tire

Abstract

To improve the overall performance of the noise damper, in terms of its peel resistance and noise reduction, in a tire in which a noise damper made of a biomass-derived material that has a low environmental impact is fixed to the tire cavity side of the inner liner. [Solution] A tire comprising a carcass extending across a pair of bead portions, an inner liner positioned radially inward of the carcass to form the tire cavity surface, and a noise damper formed using a biomass-derived material and fixed to the tire cavity side of the inner liner, wherein the absolute value K(|EBi-EBs|) of the difference between the breaking elongation EBi (%) of the inner liner and the breaking elongation EBs (%) of the noise damper is less than 480.

Description

[Technical Field]

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

[0002] Conventionally, in order to reduce noise (road noise) generated during driving, tires have been proposed in which a noise damper made of a soft porous material is fixed to the tire cavity side of the inner liner (see, for example, Patent Documents 1 to 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4960626 [Patent Document 2] JP 2022-69984 A [Patent Document 3] Patent No. 6536743 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the inner liner is repeatedly deformed during driving, which may cause the noise damper to peel off from the inner liner. Furthermore, as vehicle performance has increased and expressway networks have been developed, vehicle speeds have tended to increase, creating a demand for improved noise reduction performance. Therefore, it is desirable for noise dampers to adequately achieve both peel resistance and noise reduction performance. Furthermore, in recent years, demands for reducing environmental impact have become increasingly stringent, and it is desirable for noise dampers to use materials that can reduce environmental impact.

[0005] The present invention aims to improve the overall performance of the noise damper, in terms of its peel resistance and noise reduction, in a tire in which a noise damper made of a biomass-derived material, which has a low environmental impact, is fixed to the tire cavity side of the inner liner. [Means for solving the problem]

[0006] The present invention provides a carcass extending across a pair of bead portions; an inner liner disposed radially inward of the carcass to form a tire cavity surface; a sound-damping body formed using a biomass-derived material and fixed to the tire cavity side of the inner liner, The tire is characterized in that the absolute value K(|EBi-EBs|) of the difference between the breaking elongation EBi (%) of the inner liner and the breaking elongation EBs (%) of the noise damper is less than 480. [Effects of the Invention]

[0007] According to the present invention, in a tire in which a noise damper made of a biomass-derived material, which has a low environmental impact, is fixed to the tire cavity side of the inner liner, it is possible to improve the overall performance of the noise damper, including its peel resistance and noise reduction performance. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic cross-sectional view illustrating the configuration of a tire according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] [1] Characteristics of the tire according to the present invention First, the features of the tire according to the present invention will be described.

[0010] 1. Overview The tire according to the present invention includes a carcass extending across a pair of bead portions, an inner liner disposed radially inward of the carcass to form the tire cavity surface, and a noise damper formed using a biomass-derived material and fixed to the tire cavity side of the inner liner, wherein the absolute value K(|EBi-EBs|) of the difference between the breaking elongation EBi (%) of the inner liner and the breaking elongation EBs (%) of the noise damper is less than 480.

[0011] These characteristics, as will be described later, make it possible to improve the overall performance of the noise damper, including its peel resistance and noise reduction, in a tire in which a noise damper made from a biomass-derived material, which has a low environmental impact, is fixed to the tire cavity side of the inner liner.

[0012] 2. Mechanism of effect manifestation in the tire according to the present invention The mechanism by which the above-described effects of the tire according to the present invention are exhibited is believed to be as follows.

[0013] As described above, the inner liner is repeatedly deformed during running, which may cause the noise damper to peel off from the inner liner. In order to prevent such peeling of the noise damper from the inner liner, it is necessary for the noise damper to be able to flexibly deform so as to sufficiently follow the deformation of the inner liner.

[0014] Therefore, in the present invention, the absolute value K (|EBi-EBs|) of the difference between the breaking elongation EBi (%) of the inner liner and the breaking elongation EBs (%) of the sound damper is set to be small, less than 480 (K<480). The smaller the value of K, the better the sound damper follows the deformation of the inner liner, so the sound damper deforms more flexibly, which is thought to improve resistance to peeling from the inner liner.

[0015] The breaking elongation EBi (%) of the inner liner is a value measured in accordance with JIS-K6251:2017 using a No. 7 dumbbell-shaped test piece cut out from a tire at a measurement temperature of 23°C and a tensile speed of 200 mm / min. The thickness direction of the test piece is the radial direction of the tire.

[0016] The breaking elongation EBs (%) of the sound damper is a value measured in accordance with JIS-K6400-5 using a No. 1 dumbbell-shaped test piece cut out from a tire at a measurement temperature of 23°C and a tensile speed of 500 mm / min.

[0017] As described above, in the tire according to the present invention, which is equipped with a noise damper constructed using a biomass-derived material, which is a material that has a low environmental impact, it is believed that by appropriately setting the absolute value K of the difference between the breaking elongation EBi (%) of the inner liner and the breaking elongation EBs (%) of the noise damper, it is possible to improve the overall performance of the noise damper, including its peel resistance and noise reduction performance.

[0018] [2] More preferred embodiments of the tire according to the present invention The tire according to the present invention can obtain even greater effects by employing the following configuration of the noise damper.

[0019] 1.K(|EBi-EBs|) In the present invention, the above-mentioned K(|EBi-EBs|) is more preferably less than 460, and even more preferably less than 440. It is believed that by controlling K more strictly, the peeling resistance of the noise damper is particularly improved.

[0020] 2.Sound damping body In the present invention, the noise damper is preferably formed using a soft porous material having open cells, and more preferably made of a sponge material.

[0021] The porous surface and / or interior of sponge material can convert the vibrational energy of vibrating air into thermal energy and consume it, which is thought to reduce the sound generated in the tire cavity (cavity resonance energy) and reduce driving noise.

[0022] Furthermore, since sponge materials are easily deformed, such as by shrinking and bending, it is believed that they can adequately maintain steering stability.

[0023] In the present invention, the density of the sound damper is 30 kg / m 3 It is preferable that the saturation is 29 kg / m or less. 3 It is more preferable that the density of the sound-damping body is 30 kg / m or less. 3It is believed that the noise reduction performance of the noise damper can be improved by the following.

[0024] The lower limit of the density of the sound-damping body is, for example, 27 kg / m 3 It is preferable that the saturation is 28 kg / m or more. 3 It is more preferable that the above be satisfied, and it is believed that this will enable improvement in tire uniformity.

[0025] Here, the "density of the sound damper" means the apparent density, that is, the density determined from the outer shape including the internal air bubbles.

[0026] In the present invention, the volume of the noise damper is preferably 0.4% or more, more preferably 10% or more, of the total volume of the tire cavity, and is preferably 30% or less, more preferably 20% or less.

[0027] It is believed that the silencing effect of the noise damper can be improved by setting the volume occupied by the noise damper to 0.4% or more and 30% or less of the total volume of the tire cavity.

[0028] The volume of the noise damper mentioned above means the apparent volume, i.e., the volume determined from the outer shape including the air bubbles inside. The total volume V of the tire cavity in a normal state can be approximately calculated using the following formula: V=A×{(Di-Dr) / 2+Dr}×π A: Cross-sectional area of ​​the tire cavity obtained by CT scanning the tire-rim assembly Di: Maximum outer diameter of the tire cavity surface Dr: Rim diameter π: Pi

[0029] Here, "normal condition" refers to a state in which the tire is mounted on a normal rim, is inflated to a normal internal pressure, and is not under load.

[0030] "Genuine rim" refers to the rim specified for each tire in the standard system that includes the standard on which the tire is based. For example, for JATMA (Japan Automobile Tire Manufacturers Association), it refers to the standard rim for the applicable size listed in the "JATMA Year Book." For ETRTO (The European Tire and Rim Technical Organization), it refers to the "Measuring Rim" listed in the "Standards Manual." For TRA (The Tire and Rim Association, Inc.), it refers to the "Design Rim" listed in the "Year Book." JATMA, ETRTO, and TRA are referenced in that order, and if an applicable size is available at the time of reference, that standard is followed. For tires not specified in the standard, it refers to the rim that can be mounted on the rim and can maintain internal pressure, i.e., the rim with the smallest rim diameter and the next narrowest rim width, among rims that do not leak air between the rim and tire.

[0031] "Normal internal pressure" refers to the air pressure specified for each tire by each standard in the standard system, including the standard on which the tire is based. For JATMA, it refers to "Maximum Air Pressure," for ETRTO, it refers to "INFLATION PRESSURE," and for TRA, it refers to the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES." Refer to JATMA, ETRTO, and TRA in that order, and follow the standard if there is an applicable size at the time of reference. In the case of a tire not specified in the standard, it refers to the normal internal pressure (250 KPa or higher) of another tire size (specified in the standard) that is specified using the normal rim as the standard rim. Note that if multiple normal internal pressures of 250 KPa or higher are listed, it refers to the smallest value among them.

[0032] Considering the above, a preferred sponge material in the present invention is a polyurethane sponge whose main component is castor oil polyol. By using 80 parts by mass or more of castor oil polyol per 100 parts by mass of polyol, the biomass content of the polyurethane sponge (sound damper) can be increased to 50% or more, which is preferred.

[0033] The "biomass ratio" of the sound damper (polyurethane sponge) is a value calculated using the following formula based on the pMC (percent modern carbon) of the raw manufacturing materials measured in accordance with ASTM D6866-10, which will be described later. Biomass content of sound damper (%) = (pMC of raw material for manufacturing / 110) x 100

[0034] [3] Implementation form The present invention will be specifically described below based on embodiments.

[0035] 1. Tire according to this embodiment Fig. 1 is a schematic cross-sectional view illustrating the configuration of an example of a tire according to an embodiment of the present invention. In Fig. 1, 1 is a tire, 2 is a tire body, and 3 is a noise damper. 2a is a tread portion, 2b is a sidewall portion, 2c is a bead portion, 2d is a bead core, 2e is a carcass, 2f is an inner liner, 2g is a belt, 2i is a tire cavity surface, and 2ti is a tread region of the tire cavity surface. C and CL are center lines.

[0036] 1, the tire body 2 includes an inner liner 2f that is disposed radially inward of a carcass 2e that extends toroidally across a pair of bead portions 2c and forms a tire cavity surface 2i, and a noise damper 3 that is fixed to the tire cavity side of the inner liner 2f. In consideration of noise damping performance, running performance, and the like, the noise damper 3 is preferably disposed in a tread region 2ti of the tire cavity surface 2i.

[0037] In this embodiment, the noise damper 3 is made using a material derived from biomass. This reduces the burden on the environment. It is also believed that increasing the biomass content of the noise damper can further enhance the effect of reducing the burden on the environment.

[0038] Furthermore, sound-damping bodies made using biomass-derived materials, particularly the castor oil-derived urethane sponge described below, differ from ordinary sound-damping bodies that tend to absorb moisture and reduce soundproofing properties. However, these bodies can be made highly hydrophobic and less likely to absorb moisture from the tire cavity, which is thought to improve noise-reduction performance.

[0039] The absolute value K(|EBi-EBs|) of the difference between the breaking elongation EBi (%) of the inner liner 2f and the breaking elongation EBs (%) of the noise damper 3 is less than 480.

[0040] By adopting the above-mentioned configuration, it is possible to improve the overall performance of the noise damper in terms of its resistance to peeling and its noise reduction performance, as described above.

[0041] 2. Inner liner In this embodiment, the inner liner can be formed using, for example, a rubber composition (rubber composition for inner liner) containing the following blending materials.

[0042] (1) Rubber composition (a) Rubber component Examples of rubber components include diene rubbers such as isoprene rubber, butadiene rubber (BR), styrene butadiene rubber (SBR), styrene isoprene butadiene rubber (SIBR), chloroprene rubber (CR), and acrylonitrile butadiene rubber (NBR), as well as butyl rubber. The rubber components may be used alone or in combination of two or more. Among the above rubbers, it is preferable to use butyl rubber as the main rubber component because of its excellent air permeability resistance and heat resistance.

[0043] (a-1) Butyl rubber As the butyl rubber, those commonly used in the tire industry can be suitably used, and specific examples include ordinary butyl rubber (IIR), as well as halogenated butyl rubbers (X-IIR) such as brominated butyl rubber (Br-IIR), chlorinated butyl rubber (Cl-IIR), fluorinated butyl rubber (F-IIR), and brominated isobutylene-p-methylstyrene copolymer (Exxpro 3035 manufactured by Exxon Mobil Chemical Co.). Among these, Br-IIR is preferably used because the vulcanization reaction proceeds easily.

[0044] Furthermore, recycled butyl rubber can also be used in combination with the butyl rubber. Recycled butyl rubber typically contains a high percentage of non-halogenated butyl rubber (regular butyl rubber), so using it in combination with halogenated butyl rubber can ensure good air permeability resistance and vulcanization speed. Adding a mixture of fatty acid metal salt and fatty acid amide to a formulation containing recycled butyl rubber is particularly advantageous, as it synergistically improves the balance of sheet processability and air permeability resistance.

[0045] Recycled butyl rubber is the butyl rubber content contained in crushed rubber products containing a large amount of butyl rubber, such as tire tubes and bladders used in tire manufacturing, or in products obtained by heating and pressurizing such crushed products. It includes products in which the cross-linking bonds of the rubber components have been broken (desulfurization treatment) to make them re-vulcanizable. Generally, about 50% by mass of the crushed product is recycled butyl rubber. While recycled butyl rubber also contains sulfur, it is deactivated to the extent that it does not participate in cross-linking.

[0046] Commercially available recycled butyl rubbers include recycled tube rubber manufactured by Muraoka Rubber Co., Ltd., which is produced by heat treating butyl tubes under pressurized conditions, and recycled bladder rubber manufactured by Carquest Co., Ltd., which is obtained by crushing bladders in an extruder. These recycled butyl rubbers may be used alone or in combination of two or more.

[0047] The content of the butyl rubber in 100 parts by mass of the rubber component is preferably 70 parts by mass or more, more preferably 75 parts by mass or more, and even more preferably 80 parts by mass or more, because it has excellent air permeability resistance. The upper limit is not particularly limited and may be 100 parts by mass, but from the viewpoint of sheet processability, it is preferably 95 parts by mass or less, and more preferably 90 parts by mass or less.

[0048] From the viewpoint of the merits of using recycled butyl rubber, the content of recycled butyl rubber in 100 parts by mass of the rubber component is preferably 5 parts by mass or more, more preferably 8 parts by mass or more, and even more preferably 15 parts by mass or more. On the other hand, from the viewpoint of ensuring sufficient air permeation resistance and vulcanization rate, the content is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and even more preferably 25 parts by mass or less.

[0049] The content of the recycled butyl rubber in 100 parts by mass of the total butyl rubber is preferably 7 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 20 parts by mass or more, and is preferably 60 parts by mass or less, more preferably 45 parts by mass or less, and even more preferably 30 parts by mass or less.

[0050] (a-2) Isoprene rubber From the viewpoint of improving sheet processability, the rubber component preferably contains an isoprene-based rubber as needed.

[0051] Examples of isoprene-based rubbers include isoprene rubber (IR), natural rubber (NR), and modified natural rubber. NR includes deproteinized natural rubber (DPNR) and highly purified natural rubber (UPNR), while modified natural rubber includes epoxidized natural rubber (ENR), hydrogenated natural rubber (HNR), and grafted natural rubber. NR may be, for example, SIR20, RSS#3, TSR20, or other rubber commonly used in the tire industry. Of these, NR and IR are preferred because they can improve sheet processability and air permeation resistance in a balanced manner.

[0052] In consideration of improving sheet processability, the content of the isoprene-based rubber in 100 parts by mass of the rubber component is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and is preferably 30 parts by mass or less, more preferably 25 parts by mass or less.

[0053] (a-3) Other rubbers In addition to butyl rubber and isoprene rubber, if necessary, rubbers commonly used in the tire industry, such as diene rubbers such as butadiene rubber (BR), styrene butadiene rubber (SBR), ethylene propylene diene rubber (EPDM), styrene isoprene butadiene rubber (SIBR), chloroprene rubber (CR), and acrylonitrile butadiene rubber (NBR), may be contained. These may be used alone or in combination of two or more.

[0054] (b) Compounding materials other than rubber components (b-1) Compatibilizer The compatibilizer is included to reduce the repulsion energy at the interface between the polymer and filler or between different polymers, thereby promoting intermixing. There are no particular limitations on the compatibilizer, and any of those conventionally used in the rubber industry can be used. Specific examples of compatibilizers include non-reactive compatibilizers such as styrene-ethylene-butadiene block copolymers, styrene-methyl methacrylate block copolymers, ethylene-styrene graft copolymers, chlorinated polyethylene, aromatic hydrocarbon resin and aliphatic hydrocarbon resin mixtures (which also function as the "softener component" described below), and metal soaps of unsaturated fatty acids, as well as reactive compatibilizers such as maleic anhydride graft polypropylene, styrene-maleic anhydride copolymers, ethylene-glycidyl methacrylate copolymers, and styrene graft copolymers onto ethylene-glycidyl methacrylate copolymers. The compatibilizers may be used alone or in combination of two or more.

[0055] The content of the compatibilizer is not particularly limited, but in consideration of air permeation resistance, it is, for example, preferably 1 part by mass or more, more preferably 5 parts by mass or more, and even more preferably 8 parts by mass or more, per 100 parts by mass of the rubber component, while it is preferably 30 parts by mass or less, more preferably 15 parts by mass or less, and even more preferably 12 parts by mass or less.

[0056] (b-2) Softener component From the viewpoint of sheet processability, the rubber composition for an inner liner preferably contains oil (including extender oil), liquid rubber, resin components, etc. as softener components. The total content of these components is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, and even more preferably 8 parts by mass or more, per 100 parts by mass of the rubber component. It is also preferably 15 parts by mass or less, more preferably 12 parts by mass or less, and even more preferably 10 parts by mass or less. The oil content includes the amount of oil contained in the rubber (oil-extended rubber). The resin component also has the effect of imparting tackiness.

[0057] (a) Oil The oil is not particularly limited as long as it is an oil commonly used in the tire industry, and examples thereof include mineral oil (commonly referred to as process oil), vegetable oil, and mixtures thereof. Examples of mineral oil (process oil) that can be used include paraffinic process oil, aromatic process oil, and naphthenic process oil. Examples of vegetable oil include castor oil, cottonseed oil, linseed oil, rapeseed oil, soybean oil, palm oil, coconut oil, peanut oil, rosin, pine oil, pine tar, tall oil, corn oil, rice bran oil, safflower oil, sesame oil, olive oil, sunflower oil, palm kernel oil, camellia oil, jojoba oil, macadamia nut oil, and tung oil. These may be used alone or in combination of two or more.

[0058] In addition to the above effects, from the viewpoint of improving air permeation resistance, the content of the oil is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and even more preferably 8 parts by mass or more, per 100 parts by mass of the rubber component, and is preferably 15 parts by mass or less, more preferably 12 parts by mass or less, and even more preferably 10 parts by mass or less.

[0059] When using a process oil, it is preferable to use one with a low aromatic content, which improves compatibility with butyl rubber, suppresses bleeding onto the rubber sheet surface, and prevents a decrease in molding tack.

[0060] Specific examples of process oils (mineral oils) that can be used include products from Idemitsu Kosan Co., Ltd., Sankyo Yuka Kogyo Co., Ltd., ENEOS Corporation, Orisoi Corporation, H&R Corporation, Toyokuni Oil Mills Co., Ltd., Showa Shell Sekiyu K.K., Fuji Kosan Co., Ltd., and the like.

[0061] (b) Liquid rubber The liquid rubber mentioned as a softener component is a polymer that is in a liquid state at room temperature (25° C.) Examples of liquid rubber include liquid polymers that contain the same monomers as solid rubber, such as liquid diene polymers and hydrogenated products thereof, and farnesene polymers.

[0062] Farnesene polymers are liquid polymers obtained by polymerizing farnesene, which has structural units based on farnesene. Farnesene has isomers such as α-farnesene ((3E,7E)-3,7,11-trimethyl-1,3,6,10-dodecatetraene) and β-farnesene (7,11-dimethyl-3-methylene-1,6,10-dodecatriene).

[0063] The farnesene-based polymer may be a homopolymer of farnesene (farnesene homopolymer) or a copolymer of farnesene and a vinyl monomer (farnesene-vinyl monomer copolymer).

[0064] Examples of liquid diene polymers include liquid styrene butadiene copolymer (liquid SBR), liquid butadiene polymer (liquid BR), liquid isoprene polymer (liquid IR), and liquid styrene isoprene copolymer (liquid SIR).

[0065] The liquid diene polymer has a weight average molecular weight (Mw) of, for example, 1.0 × 10 in terms of polystyrene measured by gel permeation chromatography (GPC). 3 Super, 2.0×10 5 In this specification, the Mw of the liquid diene polymer is a polystyrene-equivalent value measured by gel permeation chromatography (GPC).

[0066] The content of the liquid rubber (total content of the liquid farnesene polymer, liquid diene polymer, etc.) is, for example, preferably more than 1 part by mass, more preferably more than 3 parts by mass, per 100 parts by mass of the rubber component. There is no particular upper limit, but it is preferably less than 12 parts by mass, more preferably less than 10 parts by mass.

[0067] As the liquid rubber, for example, products of Kuraray Co., Ltd., Cray Valley Co., Ltd., etc. can be used.

[0068] (c) Resin component Examples of resin components include aromatic hydrocarbon resins such as terpene resins and coumarone-indene resins, and aliphatic hydrocarbon resins such as non-reactive alkylphenol resins, C5 resins, and C9 resins, and two or more of these may be used in combination. Among these, a combination of an aromatic hydrocarbon resin and an aliphatic hydrocarbon resin is preferred. The content of the resin component per 100 parts by mass of the rubber component is, for example, preferably 1 part by mass or more, and more preferably 3 parts by mass or more. On the other hand, it is preferably 7 parts by mass or less, and more preferably 5 parts by mass or less.

[0069] Terpene resins include polyterpenes, terpene phenols, and aromatic modified terpene resins. Polyterpenes are resins obtained by polymerizing terpene compounds and their hydrogenated products. Terpene compounds are (C5H8) n The hydrocarbons and their oxygen-containing derivatives are represented by the following composition: monoterpenes (C 10 H 16 ), sesquiterpenes (C 15 H 24 ), diterpenes (C 20 H 32 ), and examples thereof include α-pinene, β-pinene, dipentene, limonene, myrcene, alloocimene, ocimene, α-phellandrene, α-terpinene, γ-terpinene, terpinolene, 1,8-cineole, 1,4-cineole, α-terpineol, β-terpineol, and γ-terpineol.

[0070] Examples of polyterpenes include terpene resins such as α-pinene resin, β-pinene resin, limonene resin, dipentene resin, and β-pinene / limonene resin, which are made from the above-mentioned terpene compounds, as well as hydrogenated terpene resins obtained by hydrogenating the terpene resins. Examples of terpene phenols include resins obtained by copolymerizing the above-mentioned terpene compounds with phenolic compounds, and resins obtained by hydrogenating the above-mentioned resins. Specific examples include resins obtained by condensing the above-mentioned terpene compounds, phenolic compounds, and formalin. Examples of phenolic compounds include phenol, bisphenol A, cresol, and xylenol. Examples of aromatic-modified terpene resins include resins obtained by modifying terpene resins with aromatic compounds, and resins obtained by hydrogenating the above-mentioned resins. The aromatic compound is not particularly limited as long as it is a compound having an aromatic ring, and examples thereof include phenolic compounds such as phenol, alkylphenol, alkoxyphenol, and unsaturated hydrocarbon group-containing phenol; naphthol compounds such as naphthol, alkylnaphthol, alkoxynaphthol, and unsaturated hydrocarbon group-containing naphthol; styrene derivatives such as styrene, alkylstyrene, alkoxystyrene, and unsaturated hydrocarbon group-containing styrene; coumarone, indene, and the like.

[0071] Coumarone-indene resin is a resin containing coumarone and indene as monomer components that make up the resin skeleton (main chain). Other monomer components contained in the skeleton besides coumarone and indene include styrene, α-methylstyrene, methylindene, and vinyltoluene.

[0072] The hydroxyl value (OH value) of the coumarone-indene resin is, for example, more than 15 mgKOH / g and less than 150 mgKOH / g. The OH value is the amount of potassium hydroxide, expressed in milligrams, required to neutralize acetic acid bonded to hydroxyl groups when acetylating 1 g of the resin, and is a value measured by potentiometric titration (JIS K 0070:1992).

[0073] The softening point of the coumarone-indene resin is, for example, more than 30° C. and less than 160° C. The softening point is the temperature at which the ball drops when the softening point specified in JIS K 6220-1:2001 is measured using a ring and ball softening point tester.

[0074] Non-reactive alkylphenol resins refer to those that have alkyl chains at the ortho and para positions (especially the para position) of the hydroxyl group of the benzene ring in the chain and that make little contribution to the crosslinking reaction during vulcanization, and two or more types may be used in combination.

[0075] C5 resin refers to a resin obtained by polymerizing a C5 fraction. Examples of C5 fractions include petroleum fractions having 4 to 5 carbon atoms, such as cyclopentadiene, pentene, pentadiene, and isoprene. Dicyclopentadiene resin (DCPD resin) is preferably used as a C5 petroleum resin.

[0076] C9 resin refers to a resin obtained by polymerizing a C9 fraction, and may be a hydrogenated or modified version. Examples of C9 fractions include petroleum fractions having 8 to 10 carbon atoms, such as vinyltoluene, alkylstyrene, indene, and methylindene. Specific examples of suitable aromatic vinyl resins include coumarone-indene resins, coumarone resins, indene resins, and aromatic vinyl resins. As aromatic vinyl resins, homopolymers of α-methylstyrene or styrene, or copolymers of α-methylstyrene and styrene are preferred, and copolymers of α-methylstyrene and styrene are more preferred, due to their economical efficiency, ease of processing, and excellent heat generation.

[0077] In addition, C5C9 resins obtained by copolymerizing the C5 fraction and the C9 fraction can also be used, and they may be hydrogenated or modified. Examples of C5 fractions and C9 fractions include the petroleum fractions mentioned above.

[0078] (b-3) Filler The rubber composition for an inner liner preferably contains a filler. Specific examples of the filler include carbon black, silica, calcium carbonate, talc, alumina, clay, aluminum hydroxide, and mica. Among these, carbon black is preferably used as a reinforcing agent, and silica may be used in combination.

[0079] (a) Carbon black The amount of carbon black per 100 parts by mass of the rubber component is, for example, preferably 10 parts by mass or more, more preferably 20 parts by mass or more, and even more preferably 40 parts by mass or more, while it is preferably 100 parts by mass or less, more preferably 90 parts by mass or less, and even more preferably 80 parts by mass or less.

[0080] The carbon black is not particularly limited, and examples thereof include furnace blacks (furnace carbon black) such as SAF, ISAF, HAF, MAF, FEF, SRF, GPF, APF, FF, CF, SCF, and ECF; acetylene black (acetylene carbon black); thermal blacks (thermal carbon black) such as FT and MT; channel blacks (channel carbon black) such as EPC, MPC, and CC; and graphite. These may be used alone or in combination of two or more.

[0081] From the viewpoint of sheet processability, the nitrogen adsorption specific surface area (N2SA) of carbon black is, for example, 10 m 2 / g or more, and 2 / g or more is more preferable, and 30m 2 / g or more is more preferable. 2 / g or less, and 2 / g or less is more preferable, and 2 It is more preferable that N2SA is not more than 1 / g. Note that N2SA is measured in accordance with ASTM D4820-93.

[0082] The carbon black preferably has a dibutyl phthalate (DBP) absorption of greater than 35 ml / 100 g, more preferably greater than 50 ml / 100 g, and less than 250 ml / 100 g, more preferably less than 200 ml / 100 g, as measured in accordance with ASTM D2414-93.

[0083] Specific carbon black is not particularly limited, and examples thereof include N550, N660, and N762. Commercially available carbon blacks include those manufactured by Asahi Carbon Co., Ltd., Cabot Japan Co., Ltd., Tokai Carbon Co., Ltd., Mitsubishi Chemical Corporation, Lion Corporation, Shin-Nichika Carbon Co., Ltd., Columbia Carbon Co., Ltd., etc. These may be used alone or in combination of two or more types.

[0084] (b) Silica The rubber composition for an inner liner may further contain silica as needed, and is usually used together with a silane coupling agent. However, if silica is used, the silica not covered with the silane coupling agent may re-aggregate during extrusion molding of a sheet, which may lead to deterioration in sheet processability, so it is preferable not to use silica if possible.

[0085] When used, the BET specific surface area of ​​silica is 140 m 2 / g, and preferably more than 160m 2 / g or more is more preferable, and 180m 2 / g. 2 / g, and preferably less than 250m 2 / g or less is more preferable, and 2 / g. The content of the silica per 100 parts by mass of the rubber component is preferably 5 parts by mass or more, more preferably 15 parts by mass or more, and even more preferably 25 parts by mass or more. On the other hand, it is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and even more preferably 30 parts by mass or less. The BET specific surface area mentioned above is the N2SA value measured by the BET method in accordance with ASTM D3037-93.

[0086] Examples of silica include dry process silica (anhydrous silica), wet process silica (hydrated silica), etc. Among these, wet process silica is preferred because it has a large number of silanol groups.

[0087] As silica, for example, products from Evonik Industries, Rhodia, Tosoh Silica Corporation, Solvay Japan, Tokuyama Corporation, etc. can be used.

[0088] The silane coupling agent is not particularly limited, and examples thereof include bis(3-triethoxysilylpropyl)tetrasulfide, bis(2-triethoxysilylethyl)tetrasulfide, bis(4-triethoxysilylbutyl)tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, bis(2-trimethoxysilylethyl)tetrasulfide, bis(2-triethoxysilylethyl)trisulfide, 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-dimethylthio Examples of suitable silanes include sulfide-based silanes such as thiocarbamoyl tetrasulfide, 2-triethoxysilylethyl-N,N-dimethylthiocarbamoyl tetrasulfide, and 3-triethoxysilylpropyl methacrylate monosulfide; mercapto-based silanes such as 3-mercaptopropyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, and Momentive's NXT and NXT-Z; vinyl-based silanes such as vinyltriethoxysilane and vinyltrimethoxysilane; amino-based silanes such as 3-aminopropyltriethoxysilane and 3-aminopropyltrimethoxysilane; glycidoxy-based silanes such as γ-glycidoxypropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane; nitro-based silanes such as 3-nitropropyltrimethoxysilane and 3-nitropropyltriethoxysilane; and chloro-based silanes such as 3-chloropropyltrimethoxysilane and 3-chloropropyltriethoxysilane. These silanes may be used alone or in combination of two or more.

[0089] As the silane coupling agent, for example, products from Evonik Industries, Momentive, Shin-Etsu Silicones Co., Ltd., Tokyo Chemical Industry Co., Ltd., Azumax Co., Ltd., Dow Corning Toray Co., Ltd., etc. can be used.

[0090] The content of the silane coupling agent is, for example, more than 3 parts by mass and less than 25 parts by mass relative to 100 parts by mass of silica.

[0091] (c) Other fillers In addition to the carbon black and silica described above, the rubber composition for the inner liner may further contain fillers commonly used in the tire industry, such as calcium carbonate, talc, alumina, clay, aluminum hydroxide, and mica. Among these, from the viewpoint of excellent air permeability resistance and sheet processability, one or more fillers selected from the group consisting of flat aluminum hydroxide, talc, clay, and calcium carbonate are preferred, and flat aluminum hydroxide is more preferred. The content of these fillers is, for example, more than 0.1 part by mass and less than 200 parts by mass per 100 parts by mass of the rubber component.

[0092] (b-4) Processing aids The rubber composition for an inner liner preferably contains a fatty acid compound, such as a mixture of a fatty acid metal salt and a fatty acid amide, as a processing aid, which allows for an appropriate balance between sheet processability and air permeation resistance.

[0093] The fatty acid compound constituting the fatty acid metal salt is not particularly limited, but examples thereof include saturated or unsaturated fatty acids preferably having 6 to 28 carbon atoms, more preferably having 10 to 25 carbon atoms, and even more preferably having 14 to 20 carbon atoms, and specific examples include lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, arachidic acid, behenic acid, and nervonic acid. These can be used alone or in combination of two or more. Among these, saturated fatty acids are preferred, and saturated fatty acids having 14 to 20 carbon atoms are more preferred.

[0094] Examples of metals constituting fatty acid metal salts include alkali metals such as potassium and sodium, alkaline earth metals such as magnesium, calcium and barium, zinc, nickel, molybdenum, etc. Of these, zinc and calcium are preferred.

[0095] The fatty acid amide may be saturated or unsaturated. Examples of saturated fatty acid amides include N-(1-oxooctadecyl)sarcosine, stearic acid amide, and behenic acid amide. Examples of unsaturated fatty acid amides include oleic acid amide and erucic acid amide.

[0096] The content of the processing aid per 100 parts by mass of the rubber component is preferably 0.8 parts by mass or more, more preferably 1.0 parts by mass or more, and even more preferably 1.2 parts by mass or more, and is preferably 3.2 parts by mass or less, more preferably 3.0 parts by mass or less, and even more preferably 2.8 parts by mass or less.

[0097] (b-5) Antiaging agents The rubber composition for an inner liner preferably contains an antioxidant. The content of the antioxidant is, for example, preferably 0.2 parts by mass or more, more preferably 0.7 parts by mass or more, per 100 parts by mass of the rubber component. On the other hand, the content is preferably 5.0 parts by mass or less, more preferably 3.0 parts by mass or less, and even more preferably 2.0 parts by mass or less.

[0098] Examples of the antioxidant include naphthylamine-based antioxidants such as phenyl-α-naphthylamine; diphenylamine-based antioxidants such as octylated diphenylamine and 4,4'-bis(α,α'-dimethylbenzyl)diphenylamine; p-phenylenediamine-based antioxidants such as N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine and N,N'-di-2-naphthyl-p-phenylenediamine; and heavy 2,2,4-trimethyl-1,2-dihydroquinoline. Examples of antioxidants include quinoline antioxidants such as 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline, 6-anilino-2,2,4-trimethyl-1,2-dihydroquinoline, and poly-2,2,4-trimethyl-1,2-dihydroquinoline; monophenol antioxidants such as 2,6-di-t-butyl-4-methylphenol and styrenated phenol; and bis-, tris-, and polyphenol antioxidants such as tetrakis-[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane. These antioxidants may be used alone or in combination of two or more.

[0099] As the antioxidant, for example, products available from Seiko Chemical Co., Ltd., Sumitomo Chemical Co., Ltd., Ouchi Shinko Chemical Industry Co., Ltd., Flexis, etc. can be used.

[0100] (b-6) Stearic acid The rubber composition for an inner liner may contain stearic acid. The content of stearic acid is, for example, more than 0.5 parts by mass and less than 10.0 parts by mass per 100 parts by mass of the rubber component. As the stearic acid, conventionally known ones can be used, such as products from NOF Corporation, NOF Corporation, Kao Corporation, FUJIFILM Wako Pure Chemical Industries, Ltd., Chiba Fatty Acid Co., Ltd., etc.

[0101] (b-7) Zinc oxide The rubber composition for an inner liner may contain zinc oxide. The content of zinc oxide is, for example, more than 0.5 parts by mass and less than 10 parts by mass per 100 parts by mass of the rubber component. As the zinc oxide, a conventionally known product can be used, such as products from Mitsui Mining & Smelting Co., Ltd., Toho Zinc Co., Ltd., Hakusui Tech Co., Ltd., Seido Chemical Industry Co., Ltd., Sakai Chemical Industry Co., Ltd., etc.

[0102] (b-8) Crosslinking agents and vulcanization accelerators The rubber composition for an inner liner preferably contains a crosslinking agent such as sulfur, etc. The content of the crosslinking agent is, for example, more than 0.1 parts by mass and less than 10.0 parts by mass per 100 parts by mass of the rubber component.

[0103] As the sulfur, powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersible sulfur, soluble sulfur, etc., which are commonly used in the rubber industry, can be used. These may be used alone or in combination of two or more.

[0104] As sulfur, for example, products from Tsurumi Chemical Industry Co., Ltd., Karuizawa Iso Co., Ltd., Shikoku Chemical Industry Co., Ltd., Flexis Corporation, Nippon Kanzuri Kogyo Co., Ltd., Hosoi Chemical Industry Co., Ltd., etc. can be used.

[0105] Examples of crosslinking agents other than sulfur include vulcanizing agents containing sulfur atoms, such as Tackirol V200 manufactured by Taoka Chemical Co., Ltd., DURALINK HTS (sodium 1,6-hexamethylenedithiosulfate dihydrate) manufactured by Flexsys, and KA9188 (1,6-bis(N,N'-dibenzylthiocarbamoyldithio)hexane) manufactured by Lanxess, as well as organic peroxides such as dicumyl peroxide.

[0106] The rubber composition for an inner liner preferably contains a vulcanization accelerator. The content of the vulcanization accelerator is, for example, more than 0.3 parts by mass and less than 10.0 parts by mass per 100 parts by mass of the rubber component.

[0107] Examples of the vulcanization accelerator include thiazole-based vulcanization accelerators such as 2-mercaptobenzothiazole, di-2-benzothiazolyl disulfide, and N-cyclohexyl-2-benzothiazyl sulfenamide; thiuram-based vulcanization accelerators such as tetramethylthiuram disulfide (TMTD), tetrabenzylthiuram disulfide (TBzTD), and tetrakis(2-ethylhexyl)thiuram disulfide (TOT-N); sulfenamide-based vulcanization accelerators such as N-cyclohexyl-2-benzothiazole sulfenamide, Nt-butyl-2-benzothiazolyl sulfenamide, N-oxyethylene-2-benzothiazole sulfenamide, N-oxyethylene-2-benzothiazole sulfenamide, and N,N'-diisopropyl-2-benzothiazole sulfenamide; and guanidine-based vulcanization accelerators such as diphenyl guanidine, di-orthotolyl guanidine, and orthotolyl biguanidine. These may be used alone or in combination of two or more.

[0108] (2) Preparation of inner liner The rubber composition for an inner liner is produced by a general method, for example, a manufacturing method including a base kneading step of kneading a rubber component with a filler such as carbon black, and a finish kneading step of kneading the kneaded product obtained in the base kneading step with a crosslinking agent.

[0109] The kneading can be carried out using a known (internal) kneading machine such as a Banbury mixer, a kneader, or an open roll.

[0110] The kneading temperature in the base kneading step is, for example, higher than 50° C. and lower than 200° C., and the kneading time is, for example, higher than 30 seconds and lower than 30 minutes. In the base kneading step, in addition to the above components, compounding agents conventionally used in the rubber industry, for example, softeners such as oil, stearic acid, antioxidants, waxes, vulcanization accelerators, etc., may be appropriately added and kneaded as needed.

[0111] In the final kneading step, the kneaded product obtained in the base kneading step is kneaded with a crosslinking agent. The kneading temperature in the final kneading step is, for example, higher than room temperature and lower than 80°C, and the kneading time is, for example, longer than 1 minute and shorter than 15 minutes. In the final kneading step, in addition to the above components, a vulcanization accelerator, zinc oxide, etc. may be appropriately added and kneaded as necessary.

[0112] At this time, the breaking elongation of the inner liner can be adjusted by, for example, adjusting the blending amount of filler such as carbon black, or adjusting the types and blending amounts of oil and resin components.

[0113] The obtained rubber composition for an inner liner is then molded into a predetermined shape to produce an inner liner.

[0114] 3.Sound damping body In this embodiment, the noise damper is constructed using a biomass-derived material, as described above. Among these, a preferred biomass-derived material is a polyurethane sponge whose main component is castor oil polyol. Castor oil-derived urethane sponge can increase hydrophobicity and make it difficult for the sponge to absorb moisture in the tire cavity, which is thought to improve the noise damping performance of the noise damper. Note that a noise damper made of a biomass-derived material can be formed using the following blends of materials.

[0115] (1) Compounding materials (a) Polyol component In this embodiment, the polyol component preferably contains 80 parts by mass or more of castor oil polyol per 100 parts by mass, which allows the biomass ratio of the sound damper to be 50% or more.

[0116] The castor oil polyols include modified castor oil polyols and unmodified castor oil polyols.

[0117] A specific example of the modified castor oil polyol is ester-modified castor oil polyol.

[0118] It is preferable that the amount of modified castor oil polyol in 100 parts by mass of castor oil polyol is 10 parts by mass or more and 65 parts by mass or less, with the remainder being unmodified castor oil polyol. If the proportion of modified castor oil polyol is too low, elongation and abrasion resistance will deteriorate, while if the proportion of castor oil polyol is too high, the resilience will be low.

[0119] Specific examples of unmodified castor oil polyols include refined castor oil polyols, semi-refined castor oil polyols, and unrefined castor oil polyols, with refined castor oil polyols being preferred among these.

[0120] In the above, the modified castor oil polyol preferably has a functionality of 2.0 to 3.5 and a hydroxyl value of 40 to 180 mgKOH / g, while the unmodified castor oil polyol preferably has a functionality of 2.7 and a hydroxyl value of 155 to 165 mgKOH / g.

[0121] Here, the "number of functional groups" refers to the number of functional groups per molecule, and means the average number of active hydrogen atoms in the initiator.

[0122] In addition, the "hydroxyl value" indicates the number of milligrams of potassium hydroxide required to acetylate the hydroxyl groups contained in 1 g of sample (solid content).The hydroxyl groups in the sample are acetylated using acetic anhydride, and the unused acetic acid is titrated with potassium hydroxide solution, and then the value can be calculated using the following formula. Hydroxyl value [mgKOH / g] = [((AB) × f × 28.05) / S] + acid value A: Amount (ml) of 0.5 mol / l potassium hydroxide ethanol solution used in the blank test B: Amount (ml) of 0.5 mol / l potassium hydroxide ethanol solution used in titration f: Factor S: Sample amount (g)

[0123] When the castor oil polyol accounts for less than 100% of the polyol component, the polyol contained together with the castor oil polyol may be, for example, a petroleum-derived polyol.

[0124] As the petroleum-derived polyol, one made of polyether polyol or one mainly made of polyether polyol is preferably used in order to make the flexible polyurethane foam less susceptible to hydrolysis, and polyether polyester polyols containing ester groups in part can also be used.

[0125] Examples of polyether polyols that can be used include those obtained by adding alkylene oxides such as ethylene oxide and propylene oxide to starting materials such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, hydroquinone, water, resorcinol, bisphenol A, hydrogenated bisphenol A, glycerin, trimethylolpropane, pentaerythritol, monoethanolamine, diethanolamine, triethanolamine, tripropanolamine, ethylenediamine, 1,6-hexanediamine, tolylenediamine, diphenylmethanediamine, triethylenetetraamine, sorbitol, mannitol, and dulcitol.

[0126] The petroleum-derived polyol preferably has a functionality of 2.0 to 3.0 and a hydroxyl value of 28.1 (mgKOH / g) or more and 56.1 (mgKOH / g) or less.

[0127] (b) Polyisocyanate In the present embodiment, the polyisocyanate is not particularly limited, and examples thereof include aromatic, alicyclic, and aliphatic polyisocyanates having two or more isocyanate groups; mixtures of two or more of the above polyisocyanates; and modified polyisocyanates obtained by modifying any of these, and these may be used alone or in combination.

[0128] Specific examples of polyisocyanates include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymethylene polyphenyl polyisocyanate (commonly known as crude MDI), xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), and hexamethylene diisocyanate (HMDI). Specific examples of modified polyisocyanates include prepolymer-type modified products, nurate-modified products, urea-modified products, and carbodiimide-modified products of the above-mentioned polyisocyanates. Among these, it is preferable to use MDI, crude MDI, or modified products thereof from the viewpoints of improved foaming stability, improved durability, and cost.

[0129] The isocyanate index is preferably 95 or more and 120 or less, more preferably 98 or more and 110 or less, and even more preferably 98 or more and 103 or less. If the isocyanate index is too small, a good foam cannot be produced. On the other hand, if the isocyanate index is too large, the internal heat generation temperature becomes too high and sufficient foaming cannot be achieved, resulting in the foam becoming too hard and brittle, resulting in reduced durability.

[0130] Here, the "isocyanate index" is the value obtained by dividing the number of moles of isocyanate groups in a polyisocyanate by the total number of moles of active hydrogen groups such as hydroxyl groups in a polyol and water as a blowing agent, and multiplying the result by 100, and can be calculated using the following formula. [NCO equivalent of polyisocyanate / active hydrogen equivalent x 100]

[0131] (c) Foaming agent In the present embodiment, examples of the foaming agent include water, hydrocarbons, halogen-based compounds, and the like, and two or more of these may be used in combination.

[0132] Examples of hydrocarbons include cyclopentane, isopentane, and normal pentane. Examples of halogen-based compounds include methylene chloride, trichlorofluoromethane, dichlorodifluoromethane, nonafluorobutyl methyl ether, nonafluorobutyl ethyl ether, pentafluoroethyl methyl ether, and heptafluoroisopropyl methyl ether. Among these, water is preferred from the viewpoint of reducing density. The water may be ion-exchanged water, tap water, distilled water, or the like. From the viewpoint of ensuring the stability of the urethane foam, the amount of water used as a blowing agent is preferably 1 part by mass or more and 5 parts by mass or less, more preferably 2.5 parts by mass or more and 3.5 parts by mass or less, and even more preferably 3.3 parts by mass or more and 3.5 parts by mass or less, per 100 parts by mass of polyol.

[0133] (d) Catalyst In the present embodiment, the catalyst is not particularly limited, and examples thereof include tertiary amines such as triethylenediamine, dimethylaminoethanol, bis(2-dimethylaminoethyl)ether, and N,N,N',N'-tetramethylhexamethylenediamine; metal carboxylates such as potassium acetate and potassium 2-ethylhexanoate; and organometallic compounds such as stannous octoate and dibutyltin dilaurate. The amount of catalyst added is determined appropriately depending on the type of catalyst, but is preferably 0.1 parts by mass or more and 5.0 parts by mass or less, more preferably 0.5 parts by mass or more and 2.5 parts by mass or less, and even more preferably 1.0 parts by mass or more and 1.5 parts by mass or less, per 100 parts by mass of the polyol component.

[0134] (e) Auxiliary Agents In the present embodiment, the polyurethane sponge composition may contain other auxiliary agents, such as a foam stabilizer, a crosslinking agent, a colorant, a flame retardant, an antibacterial agent, a stabilizer, and a plasticizer, as needed.

[0135] Known foam stabilizers can be used, including silicone-based foam stabilizers, fluorine-containing compound-based foam stabilizers, and surfactants. Of these, silicone-based foam stabilizers are preferred. Silicone-based foam stabilizers may consist solely of polyoxyalkylene-dimethylpolysiloxane copolymers, or may contain other co-combined components. Examples of other co-combined components include polyalkylmethylsiloxanes, glycols, and polyoxyalkylene compounds. Furthermore, compositions containing two or more selected from polyoxyalkylene-dimethylpolysiloxane copolymers, polyalkylmethylsiloxanes, and polyoxyalkylene compounds are also preferred as foam stabilizers.

[0136] Commercially available foam stabilizers include, for example, the following trade names manufactured by MOMENTIVE: L-580, L-590, L-620, L-680, L-682, L-690, SC-154, SC-155, SC-240, L-598, L-2100, L-2171, SH-210, L-2114, SE-232, L-533, L-534, L-539, M-6682B, L-626, L-627, and L-30. 01, L-3111, L-3415, L-3002, L-3010, L-3222, L-3416, L-3003, L-3333, L-3417, L-2171, L-3620, L-3630 , L-3640, L-3170, L-3360, L-3350, L-3555, L-3167, L-3150, L-3151, L-5309, SH-209, L-3184, etc. Other examples of commercially available products include those manufactured by DuPont Toray Specialty Materials under the trade names: SF-2964, SF-2962, SF-2969, SF-2971, SF-2902L, SF-2904, SF-2908, SF-2909, SRX-274C, SZ-1328, SZ-1329, SZ-1330, SZ-1336, SZ-1346, SZ-3601, SRX-294A, SRX-280A, SRX-294A, SRX-298, SH-190, SH-192, and SH-194. Other examples of commercially available products include trade names F-327, F-345, F-305, F-242T manufactured by Shin-Etsu Chemical Co., Ltd., and trade names Silbyk 9700, Silbyk 9705, Silbyk 9710 manufactured by BYK Chemie, as well as trade names B4113, B4900, B8002, B8110, B8123, B8228, B8232, B8715LF2, B8724LF2, BF2370, and BF2470 manufactured by EVONIC.

[0137] The amount of the foam stabilizer to be added is preferably 0.1 part by mass or more and 10 parts by mass or less, and more preferably 0.1 to 10 parts by mass, per 100 parts by mass of the polyol component.

[0138] Examples of the crosslinking agent include polyhydric alcohols such as ethylene glycol, diethylene glycol, glycerin, butanetetraol, and polyoxypropylene glycol, diethanolamine, and polyamines, which may be used alone or in combination of two or more.

[0139] Furthermore, fillers such as potassium carbonate and barium sulfate, surfactants such as emulsifiers, antioxidants such as antioxidants and ultraviolet absorbers, and other anti-aging agents may be added.

[0140] (2) Making a sound-damping body The above-mentioned ingredients are mixed and stirred to react the polyol component with the polyisocyanate, and foamed to obtain a polyurethane sponge, which can be cut to a predetermined size to produce a sound-damping body.

[0141] In this case, the shape of the noise damper is not particularly limited, but is preferably a long strip extending in the tire circumferential direction along the tire cavity surface, and is preferably manufactured so as to have substantially the same cross-sectional shape at each position in the tire circumferential direction. In order to prevent collapse or deformation during running, the cross-sectional shape is preferably formed into a flat, horizontally elongated shape in which the height in the tire radial direction is smaller than the width in the tire axial direction, and it is particularly preferable that a recessed groove extending continuously in the circumferential direction is arranged on the radially inner side of the noise damper.

[0142] Such noise dampers have air bubbles (cells) on their surface and inside that convert the vibration energy of the air vibrating inside the tire cavity into thermal energy and consume it, thereby reducing cavity resonance energy and reducing road noise.

[0143] In this embodiment, the number of cells in the sound damper is preferably 10 cells / 25 mm or more, more preferably 15 cells / 25 mm or more, and even more preferably 20 cells / 25 mm or more. The upper limit is preferably 100 cells / 25 mm or less, more preferably 80 cells / 25 mm or less, and even more preferably 50 cells / 25 mm or less. Here, the number of cells is a value measured in accordance with Annex 1 of JIS K6400-1:2004.

[0144] 4. Use of sustainable materials in tire components other than noise dampers In the tire according to the present embodiment, a predetermined rubber composition is used for each of the tire components other than the noise damper described above, but in consideration of the strong demand for environmental protection in recent years, it is preferable to use sustainable materials as the material for constituting this rubber composition.

[0145] (1) Rubber materials For example, instead of using petroleum-derived raw materials (monomers) for synthetic rubbers such as SBR and BR, it is possible to use those recycled from rubber products such as tires or non-rubber products such as polystyrene.

[0146] Monomers obtained by recycling (recycled monomers) are not particularly limited, and examples thereof include recycled butadiene and recycled aromatic vinyl. Examples of butadienes include 1,2-butadiene and 1,3-butadiene, and examples of aromatic vinyls include, but are not particularly limited to, styrene. Among these, it is preferable to use recycled butadiene (recycled butadiene) and / or recycled styrene (recycled styrene) as raw materials.

[0147] The method for producing the recycled monomer is not particularly limited, and examples thereof include synthesis from recycled naphtha obtained by decomposing rubber products such as tires. The method for producing recycled naphtha is also not particularly limited, and examples thereof include decomposing rubber products such as tires under high temperature and pressure, decomposing with microwaves, or mechanically crushing and then extracting.

[0148] Furthermore, the raw materials (monomers) of synthetic rubbers such as SBR and BR may be derived from biomass. Examples of biomass-derived monomers (biomass monomers) include, but are not limited to, biomass-derived butadiene and biomass-derived aromatic vinyl. Examples of butadienes include 1,2-butadiene and 1,3-butadiene. Examples of aromatic vinyl include, but are not limited to, styrene. Furthermore, methods for producing biomass monomers are also not limited, including, for example, biological and / or chemical and / or physical conversion of animals and plants. A typical example of biological conversion is fermentation using microorganisms, while examples of chemical and / or physical conversion include catalytic, high-temperature, high-pressure, electromagnetic, critical fluid, and combinations thereof. Biomass sources for these monomers include sugar, wood, plant residues after useful components have been extracted, plant-derived ethanol, and biomass naphtha.

[0149] The polymer synthesized from a biomass monomer component (biomass polymer) is not particularly limited, and examples thereof include polybutadiene rubber synthesized from biomass-derived butadiene, and aromatic vinyl / butadiene copolymer 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.

[0150] Whether or not the raw material of a polymer is derived from biomass can be determined by pMC (percent modern carbon) measured in accordance with ASTM D6866-10.

[0151] pMC is the modern standard reference 14 of sample against C concentration 14 This is the ratio of the carbon concentration, and this value is used as an index showing the biomass ratio of the compound (rubber). The significance of this value is explained below.

[0152] 1 mole of carbon atoms (6.02 × 10 23 ) contains approximately 6.02 × 10 atoms, which is about one trillionth of the number of ordinary carbon atoms. 11 pieces 14 C exists. 14 C is called a radioactive isotope, and its half-life is 5,730 years, and it decreases regularly. It takes 226,000 years for all of it to decay. Therefore, in fossil fuels such as coal, oil, and natural gas, which are thought to have been absorbed and fixed by plants and other organisms more than 226,000 years ago, C was also included in these when it was first fixed. 14 All C elements have decayed. Therefore, in the 21st century, fossil fuels such as coal, oil, and natural gas contain 14 Therefore, chemicals produced from these fossil fuels do not contain any C element. 14 It does not contain any C elements.

[0153] on the other hand, 14 C is produced continuously by nuclear reactions in the atmosphere caused by cosmic rays, and this balances with the decrease due to radioactive decay. In the Earth's atmospheric environment, 14 Therefore, the amount of carbon derived from biomass resources currently circulating in the environment is constant. 14 As mentioned above, the C concentration is approximately 1 × 10 -12The value is approximately mol%. Therefore, by using the difference between these values, it is possible to calculate the ratio (biomass ratio) of compounds derived from natural resources (compounds derived from biomass resources) in a certain compound (rubber).

[0154] this 14 C is typically measured using accelerator mass spectrometry based on a tandem accelerator. 13 C concentration ( 13 C / 12 C). 14 C concentration ( 14 C / 12 C) is measured. 14 The modern standard reference for the C concentration is the carbon circulating in nature as of 1950. 14 The specific standard substance used is the oxalic acid standard provided by NIST (National Institute of Standards and Technology). The specific activity of carbon in this oxalic acid (per gram of carbon) is 14 The radioactivity of C) is separated into carbon isotopes, 13 The standard value is the value corrected for decay from 1950 to the measurement date. 14 This is used as the C concentration value (100%). The ratio of this value to the value of the actually measured sample is the pMC value.

[0155] Therefore, if rubber is made from 100% biomass (natural) derived materials, it will show a value of approximately 110 pMC, although there may be regional differences (currently, under normal conditions, it is often not 100). On the other hand, for chemical substances derived from petroleum and other fossil fuels, 14 When the carbon concentration is measured, it will be approximately 0 pMC (for example, 0.3 pMC), which corresponds to the biomass ratio of 0% mentioned above.

[0156] From the above, it is preferable in terms of environmental protection to use a material such as rubber having a high pMC value, that is, a material such as rubber having a high biomass ratio, in a rubber composition.

[0157] It is also preferable to use vulcanized rubber particles as the rubber material.

[0158] The vulcanized rubber particles are particles made of vulcanized rubber, and specifically, rubber powder as specified in JIS K 6316:2017 can be used. From the standpoint of environmental considerations and cost, recycled rubber powder produced from crushed waste tires is preferred. These may be used alone or in combination of two or more types.

[0159] The vulcanized rubber particles are not particularly limited, and may be unmodified vulcanized rubber particles or modified vulcanized rubber particles.

[0160] As commercially available vulcanized rubber particles, for example, products from Lehigh Corporation, Muraoka Rubber Industries Co., Ltd., etc. can be used.

[0161] (2) Silica Rubber compositions generally contain silica as a reinforcing filler, but it is also preferable to use sustainable silica instead of mineral-derived raw materials such as quartz.

[0162] The silica is not particularly limited, and can be, for example, silica prepared by a dry method (anhydrous silica), silica prepared by a wet method (hydrated silica), or other silica commonly used in the tire industry. The raw material for silica is not particularly limited, and can be, for example, a biologically derived raw material such as rice husk (for example, silica made from biomass materials such as rice husk), or silica recycled from silica-containing products. Among these, hydrated silica prepared by a wet method is preferred because it contains a large number of silanol groups. These silicas can be used alone or in combination of two or more types.

[0163] Silica made from biomass materials can be obtained, for example, by extracting silicate from rice husk ash obtained by burning rice husks using a sodium hydroxide solution, and then reacting the silicate with sulfuric acid in the same manner as conventional wet-process silica to produce a silicon dioxide precipitate, which is then filtered, washed with water, dried, and pulverized.

[0164] Silica recycled from silica-containing products can be, for example, silica recovered from products containing silica, such as electronic components such as semiconductors, tires, desiccants, and filtering materials such as diatomaceous earth. The recovery method is not particularly limited, and examples include thermal decomposition and decomposition by electromagnetic waves. Among these, silica recovered from electronic components such as semiconductors or tires is preferred.

[0165] When silica crystallizes, it becomes insoluble in water, and its component, silicic acid, cannot be utilized. By controlling the combustion temperature and duration, it is possible to suppress the crystallization of silica in rice husk ash (see, for example, JP 2009-2594 A and Akita Prefectural University Web Journal B / 2019, vol. 6, pp. 216-222).

[0166] Amorphous silica extracted from rice husks may be commercially available from Wilmar Co., Ltd., etc.

[0167] (3) Carbon black It is also common for rubber compositions to contain carbon black as a reinforcing filler, and it is also preferable to use sustainable carbon black as such carbon black.

[0168] Carbon black is not particularly limited, and examples thereof include N134, N110, N220, N234, N219, N339, N330, N326, N351, N550, and N762. The raw material for carbon black may be a biomass material such as lignin or vegetable oil, or pyrolysis oil obtained by pyrolysis of waste tires. Carbon black may be produced by combustion, such as in a furnace process, by hydrothermal carbonization (HTC), or by pyrolysis of methane, such as in a thermal black process. Commercially available carbon black products include those from Asahi Carbon Co., Ltd., Cabot Japan Co., Ltd., Tokai Carbon Co., Ltd., Mitsubishi Chemical Corporation, Lion Corporation, Nippon Steel Carbon Co., Ltd., and Columbia Carbon Co., Ltd. These carbon blacks may be used alone or in combination.

[0169] (4) Oil Examples of oils commonly used as softeners include process oil, vegetable oil, and animal oil. Examples of process oil include paraffinic process oil (mineral oil), naphthenic process oil, and aromatic process oil. Specific examples of process oil include mild extract solvated (MES), distillate aromatic extract (DAE), treated distillate aromatic extract (TDAE), treated residual aromatic extract (TRAE), and residual aromatic extract (RAE). Furthermore, as an environmental measure, process oil with a low content of polycyclic aromatic compounds (PCA) can also be used. Examples of such low-PCA process oil include MES, TDAE, and heavy naphthenic oil. Furthermore, from the perspective of life cycle assessment, refined waste oil from rubber mixers and engines, or waste cooking oil from restaurants, may also be used.

[0170] Specific examples of vegetable oils include 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, grapeseed oil, and Japan wax. Furthermore, examples of vegetable oils include refined oils (e.g., salad oils) obtained by refining the above-mentioned oils, interesterified oils obtained by interesterifying the above-mentioned oils, hardened oils obtained by hydrogenating the above-mentioned oils, thermally polymerized oils obtained by thermally polymerizing the above-mentioned oils, oxidatively polymerized oils obtained by oxidizing the above-mentioned oils, and sustainable vegetable oils such as recovered waste edible oils. Vegetable oils may be liquid or solid at room temperature (25°C). These vegetable oils may be used alone or in combination of two or more.

[0171] The vegetable oil preferably contains acylglycerol, and more preferably triacylglycerol. Here, acylglycerol refers to a compound in which a hydroxyl group of glycerin is ester-bonded to a fatty acid. The acylglycerol is not particularly limited, and may be 1-monoacylglycerol, 2-monoacylglycerol, 1,2-diacylglycerol, 1,3-diacylglycerol, or triacylglycerol. Furthermore, the acylglycerol may be a monomer, a dimer, or a polymer (trimer or higher). Dimer or higher acylglycerols can be obtained by thermal polymerization, oxidative polymerization, or the like. Furthermore, the acylglycerol may be liquid or solid at room temperature (25°C).

[0172] The method for confirming whether or not the rubber composition contains the acylglycerol is not particularly limited, but may be any of the following: 1 For example, a rubber composition containing triacylglycerol is immersed in deuterated chloroform at room temperature (25°C) for 24 hours, and after removing the rubber composition, the rubber composition is immersed in deuterated chloroform at room temperature. 1When H-NMR was measured, signals were observed around 5.26 ppm, 4.28 ppm, and 4.15 ppm when the signal of tetramethylsilane (TMS) was set at 0.00 ppm. These signals are presumed to be signals derived from hydrogen atoms bonded to carbon atoms adjacent to the oxygen atoms of the ester group. In this paragraph, "around" refers to a range of ±0.10 ppm.

[0173] The fatty acid is not particularly limited and may be either an unsaturated fatty acid or a saturated fatty acid. Examples of unsaturated fatty acids include monounsaturated fatty acids such as oleic acid, and polyunsaturated fatty acids such as linoleic acid and linolenic acid. Examples of saturated fatty acids include butyric acid and lauric acid.

[0174] Among these, it is desirable that the fatty acid contains a fatty acid with few double bonds, i.e., a saturated fatty acid or a monounsaturated fatty acid, and oleic acid is preferred. As a vegetable oil containing such a fatty acid, for example, vegetable oil containing a saturated fatty acid or a monounsaturated fatty acid may be used, or vegetable oil modified by ester exchange or the like may be used. Furthermore, in order to produce vegetable oil containing such a fatty acid, plants may be improved by breeding, genetic modification, genome editing, or the like.

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

[0176] (5) Softeners other than oil In addition to the oils described above, the rubber composition may also contain softeners that are liquid (liquid state) at room temperature (25°C) or solid at room temperature (25°C) as softeners that impart plasticity to the rubber component. Examples of such softeners include resin components, liquid polymers, and ester-based plasticizers. These softeners may be derived from petroleum, biomass, or naphtha recycled from rubber or non-rubber products (sustainable softeners). Low-molecular-weight hydrocarbon components obtained by pyrolysis and extraction of used tires or products containing various components may also be used as softeners. These softeners may be used alone or in combination.

[0177] (6) Wax Rubber compositions generally contain wax, but the wax is not particularly limited, and any wax commonly used in the tire industry can be suitably used. Examples include petroleum-based waxes, mineral-based waxes, synthetic waxes, and plant-derived waxes. Of these, petroleum-based waxes and plant-derived waxes are preferred, with petroleum-based waxes being more preferred. Examples of plant-derived waxes include rice wax, carnauba wax, and candelilla wax. Examples of petroleum-based waxes include paraffin wax, microcrystalline wax, and selected special waxes thereof, with paraffin wax being preferred. Waxes that can be used include those commercially available from, for example, Ouchi Shinko Chemical Industry Co., Ltd., Nippon Seiro Co., Ltd., and Paramelt Co., Ltd. These waxes may be used alone or in combination of two or more.

[0178] (7) Antiaging agents Rubber compositions generally contain antioxidants. The antioxidants are not particularly limited, and examples thereof include naphthylamine-based antioxidants such as phenyl-α-naphthylamine; diphenylamine-based antioxidants such as octylated diphenylamine and 4,4'-bis(α,α'-dimethylbenzyl)diphenylamine; N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD), N,N'-bis(1,4-dimethylpentyl)-p-phenylenediamine (77PD), N,N'-diphenyl-p-phenylenediamine (DP ... Examples of antiaging agents include p-phenylenediamine-based antioxidants such as tolyl-p-phenylenediamine (DTPD), N-isopropyl-N'-phenyl-p-phenylenediamine (IPPD), and N,N'-di-2-naphthyl-p-phenylenediamine (DNPD); quinoline-based antioxidants such as 2,2,4-trimethyl-1,2-dihydroquinoline polymers; monophenol-based antioxidants such as 2,6-di-t-butyl-4-methylphenol and styrenated phenol; and bis-, tris-, and polyphenol-based antioxidants such as tetrakis-[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane. Among these, p-phenylenediamine-based antioxidants and quinoline-based antioxidants are preferred, and polymers of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine and 2,2,4-trimethyl-1,2-dihydroquinoline are more preferred. Commercially available products that can be used include those from Seiko Chemical Co., Ltd., Sumitomo Chemical Co., Ltd., Ouchi Shinko Chemical Industry Co., Ltd., Flexis, etc.

[0179] In the rubber composition, various materials containing carbon atoms (for example, rubber, oil, resin, vulcanization accelerator, antioxidant, surfactant, etc.) may be derived from carbon dioxide in the atmosphere. The compound of the present invention can be obtained from carbon dioxide by directly converting carbon dioxide, or by converting methane obtained through a methanation process in which methane is synthesized from carbon dioxide.

[0180] 5. Tire manufacturing (1) Manufacturing of tire bodies The tire body can be manufactured by a conventional method. First, tire components such as an inner liner, a tread, and a sidewall are manufactured. Then, these components are combined with other rubber components in a tire building machine to manufacture an unvulcanized tire.

[0181] Specifically, an inner liner as a component for ensuring the airtightness of the tire, a carcass portion as a component for withstanding the load, impact, and inflation pressure to which the tire is subjected, and a belt as a component for tightly fastening the carcass portion to increase the rigidity of the tread portion are wound around a forming drum, and both ends of the carcass ply are fixed to both side edges, and bead portions as components for fixing the tire to the rim are arranged. After forming into a toroidal shape, a tread is attached to the center of the outer periphery and a sidewall is attached to the radially outer side to form the side portion, thereby producing an unvulcanized tire.

[0182] The unvulcanized tire thus prepared is then heated and pressurized in a vulcanizer to obtain a tire. The vulcanization process can be carried out by using a known vulcanization method. The vulcanization temperature is, for example, greater than 120°C and less than 200°C, and the vulcanization time is, for example, greater than 5 minutes and less than 15 minutes.

[0183] (2) Installation of sound dampers Next, a noise damper is attached to the inner cavity side of the vulcanized tire.

[0184] Specifically, for example, an adhesive and / or double-sided adhesive tape is used to fix a long strip-shaped noise damper so that it extends in the tire circumferential direction along the tire cavity surface. At this time, the outer ends in the circumferential direction may be butted against each other to form a substantially annular shape, or the outer ends may be spaced apart in the circumferential direction.

[0185] As the adhesive, it is preferable to use a liquid adhesive of synthetic rubber, such as a solution type in which synthetic rubber is dissolved in an organic solvent, or a latex type in which synthetic rubber is dispersed in water.

[0186] Various types of double-sided adhesive tapes can be used, such as those in which adhesive layers are formed on both sides of a sheet-like substrate such as woven fabric, or those formed only with adhesive layers without a substrate.

[0187] Although not particularly limited, the double-sided pressure-sensitive adhesive tape preferably has a tensile strength of, for example, 5 (N / 10 mm) or more and less than 10 (N / 10 mm). Here, the tensile strength of the double-sided pressure-sensitive adhesive tape is a value measured in accordance with JIS Z0237 "Testing method for tensile strength of pressure-sensitive adhesive tape."

[0188] As mentioned above, the tire after the noise damper is attached can appropriately achieve both improved peel resistance of the noise damper by appropriately setting the absolute value of the difference between the breaking elongation EBi (%) of the inner liner and the breaking elongation EBs (%) of the noise damper, and improved noise reduction performance due to the noise damper being made from biomass-derived materials, and can also reduce the environmental impact.

[0189] The tire according to the present invention can be suitably used as a tire for passenger cars, a tire for large passenger cars, a tire for large SUVs, a tire for small trucks, and the like. [Example]

[0190] Examples (embodiments) that are considered preferable for carrying out the present invention will be shown below, but the scope of the present invention is not limited to these examples.

[0191] For each tire (tire size: 165 / 65R18) manufactured with the configuration shown in Figure 1, with substantially the same specifications except for the inner liner shown in Table 1 and the noise damper shown in Table 2, the overall performance of the noise damper's peeling resistance and noise reduction performance, as well as these overall performances, were evaluated. The evaluation results are also shown in Table 3.

[0192] [1] Preparation of test tires 1. Manufacturing of inner liners (1) Production of rubber composition for innerliner First, a rubber composition for an inner liner is produced using the various compounding materials shown below.

[0193] (a) Compound materials (a-1) Rubber component (a) NR:TSR20 (b) Chlorinated butyl rubber: CHLOROBUTYL 1066 manufactured by Japan Butyl Co., Ltd. (c) Brominated butyl rubber: BROMOBUTYL 2255 manufactured by Japan Butyl Co., Ltd.

[0194] (a-2) Compounding materials other than rubber components (a) Carbon black: Show Black N660 manufactured by Cabot Japan (N2SA:35m 2 / g) (b) Fatty acid compound (processing aid): WB16 manufactured by Struktol (Mixture of saturated fatty acid calcium salts with 14 to 20 carbon atoms and fatty acid amides) (c) Hydrocarbon resin: Petrotack 100V manufactured by Tosoh Corporation (C5C9 petroleum resin) (d) Compatibilizer: 40MS manufactured by Struktol (Ethylene propylene styrene copolymer resin, softening point 78°C) (E) Oil: ENEOS Process X-260 (f) Zinc oxide: Two types of zinc oxide manufactured by Mitsui Mining & Smelting Co., Ltd. (g) Anti-aging agent: Nocrac 6C manufactured by Ouchi Shinko Chemical Industry Co., Ltd. (N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine) (H) Stearic acid: Tsubaki manufactured by NOF Corporation (i) Sulfur: HK-200-5 (containing 5% oil by mass), manufactured by Hosoi Chemical Industry Co., Ltd. (J) Vulcanization accelerator 1: Noccela MP (M) manufactured by Ouchi Shinko Chemical Industry Co., Ltd. (2-mercaptobenzothiazole) (k) Vulcanization accelerator-2: Noccela DM manufactured by Ouchi Shinko Chemical Industry Co., Ltd. (Di-2-benzothiazolyl disulfide)

[0195] (b) Production of rubber composition for inner liner According to the formulations shown in Table 1, materials other than zinc oxide, sulfur, and vulcanization accelerator are kneaded for 5 minutes at 150°C using a Banbury mixer to obtain a kneaded mixture. The amounts of each ingredient are in parts by mass.

[0196] Next, zinc oxide, sulfur and a vulcanization accelerator are added to the obtained kneaded mixture, and the mixture is kneaded for 5 minutes at 80°C using an open roll to obtain rubber compositions for inner liners IL-I to IL-3.

[0197] [Table 1]

[0198] Table 1 also lists the elongation at break EBi (%) obtained by a tensile test (No. 7 dumbbell-shaped test piece, 23°C atmosphere, tensile speed 200 mm / min) in accordance with JIS K6251:2017 for each inner liner cut out from the tire after vulcanization molding.

[0199] 2. Tire body manufacturing (1) Molding the inner liner Each of the inner liner rubber compositions obtained above is molded into a predetermined shape to obtain inner liners IL-I to IL-3.

[0200] (2) Manufacturing of other tire components In parallel, each tire component other than the inner liner, such as the carcass, tread, and sidewall, is obtained using a known method.

[0201] (3) Manufacturing of tire bodies Each of the inner liners obtained above and other tire components are laminated together to form an unvulcanized tire, which is then press-vulcanized at 170° C. for 10 minutes to produce each tire body.

[0202] 3. Manufacturing of sound dampers Separately, noise dampers are manufactured using the various compounded materials shown below.

[0203] (1) Compounding materials (a) Polyol component (A-1) Castor oil-1: H-30 undenatured (refined), 100% biomass, manufactured by Ito Oil Mills (functionality 2.7, hydroxyl value 160mgKOH / g, molecular weight 947) (A-2) Castor oil-2: ELA-DR manufactured by Toyokuni Oil Mills, undenatured (refined), 100% biomass (functionality 2.7, hydroxyl value 160mgKOH / g, molecular weight 947) (A-3) Castor oil-3: A castor oil polyol with a 100% biomass content consisting of modified, refined castor oil / sebacic acid = 2 / 1 mole (functionality 3.5, hydroxyl value 86mgKOH / g, molecular weight 2182) (A-4) Castor oil-4: A 100% biomass castor oil polyol consisting of modified, refined castor oil and 1,2-hydroxystearic acid at a 1 / 5 mole ratio. (functionality 2.2, hydroxyl value 50mgKOH / g, molecular weight 2468) (A-5) Petroleum-derived: GP-3050NS polyether polyol manufactured by Sanyo Chemical Industries, Ltd. (functional groups: 3, hydroxyl value: 56.1 mg KOH / g, molecular weight: 3000)

[0204] (b) Isocyanate: Coronate T-80 manufactured by Tosoh Corporation (2,4-TDI / 2,6-TDI=80 / 20 toluene diisocyanate) (H-1) Catalyst 1: DABCO NE-300 manufactured by Evonik Japan Co., Ltd. (Aliphatic amine composition) (H-2) Catalyst-2: DABCO 33LSI manufactured by Evonik Japan Co., Ltd. (Aliphatic tertiary amine composition) (H-3) Catalyst-3: MRH-110 manufactured by Johoku Chemical Industry Co., Ltd. (Stannus octoate) (d) Foam stabilizer: SZ1136 manufactured by DuPont Toray Specialty Materials Co., Ltd. (Silicone-based) (e) Foaming agent: Water

[0205] (b) Manufacturing of sound deadeners A polyurethane sponge is manufactured according to the formulation shown in Table 2. The amounts of each formulation are in parts by mass.

[0206] [Table 2]

[0207] Table 2 shows the density (kg / m) of each polyurethane sponge. 3 ), biomass content (%), and the breaking elongation EBs (%) obtained by a tensile test in accordance with JIS K6400-5 (using a No. 1 dumbbell-shaped test piece in an atmosphere of 23°C and at a tensile speed of 500 mm / min) of each polyurethane sponge cut out from a vulcanized tire are also shown.

[0208] (2) Forming of sound damping body The polyurethane sponges obtained above are molded into predetermined shapes to obtain noise dampers SDM-1 to SDM-3.

[0209] 4. Manufacturing of test tires The noise damper obtained above was fixed to the tread region of the inner cavity surface of each tire body using an adhesive (Loctite 5970 manufactured by Henkel) so as to extend in the tire circumferential direction, to produce test tires for Examples 1 to 5 and Comparative Examples 1 to 5. The combinations of inner liners and noise dampers were as shown in Table 3, and the ratio (V1 / V2) (%) of the volume V1 of the noise damper to the volume V2 of the tire inner cavity was determined for each test tire.

[0210] 5.Performance Evaluation As described above, the performance evaluation is carried out on the peeling resistance and noise reduction performance of the sound damper, as well as on the overall performance of these.

[0211] (1) Peeling resistance of sound-damping body Each test tire is mounted on a standard rim and inflated to the standard internal pressure. Then, each test tire is mounted on all wheels of a vehicle and punctured by running a nail over each tire. The damaged area is then dismantled and the area of ​​the sound-damping material that has been pulled by the nail and peeled off from the tire cavity surface is measured.

[0212] Next, the result of Comparative Example 1 was set to 100, and the results were indexed according to the following formula to evaluate peel resistance. The larger the value, the smaller the peeled area and the better the peel resistance. Peel resistance evaluation = [(Result of Comparative Example 1) / (Result of test tire)] × 100

[0213] (2) Quiet performance of the sound damper Each test tire was mounted on a standard rim and inflated to the standard internal pressure. Then, each test tire was mounted on all wheels of a vehicle, and the vehicle was driven on a road noise measurement course (rough asphalt road) at a speed of 60 km / h. Then, 20 test drivers each performed a sensory evaluation of the noise (driving noise) during driving on a scale of 1 to 5 (the higher the number, the louder the noise), and the total score was calculated.

[0214] Next, the result of Comparative Example 1 was set to 100, and the result was indexed based on the following formula to evaluate noise reduction performance. The larger the value, the smaller the running noise and the better the noise reduction performance. Quietness performance evaluation = [(Result of Comparative Example 1) / (Result of test tire)] × 100

[0215] (3) Overall evaluation The total evaluation result for the above two items will be used to determine the overall evaluation.

[0216] [Table 3]

[0217] Although the present invention has been described above based on the embodiments, the present invention is not limited to the above-described embodiments. Various modifications can be made to the above-described embodiments within the scope of the same or equivalent to the present invention.

[0218] The present invention (1) is a carcass extending across a pair of bead portions; an inner liner disposed radially inward of the carcass to form a tire cavity surface; a sound-damping body formed using a biomass-derived material and fixed to the tire cavity side of the inner liner, The tire is characterized in that the absolute value K(|EBi-EBs|) of the difference between the breaking elongation EBi (%) of the inner liner and the breaking elongation EBs (%) of the noise damper is less than 480.

[0219] The present invention (2) is The tire according to the present invention (1) is characterized in that the K is less than 460.

[0220] The present invention (3) is The tire according to the present invention (2) is characterized in that the K is less than 440.

[0221] The present invention (4) is The density of the sound damper is 30 kg / m 3 A tire characterized by the following and any combination with any of the present inventions (1) to (3).

[0222] The present invention (5) is The volume of the noise damper is 0.4% or more and 30% or less of the total volume of the tire cavity, and the tire is an optional combination with any of the present inventions (1) to (4).

[0223] The present invention (6) is The tire is characterized in that the noise damper is made of a porous material, and is an optional combination with any of the present inventions (1) to (5).

[0224] The present invention (7) is The tire according to the present invention (6) is characterized in that the noise damper is a polyurethane sponge formed using castor oil polyol as the biomass-derived material.

[0225] The present invention (8) is The tire according to the present invention (7) is characterized in that the biomass content of the polyurethane sponge is 50% or more.

[0226] The present invention (9) is The tire is characterized in that the inner liner is formed from a rubber composition containing 70 parts by mass or more of a butyl-based rubber per 100 parts by mass of the rubber component, and is an optional combination with any of present inventions (1) to (8).

[0227] The present invention (10) is This tire is characterized in that a biomass-derived rubber material is used as the rubber material of the rubber composition constituting the tire components, and is an optional combination with any of the present inventions (1) to (9).

[0228] The present invention (11) is This tire is characterized in that vulcanized rubber particles are used as the rubber material of the rubber composition that constitutes the tire components, and is an optional combination with any of the present inventions (1) to (10).

[0229] The present invention (12) is A tire characterized in that sustainable silica is used as a reinforcing filler in a rubber composition constituting a tire component, and is an optional combination with any of the present inventions (1) to (11).

[0230] The present invention (13) is A tire characterized in that sustainable carbon black is used as a reinforcing filler in a rubber composition constituting a tire component, and is an optional combination with any of present inventions (1) to (12).

[0231] The present invention (14) is A tire characterized in that sustainable vegetable oil is used as the oil in the rubber composition constituting the tire components, and is an optional combination with any of the present inventions (1) to (13).

[0232] The present invention (15) is A tire characterized in that a sustainable softener is used as a softener for the rubber composition constituting the tire components, and is an optional combination with any of the present inventions (1) to (14). [Explanation of symbols]

[0233] 1 tire 2 Tire body 2a Tread section 2b Sidewall 2c Bead part 2d bead core 2e Carcass 2F Inner Liner 2g belt 2i Tire cavity surface 2ti Tread area of ​​tire cavity 3 Sound damping body C(CL) Center Line

Claims

1. a carcass extending across a pair of bead portions; an inner liner disposed radially inward of the carcass to form a tire cavity surface; a sound-damping body formed using a biomass-derived material and fixed to the tire cavity side of the inner liner, The tire is characterized in that the absolute value K (|EBi-EBs|) of the difference between the breaking elongation EBi (%) of the inner liner and the breaking elongation EBs (%) of the noise damper is less than 480.

2. 2. The tire of claim 1, wherein K is less than 460.

3. 3. The tire of claim 2, wherein K is less than 440.

4. The density of the noise damper is 30 kg / m ３ 4. The tire according to claim 1, wherein:

5. 4. The tire according to claim 1, wherein the volume of the noise damper is 0.4% or more and 30% or less of the total volume of the tire cavity.

6. 4. The tire according to claim 1, wherein the noise damper is made of a porous material.

7. 7. The tire according to claim 6, wherein the sound-damping body is a polyurethane sponge formed using castor oil polyol as the biomass-derived material.

8. 8. The tire according to claim 7, wherein the polyurethane sponge has a biomass content of 50% or more.

9. 4. The tire according to claim 1, wherein the inner liner is formed from a rubber composition containing 70 parts by mass or more of a butyl rubber per 100 parts by mass of a rubber component.

10. 4. The tire according to claim 1, wherein a rubber material derived from biomass is used as a rubber material for the rubber composition constituting the tire components.

11. 4. The tire according to claim 1, wherein vulcanized rubber particles are used as a rubber material of a rubber composition constituting tire components.

12. 4. The tire according to claim 1, wherein sustainable silica is used as a reinforcing filler in a rubber composition constituting tire components.

13. 4. The tire according to claim 1, wherein sustainable carbon black is used as a reinforcing filler for a rubber composition constituting tire components.

14. The tire according to any one of claims 1 to 3, wherein sustainable vegetable oil is used as oil in the rubber composition constituting the tire components.

15. 4. The tire according to claim 1, wherein a sustainable softener is used as a softener for a rubber composition constituting tire components.

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