Tire

Abstract

To provide a tire capable of improving total performance of steering stability performance and wet grip performance.SOLUTION: A tire includes a tread part and a band layer present inside in a tire radial direction of the tread part. The band layer has a band cord including a filament composed of polyester fibers. The tread part is composed of a rubber component containing styrene-butadiene rubber and / or a rubber constituent containing an isoprene system and rubber composition containing copolymer resin containing styrene and cyclopentadiene as monomer components. When a cord diameter of the band cord is D(mm) and a total styrene amount in the rubber composition of the rubber composition in the case that a mass of the rubber constituent of the rubber composition is 100 mass%, D×S is beyond 0.05.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a tire.

Background Art

[0002] Hitherto, various methods for improving handling stability and wet grip performance have been studied (see, for example, Patent Documents 1 and 2). However, in recent years, further improvements in these performances have been demanded.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a tire capable of improving the overall performance of handling stability and wet grip performance.

Means for Solving the Problems

[0005] The present invention relates to a tire including a tread portion and a band layer existing on the inner side in the tire radial direction of the tread portion, wherein the band layer has a band cord containing filaments made of polyester fiber, and the tread portion is composed of a rubber composition containing a rubber component including styrene-butadiene rubber and / or isoprene-based rubber, and a copolymer resin containing styrene and cyclopentadiene as monomer components, and when the cord diameter of the band cord is D (mm) and the total styrene amount in the rubber composition is S (mass%) when the mass of the rubber component in the rubber composition is 100 mass%, the tire is related to the case where D×S is more than 0.05.

Effects of the Invention

[0006] According to the present invention, there is provided a tire capable of improving the overall performance of handling stability performance and wet grip performance.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Mode for Carrying Out the Invention

[0008] A tire according to an embodiment of the present invention is a tire including a tread portion and a band layer existing on the inner side in the tire radial direction of the tread portion, wherein the band layer has a band cord containing filaments made of polyester fiber, and the tread portion is composed of a rubber composition containing a rubber component including styrene-butadiene rubber and / or isoprene-based rubber, and a copolymer resin containing styrene and cyclopentadiene as monomer components, and when the cord diameter of the band cord is D (mm) and the total styrene amount in the rubber composition is S (mass%) when the mass of the rubber component in the rubber composition is 100 mass%, it is a tire in which D×S is more than 0.05.

[0009] Although not intended to be bound by theory, in the tire of the present invention, as a mechanism for improving the overall performance of handling stability performance and wet grip performance, for example, it can be considered as follows.

[0010] (1) A copolymer resin containing styrene and cyclopentadiene as monomer components has high compatibility with styrene-butadiene rubber and isoprene-based rubber and is bulky. Therefore, a rubber composition containing this copolymer resin is imparted with flexibility without impairing the reinforcing effect, and thus is considered to contribute to the improvement of wet grip performance.

[0011] In addition, it is considered that the handling stability performance and the wet grip performance can be improved by making the product of the cord diameter D of the (2) band cord and the total styrene amount S in the rubber composition larger than a predetermined value.

[0012] It is considered that the above (1) and (2) cooperate to achieve a remarkable effect that the comprehensive performance of the handling stability performance and the wet grip performance is improved.

[0013] As the polyester fiber, recycled polyester fiber is preferably used.

[0014] When the complex elastic modulus of the rubber composition at 30°C is 30°C E* (MPa), 30°C E* × D is preferably 3.0 or more. It is considered that the effects of the present invention can be exhibited by setting 30°C E* × D within the above range.

[0015] The tanδ (0°C tanδ) of the rubber composition at 0°C is preferably 0.45 or more from the viewpoint of the wet grip performance.

[0016] The rubber composition preferably contains 60 parts by mass or more of silica with respect to 100 parts by mass of the rubber component. By containing 60 parts by mass or more of silica, the followability to the road surface is improved by the interaction between the silanol groups of the silica and the moisture on the road surface, which is considered to contribute to the improvement of the wet grip performance.

[0017] The content of the copolymer resin with respect to 100 parts by mass of the rubber component in the rubber composition is preferably 10 parts by mass or more from the viewpoint of the wet grip performance.

[0018] The distance G from the tread surface to the band cord is preferably 12.0 mm or less from the viewpoint of the handling stability performance.

[0019] [Definition] The "tread portion" is a member that includes the portion forming the ground contact surface of the tire. In the radial cross-section of the tire, when it includes members forming the tire skeleton, such as a belt layer, a belt reinforcing layer, and a carcass layer, made of steel or textile materials, it is a member disposed on the outer side in the tire radial direction than those members.

[0020] "Filament" refers to the smallest unit forming a cord. A plurality of the filaments twisted together is called a yarn.

[0021] The "rubber component of the rubber composition" is a component that contributes to crosslinking in the rubber composition, and generally has a weight average molecular weight (Mw) of 10,000 or more.

[0022] The "total styrene amount S in the rubber composition" is the total styrene amount (mass%) in the rubber composition when the mass of the rubber component is 100 mass%, and is the total amount of the content of the styrene part contained in the rubber component and the content of the styrene part contained in compounding agents other than the rubber component. The styrene part is not particularly limited as long as it is a group having a styrene structure, and examples thereof include styrene, α-methylstyrene, vinyltoluene, chlorostyrene, and the like.

[0023] That is, first, for each rubber component, a value obtained by multiplying the content of the styrene part (mass%) by the mass fraction in the rubber component is calculated for each, and the sum value (mass%) obtained by adding these values is used. Next, for the styrene part-containing compounding agent other than the rubber component contained in the rubber composition, a value obtained by multiplying the content of the styrene part (mass%) of each styrene part-containing compounding agent by the mass fraction with respect to 100 parts by mass of the rubber component is calculated, and the sum value (mass%) obtained by adding them is used. The value obtained by adding both sum values is defined as the total styrene amount S (mass%). Therefore, it is calculated by {Σ(content of styrene part (mass%) of each styrene part-containing rubber × content in the rubber component of each styrene part-containing rubber (mass%) / 100) + Σ(content of styrene part (mass%) of each styrene part-containing compounding agent other than the rubber component × compounding amount (parts by mass) of each styrene part-containing compounding agent with respect to 100 parts by mass of the rubber component / 100)}. In this specification, when the above-mentioned "styrene part" is styrene (for example, when the above-mentioned styrene part-containing rubber is styrene-butadiene rubber), the above-mentioned "content of the styrene part" may be expressed as "styrene content".

[0024] For example, when the rubber component consists of 30% by mass of the first SBR (styrene content: 25% by mass), 60% by mass of the second SBR (styrene content: 27.5% by mass), and 10% by mass of BR, and the rubber composition further contains, in addition to the rubber component, 20 parts by mass of the first resin having a styrene part (styrene content: 5% by mass) with respect to 100 parts by mass of the rubber component and 10 parts by mass of the second resin having a styrene part (styrene content: 1% by mass) with respect to 100 parts by mass of the rubber component, the total styrene amount St in the rubber composition with respect to 100% by mass of the rubber component is 25.1% by mass = {(25×30 / 100 + 27.5×60 / 100 + 0×10 / 100) + (5×20 / 100 + 1×10 / 100)}.

[0025] The "normal state" is a no-load state in which it is assembled to a normal rim and filled with air at normal internal pressure.

[0026] "Normal Rim" refers to the rim defined for each tire in the standard system including the standards on which the tire is based. For example, in the case of JATMA (Japan Automobile Tire Association), it refers to the "Standard Rim" in the applicable sizes described in the "JATMA YEAR BOOK"; in the case of ETRTO (The European Tyre and Rim Technical Organisation), it refers to the "Measuring Rim" described in the "STANDARDS MANUAL"; and in the case of TRA (The Tire and Rim Association, Inc.), it refers to the "Design Rim" described in the "YEAR BOOK". Refer to JATMA, ETRTO, and TRA in this order, and follow the relevant standards if there are applicable sizes during the reference. In the case of tires not defined by the above standards, it refers to the rim with the narrowest width among the rims with the smallest diameter that can be assembled with the tire and can maintain the internal pressure (i.e., does not cause air leakage between the rim and the tire).

[0027] "Normal Inflation Pressure" refers to the air pressure defined for each tire in the standard system including the standards on which the tire is based. For example, in the case of JATMA, it refers to the "Maximum Air Pressure"; in the case of ETRTO, it refers to "INFLATION PRESSURE"; and in the case of TRA, it refers to the maximum value described in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES". Similar to the case of the normal rim, refer to JATMA, ETRTO, and TRA in this order, and follow the relevant standards if there are applicable sizes during the reference. In the case of tires not defined by the above standards, it refers to the normal inflation pressure (but not less than 250 kPa) of another tire size described with the normal rim as the standard rim (however, as defined by the standards). If there are multiple normal inflation pressures not less than 250 kPa described, it refers to the minimum value among them.

[0028] The "normal load" refers to the load specified for each tire in the standard system including the standards on which the tire is based. For example, in the case of JATMA, it is the "maximum load capacity"; in the case of ETRTO, it is "LOAD CAPACITY"; in the case of TRA, it is the maximum value described in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES". Refer to JATMA, ETRTO, and TRA in this order, similar to the case of the normal rim and normal internal pressure. If there is an applicable size during the reference, follow the relevant standard. For tires not specified in the above standards, the maximum load capacity W L calculated separately is taken as the normal load.

[0029] The "maximum load capacity W L " is calculated by the following formula. "V" is the virtual volume of the tire (mm 3 ), "Dt" is the outer diameter of the tire in the normal state (mm), "Ht" is the cross-sectional height of the tire in the radial direction of the tire in the cross-section of the tire by the plane including the tire rotation axis (mm), and "Wt" is the cross-sectional width of the tire in the normal state (mm). When the rim diameter of the tire is R, Ht can be obtained by (Dt - R) / 2. When there are patterns or characters on the tire sidewall, Wt is the value obtained after excluding them. Note that the maximum load capacity is synonymous with the above normal load.

[0030]

Equation

[0031] Unless otherwise specified, the "dimensions of each part of the tire" are values specified in the normal state for those appearing on the outer surface of the tire, and for those inside the tire or on the tire cut surface, they are values specified in the state where the cut tire piece is held within the rim width of the normal rim by the plane including the tire rotation axis.

[0032] "The distance G from the tread surface to the band cord" refers to the straight-line distance from the crown portion on the tire equatorial plane to the outermost part of the band cord in the tire radial direction in a cross-section obtained by cutting the tire with a plane including the tire rotation axis. "Crown portion" refers to the outermost end in the tire radial direction of the tread portion intersecting with the tire equatorial plane when there is no circumferential groove on the tire equatorial plane, and refers to the portion where the line segment connecting the outermost tread ends of the land portions at both ends of the circumferential groove intersects with the tire equatorial plane when there is a circumferential groove on the tire equatorial plane.

[0033] "30 °C E*" is the complex elastic modulus measured under the conditions of a temperature of 30 °C, a frequency of 10 Hz, an initial strain of 5%, a dynamic strain of ±1%, and an elongation mode using a dynamic viscoelasticity measuring device (for example, the Implex series manufactured by GABO). The sample for this measurement is a vulcanized rubber composition with a length of 20 mm × width of 4 mm × thickness of 1 mm. When produced by cutting from a tire, it is cut out from the tread portion such that the tire circumferential direction is the long side and the tire radial direction is the thickness direction.

[0034] "0 °C tanδ" is the loss tangent measured under the conditions of a temperature of 0 °C, a frequency of 10 Hz, an initial strain of 10%, a dynamic strain of ±2.5%, and an elongation mode using a dynamic viscoelasticity measuring device (for example, the Implex series manufactured by GABO). The sample for this measurement is produced in the same manner as in the case of 30 °C E*.

[0035] "The content of the styrene portion" is calculated by thermal decomposition gas chromatography. In this specification, "thermal decomposition gas chromatography" refers to a method in which a sample is heated by a thermal decomposition device, the individual components contained in the gas-phase components generated by this heating are separated by a separation column, and each isolated component is analyzed.

[0036] "Vinyl content (amount of 1,2-bonded butadiene units)" is calculated by thermal decomposition gas chromatography in the same manner as the content of the above styrene portion.

[0037] The "glass transition temperature Tg" is a value determined by differential scanning calorimetry (DSC) in accordance with JIS K 7121, and is applied to, for example, SBR. For example, when SBR contains extender oil, it is measured for a sample after removing the extender oil using acetone in accordance with JIS K 6229.

[0038] The "cis content (amount of cis-1,4-bonded butadiene units)" is a value calculated by infrared absorption spectrum analysis in accordance with JIS K 6239-2:2017, and is applied to, for example, rubber components having repeating units derived from butadiene such as BR.

[0039] The "weight average molecular weight (Mw)" can be determined by standard polystyrene conversion based on the measured value by gel permeation chromatography (GPC) (for example, GPC-8000 series manufactured by Tosoh Corporation, detector: differential refractometer, column: TSKgel SuperMultipore HZ-M manufactured by Tosoh Corporation). For example, it is applied to SBR, BR, etc.

[0040] The "nitrogen adsorption specific surface area (N2SA) of carbon black" is measured in accordance with JIS K 6217-2:2017.

[0041] The "nitrogen adsorption specific surface area (N2SA) of silica" is measured by the BET method in accordance with ASTM D3037-93.

[0042] The "average primary particle diameter" is a value obtained by photographing particles with a transmission or scanning electron microscope and calculating the arithmetic mean of the particle diameters of 400 particles. When the shape of the particles is spherical, the diameter of the sphere is taken as the particle diameter, and when the shape is other than spherical, the equivalent circle diameter ({positive square root of 4×(particle area) / π}) is calculated from the microscope image and taken as the particle diameter. The average primary particle diameter is applied to silica, carbon black, etc.

[0043] The "softening point of resin" is measured with a ring and ball softening point measuring device for the softening point defined in JIS K 6220-1:2015 7.7, and is the temperature at which the ball drops.

[0044] A "plasticizer" is a material that imparts plasticity to the rubber component and is a component extracted from the rubber composition using acetone. The plasticizer includes plasticizers that are liquid (in a liquid state) at 25°C and plasticizers that are solid at 25°C. However, waxes and stearic acid commonly used in the tire industry are not included.

[0045] The "content of plasticizer" also includes the amount of plasticizer contained in the stretched rubber component previously stretched by a plasticizer such as oil, resin component, liquid rubber component, etc. The same applies to the content of oil, the content of resin component, and the content of liquid rubber. For example, when the stretching component is oil, the stretched oil is included in the content of oil.

[0046] The manufacturing procedure of the tire which is one embodiment of the present invention will be described in detail below. However, the following description is an exemplification for explaining the present invention and is not intended to limit the technical scope of the present invention only to this description scope.

[0047] [Tire] Hereinafter, a tire according to an embodiment of the present invention will be described with reference to the drawings.

[0048] Hereinafter, with reference to the drawings, the tire according to this embodiment will be described. Note that the following embodiment is merely an example, and the tire according to this embodiment is not limited to the following embodiment.

[0049] FIG. 1 illustrates the tire according to this embodiment. In FIG. 1, a part of the cross-section when the tire is cut along a plane including the tire rotation axis is shown. In FIG. 1, the vertical direction is the radial direction of the tire, the left-right direction is the axial direction of the tire, and the direction perpendicular to the paper surface is the circumferential direction of the tire. In FIG. 1, the dashed-dotted line CL represents the tire equator.

[0050] As shown in Fig. 1, a belt layer 6 and a belt layer 5 are provided on the inner side of the tread portion 1 in the tire radial direction. The belt layer 5 is laminated in two layers, and the band layer 6 is disposed between the tread portion 1 and the belt layer 5. The band layer 6 is composed of an edge band 6b that covers only the edge portion of the belt layer 5 and a full band 6a that covers the entire area of the belt layer 5. A carcass 4 and an inner liner 7 are laminated below the belt layer 5.

[0051] The tread portion according to the present embodiment may be a tread portion composed of a single rubber layer, or may be a tread portion having a layer (cap rubber layer) whose outer surface constitutes the tread surface 16 and one or more rubber layers (inner rubber layers) existing between the cap rubber layer and the band layer 6. In Fig. 1, a cap rubber layer 11 and a base rubber layer 12 laminated on the outer side in the tire radial direction of the band layer 6 are provided.

[0052] In this specification, the "rubber composition constituting the tread portion" shall refer to the rubber composition constituting the cap rubber layer when the tread portion is composed of two or more layers.

[0053] Fig. 2 shows a perspective view of the ply forming the band layer 6. As shown in Fig. 2, a plurality of band cords 31 are covered with topping rubber 32. The band cord containing filaments made of polyester fiber may be possessed by at least either the edge band 6b or the full band 6a, and it is preferable that the full band 6a has it.

[0054] The band cord 31 is spirally wound in the tire circumferential direction. The angle of the band cord with respect to the tire circumferential direction can be, for example, ±15° or less, ±10° or less, ±5° or less. Since the belt layer 5 is constrained by this band cord, an increase in the outer diameter of the tire due to the internal pressure during running is suppressed.

[0055] FIG. 3 shows a cross-sectional view of a single cord 31. As shown in FIG. 3, each of the band cords 31 is formed by twisting a plurality of filaments 34 having an outer diameter d. The band cord 31 is preferably formed by twisting a plurality of yarns 33 in which a plurality of filaments 34 are twisted together. In FIG. 3, since two yarns 33 are twisted together in the band cord 31, a part 33a (corresponding to the contact surface of the two yarns 33) on the outer surface of the yarn 33 is flattened. As a result, the cross-sectional shape of the band cord 31 is substantially oval with a reduced cross-sectional width at its central portion. However, the band cord according to the present embodiment is not limited to such a mode.

[0056] The cord diameter D of the band cord 31 is obtained by the simple average of the major axis D1 and the minor axis D2 in the cross-section of the band cord 31. The major axis D1 means the maximum diameter of the band cord 31. The minor axis D2 means the maximum diameter among the diameters of the band cord 31 in the direction orthogonal to the major axis D1.

[0057] The band cord 31 preferably extends in the length direction of the band cord 31 with a constant cross-sectional shape, but the cross-sectional shape and cross-sectional area of the band cord 31 may change in the length direction of the cord 31. In this case, it is preferable to measure the cord diameter D at the position where the cross-sectional area of the band cord 31 is the smallest. This is because the substantial tensile strength of the cord depends on the configuration of the cord at the position where the cross-sectional area of the cord is the smallest.

[0058] From the viewpoint of handling stability performance, the cord diameter D of the band cord 31 is preferably 0.40 mm or more, more preferably 0.45 mm or more, and still more preferably 0.50 mm or more. On the other hand, from the viewpoint of low fuel consumption performance, the cord diameter D is preferably 0.90 mm or less, more preferably 0.80 mm or less, still more preferably 0.75 mm or less, and particularly preferably 0.70 mm or less.

[0059] The distance G from the tread surface 16 to the band cord 31 is preferably 12.0 mm or less, more preferably 11.0 mm or less, still more preferably 10.0 mm or less, and particularly preferably 9.0 mm or less from the viewpoint of handling stability performance. Also, from the viewpoint of ensuring the thickness of the tread portion, it is preferably 3.0 mm or more, more preferably 4.0 mm or more, still more preferably 5.0 mm or more, and particularly preferably 6.0 mm or more.

[0060] The band cord 31 contains filaments made of polyester fiber and may further contain filaments made of other materials.

[0061] The polyester fiber can be obtained, for example, by spinning polyester obtained by the following method by a known method.

[0062] The polyester can be obtained by a known method, for example, by polycondensing a diol and a dicarboxylic acid or its derivative in the presence of a conventional catalyst as necessary.

[0063] The diol is not particularly limited, but an aliphatic diol having 2 to 6 carbon atoms is preferred. Specifically, for example, ethylene glycol, propylene glycol, butylene glycol, pentanediol, hexanediol, cyclohexanediol, etc. can be mentioned. Among them, ethylene glycol, propylene glycol, and butylene glycol are preferred, and ethylene glycol is more preferred.

[0064] Examples of the dicarboxylic acid include aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, and aromatic dicarboxylic acids, and aromatic dicarboxylic acids are preferred.

[0065] The aliphatic dicarboxylic acid is not particularly limited, but an aliphatic straight-chain dicarboxylic acid having 2 to 20 carbon atoms is preferred. Specifically, for example, adipic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, etc. can be mentioned. Among them, adipic acid, sebacic acid, and dodecanedioic acid are preferred.

[0066] The alicyclic dicarboxylic acid is not particularly limited, and examples thereof include 1,4-cyclohexanedicarboxylic acid, dicyclohexanemethane-4,4'-dicarboxylic acid, and norbornanedicarboxylic acid.

[0067] The aromatic dicarboxylic acid is not particularly limited, and examples thereof include phthalic acid compounds such as isophthalic acid, terephthalic acid, and orthophthalic acid, naphthalenedicarboxylic acid, diphenylmethanedicarboxylic acid, 2,5-difurancarboxylic acid, and the like. Among them, terephthalic acid, naphthalenedicarboxylic acid, and 2,5-difurancarboxylic acid are preferable, and terephthalic acid is more preferable.

[0068] As the derivative of the dicarboxylic acid, an ester of the above dicarboxylic acid is preferable. As the ester, an alkyl ester having 1 to 4 carbon atoms is preferable.

[0069] The polyester is not particularly limited. Specifically, for example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethylene furanoate (PEF), polytrimethylene terephthalate, polybutylene terephthalate, polybutylene naphthalate, and the like can be mentioned. PET and PEN are preferable, and PET is more preferable. The content of isophthalic acid in PET is preferably less than 10 mol%, more preferably less than 1 mol%, and even more preferably less than 0.1 mol% based on all the constitutional units.

[0070] The polyester may contain monomers other than diol and dicarboxylic acid as long as the effects of the present invention are not impaired, but the content thereof is preferably less than 10 mol%, more preferably less than 5 mol%, and even more preferably less than 1 mol% based on all the constitutional units.

[0071] Further, the polyester may be a high molecular weight polyester obtained by chain-extending (coupling) these copolyester polyesters. Examples of the chain extender include carbonate compounds and diisocyanate compounds.

[0072] The polyester fiber according to this embodiment may be a recycled polyester fiber or a biomass polyester fiber.

[0073] Recycled polyester is polyester obtained from used polyester articles. Examples of recycled polyester include mechanical recycled polyester and chemical recycled polyester.

[0074] Mechanical recycled polyester is polyester obtained by crushing and washing used polyester articles to remove contaminants and foreign substances, obtaining flakes, and further treating the flakes under high temperature and reduced pressure. Note that the washed flakes may be pelletized by a known method and then treated under high temperature and reduced pressure. In mechanical recycling, recycled polyester can be obtained without undergoing chemical decomposition, so it tends to be less costly than chemical recycling.

[0075] Chemical recycled polyester is polyester obtained by chemically decomposing the above-mentioned flakes back to monomer units, purifying them, and then repolymerizing them. In chemical recycling, polyester having physical properties and characteristics comparable to those of virgin polyester produced by the conventional method from dicarboxylic acids and diols using petroleum, etc. as raw materials can be obtained.

[0076] In the washing step of the above-mentioned flakes, from the viewpoint of the washing effect, alkali washing using an aqueous sodium hydroxide solution or the like may be performed. The concentration of the alkaline aqueous solution depends on the temperature, time, and stirring state, but is usually in the range of 1 to 10% by weight. Also, the time required for washing is in the range of 10 to 100 minutes, and it is preferably performed with stirring to enhance the effect. Also, when alkali washing is performed, it is preferable to then perform rinsing.

[0077] In mechanical recycling, the degree of polymerization of the polyester may decrease due to the above-mentioned alkali washing and heating in each processing step, and the moldability, strength, heat resistance, etc. of the polyester may decrease. In such a case, in order to restore the decreased degree of polymerization, it is preferable to continuously perform solid-phase polymerization of flakes or melted and pelletized flakes in an inert gas such as nitrogen gas or rare gas at 180 to 245 °C, preferably 200 to 240 °C.

[0078] The chemical decomposition (depolymerization) of polyester in chemical recycling can be carried out by a known method, for example, by mixing the above-mentioned flakes with an alkylene glycol such as ethylene glycol and / or methanol while heating in the presence of a conventional catalyst as necessary.

[0079] Biomass polyester is a polyester obtained from a raw material containing a monomer derived from biomass. Therefore, biomass polyester contains monomer units derived from biomass.

[0080] In the production of biomass polyester, monomers derived from fossil fuels may be used together with monomers derived from biomass. That is, biomass polyester may contain monomer units derived from fossil fuels in addition to monomer units derived from biomass.

[0081] Monomers derived from biomass may be directly produced from biomass-derived raw materials by extraction or fermentation methods, or may be produced by converting the products obtained by extraction or fermentation methods through chemical reactions. Also, commercially available monomers derived from biomass may be used. Examples of monomers derived from biomass include diols derived from biomass and dicarboxylic acids derived from biomass.

[0082] As a filament constituting the band code, organic fibers are preferable as those that can be used in addition to polyester fibers. Examples of organic fibers include nylon fibers, aramid fibers, polyketone fibers, polyparaphenylene nylene acrylate fibers, polyacrylate fibers, rayon fibers, cellulose fibers, carbon fibers, and the like. These fibers may be formed of synthetic fibers, biomass-derived fibers, recycled / reclaimed fibers, or the like.

[0083] When the band code contains the above other materials in addition to polyester fibers, the band code may be a hybrid code obtained by twisting a yarn formed by twisting filaments made of polyester fibers and a yarn formed by twisting filaments made of other materials; a code using a yarn having multifilaments obtained by twisting each filament; or a code having a chemical structure in which each component is chemically bonded.

[0084] The content of polyester fibers in the band code is preferably 10% by mass, more preferably 30% by mass or more, still more preferably 50% by mass or more, still more preferably 60% by mass or more, still more preferably 70% by mass or more, and particularly preferably 80% by mass or more. On the other hand, the upper limit value of the content is not particularly limited. That is, the band code may contain only filaments made of polyester fibers.

[0085] From the viewpoint of ensuring good adhesion with the coating layer, the band code is preferably subjected to a treatment in which an adhesive layer is applied in advance. Known adhesive layers can be used. For example, in addition to treatment with resorcinol formalin rubber latex (RFL), after epoxy treatment with an adhesive composition containing sorbitol polyglycidyl ether and blocked isocyanate, RFL-treated products, products treated with an adhesive composition containing a halohydrin compound, a blocked isocyanate compound, and rubber latex, etc. can be used.

[0086] The number of arrangements E (also called ends) of the band code 31 per 50 mm width in the direction orthogonal to the longitudinal direction of the band code 31 is preferably 30 or more, more preferably 35 or more, still more preferably 40 or more, and particularly preferably 45 or more. Further, the number of arrangements E is preferably 70 or less, more preferably 65 or less, still more preferably 60 or less, and particularly preferably 55 or less.

[0087] In FIGS. 2 and 3, one band code 31 is composed of two yarns 33, but it is not limited to such a mode. The fineness of the yarn is preferably 500 dtex or more, more preferably 700 dtex or more, still more preferably 800 dtex or more, and particularly preferably 1000 dtex or more. Further, the fineness of the yarn is preferably 3500 dtex or less, more preferably 3000 dtex or less.

[0088] The total fineness of the band code is preferably 1000 dtex or more, preferably 1400 dtex or more, still more preferably 1600 dtex or more, and particularly preferably 2000 dtex or more. Further, the total fineness of the band code is preferably 7000 dtex or less, more preferably 6500 dtex or less, still more preferably 6000 dtex or less.

[0089] From the viewpoint of handling stability performance, the breaking strength of the band code is preferably 3.5 cN / dtex or more, more preferably 4.0 cN / dtex or more, still more preferably 4.5 cN / dtex or more, still more preferably 5.0 cN / dtex or more, still more preferably 5.5 cN / dtex or more, and particularly preferably 6.0 cN / dtex or more. The upper limit value of the breaking strength is not particularly limited.

[0090] When the mass of the rubber component is 100% by mass, the total styrene amount S in the rubber composition is preferably 0.1% by mass or more, more preferably 1% by mass or more, still more preferably 2% by mass or more, still more preferably 4% by mass or more, still more preferably 6% by mass or more, still more preferably 8% by mass or more, and particularly preferably 10% by mass or more from the viewpoint of the effects of the present invention. Further, from the viewpoint of low fuel consumption performance, it is preferably 42% by mass or less, more preferably 38% by mass or less, still more preferably 34% by mass or less.

[0091] Note that the total styrene amount S in the rubber composition can be appropriately adjusted according to the type and blending amount of the rubber components described below. For example, the total styrene amount S can be increased by increasing the blending amount of styrene-butadiene rubber, blending styrene-butadiene rubber having a high styrene content, blending a resin containing styrene as a monomer component, etc. Conversely, the total styrene amount S can be reduced by reducing the blending amount of styrene-butadiene rubber, etc.

[0092] The 0°C tanδ of the rubber composition is preferably 0.40 or more, more preferably 0.45 or more, still more preferably 0.50 or more, and particularly preferably 0.55 or more from the viewpoint of the effects of the present invention. On the other hand, from the viewpoint of low fuel consumption performance, it is preferably 1.00 or less, more preferably 0.95 or less, still more preferably 0.90 or less, and particularly preferably 0.85 or less.

[0093] The 30°C E* of the rubber composition is preferably 4.0 MPa or more, more preferably 4.5 MPa or more, still more preferably 5.0 MPa or more, and particularly preferably 5.5 MPa or more from the viewpoint of exerting a restoring force against deformation and improving responsiveness. On the other hand, from the viewpoint of road surface followability, it is preferably 30 MPa or less, more preferably 25 MPa or less, still more preferably 20 MPa or less, still more preferably 15 MPa or less, and particularly preferably 10 MPa or less.

[0094] Note that the 0 tanδ and 30°C E* of the rubber composition can be appropriately adjusted according to the types and blending amounts of the rubber component, filler, plasticizer, etc. described below. For example, the 0°C tan can be increased by increasing the total styrene amount S in the rubber composition, increasing the content of the copolymer resin containing styrene and cyclopentadiene as monomer components, etc.

[0095] From the perspective of the effects of the present invention, D×S is greater than 0.05, preferably greater than 0.30, more preferably greater than 1.0, still more preferably greater than 3.0, and particularly preferably greater than 5.0. On the other hand, from the perspective of low fuel consumption performance, D×S is preferably less than 30.0, more preferably less than 27.0, still more preferably less than 25.0, and particularly preferably less than 23.0.

[0096] From the perspective of the effects of the present invention, 30°C E*×D is preferably 3.0 or more, more preferably 3.5 or more, and still more preferably 4.0 or more. On the other hand, from the perspective of low fuel consumption performance, 30°C E*×D is preferably 7.0 or less, more preferably 6.0 or less, still more preferably 5.0 or less, and particularly preferably 4.5 or less.

[0097] [Rubber composition] The rubber composition (hereinafter referred to as the rubber composition according to the present embodiment) constituting the tread portion according to the present embodiment contains a rubber component containing styrene-butadiene rubber and / or isoprene-based, and a copolymer resin containing styrene and cyclopentadiene as monomer components, and all of them can be produced using the raw materials described below. Hereinafter, the rubber composition according to the present embodiment will be described.

[0098] [Rubber component] In the rubber composition according to this embodiment, a diene rubber is preferably used as the rubber component. Examples of the diene rubber include isoprene rubber, butadiene rubber (BR), styrene-butadiene rubber (SBR), styrene-isoprene rubber (SIR), styrene-isoprene-butadiene rubber (SIBR), chloroprene rubber (CR), acrylonitrile-butadiene rubber (NBR), and the like. These diene rubbers may be modified rubbers treated with a modifying group capable of interacting with a filler such as carbon black or silica, or may be hydrogenated rubbers in which a part of the unsaturated bonds is hydrogenated. The diene rubber may be used alone or in combination of two or more. Further, as the diene rubber, an extended rubber preliminarily extended using a plasticizer described later may be used.

[0099] The content of the diene rubber in the rubber component is preferably 70% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, and particularly preferably 95% by mass or more. Further, the rubber component may consist only of the diene rubber.

[0100] The rubber component according to this embodiment contains styrene-butadiene rubber and / or isoprene-based as essential components. The rubber component preferably contains SBR, more preferably contains SBR and isoprene-based rubber and / or BR, still more preferably contains SBR and isoprene-based rubber, and particularly preferably contains SBR, BR, and isoprene-based rubber. Further, the rubber component may consist only of SBR, BR, and isoprene-based rubber.

[0101] (SBR) The SBR is not particularly limited, and examples thereof include unmodified solution-polymerized SBR (S-SBR), emulsion-polymerized SBR (E-SBR), and modified SBRs thereof (modified S-SBR, modified E-SBR). Examples of the modified SBR include SBRs having a modified terminal and / or main chain, and modified SBRs coupled with tin, silicon compounds, etc. (condensates, those having a branched structure, etc.). Furthermore, hydrogenated products of these SBRs (hydrogenated SBR) can also be used. These SBRs may be used alone or in combination of two or more.

[0102] From the viewpoint of the effects of the present invention, the styrene content of the SBR is preferably 15% by mass or more, more preferably 19% by mass or more, still more preferably 23% by mass or more, and particularly preferably 27% by mass or more. On the other hand, the styrene content of the SBR is preferably less than 60% by mass, more preferably less than 50% by mass, and still more preferably less than 45% by mass. When the styrene content of the SBR exceeds 60% by mass, styrene groups are adjacent to each other, the polymer becomes too hard, crosslinking tends to be non-uniform, and there is a risk of deterioration of blowability during high-temperature driving. In addition, the temperature dependence increases, the performance change with respect to temperature change becomes large, and stable grip performance during and after driving tends not to be obtained well. In this specification, the styrene content of the SBR is measured by the above measurement method.

[0103] The vinyl content of the SBR is preferably more than 10 mol%, more preferably more than 15 mol%, and still more preferably more than 20 mol%. Also, the vinyl content of the SBR is preferably less than 70 mol%, more preferably less than 65 mol%, and still more preferably less than 60 mol%. In this specification, the vinyl content of the SBR is measured by the above measurement method.

[0104] From the viewpoint of wet grip performance, the glass transition point (Tg) of the SBR is preferably above -80°C, more preferably above -75°C, and still more preferably above -65°C. Also, from the viewpoint of low fuel consumption performance, the Tg of the SBR is preferably -40°C or lower, more preferably -45°C or lower, still more preferably -50°C or lower, and particularly preferably -55°C or lower.

[0105] The weight-average molecular weight (Mw) of the SBR is preferably more than 200,000, more preferably more than 300,000, still more preferably more than 400,000, and particularly preferably more than 500,000. Further, from the viewpoints of crosslinking uniformity and the like, Mw is preferably less than 2,000,000, more preferably less than 1,500,000, and still more preferably less than 1,000,000. The Mw of the SBR is measured by the above measurement method.

[0106] As the SBR, oil-extended SBR or non-oil-extended SBR can be used. In this specification, as the SBR, those commercially available from JSR Corporation, Sumitomo Chemical Co., Ltd., UBE Industries, Ltd., Asahi Kasei Corporation, ZS Elastomers Co., Ltd., ARLANXEO, etc. can be used.

[0107] The content of SBR in the rubber component can be appropriately set so that D×S is within the above range, but is preferably 10% by mass or more, more preferably 30% by mass or more, still more preferably 50% by mass or more, still more preferably 60% by mass or more, still more preferably 70% by mass or more, and particularly preferably 75% by mass or more. On the other hand, the upper limit value of the content is not particularly limited, but can be, for example, 99% by mass or less, 95% by mass or less, 90% by mass or less, or 85% by mass or less.

[0108] (Isoprene rubber) The isoprene rubber is not particularly limited, and examples thereof include natural rubber (NR), isoprene rubber (IR), and modified natural rubber. Examples of NR include SIR20, RSS#3, and TSR20. Examples of IR include IR2200. Examples of modified natural rubber include epoxidized natural rubber (ENR), hydrogenated natural rubber (HNR), deproteinized natural rubber (DPNR), high-purity natural rubber, and grafted natural rubber. These isoprene rubbers may be used alone or in combination of two or more.

[0109] The content of isoprene rubber in the rubber component is preferably 70% by mass or less, more preferably 60% by mass or less, still more preferably 50% by mass or less, and particularly preferably 40% by mass or less. On the other hand, the lower limit of the content is not particularly limited, and for example, it can be 1% by mass or more, 3% by mass or more, 5% by mass or more, 7% by mass or more.

[0110] (BR) BR is not particularly limited. For example, 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 synthesized using a rare-earth element-based catalyst (rare-earth-based BR), BR containing syndiotactic polybutadiene crystals (SPB-containing BR), modified BR (high-cis modified BR, low-cis modified BR), etc., which are common in the tire industry, can be used. These BRs can be used alone or in combination of two or more.

[0111] As high-cis BR, for example, those commercially available from Nippon Zeon Co., Ltd., UBE Industries, Ltd., JSR Corporation, etc. can be used. By containing high-cis BR, the low-temperature properties and abrasion resistance can be improved. The cis content of high-cis BR is preferably more than 95 mol%, more preferably more than 96 mol%, and still more preferably more than 97 mol%. The cis content of BR is measured by the above measurement method.

[0112] As rare-earth-based BR, it is synthesized using a rare-earth element-based catalyst, and the vinyl content is preferably less than 1.8 mol%, more preferably less than 1.6 mol%, and still more preferably 1.5 mol% or less, and the cis content is preferably more than 95 mol%, more preferably more than 96 mol%, and still more preferably 97 mol% or more. As rare-earth-based BR, for example, those commercially available from Lanxess Co., Ltd., etc. can be used.

[0113] The SPB-containing BR includes cases where the 1,2-syndiotactic polybutadiene crystals are not simply dispersed in the BR but are dispersed after chemically bonding to the BR. As such SPB-containing BR, those commercially available from UBE Industries, Ltd. etc. can be used.

[0114] As the modified BR, modified butadiene rubber (modified BR) modified by a functional group containing at least one element selected from the group consisting of silicon, nitrogen, and oxygen at the terminal and / or in the main chain can also be preferably used.

[0115] Other modified BRs include those obtained by polymerizing 1,3-butadiene with a lithium initiator and then adding a tin compound, and further having the terminals of the modified BR molecules bonded by a tin-carbon bond (tin-modified BR), etc. The modified BR may be either unhydrogenated or hydrogenated.

[0116] From the viewpoint of wear resistance performance, the weight average molecular weight (Mw) of the BR is preferably more than 200,000, more preferably more than 300,000, and even more preferably more than 400,000. From the viewpoints of crosslinking uniformity etc., it is preferably less than 2,000,000, more preferably less than 1,000,000, and even more preferably less than 800,000. Note that Mw can be determined by the above method.

[0117] The content of BR in the rubber component is preferably 50 mass% or less, more preferably 40 mass% or less, even more preferably 30 mass% or less, and particularly preferably 20 mass% or less. On the other hand, the lower limit value of the content is not particularly limited, but for example, it can be 1 mass% or more, 3 mass% or more, 5 mass% or more, 7 mass% or more.

[0118] (Other rubber components) The rubber component may contain a rubber component other than the diene rubber (non-diene rubber) as long as it does not affect the effects of the present invention. As the non-diene rubber, rubber components generally used in the tire industry can be used. For example, butyl rubber, ethylene propylene rubber, polynorbornene rubber, silicone rubber, chlorinated polyethylene rubber, fluororubber (FKM), acrylic rubber (ACM), hydrin rubber, etc. can be mentioned. These other rubber components may be used alone or in combination of two or more. In addition to the above rubber components, a known thermoplastic elastomer may or may not be contained.

[0119] (Rubber component synthesized from recycled and biomass-derived raw materials) The monomers that are constituent units of synthetic rubbers such as SBR and BR may be derived from petroleum or recycled from rubber products such as tires and non-rubber products such as polystyrene. The monomers obtained by recycling (recycled monomers) are not particularly limited, and examples include recycled butadiene and recycled aromatic vinyl compounds. Examples of the butadiene include 1,2-butadiene and 1,3-butadiene. The aromatic vinyl compound is not particularly limited, and examples include styrene. Among them, it is preferable to use recycled butadiene (recycled butadiene) and / or recycled styrene (recycled styrene) as raw materials.

[0120] The method for producing recycled monomers is not particularly limited. For example, it can be synthesized from recycled naphtha obtained by decomposing rubber products such as tires. Also, the method for producing recycled naphtha is not particularly limited. For example, rubber products such as tires may be decomposed under high temperature and high pressure, decomposed by microwaves, or extracted after mechanical pulverization.

[0121] Furthermore, monomers that are constituent units of polymers such as SBR and BR may be derived from biomass. The biomass-derived monomers (biomass monomers) are not particularly limited, and examples include biomass-derived butadiene and biomass-derived aromatic vinyl compounds. Examples of the butadiene include 1,2-butadiene and 1,3-butadiene. The aromatic vinyl compound is not particularly limited, and examples include styrene. Also, the method for producing biomass monomers is not particularly limited, and examples include those by biological and / or chemical and / or physical conversion of animals and plants. Fermentation by microorganisms is typical as the biological conversion, and examples of the chemical and / or physical conversion include those by catalysts, high heat, high pressure, electromagnetic waves, supercritical fluids, and combinations thereof. Examples of the biomass sources of these monomers include sugars, wood, plant residues after obtaining useful components, plant-derived ethanol, biomass naphtha, and the like.

[0122] The polymers synthesized from biomass monomer components (biomass polymers) are not particularly limited, and examples include polybutadiene rubber synthesized from biomass-derived butadiene, and aromatic vinyl / butadiene copolymers synthesized from biomass-derived butadiene and / or biomass-derived aromatic vinyl. Examples of the aromatic vinyl / butadiene copolymer include styrene-butadiene rubber synthesized from biomass-derived butadiene and / or biomass-derived styrene.

[0123] Whether the raw material of the polymer is derived from biomass can be determined by pMC (percent Modern Carbon) measured in accordance with ASTM D6866-10. pMC is the ratio of the 14 C concentration of the sample to the 14 C concentration of the standard modern carbon (modern standard reference), and this value is used as an index indicating the biomass ratio of the compound (rubber). The significance of this value is described below.

[0124] One mole of carbon atoms (6.02×10 23 atoms) contains approximately 6.02×10 11 atoms of 14 C, which is about one trillionth of ordinary carbon atoms. 14 The half-life of 14 C is 5730 years, and 14 C decreases regularly. Therefore, in fossil fuels such as coal, oil, and natural gas, which are thought to have been formed more than 226,000 years after carbon dioxide in the atmosphere was taken up and fixed by plants, etc., all of the 14 C element has decayed at the time of fixation. Therefore, at present in the 21st century, fossil fuels such as coal, oil, and natural gas do not contain any 14 C element at all. Therefore, chemical substances produced from these fossil fuels also do not contain any 14 C element.

[0125] On the other hand, 14 C is constantly generated by cosmic rays undergoing nuclear reactions in the atmosphere. Therefore, 14 C is in equilibrium between the decrease due to radioactive decay and the generation due to nuclear reactions, and in the earth's atmospheric environment, 14 the amount of 14 C is constant. Therefore, the -12 C concentration of substances derived from biomass resources that are circulating in the current environment is about 1×10 -12 mol% with respect to the total carbon atoms as described above. Therefore, by utilizing the difference between these values, the ratio (biomass ratio) of the compound (biomass resource-derived compound) derived from natural resources in a certain compound (rubber) can be calculated.

[0126] This 14 C is generally measured as follows. Using accelerator mass spectrometry based on a tandem accelerator, 13 the 13 C concentration ( 13 C / 12 C), 14 the 14 C concentration ( 14 C / 12 C) is measured. In the measurement, 14As a modern standard reference for the concentration of C, the concentration of 14 C in the circulating carbon in nature as of 1950 is adopted. As a specific reference material, the oxalic acid standard provided by NIST (National Institute of Standards and Technology) is used. The specific activity of carbon in this oxalic acid (the 14 radioactivity intensity of 13 C per gram of carbon) is fractionated for each carbon isotope, and the value corrected to a constant value for 14 C and subjected to decay correction from 1950 AD to the measurement date is used as the standard

[0127] value of the 14 C concentration (100%). The ratio of this value to the value of the sample actually measured is the pMC value.

[0128] Therefore, if the rubber is made of a material derived from 100% biomass (natural system), although there are regional differences, it will show a value of approximately 110 pMC (currently, in the normal state, it often does not reach 100). On the other hand, for chemical substances derived from fossil fuels such as petroleum, when the

[0129] <filler> concentration of this

[0130] (silica) The silica is not particularly limited, and for example, silica prepared by a dry method (anhydrous silica), silica prepared by a wet method (hydrous silica), etc., which are common in the tire industry, can be used. The raw material of the silica is not particularly limited, and for example, it may be a raw material derived from a mineral such as quartz, or it may be a raw material derived from a living organism such as rice husk (for example, silica using a biomass material such as rice husk as a raw material), or silica recycled from a product containing silica may be used. Among them, hydrous silica prepared by a wet method is preferred because it has many silanol groups. These silicas may be used alone or in combination of two or more.

[0131] Silica using a biomass material as a raw material can be obtained, for example, by extracting a silicate from rice husk ash obtained by burning rice husks using a sodium hydroxide solution, and reacting the silicate with sulfuric acid in the same manner as conventional wet silica to obtain a precipitate of silicon dioxide, followed by filtration, washing with water, drying, and pulverization.

[0132] As the silica recycled from a product containing silica, for example, silica recovered from products containing silica such as electronic components such as semiconductors, tires, desiccants, and filter materials such as diatomaceous earth can be used. The recovery method is not particularly limited, and examples include thermal decomposition and decomposition by electromagnetic waves. Among them, silica recovered from electronic components such as semiconductors or tires is preferred.

[0133] When silica crystallizes, it does not dissolve in water and the silicic acid that is its component cannot be utilized. By controlling the combustion temperature and combustion time, crystallization of the silica in rice husk ash can be suppressed (see, for example, Japanese Patent Laid-Open No. 2009-2594, Akita Prefectural University Web Journal B / 2019, vol. 6, p. 216-222, etc.). Amorphous silica extracted from rice husks can be those commercially available from companies such as Wilmar.

[0134] The nitrogen adsorption specific surface area (N2SA) of the silica is preferably 100 m 2 / g or more from the viewpoint of ensuring reinforcement and grip performance, and 120 m 2 / g or more is more preferable, and 140 m 2 / g or more is even more preferable, and 160 m 2 / g or more is even more preferable, and 170 m 2 / g or more is particularly preferable. Further, from the viewpoints of heat generation property and processability, 350 m 2 / g or less is preferable, 300 m 2 / g or less is more preferable, 250 m 2 / g or less is even more preferable. The N2SA of silica is measured by the above measurement method.

[0135] The average primary particle diameter of silica is preferably 24 nm or less, more preferably 22 nm or less, even more preferably 20 nm or less, and particularly preferably 18 nm or less. The lower limit value of the average primary particle diameter is not particularly limited, but from the viewpoint of the dispersibility of silica, 1 nm or more is preferable, 3 nm or more is more preferable, and 5 nm or more is even more preferable. The average primary particle diameter of silica is measured by the above measurement method.

[0136] From the viewpoint of the effects of the present invention, the content of silica based on 100 parts by mass of the rubber component is preferably 50 parts by mass or more, more preferably 60 parts by mass or more, even more preferably 70 parts by mass or more, and particularly preferably 80 parts by mass or more. Also, the content is preferably 130 parts by mass or less, more preferably 120 parts by mass or less, and even more preferably 110 parts by mass or less.

[0137] (Silane coupling agent) Silica is preferably used in combination with a silane coupling agent. The silane coupling agent is not particularly limited. For example, sulfide-based silane coupling agents such as bis(3-triethoxysilylpropyl) disulfide and bis(3-triethoxysilylpropyl) tetrasulfide; mercapto-based silane coupling agents such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, and 2-mercaptoethyltriethoxysilane; vinyl-based silane coupling agents such as vinyltriethoxysilane and vinyltrimethoxysilane; amino-based silane coupling agents such as 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, and 3-(2-aminoethyl)aminopropyltriethoxysilane; glycidoxy-based silane coupling agents such as γ-glycidoxypropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane; nitro-based silane coupling agents such as 3-nitropropyltrimethoxysilane and 3-nitropropyltriethoxysilane; chloro-based silane coupling agents such as 3-chloropropyltrimethoxysilane and 3-chloropropyltriethoxysilane, etc. Among them, it is preferable to contain a sulfide-based silane coupling agent and / or a mercapto-based silane coupling agent. As the silane coupling agent, for example, those commercially available from Evonik Degussa, Momentive, etc. can be used. These silane coupling agents may be used alone or in combination of two or more.

[0138] (Carbon black) The carbon black is not particularly limited, and examples thereof include N134, N110, N220, N234, N219, N339, N330, N326, N351, N550, N762, etc. The raw material of the carbon black may be a biomass material such as lignin or vegetable oil, or may be a pyrolysis oil obtained by pyrolyzing waste tires. Further, the manufacturing method of the carbon black may be by combustion such as the furnace method, may be by hydrothermal carbonization (HTC), or may be by thermal decomposition of methane such as the thermal black method. As commercially available products, products of Asahi Carbon Co., Ltd., Cabot Japan Co., Ltd., Tokai Carbon Co., Ltd., Mitsubishi Chemical Corporation, Lion Corporation, Nippon Steel Carbon Co., Ltd., Columbia Carbon Company, etc. can be used. These carbon blacks may be used alone or in combination of two or more.

[0139] In addition to the above, from the perspective of life cycle assessment, etc., carbon black made from biomass materials such as lignin as a raw material, or recycled carbon black obtained by pyrolyzing and purifying products containing carbon black such as tires may also be used as the carbon black.

[0140] In this specification, "recycled carbon black" refers to carbon black obtained by pulverizing used products such as tires containing carbon black and firing the pulverized product, and when oxidized and burned by heating in air by a thermogravimetric method conforming to JIS K 6226-2:2003, it refers to carbon black in which the ratio of the mass of the component that does not burn (ash content) is 13% by mass or more. That is, the ratio of the mass (carbon amount) of the weight loss due to the oxidative combustion of the recycled carbon black is 87% by mass or less. Recycled carbon black may also be represented by rCB.

[0141] Recycled carbon black can be obtained from the pyrolysis process of used pneumatic tires. For example, European Patent Application Publication No. 3427975 refers to "Rubber Chemistry and Technology", Vol. 85, No. 3, pages 408 - 449 (2012), especially pages 438, 440, 442, and describes that it can be obtained by pyrolysis of organic materials at 550 - 800 °C with oxygen excluded, or by vacuum pyrolysis at relatively low temperatures (

[0027] ). The carbon black obtained from such a pyrolysis process usually lacks functional groups on its surface, as mentioned in

[0004] of Patent No. 6856781 (Comparison of the surface morphology and chemistry of pyrolytic carbon black and commercially available carbon black, Powder Technology 160 (2005) 190 - 193).

[0142] Recycled carbon black may lack functional groups on its surface, or may be treated to contain functional groups on its surface. The treatment to make the surface of recycled carbon black contain functional groups can be carried out by conventional methods. For example, in European Patent Application Publication No. 3173251, carbon black obtained from a pyrolysis process is treated with potassium permanganate under acidic conditions to obtain carbon black containing hydroxyl and / or carboxyl groups on its surface. Also, in Patent No. 6856781, carbon black obtained from a pyrolysis process is treated with an amino acid compound containing at least one thiol group or disulfide group to obtain carbon black with an activated surface. The recycled carbon black according to this embodiment also includes such carbon black treated to contain functional groups on its surface.

[0143] Commercially available recycled carbon black from companies such as Strable Green Carbon and LDCarbon can be used.

[0144] From the perspective of reinforcing properties, the nitrogen adsorption specific surface area (N2SA) of carbon black is preferably 30 m 2 / g or more, and 50 m2 More preferably, it is above / g, and 70 m 2 More preferably, it is above / g, and 90 m 2 More preferably, it is above / g. Also, from the viewpoints of low fuel consumption performance and processability, 200 m 2 Below / g is preferable, and 150 m 2 Below / g is more preferable, and 120 m 2 Below / g is even more preferable.

[0145] The average primary particle diameter of the carbon black is preferably 36 nm or less, more preferably 32 nm or less, even more preferably 28 nm or less, and particularly preferably 24 nm or less. The lower limit of the average primary particle diameter is not particularly limited, but preferably 5 nm or more, more preferably 8 nm or more, and even more preferably 10 nm or more. The average primary particle diameter of the carbon black is measured by the above measurement method.

[0146] When containing carbon black, the content with respect to 100 parts by mass of the rubber component is preferably 1 part by mass or more, more preferably 3 parts by mass or more, even more preferably 5 parts by mass or more, and particularly preferably 7 parts by mass or more from the viewpoint of reinforcing property. Also, from the viewpoint of suppressing heat generation, 40 parts by mass or less is preferable, 30 parts by mass or less is more preferable, 20 parts by mass or less is even more preferable, and 15 parts by mass or less is particularly preferable.

[0147] (Other fillers) The filler may contain other fillers other than silica and carbon black. The other fillers are not particularly limited, but for example, those commonly used in the tire industry such as aluminum hydroxide, calcium carbonate, alumina, clay, talc, etc. can be blended.

[0148] (Copolymer resin) The rubber composition according to the present embodiment contains a copolymer resin (hereinafter simply referred to as "copolymer resin") containing styrene and cyclopentadiene as monomer components.

[0149] The copolymer resin is not particularly limited as long as it contains styrene and cyclopentadiene as monomer components, and it may further contain other monomer components. Also, those obtained by hydrogenating them or modifying them may be used.

[0150] The "styrene" constituting the monomer component may be a compound having a styrene structure other than styrene, and examples thereof include styrene, α-methylstyrene, vinyltoluene, chlorostyrene, etc. Styrene-based monomers such as vinyltoluene (methylstyrene) are contained, for example, in the C9 fraction. The other monomer components are not particularly limited, but monomer components commonly used in petroleum resins are preferred, and examples thereof include C9 fractions other than monomers having a styrene structure. Examples of the C9 fraction other than monomers having a styrene structure include at least one selected from the group consisting of coumarone, indene, methylindene, etc.

[0151] The copolymer resin is preferably a DCPD-C9 resin which is a copolymer of cyclopentadiene and / or dicyclopentadiene and a C9 fraction. Also, those obtained by hydrogenating the DCPD-C9 resin or modifying it may be used.

[0152] As the copolymer resin containing styrene and cyclopentadiene as monomer components, for example, those commercially available from ExxonMobil, ENEOS Corporation, Nippon Zeon Co., Ltd., Maruzen Petrochemical Co., Ltd., etc. can be used. The copolymer resin may be used alone or in combination of two or more.

[0153] From the viewpoint of the effects of the present invention, the content of the styrene part in the copolymer resin is preferably 0.5% by mass or more, more preferably 0.8% by mass or more, still more preferably 1.1% by mass or more, and particularly preferably 1.4% by mass or more. Also, the upper limit value of the content of the styrene part is not particularly limited, but it can be, for example, less than 50% by mass, less than 40% by mass, less than 30% by mass, less than 20% by mass, less than 10% by mass, less than 5.0% by mass, less than 3.0% by mass.

[0154] From the viewpoint of the effects of the present invention, the softening point of the copolymer resin is preferably higher than 70°C, more preferably higher than 80°C, still more preferably higher than 90°C, and particularly preferably higher than 100°C. Further, from the viewpoints of processability and improvement in the dispersibility of the rubber component and the filler, it is preferably less than 150°C, more preferably less than 140°C, still more preferably less than 130°C. The softening point of the copolymer resin is measured by the above-mentioned measuring method.

[0155] The content of the copolymer resin with respect to 100 parts by mass of the rubber component (total content when two or more are contained) is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, still more preferably 15 parts by mass or more, and particularly preferably 20 parts by mass or more. Further, from the viewpoint of suppressing exothermic properties, it is preferably 60 parts by mass or less, more preferably 50 parts by mass or less, still more preferably 45 parts by mass or less, and particularly preferably 40 parts by mass or less.

[0156] <Other compounding agents> In addition to the above components, the rubber composition according to the present embodiment may appropriately contain compounding agents generally used in the conventional tire industry, such as plasticizers, vulcanized rubber particles, processing aids, waxes, antioxidants, stearic acid, zinc oxide, vulcanizing agents, vulcanization accelerators, and the like.

[0157] As used herein, the "plasticizer" is a material that imparts plasticity to the rubber component, and is a concept including both plasticizers that are liquid (liquid state) at room temperature (25°C) and plasticizers that are solid at room temperature (25°C). Examples of plasticizers include resins, oils, liquid rubbers, ester-based plasticizers, and the like. These plasticizers may be derived from petroleum, may be derived from biomass, or may be derived from naphtha recycled from rubber products or non-rubber products. Further, low-molecular-weight hydrocarbon components obtained by thermally decomposing and extracting used tires or products containing various components may be used as plasticizers. These plasticizers may be used alone or in combination of two or more.

[0158] (Resin) The rubber composition according to this embodiment may contain other resins than the copolymer resin. The other resins are not particularly limited, but resins commonly used in the tire industry can be used. For example, aromatic vinyl resins, dicyclopentadiene resins, C9 resins, C5 resins, C5C9 resins, terpene resins, rosin resins, phenolic resins, etc. can be mentioned. The other resins may be used alone or in combination of two or more.

[0159] ≪Aromatic vinyl resin≫ In this specification, the "aromatic vinyl resin" refers to a resin containing at least one aromatic vinyl compound selected from the group consisting of styrene, α-methylstyrene, vinyltoluene, chlorostyrene, etc. as a monomer component. As the aromatic vinyl resin, due to economic reasons, easy processing, and excellent heat generation properties, a homopolymer of α-methylstyrene or styrene or a copolymer of α-methylstyrene and styrene is preferable, and a copolymer of α-methylstyrene and styrene is more preferable. As the aromatic vinyl resin, for example, those commercially available from Kreton, Eastman Chemical, Mitsui Chemicals, Inc., etc. can be used. The resin may be used alone or in combination of two or more.

[0160] ≪Dicyclopentadiene resin≫ In this specification, the "dicyclopentadiene resin" refers to a resin containing dicyclopentadiene as a monomer component. As the dicyclopentadiene resin, for example, those commercially available from ExxonMobil, ENEOS, Inc., Nippon Zeon Co., Ltd., Maruzen Petrochemical Co., Ltd., etc. can be used. The resin may be used alone or in combination of two or more.

[0161] ≪C9 resin≫ In this specification, the "C9 resin" refers to a resin obtained by polymerizing a C9 fraction, which may be a polymer of the C9 fraction alone or a copolymer of the C9 fraction and other components. Examples of the C9 fraction include at least one petroleum fraction having 8 to 10 carbon atoms selected from the group consisting of alkylstyrenes such as vinyltoluene, coumarone, indene, methylindene, and the like. Specific examples of the C9 resin include, for example, coumarone-indene resin, coumarone resin, indene resin, and the like. The resin may be used alone or in combination of two or more.

[0162] ≪C5 resin≫ In this specification, the "C5 resin" refers to a resin obtained by polymerizing a C5 fraction other than cyclopentadiene, which may be hydrogenated or modified. Examples of the C5 fraction other than cyclopentadiene include at least one petroleum fraction having 4 to 5 carbon atoms selected from the group consisting of isoprene, pentane, isopentane, neopentane, pentene, pentadiene, and the like. The resin may be used alone or in combination of two or more.

[0163] ≪C5C9 resin≫ The "C5C9 resin" refers to a resin obtained by copolymerizing the C5 fraction and the C9 fraction, which may be hydrogenated or modified. As the C5C9 petroleum resin, for example, those commercially available from Tosoh Corporation, LUHUA Co., Ltd., and the like can be used. The resin may be used alone or in combination of two or more.

[0164] ≪Terpene resin≫ A terpene resin refers to a resin containing at least one terpene compound selected from the group consisting of α-pinene, β-pinene, limonene, dipentene, etc. as the monomer component with the highest content, preferably containing 50 mol% or more, and may be hydrogenated or modified thereof. Specific examples of terpene resins include, for example, polyterpene resins containing only one or more of the above terpene compounds as monomer components; aromatic-modified terpene resins containing the terpene compounds and aromatic compounds as monomer components; terpene phenol resins containing the terpene compounds and phenolic compounds as monomer components, etc. Examples of aromatic compounds serving as monomer components of aromatic-modified terpene resins include at least one selected from the group consisting of styrene, α-methylstyrene, vinyltoluene, divinyltoluene, etc. Examples of phenolic compounds serving as monomer components of terpene phenol resins include at least one selected from the group consisting of phenol, bisphenol A, cresol, xylenol, etc. The resin may be used alone or in combination of two or more.

[0165] ≪Rosin-based resin≫ A rosin-based resin refers to a resin containing at least one rosin acid compound selected from the group consisting of abietic acid, neoabietic acid, palustric acid, isopimaric acid, etc., and may be hydrogenated or modified thereof. The rosin-based resin is not particularly limited, and examples thereof include natural resin rosin, rosin-modified resins obtained by modifying it by hydrogenation, disproportionation, dimerization, esterification, etc. The resin may be used alone or in combination of two or more.

[0166] ≪Phenolic resin≫ The phenolic resin refers to a resin containing a phenolic compound such as phenol or cresol as the monomer component with the highest content, preferably containing 50 mol% or more. The phenolic resin is not particularly limited, and examples thereof include phenolic formaldehyde resins, alkylphenol formaldehyde resins, alkylphenol acetylene resins, and oil-modified phenolic formaldehyde resins. The resin may be used alone or in combination of two or more.

[0167] From the viewpoint of the effects of the present invention, the total content of the resin (including the copolymer resin) with respect to 100 parts by mass of the rubber component is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, still more preferably 15 parts by mass or more, and particularly preferably 20 parts by mass or more. From the viewpoint of suppressing heat generation, it is preferably 70 parts by mass or less, more preferably 60 parts by mass or less, still more preferably 55 parts by mass or less, and particularly preferably 50 parts by mass or less.

[0168] From the viewpoint of suppressing heat generation, the content of the resin other than the copolymer resin with respect to 100 parts by mass of the rubber component (the total content when two or more are contained) is preferably less than 30 parts by mass, more preferably less than 20 parts by mass, still more preferably less than 10 parts by mass, particularly preferably less than 5 parts by mass, or may not be contained.

[0169] (Oil) Examples of the oil include mineral oil, vegetable oil, animal oil, etc. Examples of the mineral oil include paraffinic mineral oil (mineral oil), naphthenic mineral oil, aromatic mineral oil, etc. Specific examples of the mineral oil include, for example, MES (Mild Extracted Solvate), DAE (Distillate Aromatic Extract), TDAE (Treated Distillate Aromatic Extract), TRAE (Treated Residual Aromatic Extract), RAE (Residual Aromatic Extract), etc. Also, mineral oil with a low content of polycyclic aromatic (polycyclic aromatic compound: PCA) compounds can be used for environmental measures. Examples of the low-PCA-content mineral oil include MES, TDAE, heavy naphthenic oil, etc. Also, from the perspective of life cycle assessment, it is also possible to use waste oil after being used in a rubber mixer or an engine, or refined waste cooking oil used in a cooking shop. The oil may be used alone or in combination of two or more kinds.

[0170] Vegetable oil includes, for example, linseed oil, rapeseed oil, safflower oil, soybean oil, corn oil, cottonseed oil, rice oil, tall oil, sesame oil, perilla oil, castor oil, tung oil, pine oil, pine tar oil, sunflower oil, coconut oil, palm oil, palm kernel oil, olive oil, camellia oil, jojoba oil, macadamia nut oil, peanut oil, grape seed oil, wood rosin, etc. Furthermore, vegetable oil includes refined oil (such as salad oil) obtained by refining the above oil, transesterified oil obtained by transesterifying the above oil, hydrogenated oil obtained by hydrogenating the above oil, thermally polymerized oil obtained by thermally polymerizing the above oil, oxidatively polymerized oil obtained by oxidizing the above oil, waste cooking oil recovered from those used as edible oil, etc. Note that the vegetable oil may be liquid or solid at room temperature (25°C).

[0171] The vegetable oil preferably contains acylglycerol, and more preferably contains triacylglycerol. In the present specification, acylglycerol refers to a compound in which a hydroxy 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. Further, the acylglycerol may be a monomer, a dimer, or a multimer of trimer or higher. Note that acylglycerols of dimer or higher can be obtained by thermal polymerization, oxidative polymerization, or the like. Also, the acylglycerol may be liquid or solid at room temperature (25°C).

[0172] The method for confirming whether the acylglycerol is contained in the rubber composition is not particularly limited, but 1 it can be confirmed by 1H-NMR measurement. For example, a rubber composition containing triacylglycerol is immersed in deuterated chloroform at room temperature (25°C) for 24 hours. After removing the rubber composition, 1 1H-NMR is measured. When the signal of tetramethylsilane (TMS) is set to 0.00 ppm, signals around 5.26 ppm, around 4.28 ppm, and around 4.15 ppm are observed, and these signals are presumed to be signals derived from hydrogen atoms bonded to carbon atoms adjacent to the oxygen atom of the ester group. In this paragraph, "around" means a range of ±0.10 ppm.

[0173] 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. Examples of the saturated fatty acid include butyric acid and lauric acid.

[0174] Among them, as the fatty acid, it is desirable to contain a fatty acid with few double bonds, that is, a saturated fatty acid or a monounsaturated fatty acid, and oleic acid is preferred. As the vegetable oil containing such a fatty acid, for example, a vegetable oil containing a saturated fatty acid or a monounsaturated fatty acid may be used, or a vegetable oil subjected to modification such as transesterification may be used. Further, in order to produce a vegetable oil containing such a fatty acid, plants may be improved by variety improvement, gene recombination, genome editing, etc.

[0175] As the vegetable oil, for example, those commercially available from Idemitsu Kosan Co., Ltd., Sankyo Yuka Kogyo Co., Ltd., ENEOS Co., Ltd., Oryz Oy, H&R Co., Ltd., Toyokuni Oil Co., Ltd., Fuji Kogyo Co., Ltd., Nisshin Oillio Group Co., Ltd., etc. can be used.

[0176] Examples of the animal oil include fish oil, beef tallow, whale oil, or oleyl alcohol derived therefrom.

[0177] From the viewpoint of processability, the content of the oil with respect to 100 parts by mass of the rubber component is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, further preferably 15 parts by mass or more, and particularly preferably 20 parts by mass or more. From the viewpoint of wear resistance performance, 80 parts by mass or less is preferred, 70 parts by mass or less is more preferred, 60 parts by mass or less is further preferred, and 50 parts by mass or less is particularly preferred. The content of the oil also includes the amount of oil contained in the oil-extended rubber.

[0178] (Liquid rubber) The liquid rubber is not particularly limited as long as it is a polymer in a liquid state at normal temperature (25 ° C). For example, liquid butadiene rubber (liquid BR), liquid styrene-butadiene rubber (liquid SBR), liquid isoprene rubber (liquid IR), liquid styrene-isoprene rubber (liquid SIR), liquid farnesene rubber, etc. can be mentioned. The liquid rubber may be used alone or in combination of two or more.

[0179] When a liquid rubber is contained, the content with respect to 100 parts by mass of the rubber component is preferably 1 part by mass or more, more preferably 3 parts by mass or more, and still more preferably 5 parts by mass or more. Also, the content of the liquid rubber is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, and still more preferably 10 parts by mass or less. The content of the liquid rubber includes the amount of the extended liquid rubber used for extending the rubber component.

[0180] (Ester plasticizer) Examples of the ester plasticizer include dibutyl adipate (DBA), diisobutyl adipate (DIBA), dioctyl adipate (DOA), bis(2-ethylhexyl) azelate (DOZ), dibutyl sebacate (DBS), diisononyl adipate (DINA), diethyl phthalate (DEP), dioctyl phthalate (DOP), diundecyl phthalate (DUP), dibutyl phthalate (DBP), dioctyl sebacate (DOS), tributyl phosphate (TBP), trioctyl phosphate (TOP), triethyl phosphate (TEP), trimethyl phosphate (TMP), thymidine triphosphate (TTP), tricresyl phosphate (TCP), trixylenyl phosphate (TXP), and the like. The ester plasticizer may be used alone or in combination of two or more.

[0181] When an ester plasticizer is contained, the content with respect to 100 parts by mass of the rubber component is preferably 1 part by mass or more, more preferably 3 parts by mass or more, and still more preferably 5 parts by mass or more. Also, the content of the liquid rubber is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, and still more preferably 10 parts by mass or less. The content of the ester plasticizer includes the amount of the extended ester plasticizer used for extending the rubber component.

[0182] From the viewpoint of the effects of the present invention, the total content of the plasticizer with respect to 100 parts by mass of the rubber component is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, still more preferably 30 parts by mass or more, and particularly preferably 40 parts by mass or more. Also, from the viewpoint of suppressing heat generation, it is preferably 90 parts by mass or less, more preferably 80 parts by mass or less, still more preferably 70 parts by mass or less, and particularly preferably 60 parts by mass or less.

[0183] (Vulcanized rubber particles) Vulcanized rubber particles are particles made of vulcanized rubber. Specifically, rubber powder etc. specified in JIS K 6316:2017 can be used. From the viewpoints of environmental consideration and cost, recycled rubber powder produced from crushed waste tires etc. is preferable. Vulcanized rubber particles may be used alone or in combination of two or more.

[0184] Vulcanized rubber particles are not particularly limited, and may be non-modified vulcanized rubber particles or modified vulcanized rubber particles. As commercially available products of vulcanized rubber, for example, products of Lehigh, Murakami Rubber Industry Co., Ltd. etc. can be used.

[0185] When containing vulcanized rubber particles, the content with respect to 100 parts by mass of the rubber component can be appropriately adjusted, for example, in the range of more than 1 part by mass and less than 80 parts by mass.

[0186] (Processing aid) Examples of the processing aid include fatty acid metal salts, fatty acid amides, amide esters, silica surfactants, fatty acid esters, mixtures of fatty acid metal salts and amide esters, mixtures of fatty acid metal salts and fatty acid amides, etc. As the processing aid, for example, those commercially available from Schill+Seilacher, Performance Additives etc. can be used. The processing aid may be used alone or in combination of two or more.

[0187] When containing the processing aid, the content with respect to 100 parts by mass of the rubber component is preferably 0.5 part by mass or more, more preferably 1.0 part by mass or more, from the viewpoint of exerting the effect of improving processability. Also, from the viewpoints of abrasion resistance performance and fracture strength, it is preferably 10 parts by mass or less, more preferably 8.0 parts by mass or less, still more preferably 5.0 parts by mass or less.

[0188] (Wax) The wax is not particularly limited, and any wax commonly used in the tire industry can be preferably used. For example, petroleum waxes, mineral waxes, synthetic waxes, plant-derived waxes, etc. can be mentioned. Among them, petroleum waxes and plant-derived waxes are preferred, and petroleum waxes are more preferred. Examples of plant-derived waxes include rice wax, carnauba wax, candelilla wax, etc. Examples of petroleum waxes include paraffin wax, microcrystalline wax, and their selected special waxes, etc., and paraffin wax is preferred. Note that the wax according to this embodiment does not contain stearic acid. As the wax, for example, those commercially available from Ouchi Shinsei Chemical Industry Co., Ltd., Nippon Seiro Co., Ltd., Paramelt Co., etc. can be used. The wax may be used alone or in combination of two or more.

[0189] When containing wax, the content based on 100 parts by mass of the rubber component is preferably 0.5 part by mass or more, more preferably 1.0 part by mass or more, and further preferably 1.5 part by mass or more from the viewpoint of the weather resistance of the rubber. Also, from the viewpoint of preventing the whitening of the tire due to blooming, it is preferably 10 parts by mass or less, and more preferably 5.0 parts by mass or less.

[0190] (Antioxidant) The anti-aging agent is not particularly limited, but examples include naphthylamine-based anti-aging agents such as phenyl-α-naphthylamine; diphenylamine-based anti-aging agents such as octylated diphenylamine and 4,4'-bis(α,α'-dimethylbenzyl)diphenylamine; p-phenylenediamine-based anti-aging agents such as N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD), N,N'-bis(1,4-dimethylpentyl)-p-phenylenediamine (77PD), N,N'-diphenyl-p-phenylenediamine (DPPD), N,N'-ditoly-p-phenylenediamine (DTPD), N-isopropyl-N'-phenyl-p-phenylenediamine (IPPD), and N,N'-di-2-naphthyl-p-phenylenediamine (DNPD); quinoline-based anti-aging agents such as polymers of 2,2,4-trimethyl-1,2-dihydroquinoline; monophenol-based anti-aging agents such as 2,6-di-t-butyl-4-methylphenol and styrenated phenol; bis, tris, polyphenol-based anti-aging agents such as tetrakis-[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, etc. Among them, p-phenylenediamine-based anti-aging agents and quinoline-based anti-aging agents are preferred, and N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine and polymers of 2,2,4-trimethyl-1,2-dihydroquinoline are more preferred. As commercial products, for example, products of Seiko Chemical Co., Ltd., Sumitomo Chemical Co., Ltd., Ouchi Shinsei Chemical Industry Co., Ltd., Flexsys, etc. can be used. The anti-aging agent may be used alone or in combination of two or more.

[0191] When containing an anti-aging agent, from the viewpoint of the ozone crack resistance of the rubber, the content per 100 parts by mass of the rubber component is preferably 0.5 part by mass or more, more preferably 1.0 part by mass or more, and even more preferably 1.5 part by mass or more. Also, from the viewpoints of abrasion resistance performance and wet grip performance, it is preferably 10 parts by mass or less, and more preferably 5.0 parts by mass or less.

[0192] (Stearic acid) When contained, the content of stearic acid with respect to 100 parts by mass of the rubber component is preferably 0.5 part by mass or more, more preferably 1.0 part by mass or more, and even more preferably 1.5 part by mass or more from the viewpoint of processability. Further, from the viewpoint of vulcanization rate, it is preferably 10 parts by mass or less, more preferably 5.0 parts by mass or less.

[0193] (Zinc oxide) When contained, the content of zinc oxide with respect to 100 parts by mass of the rubber component is preferably 0.5 part by mass or more, more preferably 1.0 part by mass or more, and even more preferably 1.5 part by mass or more from the viewpoint of processability. Further, from the viewpoint of abrasion resistance performance, it is preferably 5.0 parts by mass or less, more preferably 4.5 parts by mass or less, and even more preferably 4.0 parts by mass or less.

[0194] (Vulcanizing agent) Sulfur is preferably used as the vulcanizing agent. As sulfur, powdered sulfur, oil-treated sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersed sulfur, etc. can be used. The vulcanizing agent may be used alone or in combination of two or more.

[0195] When contained, the content of sulfur as the vulcanizing agent with respect to 100 parts by mass of the rubber component is preferably 0.1 part by mass or more, more preferably 0.3 part by mass or more, and even more preferably 0.5 part by mass or more from the viewpoint of ensuring a sufficient vulcanization reaction. Further, from the viewpoint of deterioration prevention, it is preferably 5.0 parts by mass or less, more preferably 4.0 parts by mass or less, and even more preferably 3.0 parts by mass or less. In addition, when using oil-containing sulfur as the vulcanizing agent, the content of the vulcanizing agent is the total content of pure sulfur contained in the oil-containing sulfur.

[0196] Examples of vulcanizing agents other than sulfur include alkylphenol sulfur chloride condensates, sodium 1,6-hexamethylene-dithiolsulfate dihydrate, 1,6-bis(N,N'-dibenzylthiocarbamoyldithio)hexane), etc. These vulcanizing agents other than sulfur that are commercially available from companies such as Tago Chemical Industry Co., Ltd., Rancy Co., Ltd., and Flexsys can be used. The vulcanizing agent may be used alone or in combination of two or more.

[0197] (Vulcanization accelerator) Examples of the vulcanization accelerator include, for example, sulfenamide-based, thiazole-based, thiuram-based, thiourea-based, guanidine-based, dithiocarbamic acid-based, aldehyde-amine-based or aldehyde-ammonia-based, imidazoline-based, or xanthate-based vulcanization accelerators. Among them, sulfenamide-based, thiazole-based, and guanidine-based vulcanization accelerators are preferred. The vulcanization accelerator may be used alone or in combination of two or more.

[0198] Examples of the sulfenamide-based vulcanization accelerator include, for example, N-tert-butyl-2-benzothiazolylsulfenamide (TBBS), N-cyclohexyl-2-benzothiazolylsulfenamide (CBS), N,N-dicyclohexyl-2-benzothiazolylsulfenamide (DCBS), etc. Among them, N-cyclohexyl-2-benzothiazolylsulfenamide (CBS) is preferred.

[0199] Examples of the thiazole-based vulcanization accelerator include, for example, 2-mercaptobenzothiazole, cyclohexylamine salt of 2-mercaptobenzothiazole, di-2-benzothiazolyldisulfide, etc. Among them, 2-mercaptobenzothiazole is preferred.

[0200] Examples of the guanidine-based vulcanization accelerator include, for example, 1,3-diphenylguanidine (DPG), 1,3-di-o-tolylguanidine, 1-o-tolylbiguanide, di-o-tolylguanidine salt of dicatecholborate, 1,3-di-o-cumenylguanidine, 1,3-di-o-biphenylguanidine, 1,3-di-o-cumenyl-2-propionylguanidine, etc. Among them, 1,3-diphenylguanidine (DPG) is preferred.

[0201] When containing a vulcanization accelerator, the content relative to 100 parts by mass of the rubber component is preferably 1.0 part by mass or more, more preferably 1.5 parts by mass or more, and still more preferably 2.0 parts by mass or more. Further, the content of the vulcanization accelerator relative to 100 parts by mass of the rubber component is preferably 8.0 parts by mass or less, more preferably 7.0 parts by mass or less, and still more preferably 6.0 parts by mass or less. By setting the content of the vulcanization accelerator within the above range, the breaking strength and elongation tend to be ensured.

[0202] <Various materials containing carbon atoms> In this specification, various materials containing carbon atoms (for example, rubber, oil, resin, vulcanization accelerator, anti-aging agent, surfactant, etc.) may be derived from carbon dioxide in the atmosphere. As a method for obtaining the various materials from carbon dioxide, carbon dioxide may be directly converted, or methane obtained through a methanation process of synthesizing methane from carbon dioxide may be converted.

[0203] [Manufacturing method] The rubber composition can be manufactured by a known method. For example, it can be manufactured by kneading the above-mentioned respective components using a rubber kneading device such as an open roll, a closed kneader (Banbury mixer, kneader, etc.).

[0204] The kneading process includes, for example, a base kneading process of kneading compounding agents and additives other than the vulcanizing agent and the vulcanization accelerator, and a final kneading (F kneading) process of adding the vulcanizing agent and the vulcanization accelerator to the kneaded product obtained in the base kneading process and kneading them. Further, the base kneading process can be divided into a plurality of processes if desired.

[0205] The kneading conditions are not particularly limited. For example, in the base kneading process, kneading is performed at a discharge temperature of 150 to 170 °C for 3 to 10 minutes, and in the final kneading process, kneading is performed at 70 to 110 °C for 1 to 5 minutes.

[0206] The tire according to this embodiment can be manufactured by a normal method using the rubber composition. That is, the unvulcanized rubber composition is extruded into the shape of the tread portion using an extruder equipped with a base having a predetermined shape, and on a tire molding machine, it is bonded together with other tire members while being adjusted to have a predetermined tire structure, and an unvulcanized tire is formed by molding in a normal method. By heating and pressurizing this unvulcanized tire in a vulcanizer, a tire can be manufactured. The vulcanization conditions are not particularly limited, and for example, a method of vulcanizing at 140 to 170 ° C for 10 to 40 minutes can be mentioned.

[0207] [Use] In this specification, the tire can be used for any application, 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-duty tire, a run-flat tire. Note that a passenger car tire is a tire that is assumed to be mounted on an automobile that runs on four wheels and has a maximum load capacity of less than 1400 kg. Also, a heavy-duty tire refers to a tire with a maximum load capacity of 1400 kg or more. Also, in this specification, the tire can be used for all-season tires, summer tires, and winter tires such as studless tires in addition to summer tires.

Examples

[0208] Hereinafter, examples (Examples) that are considered preferable when implementing are shown, but the scope of the present invention is not limited to the examples.

[0209] Tires having a tread portion produced using rubber compositions obtained by changing the formulation according to Table 1 using the various chemicals shown below were examined, and the results calculated based on the following evaluation methods are shown in Table 1. NR:TSR20 SBR1: HPR830E manufactured by JSR Corporation (S-SBR, Tg: -23 ° C, styrene content: 39.5 mass%, vinyl content: 38.5 mol%, containing 10.0 mass% of oil-extended oil per 100 mass parts of rubber solid content) SBR2: SBR produced according to Production Example 1 below (S-SBR, Tg: -50°C, styrene content: 30% by mass, vinyl content: 22 mol%, non-oil extended) SBR3: SBR produced according to Production Example 2 below (S-SBR, Tg: -66°C, styrene content: 19% by mass, vinyl content: 19 mol%, non-oil extended) BR: UBEPOL BR (registered trademark) 150B manufactured by UBE Industries, Ltd. (unmodified BR, cis content: 97 mol%, Mw: 440,000) Carbon black: Diablack I manufactured by Mitsubishi Chemical Corporation (N220, N2SA: 114 m 2 / g, average primary particle diameter: 22 nm) Silica: ULTRASIL VN3 manufactured by Evonik Degussa GmbH (N2SA: 175 m 2 / g, average primary particle diameter: 18 nm) Silane coupling agent: Si266 (bis(3-triethoxysilylpropyl) disulfide) manufactured by Evonik Degussa GmbH Oil: VivaTec 500 manufactured by H&R Co., Ltd. (TDAE oil) Copolymer resin: Oppera PR383 manufactured by ExxonMobil Chemical Company (hydrogenated DCPD-C9 resin, containing styrene and cyclopentadiene as monomer components, Mw: 770, softening point: 103°C, styrene content: 1.78% by mass) Terpene resin: YS Resin PX1150N manufactured by Yasuhara Chemical Co., Ltd. (polyt terpene resin, softening point: 115 ± 5°C) Antioxidant 1: Nocrack 6C (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine) manufactured by Ouchi Shinsei Chemical Industry Co., Ltd. Antioxidant 2: Nocrack RD (poly(2,2,4-trimethyl-1,2-dihydroquinoline)) manufactured by Ouchi Shinsei Chemical Industry Co., Ltd. Stearic acid: Tsubaki Bead Stearic Acid manufactured by NOF Corporation Zinc oxide: Zinc White No. 1 manufactured by Mitsui Mining & Smelting Co., Ltd. Sulfur: Powder sulfur manufactured by Karuizawa Sulfur Co., Ltd. Vulcanization accelerator 1: Nocceler CZ-G (N-cyclohexyl-2-benzothiazolylsulfenamide (CBS)) manufactured by Ouchi Shinko Chemical Industry Co., Ltd. Vulcanization accelerator 2: Nocceler D (1,3-diphenylguanidine (DPG)) manufactured by Ouchi Shinko Chemical Industry Co., Ltd.

[0210] (Production Example 1: Production of SBR2) Charge cyclohexane, tetrahydrofuran, styrene, and 1,3-butadiene into a nitrogen-substituted autoclave reactor. Adjust the ratio of styrene and 1,3-butadiene so that the styrene content is 30% by mass. After adjusting the temperature of the reactor contents to 20°C, add n-butyllithium to initiate polymerization. Polymerize under adiabatic conditions, and the maximum temperature reaches 80°C. After confirming the formation of a polymer with Mw of 854,000 by GPC, pour the polymerization solution into 4 L of ethanol and recover the precipitate. After drying the obtained precipitate by blowing air, perform vacuum drying at 80°C / 10 Pa or less until the weight loss on drying becomes 0.1% to obtain SBR2.

[0211] (Production Example 2: Production of SBR3) Charge cyclohexane, tetrahydrofuran, styrene, and 1,3-butadiene into a nitrogen-substituted autoclave reactor. Adjust the ratio of styrene and 1,3-butadiene so that the styrene content is 19% by mass. After adjusting the temperature of the reactor contents to 20°C, add n-butyllithium to initiate polymerization. Polymerize under adiabatic conditions, and the maximum temperature reaches 80°C. After confirming the formation of a polymer with Mw of 679,000 by GPC, pour the polymerization solution into 4 L of ethanol and recover the precipitate. After drying the obtained precipitate by blowing air, perform vacuum drying at 80°C / 10 Pa or less until the weight loss on drying becomes 0.1% to obtain SBR3.

[0212] (Examples and Comparative Examples) According to the formulation shown in Table 1, using a 1.7 L closed Banbury mixer, chemicals other than sulfur and vulcanization accelerators are kneaded for 1 to 10 minutes until the discharge temperature reaches 150 to 160 °C to obtain a kneaded product. Next, using a twin-screw open roll, sulfur and vulcanization accelerators are added to the obtained kneaded product and kneaded for 4 minutes until the temperature reaches 105 °C to obtain an unvulcanized rubber composition. The obtained unvulcanized rubber composition is molded according to the shape of the tread portion and bonded together with other tire members such as the belt layer to produce an unvulcanized tire, and by press-vulcanizing at 150 °C for 35 minutes, each test tire (195 / 65R15) described in Table 1 is obtained. Here, the belt cord is a yarn obtained by twisting together two yarns in which filaments made of polyester fiber (however, nylon 6 in Comparative Examples 2 and 3) are twisted together, and the distance G from the tread surface to the belt cord is 9.0 mm.

[0213] <Measurement of tanδ at 0 °C> For each vulcanized rubber test piece prepared by cutting out from the tread portion of each test tire with a length of 20 mm × width of 4 mm × thickness of 1 mm such that the tire circumferential direction is the long side and the tire radial direction is the thickness direction, using a dynamic viscoelasticity measuring device (Iplexer series manufactured by GABO), the loss tangent tanδ is measured under the conditions of a temperature of 0 °C, a frequency of 10 Hz, an initial strain of 10%, a dynamic strain of ±2.5%, and an elongation mode.

[0214] <Measurement of E* at 30 °C> For each vulcanized rubber test piece prepared by cutting out from the tread portion of each test tire with a length of 20 mm × width of 4 mm × thickness of 1 mm such that the tire circumferential direction is the long side and the tire radial direction is the thickness direction, using a dynamic viscoelasticity measuring device (Iplexer series manufactured by GABO), the complex elastic modulus E* is measured under the conditions of a temperature of 30 °C, a frequency of 10 Hz, an initial strain of 5%, a dynamic strain of ±1%, and an elongation mode.

[0215] <Handling and stability performance> Each test tire is mounted on each of the four wheels of a FF passenger car with a displacement of 2000 cc, and actual vehicle running is performed on a test course on a dry asphalt road surface. The handling characteristics are evaluated based on the feelings during straight running, lane change, acceleration and deceleration at 100 km / h by a test driver. The evaluation is performed with an integer value from 1 to 5, and the total score of 20 test drivers is calculated based on the evaluation criteria that the higher the score, the better the handling characteristics. The total score of the tire of Comparative Example 1 is converted into a reference value (100), and the evaluation results of each test tire are exponentiated and displayed in proportion to the total score.

[0216] <Wet Grip Performance> Each test tire is mounted on each of the four wheels of a FF passenger car with a displacement of 2000 cc, and the braking distance from an initial speed of 100 km / h is obtained on a wet asphalt road surface. The measurement results are exponentiated according to the following calculation formula. The larger the exponent, the shorter the braking distance and the better the wet grip performance. (Wet Grip Performance Index) =(Braking distance of the tire of Comparative Example 3) / (Braking distance of each test tire)×100

[0217] <Overall Performance> The sum of the handling stability performance and the wet grip performance index is displayed as the overall performance index.

[0218]

Table 1

[0219] <Embodiment> Examples of embodiments of the present invention are shown below. 〔1〕A tire comprising a tread portion and a belt layer existing inside the tread portion in the tire radial direction, wherein the belt layer has a belt cord containing filaments made of polyester fibers, and the tread portion is composed of a rubber composition containing a rubber component including styrene-butadiene rubber and / or isoprene-based rubber, and a copolymer resin containing styrene and cyclopentadiene as monomer components, and when the cord diameter of the belt cord is D (mm) and the total styrene amount in the rubber composition is S (%) with the mass of the rubber component being 100% by mass, a tire in which D×S is more than 0.05. 〔2〕The tire according to the above 〔1〕, wherein the polyester fiber is a recycled polyester fiber. 〔3〕The tire according to the above 〔1〕 or 〔2〕, wherein D×S is more than 1.0. 〔4〕The tire according to the above 〔3〕, wherein D×S is more than 1.0 and less than 30.0. 〔5〕When the complex elastic modulus of the rubber composition at 30 °C is 30 °C E* (MPa), The tire according to any one of the above 〔1〕 to 〔4〕, wherein 30 °C E*×D is 3.0 or more, preferably 3.5 or more and 7.0 or less. 〔6〕The tire according to any one of the above 〔1〕 to 〔5〕, wherein the tanδ (0 °C tanδ) of the rubber composition at 0 °C is 0.45 or more, preferably 0.50 or more and 0.90 or less. 〔7〕The tire according to any one of the above 〔1〕 to 〔6〕, wherein the rubber composition contains 60 parts by mass or more, preferably 70 parts by mass or more and 130 parts by mass or less of silica with respect to 100 parts by mass of the rubber component. 〔8〕The tire according to any one of the above 〔1〕 to 〔7〕, wherein the content of the copolymer resin with respect to 100 parts by mass of the rubber component in the rubber composition is 10 parts by mass or more, preferably 15 parts by mass or more and 60 parts by mass or less. 〔9〕The tire according to any one of the above 〔1〕 to 〔8〕, wherein the distance G from the tread surface to the belt cord is 12.0 mm or less, preferably 5.0 mm or more and 10.0 mm or less.

Explanation of symbols

[0220] 1 Tread part 2 Sidewall part 4 Carcass 5 Belt layer 6 Band layer 7 Inner liner 11 Layer whose outer surface constitutes the tread surface (cap rubber layer) 12 Base rubber layer 15 Circumferential groove 16 Tread surface 31 Band cord 32 Topping rubber 33 Yarn 34 Filament d Filament diameter D1 Major axis of the band cord D2 Minor axis of the band cord CL Tire equator

Claims

1. A tire comprising a tread portion and a belt layer existing on the inner side in the tire radial direction of the tread portion, wherein the belt layer has a belt cord containing filaments made of polyester fiber, the tread portion is composed of a rubber composition containing a rubber component containing styrene-butadiene rubber and / or isoprene-based rubber, and a copolymer resin containing styrene and cyclopentadiene as monomer components, when the cord diameter of the belt cord is D (mm) and the total styrene amount in the rubber composition is S (mass%) when the mass of the rubber component in the rubber composition is 100 mass%, a tire in which D×S is more than 0.

05.

2. The tire according to claim 1, wherein the polyester fiber is a recycled polyester fiber.

3. The tire according to claim 1, wherein D×S is more than 1.

0.

4. The tire according to claim 1, wherein D×S is more than 1.0 and less than 30.

0.

5. when the complex elastic modulus of the rubber composition at 30°C is 30°C E* (MPa), the tire according to any one of claims 1 to 4, wherein 30°C E*×D is 3.0 or more.

6. The tire according to any one of claims 1 to 4, wherein tanδ (0°C tanδ) of the rubber composition at 0°C is 0.45 or more.

7. The tire according to any one of claims 1 to 4, wherein the rubber composition contains 60 parts by mass or more of silica with respect to 100 parts by mass of the rubber component.

8. The tire according to any one of claims 1 to 4, wherein the content of the copolymer resin with respect to 100 parts by mass of the rubber component in the rubber composition is 10 parts by mass or more.

9. The tire according to any one of claims 1 to 4, wherein the distance G from the tread surface to the belt cord is 12.0 mm or less.

Images