferably 60 or less, and more preferably 50 or less.

[0039] 2. Particle size of silica In the present invention, the rubber composition for a tread preferably contains silica. At this time, if the particle size (average primary particle size) of the silica is too small, the processability deteriorates. Therefore, it is preferable to use silica having a particle size exceeding 8 nm, more preferably 9 nm or more, and even more preferably 10 nm or more. On the other hand, from the viewpoints of ensuring the reinforcing property of the rubber and ensuring the handling stability performance on a wet road surface during running, it is preferably 25 nm or less, more preferably 20 nm or less, and even more preferably 17 nm or less.

[0040] The average primary particle size of silica means the average value of the values measured by observing the minimum particle unit of silica constituting the aggregated structure as a circle and taking the absolute maximum length of the minimum particle as the diameter of the circle. It can be observed with a transmission or scanning electron microscope, and more than 400 primary particles of silica observed in the visual field are measured, and the average value can be obtained therefrom.

[0041] Specifically, the silica taken out from the rubber composition cut out from the tire is directly observed using an electron microscope or the like, the equivalent cross-sectional diameter is calculated from the area of each silica particle obtained, and the average value is obtained, whereby the average primary particle size can be calculated.

[0042] 3. Resin component Further, the rubber composition forming the tread preferably contains a resin component.

[0043] When the rubber composition contains a resin component, the adhesiveness of the resin component improves the ground contact property with the road surface, and thus it is considered that the rolling resistance during starting can be further improved.

[0044] Preferred resin components include rosin resins, styrene resins, coumarone resins, terpene resins, C5 resins, C9 resins, C5C9 resins, acrylic resins, etc., which will be described later. Among these, styrene resins such as α-methylstyrene are more preferred. And as the content relative to 100 parts by mass of the rubber component, it 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.

[0045] [3] Embodiments Hereinafter, the present invention will be specifically described based on the embodiments.

[0046] 1. Tire according to this embodiment FIG. 1 is a schematic cross-sectional view for explaining the tire according to this embodiment. In FIG. 1, the vertical direction is the radial direction of the tire, the left-right direction is the rotational axis direction of the tire, and the direction perpendicular to the paper surface is the circumferential direction of the tire. In FIG. 1, the dashed-dotted line CL represents the equatorial plane of the tire. Since the shape of this tire is symmetric with respect to the equatorial plane except for the tread pattern, 1 / 4 of the entire tire is shown in FIG. 1.

[0047] As shown in FIG. 1, the tire 1 includes a tread 2, a pair of sidewalls 3, a pair of chafer 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, the belt 8, the band 10, and the tread 2 are arranged from the inner side to the outer side in the tire radial direction.

[0048] With such a configuration, as described above, a single yarn twisted to include PET fibers is used as the band cord to appropriately form the tread. Furthermore, by appropriately controlling the product of the diameter (mm) of the band cord and the thickness (mm) of the tread, it is possible to improve the overall performance of high-speed durability and rolling resistance.

[0049] 2. Rubber composition for tread In the present embodiment, the tread rubber composition can be obtained by kneading various compounding materials such as a rubber component, a reinforcing material, an antioxidant, an oil, a resin material, and an antioxidant.

[0050] (1) Compounding materials (a) Rubber component The rubber component is not particularly limited. 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 may be used alone or in combination of two or more. In the present invention, the combined use of NR, SBR, and BR is preferred.

[0051] (i) 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 (amount of 1,2-bonded butadiene units) 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 70% by mass, more preferably less than 40% by mass, and even more preferably less than 30% by mass. The structure identification (measurement of styrene content and vinyl content) of SBR can be performed using, for example, an apparatus of the JNM-ECA series manufactured by JEOL Ltd.

[0052] 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. Further, hydrogenated SBR obtained by hydrogenating the butadiene moiety in SBR may be used, and the hydrogenated SBR may be obtained by post-hydrogenation treatment of the BR moiety in SBR, or styrene, ethylene, and butadiene may be copolymerized to obtain a similar structure.

[0053] The modified SBR is preferably an SBR having a functional group that interacts with a filler such as silica. For example, a terminal-modified SBR (a terminal-modified SBR having the above functional group at the terminal) in which at least one terminal of SBR is modified with a compound (modifying agent) having the above functional group, a main-chain modified SBR having the above functional group in the main chain, a main-chain terminal-modified SBR having the above functional group in the main chain and at the terminal (for example, a main-chain terminal-modified SBR having the above functional group in the main chain and at least one terminal modified with the above modifying agent), a terminal-modified SBR modified (coupled) with a polyfunctional compound having two or more epoxy groups in the molecule and having a hydroxyl group or an epoxy group introduced therein, etc. may be mentioned.

[0054] Examples of the above functional group include an amino group, an amide group, a silyl group, an alkoxysilyl group, an isocyanate group, an imino group, an imidazole group, a urea group, an ether group, a carbonyl group, an oxycarbonyl group, a mercapto group, a sulfide group, a disulfide group, a sulfonyl group, a sulfinyl group, a thiocarbonyl group, an ammonium group, an imide group, a hydrazo group, an azo group, a diazo group, a carboxyl group, a nitrile group, a pyridyl group, an alkoxy group, a hydroxyl group, an oxy group, an epoxy group, etc. Note that these functional groups may have substituents.

[0055] Further, as the modified SBR, for example, an SBR modified with a compound (modifying agent) represented by the following formula can be used.

[0056]

Chemical formula

[0057] In the formula, R 1 , R 2 and R 3 are the same or different and represent an alkyl group, an alkoxy group, a silyloxy group, an acetal group, a carboxyl group (-COOH), a mercapto group (-SH) or a derivative thereof. R 4 and R 5 are the same or different and represent a hydrogen atom or an alkyl group. R 4 and R 5 may combine to form a ring structure together with a nitrogen atom. n represents an integer.

[0058] As the modified SBR modified with the compound (modifying agent) represented by the above formula, SBR in which the polymerization terminal (active terminal) of solution-polymerized styrene-butadiene rubber (S-SBR) is modified with the compound represented by the above formula (modified SBR described in JP-A-2010-111753, etc.) can be used.

[0059] R 1 , R 2 and R 3 are preferably an alkoxy group (preferably an alkoxy group having 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms). R 4 and R 5 are 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 still more preferably 3. Further, when R 4 and R 5 combine to form a ring structure together with a nitrogen atom, a 4- to 8-membered ring is preferable. 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).

[0060] Specific examples of the above-mentioned modifier include 2-dimethylaminoethyltrimethoxysilane, 3-dimethylaminopropyltrimethoxysilane, 2-dimethylaminoethyltriethoxysilane, 3-dimethylaminopropyltriethoxysilane, 2-diethylaminoethyltrimethoxysilane, 3-diethylaminopropyltrimethoxysilane, 2-diethylaminoethyltriethoxysilane, 3-diethylaminopropyltriethoxysilane, etc. These may be used alone or in combination of two or more kinds.

[0061] In addition, as the modified SBR, modified SBR modified with the following compounds (modifying agents) can also be used. Examples of the modifying agents include polyglycidyl ethers of polyhydric alcohols such as ethylene glycol diglycidyl ether, glycerin triglycidyl ether, trimethylolethane triglycidyl ether, trimethylolpropane triglycidyl ether; polyglycidyl ethers of aromatic compounds having two or more phenolic groups such as diglycidylated bisphenol A; polyepoxy compounds such as 1,4-diglycidylbenzene, 1,3,5-triglycidylbenzene, polyepoxidized liquid polybutadiene; epoxy group-containing tertiary amines such as 4,4'-diglycidyl-diphenylmethylamine, 4,4'-diglycidyl-dibenzylmethylamine; diglycidylamino compounds such as diglycidylaniline, N,N'-diglycidyl-4-glycidyloxyaniline, diglycidyl orthotoluidine, tetraglycidyl metaxylenediamine, tetraglycidylaminodiphenylmethane, tetraglycidyl-p-phenylenediamine, diglycidylaminomethylcyclohexane, tetraglycidyl-1,3-bisaminomethylcyclohexane; amino group-containing acid chlorides such as bis-(1-methylpropyl)carbamic acid chloride, 4-morpholinecarbonyl chloride, 1-pyrrolidinecarbonyl chloride, N,N-dimethylcarbamic acid chloride, N,N-diethylcarbamic acid chloride; epoxy group-containing silane compounds such as 1,3-bis-(glycidyloxypropyl)-tetramethyldisiloxane, (3-glycidyloxypropyl)-pentamethyldisiloxane;(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 and other sulfide group-containing silane compounds; 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, N,N-bis(trimethylsilyl)aminoethyltriethoxysilane; (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, N,N,N',N'-bis-(tetraethylamino)benzophenone; benzaldehyde compounds having an amino group and / or a substituted amino group such as 4-N,N-dimethylaminobenzaldehyde, 4-N,N-diphenylaminobenzaldehyde, 4-N,N-divinylaminobenzaldehyde; N-substituted pyrrolidones such as N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, N-phenyl-2-pyrrolidone, N-t-butyl-2-pyrrolidone, N-methyl-5-methyl-2-pyrrolidone; N-substituted piperidones such as N-methyl-2-piperidone, N-vinyl-2-piperidone, N-phenyl-2-piperidone;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, N-phenyl-β-propiolactam; In addition, N,N-bis-(2,3-epoxypropoxy)-aniline, 4,4-methylene-bis-(N,N-glycidylaniline), tris-(2,3-epoxypropyl)-1,3,5-triazine-2,4,6-trione, 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-dimethylaminoacetophenone, 4-N,N-diethylaminoacetophenone, 1,3-bis(diphenylamino)-2-propanone, 1,7-bis(methylethylamino)-4-heptanone and the like can be mentioned. Note that the modification with the above compound (modifying agent) can be carried out by a known method.;

[0062] As the SBR, for example, SBR manufactured and sold by Sumitomo Chemical Co., Ltd., ENEOS MATERIALS Co., Ltd., Asahi Kasei Corporation, Zeon Corporation, etc. can be used. Note that the SBR may be used alone or in combination of two or more kinds.

[0063] The content of SBR in 100 parts by mass of the rubber component is preferably 40 parts by mass or more, more preferably 45 parts by mass or more, and still more preferably 50 parts by mass or more. As the upper limit, for example, it is preferably 70 parts by mass or less, more preferably 65 parts by mass or less, and still more preferably 60 parts by mass or less.

[0064] (b) Isoprene rubber Examples of the isoprene rubber include natural rubber (NR), isoprene rubber (IR), modified NR, modified NR, modified IR, etc. NR is preferable in terms of excellent strength.

[0065] As the NR, for example, those commonly used in the tire industry such as SVR-L, SIR20, RSS#3, TSR20, etc. can be used. The IR is not particularly limited, and for example, those commonly used in the tire industry such as IR2200 manufactured by Nippon Zeon Co., Ltd. can be used. As the modified NR, deproteinized natural rubber (DPNR), high-purity natural rubber (UPNR), etc. can be used. As the modified NR, epoxidized natural rubber (ENR), hydrogenated natural rubber (HNR), grafted natural rubber, etc. can be used. As the modified IR, epoxidized isoprene rubber, hydrogenated isoprene rubber, grafted isoprene rubber, etc. can be mentioned. These may be used alone or in combination of two or more.

[0066] The content of isoprene rubber in 100 parts by mass of the rubber component is preferably 5 parts by mass or more, more preferably 10 parts by mass or more. As the upper limit, for example, it is preferably 20 parts by mass or less, more preferably 15 parts by mass or less.

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

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

[0069] [Chemical formula]

[0070] In the formula, R 1 , R 2and R 3 is, independently or identically, an alkyl group, an alkoxy group, a silyloxy group, an acetal group, a carboxyl group (-COOH), a mercapto group (-SH), or a derivative thereof. R 4 and R 5 is, independently or identically, a hydrogen atom or an alkyl group. R 4 and R 5 may combine to form a ring structure together with the nitrogen atom. n represents an integer.

[0071] Examples of the modified BR modified with the compound (modifying agent) represented by the above formula include BR modified at the polymerization terminal (active terminal) with the compound represented by the above formula.

[0072] R 1 、R 2 and R 3 is preferably an alkoxy group (preferably an alkoxy group having 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms). R 4 and R 5 is 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 still more preferably 3. Also, when R 4 and R 5 combine to form a ring structure together with the nitrogen atom, it is preferably a 4- to 8-membered ring. 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).

[0073] Specific examples of the above modifying agent include 2-dimethylaminoethyltrimethoxysilane, 3-dimethylaminopropyltrimethoxysilane, 2-dimethylaminoethyltriethoxysilane, 3-dimethylaminopropyltriethoxysilane, 2-diethylaminoethyltrimethoxysilane, 3-diethylaminopropyltrimethoxysilane, 2-diethylaminoethyltriethoxysilane, 3-diethylaminopropyltriethoxysilane, etc. These may be used alone or in combination of two or more.

[0074] Also, as the modified BR, modified BR modified with the following compounds (modifying agents) can also be used. Examples of the modifying agent include polyglycidyl ethers of polyhydric alcohols such as ethylene glycol diglycidyl ether, glycerin triglycidyl ether, trimethylolethane triglycidyl ether, trimethylolpropane triglycidyl ether; polyglycidyl ethers of aromatic compounds having two or more phenol groups such as diglycidylated bisphenol A; polyepoxy compounds such as 1,4-diglycidylbenzene, 1,3,5-triglycidylbenzene, polyepoxidized liquid polybutadiene; epoxy group-containing tertiary amines such as 4,4'-diglycidyl-diphenylmethylamine, 4,4'-diglycidyl-dibenzylmethylamine; diglycidylamino compounds such as diglycidylaniline, N,N'-diglycidyl-4-glycidyloxyaniline, diglycidyl orthotoluidine, tetraglycidyl metaxylenediamine, tetraglycidylaminodiphenylmethane, tetraglycidyl-p-phenylenediamine, diglycidylaminomethylcyclohexane, tetraglycidyl-1,3-bisaminomethylcyclohexane; amino group-containing acid chlorides such as bis-(1-methylpropyl)carbamic acid chloride, 4-morpholinecarbonyl chloride, 1-pyrrolidinecarbonyl chloride, N,N-dimethylcarbamic acid chloride, N,N-diethylcarbamic acid chloride; epoxy group-containing silane compounds such as 1,3-bis-(glycidyloxypropyl)-tetramethyldisiloxane, (3-glycidyloxypropyl)-pentamethyldisiloxane;(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 and other sulfide group-containing silane compounds; 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, N,N-bis(trimethylsilyl)aminoethyltriethoxysilane; (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, N,N,N',N'-bis-(tetraethylamino)benzophenone; benzaldehyde compounds having an amino group and / or a substituted amino group such as 4-N,N-dimethylaminobenzaldehyde, 4-N,N-diphenylaminobenzaldehyde, 4-N,N-divinylaminobenzaldehyde; N-substituted pyrrolidones such as N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, N-phenyl-2-pyrrolidone, N-t-butyl-2-pyrrolidone, N-methyl-5-methyl-2-pyrrolidone; N-substituted piperidones such as N-methyl-2-piperidone, N-vinyl-2-piperidone, N-phenyl-2-piperidone;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, N-phenyl-β-propiolactam; In addition, N,N-bis-(2,3-epoxypropoxy)-aniline, 4,4-methylene-bis-(N,N-glycidylaniline), tris-(2,3-epoxypropyl)-1,3,5-triazine-2,4,6-trione, 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-dimethylaminoacetophenone, 4-N,N-diethylaminoacetophenone, 1,3-bis(diphenylamino)-2-propanone, 1,7-bis(methylethylamino)-4-heptanone and the like can be mentioned. Note that the modification with the above compound (modifying agent) can be carried out by a known method. These modified BRs may be used alone or in combination of two or more kinds.;

[0075] As the BR, for example, products of Ube Industries, Ltd., ENEOS MATERIALS Co., Ltd., Asahi Kasei Corporation, Nippon Zeon Co., Ltd. and the like can be used.

[0076] The content of BR in 100 parts by mass of the rubber component is preferably 25 parts by mass or more, more preferably 30 parts by mass or more. On the other hand, it is preferably 40 parts by mass or less, more preferably 35 parts by mass or less.

[0077] (ii) Other rubber components The rubber composition may contain, as other rubber components, rubber (polymer) generally used in the production of tires such as nitrile rubber (NBR), if necessary.

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

[0079] The monomers obtained by recycling (recycled monomers) are not particularly limited, and examples include isoprene derived from recycling, butadiene derived from recycling, and aromatic vinyl derived from recycling. Examples of the butadiene include 1,2-butadiene and 1,3-butadiene. The aromatic vinyl is not particularly limited, and examples include styrene. Among them, it is preferable to use isoprene derived from recycling (recycled isoprene), butadiene (recycled butadiene), and / or styrene derived from recycling (recycled styrene) as raw materials.

[0080] The method for producing recycled monomers is not particularly limited, and examples include being synthesized from recycled naphtha obtained by decomposing rubber products such as tires. Also, 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 high pressure, decomposed by microwaves, or extracted after mechanical pulverization.

[0081] Furthermore, the raw materials (monomers) of synthetic rubbers such as IR, SBR, and BR may be derived from biomass. Here, biomass refers to substances derived from natural resources such as plants. Biomass is not particularly limited, and examples include agricultural and forestry products, sugar, wood, plant residues after obtaining useful components, ethanol derived from plants, biomass naphtha, and the like. The monomers derived from biomass (biomass monomers) are not particularly limited, and examples include butadiene derived from biomass and aromatic vinyl derived from biomass. Examples of the butadiene include 1,2-butadiene and 1,3-butadiene. The aromatic vinyl is not particularly limited, and examples include styrene. Also, the method for producing biomass monomers is not particularly limited, and examples include those by biological and / or chemical and / or physical conversion of animals and plants. Fermentation by microorganisms is typical of biological conversion, and examples of chemical and / or physical conversion include those by catalysts, high heat, high pressure, electromagnetic waves, supercritical fluids, and combinations thereof.

[0082] The polymers synthesized from biomass monomer components (biomass polymers) are not particularly limited, and examples include polybutadiene rubber synthesized from butadiene derived from biomass, and aromatic vinyl / butadiene copolymers synthesized from butadiene derived from biomass and / or aromatic vinyl derived from biomass. Examples of the aromatic vinyl / butadiene copolymer include styrene-butadiene rubber synthesized from butadiene derived from biomass and / or styrene derived from biomass.

[0083] Whether the raw material of the polymer is derived from biomass can be determined by pMC (percent Modern Carbon) measured in accordance with ASTM D6866-10.

[0084] pMC refers to the 14 C concentration of the sample relative to that of the 14It is the ratio of C concentration, and this value is used as an index indicating the biomass ratio of the compound (rubber). The significance of this value will be described below.

[0085] In 1 mole (6.02×10 23 pieces) of carbon atoms, there are approximately 6.02×10 11 pieces, which is about one trillionth of the normal carbon atoms. 14 C exists. 14 14C is called a radioactive isotope, and its half-life is 5730 years and it decreases regularly. It takes 226,000 years for all of these to decay. Therefore, after carbon dioxide in the atmosphere and the like are taken up by plants and the like and immobilized, in fossil fuels such as coal, oil, and natural gas, which are considered to have passed more than 226,000 years since the initial immobilization, 14 all of the 14C elements have decayed. Therefore, in the 21st century, at present, fossil fuels such as coal, oil, and natural gas do not contain 14 any 14C elements at all. Therefore, chemical substances produced from these fossil fuels also do not contain 14 any 14C elements at all.

[0086] On the other hand, 14 14C is constantly generated by nuclear reactions of cosmic rays in the atmosphere and is in balance with the decrease due to radioactive decay. In the earth's atmospheric environment, 14 the amount of 14C is a constant. Therefore, the 14C concentration of substances derived from biomass resources that are circulating in the current environment 14 is about 1×10 -12 mol% with respect to the entire C atoms as described above. Therefore, by utilizing the difference between these values, the ratio (biomass ratio) of the compound derived from natural resources (compound derived from biomass resources) in a certain compound (rubber) can be calculated.

[0087] This 14 14C is generally measured as follows. Using accelerator mass spectrometry based on a tandem accelerator, 13 14C concentration ([14C / 13 12C), 12 14C concentration ([14C / 14 12C), 14 14C / 12 Perform the measurement of (C). In the measurement, 14 As a modern standard reference for the concentration of C, the 14 C concentration in the circulating carbon in nature in 1950 is adopted. As a specific standard substance, an oxalic acid standard provided by NIST (National Institute of Standards and Technology) is used. The specific radioactivity of carbon in this oxalic acid (the radioactivity intensity of 14 C per gram of carbon) is separated for each carbon isotope, 13 For 14 C, it is corrected to a constant value, and the value obtained by applying the decay correction from 1950 AD to the measurement date is used as the value (100%) of the standard

[0088] Therefore, if the rubber is made of a 100% biomass (natural system) - derived substance, although there are regional differences, etc., in the current normal state, it often does not reach 100, so it generally shows a value of about 110 pMC. On the other hand, for chemical substances derived from fossil fuels such as petroleum, when the 14 C concentration is measured, it shows a value of about 0 pMC (for example, 0.3 pMC). This value corresponds to a biomass ratio of 0% mentioned above.

[0089] From the above, using materials such as rubber with a high pMC value, that is, materials such as rubber with a high biomass ratio, in the rubber composition is suitable from the perspective of environmental protection (sustainable).

[0090] (b) Compound materials other than the rubber component (i) Filler The rubber composition preferably contains silica or carbon black as a reinforcing agent, but may contain other fillers as necessary, for example, calcium carbonate, talc, alumina, clay, aluminum hydroxide, mica, etc. When using silica, it is preferably used in combination with a silane coupling agent.

[0091] As the compounding amount of the filler, it is preferable to contain at least more than 75 parts by mass of silica with respect to 100 parts by mass of the rubber component. However, the total compounding amount with other fillers is preferably 80 parts by mass or more, more preferably 90 parts by mass or more with respect to 100 parts by mass of the rubber component. On the other hand, from the viewpoint of dispersibility in the rubber composition, it is preferably 150 parts by mass or less, more preferably 100 parts by mass or less.

[0092] (i) silica Since silica has OH groups on its surface, by containing more than 75 parts by mass, hydrogen bonds are formed between the silica surfaces and it also interacts with the rubber component. Therefore, during driving, force can be easily generated and transmitted inside the rubber, making it easier to transmit the force generated during turning, and excellent handling stability can be ensured. In addition, the OH groups on the surface can capture ozone, so the ozone resistance is improved and the durability of the tire can be improved. The content of silica is more preferably 80 parts by mass or more, even more preferably 90 parts by mass or more with respect to 100 parts by mass of the rubber component. The upper limit is preferably, for example, 150 parts by mass or less, more preferably 100 parts by mass or less.

[0093] The BET specific surface area of silica is preferably more than 100 m 2 / g, more preferably more than 130 m 2 / g from the viewpoint of obtaining good durability performance. On the other hand, it is preferably less than 250 m 2 / g, more preferably less than 200 m 2 / g. The above-mentioned BET specific surface area is the value of N2SA measured by the BET method in accordance with ASTM D3037-93.

[0094] The silica is not particularly limited, and for example, silica prepared by a dry method (anhydrous silica), silica prepared by a wet method (hydrous silica), etc., which are common in the tire industry, can be used. As commercially available products, products of Evonik Industries, Rhodia, Tosoh Silica Corporation, Solvay Japan K.K., Tokuyama Corporation, etc. can be used.

[0095] The raw material of the silica is not particularly limited, and for example, it may be a raw material derived from a mineral such as quartz, or it may be a raw material derived from a living organism such as rice husk (for example, silica using a biomass material such as rice husk as a raw material), or silica recycled from a product containing silica may be used. Among them, hydrous silica prepared by a wet method is preferable because it has many silanol groups.

[0096] Silica using a biomass material as a raw material (biomass silica) can be obtained, for example, by extracting silicate from rice husk ash obtained by burning rice husks using a sodium hydroxide solution, and reacting the silicate with sulfuric acid in the same manner as conventional wet silica to precipitate silicon dioxide, followed by filtration, washing with water, drying, and pulverization.

[0097] Silica recycled from a product containing silica (recycled silica) can be used, for example, silica recovered from products containing silica such as electronic components such as semiconductors, tires, desiccants, and filter materials such as diatomaceous earth. The recovery method is not particularly limited, and examples include pyrolysis and decomposition by electromagnetic waves. Among them, silica recovered from electronic components such as semiconductors or tires is preferable.

[0098] When silica crystallizes, it does not dissolve in water and the silicic acid that is its component cannot be utilized. By controlling the combustion temperature and combustion time, crystallization of silica in rice husk ash can be suppressed (see, for example, Japanese Patent Application Laid-Open No. 2009-2594, Akita Prefectural University Web Journal B / 2019, vol. 6, p. 216-222, etc.).

[0099] Amorphous silica extracted from rice husks can be those commercially available from Wilmar Co., Ltd. and the like.

[0100] These silicas may be used alone or in combination of two or more. It is preferable to use sustainable silicas such as biomass silica and recycled silica from the viewpoint of environmental protection.

[0101] As described above, the content of silica relative to 100 parts by mass of the rubber component is more than 75 parts by mass with respect to 100 parts by mass of the rubber component, more preferably 80 parts by mass or more, and even more preferably 90 parts by mass or more. As the upper limit, for example, it is preferably 150 parts by mass or less, and more preferably 100 parts by mass or less.

[0102] (ii) Silane coupling agent When using silica, it is preferable to use a silane coupling agent in combination in order to enhance the dispersibility of silica and improve mechanical properties and moldability by reaction with silica.

[0103] The silane coupling agent is not particularly limited. 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, bis(4-trimethoxysilylbutyl)trisulfide, bis(3-triethoxysilylpropyl)disulfide, bis(2-triethoxysilylethyl)disulfide, bis(4-triethoxysilylbutyl)disulfide, bis(3-trimethoxysilylpropyl)disulfide, bis(2-trimethoxysilylethyl)disulfide, bis(4-trimethoxysilylbutyl)disulfide, 3-trimethoxysilylpropyl-N,N-dimethylthiocarbamoyl tetrasulfide, 2-triethoxysilylethyl-N,N-dimethylthiocarbamoyl tetrasulfide, 3-triethoxysilylpropyl methacrylate monosulfide, etc. sulfide-based, 3-mercaptopropyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, mercapto-based such as NXT and NXT-Z manufactured by Momentive, vinyl-based such as vinyltriethoxysilane and vinyltrimethoxysilane, amino-based such as 3-aminopropyltriethoxysilane and 3-aminopropyltrimethoxysilane, glycidoxy-based such as γ-glycidoxypropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane, nitro-based such as 3-nitropropyltrimethoxysilane and 3-nitropropyltriethoxysilane, chloro-based such as 3-chloropropyltrimethoxysilane and 3-chloropropyltriethoxysilane, etc. can be mentioned. Among these, a silane coupling agent having a thiocarbonyl group such as the above-mentioned NXT is preferable. These may be used alone or in combination of two or more.

[0104] As the silane coupling agent, for example, products of Evonik Industries, Momentive, Shin-Etsu Silicone Co., Ltd., Tokyo Chemical Industry Co., Ltd., Azmax Co., Ltd., Toray Dow Corning Co., Ltd. etc. can be used.

[0105] The content of the silane coupling agent is preferably, for example, more than 3 parts by mass, more preferably 5 parts by mass or more, and even more preferably 7 parts by mass or more with respect to 100 parts by mass of silica. As the upper limit, it is preferably, for example, less than 15 parts by mass, more preferably 12 parts by mass or less, and even more preferably 9 parts by mass or less.

[0106] (iii) Carbon black Carbon black is preferably used for the purpose of improving the crack growth resistance, durability, ultraviolet degradation resistance, etc. of the tire.

[0107] The nitrogen adsorption specific surface area (N2SA) of carbon black is, from the viewpoint of the reinforcement to rubber, for example, preferably 30 m 2 / g or more, more preferably 50 m 2 / g or more, and even more preferably 60 m 2 / g or more. On the other hand, from the viewpoint of heat generation property, it is preferably 250 m 2 / g or less, more preferably 150 m 2 / g or less, and even more preferably 120 m 2 / g or less. The nitrogen adsorption specific surface area of carbon black is measured according to ASTM D4820-93.

[0108] The dibutyl phthalate (DBP) absorption amount of carbon black is, from the viewpoint of the rigidity of rubber, for example, preferably 50 ml / 100 g or more, more preferably 100 ml / 100 g or more. On the other hand, from the viewpoint of the followability to the deformation of rubber, it is preferably 250 ml / 100 g or less, more preferably 150 ml / 100 g or less. The DBP absorption amount of carbon black is measured according to ASTM D2414-93.

[0109] The carbon black is not particularly limited, and examples include furnace black (furnace carbon black) such as SAF, ISAF, HAF, MAF, FEF, SRF, GPF, APF, FF, CF, SCF, and ECF; acetylene black (acetylene carbon black); thermal black (thermal carbon black) such as FT and MT; channel black (channel carbon black) such as EPC, MPC, and CC. Also, examples of the product numbers include N134, N110, N220, N234, N219, N339, N330, N326, N351, N550, N762, etc. These may be used alone or in combination of two or more.

[0110] In addition to mineral oil, the raw material of carbon black may be biomass materials such as lignin and vegetable oil, or pyrolysis oil obtained by pyrolyzing rubber products containing carbon black such as waste tires (recycled carbon black). Using these sustainable carbon blacks is preferable from the perspective of environmental protection.

[0111] Also, the manufacturing method of carbon black may be by combustion such as the furnace method, by hydrothermal carbonization (HTC), or by thermal decomposition of methane such as the thermal black method.

[0112] As commercially available products, products of Asahi Carbon Co., Ltd., Cabot Japan Co., Ltd., Tokai Carbon Co., Ltd., Mitsubishi Chemical Corporation, Lion Corporation, Nippon Steel Carbon Co., Ltd., Columbian Carbon Company, etc. can be used. These may be used alone or in combination of two or more.

[0113] The content of carbon black relative to 100 parts by mass of the rubber component is preferably 5 parts by mass or more, more preferably 10 parts by mass or more. As the upper limit, for example, it is preferably 25 parts by mass or less, more preferably 20 parts by mass or less.

[0114] (iv) Other fillers In addition to the carbon black and silica described above, the rubber composition may further contain fillers generally used in the tire industry, such as graphite, calcium carbonate, talc, alumina, clay, aluminum hydroxide, mica, magnesium sulfate, etc. The content of these fillers is, for example, more than 0.1 part by mass and less than 150 parts by mass with respect to 100 parts by mass of the rubber component.

[0115] (b) Softening agent component In the rubber composition, from the viewpoint of imparting plasticity to the rubber component and appropriately dispersing the powder material during kneading, it is preferable to use a softening agent component as needed. Here, the softening agent component is a concept including both softening agents that are liquid at 25°C and softening agents that are solid at 25°C.

[0116] Examples of softening agents include resin components, oils, liquid polymers, ester plasticizers, etc. These softening agents may be derived from mineral resources such as petroleum and natural gas, may be derived from biomass, or may be derived from naphtha recycled from rubber products or non-rubber products. Also, low molecular weight hydrocarbon components obtained by pyrolyzing and extracting used tires and products containing various components may be used as softening agents. Among these, softening agents derived from biomass or recycling are preferable as sustainable softening agents.

[0117] In addition, these softening agents may be used alone or in combination of two or more. The content of the plasticizer component with respect to 100 parts by mass of the rubber component is preferably 15 parts by mass or more, more preferably 20 parts by mass or more, and even more preferably 25 parts by mass or more. The upper limit is preferably, for example, 40 parts by mass or less, more preferably 35 parts by mass or less, and even more preferably 30 parts by mass or less. Note that the content of the plasticizer component includes the amount of oil contained in rubber (oil-extended rubber), etc.

[0118] (i) Oil Examples of oils include mineral oils, vegetable oils, animal oils, etc. Also, from the perspective of life cycle assessment, refined waste oil used in rubber mixers or engines, or refined waste cooking oil used in restaurants may be used.

[0119] (i-1) Mineral oil Mineral oil refers to oil derived from mineral resources such as petroleum and natural gas. Examples of mineral oils include paraffinic oils (mineral oils), naphthenic oils, aromatic oils, etc.

[0120] Specific examples of mineral oils include, for example, MES (Mild Extract Solvated), DAE (Distillate Aromatic Extract), TDAE (Treated Distillate Aromatic Extract), TRAE (Treated Residual Aromatic Extract), RAE (Residual Aromatic Extract), etc.

[0121] Also, oils with a low content of polycyclic aromatic (PCA) compounds can be used for environmental protection. Examples of such low-PCA-content oils include MES, TDAE, and heavy naphthenic oils.

[0122] Examples of commercially available mineral oils include, for example, paraffinic, aromatic, and naphthenic oils. Products of, for example, Idemitsu Kosan Co., Ltd., Sankyo Yuka Kogyo Co., Ltd., ENEOS Co., Ltd., Orisoy Co., H&R Co., Toyokuni Oil Co., Ltd., Showa Shell Sekiyu K.K., Fuji Kogyo Co., Ltd., etc. can be used. These may be used alone or in combination of two or more.

[0123] (i-2) Vegetable oil Examples of vegetable oils include linseed 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 oil, sunflower oil, coconut oil, palm oil, palm kernel oil, olive oil, camellia oil, jojoba oil, macadamia nut oil, peanut oil, grape seed oil, and wood rosin.

[0124] Furthermore, examples of vegetable oils include refined oils (such as salad oil) obtained by refining each of the above oils, transesterified oils obtained by transesterification, hydrogenated hardened oils, thermally polymerized oils obtained by thermal polymerization, oxidation polymerized oils obtained by oxidation, and waste cooking oils recovered from those used as edible oils, etc. Note that the vegetable oil may be liquid or solid at normal temperature (25°C). These may be used alone or in combination of two or more.

[0125] The vegetable oil preferably contains acylglycerol, and more preferably contains triacylglycerol. Note that acylglycerol refers to a compound in which the hydroxy group of glycerin and a fatty acid are ester-bonded. 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 multimer of trimer or more. Note that acylglycerols of dimer or more can be obtained by thermal polymerization, oxidation polymerization, etc. Also, the acylglycerol may be liquid or solid at normal temperature (25°C).

[0126] The method for confirming whether acylglycerol is contained in the rubber composition is not particularly limited, but 1 it can be confirmed by 1H-NMR measurement. For example, a rubber composition containing triacylglycerol is immersed in deuterated chloroform at normal temperature (25°C) for 24 hours. After removing the rubber composition, at room temperature 1When measuring 1H-NMR and setting the signal of tetramethylsilane (TMS) to 0.00 ppm, signals around 5.26 ppm, around 4.28 ppm, and around 4.15 ppm were observed. Since these signals are presumed to be signals derived from hydrogen atoms bonded to carbon atoms adjacent to the oxygen atoms of the ester group, the content of acylglycerol can be confirmed. Here, "around" refers to the range of ±0.10 ppm.

[0127] The fatty acid is not particularly limited and may be an unsaturated fatty acid or a saturated fatty acid. 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.

[0128] Among them, it is desirable that the fatty acid contains a fatty acid with few double bonds, that is, a saturated fatty acid or a monounsaturated fatty acid, and oleic acid is preferred. As the vegetable oil containing such a fatty acid, for example, a vegetable oil containing a saturated fatty acid or a monounsaturated fatty acid may be used, or a modified vegetable oil obtained by transesterification or the like may be used. In addition, in order to produce a vegetable oil containing such a fatty acid, plants may be improved by varietal improvement, genetic recombination, genome editing, or the like.

[0129] As the vegetable oil, for example, those commercially available from Idemitsu Kosan Co., Ltd., Sankyo Yuka Kogyo Co., Ltd., ENEOS Co., Ltd., Olisoy Co., Ltd., H&R Co., Ltd., Toyokuni Oil Co., Ltd., Fuji Kogyo Co., Ltd., Nisshin Oillio Group Co., Ltd., etc. can be used.

[0130] (ii) Liquid rubber Liquid rubber is a polymer in a liquid state at room temperature (25°C) and is a rubber component that can be extracted from the vulcanized tire by acetone extraction. Examples of liquid rubber include farnesene-based polymers, liquid diene-based polymers, and hydrogenated products thereof.

[0131] The farnesene-based polymer is a polymer obtained by polymerizing farnesene and has a structural unit 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).

[0132] The farnesene-based polymer may be a homopolymer of farnesene (farnesene homopolymer) or a copolymer of farnesene and a vinyl monomer (farnesene-vinyl monomer copolymer).

[0133] Examples of the liquid diene-based polymer include liquid styrene-butadiene copolymer (liquid SBR), liquid butadiene polymer (liquid BR), liquid isoprene polymer (liquid IR), liquid styrene-isoprene copolymer (liquid SIR), and the like.

[0134] The weight average molecular weight (Mw) in terms of polystyrene measured by gel permeation chromatography (GPC) of the liquid diene-based polymer is, for example, 1.0×10 3 super, 2.0×10 5 less than. Here, the Mw of the liquid diene-based polymer is a value in terms of polystyrene measured by gel permeation chromatography (GPC).

[0135] Examples of the liquid rubber include products of Kuraray Co., Ltd., Kray Valley Co., Ltd., and the like.

[0136] (iii) Resin component The resin component also functions as an adhesiveness-imparting component and may be solid or liquid at room temperature. Specific examples of the resin component include resins such as rosin-based resins, styrene-based resins, coumarone-based resins, terpene-based resins, C5 resins, C9 resins, C5C9 resins, and acrylic resins, and two or more of them may be used in combination. These resin components may be provided with a modifying group capable of reacting with silica or the like, if necessary.

[0137] Rosin-based resins are resins mainly composed of rosin acids obtained by processing pine resin. These rosin-based resins (rosins) can be classified according to the presence or absence of modification, and can be classified into unmodified rosin (non-modified rosin) and rosin modified products (rosin derivatives). Examples of unmodified rosin include tall rosin (also known as tall oil rosin), gum rosin, wood rosin, disproportionated rosin, polymerized rosin, hydrogenated rosin, and other chemically modified rosins. Rosin modified products are modified products of unmodified rosin, and examples include rosin esters, unsaturated carboxylic acid modified rosins, unsaturated carboxylic acid modified rosin esters, amide compounds of rosin, amine salts of rosin, etc.

[0138] Styrene-based resins are polymers using styrene-based monomers as constituent monomers, and examples include polymers polymerized with styrene-based monomers as the main component (50% by mass or more). Specifically, styrene-based monomers (styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-methoxystyrene, p-tert-butylstyrene, p-phenylstyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, etc.) are each homopolymers polymerized alone, copolymers copolymerized from two or more styrene-based monomers, and also copolymers of styrene-based monomers and other monomers copolymerizable therewith.

[0139] Examples of the other monomers include acrylonitriles such as acrylonitrile and methacrylonitrile, acrylics, unsaturated carboxylic acids such as methacrylic acid, unsaturated carboxylic acid esters such as methyl acrylate and methyl methacrylate, dienes such as chloroprene, butadiene, and isoprene, olefins such as 1-butene and 1-pentene; α,β-unsaturated carboxylic acids such as maleic anhydride or their acid anhydrides; etc.

[0140] Among the coumarone resins, coumarone-indene resins are preferred. Coumarone-indene resins are resins that contain coumarone and indene as monomer components that constitute the resin skeleton (main chain). Other monomer components contained in the skeleton besides coumarone and indene include styrene, α-methylstyrene, methylindene, vinyltoluene, etc.

[0141] The hydroxyl value (OH value) of the coumarone-indene resin is, for example, more than 15 mgKOH / g and less than 150 mgKOH / g. The OH value is the amount of potassium hydroxide required to neutralize acetic acid bonded to hydroxyl groups when acetylating 1 g of the resin, expressed in milligrams, and is a value measured by potentiometric titration (JIS K 0070:1992).

[0142] The softening point of the coumarone-indene resin is, for example, more than 30° C. and less than 160° C. The softening point is the temperature at which the ball drops when the softening point specified in JIS K 6220-1:2001 is measured using a ring and ball softening point tester.

[0143] Terpene resins include polyterpene, terpene phenol, and aromatic modified terpene resins. Polyterpenes are resins obtained by polymerizing terpene compounds and their hydrogenated products. Terpene compounds are (C5H8) n The hydrocarbons and their oxygen-containing derivatives are represented by the following composition: Monoterpenes (C 10 H 16 ), sesquiterpenes (C 15 H 24 ), diterpenes (C 20 H 32 ), and examples thereof include α-pinene, β-pinene, dipentene, limonene, myrcene, alloocimene, ocimene, α-phellandrene, α-terpinene, γ-terpinene, terpinolene, 1,8-cineole, 1,4-cineole, α-terpineol, β-terpineol, and γ-terpineol.

[0144] Examples of polyterpenes include terpene resins such as α-pinene resin, β-pinene resin, limonene resin, dipentene resin, and β-pinene / limonene resin, which are made from the above-mentioned terpene compounds as raw materials, as well as hydrogenated terpene resins obtained by hydrogenating the terpene resins. Examples of terpene phenols include resins obtained by copolymerizing the above-mentioned terpene compounds and phenolic compounds, and resins obtained by hydrogenating such resins. Specifically, examples include resins obtained by condensing the above-mentioned terpene compounds, phenolic compounds, and formalin. Examples of phenolic compounds include phenol, bisphenol A, cresol, and xylenol. Examples of aromatic-modified terpene resins include resins obtained by modifying terpene resins with aromatic compounds, and resins obtained by hydrogenating such resins. The aromatic compound is not particularly limited as long as it has an aromatic ring. Examples include phenolic compounds such as phenol, alkylphenol, alkoxyphenol, and unsaturated hydrocarbon group-containing phenol; naphthol compounds such as naphthol, alkylnaphthol, alkoxynaphthol, and unsaturated hydrocarbon group-containing naphthol; styrene derivatives such as styrene, alkylstyrene, alkoxystyrene, and unsaturated hydrocarbon group-containing styrene; and coumarone and indene.

[0145] The term "C5 resin" refers to a resin obtained by polymerizing a C5 fraction. Examples of the C5 fraction include petroleum fractions corresponding to 4 to 5 carbon atoms such as cyclopentadiene, pentene, pentadiene, and isoprene. As the C5-based petroleum resin, dicyclopentadiene resin (DCPD resin) is preferably used.

[0146] "C9 resin" refers to a resin obtained by polymerizing a C9 fraction, which may be hydrogenated or modified. Examples of the C9 fraction include petroleum fractions corresponding to 8 to 10 carbon atoms such as vinyltoluene, alkylstyrene, indene, and methylindene. As specific examples, for instance, coumarone-indene resin, coumarone resin, indene resin, and aromatic vinyl resins are preferably used. Among the aromatic vinyl resins, α-methylstyrene (AMS resin) or 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 because of its economy, ease of processing, and excellent heat generation properties. As the aromatic vinyl resin, those commercially available from companies such as Crayton and Eastman Chemical can be used.

[0147] "C5C9 resin" refers to a resin obtained by copolymerizing the C5 fraction and the C9 fraction, which may be hydrogenated or modified. Examples of the C5 fraction and the C9 fraction include the above-mentioned petroleum fractions. As the C5C9 resin, those commercially available from companies such as Tosoh Corporation and LUHUA can be used.

[0148] The acrylic resin is not particularly limited, and for example, a solventless acrylic resin can be used.

[0149] The solventless acrylic resin is a (meth)acrylic resin (polymer) synthesized by a high-temperature continuous polymerization method (high-temperature continuous bulk polymerization method) (the methods described in U.S. Patent No. 4,414,370, JP-A-59-6207, JP-B-5-58005, JP-A-1-313522, U.S. Patent No. 5,010,166, and TREND2000, No. 3, p42-45 of Toagosei Research Annual Report) without using a polymerization initiator, chain transfer agent, organic solvent, etc. as auxiliary raw materials as much as possible. In the present invention, "(meth)acrylic" means methacrylic and acrylic.

[0150] Examples of the monomer components constituting the acrylic resin include (meth)acrylic acid, (meth)acrylic acid esters (such as alkyl esters, aryl esters, and aralkyl esters), (meth)acrylamide, and (meth)acrylic acid derivatives such as (meth)acrylamide derivatives.

[0151] In addition, as the monomer components constituting the acrylic resin, aromatic vinyls such as styrene, α-methylstyrene, vinyltoluene, vinylnaphthalene, divinylbenzene, trivinylbenzene, and divinylnaphthalene may be used together with (meth)acrylic acid or (meth)acrylic acid derivatives.

[0152] The acrylic resin may be a resin composed only of the (meth)acrylic component or a resin having components other than the (meth)acrylic component as constituent elements. Further, the acrylic resin may have a hydroxyl group, a carboxyl group, a silanol group, or the like.

[0153] Examples of the resin component include products of Maruzen Petrochemical Co., Ltd., Sumitomo Bakelite Co., Ltd., Yasuhara Chemical Co., Ltd., Tosoh Corporation, Rutgers Chemicals, BASF, Clayton, Nippon Paint Co., Ltd., Nippon Catalyst Co., Ltd., ENEOS Corporation, Arakawa Chemical Industries, Ltd., Tago Chemical Industry Co., Ltd., and the like.

[0154] (C) Wax The rubber composition may contain wax. The content of the wax is preferably, for example, 0.5 to 20 parts by mass, more preferably 1.0 to 15 parts by mass, and even more preferably 1.5 to 10 parts by mass with respect to 100 parts by mass of the rubber component.

[0155] The wax is not particularly limited, and any wax commonly used in the tire industry can be preferably used. For example, mineral waxes, plant-derived waxes, etc. can be mentioned. 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 them, mineral waxes are preferred.

[0156] Examples of plant-derived waxes include rice wax, carnauba wax, candelilla wax, etc. Examples of petroleum waxes include paraffin wax, microcrystalline wax, and these selected special waxes, etc., and paraffin wax is preferred. In the present invention, the wax does not contain stearic acid.

[0157] As the wax, for example, those commercially available from Ouchi Shinsei Chemical Industry Co., Ltd., Nippon Seiro Co., Ltd., Paramoelt Co., etc. can be used. These waxes may be used alone or in combination of two or more.

[0158] (ii) Antioxidant The rubber composition may contain an antioxidant. The content of the antioxidant is, for example, more than 1 part by mass and less than 10 parts by mass with respect to 100 parts by mass of the rubber component.

[0159] The anti-aging agent is not particularly limited, but examples include 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; p-phenylenediamine-based anti-aging agents such as N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD), N,N'-bis(1,4-dimethylpentyl)-p-phenylenediamine (77PD), N,N'-diphenyl-p-phenylenediamine (DPPD), N,-ditoly-p-phenylenediamine (DTPD), N-isopropyl-N'-phenyl-p-phenylenediamine (IPPD), N,N'-di-2-naphthyl-p-phenylenediamine (DNPD); quinoline-based anti-aging agents such as polymers of 2,2,4-trimethyl-1,2-dihydroquinoline; monophenol-based anti-aging agents such as 2,6-di-t-butyl-4-methylphenol and styrenated phenol; bis, tris, polyphenol-based anti-aging agents such as tetrakis-[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane. Among them, p-phenylenediamine-based anti-aging agents and quinoline-based anti-aging agents are preferred, and N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine and polymers of 2,2,4-trimethyl-1,2-dihydroquinoline are more preferred. These may be used alone or in combination of two or more kinds.

[0160] As commercially available products, for example, products of Seiko Chemical Co., Ltd., Sumitomo Chemical Co., Ltd., Ouchi Shinsei Chemical Industry Co., Ltd., Flexsys, etc. can be used.

[0161] (Co) processing aids The rubber composition may contain a processing aid. Examples of the processing aid include metal salts (compounds in which the hydrogen atoms of an acid are replaced by metal ions), fatty acid amides, amide esters, fatty acid esters, etc. These may be used alone or in combination of two or more kinds. Among them, metal salts and fatty acid amides are preferred, and metal salts are more preferred.

[0162] Examples of the metal used in the metal salt include alkali metals such as potassium and sodium, alkaline earth metals such as calcium and barium, etc. Further, magnesium, zinc, nickel, molybdenum, etc. can also be used. Among them, alkali metals are preferred.

[0163] Examples of the acid used in the metal salt include fatty acids such as lauric acid, myristic acid, palmitic acid, etc. Further, boric acid, carbonic acid, hydrochloric acid, nitric acid, sulfuric acid, etc. can also be used.

[0164] As commercially available products of the processing aid, products of Kinoshita Chemical Co., Ltd., Ken-ei Pharmaceutical Co., Ltd., Struktol, Performance Additives, etc. can be used.

[0165] The content of the processing aid is preferably 1 part by mass or more, more preferably 2 parts by mass or more, with respect to 100 parts by mass of the rubber component. As the upper limit, for example, it is preferably 6 parts by mass or less, more preferably 4 parts by mass or less.

[0166] (F) Lubricant (Stearic acid) The rubber composition may contain a lubricant. As the lubricant, lubricants based on fatty acid derivatives such as stearic acid can be preferably used. As stearic acid, conventionally known ones can be used. Specifically, for example, products of NOF Corporation, Kao Corporation, Fujifilm Wako Pure Chemical Corporation, Chiba Fatty Acids Co., Ltd., etc. can be used. Further, Struktol WB16 manufactured by Struktol can also be used.

[0167] The content of stearic acid is preferably more than 0.5 part by mass and less than 10.0 parts by mass with respect to 100 parts by mass of the rubber component.

[0168] (T) Zinc oxide The rubber composition may contain zinc oxide. The content of zinc oxide is, for example, more than 0.5 parts by mass and less than 10 parts by mass with respect to 100 parts by mass of the rubber component. As the zinc oxide, conventionally known ones can be used. For example, products of Mitsui Mining & Smelting Co., Ltd., Toho Zinc Co., Ltd., Hakusui Tech Co., Ltd., Sho Do Chemical Industry Co., Ltd., Sakai Chemical Industry Co., Ltd., etc. can be used.

[0169] (d) Crosslinking agent and vulcanization accelerator The rubber composition preferably contains a crosslinking agent such as sulfur. The content of the crosslinking agent is, for example, more than 0.1 parts by mass and less than 10.0 parts by mass with respect to 100 parts by mass of the rubber component. Note that the content of sulfur is the pure sulfur content, and when insoluble sulfur is used, it is the content excluding the oil component.

[0170] Examples of sulfur include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersed sulfur, soluble sulfur, etc. that are generally used in the rubber industry. These may be used alone or in combination of two or more.

[0171] As sulfur, for example, products of Tsukimi Chemical Industry Co., Ltd., Karuizawa Sulfur Co., Ltd., Shikoku Kasei Kogyo Co., Ltd., Flexsys, Nippon Kankyu Kogyo Co., Ltd., Hosoi Chemical Industry Co., Ltd., etc. can be used.

[0172] Crosslinking agents other than sulfur may be used. Specifically, for example, Tackiol V200 manufactured by Taoka Chemical Industry Co., Ltd., DURALINK HTS (sodium 1,6 - hexamethylene - dithiolsulfate dihydrate) manufactured by Flexsys, KA9188 (1,6 - bis(N,N’ - dibenzylthiocarbamoyldithio)hexane: hybrid crosslinking agent) manufactured by Lanxess, etc., which are vulcanizing agents containing sulfur atoms, and organic peroxides such as dicumyl peroxide can be used.

[0173] And the rubber composition preferably contains a vulcanization accelerator. The content of the vulcanization accelerator is, for example, more than 0.3 parts by mass and less than 10.0 parts by mass with respect to 100 parts by mass of the rubber component.

[0174] As vulcanization accelerators, there may be mentioned thiazole-based vulcanization accelerators such as 2-mercaptobenzothiazole, di-2-benzothiazolyldisulfide, N-cyclohexyl-2-benzothiazylsulfenamide; thiuram-based vulcanization accelerators such as tetramethylthiuram disulfide (TMTD), tetrabenzylthiuram disulfide (TBzTD), tetrakis(2-ethylhexyl)thiuram disulfide (TOT-N); sulfenamide-based vulcanization accelerators such as N-cyclohexyl-2-benzothiazole sulfenamide, N-t-butyl-2-benzothiazolylsulfenamide, N-oxyethylene-2-benzothiazole sulfenamide, N-oxyethylene-2-benzothiazole sulfenamide, N,N'-diisopropyl-2-benzothiazole sulfenamide; and guanidine-based vulcanization accelerators such as diphenylguanidine, diorthotolylguanidine, orthotolylbiguanidine. These may be used alone or in combination of two or more.

[0175] (Thi) Others In addition to the above-described components, the rubber composition may be blended with additives generally used in the tire industry, for example, organic fillers such as cellulose fibers, organic peroxides, etc., as required. The content of these additives is, for example, more than 0.1 part by mass and less than 50 parts by mass with respect to 100 parts by mass of the rubber component.

[0176] In the present invention, among the above-described various materials, various materials containing carbon atoms (for example, rubber, oil, resin, vulcanization accelerator, anti-aging agent, surfactant, etc.) may be derived from carbon dioxide in the atmosphere. As a method for obtaining the formulation of the present invention from carbon dioxide, carbon dioxide may be directly converted, or methane obtained through a methanation step of synthesizing methane from carbon dioxide may be converted.

[0177] (Li) Band cord Although it is not a compounding material of the rubber composition, the band cord will also be described. In the present invention, as described above, a single-twist PET band obtained by twisting a single yarn containing PET fiber is used as the band cord.

[0178] Note that the total fineness of the band cord is preferably 900 dtex or more and 2500 dtex or less, and more preferably 1500 tex or more and 2300 dtex or less.

[0179] And the thickness (diameter of the cord) is preferably 0.2 mm or more and 0.8 mm or less, and more preferably 0.3 mm or more and 0.6 mm or less.

[0180] Also, the ends, which are the number of cords per 50 mm width, are preferably 40 or more and 80 or less, and more preferably 50 or more and 70 or less.

[0181] Note that the fineness, thickness, and ends of the above-mentioned band cord can be measured in accordance with the method specified in JIS L1017:2002.

[0182] After treating the band cord with an adhesive and bonding it to a predetermined rubber composition for bands, it can be made into a band. As the adhesive used for bonding, for example, EX-313 (glycerin polyglycidyl ether, manufactured by Nagase ChemteX Corporation) and RFL (resorcin formaldehyde-latex) as epoxy compounds can be used.

[0183] Note that the PET fiber may be a PET fiber (recycled PET fiber) obtained by recycling plastic waste such as used PET bottles, and using such sustainable PET fibers is preferable from the viewpoint of environmental protection.

[0184] (2) Preparation of Rubber Composition The rubber composition can be prepared by a manufacturing method including a base kneading step of kneading a rubber component and a filler such as silica, and a finishing kneading step of kneading the kneaded product obtained in the base kneading step and a crosslinking agent, by a general method.

[0185] Kneading can be carried out using a known (closed-type) kneading machine such as a Banbury mixer, a kneader, an open roll, etc.

[0186] The kneading temperature in the base kneading step is, for example, above 50°C and below 200°C, and the kneading time is, for example, above 30 seconds and below 30 minutes. In the base kneading step, in addition to the above components, compounding agents used in the conventional rubber industry, such as softening agents like oil, stearic acid, zinc oxide, anti-aging agents, wax, vulcanization accelerators, etc., may be appropriately added and kneaded as required.

[0187] In the finishing kneading step, the kneaded product obtained in the base kneading step and a cross-linking agent are kneaded. The kneading temperature in the finishing kneading step is, for example, above room temperature and below 80°C, and the kneading time is, for example, above 1 minute and below 15 minutes. In the finishing kneading step, in addition to the above components, vulcanization accelerators, zinc oxide, etc. may be appropriately added and kneaded as required.

[0188] The rubber composition obtained as above can then be formed into a tread by extrusion into a predetermined shape.

[0189] 3. Tire manufacturing The tire according to this embodiment can be manufactured by a normal method. First, using the rubber composition obtained as above, it is formed into a predetermined shape to manufacture a tread. Next, it is combined with other rubber members on a tire molding machine to produce an unvulcanized tire.

[0190] Specifically, on a molding drum, an inner liner as a member for ensuring the airtightness of the tire, a carcass as a member for withstanding the load, impact, and inflation air pressure received by the tire, a belt member as a member for strongly tightening the carcass to increase the rigidity of the tread, a band, etc. are wound, and both ends of the carcass are fixed to both side edges, and a bead portion as a member for fixing the tire to a rim is arranged, and after forming it into a toroidal shape, a tread is attached to the central portion of the outer periphery, and a sidewall is bonded to the radially outer side to form a side portion, thereby producing an unvulcanized tire.

[0191] Subsequently, the unvulcanized tire produced as described above is heated and pressurized in a vulcanizer to obtain a tire. The vulcanization process can be carried out by applying known vulcanization means. The vulcanization temperature is, for example, above 120°C and below 200°C, and the vulcanization time is, for example, above 5 minutes and below 15 minutes.

[0192] As described above, the tire obtained as above can improve the overall performance of high-speed durability and rolling resistance by appropriately controlling the product of the diameter (mm) of the band cord and the thickness (mm) of the tread, so that the effects of using the single-twist PET band and the appropriately formed tread cooperate with each other.

[0193] The tire according to the present invention can be preferably used as a passenger car tire, a large passenger car tire, a large SUV tire, a truck / bus tire, a two-wheeler tire, a racing tire, a studless tire (winter tire), an all-season tire, a run-flat tire, etc., and particularly preferably as a passenger car tire.

Examples

[0194] Hereinafter, examples (Examples) considered preferable for implementation are shown, but the scope of the present invention is not limited to these examples.

[0195] A tire (tire size: 195 / 65R15) composed of a tread formed from various compounding materials shown below and tire members such as bands and belts is examined, and its high-speed durability, rolling resistance, and overall performance are evaluated. The evaluation results are shown in Table 2.

[0196] 1. Preparation of rubber composition A tread rubber composition is prepared using the various compounding materials shown below.

[0197] (1) Compounding materials (a) Rubber components (i) NR: TSR20 (b) SBR-1: Modified S-SBR produced based on Production Example 1 described below (styrene content: 25% by mass, vinyl content: 60 mol%, Tg: -24°C, non-oil product) (c) SBR-2: Modified S-SBR produced based on Production Example 2 described below (styrene content: 40% by mass, vinyl content: 35 mol%, Tg: -25°C, 25% oil product) (d) SBR-3: Modified S-SBR produced based on Production Example 3 described below (styrene content: 40% by mass, vinyl content: 36 mol%, Tg: -25°C, non-oil product) (e) SBR-4: Toughlen 3830 manufactured by Asahi Kasei Corporation (S-SBR: styrene content: 33% by mass, vinyl bond content: 31% by mass, 37.5% oil product) (f) BR: UBEPOL BR150B manufactured by Ube Industries, Ltd. (high cis BR) (cis content: 97% by mass, trans content: 2% by mass, vinyl content: 1% by mass)

[0198] (Production Example 1) The above SBR-1 is prepared according to the following procedure. First, cyclohexane, tetrahydrofuran, styrene, and 1,3-butadiene are charged into a nitrogen-substituted autoclave reactor. After adjusting the temperature of the contents of the reactor, n-butyllithium is added to initiate polymerization. Then, polymerization is carried out under adiabatic conditions. When the polymerization conversion rate reaches 99%, 1,3-butadiene is added, and polymerization is further carried out for 5 minutes. N,N-bis(trimethylsilyl)-3-aminopropyltrimethoxysilane is added as a modifier to carry out the reaction. After the polymerization reaction is completed, 2,6-di-tert-butyl-p-cresol is added, the solvent is removed by steam stripping, and drying is carried out by a hot roll to obtain SBR-1.

[0199] (Production Example 2) The above SBR-2 is obtained in the same manner as in Production Example 1, except for changing the target styrene content, vinyl content, and Tg, and adding TDAE oil.

[0200] (Production Example 3) The above SBR-3 is obtained in the same manner as in Production Example 1, except that the target styrene content, vinyl content, and Tg are changed, and the modifier is 3-dimethylaminopropyltriethoxysilane.

[0201] (b) Compounding materials other than the rubber component (i) Carbon black: Dia Black N220 manufactured by Mitsubishi Chemical Corporation (N2SA: 115 m 2 / g) (ii) Silica-1: Ultrasil VN3 manufactured by Evonik Degussa GmbH (N2SA: 175 m 2 / g, average primary particle diameter: 17 nm) (iii) Silica-2: Ultrasil 9100GR manufactured by Evonik Degussa GmbH (N2SA: 235 m 2 / g, average primary particle diameter: 15 nm) (iv) Silane coupling agent: NXT manufactured by Momentive (3-octanoylthiopropyltriethoxysilane) (v) Oil: Process Oil A / OMIX manufactured by Sankyo Yuka Kogyo Co., Ltd. (vi) Resin: YS Resin PX850 manufactured by Yasuhara Chemical Co., Ltd. (Softening point 85°C, β-pinene resin (terpene resin)) (vii) Wax: Oz Ace 0355 manufactured by Nippon Seiro Co., Ltd. (viii) Antioxidant-1: Nocrack 6C manufactured by Ouchi Shinko Chemical Industrial Co., Ltd. (N-(1, 3-dimethylbutyl)-N’-phenyl-p-phenylenediamine) (ix) Antioxidant-2: ANTAGE RD manufactured by Kawaguchi Chemical Industry Co., Ltd. (Poly(2,2,4-trimethyl-1,2-dihydroquinoline) (x) Stearic acid: Bead Stearic Acid "Tsubaki" manufactured by NOF Corporation (xi) Zinc oxide: Zinc Oxide No. 2 manufactured by Mitsui Mining & Smelting Co., Ltd. (xii) Sulfur: Powder sulfur manufactured by Karuizawa Sulfur Co., Ltd. (xiii) Accelerator-1: Nocceler CZ manufactured by Ouchi Shinko Chemical Industrial Co., Ltd. (N-Cyclohexylbenzothiazole-2-sulfenamide) (C) Accelerator - 2: Nocceler D manufactured by Ouchi Shinsei Chemical Industry Co., Ltd. (N,N'-Diphenylguanidine)

[0202] (2) Preparation of Rubber Composition for Tread Based on each formulation of A to C shown in Table 1, using a 1.7L Banbury mixer manufactured by Kobe Steel, Ltd., materials other than sulfur and vulcanization accelerator are kneaded at 150 °C for 5 minutes to obtain a kneaded product.

[0203] Next, sulfur and vulcanization accelerator are added to the kneaded product, and it is kneaded for 5 minutes at 80 °C using an open roll to obtain rubber compositions for treads of formulations A to C.

[0204] 2. Molding of Tire Members (Tread, Band, Belt) (1) Molding of Tread Next, using the rubber composition obtained above, treads are molded at each thickness shown in Table 2.

[0205] (2) Molding of Band In parallel, a predetermined rubber composition for band is topped on each band cord shown in Table 2 to mold each band.

[0206] (3) Molding of Belt Similarly, a predetermined rubber composition for belt is topped on each belt cord shown in Table 2 to mold each belt.

[0207] 3. Manufacture of Tire Next, each of the tread, band, and belt obtained above is bonded together with other tire members to form an unvulcanized tire, which is press - vulcanized at 170 °C for 10 minutes to manufacture test tires of Examples 1 to 4 and Comparative Examples 1 to 6.

[0208] 4. Performance Evaluation Test (1) High - speed Durability Evaluation Each test tire was mounted on a rim (size = 16×6.0J), filled with air, and the internal pressure was adjusted to 280 kPa. Then, it was mounted on a drum test rig, a vertical load of 4.22 kN was applied, and the speed was increased step by step from 200 km / h to 10 km / h, and the time and speed until the tire was damaged were measured. The obtained time was divided by the time required to increase to the next speed, and the value obtained by multiplying by 10 km / h was added to the obtained speed to obtain a combined value.

[0209] Next, taking the result in Comparative Example 2 as 100, it was exponentiated based on the following formula to be used as an index for high-speed durability and evaluated. The larger the numerical value, the better the durability. High-speed durability evaluation = [(result of the test tire) / (result of Comparative Example 2)] × 100

[0210] (2) Evaluation of rolling resistance Using a rolling resistance test rig, the rolling resistance coefficient (RRC) of each test tire when running on a drum at a speed of 80 km / h under the following conditions was measured. Rim used: 16×6.0J Internal pressure: 210 kPa Load: 4.82 kN

[0211] Next, taking the result in Comparative Example 3 as 100, it was exponentiated based on the following formula to be used as a rolling resistance evaluation. The larger the numerical value, the more the rolling resistance is reduced. Rolling resistance evaluation = [(result of Comparative Example 3) / (result of the test tire)] × 100

[0212] (3) Comprehensive evaluation Then, (1) and (2) were added together to obtain a comprehensive evaluation.

[0213] The results of the evaluation are shown in Table 2.

[0214]

Table 1

[0215]

Table 2

[0216] As described above, the present invention has been described based on the embodiments, but 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.

[0217] The present invention (1) is 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, a tire including a tread provided on the outer side in the tire radial direction of the band, wherein the band cord is formed by twisting one yarn containing polyethylene terephthalate fiber, the tread is formed using a rubber composition having an acetone extract content of more than 15% by mass, with a thickness of more than 6 mm and a rubber hardness (Shore hardness) Hs of more than 60, a tire characterized in that the product of the diameter (mm) of the band cord and the thickness (mm) of the tread is less than 5.0.

[0218] The present invention (2) is a tire according to the present invention (1), characterized in that the on-gauge of the band cord of the band is 0.01 mm or more and 0.05 mm or less.

[0219] The present invention (3) is a tire according to the present invention (1), characterized in that the total gauge of the band is 0.20 mm or more and 0.60 mm or less.

[0220] The present invention (4) is a tire according to the present invention (1), characterized in that the thickness of the tread is 10 mm or less.

[0221] The present invention (5) is characterized in that the product of the diameter (mm) of the band cord and the thickness (mm) of the tread is 3.0 or less, and it is the tire according to the present invention (1).

[0222] The present invention (6) is characterized in that the rubber composition contains more than 75 parts by mass of silica with respect to 100 parts by mass of the rubber component, and it is the tire according to the present invention (1).

[0223] The present invention (7) is characterized in that the total fineness of the band cord is 900 dtex or more and 2500 dtex or less, and it is the tire according to the present invention (1).

[0224] The present invention (8) is characterized in that the diameter of the band cord is 0.2 mm or more and 0.8 mm or less, and it is the tire according to the present invention (1).

[0225] The present invention (9) is characterized in that the number of cord strands per 50 mm width of the band cord is 40 or more and 80 or less, and it is the tire according to the present invention (1).

[0226] The present invention (10) is characterized in that the rubber composition contains vegetable oil, and it is the tire according to the present invention (1).

[0227] The present invention (11) is characterized in that the rubber composition contains sustainable carbon black, and it is the tire according to the present invention (1).

[0228] The present invention (12) is characterized in that the rubber composition contains sustainable silica, and it is the tire according to the present invention (1).

[0229] The present invention (13) is characterized in that The polyethylene terephthalate fiber is a sustainable polyethylene terephthalate fiber, and it is the tire according to the present invention (1).

Explanation of Signs

[0230] 1 Tire 2 Tread 3 Sidewall 4 Chafer 5 Bead 6 Innerliner 7 Carcass 8 Belt 9 Filler 10 Band CL Equatorial plane of the tire

Claims

1. 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; A tire comprising a tread provided on the outer side in the tire radial direction of the band, wherein the band cord is formed by twisting one yarn containing polyethylene terephthalate fiber; the tread is formed using a rubber composition having an acetone extract content of more than 15% by mass, with a thickness of more than 6 mm and a rubber hardness (Shore hardness) Hs of more than 60; a tire characterized in that the product of the diameter (mm) of the band cord and the thickness (mm) of the tread is less than 5.

0.

2. The tire according to claim 1, characterized in that the on-gauge of the band cord of the band is 0.01 mm or more and 0.05 mm or less.

3. The tire according to claim 1, characterized in that the total gauge of the band is 0.20 mm or more and 0.60 mm or less.

4. The tire according to claim 1, characterized in that the thickness of the tread is 10 mm or less.

5. The tire according to claim 1, characterized in that the product of the diameter (mm) of the band cord and the thickness (mm) of the tread is 3.0 or less.

6. The tire according to claim 1, characterized in that the rubber composition contains more than 75 parts by mass of silica based on 100 parts by mass of the rubber component.

7. The tire according to claim 1, characterized in that the total fineness of the band cord is 900 dtex or more and 2500 dtex or less.

8. The tire according to claim 1, characterized in that the diameter of the band cord is 0.2 mm or more and 0.8 mm or less.

9. The tire according to claim 1, characterized in that the number of cords per 50 mm width of the band cord is 40 or more and 80 or less.

10. The tire according to claim 1, characterized in that the rubber composition contains vegetable oil.

11. The tire according to claim 1, characterized in that the rubber composition contains sustainable carbon black.

12. The tire according to claim 1, characterized in that the rubber composition contains sustainable silica.

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

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