Tire

Abstract

The purpose of the present invention is to further improve the burnup performance of a tire. The tire is characterized in that the tire is provided with a carcass formed by winding a two-layer structure of a first carcass ply and a second carcass ply which are provided with carcass cords, a belt layer provided with belt layer cords, and a belt layer provided with belt layer cords containing polyethylene terephthalate fibers, a tread that is formed using a rubber composition containing more than 75 parts by mass of silica and more than 15% by mass of an acetone extraction component with respect to 100 parts by mass of the rubber component, and that is provided on the outside of the belt layer in the tire radial direction; the outer diameter (Dt) (mm) of the tire, the winding height (P1) (mm) of the first carcass ply, the winding height (P2) (mm) of the second carcass ply, the diameter (D1) (mm) of the belt ply cords, the diameter (D2) (mm) of the belt ply cords, and the diameter (D3) (mm) of the carcass cords satisfy (Equation 1) and (Equation 2). (P1-P2) / Dtlt; 0.07 (Formula 1) (D1 + D2 + D3) lt; 2.00 (Formula 2).

Description

TECHNICAL FIELD

[0001] The present application relates to a tire. BACKGROUND

[0002] In recent years, tires that seek to improve fuel consumption performance have been proposed (for example, Patent Documents 1 and 2), but such improvements are not sufficient.

PRIOR ART DOCUMENTS

PATENT DOCUMENTS

[0003]

Patent Document 1

Patent Document 2

PROBLEMS TO BE SOLVED BY THE INVENTION

[0004] The present application seeks to further improve the fuel consumption performance of a tire.

MEANS FOR SOLVING THE PROBLEMS

[0005] The present application is a tire characterized by, having: a carcass that has a carcass cord, a belt that has a belt cord and is disposed on the tire radial direction outer side of the carcass, a shoulder layer that has a shoulder layer cord and is disposed on the tire radial direction outer side of the belt, a tread that is disposed on the tire radial direction outer side of the shoulder layer, the carcass is a two-layer structure that has a first carcass ply and a second carcass ply that each have a carcass cord, and is wound around a bead to form, the shoulder layer cord is a shoulder layer cord that contains a polyethylene terephthalate fiber, the tread is formed using a rubber composition that contains more than 75 parts by mass of silica relative to 100 parts by mass of a rubber component, and has more than 15% by mass of an acetone extract component. Further, when the outer diameter of the tire is set as Dt (mm), the winding height of the first carcass ply on the outer side when the carcass is wound is set as P1 (mm), and the winding height of the second carcass ply on the inner side is set as P2 (mm), the following (Formula 1) is satisfied, and, when the diameter of the shoulder layer cord is set as D1 (mm), the diameter of the belt cord is set as D2 (mm), and the diameter of the carcass cord is set as D3 (mm), the following (Formula 2) is satisfied. (P1-P2) / Dt < 0.07 (Formula 1) (D1+D2+D3) < 2.00 (Formula 2)

EFFECT OF THE INVENTION

[0006] According to the present application, further improvement of the fuel consumption performance of the tire can be achieved. BRIEF DESCRIPTION OF DRAWINGS

[0007]

【 Figure 1 FIG. 1 is a cross-sectional view of a tire according to an embodiment of the present application.

【 Figure 2 FIG. 1 is a cross-sectional view of a tire according to an embodiment of the present application.

LEGEND

[0008] [1] Features of the tire according to the present application First, features of the tire according to the present application are described.

[0009] 1. SUMMARY The tire according to the present application has a carcass provided with a carcass cord, a belt provided with a belt cord and disposed on the tire radial direction outer side of the carcass, a band provided with a band cord and disposed on the tire radial direction outer side of the belt, and a tread disposed on the tire radial direction outer side of the band. Further, the carcass is a two-layer structure provided with a 1st carcass ply and a 2nd carcass ply each provided with a carcass cord, and is formed by winding around the bead. Further, the band cord is a band cord containing a polyethylene terephthalate fiber. Furthermore, the tread is formed using a rubber composition containing more than 75 parts by mass of silica with respect to 100 parts by mass of a rubber component, and the acetone extractable component is more than 15 mass%. Further, when the outer diameter of the tire is set as Dt (mm), the winding height of the 1st carcass ply on the outer side at the time of winding of the carcass is set as P1 (mm), and the winding height of the 2nd carcass ply on the inner side is set as P2 (mm), the following (Formula 1) is satisfied, and when the diameter of the band cord is set as D1 (mm), the diameter of the belt cord is set as D2 (mm), and the diameter of the carcass cord is set as D3 (mm), the following (Formula 2) is satisfied. (P1-P2) / Dt<0.07 (Equation 1) (D1+D2+D3)<2.00 (Equation 2)

[0010] By incorporating these features, as described below, further improvements in tire fuel efficiency can be achieved.

[0011] 2. The principle of the rendering effect in tires involved in this invention. The principle underlying the tires involved in this invention that produces the aforementioned effects can be considered as follows.

[0012] (1) Use of PET strapping layer In the tires of the present invention, the belt layer cords use belt layer cords (PET belt layer) containing polyethylene terephthalate (PET) fibers.

[0013] It can be argued that, since PET fiber has a higher modulus than nylon 66 (polyamide synthetic fiber) which is traditionally the main material used in belt layer cords, using PET cords in belt layer cords can suppress the heat generated by the movement of the belt layer during driving, thereby further improving fuel efficiency.

[0014] On the other hand, a high modulus makes the tire profile more rounded. Therefore, when the tire flexes during driving, the strain tends to concentrate in the sidewall, raising concerns about increased heat generation in the sidewall area.

[0015] (2) Fetal body Therefore, in this invention, the fetal body is made as follows: Figure 1 The tire shown is a two-layer structure consisting of a first carcass ply 7A and a second carcass ply 7B, each having carcass cords, and is formed by winding around the bead 5. Further, when the outer diameter of the tire is set to Dt (mm), the winding height of the first carcass ply 7A located on the outer side when the carcass 7 is wound is set to P1 (mm), and the winding height of the second carcass ply 7B located on the inner side is set to P2 (mm), ((P1-P2) / Dt) is controlled to be less than 0.07.

[0016] That is, by reducing (P1-P2), the rigidity of the tire sidewall can be improved, preventing strain concentration in the tire sidewall. Furthermore, since the ratio of (P1-P2) to the tire outer diameter ((P1-P2) / Dt)) can be sufficiently reduced to less than 0.07, sufficient flexing within the tire as a whole can be achieved, thus suppressing heat generation in the tire sidewall and further improving fuel efficiency.

[0017] (3) Rubber composition constituting the tread (rubber composition for tread) Also, in the present application, when forming a tread, a rubber composition (tread rubber composition) containing more than 75 parts by mass of silica in 100 parts by mass of a rubber component, and having an acetone extractable component of more than 15% by mass is used.

[0018] (a) Compounding of silica By containing more than 75 parts by mass of silica in 100 parts by mass of a rubber component, the tangent of the loss angle (30°C tan δ) can be reduced, which is measured at 30°C, a frequency of 10 Hz, an initial strain of 5%, a dynamic strain rate of 1%, and a deformation mode of stretching, and thus it is considered that heat generation due to movement of the belt layer during running can be suppressed, and further improvement in fuel consumption performance can be achieved.

[0019] That is, since the tangent of the loss angle tan δ is a viscoelasticity parameter that indicates the performance of absorbing energy, the greater the value, the greater the energy absorption and conversion to heat, and thus greater heat generation, and thus by controlling the 30°C tan δ to be small, heat generation due to movement of the belt layer during running can be suppressed, and further improvement in fuel consumption performance can be achieved.

[0020] Further, the tangent of the loss angle (tan δ) can be measured, for example, using a viscoelasticity measuring device such as "EPLEXOR (registered trademark)" manufactured by GABO.

[0021] (b) Acetone extractable component (AE amount) The AE amount can be considered to be an index indicating the amount of a material such as a softener (plasticizer) that imparts plasticity to the rubber component in the rubber composition, and can also be considered to be an index indicating the softness of the rubber composition.

[0022] It can be considered that, in the present application, since the AE amount is controlled to be a high value of more than 15% by mass, the softness of the tread can be maintained, the effect of flexing in the entire tire can be easily obtained, and further improvement in fuel consumption performance can be achieved.

[0023] Further, the measurement of the AE amount can be performed in accordance with JIS K 6229:2015. Specifically, by immersing a vulcanized rubber test piece cut from a measurement site in acetone for a prescribed time, the mass reduction rate (%) of the test piece is found, and the AE amount (% by mass) can be obtained.

[0024] More specifically, each vulcanized rubber test piece can be immersed in acetone at normal temperature and normal pressure for 72 hours, the soluble component is extracted, the mass of each test piece before and after extraction is measured, and the following equation is used to find the AE amount. AE amount (% by mass) = {(mass of the rubber test piece before extraction - mass of the rubber test piece after extraction) / (mass of the rubber test piece before extraction)} x 100

[0025] (4) diameters of the belt cord, the belt cord, the carcass cord In the present application, further, the sum (D1+D2+D3) of the diameter D1 (mm) of the belt cord, the diameter D2 (mm) of the belt cord, and the diameter D3 (mm) of the carcass cord is controlled to be less than 2.00 (Formula 2).

[0026] It can be considered that, since the weight of the belt, the belt, and the carcass can be reduced by using thin cords, further weight reduction of the tire can be achieved, and further improvement of the fuel consumption performance can be achieved.

[0027] Further, in the above, the "diameter of the belt cord" and the "diameter of the carcass cord" can be measured according to the method prescribed in JIS L1017:2002 "Chemical fiber tire cord test method", and the "diameter of the belt cord" can be measured according to the test method prescribed in JIS G3510:1992 "Steel tire cord test method". Also, the "diameter of the cord" means the diameter when the circumscribed circle of the section perpendicular to the extension direction of the cord is a perfect circle, and means the equivalent circle diameter (the diameter of the circle assuming the same sectional area) when the circumscribed circle is an ellipse or the like.

[0028] [2] More preferable mode in the tire according to the present application The tire according to the present application can achieve further greater effects by adopting the following mode.

[0029] 1. PET belt In the present application, as the PET fiber for the PET belt, a sustainable material suitable for environmental protection is preferable. As the PET fiber as the sustainable material (sustainable PET fiber), for example, a PET fiber (recycled PET fiber) which recycles a plastic waste such as a plastic bottle after use, a recycled product, a waste material, or a PET fiber (bio-PET fiber) manufactured from biomass can be exemplified.

[0030] Also, as the diameter D1 of the specific PET belt (belt cord), 0.60 mm or less, more preferably 0.55 mm or less is preferable. As the lower limit, 0.45 mm or more, more preferably 0.50 mm or more is preferable.

[0031] Further, the structure of the PET belt can be either a single-twisted belt in which one cord is twisted or a double-twisted belt in which two cords are twisted. Also, the filaments constituting the cord can be only PET fibers, or can be a mixture of PET fibers and other fibers (polyamide fibers, etc.).

[0032] Further, the number of cords per 50 mm width of the PET belt layer (belt layer cord) (warp density: cords / 5 cm) is preferably greater than 30 cords / 5 cm, more preferably greater than 40 cords / 5 cm, and further preferably greater than 45 cords / 5 cm. There is no particular limitation on the upper limit, and it is preferably less than 70 cords / 5 cm, more preferably less than 60 cords / 5 cm, and further preferably less than 55 cords / 5 cm.

[0033] The warp density of the above-described belt layer cord can be measured according to the method prescribed in JIS L1017:2002 "Chemical Fiber Tire Cord Test Method".

[0034] The PET belt layer can be produced by treating the PET cord with an adhesive and adhering it to a prescribed belt layer rubber composition. As the adhesive for adhering the PET cord, for example, EX-313 (polyglycerol glycidyl ether, manufactured by Nagase Chemtex Corporation) and RFL (resorcinol-formaldehyde latex) and the like can be used as an epoxy compound.

[0035] Further, the belt layer can be one layer or two layers. Further, the belt layer can be formed over the entire width direction of the tread, or can be formed only at both end portions of the tread.

[0036] 2. Tread (1) Content of Silica In the present application, the content of silica in the tread rubber composition is, as described above, greater than 75 parts by mass in 100 parts by mass of the rubber component, but is more preferably greater than 80 parts by mass, further preferably greater than 90 parts by mass, and further preferably greater than 100 parts by mass. In this way, it can be considered that the 30°C tan δ described above can be further reduced by further enriching the silica, and thus the fuel consumption performance can be further improved. The upper limit is, for example, preferably less than 140 parts by mass, more preferably less than 130 parts by mass, further preferably less than 120 parts by mass, and further preferably less than 110 parts by mass.

[0037] Further, when silica is contained, the processability becomes poor when the particle diameter (average primary particle diameter) is too small, and thus it is preferable to use silica of greater than 8 nm. More preferably, it is 15 nm or greater. On the other hand, from the viewpoint of ensuring the reinforcement of the rubber, it is preferably 25 nm or less, and more preferably 22 nm or less.

[0038] Furthermore, the average primary particle size of silica refers to the average value measured by taking the absolute maximum length of the smallest particle of silica that constitutes the aggregated structure as the diameter of the circle and observing it as a circle. This value can be obtained by observing the primary particles of silica in more than 400 fields of view using a transmission or scanning electron microscope and averaging them.

[0039] Specifically, using an electron microscope or similar device, the silica extracted from the rubber composition cut from the tire is directly observed. The diameter of the equal cross-sectional area is calculated from the area of ​​each silica particle, and the average primary particle size can be calculated by taking the average value.

[0040] There are no particular limitations on the raw materials used for silica. For example, it can be derived from minerals such as quartz, or from biological sources such as rice husks (e.g., silica made from biomass materials such as rice husks). Silica recovered from silica-containing products can also be used. Among these, hydrous silica prepared by a wet process is preferred due to its higher silanol group content. From an environmental protection perspective, sustainable silica (silica made from biomass materials or silica recovered from silica-containing products) is preferred.

[0041] Silica obtained from biomass materials (biomass silica), for example, can be obtained by extracting silicates from rice husk ash obtained from burning rice husks using sodium hydroxide solution. This silicate is then reacted with sulfuric acid in the same way as conventional wet silica. The resulting silica precipitate is filtered, washed with water, dried, and pulverized to obtain the final product.

[0042] Silica recovered from products containing silica (recycled silica) can be, for example, silica recovered from products containing silica such as electronic components like semiconductors, tires, desiccants, and filter materials such as diatomaceous earth. Furthermore, the method of recovery is not particularly limited, and examples include thermal decomposition and decomposition using electromagnetic waves. Of these, silica recovered from electronic components like semiconductors or tires is preferred.

[0043] If silica crystallizes, it becomes insoluble in water and cannot utilize the silicic acid that is its component. By managing the combustion temperature and combustion time, the crystallization of silica in rice husk ash can be suppressed (see Japanese Patent Application Publication No. 2009-2594, Akita Prefectural University Online Journal B, 2019, vol.6, pp.216-222, etc.).

[0044] Amorphous silica extracted from rice husks can be obtained from commercially available materials such as those from Wilmar.

[0045] Furthermore, these silicas can be used alone or in combination of two or more. Moreover, from an environmental protection (sustainability) perspective, the use of sustainable silicas such as biomass silica and recycled silica is preferred.

[0046] (2) AE quantity In this invention, the amount of AE in the tread rubber composition is, as described above, set to be greater than 15% by mass, but more preferably greater than 16% by mass, even more preferably greater than 17% by mass, and even more preferably greater than 18% by mass. Thus, it can be considered that by further increasing the amount of AE, the tread rubber becomes even softer, and a sufficient flexing effect throughout the tire can be obtained, thereby further improving fuel efficiency. As an upper limit, for example, it is preferably less than 22% by mass, more preferably less than 21% by mass, even more preferably less than 20% by mass, and even more preferably less than 19% by mass.

[0047] (3) Rubber containing isoprene In this invention, the rubber composition for tire tread preferably contains more than 25 parts by mass of isoprene-based rubber in 100 parts by mass of the rubber component.

[0048] It can be considered that by including more than 25 parts by mass of isoprene-based rubber in 100 parts by mass of the rubber component, a low-heat-generating tread can be formed that can reduce heat generation during driving, thereby further improving fuel efficiency. More preferably, it is 30 parts by mass or more, and even more preferably 40 parts by mass or more. As an upper limit, for example, it is preferably 70 parts by mass or less, and more preferably 60 parts by mass or less.

[0049] Specific isoprene-based rubbers include natural rubber (NR), modified natural rubber (modified NR), modified natural rubber (modified NR), and synthetic polyisoprene (isoprene rubber (IR), modified isoprene rubber (modified IR)), among which NR with excellent strength is preferred. Furthermore, as NR, for example, rubbers commonly used in the tire industry such as SVR-L, SIR20, RSS#3, and TSR20 can be used.

[0050] (4) 30℃ tanδ As described above, by keeping the tanδ at 30°C relatively small, further improvements in fuel efficiency can be achieved. Specifically, the tanδ at 30°C is preferably less than 0.20, more preferably less than 0.19. As a lower limit, for example, it is preferably greater than 0.15, more preferably greater than 0.16.

[0051] (5) Tread thickness In this invention, the tread thickness is preferably greater than 6 mm, which is believed to reduce the compressive stress on the belt layer and improve high-speed durability. More preferably, it is 8 mm or more, and even more preferably 10 mm or more. As an upper limit, for example, it is preferably 20 mm or less, more preferably 15 mm or less, and even more preferably 12 mm or less.

[0052] Furthermore, "tread thickness" refers to the thickness of the tread on the equatorial plane of the tire in the radial section of the tire. When the tread is formed by a single rubber composition, it refers to the thickness of that rubber composition. When it is formed by a layered structure of multiple rubber compositions, it refers to the thickness of the outermost running surface rubber layer on the contact surface side of these layers. It can be measured by cutting the tire radially in a section such that the bead portion is consistent with the width of the regular rim.

[0053] "Standard rim" refers to the rim specified for each tire within a standard system that includes the standards upon which the tire is based. For example, it refers to the standard rim with applicable dimensions listed in the JATMA (Japan Automobile Tire Association) Yearbook, the "Measuring Rim" listed in the ETRTO (European Tyre and Rim Technical Organization) Standards Manual, and the "Design Rim" listed in the TRA (Tire and Rim Association, Inc.) Yearbook. These should be referenced in the order of JATMA, ETRTO, and TRA, and if applicable dimensions are available, their standards should be followed. Furthermore, for tires not specified in the aforementioned standards, it refers to the rim with the smallest width among the smallest diameter rims that can be assembled and maintain internal pressure (i.e., no air leakage between the rim and tire).

[0054] (6) Tread layering In this invention, the tread may consist of only one layer serving as the contact patch (driving surface rubber layer), or it may consist of two layers with a base rubber layer disposed inside the driving surface rubber layer. Furthermore, it may consist of three or four or more layers. In this case, preferably, the tread rubber composition described above is used as the rubber composition forming the outermost driving surface rubber layer on the contact patch side, and satisfies the parameters described above.

[0055] In this case, the thickness of the driving surface rubber layer in the entire tread is preferably 10% or more, more preferably 30% or more, even more preferably 50% or more, and even more preferably 70% or more.

[0056] 3. Belt layer In this invention, the belt layer cord constituting the belt layer is preferably composed of four or fewer monofilaments. It can be considered that by reducing the number of monofilaments in this way, even metal monofilaments can reduce weight, achieving further weight reduction of the tire, and thus further improving fuel efficiency.

[0057] Furthermore, the material of the monofilaments constituting the bundled layer cord is not particularly limited, but is preferably made of metal, more preferably of iron, and particularly preferably of steel. Moreover, the structure of the bundled layer cord is preferably any one of the following: a 1×1 untwisted structure, a 1×2 single-twisted structure, a 1×3 structure, a 1×4 structure, or a 2+2 layered twist structure. Additionally, the monofilaments are preferably circular in cross-sectional shape, but can also be elliptical; furthermore, they can be corrugated or plated.

[0058] Furthermore, the diameter D2 of the belt layer cord is preferably 0.65 mm or less, more preferably 0.55 mm or less. As a lower limit, it is preferably 0.45 mm or more, more preferably 0.50 mm or more.

[0059] Furthermore, the number of cord strands (warp density: strands / 5cm) per 50mm width of the belt layer is preferably 20 strands / 5cm or more, more preferably 25 strands / 5cm or more, and even more preferably 30 strands / 5cm or more. Additionally, as an upper limit, for example, it is preferably 60 strands / 5cm or less, more preferably 55 strands / 5cm or less, and even more preferably 50 strands / 5cm or less.

[0060] The warp density of the belt layer cord mentioned above can be determined according to the method specified in JIS L1017:2002 "Test Method for Chemical Fiber Tire Cords".

[0061] 4. Fetal body In this invention, the tire carcass, as described above, comprises a two-layer structure of a first tire carcass ply and a second tire carcass ply, with the ratio ((P1-P2) / Dt) set to be less than 0.07, but more preferably less than 0.067, further preferably less than 0.065, and even more preferably less than 0.063. As a lower limit, for example, it is preferably greater than 0.056, more preferably greater than 0.058, and even more preferably greater than 0.060. It can be considered that this further improves the rigidity of the tire sidewall portion, more effectively prevents strain concentration in the tire sidewall portion, and further suppresses heat generation in the tire sidewall portion and improves fuel efficiency because the tire can flex more fully throughout its entire structure.

[0062] Furthermore, the carcass cord can be composed of fibers. Commonly known fibers can be used as the fibers constituting the carcass cord, such as polyester fibers like PET (polyethylene terephthalate) and PEN (polyethylene naphthalate), polyamide fibers like nylon 6 and nylon 66, and aramid fibers. Single-twist cords (where one thread is twisted together) and double-twist cords (where two threads are twisted together) are preferred. Additionally, the fibers constituting the carcass cord can be fibers recycled from secondhand or waste materials (recycled materials) or fibers synthesized from biomass (biomass materials).

[0063] Furthermore, the diameter D3 of the tire carcass cord is preferably 0.70 mm or less, more preferably 0.65 mm or less. As a lower limit, it is preferably 0.55 mm or more, more preferably 0.60 mm or more.

[0064] In addition, the structure of the tire cord can be either a single twist structure with one cord twisted together or a double twist structure with two cord twisted together.

[0065] Furthermore, the number of cords per 50mm width of the carcass cord (warp density: cords / 5cm) is preferably 40 cords / 5cm or more, more preferably 45 cords / 5cm or more. As an upper limit, for example, it is preferably 60 cords / 5cm or less, more preferably 55 cords / 5cm or less.

[0066] The warp density of the tire cords mentioned above can be determined according to the method specified in JIS L1017:2002 "Test Method for Chemical Fiber Tire Cords".

[0067] 5. D1+D2+D3 In this invention, (D1+D2+D3) is set to be less than 2.00 as described above, but more preferably less than 1.80, and even more preferably less than 1.70. It can be considered that this enables further weight reduction of the tire, and thus further improves fuel efficiency. As a lower limit, for example, it is preferably greater than 1.55, more preferably greater than 1.60, and even more preferably greater than 1.65.

[0068] [3] Implementation The present invention will be specifically described below based on the embodiments.

[0069] 1. The tire involved in this embodiment Figure 2 This is a cross-sectional schematic diagram illustrating the tire involved in this embodiment. Figure 2 In the diagram, the vertical direction represents the tire's radial direction, the horizontal direction represents the tire's axis of rotation, and the direction perpendicular to the paper is the tire's circumferential direction. Furthermore, Figure 2 In the diagram, the dashed line CL represents the equatorial plane of the tire. Furthermore, aside from the tread pattern, the tire's shape is symmetrical with respect to the equatorial plane.Figure 2 The middle represents 1 / 4 of the entire tire.

[0070] like Figure 2 As shown, the tire 1 has a tread 2, a pair of sidewalls 3, a pair of bead wraps 4, a pair of bead 5, an inner liner 6, a carcass 7, a belt layer 8, a pair of fillers 9, and a belt layer 10, and the carcass 7, belt layer 10, and tread 2 are arranged from the inner side to the outer side of the tire radially.

[0071] It can be considered that by adopting such a structure, using PET strap layers as strap layer cords to form the tire carcass, and using a properly blended tread rubber composition to form the tread, and further, by properly controlling the above-mentioned parameters, as described above, it is possible to further improve fuel efficiency.

[0072] 2. Rubber composition for tire tread In this embodiment, the tread rubber composition can be obtained by mixing various formulation materials such as rubber components, reinforcing materials, antioxidants, oils, resin materials, and antioxidants.

[0073] (1) Formulation materials (a) Rubber composition The rubber component used in the tread rubber composition is not particularly limited. For example, diene-based rubbers such as natural rubber (NR), styrene-butadiene rubber (SBR), butadiene rubber (BR), isoprene rubber (IR), acrylonitrile-butadiene rubber (NBR), chloroprene rubber (CR), and butyl rubber (IIR) can be used. These can be used alone or in combination of two or more. In this invention, it is preferred to use NR, SBR, and BR in combination.

[0074] (①)SBR In this invention, the weight-average molecular weight of the SBR is preferably greater than 100,000 and less than 2,000,000. Furthermore, the vinyl content (1,2-bonded butadiene unit content) of the SBR is preferably greater than 5% by mass, more preferably greater than 10% by mass, and even more preferably greater than 15% by mass. On the other hand, it is preferably less than 70% by mass, more preferably less than 40% by mass, and even more preferably less than 30% by mass. In addition, the structural identification of the SBR (determination of styrene content and vinyl content) can be performed, for example, using a JNM-ECA series device manufactured by Nippon Electronics Corporation.

[0075] There are no particular limitations on the type of SBR used; for example, emulsion-polymerized styrene-butadiene rubber (E-SBR) and solution-polymerized styrene-butadiene rubber (S-SBR) can be used. The SBR can be either unmodified or modified. Furthermore, hydrogenated SBR, obtained by hydrogenating the butadiene portion of the SBR, can be used. Hydrogenated SBR can be obtained by subsequently hydrogenating the BR portion of the SBR, or by copolymerizing styrene, ethylene, and butadiene to obtain the same structure.

[0076] As a modified SBR, an SBR having functional groups that interact with fillers such as silica is preferred. Examples include end-modified SBRs (end-modified SBRs with the aforementioned functional groups at the ends) which are modified by a compound (modifier) ​​having the aforementioned functional groups, main-chain modified SBRs with the aforementioned functional groups on the main chain, main-chain end-modified SBRs with the aforementioned functional groups on the main chain and at the ends (e.g., main-chain end-modified SBRs with the aforementioned functional groups on the main chain and modified by the aforementioned modifier at the ends), and end-modified SBRs that introduce hydroxyl or epoxy groups by modification (coupling) with a polyfunctional compound having two or more epoxy groups in the molecule.

[0077] Examples of the aforementioned functional groups include, for example, amino, amide, silyl, alkoxysilyl, isocyanate, imino, imidazo, urea, ether, carbonyl, oxycarbonyl, mercapto, thioether, dithioether, sulfonyl, sulfinyl, thiocarbonyl, ammonium, imino, hydrazine, azo, diazo, carboxyl, nitrile, pyridyl, alkoxy, hydroxyl, oxygen, and epoxy groups. Furthermore, these functional groups may also have substituents.

[0078] Furthermore, as a modified SBR, for example, an SBR modified by a compound (modifier) ​​represented by the following formula can be used.

[0079]

Chemical Formula 1

[0080] In addition, R in the formula 1 R 2 and R 3 Same or different, indicating alkyl, alkoxy, siloxy, acetal, carboxyl (-COOH), mercapto (-SH) or their derivatives. R 4 and R 5 Same or different, indicating hydrogen atoms or alkyl groups. R 4 and R 5 It can also bond and form a ring structure with nitrogen atoms. n represents an integer.

[0081] As a modified SBR modified by a compound (modifier) ​​represented by the above formula, an SBR can be obtained by modifying the polymerization end (active end) of solution-polymerized styrene-butadiene rubber (S-SBR) with a compound represented by the above formula (such as the modified SBR described in Japanese Patent Application Publication No. 2010-111753).

[0082] As R 1 R 2 and R 3 Preferably, it is an alkoxy group (preferably with 1 to 8 carbon atoms, more preferably an alkoxy group with 1 to 4 carbon atoms). As R 4 and R 5 Preferably, it is an alkyl group (preferably an alkyl group having 1 to 3 carbon atoms). n is preferably 1 to 5, more preferably 2 to 4, and even more preferably 3. Furthermore, R 4 and R 5 When the bond combines with a nitrogen atom to form a ring structure, a 4- to 8-membered ring is preferred. Furthermore, alkoxy groups also include cycloalkoxy groups (such as cyclohexyloxy) and aryloxy groups (such as phenoxy and benzyloxy).

[0083] Specific examples of the aforementioned modifiers include 2-dimethylaminoethyltrimethoxysilane, 3-dimethylaminopropyltrimethoxysilane, 2-dimethylaminoethyltriethoxysilane, 3-dimethylaminopropyltriethoxysilane, 2-diethylaminoethyltrimethoxysilane, 3-diethylaminopropyltrimethoxysilane, 2-diethylaminoethyltriethoxysilane, and 3-diethylaminopropyltriethoxysilane. These can be used individually or in combination of two or more.

[0084] In addition, modified SBRs modified with the following compounds (modifiers) can also be used as modified SBRs. Examples of modifiers include, for instance, polyglycidyl ethers of polyols such as ethylene glycol diglycidyl ether, glycerol triglycidyl ether, trimethylolethane triglycidyl ether, and trimethylolpropane triglycidyl ether; polyglycidyl ethers of aromatic compounds having two or more phenolic groups such as bisphenol A diglycidyl ether; polyepoxide compounds such as 1,4-diglycidylbenzene, 1,3,5-triglycidylbenzene, and polyepoxy liquid polybutadiene; tertiary amines containing epoxy groups such as 4,4'-diglycidyl diphenylmethylamine and 4,4'-diglycidyl dibenzylmethylamine; diglycidyl aniline, N,N'-diglycidyl... Glyceryl-4-glycidoxyaniline, diglycidoxyo-toluidine, tetraglycidoxym-xylenediamine, tetraglycidoxyaminodiphenylmethane, tetraglycidoxyp-phenylenediamine, diglycidoxyaminomethylcyclohexane, tetraglycidoxy-1,3-diaminomethylcyclohexane, and other diglycidoxyamino compounds; bis-(1-methylpropyl)carbamoyl chloride, 4-morpholinocarbamoyl chloride, 1-pyrrolidinecarbamoyl chloride, N,N-dimethylcarbamoyl chloride, N,N-diethylcarbamoyl chloride, and other amino-containing acyl chlorides; 1,3-bis(glycidoxypropyl)tetramethyldisiloxane, (3-glycidoxypropyl)tetramethyldisiloxane, (3-glycidoxypropyl)tetramethyldisiloxane, etc. Silane compounds containing epoxy groups, such as propyl pentamethyldisiloxane; (trimethylsilyl)[3-(trimethoxysilyl)propyl] sulfide, (trimethylsilyl)[3-(triethoxysilyl)propyl] sulfide, (trimethylsilyl)[3-(tripropoxysilyl)propyl] sulfide, (trimethylsilyl)[3-(tributoxysilyl)propyl] sulfide, (trimethylsilyl)[3-(methyldimethoxysilyl)propyl] sulfide, (trimethylsilyl)[3-(methyldiethoxysilyl)propyl] sulfide, (trimethylsilyl) Silane compounds containing thioether groups, such as alkyl(3-(methyldipropoxysilyl)propyl)sulfide and (trimethylsilyl)[3-(methyldibutoxysilyl)propyl]sulfide; N-substituted aziridine compounds such as ethyleneimine and acrylimine; alkoxysilanes such as methyltriethoxysilane, N,N-bis(trimethylsilyl)-3-aminopropyltrimethoxysilane, N,N-bis(trimethylsilyl)-3-aminopropyltriethoxysilane, N,N-bis(trimethylsilyl)aminoethyltrimethoxysilane, and N,N-bis(trimethylsilyl)aminoethyltriethoxysilane.4-N,N-dimethylaminobenzophenone, 4-N,N-di-tert-butylaminobenzophenone, 4-N,N-diphenylaminobenzophenone, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, 4,4'-bis(diphenylamino)benzophenone, N,N,N',N'-bis-(tetraethylamino)benzophenone, and other (thio)benzophenone compounds having amino and / or substituted amino groups; 4-N,N-dimethylaminobenzophenone Formaldehyde, 4-N,N-diphenylaminobenzaldehyde, 4-N,N-divinylaminobenzaldehyde, and other benzaldehyde compounds containing amino groups and / or substituted amino groups; N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, N-phenyl-2-pyrrolidone, N-tert-butyl-2-pyrrolidone, N-methyl-5-methyl-2-pyrrolidone, and other N-substituted pyrrolidones; N-methyl-2-piperidinone, N-vinyl-2-piperidinone, N-phenyl-2-piperidinone, etc. N-substituted piperidinones; N-methyl-ε-caprolactam, N-phenyl-ε-caprolactam, N-methyl-ω-lauramide, N-vinyl-ω-lauramide, N-methyl-β-propiolactam, N-phenyl-β-propiolactam, and other N-substituted lactams; in addition, N,N-bis-(2,3-epoxypropyl)-aniline, 4,4-methylene-bis(N,N-glycidylaniline), tris(2,3-epoxypropyl)-1,3,5-triazine- 2,4,6-Triones, N,N-diethylacetamide, N-methylmaleimide, N,N-diethylurea, 1,3-dimethylvinylurea, 1,3-divinylvinylurea, 1,3-diethyl-2-imidazolinone, 1-methyl-3-ethyl-2-imidazolinone, 4-N,N-dimethylaminoacetophenone, 4-N,N-diethylaminoacetophenone, 1,3-bis(diphenylamino)-2-propanone, 1,7-bis(methylethylamino)-4-heptanone, etc. Furthermore, modification based on the above compounds (modifiers) can be carried out by known methods.

[0085] As an SBR (Self-Borne Blender), for example, SBRs manufactured and sold by companies such as Sumitomo Chemical Co., Ltd., ENEOS Materials Co., Ltd., Asahi Kasei Corporation, and Zeon Corporation of Japan can be used. Furthermore, SBRs can be used alone or in combination of two or more types.

[0086] The SBR content in 100 parts by weight of the rubber component is preferably 55 parts by weight or more, more preferably 60 parts by weight or more. As an upper limit, for example, it is preferably 85 parts by weight or less, more preferably 80 parts by weight or less.

[0087] (②) Isoprene rubber Examples of isoprene-based rubbers include natural rubber (NR), isoprene rubber (IR), modified NR, modified NR, and modified IR. As mentioned above, NR is preferred for its superior strength.

[0088] As described above, for example, conventional NRs used in the tire industry, such as SVR-L, SIR20, RSS#3, and TSR20, can be used as NRs. There are no particular limitations on IRs; for example, conventional IRs used in the tire industry, such as IR2200 manufactured by Zeon Corporation of Japan, can be used. Examples of modified NRs include deproteinized natural rubber (DPNR) and high-purity natural rubber (UPNR). Examples of modified NRs include epoxidized natural rubber (ENR), hydrogenated natural rubber (HNR), and grafted natural rubber. Examples of modified IRs include epoxidized isoprene rubber, hydrogenated isoprene rubber, and grafted isoprene rubber. These can be used individually or in combination of two or more.

[0089] The preferred content of isoprene-based rubber in 100 parts by weight of the rubber component is as described above.

[0090] (③)BR The weight-average molecular weight of BR is, for example, greater than 100,000 and less than 2,000,000. The vinyl content of BR is, for example, greater than 1% by mass and less than 30% by mass. The cis content of BR is, for example, greater than 1% by mass and less than 98% by mass. The trans content of BR is, for example, greater than 1% by mass and less than 60% by mass. Furthermore, the cis content can be determined by infrared absorption spectroscopy.

[0091] There are no particular limitations on the type of BR used; BR with high cis content (cis content of 90% or more), BR with low cis content, and BR containing syndiotactic polybutadiene crystals can be used. BR can be either unmodified BR or modified BR. As a modified BR, for example, BR modified with a compound (modifier) ​​represented by the following formula can be used.

[0092] [Chemical Formula 2]

[0093] In addition, R in the formula 1 R 2 and R 3 Same or different, indicating alkyl, alkoxy, silyloxy, acetal, carboxyl (-COOH), mercapto (-SH) or their derivatives. R 4 and R 5 Same or different, indicating hydrogen atoms or alkyl groups. R 4 and R 5 It can also bond and form a ring structure with nitrogen atoms. n represents an integer.

[0094] Examples of modified BRs that are modified by compounds (modifiers) represented by the above formula include BRs whose polymerization ends (active ends) are modified by compounds represented by the above formula.

[0095] As R 1 R 2 and R 3 Preferably, it is an alkoxy group (preferably with 1 to 8 carbon atoms, more preferably an alkoxy group with 1 to 4 carbon atoms). As R 4 and R 5 Preferably, it is an alkyl group (preferably an alkyl group having 1 to 3 carbon atoms). n is preferably 1 to 5, more preferably 2 to 4, and even more preferably 3. Furthermore, R 4 and R 5 When the bond combines with a nitrogen atom to form a ring structure, a 4- to 8-membered ring is preferred. Furthermore, alkoxy groups also include cycloalkoxy groups (such as cyclohexyloxy) and aryloxy groups (such as phenoxy and benzyloxy).

[0096] Specific examples of the aforementioned modifiers include 2-dimethylaminoethyltrimethoxysilane, 3-dimethylaminopropyltrimethoxysilane, 2-dimethylaminoethyltriethoxysilane, 3-dimethylaminopropyltriethoxysilane, 2-diethylaminoethyltrimethoxysilane, 3-diethylaminopropyltrimethoxysilane, 2-diethylaminoethyltriethoxysilane, and 3-diethylaminopropyltriethoxysilane. These can be used individually or in combination of two or more.

[0097] In addition, modified BRs can also be used as modified BRs by the following compounds (modifiers). Examples of modifiers include, for instance, polyglycidyl ethers of polyols such as ethylene glycol diglycidyl ether, glycerol triglycidyl ether, trimethylolethane triglycidyl ether, and trimethylolpropane triglycidyl ether; polyglycidyl ethers of aromatic compounds having two or more phenolic groups such as bisphenol A diglycidyl ether; polyepoxide compounds such as 1,4-diglycidylbenzene, 1,3,5-triglycidylbenzene, and polyepoxide liquid polybutadiene; tertiary amines containing epoxy groups such as 4,4'-diglycidyl-diphenylmethylamine and 4,4'-diglycidyl-dibenzylmethylamine; diglycidyl aniline, N,N'-di... Glycidyl-4-glycidyloxyaniline, diglycidyl-o-toluidine, tetraglycidyl-m-xylenediamine, tetraglycidylaminodiphenylmethane, tetraglycidyl-p-phenylenediamine, diglycidylaminomethylcyclohexane, tetraglycidyl-1,3-diaminomethylcyclohexane, and other diglycidylamino compounds; bis-(1-methylpropyl)carbamoyl chloride, 4-morpholinocarbamoyl chloride, 1-pyrrolidinecarbamoyl chloride, N,N-dimethylcarbamoyl chloride, N,N-diethylcarbamoyl chloride, and other amino-containing acyl chlorides; 1,3-bis-(glycidyloxypropyl)tetramethyldisiloxane, (3-glycidyl... Silane compounds containing epoxy groups, such as oxopropyl)pentamethyldisiloxane; (trimethylsilyl)[3-(trimethoxysilyl)propyl] sulfide, (trimethylsilyl)[3-(triethoxysilyl)propyl] sulfide, (trimethylsilyl)[3-(tripropoxysilyl)propyl] sulfide, (trimethylsilyl)[3-(tributoxysilyl)propyl] sulfide, (trimethylsilyl)[3-(methyldimethoxysilyl)propyl] sulfide, (trimethylsilyl)[3-(methyldieth ... Silane compounds containing thioether groups, such as silyl(3-(methyldipropoxysilyl)propyl)sulfide and (trimethylsilyl)[3-(methyldibutoxysilyl)propyl]sulfide; N-substituted aziridine compounds such as ethyleneimine and acrylimine; alkoxysilanes such as methyltriethoxysilane, N,N-bis(trimethylsilyl)-3-aminopropyltrimethoxysilane, N,N-bis(trimethylsilyl)-3-aminopropyltriethoxysilane, N,N-bis(trimethylsilyl)aminoethyltrimethoxysilane, and N,N-bis(trimethylsilyl)aminoethyltriethoxysilane.4-N,N-dimethylaminobenzophenone, 4-N,N-di-tert-butylaminobenzophenone, 4-N,N-diphenylaminobenzophenone, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, 4,4'-bis(diphenylamino)benzophenone, N,N,N',N'-bis-(tetraethylamino)benzophenone, and other (thio)benzophenone compounds having amino and / or substituted amino groups; 4-N,N-dimethylaminobenzophenone Formaldehyde, 4-N,N-diphenylaminobenzaldehyde, 4-N,N-divinylaminobenzaldehyde, and other benzaldehyde compounds containing amino groups and / or substituted amino groups; N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, N-phenyl-2-pyrrolidone, N-tert-butyl-2-pyrrolidone, N-methyl-5-methyl-2-pyrrolidone, and other N-substituted pyrrolidones; N-methyl-2-piperidinone, N-vinyl-2-piperidinone, N-phenyl-2-piperidinone, etc. N-substituted piperidinones; N-methyl-ε-caprolactam, N-phenyl-ε-caprolactam, N-methyl-ω-lauramide, N-vinyl-ω-lauramide, N-methyl-β-propiolactam, N-phenyl-β-propiolactam, and other N-substituted lactams; in addition, N,N-bis-(2,3-epoxypropyl)-aniline, 4,4-methylene-bis-(N,N-glycidylaniline), and tris(2,3-epoxypropyl)-1,3,5-triazine can also be listed. -2,4,6-triones, N,N-diethylacetamide, N-methylmaleimide, N,N-diethylurea, 1,3-dimethylvinylurea, 1,3-divinylvinylurea, 1,3-diethyl-2-imidazolinone, 1-methyl-3-ethyl-2-imidazolinone, 4-N,N-dimethylaminoacetophenone, 4-N,N-diethylaminoacetophenone, 1,3-bis(diphenylamino)-2-propanone, 1,7-bis(methylethylamino)-4-heptanone, etc. Furthermore, modification based on the above compounds (modifiers) can be carried out by known methods. Moreover, these modified BRs can be used alone or in combination of two or more.

[0098] As a BR (Brandinger), products from companies such as Ube Industries, Inc., ENEOS Materials Co., Ltd., Asahi Kasei Corporation, and Zeon Corporation can be used.

[0099] The BR content in 100 parts by weight of the rubber component is preferably 8 parts by weight or more, more preferably 10 parts by weight or more. On the other hand, it is preferably 15 parts by weight or less, more preferably 12 parts by weight or less.

[0100] (④) Other rubber components The tread rubber composition may also contain, as other rubber components, rubbers (polymers) commonly used in tire manufacturing, such as nitrile rubber (NBR), as required.

[0101] In addition, the raw materials (monomers) of the aforementioned SBR, BR and other synthetic rubbers can be substances derived from underground resources such as petroleum and natural gas, or substances recycled from rubber products such as tires or non-rubber products such as polystyrene.

[0102] The monomer obtained through recycling (recycled monomer) is not particularly limited, and examples include recycled isoprene, recycled butadiene, and recycled aromatic vinyl compounds. Examples of butadiene include 1,2-butadiene and 1,3-butadiene. Examples of aromatic vinyl compounds are not particularly limited, and examples include styrene. Preferably, recycled isoprene, butadiene, and / or recycled styrene are used as raw materials.

[0103] There are no particular limitations on the manufacturing method of the recycled monomer. For example, it can be synthesized from recycled naphtha obtained by pyrolyzing rubber products such as tires. Furthermore, there are no particular limitations on the manufacturing method of the recycled naphtha. For example, rubber products such as tires can be pyrolyzed under high temperature and pressure, microwave pyrolysis can be used, or extraction can be performed after mechanical crushing.

[0104] Furthermore, the raw materials (monomers) for synthetic rubbers such as IR, SBR, and BR can also be substances derived from biomass. Here, biomass refers to substances derived from natural resources such as plants. There are no particular limitations on biomass; examples include: substances derived from agricultural, forestry, and aquatic products, sugar, sawdust, plant residues after extracting useful components, plant ethanol, and biomass naphtha. There are no particular limitations on the monomers derived from biomass (biomass monomers); examples include butadiene derived from biomass and aromatic vinyl compounds derived from biomass. Examples of butadiene include 1,2-butadiene and 1,3-butadiene. There are no particular limitations on the aromatic vinyl compounds; examples include styrene. In addition, there are no particular limitations on the manufacturing methods of biomass monomers; for example, substances derived from the biological and / or chemical and / or physical transformations of plants and animals can be listed. As for biological transformations, microbial fermentation is representative; as for chemical and / or physical transformations, examples include catalyst-based transformations, high-temperature transformations, high-pressure transformations, electromagnetic wave-based transformations, supercritical fluid-based transformations, and combinations thereof.

[0105] The term "biomass polymer" is not particularly limited to polymers synthesized from biomass monomer components. Examples include polybutadiene rubber synthesized from butadiene derived from biomass, and aromatic vinyl compound / butadiene copolymers synthesized from butadiene derived from biomass and / or aromatic vinyl compounds derived from biomass. Examples of such aromatic vinyl compound / butadiene copolymers include, for instance, styrene-butadiene rubber synthesized from butadiene derived from biomass and / or styrene derived from biomass.

[0106] Whether the polymer's raw materials are derived from biomass can be determined by the pMC (percent Modern Carbon) measured according to ASTM D6866-10.

[0107] pMC refers to: the sample 14 C concentration relative to standard modern carbon (modern standard reference) 14 The C concentration ratio is a value used as an indicator of the biomass proportion of the compound (rubber). The significance of this value is described below.

[0108] One mole of carbon atoms (6.02 × 10⁻⁶) 23 Of these, approximately one trillionth, or about 6.02 × 10⁻⁶, is present. 11 indivual 14 C. 14 Carbon (C) is known as a radioactive isotope with a half-life of 5,730 years, decreasing regularly. It takes 226,000 years for it to completely decay. Therefore, it is believed that carbon dioxide and other atmospheric pollutants, after being absorbed and fixed by plants and other organisms over 226,000 years, are contained in fossil fuels such as coal, oil, and natural gas during their initial fixation. 14 All carbon (C) decays. Therefore, in the 21st century, fossil fuels such as coal, oil, and natural gas contain absolutely no carbon. 14 Therefore, the chemicals produced using these fossil fuels as raw materials also contain absolutely no carbon (C). 14 C element.

[0109] on the other hand, 14 C is continuously generated through nuclear reactions of cosmic rays in the atmosphere, reaching equilibrium with reductions based on radioactive decay in Earth's atmospheric environment. 14 The amount of C is constant. Therefore, in the current environment, the matter originating from biomass resources in the material cycle... 14 As mentioned above, the C concentration is approximately 1 × 10⁻⁶ relative to all carbon atoms. -12The values ​​are approximately in the mole percent range. Therefore, by using the differences between these values, the proportion of compounds derived from natural resources (compounds derived from biomass resources) in a certain compound (rubber) can be calculated (biomass proportion).

[0110] Typically, the 14 C was determined as described below. Accelerator mass spectrometry based on a tandem accelerator was used for the determination. 13 C concentration ( 13 C / 12 C) 14 C concentration ( 14 C / 12 C) Determination. During the determination, as... 14 The concentration of carbon is based on the modern standard reference, which uses the carbon cycling in nature in 1950. 14 C concentration. As a specific standard substance, the oxalic acid standard provided by NIST (National Institute of Standards and Technology) was used. The radioactivity of carbon in this oxalic acid (carbon content per gram of carbon) was determined. 14 The radioactivity intensity of carbon (C) is classified according to its carbon isotopes. 13 The C-correction is a fixed value, using the value with attenuation correction applied from 1950 to the date of measurement as the standard. 14 The C concentration value (100%) is used. The ratio of the actual measured value of the sample to this value is the pMC value.

[0111] Therefore, if the rubber is made from 100% biomass (natural) materials, then despite regional differences, it is expected to have a value of around 110 pMC, as it is generally not 100 pMC under normal conditions. On the other hand, for chemicals derived from fossil fuels such as petroleum, the measured value... 14 At C concentrations, the value is around 0 pMC (e.g., 0.3 pMC). This value corresponds to 0% of the biomass ratio mentioned above.

[0112] In summary, using rubber and other materials with high pMC values, i.e., rubber and other materials with a high proportion of biomass, in rubber compositions is preferred from an environmental protection (sustainability) perspective.

[0113] (b) Formulation materials other than rubber components (①) Filler The tread rubber composition, as described above, contains silica as a reinforcing agent, but may also contain other fillers as needed, such as carbon black, calcium carbonate, talc, alumina, clay, aluminum hydroxide, mica, etc. Furthermore, when using silica, it is preferable to use it in conjunction with a silane coupling agent.

[0114] Regarding the mixing amount of filler, firstly, as described above, silica is set to be greater than 75 parts by mass relative to 100 parts by mass of the rubber component, but the total mixing amount of silica and other fillers is preferably 85 parts by mass or more, more preferably 100 parts by mass or more, relative to 100 parts by mass of the rubber component. On the other hand, from the viewpoint of dispersibility in the rubber composition, it is preferably 130 parts by mass or less, more preferably 115 parts by mass or less.

[0115] (i) Silicon dioxide The content of silica in the tread rubber composition relative to 100 parts by weight of the rubber component is as described above.

[0116] From the viewpoint of achieving good durability, the BET specific surface area of ​​silica is preferably greater than 100 m². 2 / g, more preferably greater than 130m 2 / g. On the other hand, it is preferable to have less than 250m. 2 / g, more preferably less than 200m 2 / g. Furthermore, the BET specific surface area mentioned above is the N2SA value determined by the BET method according to ASTM D3037-93.

[0117] There are no particular limitations on the silica used. For example, silica commonly used in the tire industry, such as silica prepared by dry process (anhydrous silica) or silica prepared by wet process (hydrated silica), can be used. As commercially available products, products from Evonik Industries, Rhodia, Tosoh Silicon Chemicals, Solvay Japan, Tokuyama Corporation, etc., can be used.

[0118] (ii) Silane coupling agents When using silica, in order to improve the dispersibility of silica and enhance mechanical properties and formability through its reaction with silica, it is preferable to use a silane coupling agent simultaneously.

[0119] As a silane coupling agent, there are no particular limitations; examples include bis(3-triethoxysilylpropyl)tetrasulfide, bis(2-triethoxysilylethyl)tetrasulfide, bis(4-triethoxysilylbutyl)tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, bis(2-trimethoxysilylethyl)tetrasulfide, bis(2-triethoxysilylethyl)trisulfide, and bis(4-trimethoxysilane)tetrasulfide. 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-dimethylthiomethyl Sulfide systems such as amide tetrasulfide, 2-triethoxysilyl ethyl-N,N-dimethylthioformamide tetrasulfide, and 3-triethoxysilyl propyl methacrylate monosulfide; thiol-based systems such as 3-mercaptopropyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, and Momentive's NXT and NXT-Z; vinyl-based systems such as vinyltriethoxysilane and vinyltrimethoxysilane; 3-aminopropyltriethoxysilane... Amino-based silanes such as 3-aminopropyltrimethoxysilane; glycidyl etheroxy-based silanes such as γ-glycidyl etheroxypropyltriethoxysilane; nitro-based silanes such as 3-nitropropyltrimethoxysilane; and chlorinated silanes such as 3-chloropropyltrimethoxysilane and 3-chloropropyltriethoxysilane, etc., are preferred among these, especially silane coupling agents with a thiocarbonyl group such as NXT mentioned above. These can be used alone or in combination of two or more.

[0120] As silane coupling agents, products from companies such as Evonik Industries, Momentive, Shin-Etsu Silicones, Tokyo Chemical Industries, Azmax, and Toray Dow Corning can be used.

[0121] The content of the silane coupling agent relative to 100 parts by weight of silicon dioxide is preferably greater than 3 parts by weight, more preferably 5 parts by weight or more, and even more preferably 7 parts by weight or more. As an upper limit, it is preferably less than 15 parts by weight, more preferably 12 parts by weight or less, and even more preferably 9 parts by weight or less.

[0122] (iii) Carbon black In tire tread rubber compositions, carbon black is preferably included to improve the tire's resistance to crack growth, durability, and resistance to UV degradation.

[0123] From the viewpoint of reinforcing rubber, the nitrogen adsorption specific surface area (N2SA) of carbon black is preferably, for example, 30 m² / s. 2 / g or more, preferably 50m 2 / g or more, further preferably 60m 2 / g or more. On the other hand, from the viewpoint of pyrogenicity, 250m is preferred. 2 / g or less, more preferably 150m 2 / g or less, more preferably 120m 2 / g or less. Furthermore, the nitrogen adsorption specific surface area of ​​the carbon black was determined according to ASTM D4820-93.

[0124] From the viewpoint of rubber rigidity, the dibutyl phthalate (DBP) absorption of carbon black is preferably 50 ml / 100g or more, more preferably 100 ml / 100g or more. On the other hand, from the viewpoint of rubber's adaptability to deformation, it is preferably 250 ml / 100g or less, more preferably 150 ml / 100g or less. Furthermore, the DBP absorption of carbon black is determined according to ASTM D2414-93.

[0125] As for carbon black, there are no particular limitations. Examples include furnace black (reaction furnace carbon black) such as SAF, ISAF, HAF, MAF, FEF, SRF, GPF, APF, FF, CF, SCF, and ECF; acetylene black; thermal black such as FT and MT; and channel black such as EPC, MPC, and CC. Additionally, as product codes, examples include N134, N110, N220, N234, N219, N339, N330, N326, N351, N550, and N762. These can be used individually or in combination.

[0126] Besides mineral oil, carbon black can be made from biomass materials such as lignin and vegetable oil, or it can be obtained by thermal cracking oil (recycled carbon black) from waste tires and other rubber products containing carbon black. From an environmental protection point of view, using these sustainable carbon blacks is the preferred option.

[0127] In addition, carbon black can be manufactured by combustion-based methods such as the reactor method, or by hydrothermal carbonization (HTC) methods, or by thermal cracking of methane derived from thermal cracking carbon black methods.

[0128] As commercially available products, those from Asahi Carbon Co., Ltd., Cabot Japan Co., Ltd., Tokai Carbon Co., Ltd., Mitsubishi Chemical Co., Ltd., Lion Corporation, Nippon Steel Carbon Black Co., Ltd., Columbia Carbon Co., Ltd., etc., can be used. These can be used alone or in combination of two or more.

[0129] The content of carbon black relative to 100 parts by weight of the rubber component is preferably 3 parts by weight or more, more preferably 5 parts by weight or more. As an upper limit, for example, it is preferably 15 parts by weight or less, more preferably 10 parts by weight or less.

[0130] (iv) Other fillers In addition to silica and carbon black, the tread rubber composition may further contain fillers commonly used in the tire industry, such as graphite, calcium carbonate, talc, alumina, clay, aluminum hydroxide, mica, and magnesium sulfate. The content of these fillers relative to 100 parts by weight of the rubber component is, for example, greater than 0.1 parts by weight and less than 150 parts by weight.

[0131] (②) Softener components In rubber compositions, a softener component is preferably used as needed, taking into account the proper dispersion of powdered materials during compounding. Furthermore, the softener component here refers to a material that imparts plasticity to the rubber composition, encompassing both softeners that are liquid at 25°C and softeners that are solid at 25°C.

[0132] Examples of plasticizers include resin components, oils, liquid polymers, and ester-based plasticizers. These plasticizers can be derived from mineral resources such as petroleum and natural gas, biomass, or naphtha recycled from rubber and non-rubber products. Furthermore, low-molecular-weight hydrocarbon components obtained through the thermal cracking and extraction of used tires and products containing various components can also be used as plasticizers. Among these, plasticizers derived from biomass or recycled materials are preferred as sustainable plasticizers.

[0133] Furthermore, these plasticizers can be used alone or in combination of two or more. The content of the plasticizer component relative to 100 parts by weight of the rubber component is preferably 30 parts by weight or more, more preferably 35 parts by weight or more. As an upper limit, for example, it is preferably 45 parts by weight or less, more preferably 40 parts by weight or less. Furthermore, the content of the plasticizer component also includes the amount of oil contained in the rubber (oil-extended rubber), etc.

[0134] (i)Oil Examples of oils include mineral oils, vegetable oils, and animal oils. Furthermore, from a life cycle assessment perspective, refined oil derived from waste oil used in rubber mixers or engines, or waste cooking oil used in restaurants, can also be used.

[0135] (i-1) mineral oil Mineral oil refers to oil derived from mineral resources such as petroleum and natural gas. Examples of mineral oils include paraffinic oils, naphthenic oils, and aromatic oils.

[0136] Specific examples of mineral oils include MES (Mild Extract Solvated), DAE (Distillate Aromatic Extract), TDAE (Treated Distillate Aromatic Extract), TRAE (Treated Residual Aromatic Extract), and RAE (Residual Aromatic Extract).

[0137] Furthermore, due to environmental countermeasures, oils with lower polycyclic aromatic compounds (PCA) content can also be used. Examples of oils with low PCA content include MES, TDAE, and heavy naphthenic oils.

[0138] Commercially available mineral oils, such as paraffinic, aromatic, and naphthenic oils, can be produced by companies such as Idemitsu Kosan Co., Ltd., Sankyo Oil & Chemical Co., Ltd., ENEOS Co., Ltd., Olisoy Co., Ltd., H&R Co., Ltd., Toyokuni Oil Co., Ltd., Showa Shell Oil Co., Ltd., and Fuji Kosan Co., Ltd. These can be used alone or in combination with two or more.

[0139] (i-2) Vegetable oils Examples of vegetable oils include flaxseed oil, rapeseed oil, safflower oil, soybean oil, corn oil, cottonseed oil, rice bran oil, tall oil, sesame oil, perilla seed oil, castor oil, tung oil, pine oil, pine tar, sunflower seed oil, coconut oil, palm oil, palm kernel oil, olive oil, camellia oil, jojoba oil, macadamia nut oil, peanut oil, grapeseed oil, and wood wax.

[0140] Furthermore, examples of vegetable oils include refined oils (such as salad oil) obtained by refining the aforementioned oils, transesterified oils obtained by transesterification of the aforementioned oils, hydrogenated oils obtained by hydrogenation of the aforementioned oils, thermally polymerized oils obtained by thermal polymerization of the aforementioned oils, oxidatively polymerized oils obtained by oxidizing the aforementioned oils, and waste edible oils recovered from oils used as cooking oils, etc. In addition, vegetable oils can be liquid or solid at room temperature (25°C). One type of these can be used alone, or two or more can be used in combination.

[0141] As a vegetable oil, it is preferable to contain acylglycerol, and more preferably triacylglycerol. Furthermore, acylglycerol refers to a compound in which the hydroxyl group of glycerol forms an ester bond with a fatty acid. There is no particular limitation on the type of acylglycerol; it can be 1-monoacylglycerol, 2-monoacylglycerol, 1,2-diacylglycerol, 1,3-diacylglycerol, or triacylglycerol. Further, acylglycerol can be a monomer, a dimer, or a polymer of trimer or more. Moreover, acylglycerols of dimer or more can be obtained by thermal polymerization, oxidative polymerization, etc. Furthermore, acylglycerol can be liquid or solid at room temperature (25°C).

[0142] There is no particular limitation on the method for confirming whether a rubber composition contains acylglycerol; it can be achieved through... 1 Confirmed by ¹H-NMR determination. For example, a rubber composition containing triacylglycerol was impregnated in deuterated chloroform at room temperature (25°C) for 24 hours, and after removing the rubber composition, the concentration was determined at room temperature. 1 ¹H NMR, with the tetramethylsilane (TMS) signal set to 0.00 ppm, observed signals around 5.26 ppm, 4.28 ppm, and 4.15 ppm. These signals are presumably derived from hydrogen atoms bonded to the carbon atom adjacent to the oxygen atom of the ester group, thus confirming the presence of acylglycerol. Furthermore, "around" here refers to a range of ±0.10 ppm.

[0143] Furthermore, as a fatty acid, there are no particular limitations; it can be either an unsaturated or saturated fatty acid. Examples of unsaturated fatty acids include monounsaturated fatty acids such as oleic acid, or polyunsaturated fatty acids such as linoleic acid and linolenic acid. Examples of saturated fatty acids include butyric acid and lauric acid.

[0144] Of these, fatty acids with fewer double bonds are preferred, namely saturated fatty acids or monounsaturated fatty acids, with oleic acid being the most preferred. As a vegetable oil containing such fatty acids, for example, vegetable oils containing saturated or monounsaturated fatty acids can be used, or vegetable oils that have undergone transesterification or other modifications can be used. Furthermore, to produce such a vegetable oil containing fatty acids, plants can be improved through variety improvement, genetic engineering, gene editing, etc.

[0145] As a vegetable oil, for example, commercially available substances from companies such as Idemitsu Kosan Co., Ltd., Sankyo Oil & Chemical Co., Ltd., ENEOS Co., Ltd., Olisoy Co., Ltd., H&R Co., Ltd., Toyokuni Oil Co., Ltd., Fuji Kosan Co., Ltd., and Nissin Oliyo Group Co., Ltd. can be used.

[0146] (ii) Liquid rubber Liquid rubber refers to polymers that are liquid at room temperature (25°C) and are rubber components that can be extracted from vulcanized tires using acetone. Examples of liquid rubber include farnesene polymers, liquid diene polymers, and their hydrides.

[0147] Farnesene polymers refer to polymers obtained by polymerizing farnesenes, possessing structural units based on farnesenes. Farnesenes include isomers such as α-farnesene ((3E,7E)-3,7,11-trimethyl-1,3,6,10-dodecathetene) and β-farnesene (7,11-dimethyl-3-methylene-1,6,10-dodecathetene).

[0148] Farnesene polymers can be homopolymers of farnesene (farnesene homopolymers) or copolymers of farnesene and vinyl monomers (farnesene-vinyl monomer copolymers).

[0149] Examples of liquid diene polymers include liquid styrene-butadiene copolymer (liquid SBR), liquid butadiene polymer (liquid BR), liquid isoprene polymer (liquid IR), and liquid styrene-isoprene copolymer (liquid SIR).

[0150] In liquid diene polymers, the weight-average molecular weight (Mw) of polystyrene, as determined by gel permeation chromatography (GPC), is, for example, greater than 1.0 × 10⁻⁶. 3 Less than 2.0×10 5 Here, the Mw of the liquid diene polymer is the polystyrene equivalent determined by gel permeation chromatography (GPC).

[0151] As a liquid rubber, products from companies such as Kuraray Corporation and Clayville Corporation can be used.

[0152] (iii) Resin composition Resin components also function as tackifiers. They can be solid or liquid at room temperature. Specific resin components include, for example, rosin-based resins, styrene-based resins, coumarone-based resins, terpene-based resins, C5 resins, C9 resins, C5C9 resins, and acrylic resins, and two or more can be used in combination. Furthermore, these resin components can be endowed with modifying groups capable of reacting with silica and other similar materials, as needed.

[0153] Rosin-based resins are resins whose main component is rosin acid, obtained through the processing of rosin. These rosin-based resins (rosin derivatives) can be classified according to whether they are modified or not, into unmodified rosin and modified rosin derivatives. Examples of unmodified rosin include tall rosin (also known as tall oil rosin), gum rosin, wood rosin, disproportionated rosin, polymerized rosin, hydrogenated rosin, and other chemically modified rosin. Modified rosin derivatives are modified forms of unmodified rosin, and examples include rosin esters, unsaturated carboxylic acid-modified rosin derivatives, unsaturated carboxylic acid-modified rosin esters, rosin amide compounds, and rosin amine salts.

[0154] Styrene-based resins are polymers that use styrene-based monomers as constituent monomers. Examples include polymers polymerized with styrene-based monomers as the main component (50% by mass or more). Specifically, in addition to homopolymers obtained by homopolymerizing styrene-based monomers (styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-methoxystyrene, p-tert-butylstyrene, p-phenylstyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, etc.) individually, copolymers obtained by copolymerizing two or more styrene-based monomers, copolymers of styrene-based monomers with other monomers that can be copolymerized with them can also be listed.

[0155] Other monomers mentioned above may include acrylonitrile, methacrylonitrile, and other acrylonitrile derivatives; unsaturated carboxylic acids such as acrylic acid and methacrylic acid; unsaturated carboxylic acid esters such as methyl acrylate and methyl methacrylate; dienes such as chloroprene, butadiene, and isoprene; alkenes such as 1-butene and 1-pentene; and α,β-unsaturated carboxylic acids or their anhydrides, such as maleic anhydride.

[0156] Among coumarone-based resins, coumarone-indene resin is preferred. Coumarin-indene resin is a resin containing coumarone and indene as monomeric components constituting the resin backbone (main chain). Other monomeric components besides coumarone and indene contained in the backbone include styrene, α-methylstyrene, methylindene, and vinyltoluene.

[0157] The hydroxyl value (OH value) of coumarin indole resin is, for example, greater than 15 mg KOH / g and less than 150 mg KOH / g. Furthermore, the OH value refers to the amount of potassium hydroxide, expressed in milligrams, required to neutralize acetic acid bonded to the hydroxyl groups when 1 g of resin is acetylated; this value is determined by potentiometric titration (JIS K 0070:1992).

[0158] The softening point of the coumarin indene resin is, for example, greater than 30°C and less than 160°C. Furthermore, the softening point is the temperature at which the ball drops when measured using a ring-and-ball softening point tester as specified in JIS K 6220-1:2001.

[0159] Examples of terpene-based resins include polyterpenes, terpene phenols, and aromatic modified terpene resins. Polyterpenes are resins obtained by polymerizing terpene compounds, as well as their hydrides. Terpene compounds are composed of (C5H8) resins. n The composition of hydrocarbons and their oxygen-containing derivatives is represented by the class of monoterpenes (C64- ... 10 H 16 ), sesquiterpenes (C 15 H 24 ), diterpenes (C 20 H 32 Compounds with terpenes as their basic skeleton include, for example, α-pinene, β-pinene, dipentene, limonene, myrcene, alloocimene, ocimene, α-phellandrene, α-terpinene, γ-terpinene, terpinolene, 1,8-cineole, 1,4-cineole, α-terpineol, β-terpineol, and γ-terpineol.

[0160] As polyterpenes, in addition to terpene resins such as α-pinene resin, β-pinene resin, limonene resin, dipentene resin, and β-pinene / limonene resin, which use the aforementioned terpene compounds as raw materials, hydrogenated terpene resins that have undergone hydrogenation treatment of these terpene resins can also be listed. As terpene phenols, resins copolymerized from the aforementioned terpene compounds and phenolic compounds, as well as resins that have undergone hydrogenation treatment of these resins, can be listed. Specifically, resins formed by condensing the aforementioned terpene compounds, phenolic compounds, and formaldehyde can be listed. Furthermore, phenolic compounds, for example, phenol, bisphenol A, cresol, and xylenol can be listed. As aromatic modified terpene resins, resins obtained by modifying terpene resins with aromatic compounds, as well as resins that have undergone hydrogenation treatment of these resins, can be listed. Furthermore, as aromatic compounds, there are no particular limitations as long as the compound has an aromatic ring. Examples include phenols such as phenol, alkylphenol, alkoxyphenol, and phenols containing unsaturated hydrocarbon groups; naphthols such as naphthol, alkylnaphthol, alkoxynaphthol, and naphthols containing unsaturated hydrocarbon groups; styrene derivatives such as styrene, alkylstyrene, alkoxystyrene, and styrene containing unsaturated hydrocarbon groups; coumarone, indene, etc.

[0161] "C5 resin" refers to a resin obtained by polymerizing C5 fractions. Examples of C5 fractions include petroleum fractions with 4 to 5 carbon atoms, such as cyclopentadiene, pentene, pentadiene, and isoprene. Dicyclopentadiene resin (DCPD resin) is preferred as a C5-based petroleum resin.

[0162] "C9 resin" refers to a resin obtained by polymerizing C9 fractions, or its hydrogenated or modified products. Examples of C9 fractions include, for instance, petroleum fractions with 8 to 10 carbon atoms such as vinyltoluene, alkylstyrene, indene, and methylindene. Specifically, coumarone-indene resin, coumarone resin, indene resin, and aromatic vinyl compound resins are preferred. As aromatic vinyl compound resins, α-methylstyrene (AMS resin) or homopolymers of styrene or copolymers of α-methylstyrene and styrene are preferred for economic reasons, ease of processing, and excellent exothermic properties; copolymers of α-methylstyrene and styrene are more preferred. For example, commercially available substances from companies such as Kraton and Eastman Chemical Company can be used as aromatic vinyl compound resins.

[0163] "C5C9 resin" refers to a resin obtained by copolymerizing the aforementioned C5 fraction and the aforementioned C9 fraction, or it may be a hydrogenated or modified product of these fractions. Examples of C5 and C9 fractions include the aforementioned petroleum fractions. For example, commercially available substances from companies such as Tosoh Corporation and Luhua Corporation can be used as C5C9 resin.

[0164] There are no particular limitations on the acrylic resin used; for example, solvent-free acrylic resins can be used.

[0165] Solvent-free acrylic resins include (meth)acrylic resins (polymers) synthesized via high-temperature continuous polymerization (high-temperature continuous bulk polymerization) without using polymerization initiators, chain transfer agents, organic solvents, etc., as byproducts (as described in US Patent No. 4,414,370, Japanese Patent Application Publication Nos. 59-6207, 5-58005, 1-313522, US Patent No. 5,010,166, and the Toa Synthetic Research Yearbook TREND2000 No. 3, pp. 42-45). Furthermore, in this invention, (meth)acrylic acid refers to both methacrylic acid and acrylic acid.

[0166] Examples of monomeric components constituting the above-mentioned acrylic resins include (meth)acrylic acid, (meth)acrylates (alkyl esters, aryl esters, aralkyl esters, etc.), (meth)acrylamide, and (meth)acrylamide derivatives.

[0167] In addition, as monomer components constituting the above-mentioned acrylic resins, aromatic vinyl compounds such as styrene, α-methylstyrene, vinyltoluene, vinylnaphthalene, divinylbenzene, trivinylbenzene, and divinylnaphthalene may also be used together with (meth)acrylic acid and (meth)acrylic acid derivatives.

[0168] The aforementioned acrylic resins can be resins composed solely of (meth)acrylic acid, or resins in which components other than (meth)acrylic acid are also structural elements. Furthermore, the aforementioned acrylic resins may also possess hydroxyl, carboxyl, or silanol groups, etc.

[0169] As a resin component, products from companies such as Maruzen Petrochemical Co., Ltd., Sumitomo Bakelite Co., Ltd., Yasuhara Chemical Co., Ltd., Tosoh Co., Ltd., Rutgers Chemicals Co., Ltd., BASF Co., Ltd., Kraton Corporation, Nippon Paint Co., Ltd., Nippon Shokubai Co., Ltd., ENEOS Co., Ltd., Arakawa Chemical Industry Co., Ltd., Taoka Chemical Industry Co., Ltd., etc. can be used.

[0170] (③) Wax The rubber composition may also contain wax. The wax content relative to 100 parts by weight of the rubber component is, for example, preferably 0.5 to 20 parts by weight, more preferably 1.0 to 15 parts by weight, and even more preferably 1.5 to 10 parts by weight.

[0171] There are no particular limitations on the type of wax used; any substance commonly used in the tire industry can be preferred. Examples include mineral-based waxes and plant-derived waxes. Mineral-based waxes refer to waxes derived from mineral resources such as oil and natural gas. Plant-derived waxes refer to waxes derived from natural resources such as plants. Among these, mineral-based waxes are preferred.

[0172] Plant-derived waxes include, for example, rice bran wax, carnauba wax, and candelilla wax. Petroleum-based waxes include, for example, paraffin wax, microcrystalline wax, and selected special waxes thereof, with paraffin wax being preferred. Furthermore, in this invention, the wax is designed to be free of stearic acid.

[0173] In addition, as waxes, commercially available substances such as those from Ouchi Shinsei Chemical Industry Co., Ltd., Nippon Seiwa Co., Ltd., and Paramelt Co., Ltd. can be used. These waxes can be used alone or in combination of two or more.

[0174] (④) Anti-aging agents The rubber composition may also contain antioxidants. The antioxidant content is greater than 1 part by weight and less than 10 parts by weight relative to 100 parts by weight of the rubber component.

[0175] As an antioxidant, there are no particular limitations; examples include naphthylamine-based antioxidants such as phenyl-α-naphthylamine; diphenylamine-based antioxidants such as octyl diphenylamine and 4,4'-bis(α,α'-dimethylbenzyl)diphenylamine; 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), and N,N'-xylyl Antioxidants include p-phenylenediamine (DTPD), N-isopropyl-N'-phenyl-p-phenylenediamine (IPPD), and N,N'-di-2-naphthyl-p-phenylenediamine (DNPD); quinoline-based antioxidants such as polymers of 2,2,4-trimethyl-1,2-dihydroquinoline; monophenol-based antioxidants such as 2,6-di-tert-butyl-4-methylphenol and styrene-modified phenol; and bis, tri, and polyphenol-based antioxidants such as tetra[methylene-3-(3,5'-di-tert-butyl-4'-hydroxyphenyl)propionate]methane. Preferably, p-phenylenediamine-based antioxidants and quinoline-based antioxidants are used, more preferably N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine and polymers of 2,2,4-trimethyl-1,2-dihydroquinoline. These can be used alone or in combination of two or more.

[0176] As commercially available products, for example, products from Seiko Chemical Co., Ltd., Sumitomo Chemical Co., Ltd., Ouchi Shinsei Chemical Co., Ltd., Flexis Co., Ltd., etc. can be used.

[0177] (⑤) Processing aids The rubber composition may also contain processing aids. Examples of processing aids include metal salts (compounds in which the hydrogen atoms of an acid are replaced by metal ions), fatty acid amides, amide esters, and fatty acid esters. These can be used alone or in combination of two or more. Among these, metal salts and fatty acid amides are preferred, and metal salts are more preferred.

[0178] Examples of metals used in metal salts include alkali metals such as potassium and sodium, and alkaline earth metals such as calcium and barium. Magnesium, zinc, nickel, and molybdenum can also be used. Alkali metals are preferred.

[0179] Examples of acids used for metal salts include fatty acids such as lauric acid, myristic acid, and palmitic acid. Other acids that can be used include boric acid, carbonic acid, hydrochloric acid, nitric acid, and sulfuric acid.

[0180] Commercially available processing aids include products from companies such as Kishida Chemical Co., Ltd., Kenei Pharmaceutical Co., Ltd., STRUKTOL Co., Ltd., and Performance Additives Co., Ltd.

[0181] The content of processing aids relative to 100 parts by weight of rubber component is preferably 1 part by weight or more, more preferably 2 parts by weight or more. As an upper limit, for example, it is preferably 6 parts by weight or less, more preferably 4 parts by weight or less.

[0182] (⑥) Lubricant (stearic acid) The rubber composition may also contain a lubricant. As a lubricant, a fatty acid derivative-based lubricant such as stearic acid is preferably used. As stearic acid, conventionally known substances can be used; specifically, products from companies such as Nippon Oil Co., Ltd., NOF Corporation, Kao Corporation, Fujifilm, Kojun Pharmaceutical Co., Ltd., and Chiba Fatty Acid Co., Ltd. can be used. Additionally, products such as STRUKTOL WB16 manufactured by STRUKTOL Co., Ltd. can also be used.

[0183] The content of stearic acid relative to 100 parts by weight of the rubber component is preferably greater than 0.5 parts by weight and less than 10.0 parts by weight.

[0184] (⑦) Zinc oxide The rubber composition may also contain zinc oxide. The content of zinc oxide relative to 100 parts by weight of the rubber component is, for example, greater than 0.5 parts by weight and less than 10 parts by weight. As zinc oxide, conventionally known substances can be used, such as products from Mitsui Metal Mining Co., Ltd., Toho Co., Ltd., HAKUSUI TECH Co., Ltd., Seido Chemical Industry Co., Ltd., Sakai Chemical Industry Co., Ltd., etc.

[0185] (⑧) Crosslinking agents and vulcanization accelerators The rubber composition preferably contains a crosslinking agent such as sulfur. The content of the crosslinking agent relative to 100 parts by weight of the rubber component is, for example, greater than 0.1 parts by weight and less than 10.0 parts by weight. Furthermore, the sulfur content is the amount of pure sulfur, or, when insoluble sulfur is used, the amount after removing oil.

[0186] Examples of sulfur used in the rubber industry include powdered sulfur, settled sulfur, colloidal sulfur, insoluble sulfur, highly dispersed sulfur, and soluble sulfur. These can be used individually or in combination.

[0187] In addition, products made from companies such as Tsurumi Chemical Industry Co., Ltd., Karuizawa Sulfur Co., Ltd., Shikoku Chemical Industry Co., Ltd., Flexis Co., Ltd., Nippon Kanryu Kogyo Co., Ltd., and Hosoi Chemical Industry Co., Ltd. can be used as sulfur.

[0188] Crosslinking agents other than sulfur can also be used. Specifically, for example, sulfur-containing vulcanizing agents such as TACKIROL V200 manufactured by Taoka Chemical Industry Co., Ltd., DURALINK HTS (sodium 1,6-hexamethylene dithiosulfate dihydrate) manufactured by Flexis, KA9188 (1,6-bis(N,N'-dibenzylthiocarbamoyl dithio)hexane: mixed crosslinking agent) manufactured by Lanxess, and organic peroxides such as dicumyl peroxide can be used.

[0189] Furthermore, the rubber composition preferably contains a vulcanization accelerator. The content of the vulcanization accelerator relative to 100 parts by weight of the rubber component is, for example, greater than 0.3 parts by weight and less than 10.0 parts by weight.

[0190] Examples of vulcanization accelerators include thiazole-based accelerators such as 2-mercaptobenzothiazole, di-2-benzothiazole disulfide, and N-cyclohexyl-2-benzothiazole sulfenamide; thiuram-based accelerators such as tetramethylthiuram disulfide (TMTD), tetrabenzylthiuram disulfide (TBzTD), and tetra(2-ethylhexyl)thiuram disulfide (TOT-N); sulfenamide-based accelerators such as N-cyclohexyl-2-benzothiazole sulfenamide, N-tert-butyl-2-benzothiazole sulfenamide, N-ethoxyethylene-2-benzothiazole sulfenamide, N-ethoxyethylene-2-benzothiazole sulfenamide, and N,N'-diisopropyl-2-benzothiazole sulfenamide; and guanidine-based accelerators such as diphenylguanidine, di-o-toluidine, and o-toluidine biguanide. These can be used alone or in combination of two or more.

[0191] (⑨) Other In addition to the components mentioned above, the rubber composition may also contain additives commonly used in the tire industry, such as organic fillers like cellulose fibers and organic peroxides, as needed. The content of these additives relative to 100 parts by weight of the rubber component is, for example, greater than 0.1 parts by weight and less than 50 parts by weight.

[0192] Furthermore, in this invention, the various materials mentioned above, including those containing carbon atoms (e.g., rubber, oil, resin, vulcanization accelerator, antioxidant, surfactant, etc.), can also be derived from carbon dioxide in the atmosphere. As a method for obtaining the compound of this invention from carbon dioxide, carbon dioxide can be directly converted, or methane obtained through a methanation process from carbon dioxide can be converted.

[0193] (2) Preparation of rubber composition for tire tread The rubber composition for tire tread can be made by conventional methods, for example, including a manufacturing method that involves a basic kneading process in which rubber components are mixed with fillers such as silica, and a final kneading process in which the mixture obtained in the basic kneading process is mixed with a crosslinking agent.

[0194] Mixing can be carried out using known (closed) mixing machines such as Banbury internal mixers, kneaders, and open roll mills.

[0195] The mixing temperature in the basic kneading process is, for example, greater than 50°C and less than 200°C, and the mixing time is, for example, greater than 30 seconds and less than 30 minutes. In addition to the above-mentioned components, in the basic kneading process, compounding agents used in traditional rubber industry can be added as needed and mixed, such as softeners like oils, stearic acid, zinc oxide, antioxidants, waxes, vulcanization accelerators, etc.

[0196] In the final refining process, the mixture obtained in the basic kneading process is kneaded with a crosslinking agent. The kneading temperature in the final refining process is, for example, above room temperature and below 80°C, and the kneading time is, for example, above 1 minute and below 15 minutes. In addition to the above-mentioned components, vulcanization accelerators, zinc oxide, etc., may be added as needed and kneaded in the final refining process.

[0197] The rubber composition obtained above can then be extruded into a specified shape to form a tire tread.

[0198] 3. Tire manufacturing The tire described in this embodiment can be manufactured using conventional methods. First, the rubber composition obtained above is shaped into a predetermined shape to create the tread. Then, it is combined with other rubber components on a tire forming machine to produce an uncured tire.

[0199] Specifically, an uncured tire is manufactured by winding an inner liner layer (which serves as a component to ensure the tire's airtightness), a carcass (which serves as a component to withstand the load, impact, and air pressure on the tire), a belt layer (which serves as a component to strongly fasten the carcass and improve the rigidity of the tread) and other components onto a forming drum. The two side edges are fixed to the two ends of the carcass, and a bead portion (which serves as a component to fix the tire to the rim) is also provided. After being formed into a ring shape, the sidewall portion is formed by attaching the tread to the center of the outer periphery and attaching the sidewall to the radially outer side.

[0200] Then, the uncured tires produced above are heated and pressurized in a vulcanizing machine to obtain a tire. The vulcanization process can be carried out using known vulcanization methods. For example, the vulcanization temperature is greater than 120°C and less than 200°C, and the vulcanization time is, for example, greater than 5 minutes and less than 15 minutes.

[0201] The tire obtained as described above uses PET belt layer as belt layer cord to form the tire carcass. In addition, the tread is formed using a properly blended tread rubber composition. Furthermore, by properly controlling the above parameters, the fuel efficiency can be further improved.

[0202] Furthermore, the tires involved in this invention can be preferably used for passenger car tires, large passenger car tires, large SUV tires, truck / bus tires, two-wheeled motor vehicle tires, racing tires, studless anti-skid tires (winter tires), all-season tires, run-flat tires, etc., and are especially preferred as passenger car tires.

Example

[0203] The following are examples (embodiments) that are considered preferred in practice, but the scope of the invention is not limited to these embodiments.

[0204] The study investigated tires (tire size: 235 / 55R19) composed of treads and tire components such as belt layers, belt ply, and carcass formed from the various compound materials shown below. The results calculated based on the following evaluation method regarding fuel consumption performance are shown together at the bottom of Tables 2 and 3.

[0205] 1. Preparation of rubber composition Rubber compositions for tire treads are prepared using the various formulation materials shown below.

[0206] (1) Formulation materials (a) Rubber composition (①)NR: TSR20 (②) SBR-1: HPR850 (modified S-SBR) manufactured by ENEOS Materials (styrene content: 26% by mass, vinyl content: 59% by mass, Tg: -25℃, non-oil-extended) (③) SBR-2: Modified S-SBR manufactured based on Manufacturing Example 1 below (styrene content: 33% by mass, vinyl content: 46% by mass, Tg: -34°C, non-oil-extended). (④) SBR-3: Modified S-SBR manufactured based on Manufacturing Example 2 below (styrene content: 25% by mass, vinyl content: 17% by mass, Tg: -54°C, non-oil-extended). (⑤)BR: BR150B manufactured by Ube Industries (cis content: 96% by mass)

[0207] (Manufacturing Example 1) The SBR-2 described above was prepared according to the following steps. First, cyclohexane, tetrahydrofuran, styrene, and 1,3-butadiene were added to a nitrogen-purged autoclave reactor. After adjusting the temperature of the reactor contents to 20°C, n-butyllithium was added to initiate polymerization. Then, polymerization was carried out under adiabatic conditions. At the point where the maximum temperature reached 85°C and the polymerization conversion rate was 99%, 1,3-butadiene was added again, and polymerization was further induced for 5 minutes. Then, a mixture of tetraglycidyl-1,3-diaminomethylcyclohexane (monomer) and its oligomer components was added as a modifier to carry out the reaction. After the polymerization reaction was completed, 2,6-di-tert-butyl-p-cresol was added, and the solvent was removed by steam stripping. The product was then dried by hot roller drying at a temperature of 110°C to obtain SBR-2.

[0208] (Manufacturing Example 2) In the above SBR-3, except that N,N-bis(trimethylsilyl)-3-aminopropyltriethoxysilane is used as a modifier, it is manufactured in the same manner as in Manufacturing Example 1.

[0209] (b) Formulation materials other than rubber components (①) Carbon Black-1: SHOBLACK N220 (N2SA: 111m) manufactured by Cabot Japan Co., Ltd. 2 / g) (②) Carbon black-2: SEAST SO(FEF) (N2SA: 42m) manufactured by Tokai Carbon Co., Ltd. 2 / g) (③) Silica-1: ULTRASIL VN3 (N2SA: 175m) manufactured by Evonik Industries 2 / g, average primary particle size: 17nm) (④) Silica-2: ULTRASIL 5000GR (N2SA: 115m) manufactured by Evonik Industries. 2 / g, average primary particle size: 21nm) (⑤) Silane coupling agent-1: Si266 (bis(3-triethoxysilylpropyl) disulfide) manufactured by Evonik Industries, Inc. (⑥) Silane coupling agent-2: NXT Z 45 (3-octanoylthiopropyltriethoxysilane) manufactured by Momentive. (⑦) Oil: Vivacatec 500 (TDAE, aromatic processing oil) manufactured by H&R Company (⑧) Resin: Sylvatraxx4401 (a copolymer of α-methylstyrene and styrene) manufactured by Kraton. (9) Wax: OZOACE 0355 (paraffin wax) manufactured by Japan Fine Wax Co., Ltd. (⑩) Antioxidant-1: NOCRAC 6C (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine) manufactured by Ouchi Shinshin Chemical Industry Co., Ltd. Antioxidant-2: ANTAGE RD (2,2,4-trimethyl-1,2-dihydroquinoline) manufactured by Kawaguchi Chemical Co., Ltd. Stearic acid: TSUBAKI stearic acid beads manufactured by Nippon Oil Company. Zinc oxide: Zinc oxide No. 1 manufactured by Mitsui Metals & Mining Co., Ltd. Sulfur: HK-200-5 (powdered sulfur) manufactured by Hosoi Chemical Industry Co., Ltd. Vulcanization accelerator-1: NOCCELLER CZ (N-cyclohexyl-2-benzothiazole sulfenamide (CBS)) manufactured by Ouchi Shinshin Chemical Industry Co., Ltd. Vulcanization accelerator-2: NOCCELLER D (N,N'-diphenylguanidine (DPG)) manufactured by Ouchi Shinsei Chemical Co., Ltd.

[0210] (2) Preparation of rubber composition for tire tread Based on the formulations A to F shown in Table 1, the mixture was obtained by mixing materials other than sulfur and vulcanization accelerator at 150°C for 5 minutes using a 1.7L Banbury internal mixer manufactured by Kobe Steel Corporation.

[0211] Then, sulfur and vulcanization accelerator are added to the compound, and the mixture is kneaded for 5 minutes at 80°C using an open rolling mill to obtain the tread rubber compositions of formulations A to F.

[0212] Table 1 (mass parts) Formulation A Formulation B Formulation C Formulation D Formulation E Formulation F NR 13 10 10 10 10 28 SBR-1 72 58 58 40 35 0 SBR-2 0 20 20 0 0 0 SBR-3 0 0 0 38 43 62 BR 15 12 12 12 12 10 Carbon black-1 10 7 0 0 0 0 Carbon black-2 0 0 6 4 4 4 Silica-1 63 0 0 0 0 0 Silica-2 0 80 95 105 105 105 Silane coupling agent-1 5.5 6 0 0 0 0 Silane coupling agent-2 0 0 7 6.5 6.5 6.5 Oil 8 19 21 29.5 32.75 31.5 Resin 7.4 6.5 6.5 6.5 6.5 6.5 Wax 1.7 1.9 1.9 1.9 1.9 1.9 Antioxidant-1 2.1 2.5 2.5 2.5 2.5 2.5 Antioxidant-2 1 1 1 1 1 1 Stearic acid 3 2 2 2 2 2 Zinc oxide 2.5 2 2 2 2 2 Sulfur 1.6 1.35 1.35 1.6 1.6 1.6 Vulcanization accelerator-1 1.3 2.2 2.2 2.2 2.2 2.2 Vulcanization accelerator-2 1.7 2 2 2 2 2 AE amount (mass %) 12.4 15.9 15.6 18.0 18.9 18.7 30°C tan delta 0.21 0.20 0.19 0.18 0.17 0.16

[0213] 2. Forming of tire components (tread, belt layer, belt ply) (1) Tread Formation Then, using the rubber composition obtained above, the tire tread (tread running surface) is formed according to the thicknesses shown in Tables 2 and 3.

[0214] (2) Forming of the band layer Simultaneously, a specified rubber composition for the strap layer is bonded to each strap layer cord shown in Tables 2 and 3 to form each strap layer.

[0215] (3) Forming of the belt layer Similarly, the specified belt layer rubber composition is bonded to each belt layer cord shown in Tables 2 and 3 to form each belt layer.

[0216] (4) Formation of the fetus Similarly, the specified tire carcass rubber composition is bonded to each tire carcass cord shown in Tables 2 and 3 to form each tire carcass.

[0217] 3. Tire manufacturing Then, the tread, belt layer, belt layer, carcass and other tire components obtained above are bonded together to form an uncured tire, which is then pressurized at 170°C for 10 minutes to manufacture the test tires (outer diameter Dt: 741.1 mm) of Examples 1 to 9 and Comparative Examples 1 to 5.

[0218] 4. Performance evaluation test (evaluation of fuel consumption performance) Using a rolling resistance testing machine, the rolling resistance coefficient (RRC) of each test tire was determined when it was driven on a drum at a speed of 80 km / h under the following conditions. Wheel rim: 19×7.5J Internal pressure: 210 kPa Load: 6.47kN

[0219] Then, taking the result from Comparative Example 1 as 100, we exponentiated it based on the following formula and set it as the fuel consumption performance evaluation. The larger the value, the smaller the rolling resistance and the better the fuel consumption performance. Fuel efficiency evaluation = [(Result of Comparative Example 1) / (Result of the Test Tire)] × 100

[0220] Table 2

[0221] Table 3

[0222] The present invention has been described above based on embodiments, but the present invention is not limited to the embodiments described above. Various modifications can be made to the above embodiments within the same or equivalent scope as the present invention.

[0223] The present invention (1) is a tire, characterized in that the tire has: A tire body with tire cords, A belt layer having belt-layer cords and disposed on the radially outer side of the tire carcass. A belt layer having belt layer cords and disposed on the radially outer side of the belt layer of a tire, and The tire tread located on the radially outer side of the belt layer; The tire carcass is a two-layer structure consisting of a first tire carcass ply and a second tire carcass ply, each having tire carcass cords, and is formed by wrapping around the tire bead. The belt layer cord is a belt layer cord containing polyethylene terephthalate fibers. The tread is formed using a rubber composition containing more than 75 parts by mass of silica per 100 parts by mass of rubber components, and more than 15% by mass of acetone-extracted components. Furthermore, when the outer diameter of the tire is set to Dt (mm), the winding height of the first tire carcass ply located on the outer side during tire winding is set to P1 (mm), and the winding height of the second tire carcass ply located on the inner side is set to P2 (mm), the following (Equation 1) is satisfied, and, When the diameter of the belt layer cord is set to D1 (mm), the diameter of the belt layer cord is set to D2 (mm), and the diameter of the carcass cord is set to D3 (mm), the following (Equation 2) is satisfied. (P1-P2) / Dt<0.07 (Equation 1) (D1+D2+D3)<2.00 (Equation 2)

[0224] The present invention (2) is a tire according to the present invention (1), characterized in that, The ((P1-P2) / Dt) is less than 0.067.

[0225] The present invention (3) is a tire according to the present invention (2), characterized in that, The ((P1-P2) / Dt) is less than 0.065.

[0226] The present invention (4) is a tire according to the present invention (4), characterized in that, The ((P1-P2) / Dt) is less than 0.063.

[0227] The present invention (5) is a tire of any combination of any one of the claims (1) to (4) of the present invention, characterized in that (D1+D2+D3) is less than 1.80.

[0228] The present invention (6) is a tire according to the present invention (5), characterized in that, The (D1+D2+D3) is less than 1.70.

[0229] The present invention (7) is a tire according to any combination of any one of (1) to (4) of the present invention, characterized in that, in the rubber composition, the content of silica is greater than 80 parts by mass relative to 100 parts by mass of rubber component.

[0230] The present invention (8) is a tire according to the present invention (7), characterized in that, In the rubber composition, the content of silica is greater than 90 parts by mass relative to 100 parts by mass of rubber component.

[0231] The present invention (9) is a tire according to the present invention (8), characterized in that, In the rubber composition, the content of silica is greater than 100 parts by mass relative to 100 parts by mass of rubber components.

[0232] The present invention (10) is a tire according to any combination of any one of (1) to (4) of the present invention, characterized in that the acetone extract component in the rubber composition is greater than 17% by mass.

[0233] The present invention (11) is a tire according to any combination of any one of (1) to (4) of the present invention, characterized in that the thickness of the tread is greater than 6 mm.

[0234] The present invention (12) is a tire made up of any combination of any one of (1) to (4) of the present invention, characterized in that the tread is composed of two layers.

[0235] The present invention (13) is a tire according to any combination of any one of (1) to (4) of the present invention, characterized in that the rubber composition contains more than 25 parts by mass of isoprene rubber in 100 parts by mass of rubber components.

[0236] The present invention (14) is a tire according to the present invention (13), characterized in that, The isoprene-based rubber is a natural rubber.

[0237] The present invention (15) is a tire according to any combination of any one of (1) to (4) of the present invention, characterized in that, The rubber composition, under the conditions of 30°C, 10Hz frequency, 5% initial strain, and 1% dynamic strain rate and deformation mode, has a loss tangent (tanδ at 30°C) of less than 0.19 when measured under tension.

[0238] The present invention (16) is a tire according to any combination of any one of (1) to (4) of the present invention, characterized in that the belt layer cord is composed of one or more but less than four monofilaments.

[0239] The present invention (17) is a tire according to any combination of any one of (1) to (4) of the present invention, characterized in that the polyethylene terephthalate fiber is a sustainable PET fiber.

[0240] The present invention (18) is a tire according to any combination of any one of (1) to (4) of the present invention, characterized in that the rubber composition contains vegetable oil.

[0241] The present invention (19) is a tire according to any combination of any one of (1) to (4) of the present invention, characterized in that the rubber composition contains sustainable carbon black.

[0242] The present invention (20) is a tire according to any combination of any one of (1) to (4) of the present invention, characterized in that the rubber composition contains sustainable silica.

Claims

1. A tire characterized by, The tire has: a carcass provided with a carcass cord, a belt provided with a belt cord and disposed on a tire radial direction outer side of the carcass, a shoulder layer provided with a shoulder layer cord and disposed on a tire radial direction outer side of the belt, and a tread disposed on a tire radial direction outer side of the shoulder layer; the carcass is a two-layer structure of a first carcass ply and a second carcass ply each provided with a carcass cord, and is wound around a bead to form, the shoulder layer cord is a shoulder layer cord containing a polyethylene terephthalate fiber, the tread is formed using a rubber composition containing, with respect to 100 parts by mass of a rubber component, more than 75 parts by mass of silica, and more than 15% by mass of an acetone extract component, Further, when an outer diameter of the tire is set as Dt, a winding height of the first carcass ply on an outer side at the time of winding of the carcass is set as P1, and a winding height of the second carcass ply on an inner side is set as P2, the following (Formula 1) is satisfied, and, when a diameter of the shoulder layer cord is set as D1, a diameter of the belt cord is set as D2, and a diameter of the carcass cord is set as D3, the following (Formula 2) is satisfied, (P1-P2) / Dt < 0.07 (Formula 1), (D1+D2+D3) < 2.00 (Formula 2), units of the Dt, P1, P2, D1, D2, and D3 are mm.

2. Tyre according to Claim 1, characterized in that, The ((P1-P2) / Dt) is less than 0.

067.

3. Tyre according to Claim 2, characterized in that, The ((P1-P2) / Dt) is less than 0.

065.

4. Tyre according to Claim 3, characterized in that, The ((P1-P2) / Dt) is less than 0.

063.

5. Tyre according to any one of claims 1 to 4, characterised in that, The (D1+D2+D3) is less than 1.

80.

6. Tyre according to Claim 5, characterized in that, The (D1+D2+D3) is less than 1.

70.

7. A tyre according to any one of claims 1 to 4, characterised in that The content of the silica in the rubber composition is more than 80 parts by mass with respect to 100 parts by mass of a rubber component.

8. Tyre according to Claim 7, characterised in that, The content of the silica in the rubber composition is more than 90 parts by mass with respect to 100 parts by mass of a rubber component.

9. Tyre according to Claim 8, characterized in that, The content of the silica in the rubber composition is more than 100 parts by mass with respect to 100 parts by mass of a rubber component.

10. A tyre according to any one of claims 1 to 4, characterised in that, The acetone extract component in the rubber composition is more than 17% by mass.

11. A tyre according to any one of claims 1 to 4, characterised in that, The thickness of the tread is more than 6 mm.

12. A tyre according to any one of claims 1 to 4, characterised in that, The tread is composed of two layers.

13. A tyre according to any one of claims 1 to 4, characterised in that The rubber composition contains more than 25 parts by mass of an isoprene rubber in 100 parts by mass of a rubber component.

14. Tyre according to Claim 13, characterized in that, The isoprene rubber is a natural rubber.

15. A tyre according to any one of claims 1 to 4, characterised in that The rubber composition has a loss tangent 30°C tan δ of less than 0.19, which is measured under conditions of 30°C, a frequency of 10 Hz, an initial strain of 5%, a dynamic strain rate of 1%, and a deformation mode of tensile.

16. A tyre according to any one of claims 1 to 4, characterised in that The belt cord is composed of one or more than four monofilaments.

17. A tyre according to any one of claims 1 to 4, characterised in that The polyethylene terephthalate fiber is a sustainable PET fiber.

18. A tyre according to any one of claims 1 to 4, characterised in that The rubber composition contains a plant oil.

19. A tyre according to any one of claims 1 to 4, characterised in that The rubber composition contains a sustainable carbon black.

20. A tyre according to any one of claims 1 to 4, characterised in that The rubber composition contains a sustainable silica.

21. A tyre according to any one of claims 1 to 4, characterised in that, The (P1-P2) / Dt is more than 0.

056.

22. A tyre according to any one of claims 1 to 4, characterised in that The (D1+D2+D3) is more than 1.

55.

23. A tyre according to any one of claims 1 to 4, characterised in that The content of the silica is less than 140 parts by mass with respect to 100 parts by mass of the rubber component in the rubber composition.

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