Tire

Abstract

To provide a tire with improved durability performance.SOLUTION: A tire includes a tread, side walls, clinches, a pair of bead parts in each of which a bead core is embedded; an inner liner; and at least one tire member having a steel cord. The at least one tire member having the steel cord includes at least one layer ply having a steel cord of a 1×4 structure.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a tire. [Background technology]

[0002] Various methods for improving various tire performances have been studied in the past. For example, Patent Document 1 describes a heavy-duty pneumatic tire that is equipped with a belt including a large number of parallel belt cords and a band including a spirally wound band cord, thereby suppressing deformation due to running and achieving improved resistance to uneven wear. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-47999 A Summary of the Invention [Problem to be solved by the invention]

[0004] On the other hand, from the viewpoint of improving life performance, improvement in the durability of tires is desired, and therefore it is considered that further improvement in the durability of tires is desired. An object of the present invention is to solve the above-mentioned problems and to improve the durability. [Means for solving the problem]

[0005] The present invention relates to Tread and The sidewall and Clinch and A pair of bead portions each having a bead core embedded therein; An inner liner, At least one tire component having a steel cord, The at least one tire component having the steel cords is a tire including at least one ply having steel cords of 1×4 construction. Effect of the Invention

[0006] According to the present invention, a tire having improved durability performance is provided. [Brief description of the drawings]

[0007] [Figure 1] 1 is a cross-sectional view of a tire taken along a plane passing through the tire rotation axis. [Diagram 2] FIG. 1 is a diagram showing a schematic diagram of a tread pattern of a tire. [Diagram 3] FIG. 1 is a diagram showing a schematic diagram of a tread pattern of a tire. [Figure 4] FIG. 2 is a schematic diagram showing a belt layer as viewed in a tire radial direction. [Diagram 5] FIG. 2 is a schematic diagram showing a cross section of a belt layer taken along a plane passing through a tire rotation axis. [Figure 6] FIG. 2 is a schematic diagram showing a cross section of one belt ply taken along a plane perpendicular to the longitudinal direction of the belt cords. [Figure 7] 1 is a cross-sectional view of a run-flat tire taken along a plane passing through a tire rotation axis. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] One embodiment of the present invention is a tire comprising a tread, a sidewall, a clinch, a pair of bead portions each having a bead core embedded therein, an inner liner, and at least one tire component having a steel cord, the at least one tire component having a steel cord including at least one ply having a 1x4 steel cord structure.

[0009] The steel cord preferably has an outer diameter D mm of 0.50 mm or less.

[0010] The number of the steel cords arranged per 50 mm in the tire width direction is preferably 60 cords / 50 mm or less.

[0011] The tread is made of a rubber composition containing a rubber component, and the tread includes a cap rubber layer that constitutes a tread ground contact surface, and the tan δ at 30° C. (30° C. tan δTc) of the cap rubber layer and the thickness G of the tread T mm (30℃ tan δ Tc ×G T ) is preferably 9.0 or less.

[0012] The tread is made of a rubber composition containing a rubber component, the tread includes a cap rubber layer that constitutes a tread contact surface, and the tread has a thickness G T The complex modulus of elasticity of the cap rubber layer at 30°C (30°C E* Tc ) ratio (30℃E* Tc / G T ) is preferably 0.2 or less.

[0013] The land area ratio of the tread is preferably 40% or more.

[0014] The sidewall is made of a rubber composition containing a rubber component, and the tan δ at 70° C. of the rubber composition (70° C. tan δ s ) is preferably 0.03 or more and 0.20 or less.

[0015] The sidewall is made of a rubber composition containing a rubber component, and the complex modulus of elasticity at 70° C. (70° C.E* s ) is preferably 2.5 MPa or more and 6.5 MPa or less.

[0016] It is preferable that the ratio (Hc / Ht) of the clinch height Hcmm to the tire cross-sectional height Htmm is 0.45 or less.

[0017] The clinch is made of a rubber composition containing a rubber component, and the tan δ at 70° C. (70° C. tan δ cThe product of the heat transfer coefficient Hcmm and the clinch height Hcmm (70° C. tan δc×Hc) is preferably 0.6 or more and 14.0 or less.

[0018] The clinch is preferably composed of a rubber composition containing a rubber component, and the ratio (70°C E*c / Hc) of the complex modulus of elasticity at 70°C (70°C E*c) of the rubber composition to Hcmm is preferably 0.07 or more and 0.75 or less.

[0019] The clinch is made of a rubber composition containing a rubber component, and when the complex modulus of the rubber composition at 70 ° C. is 70 ° C. E * c, the thickness G of the clinch is c mm and 70℃E*c product (G c ×70°C E*c) is preferably 25 or more and 450 or less.

[0020] The bead portion includes a bead apex, the bead apex being made of a rubber composition containing a rubber component, and the tire radial direction height H of the bead apex BA mm and tan δ(70°C) of the rubber composition BA ) and its product (H BA ×70℃ tanδ BA ) is preferably 0.3 or more and 12.0 or less.

[0021] The bead portion includes a bead apex, the bead apex being made of a rubber composition containing a rubber component, and the tire radial direction height H of the bead apex BA mm and the complex modulus of elasticity of the rubber composition at 70 ° C. (70 ° C. E * BA ) and its product (H BA ×70℃E* BA ) is preferably 100 or more and 9000 or less.

[0022] The inner liner is made of a rubber composition containing a rubber component, and has a thickness G of the inner liner. I mm and the tan δ of the rubber component at 70°C (70°C tan δ I ) product (G I ×70℃ tanδI ) is preferably 0.02 or more and 1.40 or less.

[0023] It is preferable that the at least one tire component having the steel cord is a belt layer, and the belt layer includes at least one belt ply composed of a belt cord made of a steel cord having a 1×4 structure and a belt topping rubber covering the belt cord.

[0024] The thickness G of the belt ply b It is preferable that the thickness is 0.5 mm or more and 1.2 mm or less.

[0025] It is preferable that the belt cord is formed in a longitudinal direction, and the forming pitch P is 2.7 mm or more and 3.7 mm or less.

[0026] The strength of the belt cord is preferably 200N or more and 580N or less.

[0027] It is preferable that the occupied area ratio of the belt cord is 9% or more and 18% or less.

[0028] The tan δ of the belt topping rubber at 70°C (70°C tan δ BE ) is preferably 0.13 or more.

[0029] The 100% modulus of the belt topping rubber is preferably 5.0 MPa or more and 10.0 MPa or less.

[0030] The pull-out force of the steel cord from the belt topping rubber, measured in accordance with ASTM-1871, is preferably 500N or more and 2000N or less.

[0031] The belt layer is composed of two or more belt plies, and the distance G on the tire equatorial plane between two adjacent steel cord layers in a cross section passing through the tire rotation axis is BB It is preferable that the thickness is 0.5 mm or more.

[0032] The tire is preferably a passenger tire.

[0033] It is preferable that the at least one tire component having the steel cord is a band, and the band includes at least one band ply composed of a band cord made of a steel cord having a 1×4 structure and a band topping rubber covering the band cord.

[0034] The occupied area ratio of the band cord is preferably 30% or more and 60% or less.

[0035] The intermediate elongation of the band cord under a load of 44 N is preferably 1.2% or more and 9.5% or less.

[0036] The heat shrinkage rate of the band cord is preferably 0.1% or more and 5.0% or less.

[0037] The strength of the band cord is preferably 120N or more and 700N or less.

[0038] The tire is preferably a heavy duty tire.

[0039] [Definition] 1 shows a cross section including the tire's rotation axis, with the tire's width direction indicated as X and its radial direction indicated as Y. In addition, in the cross section including the tire's rotation axis, the center CL in the width direction is the tire equatorial plane.

[0040] "Normal condition" refers to a condition in which the tire is mounted on a normal rim, inflated to normal internal pressure, and unloaded. Unless otherwise specified, "the dimensions of each part of the tire" refers to values ​​specified in the normal condition, or when the tire is cut in a plane including the tire rotation axis (the tire equatorial plane) and the piece of tire is kept within the rim width of the normal rim.

[0041] "Genuine rim" refers to the rim that is specified for each tire by the standard system that includes the standard on which the tire is based, for example, "Standard rim" in the applicable size listed in the "JATMA YEAR BOOK" for JATMA (Japan Automobile Tire Manufacturers Association), "Measuring Rim" in the "STANDARDS MANUAL" for ETRTO (The European Tire and Rim Technical Organisation), and "Design Rim" in the "YEAR BOOK" for TRA (The Tire and Rim Association, Inc.). Refer to JATMA, ETRTO, and TRA in that order, and follow the standard if there is an applicable size at the time of reference. In the case of a tire not specified in the standard, it refers to the rim that can be assembled to the rim and can hold internal pressure, that is, the rim with the smallest rim diameter and the next narrowest rim width among the rims that do not leak air from between the rim and tire.

[0042] "Regular internal pressure" refers to the air pressure specified for each tire by each standard in the standard system including the standard on which the tire is based. For JATMA, it refers to the "Maximum Air Pressure", for ETRTO, it refers to the "INFLATION PRESSURE", and for TRA, it refers to the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES". As with "regular rims", refer to JATMA, ETRTO, and TRA in that order and follow those standards. For tires not specified in the standard, it refers to the regular internal pressure (250kPa or more) of another tire size (specified in the standard) that is specified with the regular rim as the standard rim. Note that if multiple regular internal pressures of 250kPa or more are specified, it refers to the smallest value among them.

[0043] "Normal load" means the load specified in the standard system including the standard on which the tire is based. The "maximum load capacity" in the JATMA standard, the "maximum value" listed in "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" in the TRA standard, and the "LOAD CAPACITY" in the ETRTO standard are normal loads, and like normal rims and normal internal pressures, they should be referenced in the order of JATMA, ETRTO, and TRA, and if there is an applicable size at the time of reference, that standard should be followed. For tires not specified in the standard, the normal load W is calculated as follows: L Request. V = {(Dt / 2) 2 -(Dt / 2-Ht) 2}×π×Wt W L =0.000011×V+175 V: Virtual volume of the tire (mm 3 ) Dt: Tire outer diameter Dt (mm) Ht: Section height of the tire (mm) Wt: tire section width (mm)

[0044] "Tire outer diameter Dt" refers to the outer diameter of the tire in a normal condition.

[0045] "Sectional width Wt of tire" refers to the maximum width between the outer surfaces of the sidewalls in a normal state, excluding any patterns or lettering on the sidewalls of the tire.

[0046] "Tire section height Ht" refers to the radial height of the tire in a section that includes the tire axis, and corresponds to half the difference between the tire's outer diameter Dt and the rim diameter R, where R is the tire rim diameter (mm). In other words, the section height Ht can be calculated by (Dt-R) / 2.

[0047] The "weight of the tire" refers to the weight of the tire itself, not including the weight of the rim. On the other hand, if the tire has sponge or sealant members or sensor members in the tire cavity, the weight includes these members.

[0048] A "groove" refers to a recess formed on the tread surface of a tire, and a groove with an opening width of less than 2 mm on the tread surface is called a "sipe." A groove whose width on the inner side in the tire's radial direction is wider than the groove width on the tread surface is called a "widened groove."

[0049] The term "circumferential groove" refers to a groove that extends continuously in the circumferential direction of the tire. The circumferential groove may extend linearly along the circumferential direction, or may extend in a wavy, sinusoidal, or zigzag shape along the circumferential direction.

[0050] "Groove depth" refers to the maximum straight-line distance between the straight line connecting the ends of the groove on the tread surface and the lowest point of the groove in the tire radial direction. If the groove depth of the groove varies in the tire width direction or circumferential direction, this maximum value is the groove depth of the groove. In addition, the depth at a point where multiple grooves intersect at three or more intersections is excluded from the groove depth.

[0051] The "groove angle" is the angle between a straight line obtained by connecting the ends of grooves provided in the tread and a straight line parallel to the tire circumferential direction.

[0052] The "ground contact area" refers to the area where the tread surface comes into contact with the ground when the tire is mounted on a standard rim, inflated to a standard internal pressure, and subjected to a standard load. The maximum width of the ground contact area in the tire width direction is called the "ground contact width TW."

[0053] "Land portion" means the area of ​​the tread bounded by said circumferential grooves and the ground contact edge of the ground contact area.

[0054] "Land portion width" refers to the maximum width of the land portion in the tire width direction.

[0055] The "land area ratio" is the ratio (%) of the area of ​​the ground contact area excluding the area of ​​the grooves to the total area of ​​the ground contact area when all the grooves present in the ground contact area are filled.

[0056] "Tread radius" means the radius of curvature of the circular arc formed by the tread surface from the intersection of the tire equatorial plane and the tread surface to the outer side in the tire width direction in a meridian cross section of the tire.

[0057] "The thickness of each rubber layer constituting the tread" refers to the thickness of each rubber layer constituting the tread in the radial direction of the tire on the tire equatorial plane. When the tread is formed from multiple rubber layers, the total thickness of those layers is called the "tread thickness G T In addition, when the tire has a groove on the equatorial plane, the thickness of the rubber layer at the center in the tire width direction of the land part closest to the equatorial plane of the tire is the thickness of each rubber layer constituting the tread, or the thickness G of the tread. T Let us assume that.

[0058] "The thickness of the rubber layer constituting the sidewall" refers to the thickness in a direction parallel to the tire width direction of the rubber layer forming the sidewall at the position where the distance between both sidewalls is the longest on a cross section including the tire rotation axis.

[0059] "The thickness of the rubber layer constituting the side reinforcing layer" is the maximum thickness in the tire width direction on a cross section including the tire rotation axis.

[0060] "The thickness of each rubber layer constituting the clinch" refers to the thickness of the rubber layer measured along the normal line of the main body of the carcass that passes through the point Pc where the sidewall and the clinch meet on the outer surface of the tire. When the clinch is formed from multiple rubber layers, the sum of their thicknesses is the "thickness Gc of the clinch."

[0061] "Thickness of inner liner", "thickness of carcass", "thickness of belt layer" and "thickness of band (belt reinforcing layer)" refer to the thickness of each layer of each component in the tire radial direction on the equatorial plane of a cross section including the tire rotation axis. If the component does not exist on the equatorial plane, it refers to the thickness of each layer of the component in the tire radial direction at the center position of the component in the tire width direction.

[0062] The "side reinforcing layer height" and "height of the radially outer end of the clinch" are the linear distances from the lower end to the upper end of each component in the radial direction of the tire on a cross section including the tire rotation axis.

[0063] The "height of the bead apex" is the linear distance from the lower end of the bead core to the radially outer end of the bead apex on a cross section including the tire rotation axis. If a bead reinforcing layer is provided, it is the linear distance to the radially outer end of the bead apex including the bead reinforcing layer.

[0064] "Filament" refers to the smallest unit that forms a steel cord or a fiber cord. A yarn is made by twisting together multiple filaments.

[0065] The "outer diameter of the filament" is the diameter of the cross section perpendicular to the longitudinal direction of the filament forming the steel cord or fiber cord. When the cross-sectional shape of the filament has a major axis and a minor axis, such as an ellipse, the simple average of these axes is treated as the outer diameter of the filament.

[0066] The "outer diameter of a yarn" refers to the diameter of a circumscribing circle of the yarn in a cross section perpendicular to the longitudinal direction of the yarn, when the steel cord or fiber cord is formed by twisting together a plurality of filaments to form a yarn.

[0067] The "outer diameter D of the cord" is the diameter of the cross section perpendicular to the longitudinal direction of the steel cord or fiber cord. If the cord is a cord made by twisting together multiple filaments or yarns, the diameter of the circumscribed circle is defined as the cord diameter. If the cord is not twisted and has a long axis and a short axis, such as a flat cross-sectional shape, the simple average of the long axis and the short axis is treated as the outer diameter of the cord.

[0068] "Number of arranged cords" refers to the number of arranged cords per 50 mm in the arrangement direction in a cross section perpendicular to the longitudinal direction of the steel cord or fiber cord.

[0069] The "area ratio of the cord" is the area ratio of the cord in a cross section perpendicular to the longitudinal direction of the steel cord or fiber cord in a member containing the cord. The cross-sectional area of ​​one cord is S (mm 2 ), the number of cords arranged is E (cords / 50 mm), and the thickness of the component is G (mm), it is defined as S × E / 50 × G × 100%.

[0070] When the cord is a fiber cord, the "fineness" refers to the weight (g) per 1000 m of the fiber cord, and the fineness of the entire cord is called the "total fineness."

[0071] "Twists" refers to the number of twists (turns / 10 cm) per 10 cm in the longitudinal direction of the steel cord or fiber cord inside the tire. If the cord is made of multiple yarns each made of multiple twisted filaments, the number of twists of the filaments in the yarn is called the primary twist, and the number of twists when the yarns in the cord are twisted together is called the final twist.

[0072] The "twist factor" is calculated using the number of twists and the cord fineness according to the following formula: Twist factor = number of twists x fineness 1 / 2 .

[0073] "Forming" refers to forming a wavy shape in the longitudinal direction of a steel cord or fiber cord.

[0074] The "intermediate elongation" is a value measured in accordance with the test method for "elongation at constant load" of JIS L 1017.

[0075] The "heat shrinkage rate" is the dry heat shrinkage rate (%) of a sample cord measured in accordance with JIS L 1017:2002 "Testing method for synthetic fiber tire cords" under the conditions of a sample length of 500 mm and heating conditions of 150°C x 30 minutes. The measurement is performed by the same method for both steel cords and organic fiber cords.

[0076] "Cord strength" refers to the force (N: Newton) measured when a tensile test is conducted in accordance with JIS G 3510:1992 "Testing methods for steel tire cords" in the case of steel cords. In the case of fiber cords, it refers to the force (N: Newton) measured when a tensile test is conducted at a temperature of 20°C in accordance with JIS L 1017:2002 "Testing methods for synthetic fiber tire cords."

[0077] The "elastic modulus of the cord" refers to the elastic modulus (cN / dtex) of a single cord calculated from the slope (ss curve) when the single cord is stretched by 1.5% in accordance with JIS L 1017:2002 "Testing methods for synthetic fiber tire cords." The measurement is performed by the above-mentioned measurement method whether the cord is a steel cord or a fiber cord.

[0078] The "cord pull-out force" is the maximum load (N) until the cord is pulled out, measured at room temperature (23°C) and at a speed of 50 mm / min in accordance with ASTM-1871 "Standard Test Method for Adhesion Between Tire Bead Wire and Rubber."

[0079] "Styrene content (mass%) of rubber component" is the sum of all the values ​​calculated by multiplying the styrene content of each rubber that constitutes the entire rubber component (100 mass%) by its styrene content in the entire rubber component.

[0080] "Vinyl content of rubber component (mass%)" is calculated by multiplying the vinyl butadiene unit content derived from 1,2-butadiene bonds of each rubber constituting the entire rubber component (100 mass%) by its content in the entire rubber component, and then adding up all the results.

[0081] The "glass transition temperature of a rubber composition" is the temperature at which the loss tangent (tan δ) in the temperature dispersion curve of the rubber composition after vulcanization in the range of -60°C to 40°C gives the maximum value of tan δ. In the range of -60°C to 40°C, when tan δ continues to increase with increasing temperature, the glass transition temperature of the rubber composition is 40°C according to the above definition. On the other hand, when tan δ continues to decrease with increasing temperature in the range of -60°C to 40°C, the glass transition temperature of the rubber composition is similarly -60°C. In addition, when there are two or more points at which tan δ is maximum in the range of -60°C to 40°C, the lowest temperature among them is treated as the glass transition temperature of the rubber composition.

[0082] The "rubber component of the rubber composition" refers to a component that contributes to crosslinking in the rubber composition, and generally has a weight average molecular weight (Mw) of 10,000 or more.

[0083] "Softener" is a material that imparts plasticity to the rubber component, and is a component that is extracted from the rubber composition using acetone. Softeners include softeners that are liquid (liquid state) at 25°C and softeners that are solid at 25°C. However, this does not include wax and stearic acid that are commonly used in the tire industry.

[0084] The "softener content" includes the amount of softener contained in the extended rubber component that has been extended in advance with a softener such as oil, a resin component, a liquid rubber component, etc. The same applies to the oil content, the resin component content, and the liquid rubber content. For example, if the extended component is oil, the extended oil is included in the oil content.

[0085] The "amount of sulfur in a rubber composition" refers to the amount of sulfur contained in the entire rubber composition, which is derived from a crosslinking agent, a vulcanization accelerator, carbon black, etc. contained in the rubber composition.

[0086] The "glass transition temperature of the rubber component" is the average value obtained by multiplying the glass transition temperature of each rubber component constituting the rubber composition by the mass% contained in the rubber component. The glass transition temperature of each rubber component is different from the glass transition temperature of the rubber composition and is the static glass transition temperature of each rubber component determined by a differential scanning calorimeter (DSC).

[0087] [Measurement method] The "contact area" is obtained by mounting the tire on a standard rim, inflating it to the standard internal pressure, applying ink to the surface of the tire tread, applying the standard load, pressing it vertically onto cardboard, and transferring it. The same transfer process is performed by rotating the tire 72 degrees each time, obtaining a total of five locations, and then calculating the average maximum width of each contact area shape to calculate the "contact width TW."

[0088] "Land width" refers to the maximum width in the tire width direction of each land portion in the shape of the contact area at five points obtained in measuring the contact area, and the average value of the maximum widths of the same land portion obtained in the measurements at five points is used.

[0089] The "land area ratio" can be calculated by finding the ratio (%) of the area of ​​the five contact zone shapes to the average of the five total areas obtained by smoothly joining the outer ring corners interrupted by the grooves in the shapes of the five contact zone shapes obtained in the measurement of the contact zone. In other words, it can be calculated as the average area of ​​the five contact zone shapes ÷ the average area of ​​the five total areas × 100.

[0090] The "groove width" can be determined from the length between the groove edges as seen on the tread surface in a tire meridian cross section.

[0091] "Thickness of each rubber layer constituting the tread", "Thickness of the rubber layer constituting the sidewall", "Thickness of the rubber layer constituting the side reinforcement layer", "Thickness of each rubber layer constituting the clinch", "Thickness of the inner liner", "Thickness of the carcass layer", "Thickness of the belt layer", "Thickness of the belt reinforcement layer", "Height of the side reinforcement layer", "Height of the clinch", and "Height of the bead apex" are the average values ​​measured on a cross section including the tire rotation axis at five points after rotating the tire 72 degrees each. These can be measured by creating a cross-sectional section including the tire rotation axis and aligning the space between the beads to the regular rim width.

[0092] The "outer diameter of the filament," "outer diameter of the yarn," "outer diameter of the cord," "cross-sectional area of ​​the cord," and "number of arranged cords" can be calculated from the average value of each value determined within a range of ±25 mm from the intersection with the equatorial plane in a cross-sectional section cut out in the longitudinal direction of the cord. If the arrangement direction of the cord is perpendicular to the circumferential direction of the tire, the values ​​can be determined by calculating each value of the cord within an arbitrary range of 50 mm for the cut cord on the equatorial plane.

[0093] The "fineness" can be calculated by calculating the weight of a 1000m length of the fiber cord after removing the covering rubber layer attached around the fiber cord extracted from the tire. If it is not possible to extract 1000m of the fiber cord from the tire, the fineness can be calculated by extracting a length of 10cm or more and calculating the weight per 1000m.

[0094] The "loss tangent and complex modulus of rubber composition" are the loss tangent (tan δ) and complex modulus E* (MPa) under each condition measured in extension mode using a dynamic viscoelasticity measuring device (for example, Iplexer series manufactured by GABO). The sample used for dynamic viscoelasticity measurement is a vulcanized rubber composition having a length of 20 mm, a width of 4 mm, and a thickness of 1 mm. When cutting out a sample from a tire to prepare a sample, if the member for preparing the sample is a tread, a belt reinforcing layer, a belt layer, or an inner liner, the length direction is aligned with the tire circumferential direction, and the thickness direction is aligned with the tire radial direction. If the member for preparing the sample is a sidewall, a clinch, a bead apex, or a side reinforcing layer, the length direction of the sample is aligned with the tangent direction to the tire circumferential direction, and the thickness direction is aligned with the tire width direction. In any case, the sample is prepared in a state where the sample is as close to the specified dimensions as possible. This is because the strain applied to the sample is normalized to the length, and both tan δ and E* measured are normalized to the width and thickness of the sample, so it is considered that there is no effect from the size of the sample. Tan δ at 0°C is measured under the conditions of temperature 0°C, frequency 10Hz, initial strain 10%, and dynamic strain ±2.5%. E* at 0°C is measured under the conditions of temperature 0°C, frequency 10Hz, initial strain 10%, and dynamic strain ±2.5%. Tan δ and E* at 30°C are measured under the conditions of temperature 30°C, frequency 10Hz, initial strain 5%, and dynamic strain ±1%. Tan δ and E* at 70°C are measured under the conditions of temperature 70°C, frequency 10Hz, initial strain 5%, and dynamic strain ±1%.

[0095] The "glass transition temperature of a rubber composition" is measured in extension mode using a dynamic viscoelasticity measuring device (e.g., Iplexer series manufactured by GABO) on a sample prepared in the same manner as the loss tangent and complex modulus of a rubber composition. The temperature distribution curve of tan δ is measured in the range from -60°C to 40°C under the conditions of a frequency of 10Hz, an initial strain of 10%, a dynamic strain of ±0.5%, and a heating rate of 2°C / min, and the glass transition temperature is determined as the temperature corresponding to the largest tan δ value in the obtained temperature distribution curve.

[0096] The "Shore hardness of a rubber composition" is measured by pressing a type A durometer against a sample at 23°C in accordance with JIS K 6253. When a hardness measurement sample is prepared from a test tire, if the sample is a tread, the tread is cut out from the surface side forming the contact surface of the test tire so that the tire radial direction is the thickness direction, and a type A durometer is pressed against the sample from the surface side for measurement. If the sample is a member other than a tread, the tire is cut out at a cross section including the rotation axis, the cross section is smoothed, and then a type A durometer is pressed against the member from the cross-sectional direction for measurement.

[0097] The "100% modulus of the rubber composition", "breaking strength of the rubber composition", and "breaking elongation of the rubber composition" are the stress at 100% elongation (MPa), breaking strength (MPa), and breaking elongation (%) when a tensile test is performed on a 1 mm thick dumbbell-shaped test piece in accordance with JIS K 6251 "Vulcanized rubber and thermoplastic rubber - Determination of tensile properties" at a tensile speed of 3.3 mm / sec in a 23°C atmosphere. The longitudinal direction and thickness direction when the measurement sample is prepared from the test tire are the same as those of the measurement sample for tan δ and E* of the rubber composition. In addition, if it is difficult to take the sample at a thickness of 1 mm, the sample is taken as close to 1 mm as possible. This is because the 100% modulus, breaking strength, and breaking elongation are all measured as standardized values, and therefore are considered to be unaffected by the thickness.

[0098] The "glass transition temperature of the rubber component" is measured in accordance with JIS K 7121 using a differential scanning calorimeter (e.g., a differential scanning calorimeter (Q200) manufactured by TA Instruments Japan, Inc.) while increasing the temperature at a rate of 10°C / min.

[0099] "Styrene content" is 1 This is a value calculated by H-NMR measurement and is applied to, for example, rubber components having repeating units derived from styrene (styrene unit-containing rubber), such as SBR.

[0100] "Vinyl content (amount of 1,2-bonded butadiene units)" is a value calculated by infrared absorption spectroscopy in accordance with JIS K 6239-2:2017, and applies to rubber components having repeating units derived from butadiene, such as SBR and BR.

[0101] The "cis content (amount of cis-1,4-bonded butadiene units)" is a value calculated by infrared absorption spectroscopy in accordance with JIS K 6239-2:2017, and is applied to rubber components having repeating units derived from butadiene, such as BR.

[0102] The "weight average molecular weight (Mw)" can be determined by converting the measured value into standard polystyrene equivalent value using gel permeation chromatography (GPC) (e.g., GPC-8000 series manufactured by Tosoh Corporation, detector: differential refractometer, column: TSKGEL SUPERMALTIPORE HZ-M manufactured by Tosoh Corporation). For example, it is applied to SBR, BR, softeners, etc.

[0103] The "nitrogen adsorption specific surface area (N2SA) of carbon black" is measured in accordance with JIS K 6217-2:2017. The "nitrogen adsorption specific surface area (N2SA) of silica" is measured by the BET method in accordance with ASTM D3037-93.

[0104] The "average primary particle size" is calculated by photographing particles with a transmission or scanning electron microscope and taking the arithmetic average of the particle sizes of 400 particles. If the particle shape is nearly circular, the diameter of the circle is used as the particle size, if it is needle-like or rod-like, the short diameter is used as the particle size, and in other cases, the equivalent circle diameter is calculated from the electron microscope image. The equivalent circle diameter is calculated as "4 x (particle area) / positive square root of π". The average primary particle size is applied to silica, carbon black, etc.

[0105] The "softening point of the resin component" is the temperature at which the ball drops when the softening point specified in JIS K 6220-1:2001 is measured using a ring and ball softening point tester.

[0106] [tire] Hereinafter, a tire according to an embodiment of the present invention will be described with reference to the drawings. Note that the embodiment described below is merely an example, and the tire of the present invention is not limited to the embodiment described below.

[0107] Fig. 1 is a drawing illustrating a cross section including the rotation axis of a tire. In Fig. 1, the Y direction is the radial direction of the tire 1, and the X direction is the width direction of the tire 1. The tread 2 includes a cap rubber layer 2a that constitutes the tread contact surface and a base rubber layer 2b that is disposed on the innermost side of the tread in the tire radial direction.

[0108] In addition, while Fig. 1 shows an example of a two-layer structure tread 2 consisting of a cap rubber layer 2a and a base rubber layer 2b, the tread 2 may be a single-layer structure tread or a tread having a structure of three or more layers. The tread 2 may also have a plurality of different rubber layers in the width direction of the tire. In Fig. 1, the cap rubber layer 2a is divided by circumferential grooves, resulting in a plurality of rubber layers in the width direction of the tire.

[0109] In addition, when the amount of carbon black contained in the rubber composition of the cap rubber layer of the tread 2 is small and it is difficult to ensure electrical conductivity, the tread 2 may be provided with an electrically conductive rubber member 2c.

[0110] Tread 2 thickness G T is preferably 4.0 mm or more, more preferably 4.5 mm or more, and even more preferably 5.0 mm or more. On the other hand, the upper limit is not particularly limited, but is preferably 18.0 mm or less, more preferably 17.0 mm or less, and even more preferably 16.0 mm or less.

[0111] When the tread 2 is formed of a plurality of rubber layers in the tire radial direction, the thickness G of the cap rubber layer of the tread 2 TC is preferably 1.0 mm or more, and more preferably 2.0 mm or more. On the other hand, although there is no particular upper limit, it is preferably 16.0 mm or less, and more preferably 14.0 mm or less.

[0112] In addition, when the tread 2 is formed of a plurality of rubber layers, the thickness G of the base rubber layer of the tread 2 TB is preferably 0.5 mm or more, more preferably 0.7 mm or more, and even more preferably 1.0 mm or more. On the other hand, although there is no particular upper limit, it is preferably 8.0 mm or less, more preferably 7.5 mm or less, and even more preferably 7.0 mm or less.

[0113] In addition, when the tread 2 is formed of multiple rubber layers, the thickness G of the tread 2 T Thickness G of the cap rubber layer forming the tread 2 Tc Ratio (G Tc / G T ) is preferably 0.10 or more, and more preferably 0.15 or more. On the other hand, although there is no particular upper limit, it is preferably 0.95 or less, and more preferably 0.90 or less.

[0114] In addition, when the tread 2 is formed of multiple rubber layers, the thickness G of the tread 2 T The thickness G of the base rubber layer of the rubber layer forming the tread 2 TB Ratio (G TB / G T ) is preferably 0.70 or less, and more preferably 0.50 or less. On the other hand, although there is no particular lower limit, it is preferably 0.05 or more, and more preferably 0.10 or more.

[0115] The tan δ of the cap rubber layer of the tread 2 at 0°C (0°C tan δ TC ) is preferably 0.20 or more and 0.90 or less.

[0116] The tan δ of the cap rubber layer of the tread 2 at 30°C (30°C tan δ TC ) is preferably 0.10 or more and 0.40 or less.

[0117] E* of the cap rubber layer of the tread 2 at 30°C (30°C E* TC The compressive strength (MPa) is preferably 4.0 MPa or more and 25 MPa or less.

[0118] The glass transition temperature (Tg TC :°C) is preferably -60°C or higher and 0°C or lower.

[0119] Hardness of the cap rubber layer of the tread 2: HS TC is preferably 55 or more and 80 or less.

[0120] Modulus M100 of the cap rubber layer of tread 2 at 100% elongation TC (MPa) is preferably 0.5 MPa or more and 5.0 MPa or less.

[0121] Breaking strength TB of the cap rubber layer of tread 2 TC (MPa) is preferably 10 MPa or more and 30 MPa or less.

[0122] Breaking elongation EB of the cap rubber layer of tread 2 TC (%) is preferably 350% or more and 900% or less.

[0123] The tan δ of the base rubber layer of the tread 2 at 70°C (70°C tan δ TB ) is preferably 0.25 or less, more preferably 0.20 or less, and even more preferably 0.15 or less. There is no particular lower limit, but it is preferably 0.01 or more, more preferably 0.02 or more, and even more preferably 0.03 or more.

[0124] E* of the base rubber layer of tread 2 at 70°C (70°C E* TB) is preferably 1.5 MPa or more, more preferably 2.0 MPa or more, and even more preferably 3.0 MPa or more. On the other hand, the upper limit is not particularly limited, but is preferably 25.0 MPa or less, more preferably 20 MPa or less, and even more preferably 15 MPa or less.

[0125] Glass transition temperature Tg of the base rubber layer of tread 2 TB is preferably 0° C. or lower, more preferably −15° C. or lower, and further preferably −20° C. or lower. There is no particular restriction on the lower limit, but −60° C. or higher is preferred.

[0126] Hardness of the base rubber layer of tread 2 HS TB is preferably 40 or more and 75 or less.

[0127] Modulus M100 of the base rubber layer of tread 2 at 100% elongation TB is preferably 1.5 MPa or more and 10.0 MPa or less.

[0128] Breaking strength TB of the base rubber layer of tread 2 TB is preferably 10 MPa or more and 40 MPa or less.

[0129] Breaking elongation EB of the base rubber layer of tread 2 TB is preferably 150% or more and 500% or less.

[0130] When the tread 2 is formed from three or more rubber layers, the 0°C tan δ, 0°C E*, 30°C tan δ, 30°C E*, 70°C tan δ, 70°C E*, Tg, HS, M100, TB and EB of the intermediate rubber layers other than the cap rubber layer and the base rubber layer are not particularly limited and can be set to any range depending on the application.

[0131] The physical properties of the rubber composition, such as tan δ, E*, rubber hardness Hs, modulus, TB, EB, etc., can be appropriately adjusted by the types and amounts of the rubber components, fillers, softeners, etc., described below. For example, the 30°C E* can be increased by increasing the amount of the filler in the rubber composition or decreasing the content of the softener, and the rubber hardness Hs can be increased by increasing the amount of the filler in the rubber composition or decreasing the content of the softener.

[0132] The tread may have a circumferential groove extending in the circumferential direction. In the tire 1, the tread has two circumferential grooves 12 extending in the circumferential direction. The circumferential grooves 12 may extend linearly along the circumferential direction, may be curved along the circumferential direction, or may extend in a zigzag manner along the circumferential direction. The circumferential grooves 12 do not necessarily need to be continuous without interruption in the circumferential direction, and may be divided by, for example, lateral grooves.

[0133] Groove depth D of the deepest part of the circumferential groove 12 S is preferably 3.0 mm or more, more preferably 3.5 mm or more, and even more preferably 4.0 mm or more. On the other hand, the upper limit is not particularly limited, but is preferably 15.0 mm or less, preferably 14.0 mm or less, and even more preferably 12.0 mm or less.

[0134] Tread 2 thickness G T and the groove depth D of the deepest part of the circumferential groove 12 S Difference (G T -D S ) is preferably 5.0 mm or less, more preferably 3.0 mm or less, and more preferably 2.0 mm or less. On the other hand, although there is no particular restriction on the lower limit, it is preferably 0.2 mm or more, more preferably 0.3 mm or more, and even more preferably 0.5 mm or more.

[0135] Tread 2 thickness G T and 30℃ tanδ of the cap rubber layer of tread 2 TC Product of (30℃ tan δ TC ×G T) is preferably 9.0 mm or less.

[0136] Tread 2 thickness G T 30℃E* of the cap rubber layer of tread 2 TC Ratio (30℃E* TC / G T ) is preferably 0.2 MPa / mm or more.

[0137] When the tread 2 is formed of three or more rubber layers, the thickness G of the cap rubber layer of the tread 2 TC is the groove depth D of the deepest part of the circumferential groove 12 S It is preferable that it is smaller than .

[0138] The maximum opening width W of the circumferential groove 12 in the tire width direction on the tread surface S is preferably 2.0 mm or more and 15.0 mm or less.

[0139] The circumferential groove 12 has an opening width W S Alternatively, the groove may be a widened groove whose width increases on the inner side in the tire radial direction.

[0140] A schematic diagram of an example of a tread pattern is shown in Figure 2. As shown in Figure 2, the tread pattern has three circumferential grooves 12 extending continuously in the tire circumferential direction, lateral grooves 13 and 18 extending in the tire width direction, and sipes 14 and 15.

[0141] 2, three circumferential grooves 12 are provided, but the number of circumferential grooves is not particularly limited and may be, for example, 2 to 5. Furthermore, although the circumferential grooves 12 extend linearly along the circumferential direction, they are not limited to this form and may extend, for example, in a wave-like, sinusoidal, or zigzag shape along the circumferential direction.

[0142] The tread pattern in Fig. 2 has land portions 16, 17 separated by three circumferential grooves 12 and a tread ground contact edge Te. The pair of land portions 17 separated by the outermost circumferential groove 12 in the tire width direction and the tread ground contact edge Te is called a shoulder land portion, and the land portion 16 present on the inner side of the shoulder land portion in the tire width direction is called a center land portion. In Fig. 2, there are two shoulder land portions and two center land portions, totaling four, but the number of land portions is not particularly limited and may be, for example, one to six.

[0143] The land portion may be provided with lateral grooves (widthwise grooves) and / or sipes. In Fig. 2, the shoulder land portion 17, which is separated by two tread ground contact edges Te and the circumferential groove 12, is provided with a plurality of shoulder lateral grooves 13 whose ends open into the circumferential groove 12 and the ground contact edge Te, and a plurality of shoulder sipes 14 whose one end opens into the circumferential groove 12. In addition to the above embodiment, the tire may be provided with a lateral groove whose one end opens into the circumferential groove 12 and whose other end terminates within the land portion 17, or a sipe whose one end opens into the circumferential groove 12 and whose other end opens into the ground contact edge Te.

[0144] When the shoulder land portion 17 has shoulder lateral grooves 13, the interval between the shoulder lateral grooves 13 in the tire circumferential direction is preferably 3.0 mm or more. On the other hand, the interval between the shoulder lateral grooves 13 is not particularly limited, but is preferably 80.0 mm or less.

[0145] When the shoulder land portion 17 has a shoulder lateral groove 13, the groove depth D of the shoulder lateral groove 13 SH The upper limit is preferably 17.0 mm or less, and more preferably 15.0 mm or less.

[0146] When the shoulder land portion 17 has a shoulder lateral groove 13, the groove angle C is an angle between the longitudinal direction of the shoulder lateral groove 17 and the tire width direction on the tread surface. S It is preferable that the angle is in the range of 75 to 115 degrees.

[0147] Width W of one shoulder land part 17 LS It is preferable that the width of each of the pair of shoulder land portions 17 is equal to or less than 40% of the contact width TW.

[0148] When the shoulder land portion 17 has shoulder sipes 14, the spacing between the shoulder sipes 14 in the tire circumferential direction is preferably 1.0 mm or more. On the other hand, the upper limit of the spacing between the shoulder sipes 14 is not particularly limited, but is preferably 60.0 mm or less.

[0149] When the shoulder land portion 17 has the shoulder sipes 14, the depth of the shoulder sipes 14 is preferably 2.0 mm or more. On the other hand, although there is no particular upper limit, it is preferably 10.0 mm or less, and more preferably 8.0 mm or less.

[0150] Further, the center land portion 16, which is separated only by the circumferential groove 12, is provided with a plurality of center sipes 15, one end of which opens into the circumferential groove 12, and lateral grooves 18, both ends of which open into the circumferential groove 12. Furthermore, the present invention is not limited to this embodiment, and the land portion 16 may have sipes, both ends of which open into the circumferential groove 12, and lateral grooves, which open into only the circumferential groove on one side.

[0151] The land area ratio of the tread pattern is preferably 40% or more, more preferably 45% or more, and even more preferably 55% or more. On the other hand, there is no particular upper limit and it may be 100%.

[0152] The land portions 16, 17 may have one or more small holes. In FIG. 2, a small hole 19 is provided in the center land portion 16 separated by a circumferential groove. The opening area of ​​the small hole on the tread surface is 0.1 to 15 mm 2 is preferred.

[0153] In one land portion 16 or 17, the length L in the circumferential direction of the tire T(mm) Total number of small holes 19 N (N / L T ) is preferably from 0.05 to 2.0, more preferably from 0.1 to 1.0, and further preferably from 0.2 to 0.8.

[0154] The depth of the small holes 19 at their deepest portions is preferably 30 to 90% of the depth of the circumferential groove 12 .

[0155] In another embodiment of the present invention, as shown in FIG. 3, the tread 2 may have grooves extending in the tire circumferential direction composed of inclined lateral grooves and inclined connecting grooves connecting adjacent inclined lateral grooves.

[0156] 3, the tread 2 has a first tread pattern portion P1 disposed on one side in the tire width direction of the tire equator CL, and a second tread pattern portion P2 disposed on the other side in the tire axial direction. The first and second tread pattern portions P1 and P2 have line-symmetrical pattern designs that are shifted from each other in the tire circumferential direction (i.e., out of phase with each other in the tire circumferential direction).

[0157] The first and second tread pattern portions P1 and P2 each include a plurality of inclined lateral grooves 20 arranged at intervals in the tire circumferential direction, and at least one inclined joint groove 21 connecting adjacent inclined lateral grooves 20, 20 in the tire circumferential direction. In this example, the inclined joint groove 21 is arranged in a line approximately in the center of each of the tread pattern portions P1 and P2. In addition, the present invention is not limited to this embodiment, and may be composed of, for example, an inner inclined joint groove arranged on the inner side in the tire width direction and an outer inclined joint groove arranged on the outer side in the tire width direction.

[0158] Also, the tread is provided with sipes 22 which intersect with the inclined connection grooves 21 of the first and second tread pattern portions P1 and P2.

[0159] In the tire 1 of Fig. 1, each sidewall 3 extends substantially radially inward from an end of the tread 2. A radially outer portion of the sidewall 3 is joined to the tread 2 and a wing 4. The radially outer end of the sidewall 3 may terminate on the radially inner side of the tread 2 as shown in Fig. 1, or may terminate on the radially outer side of the cap rubber layer of the tread 2 so as to cover the tread 2.

[0160] The radially inner portion of the sidewall 3 is joined to the clinch 5. The radially inner end portion of the sidewall 3 may be exposed to the tire surface side, or may be hidden inside the clinch 5 in the tire width direction and not exposed to the tire surface.

[0161] The sidewall 3 may be formed of two or more rubber layers, including a layer that is partially or completely hidden from the tire surface. The partially hidden layer may be a rubber layer that is colored other than black from the viewpoint of aesthetics.

[0162] From the viewpoint of aesthetics, the sidewall 3 may be provided with periodic unevenness. As the unevenness, in addition to decorations such as letters and patterns, it is possible to have various types such as serrations that make unevenness caused by the joints of internal members less visible, and minute protrusions that are set to optically increase the blackness by providing unevenness that is finer than serrations.

[0163] Furthermore, an electronic tag or the like that enables communication with the outside may be embedded inside the sidewall 3.

[0164] Sidewall 3 thickness G S is preferably 7.0 mm or less, more preferably 6.0 mm or less, and even more preferably 5.0 mm or less. On the other hand, the lower limit is not particularly limited, but is preferably 0.1 mm or more, preferably 0.5 mm or more, and even more preferably 0.8 mm or more.

[0165] Sidewall 3 tan δ at 70°C (70°C tan δ S ) is preferably 0.30 or less, more preferably 0.25 or less, and even more preferably 0.20 or less. There is no particular lower limit, but it is preferably 0.01 or more, more preferably 0.02 or more, and even more preferably 0.03 or more.

[0166] Sidewall 3 E* at 70°C (70°C E* S ) is preferably 1.5 MPa or more, more preferably 2.0 MPa or more, and even more preferably 2.5 MPa or more. On the other hand, although there is no particular upper limit, it is preferably 10.0 MPa or less, more preferably 8.0 MPa or less, and even more preferably 6.5 MPa or less.

[0167] Glass transition temperature Tg of the rubber composition of the sidewall 3 S is preferably 0° C. or lower, more preferably −15° C. or lower, and further preferably −20° C. or lower. There is no particular restriction on the lower limit, but −60° C. or higher is preferred.

[0168] Sidewall 3 Hardness HS S is preferably 40 or more and 60 or less.

[0169] Sidewall 3 100% elongation modulus M100 S (MPa) is preferably 0.5 MPa or more and 5.0 MPa or less.

[0170] Sidewall 3 Breaking Strength TB S is preferably 10 MPa or more and 40 MPa or less.

[0171] Sidewall 3 Breaking Elongation EB S is preferably 150% or more and 500% or less.

[0172] The wing 4 in Fig. 1 is located between the tread 2 and the sidewall 3. The wing 4 is joined to both the tread 2 and the sidewall 3. Note that the wing 4 may or may not be provided.

[0173] The clinch 5 in Fig. 1 is located approximately radially inward of the sidewall 3 and has at least one portion that contacts the rim. A chafer 11 may be provided in a portion of the portion that contacts the rim from the viewpoint of durability of the clinch 5. The chafer 11 may be a canvas chafer having organic fibers therein, or a rubber chafer formed of a rubber composition.

[0174] The radially outer end of the clinch 5 may or may not be exposed to the tire surface. The height Hc of the clinch 5 is preferably 75 mm or less, more preferably 70 mm or less. On the other hand, the lower limit is not particularly limited, but is preferably 10 mm or more, more preferably 15 mm or more.

[0175] The ratio (Hc / Ht) of the height Hc (mm) of the clinch 5 to the tire cross-sectional height Ht (mm) is preferably 0.5 or less, more preferably 0.45 or less. Although there is no particular lower limit, it is preferably 0.1 or more.

[0176] The maximum thickness Gc of the clinch 5 is preferably 30 mm or less, more preferably 20 mm or less. On the other hand, although there is no particular lower limit, it is preferably 2 mm or more, and more preferably 4 mm or more.

[0177] The tan δ at 70° C. (70° C. tan δc) of the rubber composition constituting the clinch is preferably 0.25 or less, more preferably 0.15 or less, while the lower limit is not particularly limited, it is preferably 0.02 or more, more preferably 0.03 or more.

[0178] The E* (70°C E*c) at 70°C of the rubber composition constituting the clinch 5 is preferably 4 MPa or more, more preferably 5 MPa or more. On the other hand, although there is no particular upper limit, it is preferably 20 MPa or less, more preferably 15 MPa or less.

[0179] The product of the height Hc of the clinch 5 and 70° C. tan δc (70° C. tan δc×Hc) is preferably 14.0 mm or less, more preferably 12.0 mm or less. On the other hand, although there is no particular lower limit, it is preferably 0.4 mm or more, more preferably 0.6 mm or more.

[0180] The ratio of 70°C E*c to the height Hc of the clinch 5 (70°C E*c / Hc) is preferably 0.05 MPa / mm or more, more preferably 0.07 MPa / mm or more. On the other hand, although there is no particular upper limit, it is preferably 1.00 MPa / mm or less, more preferably 0.75 MPa / mm or less.

[0181] The product of the thickness Gc of the clinch 5 and 70° C. tan δc (Gc×70° C. tan δc) is preferably 7.50 mm or less, more preferably 6.00 mm or less. On the other hand, although there is no particular lower limit, it is preferably 0.10 mm or more, more preferably 0.25 mm or more.

[0182] The product of the thickness Gc of the clinch 5 and 70°C E*c (Gc×70°C E*c) is preferably 20 MPa·mm or more, more preferably 25 MPa·mm or more. On the other hand, although there is no particular upper limit, it is preferably 600 MPa·mm or less, more preferably 450 MPa·mm or less.

[0183] The glass transition temperature Tgc of the rubber composition constituting the clinch 5 is preferably 0° C. or lower, more preferably −15° C. or lower, and further preferably −20° C. or lower. There is no particular lower limit, but it is preferably −60° C. or higher.

[0184] The hardness HSc of the rubber composition constituting the clinch 5 is preferably 50 or more and 90 or less.

[0185] Modulus M100 at 100% elongation of the rubber composition constituting Clinch 5 S is preferably 2.0 MPa or more and 15.0 MPa or less.

[0186] The breaking strength TBc of the rubber composition constituting the clinch 5 is preferably 10 MPa or more and 40 MPa or less.

[0187] The breaking strength TBc of the rubber composition constituting the clinch 5 is preferably 10 MPa or more and 40 MPa or less.

[0188] The bead portion 6 in FIG. 1 includes a bead core 6a, a bead apex 6b, and a bead reinforcing layer 6c.

[0189] Each bead core 6a is preferably ring-shaped and includes a wound non-stretchable wire. The bead core 6a may be manufactured by winding a tape of aligned bead wires, or a cable-like bead core may be used in which multiple wires are helically wound around a single core wire.

[0190] When the bead core 6a is manufactured by winding a tape in which multiple bead wires are aligned, the number of bead wires in the tape arranged in the tire radial direction may differ for each layer. In this case, the type of tape to be wound may be changed for each winding in the tire circumferential direction.

[0191] On the other hand, when the bead core 6a is a cable-shaped bead core obtained by winding multiple wires spirally around a single core wire, the core cord may be composed of one wire or multiple wires, and the number of wires surrounding the core cord may be 3 to 10.

[0192] The bead core 6a includes a bead apex 6b extending radially outward from the bead core 6a. The bead apex 6b tapers radially outward.

[0193] In addition, in FIG. 1, the bead portion 6 includes a bead reinforcing layer 6c on the outer side of the carcass layer 8 in the tire width direction.

[0194] Bead apex radial height H BA The height H of the bead apex is preferably 5 mm or more, and more preferably 7 mm or more. On the other hand, although there is no particular upper limit, the height H of the bead apex is preferably 60 mm or less, and more preferably 55 mm or less. In addition, when the bead reinforcing layer 6c is provided, the height H of the bead apex is preferably 50 mm or less. BA is the greater value of either the height of the bead apex 6b or the height of the bead reinforcing layer 6c.

[0195] The tan δ at 70°C of the rubber composition constituting the bead apex 6b (70°C tan δ BA ) is preferably 0.25 or less, and more preferably 0.22 or less. On the other hand, the lower limit is not particularly limited, but is preferably 0.02 or more, and more preferably 0.03 or more. In addition, when the bead reinforcing layer 6c is provided, the 70°C tan δ of the bead apex 6b is BA is the lower value of 70° C. tan δ of the rubber composition constituting the bead apex 6b or the bead reinforcing layer 6c.

[0196] In addition, the complex modulus of elasticity at 70°C (70°CE* BA ) is preferably 8 MPa or more, more preferably 10 MPa or more. On the other hand, the upper limit is not particularly limited, but is preferably 200 MPa or less, more preferably 150 MPa or less. In addition, when the bead reinforcing layer 6c is provided, the 70°C E* of the rubber composition constituting the bead apex 6b is BA is the higher value of 70° C.E*δ of the bead apex 6b or the bead reinforcing layer 6c.

[0197] Tire radial height H of bead apex 6b BA and 70℃ tan δ BA The product of (H BA ×70℃ tanδ BA) is preferably 15.0 mm or less, and more preferably 12.0 mm or less. On the other hand, although there is no particular lower limit, it is preferably 0.2 mm or more, and more preferably 0.3 mm or more.

[0198] Tire radial height H of bead apex 6b BA and 70°C E* BA The product of (H BA ×70℃E* BA ) is preferably 80 MPa·mm or more, and more preferably 100 MPa·mm or more. On the other hand, although there is no particular lower limit, it is preferably 12000 MPa·mm or less, and more preferably 9000 MPa·mm or less.

[0199] Hardness HS of the rubber composition constituting the bead apex 6b BA The hardness HS of the bead apex 6b is preferably 70 or more and 100 or less. BA is the higher value of the hardness of the bead apex 6b or the bead reinforcing layer 6c.

[0200] Modulus M100 at 100% elongation of the rubber composition constituting the bead apex 6b BA In the case where the bead reinforcing layer 6c is provided, the modulus M100 at 100% elongation of the bead apex 6b is preferably 5.0 MPa or more and 30 MPa or less. BA is the higher value of the modulus at 100% elongation of the bead apex 6b or the bead reinforcing layer 6c.

[0201] Breaking strength TB of the rubber composition constituting the bead apex 6b BA In the case where the bead reinforcing layer 6c is provided, the breaking strength TB of the bead apex 6b is preferably 10 MPa or more and 40 MPa or less. BA is the breaking strength of either the bead apex 6b or the bead reinforcing layer 6c, whichever is higher.

[0202] Breaking elongation EB of the rubber composition constituting the bead apex 6b BA It is preferable that the breaking elongation EB of the bead apex 6b is 70% or more and 250% or less. BA is the higher value of the breaking elongation of either the bead apex 6b or the bead reinforcing layer 6c.

[0203] The inner liner 7 is formed to form the inner cavity surface of the tire, and this member reduces the amount of air permeation and can maintain the tire internal pressure. An insulation layer may be provided between the inner liner 7 and the carcass layer 8 from the viewpoint of adhesion.

[0204] Thickness of inner liner 7 G I The upper limit is not particularly limited, but is preferably 5.0 mm or less, and more preferably 4.0 mm or less.

[0205] The tan δ at 70° C. of the rubber composition constituting the inner liner 7 (70° C. tan δ I ) is preferably 0.30 or less, and more preferably 0.28 or less. On the other hand, although there is no particular lower limit, it is preferably 0.05 or more, and more preferably 0.08 or more.

[0206] In addition, the complex modulus of elasticity at 70° C. (70° C.E* I ) is preferably 2.0 MPa or more, more preferably 2.5 MPa or more. On the other hand, although there is no particular upper limit, it is preferably 8.0 MPa or less, more preferably 7.0 MPa or less.

[0207] Inner liner 7 thickness G I and 70℃ tan δ I The product of (G I ×70℃ tanδ I) is preferably 1.50 mm or less, and more preferably 1.40 mm or less. On the other hand, although there is no particular lower limit, it is preferably 0.01 mm or more, and more preferably 0.02 mm or more.

[0208] Inner liner 7 thickness G I and 70℃E*(G I ×70℃E* I ) is preferably 40.0 MPa·mm or less, and more preferably 35.0 MPa·mm or less. On the other hand, although there is no particular lower limit, it is preferably 0.4 MPa·mm or more, and more preferably 0.5 MPa·mm or more.

[0209] Hardness HS of the rubber composition constituting the inner liner 7 I is preferably 35 or more and 55 or less.

[0210] The modulus M100 at 100% elongation of the rubber composition constituting the inner liner 7 I is preferably 0.2 MPa or more and 5.0 MPa or less.

[0211] Breaking strength TB of the rubber composition constituting the inner liner 7 I is preferably 7 MPa or more and 25 MPa or less.

[0212] Breaking elongation EB of the rubber composition constituting the inner liner 7 I is preferably 400% or more and 1000% or less.

[0213] A sealant layer for sealing a hole in the event of a puncture may be attached to the tire cavity surface side of the inner liner layer 7. Also, one or more low-density members selected from the group consisting of a sound-damping body and a three-dimensional mesh structure may be attached to the tire cavity surface side of the inner liner layer 7. By providing low-density members, when vibrations are transmitted from the tread surface, these low-density members vibrate inside the tire, making it possible to offset vibrations within the tread portion.

[0214] As the sealant layer, a layer generally used on the inner peripheral surface of the tire tread portion for puncture prevention can be suitably used. Specific examples of such a sealant layer include those described in JP 2020-23152 A. The thickness of the sealant layer is usually preferably 1 to 10 mm. The width of the sealant layer is usually preferably 85 to 115% of the maximum width of the belt layer, and preferably 95 to 105%.

[0215] Any sound-damping body can be suitably used as long as it can exert a sound-damping effect in the tire cavity. Specific examples of such sound-damping bodies include those described in JP 2019-142503 A. The sound-damping body is, for example, made of a porous sponge material. The sponge material is a spongy porous structure, and includes, for example, a so-called sponge having continuous bubbles formed by foaming rubber or synthetic resin, as well as a web-like structure in which animal fibers, plant fibers, synthetic fibers, etc. are intertwined and connected together. In addition, the "porous structure" includes those having not only continuous bubbles but also closed bubbles. An example of the sound-damping body is a sponge material having continuous bubbles made of polyurethane. Suitable sponge materials include synthetic resin sponges such as ether-based polyurethane sponge, ester-based polyurethane sponge and polyethylene sponge, and rubber sponges such as chloroprene rubber sponge (CR sponge), ethylene propylene rubber sponge (EDPM sponge) and nitrile rubber sponge (NBR sponge). In particular, polyurethane-based or polyethylene-based sponges including ether-based polyurethane sponge are preferred from the standpoints of sound-damping properties, light weight, foaming adjustability, durability, and the like.

[0216] Generally, any three-dimensional mesh structure can be suitably used as long as it acts as a sound absorbing material. Specific examples of such sound absorbing materials include those described in JP 2018-90131 A. More specifically, the three-dimensional mesh structure is formed by irregularly entangling a plurality of filaments made of melted resin and welding the entangled portions.

[0217] The three-dimensional mesh structure is preferably fixed to the tire cavity. The method of fixing to the tire cavity is not particularly limited, and may be, for example, by adhering to the tire inner surface with an adhesive or the like, but it may also be fixed by the sealant material constituting the sealant layer, and is preferably fixed in this manner.

[0218] The thickness of the three-dimensional mesh structure is not particularly limited, but is preferably 1.0 to 150 mm, more preferably 30 to 120 mm. The width is not particularly limited, but is preferably 50 to 95% of the width of the sealant layer, more preferably 60 to 90%, because the effect can be more suitably obtained.

[0219] A sensing core or the like for monitoring the state of the tire in real time may be attached to the tire cavity surface side of the inner liner 7.

[0220] The carcass 8 includes a carcass ply 8a. In the tire 1 of Fig. 1, the carcass 8 includes one carcass ply 8a, but may include two or more carcass plies 8a.

[0221] In the tire 1 of Fig. 1, the carcass ply 8a is laid between the bead cores 6a on both sides and extends along the tread 2 and the sidewall 3. The carcass ply 8a is turned up around the bead cores 6a from the inside to the outside in the axial direction. That is, the carcass ply 8a has a main portion and a turned-up portion at the bead core.

[0222] Furthermore, in the case where a plurality of carcass plies 8a are provided, all of the carcass plies 8a may have turned-up portions, and as long as any one of the carcass plies 8a has a turned-up portion, the remaining carcass plies 8a may not have a turned-up portion.

[0223] When the carcass ply 8a of the tire 1 has a turn-up portion, the turn-up portion may be adjacent to the main body portion, or may not be adjacent to the main body portion. Also, the height HK of the carcass turn-up portion, which is the height of the tire radial direction outer end of the carcass turn-up portion, is lower than the height HBE of the belt layer end. Also, HK may be higher or lower than the height of the clinch end. Also, HK may be higher or lower than the tire radial direction height HBA of the bead apex.

[0224] Although not shown, the carcass ply 8a is preferably made of a large number of parallel cords (carcass cords) and a coating rubber layer. The absolute value of the angle that each cord makes with respect to the equatorial plane CL is preferably 75° to 90°. In other words, the carcass 8 preferably has a radial structure.

[0225] Furthermore, the angles that the multiple cords arranged in the main body portion and the folded-back portion of the carcass ply make with respect to the equatorial plane CL may be the same or different.

[0226] As the carcass cord, an organic fiber cord or a steel cord, which will be described later, can be used.

[0227] Carcass cord outer diameter d K is preferably 0.50 mm or more and 1.00 mm or less.

[0228] Number of carcass cords E K It is preferable that the number of wires per 50 mm is 25 wires / 50 mm or more and 45 wires / 50 mm or less.

[0229] Carcass cord outer diameter d K and the number of sequences E K The product of (D K ×E K ) is preferably 20 or more and preferably 30 or less.

[0230] The occupied area ratio of the carcass cords is preferably 30% or more and 50% or less.

[0231] The intermediate elongation of the carcass cord under a load of 44 N is preferably 1.0 or more and 8.5 or less.

[0232] The heat shrinkage rate of the carcass cord is preferably 0.2% or more and 5.0% or less.

[0233] The strength of the carcass cord is preferably 140N or more and 630N or less.

[0234] The tan δ at 70°C of the rubber composition constituting the coating rubber layer of the carcass cord (70°C tan δ K ) is preferably 0.30 or less. Although there is no particular lower limit, it is preferably 0.05 or more.

[0235] The tan δ at 70°C of the rubber composition constituting the coating rubber layer of the carcass cord (70°C tan δ K ) is preferably 0.30 or less. Although there is no particular lower limit, it is preferably 0.05 or more.

[0236] The belt layer 9 in FIG. 1 is located on the inner side of the tread 2 in the tire radial direction. The belt layer 9 is laminated on the carcass 8. The belt layer 9 reinforces the carcass 8. In the tire 1 in FIG. 1, the belt layer 9 is composed of two belt plies, an inner belt ply 9a and an outer belt ply 9b. As is clear from FIG. 1, in the tire width direction, it is preferable that the width W9a of the inner belt ply 9a in the tire width direction is larger than the width W9b of the outer belt ply 9b. In this tire 1, the axial width of the belt layer 9 is preferably 0.6 times or more and preferably 0.9 times or less of the cross-sectional width of the tire 1.

[0237] Although FIG. 1 shows an example of the belt layer 9 consisting of two belt plies, that is, the inner belt ply 9a and the outer belt ply 9b, the belt layer 9 may be composed of a single belt ply or three or more belt plies.

[0238] The inner belt ply 9a and the outer belt ply 9b in FIG. 1 are configured by arranging a plurality of belt cords in parallel and covering them with a belt topping rubber.

[0239] Here, Fig. 4 is a schematic diagram of the belt layer viewed from the tire radial direction, Fig. 5 is a schematic diagram of the belt layer cross section taken along a plane passing through the tire rotation axis, and Fig. 6 is a schematic diagram of the cross section of one belt ply taken along a plane perpendicular to the longitudinal direction of the belt cords. Note that Fig. 4 shows the band layer 10a (also called full band or band ply) adjacent to the belt layer 9, but omits the band layer 10b (also called edge band or edge band ply). Also, the oblique lines on the belt plies 9a, 9b and the band layer 10a indicate the arrangement direction of the belt cords contained therein.

[0240] As shown in Fig. 4, the belt cords in the inner belt ply 9a and the belt cords in the outer belt ply 9b are inclined at angles θ9a and θ9b, respectively, with respect to the tire circumferential direction. θ9a and θ9b are not particularly limited, but are preferably within a range of ±15 to 60 degrees. In addition, when there are multiple belt plies as shown in Fig. 4, it is preferable that the angles θ between the belt cords in adjacent belt plies and the tire circumferential direction are opposite in positive and negative. In this way, a hoop effect can be generated, making it easier to restrain the carcass 8.

[0241] In Figure 5, G BB is the distance on the tire equatorial plane of a line segment connecting the centers of the cross sections of the belt cords included in the two adjacent belt plies 9a and 9b. BB is preferably 0.5 mm or more and 1.2 mm or less.

[0242] In addition, since the belt cords are arranged at an angle θ with respect to the tire circumferential direction, even if the cross-sectional shape of the belt cord perpendicular to the longitudinal direction is a perfect circle, the cross-sectional shape of the belt cord in the cross section in the tire width direction becomes an ellipse or the like.

[0243] In FIG. 6, the cross-sectional shape of the belt cord is a perfect circle, but is not limited to this, and the cross-sectional shape of the belt cord may be an ellipse or a track.

[0244] Belt cord outer diameter d B The outer diameter d of the belt cord is 0.2 mm or more and 0.5 mm or less. By setting the outer diameter d of the belt cord in this range, the amount of bending of the cord due to input from the road surface is optimized, and durability against cord breakage can be improved. B If the thickness is less than 0.2 mm, the strength of each cord is low, and if the thickness exceeds 0.5 mm, the tension on the outer side of the bending center of the cord becomes large, making the cord more likely to break.

[0245] When the cross-sectional shape of the belt cord is a shape having a major axis and a minor axis, such as an ellipse, the ratio of the major axis to the minor axis (major axis / minor axis) is preferably 1.05 or more, and more preferably 1.10 or more. On the other hand, although there is no particular upper limit, it is preferably 2.00 or less, and more preferably 1.80 or less.

[0246] From the viewpoint of durability, the belt cord may be pre-formed in the longitudinal direction. When the belt cord is pre-formed, the pitch P of the pre-formation in the longitudinal direction is preferably 2.7 mm or more and 3.7 mm or less.

[0247] In addition, the number of belt cords arranged in a cross section perpendicular to the longitudinal direction of the belt cord, E B The cord spacing is preferably 60 cords / 50 mm or less, and more preferably 55 cords / 50 mm or less. By arranging the cords in this manner, it is believed that the cord spacing in the lateral direction is ensured and the crack growth rate can be suppressed. On the other hand, the lower limit is preferably 30 cords / 50 mm or more, and more preferably 35 cords / 50 mm or more.

[0248] In addition, the distance d between adjacent belt cords in a cross section perpendicular to the longitudinal direction of the belt cord BBis preferably 0.20 mm or more and 0.80 mm or less.

[0249] The strength of the belt cord is preferably 200N or more and 580N or less.

[0250] In addition, the thickness G of one belt ply B is preferably 1.20 mm or less, and is preferably 0.5 mm or more.

[0251] The occupied area ratio of the belt cord is preferably 9% or more and 18% or less.

[0252] Belt cord outer diameter d B and the number of sequences E B The product of (d B ×E B ) is preferably 15 or more and 30 or less.

[0253] The belt cord is preferably covered with a belt topping rubber. The tan δ at 70° C. (70° C. tan δ BE ) is preferably 0.20 or less. On the other hand, although there is no particular lower limit, it is preferably 0.04 or more.

[0254] The modulus M100 at 100% elongation of the rubber composition constituting the belt topping rubber BE is preferably 1.0 MPa or more and 4.0 MPa or less.

[0255] Breaking strength TB of the rubber composition constituting the belt topping rubber BE is preferably 10 MPa or more and 40 MPa or less.

[0256] Breaking elongation EB of the rubber composition constituting the belt topping rubber BE is preferably 150% or more and 500% or less.

[0257] In order to improve the adhesion between the belt cord and the belt topping rubber, the belt topping rubber preferably contains a salt of a metal element whose ionization tendency is between that of copper and zinc, such as cobalt, nickel, bismuth, antimony, iron, etc. In order to improve other adhesion properties, the belt topping rubber may contain an adhesive resin, such as a polybenzoxazine compound or a phenol resin.

[0258] From the viewpoint of improving the adhesion between the belt cord and the belt topping rubber, it is preferable that a plating layer containing copper and zinc is formed on the surface of the belt cord. It is more preferable that, in addition to the copper and zinc, a plating containing a metal element whose ionization tendency is between that of copper and zinc, such as cobalt, nickel, bismuth, or antimony, is applied.

[0259] The band (belt reinforcing layer) 10 in Fig. 1 is located radially outward of the belt layer 9. In the tire 1 in Fig. 1, the band 10 has a width equal to that of the belt ply 9a in the tire width direction, but may have a width larger than that of the belt ply 9a.

[0260] In Fig. 1, the band 10 is formed of a radially inner band ply 10a that covers the entire belt and an edge band ply 10b that covers only the edge portion of the belt layer, but is not limited to this embodiment, and for example, the band may include a layer that is continuous in the tire width direction, or may cover only the tire radially outer side of both ends of the belt layer in the tire width direction. Also, in Fig. 1, the band is formed of two layers, but is not limited to this embodiment, and may be formed of one layer, or three or more layers.

[0261] Although not shown, the band 10 is preferably made of a band cord and a band topping rubber. The band cord is wound spirally in the tire circumferential direction. Such a band has a so-called jointless structure. The band cord extends substantially in the tire circumferential direction. The angle of the band cord with respect to the tire circumferential direction is preferably ±10° or less, and more preferably ±5° or less. The band cord restrains the belt layer 9, so that the tire outer diameter is prevented from increasing due to the internal pressure during running.

[0262] The band 10 may be made of a steel cord or an organic fiber cord, which will be described later.

[0263] Outer diameter of band cord d BAND is preferably 0.50 mm or more and 0.90 mm or less.

[0264] Number of band cords E BAND It is preferable that the number of fibers per 50 mm is 40 or more and 60 or less.

[0265] The occupied area ratio of the band cord is preferably 30% or more and 60% or less.

[0266] The intermediate elongation of the band cord is preferably 1.2% or more and 9.5% or less.

[0267] The thermal shrinkage rate of the band cord is preferably 0.1% or more and 5.0% or less.

[0268] The strength of the band cord is preferably 130N or more and 700N or less.

[0269] Outer diameter of band cord d BAND and the number of sequences E BAND The product of (d BAND ×E BAND ) is preferably 2.0 or more and 5.4 or less.

[0270] The tan δ at 70°C of the rubber composition constituting the band cord covering rubber (70°C tan δ BAND ) is preferably 0.30 or less. Although there is no particular lower limit, it is preferably 0.05 or more.

[0271] The E* at 70°C of the rubber composition constituting the covering rubber of the band cord (70°C E* BAND ) is preferably 3.0 MPa or more and 10.0 MPa or less.

[0272] Another embodiment of the tire is a run-flat tire. A run-flat tire is a tire that is configured to support a vehicle even when air pressure is lost, and typically includes a side reinforcing layer for this purpose. Here, the side reinforcing layer refers to a rubber layer disposed on the inside of the sidewall portion of the run-flat tire.

[0273] FIG. 7 shows the right half of a cross-sectional view of a run-flat tire. FIG. 7 is a schematic diagram in which unnecessary components such as wings and bands are omitted. In FIG. 7, the side reinforcing layer 23 is disposed in contact with the inner side of the carcass, from the bead portion to the shoulder portion of the tread. The side reinforcing layer 23 is disposed between the carcass main body portion and its folded-up portion, from the bead portion to the tread portion, or disposed in two layers between a plurality of carcass plies or reinforcing plies. The side reinforcing layer 23 is disposed in a generally crescent shape whose cross-sectional shape gradually decreases toward both ends in the vertical direction, but is not limited to this shape.

[0274] [code] The tire of the present invention includes at least one tire component having a steel cord, and the at least one tire component having the steel cord includes at least one ply having a steel cord of a 1×4 structure. Here, the steel cord of the 1×4 structure is formed by twisting together four filaments, which are the minimum unit constituting a steel cord.

[0275] In the tire of the present invention, the tire component including at least one ply having a 1×4 steel cord is not particularly limited and may be, for example, the above-mentioned carcass, belt layer, band, etc., but the tire component is preferably at least one tire component selected from the group consisting of a belt layer and a band.

[0276] In the tire of the present invention, when the tire component including at least one ply having a 1×4 steel cord is a belt layer, the tire of the present invention can be used for various applications, and is preferably a passenger tire. In the tire of the present invention, when the tire component including at least one ply having a 1×4 steel cord is a band, the tire of the present invention is preferably a heavy-duty tire.

[0277] In the tire of the present invention, for tire components other than the tire component including at least one ply having the steel cord of the 1×4 structure, cords of various structures including steel cords of other structures can be used. Examples of cords of such structures include monofilament, steel cords of 1×N structure in which N filaments are twisted together, steel cords of M×N structure in which M yarns each made of N filaments are twisted together, steel cords of N+M structure in which M filaments are twisted around N core filaments, and cords other than steel cords, such as fiber cords.

[0278] <Steel cord> In the present invention, the material of the steel filaments forming the steel cord is not particularly limited, and it is possible to use HT material (High Tensile), SHT material (Super High Tensile), UHT material (Ultra High Tensile), etc. In addition, recycled iron obtained by melting used iron products may be used.

[0279] The steel cord according to the present invention may be provided with a plating layer. A steel cord having a plating layer exhibits high moisture and heat resistant adhesion performance even under harsh conditions of high temperature and high humidity, and therefore can prevent peeling between the topping rubber and the steel cord, thereby improving the durability of the tire under moist and hot conditions. When the steel cord has multiple filaments, a plating layer can be provided on the surface of each filament.

[0280] The plating layer can be formed by plating a copper layer, a zinc layer, a cobalt layer, etc., on the filament before wire drawing, and then diffusing the metals of each layer formed on the surface of the filament by heat treatment. Note that the order of layers formed on the filament to form the plating layer is not particularly limited.

[0281] When a steel cord formed by twisting a plurality of steel filaments is used in a tire component having a steel cord, the steel filament may be pre-formed in the longitudinal direction in order to improve durability by making it easier for the coating rubber layer to penetrate into the steel cord.

[0282] <Cords other than steel cord> The tire of the present invention may have a cord other than the steel cord. Examples of the cord other than the steel cord include a fiber cord, and examples of the fiber cord include an organic fiber cord. Examples of the organic fiber cord include polyester, polyamide, cellulose, and the like. These may be synthetic fibers or fibers derived from biomass. From the viewpoint of life cycle assessment, it is preferable that the fibers are derived from recycled or regenerated materials. These fibers may be formed of a single component of synthetic fiber, biomass fiber, or recycled / regenerated fiber, and may be any of a hybrid cord in which these are twisted together, a cord using a multifilament in which each filament is combined, and a cord having a chemical structure in which each component is chemically bonded.

[0283] Examples of polyester cords include polyethylene terephthalate (PET) cords, polyethylene naphthalate (PEN) cords, and polyethylene furanoate (PEF) cords. Compared with other polyester cords, PEF cords may be used because they have excellent air permeability resistance and are easy to maintain air pressure inside the tire. In addition, a hybrid cord may be used in which a part of the polyester cord is replaced with a cord made of other organic fiber such as polyamide fiber.

[0284] When the polyester cord is a biomass-derived polyester cord, for example, a biomass PET cord using terephthalic acid or ethylene glycol derived from biomass, or a biomass PEF cord using furandicarboxylic acid derived from biomass can be suitably used.

[0285] Biomass polyester cord can be obtained, for example, from bioethanol, furfurals, carenes, cymenes, terpenes, etc., or from compounds derived from various animals and plants, or from biomass terephthalic acid or biomass ethylene glycol produced by direct fermentation from microorganisms, etc.

[0286] Examples of the polyamide cord include aliphatic polyamides, semi-aromatic polyamides, and fully aromatic polyamides.

[0287] Aliphatic polyamides are polyamides having a skeleton in which linear carbon chains are linked by amide bonds, and examples thereof include nylon 4 (PA4), nylon 410 (PA410), nylon 6 (PA6), nylon 66 (PA66), nylon 610 (PA610), nylon 1010 (PA1010), nylon 1012 (PA1012), nylon 11 (PA11), etc. Among them, nylon 4, nylon 410, nylon 610, nylon 10, nylon 1010, nylon 11, etc. can be mentioned from the viewpoint of being easily obtainable partially or completely from biomass-derived materials.

[0288] Nylon 6 and nylon 66 may be produced by ring-opening polymerization of caprolactam derived from conventional chemical synthesis, condensation polymerization of hexamethylenediamine and adipic acid, or may be produced by using biocaprolactam, bioadipic acid, or biohexamethylenediamine produced from bio-derived cyclohexane as a starting material, and used to produce nylon 6 or nylon 66. The bio-based materials may also be obtained from sugars such as glucose. These nylon 6 and nylon 66 are considered to have the same strength as those that have been used conventionally.

[0289] A representative example of nylon 4 is one made from 2-pyrrolidone, which is obtained by converting glutamic acid derived from biofermentation into γ-aminobutyric acid, but this is not limited to this. Nylon 4 has good thermal and mechanical stability and is easy to design the polymer structure, so it can be used favorably as it contributes to improving the performance and strength of tires.

[0290] Nylon 410, nylon 610, nylon 1010, nylon 1012, nylon 11, etc. can be obtained from raw materials such as ricinoleic acid obtained from castor oil (castor bean). Specifically, nylon 410, nylon 610, and nylon 1010 can be obtained by condensation polymerization of sebacic acid and dodecanedioic acid obtained from castor oil with any diamine compound, and nylon 11 can be obtained by condensation polymerization of 11-aminoundecanoic acid obtained from castor oil.

[0291] Nylon 4T, Nylon 6T, and Nylon 10T can be obtained by using terephthalic acid as a dicarboxylic acid and carrying out condensation polymerization with a diamine compound having an arbitrary number of carbon atoms. In this case, it is also possible to obtain these nylon materials using the above-mentioned terephthalic acid derived from biomass. These nylons have a rigid cyclic structure in the molecular chain, and therefore excel in terms of heat resistance, etc.

[0292] Further, examples of the aliphatic polyamides and semi-aromatic polyamides mentioned above include polyamide 5X (X is the number of carbon atoms derived from a dicarboxylic acid, and T represents an integer or terephthalic acid) obtained by polymerizing 1,5-pentanediamine derived from lysine with dicarboxylic acids.

[0293] The fully aromatic polyamide is a polyamide having a skeleton in which aromatic rings are linked by amide bonds, and examples thereof include polyparaphenylene terephthalamide, etc. As with the above-mentioned aliphatic polyamides and semi-aromatic polyamides, the fully aromatic polyamide may also be obtained by bonding terephthalic acid derived from biomass with phenylenediamine.

[0294] Examples of cellulose fibers include rayon, polynosic, cupra, acetate, lyocell, modal, etc., which are produced from plant materials such as wood pulp. These cellulose fibers are preferred because they are not only made from carbon-neutral raw materials, but also have excellent environmental performance, such as being biodegradable and not emitting harmful gases even when incinerated after use. Among the above, rayon, polynosic, and lyocell are particularly preferred in terms of the balance between process efficiency, environmental friendliness, and mechanical strength.

[0295] In addition, the organic fiber cord may be a recycled cord obtained by collecting and refining used items such as beverage bottles and clothing, regardless of whether it is synthetic or derived from biomass, and then re-spinning the collected organic fiber cord.

[0296] The organic fiber cord may be formed by twisting one or more filaments. For example, two 1100 decitex multifilaments (in other words, 1100 / 2 decitex) are twisted 48 times / 10 cm, and then two of these first twisted cords are twisted together and twisted the same number of times in the opposite or same direction as the first twist, or two 1670 decitex multifilaments (in other words, 1670 / 2 decitex) are twisted 40 times / 10 cm, and then two of these first twisted cords are twisted together and twisted.

[0297] In addition, from the viewpoint of ensuring good adhesion to the coating layer, the organic fiber cord is preferably treated in advance by coating with an adhesive layer. Any known adhesive layer can be used, and examples of such adhesive layers include those treated with resorcinol-formalin-rubber latex (RFL), those epoxy-treated with an adhesive composition containing sorbitol polyglycidyl ether and blocked isocyanate, and then RFL-treated, and those treated with an adhesive composition containing a halohydrin compound, a blocked isocyanate compound, and rubber latex.

[0298] Resorcinol-formaldehyde-rubber latex (RFL) is, for example, an adhesive composition containing natural rubber and / or synthetic rubber latex and a co-condensation product of phenol-formaldehyde and resorcinol, as described in JP-A-48-11335. Such an adhesive composition can be produced, for example, by a production method including a step of condensing phenol and formaldehyde in the presence of an alkaline catalyst, a step of copolymerizing an aqueous phenol-formaldehyde resin solution with resorcinol, and a step of mixing the resulting phenol-formaldehyde-resorcinol resin solution with latex rubber.

[0299] Examples of the synthetic rubber latex include butadiene polymer latex, styrene / butadiene copolymer latex, isoprene polymer latex, butadiene / acrylonitrile copolymer latex, butadiene / vinylpyridine polymer latex, and butadiene / vinylpyridine / styrene copolymer latex.

[0300] The adhesive layer made of resorcinol-formaldehyde-rubber latex (RFL) can be formed by applying an RFL adhesive (such as by immersing the organic fiber cord in an RFL liquid (DIP: dipping)). The RFL adhesive is usually applied after the fiber cord is obtained by twisting, but it may be applied before or during the twisting.

[0301] The composition of the RFL adhesive is not particularly limited and may be selected as appropriate. Among them, a composition containing 0.1 to 10 mass % of resorcinol, 0.1 to 10 mass % of formalin, and 1 to 28 mass % of latex is preferable, and a composition containing 0.5 to 3 mass % of resorcinol, 0.5 to 3 mass % of formalin, and 10 to 25 mass % of latex is more preferable.

[0302] An example of a heating method for the heat treatment is a method in which the fiber cord to which the RFL adhesive composition is attached is dried at 100 to 250° C. for 1 to 5 minutes, and then further heat-treated at 150 to 250° C. for 1 to 5 minutes. The heat treatment conditions after the drying treatment are preferably 180 to 240° C. for 1 to 2 minutes.

[0303] An example of a heating method for the heat treatment is a method in which the fiber cord to which the RFL adhesive composition is attached is dried at 100 to 250° C. for 1 to 5 minutes, and then further heat-treated at 150 to 250° C. for 1 to 5 minutes. The heat treatment conditions after the drying treatment are preferably 180 to 240° C. for 1 to 2 minutes.

[0304] Examples of sorbitol polyglycidyl ether include sorbitol diglycidyl ether, sorbitol triglycidyl ether, sorbitol tetraglycidyl ether, sorbitol pentaglycidyl ether, sorbitol hexaglycidyl ether, and mixtures thereof, and may include sorbitol monoglycidyl ether. Sorbitol polyglycidyl ether has many epoxy groups in one molecule and can form a highly crosslinked structure.

[0305] The chlorine content of the sorbitol polyglycidyl ether is preferably 9.6% by mass or less, more preferably 9.5% by mass or less, even more preferably 9.4% by mass or less, and particularly preferably 9.3% by mass or less. The lower limit of the chlorine content is not particularly limited, and is, for example, 1% by mass or more. In the present invention, the chlorine content of the sorbitol polyglycidyl ether can be determined by the method described in JIS K 7243-3.

[0306] The chlorine content of the sorbitol polyglycidyl ether can be reduced by, for example, reducing the amount of epichlorohydrin used in synthesizing the epoxy compound.

[0307] A blocked isocyanate is a compound that is produced by the reaction of an isocyanate compound with a blocking agent and is temporarily inactivated by a group derived from the blocking agent. When heated at a predetermined temperature, the group derived from the blocking agent dissociates to produce an isocyanate group.

[0308] Examples of isocyanate compounds include those having two or more isocyanate groups in the molecule. Examples of diisocyanates having two isocyanate groups include hexamethylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, isophorone diisocyanate, phenylene diisocyanate, tolylene diisocyanate, trimethylhexamethylene diisocyanate, metaphenylene diisocyanate, naphthalene diisocyanate, diphenyl ether diisocyanate, diphenylpropane diisocyanate, biphenyl diisocyanate, and their isomers, alkyl substitution products, halides, and hydrogenated products of benzene rings. In addition, triisocyanates having three isocyanate groups, tetraisocyanates having four isocyanate groups, and polymethylene polyphenyl polyisocyanate can be used. These isocyanate compounds can be used alone or in combination of two or more. Among these, tolylene diisocyanate, metaphenylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and polymethylene polyphenyl polyisocyanate are preferred.

[0309] Examples of blocking agents include lactam-based agents such as ε-caprolactam, δ-valerolactam, γ-butyrolactam, and β-propiolactam; phenol-based agents such as phenol, cresol, resorcinol, and xylenol; alcohol-based agents such as methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, and benzyl alcohol; oxime-based agents such as formamidoxime, acetaldoxime, acetoxime, methylethylketoxime, diacetylmonoxime, benzophenoneoxime, and cyclohexanoneoxime; and active methylene-based agents such as dimethyl malonate, diethyl malonate, ethyl acetoacetate, methyl acetoacetate, and acetylacetone. Among these, lactam-based, phenol-based, and oxime-based blocking agents are preferred.

[0310] In the adhesive composition containing the sorbitol polyglycidyl ether and the blocked isocyanate, the content of the blocked isocyanate is preferably 50 parts by mass or more, more preferably 200 parts by mass or more, relative to 100 parts by mass of the sorbitol polyglycidyl ether. The upper limit is preferably 500 parts by mass or less, more preferably 400 parts by mass or less.

[0311] The adhesive composition containing sorbitol polyglycidyl ether and blocked isocyanate may contain the following optional components as necessary, such as epoxy compounds other than sorbitol polyglycidyl ether, resins copolymerizable with sorbitol polyglycidyl ether, curing agents other than blocked isocyanates, organic thickeners, antioxidants, light stabilizers, adhesion improvers, reinforcing agents, softeners, colorants, leveling agents, flame retardants, and antistatic agents.

[0312] Examples of epoxy compounds other than sorbitol polyglycidyl ether include glycidyl ethers such as ethylene glycol glycidyl ether, glycerol polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, bisphenol A diglycidyl ether, bisphenol S diglycidyl ether, novolac glycidyl ether, and brominated bisphenol A diglycidyl ether; glycidyl esters such as hexahydrophthalic acid glycidyl ester and dimer acid glycidyl ester; triglycidyl ethers such as hexahydrophthalic acid glycidyl ester and dimer acid glycidyl ester; Examples of suitable glycidyl amines include glycidyl isocyanurate, glycidyl hindantoin, tetraglycidyl diaminodiphenylmethane, triglycidyl para-aminophenol, triglycidyl meta-aminophenol, diglycidyl aniline, diglycidyl toluidine, tetraglycidyl meta-xylylenediamine, diglycidyl tribromoaniline, and tetraglycidyl bisaminomethylcyclohexane; and alicyclic or aliphatic epoxides such as 3,4-epoxycyclohexylmethylcarboxylate, epoxidized polybutadiene, and epoxidized soybean oil.

[0313] The treatment with the adhesive composition containing the above-mentioned sorbitol polyglycidyl ether and blocked isocyanate includes a treatment carried out for adhering various components contained in the RFL to a fiber cord, and a treatment including a subsequent heat treatment if necessary.

[0314] The adhesion method may be any method such as application using a roller, spraying from a nozzle, immersion in a bath liquid (adhesive composition), etc. From the viewpoints of uniform adhesion and removal of excess adhesive, adhesion by immersion is preferred.

[0315] In order to adjust the amount of adhesion to the fiber cord, means such as squeezing with a pressure roller, scraping with a scraper or the like, blowing off with air blowing, suction, beating with a beater, etc. may be further adopted.

[0316] The amount of the RFL adhesive attached to the fiber cord is preferably 1.0 mass % or more, more preferably 1.5 mass % or more, and is preferably 3.0 mass % or less, more preferably 2.5 mass % or less. The amount of the RFL adhesive attached to the fiber cord is the amount of solid content in the RFL adhesive attached to 100 parts by mass of the fiber cord.

[0317] The total solids concentration of the adhesive composition containing the above-mentioned sorbitol polyglycidyl ether and blocked isocyanate is preferably 0.9 mass% or more, more preferably 14 mass% or more, and is preferably 29 mass% or less, more preferably 23 mass% or less.

[0318] The adhesive composition containing the sorbitol polyglycidyl ether and the blocked isocyanate may contain, in addition to resorcin, formalin, and rubber latex, vulcanization regulators, zinc oxide, antioxidants, defoamers, and the like.

[0319] An example of a heating method for the heat treatment is to dry the reinforcing material 16 to which the RFL adhesive composition is attached at 100 to 250° C. for 1 to 5 minutes, and then to further heat treat it at 150 to 250° C. for 1 to 5 minutes. The conditions for the heat treatment after the drying treatment are desirably 180 to 240° C. for 1 to 2 minutes.

[0320] The adhesive composition containing the above-mentioned halohydrin compound, blocked isocyanate compound, and rubber latex is not particularly limited as long as it contains these components, but an adhesive composition containing a halohydrin compound, a blocked isocyanate compound, and rubber latex, but not containing resorcinol and formaldehyde, is preferable.

[0321] Examples of halohydrin compounds include compounds obtained by reacting a polyol compound with an epihalohydrin compound (halohydrin ether). A polyol compound is a compound having two or more hydroxyl groups in the molecule, and examples of such compounds include glycols such as ethylene glycol, propylene glycol, polyethylene glycol, and polypropylene glycol, hydroxyl acids such as erythritol, xylitol, sorbitol, and tartaric acid, glyceric acid, glycerin, diglycerin, polyglycerin, trimethylolpropane, trimethylolethane, and pentaerythritol. Examples of epihalohydrin compounds include epichlorohydrin and epibromohydrin.

[0322] Examples of the halohydrin compound include a fluoroalcohol compound, a chlorohydrin compound, a bromohydrin compound, an iodohydrin compound, etc. Among these, halogenated sorbitol and halogenated glycerol are preferred.

[0323] The halogen content in 100% by mass of the halohydrin compound is preferably from 5.0 to 15.0% by mass, more preferably from 7.0 to 13.0% by mass, and even more preferably from 9.0 to 12.0% by mass.

[0324] Examples of the blocked isocyanate compound include the same compounds as the blocked isocyanate described above. Examples of the rubber latex include the same rubber latex as the rubber latex described above.

[0325] The adhesive composition containing the halohydrin compound, the blocked isocyanate compound, and the rubber latex preferably contains 10.0 to 30.0 parts by mass of the halohydrin compound, 10.0 to 30.0 parts by mass of the blocked isocyanate compound, and 80.0 to 240.0 parts by mass of the rubber latex. The adhesive composition does not contain resorcinol or formaldehyde.

[0326] An adhesive layer made of an adhesive composition containing the above-mentioned halohydrin compound, a blocked isocyanate compound, and a rubber latex is formed on the surface of the fiber cord using the adhesive composition. The adhesive layer is formed by, for example, dipping, brushing, casting, spraying, roll coating, knife coating, etc., but is not limited thereto.

[0327] [Rubber composition for tire components] The rubber composition for tire components according to the present invention (hereinafter referred to as the rubber composition of the present invention) will be described. Unless otherwise specified, the rubber composition can be commonly used in any tire components such as each rubber layer of the tread, belt topping rubber, band topping rubber, sidewall, bead portion, clinch, inner liner, etc.

[0328] <Rubber component> The rubber composition of the present invention contains a rubber component. The rubber component preferably contains a diene rubber. Any diene rubber commonly used in the tire industry can be suitably used. Specific examples include isoprene rubber, butadiene rubber (BR), styrene butadiene rubber (SBR), styrene isoprene rubber (SIR), styrene isoprene butadiene rubber (SIBR), chloroprene rubber (CR), and acrylonitrile butadiene rubber (NBR). These diene rubbers may be used alone or in combination of two or more.

[0329] The rubber component is a component that contributes to crosslinking, and generally refers to a polymer with a weight average molecular weight (Mw) of 10,000 or more that is not extracted with acetone. The rubber component is in a solid state at room temperature (25°C).

[0330] (Isoprene rubber) As the isoprene-based rubber, for example, isoprene rubber (IR) and natural rubber, which are common in the tire industry, can be used. In addition to unmodified natural rubber (NR), natural rubber also includes modified natural rubber such as epoxidized natural rubber (ENR), hydrogenated natural rubber (HNR), deproteinized natural rubber (DPNR), high-purity natural rubber, and grafted natural rubber. These isoprene-based rubbers may be used alone or in combination of two or more.

[0331] The NR is not particularly limited, and any NR commonly used in the tire industry can be used, such as SIR20, RSS#3, and TSR20.

[0332] The content of the isoprene-based rubber in the rubber component can be 0 to 100 mass% (for example, 1, 3, 5, 7, 10, 12, 15, 17, 20, 22, 25, 28, 30, 32, 35, 37, 40, 42, 45, 47, 50, 52, 55, 57, 60, 62, 65, 68, 70, 72, 74, 76, 80, 82, 85, 88, 90, 92, 95, 99).

[0333] (BR) The BR is not particularly limited, and can be one that is commonly used in the tire industry, such as BR with a cis content of less than 50 mol% (low cis BR), BR with a cis content of 90 mol% or more (high cis BR), rare earth butadiene rubber (rare earth BR) synthesized using a rare earth catalyst, BR containing syndiotactic polybutadiene crystals (SPB-containing BR), modified BR (high cis modified BR, low cis modified BR), etc. These BRs can be used alone or in combination of two or more.

[0334] As the high-cis BR, for example, those commercially available from Zeon Corporation, Ube Industries, Ltd., JSR Corporation, etc. can be used. By containing high-cis BR, low-temperature properties and wear resistance can be improved. The cis content of the high-cis BR is preferably 95 mol % or more, more preferably 96 mol % or more, and even more preferably 97 mol % or more. The cis content of BR is measured by the above-mentioned measurement method.

[0335] When BR is contained, the content of BR in the rubber component can be 0 to 100 mass% (for example, 1, 3, 5, 7, 10, 12, 15, 17, 20, 22, 25, 28, 30, 32, 35, 37, 40, 42, 45, 47, 50, 52, 55, 57, 60, 62, 65, 68, 70, 72, 74, 76, 80, 82, 85, 88, 90, 92, 95, 99).

[0336] (SBR) There are no particular limitations on the SBR, and examples thereof include solution-polymerized SBR (S-SBR), emulsion-polymerized SBR (E-SBR), and modified SBRs thereof (modified S-SBR, modified E-SBR). Modified SBRs include SBRs whose ends and / or main chains are modified, and modified SBRs (condensates, those having a branched structure, etc.) coupled with tin, silicon compounds, etc. Furthermore, hydrogenated products of these SBRs (hydrogenated SBR), etc. can also be used. These SBRs may be used alone or in combination of two or more.

[0337] As the SBR, oil-extended SBR or non-oil-extended SBR can be used. As the SBR that can be used in the present invention, commercially available SBRs from JSR Corporation, Sumitomo Chemical Co., Ltd., Ube Industries, Ltd., Asahi Kasei Corporation, ZS Elastomers Co., Ltd., ARLANXEO, etc. can be used.

[0338] The styrene content of SBR can be 5% by mass to 90% by mass (for example, 8, 10, 12, 15, 17, 20, 22, 25, 28, 30, 32, 35, 37, 40, 42, 45, 47, 50, 52, 55, 57, 60, 62, 65, 68, 70, 72, 74, 76, 80, 82, 85, 88). The styrene content of SBR is measured by the above-mentioned measurement method.

[0339] When SBR is contained, the content in the rubber component can be 0 to 100 mass% (for example, 1, 3, 5, 7, 10, 12, 15, 17, 20, 22, 25, 28, 30, 32, 35, 37, 40, 42, 45, 47, 50, 52, 55, 57, 60, 62, 65, 68, 70, 72, 74, 76, 80, 82, 85, 88, 90, 92, 95, 99).

[0340] The content of the diene rubber in the rubber component is preferably 50 mass% or more (for example, 50, 52, 55, 57, 60, 62, 65, 68, 70, 72, 74, 76, 80, 82, 85, 88, 90, 92, 95, 98, 100).

[0341] (Non-diene rubber) The rubber component may contain a non-diene rubber. Examples of the non-diene rubber include butyl rubber (IIR), hydrogenated nitrile rubber (HNBR), ethylene propylene rubber, silicone rubber, chlorinated polyethylene rubber, fluororubber (FKM), acrylic rubber (ACM), and hydrin rubber. The non-diene rubber may be used alone or in combination of two or more kinds.

[0342] (Butyl rubber) Among the other rubber components, examples of butyl-based rubbers include non-halogenated butyl rubber (regular butyl rubber, IIR), halogenated butyl rubbers (X-IIR) such as brominated butyl rubber (Br-IIR) and chlorinated butyl rubber (Cl-IIR), and copolymers of isobutylene and p-alkylstyrene.

[0343] When a non-diene rubber is contained, the content in the rubber component can be 0 to 100 mass% (for example, 1, 3, 5, 7, 10, 12, 15, 17, 20, 22, 25, 28, 30, 32, 35, 37, 40, 42, 45, 47, 50, 52, 55, 57, 60, 62, 65, 68, 70, 72, 74, 76, 80, 82, 85, 88, 90, 92, 95, 99).

[0344] In the case of the rubber composition used for each rubber layer of the tread, the belt topping rubber, the band topping rubber, the sidewall, the bead portion and the clinch, the rubber component preferably contains a rubber component selected from the group consisting of isoprene-based rubber, BR and SBR. In the case of the rubber composition used for the inner liner, the rubber component preferably contains a rubber component selected from the group consisting of isoprene-based rubber, BR, CR and non-diene-based rubber. Here, the non-diene-based rubber is preferably a butyl-based rubber.

[0345] <Filler> The rubber composition of the present invention preferably contains a filler. As the filler, those generally used in the tire industry can be used, and in addition to silica and carbon black, further examples include aluminum hydroxide, alumina (aluminum oxide), clay, calcium carbonate, mica, biochar, etc. The filler may be used alone or in combination of two or more kinds.

[0346] <Silica> The silica is not particularly limited, and for example, silica prepared by a dry method (anhydrous silica), silica prepared by a wet method (hydrated silica), and other silicas commonly used in the tire industry can be used. Among them, hydrated silica prepared by a wet method is preferred because it has a large number of silanol groups. In addition to these silicas, silica made from biomass materials such as rice husks can also be used. Silica may be used alone or in combination of two or more types.

[0347] In addition to the above, from the viewpoint of life cycle assessment, silica made from biomass materials such as rice husks may be used as the silica.

[0348] The nitrogen adsorption specific surface area (N2SA) of silica is 50m 2 / g~500m 2 / g (for example, 80, 100, 120, 150, 180, 200, 220, 250, 280, 300, 350, 400). The N2SA of silica is measured by the above-mentioned measurement method.

[0349] The average primary particle size of silica can be 5 nm to 300 nm (for example, 5, 7, 8, 10, 12, 15, 17, 20, 22, 25, 28, 30, 32, 35, 37, 40, 42, 45, 47, 50, 52, 55, 57, 60, 62, 65, 68, 70, 72, 74, 76, 80, 82, 85, 88, 90, 95, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 220, 250, 280). The average primary particle size of silica is measured by the above-mentioned measuring method.

[0350] The amount of silica per 100 parts by mass of the rubber component can be 0 to 200 parts by mass (e.g., 1, 3, 5, 7, 8, 10, 12, 15, 17, 20, 22, 25, 28, 30, 32, 35, 37, 40, 42, 45, 47, 50, 52, 55, 57, 60, 62, 65, 68, 70, 72, 74, 76, 80, 82, 85, 88, 90, 95, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200).

[0351] <Carbon black> The carbon black is not particularly limited, and GPF, FEF, HAF, ISAF, SAF, and other carbon blacks commonly used in the tire industry can be used. Specifically, N110, N115, N120, N125, N134, N135, N219, N220, N231, N234, N293, N299, N326, N330, N339, N343, N347, N351, N356, N358, N375, N539, N550, N582, N630, N642, N650, N660, N683, N754, N762, N765, N772, N774, N787, N907, N908, N990, N991, and the like can be suitably used. In addition to these, in-house synthesized products and the like can also be suitably used. As commercially available products, products available from Asahi Carbon Co., Ltd., Cabot Japan Co., Ltd., Tokai Carbon Co., Ltd., Mitsubishi Chemical Corporation, Lion Corporation, Shin-Nichika Carbon Co., Ltd., Columbia Carbon Co., Ltd., etc. may be used alone or in combination of two or more kinds.

[0352] In addition to the above, from the viewpoint of life cycle assessment, carbon black made from a biomass material such as lignin or recovered carbon purified by pyrolysis of a product containing carbon black, such as a tire, may be used as the carbon black.

[0353] In this specification, "recovered carbon black" refers to carbon black obtained by crushing products such as used tires that contain carbon black and calcining the crushed material, and which has a mass ratio of ash (ash content) that is a non-combustible component when subjected to oxidative combustion by heating in air in a thermogravimetric measurement method conforming to JIS K 6226-2:2003 of 13 mass% or more. In other words, the mass ratio (carbon content) of the amount of weight lost by the oxidative combustion of the recycled carbon black is 87 mass% or less. Recovered carbon black is also called regenerated carbon black, and may be expressed as rCB.

[0354] The nitrogen adsorption specific surface area (N2SA) of carbon black is 50m 2 / g~500m 2 / g (for example, 80, 100, 120, 150, 180, 200, 220, 250, 280, 300, 350, 400). The N2SA of carbon black is measured by the above-mentioned measurement method.

[0355] The amount of carbon black per 100 parts by mass of the rubber component can be 0 to 200 parts by mass (e.g., 1, 3, 5, 7, 8, 10, 12, 15, 17, 20, 22, 25, 28, 30, 32, 35, 37, 40, 42, 45, 47, 50, 52, 55, 57, 60, 62, 65, 68, 70, 72, 74, 76, 80, 82, 85, 88, 90, 95, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200).

[0356] The average primary particle diameter of carbon black can be 5 nm to 300 nm (for example, 5, 7, 8, 10, 12, 15, 17, 20, 22, 25, 28, 30, 32, 35, 37, 40, 42, 45, 47, 50, 52, 55, 57, 60, 62, 65, 68, 70, 72, 74, 76, 80, 82, 85, 88, 90, 95, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 220, 250, 280). The average primary particle diameter of carbon black is measured by the above-mentioned measurement method.

[0357] <Other fillers> When fillers other than silica and carbon black are contained, the total content of the other fillers per 100 parts by mass of the rubber component can be 0 to 100 parts by mass (e.g., 1, 3, 5, 7, 8, 10, 12, 15, 17, 20, 22, 25, 28, 30, 32, 35, 37, 40, 42, 45, 47, 50, 52, 55, 57, 60, 62, 65, 68, 70, 72, 74, 76, 80, 82, 85, 88, 90, 95).

[0358] <Other compounding agents> In addition to the rubber component and filler, the rubber composition according to the present embodiment may appropriately contain compounding agents that are generally used in the tire industry, such as softeners, waxes, stearic acid, zinc oxide, antioxidants, vulcanizing agents, and vulcanization accelerators.

[0359] <Softener> The rubber composition of the present invention may contain a softener. Examples of the softener include a resin component, oil, liquid rubber, and an ester-based plasticizer. The softener also includes an extended oil, extended resin, or extended liquid rubber component of a rubber component that has been oil-extended, resin-extended, or liquid rubber-extended. These softeners may be derived from petroleum or biomass. In addition, a low molecular weight hydrocarbon component obtained by pyrolyzing and extracting used tires or products containing various components may be used as a softener.

[0360] (Resin component) The resin component is not particularly limited, but examples thereof include petroleum resins, terpene resins, rosin resins, phenol resins, etc. These resin components may be used alone or in combination of two or more.

[0361] Examples of the petroleum resin include C5 petroleum resin, aromatic petroleum resin, and C5C9 petroleum resin.

[0362] In this specification, the term "C5 petroleum resin" refers to a resin obtained by polymerizing a C5 fraction. Examples of C5 fractions include petroleum fractions having 4 to 5 carbon atoms, such as cyclopentadiene, pentene, pentadiene, and isoprene. As the C5 petroleum resin, dicyclopentadiene resin (DCPD resin) is preferably used.

[0363] In this specification, the term "aromatic petroleum resin" refers to a resin obtained by polymerizing a C9 fraction, and may be a hydrogenated or modified resin. Examples of C9 fractions include petroleum fractions having 8 to 10 carbon atoms, such as vinyltoluene, alkylstyrene, indene, and methylindene. Specific examples of aromatic petroleum resins that are preferably used include coumarone-indene resins, coumarone resins, indene resins, and aromatic vinyl resins. As aromatic vinyl resins, homopolymers of α-methylstyrene or styrene or copolymers of α-methylstyrene and styrene are preferred, and copolymers of α-methylstyrene and styrene are more preferred, because they are economical, easy to process, and have excellent heat generation properties. As aromatic vinyl resins, those commercially available from Kraton, Eastman Chemical, Mitsui Chemicals, Inc., etc., can be used.

[0364] In this specification, the term "C5C9 petroleum resin" refers to a resin obtained by copolymerizing the C5 fraction and the C9 fraction, and may be a hydrogenated or modified resin. Examples of the C5 fraction and the C9 fraction include the petroleum fractions described above. As the C5C9 petroleum resin, for example, those commercially available from Tosoh Corporation, LUHUA, etc. can be used.

[0365] As the resin component, petroleum resins obtained by partially or completely hydrogenating the above-mentioned petroleum resins can also be used. Such hydrogenated petroleum resins are preferably used in the rubber composition constituting the outer tread rubber layer, from the viewpoint that they have excellent compatibility and good dispersion in the system due to the similarity of the hydrogenated structure. The hydrogenated petroleum resins used in the present invention have unsaturated bonds in the molecule partially or completely hydrogenated, and for example, when a petroleum resin having an aromatic ring such as a benzene ring in the main chain or side chain is hydrogenated, the aromatic ring is reduced (for example, if the aromatic ring is a benzene ring, it is reduced to a cyclohexane ring, etc.).

[0366] Examples of the terpene resin include polyterpene resins consisting of at least one selected from terpene compounds such as α-pinene, β-pinene, limonene, and dipentene; aromatic modified terpene resins made from the terpene compounds and aromatic compounds; terpene phenolic resins made from terpene compounds and phenolic compounds; and terpene resins obtained by subjecting these terpene resins to hydrogenation treatment (hydrogenated terpene resins). Examples of aromatic compounds that are raw materials for aromatic modified terpene resins include styrene, α-methylstyrene, vinyltoluene, and divinyltoluene. Examples of phenolic compounds that are raw materials for terpene phenolic resins include phenol, bisphenol A, cresol, and xylenol.

[0367] The rosin-based resin is not particularly limited, but examples thereof include natural rosin resin and rosin-modified resins obtained by modifying rosin by hydrogenation, disproportionation, dimerization, esterification, or the like.

[0368] The phenol-based resin is not particularly limited, but examples thereof include phenol formaldehyde resin, alkylphenol formaldehyde resin, alkylphenol acetylene resin, and oil-modified phenol formaldehyde resin.

[0369] When a resin component is contained, the content thereof relative to 100 parts by mass of the rubber component can be 0 to 100 parts by mass (for example, 1, 3, 5, 7, 8, 10, 12, 15, 17, 20, 22, 25, 28, 30, 32, 35, 37, 40, 42, 45, 47, 50, 52, 55, 57, 60, 62, 65, 68, 70, 72, 74, 76, 80, 82, 85, 88, 90, 95, 100).

[0370] (oil) Examples of the oil include paraffinic process oil, naphthenic process oil, aromatic process oil, vegetable oil, etc. In addition, as an environmental measure, process oil with a low content of polycyclic aromatic compound (PCA) compounds can be used. Examples of the low PCA content process oil include light extract solvate (MES), treated distillate aromatic extract (TDAE), heavy naphthenic oil, etc. In addition, from the viewpoint of life cycle assessment, refined waste oil from rubber mixers and engines, and waste oil from cooking in restaurants may be used.

[0371] In the present invention, examples of "vegetable oil" include linseed oil, rapeseed oil, safflower oil, soybean oil, corn oil, cottonseed oil, rice oil, tall oil, sesame oil, perilla oil, castor oil, paulownia oil, pine oil, pine tar oil, sunflower oil, coconut oil, palm oil, palm kernel oil, olive oil, camellia oil, jojoba oil, macadamia nut oil, peanut oil, grapeseed oil, and wood wax. In addition, examples of vegetable oil include refined oils (such as salad oils) obtained by refining the above oils, transesterified oils obtained by transesterifying the above oils, hardened oils obtained by hydrogenating the above oils, thermally polymerized oils obtained by thermally polymerizing the above oils, oxidatively polymerized oils obtained by oxidizing the above oils, and waste edible oils obtained by recovering oils that have been used as edible oils, etc. The vegetable oils may be liquid or solid at room temperature (25°C). These may be used alone or in combination of two or more. The vegetable oil is a component contained in the softener described below, and may be used in combination with other softeners. A part of the softener components in known rubber compositions may be replaced with an equal amount of the vegetable oil to satisfy the relationship of the present invention.

[0372] The vegetable oil according to the present embodiment preferably contains acylglycerol, and more preferably contains triacylglycerol. In this specification, acylglycerol refers to a compound in which a hydroxyl group of glycerin and a fatty acid are ester-bonded. The acylglycerol is not particularly limited, and may be 1-monoacylglycerol, 2-monoacylglycerol, 1,2-diacylglycerol, 1,3-diacylglycerol, or triacylglycerol. Furthermore, the acylglycerol may be a monomer, a dimer, or a polymer of trimer or more. Incidentally, dimer or more acylglycerols can be obtained by thermal polymerization, oxidative polymerization, or the like. Furthermore, the acylglycerol may be liquid or solid at room temperature (25°C).

[0373] The method for confirming whether the rubber composition contains the acylglycerol is not particularly limited, but may be any of the following methods: 1 For example, a rubber composition containing triacylglycerol is immersed in deuterated chloroform at room temperature (25°C) for 24 hours, and after removing the rubber composition, 1 When H-NMR was measured, signals were observed at around 5.26 ppm, around 4.28 ppm, and around 4.15 ppm when the signal of tetramethylsilane (TMS) was set at 0.00 ppm, and the signals were presumed to be signals derived from hydrogen atoms bonded to carbon atoms adjacent to oxygen atoms of ester groups. Note that "around" in this paragraph refers to a range of ±0.10 ppm.

[0374] The fatty acid 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 polyunsaturated fatty acids such as linoleic acid and linolenic acid.

[0375] As the vegetable oil, for example, commercially available oils from Idemitsu Kosan Co., Ltd., Sankyo Yuka Kogyo Co., Ltd., ENEOS Corporation, Orisoi Co., Ltd., H&R Corporation, Toyokuni Oil Mills Co., Ltd., Fuji Kosan Co., Ltd., Nisshin Oillio Group Co., Ltd., etc. can be used.

[0376] When oil is contained, the content thereof per 100 parts by mass of the rubber component can be 0 to 100 parts by mass (for example, 1, 3, 5, 7, 8, 10, 12, 15, 17, 20, 22, 25, 28, 30, 32, 35, 37, 40, 42, 45, 47, 50, 52, 55, 57, 60, 62, 65, 68, 70, 72, 74, 76, 80, 82, 85, 88, 90, 95, 100).

[0377] (Liquid Rubber) The liquid rubber is not particularly limited as long as it is a polymer that is in a liquid state at room temperature (25° C.), and examples thereof include liquid butadiene rubber (liquid BR), liquid styrene butadiene rubber (liquid SBR), liquid isoprene rubber (liquid IR), liquid styrene isoprene rubber (liquid SIR), liquid farnesene rubber, etc. These liquid rubbers may be used alone or in combination of two or more kinds.

[0378] The content of the softener per 100 parts by mass of the rubber component (the total amount of all softeners when multiple softeners are used in combination) can be 0 to 200 parts by mass (for example, 1, 3, 5, 7, 8, 10, 12, 15, 17, 20, 22, 25, 28, 30, 32, 35, 37, 40, 42, 45, 47, 50, 52, 55, 57, 60, 62, 65, 68, 70, 72, 74, 76, 80, 82, 85, 88, 90, 95, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200).

[0379] The antiaging agent is not particularly limited, but examples thereof include amine-based, quinoline-based, quinone-based, phenol-based, and imidazole-based compounds, and carbamic acid metal salts, and the like. Phenylenediamine-based antiaging agents such as N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, N-isopropyl-N'-phenyl-p-phenylenediamine, N,N'-diphenyl-p-phenylenediamine, N,N'-di-2-naphthyl-p-phenylenediamine, and N-cyclohexyl-N'-phenyl-p-phenylenediamine, and quinoline-based antiaging agents such as 2,2,4-trimethyl-1,2-dihydroquinoline polymer and 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline are preferred. These antiaging agents may be used alone or in combination of two or more.

[0380] When an antioxidant is contained, the content thereof per 100 parts by mass of the rubber component can be 0.5 to 10.0 parts by mass (for example, 0.5, 0.8, 1.0, 1.2, 1.5, 1.8, 2.0, 2.5, 2.8, 3.0, 3.2, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5).

[0381] When wax is contained, the content thereof per 100 parts by mass of the rubber component can be 0.5 to 10.0 parts by mass (for example, 0.5, 0.8, 1.0, 1.2, 1.5, 1.8, 2.0, 2.5, 2.8, 3.0, 3.2, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5).

[0382] When stearic acid is contained, the content thereof per 100 parts by mass of the rubber component can be 0.5 to 10.0 parts by mass (for example, 0.5, 0.8, 1.0, 1.2, 1.5, 1.8, 2.0, 2.5, 2.8, 3.0, 3.2, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5).

[0383] When zinc oxide is contained, the content thereof per 100 parts by mass of the rubber component can be 0.5 to 10.0 parts by mass (for example, 0.5, 0.8, 1.0, 1.2, 1.5, 1.8, 2.0, 2.5, 2.8, 3.0, 3.2, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5).

[0384] <Crosslinking agent> As the crosslinking agent, sulfur is preferably used. As the sulfur, powdered sulfur, oil-treated sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersible sulfur, etc. can be used.

[0385] When sulfur is contained, the content thereof per 100 parts by mass of the rubber component can be 0.5 to 10.0 parts by mass (for example, 0.5, 0.8, 1.0, 1.2, 1.5, 1.8, 2.0, 2.5, 2.8, 3.0, 3.2, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5).

[0386] As a crosslinking agent other than sulfur, a known organic crosslinking agent can also be used. The organic crosslinking agent is not particularly limited as long as it can form a crosslinked chain other than a polysulfide bond, and examples thereof include alkylphenol-sulfur chloride condensate, 1,6-hexamethylene-sodium dithiosulfate dihydrate, 1,6-bis(N,N'-dibenzylthiocarbamoyldithio)hexane, dicumyl peroxide, and the like, with 1,6-bis(N,N'-dibenzylthiocarbamoyldithio)hexane being preferred. As these organic crosslinking agents, commercially available ones from Taoka Chemical Co., Ltd., Lanxess Co., Ltd., Flexis, and the like can be used.

[0387] The vulcanization accelerator is not particularly limited, but examples thereof include sulfenamide-based, thiazole-based, thiuram-based, thiourea-based, guanidine-based, dithiocarbamic acid-based, aldehyde-amine-based or aldehyde-ammonia-based, imidazoline-based, and xanthate-based vulcanization accelerators. These vulcanization accelerators may be used alone or in combination of two or more.

[0388] Examples of the sulfenamide vulcanization accelerator include N-tert-butyl-2-benzothiazolylsulfenamide (TBBS), N-cyclohexyl-2-benzothiazolylsulfenamide (CBS), and N,N-dicyclohexyl-2-benzothiazolylsulfenamide (DCBS).

[0389] Examples of the thiazole-based vulcanization accelerator include 2-mercaptobenzothiazole (MBT) or a salt thereof, di-2-benzothiazolyl disulfide (MBTS), 2-(2,4-dinitrophenyl)mercaptobenzothiazole, and 2-(2,6-diethyl-4-morpholinothio)benzothiazole.

[0390] Examples of thiuram vulcanization accelerators include tetrakis(2-ethylhexyl)thiuram disulfide (TOT-N), tetramethylthiuram disulfide (TMTD), tetraethylthiuram disulfide, tetramethylthiuram monosulfide (TMTM), dipentamethylene thiuram disulfide, and dipentamethylene thiuram tetrasulfide.

[0391] Examples of the thiourea vulcanization accelerator include thiourea compounds such as thiacarbamide, diethylthiourea, dibutylthiourea, trimethylthiourea, and diorthotolylthiourea, N,N'-diphenylthiourea, trimethylthiourea, and N,N'-diethylthiourea.

[0392] Examples of the guanidine vulcanization accelerator include 1,3-diphenylguanidine (DPG), 1,3-di-o-tolylguanidine, 1-o-tolylbiguanide, di-o-tolylguanidine salt of dicatechol borate, 1,3-di-o-cumenylguanidine, 1,3-di-o-biphenylguanidine, and 1,3-di-o-cumenyl-2-propionylguanidine.

[0393] Examples of dithiocarbamate vulcanization accelerators include piperidinium pentamethylene dithiocarbamate (PPDC), zinc dimethyldithiocarbamate (ZnMDC), zinc diethyldithiocarbamate (ZnEDC), zinc dibutyldithiocarbamate (ZnBDC), zinc dibenzyldithiocarbamate (ZDBzC), zinc N-ethyl-N-phenyldithiocarbamate (ZnEPDC), zinc N-pentamethylenedithiocarbamate (ZnPDC), sodium dibutyldithiocarbamate (NaBDC), copper dimethyldithiocarbamate (CuMDC), iron dimethyldithiocarbamate (FeMDC), and tellurium diethyldithiocarbamate (TeEDC).

[0394] When a vulcanization accelerator is contained, the content thereof per 100 parts by mass of the rubber component can be 0.5 to 10.0 parts by mass (for example, 0.5, 0.8, 1.0, 1.2, 1.5, 1.8, 2.0, 2.5, 2.8, 3.0, 3.2, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5).

[0395] [Manufacturing] The rubber composition of the present invention can be produced by a known method, for example, by kneading the above-mentioned components using a rubber kneading device such as an open roll or an internal kneader (Banbury mixer, kneader, etc.).

[0396] The kneading step includes, for example, a base kneading step in which compounding ingredients and additives other than the vulcanizing agent and the vulcanization accelerator are kneaded, and a final kneading (F kneading) step in which the vulcanizing agent and the vulcanization accelerator are added to the kneaded product obtained in the base kneading step and kneaded. Furthermore, the base kneading step can be divided into a plurality of steps as desired.

[0397] The kneading conditions are not particularly limited, but examples thereof include a method in which in the base kneading step, kneading is performed for 3 to 10 minutes at a discharge temperature of 150 to 170° C., and in the final kneading step, kneading is performed for 1 to 5 minutes at 70 to 110° C. The vulcanization conditions are not particularly limited, but examples thereof include a method in which vulcanization is performed for 10 to 30 minutes at 150 to 200° C.

[0398] The tire of the present invention, which is equipped with tire components made of the rubber composition of the present invention, can be manufactured by a normal method. That is, the unvulcanized rubber composition prepared by blending the above-mentioned components with the rubber component as necessary is extruded according to the shape of each tire component, and steel cords are embedded as necessary. The tire components thus obtained are laminated on a tire building machine and molded by a normal method to form an unvulcanized tire, and the unvulcanized tire is heated and pressurized in a vulcanizer to manufacture a tire. The vulcanization conditions are not particularly limited, and examples thereof include a method of vulcanizing at 150 to 200°C for 10 to 30 minutes.

[0399] [Application] The tire of the present invention can be used for any purpose, regardless of whether it is a pneumatic tire or a non-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 load tire, or a run-flat tire. A passenger car tire is a tire that is intended to be mounted on a four-wheeled vehicle and has a maximum load capacity of less than 1400 kg. A heavy load tire is a tire that has a maximum load capacity of 1400 kg or more. The tire of the present invention can be used as an all-season tire, a summer tire, or a winter tire such as a studless tire. [Explanation of symbols]

[0400] 1 Tire 2 Tread 2a Cap rubber layer 2b Base rubber layer 2c Conductive rubber material 3 Sidewall 4 Wing 5. Clinch 6 Bead section 6a bead core 6b Bead Apex 6c Bead reinforcement layer 7 Inner Liner 8. Carcass 8a Carcass ply 9 Belt Layer 9a Inner belt ply 9b Outer belt ply 10 Band (belt reinforcement layer) 10a band ply 10b Edgeband Ply 11 Chafer 12 Circumferential groove 13 Horizontal groove (shoulder horizontal groove) 14 Sipes (shoulder sipes) 15 Sipe (center sipe) 16 Center Land Section 17 Shoulder Land Section 18 Yokomizo 19 Small hole 20 Inclined Horizontal Groove 21 Inclined joint groove 22 Sipe 23 Side reinforcement layer CL Tire Equator X Tire width direction Y Tire radial direction G T Tread thickness G TC Cap rubber layer thickness G TB Base rubber layer thickness D S Depth of deepest circumferential groove W S Maximum opening width of circumferential groove in tire width direction C S The angle between the longitudinal direction of the lateral groove and the width direction of the tire W LS Shoulder width G S Sidewall Thickness G C Clinch Thickness PC sidewall and clinch joint on tire surface Ht Tire section height H BE Belt layer end height H K Carcass folded height H BA Bead apex height H C Clinch Height Te Tread Edge P1 First tread pattern section P2 Second tread pattern

Claims

1. Tread and The sidewall and Clinch and A pair of bead portions each having a bead core embedded therein; An inner liner, At least one tire component having a steel cord, The at least one tire component having steel cords includes at least one ply having steel cords of 1x4 construction.

2. 2. The tire according to claim 1, wherein the steel cord has an outer diameter D mm of 0.50 mm or less.

3. The tire according to claim 1 or 2, wherein the number of the steel cords arranged per 50 mm in the tire width direction is 60 cords / 50 mm or less.

4. The tread is made of a rubber composition containing a rubber component, and the tread includes a cap rubber layer that constitutes a tread ground contact surface, and the tan δ at 30° C. (30° C. tan δ) of the cap rubber layer is T c) and the tread thickness G T mm (30°C tan δ T c×G T 4. The tire according to claim 1, wherein the axial length of the tire is 9.0 or less.

5. The tread is made of a rubber composition containing a rubber component, the tread includes a cap rubber layer that constitutes a tread contact surface, and the tread has a thickness G T The complex modulus of elasticity of the cap rubber layer at 30° C. (30° C. E* T c) ratio (30°C E* T c / G T 5. The tire according to claim 1, wherein the axial length of the tire is 0.2 or less.

6. The tire according to any one of claims 1 to 5, wherein a land area ratio of the tread is 40% or more.

7. The sidewall is made of a rubber composition containing a rubber component, and the tan δ at 70° C. (70° C. tan δ s 7. The tire according to claim 1, wherein the ratio of the axial length of the tire to the axial length of the tire is 0.03 or more and 0.20 or less.

8. The sidewall is made of a rubber composition containing a rubber component, and the complex modulus of elasticity at 70° C. (70° C. E* s 8. The tire according to claim 1, wherein the compressive strength (MPa) of the tire is 2.5 MPa or more and 6.5 MPa or less.

9. The tire according to any one of claims 1 to 8, wherein a ratio (Hc / Ht) of a height Hcmm of the clinch to a tire cross-section height Htmm is 0.45 or less.

10. The clinch is made of a rubber composition containing a rubber component, and the tan δ of the rubber composition at 70° C. (70° C. tan δ c ) and the product of the clinch height Hcmm (70°C tan δ c The tire according to any one of claims 1 to 9, wherein the total length of the tyre is 0.6 or more and 14.0 or less.

11. The clinch is made of a rubber composition containing a rubber component, and the complex modulus of elasticity at 70° C. (70° C. E*) of the rubber composition relative to the height Hcmm of the clinch is c ) ratio (70°C E* c The tire according to any one of claims 1 to 10, wherein the ratio of the axial length of the tyre to the longitudinal length of the tire is 0.07 or more and 0.75 or less.

12. The clinch is made of a rubber composition containing a rubber component, and when the complex modulus of the rubber composition at 70° C. is 70° C. E*c, the thickness G of the clinch is c mm and 70°C E*c product (G c ×70℃E* c 12. The tire according to claim 1, wherein the axial length of the tire is 25 or more and 450 or less.

13. The bead portion includes a bead apex, the bead apex being made of a rubber composition containing a rubber component, and the height H of the bead apex in the tire radial direction is BA mm and tan δ (70 ° C.) of the rubber composition BA ) and the product (H BA ×70℃ tan δ BA 13. The tire according to claim 1, wherein the ratio of the axial length of the tire to the radial length of the tire is 0.3 or more and 12.0 or less.

14. The bead portion includes a bead apex, the bead apex being made of a rubber composition containing a rubber component, and the height H of the bead apex in the tire radial direction is BA mm and the complex modulus of elasticity of the rubber composition at 70 ° C. (70 ° C. E * BA ) and the product (H BA ×70℃E* BA 14. The tire according to claim 1, wherein the average particle diameter is 100 or more and 9000 or less.

15. The inner liner is made of a rubber composition containing a rubber component, and the thickness of the inner liner G I mm and the tan δ of the rubber component at 70 ° C. (70 ° C. tan δ I ) product (G I ×70℃ tan δ I 15. The tire according to claim 1, wherein the value of the saturation coefficient is 0.02 or more and 1.40 or less.

16. At least one tire component having the steel cord is a belt layer, The tire according to any one of claims 1 to 15, wherein the belt layer includes at least one belt ply composed of a belt cord made of a steel cord having a 1 x 4 structure and a belt topping rubber covering the belt cord.

17. The thickness G of the belt ply b The tire of claim 16, wherein the axial length is equal to or greater than 0.5 mm and equal to or less than 1.2 mm.

18. 18. The tire according to claim 16, wherein the belt cord is formed in a longitudinal direction, and a pitch P of the forming is 2.7 mm or more and 3.7 mm or less.

19. The tire according to any one of claims 16 to 18, wherein the strength of the belt cord is 200N or more and 580N or less.

20. The tire according to any one of claims 16 to 19, wherein the belt cord has an occupied area ratio of 9% or more and 18% or less.

21. The tan δ of the belt topping rubber at 70° C. (70° C. tan δ BE 21. The tire according to claim 16, wherein the axial length of the tire is 0.13 or more.

22. The tire according to any one of claims 16 to 21, wherein the 100% modulus of the belt topping rubber is 5.0 MPa or more and 10.0 MPa or less.

23. The tire according to any one of claims 16 to 22, wherein a pull-out force of the steel cord from the belt topping rubber measured in accordance with ASTM-1871 is 500 N or more and 2000 N or less.

24. The belt layer is composed of two or more belt plies, and in a cross section passing through the tire rotation axis, the distance G on the tire equatorial plane between two adjacent layers of steel cords is BB The tire according to any one of claims 16 to 23, wherein the axial length of the tyre is 0.5 mm or more.

25. The tire according to any one of claims 1 to 24, which is a passenger car tire.

26. At least one tire component having the steel cord is a band, The tire according to any one of claims 1 to 24, wherein the band includes at least one band ply composed of a band cord made of a steel cord having a 1 x 4 structure and a band topping rubber covering the band cord.

27. The tire according to claim 26, wherein the occupied area ratio of the band cord is 30% or more and 60% or less.

28. The tire according to claim 26 or 27, wherein an intermediate elongation of the band cord under a load of 44 N is 1.2% or more and 9.5% or less.

29. The tire according to any one of claims 26 to 28, wherein the heat shrinkage rate of the band cord is 0.1% or more and 5.0% or less.

30. The tire according to any one of claims 26 to 29, wherein the strength of the band cord is 120N or more and 700N or less.

31. The tire according to any one of claims 1 to 24 and 26 to 30, which is a heavy duty tire.

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