Tire

Abstract

To provide a tire with improved air permeability resistance.SOLUTION: A tire comprises an inner liner, and an insulation which contacts the inner liner on a tire radial direction outer side of the inner liner. The insulation is constituted from a rubber composition containing recovered carbon black, an air permeation coefficient of the rubber composition constituting the inner liner is less than 18×10-11 cm3 cm / (cm2 s cmHg), a thickness of the inner liner on an equatorial plane of the tire is 1.5 mm or less, and a loss tangent 70°Ctanδ of a composite of the insulation and the inner liner at 70°C is 0.22 or less.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a tire.

Background Art

[0002] An inner liner is provided on the inner cavity surface of the tire as an air permeation suppression layer to maintain the air pressure of the tire. In recent years, the demand for lower fuel consumption of vehicles has been increasing, and the inner liner has also been improved for this purpose. Consideration has been given to reducing fuel consumption by thinning the inner liner and improving air permeation suppression performance. On the other hand, there are also problems such as curling and peeling at the interface between the inner liner and the insulation (also called the tiger gum layer) adjacent to the inner liner, and further improvement is required.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a tire with improved tire air permeation suppression performance.

Means for Solving the Problems

[0005] The present invention is a tire including an inner liner and an insulation that contacts the inner liner on the outer side in the tire radial direction of the inner liner, wherein the insulation is composed of a rubber composition containing recycled carbon black, and the air permeation coefficient of the rubber composition constituting the inner liner is 18×10 -11 cm 3 ·cm / (cm 2... is less than ·s·cmHg), the thickness of the inner liner on the tire equatorial plane is 1.5 mm or less, and the loss tangent tanδ at 70 °C of the composite of the insulation and the inner liner is 0.22 or less. The present invention relates to a tire.

Advantages of the Invention

[0006] According to the present invention, it is possible to provide a tire with improved suppression of tire air permeation.

[0007] Although not intended to be bound by theory, the reason why the air permeation suppression performance can be improved in the present invention is considered as follows. That is, by reducing the tanδ of the composite of the insulation and the inner liner and making the thickness of the composite thinner, it is considered that the entire tire becomes less likely to generate heat and air becomes less likely to pass through. It is considered that the synergistic effect of this and improving the air permeation coefficient of the inner liner contributes to the improvement of the air permeation suppression performance during driving as a tire.

Brief Description of the Drawings

[0008]

Figure 1

Embodiments for Carrying Out the Invention

[0009] A tire according to an embodiment of the present invention is a tire including an inner liner and insulation that is in contact with the inner liner on the outer side in the tire radial direction of the inner liner, wherein the insulation is composed of a rubber composition containing recycled carbon black, and the air permeation coefficient of the rubber composition constituting the inner liner is 18×10 -11 cm 3 ·cm / (cm 2It is a tire with an air permeability coefficient of the inner liner on the tire equator plane of less than 17×10

[0010] The thickness of the inner liner on the tire equator plane is preferably 1.4 mm or less, more preferably 1.2 mm or less, and even more preferably 1.1 mm or less.

[0011] It is considered that the strain of the inner liner becomes small, heat generation is suppressed, and the air permeation suppression performance is improved.

[0012] The air permeability coefficient of the rubber composition constituting the inner liner is 17×10 -11 cm 3 ·cm / (cm 2 ·s·cmHg) or less is preferable, 16×10 -11 cm 3 ·cm / (cm 2 ·s·cmHg) or less is more preferable, 15×10 -11 cm 3 ·cm / (cm 2 ·s·cmHg) less is even more preferable, 14.0×10 -11 cm 3 ·cm / (cm 2 ·s·cmHg) or less is even more preferable.

[0013] It is considered that air is retained, shape stability is improved, rolling resistance is reduced, heat generation is suppressed, and further improvement in air permeation suppression performance is achieved.

[0014] The rubber composition constituting the insulation preferably contains a rubber component containing more than 20% by mass of an isoprene-based rubber, and the rubber composition constituting the inner liner preferably contains a rubber component containing more than 70% by mass of a butyl-based rubber.

[0015] The statistical thickness specific surface area (STSA) (m 2(g) is preferably more than 37 and less than 77, and the ash content (mass %) is preferably more than 11 and less than 27.

[0016] <Definition> The "normal state" means a no-load state in which the tire is mounted on a normal rim and filled with air at normal internal pressure.

[0017] 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, unless otherwise specified. On the other hand, those existing inside the tire or on the tire cut surface are values specified in a state where the tire is cut by a plane including the tire rotation axis and the cut tire piece is held in the rim width of the normal rim.

[0018] The "weight of the tire" is represented by G (kg) and refers to the weight of the tire alone without including the weight of the rim. On the other hand, when the inner cavity of the tire is provided with a member made of sponge or sealant or a sensor member, etc., the weight including them is used.

[0019] The "normal rim" is the rim defined for each tire in the standard system including the standard based on the tire. For example, in the case of JATMA (Japan Automobile Tire Association), it refers to the standard rim in the applicable size 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 that order, and follow the standard if there is an applicable size at the time of reference. In the case of a tire not defined by the above standards, it refers to the rim with the narrowest rim width among the rims with the smallest diameter that can be mounted on the tire and can maintain the internal pressure (i.e., does not cause air leakage between the rim / tire).

[0020] "Normal internal pressure" refers to the air pressure 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 air pressure"; in the case of ETRTO, it is "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 normal rims, refer to JATMA, ETRTO, and TRA in this order, and follow the relevant standard if there is an applicable size during the reference. For tires not specified in the above standards, it refers to the normal internal pressure (however, 250 kPa or more) of another tire size described with the normal rim as the standard rim (however, those specified in the standard), and if there are multiple normal internal pressures of 250 kPa or more described, it refers to the minimum value among them.

[0021] "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"; and in the case of TRA, it is the maximum value described in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES". Similar to the cases of normal rims and normal internal pressures, refer to JATMA, ETRTO, and TRA in this order, and follow the relevant standard if there is an applicable size during the reference. For tires not specified in the above standards, the maximum load capacity W L calculated separately is taken as the normal load.

[0022] "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 (mm) in the normal state, "Ht" is the cross-sectional height of the tire in the tire cross-section by the plane including the tire rotation axis (mm) in the tire radial direction, and "Wt" is the cross-sectional width of the tire (mm) in the normal state. When the rim diameter of the tire is R, Ht can be obtained by (Dt - R) / 2. Wt is the value obtained excluding patterns, characters, etc. on the tire sidewall. Note that the maximum load capacity is synonymous with the above-mentioned normal load.

[0023]

Number

[0024] "Recycled carbon black" refers to carbon black obtained from the thermal decomposition process of products such as used tires containing carbon black, and when oxidized and burned by heating in air using 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 more than 11% by mass. That is, the mass of the weight loss due to the oxidation combustion (carbon amount) is less than 89% by mass. Recycled carbon black is also called recycled carbon or recycled carbon black, and may be represented by rCB.

[0025] "Inner liner thickness" is the thickness in the tire radius direction at the equator in the tire cross-section by the plane including the tire rotation axis. L in Figure 1 corresponds to this. The "inner liner thickness" uses the average value of the respective values measured in the tire cross-section by the plane including the tire rotation axis at five locations where the tire is rotated by 72 degrees each. Note that the measurement can be carried out by creating a tire cross-section piece by the plane including the tire rotation axis and holding it in a state where the distance between the beads is adjusted to the normal rim width.

[0026] "The loss tangent of the rubber composition" is the loss tangent (tanδ) under each condition measured in the elongation mode using a dynamic viscoelasticity measuring device (for example, the Implex series manufactured by GABO). The sample used for dynamic viscoelasticity measurement is a vulcanized rubber composition with a length of 20 mm, a width of 4 mm, and a thickness of 1 mm. When preparing a sample by cutting it out from a tire, the length direction of the sample is aligned with the tire circumferential direction, and the thickness direction of the sample is aligned with the tire radial direction. When collecting a sample of the composite of the insulation and the inner liner, the thickness of the inner liner is appropriately adjusted so that the thickness of the composite becomes 1 mm in combination with the total thickness of the insulation and is cut out.

[0027] "tanδ at 70°C" is the loss tangent (tanδ) measured under the conditions of a temperature of 70°C, a frequency of 10 Hz, an initial strain of 10%, a dynamic strain of ±1%, and an elongation mode.

[0028] <Measurement method> "Styrene content" is calculated by pyrolysis gas chromatography.

[0029] "Vinyl bond content (amount of 1,2-bonded butadiene units)" is measured by infrared absorption spectroscopy analysis.

[0030] "Cis content (amount of cis-1,4-bonded butadiene units)" is measured by infrared absorption spectroscopy analysis.

[0031] "Ash content of recycled carbon black" is measured by the thermogravimetric measurement method of JIS K 6226-2:2003.

[0032] "Statistical thickness specific surface area (STSA) of recycled carbon black" is a value determined according to JIS K 6217-7:2017. Also, "nitrogen adsorption specific surface area (N2SA) of recycled carbon black" is a value determined according to JIS K 6217-2:2017.

[0033] "Average primary particle diameter of carbon black" and "average primary particle diameter of recycled carbon black" are values 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 particle is spherical, the diameter of the sphere is taken as the particle diameter, and when it is non-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.

[0034] "Nitrogen adsorption specific surface area (N2SA) of silica" is a value measured by the BET method in accordance with ASTM D3037-93.

[0035] "Air permeability coefficient" is a value measured in accordance with Appendix 2 of JIS K 7126-1 (Gas Permeability Test Method by Gas Chromatography).

[0036] <Tire> Hereinafter, a tire according to an embodiment of the present invention will be described with appropriate reference to the drawings. However, the drawings are merely examples for explanation.

[0037] FIG. 1 is a schematic view showing a part (upper right part of the cross section) of the cross section of a tire according to an embodiment of the present invention along the tire meridian. In FIG. 1, the inner liner 3 constitutes the inner surface of the tire 1 and holds the internal pressure of the tire 1. The insulation 2 is adjacent to the outer side of the inner liner in the tire rotation axis direction, and the inner liner is joined to other members such as the carcass through the insulation. The thickness along the tire center line of the inner liner is indicated by L.

[0038] The thickness L (mm) of the inner liner on the tire equatorial plane is 1.5 mm or less, preferably 1.4 mm or less, more preferably 1.2 mm or less, and even more preferably 1.1 mm or less. There is no particular lower limit, but for example, it is 0.01 mm or more. It is considered that the heat generation of the inner liner is suppressed, the distortion is also suppressed, and the air permeation resistance suppression performance is improved.

[0039] In addition, the rubber composition for an inner liner according to the present invention is formed so as to form the inner cavity surface of a tire and is used for an inner liner that functions to reduce the air permeation amount and maintain the tire internal pressure, and thus excellent air permeability resistance is required. The air permeability coefficient of the rubber composition is less than 18×10 -11 cm 3 ·cm / (cm 2 ·s·cmHg) because excellent air permeation suppression properties required for the inner liner can be obtained. It is preferably less than 17×10 -11 cm 3 ·cm / (cm 2 ·s·cmHg), more preferably less than 16×10 -11 cm 3 ·cm / (cm 2 ·s·cmHg), still more preferably less than 15×10 -11 cm 3 ·cm / (cm 2 ·s·cmHg), and even more preferably less than 14.0×10 -11 cm 3 ·cm / (cm 2 ·s·cmHg). There is no particular lower limit, but for example, it is 1.0×10 -13 cm 3 ·cm / (cm 2 ·s·cmHg) or more.

[0040] The air permeability coefficient can be changed by changing the types and contents of rubber components, fillers, resins, etc. in the rubber composition. Specifically, for example, increasing the amount of the filler or reducing its particle size can reduce the air permeability coefficient.

[0041] The loss tangent tanδ at 70°C of the composite of the inner liner and the insulation is 0.22 or less, preferably 0.21 or less, and more preferably 0.20 or less. There is no particular lower limit, but for example, it is 0.01 or more. It is considered that heat generation suppression is improved and air permeation suppression performance is improved. The 70°C tanδ can be appropriately adjusted according to the types and blending amounts of the polymer components, fillers, oils, resin components, etc. described later. For example, increasing the amount of the filler, decreasing its particle size, and reducing the amounts of the vulcanizing agent and the vulcanization accelerator tend to increase the 70°C tanδ, and conversely, the 70°C tanδ can be decreased by the reverse operation.

[0042] Also, the loss tangent at 70°C of the rubber composition constituting the insulation is, for example, less than 0.185, preferably 0.18 or less, more preferably 0.17 or less, and even more preferably 0.15 or less. It is considered that the air permeation suppression performance is further improved within this range.

[0043] Also, the loss tangent at 70°C of the rubber composition constituting the inner liner is, for example, less than 0.25, preferably 0.24 or less, more preferably 0.22 or less, and even more preferably 0.21 or less. It is considered that the air permeation suppression performance is further improved within this range.

[0044] <Rubber composition> Hereinafter, the rubber composition for insulation and the rubber composition for inner liner will be described.

[0045] [Rubber composition for insulation] Each component of the rubber composition for insulation will be described. The rubber composition constituting the insulation contains recycled carbon black.

[0046] <Rubber component> The rubber composition constituting the insulation includes a rubber component containing isoprene rubber (IR rubber) and styrene-butadiene rubber (SBR). In this case, the rubber component can include rubber components other than IR rubber and SBR. Also, the rubber component may consist only of IR rubber and SBR. The description of each rubber that can constitute the rubber component is as follows.

[0047] (Isoprene rubber) Examples of isoprene rubber include natural rubber (NR), isoprene rubber (IR), modified NR, denatured NR, denatured IR, etc. As NR, for example, those generally used in the rubber industry such as SIR20, RSS#3, TSR20, SVR-L, etc. can be used. IR is not particularly limited, and for example, those generally used in the rubber industry such as IR2200, etc. can be used. Examples of modified NR include deproteinized natural rubber (DPNR), high-purity natural rubber (UPNR), etc. Examples of denatured NR include epoxidized natural rubber (ENR), hydrogenated natural rubber (HNR), grafted natural rubber, etc. Examples of denatured IR include epoxidized isoprene rubber, hydrogenated isoprene rubber, grafted isoprene rubber, etc. The isoprene rubber may be used alone or in combination of two or more.

[0048] The content of IR rubber in 100% by mass of the rubber component is, for example, more than 20% by mass, preferably more than 30% by mass, more preferably more than 40% by mass, and still more preferably 50% by mass or more. On the other hand, the content is, for example, 100% by mass or less, preferably less than 90% by mass, more preferably less than 80% by mass.

[0049] (SBR) The styrene-butadiene rubber (SBR) is not particularly limited. For example, there are unmodified emulsion polymerization styrene-butadiene rubber (E-SBR), solution polymerization styrene-butadiene rubber (S-SBR), modified SBR such as modified emulsion polymerization styrene-butadiene rubber (modified E-SBR) and modified solution polymerization styrene-butadiene rubber (modified S-SBR). Examples of the modified SBR include modified SBR with a modified terminal and / or main chain, and modified SBR coupled with tin, silicon compounds, etc. (condensates, those having a branched structure, etc.). Also, as SBR, there are an oil-extended type with extender oil added to adjust flexibility and a non-oil-extended type without extender oil added, and either of these can be used. As such SBR, for example, those manufactured by JSR Corporation, Asahi Kasei Chemicals Corporation, Nippon Zeon Co., Ltd., ZS Elastomer Co., Ltd., etc. can be used. SBR can be used alone or in combination of two or more.

[0050] The styrene content of SBR is preferably more than 15% by mass, more preferably more than 20% by mass, and even more preferably more than 23% by mass. Also, from the viewpoint of low fuel consumption, the styrene content is preferably less than 40% by mass, more preferably less than 30% by mass, and even more preferably less than 25% by mass. The styrene content of SBR is a value calculated by H-NMR measurement. 1 It is a value calculated by H-NMR measurement.

[0051] The vinyl content (amount of 1,2-bonded butadiene units) of SBR is preferably more than 10% by mass, more preferably more than 15% by mass. Also, the vinyl content is preferably less than 80% by mass, preferably less than 50% by mass, and more preferably less than 30% by mass. The vinyl content of SBR is a value measured by infrared absorption spectrum analysis.

[0052] The content of SBR-based rubber in 100% by mass of the rubber component is, for example, more than 5% by mass, preferably more than 10% by mass, more preferably more than 20% by mass, and even more preferably more than 25% by mass. On the other hand, the content is, for example, 100% by mass or less, preferably less than 90% by mass, and more preferably less than 80% by mass.

[0053] Also, the total content of IR-based rubber and SBR in 100% by mass of the rubber component is preferably more than 80% by mass, more preferably more than 90% by mass, still more preferably more than 95% by mass, and may be 100% by mass.

[0054] (Other rubbers) Other rubbers that can be used in addition to the above are not particularly limited, and rubbers used in the tire field and the like can be used. For example, diene rubbers such as butadiene rubber (BR), acrylonitrile-butadiene rubber (NBR), chloroprene rubber (CR), and styrene-isoprene-butadiene copolymer rubber (SIBR) can be mentioned. Other rubbers may be used alone or in combination of two or more.

[0055] (BR) BR is not particularly limited. For example, BR with a high cis content, BR containing 1,2-syndiotactic polybutadiene crystals (BR containing SPB), butadiene rubber synthesized using a rare earth element-based catalyst (rare earth-based BR), tin-modified butadiene rubber modified with a tin compound (tin-modified BR), and other modified butadiene rubbers (modified BR) are examples of those commonly used in the tire industry. As commercially available BR, products of Ube Industries, Ltd., JSR Corporation, Asahi Kasei Corporation, Nippon Zeon Co., Ltd., etc. can be used. As the modified BR, any BR having a functional group that interacts with a filler such as silica may be used. For example, a terminal-modified BR in which at least one terminal of BR is modified with a compound (modifying agent) having the above functional group (terminal-modified BR having the above functional group at the terminal), a main-chain-modified BR having the above functional group in the main chain, a main-chain and terminal-modified BR having the above functional group in the main chain and at the terminal (for example, a main-chain and terminal-modified BR having the above functional group in the main chain and at least one terminal modified with the above modifying agent), and a terminal-modified BR modified (coupled) with a polyfunctional compound having two or more epoxy groups in the molecule and having a hydroxyl group or an epoxy group introduced therein can be mentioned. Examples of the above functional group include an amino group, an amide group, a silyl group, an alkoxysilyl group, an isocyanate group, an imino group, an imidazole group, a urea group, an ether group, a carbonyl group, an oxycarbonyl group, a mercapto group, a sulfide group, a disulfide group, a sulfonyl group, a sulfinyl group, a thiocarbonyl group, an ammonium group, an imide group, a hydrazo group, an azo group, a diazo group, a carboxyl group, a nitrile group, a pyridyl group, an alkoxy group, a hydroxyl group, an oxy group, an epoxy group, etc. These functional groups may have a substituent. Among them, an amino group (preferably an amino group in which a hydrogen atom of the amino group is substituted with an alkyl group having 1 to 6 carbon atoms), an alkoxy group (preferably an alkoxy group having 1 to 6 carbon atoms), and an alkoxysilyl group (preferably an alkoxysilyl group having 1 to 6 carbon atoms) are preferred.

[0056] The cis amount (cis content) of BR is preferably more than 90% by mass, more preferably more than 93% by mass, still more preferably more than 95% by mass, and still more preferably 97% by mass or more. The cis amount of BR can be measured by infrared absorption spectroscopy.

[0057] As the BR, for example, products of UBE Corporation, JSR Corporation, Asahi Kasei Corporation, Nippon Zeon Co., Ltd., etc. can be used. The BR may be used alone or in combination of two or more kinds.

[0058] (Rubber component synthesized from recycled and biomass-derived raw materials) The monomers that are the constituent units of synthetic rubbers such as IR, SBR, and BR may be derived from underground resources such as petroleum and natural gas, or may be 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 polyisoprene, 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 polyisoprene (recycled isoprene), recycled butadiene (recycled butadiene), and / or recycled styrene (recycled styrene) as raw materials.

[0059] The method for producing the recycled monomer is not particularly limited, and examples include being synthesized from recycled naphtha obtained by decomposing rubber products such as tires. Also, the method for producing recycled naphtha is not particularly limited, and for example, rubber products such as tires may be decomposed under high temperature and high pressure, decomposed by microwaves, or extracted after mechanical pulverization.

[0060] Furthermore, the monomers that are the constituent units of polymers such as IR, SBR, and BR may be derived from biomass. In this specification, biomass refers to substances derived from natural resources such as plants. Biomass is not particularly limited, and examples include agricultural and forestry products, sugars, wood chips, plant residues after obtaining useful components, plant-derived ethanol, biomass naphtha, and the like. The monomers derived from biomass (biomass monomers) are not particularly limited, and examples include butadiene derived from biomass and aromatic vinyl compounds derived from biomass. 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 of biological conversion, and examples of chemical and / or physical conversion include those by catalysts, high heat, high pressure, electromagnetic waves, supercritical fluids, and combinations thereof.

[0061] The polymers synthesized from biomass monomer components (biomass polymers) are not particularly limited, and examples include polybutadiene rubber synthesized from butadiene derived from biomass and aromatic vinyl / butadiene copolymers synthesized from butadiene derived from biomass and / or aromatic vinyl compounds derived from biomass. Examples of the aromatic vinyl / butadiene copolymer include styrene-butadiene rubber synthesized from butadiene derived from biomass and / or styrene derived from biomass.

[0062] Whether the raw material of the polymer is derived from biomass can be determined by pMC (percent Modern Carbon) measured in accordance with ASTM D 6866-10.

[0063] pMC is the 14 C concentration of the sample relative to that of the 14It is the ratio of C concentration and is a value used as an index indicating the biomass ratio of a compound. The significance of this value is described below.

[0064] In 1 mole (6.02×10 23 pieces) of carbon atoms, there are approximately 6.02×10 11 pieces, which is about one trillionth of ordinary carbon atoms. 14 14C exists. 14 The half-life of 14C is 5730 years, 14 and 14C decreases regularly. Therefore, after carbon dioxide in the atmosphere is taken up and fixed by plants, etc., in fossil fuels such as coal, oil, and natural gas, which are considered to have passed more than 226,000 years since fixation, all of the 14 14C elements contained in them have decayed. Therefore, in the 21st century, fossil fuels such as coal, oil, and natural gas do not contain any 14 14C elements. Therefore, chemical substances produced from these fossil fuels also do not contain any 14 14C elements.

[0065] On the other hand, 14 14C is constantly generated by nuclear reactions of cosmic rays in the atmosphere. Therefore, 14 14C is in balance between decrease due to radioactive decay and generation due to nuclear reactions, and in the atmospheric environment of the Earth, 14 the amount of 14C is constant. Therefore, the 14 14C concentration of substances derived from biomass resources circulating in the current environment is about 1×10 -12 mol% with respect to the whole C atoms as described above. Therefore, by using the difference between these values, the biomass ratio in a certain compound can be calculated.

[0066] This 14 14C is generally measured as follows. Using accelerator mass spectrometry based on a tandem accelerator, 13 14C concentration ( 13 14C / 12 12C), 14 13C concentration ( 14 13C / 12Measure (C). In the measurement, 14 As a modern standard reference serving as the standard for the concentration of C, the 14 C concentration 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 radioactivity of carbon in this oxalic acid (the radioactivity intensity of 14 C per 1 g of carbon) is separated for each carbon isotope, 13 For 14 C, it is corrected to a constant value, and the value obtained by applying the decay correction from 1950 AD to the measurement date is used as the value (100%) of the standard

[0067] Therefore, if the rubber is made of 100% biomass-derived substances, although there are regional differences and the like, it often does not reach 100 under normal current conditions, so it generally shows a value of about 110 pMC. On the other hand, for chemical substances derived from fossil fuels such as petroleum, when the 14 C concentration is measured, it shows a value of about 0 pMC (for example, 0.3 pMC). This value corresponds to a biomass ratio of 0% mentioned above.

[0068] From the above, using a material such as rubber with a high pMC value, that is, a material such as rubber with a high biomass ratio, in a rubber composition is suitable from the perspective of environmental protection.

[0069] <Filler> The rubber composition for insulation according to an embodiment of the present invention contains a filler containing recycled carbon black (rCB). The filler may also contain carbon black, silica, and other reinforcing fillers used in the tire industry. Preferably, the filler contains recycled carbon black and other carbon black in addition to recycled carbon black. When the filler contains silica, it may further contain a silane coupling agent.

[0070] (Recycled Carbon Black) In the present invention, recycled carbon black is carbon black obtained from the thermal decomposition process of products such as used tires containing carbon black, and when oxidized and burned by heating in air by thermogravimetric measurement method conforming to JIS K 6226-2:2003, it refers to carbon black in which the ratio of the mass of the ash content (ash amount), which is a non-combustible component, is more than 11% by mass. The ash amount of the recycled carbon black is preferably 13% by mass or more, more preferably 15% by mass or more, still more preferably 16% by mass or more, and even more preferably 17% by mass or more. Also, the ash amount is preferably less than 27% by mass, more preferably less than 26% by mass, and still more preferably less than 25% by mass.

[0071] Recycled carbon black can be obtained from the thermal decomposition process of used pneumatic tires. For example, European Patent Application Publication No. 3427975 mentions in "Rubber Chemistry and Technology", Vol. 85, No. 3, pages 408 to 449 (2012), especially pages 438, 440, 442, and it is described that it can be obtained by thermal decomposition of organic materials at 550 to 800 °C with oxygen excluded or by vacuum thermal decomposition at a relatively low temperature (

[0027] ). Carbon black obtained from such a thermal decomposition process usually lacks surface functional groups as mentioned in

[0004] of Japanese Patent No. 6856781 (Comparison of surface morphology and chemistry between thermally decomposed carbon black and commercially available carbon black, Powder Technology 160 (2005) 190 to 193). Thus, since recycled carbon black has few surface functional groups, the interaction with the rubber component becomes small, and it is considered that the heat generation due to friction with the rubber decreases.

[0072] Recycled carbon black may lack functional groups on its surface, or may be processed 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 Japanese 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 the embodiments of the present invention also includes carbon black treated to contain functional groups on these surfaces.

[0073] The average primary particle size of the recycled carbon black is preferably 20 nm or more, more preferably 25 nm or more, still more preferably 30 nm or more, and particularly preferably 35 nm or more. By making the average primary particle size of the carbon black within the above range, the rubber molecules bound by the carbon black can be minimized and it becomes easier to move flexibly. Therefore, it is considered that the polymer molecular chains can also relieve stress against the input. On the other hand, the average primary particle size is preferably 90 nm or less, more preferably 75 nm or less, and still more preferably 60 nm or less. The average primary particle size of the carbon black is measured by the above measurement method.

[0074] The nitrogen adsorption specific surface area (N2SA) of the recycled carbon black is not particularly limited. However, from the viewpoint of obtaining sufficient reinforcing properties and good abrasion resistance, it is preferably more than 30 m 2 / g, more preferably more than 40 m 2 / g, still more preferably more than 50 m 2 / g, still more preferably more than 60 m 2 / g, still more preferably more than 70 m 2 / g, still more preferably more than 70 m. Also, from the viewpoint of excellent dispersibility and low heat generation, the N2SA is preferably 300 m 2Less than / g is preferable, 200 m 2 Less than / g is more preferable, 150 m 2 Less than / g is even more preferable, 120 m 2 Less than / g is even more preferable, 110 m 2 Less than / g is even more preferable, 100 m 2 Less than / g is even more preferable, 90 m 2 Less than / g is even more preferable. The N2SA of the recycled carbon black in this specification is a value measured in accordance with JIS K 6217-2:2017.

[0075] The statistical thickness specific surface area (STSA) of the recycled carbon black is not particularly limited, but from the viewpoint of obtaining sufficient reinforcing properties and good abrasion resistance, it is more than 37 m 2 / g, preferably more than 40 m 2 / g, more preferably more than 45 m 2 / g, even more preferably. Also, from the viewpoint of excellent dispersibility and low heat generation, the STSA is less than 77 m 2 / g, preferably less than 75 m 2 / g, more preferably less than 73 m 2 / g, even more preferably. The STSA of the recycled carbon black in this specification is a value measured in accordance with JIS K 6217-7:2017.

[0076] From the viewpoint of reinforcing properties, the content of the recycled carbon black is, for example, more than 10 parts by mass, preferably more than 20 parts by mass, more preferably 30 parts by mass or more, and even more preferably more than 50 parts by mass with respect to 100 parts by mass of the rubber component.

[0077] (Carbon black other than rCB) Other carbon blacks for the regenerated carbon black are not particularly limited, and examples 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. Also, 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 commercial 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., Columbian Carbon Company, etc. can be used. These may be used alone or in combination of two or more kinds.

[0078] The average primary particle diameter of the carbon black is preferably 20 nm or more, more preferably 25 nm or more, still more preferably 30 nm or more, and particularly preferably 35 nm or more. By making the average primary particle diameter of the carbon black within the above range, the rubber molecules bound by the carbon black are minimized and it becomes easier to move flexibly, so it is considered that the stress can be relaxed by the polymer molecular chain even for the input. On the other hand, the average primary particle diameter is preferably 90 nm or less, more preferably 75 nm or less, and still more preferably 60 nm or less. The average primary particle diameter of the carbon black is measured by the above measurement method.

[0079] The nitrogen adsorption specific surface area (N2SA) of the carbon black is not particularly limited, but from the viewpoint of obtaining sufficient reinforcing property and good abrasion resistance, it is preferably more than 30 m 2 / g, more preferably more than 40 m 2 / g, still more preferably more than 50 m 2 / g, still more preferably more than 60 m 2 / g, still more preferably more than 70 m 2 / g. Also, from the viewpoint of excellent dispersibility and low heat generation, the N2SA is preferably less than 300 m 2 / g, more preferably less than 200 m 2Less than / g is more preferable, and less than 150 m 2 Less than / g is even more preferable, and less than 120 m 2 Less than / g is even more preferable, and less than 110 m 2 Less than / g is even more preferable, and less than 100 m 2 Less than / g is even more preferable, and less than 90 m 2 Less than / g is even more preferable. The N2SA of the carbon black in this specification is a value measured in accordance with JIS K 6217-2:2017.

[0080] The statistical thickness specific surface area (STSA) of the carbon black is not particularly limited. From the viewpoint of obtaining sufficient reinforcing properties and good abrasion resistance, more than 37 m 2 / g is preferable, and more than 40 m 2 More than / g is more preferable, and more than 45 m 2 More than / g is even more preferable. Also, from the viewpoint of excellent dispersibility and low heat generation, less than 77 m 2 / g is preferable, and less than 75 m 2 Less than / g is more preferable, and less than 73 m 2 Less than / g is even more preferable. The STSA of the carbon black in this specification is a value measured in accordance with JIS K 6217-7:2017.

[0081] (Content of carbon black) When carbon black is contained, the content of carbon black is, for example, more than 10 parts by mass, preferably more than 20 parts by mass, more preferably 30 parts by mass or more, based on 100 parts by mass of the rubber component. The total content of carbon black including recycled carbon black is, for example, more than 20 parts by mass, preferably more than 30 parts by mass, more preferably more than 40 parts by mass, even more preferably more than 50 parts by mass, even more preferably 60 parts by mass or more, based on 100 parts by mass of the rubber component. On the other hand, the total content is preferably less than 100 parts by mass, more preferably less than 90 parts by mass, even more preferably less than 80 parts by mass. When the content of carbon black is within the above range, sufficient reinforcing properties, good dispersion in the rubber, and sufficient rubber strength and crack growth resistance tend to be obtained.

[0082] 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 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 preferable because of its large number of silanol groups. These silicas may be used alone or in combination of two or more.

[0083] 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 filter, wash with water, dry, and pulverize the resulting silicon dioxide precipitate.

[0084] 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 pyrolysis and decomposition by electromagnetic waves. Among them, silica recovered from electronic components such as semiconductors or tires is preferable.

[0085] When silica crystallizes, it is insoluble in water and the silicic acid that is its component cannot be utilized. By controlling the combustion temperature and combustion time, crystallization of silica in rice husk ash can be suppressed (see, for example, Japanese Patent Application Laid-Open No. 2009-2594, Akita Prefectural University Web Journal B / 2019, vol. 6, p. 216-222, etc.).

[0086] Amorphous silica extracted from rice husks can be those commercially available from Wilmar Co., Ltd. and the like.

[0087] The nitrogen adsorption specific surface area (N2SA) of the silica is preferably 50 m2 more than / g, preferably more than 100 m 2 more than / g, more preferably more than 150 m 2 more than / g, particularly preferably more than 170 m 2 more than / g. Also, the upper limit of the N2SA of silica is not particularly limited, but preferably less than 350 m 2 / g, more preferably less than 250 m 2 / g, more preferably less than 200 m 2 / g. By setting it within the above range, the cut resistance tends to be improved. The N2SA of silica is a value measured by the BET method in accordance with ASTM D3037-93.

[0088] (Content of silica) When containing silica, the content with respect to 100 parts by mass of the rubber component is not particularly limited, but from the viewpoints of ensuring low fuel consumption and riding comfort performance, more than 1 part by mass is preferable, more than 5 parts by mass is preferable, more than 10 parts by mass is more preferable, and more than 20 parts by mass is even more preferable. Also, from the viewpoints of the dispersibility and processability of silica, less than 150 parts by mass is preferable, less than 100 parts by mass is more preferable, less than 50 parts by mass is even more preferable, and less than 30 parts by mass is even more preferable.

[0089] (Silane coupling agent) When using silica as a filler, it is preferably further contained with a silane coupling agent. The silane coupling agent is not particularly limited. For example, bis(3-triethoxysilylpropyl)tetrasulfide, bis(2-triethoxysilylethyl)tetrasulfide, bis(4-triethoxysilylbutyl)tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, bis(2-trimethoxysilylethyl)tetrasulfide, bis(2-triethoxysilylethyl)trisulfide, bis(4-trimethoxysilylbutyl)trisulfide, bis(3-triethoxysilylpropyl)disulfide, bis(2-triethoxysilylethyl)disulfide, bis(4-triethoxysilylbutyl)disulfide, bis(3-trimethoxysilylpropyl)disulfide, bis(2-trimethoxysilylethyl)disulfide, bis(4-trimethoxysilylbutyl)disulfide, 3-trimethoxysilylpropyl-N,N-dimethylthiocarbamoyl tetrasulfide, 2-triethoxysilylethyl-N,N-dimethylthiocarbamoyl tetrasulfide, 3-triethoxysilylpropyl methacrylate monosulfide, etc. of sulfide series, 3-mercaptopropyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, NXT, NXT-Z manufactured by Momentive, etc. of mercapto series, vinyltriethoxysilane, vinyltrimethoxysilane, etc. of vinyl series, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, etc. of amino series, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, etc. of glycidoxy series, 3-nitropropyltrimethoxysilane, 3-nitropropyltriethoxysilane, etc. of nitro series, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, etc. of chloro series and the like can be mentioned. As commercially available products, products of Evonik Degussa, Momentive, Shin-Etsu Silicone Co., Ltd., Tokyo Chemical Industry Co., Ltd., Azmax Co., Ltd., Toray Dow Corning Co., Ltd., etc. can be used. These may be used alone or in combination of two or more.

[0090] (Content of silane coupling agent) When a silane coupling agent is contained, the content of the silane coupling agent is preferably more than 1 part by mass, more preferably more than 3 parts by mass, still more preferably more than 5 parts by mass, and even more preferably more than 7 parts by mass with respect to 100 parts by mass of silica. On the other hand, the content is preferably less than 20 parts by mass, more preferably less than 18 parts by mass, still more preferably less than 16 parts by mass, and even more preferably less than 14 parts by mass. By setting it within the above range, the dispersibility of silica tends to be improved.

[0091] (Other fillers) Other fillers are not particularly limited, and materials known in the field of the tire industry can be used. For example, inorganic fillers such as calcium carbonate, talc, alumina, clay, aluminum hydroxide, aluminum oxide, mica, etc. can be mentioned. These may be used alone or in combination of two or more.

[0092] <Other compounding agents> In addition to the rubber component and the filler, the rubber composition can appropriately contain compounding agents generally used in the conventional tire industry, such as plasticizers, processing aids, vulcanized rubber particles, waxes, stearic acid, zinc oxide, antioxidants, vulcanizing agents, vulcanization accelerators, etc.

[0093] (Plasticizer) A plasticizer is a material that imparts plasticity to the rubber component, and is a concept that includes both plasticizers that are liquid (liquid state) at normal temperature (25°C) and plasticizers that are solid at normal temperature (25°C). Examples of plasticizers include resin components, oils, liquid polymers, ester-based plasticizers, etc. 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. Also, low-molecular-weight hydrocarbon components obtained by thermally decomposing and extracting used tires and products containing various components may be used as plasticizers. These plasticizers may be used alone or in combination of two or more.

[0094] ≪Oil≫ Examples of the oil include mineral oil, vegetable oil, animal oil, and the like. 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.

[0095] In this specification, the mineral oil refers to oil derived from mineral resources such as petroleum and natural gas. Examples of the mineral oil include paraffinic oil (mineral oil), naphthenic oil, aromatic oil, and the like. 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), and the like. It is also possible to use oil with a low content of polycyclic aromatic (PCA) compounds for environmental protection. Examples of the low-PCA-content oil include MES, TDAE, and heavy naphthenic oil.

[0096] In this specification, the vegetable oil refers to, 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 wax, and the like. Further, examples of the vegetable oil include refined oil (such as salad oil) obtained by refining the above-mentioned oil, transesterified oil obtained by transesterifying the above-mentioned oil, hydrogenated oil obtained by hydrogenating the above-mentioned oil, thermally polymerized oil obtained by thermally polymerizing the above-mentioned oil, oxidatively polymerized oil obtained by oxidizing the above-mentioned oil, and waste cooking oil recovered from those used as edible oil and the like. Note that the vegetable oil may be liquid or solid at room temperature (25°C). These vegetable oils may be used alone or in combination of two or more kinds.

[0097] The vegetable oil according to this embodiment preferably contains acylglycerol, more preferably contains triacylglycerol. In this 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 three or more units. Note that acylglycerols of two or more units can be obtained by thermal polymerization, oxidative polymerization, or the like. Also, the acylglycerol may be liquid or solid at room temperature (25°C).

[0098] As a method for confirming whether the acylglycerol is contained in the rubber composition, it 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 are observed around 5.26 ppm, around 4.28 ppm, and around 4.15 ppm. 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.

[0099] 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.

[0100] Among these, 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 such a vegetable oil containing a fatty acid, plants may be improved by variety improvement, genetic recombination, genome editing, or the like.

[0101] As the vegetable oil, for example, those commercially available from Idemitsu Kosan Co., Ltd., Sankyo Yuka Kogyo Co., Ltd., ENEOS Co., Ltd., Oryzoi Co., Ltd., H&R Co., Ltd., Toyokuni Oil Co., Ltd., Fuji Kogyo Co., Ltd., Nisshin Oillio Group Co., Ltd., etc. can be used.

[0102] The content with respect to 100 parts by mass of the rubber component of the oil is preferably more than 1 part by mass, more preferably more than 3 parts by mass, and even more preferably more than 5 parts by mass. Further, the content is preferably less than 20 parts by mass, more preferably less than 15 parts by mass, and even more preferably less than 10 parts by mass. The content of the oil includes the amount of oil contained in the rubber component as the extender oil and the amount of oil contained in other components such as sulfur.

[0103] ≪Liquid Polymer≫ A liquid polymer is a polymer that is liquid at normal temperature (25 °C), and examples thereof include liquid diene polymers. Examples of the liquid diene polymer include liquid styrene-butadiene copolymer (liquid SBR), liquid butadiene polymer (liquid BR), liquid isoprene polymer (liquid IR), liquid styrene-isoprene copolymer (liquid SIR), and the like. The liquid diene polymer preferably has a number average molecular weight (Mn) in terms of polystyrene measured by gel permeation chromatography (GPC) of more than 1,000, more preferably more than 3,000. On the other hand, the Mn is preferably less than 100,000, more preferably less than 15,000. The Mn of the liquid polymer is a polystyrene conversion value measured by gel permeation chromatography (GPC). As the liquid diene polymer, for example, products of Sartomer Company, Kuraray Co., Ltd., etc. can be used. The liquid polymer may be used alone or in combination of two or more.

[0104] (Resin) The rubber composition preferably contains a resin among the above-mentioned other compounding agents. The resin is 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, C5-C9 resins, terpene resins, rosin resins, phenolic resins, etc. can be mentioned. Among these, petroleum resins, aromatic vinyl resins, dicyclopentadiene resins, C9 resins, and terpene resins are preferred. The resin may be used alone or in combination of two or more.

[0105] ≪C9 Resin≫ "C9 resin" refers to a resin obtained by polymerizing a C9 fraction. It can be a resin obtained by polymerizing the C9 fraction alone or a copolymer obtained by copolymerizing the C9 fraction with other components. For example, a resin obtained by copolymerizing dicyclopentadiene (DCPD) and a C9 fraction is called a DCPD / C9 resin. Also, it may be hydrogenated or modified. Examples of the C9 fraction include at least one petroleum fraction corresponding to 8 to 10 carbon atoms selected from the group consisting of vinyltoluene, alkylstyrene, coumarone, indene, methylindene, dicyclopentadiene, etc. Specific examples of the C9 resin include, for example, coumarone-indene resin, coumarone resin, indene resin, etc. The resin may be used alone or in combination of two or more.

[0106] ≪C5 resin≫ "C5 resin" refers to a resin obtained by polymerizing a C5 fraction other than dicyclopentadiene, and it may be hydrogenated or modified. Examples of the C5 fraction other than dicyclopentadiene include at least one petroleum fraction corresponding to 4 to 5 carbon atoms selected from the group consisting of cyclopentadiene, isoprene, pentane, isopentane, neopentane, pentene, pentadiene, etc. The resin may be used alone or in combination of two or more.

[0107] ≪C5C9 resin≫ "C5C9 resin" refers to a resin obtained by copolymerizing the C5 fraction and the C9 fraction, and it may be hydrogenated or modified. As the C5C9 petroleum resin, for example, those commercially available from Tosoh Corporation, LUHUA Co., etc. can be used. The resin may be used alone or in combination of two or more.

[0108] ≪Dicyclopentadiene resin≫ The term "dicyclopentadiene-based resin" refers to a resin containing dicyclopentadiene (DCPD) as the monomer component with the highest content, and it may be hydrogenated or modified. Examples of dicyclopentadiene-based resins include DCPD / C9 resins obtained by copolymerizing dicyclopentadiene and the C9 fraction, and DCPD / C9 resins are preferred. As DCPD resins, for example, those commercially available from ExxonMobil, ENEOS Corporation, 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.

[0109] ≪Aromatic vinyl-based resin≫ The term "aromatic vinyl-based resin" refers to a resin containing at least one aromatic vinyl compound selected from the group consisting of styrene, α-methylstyrene, vinyltoluene, p-chlorostyrene, etc. as the monomer component with the highest content, preferably containing 50 mol% or more, and it may be hydrogenated or modified. As aromatic vinyl-based resins, due to economic reasons, ease of processing, and excellent heat generation properties, a homopolymer of α-methylstyrene or styrene or a copolymer of α-methylstyrene and styrene is preferred, and a copolymer of α-methylstyrene and styrene is more preferred. As aromatic vinyl-based resins, for example, those commercially available from Crayton, Eastman Chemical, Mitsui Chemicals, etc. can be used. The resin may be used alone or in combination of two or more.

[0110] ≪Terpene-based resin≫ A terpene resin refers to a resin that contains, as the monomer component with the highest content, at least one terpene compound selected from the group consisting of α-pinene, β-pinene, limonene, dipentene, etc., preferably containing 50 mol% or more, and may be hydrogenated or modified. 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 the aromatic compounds that are 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 the phenolic compounds that are 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.

[0111] ≪Rosin-based resin≫ A rosin-based resin refers to a resin that contains at least one rosin acid compound selected from the group consisting of abietic acid, neoabietic acid, palustric acid, isopimaric acid, etc., preferably containing it as the monomer component with the highest content, more preferably containing 50 mol% or more, and may be hydrogenated or modified. 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.

[0112] ≪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 include phenol formaldehyde resin, alkylphenol formaldehyde resin, alkylphenol acetylene resin, oil-modified phenol formaldehyde resin, and the like. The resin may be used alone or in combination of two or more.

[0113] When containing the resin, the content relative to 100 parts by mass of the rubber component is preferably more than 2 parts by mass, more preferably more than 3 parts by mass, and even more preferably more than 4 parts by mass. On the other hand, the content is preferably less than 20 parts by mass, more preferably less than 15 parts by mass, and even more preferably less than 10 parts by mass.

[0114] ≪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.

[0115] (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), 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. 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 Co., etc. can be used. The anti-aging agent may be used alone or in combination of two or more kinds.

[0116] When containing the anti-aging agent, the content relative to 100 parts by mass of the rubber component is preferably more than 0.5 part by mass, more preferably more than 0.8 part by mass, and still more preferably more than 1.0 part by mass. On the other hand, the content is preferably less than 7.0 parts by mass, more preferably less than 5.0 parts by mass, and still more preferably 3.0 parts by mass or less.

[0117] (Vulcanized rubber particles) The vulcanized rubber particles are particles made of vulcanized rubber. Specifically, rubber powder etc. specified in JIS K 6316:2017 can be used. From the perspectives of environmental consideration and cost, recycled rubber powder produced from crushed waste tires etc. is preferable. These may be used alone or in combination of two or more.

[0118] The vulcanized rubber particles are not particularly limited and may be non-modified vulcanized rubber particles or modified vulcanized rubber particles.

[0119] As commercially available products of vulcanized rubber, for example, products of Lehigh, Murakami Rubber Industry Co., Ltd. etc. can be used.

[0120] (Processing aid) Examples of the processing aid include fatty acid metal salts, fatty acid amides, amide esters, silica surfactants, mixtures of fatty acid metal salts and amide esters, mixtures of fatty acid metal salts and fatty acid amides etc. These processing aids may be used alone or in combination of two or more. As the processing aid, for example, those commercially available from Schill+Seilacher, Performance Additives etc. can be used.

[0121] When containing the processing aid, the content relative to 100 parts by mass of the rubber component is preferably more than 0.5 part by mass, more preferably more than 1 part by mass, still more preferably more than 1.5 parts by mass from the perspective of exerting the effect of improving processability. Also, from the perspectives of abrasion resistance and breaking strength, it is preferably less than 10 parts by mass, more preferably less than 8.0 parts by mass, still more preferably less than 5.0 parts by mass.

[0122] (Wax) The wax is not particularly limited, and any wax commonly used in the tire industry can be preferably used. For example, mineral waxes, plant-derived waxes, etc. can be mentioned. Mineral waxes refer to waxes derived from mineral resources such as oil and natural gas. Plant-derived waxes refer to waxes derived from natural resources such as plants. Among them, mineral waxes are preferred. Examples of plant-derived waxes include rice wax, carnauba wax, candelilla wax, etc. Examples of mineral waxes include paraffin wax, microcrystalline wax, these 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 kinds.

[0123] When containing wax, the content with respect to 100 parts by mass of the rubber component is preferably more than 0.3 part by mass, more preferably more than 0.7 part by mass, and still more preferably more than 1.0 part by mass. On the other hand, the content is preferably less than 4.0 parts by mass, more preferably less than 3.0 parts by mass, and still more preferably less than 2.5 parts by mass.

[0124] (Stearic acid) When containing stearic acid, the content with respect to 100 parts by mass of the rubber component is preferably more than 0.5 part by mass, more preferably more than 0.7 part by mass, and still more preferably 1.0 part by mass or more from the viewpoint of processability. On the other hand, from the viewpoint of vulcanization rate, the content is preferably less than 10 parts by mass, more preferably less than 5 parts by mass, and still more preferably less than 3 parts by mass.

[0125] (Zinc oxide) When zinc oxide is contained, the content thereof relative to 100 parts by mass of the rubber component is preferably more than 0.5 part by mass, more preferably more than 0.7 part by mass, and still more preferably 1 part by mass or more from the viewpoint of processability. On the other hand, the content is preferably 10 parts by mass or less, more preferably less than 7 parts by mass, and still more preferably 5 parts by mass or less from the viewpoint of abrasion resistance.

[0126] (Vulcanizing agent) The vulcanizing agent is not particularly limited, and known vulcanizing agents can be used. Examples thereof include organic peroxides, sulfur-based vulcanizing agents, resin vulcanizing agents, and metal oxides such as magnesium oxide. Among them, sulfur-based vulcanizing agents are preferred. As the sulfur-based vulcanizing agent, for example, sulfur, sulfur donors such as morpholine disulfide, and the like can be used. Among these, it is preferable to use sulfur. The vulcanizing agent can be used alone or in combination of two or more.

[0127] Examples of sulfur include powdered sulfur, precipitated sulfur, colloidal sulfur, surface-treated sulfur (oil-treated sulfur, special sulfur treated with a dispersant, masterbatch-type sulfur, etc.), insoluble sulfur (oil-treated insoluble sulfur, etc.), and all of them can be preferably used. Among them, powdered sulfur is preferred. Sulfur can be used, for example, those manufactured and sold by Tsurumi Chemical Industry Co., Ltd., Karuizawa Sulfur Co., Ltd., Shikoku Chemicals Corporation, Flexsys, Nippon Dry Distillation Industry Co., Ltd., Hosoi Chemical Industry Co., Ltd., and the like.

[0128] Known organic crosslinking agents can also be used as the vulcanizing agent. The organic crosslinking agent is not particularly limited as long as it can form a crosslinking chain other than a polysulfide bond. Examples thereof include alkylphenol-sulfur chloride condensates, sodium 1,6-hexamethylene-dithiosulfate dihydrate, 1,6-bis(N,N'-dibenzylthiocarbamoyldithio)hexane, dicumyl peroxide, and the like. Among them, 1,6-bis(N,N'-dibenzylthiocarbamoyldithio)hexane is preferred. These organic crosslinking agents can be those commercially available from Taoka Chemical Industry Co., Ltd., Rancess Co., Ltd., Flexsys, and the like.

[0129] When contained, the content relative to 100 parts by mass of the rubber component is preferably more than 0.4 part by mass, more preferably more than 0.5 part by mass, still more preferably more than 1.0 part by mass, and even more preferably more than 1.5 parts by mass. On the other hand, the content is preferably less than 6.0 parts by mass, more preferably 5.0 parts by mass or less, and still more preferably less than 4.0 parts by mass. When the content of the vulcanizing agent is within the above range, an appropriate reinforcing effect tends to be obtained. When the vulcanizing agent contains components other than sulfur such as oil-treated sulfur, the content of the vulcanizing agent means the content of the sulfur component itself.

[0130] (Vulcanization accelerator) The vulcanization accelerator is not particularly limited, and known vulcanization accelerators can be used. 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 can be mentioned. Among them, sulfenamide-based, thiuram-based, and guanidine-based are preferred, and sulfenamide-based is more preferred. As the vulcanization accelerator, for example, those manufactured and sold by Ouchi Shinsei Chemical Industry Co., Ltd., Sanshin Chemical Industry Co., Ltd., etc. can be used. These vulcanization accelerators can be used alone or in combination of two or more.

[0131] Examples of the sulfenamide-based vulcanization accelerator include N-tert-butyl-2-benzothiazolylsulfenamide (TBBS), N-cyclohexyl-2-benzothiazolylsulfenamide (CBS), N,N'-dicyclohexyl-2-benzothiazolylsulfenamide (DZ), etc. Examples of the thiuram-based vulcanization accelerator include tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetrabenzylthiuram disulfide (TBzTD), etc. Examples of the guanidine-based vulcanization accelerator include 1,3-diphenylguanidine (DPG), diorthotolylguanidine, orthotolylbiguanidine, etc.

[0132] The content of the vulcanization accelerator relative to 100 parts by mass of the rubber component is preferably more than 0.3 part by mass, more preferably more than 0.4 part by mass, and still more preferably more than 0.5 part by mass. On the other hand, the content is preferably less than 4.0 parts by mass, more preferably less than 3.0 parts by mass, and still more preferably less than 2.0 parts by mass. When the content of the vulcanization accelerator is within the above range, the breaking strength and elongation tend to be ensured.

[0133] [Rubber composition for inner liner] Each component of the rubber composition for inner liner will be described.

[0134] (Rubber component) The description of the rubber component is as follows, and it is also as described in the rubber composition for insulation. The rubber composition for inner liner contains a rubber component containing butyl rubber. In this case, the rubber component can contain rubber components other than butyl rubber. As such rubber components other than butyl rubber, the rubber components described in the rubber composition for insulation can be used. Also, the rubber component may consist only of butyl rubber. The description of butyl rubber is as follows.

[0135] ≪Butyl rubber≫ As the butyl rubber, polymers and their derivatives containing isobutylene units and isoprene units as repeating units are preferred. Such butyl rubbers include butyl rubber (IIR); halogenated butyl rubbers such as brominated butyl rubber (Br-IIR) and chlorinated butyl rubber (Cl-IIR). Among them, halogenated butyl rubber is preferred, and brominated butyl rubber and chlorinated butyl rubber are more preferred, from the viewpoint of being able to improve the sheet processability and air barrier property in a well-balanced manner. These can be used singly or in combination of two or more.

[0136] As the butyl rubber, in addition to ordinary butyl rubber (butyl rubber other than recycled butyl rubber), recycled butyl rubber can be used in combination. Since recycled butyl rubber usually has a high content of non-halogenated butyl rubber (regular butyl rubber), by using it in combination with halogenated butyl rubber, good air barrier properties and vulcanization rate can be ensured. The recycled butyl rubber may be used alone or in combination of two or more kinds.

[0137] The rubber component may contain other rubber components in addition to the butyl rubber. For example, diene rubbers such as isoprene rubber (IR rubber), butadiene rubber (BR), styrene-butadiene rubber (SBR), styrene-isoprene-butadiene rubber (SIBR), chloroprene rubber (CR), acrylonitrile-butadiene rubber (NBR), etc. can be mentioned. The explanations given for the rubber composition for insulation are equally applicable to these other rubber components. These other rubber components may be used alone or in combination of two or more kinds.

[0138] ≪Content≫ From the viewpoint of sufficient air barrier properties, the content of butyl rubber in 100% by mass of the rubber component is preferably more than 70% by mass, more preferably more than 75% by mass, still more preferably 80% by mass or more, and particularly preferably 90% by mass or more.

[0139] (Filler) The filler may contain carbon black. The filler may also contain recycled carbon black (rCB) or silica. When the filler contains silica, a silane coupling agent may further be contained. The filler may further contain other fillers other than carbon black and silica. Preferably, the filler contains carbon black and recycled carbon black. The explanations for each component that can constitute the filler are as described in the column of the rubber composition for insulation.

[0140] ≪Content of carbon black≫ When carbon black is contained, the total content of carbon black including recycled carbon black is, for example, more than 20 parts by mass, preferably more than 40 parts by mass, more preferably 50 parts by mass or more, and still more preferably 60 parts by mass or more with respect to 100 parts by mass of the rubber component. On the other hand, the total content is preferably less than 150 parts by mass, more preferably less than 110 parts by mass, and still more preferably less than 80 parts by mass. When the content of carbon black is within the above range, sufficient reinforcing property and good dispersion in the rubber can be obtained, and sufficient rubber strength and crack growth resistance tend to be obtained.

[0141] When recycled carbon black is included in the filler, the content ratio of recycled carbon black in the total content of carbon black is, from the viewpoint of reinforcing property, for example, more than 10% by mass, preferably more than 20% by mass, more preferably more than 30% by mass, and still more preferably 40% by mass or more.

[0142] Regarding other carbon black (including recycled carbon black), the description made for the rubber composition for insulation can be similarly applied.

[0143] (Other compounding agents) Regarding the descriptions other than the above, the description made for the rubber composition for insulation can be similarly applied.

[0144] (Other rubber members constituting the tire) In this specification, the tire can include other rubber members other than the above. Such other rubber members are not particularly limited, and various ones generally used for tires can be used.

[0145] In this specification, various materials containing carbon atoms (for example, rubber, oil, resin, vulcanization accelerator, antioxidant, surfactant, etc.) may be derived from carbon dioxide in the atmosphere. As a method for obtaining the formulation according to the embodiment of the present invention from carbon dioxide, carbon dioxide may be directly converted, or methane obtained through a methanation process for synthesizing methane from carbon dioxide may be converted.

[0146] <Use> In this specification, the tire can be either a pneumatic tire or a non-pneumatic tire, and it can be preferably used as a pneumatic tire. Also, in this specification, the tire can be used for various applications such as passenger car tires, heavy-duty tires for trucks and buses, motorcycle tires, and high-performance tires.

[0147] <Manufacturing method> The tire according to this embodiment can be manufactured by a known method.

[0148] (Manufacture of rubber composition) Each of the above rubber compositions can be manufactured by a known method. For example, it can be manufactured by kneading each of the above components using a rubber kneading device such as an open roll or a closed kneader (Banbury mixer, kneader, etc.). The kneading process includes, for example, a base kneading process of kneading compounding agents and additives other than vulcanizing agents and vulcanization accelerators, and a final kneading (F kneading) process of adding and kneading vulcanizing agents and vulcanization accelerators to the kneaded product obtained in the base kneading process. Further, the base kneading process can be divided into a plurality of processes if desired. The kneading conditions are not particularly limited, but 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 50 to 110°C for 1 to 5 minutes.

[0149] (Manufacture of tire) Each of the rubber compositions obtained as described above can be extruded in accordance with the shape of a desired tire member at the unvulcanized stage and can be used as an unvulcanized insulation and inner liner, respectively. The tire according to the present embodiment can be made into an unvulcanized tire by molding in a normal manner on a tire molding machine together with other tire members using the insulation and inner liner thus obtained. By heating and pressurizing (vulcanizing) this unvulcanized tire in a vulcanizer, a tire can be obtained. The vulcanization conditions are not particularly limited, and examples thereof include a method of vulcanizing at 150 to 200 °C for 5 to 30 minutes.

Examples

[0150] Hereinafter, examples (Examples) considered to be preferable in practice are shown, but the scope of the present invention is not limited to the examples. Using the various chemicals shown below, the rubber compositions and tires obtained according to each table were examined, and the results calculated based on the following evaluation methods are shown as durability indices at the bottom of each table.

[0151] <Materials> The materials used in the examples and comparative examples are collectively described below. Natural rubber: SVR-L SBR: SBR1502 (manufactured by JSR Corporation, styrene content: 23.5% by mass, vinyl content: 18% by mass, Mw: 500,000) Butyl rubber 1: BB2222 (manufactured by ExxonMobil, bromobutyl rubber) Butyl rubber 2: chlorobutyl HT1066 (manufactured by ExxonMobil, chlorobutyl rubber) Carbon black: Show black N660 (manufactured by Cabot Japan Ltd., N2SA: 35 m 2 / g; ash content: 0.5% by mass) Recycled carbon black (rCB): Carbon black obtained from the thermal decomposition process of tires (ash content: 17% by mass) Oil 1: Diana Process NH-70S (manufactured by Idemitsu Kosan Co., Ltd., aromatic process oil) Oil 2: PS-32 (manufactured by Idemitsu Kosan Co., Ltd., mineral oil) Zinc oxide: Two types of zinc oxide (manufactured by Mitsui Mining & Smelting Co., Ltd.) Stearic acid: Camellia bead stearic acid (manufactured by NOF Corporation) Sulfur: HK-200-5 (manufactured by Hosoi Chemical Industry Co., Ltd., powdered sulfur, oil content: 5% by mass) Vulcanization accelerator 1: Nocceler CZ (manufactured by Ouchi Shinko Chemical Industry Co., Ltd., N-cyclohexyl-2-benzothiazole sulfenamide) Vulcanization accelerator 2: Nocceler DM (manufactured by Ouchi Shinko Chemical Industry Co., Ltd., di-2-benzothiazolyl disulfide)

[0152] <Rubber composition for insulation> According to the formulation shown in Table 1 and Table 2, using a 1.7L closed Banbury mixer, chemicals other than sulfur and vulcanization accelerators are kneaded at a discharge temperature of 150°C for 5 minutes. Next, sulfur and vulcanization accelerators are added to the obtained kneaded material, and it is kneaded on an open roll for 4 minutes until it reaches 105°C to obtain an unvulcanized rubber composition for insulation.

[0153] <Rubber composition for inner liner> According to the formulation shown in Table 1 and Table 2, using a 1.7L closed Banbury mixer, chemicals other than sulfur and vulcanization accelerators are kneaded for 4 minutes until the discharge temperature reaches 130°C to obtain a kneaded material. Next, using a twin-screw open roll, sulfur and vulcanization accelerators are added to the obtained kneaded material, and it is kneaded for 4 minutes until it reaches 80°C to obtain an unvulcanized rubber composition for inner liner.

[0154] <Tire> According to the description in Table 1 and Table 2, the unvulcanized rubber composition for insulation and the unvulcanized rubber composition for inner liner are respectively formed into the shape of insulation (thickness 0.4mm) and the shape of the inner liner, and further bonded to other members to form an unvulcanized tire, which is press-vulcanized at 170°C for 12 minutes to manufacture each test tire (size: 195 / 65R15).

[0155] <Evaluation> For each test tire, the results evaluated by the following evaluation method are described in the corresponding columns of the above tables.

[0156] <tan δ at 70°C> Using a dynamic viscoelasticity measuring device, measure at a temperature of 70°C, a frequency of 10 Hz, an initial strain of 10%, a dynamic strain of ±1%, and in the elongation mode. The sample is cut out from the tire as a composite of insulation and inner liner with a length of 20 mm × width of 4 mm × thickness of 1 mm. Align the length direction of the sample with the tire circumferential direction and the thickness direction of the sample with the tire radial direction. In sampling the sample, the thickness of the inner liner is appropriately adjusted so that the total thickness of the insulation is combined to cut out the composite with a thickness of 1 mm.

[0157] <Air permeability coefficient> The air permeability coefficient at 20°C (cm 3 ·cm / (cm 2 ·s·cmHg)) was calculated from the results of measuring the inner liner using a gas permeability measuring device (GTR-11A / 31A manufactured by GTR Tech Co., Ltd.) in accordance with Appendix 2 of JIS K 7126-1 (Gas Permeability Test Method by Gas Chromatography Method). The smaller the air permeability coefficient, the smaller the air permeation amount, indicating excellent air barrier properties.

[0158] <Air permeation resistance performance> Install each test tire on a regular rim 15×6.0JJ, fill it with air, and set the internal pressure to 230 kPa. Mount this tire on a drum-type running test machine and apply a regular load. Run this tire on the drum for 30,000 km under the condition of a speed of 80 km / h and measure the air pressure. The air permeation resistance performance index is expressed as an index with the air pressure of the comparison reference example (Comparative Example 2) after running set to 100. The larger this value, the better the air permeation resistance performance after long-term running.

[0159] <Tire durability performance> Each test tire is mounted on a standard rim 15×6.0JJ, filled with air, and the internal pressure is set to 230 kPa. This tire is mounted on a drum-type running test machine and loaded with the standard load. This tire is run on the drum under the condition of a speed of 80 km / h, and the running distance until the inner liner or the insulation is destroyed is measured. The results are displayed as an index with the running distance of the comparative reference example (Comparative Example 2) set to 100. The larger the numerical value, the better.

[0160] The sum of the air permeation resistance performance index and the tire durability performance index is defined as the comprehensive performance index.

[0161]

Table 1

[0162]

Table 2

[0163] <Embodiment> Preferred embodiments are shown below.

[0164] [1] A tire comprising an inner liner and an insulation that contacts the inner liner on the outer side in the tire radial direction of the inner liner, wherein the insulation is composed of a rubber composition containing recycled carbon black, the air permeation coefficient of the rubber composition constituting the inner liner is less than 18×10 -11 cm 3 ·cm / (cm 2 ·s·cmHg), the thickness of the inner liner on the tire equatorial plane is 1.5 mm or less, preferably 1.4 mm or less, and the loss tangent 70℃ tanδ of the composite of the insulation and the inner liner at 70°C is 0.22 or less, preferably 0.21 or less, more preferably 0.20 or less. The tire according to [1], wherein the thickness of the inner liner on the tire equator plane is 1.2 mm or less, more preferably 1.1 mm or less. [3] The air permeability coefficient of the rubber composition constituting the inner liner is 17×10 -11 cm 3 ·cm / (cm 2 ·s·cmHg) or less, preferably 16×10 -11 cm 3 ·cm / (cm 2 ·s·cmHg) or less, more preferably 15×10 -11 cm 3 ·cm / (cm 2 ·s·cmHg) less than, even more preferably 14.0×10 -11 cm 3 ·cm / (cm 2 ·s·cmHg) or less, the tire according to [1] or [2]. [4] The rubber composition constituting the insulation contains a rubber component containing more than 20% by mass, preferably more than 30% by mass, more preferably more than 40% by mass, and even more preferably 50% by mass or more of an isoprene-based rubber, and the rubber composition constituting the inner liner contains a rubber component containing more than 70% by mass, preferably more than 75% by mass, more preferably 80% by mass or more, and even more preferably 90% by mass or more of a butyl-based rubber, the tire according to any one of [1] to [3]. [5] The statistical thickness specific surface area (STSA) (m 2 / g) of the recycled carbon black is more than 37, preferably more than 40 m 2 / g, more preferably more than 45 m 2 / g, and also less than 77, preferably less than 75 m 2 / g, more preferably less than 73 m 2 / g, and the ash content (% by mass) is more than 11% by mass, preferably 13% by mass or more, more preferably 15% by mass or more, even more preferably 16% by mass or more, and even more preferably 17% by mass or more, and less than 27% by mass, preferably less than 26% by mass, more preferably less than 25% by mass, the tire according to any one of [1] to [4].

Explanation of reference signs

[0165] 1 Tire 2 Insulation Rubber 3 Inner Liner Rubber CL Tire Equatorial Plane L Thickness of Inner Liner Rubber at Tire Equatorial Plane R Rim

Claims

Claim 1 A tire comprising an inner liner and an insulation that contacts the inner liner on the outer side in the tire radial direction of the inner liner, wherein the insulation is composed of a rubber composition containing recycled carbon black, The air permeability coefficient of the rubber composition constituting the inner liner is less than 18×10 -11 cm 3 ·cm / (cm 2 ·s·cmHg), and the thickness of the inner liner on the tire equatorial plane is 1.5 mm or less, and the loss tangent tanδ at 70° C. of the composite of the insulation and the inner liner is 0.22 or less. Claim 2 The tire according to claim 1, wherein the thickness of the inner liner on the tire equatorial plane is 1.2 mm or less. Claim 3 The air permeability coefficient of the rubber composition constituting the inner liner is less than 15×10 -11 cm 3 ·cm / (cm 2 ·s·cmHg), the tire according to claim 1 or 2. Claim 4 The tire according to claim 1 or 2, wherein the rubber composition constituting the insulation contains a rubber component containing more than 20% by mass of an isoprene-based rubber, and the rubber composition constituting the inner liner contains a rubber component containing more than 70% by mass of a butyl-based rubber. Claim 5 The statistical thickness specific surface area (STSA) (m 2 / g) of the regenerated carbon black is more than 37 and less than 77, and the ash content (mass %) is more than 11 and less than 27. The tire according to claim 1 or 2.

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