Tire

Abstract

To improve total performance of high-speed durability, steering stability, 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 polyethylene terephthalate fiber. The tread is formed, by using a rubber composition comprising more than 75 pts.mass of silica based on 100 pts.mass of a rubber component, 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 10.0.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, handling stability, 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, a tire including 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 containing more than 75 parts by mass of silica with respect to 100 parts by mass of a rubber component, having 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 10.0.

Advantages of the Invention

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

Brief Description of the Drawings

[0007]

Figure 1

Embodiments 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 carcass cords, a belt provided with belt cords and disposed on the outer side in the tire radial direction of the carcass, a band provided with band cords 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) containing more than 75 parts by mass of silica with respect to 100 parts by mass of the rubber component, having 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 10.0.

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

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

[0012] (1) Use of single-twist PET band In the tire according to the present invention, as the band cord, a single-twist PET band obtained by twisting one yarn containing PET fibers is used. The filaments constituting the yarn may be only PET fibers, or may be a mixture of PET fibers and other fibers (such as polyamide fibers).

[0013] PET fibers are highly elastic compared to nylon 66 (a polyamide synthetic fiber) that has been mainly used conventionally and can reduce the cord diameter. Therefore, it is considered that the thickness (prep gauge) of the band and the weight (prep weight) of the band can be reduced, and the rolling resistance can be reduced.

[0014] (2) Tread However, a tire manufactured using a band with a reduced cord diameter may have inferior compression fatigue resistance, which may reduce high-speed durability.

[0015] In order to improve the compression fatigue resistance, the tread may be thickened to reduce the compression received by the band.

[0016] As a result of further studies by the present inventor, when an appropriate rubber composition, specifically, a rubber composition containing more than 75 parts by mass of silica with respect to 100 parts by mass of the rubber component is used as the tread rubber composition, and the tread is formed to have a thickness of more than 6 mm and a rubber hardness (Shore hardness) Hs of more than 60, it is considered that while reducing the rolling resistance, the compression fatigue of the band can be prevented (durability improvement), and furthermore, the handling stability can be ensured.

[0017] That is, by making the tread rubber composition contain more than 75 parts by mass of silica having OH groups on the surface with respect to 100 parts by mass of the rubber component, hydrogen bonds are formed between the silica surfaces and interact with the rubber component as well. Therefore, during driving, force can be easily generated and transmitted inside the rubber. As a result, it is possible to easily transmit the force generated during turning and ensure excellent handling stability. The silica content is more preferably 80 parts by mass or more, even more preferably 85 parts by mass or more, and 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, 200 parts by mass or less, more preferably 150 parts by mass or less, even more preferably 120 parts by mass or less, and even more preferably 100 parts by mass or less.

[0018] And by making the tread thickness more than 6 mm, 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 even more preferably 10 mm or more. The upper limit is preferably, for example, 20 mm or less, more preferably 15 mm or less, even more preferably 12 mm or less.

[0019] Also, by increasing the rubber hardness (Shore hardness) Hs of the tread to more than 60, the deformation amount of the tread can be reduced and the compression applied to the band can be reduced. Therefore, the compression fatigue of the band can be suppressed and the compression fatigue resistance (high-speed durability) can be improved.

[0020] Furthermore, a tread with a rubber hardness (Shore hardness) Hs of more than 60 can ensure sufficient rigidity, suppress the deformation of the tread during turning, and easily transmit the generated force. Therefore, excellent handling stability can be ensured.

[0021] The rubber hardness (Shore hardness) Hs can be measured using a Type A durometer in accordance with the method specified in JIS K6253-3:2012.

[0022] 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.

[0023] In the above description, it is described as a single layer of only the layer (cap rubber layer) where the tread becomes the ground contact surface. However, it may be composed of two layers with a base rubber layer provided inside the cap rubber layer, or three layers, or four or more layers. In this case, the rubber composition for the tread described above preferably becomes a rubber composition that forms the cap rubber layer, which is the outermost layer on the ground contact surface side, and satisfies the above parameters.

[0024] In this case, the thickness of the cap rubber layer in the entire tread is preferably 10% or more, more preferably 30% or more, even more preferably 50% or more, and even more preferably 70% or more.

[0025] Here, the tread thickness refers to the thickness of the tread on the tire equator plane in the radial cross-section of the tire. In the case where the tread is formed of a single rubber composition, it is the thickness of the rubber composition. In the case where it is formed of a laminated structure of a plurality of rubber compositions, it refers to the thickness of the cap rubber layer, which is the outermost layer on the ground contact surface side among these layers. In the cross-section obtained by cutting the tire in the radial direction, it can be measured by making the bead portion conform to the normal rim width.

[0026] Note that the "regular rim" is the rim defined for each tire in the 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 standards if there are applicable sizes during the reference. In the case of a tire not defined in the standards, it refers to the 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 / tire, the one with the smallest rim diameter and then the narrowest rim width.

[0027] (3) The product of the diameter (mm) of the band cord and the tread thickness (mm) As a result of further studies by the present inventor, when the product of the diameter (mm) of the band cord and the tread thickness (mm) is less than 10.0, the above-described effects cooperate to improve the overall performance of high-speed durability, handling stability, and rolling resistance. Note that the product of the diameter (mm) of the band cord and the tread thickness (mm) is more preferably 8.00 or less, and even more preferably 6.00 or less. As the lower limit, for example, it is preferably 2.00 or more, more preferably 3.00 or more, and even more preferably 4.00 or more.

[0028] Note that in the above, the "diameter of the band cord" refers to the diameter when the circumscribed circle of the cross-section perpendicular to the extending direction of the cord is a perfect circle, and in the case of an ellipse or the like, it refers to the equivalent circle diameter (the diameter of the circle assumed when the cross-sectional area is the same perfect circle). The same applies to the "diameter of the belt cord" described later.

[0029] [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 aspects.

[0030] 1. Belt cord In the present invention, as the belt cord constituting the belt, a steel cord is preferable, and it is preferably composed of 1 or more and 4 or less filaments from the viewpoint of reducing the weight of the tire. It may have a non-twisted 1×1 structure, a single-twisted 1×4 structure, or a layer-twisted 2+2 structure.

[0031] Also, in the tire width direction, the number of cord strands (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.

[0032] 2. Particle size of silica As described above, in the present invention, the tread rubber composition contains silica. At this time, if the particle size (average primary particle size) of silica is too small, the processability deteriorates, so 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 rubber reinforcing property and 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.

[0033] 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, observing with a transmission type or scanning type electron microscope, measuring 400 or more primary particles of silica observed in the visual field, and obtaining it by averaging.

[0034] Specifically, the silica taken out from the rubber composition cut out from the tire is directly observed using an electron microscope or the like, and 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 diameter can be calculated.

[0035] 3. Resin component Moreover, it is preferable that the rubber composition forming the tread contains a resin component.

[0036] When the rubber composition contains a resin component, the adhesiveness of the resin component improves the ground contact property with the road surface, so it is considered that the rolling resistance during starting can be further improved.

[0037] Preferred resin components include rosin-based resins, styrene-based resins, coumarone-based resins, terpene-based resins, C5 resins, C9 resins, C5C9 resins, acrylic resins, etc. described later. Among these, styrene-based resins such as α-methylstyrene are more preferable. And as the content with respect 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.

[0038] [3] Embodiment Hereinafter, the present invention will be specifically described based on the embodiments.

[0039] 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 horizontal 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 alternate long and short dash line CL represents the equatorial plane of the tire. Note that 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.

[0040] 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.

[0041] With such a configuration, as described above, by using a single yarn twisted with a PET fiber as a band cord, forming a tread appropriately, and further appropriately controlling the product of the diameter (mm) of the band cord and the thickness (mm) of the tread, it is considered that the overall performance of high-speed durability, handling stability, and rolling resistance can be improved.

[0042] 2. Rubber composition for tread In the present embodiment, the rubber composition for tread 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.

[0043] (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.

[0044] (i) SBR The weight average molecular weight of the SBR is, for example, over 100,000 and less than 2,000,000. The styrene content of the SBR is preferably, for example, over 5% by mass, more preferably over 10% by mass, and even more preferably over 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 the SBR is preferably, for example, over 5% by mass, more preferably over 10% by mass, and even more preferably over 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. Incidentally, the structure identification (measurement of styrene content and vinyl content) of the SBR can be carried out using, for example, an apparatus of the JNM-ECA series manufactured by JEOL Ltd.

[0045] The SBR is not particularly limited, and for example, emulsion polymerization styrene butadiene rubber (E-SBR), solution polymerization styrene butadiene rubber (S-SBR), etc. can be used. The SBR may be either non-modified SBR or modified SBR. Further, hydrogenated SBR obtained by hydrogenating the butadiene part in the SBR may be used, and the hydrogenated SBR may be obtained by post-hydrogenation treatment of the BR part in the SBR, or styrene, ethylene, and butadiene may be copolymerized to obtain a similar structure.

[0046] 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 (terminal-modified SBR having the above functional group at the terminal) in which at least one terminal of the 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), and 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.

[0047] Examples of the functional group include an amino group, an amide group, a silyl group, an alkoxysilyl group, an isocyanate group, an imino group, an imidazole group, a urea group, an ether group, a carbonyl group, an oxycarbonyl group, a mercapto group, a sulfide group, a disulfide group, a sulfonyl group, a sulfinyl group, a thiocarbonyl group, an ammonium group, an imide group, a hydrazo group, an azo group, a diazo group, a carboxyl group, a nitrile group, a pyridyl group, an alkoxy group, a hydroxyl group, an oxy group, an epoxy group, etc. These functional groups may have substituents.

[0048] Moreover, as the modified SBR, for example, SBR modified with a compound (modifying agent) represented by the following formula can be used.

[0049] [Chemical formula]

[0050] 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 derivatives 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.

[0051] 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.

[0052] R 1 , R 2 and R 3As the [group], an alkoxy group is preferable (preferably an alkoxy group having 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms). R 4 and R 5 As the [group], an alkyl group (preferably an alkyl group having 1 to 3 carbon atoms) is preferable. n is preferably 1 to 5, more preferably 2 to 4, and still more preferably 3. Also, R 4 and R 5 When they are bonded to form a ring structure together with the 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).

[0053] Specific examples of the above-mentioned modifier include 2-dimethylaminoethyltrimethoxysilane, 3-dimethylaminopropyltrimethoxysilane, 2-dimethylaminoethyltriethoxysilane, 3-dimethylaminopropyltriethoxysilane, 2-diethylaminoethyltrimethoxysilane, 3-diethylaminopropyltrimethoxysilane, 2-diethylaminoethyltriethoxysilane, 3-diethylaminopropyltriethoxysilane, and the like. These may be used alone or in combination of two or more kinds.

[0054] In addition, as the modified SBR, modified SBR 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-dimethyl ethyleneurea, 1,3-divinyl ethyleneurea, 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. In addition, the modification with the above compound (modifying agent) can be carried out by a known method.;

[0055] As the SBR, for example, SBR manufactured and sold by Sumitomo Chemical Co., Ltd., ENEOS MATERIALS Co., Ltd., Asahi Kasei Co., Ltd., Nippon Zeon Co., Ltd. and the like can be used. In addition, the SBR may be used alone or in combination of two or more kinds.

[0056] 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.

[0057] (B) Isoprene rubber Examples of the isoprene rubber include natural rubber (NR), isoprene rubber (IR), modified NR, modified NR, modified IR, etc., and NR is preferred in terms of excellent strength.

[0058] 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.

[0059] 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.

[0060] (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. The cis content can be measured by infrared absorption spectroscopy.

[0061] 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.

[0062] [Chemical formula]

[0063] 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 a nitrogen atom. n represents an integer.

[0064] Examples of the modified BR modified with the compound (modifying agent) represented by the above formula include BR modified with the compound represented by the polymerization terminal (active terminal) with the above formula.

[0065] 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 even more preferably 3. Also, when R 4 and R 5 combine to form a ring structure together with a nitrogen atom, it is preferably a 4- to 8-membered ring. 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).

[0066] 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.

[0067] In addition, 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-triones, 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, etc. can be mentioned. The modification with the above compounds (modifying agents) can be carried out by known methods. These modified BRs may be used alone or in combination of two or more.;

[0068] As BR, for example, products of Ube Industries, Ltd., ENEOS MATERIAL Co., Ltd., Asahi Kasei Corporation, Nippon Zeon Co., Ltd., etc. can be used.

[0069] The content of BR in 100 parts by mass of the rubber component is preferably 25 parts by mass or more, and more preferably 30 parts by mass or more. On the other hand, it is preferably 40 parts by mass or less, and more preferably 35 parts by mass or less.

[0070] (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), etc., if necessary.

[0071] Incidentally, 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.

[0072] 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.

[0073] 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. 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.

[0074] 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, sugars, 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.

[0075] 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.

[0076] 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.

[0077] pMC is 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 is described below.

[0078] In 1 mole (6.02×10 23 pieces) of carbon atoms, there are about 6.02×10 11 pieces, which is about one trillionth of ordinary 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 and fixed by plants and the like, in fossil fuels such as coal, oil, and natural gas where it is considered that more than 226,000 years have passed, 14 all of the 14C element has decayed. Therefore, at present in the 21st century, fossil fuels such as coal, oil, and natural gas do not contain 14 any 14C element at all. Therefore, chemical substances produced from these fossil fuels also do not contain 14 any 14C element.

[0079] On the other hand, 14 14C is constantly generated by nuclear reactions of cosmic rays in the atmosphere, and balances the decrease due to radioactive decay. In the earth's atmospheric environment, 14 the amount of 14C is 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.

[0080] 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, the oxalic acid standard provided by NIST (National Institute of Standards and Technology) is used. The specific activity of carbon in this oxalic acid (the 14 radioactivity intensity of C per gram of carbon) is fractionated for each carbon isotope, 13 For 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 of the standard 14 C concentration (100%). The ratio of this value to the value of the sample actually measured is the pMC value.

[0081] Therefore, if the rubber is made of a 100% biomass (natural system) - derived substance, although there are regional differences and so on, currently in the normal state, it often does not reach 100, so it will show 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 will show a value of about 0 pMC (for example, 0.3 pMC). This value corresponds to a biomass ratio of 0% mentioned above.

[0082] 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).

[0083] (b) Compounding materials other than the rubber component (i) Filler The rubber composition contains silica as a reinforcing agent, but if necessary, it may also contain other fillers, for example, carbon black, calcium carbonate, talc, alumina, clay, aluminum hydroxide, mica, etc. When using silica, it is preferable to use it in combination with a silane coupling agent.

[0084] As the compounding amount of the filler, first, as described above, silica is more than 75 parts by mass 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.

[0085] (i) Silica As described above, since silica has OH groups on its surface, by containing more than 75 parts by mass, hydrogen bonds are generated 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 enhanced.

[0086] 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.

[0087] Silica is not particularly limited. For example, silica prepared by the dry method (anhydrous silica), silica prepared by the 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 Co., Ltd., Tokuyama Corporation, etc. can be used.

[0088] The raw material for silica is not particularly limited. For example, it may be a raw material derived from minerals such as quartz, or it may be a raw material derived from organisms such as rice husks (for example, silica obtained from biomass materials such as rice husks), or silica recycled from products containing silica may also be used. Among them, hydrous silica prepared by the wet method is preferred because it has many silanol groups.

[0089] Silica made from biomass materials (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 obtain a precipitate of silicon dioxide, which is then filtered, washed with water, dried, and pulverized.

[0090] Silica recycled from products containing silica (recycled silica) can be obtained, for example, by using 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 includes pyrolysis, decomposition by electromagnetic waves, etc. Among them, silica recovered from electronic components such as semiconductors or tires is preferred.

[0091] When silica crystallizes, it is insoluble 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 Laid-Open No. 2009-2594, Akita Prefectural University Web Journal B / 2019, vol. 6, p. 216-222, etc.).

[0092] Amorphous silica extracted from rice husks can be those commercially available from companies such as Wilmar.

[0093] These silicas may be used alone or in combination of two or more. Using sustainable silicas such as biomass silica and recycled silica is preferable from the perspective of environmental protection (sustainability).

[0094] As described above, the content of silica relative to 100 parts by mass of the rubber component is more than 75 parts by mass relative to 100 parts by mass of the rubber component, preferably 80 parts by mass or more, and 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.

[0095] (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 to improve mechanical properties and moldability by reaction with silica.

[0096] 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. of sulfide series, 3-mercaptopropyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, mercapto series such as NXT and NXT-Z manufactured by Momentive, vinyl series such as vinyltriethoxysilane and vinyltrimethoxysilane, amino series such as 3-aminopropyltriethoxysilane and 3-aminopropyltrimethoxysilane, glycidoxy series such as γ-glycidoxypropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane, nitro series such as 3-nitropropyltrimethoxysilane and 3-nitropropyltriethoxysilane, chloro series 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.

[0097] 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.

[0098] 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.

[0099] (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.

[0100] The nitrogen adsorption specific surface area (N2SA) of carbon black is, from the viewpoint of the reinforcing property 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.

[0101] 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.

[0102] The carbon black is not particularly limited, and examples thereof 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. In addition, examples of the product number include N134, N110, N220, N234, N219, N339, N330, N326, N351, N550, N762, and the like. These may be used alone or in combination of two or more.

[0103] In addition to mineral oil, the raw material of carbon black may be biomass materials such as lignin and vegetable oil, or may be 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 viewpoint of environmental protection.

[0104] Also, the manufacturing method of carbon black may be by combustion such as the furnace method, may be by hydrothermal carbonization (HTC), or may be by thermal decomposition of methane such as the thermal black method.

[0105] 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.

[0106] The content of carbon black with respect 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. The upper limit is preferably, for example, 25 parts by mass or less, more preferably 20 parts by mass or less.

[0107] (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 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.

[0108] (b) Softening agent component Considering the proper dispersion of the powder material during kneading, it is preferable to use a softening agent component as needed. Here, the softening agent / plasticizer component refers to a material that imparts plasticity to the rubber component, and is a concept that includes both softening agents that are liquid at 25°C and softening agents that are solid at 25°C.

[0109] Examples of softening agents include resin components, oils, liquid polymers, ester-based 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 thermally decomposing 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.

[0110] 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.

[0111] (i) Oil Examples of the oil include mineral oil, vegetable oil, animal oil, etc. From the perspective of life cycle assessment, it is also possible to use waste oil after being used in a rubber mixer or an engine, or refined waste cooking oil used in a restaurant.

[0112] (i-1) Mineral oil Mineral oil refers to oil derived from mineral resources such as petroleum and natural gas. Examples of mineral oil include paraffinic oil (mineral oil), naphthenic oil, aromatic oil, etc.

[0113] Specific examples of mineral oil 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.

[0114] In addition, it is also possible to use oil with a low content of polycyclic aromatic (PCA) compounds for environmental protection. Examples of the low-PCA-content oil include MES, TDAE, heavy naphthenic oil, etc.

[0115] Examples of commercially available mineral oil include, for example, paraffinic, aromatic, naphthenic oils, etc. For example, products of Idemitsu Kosan Co., Ltd., Sankyo Oil & Chemical Industry Co., Ltd., ENEOS Co., Ltd., Orisoy Co., Ltd., H&R Co., Ltd., Toyokuni Oil Co., Ltd., Showa Shell Sekiyu KK, Fuji Kogyo Co., Ltd., etc. can be used. These can be used alone or in combination of two or more.

[0116] (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.

[0117] Furthermore, examples of vegetable oils include refined oils (such as salad oil) obtained by refining the above-mentioned oils, transesterified oils obtained by transesterification, hydrogenated hardened oils, thermally polymerized oils obtained by thermal polymerization, oxidatively 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.

[0118] 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 three or more units. Note that acylglycerols of two or more units can be obtained by thermal polymerization, oxidative polymerization, etc. Also, the acylglycerol may be liquid or solid at normal temperature (25°C).

[0119] 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 with the signal of tetramethylsilane (TMS) set at 0.00 ppm, signals around 5.26 ppm, around 4.28 ppm, and around 4.15 ppm were observed. Since these signals are presumably from hydrogen atoms bonded to carbon atoms adjacent to the oxygen atom of the ester group, the presence of acylglycerol can be confirmed. Here, "around" refers to the range of ±0.10 ppm.

[0120] 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.

[0121] 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 breeding, genetic recombination, genome editing, or the like.

[0122] As the vegetable oil, for example, those commercially available from Idemitsu Kosan Co., Ltd., Sankyo Oil Chemical Industry Co., Ltd., ENEOS Co., Ltd., Oliso Co., H&R Co., Toyokuni Oil Co., Ltd., Fuji Kogyo Co., Ltd., Nisshin Oillio Group Co., Ltd., etc. can be used.

[0123] (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.

[0124] 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).

[0125] 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).

[0126] 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.

[0127] 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, more than 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).

[0128] As the liquid rubber, for example, products of Kuraray Co., Ltd., Kraton Corporation, etc. can be used.

[0129] (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. In addition, these resin components may be provided with a modifying group capable of reacting with silica or the like as necessary.

[0130] Rosin-based resins are resins mainly composed of rosin acid obtained by processing pine resin. This rosin-based resin (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, and amine salts of rosin.

[0131] 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.

[0132] Examples of the other monomers include acrylonitriles such as acrylonitrile and methacrylonitrile, acrylates, 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.

[0133] 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.

[0134] 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).

[0135] 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.

[0136] 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.

[0137] 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 copolymerized from the above terpene compounds and phenolic compounds, and resins obtained by hydrogenating such resins. Specifically, examples include resins obtained by condensing the above 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 compounds are not particularly limited as long as they have 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; coumarone; and indene.

[0138] "C5 resin" refers to a resin obtained by polymerizing a C5 fraction. Examples of the C5 fraction include petroleum fractions equivalent 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.

[0139] "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.

[0140] "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.

[0141] The acrylic resin is not particularly limited, and for example, a solventless acrylic resin can be used.

[0142] 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 US Patent No. 4,414,370, JP-A-59-6207, JP-B-5-58005, JP-A-1-313522, US Patent No. 5,010,166, and TREND 2000, 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.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] 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 Shokubai Co., Ltd., ENEOS Corporation, Arakawa Chemical Industries, Ltd., and Tago Chemical Industry Co., Ltd.

[0147] (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.

[0148] 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.

[0149] Examples of plant-derived waxes include rice wax, carnauba wax, candelilla wax, etc. Examples of petroleum waxes include paraffin wax, microcrystalline wax, these selected special waxes, etc., and paraffin wax is preferred. In the present invention, the wax does not contain stearic acid.

[0150] As the wax, for example, those commercially available from Ouchi Shinsei Chemical Industry Co., Ltd., Nippon Seiro Co., Ltd., Paramelt Co., etc. can be used. These waxes may be used alone or in combination of two or more.

[0151] (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.

[0152] The antioxidant is not particularly limited, but Naphthylamine-based antioxidants such as phenyl-α-naphthylamine; diphenylamine-based antioxidants such as octylated diphenylamine, 4,4'-bis(α,α'-dimethylbenzyl)diphenylamine; p-phenylenediamine-based antioxidants such as N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD), N,N'-bis(1,4-dimethylpentyl)-p-phenylenediamine (77PD), N,N'-diphenyl-p-phenylenediamine (DPPD), N,N'-ditoly-p-phenylenediamine (DTPD), N-isopropyl-N'-phenyl-p-phenylenediamine (IPPD), N,N'-di-2-naphthyl-p-phenylenediamine (DNPD); quinoline-based antioxidants such as polymers of 2,2,4-trimethyl-1,2-dihydroquinoline; monophenol-based antioxidants such as 2,6-di-t-butyl-4-methylphenol, styrenated phenol; bis, tris, polyphenol-based antioxidants such as tetrakis-[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane and the like can be mentioned. Among them, p-phenylenediamine-based antioxidants and quinoline-based antioxidants 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.

[0153] As commercially available products, for example, products of Seiko Chemical Co., Ltd., Sumitomo Chemical Co., Ltd., Ouchi Shinko Chemical Industrial Co., Ltd., Flexsys Co., Ltd. and the like can be used.

[0154] (Co)processing aids The rubber composition may contain a processing aid. Examples of the processing aid include metal salts (compounds in which the hydrogen atom of an acid is replaced by a metal ion), fatty acid amides, amide esters, fatty acid esters and the like. These may be used alone or in combination of two or more. Among them, metal salts and fatty acid amides are preferred, and metal salts are more preferred.

[0155] 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. Also, magnesium, zinc, nickel, molybdenum, etc. can also be used. Among them, alkali metals are preferred.

[0156] Examples of the acid used in the metal salt include fatty acids such as lauric acid, myristic acid, palmitic acid, etc. Also, boric acid, carbonic acid, hydrochloric acid, nitric acid, sulfuric acid, etc. can also be used.

[0157] 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.

[0158] 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.

[0159] (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. Also, Struktol WB16 manufactured by Struktol can be used.

[0160] The content of stearic acid is preferably, for example, 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.

[0161] (t) Zinc oxide The rubber composition may contain zinc oxide. The content of zinc oxide is, for example, more than 0.5 part 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-Doh Chemical Industry Co., Ltd., Sakai Chemical Industry Co., Ltd., etc. can be used.

[0162] (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 part by mass and less than 10.0 parts by mass with respect to 100 parts by mass of the rubber component. Note that the sulfur content is the pure sulfur content, and when insoluble sulfur is used, it is the content excluding the oil content.

[0163] Examples of sulfur include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersed sulfur, soluble sulfur, etc., which are generally used in the rubber industry. These may be used alone or in combination of two or more.

[0164] As sulfur, for example, products of Tsurumi 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.

[0165] Crosslinking agents other than sulfur may be used. Specifically, for example, Tackiol V200 manufactured by Tago 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 Rhenus, etc., vulcanizing agents containing sulfur atoms, organic peroxides such as dicumyl peroxide, etc. can be used.

[0166] And the rubber composition preferably contains a vulcanization accelerator. The content of the vulcanization accelerator is, for example, more than 0.3 part by mass and less than 10.0 parts by mass with respect to 100 parts by mass of the rubber component.

[0167] Examples of the vulcanization accelerator include thiazole-based vulcanization accelerators such as 2-mercaptobenzothiazole, di-2-benzothiazolyldisulfide, and N-cyclohexyl-2-benzothiazylsulfenamide; thiuram-based vulcanization accelerators such as tetramethylthiuram disulfide (TMTD), tetrabenzylthiuram disulfide (TBzTD), and tetrakis(2-ethylhexyl)thiuram disulfide (TOT-N); sulfenamide-based vulcanization accelerators such as N-cyclohexyl-2-benzothiazole sulfenamide, N-t-butyl-2-benzothiazolylsulfenamide, N-oxyethylene-2-benzothiazole sulfenamide, N-oxyethylene-2-benzothiazole sulfenamide, and N,N'-diisopropyl-2-benzothiazole sulfenamide; and guanidine-based vulcanization accelerators such as diphenylguanidine, diorthotolylguanidine, and orthotolylbiguanidine. These may be used alone or in combination of two or more.

[0168] (Ch) Others In addition to the above-described components, the rubber composition may be blended with additives generally used in the tire industry, such as organic fillers such as cellulose fibers and organic peroxides, as necessary. 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.

[0169] 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 process for synthesizing methane from carbon dioxide may be converted.

[0170] (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, as the band cord, a single-twist PET band obtained by twisting a single yarn containing PET fiber is used.

[0171] 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.

[0172] 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.

[0173] Also, the number of cords (ends) per 50 mm width in the tire width direction is preferably 40 or more and 80 or less, and more preferably 50 or more and 70 or less.

[0174] 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.

[0175] After treating the band cord with an adhesive, it can be made into a band by adhering it to a predetermined rubber composition for bands. As the adhesive used for adhesion, for example, EX-313 (glycerin polyglycidyl ether, manufactured by Nagase ChemteX Corporation) and RFL (resorcinol-formalin-latex) as epoxy compounds can be used.

[0176] Note that the PET fiber may be a PET fiber (recycled PET fiber) obtained by collecting and recycling plastic waste such as used PET bottles. Using such sustainable PET fibers is preferable from the viewpoint of environmental protection.

[0177] (2) Preparation of rubber composition The rubber composition can be prepared by a production 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, which are general methods.

[0178] Kneading can be carried out using known (closed-type) kneading machines such as Banbury mixers, kneaders, open rolls, etc.

[0179] The kneading temperature in the base kneading process 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 process, 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, waxes, vulcanization accelerators, etc., may be appropriately added and kneaded as required.

[0180] In the finishing kneading process, the kneaded product obtained in the base kneading process and a crosslinking agent are kneaded. The kneading temperature in the finishing kneading process 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 process, in addition to the above components, vulcanization accelerators, zinc oxide, etc. may be appropriately added and kneaded as required.

[0181] The rubber composition obtained as above can then be formed into a tread by extrusion into a predetermined shape.

[0182] 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.

[0183] Specifically, on a forming 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 clamping 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 part as a member for fixing the tire to a rim is arranged, and after forming into a toroidal shape, a tread is attached to the central part of the outer circumference, and a sidewall is bonded to the radially outer side to form a side part, thereby producing an unvulcanized tire.

[0184] 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.

[0185] As described above, the tire obtained above can improve the overall performance of high-speed durability, handling stability, 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 effects of the appropriately formed tread cooperate with each other.

[0186] 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. In particular, it is preferably used as a passenger car tire.

Examples

[0187] Hereinafter, examples (Examples) considered to be preferable in carrying out the invention are shown, but the scope of the present invention is not limited to these examples.

[0188] 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 the results calculated based on the evaluation methods described later regarding high-speed durability, handling stability, rolling resistance, and overall performance are also shown at the bottom of Table 2.

[0189] 1. Preparation of rubber composition Using the various compounding materials shown below, a rubber composition for the tread is prepared.

[0190] (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: 63 mol%, Tg: -20°C, non-oil extended product) (c) SBR-2: Modified S-SBR produced based on Production Example 2 described below (styrene content: 24% by mass, vinyl content: 59 mol%, Tg: -25°C, non-oil extended product) (d) SBR-3: HPR840 manufactured by ENEOS MATERIALS (modified S-SBR, styrene content: 10% by mass, vinyl content: 42 mol%, Tg: -60°C, non-oil extended product) (e) BR-1: BR730 manufactured by ENEOS MATERIALS (cis content: 96% by mass, trans content: 3% by mass, vinyl content: 1% by mass) (f) BR-2: ASAPREN N103 manufactured by Asahi Kasei Corporation (cis content: 38% by mass, Tg: -90°C) (g) BR-3: BR360B manufactured by Ube Industries, Ltd. (cis content: 97% by mass, trans content: 1% by mass, vinyl content: 2% by mass)

[0191] (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 using a hot roll to obtain SBR-1.

[0192] (Production Example 2) The above SBR-2 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.

[0193] (b) Ingredients other than the rubber component (a) Carbon black: Dia Black N220 manufactured by Mitsubishi Chemical Corporation (N2SA: 115 m2 / g) (b) Silica: Ultrasil VN3 manufactured by Evonik Industries (N2SA: 175 m2 / g, average primary particle size: 17 nm) (c) Silane coupling agent: NXT manufactured by Momentive (3 - Octanoylthiopropyltriethoxysilane) (d) Oil: Process Oil A / OMIX manufactured by Sankyo Yuka Kogyo Co., Ltd. (e) Resin: YS Resin PX850 manufactured by Yasuhara Chemical Co., Ltd. (Softening point 85°C, β - pinene resin (terpene resin)) (f) Wax: Oz Ace 0355 manufactured by Nippon Seiro Co., Ltd. (g) Antioxidant - 1: No Crack 6C manufactured by Ouchi Shinko Chemical Industry Co., Ltd. (N - (1,3 - dimethylbutyl) - N’ - phenyl - p - phenylenediamine) (h) Antioxidant - 2: ANTAGE RD manufactured by Kawaguchi Chemical Industry Co., Ltd. (Poly(2,2,4 - trimethyl - 1,2 - dihydroquinoline) (i) Antioxidant - 3: Sirantech S - TMQ manufactured by Sennics (Poly(2,2,4 - trimethyl - 1,2 - dihydroquinoline) (j) Processing aid - 1: Noxteller CZ manufactured by Ouchi Shinko Chemical Industry Co., Ltd. (N - cyclohexylbenzothiazole - 2 - sulfenamide) (k) Processing aid - 2: Noxteller D manufactured by Ouchi Shinko Chemical Industry Co., Ltd. (1,3 - diphenylguanidine (DPG)) (l) Processing aid - 3: Noxteller M - P manufactured by Ouchi Shinko Chemical Industry Co., Ltd. (2 - mercaptobenzothiazole) (m) Stearic acid: Bead Stearic Acid "Tsubaki" manufactured by NOF Corporation (n) Zinc oxide: Two types of zinc oxide manufactured by Mitsui Mining & Smelting Co., Ltd. (Yo) Sulfur: Powder sulfur manufactured by Karuizawa Sulfur Co., Ltd. (Ta) Accelerator - 1: Sunseller CM - G manufactured by Sanshin Chemical Industry Co., Ltd. (N - cyclohexyl - 2 - benzothiazolylsulfenamide (CBS) (Re) Accelerator - 2: Succinol DG manufactured by Sumitomo Chemical Co., Ltd. (1,3 - diphenylguanidine (DPG) (So) Accelerator - 3: SUNSINE MBT manufactured by Shandong Shangshun Chemical Co., Ltd. (2 - mercaptobenzothiazole)

[0194] (2) Preparation of rubber composition for tread Based on each formulation of A - 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.

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

[0196] 2. Molding of tire components (tread, band, belt) (1) Molding of tread Next, using the rubber composition obtained above, treads (cap treads) are molded at each thickness shown in Table 2.

[0197] (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.

[0198] (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.

[0199] 3. Manufacture of tire Next, each tread, band, and belt obtained above is bonded together with other tire members to form an unvulcanized tire, which is then press-vulcanized at 170°C for 10 minutes to manufacture the test tires of Examples 1 to 4 and Comparative Examples 1 to 3.

[0200] 4. Performance Evaluation Test (1) Evaluation of Rolling Resistance Using a rolling resistance tester, measure the rolling resistance coefficient (RRC: Rolling Resistance Coefficient) when each test tire runs on a drum at a speed of 80 km / h under the following conditions. Service Rim: 15×6J Inner Pressure: 210 kPa Load: 4.35 kN

[0201] Next, taking the result in Comparative Example 3 as 100, index it based on the following formula for the 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 Test Tire)] × 100

[0202] (2) Handling Stability Evaluation Mount each test tire on all four wheels of a vehicle (a domestic FR car with a displacement of 2000 cc), and 20 test drivers each subjectively evaluate the handling stability when the test course is driven around at a speed of 70 km / h or more on a scale of 1 to 10 (the larger the numerical value, the better), and calculate the total score.

[0203] Next, taking the result in Comparative Example 2 as 100, index it based on the following formula for the handling stability evaluation. The larger the numerical value, the better the handling stability during high-speed driving. Handling Stability Evaluation = [(Result of Test Tire) / (Result of Comparative Example 2)] × 100

[0204] (3) High-Speed Durability Evaluation Each test tire was mounted on a rim (size = 15×6J), filled with air, and the internal pressure was adjusted to 230 kPa. Then, it was mounted on a drum test machine, a vertical load of 5.88 kN was applied, and the speed was gradually increased from 210 km / h in steps of 10 km / h to measure the time until the tire was damaged.

[0205] Next, taking the result in Comparative Example 3 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 longer the time until damage, indicating excellent durability after driving. High-speed durability evaluation = [(result of the test tire) / (result of Comparative Example 3)] × 100

[0206] (4) Comprehensive evaluation Then, (1) to (3) were added together to obtain a comprehensive evaluation.

[0207]

Table 1

[0208]

Table 2

[0209] Although the present invention has been described based on the embodiments, the present invention is not limited to the above embodiments. Various changes can be made to the above embodiments within the same and equivalent scope as the present invention.

[0210] The present invention (1) includes a carcass provided with carcass cords, a belt provided with belt cords and disposed on the outer side in the tire radial direction of the carcass, a band provided with band cords 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, and is a tire comprising The band cord is obtained by twisting one yarn containing polyethylene terephthalate fibers, The tread is formed using a rubber composition containing more than 75 parts by mass of silica with respect to 100 parts by mass of a rubber component, having a thickness of more than 6 mm and a rubber hardness (Shore hardness) Hs of more than 60, The tire is characterized in that the product of the diameter (mm) of the band cord and the thickness (mm) of the tread is less than 10.0.

[0211] The present invention (2) is the tire according to the present invention (1), characterized in that the diameter of the band cord is 0.2 mm or more and 0.8 mm or less.

[0212] The present invention (3) is the tire according to the present invention (1), characterized in that the number of cord strands per 50 mm width of the band cord in the tire width direction is 40 or more and 80 or less.)

[0213] The present invention (4) is the tire according to the present invention (1), characterized in that the belt cord is composed of 1 or more and 4 or less filaments.

[0214] The present invention (5) is the tire according to the present invention (1), characterized in that the number of cord strands per 50 mm width of the belt cord in the tire width direction is 20 or more and 60 or less.

[0215] The present invention (6) is the tire according to the present invention (1), characterized in that the rubber composition contains vegetable oil.

[0216] The present invention (7) is the tire according to the present invention (1), characterized in that the rubber composition contains sustainable carbon black.

[0217] The present invention (8) The rubber composition contains sustainable silica, and it is the tire according to the present invention (1).

[0218] The present invention (9) The polyethylene terephthalate fiber is a sustainable polyethylene terephthalate fiber, and it is the tire according to the present invention (1).

Explanation of reference numerals

[0219] 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 containing more than 75 parts by mass of silica with respect to 100 parts by mass of a rubber component, having 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 10.

0.

2. 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.

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

4. The tire according to claim 1, characterized in that the belt cord is composed of one or more and four or less filaments.

5. The tire according to claim 1, characterized in that the number of cords per 50 mm width of the belt cord in the tire width direction is 20 or more and 60 or less.

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

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

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

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

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