TIRES

Abstract

A tire comprising a bead section, a carcass layer, and a clinch section. where a bead core is embedded in the bead section, wherein the clinch section is made of a rubber composition comprising a rubber component, wherein a complex elastic modulus at 70 °C of the rubber composition forming the clinch section, (70 °CE* C ) 20 MPa or less, and where a maximum load capacity W L in kg of the tire and a tanδ at 70 °C of the rubber composition forming the clinch section, (70 °C-tanδ C ) satisfy the following inequality (1): (70 °C − tan δ c + 0.205 ) / WL < 2.57 × 10 − 4

Description

TECHNICAL AREA

[0001] The present invention relates to a tire. BACKGROUND OF THE INVENTION

[0002] With the increasing need to improve tire lifespan performance, it is necessary to extend the lifespan not only of the tread section, but also of elements such as the clinch section, sidewall section, bead section, and the like. The clinch section, in particular, is susceptible to repeated deformation.

[0003] WO 2020 / 080150 A1 describes a tire which incorporates a clinch apex of a predetermined rubber composition for a clinch apex and exhibits improved low heat generation and durability at high speed. SUMMARY OF THE INVENTION

[0004] Meanwhile, in recent years, demands have increased, taking environmental impact into account, and electric vehicles have become increasingly popular. The weight of a battery is also added to the electric vehicle's overall weight. Therefore, it is assumed that tires must have the durability to withstand driving under a higher assumed load than before.

[0005] One object of the present invention is to provide a tire that exhibits improved durability during driving under high load.

[0006] The present invention relates to a tire comprising: a bead section, a carcass layer and a clinch section, where a bead core is embedded in the bead section, wherein the clinch section is made of a rubber composition comprising a rubber component, wherein a complex elastic modulus at 70 °C of the rubber composition forming the clinch section, (70 °CE* C ) 20 MPa or less, and where a maximum load capacity W L in kg of the tire and a tanδ at 70 °C of the rubber composition forming the clinch section, (70 °C-tanδ C ) satisfy the following inequality (1): (70 °C−tanδc+0.205) / WL<2.57×10−4

[0007] According to the present invention, a tire is provided which has improved durability when driving under high load. BRIEF DESCRIPTION OF THE FIGURES Fig. Figure 1 is a schematic cross-sectional partial view of a tire according to an embodiment of the present invention. Fig. Figure 2 is a schematic cross-sectional partial view of the tire according to a further embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0008] The tire, which is an embodiment of the present invention, is a tire comprising a bead section, a carcass layer, and a clinch section, wherein a bead core is embedded in the bead section, and wherein the clinch section is composed of a rubber composition comprising a rubber component, wherein the rubber composition forming the clinch section has a complex modulus of elasticity at 70 °C (70 °CE*). C ) 20 MPa or less and where a maximum load capacity W L in kg of the tire and a tanδ at 70 °C of the rubber composition forming the clinch section, (70 °C-tanδ C ) satisfy the following inequality (1): (70 °C−tanδc+0.205) / WL<2.57×10−4

[0009] Although it is not intended to adhere to any particular theory, the following, for example, can be regarded as a mechanism for improving the durability of the tire of the present invention during driving under high load.

[0010] The clinch section is susceptible to repeated deformation. In the tire of the present invention, (1) if the complex modulus of elasticity at 70 °C of the rubber composition forming the clinch section is 20 MPa or less, the flexibility of the rubber composition is improved so that the rubber composition can be flexibly deformed in accordance with the deformation of the clinch section, thereby improving durability.

[0011] If the maximum load capacity W LIf the tire's volume is large, the tire's overall volume will be large, making it less likely that local elongation will occur throughout the tire. Furthermore, by reducing the tanδ at 70 °C of the rubber compound, a temperature rise in the clinch section during driving can be suppressed. Therefore, (2) if 70 °C tanδ and W L satisfy the inequality described above, W L The temperature coefficient is large, and the 70°C tanδ becomes small, thus reducing the strain and heat generation exerted on the clinch section. It is therefore assumed that the combination of these features can achieve a significant improvement in durability during high-load driving.

[0012] If a maximum thickness of the clinch section is defined as T in mm, a product (T × 70 °CE* C ) of T and 70 °CE* C Preferably 270 or less.

[0013] If the thickness of the clinch section decreases, the volume of the rubber compound in that section is reduced, and heat generation in the clinch section can be suppressed, thus reducing the temperature rise in the clinch section during driving. (If T × 70 °CE*) C If the temperature rise in the clinch section is 270 or less, it can be suppressed even if the flexibility of the rubber composition is low, so it is assumed that durability is further improved.

[0014] The rubber component preferably comprises a styrene-butadiene rubber (SBR). When the rubber component comprises an SBR, a domain in which styrene of the SBR is aggregated is formed in the rubber composition, and this domain can relieve stress during clinch deformation, so that the temperature rise in the clinch section is assumed to be suppressed.

[0015] The rubber composition preferably includes recycled carbon black (rCB). Since a surface of the rCB has been burned, its bond with a polymer in the rubber composition is weaker than that of other fillers, and when the rubber composition is deformed, it is easier for a rubber molecular chain to relieve stress, and shock during tire rolling is easily absorbed within the clinch section, so that durability is assumed to be further improved.

[0016] W L preferably 1000 kg or more. If W L The larger the tire's volume, the less likely it is that local elongation will occur throughout the entire tire, thus improving durability.

[0017] The bead core can be formed from a strip obtained by laminating one or more rows arranged parallel to each other (hereinafter referred to as a strip bead structure) or from a core cord and one or more outer cords arranged helically around the core cord (hereinafter referred to as a cable bead structure). However, the bead core is preferably formed from a core cord and one or more outer cords arranged helically around the core cord. Furthermore, the diameter of the core cord is preferably larger than any diameter of the one or more outer cords. The number of one or more outer cords is preferably 5 to 10.

[0018] If the bead core, which abuts the clinch section, has a predetermined structure, the clinch section will be able to move away from the surrounding area of ​​the bead core when deformation occurs in the clinch section, and the concentration of strain can be suppressed, so that durability is assumed to be further improved.

[0019] The bead section has a bead tapex located on an outside side in a tire radial direction relative to the bead core, and a bead reinforcement layer located on an outside side in the tire radial direction relative to a wound part of the carcass layer.

[0020] If the bead section has a predetermined structure, stiffness in one tire width direction is increased, and local deformation of the clinch section is suppressed, so it is assumed that durability is further improved.

[0021] The clinch section is preferably located on the outer side of the tire in the radial direction, relative to the bead reinforcement layer. This is because it is assumed that stiffness is increased in the tire's width direction, thus further improving durability.

[0022] The bead core comprises one or more cords and a cord cover rubber covering the cords, with a 100% modulus of the cord cover rubber preferably being 5.0 MPa or more and 10.0 MPa or less. Furthermore, the force required to pull the cord off the cord cover rubber, measured in accordance with ASTM 1871, is preferably 500 N or more and 2000 N or less. This is because it is believed to increase the stiffness of the bead section, thus further improving tire durability. <definitionen>

[0023] A "maximum thickness T in mm of a clinch section" is the maximum thickness of the clinch section measured along a normal L on an outer surface of the clinch section. Furthermore, the "maximum thickness T in mm of the clinch section" is measured in a state where a tire is cut on a plane containing a tire axis of rotation and the width of a bead section is matched to the width of a standardized rim.

[0024] A "standardized rim" is a rim within a standard system that includes a standard on which the tire is based, defined by the standard for each tire—that is, a "standard rim" for JATMA, a "Measuring Rim" for ETRTO, or a "Design Rim" for TRA—referenced in that order. If an applicable size exists at the time of reference, the rim conforms to its standard. Furthermore, if a tire size is not defined in the standard system described above, the standardized rim is a rim that can be fitted to the tire and whose width is the narrowest among rims with the smallest diameter that will not cause air leakage between the rim and the tire.

[0025] A "standardized internal pressure" is an air pressure in a standard system containing a standard on which the tire is based, defined by the standard for each tire, that is, a "MAXIMUM AIR PRESSURE" for JATMA, "INFLATION PRESSURE" for ETRTO, or a maximum value described in the "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" table for TRA, to which reference is made in that order, as in the case of the standardized rim, and if there is an applicable size at the time of reference, the rim conforms to its standard. In the case of a tire not defined by the standard, the standardized internal pressure refers to a standardized internal pressure (250 kPa or more) of another tire size (defined by the standard) for which the standardized rim is described as a standard rim.Furthermore, if several standardized internal pressures of 250 kPa or more are described, reference is made to the minimum value below that.

[0026] A "standardized condition" is a condition in which the tire is mounted on a standardized rim, filled with a standardized internal pressure, and no load is applied.

[0027] A "maximum load capacity (W)" L ) in kg" is a value calculated by the following equations (2) and (3) when a tire cross-sectional width is defined as Wt in mm, a tire cross-sectional height is defined as Ht in mm, and a tire outer diameter is defined as Dt in mm, as measured under a standardized condition. V is a virtual volume of a space occupied by the tire. The tire cross-sectional width Wt described above is a maximum width between outer surfaces of sidewalls, excluding, if present, patterns or markings on a sidewall of the tire, under a standardized condition. The tire cross-sectional height Ht described above is a distance from a bottom face of a bead section to an outermost surface of a tread, which is half the difference between the outer diameter of the tire and a nominal size of a rim. V={(Dt / 2)2−(Dt / 2−Ht)2}×π×Wt WL=0.000011×V+100

[0028] A “recovered carbon black” refers to carbon black obtained from a pyrolysis process for a product, such as a used tire or similar material, containing carbon black, where, when the product is subjected to oxidative combustion by heating in air using a thermal weight measurement method according to JIS K 6226-2:2003, the ratio of mass to ash (ash content), which is a non-combustible component, is 13% by mass or more. That is, the mass (amount of carbon) of content loss due to the oxidative combustion described above is less than 87% by mass. The recovered carbon black is also referred to as reclaimed carbon black or can be expressed as rCB.

[0029] An “oil content” also includes the amount of oil contained in an oil-extended rubber. <messverfahren>

[0030] "70 °C-tanδ" is a loss tangent measured using a viscoelasticity measuring device manufactured by gabo Systemtechnik GmbH, e.g., the EPLEXOR series, under conditions of a temperature of 70 °C, a frequency of 10 Hz, an initial strain of 5%, a dynamic strain of ±1%, and an elongation mode. The sample used to measure the loss tangent is a vulcanized rubber compound measuring 20 mm in length × 4 mm in width × 1 mm in thickness. If the sample is produced by cutting it from a tire, it is cut from the tire's clinch section such that a side tangential to a tire circumference becomes a long side, and a side tangential to the tire width becomes a thickness side.

[0031] “70 °CE*” is a complex elastic modulus (MPa) measured under conditions of a temperature of 70 °C, a frequency of 10 Hz, and a dynamic strain of 1%. A sample for measuring the complex elastic modulus is prepared in the same way as in the case for 70 °C tanδ.

[0032] A “100% modulus” is a stress at 100% strain (MPa) obtained by producing a test piece in the shape of dumbbell No. 7 with a thickness of 1 mm and performing a tensile test under a tensile speed of 3.3 mm / sec in an atmosphere of 23 °C according to JIS K 6251 “Rubber, vulcanized or thermoplastics - Determination of tensile stress strain properties”.

[0033] A “force of pulling a cord” is a maximum load (N) until it is pulled out, measured under a condition at room temperature (23 °C) and a speed of 50 mm / min in accordance with ASTM-1871 “Standard Test Method for Adhesion Between Tire Bead Wire and Rubber”.

[0034] An "average primary particle size" is a value obtained by photographing particles using a transmission or scanning electron microscope and calculating the arithmetic mean of the particle sizes of 400 particles. If the particle shape is spherical, the diameter of a sphere is defined as a particle size; if the shape is not spherical, an equivalent circle diameter (positive square root of {4 × (area of ​​particle) ÷ π}) is calculated from a microscope image and defined as a particle size. This definition is applied to soot, etc.

[0035] The "N2SA of soot" is measured according to JIS K 6217-2:2017.

[0036] A "styrene content" is a value determined by 1 A “cis content (cis-1,4-bonded butadiene unit quantity)” is calculated by infrared absorption spectrometry according to JIS K 6239-2:2017 and is applied, for example, to a rubber component with a repeating unit derived from butadiene, such as an SBR and the like. <reifen>

[0037] A process for producing a tire, which is an embodiment of the present invention, is described in detail below. However, the following descriptions are for illustrative purposes only and are not intended to limit the technical scope of the present invention to this description. Furthermore, in this description, a numerical range identified as "to" means that it contains the numerical values ​​from both ends.

[0038] The maximum load capacity W L The load capacity of the tire according to the present embodiment, from the perspective of the effects of the present invention, is more preferably 800 kg or more, more preferably 900 kg or more, more preferably 1000 kg or more, and most preferably 1100 kg or more. Furthermore, the maximum load capacity W L From the point of view of better demonstrating the effects of the present invention, for example, 1800 kg or less, 1500 kg or less or 1300 kg or less.

[0039] The tire according to the present embodiment is suitably described below with reference to the drawings, but the drawings are for illustrative purposes only. A Fig. The tire 1 shown, which is an embodiment of the present invention, comprises a tread section 2, at least one carcass layer 9, a pair of sidewall sections 3 located on both sides of the tread section, a pair of bead sections 6, each having an embedded bead core 5, a clinch section 4 and at least one belt layer 7 located on an outside of the carcass layer 9 in a tire radial direction.

[0040] The bead section 6 of the tire according to the present invention is located on an inner sidewall section 3 in a tire axial direction. The bead section 6 preferably comprises a bead core 5 and a bead tapex 11, which is located on the outer side of the tire in the tire radial direction with respect to the bead core.

[0041] The tire according to the present embodiment preferably has a bead tapex 11 located on the outside of the bead core 5 in the tire radial direction, and a bead reinforcement layer 10 located on the outside of the carcass layer 9 in the tire radial direction. In this case, the clinch section 4 is preferably located on the outside of the bead reinforcement layer 10 in the tire radial direction. < <wulstabschnitt>>

[0042] In Fig. 1. The bead taper 11 tapers outwards in the tire radial direction. The carcass layer 9 is locked around the bead core 5 at its end, which is wound from the inside to the outside in the tire axial direction. A portion of the carcass layer 9 that is wound up is referred to as a wound portion of the carcass layer 9.

[0043] A bead core 5 is embedded in the bead section 6. The bead core preferably has two or more layers, more preferably two layers consisting of a core layer comprising one to three core cords and one or more outer cords. More preferably, the bead core has two layers consisting of a core cord and one or more outer cords arranged helically around the core cord. The diameter of the core cord is preferably larger than any diameter of the outer cords.

[0044] The number of outer cords is preferably 3 or more, more preferably 5 or more, and most preferably 6 or more. Furthermore, the number of outer cords is preferably 15 or fewer, more preferably 10 or fewer, and most preferably 8 or fewer.

[0045] If the bead core has two layers consisting of a core cord and one or more outer cords arranged spirally around the core cord, the size is reduced more than in a case where there are two or more core cords, and the strength per cord cross-section is increased, so durability is assumed to be further improved.

[0046] The bead core preferably comprises a cord cover rubber that covers the cord. The cord cover rubber is composed of a rubber composition comprising a rubber component. Furthermore, the joining of the rubber composition forming the cord cover rubber is not particularly restricted. The 100% modulus of the cord cover rubber is preferably 2.5 MPa or more, more preferably 5.0 MPa or more, and most preferably 7.0 MPa or more. In addition, the 100% modulus is preferably 15.0 MPa or less, and more preferably 10.0 MPa or less.

[0047] Furthermore, the 100% modulus of the rubber compound can be appropriately adjusted depending on the types and quantities of fillers, softeners, vulcanizing agents, vulcanization accelerators, and the like. For example, the 100% modulus can be increased by increasing the total amount of styrene in the rubber component of the rubber compound, increasing the quantity of filler, increasing the quantities of vulcanizing agent and vulcanization accelerator, using a resin with a high glass transition temperature or the like as a softener, decreasing the quantity of softener, or the like.

[0048] The force required to pull the cord from the cord-cover rubber is preferably 500 N or more, more preferably 900 N or more, still more preferably 1000 N or more, and most preferably 1200 N or more. Furthermore, the force is preferably 2500 N or less, more preferably 2000 N or less, and most preferably 1600 N or less. The force required to pull the cord from the cord-cover rubber is also measured by the method described above in accordance with ASTM 1871.

[0049] Furthermore, the force of pulling the cord from the cord-top rubber can be appropriately adjusted depending on the types and quantities of fillers, softeners, vulcanizing agents, vulcanization accelerators, and the like in the rubber composition that forms the cord-top rubber. < <clinchabschnitt>>

[0050] As in Fig. As shown in Figure 2, the clinch section 4 can have rim protection on the outside in the tire radial direction.

[0051] The maximum thickness T of the clinch section 4, from the perspective of the effects of the present invention, is preferably 5.0 mm or more, more preferably 8.0 mm or more, still more preferably 10.0 mm or more, still more preferably 12.0 mm or more, and most preferably 15.0 mm or more. Furthermore, the maximum thickness T of the clinch section 4, from the perspective of the effects of the present invention, is preferably 40.0 mm or less, more preferably 35.0 mm or less, still more preferably 30.0 mm or less, and most preferably 20.0 mm or less.

[0052] In the present invention, the clinch section is composed of a rubber composition comprising a rubber component. The complex modulus of elasticity at 70 °C of the rubber composition forming the clinch section (70 °CE*) is C ) from the perspective of improving the flexibility of the rubber composition, is 20 MPa or less, preferably 18 MPa or less, more preferably 15 MPa or less, even more preferably 10 MPa or less, and most preferably 8.0 MPa or less. Furthermore, 70 °CE* C From the perspective of suppressing deformation of the clinch section, preferably 3.0 MPa or more, further preferably 5.0 MPa or more, and most preferably 7.0 MPa or more. Furthermore, 70 °CE* C measured using the measurement method described above.

[0053] 70 °CE* C can be appropriately adjusted depending on the type and quantity of filler, softener, vulcanizing agent, vulcanization accelerator, and the like. For example, if the quantity of vulcanizing agent (especially sulfur) or vulcanization accelerator is increased, the value of 70 °CE* tends to increase. C .

[0054] The tanδ at 70 °C of the rubber composition forming the clinch section, (70 °C-tanδ C From the perspective of suppressing a temperature rise in the clinch section during driving, the tanδ is preferably 0.100 or less, more preferably 0.090 or less, still more preferably 0.080 or less, still more preferably 0.075 or less, still more preferably 0.070 or less, and most preferably 0.065 or less. Furthermore, the tanδ at 70 °C is... C preferably 0.020 or more, further preferably 0.030 or more, and most preferably 0.040 or more. Furthermore, 70 °C tanδ C measured using the measurement method described above.

[0055] 70 °C-tanδ C can be appropriately adjusted depending on the type and quantity of filler, plasticizer, vulcanizing agent, vulcanization accelerator, and the like. For example, if the quantity of filler (especially carbon black) is reduced, the 70 °C tanδ C tends to decrease.

[0056] In the present invention (70 °C-tanδ C + 0.205) / W L smaller than 2.57 × 10 -4 preferably smaller than 2.55 × 10 -4 , preferably 2.50 × 10 -4 or smaller, preferably 2.48 × 10 -4 or smaller and most preferred 2.45 × 10 -4 or smaller. A lower limit for the right-hand side of inequality (1) is not particularly restricted, but could, for example, be 1.00 × 10 -4 or more, 1.50 × 10 -4 or more or 2.00 × 10 -4 or more.

[0057] In the present invention, the product is (T × 70 °CE* C ) of the maximum thickness T in mm of the clinch section 4 and 70 °CE* C From the perspective of suppressing a temperature rise in the clinch section, even if the flexibility of the rubber composition is low, which improves durability, preferably 300 or less, further preferably 270 or less, still more preferably 250 or less, still more preferably 200 or less, and most preferably 150 or less. Furthermore, a lower limit of T × 70 °CE* is desirable. C not particularly restricted, but could be, for example, 80 or more, 90 or more, or 100 or more. <kautschukkomponente>

[0058] The rubber composition forming the clinch section according to the present embodiment (hereinafter referred to as the rubber composition according to the present embodiment, unless otherwise specified) preferably comprises an isoprene-based rubber, a butadiene rubber (BR), or a styrene-butadiene rubber (SBR) as rubber components; more preferably comprises an isoprene-based rubber and a BR; more preferably comprises an SBR; and most preferably comprises three components: an isoprene rubber, a BR, and an SBR. Furthermore, the rubber composition may include other rubber components than those listed above. In addition, the rubber component may be a rubber component consisting of an isoprene-based rubber, a BR, and an SBR. (Isoprene-based rubber)

[0059] Isoprene-based rubbers can include those commonly used in the tire industry, such as isoprene rubber (IR), natural rubber, and the like. Examples of natural rubber include unrefined natural rubber (NR) and refined natural rubbers, such as epoxidized natural rubber (ENR), hydrogenated natural rubber (HNR), deproteinized natural rubber (DPNR), ultrapure natural rubber, grafted natural rubber, and the like. These isoprene-based rubbers can be used individually, or two or more can be used in combination.

[0060] The NR is not particularly restricted, and those commonly used in the tire industry can be used, examples of which include SIR20, RSS#3, TSR20 and the like.

[0061] The content of isoprene-based rubber in the rubber component is preferably 20 wt% or more, further preferably 30 wt% or more, even more preferably 40 wt% or more, and most preferably 45 wt% or more. Furthermore, the content of isoprene-based rubber in the rubber component is preferably 90 wt% or less, further preferably 85 wt% or less, even more preferably 80 wt% or less, and most preferably 70 wt% or less. (BR)

[0062] The type of rubber (BR) is not particularly restricted, and those commonly used in the tire industry can be employed, such as a BR with a cis content of less than 50 mol% (a cis-poor BR), a BR with a cis content of 90 mol% or more (a cis-rich BR), a rare-earth-based butadiene rubber synthesized using a rare-earth-based catalyst (a rare-earth-based BR), a BR containing a syndiotactic polybutadiene crystal (an SPB-containing BR), a modified BR (a cis-rich modified BR, a cis-poor modified BR), and the like. These BRs can be used individually, or two or more of them can be used in combination.

[0063] For example, the high-cis BR can be one commercially available from Zeon Corporation, Ube Industries, Ltd., JSR Corporation, etc. When the high-cis BR is used, low-temperature properties and abrasion resistance can be improved. The cis content of the high-cis BR is preferably 95 mol% or more, more preferably 96 mol% or more, and most preferably 97 mol% or more. Furthermore, the cis content of the BR is measured using the measurement method described above.

[0064] For the purposes of the present invention, the content of BR, when combined, in the rubber component is preferably 10 wt% or more, more preferably 15 wt% or more, still more preferably 20 wt% or more, still more preferably 25 wt% or more, and most preferably 30 wt% or more. Furthermore, the content of SBR, when combined, in the rubber component is preferably 85 wt% or less, more preferably 80 wt% or less, still more preferably 75 wt% or less, still more preferably 70 wt% or less, and most preferably 65 wt% or less. (SBR)

[0065] The SBR is not particularly restricted; examples include solution-polymerized SBR (S-SBR), emulsion-polymerized SBR (E-SBR), modified SBRs (a modified S-SBR, a modified E-SBR), and the like. Examples of modified SBRs include SBRs modified at their end and / or main chain, modified SBRs coupled with tin, a silicon compound, etc. (a modified SBR of condensate or with a branched structure, etc.), and the like. Among these, S-SBRs and modified SBRs are preferred. Furthermore, hydrogenated versions of these SBRs (hydrogenated SBRs) and the like may also be used. These SBRs may be used individually, or two or more of them may be used in combination.

[0066] The styrene content of the SBR is preferably 40 wt% or less, more preferably 36 wt% or less, even more preferably 32 wt% or less, and most preferably 28 wt% or less. Furthermore, the styrene content of the SBR is preferably 5 wt% or more, more preferably 7 wt% or more, even more preferably 10 wt% or more, even more preferably 13 wt% or more, and most preferably 16 wt% or more. The styrene content of the SBR is also measured using the measurement method described above.

[0067] Furthermore, the SBR content, when combined, in the rubber component is preferably 5 wt% or more, more preferably 10 wt% or more, and most preferably 15 wt% or more. In addition, the SBR content in the rubber component is preferably 50 wt% or less, more preferably 45 wt% or less, still more preferably 40 wt% or less, still more preferably 35 wt% or less, and most preferably 30 wt% or less. (Other rubber components)

[0068] The rubber component may also comprise other rubber components than those described above, as long as the effects of the present invention are not impaired. Examples include non-diene-based rubbers such as hydrogenated nitrile rubber (HNBR), butyl rubber (IIR), halogenated butyl rubber, ethylene propylene rubber, polynorbornene rubber, silicone rubber, chlorinated polyethylene rubber, fluororubber (FKM), acrylic rubber (ACM), hydrin rubber, and the like. <Füllstoff>

[0069] The rubber composition according to the present embodiment preferably comprises carbon black and / or silicon dioxide as a filler and further preferably comprises carbon black. In addition, the filler can be a filler consisting of carbon black. (Soot)

[0070] The carbon black is not particularly restricted, and those commonly used in the tire industry, such as GPF, FEF, HAF, ISAF, SAF, and the like, can be used. Furthermore, from the perspective of environmental impact and reducing friction between a carbon black surface and a rubber molecule chain to suppress heat generation, recovered carbon black (rCB) obtained from the pyrolysis of a used tire can be used. These carbon blacks can be used alone, or two or more can be used in combination. In particular, it is preferred to use an rCB in combination with a carbon black other than the rCB.

[0071] The recovered carbon black can be obtained from a pyrolysis process of a used pneumatic tire. EP 3427975 A, for example, describes, with reference to “Rubber Chemistry and Technology”, Vol. 85, No. 3, pages 408 to 449 (2012), in particular pages 438, 440 and 442, that the recovered carbon black can be obtained by pyrolysis of an organic material at 550 °C to 800 °C in the absence of oxygen or by vacuum pyrolysis at a relatively low temperature (

[0027] ). As mentioned in

[0004] of JP 6856781 B (A comparison of surface morphology and chemistry of pyrolytic carbon blacks with commercial carbon blacks, Powder Technology 160 (2005) 190-193), such carbon black obtained by the pyrolysis process typically lacks a functional group on its surface.

[0072] The recovered carbon black may lack a functional group on its surface, or it may be treated so that its surface includes a functional group. The treatment, which is carried out so that the surface of the recovered carbon black includes a functional group, can be implemented by a conventional method. In EP 3173251 A, carbon black comprising a hydroxyl and / or carboxyl group on its surface is obtained by treating carbon black obtained from a pyrolysis process with potassium permanganate under acidic conditions. Furthermore, in JP 6856781 B, carbon black with an activated surface is obtained by treating carbon black obtained from a pyrolysis process with an amino acid compound comprising at least one thiol or disulfide group. The recovered carbon black according to the present embodiment also includes carbon black whose surface has been treated to include a functional group.

[0073] The recovered carbon black can be that which is commercially available from Strebl Green Carbon Pte Ltd., LDC Co., Ltd. etc.

[0074] The average primary particle size of the carbon black is preferably 40 nm or more, more preferably 50 nm or more, still more preferably 60 nm or more, and most preferably 70 nm or more. Furthermore, to achieve reinforcing properties, the average primary particle size is preferably 100 nm or less, more preferably 95 nm or less, and most preferably 90 nm or less. The average primary particle size of the carbon black is also measured using the measurement method described above.

[0075] A specific nitrogen adsorption surface area (N2SA) of the soot is preferably 90 m² from the point of view of the effects of the present invention. 2 / g or less, preferably 80 m 2 / g or less, preferably 70 m 2 / g or smaller and most preferred 60 m 2 / g or less. Furthermore, N2SA is preferably 10 m 2 / g or larger, preferably 20 m 2 / g or larger and most preferred 30 m 2 / g or greater. Furthermore, the N2SA of soot is measured using the measurement method described above.

[0076] When combined, the carbon black content, based on 100 parts by mass of the rubber component, is preferably 30 parts by mass or more, further preferably 35 parts by mass or more, still more preferably 40 parts by mass or more, and most preferably 45 parts by mass or more, from the perspective of maintaining reinforcing properties. Furthermore, from the perspective of maintaining flexibility for stress relief, it is preferably 100 parts by mass or less, further preferably 90 parts by mass or less, still more preferably 80 parts by mass or less, still more preferably 70 parts by mass or less, still more preferably 60 parts by mass or less, and most preferably 50 parts by mass or less.

[0077] The proportion of recovered carbon black in the total carbon black content is not particularly restricted, but may, for example, be more than 1% by mass, more than 5% by mass, more than 10% by mass, more than 20% by mass, more than 25% by mass, or more than 30% by mass. Furthermore, from the perspective of maintaining reinforcing properties, it is preferably less than 95% by mass, more preferably less than 90% by mass, and most preferably less than 85% by mass. (Silicon dioxide)

[0078] The type of silicon dioxide is not particularly restricted, and those commonly used in the tire industry can be employed, such as silicon dioxide produced by a dry process (anhydrous silicon dioxide), silicon dioxide produced by a wet process (hydrous silicon dioxide), and the like. Hydrous silicon dioxide produced by a wet process is preferred because it contains many silanol groups. Furthermore, in addition to the silicon dioxide described above, silicon dioxide derived from biomass materials, such as rice husks, can also be suitable. This silicon dioxide can be used alone, or two or more types can be used in combination.

[0079] The silicon dioxide content, when combined, based on 100 parts by mass of the rubber component, is preferably 5 parts by mass or more, further preferably 10 parts by mass or more, more preferably 15 parts by mass or more, and most preferably 20 parts by mass or more, from the perspective of ensuring stiffness and reinforcing properties without excessively increasing heat generation. Furthermore, from the perspective of reducing the specific gravity of the rubber, it is preferably 100 parts by mass or less, more preferably 90 parts by mass or less, and most preferably 80 parts by mass or less. (Other fillers)

[0080] Other fillers besides carbon black and silicon dioxide can be those that are conventionally and commonly used in the tire industry, such as aluminum hydroxide, calcium carbonate, alumina, clay, talc and the like. (Other connecting means)

[0081] The rubber composition according to the present embodiment may, in addition to the components described above, suitably include bonding agents that are conventionally and commonly used in the tire industry, for example a softening agent, wax, stearic acid, zinc oxide, an antioxidant, a vulcanizing agent, a vulcanization accelerator and the like.

[0082] Examples of the softening agent include oil, a resin component, liquid rubber, and the like.

[0083] Examples of oils include process oils, vegetable fats and oils, animal fats and oils, and the like. Examples of process oils include paraffin-based process oils, naphthene-based process oils, aromatic-based process oils, and the like. Furthermore, as an environmental measure, a process oil with a low polycyclic aromatic compound (PCA) content can be used. Examples of low PCA process oils include mild extraction solvents (MES), treated distillate aromatic extracts (TDAE), heavy naphthenic oils, and the like. Additionally, from a life cycle assessment perspective, those obtained by cleaning used oil after use in a rubber mixer or engine, or used cooking oil used in a restaurant, can be used.

[0084] The oil content, when combined, based on 100 parts by mass of the rubber component, is preferably 0.5 parts by mass or more, further preferably 1 part by mass or more, still more preferably 3 parts by mass or more, and most preferably 5 parts by mass or more, from the point of view of processability. Furthermore, the content is preferably 20 parts by mass or less, further preferably 15 parts by mass or less, and most preferably 10 parts by mass or less.

[0085] The resin component is not particularly restricted; examples include petroleum-based resins, terpene-based resins, rosin-based resins, phenol-based resins, and the like, which are commonly used in the tire industry. These resin components can be used alone, or two or more of them can be used in combination.

[0086] The resin component content, when combined, is preferably 1 part by mass or more per 100 parts by mass of the rubber component, more preferably 3 parts by mass or more, and most preferably 5 parts by mass or more. Furthermore, from the perspective of suppressing heat generation, it is preferably 40 parts by mass or less, more preferably 30 parts by mass or less, and most preferably 20 parts by mass or less.

[0087] Liquid rubber is not particularly restricted as long as it is a polymer in a liquid state at room temperature (25 °C), examples of which include liquid butadiene rubber (liquid BR), liquid styrene-butadiene rubber (liquid SBR), liquid isoprene rubber (liquid IR), liquid styrene-isoprene rubber (liquid SIR), liquid farnesene rubber, and the like. These liquid rubbers can be used alone, or two or more of them can be used in combination.

[0088] The liquid rubber content, when combined, is preferably 1 part or more per 100 parts by mass of the rubber component, more preferably 3 parts or more, and most preferably 5 parts or more. Furthermore, the liquid rubber content is preferably 50 parts or less by mass, more preferably 40 parts or less, and most preferably 20 parts or less.

[0089] For the purposes of the present invention, the total content of softening agents based on 100 parts by mass of the rubber component is preferably 1 part by mass or more, more preferably 3 parts by mass or more, even more preferably 5 parts by mass or more, and most preferably 7 parts by mass or more. Furthermore, the total content of softening agents is preferably 100 parts by mass or less, more preferably 80 parts by mass or less, and most preferably 60 parts by mass or less.

[0090] The wax content, when combined, based on 100 parts by mass of the rubber component, is preferably 0.5 parts by mass or more, more preferably 1.0 parts by mass or more, and most preferably 1.5 parts by mass or more, from the perspective of improving the weather resistance of the rubber. Furthermore, from the perspective of preventing the whitening of a tire due to blooming, it is preferably 10 parts by mass or less, and more preferably 5.0 parts by mass or less.

[0091] Examples of the antioxidant include, but are not particularly limited to, compounds based on amines, quinolines, quinones, phenols and imidazoles, a carbamic acid metal salt and the like, preferably phenylenediamine-based antioxidants such as N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, N-isopropyl-N'-phenyl-p-phenylenediamine, N,N'-diphenyl-p-phenylenediamine, N,N'-di-2-naphthyl-p-phenylenediamine, N-cyclohexyl-N'-phenyl-p-phenylenediamine and the like, and quinoline-based antioxidants such as 2,2,4-trimethyl-1,2-dihydroquinoline polymer, 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline and the like. These antioxidants can be used alone, or two or more of them can be used in combination.

[0092] The antioxidant content, when combined, based on 100 parts by mass of the rubber component, is preferably 0.5 parts by mass or more, more preferably 1.0 parts by mass or more, and most preferably 1.5 parts by mass or more, with regard to the ozone crack resistance of a rubber. Furthermore, with regard to abrasion resistance and wet adhesion performance, it is preferably 10 parts by mass or less, and more preferably 5.0 parts by mass or less.

[0093] The stearic acid content, when combined, based on 100 parts by mass of the rubber component, is preferably 0.5 parts by mass or more, more preferably 1.0 parts by mass or more, and most preferably 1.5 parts by mass or more, from the point of view of processability. Furthermore, from the point of view of vulcanization rate, it is preferably 10 parts by mass or less, and more preferably 5.0 parts by mass or less.

[0094] The zinc oxide content, when compounded, based on 100 parts by mass of the rubber component, is preferably 0.5 parts by mass or more, more preferably 1.0 parts by mass or more, and most preferably 1.5 parts by mass or more, from the point of view of processability. Furthermore, from the point of view of abrasion resistance, it is preferably 10 parts by mass or less, and more preferably 5.0 parts by mass or less.

[0095] Sulfur is suitable for use as a vulcanizing agent. The sulfur used can be powdered, oil-processing, precipitated, colloidal, insoluble, highly dispersible, and the like.

[0096] When combined as a vulcanizing agent, the sulfur content, based on 100 parts by mass of the rubber component, is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and most preferably 1.0 parts by mass or more, to ensure a sufficient vulcanization reaction. Furthermore, to prevent deterioration, it is preferably 5.0 parts by mass or less, more preferably 4.0 parts by mass or less, and most preferably 3.5 parts by mass or less. Moreover, when an oil-based sulfur is used as the vulcanizing agent, the sulfur content should be the total amount of pure sulfur contained in the oil-based sulfur.

[0097] Examples of vulcanizing agents other than sulfur include an alkylphenol-sulfur chloride condensate, sodium hexamethylene 1,6-bisthiosulfate dihydrate, 1,6-bis(N,N'-dibenzylthiocarbamoyldithio)hexane, and the like. These alternative vulcanizing agents include those commercially available from Taoka Chemical Co., Ltd., LANXESS, Flexsys, etc.

[0098] Examples of vulcanization accelerators include sulfenamide-based, thiazole-based, thiuram-based, thiourea-based, guanidine-based, dithiocarbamic acid-based, aldehyde-amine-based, aldehyde-ammonia-based, imidazoline-based, and xantate-based accelerators, and the like. These vulcanization accelerators can be used individually, or two or more can be used in combination. Among these, one or more vulcanization accelerators selected from the group consisting of sulfenamide-based, guanidine-based, and thiazole-based accelerators are preferred, and sulfenamide-based vulcanization accelerators are further preferred for the sake of better preserving desired effects.

[0099] Examples of sulfenamide-based vulcanization accelerators include N-tert-butyl-2-benzothiazolylsulfenamide (TBBS), N-cyclohexyl-2-benzothiazolylsulfenamide (CBS), N,N-dicyclohexyl-2-benzothiazolylsulfenamide (DCBS), and the like. Among these, N-tert-butyl-2-benzothiazolylsulfenamide (TBBS) and N-cyclohexyl-2-benzothiazolylsulfenamide (CBS) are preferred.

[0100] Examples of guanidine-based vulcanization accelerators include 1,3-diphenylguanidine (DPG), 1,3-di-o-tolylguanidine, 1-o-tolylbiguanide, di-o-tolylguanidine salt of dicatechol borate, 1,3-di-o-cumenylguanidine, 1,3-di-o-biphenylguanidine, 1,3-di-o-cumenyl-2-propionylguanidine, and the like. Among these, 1,3-diphenylguanidine (DPG) is preferred.

[0101] Examples of thiazole-based vulcanization accelerators include 2-mercaptobenzothiazole, a cyclohexylamine salt of 2-mercaptobenzothiazole, di-2-benzothiazolyl disulfide, and the like. Among these, 2-mercaptobenzothiazole is preferred.

[0102] The vulcanization accelerator content, when combined, based on 100 parts by mass of the rubber component, is preferably 1.0 parts by mass or more, more preferably 1.5 parts by mass or more, and most preferably 2.0 parts by mass or more. Furthermore, the vulcanization accelerator content, based on 100 parts by mass of the rubber component, is preferably 8.0 parts by mass or less, more preferably 7.0 parts by mass or less, still more preferably 6.0 parts by mass or less, and most preferably 5.0 parts by mass or less. When the vulcanization accelerator content is within the ranges described above, fracture toughness and elongation tend to be ensured. <produktion>

[0103] The rubber composition according to the present embodiment can be produced by a known method. It can be produced, for example, by kneading each of the components described above using a rubber kneading device, such as an open roller, a closed-type kneader (Bunbury mixer, kneader, etc.), and the like.

[0104] The kneading step includes, for example, a basic kneading step involving the kneading of bonding agents and additives other than vulcanizing agents and vulcanization accelerators, and a final kneading step (F-kneading) involving the addition of vulcanizing agents and vulcanization accelerators to the kneaded product obtained by the basic kneading step, and the kneading of this product. Furthermore, the basic kneading step can be subdivided into several steps if desired.

[0105] A kneading condition is not particularly restricted. Examples of kneading include, for instance, a process of kneading at a discharge temperature of 150 °C to 170 °C for 3 to 10 minutes for the initial kneading step, and a process of kneading at 70 °C to 110 °C for 1 to 5 minutes for the final kneading step. A vulcanization condition is not particularly restricted. Examples of vulcanization include, for instance, a process of vulcanizing at 150 °C to 200 °C for 10 to 30 minutes.

[0106] The tire according to the present embodiment, which comprises the clinch section of the rubber composition described above, can be produced by a conventional method. That is, the tire can be produced by extruding an unvulcanized rubber composition, which is made up of each of the rubber components combined as required, into a clinch section mold, by joining this with a tread section, a carcass layer, a sidewall section, a bead section, and other tire elements on a tire forming machine, and by forming this unvulcanized tire using a conventional method, followed by heating and pressurizing this unvulcanized tire in a vulcanizing machine. No particular restrictions apply to the vulcanization process.Examples of vulcanization include, for example, a process of vulcanizing at 150 °C to 200 °C for 10 to 30 minutes. <anwendung>

[0107] The tire according to the present embodiment can be used as a tire for a passenger car, a heavy-duty tire, a motorcycle tire, or a racing tire. Furthermore, the tire for a passenger car is a tire provided it is mounted on a four-wheeled vehicle and refers to one with a maximum load capacity W. L of 1400 kg or less. Furthermore, according to the present embodiment, the tire can be used as an all-season tire, a summer tire, or a winter tire, such as a studless tire and the like. EXAMPLES

[0108] Examples that are considered preferred for implementation (examples) are shown below, but the scope of protection of the present invention is not limited to the examples.

[0109] Results are shown in Tables 1 to 4, calculated on the basis of the evaluation procedures described below, considering a tire that includes a clinch section produced using a rubber composition obtained by changing compounds according to Tables 1 to 4 using various chemicals shown below. NR: TSR20 BR: UBEPOL BR (registered trademark) 150B, manufactured by Ube Industries, Ltd. (cis content: 97 mol%) SBR: HPR850, manufactured by JSR Corporation (S-SBR, styrene content: 27.5 wt%, vinyl content: 59.0 mol%, non-oil-diluted product) Carbon black (CB) 1: DIABLACK E, manufactured by Mitsubishi Chemical Corporation (N550, N2SA: 41 m 2 / g, average primary particle size: 81 nm) Carbon black (CB) 2: Show Black N660, manufactured by Cabot Japan KK (N2SA: 35 m 2 / g, average primary particle size: 80 nm) rCB: Soot obtained from the pyrolysis process of a tire (ash content: 17% by mass). Wax: OZOACE 0355, manufactured by Nippon Seiro Co., Ltd. Antioxidant 1: Nocrac 6C, manufactured by Ouchi Shinko Chemical Industry Co., Ltd. (N-(1,3-Dimethylbutyl)-N'-phenyl-p-phenylenediamine) Antioxidant 2: Nocrac RD, manufactured by Ouchi Shinko Chemical Industry Co., Ltd. (Poly(2, 2, 4-Trimethyl-1,2-dihydroquinoline)) Oil: Diana Process NH-70S, manufactured by Idemitsu Kosan Co., Ltd. (Aroma-based process oil) Zinc oxide: Zinc oxide No. 1, manufactured by Mitsui Mining & Smelting Co., Ltd. Stearic acid: Stearic acid “CAMELLIA”, manufactured by NOF CORPORATION Sulfur: Seimi OT, manufactured by Nippon Kanryu Industry Co., Ltd. (10% oil-containing insoluble sulfur) Vulcanization accelerator: Nocceler CZ, manufactured by Ouchi Shinko Chemical Industry Co., Ltd. (N-Cyclohexyl-2-benzothiazolylsulfenamide) (CBS))(Examples and comparative examples)

[0110] According to the compound formulations shown in Tables 1 and 4, using a closed 1.7-liter Banbury mixer, all chemicals other than sulfur and vulcanization accelerator are kneaded for 5 minutes until a discharge temperature of 170 °C is reached to obtain a kneaded product. Next, using an open twin-screw mixer, sulfur and vulcanization accelerator are added to the resulting kneaded product, and the mixture is kneaded for 4 minutes until the temperature reaches 105 °C to obtain an unvulcanized rubber composition.The resulting unvulcanized rubber composition is extruded into a clinch section shape using an extruder equipped with a die of a predetermined shape and joined with a tread section, carcass layer, sidewall section, bead section formed as a cord-rubber composite (the bead core has a cord and a cord cover rubber covering the cord, where a 100% modulus of the cord cover rubber is defined as 7.0 MPa and where a force of pulling the cord from the cord cover rubber is defined as 1300 N) and other tire elements, forming an unvulcanized tire, and the unvulcanized tire is press-vulcanized under a condition of 170 °C for 12 minutes to produce each test tire.Furthermore, Tables 1 to 4 show a structure of the bead core embedded in the bead section, in a case where it is brought into a strip obtained by laminating a series of four cords arranged parallel to each other in four layers, as a ribbon bead structure, or in a case where it is formed from a core cord and one or more outer cords arranged spirally around the core cord, as a cable bead structure. <Messung von 70 °C-tanδ und 70 °C-E*>

[0111] A rubber test piece is produced by cutting a 20 mm long × 4 mm wide × 1 mm thick section from a clinch section of each test tire, such that a side tangential to a tire circumference direction becomes a long side and a tire width direction (a normal direction to the surface of the clinch section) becomes a thickness direction. For each rubber test piece, a tanδ and a complex modulus of elasticity (E*) are measured using the EPLEXOR series manufactured by gabo Systemtechnik GmbH under conditions of a temperature of 70 °C, a frequency of 10 Hz, an initial strain of 10%, a dynamic strain of ±1%, and an elongation mode. <Haltbarkeit während Fahren unter hoher Last>

[0112] Each test tire is mounted in a standardized rim, inflated to a standardized internal pressure, and then driven on a drum at a speed of 80 km / h with a 1000 kg load. The distance to tire failure is measured, with a reference comparison example (Comparison Example 9 in Tables 1 and 2, Comparison Example 18 in Tables 3 and 4) of 100, which serves as a durability index during high-load driving. The results show that the higher the index, the better the durability during high-load driving. Table 1 Tire size: 265 / 70R18 Example 1 2 3 4 5 6 Composite quantity (mass parts) NR 50 50 50 50 50 50 BR 50 50 50 30 20 20 SBR - - - 20 30 30 CB1 60 60 60 60 60 50 CB2 - - - - - - rCB - - - - - 10 wax 1,2 1,2 1,2 1,2 1,2 1,2 Antioxidant 1 2,0 2,0 2,0 2,0 2,0 2,0 Antioxidant 1 1,5 1,5 1,5 1,5 1,5 1,5 Öl 0,5 7,0 7,0 7,0 7,0 7,0 zinc oxide 4,0 4,0 4,0 4,0 4,0 4,0 Stearic acid 4,0 4,0 4,0 4,0 4,0 4,0 sulfur 2,6 2,6 2,6 2,6 2,6 2,6 Vulcanization accelerator 2,6 2,6 2,6 2,6 2,6 2,6 Physical property 70 °CE* C (MPa) 10,0 7,0 7,0 7,2 7,3 7,3 70 °C-tanδ C 0,080 0,080 0,080 0,077 0,075 0,075 dimension T (mm) 30,0 30,0 15,0 15,0 15,0 15,0 At game 1 2 3 4 5 6 W L (kg) 1192 1192 1192 1192 1192 1192 (70 °C-tanδ C + 0,205) / W L 2,39 × 10 -4 2,39 × 10 -4 2,39 × 10 -4 2,37 × 10 -4 2,35 × 10 -4 2,35 × 10 -4 T × 70 °C-E* C 300 210 105 108 110 110 bead section Cord structure band band band band band band Number of core cords (pieces) 0 0 0 0 0 0 Number of outer cords (pieces) - - - - - - Bead reinforcement layer Available Available Available Available Available Available index Durability during driving under high load 102 106 108 111 111 114 Example 7 8 9 10 11 Composite quantity (mass parts) NR 50 50 50 50 50 BR 20 20 20 20 20 SBR 30 30 30 30 30 CB1 40 - 40 40 40 CB2 - 40 - - - rCB 20 20 20 20 20 wax 1,2 1,2 1,2 1,2 1,2 Antioxidant 1 2,0 2,0 2,0 2,0 2,0 Antioxidant 1 1,5 1,5 1,5 1,5 1,5 Öl 7,0 7,0 7,0 7,0 7,0 zinc oxide 4,0 4,0 4,0 4,0 4,0 Stearic acid 4,0 4,0 4,0 4,0 4,0 sulfur 2,6 2,6 2,6 2,6 2,6 Vulcanization accelerator Vulcanization accelerator 2,6 2,6 2,6 2,6 2,6 Physical property 70 °CE* C (MPa) 7,3 7,1 7,3 7,3 7,3 70 °C-tanδ C 0,075 0,071 0,075 0,075 0,075 dimension T (mm) 15,0 15,0 15,0 15,0 15,0 W L (kg) 1192 1192 1192 1192 1192 (70 °C-tanδ C + 0,205) / W L 2,35 × 10 -4 2,32 × 10 -4 2,35 × 10 -4 2,35 × 10 -4 2,35 × 10 -4 T × 70 °C-E* C 110 107 110 110 110 bead section Cord structure band band Cable Cable Cable Number of core cords (pieces) 0 0 1 1 1 Number of outer cords (pieces) - - 6 3 6 Bead reinforcement layer Available Available Available Available Unavailable index Durability during driving under high load 115 116 121 119 118 Table 2 Tire size: 265 / 70R18 Comparative example 1 2 3 4 5 6 7 8 9 Composite quantity (mass parts) NR 50 50 50 50 50 50 50 50 50 BR 50 50 50 50 50 30 20 20 20 SBR - - - - - 20 30 30 30 CB1 100 - 90 90 90 90 90 80 70 CB2 - 90 - - - - - - - rCB - - - - - - - 10 20 wax 1,2 1,2 1,2 1,2 1,2 1,2 1,2 1,2 1,2 Antioxidant 1 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 Antioxidant 1 1,5 1,5 1,5 1,5 1,5 1,5 1,5 1,5 1,5 Öl 0,5 0,5 0,5 7,0 7,0 7,0 7,0 7,0 7,0 zinc oxide 4,0 4,0 4,0 4,0 4,0 4,0 4,0 4,0 4,0 Stearic acid 4,0 4,0 4,0 4,0 4,0 4,0 4,0 4,0 4,0 sulfur 2,6 2,6 2,6 2,6 2,6 2,6 2,6 2,6 2,6 Vulcanization accelerator 2,6 2,6 2,6 2,6 2,6 2,6 2,6 2,6 2,6 Physical property 70 °CE* C (MPa) 22,0 21,0 18,0 15,0 15,0 15,2 15,5 15,5 15,5 70 °C-tanδ C 0,120 0,090 0,110 0,110 0,110 0,107 0,105 0,105 0,105 dimension T (mm) 30,0 30,0 30,0 30,0 15,0 15,0 15,0 15,0 15,0 W L (kg) 1192 1192 1192 1192 1192 1192 1192 1192 1192 (70 °C-tanδ C + 0,205) / W L 2,73 × 10 -4 2,48 × 10 -4 2,64 × 10 -4 2,64 × 10 -4 2,64 × 10 -4 2,62 × 10 -4 2,60 × 10 -4 2,60 × 10 -4 2,60 × 10 -4 T × 70 °C-E* C 660 630 540 450 225 228 233 233 233 bead section Cord structure band band band band band band band band band Number of core cords (pieces) 0 0 0 0 0 0 0 0 0 Number of outer cords (pieces) - - - - - - - - - Bead reinforcement layer Available Available Available Available Available Available Available Available Available index Durability during driving under high load 72 77 86 92 94 97 98 99 100 Table 3 Tire size: 255 / 70R18 Example 12 13 14 15 16 Composite quantity (mass parts) NR 50 50 50 50 50 BR 50 50 50 30 20 SBR - - - 20 30 CB1 60 60 60 60 60 - - - - - rCB - - - - - wax 1,2 1,2 1,2 1,2 1,2 Antioxidant 1 2,0 2,0 2,0 2,0 2,0 Antioxidant 1 1,5 1,5 1,5 1,5 1,5 Öl 0,5 7,0 7,0 7,0 7,0 zinc oxide 4,0 4,0 4,0 4,0 4,0 Stearic acid 4,0 4,0 4,0 4,0 4,0 sulfur 2,6 2,6 2,6 2,6 2,6 Vulcanization accelerator 2,6 2,6 2,6 2,6 2,6 Physical property 70 °CE* C (MPa) 10,0 7,0 7,0 7,2 7,3 70 °C-tanδ C 0,070 0,070 0,070 0,068 0,065 dimension T (mm) 30,0 30,0 15,0 15,0 15,0 Example 12 13 14 15 16 W L (kg) 1100 1100 1100 1100 1100 (70 °C-tanδ C + 0,205) / W L 2,50 × 10 -4 2,50 × 10 -4 2,50 × 10 -4 2,48 × 10 -4 2,45 × 10 4 T × 70 °C-E* C 300 210 105 108 110 bead section Cord structure band band band band band Number of core cords (pieces) 0 0 0 0 0 Number of outer cords (pieces) - - - - - Bead reinforcement layer Available Available Available Available Available index Durability during driving under high load 103 106 109 112 112 Example 17 18 19 20 21 Composite quantity (mass parts) NR 50 50 50 50 50 BR 20 20 20 20 20 SBR 30 30 30 30 30 CB1 50 40 40 40 40 CB2 - - - - - rCB 10 20 20 20 20 wax 1,2 1,2 1,2 1,2 1,2 Antioxidant 1 2,0 2,0 2,0 2,0 2,0 Antioxidant 1 1,5 1,5 1,5 1,5 1,5 Öl 7,0 7,0 7,0 7,0 7,0 zinc oxide 4,0 4,0 4,0 4,0 4,0 Stearic acid 4,0 4,0 4,0 4,0 4,0 sulfur 2,6 2,6 2,6 2,6 2,6 Vulcanization accelerator Vulcanization accelerator 2,6 2,6 2,6 2,6 2,6 Physical property 70 °CE* C (MPa) 7,3 7,3 7,3 7,3 7,3 70 °C-tanδ C 0,065 0,065 0,065 0,065 0,065 dimension T (mm) 15,0 15,0 15,0 15,0 15,0 W L (kg) 1100 1100 1100 1100 1100 (70 °C-tanδ C + 0,205) / W L 2,45 × 10 -4 2,45 × 10 -4 2,45 × 10 -4 2,45 × 10 -4 2,45 × 10 -4 T × 70 °C-E* C 110 110 110 110 110 bead section Cord structure band band Cable Cable Cable Number of core cords (pieces) 0 0 1 1 1 Number of outer cords (pieces) - - 6 3 6 Bead reinforcement layer Available Available Available Available Unavailable index Durability during driving under high load 116 119 125 122 121 Table 4 Tire size: 255 / 70R18 Comparative example 10 11 12 13 14 15 16 17 18 Composite quantity (mass parts) NR 50 50 50 50 50 50 50 50 50 BR 50 50 50 50 50 30 20 20 20 SBR - - - - - 20 30 30 30 CB1 100 - 90 90 90 90 90 80 70 CB2 - 90 - - - - - - - rCB - - - - - - - 10 20 wax 1,2 1,2 1,2 1,2 1,2 1,2 1,2 1,2 1,2 Antioxidant 1 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 Antioxidant 1 1,5 1,5 1,5 1,5 1,5 1,5 1,5 1,5 1,5 Öl 0,5 0,5 0,5 7,0 7,0 7,0 7,0 7,0 7,0 zinc oxide 4,0 4,0 4,0 4,0 4,0 4,0 4,0 4,0 4,0 Stearic acid 4,0 4,0 4,0 4,0 4,0 4,0 4,0 4,0 4,0 sulfur 2,6 2,6 2,6 2,6 2,6 2,6 2,6 2,6 2,6 Vulcanization accelerator 2,6 2,6 2,6 2,6 2,6 2,6 2,6 2,6 2,6 Physical property 70 °CE* C (MPa) 22,0 21,0 18,0 15,0 15,0 15,2 15,5 15,5 15,5 70 °C-tanδ C 0,110 0,077 0,100 0,100 0,100 0,098 0,095 0,095 0,095 dimension T (mm) 30,0 30,0 30,0 30,0 15,0 15,0 15,0 15,0 15,0 W L (kg) 1100 1100 1100 1100 1100 1100 1100 1100 1100 (70 °C-tanδ C + 0,205) / W L 2,86 × 10 -4 2,56 × 10 -4 2,77 × 10 -4 2,77 × 10 -4 2,77 × 10 -4 2,75 × 10 -4 2,73 × 10 -4 2,73 × 10 -4 2,73 × 10 -4 T × 70 °C-E* C 660 630 540 450 225 228 233 233 233 bead section Cord structure band band band band band band band band band Number of core cords (pieces) 0 0 0 0 0 0 0 0 0 Number of outer cords (pieces) - - - - - - - - - Bead reinforcement layer Available Available Available Available Available Available Available Available Available index Durability during driving under high load 72 77 86 92 95 97 98 99 100 <Ausführungsformen>

[0113] Examples of embodiments of the present invention are shown below. [1] A tire comprising a bead section, a carcass layer and a clinch section, where a bead core is embedded in the bead section, wherein the clinch section is made of a rubber composition comprising a rubber component, wherein a complex elastic modulus at 70 °C of the rubber composition forming the clinch section, (70 °CE* C ) 20 MPa or less, and where a maximum load capacity W L in kg of the tire and a tanδ at 70 °C of the rubber composition forming the clinch section, (70 °C-tanδ C ) satisfy the following inequality (1): (70 °C−tanδc+0.205) / WL<2.57×10−4 [2] The tire of [1] above, wherein, if a maximum thickness of the clinch section is defined as T in mm, a product (T × 70 °CE* C ) of T and 70 °CE* C 270 or less. [3] The tire of [1] or [2] above, wherein the rubber component comprises a styrene-butadiene rubber. [4] The tire from one of [1] to [3] above, wherein the rubber composition includes recovered carbon black. [5] The tire of one of [1] to [4] above, where W L 1000 kg or more. [6] The tire from [1] to [5] above, wherein the bead core consists of a core cord and one or more outer cords arranged spirally around the core cord. [7] The tire of [6] above, wherein a diameter of the core cord is larger than any diameter of one or more outer cords. [8] The tire of [6] or [7] above, wherein the number of one or more outer cords is 5 to 10. [9] The tire from [1] to [8] above, wherein the bead section has a bead tapex located on an outside in a tire radial direction with respect to the bead core, and a bead reinforcement layer located on an outside in the tire radial direction with respect to a wound part of the carcass layer.

[10] The tire from [9] above, wherein the clinch section is located on an outside side in the tire radial direction with respect to the bead reinforcement layer.

[11] The tire from one of [1] to

[10] above, wherein the bead core has one or more cords and a cord cover rubber covering the cords and a 100% modulus of the cord cover rubber is 5.0 MPa or more and 10.0 MPa or less.

[12] The tire of

[11] above, wherein a force of pulling the cord from the cord cover rubber, measured in accordance with ASTM-1871, is 500 N or more and 2000 N or less. REFERENCE MARK LIST 1 tire 2. Tread section 3 Side wall section 4 Clinch section 5 bead core 6 bead section 7th belt layer 8 rim 9 Carcass layer 10 Bead reinforcement layer 11 Bead Tape< / anwendung> < / produktion> < / kautschukkomponente> < / clinchabschnitt> < / wulstabschnitt> < / reifen> < / messverfahren> < / definitionen>

Claims

[1] Tire comprising a bead section, a carcass layer and a clinch section, where a bead core is embedded in the bead section, wherein the clinch section is made of a rubber composition comprising a rubber component, wherein a complex elastic modulus at 70 °C of the rubber composition forming the clinch section, (70 °CE* C ) 20 MPa or less, and where a maximum load capacity W L in kg of the tire and a tanδ at 70 °C of the rubber composition forming the clinch section, (70 °C-tanδ C ) satisfy the following inequality (1): (70 °C−tanδc+0.205) / WL<2.57×10−4 [2] Tire according to claim 1, wherein, if a maximum thickness of the clinch section is defined as T in mm, a product (T × 70 °CE* C ) of T and 70 °CE* C 270 or less. [3] Tires according to claim 1 or 2, wherein the rubber component comprises a styrene-butadiene rubber. [4] Tires according to any one of claims 1 to 3, wherein the rubber composition comprises recovered carbon black. [5] Tires according to any one of claims 1 to 4, wherein W L 1000 kg or more. [6] Tire according to any one of claims 1 to 5, wherein the bead core consists of a core cord and one or more outer cords arranged spirally around the core cord. [7] Tire according to claim 6, wherein a diameter of the core cord is larger than any diameter of one or more outer cords. [8] Tires according to claim 6 or 7, wherein the number of one or more outer cords is 5 to 10. [9] Tire according to any one of claims 1 to 8, wherein the bead section comprises a bead tapex located on an outside in a tire radial direction with respect to the bead core, and a bead reinforcement layer located on an outside in the tire radial direction with respect to a wound part of the carcass layer. [10] Tire according to claim 9, wherein the clinch section is located on an outer side in the tire radial direction with respect to the bead reinforcement layer. [11] Tire according to any one of claims 1 to 10, wherein the bead core has one or more cords and a cord cover rubber covering the cords and a 100% modulus of the cord cover rubber is 5.0 MPa or more and 10.0 MPa or less. [12] Tire according to claim 11, wherein a force of pulling the cord from the cord cover rubber, measured in accordance with ASTM-1871, is 500 N or more and 2000 N or less.

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