TIRES

Abstract

Tires, comprehensive: a carcass containing a carcass cord; a belt containing a belt cord and positioned on the outside of the carcass in a tire radial direction; a band containing a tape cord and positioned on the outside of the belt in the radial direction of the tire; and a tread surface that is provided on an outside of the belt in the tire radial direction, the bandcord is obtained by twisting a filament of yarn containing a polyethylene terephthalate fiber, the tread is formed from a rubber composition containing 75 parts by mass or more of silicon dioxide in relation to 100 parts by mass of a rubber component, and has a thickness of more than 6 mm and a rubber hardness (Shore hardness) Hs of more than 60, and a product of the diameter (mm) of the band cord and the thickness (mm) of the running surface is less than 10.0.

Description

Technical field

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

[0002] As disclosed in PTL 1, in a tire for a passenger car, a band (also referred to as a cover layer) is generally provided between a tread and a belt from the point of view of preventing deformation of the tire due to centrifugal force during high-speed driving. List of citations from patent literature

[0003] [PTL 1] Japanese unexamined patent publication JP 2022-38812 A Summary of the invention: Technical problem

[0004] One object of the present invention is to improve overall performance in terms of durability at high speed, steering stability and rolling resistance. Solution to the problem

[0005] According to one embodiment of the present invention, a tire is provided which comprises: a carcass containing a carcass cord; a belt containing a belt cord and positioned on the outside of the carcass in a tire radial direction; a band containing a tape cord and positioned on the outside of the belt in the radial direction of the tire; and a tread surface that is provided on an outside of the belt in the tire radial direction, the bandcord is obtained by twisting a filament of yarn containing a polyethylene terephthalate fiber, the tread is formed from a rubber composition containing 75 parts by mass or more of silicon dioxide in relation to 100 parts by mass of a rubber component, and has a thickness of more than 6 mm and a rubber hardness (Shore hardness) Hs of more than 60, and a product of the diameter (mm) of the band cord and the thickness (mm) of the running surface is less than 10.0. Advantageous effects of the invention

[0006] According to the present invention, it is possible to improve the overall performance in terms of durability at high speed, steering stability and rolling resistance. Brief description of the drawings Fig. Figure 1 is a schematic cross-sectional view for an explanatory description of a tire according to an embodiment of the present invention. Description of embodiments[1] Properties of tires according to the present invention

[0007] First, the properties of a tire according to the present invention are described. 1. Overview

[0008] A tire according to the present invention comprises a carcass containing a carcass cord; a belt containing a belt cord, arranged on the outside of the carcass in a tire radial direction; a band containing a band cord, arranged on the outside of the belt in the tire radial direction; and a tread, arranged on the outside of the band in the tire radial direction. The band cord is obtained by twisting a filament of yarn containing a polyethylene terephthalate (PET) fiber. The tread is formed from a rubber composition (a tread rubber composition) containing 75 parts by mass or more of silicon dioxide per 100 parts by mass of a rubber component, and has a thickness of more than 6 mm and a rubber hardness (Shore hardness) Hs of more than 60.Furthermore, the product of the diameter (mm) of the tape cord and the thickness (mm) of the running surface is less than 10.0.

[0009] Due to the presence of these properties, it is possible, as will be described later, to improve the overall performance of durability at high speed, steering stability and rolling resistance in a tire where the band is used. 2. Mechanism for showing effect on tires according to the present invention

[0010] A mechanism for demonstrating the above-described effect in the tire according to the present invention is designed as follows. (1) Use of a simply twisted PET tape

[0011] In the tire according to the present invention, a simply twisted PET band, obtained by twisting a filament of yarn containing a PET fiber, is used as the band cord. The filament forming the yarn can be solely a PET fiber or it can be a mixture of a PET fiber and other fibers (such as a polyamide fiber).

[0012] Compared to Nylon 66 (synthetic polyamide fiber), which was primarily used in prior art applications, PET fiber exhibits high elasticity, thus allowing for a reduction in cord diameter. Therefore, it is assumed that the tape's thickness (preparation gauge) and weight (preparation weight) can be reduced, thereby lowering rolling resistance. (2) Running surface

[0013] However, a tire produced using a tape with a reduced cord diameter exhibits poor resistance to compression fatigue, and thus there are concerns that durability at high speeds may be reduced.

[0014] To improve resistance to compression fatigue, the running surface only needs to be thickened to reduce the compression received by the belt.

[0015] As a result of further investigations, the inventors of the present invention have assumed that in a case where a suitable rubber composition, in particular a rubber composition containing 75 parts by mass or more of silicon dioxide in relation to 100 parts by mass of a rubber component, is used for a rubber composition for a tread, and then a tread is formed such that it has a thickness of more than 6 mm and a rubber hardness (Shore hardness) Hs of more than 60, it is possible to prevent compression fatigue of the belt (to improve durability) while reducing rolling resistance, and it is furthermore possible to ensure steering stability.

[0016] This means that by including 75 parts by mass or more of silicon dioxide with an OH group on its surface in the rubber composition for a tread, relative to 100 parts by mass of the rubber component, hydrogen bonding occurs between the silicon dioxide surfaces and interacts with the rubber component. Therefore, a force can be easily generated and transmitted within the rubber during driving. Consequently, a force generated during turning can be easily transmitted, and excellent steering stability can be ensured. It should be noted that the silicon dioxide content relative to 100 parts by mass of the rubber component is more preferably 80 parts by mass or more, even more preferably 85 parts by mass or more, and yet more preferably 90 parts by mass or more.The upper limit of this is, for example, preferably 200 parts or less, more preferably 150 parts or less, even more preferably 120 parts or less, and even more preferably 100 parts or less.

[0017] Furthermore, by increasing the thickness of the running surface to more than 6 mm, the compression received by the belt can be reduced. Therefore, resistance to compression fatigue can be improved, thus enhancing durability at high speeds. The thickness of the running surface is more preferably 6.5 mm or more, more preferably 8 mm or more, more preferably 8.5 mm or more, and even more preferably 10 mm or more. The upper limit of this thickness is, for example, preferably 20 mm or less, more preferably 15 mm or less, and even more preferably 12 mm or less.

[0018] Furthermore, by increasing the rubber hardness (Shore hardness) Hs of the running surface to a value greater than 60, the amount of deformation of the running surface can be reduced, and thus the compression applied to the belt can be reduced. Therefore, compression fatigue of the belt can be suppressed, and its resistance to compression fatigue (durability at high speed) can be improved.

[0019] Furthermore, a tread with a rubber hardness (Shore hardness) Hs greater than 60 ensures sufficient stiffness, suppresses tread deformation during cornering, and easily transmits the generated force. Therefore, excellent steering stability can be guaranteed.

[0020] It should be noted that the rubber hardness (Shore hardness) Hs described above can be measured in accordance with a method specified in JIS K 6253-3:2012 using a Type A hardness tester.

[0021] Furthermore, the rubber hardness (Shore hardness) Hs is preferably 65 or more, and even more preferably 70 or more. The upper limit of this is, for example, preferably 85 or less, and even more preferably 80 or less.

[0022] It should be noted that in the above description, although the tread is described as a single layer (rubber top layer) serving as a ground contact surface, the tread may be constructed of two layers, with a rubber base layer within the rubber top layer, and the tread may have three layers or four or more layers. In this case, the rubber composition for a tread serves as a rubber composition forming a rubber top layer, which is the outermost layer on the ground contact surface, and it is preferred that the rubber composition fulfills each of the parameters described above.

[0023] In this case, the thickness of the rubber top layer over the entire running surface is preferably 10% or more, more preferably 30% or more, even more preferably 50% or more and even more preferably 70% or more.

[0024] Here, tread thickness refers to the thickness of the tread on a tire's equator plane in a cross-section along the tire's radial direction. It is the thickness of the rubber compound in cases where the tread is made of a single rubber compound. In cases where the tread is a laminated structure of multiple rubber compounds, it refers to the thickness of the rubber top layer, which, among these layers, is the outermost layer on the contact patch side. Tread thickness can be measured by adjusting a bead section so that it matches a standard rim width in a cross-section obtained by cutting the tire radially.

[0025] It should be noted that the term "standard rim" refers to a rim defined for each tire by a standard within a standards system that includes the standard on which the tire is based. For example, in one instance, The Japan Automobile Tyre Manufacturers Association, Inc. refers to a standard rim with respect to the applicable size described in the "JATMA YEAR BOOK" (JATMA); in another instance, The European Tyre and Rim Technical Organisation (ETRTO) refers to a "Measuring Rim" described in the "STANDARDS MANUAL"; and in another instance, The Tire and Rim Association, Inc. refers to a "Design Rim" described in the "YEAR BOOK" (TRA). It should be noted that references to JATMA, ETRTO, and TRA are made in that order, following a standard with respect to an applicable size in a case where an applicable size exists.Furthermore, a normal rim refers to a rim that, in a case where the tire is not defined in the standard, is capable of mounting a tire on the rim while maintaining internal pressure; that is, a rim with the smallest rim diameter and then a rim with the narrowest rim width among rims that do not cause air leakage between a rim and a tire. (3) Product of diameter (mm) of band cord and thickness (mm) of running surface

[0026] As a result of further investigations, the inventors of the present invention have assumed that, in a case where the product of the diameter (mm) of the belt cord and the thickness (mm) of the tread is less than 10.0, the respective effects described above interact to exhibit an overall improvement in high-speed durability, steering stability, and rolling resistance. It should be noted that the product of the diameter (mm) of the belt cord and the thickness (mm) of the tread is more preferably 8.00 or less, and more preferably 6.00 or less. The lower limit of this is, for example, preferably 2.00 or more, more preferably 2.60 or more, more preferably 3.00 or more, more preferably 3.40 or more, more preferably 3.575 or more, and even more preferably 4.00 or more.

[0027] It should be noted that in the above description, the term "diameter of the band cord" refers to a diameter in a case where a circumscribed circle of cross-section perpendicular to a direction of extension of the cord is a perfect circle, and it refers to an equivalent circle diameter (a diameter of a circle in a case where a perfect circle with the same cross-sectional area is assumed) in a case of an ellipse or the like. The same applies to "diameter of the belt cord," which is described later. For example, "diameter of the band cord" can be measured in accordance with a method specified in JIS L 1017:2002 "Test methods for chemical fiber tire cords." [2] Another preferred aspect of tires according to the present invention

[0028] The tire according to the present invention can achieve a greater effect by utilizing the following aspect. 1. Belt cord

[0029] In the present invention, a steel cord is preferred as the belt cord forming the belt, and from the point of view of reducing the tire's weight, it is preferred that the belt cord be composed of 1 or more and 4 or fewer filaments. The structure thereof can be a non-twisted 1 × 1 structure, a simply twisted 1 × 2 structure, a simply twisted 1 × 4 structure, or a layer-twisted 2+2 structure.

[0030] Furthermore, the number of cords (ends) per 50 mm in width in one tire width direction is preferably 20 or more, more preferably 24 or more, even more preferably 30 or more, and even more preferably 40 or more. It should be noted that the upper limit of this number is, for example, preferably 60 or less, more preferably 50 or less, and even more preferably 46 or less. It should be noted that the ends can be measured, for example, in accordance with a method specified in JIS L 1017:2002. 2. Particle diameter of silicon dioxide

[0031] As described above, the rubber composition for a tread in the present invention contains silicon dioxide. However, if the particle diameter (average primary particle diameter) of the silicon dioxide is too small, process efficiency is reduced. Therefore, it is preferred to use silicon dioxide with a particle diameter greater than 8 nm. It is further preferably 9 nm or more, and even more preferably 10 nm or more. On the other hand, from the point of view of ensuring the reinforcing properties of the rubber and ensuring steering stability performance on a wet road surface while driving, it is preferably 25 nm or less, more preferably 20 nm or less, and even more preferably 17 nm or less.

[0032] It should be noted that the average primary particle diameter of silicon dioxide represents an average of values ​​obtained by observing the minimum particle unit of silicon dioxide forming an aggregated structure as a circle and measuring the absolute maximum length of the minimum particle as the diameter of the circle, and it can be determined by conducting an observation with a transmission or scanning electron microscope, subjecting 400 or more primary particles of silicon dioxide observed in a field of view to measurement and averaging the measured values.

[0033] In particular, the silicon dioxide extracted from the rubber composition cut from the tire is directly observed using an electron microscope or the like, and the equivalent cross-sectional area diameter is calculated from the area of ​​each of the particles of the obtained silicon dioxide, and the average value is determined, whereby the average primary particle diameter can be calculated. 3. Resin component

[0034] Furthermore, it is preferred that the rubber composition forming the running surface contains a resin component.

[0035] In a case where the resin component is included in the rubber compound, the ground contact property with respect to the road surface is improved by the adhesive properties of the resin component. Therefore, it is assumed that the rolling resistance at the point of starting can be further improved.

[0036] The preferred resin component is a rosin-based resin, a styrene-based resin, a coumaron-based resin, a terpene-based resin, a C5 resin, a C9 resin, a C5C9 resin, an acrylic resin, or the like, which will be described later. Among these, a styrene-based resin, such as α-methylstyrene, is further preferred. Furthermore, the content of this resin per 100 parts by mass of the rubber component is preferably 10 parts by mass or more, more preferably 30 parts by mass or more, and still more preferably 50 parts by mass or more. [3] Formations

[0037] The present invention is described in detail below based on the embodiments. 1. Tires according to the present embodiment

[0038] Fig. Figure 1 is a schematic cross-sectional view for an explanatory description of a tire according to the present embodiment. Fig. 1 is an up-down direction, the radial direction of the tire; a left-right direction is a rotational wave direction of the tire; and a direction perpendicular to a paper surface is a circumferential direction of the tire. It is in Fig. 1. It should be noted that a dashed line CL indicates an equatorial plane of the tire. It should be noted that, since the shape of the tire, with the exception of the tread pattern, is symmetrical with respect to the equatorial plane, 1 / 4 of the entire tire is in Fig. 1 is shown.

[0039] As in Fig. As shown in Figure 1, a tire 1 comprises a tread 2, a pair of sidewalls 3, a pair of bead strips 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, and the carcass 7, the belt 8, the band 10 and the tread 2 are arranged in the tire radial direction from the inside out.

[0040] It is assumed that in a case where the configuration described above is used and, as described above, a band cord obtained by twisting a filament of yarn containing a PET fiber is used as the band cord to appropriately form the tread, and furthermore, the product of the diameter (mm) of the band cord and the thickness (mm) of the tread is appropriately controlled, it is possible to improve the overall performance of durability at high speed, steering stability and rolling resistance. 2. Rubber composition for tread

[0041] In the present embodiment, the rubber composition for a running surface can be obtained by kneading various mixed materials, such as a rubber component, a reinforcing material, an antioxidant, an oil, a resin material and an antioxidant. (1) Mixed material(a) Rubber component

[0042] The rubber component is not particularly restricted. For example, it is possible to use a diene-based rubber, such as natural rubber (NR), styrene-butadiene rubber (SBR), butadiene rubber (BR), isoprene rubber (IR), acrylonitrile butadiene rubber (NBR), chloroprene rubber (CR), or butyl rubber (IIR). These can be used alone, or two or more types can be used in combination, and in the present invention, a combined use of NR, SBR, and BR is preferred. (a-1) SBR

[0043] The weight-average molecular weight of SBR is, for example, greater than 100,000 and less than 2,000,000. The styrene content of the SBR is, for example, preferably greater than 5 wt%, more preferably greater than 10 wt%, and even more preferably greater than 15 wt%. On the other hand, it is preferably less than 40 wt%, more preferably less than 35 wt%, and even more preferably less than 30 wt%. The vinyl content (the amount of the 1,2-bonded butadiene unit) of the SBR is, for example, preferably greater than 5 wt%, more preferably greater than 10 wt%, and even more preferably greater than 15 wt%. On the other hand, it is preferably less than 70 wt%, more preferably less than 40 wt%, and even more preferably less than 30 wt%. It should be noted that the identification of the structure of the SBR (the measurement of the styrene content and the vinyl content) can be carried out, for example, using a device from JEOL Ltd.can be performed using the manufactured device of the JNM-ECA series.

[0044] The SBR is not particularly restricted, and it is possible, for example, to use an emulsified polymerized styrene-butadiene rubber (E-SBR) or a solution-polymerized styrene-butadiene rubber (S-SBR). The SBR can be an unmodified SBR or a modified SBR. Furthermore, a hydrogenated SBR, obtained by hydrogenating a butadiene portion in the SBR, can be used. The hydrogenated SBR can be obtained by subsequent hydrogenation of the BR portion in the SBR, or a similar structure can be obtained by copolymerizing styrene, ethylene, and butadiene.

[0045] The modified SBR is preferably an SBR with a functional group that interacts with a filler, such as silicon dioxide. Examples include an end-modified SBR obtained by modifying at least one end of the SBR with a compound (a modifier) ​​having the functional group described above (an end-modified SBR having the functional group described above at the end), a main-chain modified SBR having the functional group described above in the main chain, a main-chain / end-modified SBR having the functional group described above in both the main chain and at the end (for example, a main-chain / end-modified SBR in which the functional group described above is provided in the main chain and at least one end is modified with the modifier described above), and an end-modified SBR.which has undergone a modification (coupling) with a polyfunctional compound having two or more epoxy groups in the molecule and into which a hydroxyl group or an epoxy group has been introduced.

[0046] Examples of functional groups 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, and an epoxy group. It should be noted that these functional groups may contain a substituent.

[0047] Furthermore, it is possible to use, for example, a modified SBR that is modified with a compound (modifier) ​​represented by the following formula.

[0048] It should be noted that in formula R 1 , R 2 and R 3 are the same or different from each other, representing an alkyl group, an alkoxy group, a silyloxy group, an acetal group, a carboxyl group (-COOH), a mercapto group (-SH), or a derivative thereof. R 4 and R 5 are the same or different from each other, representing either a hydrogen atom or an alkyl group. R 4 and R 5 They can be bonded together to form a ring structure with the nitrogen atom. Here, n represents an integer.

[0049] As the modified SBR, which is modified with a compound (modifier) ​​represented by the formula above, it is possible to use an SBR (the modified SBR or the like, as described in Japanese unexamined patent publication No. 2010-111753) obtained by subjecting a polymerization end (active end) of a solution polymerized styrene-butadiene rubber (S-SBR) modified with a compound represented by the formula above.

[0050] R 1 , R 2 and R 3 are suitable an alkoxy group (preferably an alkoxy group with 1 to 8 carbon atoms and more preferably an alkoxy group with 1 to 4 carbon atoms). R 4 and R 5are suitable for an alkyl group (preferably an alkyl group with 1 to 3 carbon atoms). Here, n is preferably 1 to 5, more preferably 2 to 4, and even more preferably 3. Furthermore, in a case where R 4 and R 5 The two groups are bonded together to form a ring structure with the nitrogen atom, preferably a 4- to 8-membered ring. It should be noted that the alkoxy group also contains a cycloalkoxy group (a cyclohexyloxy group or the like) and an aryloxy group (a phenoxy group, a benzyloxy group, or the like).

[0051] Specific examples of the modifier include 2-dimethylaminoethyltrimethoxysilane, 3-dimethylaminopropyltrimethoxysilane, 2-dimethylaminoethyltriethoxysilane, 3-dimethylaminopropyltriethoxysilane, 2-diethylaminoethyltrimethoxysilane, 3-diethylaminopropyltrimethoxysilane, 2-diethylaminoethyltriethoxysilane, and 3-diethylaminopropyltriethoxysilane. These can be used alone, or two or more of them can be used in combination.

[0052] Furthermore, a modified SBR can also be used that is modified with the following compound (modifier). Examples of the modifier include a polyglycidyl ether of a polyhydric alcohol, such as ethylene glycol diglycidyl ether, glycerol triglycidyl ether, trimethyl oleate ethane triglycidyl ether, or trimethylolpropane triglycidyl ether; a polyglycidyl ether of an aromatic compound with two or more phenol groups, such as diglycidylated bisphenol A; a polyepoxy compound, such as 1,4-diglycidylbenzene, 1,3,5-triglycidylbenzene, or a polyepoxylated liquid polybutadiene; an epoxy-containing tertiary amine, such as 4,4'-diglycidyldiphenylmethylamine or 4,4'-diglycidyldibenzylmethylamine;a diglycidylamino compound, such as diglycidylaniline, N,N'-diglycidyl-4-glycidyloxyaniline, diglycidyl ortholuidine, tetraglycidylmethoxylenidamine, tetraglycidylaminodiphenylmethane, tetraglycidyl-p-phenylenediamine, diglycidylaminomethylcyclohexane, or tetraglycidyl-1,3-bisaminomethylcyclohexane; an acid chloride containing an amino group, such as bis-(1-methylpropyl)carbamic acid chloride, 4-morpholine carbonyl chloride, 1-pyrrolidine carbonyl chloride, N,N-dimethylcarbamic acid chloride, or N,N-diethylcarbamic acid chloride; a silane compound containing an epoxy group, such as 1,3-bis-(glycidyloxypropyl)tetramethyldisiloxane or (3-glycidyloxypropyl)pentamethyldisiloxane;a silane compound containing a sulfide group, such as (trimethylsilyl)[3-(trimethoxysilyl)propyl]sulfide, (trimethylsilyl)[3-(triethoxysilyl)propyl]sulfide, (trimethylsilyl)[3-(tripropoxysilyl)propyl]sulfide, (trimethylsilyl)[3-(tributoxysilyl)propyl]sulfide, (trimethylsilyl)[3-(methyldimethoxysilyl)propyl]sulfide, (trimethylsilyl)[3-(methyldiethoxysilyl)propyl]sulfide, (trimethylsilyl)[3-(methyldipropoxysilyl)propyl]sulfide or (trimethylsilyl)[3-(methyldibutoxysilyl)propyl]sulfide; an N-substituted aziridine compound, such as ethyleneimine or propylenimine; an alkoxysilane, such as methyltriethoxysilane, N,N-bis(trimethylsilyl)-3-aminopropyltrimethoxysilane, N,N-bis(trimethylsilyl)-3-aminopropyltriethoxysilane, N,N-bis(trimethylsilyl)aminoethyltrimethoxysilane or N,N-bis(trimethylsilyl)aminoethyltriethoxysilane;a (thio)benzophenone compound with 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 or N,N,N',N'-bis-(tetraethylamino)benzophenone; a benzaldehyde compound with an amino group and / or a substituted amino group, such as 4-N,N-dimethylaminobenzaldehyde, 4-N,N-diphenylaminobenzaldehyde or 4-N,N-divinylaminobenzaldehyde; an N-substituted pyrrolidone, such as N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, N-phenyl-2-pyrrolidone, Nt-butyl-2-pyrrolidone or N-methyl-5-methyl-2-pyrrolidone; an N-substituted piperidone, such as N-methyl-2-piperidone, N-vinyl-2-piperidone or N-phenyl-2-piperidone;and an N-substituted lactam, such as N-methyl-ε-caprolactam, N-phenyl-ε-caprolactam, N-methyl-ω-laurolactam, N-vinyl-ω-laurolactam, N-methyl-β-propiolactam or N-phenyl-β-propiolactam; and as well as N,N-Bis-(2,3-epoxypropoxy)-aniline, 4,4-Methylene-bis-(N,N-glycidylaniline), Tris-(2,3-epoxypropyl)-1,3,5-triazine-2,4,6-trione, N,N-Diethylacetamide, N-Methylmaleimide, N,N-Diethylurea, 1,3-Dimethylethyleneurea, 1,3-Divinylethyleneurea, 1,3-Diethyl-2-imidazolidinone, 1-Methyl-3-ethyl-2-imidazolidinone, 4-N,N-Dimethylaminoacetophenone, 4-N,N-Diethylaminoacetophenone, 1,3-Bis(diphenylamino)-2-propanone and 1,7-Bis(methylethylamino)-4-heptanone. It should be noted that the modification with the above compound (modifying agent) can be carried out by a publicly known procedure.

[0053] SBR can be manufactured and sold by companies such as Sumitomo Chemical Co., Ltd., ENEOS Materials Corporation, Asahi Kasei Corporation, or Zeon Corporation. It should be noted that SBR can be used alone or in combination with other types.

[0054] The SBR content 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 even more preferably 50 parts by mass or more. The upper limit is, for example, preferably 70 parts by mass or less, more preferably 65 parts by mass or less, and even more preferably 60 parts by mass or less. (a-2) Isoprene-based rubber

[0055] Examples of isoprene-based rubber include natural rubber (NR), isoprene rubber (IR), reformulated NR, modified NR and modified IR, with NR being preferred from the point of view of excellent strength.

[0056] For natural rubber (NR), it is possible to use those commonly used in the tire industry, such as SVR-L, SIR20, RSS#3, and TSR20. For isotopic rubber (IR), there are no particular restrictions, and it is possible to use those commonly used in the tire industry, such as IR 2200, manufactured by Zeon Corporation. Examples of reformulated NR include deproteinized natural rubber (DPNR) and high-purity natural rubber (UPNR); examples of modified NR include epoxidized natural rubber (ENR), hydrogenated natural rubber (HNR), and grafted natural rubber; and examples of modified IR include epoxidized isoprene rubber, hydrogenated isoprene rubber, and grafted isoprene rubber. These can be used individually, or two or more types can be used in combination.

[0057] The isoprene-based rubber content in 100 parts by mass of the rubber component is preferably 5 parts by mass or more, and more preferably 10 parts by mass or more. The upper limit of this is, for example, preferably 20 parts by mass or less, and more preferably 15 parts by mass or less. (a-3) BR

[0058] The weight-mean molecular weight of BR, for example, is greater than 100,000 and less than 2,000,000. The vinyl content of BR, for example, is greater than 1 wt% and less than 30 wt%. The cis content of BR, for example, is greater than 1 wt% and 98 wt% or less. The trans content of BR is greater than 1 wt% and less than 60 wt%. It should be noted that the cis content can be measured according to an infrared absorption spectrum analysis method.

[0059] The BR is not particularly restricted, and it is possible to use a BR with a high cis content (90% or more), a BR with a low cis content, a BR containing a syndiotactic polybutadiene crystal, or the like. The BR can be an unmodified BR or a modified BR, and as a modified BR, it is possible, for example, to use a BR modified with a compound (modifier) ​​represented by the following formula.

[0060] It should be noted that in formula R 1 , R 2 and R 3 are the same or different from each other, representing 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 5are the same or different from each other, representing either a hydrogen atom or an alkyl group. R 4 and R 5 They can be bonded together to form a ring structure with the nitrogen atom. Here, n represents an integer.

[0061] Examples of modified BR, which is modified with a compound (modifier) ​​represented by the formula above, include a BR obtained by subjecting a polymerization end (active end) to modification with the compound represented by the formula above.

[0062] R 1 , R 2 and R 3 are suitable an alkoxy group (preferably an alkoxy group with 1 to 8 carbon atoms and more preferably an alkoxy group with 1 to 4 carbon atoms). R 4 and R 5are suitable for an alkyl group (preferably an alkyl group with 1 to 3 carbon atoms). Here, n is preferably 1 to 5, more preferably 2 to 4, and even more preferably 3. Furthermore, in a case where R 4 and R 5 The two groups are bonded together to form a ring structure with the nitrogen atom, preferably a 4- to 8-membered ring. It should be noted that the alkoxy group also contains a cycloalkoxy group (a cyclohexyloxy group or the like) and an aryloxy group (a phenoxy group, a benzyloxy group, or the like).

[0063] Specific examples of the modifier include 2-dimethylaminoethyltrimethoxysilane, 3-dimethylaminopropyltrimethoxysilane, 2-dimethylaminoethyltriethoxysilane, 3-dimethylaminopropyltriethoxysilane, 2-diethylaminoethyltrimethoxysilane, 3-diethylaminopropyltrimethoxysilane, 2-diethylaminoethyltriethoxysilane, and 3-diethylaminopropyltriethoxysilane. These can be used alone, or two or more of them can be used in combination.

[0064] Furthermore, a modified BR can also be used that is modified with the following compound (modifier). Examples of the modifier include a polyglycidyl ether of a polyhydric alcohol, such as ethylene glycol diglycidyl ether, glycerol triglycidyl ether, trimethyl oleate ethane triglycidyl ether, or trimethylolpropane triglycidyl ether; a polyglycidyl ether of an aromatic compound with two or more phenol groups, such as diglycidylated bisphenol A; a polyepoxy compound, such as 1,4-diglycidylbenzene, 1,3,5-triglycidylbenzene, or a polyepoxylated liquid polybutadiene; an epoxy-containing tertiary amine, such as 4,4'-diglycidyldiphenylmethylamine or 4,4'-diglycidyldibenzylmethylamine;a diglycidylamino compound, such as diglycidylaniline, N,N'-diglycidyl-4-glycidyloxyaniline, diglycidyl ortholuidine, tetraglycidylmethoxylenidamine, tetraglycidylaminodiphenylmethane, tetraglycidyl-p-phenylenediamine, diglycidylaminomethylcyclohexane, or tetraglycidyl-1,3-bisaminomethylcyclohexane; an acid chloride containing an amino group, such as bis-(1-methylpropyl)carbamic acid chloride, 4-morpholine carbonyl chloride, 1-pyrrolidine carbonyl chloride, N,N-dimethylcarbamic acid chloride, or N,N-diethylcarbamic acid chloride; a silane compound containing an epoxy group, such as 1,3-bis-(glycidyloxypropyl)tetramethyldisiloxane or (3-glycidyloxypropyl)pentamethyldisiloxane;a silane compound containing a sulfide group, such as (trimethylsilyl)[3-(trimethoxysilyl)propyl]sulfide, (trimethylsilyl)[3-(triethoxysilyl)propyl]sulfide, (trimethylsilyl)[3-(tripropoxysilyl)propyl]sulfide, (trimethylsilyl)[3-(tributoxysilyl)propyl]sulfide, (trimethylsilyl)[3-(methyldimethoxysilyl)propyl]sulfide, (trimethylsilyl)[3-(methyldiethoxysilyl)propyl]sulfide, (trimethylsilyl)[3-(methyldipropoxysilyl)propyl]sulfide or (trimethylsilyl)[3-(methyldibutoxysilyl)propyl]sulfide; an N-substituted aziridine compound, such as ethyleneimine or propylenimine; an alkoxysilane, such as methyltriethoxysilane, N,N-bis(trimethylsilyl)-3-aminopropyltrimethoxysilane, N,N-bis(trimethylsilyl)-3-aminopropyltriethoxysilane, N,N-bis(trimethylsilyl)aminoethyltrimethoxysilane or N,N-bis(trimethylsilyl)aminoethyltriethoxysilane;a (thio)benzophenone compound with 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 or N,N,N',N'-bis-(tetraethylamino)benzophenone; a benzaldehyde compound with an amino group and / or a substituted amino group, such as 4-N,N-dimethylaminobenzaldehyde, 4-N,N-diphenylaminobenzaldehyde or 4-N,N-divinylaminobenzaldehyde; an N-substituted pyrrolidone, such as N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, N-phenyl-2-pyrrolidone, Nt-butyl-2-pyrrolidone or N-methyl-5-methyl-2-pyrrolidone; an N-substituted piperidone, such as N-methyl-2-piperidone, N-vinyl-2-piperidone or N-phenyl-2-piperidone;and an N-substituted lactam, such as N-methyl-ε-caprolactam, N-phenyl-ε-caprolactam, N-methyl-ω-laurolactam, N-vinyl-ω-laurolactam, N-methyl-β-propiolactam or N-phenyl-β-propiolactam; and as well as N,N-Bis-(2,3-epoxypropoxy)-aniline, 4,4-Methylene-bis-(N,N-glycidylaniline), Tris-(2,3-epoxypropyl)-1,3,5-triazine-2,4,6-trione, N,N-Diethylacetamide, N-Methylmaleimide, N,N-Diethylurea, 1,3-Dimethylethyleneurea, 1,3-Divinylethyleneurea, 1,3-Diethyl-2-imidazolidinone, 1-Methyl-3-ethyl-2-imidazolidinone, 4-N,N-Dimethylaminoacetophenone, 4-N,N-Diethylaminoacetophenone, 1,3-Bis(diphenylamino)-2-propanone and 1,7-Bis(methylethylamino)-4-heptanone. It should be noted that the modification with the above compound (modifying agent) can be carried out by a publicly known procedure. It should also be noted that these modified BRs can be used alone, or two or more types of them can be used in combination.

[0065] As the BR, it is possible to use a product manufactured, for example, by UBE Corporation, ENEOS Materials Corporation, Asahi Kasei Corporation or Zeon Corporation.

[0066] The BR content 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. Alternatively, it is preferably 40 parts by mass or less, and more preferably 35 parts by mass or less. (a-4) Another rubber component

[0067] The rubber composition may, if required, include another rubber component such as rubber (a polymer) commonly used in tire manufacturing, like nitrile rubber (NBR).

[0068] It should be noted that the raw material (monomer) of the synthetic rubber described above, such as SBR and BR, may be a raw material derived from an underground resource, such as petroleum or natural gas, or a raw material recycled from a rubber product, such as a tire, or a non-rubber product, such as polystyrene.

[0069] The monomer obtained through recycling (recycled monomer) is not particularly restricted, and examples include recycled isoprene, recycled butadiene, and recycled aromatic vinyl. Examples of butadiene include 1,2-butadiene and 1,3-butadiene. Aromatic vinyl is not particularly restricted, and examples include styrene. Among these, it is preferred to use recycled isoprene (recycled isoprene), recycled butadiene, and / or recycled styrene as a feedstock.

[0070] A production process for the recycled monomer is not particularly restricted, and one example involves synthesizing the recycled monomer from recycled naphtha obtained by decomposing a rubber product, such as a tire. Furthermore, a production process for the recycled naphtha is not particularly restricted, and, for example, a rubber product, such as a tire, can be decomposed under high temperature and pressure, can be decomposed using a microwave oven, or can be extracted after mechanical shredding.

[0071] Furthermore, the raw material (monomer) of synthetic rubber, such as IR, SBR, and BR, can be a biomass-derived raw material. Here, biomass refers to a substance derived from a natural resource, such as a plant. The biomass is not particularly restricted, and examples include agricultural, forestry, and fishery products; sugar; wood; plant residues after the collection of useful components; plant-derived ethanol; and biomass aphtha. The biomass-derived monomer is not particularly restricted, and examples include biomass-derived butadiene and biomass-derived aromatic vinyl compounds. Examples of butadiene include 1,2-butadiene and 1,3-butadiene. The aromatic vinyl is not particularly restricted, and examples include styrene.Furthermore, the production process for the biomass monomer is not particularly restricted, and examples include those obtained through biological, chemical, and / or physical conversion of animals and plants. Fermentation by microorganisms is typical of biological conversion, and chemical and / or physical conversion includes conversion by a catalyst, conversion by high temperature, conversion by high pressure, conversion by electromagnetic waves, conversion by a critical fluid, and a combination thereof.

[0072] A polymer synthesized from the biomass monomer component (biomass polymer) is not particularly restricted, and examples include polybutadiene rubber, synthesized from biomass-derived butadiene, and an aromatic vinyl butadiene copolymer, synthesized from biomass-derived butadiene and / or biomass-derived aromatic vinyl. Examples of aromatic vinyl / butadiene copolymers include a styrene butadiene rubber, synthesized from biomass-derived butadiene and / or biomass-derived styrene.

[0073] Whether the raw material of the polymer is derived from biomass or not can be determined by pMC (Percent Modern Carbon), which is measured in accordance with D6866-10.

[0074] The pMC is a ratio of 14 C concentration of a sample to a 14The carbon concentration of modern standard reference carbon (C-C) is used as an index indicating the biomass content of the compound (rubber). The meaning of this value is described below.

[0075] In one mole of carbon atoms (6.02 × 10 23 atoms) are approximately 6.02 × 10 11 atoms of 14 C, which is about one trillionth of the total carbon atoms, is present. 14 Carbon-14 is classified as a radioisotope, has a half-life of 5,730 years, and its quantity is steadily decreasing. It takes 226,000 years for its complete decay. Therefore, in the case of fossil fuels, such as coal, oil, and natural gas, where 226,000 years or more may have passed since carbon dioxide and similar substances were incorporated into plants and other organisms from the atmosphere and then fixed in the atmosphere, all the carbon dioxide and other carbon dioxide present in the atmosphere has decayed. 14Carbon elements, initially contained in these fuels, decay. Therefore, fossil fuels such as coal, oil, and natural gas contain no carbon at all in the current 21st century. 14 Carbon elements. Therefore, the chemical substances produced from these fossil fuels as raw materials contain none at all. 14 C-elements.

[0076] On the other hand 14 C is constantly produced by the nuclear reaction of cosmic rays in the air, the generation of 14 Carbon is balanced by a decrease due to radioactive decay, and thus the amount of 14 Carbon-14 is a constant amount in the Earth's atmospheric environment. Consequently, the 14 Carbon concentration of the substance derived from biomass resources that are in circulation in the current environment, a value of approximately 1 × 10 -12Moles or the like in relation to the total sulfur atoms, as described above. Consequently, the rate (biomass fraction) of the compound derived from a natural resource (a compound derived from a biomass resource) in a given compound (rubber) can be calculated by using the difference between these values.

[0077] This 14 C is generally measured as follows. The accelerator mass spectrometry method using a tandem accelerator is used to determine a 13 C concentration ( 13 C / 12 C}) and a 14 C concentration ( 14 C / 12 C) to measure. During the measurement, the 14 C concentration in circulating carbon in the natural world in 1950 as the modern standard reference, which serves as the reference for the concentration of 14C is used. A specific standard substance is an oxalic acid standard substance provided by the National Institute of Standards and Technology (NIST). The specific radioactivity of carbon in the oxalic acid (the radioactivity intensity of 14 C per 1 g carbon) is separated for each carbon isotope, for 13 C corrected to a constant value and subjected to attenuation correction from 1950 to the measurement date, resulting in a value that is considered the value (100%) of the standard 14 The C concentration is used. A ratio of this value to the value of the sample that was actually measured is the pMC value.

[0078] Consequently, in a case where the rubber is produced from 100% biomass-derived material (natural base), the rubber under normal conditions often does not currently reach 100, although there may be regional variations, and thus the rubber exhibits a pMC value of approximately 110. On the other hand, in a case where the 14 When the carbon concentration of a chemical substance derived from a fossil fuel, such as petroleum, is measured, the chemical substance will have a value of approximately 0 pMC (for example, 0.3 pMC). This value corresponds to 0% of the biomass fraction described above.

[0079] From the above, from the point of view of environmental protection (sustainability), it is suitable to use a material in the rubber composition, such as rubber with a high pMC value, that is, a material such as rubber with a high biomass content. (b) Mixture material other than rubber component (b-1) Filler

[0080] The rubber composition contains silicon dioxide as a reinforcing agent; however, it may, as required, contain another filler, for example, carbon black, calcium carbonate, talc, alumina, clay, aluminum hydroxide, mica, or the like. It should be noted that in any case where silicon dioxide is used, the silicon dioxide is preferably used in combination with a silane coupling agent.

[0081] Regarding the proportion of the filler, as described above, the silicon dioxide is adjusted to be 75 parts by mass or more per 100 parts by mass of the rubber component; however, the total proportion of the silicon dioxide and the other filler is preferably 80 parts by mass or more, and more preferably 90 parts by mass or more, per 100 parts by mass of the rubber component. On the other hand, from the point of view of dispersibility in the rubber composition, it is preferably 150 parts by mass or less, and more preferably 100 parts by mass or less. (i) Silicon dioxide

[0082] Since silicon dioxide has an OH group on its surface, hydrogen bonding occurs between the silicon dioxide surfaces and interacts with the rubber component when the silicon dioxide content is 75 parts by mass or more, as described above. This facilitates the generation of force within the rubber during driving, enabling power transmission, and also allows for the efficient transfer of forces generated during cornering, thus ensuring excellent steering stability. Furthermore, the OH group on the surface can trap ozone, thereby improving ozone resistance and extending the tire's lifespan.

[0083] From the perspective of obtaining favorable durability performance, the specific BET surface area of ​​the silicon dioxide is preferably more than 100 m². 2 / g and preferably more than 130 m2 / g. On the other hand, it is preferably less than 250 m 2 / g and preferably less than 200 m 2 / g. It should be noted that the specific BET surface area described above is a value of N2SA measured by the BET method according to ASTM D3037-93.

[0084] The silicon dioxide used is not particularly restricted, and it is possible to use those commonly used in the tire industry, such as anhydrous silicon dioxide produced by a dry-type process and hydrated silicon dioxide produced by a wet-type process. A commercially available product of this type could be manufactured by Evonik Industries AG, Rhodia, Tosoh Silica Corporation, Nippon Solvay KK, Tokuyama Corporation, or similar companies.

[0085] The raw material for silicon dioxide is not particularly restricted. It can be, for example, a mineral-derived raw material such as quartz, or a biologically derived raw material such as rice husks (for example, silicon dioxide obtained by using a biomass material such as rice husks as a feedstock), and recycled silicon dioxide from a product containing silicon dioxide can also be used. Among the above, aqueous silicon dioxide produced by a wet-type process is preferred because of its high number of silanol groups.

[0086] Silicon dioxide (biomass silicon dioxide) obtained by using a biomass material as a feedstock can, for example, be obtained by extracting a silicate from rice hull ash obtained by burning rice hulls, using a sodium hydroxide solution, and then by filtering, washing, drying, and crushing a precipitate of silicon dioxide produced by reacting the silicate with sulfuric acid in the same way as in the case of wet-type silicon dioxide in the prior art.

[0087] For the silicon dioxide (recycled silicon dioxide) recycled from a product containing silicon dioxide, silicon dioxide recovered from a product containing silicon dioxide, such as an electronic component like a semiconductor, or a filter material like a tire, desiccant, or diatomaceous earth, can be used. Furthermore, the method for carrying out the recovery is not particularly restricted, and examples include thermal decomposition, decomposition by electromagnetic waves, and the like. Among the above, silicon dioxide recovered from an electronic component like a semiconductor or from a tire is preferred.

[0088] In cases where silicon dioxide crystallizes, it is insoluble in water, and the component of silicon dioxide, namely silicic acid, cannot be used. By controlling the combustion temperature and duration, it is possible to suppress the crystallization of silicon dioxide in rice hull ash (see Japanese Unexamined Patent Publication No. 2009-2594, Akita Prefectural University Web Journal B / 2019, vol. 6, pp. 216-222, and similar sources).

[0089] For the amorphous silicon dioxide extracted from the rice husks, amorphous silicon dioxide commercially available from Wilmar International Limited and the like can be used.

[0090] It should be noted that this silicon dioxide can be used alone or in combination with two or more types. Furthermore, from an environmental (sustainability) perspective, it is advisable to use sustainable silicon dioxide, such as biomass-derived silicon dioxide or recycled silicon dioxide.

[0091] As described above, the silicon dioxide content is adjusted to be 75 parts by mass or more per 100 parts by mass of the rubber component; however, it is more preferably 80 parts by mass or more, and even more preferably 90 parts by mass or more. The upper limit of this is, for example, preferably 150 parts by mass or less, and more preferably 100 parts by mass or less. (ii) Silane coupling agents

[0092] In a case where silicon dioxide is used, it is preferred to use a silane coupling agent in combination to improve the dispersibility of the silicon dioxide and to improve the mechanical properties, malleability and the like by reacting with the silicon dioxide.

[0093] The silane coupling agent is not particularly restricted, and examples include sulfide-based silane coupling agents such as bis(3-triethoxysilylpropyl)tetrasulfide, bis(2-triethoxysilylethyl)tetrasulfide, bis(4-triethoxysilylbutyl)tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, bis(2-trimethoxysilylethyl)tetrasulfide, bis(2-triethoxysilylethyl)trisulfide, bis(4-trimethoxysilylbutyl)trisulfide, bis(3-triethoxysilylpropyl)disulfide, bis(2-triethoxysilylethyl)disulfide, bis(4-triethoxysilylbutyl)disulfide, bis(3-trimethoxysilylpropyl)disulfide, bis(2-trimethoxysilylethyl)disulfide, bis(4-trimethoxysilylbutyl)disulfide, bis(3-trimethoxysilylpropyl)disulfide, bis(2-trimethoxysilylethyl)disulfide, bis(4-trimethoxysilylbutyl)disulfide, 3-trimethoxysilylpropyl-N,N-dimethylthiocarbamoyl tetrasulfide, 2-triethoxysilylethyl-N,N-dimethylthiocarbamoyl tetrasulfide and 3-triethoxysilylpropyl methacrylate monosulfide;Mercapto-based silane coupling agents, such as 3-mercaptopropyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, and NXT and NXT-Z, manufactured by Momentive Performance Materials Inc.; vinyl-based silane coupling agents, such as vinyltriethoxysilane and vinyltrimethoxysilane; amino-based silane coupling agents, such as 3-aminopropyltriethoxysilane and 3-aminopropyltrimethoxysilane; glycidoxy-based silane coupling agents, such as γ-glycidoxypropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane; nitro-based silane coupling agents, such as 3-nitropropyltrimethoxysilane and 3-nitropropyltriethoxysilane;and chlorine-based silane coupling agents, such as 3-chloropropyltrimethoxysilane and 3-chloropropyltriethoxysilane. Among these, a silane coupling agent with a thiocarbonyl group, such as the NXT described above, is preferred. These can be used alone, or two or more types can be used in combination.

[0094] The silane coupling agent can be a product manufactured, for example, by Evonik Industries AG, Momentive Performance Materials Inc., Shin-Etsu Chemical Co., Ltd., Tokyo Chemical Industry Co., Ltd., AZmax Co., Ltd. or DuPont Toray Specialty Materials KK.

[0095] The content of the silane coupling agent is, for example, preferably more than 3 parts by mass, more preferably 5 parts by mass or more, and even more preferably 7 parts by mass or more, with respect to 100 parts by mass of silicon dioxide. The upper limit of this is, for example, preferably less than 15 parts by mass, more preferably 12 parts by mass or less, and even more preferably 9 parts by mass or less. (iii) soot

[0096] It is preferred that the carbon black be used for the intended purpose of improving the tire's resistance to crack growth, durability, resistance to ultraviolet deterioration, and the like.

[0097] From the perspective of the reinforcing properties of the rubber, the specific nitrogen adsorption surface area (N2SA) of the carbon black is preferably, for example, 30 m². 2 / g or more, preferably 50 m 2 / g or more and preferably 60 m 2 / g or more. On the other hand, from the point of view of exothermicity, it is preferably 250 m. 2 / g or less, preferably 150 m 2 / g or less and even more preferably 120 m 2 / g or less. It should be noted that the specific nitrogen adsorption surface area of ​​the carbon black is measured according to ASTM D4820-93.

[0098] From the perspective of rubber stiffness, the amount of dibutyl phthalate (DBP) absorbed by the carbon black is, for example, preferably 50 ml / 100 g or more, and more preferably 100 ml / 100 g or more. On the other hand, from the perspective of resistance to rubber deformation, it is preferably 250 ml / 100 g or less, and more preferably 150 ml / 100 g or less. It should be noted that the amount of DBP absorbed by the carbon black is measured in accordance with ASTM D2414-93.

[0099] The type of carbon black is not particularly restricted, and examples include furnace black (SAF, ISAF, HAF, MAF, FEF, SRF, GPF, APF, FF, CF, SCF, and ECF); acetylene black (acetylene carbon black); thermal black (FT and MT); and duct black (duct black) (EPC, MPC, and CC). Furthermore, examples of product numbers include N134, N110, N220, N234, N219, N339, N330, N326, N351, N550, and N762. One type can be used alone, or two or more types can be used in combination.

[0100] In addition to mineral oil, the raw material for carbon black can be a biomass material, such as lignin and vegetable oil, or it can be a thermally decomposed oil obtained by subjecting a rubber product containing carbon black, such as an old tire, to thermal decomposition (regenerated carbon black), and it is suitable from an environmental protection point of view to use these sustainable carbon blacks.

[0101] Furthermore, a production process for the soot can be a production process by combustion, such as a furnace process, a production process by a hydrothermal carbonization (HTC) process, or a production process by thermal decomposition of methane by a thermal soot process or the like.

[0102] As a commercially available product, it is possible to use one manufactured by ASAHI CARBON CO., LTD., Cabot Japan KK, TOKAI CARBON CO., LTD., Mitsubishi Chemical Corporation, Lion Specialty Chemicals Co., Ltd., NIPPON STEEL Chemical & Material Co., Ltd., or Columbia Carbon. These can be used alone, or two or more types can be used in combination.

[0103] The carbon black content per 100 parts by mass of the rubber component is preferably 5 parts by mass or more, and further preferably 10 parts by mass or more. The upper limit of this is, for example, preferably 25 parts by mass or less, and further preferably 20 parts by mass or less. (iv) Another filler

[0104] In addition to the carbon black and silicon dioxide described above, the rubber composition may also contain a filler commonly used in the tire industry, such as graphite, calcium carbonate, talc, alumina, clay, aluminum hydroxide, mica, or magnesium sulfate. The levels of these fillers may be, for example, more than 0.1 parts by mass and less than 150 parts by mass per 100 parts by mass of the rubber component. (b-2) Softener component

[0105] For the rubber composition, it is preferable, taking into account the suitable dispersion of a powder material during kneading, to use a plasticizer component as needed. It should be noted that here the plasticizer component refers to a material that imparts plasticity to the rubber component, and the concept of the plasticizer component includes both a liquid plasticizer at 25 °C and a solid plasticizer at 25 °C.

[0106] Examples of plasticizers include a resin component, an oil, a liquid polymer, and an ester-based plasticizer. The plasticizer can be derived from a mineral resource, such as petroleum or natural gas; it can be derived from biomass; or it can be derived from naphtha recycled from rubber or non-rubber products. Additionally, a low molecular weight hydrocarbon component obtained through the thermal decomposition and extraction of a used tire or a used product containing various components can be used as a plasticizer. Among these, a biomass-derived or recycled plasticizer is preferred as a sustainable option.

[0107] It should be noted that these plasticizers can be used alone, or two or more types can be used in combination. The content of the plasticizer component per 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, for example, preferably 40 parts by mass or less, more preferably 35 parts by mass or less, and even more preferably 30 parts by mass or less. It should be noted that the content of the plasticizer component also includes the amount of oil contained in rubber (oil-extended rubber) or the like. (i) oil

[0108] Examples of oil include mineral oil, vegetable oil, and animal oil. Furthermore, from a life cycle assessment perspective, used oil from a rubber mixer or engine, or oil obtained by refining used cooking oil from a restaurant, can be used. (i-1) Mineral oil

[0109] Mineral oil refers to oil derived from a mineral resource, such as petroleum or natural gas. Examples of mineral oil include paraffin-based oil (mineral oil), naphthene-based oil, and aromatic oil.

[0110] Examples of the specific mineral oil include Mild Extract Solvate (MES), Distillate Aromatic Extract (DAE), Treated Distillate Aromatic Extract (TDAE), Treated Residual Aromatic Extract (TRAE) and Residual Aromatic Extract (RAE).

[0111] Furthermore, for environmental measures, an oil with a low polycyclic aromatic compound (PCA) content can also be used. Examples of low-PCA oils include MES, TDAE, and a heavy naphthene-based oil.

[0112] Examples of commercially available mineral oils include paraffin-based, aroma-based, and naphthene-based oils. It is possible to use a product manufactured by, for example, Idemitsu Kosan Co., Ltd., SANKYO YUKA KOGYO KK, ENEOS Corporation, Olisoy, H&R Group, HOKOKU CORPORATION, Showa Shell Sekiyu KK, or Fuji Kosan Company, Ltd. These can be used alone, or two or more types can be used in combination. (i-2) Vegetable oil

[0113] Examples of vegetable oils include linseed oil, rapeseed oil, safflower oil, soybean oil, corn oil, cottonseed oil, rice bran oil, tall oil, sesame oil, wild sesame oil, castor oil, tung oil, pine oil, pine tar oil, sunflower oil, coconut oil, palm oil, palm kernel oil, olive oil, camellia oil, jojoba oil, macadamia nut oil, peanut oil, grapeseed oil, and Japanese wax.

[0114] Furthermore, examples of vegetable oil also include refined oil (salad oil or the like), obtained by refining any of the oils mentioned above; ester-exchange modified oil, which has undergone ester exchange; hydrogenated hydrogenated oil; thermally polymerized oil, which has undergone thermal polymerization; oxidation-polymerized oil, which has undergone oxidation; and waste cooking oil, obtained by recovering oil used as cooking oil. It should be noted that vegetable oil can be a liquid or a solid at room temperature (25°C). One type can be used alone, or two or more types can be used in combination.

[0115] The vegetable oil preferably contains acylglycerol and further preferably triacylglycerol. It should be noted that acylglycerol refers to a compound obtained by subjecting a hydroxyl group of glycerol and a fatty acid to an ester bond. The acylglycerol is not particularly restricted and can be 1-monoacylglycerol, 2-monoacylglycerol, 1,2-diacylglycerol, 1,3-diacylglycerol, or triacylglycerol. Furthermore, the acylglycerol can be a monomer, a dimer, or a multimer, which may be a trimer or more. It should be noted that an acylglycerol that is a dimer or more can be obtained by thermal polymerization, oxidative polymerization, or the like. Additionally, the acylglycerol can be a liquid or a solid at room temperature (25 °C).

[0116] A method for checking whether or not acylglycerol is present in the rubber composition is not particularly restricted; however, the check can be modified by 1 H-NMR measurements are performed. For example, in a case where a rubber composition mixed with triacylglycerol is immersed in heavy chloroform for 24 hours at room temperature (25 °C), the rubber composition is removed. 1When 1H NMR was subsequently measured at room temperature and a signal for tetramethylsilane (TMS) was set to 0.00 ppm, signals of approximately 5.26 ppm, approximately 4.28 ppm, and approximately 4.15 ppm were observed. It is suggested that these signals are derived from a hydrogen atom bonded to a carbon atom adjacent to the oxygen atom of the ester group, thus confirming the inclusion of the acylglycerol. It should be noted that the term "approximately" refers to a range of ±0.10 ppm.

[0117] It should be noted that the fatty acid category is not particularly restricted and can be either unsaturated or saturated. Examples of unsaturated fatty acids include monovalent unsaturated fatty acids, such as oleic acid, and polyvalent unsaturated fatty acids, such as linoleic acid or linolenic acid. Furthermore, examples of saturated fatty acids include butyric acid and lauric acid.

[0118] It is desirable that the fatty acid be one with a low number of double bonds, i.e., a saturated fatty acid or a monovalent unsaturated fatty acid, and oleic acid is preferred. For example, a vegetable oil containing such a fatty acid could be one that already contains a saturated fatty acid or a monovalent unsaturated fatty acid, or one that has undergone a modification, such as ester exchange. Furthermore, a plant can be improved to produce a vegetable oil containing such a fatty acid through breeding, genetic recombination, genome editing, or similar methods.

[0119] For the vegetable oil, it is possible to use those that are commercially available, for example, from Idemitsu Kosan Co., Ltd., SANKYO YUKA KOGYO KK, ENEOS Corporation, Olisoy, H&R Group, HOKOKU CORPORATION, Fuji Kosan Company, Ltd. and Nisshin OilliO Group, Ltd. (ii) Liquid rubber

[0120] Liquid rubber is a polymer in a liquid state at room temperature (25 °C), and it is a rubber component that can be extracted from a vulcanized tire by acetone extraction. Examples of liquid rubber include a farnesene-based polymer, a diene-based liquid polymer, and a hydrogenated version thereof.

[0121] Farnesene-based polymers are polymers obtained by polymerizing farnesene and feature a farnesen-based structural unit. 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).

[0122] The farnesen-based polymer can be a homopolymer of farnesen (a farnesen homopolymer) or a copolymer of farnesen and a vinyl monomer (a farnesen vinyl monomer copolymer).

[0123] Examples of liquid diene-based polymers include a liquid styrene-butadiene copolymer (liquid SBR), a liquid butadiene polymer (liquid BR), a liquid isoprene polymer (liquid IR), and a liquid styrene-isoprene copolymer (liquid SIR).

[0124] For the liquid diene-based polymer, the polystyrene equivalent weight-average molecular weight (Mw), measured by gel permeation chromatography (GPC), is, for example, more than 1.0 × 10 3 and less than 2.0 × 10 5 . Here, Mw of the liquid diene-based polymer is a polystyrene equivalent value measured by gel permeation chromatography (GPC).

[0125] For the liquid rubber, it is possible to use a product manufactured, for example, by Kuraray Co., Ltd. or Cray Valley. (iii) Resin component

[0126] The resin component also acts as an adhesion promoter and can be a solid or a liquid at room temperature. Specific examples of the resin component include resins such as a rosin-based resin, a styrene-based resin, a coumaron-based resin, a terpene-based resin, a C5 resin, a C9 resin, a C5C9 resin, and an acrylic resin, with two or more types of these potentially being used in combination. It should be noted that the resin components can be modified, as required, with a modifier capable of reacting with silicon dioxide or the like.

[0127] Rosin-based resin is a resin containing rosin acid as a major component, obtained by processing pine resin. Rosin-based resin (rosin) can be classified according to the presence or absence of modifications, and can be further divided into unmodified rosin and modified rosin derivatives. Examples of unmodified rosin include tall rosin (also known as tallow rosin), balsam rosin, wood rosin, disproportionated rosin, polymerized rosin, hydrogenated rosin, and other chemically modified rosin.The rosin-modified product is a modified product of the unmodified rosin, examples of which include rosin esters, rosin modified with unsaturated carboxylic acid, rosin esters modified with unsaturated carboxylic acid, amide compounds of rosin, and amine salts of rosin.

[0128] Styrene-based resin is a polymer that uses a styrene-based monomer as a constituent monomer, and examples include a polymer obtained by carrying out polymerization using the styrene-based monomer as a major component (50 wt% or more). Specific examples include a homopolymer obtained by subjecting each of styrene-based monomers (styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-methoxystyrene, p-tert-butylstyrene, p-phenylstyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene and the like) to homopolymerization, and a copolymer obtained by copolymerizing two or more styrene-based monomers, as well as a copolymer of a styrene-based monomer and another monomer that can undergo copolymerization with the styrene-based monomer.

[0129] Examples of the other monomer include acrylonitriles such as acrylonitrile and methacrylonitrile; unsaturated carboxylic acids such as acrylic and methacrylic acid; unsaturated carboxylic acid esters such as methyl acrylate and methyl methacrylate; dienes such as chloroprene, butadiene, and isoprene; olefins such as 1-butene and 1-pentene; and α,β-unsaturated carboxylic acids such as maleic anhydride or acid anhydrides thereof.

[0130] Among coumaron-based resins, a coumaron-indene resin is preferred. This resin contains coumaron and indene as monomer components that form the resin's skeleton (main chain). Examples of monomer components other than coumaron and indene that are included in the skeleton include styrene, α-methylstyrene, methylindene, and vinyltoluene.

[0131] The hydroxyl group value (OH value) of coumaron-indene resin, for example, is greater than 15 mg KOH / g and less than 150 mg KOH / g. It should be noted that the OH value is a value obtained by expressing, in milligrams, the amount of potassium hydroxide required to neutralize the acetic acid bound to the hydroxyl group in a case where 1 g of the resin is acetylated, and it is a value measured according to a potentiometric method (JIS K 0070: 1992).

[0132] The softening point of coumaron indene resin, for example, is higher than 30 °C and lower than 160 °C. It should be noted that the softening point is the temperature at which a ball falls in a drop test where the softening point specified in JIS K 6220-1: 2001 is measured using a ring-and-ball type softening point tester.

[0133] Examples of terpene-based resins include polyterpenes, terpenophenols, and an aromatically modified terpene resin. A polyterpene is a resin obtained by polymerizing a terpene compound and a hydrogenated derivative thereof. The terpene compound is a hydrocarbon with the composition (C5H8) n and an oxygen-containing derivative thereof and is a compound that has a terpene as its basic skeleton, which is divided into a monoterpene (C 10 H 16 ), a sesquiterpene (C 15 H 24 ) or a diterpene (C 20 H 32 ) is classified. Examples include α-pinene, β-pinene, dipentene, limonene, myrcene, alloocimene, osimene, α-phellandrene, α-terpinene, γ-terpinene, terpinolene, 1,8-cineole, 1,4-cineole, α-terpineol, β-terpineol and γ-terpineol.

[0134] Examples of polyterpenes also include terpene resins, such as an α-pinene resin, a β-pinene resin, a limonene resin, a dipentene resin, and a β-pinene / limonene resin, for which the terpene compounds described above are used as raw materials, as well as hydrogenated terpene resins obtained by subjecting the terpene resins to a hydrogenation treatment. Examples of terpene phenols include a resin obtained by copolymerizing the terpene compound described above with a phenol-based compound, and a resin obtained by subjecting the resin to a hydrogenation treatment. Specific examples of the latter include a resin obtained by condensing the terpene compound described above, a phenol-based compound, and formalin. It should be noted that examples of the phenol-based compound include phenol, bisphenol A, cresol, and xylenol.Examples of aromatically modified terpene resins include a resin obtained by modifying a terpene resin with an aromatic compound and a resin obtained by subjecting the resin to a hydrogenation treatment. It should be noted that the aromatic compound is not particularly restricted, as long as it is a compound containing an aromatic ring. Examples include a phenolic compound, such as phenol, an alkylphenol, an alkoxyphenol, or a phenol containing an unsaturated hydrocarbon group; a naphthol compound, such as naphthol, an alkylnaphthol, an alkoxynaphthol, or a naphthol containing an unsaturated hydrocarbon group; a styrene derivative, such as styrene, an alkylstyrene, an alkoxystyrene, and a styrene containing an unsaturated hydrocarbon group; and coumaron and indene.

[0135] The term "C5 resin" refers to a resin obtained by polymerizing a C5 fraction. Examples of the C5 fraction include petroleum fractions equivalent to those with 4 to 5 carbon atoms, such as cyclopentadiene, pentene, pentadiene, and isoprene. A dicyclopentadiene resin (DCPD resin) is suitable as the C5-based petroleum resin.

[0136] The term "C9 resin" refers to a resin obtained by polymerizing a C9 fraction, and it can be a resin obtained by hydrogenating or modifying the resulting resin. Examples of the C9 fraction include petroleum fractions equivalent to those with 8 to 10 carbon atoms, such as vinyltoluene, alkylstyrene, indene, and methylindene. A coumaron-indene resin, a coumaron resin, an indene resin, and an aromatic vinyl-based resin are suitable examples. The aromatic vinyl-based resin is preferably a homopolymer of α-methylstyrene (AMS resin) or styrene, or a copolymer of α-methylstyrene and styrene, and more preferably a copolymer of α-methylstyrene and styrene, due to its economic advantages, ease of processing, and excellent exothermicity.As for the aromatic vinyl-based resin, it is possible to use those that are commercially available from companies such as Kraton Corporation and Eastman Chemical Company.

[0137] The term "C5C9 resin" refers to a resin obtained by copolymerizing the C5 and C9 fractions, and it can also be a resin obtained by hydrogenating or modifying the resulting resin. Examples of the C5 and C9 fractions include the petroleum fraction described above. C5C9 resin can be used in products commercially available from companies such as Tosoh Corporation and Shandong Luhua Group Co., Ltd.

[0138] The acrylic resin is not particularly restricted, however, a solvent-free acrylic resin can be used, for example.

[0139] Examples of the solvent-free acrylic resin include a (meth)acrylic resin (polymer) synthesized by a continuous high-temperature polymerization process (continuous high-temperature bulk polymerization process) (the process described in US Patent No. 4414370, Japanese Unexamined Patent Publication No. S59-6207, Japanese Examined Patent Publication No. H5-58005, Japanese Unexamined Patent Publication No. H1-313522, US Patent No. 5010166, TOAGOSEI Annual Research Report, TREND 2000 No. 3, pp. 42-45, or the like) without the use, as far as possible, of a polymerization initiator, a chain transfer agent, an organic solvent, and the like, which are auxiliary raw materials. It should be noted that in the present invention, (meth)acrylic means methacrylic and acrylic.

[0140] Examples of the monomer component that forms the acrylic resin include (meth)acrylic acid, a (meth)acrylic acid ester (alkyl ester, aryl ester, aralkyl ester or the like), (meth)acrylamide and a (meth)acrylic acid derivative, such as a (meth)acrylamide derivative.

[0141] Furthermore, an aromatic vinyl, such as styrene, α-methylstyrene, vinyltoluene, vinylnaphthalene, divinylbenzene, trivinylbenzene or divinylnaphthalene, together with (meth)acrylic acid or a (meth)acrylic acid derivative, can be used as the monomer component that forms the acrylic resin.

[0142] The acrylic resin can be a resin composed solely of a (meth)acrylic component, or it can be a resin that also contains a component other than the (meth)acrylic component. Furthermore, the acrylic resin can contain a hydroxyl group, a carboxyl group, a silanol group, or similar components.

[0143] The resin component can be a product manufactured, for example, by Maruzen Petrochemical CO., LTD., Sumitomo Bakelite Co., Ltd., Yasuhara Chemical Co., Ltd., Tosoh Corporation, Rutgers Chemicals AG, BASF SE, Kraton Corporation, NITTO CHEMICAL CO., LTD., Nippon Shokubai Co., Ltd., ENEOS Corporation, Arakawa Chemical Industries, Ltd. or Taoka Chemical Co., Ltd. (b-3) Wax

[0144] The rubber composition may contain wax. The wax content is preferably 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 per 100 parts by mass of the rubber component.

[0145] The type of wax is not particularly restricted, and any wax commonly used in the tire industry can be used appropriately. Examples include mineral-based and plant-based waxes. Mineral-based wax refers to wax derived from a mineral resource, such as oil or natural gas. Plant-derived wax refers to wax derived from a natural resource, such as a plant. Of the above, mineral-based wax is preferred.

[0146] Examples of plant-derived waxes include rice wax, carnauba wax, and candelilla wax. Examples of petroleum-based waxes include paraffin wax, microcrystalline wax, and a carefully selected specialty wax thereof, with paraffin wax being preferred. It should be noted that in the present invention, the wax does not contain stearic acid.

[0147] It should be noted that the wax used can be any commercially available product from, for example, OUCHI SHINKO CHEMICAL INDUSTRIAL CO., LTD., NIPPON SEIRO Co., Ltd., or Paramelt BV. These waxes can be used individually, or two or more can be used in combination. (b-4) Antioxidants

[0148] Any rubber compound can contain an antioxidant. The antioxidant content can be, for example, more than 1 part by mass and less than 10 parts by mass per 100 parts by mass of the rubber component.

[0149] The antioxidant is not particularly restricted; however, examples include: an antioxidant based on naphthylamine, such as phenyl-α-naphthylamine; an antioxidant based on diphenylamine, such as octylated diphenylamine or 4,4'-bis(α,α'-dimethylbenzyl)diphenylamine; an antioxidant based on p-phenylenediamine, such as N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD), N,N'-bis(1,4-dimethylpentyl)-p-phenylenediamine (77PD), N,N'-diphenyl-p-phenylenediamine (DPPD), N,N'-ditolyl-p-phenylenediamine (DTPD), N-isopropyl-N'-phenyl-p-phenylenediamine (IPPD) or N,N'-di-2-naphthyl-p-phenylenediamine (DNPD); an antioxidant based on quinoline, such as a polymer of 2,2,4-trimethyl-1,2-dihydroquinoline; an antioxidant based on monophenols, such as 2,6-di-t-butyl-4-methylphenol or styrenized phenol;An antioxidant based on bisphenol, trisphenol, or polyphenol, such as tetrakis-[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane. Among the above, a p-phenylenediamine-based or a quinoline-based antioxidant is preferred, and a polymer of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine and 2,2,4-trimethyl-1,2-dihydroquinoline is further preferred. These can be used alone, or two or more types can be used in combination.

[0150] As a commercially available product of this, it is possible to use a product manufactured, for example, by Seiko Chemical Co., Ltd., Sumitomo Chemical Co., Ltd., OUCHI SHINKO CHEMICAL INDUSTRIAL CO., LTD. or FLEXSYS. (b-5) Processing aids

[0151] The rubber composition may contain a processing aid. Examples of processing aids include a metal salt (a compound in which a hydrogen atom of an acid is replaced by a metal ion), a fatty acid amide, an amide ester, and a fatty acid ester. These may be used alone, or two or more types may be used in combination. Of the above, a metal salt or a fatty acid amide is preferred, and a metal salt is further preferred.

[0152] Examples of metals used for the metal salt include alkali metals such as potassium or sodium, and alkaline earth metals such as calcium and barium. Magnesium, zinc, nickel, molybdenum, or similar metals may also be used. Of the above, an alkali metal is preferred.

[0153] Examples of acids used for the metal salt include fatty acids such as lauric acid, myristic acid, and palmitic acid. In addition, boric acid, carbonic acid, hydrochloric acid, nitric acid, sulfuric acid, or similar acids can also be used.

[0154] A commercially available processing aid product from KISHIDA CHEMICAL CO., LTD., Kenei Pharmaceutical Co., Ltd., Struktol Company of America, LLC, Performance Additives or the like may be used.

[0155] The processing aid content is preferably 1 part by mass or more, and more preferably 2 parts by mass or more, per 100 parts by mass of the rubber component. The upper limit of this is, for example, preferably 6 parts by mass or less, and more preferably 4 parts by mass or less. (b-6) Lubricant (stearic acid)

[0156] The rubber composition may contain a lubricant. A lubricant based on a fatty acid derivative, such as stearic acid, may preferably be used. Any stearic acid known in the prior art may be used. In particular, a product manufactured, for example, by NOF Corporation, Kao Corporation, FUJIFILM Wako Pure Chemical Corporation, or Chiba Fatty Acid Co., Ltd. may be used. Furthermore, STRUKTOL WB16, manufactured by Struktol Company of America, LLC., may be used.

[0157] The stearic acid content, for example, is preferably more than 0.5 parts by mass and less than 10.0 parts by mass in relation to 100 parts by mass of the rubber component. (b-7) Zinc oxide

[0158] The rubber composition may contain zinc oxide. The zinc oxide content may be, for example, more than 0.5 parts by mass and less than 10 parts by mass per 100 parts by mass of the rubber component. It is possible to use zinc oxide that is publicly known in the prior art, and it is possible to use a product manufactured, for example, by Mitsui Mining & Smelting Co., Ltd., Toho Zinc Co., Ltd., Hakusui Tech Co., Ltd., Shodo Chemical Industry Co., Ltd., or Sakai Chemical Industry Co., Ltd. (b-8) Crosslinking agents and vulcanization accelerators

[0159] The rubber composition preferably contains a crosslinking agent, such as sulfur. The crosslinking agent content is, for example, more than 0.1 parts by mass and less than 10.0 parts by mass per 100 parts by mass of the rubber component. It should be noted that the sulfur content is pure sulfur and is a content that excludes an oil component in cases where insoluble sulfur is used.

[0160] Examples of sulfur include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersible sulfur, and soluble sulfur, which are commonly used in the rubber industry. These can be used alone, or two or more types can be used in combination.

[0161] It should be noted that instead of sulfur, it is possible to use a product manufactured, for example, by Tsurumi Chemical Industry Co., Ltd., Karuizawa Sulfur Co., Ltd., SHIKOKU CHEMICALS CORPORATION, FLEXSYS, Nippon Inui Kogyo Co., Ltd. or NIPPON KANRYU INDUSTRY CO., LTD.

[0162] A crosslinking agent other than sulfur can be used. In particular, it is possible, for example, to use a vulcanizing agent containing sulfur atoms, such as TACKIROL V200, manufactured by Taoka Chemical Co., Ltd., DURALINK HTS (1,6-hexamethylene sodium dithiosulfate dihydrate), manufactured by FLEXSYS, or KA9188 (1,6-bis(N,N'-dibenzylthiocarbamoyldithio)hexane). hybrid crosslinking agent), manufactured by Lanxess AG, or an organic peroxide, such as dicumyl peroxide.

[0163] Furthermore, it is preferred that the rubber composition contains a vulcanization accelerator. The content of the vulcanization accelerator is, for example, more than 0.3 parts by mass and less than 10.0 parts by mass per 100 parts by mass of the rubber component.

[0164] Examples of vulcanization accelerators include thiazole-based vulcanization accelerators, such as 2-mercaptobenzothiazole, di-2-benzothiazolyl disulfide, and N-cyclohexyl-2-benzothiazolylsulfenamide; thiuram-based vulcanization accelerators, such as tetramethylthiuram disulfide (TMTD), tetrabenzylthiuram disulfide (TBzTD), and tetrakis(2-ethylhexyl)thiuram disulfide (TOT-N); and sulfenamide-based vulcanization accelerators, such as N-cyclohexyl-2-benzothiazolesulfenamide, Nt-butyl-2-benzothiazolylsulfenamide, N-oxyethylene-2-benzothiazolesulfenamide, N-oxyethylene-2-benzothiazolesulfenamide, and N,N'-diisopropyl-2-benzothiazolesulfenamide. and guanidine-based vulcanization accelerators, such as diphenylguanidine, diortho-tolylguanidine, and ortho-tolylbiguanidine. These can be used alone, or two or more types can be used in combination. (b-8) Others

[0165] In addition to each of the components described above, the rubber composition can be blended, as required, with additives commonly used in the tire industry, such as an organic filler like cellulose fiber and an organic peroxide. The levels of these additives are, for example, more than 0.1 parts by mass and less than 50 parts by mass per 100 parts by mass of the rubber component.

[0166] It should be noted that, in the present invention, various materials (for example, a rubber, oil, resin, vulcanization accelerator, antioxidant, and surfactant) containing a carbon atom can be derived from carbon dioxide in the air. Regarding a method for obtaining a mixture according to the present invention from carbon dioxide, carbon dioxide can be subjected to direct conversion, or methane obtained from carbon dioxide can be converted by a methanation process. (b-9) Bandcord

[0167] Although the tape cord is not a rubber compound, it is also described. In the present invention, as described above, a simply twisted PET tape, obtained by twisting a filament of yarn containing a PET fiber, is used as the tape cord.

[0168] It should be noted that the total thickness of the tape cord is preferably 900 dtex or more, more preferably 1,500 dtex or more, and even more preferably 1,670 dtex or more. On the other hand, it is preferably 2,500 dtex or less, more preferably 2,300 dtex or less, and even more preferably 2,200 dtex or less.

[0169] Furthermore, the thickness (diameter) of the cord is preferably 0.2 mm or more, more preferably 0.3 mm or more, and even more preferably 0.4 mm or more. On the other hand, it is preferably 0.8 mm or less, more preferably 0.6 mm or less, and even more preferably 0.55 mm or less.

[0170] Furthermore, the number of cords (ends) per 50 mm in width in the tire width direction is preferably 40 or more, more preferably 50 or more, and even more preferably 60 or more. On the other hand, it is preferably 80 or less, more preferably 70 or less, and even more preferably 68 or less.

[0171] It should be noted that the thickness, thickness and ends of the band cord described above can be measured in accordance with the procedure specified in JIS L1017: 2002.

[0172] After the tape cord has been treated with an adhesive, it can be used as a tape by bonding it to a predetermined rubber compound designed for tape. It should be noted that, for example, EX-313 (glycerol polyglycidyl ether, manufactured by Nagase ChemteX Corporation) and RFL (resorcinol formalin latex) can be used as an epoxy compound for bonding.

[0173] It should be noted that the PET fiber can be a PET fiber (regenerated PET fiber) that is obtained by recovering and recycling plastic waste, such as used PET bottles, and that from an environmental protection point of view, it is appropriate to use such a sustainable PET fiber. (2) Production of rubber composition

[0174] The rubber composition can be produced by a general process, for example a manufacturing process, which includes a basic kneading process of kneading a rubber component and a filler, such as silicon dioxide, and a final kneading process of kneading a kneaded product obtained in the basic kneading process and a crosslinking agent.

[0175] The kneading can be carried out using a publicly known kneader (of the closed type), for example a Banbury mixer, a kneader or an open roller.

[0176] In the basic kneading process, the kneading temperature is, for example, higher than 50 °C and lower than 200 °C, and the kneading time is, for example, more than 30 seconds and less than 30 minutes. In the basic kneading process, a mixing agent used in the prior art of the rubber industry, such as a softener like oil, stearic acid, zinc oxide, an antioxidant, a wax, or a vulcanization accelerator, can be added and kneaded as needed, in addition to the components described above.

[0177] In the final kneading process, the kneaded product obtained in the initial kneading process is combined with a curing agent. For example, the kneading temperature in the final kneading process is higher than room temperature but lower than 80 °C, and the kneading time is higher than 1 minute but lower than 15 minutes. In addition to the components described above, a vulcanization accelerator, zinc oxide, or similar substances can be added and kneaded as needed in the final kneading process.

[0178] Afterwards, a rubber composition obtained as described above can be formed into a running surface by extrusion processing into a predetermined shape. 3. Tire manufacturing

[0179] The tire according to the present embodiment can be manufactured by a typical process. First, the rubber composition obtained as described above is used to produce a tread by molding the rubber composition into a predetermined shape. Next, it is subsequently combined with other rubber elements on a tire molding machine, thereby producing an unvulcanized tire.

[0180] Specifically, an inner liner, as an element to ensure the tire's airtightness, a carcass, as an element to withstand the load, impact, and inflation pressure exerted on the tire, and a belt element, band, or the like, as an element to tightly tension the carcass and increase the tread stiffness, are wound onto a forming drum, and a bead section, as an element to fix the tire to the rim, while both ends of the carcass are attached to edge sections on both sides, is arranged so that it is formed into a toroidal shape. Then the tread is bonded to a central section of an outer circumference, and the sidewall is bonded to an outer surface in the radial direction to form a side panel, thus producing an unvulcanized tire.

[0181] The unvulcanized tire, produced as described above, is then subjected to heating and pressure in a vulcanizing machine to create a tire. The vulcanization process can be carried out using a publicly available vulcanizing agent. For example, a vulcanization temperature might be higher than 120°C and lower than 200°C, and a vulcanization time might be more than 5 minutes and less than 15 minutes.

[0182] As described above, the tire, obtained as described above, allows for the improvement of overall performance in terms of durability at high speed, steering stability and rolling resistance through the interaction of the effect due to the use of the simply twisted PET band and the effect due to the appropriately formed tread.

[0183] Furthermore, the tire according to the present invention can be suitablely used as a tire for a passenger car, a tire for a large passenger car, a tire for a large SUV, a tire for a truck / bus, a tire for a motorcycle, a racing tire, a studless tire (a winter tire), an all-season tire, a run-flat tire, or the like. In particular, it is preferably used as a tire for a passenger car. [Examples]

[0184] Examples are shown below which are considered preferred in carrying out the present embodiment; however, the scope of protection of the present invention is not limited to these examples.

[0185] A tire (tire size: 195 / 65R15) consisting of a tread formed from the various mixed materials shown below and tire elements such as a band and a belt is examined, and the results calculated on the basis of the evaluation procedures described later, relating to durability at high speed, steering stability, rolling resistance and overall performance, are shown together in the lower part of Table 2. 1. Production of rubber compound

[0186] A rubber composition for a tread is produced using various mixed materials, which are shown below. (1) Mixed material(a) Rubber component (a-1) NR: TSR20 (a-2) SBR-1: Modified S-SBR (styrene content: 25 wt%, vinyl content: 63 mol%, Tg: -20 °C, non-oil-diluted product), produced on the basis of production example 1 described below (a-3) SBR-2: Modified S-SBR (styrene content: 24 wt%, vinyl content: 59 mol%, Tg: -25 °C, non-oil-diluted product), produced on the basis of production example 2 described below. (a-4) SBR-3: HPR840 (modified SBR, styrene content: 10 wt%, vinyl content: 42 mol%, Tg: -60 °C, non-oil-diluted product), manufactured by ENEOS Materials Corporation (a-5) BR-1: BR730 (cis content: 96 wt%, trans content: 3 wt%, vinyl content: 1 wt%, manufactured by ENEOS Materials Corporation (a-6) BR-2: ASAPREN N103 (cis content: 38 wt%, Tg: -90 °C), manufactured by Asahi Kasei Corporation (a-7) BR-3: BR360B (cis content: 97 wt%, trans content: 1 wt%, vinyl content: 2 wt%), manufactured by UBE Corporation (Production example 1)

[0187] SBR-1 is produced according to the following procedure. First, cyclohexane, tetrahydrofuran, styrene, and 1,3-butadiene are loaded into a nitrogen-substituted autoclave reactor. After adjusting the temperature of the reactor contents, n-butyllithium is added to initiate polymerization. Polymerization is then carried out under thermally insulated conditions, and 1,3-butadiene is added when the polymerization conversion rate reaches 99%. Polymerization is then continued for 5 minutes, and N,N-bis(trimethylsilyl)-3-aminopropyltrimethoxysilane is added as a modifier to initiate the reaction. After completion of the polymerization reaction, 2,6-di-tert-butyl-p-cresol is added, the solvent is removed by steam stripping, and then hot rolling is performed to obtain SBR-1. (Production example 2)

[0188] The SBR-2 is obtained in the same way as in Preparation Example 1, except that the target styrene content, target vinyl content and target Tg are changed and that 3-dimethylaminopropyltriethoxysilane is used as the modifier. (b) Mixed material other than the rubber component (b-1) Carbon black: DIABLACK N220, manufactured by Mitsubishi Chemical Corporation (N2SA: 115 m2 / g) (b-2) Silicon dioxide: ULTRASIL VN3, manufactured by Evonik Industries AG (N2SA: 175 m2 / g, average primary particle diameter: 17 nm) (b-3) Silane coupling agent: NXT, manufactured by Momentive Performance Materials Inc. (3-Octanoylthiopropyltriethoxysilane) (b-4) Oil: Process oil A / OMIX manufactured by SANKYO YUKA KOGYO KK (b-5) Resin: YS resin PX850, manufactured by YASUHARA CHEMICAL CO., LTD. (Softening point: 85 °C, β-pinene resin (resin based on terpene resin)) (b-6) Wax: OZOACE 0355, manufactured by NIPPON SEIRO CO., LTD. (b-7) Antioxidant-1: NOCRAC 6C, manufactured by OUCHI SHINKO CHEMICAL INDUSTRIAL CO., LTD. (N-(1,3-Dimethylbutyl)-N'-phenyl-p-phenylenediamine) (b-8) Antioxidant-2: ANTAGE RD, manufactured by Kawaguchi Chemical Industry Co., Ltd. (Poly(2,2,4-trimethyl-1,2-dihydroquinoline)) (b-9) Antioxidant-3: Sirantech S-TMQ, manufactured by Sennics Co., Ltd. (Poly(2,2,4-trimethyl-1,2-dihydroquinoline)) (b-10) Processing aid-1: NOCCELER CZ, manufactured by OUCHI SHINKO CHEMICAL INDUSTRIAL CO., LTD. (N-Cyclohexylbenzothiazole-2-sulfenamide) (b-11) Processing aid-2: NOCCELER D, manufactured by OUCHI SHINKO CHEMICAL INDUSTRIAL CO., LTD. (1,3-Diphenylguanidine (DPG)) (b-12) Processing aid-3: NOCCELER MP, manufactured by OUCHI SHINKO CHEMICAL INDUSTRIAL CO., LTD. (2-Mercaptobenzothiazole) (b-13) Stearic acid: Bead-shaped stearic acid “Tsubaki”, manufactured by NOF Corporation (b-14) Zinc oxide: Two types of zinc oxide produced by Mitsui Mining & Smelting Co., Ltd. (b-15) Sulfur: Powdered sulfur, manufactured by Karuizawa Sulfur Co., Ltd. (b-16) Accelerator-1: SANCELER CM-G, manufactured by SANSHIN CHEMICAL INDUSTRY CO., LTD. (N-Cyclohexyl-2-benzothiazolylsulfenamide (CBS) (b-17) Accelerator-2: SOXINOL DG, manufactured by Sumitomo Chemical Co., Ltd. (1,3-Diphenylguanidine (DPG) (b-18) Accelerator-3: SUNSINE MBT, manufactured by Shandong Sunsine Chemical Co., Ltd. (2-Mercaptobenzothiazole) (2) Production of rubber compound for tread

[0189] Based on each of the mixtures A to C shown in Table 1, a kneaded product is obtained by kneading materials other than sulfur and a vulcanization accelerator for 5 minutes under a condition of 150 °C using a 1.7 L Banbury mixer manufactured by Kobe Steel, Ltd.

[0190] Next, sulfur and a vulcanization accelerator are added to the kneaded product, and kneading is carried out for 5 minutes under a condition of 80 °C using an open roller to obtain rubber compositions for a running surface according to mixtures A to C. 2. Shapes of tire elements (tread, band and belt)(1) Shapes of tread

[0191] Next, the tread (top tread) is formed at each thickness shown in Table 2 using the rubber composition obtained above. (2) Forms of band

[0192] In parallel, each band cord shown in Table 2 is coated with a predetermined rubber composition for a band to form each band. (3) Forms of belts

[0193] In the same way, each belt cord shown in Table 2 is covered with a predetermined rubber composition for a belt to form each belt. 3. Tire manufacturing

[0194] Next, each of the treads, each of the ribs and each of the belts obtained as above is bonded to other tire elements to form an unvulcanized tire, and the unvulcanized tire is subjected to pressure vulcanization for 10 minutes under a condition of 170 °C to produce one test tire each of Example 1 to Example 4 and Comparison Example 1 to Comparison Example 3. 4. Performance evaluation test(1) Evaluation of rolling resistance

[0195] Using a rolling resistance test machine, a coefficient of rolling resistance (RRC) is measured in a case in which each test tire is subjected to driving on a drum at a speed of 80 km / h under the following conditions. Rim to be used: 15 × 6 J Internal pressure: 210 kPa Load: 4.35 kN

[0196] Next, the result in comparison example 3 is set to 100, and the assessment of rolling resistance is carried out by indexing based on the following expression. This indicates that the larger the numerical value, the greater the reduction in rolling resistance. Rolling resistance rating = [(Result of comparison example 3) / (Result of test tires)] × 100 (2) Assessment of steering stability

[0197] Steering stability in a case where each test tire is fitted to all wheels of a vehicle (a domestically produced FR vehicle with a 2,000 cc engine) and the vehicle is then subjected to driving around a test track at a speed of 70 km / h or more, is subjected to sensory evaluation by each of 20 test drivers by awarding 1 to 10 points (the higher the numerical value, the more favorable), and the total points are calculated.

[0198] Next, the result in comparison example 2 is set to 100, and the steering stability assessment is performed by indexing based on the following expression. This indicates that the higher the numerical value, the more excellent the steering stability is during high-speed driving. Steering stability rating = [(Result of test tires) / (Result of comparison example 2)] × 100 (3) Assessment of durability at high speed

[0199] Each test tire is fitted into a rim (size = 15 × 6J), the tire is filled with air, the internal pressure is adjusted to 230 kPa, the tire is mounted on a drum rolling test machine, a vertical load of 5.88 kN is applied, and the speed is gradually increased from 210 km / h in 10 km / h increments to measure the time until the tire is damaged.

[0200] Next, the result in comparison example 3 is set to 100. Indexing is performed based on the following expression to obtain a high-speed durability index, and then an evaluation is carried out. This indicates that the higher the numerical value, the longer the time until the tire is damaged, and the more excellent its durability after driving. Durability rating at high speed = [(Result of test tire) / (Result of comparison example)3)] × 100 (4) Overall rating

[0201] Then the results from (1) to (3) are added together to perform the overall evaluation. [Table 1] (Mass-produced parts) Mixture A Mixture B Mixture C NR 40 40 11,15 SBR-1 - 34,3 - SBR-2 - - 46,31 SBR-3 - - 11,58 BR-1 48 - - BR-2 12 - - BR-3 - 25,7 30,96 soot 5 5 15 silicon dioxide 60 80 75 Silane coupling agent 4, 8 6,4 6 Öl 22 37 20 resin 7, 9 14 7 wax 1,4 2,06 1,93 Antioxidant-1 1,7 3,22 2,42 Antioxidant-2 0,5 1,04 - Antioxidants-3 - - 0, 96 Processing aid-1 1,5 2 - Processing aids-2 0,5 0,74 - Processing aids-3 - - 2 Stearic acid 4 3 2 zinc oxide 2 2,2 2 sulfur 1, 25 1,4 1,6 Accelerator-1 1 2,2 2 Accelerator-2 1,6 1,6 1,7 Accelerator-3 0,2 - - HS 50 55 65 [Table 2] Comparative example 1 Comparative example 2 Comparative example 3 Example 1 Example 2 Example 3 Example 4 (Bandcord) material N66 PET PET PET PET PET PET configuration Double twisted Double twisted Simply twisted Simply twisted Simply twisted Simply twisted Simply twisted Cord diameter (mm) 0,66 0,54 0,4 0,4 0,4 0,4 0,55 Total thickness (dtex) 2800 2200 1670 1670 1670 1670 2200 Ends (cords / 5 cm) 48 52 68 68 68 68 60 (Running surface) mixture A ← ← C ← ← ← Thickness (mm) 5,5 5,5 8 6,5 10 8,5 6,5 Silicon dioxide (parts by mass) 60 60 80 75 75 75 75 Hs (pt) 50 50 55 65 65 65 65 Cord diameter x tread thickness 3,63 2,97 3,2 2,6 4 3,4 3,575 (belt cord) Number of filaments 4 8 8 8 8 2 4 configuration 2 + 2 1 × 8 1 × 8 1 × 8 1 × 8 1 × 2 2 + 2 Ends (cords / 5 cm) 40 24 24 24 24 46 40 (Evaluation) Rolling resistance 93 79 100 102 97 106 100 Steering stability 98 100 88 113 106 108 101 Shelf life (GP) 95 92 100 100 107 105 100 Overall rating 286 271 288 315 310 319 301

[0202] The present invention (1) is a tire characterized in that it comprises: a carcass containing a carcass cord; a belt containing a belt cord and positioned on the outside of the carcass in a tire radial direction; a band containing a tape cord and positioned on the outside of the belt in the radial direction of the tire; and a tread surface that is provided on an outside of the belt in the tire radial direction, the bandcord is obtained by twisting a filament of yarn containing a polyethylene terephthalate fiber, the tread is formed from a rubber composition containing 75 parts by mass or more of silicon dioxide in relation to 100 parts by mass of a rubber component, and has a thickness of more than 6 mm and a rubber hardness (Shore hardness) Hs of more than 60, and a product of the diameter (mm) of the band cord and the thickness (mm) of the running surface is less than 10.0.

[0203] 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.

[0204] The present invention (3) is the tire according to one of the present invention (1) or the present invention (2), which is characterized in that the number of cords per 50 mm in width of the band cord is 40 or more and 80 or less in one tire width direction.

[0205] The present invention (4) is the tire of any combination of the present inventions (1) to (3), which is characterized by the fact that the belt cord is made up of one or more and four or fewer filaments.

[0206] The present invention (5) is the tire according to any combination of the present inventions (1) to (4), which is characterized in that the number of cords per 50 mm in width of the belt cord is 20 or more and 60 or less in one tire width direction.

[0207] The present invention (6) is the tire according to any combination of the present inventions (1) to (5), which is characterized by the fact that the rubber composition contains a vegetable oil.

[0208] The present invention (7) is the tire according to any combination of the present inventions (1) to (6), which is characterized by the fact that the rubber composition contains sustainable carbon black.

[0209] The present invention (8) is the tire according to any combination of the present inventions (1) to (7), which is characterized by the fact that the rubber composition contains sustainable silicon dioxide.

[0210] The present invention (9) is the tire according to any combination of the present inventions (1) to (8), which is characterized by the fact that the polyethylene terephthalate fiber is a sustainable polyethylene terephthalate fiber. Reference symbol list 1 tire 2 Running surface 3 side wall 4 bead band 5 bulge 6 Innerliner 7 Carcass 8 belts 9 Filler Volume 10 CL equator plane of tires

Claims

[1] Tires, including: a carcass containing a carcass cord; a belt containing a belt cord and positioned on the outside of the carcass in a tire radial direction; a band containing a tape cord and positioned on the outside of the belt in the radial direction of the tire; and a tread surface that is provided on an outside of the belt in the tire radial direction, the bandcord is obtained by twisting a filament of yarn containing a polyethylene terephthalate fiber, the tread is formed from a rubber composition containing 75 parts by mass or more of silicon dioxide in relation to 100 parts by mass of a rubber component, and has a thickness of more than 6 mm and a rubber hardness (Shore hardness) Hs of more than 60, and a product of the diameter (mm) of the band cord and the thickness (mm) of the running surface is less than 10.

0. [2] Tires according to claim 1, wherein the diameter of the band cord is 0.2 mm or more and 0.8 mm or less. [3] Tires according to claim 1 or 2, wherein the number of cords per 50 mm in width of the band cord in one tire width direction is 40 or more and 80 or less. [4] Tires according to any one of claims 1 to 3, wherein the belt cord is composed of one or more and four or fewer filaments. [5] Tires according to any one of claims 1 to 4, wherein the number of cords per 50 mm in width of the belt cord in one tire width direction is 20 or more and 60 or less. [6] Tires according to any one of claims 1 to 5, wherein the rubber composition contains a vegetable oil. [7] Tires according to any one of claims 1 to 6, wherein the rubber composition contains sustainable carbon black. [8] Tires according to any one of claims 1 to 7, wherein the rubber composition contains sustainable silicon dioxide. [9] Tires according to any one of claims 1 to 8, wherein the polyethylene terephthalate fiber is a sustainable polyethylene terephthalate fiber.

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