TIRES

Abstract

A tire is provided which comprises a tread portion, the tread portion comprising one or more circumferential grooves, the tread portion being composed of a rubber composition comprising a rubber component and silica, the rubber component comprising an isoprene-based rubber and a styrene-butadiene rubber, wherein a content of the isoprene-based rubber in the rubber component is 40 mass% or more, a styrene content S1 in mass% of the styrene-butadiene rubber is 30 or less, a content of the silica based on 100 parts by mass of the rubber component is 80 parts by mass or less, and an acetone-extractable amount AE in mass% of the rubber composition is greater than 17.0 mass%.wherein a half-width of a peak within a range of -20 °C to -70 °C in a tanδ temperature distribution curve of the rubber composition is 35 °C or higher, and wherein, when 30 °CE* represents a complex elastic modulus at 30 °C of the rubber composition and H in mm represents a groove depth of a deepest part of the circumferential grooves, 30 °CE* / H is 1.25 or more.

Description

TECHNICAL FIELD

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

[0002] JP 2022-182842 A describes that a tire tread and a tire having improved balance of wet grip performance, low rolling resistance, and the like are provided by a rubber composition for tires comprising: a rubber component comprising a conjugated diene-based polymer modified with a functional group having a skeleton derived from hexamethyleneimine; and a conjugated diene-based polymer modified with a modifier comprising a specific compound; and a filler. SUMMARY OF THE INVENTION

[0003] Recently, further improvement of a tire's abrasion resistance and wet grip performance has been desired.

[0004] An object of the present invention is to provide a tire which can improve overall performance of abrasion resistance and wet grip performance.

[0005] The present invention relates to a tire comprising a tread portion, wherein the tread portion comprises one or more circumferential grooves, wherein the tread portion is constructed from a rubber composition comprising a rubber component and silicon dioxide, wherein the rubber component comprises an isoprene-based rubber and a styrene-butadiene rubber, wherein a content of the isoprene-based rubber in the rubber component is 40 mass% or more, wherein a styrene content S1 in mass% of the styrene-butadiene rubber is 30 or less, wherein a content of the silicon dioxide based on 100 parts by mass of the rubber component is preferably 80 parts by mass or more, wherein an acetone-extractable amount AE in mass% of the rubber composition is greater than 17.0 mass%, wherein a half-width of a peak within a range of -20 °C to -70 °C in a tanδ temperature distribution curve of the rubber composition is 35 °C or higher, and where, when 30 °CE* represents a complex elastic modulus at 30 °C of the rubber composition and H in mm represents a groove depth of a deepest part of the circumferential grooves, 30 °CE* / H is 1.25 or more.

[0006] According to the present invention, an overall performance of abrasion resistance and wet grip performance can be improved. SHORT DESCRIPTION OF THE CHARACTERS Fig.1 is a cross-sectional view passing through a tire rotation axis for a tire according to an embodiment of the present invention. Fig. 2 is a cross-sectional view passing through a tire rotational axis for a tread portion of a tire relating to an embodiment of the present invention. Fig. 3 is a schematic development view of a tread portion showing an embodiment of the present invention. Fig. 4 is a cross-sectional view along a CC line of Fig. 3. DETAILED DESCRIPTION

[0007] A tire that is an embodiment of the present invention is a tire that includes a tread portion, the tread portion including one or more circumferential grooves, the tread portion being composed of a rubber composition that includes a rubber component and silica, the rubber component including an isoprene-based rubber and a styrene-butadiene rubber, a content of the isoprene-based rubber in the rubber component being 40 mass% or more, a styrene content S1 in mass% of the styrene-butadiene rubber being 30 or less, a content of the silica based on 100 parts by mass of the rubber component being 80 parts by mass or less, and an acetone-extractable amount AE in mass% of the rubber composition being greater than 17.0 mass%.wherein a half-width of a peak within a range of -20 °C to -70 °C in a tanδ temperature distribution curve of the rubber composition is 35 °C or higher, and wherein, when 30 °CE* represents a complex elastic modulus at 30 °C of the rubber composition and H in mm represents a groove depth of a deepest part of the circumferential grooves, 30 °CE* / H is 1.25 or more.

[0008] Although the following assumption is not intended to be bound by any theory, one reason why the overall performance of abrasion resistance and wet grip performance is improved in the tire of the present invention is assumed as follows.

[0009] In the rubber composition constituting the tread portion of the tire of the present invention, (1) when a content of an isoprene-based rubber is 40 mass% or more, an isoprene-based rubber phase of a certain size or more is formed in a rubber matrix, and an interface between a phase and another rubber component is created, thereby enabling attenuation of input force from a road surface during running, which contributes to improvement of abrasion resistance.Furthermore, (2) when the styrene content S1 in mass % of the styrene-butadiene rubber is 30 parts by mass or less, a tiny styrene domain is formed in the rubber matrix, and the tiny domain moves flexibly, thus improving the motility of the entire polymer in the rubber composition and improving the adherence of the rubber composition to a road surface, thereby improving wet grip performance and abrasion resistance. Furthermore, (2) when the silica content is 30 parts by mass or more, silica aggregates aggregate in a polymer layer, which contributes to further improving wet grip performance.

[0010] Furthermore, in the rubber composition constituting the tread portion of the tire of the present invention, (4) when an acetone-extractable amount AE of the rubber composition is greater than 17.0 mass %, a plasticizer is contained in the rubber composition to a certain extent, dispersibility of a filler is improved, and dispersion of the filler is carried out efficiently. Therefore, abrasion resistance and wet grip performance are improved. Furthermore, (5) when a half-width of a peak within a range of -20°C to -70°C in a tanδ temperature distribution curve is 35°C or higher, energy loss can be caused to occur in a wide frequency band, and force input from a road surface can be released as heat even in a deformation speed range of a rubber crack piece, so that crack growth can be suppressed, thereby improving abrasion resistance.Furthermore, even in a frequency band during wet braking, energy loss can be made to occur in a wide range, thereby contributing to further improvement of wet grip performance.

[0011] In the tire of the present invention, (6) when 30°CE* / H is 1.25 or more, a block stiffness of a tread pattern becomes equal to or greater than a certain value, which contributes to further improving abrasion resistance. Then, with the cooperation of the above-described (1) to (6), it is expected that a remarkable effect of improving the overall performance of abrasion resistance and wet grip performance is achieved.

[0012] An average primary particle size of the silica is preferably 18 nm or less. When a particle size of the silica is reduced, the flexibility of a styrene domain is further improved, and wet grip performance and abrasion resistance are expected to be further improved.

[0013] The rubber composition preferably comprises a resin component containing dicyclopentadiene, styrene, and indene as monomer components. When the rubber composition comprises the above-described resin component, compatibility of the resin component with an isoprene-based rubber or a styrene-butadiene rubber is improved, and dispersibility of the resin component into a polymer is improved, so it is expected that abrasion resistance is further improved.

[0014] From the perspective of abrasion resistance, 30 °CE* is preferably 8.0 MPa or more. When 30 °CE* is within the above-described range, the rigidity of a rubber per se equal to or greater than a certain value can be ensured, and thus, abrasion resistance is expected to be further improved.

[0015] From the perspective of abrasion resistance, 30 °CE* / H is preferably 1.30 or more. When 30 °CE* / H is within the above-described range, the block stiffness of the tread pattern becomes equal to or greater than a certain value, and thus, abrasion resistance is expected to be further improved.

[0016] The total styrene content S2 in the rubber component in mass % is preferably 15 or less. When the total styrene content S2 is 15 mass % or less, a tiny styrene domain is formed in the rubber matrix, and the tiny styrene domain exhibits flexibility. Therefore, the motility of a polymer is improved, and the rubber composition's adherence to a road surface is improved, so that the overall performance of wet grip and abrasion resistance is expected to be further improved.

[0017] When T in mm represents the total thickness of the tread portion, 30 °C-tanδ × T is preferably 2.5 or more and 4.5 or less. When 30 °C-tanδ × T is within the range described above, hysteresis friction due to deformation of the entire tread portion is improved, and thus, wet grip performance is expected to be further improved.

[0018] The rubber composition preferably comprises 20 parts by mass or more of carbon black based on 100 parts by mass of the rubber component. When the rubber composition comprises 20 parts by mass or more of carbon black, a filler and a polymer are firmly bonded in the rubber component, and the polymer and filler are fixed in the rubber composition, and energy loss is reduced, so it is expected that abrasion resistance is further improved.

[0019] S1 × R is preferably 11.0 or more. When S1 × R is 11.0 or more, a minute styrene domain to be formed is formed in an amount equal to or greater than a certain value, the motility of the entire polymer in the rubber composition is improved, and the following ability of the rubber composition to a road surface is improved, so that the overall performance of wet grip performance and abrasion resistance is expected to be further improved.

[0020] Where G in kg represents the tire weight, S1 / G is preferably 3.0 or less. The lighter the tire becomes, the smaller the force of pressing the land portion against the road surface becomes. Therefore, it is believed that even a slight aggregation of the styrene part has a greater effect on the tread surface as the tire becomes lighter. By reducing S1 as the tire weight decreases, stress concentration due to aggregation of the styrene part can be suppressed, so it is believed that abrasion resistance can be improved.

[0021] It is preferable that the tread portion has land portions separated by the one or more circumferential grooves, the land portion has lateral grooves extending to an inner side in a tire radial direction, and at least one of the lateral grooves has a groove width wider than a groove width on a tread surface on the inner side in the tire radial direction.

[0022] By arranging the lateral grooves at the land portions, an increase in compression stiffness can be suppressed even when abrasion progresses, so it is believed that wet grip performance can be ensured.

[0023] When a region of 30% of a tread ground contact width centered on a tire equator is defined as a center region and regions that are both outer sides of the center region and located within the tread ground contact width are defined as a pair of shoulder regions, a groove depth of the deepest part of the circumferential groove present in the shoulder regions is preferably 6.0 mm or more.

[0024] The configuration described above can improve drainage performance, which is why it is believed to contribute to improving wet grip performance.

[0025] When t1 in mm represents a thickness of a layer of the tread portion whose outer surface forms a tread surface and B in mm represents a thickness of a belt layer of the tread portion, B is 0.9 or more and 1.2 or less, and t1 / B is preferably 7.0 or less.

[0026] When the thickness B of the belt layer is 0.9 mm or more, the tire's rigidity is improved, so wear resistance can be further improved. When the thickness B of the belt layer is 1.2 mm or less, the tire weight can be reduced, so fuel efficiency is expected to be improved. When t1 / B is 7.0 or less, the thickness of the layer whose outer surface forms the tread surface can be thinned, and rolling resistance is reduced, so grip performance is expected to be improved. [Definitions]

[0027] A "styrene content S1 in mass % of a styrene-butadiene rubber" is a styrene content in mass % of a styrene-butadiene rubber (SBR). In a case where a rubber component comprises only one SBR, S1 is a styrene content of the SBR. In a case where the rubber component comprises multiple SBRs, S1 is calculated by a sum of a product of a styrene content of each SBR and a composite amount in mass % of the SBR, where the total SBR is 100 mass %.

[0028] For example, if the rubber component consists of 20 mass% of a first SBR (styrene content: 25 mass%), 30 mass% of a second SBR (styrene content: 27.5 mass%) and 50 mass% of a BR, the styrene content S1 of the styrene-butadiene rubber is 26.5 mass% (= (25 × 40 / 100) + (27.5 × 60 / 100)).

[0029] A "total styrene content S2 in mass% in the rubber component" is a total content in mass% of the styrene parts contained in 100 mass% of the rubber component, and is a value obtained by calculating, for each rubber component, a value obtained by multiplying a styrene content in mass% by a mass fraction in the rubber component and summing these values. Specifically, it is calculated by Σ (styrene content (mass%) of each styrene-containing rubber × content (mass%) of each styrene-containing rubber in the rubber component / 100).

[0030] For example, if the rubber component consists of 20 mass% of a first SBR (styrene content: 25 mass%), 30 mass% of a second SBR (styrene content: 27.5 mass%), and 50 mass% of a BR, the total styrene amount S2 in 100 mass% of the rubber component is about 13.3 mass% (=(25 × 20 / 100) + (27.5 × 30 / 100) + (0 × 10 / 100)).

[0031] An “acetone extractable amount (AE)” is a value calculated by the following equation by immersing each vulcanized rubber test piece in acetone at normal temperature (around 25 °C) for 72 hours to extract a soluble component in accordance with JIS K 6229:2015, and measuring a mass of each test piece before and after extraction, (Amount extractable by acetone (mass %)) = {(Mass of rubber test piece before extraction − Mass of rubber test piece after extraction) / (Mass of rubber test piece before extraction)} × 100.

[0032] A “half-width of a peak within a range of -20 °C to -70 °C in a tanδ temperature distribution curve of a rubber composition (half-width of a tano peak)” can be calculated from a temperature distribution curve of tanδ measured by a method disclosed in JP 2021-54377 A. That is, for each vulcanized test piece, a temperature distribution curve of tanδ is measured in a temperature range of -20 °C to -70 °C using a dynamic viscoelasticity measuring device (e.g., EPLEXOR series, manufactured by gabo Systemtechnik GmbH) under a condition of a frequency of 10 Hz, an initial strain of 10%, a dynamic strain of ± 0.5%, and a temperature rise rate of 2 °C / min, thereby obtaining a temperature dispersion curve in which the X-axis represents temperature and the Y-axis represents tanδ.Where A represents a tanδ at a peak position of the obtained temperature distribution curve, B represents an intersection point between a straight line passing A and parallel to the Y-axis and the X-axis, C represents a midpoint of a line segment AB, D represents a straight line passing C and parallel to the X-axis, and E and F represent two intersection points between D and the temperature distribution curve, the half-width is defined as an absolute value of a temperature difference between E and F.

[0033] A "tan δ at a peak position within a range of -20°C to -70°C in a tan δ temperature distribution curve of a rubber composition" can be calculated from a temperature distribution curve of tan δ measured by a method disclosed in JP 2021-54377 A. That is, it is a tan δ at a peak position of a temperature distribution curve of tan δ obtained for each vulcanized test piece in a temperature range of -20°C to -70°C using a dynamic viscoelasticity measuring device (e.g., EPLEXOR series, manufactured by gabo Systemtechnik GmbH) under a condition of a frequency of 10 Hz, an initial strain of 10%, a dynamic strain of ±0.5%, and a temperature rise rate of 2°C / min, where the X-axis represents temperature and the Y-axis represents tan δ in the temperature distribution curve.

[0034] A "glass transition temperature (Tg) of a rubber composition" is a temperature corresponding to a maximum value (tan δ peak temperature) within a range of -60°C or higher and 40°C or lower on a temperature distribution curve of tan δ obtained by measurement under a condition of a frequency of 10 Hz, an initial strain of 10%, a dynamic strain of ±0.5%, and a temperature rise rate of 2°C / min using a dynamic viscosity measuring device (e.g., EPLEXOR series, manufactured by gabo Systemtechnik GmbH). Furthermore, when measured in the range of -60 to 40°C, if the tan δ value continues to gradually increase or decrease as the temperature rises, the glass transition temperature of the rubber composition shall be 40°C or -60°C, respectively.In addition, in the range of -60 °C or higher and 40 °C or lower, if there are two or more points indicating the maximum value, a point with the lowest temperature shall be a glass transition temperature.

[0035] "30°C tanδ" is a loss tangent (tanδ) measured using a dynamic viscoelasticity measuring device (e.g., EPLEXOR series, manufactured by gabo Systemtechnik GmbH) under conditions of a temperature of 30°C, a frequency of 10 Hz, an initial strain of 5%, a dynamic strain of ± 1%, and a strain mode. A sample for measuring 30°C tanδ is a vulcanized rubber composition with a length of 20 mm, a width of 4 mm, and a thickness of 1 mm. In a case where the sample is prepared by cutting from a tire, the sample is cut from a tread portion such that a tire circumferential direction becomes a long side and the tire radial direction becomes a thickness direction.

[0036] "30 °CE*" is a complex elastic modulus measured using a dynamic viscoelasticity measuring device (e.g., EPLEXOR series, manufactured by gabo Systemtechnik GmbH) under a condition of a temperature of 30 °C, a frequency of 10 Hz, an initial strain of 5%, a dynamic strain of ± 1%, and a strain mode. A sample for measuring 30 °CE* is prepared in the same way as in the case of 30 °C-tanδ.

[0037] A "tread portion" is a portion constituting a ground contact surface of a tire, and is a member located on an outer side in the tire radial direction with respect to members constituting a tire skeleton with steel or a textile material, such as a belt layer, a belt reinforcing layer, a carcass layer, and the like, in a cross section in a tire radial direction when the tire includes these members.

[0038] A “standardized condition” is a condition in which the tire is rim-mounted on a standardized rim, filled with air at a standardized internal pressure, and is not subjected to any load.

[0039] A "dimension of any part of a tire" is, unless otherwise specified, a value specified in a standardized condition for one appearing on the outer surface of the tire, while for one present inside the tire or for one on a tire cut surface, it is a value specified in a condition in which, for example, the tire is cut along a plane containing a tire axis of rotation and the cut tire piece is held to a rim width of a standardized rim.

[0040] A "standardized rim" is a rim in a standards system containing a standard on which the tire is based, which is defined by the standard for each tire. For example, a "standardized rim" refers to a standard rim of an applicable size described in the "Jatma Year Book" of JATMA (The Japan Automobile Tire Manufacturers Association, Inc.), the "Measuring Rim" described in the "STANDARDS MANUAL" of ETRTO (The European Tire and Rim Technical Organization), or the "Design Rim" described in the "YEAR BOOK" of TRA (The Tire and Rim Association, Inc.), which are referred to in that order. If there is an applicable size at the time of reference, the rim conforms to its standard.In addition, in a case of a tire not defined by the standard, the "standardized rim" refers to a rim with the narrowest rim width among rims that can be rim-mounted on the tire, that can maintain internal pressure (that is, does not cause air leakage between the rim and the tire), and that has the smallest rim diameter.

[0041] A "standardized internal pressure" is an air pressure in a standard system containing a standard on which the tire is based, which is defined by the standard for each tire. It refers, for example, to a "MAXIMUM AIR PRESSURE" at JATMA, "INFLATION PRESSURE" at ETRTO or a maximum value described in table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" at TRA, referred to in that order, as in the case of the standardized rim, and if there is an applicable size at the time of reference, the standardized internal pressure conforms to its standard.In addition, in the case of tires not defined by the standard, the standardized internal pressure shall refer to a standardized internal pressure (250 kPa or more) of another tire size (specified in the standard) for which the standardized rim is described as a standard rim, and if multiple standardized internal pressures of 250 kPa or more are described, it shall refer to a minimum value among them.

[0042] A “standardized load” is a load in a standard system containing a standard on which the tire is based, which is defined by the standard for each tire, for example a “MAXIMUM LOAD CAPACITY” at JATMA, a “LOAD CAPACITY” at ETRTO or a maximum value described in the table “TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES” at TRA, which is referred to in this order, as in the case of a standardized rim and a standardized internal pressure, and if there is an applicable size at the time of reference, the load conforms to its standard. Then, in the case of tires not defined by the standard, a maximum load capacity W L obtained by another calculation is defined as a standardized load.

[0043] A “maximum load capacity W L “ is calculated by the following equation. “V” represents a virtual volume in mm 3of a tire, "Dt" represents a tire outer diameter in mm in a standardized state, "Ht" represents a section height in mm of the tire in a tire radial direction in a cross section of the tire on a plane containing a tire rotational axis, and "Wt" represents a section width in mm of the tire in the standardized state. When R represents a rim diameter of the tire, Ht can be calculated by the following equation: (Dt-R) / 2. Wt is a value obtained by excluding, if any, patterns, letters, or the like on the side surface of the tire. In addition, the maximum load capacity has the same meaning as the standardized load described above. WL=0.000011×V+175 V={(Dt / 2)2−(Dt / 2−Ht)2}× π ×Wt

[0044] A "ground contact region" is a region of a tread obtained from a contour when a tire is pressed against a ground. The ground contact area is obtained by mounting the tire on a standardized rim, filling the tire with air under a standardized internal pressure, and leaving the tire at 25°C for 24 hours, followed by applying ink to a tire tread surface, applying a standardized load (maximum load capacity) to the tire to press the tire tread surface perpendicularly onto cardboard (a camber angle is 0°), and performing transcription of the ink. An area of ​​the ground contact region is referred to as the "total ground contact area."The total ground contact area can be calculated as an average value of areas of five locations obtained by rotating the tire in 72-degree increments to perform the transcription operation described above at the total five locations.

[0045] An "effective ground contact area" is the area of ​​a tire's tread with which it contacts the ground when the tire is pressed against the ground. The effective ground contact area is obtained by mounting the tire on a standardized rim, filling the tire with air at a standardized internal pressure, and allowing the tire to stand at 25°C for 24 hours. This is followed by applying ink to a tire tread surface, applying a standardized load (maximum load capacity) to the tire to press the tire tread surface perpendicularly onto cardboard (a camber angle is 0°), and transcribing the ink. An area of ​​the effective ground contact region is called the "effective ground contact area."The effective ground contact area can be calculated as an average value of areas of five locations obtained by rotating the tire in 72-degree increments to perform the transcription process described above at the total of five locations.

[0046] An “elevation ratio R” is calculated from the total ground contact area of ​​the ground contact area and the effective ground contact area of ​​the effective ground contact area by the following equation, Elevation ratio = (effective bond contact area / total ground contact area).

[0047] A "groove" refers to a depression formed on a tire tread surface that extends toward the inner side in the tire radial direction and has a groove width (opening width) of 2.0 mm or more on a tread surface. A depression with a groove width (opening width) of less than 2.0 mm or more on a tread surface is called a "sipe."

[0048] A "circumferential groove" refers to a groove that extends continuously in a tire circumferential direction. The circumferential groove may extend linearly along the circumferential direction or may extend in a wave-like, sinusoidal, or zigzag pattern along the circumferential direction.

[0049] A "groove depth H in mm of a deepest part of a circumferential groove" refers to a linear distance between a straight line connecting ends of the groove on a tread surface and a deepest part of the groove in the tire radial direction in a cross-section of a tire taken along a plane containing a tire rotation axis. In a case where the groove depth of the groove varies in the tire width direction and / or the circumferential direction, the groove depth of the groove shall be the maximum value of the straight line. In addition, a depth at a point of three or more intersections where multiple grooves intersect is excluded from items to be defined as a groove depth in the present specification.

[0050] A "groove width" refers to the distance between groove walls. The groove width can be identified at specific positions along a direction of a groove extending from a tread surface to a groove bottom.

[0051] A “widened groove” refers to a groove whose groove width on the inside in the tire radial direction becomes wider than a groove width on a tread surface (opening width).

[0052] A "total thickness T in mm of a tread portion" is a thickness of a tread portion measured along a normal line on a tire equator in a cross-section of a tire along a plane containing a tire rotation axis. In a case where a circumferential groove is included on the tire equator, the total thickness T is a thickness measured along a normal line on the center portion in a tire width direction of a land portion that is one of land portions present in the tire width direction on both side surfaces of the circumferential groove and whose center portion in the tire width direction is close to the tire equator. In addition, the total thickness T of the tread portion is an average value of tread portion thicknesses calculated at the five locations by rotating the tire in 72-degree increments in a circumferential direction.

[0053] A "thickness t1 in mm of a layer whose outer surface forms a tread surface" is a thickness of a rubber layer whose outer surface forms a tread surface, the thickness of the rubber layer being measured along a normal line on a tire equator in a cross section of a tire taken along a plane including a tire rotation axis. In a case where a circumferential groove is included on the tire equator, the total thickness T is a thickness measured along a normal line on the tire width-direction center portion of a land portion, in which the tire width-direction center portion of the land portion is closest to a tire equator, among land portions present on both side surfaces of the circumferential groove in the tire width direction.In addition, t1 is an average value of tread thicknesses calculated at the five locations by rotating the tire in 72-degree increments in a circumferential direction.

[0054] A "thickness B in mm of a belt layer" is a thickness of a belt layer in the tire radial direction on a tire equator in a cross-section of a tire taken along a plane containing a tire rotation axis. In a case where there is no belt layer on the tire equator, the thickness B is a thickness in a tire radial direction per layer at a tire center position of a belt layer whose center part in a tire width direction is close to the tire equator.

[0055] A "tire weight G in kg" refers to the weight of a single tire, excluding the weight of a rim. On the other hand, in a case where a member consisting of a sponge and a sealant, a sensor element, or the like is provided in a tire lumen, G is a weight including the weight of such a member.

[0056] A "land portion" means a portion of a tread where a tire contacts the ground when the tire is pressed against the ground, and a portion of the tread that forms the effective ground contact area described above.

[0057] A “rubber component of a rubber composition” refers to a component that contributes to crosslinking in a rubber composition and generally has a weight average molecular weight (Mw) of 10,000 or more.

[0058] A “glass transition temperature (Tg) of a rubber component” means a static glass transition temperature of each rubber component calculated by a differential scanning calorimeter (for example, Q200, manufactured by TA Instruments Japan Inc.).

[0059] A “styrene content” is a value determined by 1 H-NMR measurement, and is applied to a rubber component having a repeating unit derived from styrene, such as an SBR and the like (styrene unit-containing rubber).

[0060] A “vinyl content (1,2-bonded butadiene unit amount)” is a value calculated by infrared absorption spectrometry in accordance with JIS K 6239-2:2017, and is applied to a rubber component having a repeating unit derived from butadiene, such as an SBR, a BR, and the like.

[0061] A “cis content (cis-1,4-bonded butadiene unit amount)” is a value calculated in accordance with JIS K 6239-2:2017 by infrared absorption spectrometry, and is applied to a rubber component having a repeating unit derived from butadiene, such as a BR and the like.

[0062] A "weight-average molecular weight (Mw)" can be calculated with respect to a standard polystyrene based on measured values ​​obtained by gel permeation chromatography (GPC) (e.g., GPC-8000 series manufactured by Tosoh Corporation, detector: differential refractometer, column: TSKGEL SUPERMULTIPORE HZ-M manufactured by Tosoh Corporation). For example, Mw is applied to an SBR, a BR, a plasticizer, and the like.

[0063] A "nitrogen adsorption specific surface area (N2SA) of carbon black" is measured according to JIS K 6217-2:2017. A "nitrogen adsorption specific surface area (N2SA) of silica" is measured by a BET method according to ASTM D3037-93.

[0064] An "average primary particle size" is calculated by taking the arithmetic mean of particle sizes of 400 particles photographed with a transmission or scanning electron microscope. Regarding particle size, in a case where the particle is substantially circular, a diameter of the circle is defined as a particle size; in a case where it is needle- or rod-shaped, a minor axis is defined as a particle size; and in other cases, an equivalent circle diameter calculated from an electron microscope image is defined as a particle size. The equivalent circle diameter is calculated as the positive square root of "4 × (particle area) / n." The average primary particle size is applied to silica, carbon black, etc.

[0065] A "plasticizer content" also includes an amount of a plasticizer contained in an extended rubber component pre-extended with the plasticizer, such as oil, a resin component, a liquid rubber component, and the like. Furthermore, this also applies to an oil content, a resin component content, and a liquid rubber content. For example, in a case where the extender component is oil, the extender oil is included in the oil content.

[0066] A “softening point of a resin component” is specified as a temperature at which a ball falls when the softening point defined in JIS K 6220-1:2015 7.7 is measured with a ring-and-ball softening point measuring device. [Tires]

[0067] The tire according to the present embodiment will be described below with reference to the drawings. Furthermore, the embodiment described below is merely an example, and the tire according to the present invention is not limited to the embodiment described below.

[0068] Fig. 1 illustrates a tire according to the present embodiment. Fig. Figure 1 shows a portion of a cross-section when a tire is cut along a plane containing a tire rotation axis. In Fig. 1, a vertical direction is a tire radial direction, a horizontal direction is a tire axial direction, and a direction perpendicular to a paper surface is a tire circumferential direction. In Fig. 1, the alternating long and short dash-dot line CL indicates a tire equator.

[0069] The tire of Fig.1 comprises a tread portion 1 which comes into contact with the ground during running, a pair of sidewall portions 2 which extend to an outer side in a tire radial direction, and a pair of bead portions 3.

[0070] As in Fig.1, a belt layer 5 is provided on an inner side of the tread portion 1 in the tire radial direction. A carcass 4 and an inner liner 7 are laminated on the lower part of the belt layer 5. Furthermore, a tape layer 6 may be provided between the tread portion 1 and the belt layer 5. Each of the bead portions 3 includes a bead core 14 and a bead apex 13 extending from this core to the outer side in the tire radial direction. The bead apex 13 is tapered outward in the tire radial direction. In the bead portion 3, a clinch portion 10, which comes into contact with a rim 8 upon assembly, is provided on the outer side of the carcass 4, and the clinch portion 10 is composed of a rubber composition comprising a rubber component. A rim bead band 9 may be present between the clinching section 10 and the rim 8.

[0071] The tread portion according to the present embodiment may be a tread portion consisting of a single rubber layer, or may be a tread portion comprising a layer whose outer surface forms a tread surface (cover rubber layer) and one or more rubber layers (inside rubber layer) provided between the cover rubber layer and a belt layer. Fig. 1, the tread portion includes a cap rubber layer 11 and a base rubber layer 12 laminated on the outer side of the belt layer 5 in the tire radial direction. A double-headed arrow t1 indicates a thickness of the cap rubber layer 11, and a double-headed arrow t2 indicates a thickness of the base rubber layer 12.

[0072] A thickness t1 of the rubber cover layer is preferably 3.0 mm or more, more preferably 4.0 mm or more, even more preferably 5.0 mm or more, and particularly preferably 6.0 mm or more, but is not particularly limited. Furthermore, t1 is preferably 10.0 mm or less, more preferably 9.5 mm or less, even more preferably 9.0 mm or less, and particularly preferably 8.5 mm or less.

[0073] A thickness t2 of the rubber base layer is preferably 0.8 mm or more, more preferably 1.0 mm or more, even more preferably 1.2 mm or more, and particularly preferably 1.4 mm or more, but is not particularly limited. Furthermore, t2 is preferably 5.0 mm or less, more preferably 4.0 mm or less, and even more preferably 3.0 mm or less.

[0074] A total thickness T of the tread section (t1 + t2 in Fig.1) is preferably 6.0 mm or more, more preferably 6.5 mm or more, even more preferably 7.0 mm or more, even more preferably 7.5 mm or more, and particularly preferably 8.0 mm or more. On the other hand, an upper limit of T is preferably 11.0 mm or less, more preferably 10.5 mm or less, even more preferably 10.0 mm or less, and particularly preferably 9.5 mm or less, but is not particularly limited.

[0075] A thickness B of the belt layer 5 is preferably 0.6 mm or more, more preferably 0.7 mm or more, even more preferably 0.8 mm or more, and particularly preferably 0.9 mm or more. Furthermore, the thickness B of the belt layer 5 is preferably 1.6 mm or less, more preferably 1.4 mm or less, even more preferably 1.2 mm or less, and particularly preferably 1.1 mm or less.

[0076] From the viewpoint of reducing rolling resistance to improve grip performance, t1 / B is preferably 8.0 or less, more preferably 7.5 or less, and even more preferably 7.0 or less. Furthermore, t1 / B is preferably 2.0 or more, more preferably 2.5 or more, even more preferably 3.0 or more, and particularly preferably 3.5 or more. <<Laufflächenabschnitte> >

[0077] Fig. 2 is a cross-sectional view showing a cross section passing through a tire rotational axis of the tread portion of the tire. In Fig. 2. A vertical direction is a tire radial direction, a horizontal direction is a tire width direction, and a direction perpendicular to a paper surface is a tire circumferential direction. A center point in a tire width direction of a land portion 20 is Fig.2 denoted by a symbol P. A straight line denoted by a symbol N is a straight line (normal) that passes through the point P and is perpendicular to a tangent plane at the point P.

[0078] The tread portion relating to the present embodiment includes at least one or more circumferential grooves 15. The tread portion includes land portions 20 separated by the circumferential grooves 15 in a tire width direction.

[0079] In Fig.2, a groove depth H of a deepest part of a circumferential groove 15 refers to a linear distance between a straight line 17 connecting ends of a circumferential groove on a tread surface 16 and an extension line of a deepest part of the groove in a tire radial direction. Furthermore, in a case where a plurality of circumferential grooves 15 are provided, the groove depth H may be defined, for example, as a linear distance between the straight line 17 and an extension line 19 of a deepest part in the tire radial direction of a circumferential groove 15 (circumferential groove 15 on the left side in Fig. 1) with the deepest groove depth among the plurality of circumferential grooves 15.

[0080] The groove depth H of the deepest part in the circumferential direction is preferably 4.5 mm or more, more preferably 5.0 mm or more, even more preferably 5.5 mm or more, and particularly preferably 6.0 mm or more from the viewpoint of abrasion resistance. Moreover, the groove depth H of the deepest part in the circumferential groove is preferably 10.0 mm or less, more preferably 9.5 mm or less, even more preferably 9.0 mm or less, and particularly preferably 8.5 mm or less from the viewpoint of wet grip performance.

[0081] As in Fig. 1 and Fig. 2, the tread portion may comprise a layer whose outer surface forms the tread surface 16 (rubber cover layer 11), and a rubber base layer 12, which in the radial direction lies against the inner side of the rubber cover layer 11. A Fig.The circumferential groove 15 shown on the left side of FIG. 2 is formed such that a deepest part of a groove bottom of the circumferential groove 15 is located on the inner side in the tire radial direction with respect to an outer surface of the rubber base layer 12. Specifically, the rubber base layer 12 has a depressed part that is depressed inwardly with respect to the outer surface in the tire radial direction, and a part of the rubber cap layer 11 is formed with a predetermined thickness within the depressed part of the rubber base layer 12. The circumferential grooves 15 are formed such that they extend beyond the outer surface of the rubber base layer 12 and enter the inner side of the depressed part of the rubber base layer 12. In addition, as shown in FIG. Fig. 2 circumferential groove 15 shown on the right side, the circumferential grooves 15 may be formed at a groove depth which does not reach the outer surface of the rubber base layer 12.

[0082] In the present specification, a “rubber composition constituting a tread portion” in a case where a tread portion is composed of two or more layers refers to a rubber composition constituting a rubber cover layer.

[0083] An acetone extractable amount AE of a rubber composition constituting the tread portion is greater than 17.0 mass%, preferably greater than 20.0 mass%, more preferably greater than 22.0 mass%, and even more preferably greater than 23.0 mass% from the viewpoint of improving dispersion and distribution efficiency of a filler to reduce rigidity at a low temperature. Furthermore, the acetone extractable amount (AE) is preferably less than 35.0 mass%, more preferably less than 33.0 mass%, and even more preferably less than 30.0 mass% from the viewpoint of abrasion resistance.

[0084] From the viewpoint of wet grip performance, AE × H is preferably 140.0 or more, more preferably 142.0 or more, and even more preferably 145.0 or more. Furthermore, from the viewpoint of abrasion resistance, AE × H is preferably 210.0 or less, more preferably 200.0 or less, and even more preferably 190.0 or less.

[0085] A tanδ at a peak position within a range of -20°C to -70°C in a tanδ temperature distribution curve of the rubber composition constituting the tread portion is preferably 0.40 or more, more preferably 0.44 or more, and still more preferably 0.48 or more from the viewpoint of the effects of the present invention.

[0086] A half-width of the peak (half-width of tanδ peak) is 35°C or higher, preferably 36°C or higher, more preferably 37°C or higher, even more preferably 38°C or higher, and particularly preferably 40°C or higher. When the half-width of the peak is 35°C or higher, energy loss can be caused to occur in a wide frequency band, and force input from a road surface can be released as heat even in a deformation speed range of a rubber crack piece, so that crack growth can be suppressed, which improves abrasion resistance. Furthermore, energy loss can be caused to occur in a wide range even in a frequency band during wet braking, and thus wet grip performance is improved.In addition, multiple peak peaks may be present in the tanδ temperature distribution curve, and in such a case, a half-width of at least one peak (curve) may be within the ranges described above.

[0087] 30°CE* of the rubber composition constituting the tread portion is preferably 6.0 MPa or more, more preferably 6.5 MPa or more, even more preferably 7.0 MPa or more, even more preferably 7.5 MPa or more, and particularly preferably 8.0 MPa or more, from the viewpoint of the effects of the present invention. Furthermore, from the viewpoint of noise suppression of a tire tread, it is preferably 14.0 MPa or less, more preferably 13.0 MPa or less, and even more preferably 12.0 MPa or less.

[0088] From the viewpoint of abrasion resistance, 30 °CE* / H is preferably 1.25 or more, more preferably 1.28 or more, even more preferably 1.30 or more, and even more preferably 1.32 or more. An upper limit of 30 °CE* / H is preferably 2.00 or less, more preferably 1.95 or less, and even more preferably 1.90 or less, but is not particularly limited.

[0089] The 30°C tan δ of the rubber composition constituting the tread portion is preferably 0.20 or more, more preferably 0.25 or more, even more preferably 0.30 or more, and particularly preferably 0.35 or more from the viewpoint of wet grip performance. Furthermore, from the viewpoint of fuel efficiency, it is preferably 0.55 or less, more preferably 0.50 or less, and even more preferably 0.45 or less.

[0090] From the viewpoint of wet grip performance, 30°C-tan δ × T is preferably 2.5 or more, more preferably 2.8 or more, and even more preferably 3.0 or more. However, an upper limit of 30°C-tan δ × T is preferably 6.0 or less, more preferably 5.5 or less, even more preferably 5.0 or less, and particularly preferably 4.5 or less, but is not particularly limited.

[0091] A glass transition temperature (Tg) of the rubber composition constituting the tread portion is preferably higher than -36°C, more preferably higher than -34°C, and even more preferably higher than -32°C from the viewpoint of the effects of the present invention. Moreover, from the viewpoint of abrasion resistance, it is preferably lower than -16°C, more preferably lower than -18°C, and even more preferably lower than -20°C.

[0092] In addition, each physical property of the rubber composition, such as 30°C tan δ, 30°CE*, Tg, and the like, can be appropriately adjusted depending on the types or compound amounts of a rubber component, a filler, a plasticizer, and the like described below. For example, 30°C tan δ can be adjusted depending on the types of a resin component. <<Laufflächenprofil> >

[0093] Fig. Fig. 3 is a view showing a tread pattern of a tire relating to an embodiment of the present invention. However, the tread pattern of the tire according to the present embodiment is not limited to that shown in Fig. 3 is shown. In Fig.3, the tread surface has three circumferential grooves extending continuously in the tire circumferential direction. Although a circumferential groove located at the center (center circumferential groove) extends in a zigzag shape, the present invention is not limited to such an aspect, and the center circumferential groove may be in a linear shape. Furthermore, although a pair of circumferential grooves located on both sides of the center circumferential groove (a pair of outermost circumferential grooves) extend in a linear shape, the present invention is not limited to such an aspect, and the outermost circumferential grooves may be in a zigzag shape. The tread surface is divided by these circumferential grooves into a pair of center land portions 21 and a pair of shoulder land portions 22.The center land portions 21 are provided with lateral grooves 31 extending toward the inner side in the tire radial direction, and the shoulder land portions 22 are provided with lateral grooves 32 extending toward the inner side in the tire radial direction. The lateral grooves 31 are widened grooves, each having a part whose groove width in a cross section perpendicular to the extending direction is wider than a groove width on the tread surface. On the other hand, groove widths of the lateral grooves 32 are constant in a cross section perpendicular to the extending direction, and thus the lateral grooves 32 are not widened grooves. Although neither end of each lateral groove 31 communicates with any circumferential groove, the present invention is not limited to such an aspect, and at least one end of a lateral groove may communicate with a circumferential groove.Although one end of each lateral groove 32 communicates with a circumferential groove and the other end of each lateral groove 32 extends to a ground-contacting tread end Te, the present invention is not limited to such an aspect. However, like the lateral grooves 32, from the viewpoint of drainage performance, a lateral groove whose one end communicates with a circumferential groove and whose other end extends to a ground-contacting tread end Te is preferable.

[0094] The tread portion of the tire according to the present embodiment preferably comprises two or more land portions separated by one or more circumferential grooves, at least one of the land portions preferably comprises a plurality of lateral grooves extending toward the inner side in the tire radial direction, and at least one of the lateral grooves is preferably a widened groove.

[0095] Fig. Fig. 4 shows a cross-sectional view along CC line of a lateral groove 31 formed in Fig. 3. This cross section is a cross section perpendicular to the extending direction of the lateral groove 31 extending to the inside in the tire radial direction.

[0096] Shapes of the widened portions of the widened grooves are not particularly limited as long as they improve drainage performance in response to abrasion of a tire, so that grip performance can be improved. For example, the widened portions of the widening lateral grooves 31 of Fig. 3 and Fig. 4 Those whose groove widths widen evenly along the tire's radial direction from the tread surface to the groove bottoms, i.e., those with the widest groove widths at the groove bottoms. Therefore, the more the tire is worn, the higher the drainage performance.

[0097] In Fig. 4, groove walls 42 on both sides of the lateral groove 31 of a widened groove are depressed from a groove edge of the tread surface to the groove bottom, and depressed amounts thereof are represented by C1 and C2. C1 and C2 are each independently preferably 0.05 times or more, more preferably 0.07 times or more, and even more preferably 0.10 times or more of a groove width with a distance between groove edges of the lateral groove (a groove width on the tread surface, an opening width) W1, while these values ​​are preferably 0.45 times or less, more preferably 0.40 times or less, and even more preferably 0.35 times or less.

[0098] A bump ratio R of the tire relating to the present embodiment is preferably 0.80 or less, more preferably 0.75 or less, even more preferably 0.70 or less from the viewpoint of the effects of the present invention. Moreover, from the viewpoint of abrasion resistance, the bump ratio R is preferably 0.50 or more, more preferably 0.55 or more, and even more preferably 0.60 or more.

[0099] In Fig.3, the central circumferential groove is provided in a central region, which is a region of 30% of a tread ground contact width centered on a tire equator on a tread surface, and has a zigzag shape in a form of a linear groove that is repeatedly bent. The tread portion of the tire according to the present embodiment preferably includes a circumferential groove in the central region, which is a region of 30% of the tread ground contact width centered on the tire equator on the tread surface.

[0100] In the tread portion of the tire according to the present embodiment, when the area of ​​30% of the tread ground contact width centered on the tire equator on the tread surface is defined as a center region, and areas that are both outer sides of the center region and located within the tread ground contact width are defined as a pair of shoulder regions, it is preferable that circumferential grooves are provided even in the shoulder regions. When circumferential grooves are provided in the shoulder regions, a groove depth of the deepest part of the circumferential groove is preferably 4.5 mm or more, more preferably 5.0 mm or more, even more preferably 5.5 mm or more, and particularly preferably 6.0 mm or more. The above-described configuration can improve drainage performance, and therefore is believed to contribute to improving wet grip performance.On the other hand, the groove depth of the deepest part of the circumferential groove present in the shoulder regions is preferably 10.0 mm or less, more preferably 9.5 mm or less, even more preferably 9.0 mm or less, and particularly preferably 8.5 mm or less.

[0101] The circumferential grooves present in the shoulder regions are different circumferential grooves from the circumferential grooves present on the tread surface, as mentioned above, from the circumferential grooves present in the center region. That is, the circumferential grooves present in the shoulder regions are circumferential grooves, and even if the groove is present simultaneously across both the center region and the shoulder regions, more than half of the groove is present in the shoulder regions. Furthermore, when multiple circumferential grooves are present in the shoulder regions, the groove depth of the deepest part of the circumferential groove present in the shoulder regions is a groove depth of a circumferential groove with the deepest groove depth.In addition, the groove depth of the deepest part of the circumferential groove present in the shoulder areas here refers to a groove depth of a circumferential groove when the circumferential groove is present in the shoulder areas, which is different from a groove depth H in mm of the deepest part, which refers to a groove depth of a circumferential groove having the deepest groove depth among all circumferential grooves.

[0102] A tire weight G of the tire according to the present embodiment is preferably 8.0 kg or more, more preferably 8.5 kg or more, even more preferably 9.0 kg or more, and particularly preferably 9.5 kg or more. However, an upper limit of the tire weight G is normally not particularly limited to 100 kg or less, and may be, for example, 80 kg or less, 60 kg or less, 40 kg or less, 20 kg or less, 15 kg or less, or the like. [Rubber composition]

[0103] Any rubber composition constituting the tread portion of the tire according to the present embodiment (hereinafter referred to as the "rubber compositions according to the present embodiment") comprises a rubber component including an isoprene-based rubber and a styrene-butadiene rubber, and silica, and can be produced using raw materials described below. The rubber composition according to the present embodiment is described below. <kautschukkomponente>

[0104] For the rubber composition according to the present embodiment, a diene-based rubber is suitably used as a rubber component. Examples of the diene-based rubbers include, for example, an isoprene-based rubber, a butadiene rubber (BR), a styrene-butadiene rubber (SBR), a styrene-isoprene rubber (SIR), a styrene-isoprene-butadiene rubber (SIBR), a chloroprene rubber (CR), an acrylonitrile-butadiene rubber (NBR), and the like. These diene-based rubbers may be modified rubbers each treated with a modified group capable of interacting with a filler such as carbon black, silica, and the like, or may be hydrogenated rubbers in which hydrogenation treatment has been performed on a portion of an unsaturated bond. The diene-based rubber can be used alone, or two or more of them can be used in combination.In addition, as a diene-based rubber, an extended rubber previously extended with a plasticizer described below can be used.

[0105] The content of a diene-based rubber in a rubber component is preferably 70 mass% or more, more preferably 80 mass% or more, even more preferably 90 mass% or more, and particularly preferably 95 mass% or more. Furthermore, the rubber component may be made of a diene-based rubber.

[0106] The rubber component according to the present embodiment is a rubber component comprising an isoprene-based rubber and a styrene-butadiene rubber, and preferably comprises an isoprene-based rubber, a styrene-butadiene rubber, and a butadiene rubber. Furthermore, the rubber component according to the present embodiment may also be a rubber component consisting of an isoprene-based rubber and a styrene-butadiene rubber, or a rubber component consisting of an isoprene-based rubber, a styrene-butadiene rubber, and a butadiene rubber. (Isoprene-based rubber)

[0107] As an isoprene-based rubber, for example, those commonly used in the tire industry can be used, such as isoprene rubber (IR), natural rubber, and the like. Examples of natural rubber include not only unrefined natural rubber (NR) but also refined natural rubber, such as epoxidized natural rubber (ENR), hydrogenated natural rubber (HNR), deproteinized natural rubber (DPNR), ultrapure natural rubber, grafted natural rubber, and the like. These isoprene-based rubbers can be used alone, or two or more of them can be used in combination.

[0108] The NR is not particularly limited, and those commonly used in the tire industry can be used, examples of which include SIR20, RSS#3, TSR20 and the like.

[0109] A content of an isoprene-based rubber in the rubber component is 40 mass% or more, preferably more than 40 mass%, more preferably 45 mass% or more, and even more preferably 50 mass% or more, from the viewpoint of the effects of the present invention. Furthermore, the content of an isoprene-based rubber is preferably 90 mass% or less, more preferably 80 mass% or less, even more preferably 75 mass% or less, and particularly preferably 70 mass% or less. (SBR)

[0110] The SBR is not particularly limited, and examples thereof include an unmodified solution-polymerized SBR (S-SBR), an unmodified emulsion-polymerized SBR (E-SBR), modified SBRs (a modified S-SBR, a modified E-SBR) thereof, and the like. Examples of the modified SBR include an SBR modified at its terminal and / or main chain using a compound having a functional group described below (a modifier), a modified SBR coupled with tin, a silicon compound, etc. (a modified SBR of condensate or having a branched structure, etc.), and the like. Furthermore, hydrogenated SBRs (hydrogenated SBRs) and the like can also be used. These SBRs can be used alone, or two or more of them can be used in combination.

[0111] The functional group of the modifier is preferably a functional group containing at least one element selected from the group consisting of silicon, nitrogen and oxygen. Examples of such a functional group include, for example, an amino group, an amide group, a silyl group, an alkoxysilyl group, an isocyanate group, an imino group, an imidazole group, a urea group, an ether group, a carbonyl group, an oxycarbonyl group, a mercapto group, a sulfide group, a disulfide group, a sulfonyl group, a sulfinyl group, a thiocarbonyl group, an ammonium group, an imide group, a hydrazo group, an azo group, a diazo group, a carboxyl group, a nitrile group, a pyridyl group, an alkoxy group (preferably an alkoxy group having 1 to 6 carbon atoms), a hydroxyl group, an oxy group, an epoxy group, and the like, and an amino group and / or alkoxysilyl group are preferred.The amino group is preferably an amino group substituted with one or two alkyl groups having 1 to 6 carbon atoms. Specific examples of alkoxysilyl include, for example, trimethoxysilyl, triethoxysilyl, triisopropoxysilyl, dimethoxymethylsilyl, diethoxymethylsilyl, dimethylmethoxysilyl, dimethylethoxysilyl, and the like.

[0112] An oil-extended SBR or a non-oil-extended SBR can be used as an SBR. As the SBR that can be used in the present embodiment, those commercially available from JSR Corporation, Sumitomo Chemical Co., Ltd., Ube Corporation, Asahi Kasei Corporation, ZS Elastomer Co., Ltd., ARLANXEO, etc. can be used.

[0113] A styrene content S1 of an SBR is 30 mass% or less, preferably 28 mass% or less, more preferably 25 mass% or less, and even more preferably 22 mass% or less, from the viewpoint of the effects of the present invention. Furthermore, from the viewpoint of adhesion performance, S1 is preferably 5 mass% or more, more preferably 8 mass% or more, and even more preferably 10 mass% or more.

[0114] A vinyl content of an SBR is preferably 5 mol% or more, more preferably 10 mol% or more, and even more preferably 15 mol% or more, from the viewpoint of ensuring reactivity with silica and abrasion resistance. Furthermore, from the viewpoint of wet grip performance, the vinyl content of the SBR is preferably 45 mol% or less, more preferably 40 mol% or less, and even more preferably 35 mol% or less. Furthermore, in the present specification, the vinyl content of the SBR is measured by the measurement method described above.

[0115] From the viewpoint of the effects of the present invention, S1 × R is preferably 10.0 or more, more preferably 11.0 or more, even more preferably 12.0 or more, and particularly preferably 13.0 or more. Furthermore, S1 × R is preferably 20.0 or less, more preferably 18.0 or less, and even more preferably 17.0 or less.

[0116] From the viewpoint of the effects of the present invention, S1 / G is preferably 1.2 or more, more preferably 1.5 or more, and even more preferably 1.8 or more. Furthermore, S1 / G is preferably 4.0 or less, more preferably 3.5 or less, even more preferably 3.0 or less, and particularly preferably 2.7 or less.

[0117] A glass transition temperature (Tg) of an SBR is preferably -40°C or lower, more preferably -45°C or lower, even more preferably -50°C or lower, and particularly preferably -55°C or lower from the viewpoint of the effects of the present invention. Furthermore, from the viewpoint of abrasion resistance, it is preferably -90°C or higher, more preferably -80°C or higher, and even more preferably -70°C or higher.

[0118] A weight-average molecular weight (Mw) of an SBR is preferably greater than 80,000, more preferably greater than 100,000, even more preferably greater than 150,000, and particularly preferably greater than 500,000 from the viewpoint of the effects of the present invention. Furthermore, Mw is preferably less than 2,000,000, more preferably less than 1,500,000, and even more preferably less than 1,100,000 from the viewpoint of crosslinking uniformity, etc. In addition, Mw of the SBR is measured by the measurement method described above.

[0119] A content of an SBR in the rubber component is preferably 10 mass% or more, more preferably 20 mass% or more, even more preferably 25 mass% or more, even more preferably 30 mass% or more, and particularly preferably 35 mass% or more from the viewpoint of the effects of the present invention. Moreover, the content of the SBR in the rubber component is preferably 60 mass% or less, more preferably 55 mass% or less, even more preferably 50 mass% or less, and particularly preferably 45 mass% or less. (BR)

[0120] The BR is not particularly limited, and those commonly used in the tire industry can be used, such as a BR with a cis content of less than 50 mol% (a low-cis BR), a BR with a cis content of 90 mol% or more (a high-cis BR), a rare earth-based butadiene rubber synthesized using a rare earth element-based catalyst (a rare earth-based BR), a BR containing a syndiotactic polybutadiene crystal (a SPB-containing BR), a modified BR (a high-cis modified BR, a low-cis modified BR), and the like. These BRs can be used alone, or two or more of them can be used in combination.

[0121] As the cis-rich BR, for example, those commercially available from Zeon Corporation, UBE Corporation, JSR Corporation, etc. can be used. When the rubber composition comprises a cis-rich BR, low-temperature property and abrasion resistance can be improved. A cis content of a cis-rich BR is preferably more than 95 mol%, more preferably more than 96 mol%, and even more preferably more than 97 mol%. In addition, a cis content of a BR is measured by the measurement method described above.

[0122] The rare earth-based BR is synthesized using a rare earth element-based catalyst, and has a vinyl content of preferably less than 1.8 mol%, more preferably less than 1.6 mol%, and even more preferably 1.5 mol% or less, and a cis content of preferably more than 95 mol%, more preferably more than 96 mol%, and even more preferably 97 mol% or more. As the rare earth-based BR, for example, those commercially available from LANXESS, etc., can be used.

[0123] Examples of the SPB-containing BR include those in which a 1,2-syndiotactic polybutadiene crystal is chemically bonded and dispersed with BR, but not those in which the crystal is simply dispersed in the BR. As such SPB-containing BR, those commercially available from UBE Corporation, etc., can be used.

[0124] Examples of the modified BR include BRs modified with the same functional group as for the SBR described above and the like, and a modified butadiene rubber (modified BR) modified at its terminal and / or main chain with a functional group containing at least one member selected from the group consisting of silicon, nitrogen, and oxygen can also be suitably used.

[0125] Examples of other modified BRs include those obtained by adding a tin compound after polymerizing 1,3-butadiene via a lithium initiator, wherein the end of the modified BR molecule is further bonded by a tin-carbon bond (tin-modified BRs), and the like. Furthermore, the modified BR can be either non-hydrogenated or hydrogenated.

[0126] A weight-average molecular weight (Mw) of the BR is preferably greater than 300,000, more preferably greater than 350,000, and even more preferably greater than 400,000 from the viewpoint of abrasion resistance. Furthermore, it is preferably less than 2,000,000, more preferably less than 1,000,000, and even more preferably less than 500,000 from the viewpoint of crosslinking uniformity, etc. In addition, the Mw is calculated by the measurement method described above.

[0127] However, the content of a BR in the rubber component is not particularly limited and is preferably 1 mass% or more, more preferably 5 mass% or more, even more preferably 10 mass% or more, and particularly preferably 15 mass% or more. Moreover, the content of the BR in the rubber component is preferably 50 mass% or less, more preferably 40 mass% or less, even more preferably 30 mass% or less, and particularly preferably 25 mass% or less.

[0128] A total styrene amount S2 in the rubber component is preferably 15 mass% or less, more preferably 12 mass% or less, and even more preferably 10 mass% or less, from the viewpoint of the effects of the present invention. Furthermore, S2 is preferably 3 mass% or more, more preferably 5 mass% or more, and even more preferably 7 mass% or more. (Other rubber components)

[0129] The rubber component may comprise a rubber component other than diene-based rubbers (non-diene-based rubber) as long as it does not affect the effects of the present invention. As a non-diene-based rubber, a rubber component commonly used in the tire industry can be used, examples of which include, for example, a butyl-based rubber, an ethylene-propylene rubber, a polynorbornene rubber, a silicone rubber, a polyethylene chloride rubber, a fluororubber (FKM), an acrylic rubber (ACM), a hydrin rubber, and the like. These non-diene-based rubbers may be used alone, or two or more of them may be used in combination. Furthermore, it may or may not comprise a known thermoplastic elastomer besides the rubber components described above. (Rubber component synthesized from recycled / biomass-derived raw material)

[0130] A monomer that is a structural unit of a synthetic rubber such as an IR, a BR, an SBR, and the like may be one derived from underground resources such as petroleum, a natural gas, and the like, or one recycled from a rubber product such as a tire and the like, or a non-rubber product such as polystyrene and the like. Examples of monomers obtained by recycling (recycled monomers) include a recycled polyisoprene, a recycled butadiene, a recycled aromatic vinyl compound, and the like, but are not particularly limited. Examples of the above-described butadiene include 1,2-butadiene and 1,3-butadiene. Examples of the aromatic vinyl compound include, but are not particularly limited to, styrene and the like.Among them, recycled polyisoprene (recycled isoprene), recycled butadiene (recycled butadiene) and recycled styrene (recycled styrene) are preferred as raw materials.

[0131] A method of producing a recycled monomer is not particularly limited, examples of which include, for example, synthesizing a recycled monomer from recycled naphtha obtained by decomposing a rubber product such as a tire and the like. Moreover, a method of producing a recycled naphtha is not particularly limited and can be carried out, for example, by decomposing a rubber product such as a tire and the like under high temperature and high pressure, by decomposing it by microwaves, or by extracting it after mechanically pulverizing it.

[0132] Furthermore, a monomer that is a structural unit of a synthetic rubber such as an IR, a BR, an SBR, and the like may be one derived from biomass. In the present specification, "biomass" refers to a material derived from natural resources such as plants and the like. Examples of biomass include, for example, agricultural, forestry, and fishery products, sugar, wood waste, a plant residue after capture of a useful component, a plant-derived ethanol, a biomass naphtha, and the like, but are not particularly limited.

[0133] Examples of the biomass-derived monomer (biomass monomer) include a biomass-derived butadiene, a biomass-derived aromatic vinyl compound, and the like, but they are not particularly limited. Examples of the above-described butadiene include 1,2-butadiene and 1,3-butadiene. Examples of the above-described aromatic vinyl compound include, but are not particularly limited to, styrene and the like. Furthermore, a method of producing a biomass monomer is not particularly limited; examples thereof include, for example, a method by biological and / or chemical and / or physical conversion of an animal or plant, and the like.Microbial fermentation is representative of biological conversion, and examples of chemical and physical conversion include a process using a catalyst, a process using high heat, a process using high pressure, a process using an electromagnetic wave, a process using a critical fluid, combinations thereof, and the like.

[0134] Examples of a polymer synthesized from a biomass monomer component (biomass polymer) include a polybutadiene rubber synthesized from biomass-derived butadiene, an aromatic vinyl-butadiene copolymer synthesized from biomass-derived butadiene and / or a biomass-derived aromatic vinyl compound, and the like, but are not particularly limited. Examples of the aromatic vinyl-butadiene copolymer include, for example, a styrene-butadiene rubber synthesized from biomass-derived butadiene and / or biomass-derived styrene, and the like.

[0135] Whether a polymer raw material is derived from biomass or not can be determined by pMC (percent modern carbon) measured according to ASTM D6866-10.

[0136] Here, "pMC" means a ratio of 14 C concentration of a sample to 14 C concentration of a modern standard reference carbon (modern standard reference) and is a value used as an index indicating the biomass ratio of a compound. The meaning of this value is mentioned below.

[0137] In 1 mole of carbon atoms (approx. 6.02 × 10 23 ) there are approximately 6.02 × 10 11 14 C, which are about one trillionth the number of normal carbon atoms. A half-life of 14 C is 5730 years, and 14 C decreases regularly. Therefore, for fossil fuels such as coal, petroleum, natural gas and the like, where it is assumed that 226,000 years or more have passed since carbon oxide in the atmosphere was absorbed by plants to fix it, all 14 C elements that were present in it at the beginning of fixation. Therefore, fossil fuels such as coal, petroleum, natural gas and the like do not contain any 14 C element. Accordingly, the chemical substances produced using these fossil fuels as raw materials also do not contain 14 C element.

[0138] On the other hand, 14 C is constantly generated by cosmic rays, which cause nuclear reactions in the atmosphere. Thus, decreases in 14 C due to radioactive decay and production of 14 C due to nuclear reactions and the amount of 14 C in the Earth's atmospheric environment. Therefore, the 14 C concentration of substances derived from biomass resources that have circulated in the current environment to a value of about 1 × 10 -12 Mole%, based on total C atoms, as described above. Accordingly, by using a difference between these values, a biomass ratio in a particular compound can be calculated.

[0139] This 14 C is generally measured as follows. Using accelerator mass spectrometry based on a tandem accelerator, a 13 C concentration ( 13 C / 12 C) and a 14 C concentration ( 14 C / 12 C) is measured. During the measurements, a 14 C concentration in a circulating carbon in nature from 1950 as the modern standard reference for the 14 C concentration is used. An oxalic acid standard body provided by the National Institute of Standards and Technology (NIST) is used as a specific reference material. The specific radioactivity of carbon in this oxalic acid (radioactivity intensity of 14C per gram of carbon) is sorted for each carbon isotope, 13 C is corrected to a constant value, and a value corrected for attenuation correction from 1950 to the measurement date is used as a standard 14 C concentration value (100%) is used. The ratio of this value to an actually measured value for a sample is called a pMC value.

[0140] Thus, when a rubber is produced from a material derived from 100% biomass, the 14 C concentration is approximately 110 pMC, currently it often does not reach 100 under normal conditions, although there are regional differences and the like. On the other hand, it shows that if this 14 C concentration measured for a chemical substance derived from a fossil fuel, such as petroleum and the like, has a value of approximately 0 pMC (e.g., 0.3 pMC). This value corresponds to a biomass ratio of 0%, as mentioned above.

[0141] Due to the above, it is suitable in terms of environmental protection to use a material such as a rubber having a high pMC value, that is, a material such as a rubber having a high biomass ratio, for a rubber composition. [Filler]

[0142] The rubber composition according to the present embodiment comprises silica as a filler, and more preferably comprises silica and carbon black. Furthermore, the filler may be a filler consisting of carbon black and silica. (silicon dioxide)

[0143] Silica is not particularly limited, and those commonly used in the tire industry can be used, such as silica produced by a dry process (anhydrous silica), silica produced by a wet process (hydrous silica), and the like. A raw material of silica is not particularly limited, and may be, for example, a raw material derived from a mineral such as quartz, or a raw material derived from a biological substance such as rice husk (e.g., silica from a biomass material such as rice husk and the like), or silica recycled from a silica-containing product can be used. Among them, hydrous silica produced by a wet process is preferable because it has many silanol groups.This silica can be used alone, or two or more of them can be used in combination.

[0144] Silica from a biomass material can be obtained, for example, by burning rice husks to obtain rice husk ash, extracting silicate from the rice husk ash using a sodium hydroxide solution, producing silica by reacting the silicate with sulfuric acid in the same manner as for a conventional wet silica, and filtering, washing with water, drying, and pulverizing precipitates of the silica.

[0145] As the silica recycled from a product containing silica, for example, silica recovered from an electronic component such as a semiconductor, a tire, a product containing silica such as a desiccant, a filter material such as diatomaceous earth, and the like can be used. Furthermore, a recovery method is not particularly limited; examples include pyrolysis, decomposition by electromagnetic waves, and the like. Among them, silica recovered from an electronic component such as a semiconductor, etc., or from a tire is preferable.

[0146] When silica crystallizes, it is insoluble in water, and silicic acid, which is a component of silica, cannot be used. By controlling the firing temperature and firing time, crystallization of silica in rice husk ash can be suppressed (see JP 2009-2594 A, Akita Prefectural University Web Journal B / 2019, vol. 6, pp. 216-222, etc.).

[0147] As an amorphous silica extracted from rice husk, those commercially available from Wilmar etc. can be used.

[0148] A specific nitrogen adsorption surface area (N2SA) of silica is preferably larger than 110 m from the viewpoint of reinforcement property 2 / g, more preferably greater than 130 m 2 / g, even more preferably greater than 150 m 2 / g and particularly preferably greater than 170 m 2 / g. Furthermore, from the point of view of heat generation and processability, it is preferably less than 220 m 2 / g, more preferably less than 200 m 2 / g and even more preferably less than 180 m 2 / g or less. In addition, the N2SA of silicon dioxide is measured by the measurement method described above.

[0149] An average primary particle size of silica is preferably larger than 10 nm, more preferably larger than 12 nm, and even more preferably larger than 14 nm from the viewpoint of the effects of the present application. Furthermore, an average primary particle size of silica is preferably less than 20 nm, more preferably 18 nm or less, even more preferably 17 nm or less, and particularly preferably 16 nm or less. Furthermore, the average primary particle size of silica is measured by the measurement method described above.

[0150] A content of silica based on 100 parts by mass of the rubber component is 80 parts by mass or more, preferably more than 80 parts by mass, more preferably 85 parts by mass or more, and even more preferably 90 parts by mass or more, from the viewpoint of the effects of the present invention. Furthermore, from the viewpoint of compatibility with an isoprene-based rubber, the content is preferably 140 parts by mass or less, more preferably 130 parts by mass or less, even more preferably 120 parts by mass or less, and particularly preferably 110 parts by mass or less.

[0151] A content of silica in the filler is preferably 55 mass% or more, more preferably 65 mass% or more, even more preferably 75 mass% or more, and particularly preferably 80 mass% or more, from the viewpoint of the effects of the present invention. Furthermore, from the viewpoint of abrasion resistance, it is preferably 95 mass% or less, more preferably 92 mass% or less, and even more preferably 90 mass% or less. <Ruß>

[0152] Examples of carbon black include, but are not particularly limited to, N134, N110, N220, N234, N219, N339, N330, N326, N351, N550, N762, and the like. A raw material of carbon black may be a biomass material such as lignin, vegetable oil, and the like, or may be pyrolysis oil obtained by pyrolyzing a scrap tire. Furthermore, a method of producing carbon black may be a method using combustion such as a furnace method, a method using hydrothermal carbonization (HTC), or a method using pyrolysis of methane by a thermal carbon black method, and the like. As a commercially available product, products from ASAHI CARBON CO., LTD., Cabot Japan KK, TOKAI CARBON CO., LTD., Mitsubishi Chemical Corporation, Lion Corporation, NIPPON STEEL Carbon Co., Ltd., Columbia Carbon Corporation, etc. can be used.These carbon blacks can be used alone, or two or more of them can be used in combination.

[0153] In addition, as carbon black other than the carbon black described above, from the viewpoint of an environmental performance assessment, etc., carbon black from a biomass material such as lignin and the like, or a recovered carbon black refined by pyrolyzing a product comprising carbon black such as a tire and the like may be used.

[0154] The term "recovered carbon black" in the present specification refers to a carbon black obtained by pulverizing a product such as a used tire comprising carbon black and the like and burning the pulverized product, in which, when the product is subjected to oxidative combustion by heating in the air using a thermal gravity measurement method according to JIS K 6226-2:2003, a mass ratio of ash (ash content), which is a component that does not burn, is 13 mass% or more. That is, a mass ratio (carbon amount) of a weight loss content due to oxidative combustion of the recovered carbon black is 87 mass% or less. The recovered carbon black can be expressed by rCB.

[0155] Recovered carbon black can be obtained from a pyrolysis process of a used pneumatic tire. For example, EP 3427975 A refers to "Rubber Chemistry and Technology", vol. 85, no. 3, pp. 408-449 (2012), particularly pages 438, 440, and 442, and describes that recovered carbon black can be obtained by pyrolysis of an organic material at 550 to 800 °C under an oxygen-depleted environment or by vacuum pyrolysis at a relatively low temperature (

[0027] ). As described in

[0004] of JP 6856781 B, such carbon black obtained by the pyrolysis process usually lacks a functional group on its surface (A Comparison of Surface Morphology and Chemistry of Pyrolytic Carbon Blacks with Commercial Carbon Blacks, Powder Technology 160 (2005) 190-193).

[0156] The recovered carbon black may be one lacking a functional group on its surface, or it may be one treated to contain a functional group on its surface. The treatment of the recovered carbon black is carried out so that the recovered carbon black contains a functional group on its surface and can be carried out by a conventional method. For example, in EP 3173251 A, carbon black obtained from a pyrolysis process is treated with potassium permanganate under an acidic condition, thereby obtaining carbon black containing a hydroxyl group and / or a carboxyl group on its surface. Furthermore, in JP 6856781 B, carbon black obtained from a pyrolysis process is treated with an amino acid compound containing at least one thiol group or disulfide group, thereby obtaining carbon black whose surface is activated.Examples of the recovered carbon black according to the present embodiment also include carbon black treated to contain a functional group on its surface.

[0157] As the recovered carbon black, those commercially available from Strebl Green Carbon Pte Ltd., LDCarbon Co., Ltd. etc. can be used.

[0158] A specific nitrogen adsorption surface area (N2SA) of carbon black is preferably larger than 70 m from the viewpoint of reinforcement property 2 / g, more preferably greater than 100 m 2 / g, even more preferably greater than 120 m 2 / g and particularly preferably greater than 140 m 2 / g. Furthermore, from the point of view of heat generation and processability, it is preferably less than 250 m 2 / g, more preferably less than 220 m 2 / g and even more preferably less than 190 m 2 / g. In addition, the N2SA of the soot is measured using the measurement method described above.

[0159] An average primary particle size of carbon black is preferably less than 32 nm, more preferably less than 28 nm, even more preferably less than 24 nm, even more preferably less than 20 nm, and particularly preferably less than 18 nm. In addition, the average primary particle size is preferably greater than 8 nm, more preferably greater than 10 nm, even more preferably greater than 12 nm, and particularly preferably greater than 14 nm. In addition, the average primary particle size of carbon black is measured by the measuring method described above.

[0160] A content of carbon black based on 100 parts by mass of the rubber component is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, even more preferably 15 parts by mass or more, and particularly preferably 20 parts by mass or more from the viewpoint of abrasion resistance. Furthermore, the content is preferably 50 parts by mass or less, more preferably 45 parts by mass or less, and even more preferably 40 parts by mass or less. <Andere Füllstoffe>

[0161] The filler may include fillers other than silica and carbon black. The other filler is not particularly limited, and those conventionally and commonly used in the tire industry, such as aluminum hydroxide, calcium carbonate, alumina, clay, talc, and the like, may be incorporated as the other filler.

[0162] A total content of fillers based on 100 parts by mass of the rubber component is preferably 40 parts by mass or more, more preferably 50 parts by mass or more, even more preferably 60 parts by mass or more, and particularly preferably 70 parts by mass or more. Furthermore, the content is preferably 140 parts by mass or less, more preferably 130 parts by mass or less, and even more preferably 120 parts by mass or less. <silankupplungsmittel>

[0163] The silica is preferably used in combination with a silane coupling agent. The silane coupling agent is not particularly limited, and examples of the silane coupling agent include, for example, a sulfide-based silane coupling agent such as bis(3-triethoxysilylpropyl)disulfide, bis(3-triethoxysilylpropyl)tetrasulfide, and the like; a mercapto-based silane coupling agent such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, and the like; a vinyl-based silane coupling agent such as vinyltriethoxysilane, vinyltrimethoxysilane, and the like; an amino-based silane coupling agent such as 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropyltriethoxysilane, and the like.a glycidoxy-based silane coupling agent such as γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, and the like; a nitro-based silane coupling agent such as 3-nitropropyltrimethoxysilane, 3-nitropropyltriethoxysilane, and the like; a chlorine-based silane coupling agent such as 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, and the like; and the like. Among them, a sulfide-based silane coupling agent and / or a mercapto-based silane coupling agent are preferably combined in the rubber composition. As the silane coupling agent, for example, those commercially available from Evonik Industries AG, Momentive Performance Materials, etc. can be used. These silane coupling agents can be used alone, or two or more of them can be used in combination.

[0164] A content of a silane coupling agent based on 100 parts by mass of the rubber component (a total amount of all of a plurality of silane coupling agents when used in combination) is preferably more than 3.0 parts by mass, more preferably more than 5.0 parts by mass, and even more preferably more than 6.0 parts by mass from the viewpoint of enhancing silica dispersibility. Furthermore, from the viewpoint of preventing deterioration of abrasion resistance, it is preferably less than 15 parts by mass, more preferably less than 10 parts by mass, and even more preferably less than 8.0 parts by mass. [Other connecting devices]

[0165] The rubber composition according to the present embodiment may suitably comprise, in addition to the rubber component and the filler, coupling agents conventionally and usually used in the tire industry, for example, a plasticizer, a vulcanized rubber particle, processing aids, wax, stearic acid, zinc oxide, an antioxidant, a vulcanizing agent, a vulcanization accelerator, and the like. <weichmacher>

[0166] A plasticizer is a material that imparts plasticity to a rubber component, and is a concept that includes both a plasticizer that is liquid at (25°C) and a plasticizer that is solid at normal temperature (25°C). Examples of the plasticizer include a resin component, oil, a liquid rubber, an ester-based plasticizer, and the like. These plasticizers may be those derived from mineral resources such as petroleum, natural gas, and the like, those derived from biomass, or those derived from naphtha recycled from a rubber or non-rubber product. In addition, low-molecular-weight hydrocarbon components obtained by pyrolyzing used tires or products containing various components and extracting them may be used as the plasticizer.These plasticizers can be used alone, or two or more of them can be used in combination. (resin component)

[0167] The resin component is not particularly limited, and as the resin component, a resin component commonly used in the tire industry can be used. Examples of the resin component include, for example, adhesive resins such as a dicyclopentadiene-based resin, an aromatic vinyl-based resin, a C9-based resin, a C5-based resin, a C5 / C9-based resin, a coumarone-based resin, an indene-based resin, a terpene-based resin, a rosin-based resin, a phenol-based resin, and the like. These resin components can be used alone, or two or more of them can be used in combination.The rubber composition according to the present embodiment preferably comprises one or more resin components selected from the group consisting of a dicyclopentadiene-based resin, an aromatic vinyl-based resin, and a terpene-based resin, more preferably comprises a dicyclopentadiene-based resin component, or preferably further comprises a resin component comprising dicyclopentadiene, styrene, and indene as a monomer component. <<Harz auf Dicyclopentadien-Basis> >

[0168] A "dicyclopentadiene-based resin" means a resin comprising, as a monomer component, cyclopentadiene (CPD) or dicyclopentadiene (DCPD), and may be one subjected to hydrogenation or modification. Examples of the dicyclopentadiene-based resin include, for example, a DCPD / C9 resin comprising dicyclopentadiene and a C9 fraction described below as a monomer component (the DCPD / C9 resin may be one subjected to hydrogenation or modification), and the like. A DCPD / C9 resin comprising dicyclopentadiene and styrene as a monomer component is preferable, and a DCPD / C9 resin comprising dicyclopentadiene, styrene, and indene as a monomer component is more preferable. As a dicyclopentadiene-based resin, for example, those commercially available from Exxon Mobil Chemical Corporation, ENEOS Corporation, Zeon Corporation, Maruzen Petrochemical Co., Ltd., etc. can be used.These dicyclopentadiene-based resins can be used alone, or two or more of them can be used in combination. <<Harz auf aromatischer Vinyl-Basis> >

[0169] An "aromatic vinyl-based resin" means a resin comprising, as a monomer component whose content is highest in the resin, an aromatic vinyl compound such as styrene, α-methylstyrene, vinyltoluene, p-chlorostyrene, and the like, and may be one subjected to hydrogenation or modification. As the aromatic vinyl-based resin, a homopolymer of α-methylstyrene or styrene, or a copolymer of α-methylstyrene and styrene is preferred because it is economical, easy to process, and excellent in heat generation. The copolymer of α-methylstyrene and styrene is more preferred. As the aromatic vinyl-based resin, for example, those commercially available from Kraton Corporation, Eastman Chemical Company, Mitsui Chemicals, Inc., etc. can be used. These aromatic vinyl-based resins can be used alone, or two or more of them can be used in combination. <<Harz auf C9-Basis> >

[0170] A "C9-based resin" means a resin obtained by polymerizing C9 fractions, and may be one obtained by homopolymerizing C9 fractions, or may be a copolymer obtained by copolymerizing C9 fractions with another component. For example, a resin obtained by copolymerizing dicyclopentadiene (DCPD) and C9 fractions is referred to as a "DCPD / C9 resin." Furthermore, the C9-based resin may be those subjected to hydrogenation or modification. Examples of C9 fractions include, for example, petroleum fractions having 8 to 10 carbon atoms, such as vinyltoluene, alkylstyrene, coumarone, indene, methylindene, dicyclopentadiene, and the like. These C9-based resins can be used alone, or two or more of them can be used in combination. <<Harz auf C5-Basis> >

[0171] A "C5-based resin" means a resin obtained by polymerizing C5 fractions, and may be those subjected to hydrogenation or modification. Examples of C5 fractions include, for example, petroleum fractions having 4 to 5 carbon atoms, such as cyclopentadiene, isoprene, pentane, isopentane, neopentane, pentene, pentadiene, and the like. These C5-based resins may be used alone, or two or more of them may be used in combination. <<Harz auf C5 / C9-Basis> >

[0172] A "C5 / C9-based resin" means a resin obtained by copolymerizing the above-described C5 fractions and the above-described C9 fractions, and may be those subjected to hydrogenation or modification. As the C5 / C9-based petroleum resin, for example, those commercially available from Tosoh Corporation, Zibo Luhua Hongjin New Material Group Co., Ltd., etc. can be used. These C5 / C9-based resins can be used alone, or two or more of them can be used in combination. <<Harz auf Cumaron-Basis> >

[0173] A "coumarone-based resin" means a resin comprising coumarone as a monomer component, and may be those subjected to hydrogenation or modification. Examples of the coumarone-based resin include, for example, a coumarone-indene resin comprising coumarone and indene as a monomer component; a coumarone-indene-styrene resin comprising coumarone, indene, and styrene as a monomer component; and the like. These coumarone-based resins may be used alone, or two or more of them may be used in combination. <<Harz auf Inden-Basis> >

[0174] An "indene-based resin" means a resin comprising indene as a monomer component, and may be those subjected to hydrogenation or modification. Examples of the indene-based resin include, for example, a coumarone-indene resin comprising coumarone and indene as a monomer component; a coumarone-indene-styrene resin comprising coumarone, indene, and styrene as a monomer component; and the like. These indene-based resins may be used alone, or two or more of them may be used in combination. <<Harz auf Terpen-Basis> >

[0175] A "terpene-based resin" means a resin comprising, as a monomer component whose content is highest in the resin, a terpene compound such as α-pinene, β-pinene, limonene, dipentene, and the like, and may be one subjected to hydrogenation or modification. Specific examples of the terpene-based resin include, for example, a polyterpene resin comprising only one or more terpene compounds described above as a monomer component; an aromatic-modified terpene resin comprising a terpene compound described above and an aromatic compound as a monomer component; a terpene-phenolic resin comprising a terpene compound described above and a phenol-based compound as a monomer component; and the like.Examples of the aromatic compound that becomes a monomer component of the aromatic-modified terpene resin include, for example, styrene, α-methylstyrene, vinyltoluene, divinyltoluene, and the like. Examples of the phenol-based compound that becomes a monomer component of the terpene-phenolic resin include, for example, phenol, bisphenol A, cresol, xylenol, and the like. These terpene-based resins can be used alone, or two or more of them can be used in combination. <<Harz auf Kolophonium-Basis> >

[0176] A "rosin-based resin" means a resin comprising a rosin acid compound such as abietic acid, neoabietic acid, palustric acid, isopimaric acid, and the like, and may be one subjected to hydrogenation or modification. Examples of the rosin-based resin include, for example, but are not particularly limited to: a natural resin rosin; and a rosin-modified resin obtained by modifying it through hydrogenation, disproportionation, dimerization, esterification, or the like. These rosin-based resins may be used alone, or two or more of them may be used in combination. <<Harz auf Phenol-Basis> >

[0177] A "phenol-based resin" means a resin comprising, as a monomer component whose content is highest in the resin, a phenol compound such as phenol, cresol, and the like. Examples of the phenol-based resin include, but are not particularly limited to, a phenol-formaldehyde resin, an alkylphenol-formaldehyde resin, an alkylphenol-acetylene resin, an oil-modified phenol-formaldehyde resin, and the like. These phenol-based resins may be used alone, or two or more of them may be used in combination. < <erweichungspunkt>>

[0178] From the viewpoint of wet grip performance, a softening point of a resin component is preferably 80°C or higher, more preferably 90°C or higher, and even more preferably 100°C or higher. Furthermore, from the viewpoint of processability and improvement in dispersibility of a filler in a rubber component, it is preferably 150°C or lower, more preferably 140°C or lower, and even more preferably 130°C or lower. In addition, the softening point of the resin is measured by the measurement method described above. < <gehalt>>

[0179] A total content of a resin component based on 100 parts by mass of the rubber component is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 25 parts by mass or more, even more preferably 30 parts by mass or more, and particularly preferably 35 parts by mass or more. On the other hand, from the viewpoint of suppressing heat generation, the content is preferably 70 parts by mass or less, more preferably 65 parts by mass or less, and even more preferably 60 parts by mass or less. (Oil)

[0180] Examples of oil include mineral oils, vegetable oils, animal oils, and the like. Furthermore, from an environmental performance perspective, one obtained by refining waste oil after use in a rubber mixer or engine, or waste cooking oil used in a restaurant, can be used.

[0181] In the present specification, "mineral oil" refers to oil derived from mineral resources such as petroleum, natural gas, and the like. Examples of mineral oil include paraffinic oils (mineral oils), naphthenic oils, aromatic oils, and the like. Specific examples of the mineral oils include, for example, mild extracted solvate (MES), distillate aromatic extract (DAE), treated distillate aromatic extract (TDAE), treated residual aromatic extract (TRAE), residual aromatic extract (RAE), and the like. In addition, as an environmental measure, oils each having a low content of a polycyclic aromatic compound (PCA) can also be used. Examples of the oils each having a low content of a PCA include MES, TDAE, heavy naphthenic oil, and the like.

[0182] In the present specification, examples of the vegetable oil include, for example, linseed oil, rapeseed oil, safflower oil, soybean oil, corn oil, cottonseed oil, rice bran oil, tall oil, sesame oil, perilla oil, castor oil, tung oil, pine oil, pine tar oil, sunflower oil, coconut oil, palm oil, palm kernel oil, olive oil, camellia oil, jojoba oil, macadamia nut oil, peanut oil, grape seed oil, Japan wax, and the like. Furthermore, examples of the vegetable oil also include a refined oil obtained by refining the above-described oil (edible oil, etc.).), a transesterified oil obtained by transesterifying the above-described oil, a hydrogenated oil obtained by hydrogenating the above-described oil, a thermally polymerized oil obtained by thermally polymerizing the above-described oil, an oxidized polymerized oil obtained by oxidizing the above-described oils, a used edible oil obtained by reclaiming what was used as an edible oil, etc., and the like. In addition, the vegetable oil may be liquid or solid at normal temperature (25°C). These vegetable oils may be used alone, or two or more of them may be used in combination.

[0183] The vegetable oil according to the present embodiment preferably comprises acylglycerol, and more preferably comprises triacylglycerol. In addition, in the present specification, acylglycerol refers to a compound in which a hydroxy group of glycerin and a fatty acid are ester-bonded. Acylglycerol is not particularly limited and may be any of 1-monoacylglycerol, 2-monoacylglycerol, 1,2-diacylglycerol, 1,3-diacylglycerol, and triacylglycerol. Further, the acylglycerol may be a monomer, a dimer, or a multimer that is a trimer or higher. In addition, acylglycerol that is a dimer or higher can be obtained by thermal polymerization, oxidative polymerization, or the like. Furthermore, acylglycerol may be liquid or solid at normal temperature (25°C).

[0184] As a method of confirming whether the rubber composition comprises the above-described acylglycerol, the confirmation may be carried out, for example, by 1 H-NMR measurement can be performed below, but is not particularly limited thereto. Specifically, a rubber composition in which triacylglycerol is combined is immersed in heavy chloroform at normal temperature (25 °C) for 24 hours and removed to 1 H NMR measurements at room temperature, and when a signal from tetramethylsilane (TMS) is set to 0.00 ppm, signals near 5.26 ppm, near 4.28 ppm, and near 4.15 ppm are observed, which are presumed to be derived from hydrogen atoms bonded to carbon atoms adjacent to oxygen atoms of an ester group. Furthermore, "near" in this paragraph is a range of ± 0.10 ppm.

[0185] The fatty acid described above is not particularly limited and may be an unsaturated fatty acid or a saturated fatty acid. Examples of the unsaturated fatty acid include monounsaturated fatty acids such as oleic acid and the like; and polyunsaturated fatty acids such as linoleic acid, linolenic acid, and the like. Furthermore, examples of the saturated fatty acid include butyric acid, lauric acid, and the like.

[0186] Among them, as the fatty acid described above, a fatty acid with few double bonds, that is, a saturated fatty acid or a monounsaturated fatty acid, is desirable, and oleic acid is preferred. As a vegetable oil comprising such a fatty acid, for example, a vegetable oil comprising a saturated fatty acid or a monounsaturated fatty acid, or a vegetable oil modified by interesterification or the like can be used. Furthermore, to produce a vegetable oil comprising such a fatty acid, a plant can be improved by selective breeding, gene recombination, or the like.

[0187] As a vegetable oil, for example, those commercially available from Idemitsu Kosan Co., Ltd., Sankyo Yuka Kogyo KK, ENEOS Corporation, Olisoy, H&R Group, HOKOKU Corporation, Fuji Kosan Co., Ltd., The Nisshin Oillio Group, etc. can be used.

[0188] Examples of animal oils include fish oils, beef tallow, oleyl alcohol which can be derived therefrom, and the like.

[0189] A content of oil when combined based on 100 parts by mass of the rubber component is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and even more preferably 7 parts by mass or more from the viewpoint of the effects of the present invention. Moreover, the content is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and even more preferably 30 parts by mass or less. (liquid rubber)

[0190] The liquid rubber is not particularly limited as long as it is a polymer in a liquid state at normal temperature (25°C). Examples include, for example, liquid butadiene rubber (liquid BR), liquid styrene-butadiene rubber (liquid SBR), liquid isoprene rubber (liquid IR), liquid styrene-isoprene rubber (liquid SIR), liquid farnesene rubber, and the like. These liquid rubbers can be used alone, or two or more of them can be used in combination. (Ester-based plasticizer)

[0191] Examples of the ester-based plasticizer include, for example, dibutyl adipate (DBA), diisobutyl adipate (DIBA), dioctyl adipate (DOA), di(2-ethylhexyl)azelate (DOZ), dibutyl sebacate (DBS), diisononyl adipate (DINA), diethyl phthalate (DEP), dioctyl phthalate (DOP), diundecyl phthalate (DUP), dibutyl phthalate (DBP), dioctyl sebacate (DOS), tributyl phosphate (TBP), trioctyl phosphate (TOP), triethyl phosphate (TEP), trimethyl phosphate (TMP), thymidine triphosphate (TTP), tricresyl phosphate (TCP), trixylenyl phosphate (TXP), and the like. These ester-based plasticizers can be used alone, or two or more of them can be used in combination.

[0192] A content of a plasticizer based on 100 parts by mass of the rubber component (a total amount of all of a plurality of plasticizers when used in combination) is preferably 20 parts by mass or more from the viewpoint of wet grip performance, more preferably 30 parts by mass or more, even more preferably 40 parts by mass or more, and particularly preferably more than 50 parts by mass. Furthermore, from the viewpoint of processability, it is preferably 100 parts by mass or less, more preferably 90 parts by mass or less, even more preferably 80 parts by mass or less, and particularly preferably 70 parts by mass or less. <<vulkanisierte Kautschukpartikel> >

[0193] A vulcanized rubber particle is a particle made from a vulcanized rubber. Specifically, rubber powder specified in JIS K 6316:2017 and the like can be used. Recycled rubber powder produced from a pulverized product of a scrap tire and the like is preferable from the viewpoint of environmental performance and cost. They can be used alone, or two or more of them can be used in combination.

[0194] The vulcanized rubber particle is not particularly limited and can be an unmodified vulcanized rubber particle or a modified vulcanized rubber particle. Commercially available vulcanized rubber products include products manufactured by Lehigh Technologies, Muraoka Rubber Reclaiming Co., Ltd., etc.

[0195] A content of the vulcanized rubber particle when bonded based on 100 parts by mass of the rubber component can be appropriately adjusted, for example, within a range of more than 1 part by mass and less than 80 parts by mass. < <verarbeitungshilfsmittel>>

[0196] Examples of processing aids include, for example, a fatty acid metal salt, a fatty acid amide, an amide ester, a silica surfactant, a fatty acid ester, a mixture of a fatty acid metal salt and an amide ester, a mixture of a fatty acid metal salt and a fatty acid amide, and the like. As processing aids, for example, those commercially available from Schill+Seilacher GmbH, Performance Additives, etc. can be used. The processing aid can be used alone, or two or more of them can be used in combination.

[0197] A content of the processing aid when combined based on 100 parts by mass of the rubber component is preferably greater than 0.5 parts by mass, more preferably greater than 1 part by mass, and even more preferably greater than 1.5 parts by mass from the viewpoint of exhibiting an effect of improving processability. Furthermore, from the viewpoint of abrasion resistance and fracture toughness, it is preferably less than 10 parts by mass, more preferably less than 8.0 parts by mass, and even more preferably less than 5.0 parts by mass. < <wachs>>

[0198] Wax is not particularly limited, and any of those commonly used in the tire industry can be suitably used. Examples thereof include, for example, a mineral-based wax, a plant-derived wax, and the like. The mineral-based wax refers to a wax derived from mineral resources such as oil, natural gas, and the like. The plant-derived wax refers to a wax derived from natural resources such as plants. Among them, the mineral-based wax is preferable. Examples of the plant-derived wax include, for example, a rice bran wax, a carnauba wax, a candelilla wax, and the like. Examples of the mineral-based wax include, for example, a paraffin wax, a microcrystalline wax, a specially selected wax thereof, and the like, and the paraffin wax is preferable.Furthermore, the wax relating to the present embodiment should not contain stearic acid. As the wax, for example, those commercially available from Ouchi Shinko Chemical Industry Co., Nippon Seiro Co., Ltd., PARAMELT, etc. can be used. These waxes can be used alone, or two or more of them can be used in combination.

[0199] A wax content when combined based on 100 parts by mass of the rubber component is preferably more than 0.5 parts by mass, more preferably more than 1.0 parts by mass, and even more preferably more than 1.5 parts by mass from the viewpoint of weather resistance of a rubber. Furthermore, from the viewpoint of preventing whitening of a tire due to blooming, it is preferably less than 10 parts by mass, more preferably less than 7.0 parts by mass, and even more preferably less than 5.0 parts by mass. (antioxidant)

[0200] Examples of the antioxidant include, but are not particularly limited to, a naphthylamine-based antioxidant such as phenyl-α-naphthylamine and the like; a diphenylamine-based antioxidant such as octylated diphenylamine, 4,4'-bis(α,α'-dimethylbenzyl)diphenylamine and the like; a p-phenylenediamine-based antioxidant such as N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD), N,N'-bis(1,4-dimethylpentyl)-p-phenylenediamine (77PD), N,N'-diphenyl-p-phenylenediamine (DPPD), N,N'-ditolyl-p-phenylenediamine (DTPD), N-isopropyl-N'-phenyl-p-phenylenediamine (IPPD), N,N'-di-2-naphthyl-p-phenylenediamine (DNPD), and the like; a quinoline-based antioxidant such as a polymer of 2,2,4-trimethyl-1,2-dihydroquinoline, and the like;a monophenol-based antioxidant such as 2,6-di-t-butyl-4-methylphenol, a styrenated phenol, and the like; and bisphenol-based, trisphenol-based, and polyphenol-based antioxidants such as tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane and the like. Among them, the p-phenylenediamine-based antioxidant and the quinoline-based antioxidant are preferable, and N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine and a polymer of 2,2,4-trimethyl-1,2-dihydroquinoline are more preferable. As the commercially available products, for example, products manufactured by Seiko Chemical Co., Ltd., Sumitomo Chemical Co., Ouchi Shinko Chemical Industry Co., Flexsys, etc. can be used. These antioxidants can be used alone, or two or more of them can be used in combination.;

[0201] A content of an antioxidant when combined based on 100 parts by mass of the rubber component (a total amount of all of a plurality of antioxidants when used in combination) is preferably greater than 1.0 parts by mass, more preferably greater than 2.0 parts by mass, and even more preferably greater than 2.5 parts by mass from the viewpoint of ozone cracking resistance of a rubber. Furthermore, from the viewpoint of abrasion resistance and wet grip performance, it is preferably less than 10 parts by mass, more preferably less than 8.0 parts by mass, and even more preferably less than 5.0 parts by mass. (Stearic acid)

[0202] A content of stearic acid when combined based on 100 parts by mass of the rubber component is preferably more than 0.5 parts by mass, more preferably more than 1.0 parts by mass, and even more preferably more than 1.5 parts by mass from the viewpoint of processability. Furthermore, from the viewpoint of vulcanization rate, it is preferably less than 10 parts by mass, more preferably less than 8.0 parts by mass, and even more preferably less than 5.0 parts by mass. (Zinc oxide)

[0203] A content of zinc oxide when combined based on 100 parts by mass of the rubber component is preferably more than 0.5 parts by mass, more preferably more than 1.0 parts by mass, and even more preferably more than 1.5 parts by mass from the viewpoint of processability. Furthermore, from the viewpoint of abrasion resistance, it is preferably less than 10 parts by mass, more preferably less than 8.0 parts by mass, and even more preferably less than 5.0 parts by mass. (vulcanizing agent)

[0204] Sulfur is suitably used as a vulcanizing agent. Powdered sulfur, oil-processing sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersible sulfur, and the like can be used as sulfur.

[0205] A content of sulfur when combined as a vulcanizing agent based on 100 parts by mass of the rubber component is preferably greater than 0.1 part by mass, more preferably greater than 0.5 part by mass, and even more preferably greater than 1.0 part by mass from the viewpoint of ensuring a sufficient vulcanization reaction. Furthermore, from the viewpoint of preventing deterioration, it is preferably less than 5.0 parts by mass, more preferably less than 3.0 parts by mass, and even more preferably less than 2.0 parts by mass. In addition, a content of a vulcanizing agent when an oily sulfur is used as the vulcanizing agent is defined as a total content of pure sulfur contained in the oily sulfur.

[0206] A known organic crosslinking agent can also be used as a vulcanizing agent other than sulfur. Although the organic crosslinking agent is not particularly limited as long as it can form a crosslinking chain other than a polysulfide bond, examples of the organic crosslinking agent include, for example, an alkylphenol sulfur chloride condensate, sodium hexamethylene 1,6-bisthiosulfate dihydrate, 1,6-bis(N,N'-dibenzylthiocarbamoyldithio)hexane, dicumyl peroxide, and the like, and 1,6-bis(N,N'-dibenzylthiocarbamoyldithio)hexane is preferable. As these organic crosslinking agents, those commercially available from Taoka Chemical Co., Ltd., LANXESS, Flexsys, etc. can be used. (vulcanization accelerator)

[0207] Examples of the vulcanization accelerator include, but are not particularly limited to, a sulfenamide-based vulcanization accelerator, a thiazole-based vulcanization accelerator, a guanidine-based vulcanization accelerator, a thiuram-based vulcanization accelerator, a thiourea-based vulcanization accelerator, a dithiocarbamic acid salt-based vulcanization accelerator, an aldehyde-amine-based vulcanization accelerator, an aldehyde-ammonia-based vulcanization accelerator, an imidazoline-based vulcanization accelerator, a xanthate-based vulcanization accelerator, a caprolactam disulfide, and the like. These vulcanization accelerators can be used alone, or two or more of them can be used in combination.Among them, one or more vulcanization accelerators selected from the group consisting of a sulfenamide-based vulcanization accelerator, a thiazole-based vulcanization accelerator, and a guanidine-based vulcanization accelerator are preferred from the viewpoint that suitable effects can be more suitably obtained.

[0208] Examples of the sulfenamide-based vulcanization accelerator include, for example, N-tert-butyl-2-benzothiazolylsulfenamide (TBBS), N-cyclohexyl-2-benzothiazolylsulfenamide (CBS), N,N-dicyclohexyl-2-benzothiazolylsulfenamide (DZ) and the like.

[0209] Examples of the thiazole-based vulcanization accelerator include, for example, 2-mercaptobenzothiazole (MBT) or salt thereof, di-2-benzothiazolyl disulfide (MBTS), 2-(2,4-dinitrophenyl)mercaptobenzothiazole, 2-(2,6-diethyl-4-morpholinothio)benzothiazole and the like.

[0210] Examples of the guanidine-based vulcanization accelerator include, for example, 1,3-diphenylguanidine (DPG), 1,3-di-o-tolylguanidine, 1-o-tolylbiguanide, di-o-tolylguanidine salt of dicachol borate, 1,3-di-o-cumenylguanidine, 1,3-di-o-biphenylguanidine, 1,3-di-o-cumenyl-2-propionylguanidine and the like.

[0211] Examples of the thiuram-based vulcanization accelerator include, for example, tetrakis(2-ethylhexyl)thiuram disulfide (TOT-N), tetramethylthiuram disulfide (TMTD), tetraethylthiuram disulfide, tetramethylthiuram monosulfide (TMTM), dipentamethylenethiuram disulfide, dipentamethylenethiuram tetrasulfide and the like.

[0212] Examples of the thiourea-based vulcanization accelerator include, for example, a thiourea compound such as thiocarbamide, diethylthiourea, dibutylthiourea, trimethylthiourea, diorthotolylthiourea and the like, N,N'-diphenylthiourea, trimethylthiourea, N,N'-diethylthiourea and the like.

[0213] Examples of the dithiocarbamic acid salt-based vulcanization accelerator include, for example, piperidinium pentamethylenedithiocarbamate (PPDC), zinc dimethyldithiocarbamate (ZnMDC), zinc diethyldithiocarbamate (ZnEDC), zinc dibutyldithiocarbamate (ZnBCD), zinc dibenzyldithiocarbamate (ZDBzC), zinc N-ethyl-N-phenyldithiocarbamate (ZnEPDC), zinc N-pentamethylenedithiocarbamate (ZnPDC), sodium dibutyldithiocarbamate (NaBCD), copper dimethyldithiocarbamate (CuMDC), iron dimethyldithiocarbamate (FeMDC), tellurium diethyldithiocarbamate (TeEDC) and the like.

[0214] A content of a vulcanization accelerator when combined based on 100 parts by mass of the rubber component (a total amount of all plural vulcanization accelerators when used in combination) is preferably more than 3.0 parts by mass, more preferably more than 4.0 parts by mass, and even more preferably 5.0 parts by mass or more. Furthermore, the content of the vulcanization accelerator based on 100 parts by mass of the rubber component is preferably less than 8.0 parts by mass, more preferably less than 7.0 parts by mass, and even more preferably less than 6.0 parts by mass.

[0215] In the present specification, various materials each comprising a carbon atom (for example, a rubber, oil, a resin, a vulcanization accelerator, an antioxidant, a surfactant, and the like) may be derived from carbon dioxide in the atmosphere. As a method of obtaining these various materials from carbon dioxide, carbon dioxide may be directly converted, or methane obtained via a methanation process by which methane is synthesized from carbon dioxide may be converted. [Production]

[0216] The rubber composition according to the present embodiment can be produced by a known method. For example, it can be produced by kneading the respective components described above with a rubber kneading machine such as an open roll, a sealed type kneader (a Banbury mixer, a kneader, and the like), and the like.

[0217] The kneading step includes, for example, a basic kneading step of kneading coupling agents and additives other than a vulcanizing agent and a vulcanization accelerator; and a final kneading step (F-kneading) of adding the vulcanizing agent and the vulcanization accelerator to the kneaded product obtained in the basic kneading step and kneading them. Furthermore, the basic kneading step can also be divided into multiple steps if necessary.In a case of dividing the basic kneading step, a method of dividing the basic kneading step may be: (1) A method of previously kneading a part of the coupling agents and additives into a masterbatch and then adding the remaining coupling agents and additives to the obtained masterbatch to knead it; (2) A method of kneading all the coupling agents and additives to be kneaded in the basic kneading step at once and then rolling the kneaded product one or more times; or the like. In the method (1) described above, the number of masterbatches is not limited and may be two or more. Moreover, when the number of masterbatches is two or more, all the coupling agents and additives used in the basic kneading step may be assigned to any of the masterbatches.

[0218] Examples of kneading conditions include, but are not particularly limited to, a method of kneading at a discharge temperature of 150°C to 170°C for 3 to 10 minutes in the initial kneading step and kneading at 70°C to 110°C for 1 to 5 minutes in the final kneading step. Examples of vulcanization conditions include, but are not particularly limited to, a method of vulcanizing at 150°C to 200°C for 10 to 30 minutes.

[0219] A tire according to the present embodiment, which includes a tread portion composed of the above-described rubber composition, can be produced by a conventional method. That is, the tire can be produced by extruding an unvulcanized rubber composition prepared by combining the above-described rubber components as needed for a rubber component into a tread portion shape, assembling the thus-obtained tread portion with other tire elements on a tire molding machine, and molding it via a conventional method for forming an unvulcanized tire, followed by heating and pressurizing the thus-obtained unvulcanized tire in a vulcanizing machine.Examples of vulcanization conditions include, for example, a process of vulcanizing at 150 °C to 200 °C for 10 to 30 minutes, but are not particularly limited thereto. [Applications]

[0220] The tire according to the present embodiment can be used for any application, regardless of whether the tire is a pneumatic tire or a pneumatic tire, and can be used as a passenger car tire, a large passenger car tire, a large SUV tire, a racing tire, a motorcycle tire, a heavy-duty tire, or a run-flat tire. Furthermore, the "passenger car tire" refers to a tire that is expected to be mounted on a vehicle that travels with four wheels and has a maximum load capacity of less than 1400 kg. The "heavy-duty tire" refers to a tire that has a maximum load capacity of 1400 kg or more.Furthermore, the tire according to the present embodiment can be used as an all-season tire and a summer tire as well as a winter tire such as a studless tire. EXAMPLES

[0221] Examples considered preferable in implementing the present invention (Examples) are described below, although the scope of the present invention is not limited to these examples. Results calculated based on the evaluation methods described below, considering a tire obtained according to Table 1 or 2 using various chemicals described below, are shown in Tables 1 and 2. <Verschiedene Chemikalien> No.: TSR 20 SBR1: SBR produced in Production Example 1 described below (S-SBR, Tg: -50 °C, styrene content: 25 mass%, vinyl content: 25 mol%, Mw: 1,000,000, non-oil-extended) SBR2: SBR produced in Production Example 2 described below (S-SBR, Tg: -60 °C, styrene content: 20 mass%, vinyl content: 20 mol%, Mw: 700,000, non-oil-extended) SBR3: Tufdene 3830, manufactured by Asahi Kasei Corporation (unmodified S-SBR, Tg: -35 °C, styrene content: 36 mass%, vinyl content: 31 mol%, Mw: 420,000, comprising 37.5 parts by mass of an extended oil content based on 100 parts by mass of a rubber solid content) BR: Ubepol BR (registered trademark) 150B, manufactured by UBE Corporation (unmodified BR, cis content: 97 mass%, Mw: 440,000) Soot: Soot of the prototype (N2SA: 180 m 2 / g, average primary particle size: 16 nm) Silicon dioxide 1: ULTRASIL VN3, manufactured by Evonik Industries AG (N2SA: 175 m 2 / g, average primary particle size: 17 nm) Silicon dioxide 2: Ultrasil 9100GR, manufactured by Evonik Industries AG (N2SA: 230 m 2 / g, average primary particle size: 15 nm) Silane coupling agent: Si266, manufactured by Evonik Industries AG (bis(3-triethoxysilylpropyl) disulfide) Resin component 1: SYLVATRAXX 4401, manufactured by Kraton Corporation (α-methylstyrene resin, softening point: 85 °C) Resin component 2: SYLVATRAXX 4150, manufactured by Kraton Corporation (polyterpene resin, softening point: 115 °C) Resin component 3: Oppera PR395, manufactured by Exxon Mobil Chemical (hydrogenated DCPD / C9 resin, resin containing dicyclopentadiene, styrene, and indene as monomer components, softening point: 118 °C) Oil: VivaTec 500, manufactured by H&R Group (TDAE oil). Wax: OZOACE 0355 (paraffin wax), manufactured by Nippon Seiro Co., Ltd. Antioxidant 1: Nocrac 6C, manufactured by Ouchi Shinko Chemical Industry Co., Ltd. (N-(1,3-Dimethylbutyl)-N'-phenyl-p-phenylenediamine) Antioxidant 2: Nocrac RD, manufactured by Ouchi Shinko Chemical Industry Co., Ltd. (Poly(2,2,4-trimethyl-1,2-dihydroquinoline)) Stearic acid: Stearic acid "CAMELLIA", manufactured by NOF CORPORATION Zinc oxide: Zinc oxide No. 1, manufactured by Mitsui Mining & Smelting Co., Ltd. Sulfur: HK-200-5, manufactured by Hosoi Chemical Industry Co., Ltd. (5% oil-based sulfur powder) Vulcanization accelerator 1: Nocceler CZ, manufactured by Ouchi Shinko Chemical Industry Co., Ltd. (N-cyclohexyl-2-benzothiazolylsulfenamide (CBS)) Vulcanization accelerator 2: Nocceler D, manufactured by Ouchi Shinko Chemical Industry Co., Ltd. (1,3-Diphenylguanidine (DPG)) (Production example 1: Production of SBR1)

[0222] Cyclohexane, tetrahydrofuran, styrene, and 1,3-butadiene were charged into a nitrogen-purged autoclave reactor. The ratio of styrene to 1,3-butadiene was adjusted so that the styrene content was 25 mass%. After adjusting the temperature of the reactor contents to 20°C, n-butyllithium was added to initiate polymerization. Polymerization was carried out under adiabatic conditions, and the maximum temperature reached 80°C. After confirming the production of a polymer with a Mw of 1,000,000 by GPC, the polymerization solution was poured into 4 L of ethanol to collect a precipitate. After drying the obtained precipitate, it was dried under reduced pressure at 80°C / 10 Pa or lower until a drying loss of 0.1% was obtained to obtain SBR-1. (Production example 2: Production of SBR2)

[0223] Cyclohexane, tetrahydrofuran, styrene, and 1,3-butadiene were charged into a nitrogen-purged autoclave reactor. The ratio of styrene to 1,3-butadiene was adjusted so that the styrene content was 20 mass%. After adjusting the temperature of the contents in the reactor to 20°C, n-butyllithium was added to initiate polymerization. Polymerization was carried out under adiabatic conditions, and the maximum temperature reached 80°C. After verifying the production of a polymer with a Mw of 700,000 by GPC, the polymerization solution was poured into 4 L of ethanol to collect a precipitate. After drying the obtained precipitate, it was dried under reduced pressure at 80°C / 10 Pa or lower until a drying loss of 0.1% was obtained to obtain SBR-2. (Examples and comparison examples)

[0224] According to the compound recipes shown in Table 1 or Table 2, using a 1.7-liter closed-type Banbury mixer, chemicals other than sulfur and vulcanization accelerator were kneaded for 4 minutes at a discharge temperature of 160°C to obtain a kneaded product. Next, using an open-type roller, sulfur and the vulcanization accelerator were added to the resulting kneaded product, and the mixture was kneaded for 4 minutes until the temperature reached 105°C to obtain an unvulcanized rubber composition.The obtained unvulcanized rubber composition is molded into a shape of a tread portion, and the molded rubber composition is combined with other tire members to prepare an unvulcanized tire, and the unvulcanized tire is vulcanized at 170°C, thereby obtaining each test tire (size: 205 / 65R15, rim: 15 × 6JJ, internal pressure: 230 kPa). In addition, a thickness t1 of a cover rubber layer is 6.5 mm, a thickness B of a belt rubber layer is 1.0 mm, and a groove depth of a deepest part of a circumferential groove present in a shoulder region is 6.0 mm. A lateral groove present in a center region is a widened groove having a groove diameter of . Fig. 4 shown cross-sectional shape. <Messung von durch Aceton extrahierbarer Menge (AE-Menge)>

[0225] An AE amount is measured for each rubber test piece prepared by cutting from a tread portion of each test tire. The AE amount is calculated by the following equation after each vulcanized rubber test piece is immersed in acetone at normal temperature (around 25°C) for 24 hours in accordance with JIS K 6229:2015 to extract a soluble component, and a mass of each test piece is measured before and after extraction. Acetone extractable amount (mass %) = {(mass of vulcanized rubber test piece before extraction−mass of vulcanized rubber test piece before extraction) / (mass of vulcanized rubber test piece before extraction)} × 100. <Temperaturverteilungskurve von tanδ>

[0226] For each rubber test piece prepared to have a length of 20 mm, a width of 4 mm, and a thickness of 1 mm by cutting it from a tread portion of each test tire so that a tire circumferential direction becomes a long side and a tire radial direction becomes a thickness direction, a temperature distribution curve of tanδ is measured in a temperature range of -20 °C to 70 °C using a dynamic viscoelasticity measuring device (EPLEXOR series, manufactured by gabo Systemtechnik GmbH) under a condition of a frequency of 10 Hz, an initial strain of 10%, a dynamic strain of ± 0.5%, and a temperature rise rate of 2 °C / min. Then, based on the obtained temperature distribution curve of tanδ, a tanδ at a peak position within a range of -20 °C to -70 °C and a half-width are measured. <Messungen von 30 °C-tanδ und 30 °C-E*>

[0227] For each unvulcanized rubber test piece prepared to have a length of 20 mm, a width of 4 mm, and a thickness of 1 mm by cutting it from a tread portion of each test tire so that a tire circumferential direction becomes a long side and a tire radial direction becomes a thickness direction, a loss tangent tanδ and a complex elastic modulus E* are measured using a dynamic viscoelasticity measuring device (EPLEXOR series manufactured by gabo Systemtechnik GmbH) under a condition of a temperature at 30 °C, a frequency of 10 Hz, an initial strain of 5%, a dynamic strain of ± 1%, and a strain mode. <Messung von Glasübergangstemperatur (Tg) von Kautschukzusammensetzung>

[0228] For each rubber test piece prepared to have a length of 20 mm, a width of 4 mm, and a thickness of 1 mm by cutting it from a tread portion of each test tire so that a tire circumferential direction becomes a long side and a tire radial direction becomes a thickness direction, a temperature distribution curve of tanδ is measured in a range of -60 °C to 40 °C under a condition of a frequency of 10 Hz, an initial strain of 10%, a dynamic strain of ± 0.5%, and a temperature rise rate of 2 °C / min using a dynamic viscoelasticity measuring device (EPLEXOR series manufactured by gabo Systemtechnik GmbH), and a temperature corresponding to the largest tanδ value in the obtained temperature distribution curve (tanδ peak temperature) is determined as Tg of a rubber composition. <abriebfestigkeit>

[0229] For each vulcanized rubber test piece prepared to have a length of 20 mm, a width of 4 mm, and a thickness of 1 mm by cutting it from a tread portion of each test tire so that a tire circumferential direction becomes a long side, an amount of volume loss of each test piece is measured using a LAT tester (Laboratory Abrasion and Skid Tester) under a condition of a load of 100 N, a speed of 20 km / h, and a slip angle of 6°, and abrasion resistance of each test tire is expressed as an index by the following equation. The results show that the larger the index, the better the abrasion resistance. Abrasion resistance = (amount of volume loss for Comparative Example 3) / (amount of volume loss of each test piece) × 100. <nasshaftungsleistung>

[0230] Each test tire is mounted on each of the four wheels of a 2000cc FF passenger car, and the braking distance from the point where the vehicle was decelerated while traveling at 100 km / h on a wet road surface is measured. Furthermore, the wet grip performance of each tire is expressed as an index by the following equation, where the braking distance of a test tire of Comparative Example 3 is 100. The results show that the higher the index, the better the wet grip performance. (Wet grip performance index) = (braking distance of test tire of Comparative Example 3) / (braking distance of each test tire) × 100. <gesamtleistung>

[0231] A total value of abrasion resistance and wet grip performance described above is given as an overall performance index. Table 1 Example 1 2 3 4 5 6 7 8 9 Composite quantity (mass parts) NR 40 40 40 40 40 40 40 40 40 SBR1 40 - 40 40 40 - - - 40 SBR2 - 40 - - - 40 40 40 - BR 20 20 20 20 20 20 20 20 20 soot 20 20 20 20 20 20 20 20 20 Silicon dioxide 1 80 80 - 80 80 - 80 80 - Silicon dioxide 2 - - 80 - - 80 - - 80 Silane coupling agent 6 6 8 6 6 8 6 6 8 (resin component) 1 35 45 35 - - 45 - - - (resin component) 2 - - - 35 - - 45 - 35 (resin component) 3 - - - - 35 - - 45 - Öl 15 5 20 15 15 10 5 5 20 wax 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 Antioxidant 1 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 Antioxidant 2 1,0 1,0 1,0 1,0 1,0 1,0 1,0 1,0 1,0 Stearic acid 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 zinc oxide 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 sulfur 1,4 1,4 1,4 1,4 1,4 1,4 1,4 1,4 1,4 Vulcanization accelerator 1 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 Vulcanization accelerator 2 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 Styrene content S1 of SBR (mass%) 25 20 25 25 25 20 20 20 25 Acetone extractable amount AE (mass%) 23,6 23,6 24,8 23,6 23,6 24,8 23,6 23,6 24,8 Half-width of tanδ peak (°C) 35 35 36 50 36 36 58 36 49 30 °C* 9, 4 8,8 10,8 10,2 9, 0 10,0 10,0 8,1 11,5 30 °C-tanδ 0,37 0, 37 0,37 0,43 0,35 0,38 0, 45 0,35 0,42 Tg of rubber composition (°C) -26 -29 -27 -27 -27 -28 -29 -29 -27 Total styrene amount S2 in rubber component (mass %) 10 8 10 10 10 8 8 8 10 Groove depth H from deepest part of circumferential groove (mm) 6,5 6,5 6,5 6,5 6,5 6,5 6,5 6,0 6,5 30 °C* / H 1,45 1,35 1,66 1,57 1,38 1,54 1,54 1,35 1,77 AE × H 153 153 161 153 153 161 153 142 161 Survey ratio R 0,66 0, 70 0,66 0,66 0,66 0,70 0,70 0,70 0,66 S1×R 16,5 14,0 16,5 16,5 16,5 14,0 14,0 14,0 16,5 Total thickness T of tread section (mm) 9,0 9,0 9,0 9,0 9,0 9,0 9,0 9,0 9,0 30 °C-tanδ × T 3,3 3,3 3,3 3,9 3,2 3,4 4,1 3,2 3,8 Tire weight G (kg) 9,6 9,6 9,6 9,6 9,6 9,6 9,6 9,6 9,6 S1 / G 2,6 2,1 2,6 2,6 2,6 2,1 2,1 2,1 2,6 Evaluation Abrasion resistance 108 110 116 120 111 118 126 114 128 Wet grip performance 109 125 117 118 121 135 134 140 125 Total performance 217 235 233 238 233 253 260 254 253 Example 10 11 12 13 14 15 16 17 18 Composite quantity (mass parts) NR 40 40 40 40 40 40 40 40 70 SBR1 40 40 - - - 40 - - - SBR2 - - 40 40 40 - 40 40 30 BR 20 20 20 20 20 20 20 20 - soot 20 20 20 20 20 20 20 20 20 Silicon dioxide 1 - 80 - - 80 - - - - Silicon dioxide 2 80 - 80 80 - 80 80 100 80 Silane coupling agent 8 6 8 8 6 8 8 10 8 (resin component) 1 - - - - - - - 45 45 (resin component) 2 - 10 45 - 10 10 10 - - (resin component) 3 35 25 - 45 35 25 35 - - Öl 20 15 10 10 5 20 10 10 30 wax 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 Antioxidant 1 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 Antioxidant 2 1,0 1,0 1,0 1,0 1,0 1,0 1,0 1,0 1,0 Stearic acid 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 zinc oxide 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 sulfur 1,4 1,4 1,4 1,4 1,4 1,4 1,4 1,4 1,4 Vulcanization accelerator 1 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 Vulcanization accelerator 2 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 Styrene content S1 of SBR (mass%) 25 25 20 20 20 25 20 20 20 Acetone extractable amount AE (mass%) 24,8 24,8 24,8 24,8 23,6 24,8 24,8 27,8 25,0 Half-width of tanδ peak (°C) 37 36 56 37 36 36 36 38,5 37 30 °C* 10,1 10,1 10,9 9,0 8,0 10,1 9,0 10,2 10,1 30 °C-tanδ 0,36 0,37 0,44 0,36 0,37 0,37 0,38 0,42 0,41 Tg of rubber composition (°C) -27 -29 -28 -28 -30 -29 -30 -31 -29 Total styrene amount S2 in rubber component (mass %) 10 10 8 8 8 10 8 8 6 Groove depth H from deepest part of circumferential groove (mm) 6,5 6,5 6,5 6,5 6,0 6,5 6,5 6,5 6,5 30 °C* / H 1,55 1,55 1,68 1,38 1,33 1,55 1,38 1,57 1,55 AE × H 161 161 161 161 142 161 161 181 163 Survey ratio R 0,66 0,66 0,70 0,70 0,70 0,66 0,70 0,70 0,70 S1×R 16,5 16,5 14,0 14,0 14,0 16,5 14,0 14,0 14,0 Total thickness T of tread section (mm) 9,0 9,0 9,0 9,0 9,0 9,0 9,0 9,0 9,0 30 °C-tanδ × T 3,2 3,3 4,0 3,2 3,3 3,3 3,4 3,8 3,7 Tire weight G (kg) 9,6 9,6 9,6 9,6 9,6 9,6 9,6 9,6 9,6 S1 / G 2,6 2,6 2,1 2,1 2,1 2,6 2,1 2,1 2,1 Evaluation Abrasion resistance 119 118 134 118 117 122 122 118 101 Wet grip performance 128 129 144 153 154 140 166 167 162 Total performance 247 247 278 271 271 262 288 285 263 Table 2 Comparison example 1 2 3 4 5 6 7 8 9 Composite quantity (mass parts) NR 40 30 40 40 40 40 40 40 40 SBR1 - 50 50 40 40 40 40 - - SBR3 (oil content) 55 (15) - - - - - - 55 (15) 55 (15) BR 20 20 10 20 20 20 20 20 20 soot 20 20 20 35 30 30 20 20 20 Silicon dioxide 1 80 80 80 80 70 80 80 80 80 Silane coupling agent 6 6 6 6 6 6 6 6 6 (resin component) 1 20 35 35 20 35 35 35 20 20 Öl 15 14,5 14,5 10 15 40 15 22 15 wax 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 Antioxidant 1 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 Antioxidant 2 1,0 1,0 1,0 1,0 1,0 1,0 1,0 1,0 1,0 Stearic acid 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 zinc oxide 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 sulfur 1,4 1,4 1,4 1,4 1,4 1,4 1,4 1,4 1,4 Vulcanization accelerator 1 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 Vulcanization accelerator 2 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 2,0 Styrene content S1 of SBR (mass%) 36 25 25 25 25 25 25 36 36 Acetone extractable amount AE (mass%) 23,6 23,3 23,4 16,6 23,6 29,0 23,6 25,5 23,6 Half-width of tanδ peak (°C) 31 35 31 43 35 35 35 31 31 30 °C* 9,6 9,4 9,2 22,7 10,1 6,5 9,4 7,9 9,6 30 °C-tanδ 0,37 0,36 0,36 0,42 0,38 0,39 0,37 0,37 0,37 Tg of rubber composition (°C) -26 -24 -24 -34 -27 -29 -26 -27 -26 Total styrene amount S2 in rubber component (mass %) 14 13 13 10 10 10 10 14 14 Groove depth H from deepest part of circumferential groove (mm) 6,5 6,5 6,5 6,5 6,5 6,5 8,0 6,5 8,0 30 °C* / H 1,48 1,45 1,42 3,49 1,55 1,00 1,18 1,22 1,20 AE × H 153 151 152 108 153 189 189 166 189 Survey ratio R 0,66 0,66 0,66 0,66 0,66 0,66 0,66 0,66 0,66 S1×R 23,8 16,5 16,5 16,5 16,5 16,5 16,5 23,8 23,8 Total thickness T of tread section (mm) 9,0 9,0 9,0 9,0 9,0 9,0 11,0 9,0 11,0 30 °C-tanδ × T 3,3 3,2 3,2 3,8 3,4 3,5 4,1 3,3 4,1 Tire weight G (kg) 9,6 9,6 9,6 9,6 9,6 9,6 9,6 9,6 9,6 S1 / G 3,8 2,6 2,6 2,6 2,6 2,6 2,6 3,8 3,8 Evaluation Abrasion resistance 99 103 100 112 107 100 100 99 98 Wet grip performance 82 97 100 69 91 98 98 81 81 Total performance 181 200 200 181 198 198 198 180 179 <Ausführungsformen>

[0232] Examples of embodiments of the present invention are described below.

[0233] [1] A tire comprising a tread portion, the tread portion comprising one or more circumferential grooves, the tread portion being composed of a rubber composition comprising a rubber component and silica, the rubber component comprising an isoprene-based rubber and a styrene-butadiene rubber, a content of the isoprene-based rubber in the rubber component being 40 mass% or more, a styrene content S1 in mass% of the styrene-butadiene rubber being 30 or less, a content of the silica based on 100 parts by mass of the rubber component being 80 parts by mass or less, an acetone extractable amount AE in mass% of the rubber composition being greater than 17.0 mass%, preferably greater than 20.0 mass%, and more preferably greater than 22.0 mass% and less than 35.0 mass%,wherein a half-width of a peak within a range of -20 °C to -70 °C in a tanδ temperature distribution curve of the rubber composition is 35 °C or higher, and wherein, when 30 °CE* represents a complex elastic modulus at 30 °C of the rubber composition and H in mm represents a groove depth of a deepest part of the circumferential grooves, 30 °CE* / H is 1.25 or more.

[0234] [2] The tire of [1] above, where S1 is 22 or less.

[0235] [3] The tire of [1] or [2] above, wherein an average primary particle size of the silica is 18 nm or less.

[0236] [4] The tire of any one of [1] to [3] above, wherein the rubber composition comprises one or more resin components selected from the group consisting of a terpene-based resin, a C9-based resin, a dicyclopentadiene-based resin, and an aromatic vinyl-based resin.

[0237] [5] The tire of any one of [1] to [4] above, wherein the rubber composition comprises a resin component comprising dicyclopentadiene, styrene and indene as monomer components.

[0238] [6] The tire of one of [1] to [5] above, where 30 °CE* is 8.0 MPa or more.

[0239] [7] The tire of any one of [1] to [6] above, where 30 °CE* / H is 1.30 or more.

[0240] [8] The tire of any one of [1] to [7] above, wherein a total styrene amount S2 in mass% in the rubber component is 15 or less, and preferably 3 or more and 12 or less.

[0241] [9] The tire of any one of [1] to [8] above, wherein when 30 °C-tanδ represents a tanδ at 30 °C of the rubber composition and T in mm represents a total thickness of the tread portion, 30 °C-tanδ × T is 2.5 or more and 4.5 or less.

[0242]

[10] The tire according to any one of [1] to [9] above, wherein the rubber composition preferably comprises 20 parts by mass or more of carbon black based on 100 parts by mass of the rubber component.

[0243]

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

[10] above, wherein when R represents a land ratio of the tread portion, S1 × R is 11.0 or more, preferably 12.0 or more, and more preferably 13.0 or more and 20.0 or less.

[0244]

[12] The tire of any one of [1] to

[11] above, wherein when G in kg represents a tire weight, S1 / G is 3.0 or less, and preferably 1.2 or more and 2.7 or less.

[0245]

[13] The tire of any one of [1] to

[12] above, wherein the tread portion has a land portion separated by the one or more circumferential grooves, the land portion having lateral grooves extending to an inner side in a tire radial direction, and at least one of the lateral grooves has a groove width wider than a groove width on a tread surface on the inner side in the tire radial direction.

[0246]

[14] The tire of any one of [1] to

[13] above, wherein, in a tread surface of the tread portion, when an area of ​​30% of a tread ground contact width centered on a tire equator is defined as a center area and areas that are both outer sides of the center area and located inside the tread ground contact width are defined as a pair of shoulder areas, a groove depth of the deepest part of the circumferential groove present in the shoulder areas is 6.0 mm or more.

[0247]

[15] The tire of any one of [1] to

[14] above, wherein when t1 in mm represents a thickness of a layer of the tread portion whose outer surface forms a tread surface, and B in mm represents a thickness of a belt layer of the tread portion, B is 0.9 or more and 1.2 or less, and t1 / B is 7.0 or less. LIST OF REFERENCE SYMBOLS 1 tread section 2 side wall part 3 bead section 4 Carcass 5 belt layer 6 belt layer 7 inner liners 8 rim 9 Rim bead band 10 clinch section 11 Layer whose outer surface forms the tread surface (rubber top layer) 12 Rubber base layer 13 Bead Apex 14 Bead core CL Tire Equator H Groove depth of deepest part of circumferential grooves P Center in tire width direction N Line perpendicular to tangent plane at point P T Total thickness of tread section B Thickness of belt layer t1 Layer thickness, the outer surface of which forms the tread surface (rubber top layer) t2 Thickness of rubber base layer 15 circumferential groove 16 Tread surface 17 Straight line connecting ends of circumferential groove 18 Extension line of outer surface of rubber base layer 19 Extension line of deepest part of circumferential groove 20 bridge section 21 middle bridge section 22 shoulder bar section 31 side groove 32 side groove TW tread ground contact width CR mid-range SR shoulder area The tread end 40 grooved base 41 Grooved edge 42 grooved wall W1 Opening width (groove width on tread surface) C1 Amount of recess from groove edge to groove bottom C2 Amount of depression from groove edge to groove bottom QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2022-182842 A

[0002] JP 2021-54377 A [0032, 0033] JP 2009-2594 A

[0146] EP 3427975 A

[0155] JP 6856781 B [0155, 0156] EP 3173251 A

[0156] Cited non-patent literature

[0000] JIS K 6239-2:2017

[0061] JIS K 6220-1:2015 7.7

[0066] JIS K 6226-2:2003

[0154] Rubber Chemistry and Technology", vol. 85, no. 3, pp. 408-449 (2012), especially pages 438, 440 and 442

[0155] A Comparison of Surface Morphology and Chemistry of Pyrolytic Carbon Blacks with Commercial Carbon Blacks, Powder Technology 160 (2005) 190-193

[0155] JIS K 6316:2017

[0193] < / gesamtleistung> < / nasshaftungsleistung> < / abriebfestigkeit> < / wachs> < / verarbeitungshilfsmittel> < / gehalt> < / erweichungspunkt> < / weichmacher> < / silankupplungsmittel> < / kautschukkomponente>

Claims

[1] Tire comprising a tread portion, wherein the tread portion comprises one or more circumferential grooves, wherein the tread portion is constructed from a rubber composition comprising a rubber component and silicon dioxide, wherein the rubber component comprises an isoprene-based rubber and a styrene-butadiene rubber, wherein a content of the isoprene-based rubber in the rubber component is 40 mass% or more, wherein a styrene content S1 in mass% of the styrene-butadiene rubber is 30 or less, wherein a content of the silicon dioxide based on 100 parts by mass of the rubber component is preferably 80 parts by mass or more, wherein an acetone-extractable amount AE in mass% of the rubber composition is greater than 17.0 mass%, wherein a half-width of a peak within a range of -20 °C to -70 °C in a tanδ temperature distribution curve of the rubber composition is 35 °C or higher, and where, when 30 °CE* represents a complex elastic modulus at 30 °C of the rubber composition and H in mm represents a groove depth of a deepest part of the circumferential grooves, 30 °CE* / H is 1.25 or more. [2] The tire of claim 1, wherein S1 is 22 or less. [3] The tire according to claim 1 or 2, wherein an average primary particle size of the silica is 18 nm or less. [4] The tire according to any one of claims 1 to 3, wherein the rubber composition comprises one or more resin components selected from the group consisting of a terpene-based resin, a C9-based resin, a dicyclopentadiene-based resin, and an aromatic vinyl-based resin. [5] A tire according to any one of claims 1 to 4, wherein the rubber composition comprises a resin component comprising dicyclopentadiene, styrene and indene as monomer components. [6] A tire according to any one of claims 1 to 5, wherein 30 °CE* × R is 8.0 MPa or more. [7] A tire according to any one of claims 1 to 6, wherein 30 °CE* / H is 1.30 or more. [8] A tire according to any one of claims 1 to 7, wherein a total styrene amount S2 in mass% in the rubber component is 15 or less. [9] A tire according to any one of claims 1 to 8, wherein when 30°C-tanδ represents a tanδ at 30°C of the rubber composition and T in mm represents a total thickness of the tread portion, 30°C-tanδ × T is 2.5 or more and 4.5 or less. [10] The tire according to any one of claims 1 to 9, wherein the rubber composition comprises 20 parts by mass or more of carbon black based on 100 parts by mass of the rubber component. [11] A tire according to any one of claims 1 to 10, wherein when R represents a land ratio of the tread portion, S1 × R is 11.0 or more. [12] A tire according to any one of claims 1 to 11, wherein, when G in kg represents a tire weight, S1 / G is 3.0 or less. [13] Tire according to one of claims 1 to 12, wherein the tread portion has a land portion separated by the one or more circumferential grooves, wherein the land portion has lateral grooves extending in a tire radial direction toward an inner side, and wherein at least one of the lateral grooves has a groove width wider than a groove width on a tread surface on the inner side in the tire radial direction. [14] The tire according to any one of claims 1 to 13, wherein, in a tread surface of the tread portion, when a region of 30% of a tread ground contact width centered on a tire equator is defined as a center region and regions that are both outer sides of the center region and are inside the tread ground contact width are defined as a pair of shoulder regions, a groove depth of the deepest part of the circumferential groove present in the shoulder regions is 6.0 mm or more. [15] A tire according to any one of claims 1 to 14, wherein when t1 in mm represents a thickness of a layer of the tread portion whose outer surface forms a tread surface and B in mm represents a thickness of a belt layer of the tread portion, B is 0.9 or more and 1.2 or less, and t1 / B is 7.0 or less.

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