Cap tread and passenger car tire

Abstract

To provide a cap tread and a passenger car tire capable of improving overall performance of fuel economy and fracture strength while having good dimensional stability.SOLUTION: There is provided a cap tread of a passenger car tire having a rubber composition A phase and a rubber composition B phase which each independently have a boundary, wherein the rubber composition A phase contains 100 pts.mass or more of silica and 10 pts.mass or less of carbon black based on 100 pts.mass of a rubber component and the rubber composition B phase contains 10 pts.mass or more of carbon black and 13 to 20 pts.mass of silica based on 100 pts.mass of a rubber component and the rubber composition B phase is divided into the rubber composition A phase and independently exists in the rubber composition A phase.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a cap tread and a passenger car tire.

Background Art

[0002] With the problems of the environment and resource depletion, various efforts have been made to reduce the use of petroleum resources. For example, a technique using silica is known (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, as a result of the inventors' studies, it has become clear that there is still room for improvement in providing a rubber composition for tires that has good dimensional stability while improving the overall performance of low fuel consumption and fracture strength. An object of the present invention is to solve the above problems and provide a cap tread and a passenger car tire that have good dimensional stability while improving the overall performance of low fuel consumption and fracture strength.

Means for Solving the Problems

[0005] The present invention has a rubber composition A phase and a rubber composition B phase that have boundaries independently of each other. In the rubber composition A phase, 100 parts by mass or more of silica and 10 parts by mass or less of carbon black are contained with respect to 100 parts by mass of the rubber component. In the rubber composition B phase, 10 parts by mass or more of carbon black and 13 to 20 parts by mass of silica are contained with respect to 100 parts by mass of the rubber component. The present invention relates to a cap tread of a passenger car tire in which a rubber composition B phase is divided into a rubber composition A phase and exists independently in the rubber composition A phase.

[0006] It is preferable that the volume average particle diameter of the rubber composition B phase is 1000 μm or less.

[0007] In the rubber composition A phase, it is preferable that the content of the unit derived from isoprene is 50% by mass or more based on 100% by mass of the units of all rubber components.

[0008] In the rubber composition A phase, it is preferable that the content of the unit derived from isoprene is 1 to 10% by mass based on 100% by mass of the units of all rubber components.

[0009] It is preferable that the content of the rubber composition A phase is 40 to 99% by mass based on 100% by mass of the cap tread rubber.

[0010] In the rubber composition A phase, it is preferable that the rubber component contains a unit derived from at least one biomass-derived component selected from the group consisting of butadiene, aromatic vinyl, and ethylene.

[0011] In the rubber composition A phase, it is preferable to contain 50 parts by mass or more of resin with respect to 100 parts by mass of the rubber component.

[0012] It is preferable that the resin is at least one selected from the group consisting of terpene resins and rosin resins.

[0013] It is preferable that the resin is at least one selected from the group consisting of cyclopentadiene resins, C5 resins, C5 / C9 resins, and C9 resins.

[0014] It is preferable that the resin is an aromatic resin.

[0015] It is preferable that the resin is modified with a polar functional group that interacts with silica.

[0016] In the rubber composition A phase, it is preferable to contain silica derived from rice husk.

[0017] In the rubber composition B phase, it is preferable that the content of units derived from isoprene is 50% by mass or more in 100% by mass of the units of all rubber components.

[0018] In the rubber composition B phase, it is preferable to contain 1 to 40% by mass of butadiene rubber having a cis content of 90% by mass or more in 100% by mass of the rubber components.

[0019] It is preferable that the rubber composition B phase is rubber powder.

[0020] The present invention also relates to a passenger car tire having the above-mentioned cap tread.

Effects of the Invention

[0021] The present invention has a rubber composition A phase and a rubber composition B phase having boundaries independent of each other. In the rubber composition A phase, 100 parts by mass or more of silica and 10 parts by mass or less of carbon black are contained with respect to 100 parts by mass of the rubber component. In the rubber composition B phase, 10 parts by mass or more of carbon black and 13 to 20 parts by mass of silica are contained with respect to 100 parts by mass of the rubber component. Since the rubber composition B phase is divided into the rubber composition A phase and exists independently in the rubber composition A phase, it is a cap tread of a passenger car tire, so that while having good dimensional stability, it is possible to improve the overall performance of low fuel consumption and fracture strength.

Brief Description of the Drawings

[0022]

Figure 1

Modes for Carrying Out the Invention

[0023] The cap tread of the passenger car tire of the present invention has a rubber composition A phase and a rubber composition B phase having boundaries independent of each other. In the rubber composition A phase, 100 parts by mass or more of silica and 10 parts by mass or less of carbon black are contained with respect to 100 parts by mass of the rubber component. In the rubber composition B phase, 10 parts by mass or more of carbon black and 13 to 20 parts by mass of silica are contained with respect to 100 parts by mass of the rubber component. The rubber composition B phase is divided into the rubber composition A phase and exists independently in the rubber composition A phase. Thereby, while having good dimensional stability, the overall performance of low fuel consumption and fracture strength can be improved.

[0024] The reason why the above-described effects are obtained with the cap tread is presumed as follows. The cap tread has a rubber composition A phase and a rubber composition B phase having boundaries independent of each other, and the rubber composition B phase is divided into the rubber composition A phase and exists independently in the rubber composition A phase. That is, by the independent existence of the rubber composition B phase (for example, rubber powder) with a specific formulation in the rubber composition A phase having a high silica content, specifically, by the dispersion of the rubber composition B phase (for example, rubber powder) with a specific formulation in the rubber composition A phase having a high silica content, while having good dimensional stability, the overall performance of low fuel consumption and fracture strength (represented by the sum of two indices of low fuel consumption and fracture strength) can be synergistically improved. Although the details are not clear, since the conditions for the occurrence of fracture in the A phase and the B phase are different, even if a crack occurs in one phase, the crack propagation stops at the interface with the other phase, or since the viscoelastic properties of both phases are greatly different, it is presumed that a synergistic effect occurs because the vibration received from external stimuli does not spread throughout the rubber component.

[0025] In this specification, when the cap tread rubber has a rubber composition A phase and a rubber composition B phase that have boundaries independently of each other, it means that in the cap tread rubber, the rubber composition A phase and the rubber composition B phase exist independently of each other and have boundaries in both phases. Specifically, the B phase with respect to the A phase exists as an incompatible and independent phase as a rubber component, or there is a form such that they are independently kneaded and do not mix, but it is not limited to this. In this specification, when the rubber composition B phase is divided into the rubber composition A phase and exists independently in the rubber composition A phase, it means that the rubber composition B phase exists as a foreign substance in the rubber composition A phase. Specifically, the A phase and the B phase are incompatible as rubber components or are independently kneaded and remain in a state where they do not mix with each other. As an example, there are cases where the rubber composition A phase is a continuous phase and the B phase is a dispersed phase, or a form where the separately kneaded B phase is kneaded again with the material constituting the A phase, but it is not limited to this.

[0026] (rubber component) In this specification, the rubber component is a component that contributes to crosslinking. Generally, it has a weight average molecular weight (Mw) of 10,000 or more.

[0027] The weight average molecular weight of the rubber component is preferably 50,000 or more, more preferably 150,000 or more, still more preferably 200,000 or more, and is preferably 2,000,000 or less, more preferably 1,500,000 or less, still more preferably 1,300,000 or less. When within the above range, the effect tends to be obtained more favorably.

[0028] In addition, in this specification, the weight average molecular weight (Mw) and the number average molecular weight (Mn) can be determined by standard polystyrene conversion based on the measured values by gel permeation chromatography (GPC) (GPC-8000 series manufactured by Tosoh Corporation, detector: differential refractometer, column: TSKGEL SUPERMULTIPORE HZ-M manufactured by Tosoh Corporation).

[0029] In the A phase of the rubber composition, the content of units derived from isoprene is preferably 40% by mass or more, more preferably 45% by mass or more, still more preferably 50% by mass or more, based on 100% by mass of the units of all rubber components. The upper limit is not particularly limited, but is preferably 90% by mass or less, more preferably 70% by mass or less. When within the above range, the effect tends to be obtained more favorably. In this case, in the A phase of the rubber composition, the content of units derived from butadiene is preferably 10% by mass or more, more preferably 15% by mass or more, and preferably 60% by mass or less, more preferably 55% by mass or less, still more preferably 50% by mass or less, based on 100% by mass of the units of all rubber components. When within the above range, the effect tends to be obtained more favorably.

[0030] In another aspect, in the A phase of the rubber composition, the content of units derived from isoprene is preferably 1 to 10% by mass, based on 100% by mass of the units of all rubber components. The lower limit is preferably 3% by mass or more, and the upper limit is preferably 7% by mass or less. When within the above range, the effect tends to be obtained more favorably. In this case, in the A phase of the rubber composition, the content of units derived from butadiene is preferably 85% by mass or more, more preferably 90% by mass or more, and the upper limit is preferably 99% by mass or less, more preferably 97% by mass or less, based on 100% by mass of the units of all rubber components. When within the above range, the effect tends to be obtained more favorably.

[0031] In this specification, "unit" means a structural unit of a polymer. "Unit derived from butadiene" means a structural unit in a polymer composed based on the monomer butadiene, and "unit derived from isoprene" means a structural unit (including isoprene units in natural rubber) in a polymer composed based on the monomer isoprene. In addition, in this specification, the content of each unit is measured by NMR.

[0032] In the rubber composition A phase, in order to make the content of the unit within the above range, for example, butadiene rubber (BR), aromatic vinyl / butadiene copolymer (for example, styrene butadiene rubber (SBR)), isoprene rubber may be appropriately combined and used.

[0033] BR is not particularly limited, and BR with a high cis content, BR with a low cis content, BR containing syndiotactic polybutadiene crystals, etc. can be used. Commercially available products include products of Ube Industries, Ltd., JSR Corporation, Asahi Kasei Corporation, Nippon Zeon Co., Ltd., etc. These may be used alone or in combination of two or more.

[0034] The cis amount (cis content) of BR is preferably 30% by mass or more, more preferably 50% by mass or more, still more preferably 70% by mass or more, particularly preferably 90% by mass or more, and the upper limit is not particularly limited. When within the above range, the effect tends to be obtained more favorably. Incidentally, the cis amount of BR can be measured by NMR.

[0035] The aromatic vinyl / butadiene copolymer (for example, SBR) is not particularly limited, and for example, an emulsion polymerization aromatic vinyl / butadiene copolymer (for example, emulsion polymerization styrene butadiene rubber (E-SBR)), a solution polymerization aromatic vinyl / butadiene copolymer (for example, solution polymerization styrene butadiene rubber (S-SBR)), etc. can be used. Commercially available products include products of Sumitomo Chemical Co., Ltd., JSR Corporation, Asahi Kasei Corporation, Nippon Zeon Co., Ltd., etc. These may be used alone or in combination of two or more.

[0036] Examples of the aromatic vinyl (aromatic vinyl monomer) include styrene, vinyl naphthalene, divinyl naphthalene, etc. These may be used alone or in combination of two or more. Among them, styrene (particularly, styrene derived from biomass) is preferable. That is, as the aromatic vinyl / butadiene copolymer, SBR is preferable. Incidentally, styrene may have a substituent.

[0037] The aromatic vinyl content (content of units derived from aromatic vinyl, preferably styrene content) of the aromatic vinyl / butadiene copolymer is preferably 5% by mass or more, preferably 60% by mass or less, more preferably 50% by mass or less, still more preferably 40% by mass or less, particularly preferably 30% by mass or less, most preferably 20% by mass or less, and even most preferably 10% by mass or less. When within the above range, the effect tends to be obtained more favorably. In the present specification, the aromatic vinyl content (preferably styrene content) of the rubber 1 is calculated by 1H-NMR measurement.

[0038] Examples of the isoprene rubber include natural rubber (NR), isoprene rubber (IR), modified NR, denatured NR, denatured IR, etc. As NR, for example, those commonly used in the tire industry such as SIR20, RSS#3, TSR20, etc. can be used. IR is not particularly limited, and for example, those commonly used in the tire industry such as IR2200, etc. can be used. Examples of the modified NR include deproteinized natural rubber (DPNR), high-purity natural rubber (UPNR), etc., examples of the denatured NR include epoxidized natural rubber (ENR), hydrogenated natural rubber (HNR), grafted natural rubber, etc., and examples of the denatured IR include epoxidized isoprene rubber, hydrogenated isoprene rubber, grafted isoprene rubber, etc. These may be used alone or in combination of two or more. Among them, NR is preferred.

[0039] In the rubber composition A phase, the content of the isoprene rubber (preferably natural rubber) in 100% by mass of the rubber component is preferably 40% by mass or more, more preferably 45% by mass or more, still more preferably 50% by mass or more, and the upper limit is not particularly limited, but is preferably 90% by mass or less, more preferably 70% by mass or less. When within the above range, the effect tends to be obtained more favorably. In this case, in the A phase of the rubber composition, the content of BR in 100% by mass of the rubber component is preferably 5% by mass or more, more preferably 10% by mass or more, and preferably 60% by mass or less, more preferably 55% by mass or less, still more preferably 50% by mass or less. When it is within the above range, the effect tends to be obtained more favorably.

[0040] In another aspect, in the A phase of the rubber composition, the content of the isoprene rubber (preferably natural rubber) in 100% by mass of the rubber component is preferably 0.1% by mass or more, more preferably 1% by mass or more, still more preferably 3% by mass or more, and preferably 10% by mass or less, more preferably 7% by mass or less. When it is within the above range, the effect tends to be obtained more favorably. In this case, in the A phase of the rubber composition, the content of BR in 100% by mass of the rubber component is preferably 20% by mass or more, more preferably 25% by mass or more, still more preferably 30% by mass or more, particularly preferably 70% by mass or more, most preferably 80% by mass or more, even most preferably 85% by mass or more, still most preferably 90% by mass or more, and preferably 99.9% by mass or less, more preferably 99% by mass or less, still more preferably 97% by mass or less. When it is within the above range, the effect tends to be obtained more favorably.

[0041] Examples of rubber components other than BR, aromatic vinyl / butadiene copolymer (e.g., SBR), and isoprene rubber that can be used include diene rubbers such as acrylonitrile-butadiene rubber (NBR), chloroprene rubber (CR), butyl rubber (IIR), and styrene-isoprene-butadiene copolymer rubber (SIBR). These may be used alone or in combination of two or more.

[0042] The rubber component may have a functional group introduced therein by modification to interact with a filler such as silica. Examples of the functional group include an amino group, an amide group, a silyl group, an alkoxysilyl group, an isocyanate group, an imino group, an imidazole group, a urea group, an ether group, a carbonyl group, an oxycarbonyl group, a mercapto group, a sulfide group, a disulfide group, a sulfonyl group, a sulfinyl group, a thiocarbonyl group, an ammonium group, an imide group, a hydrazo group, an azo group, a diazo group, a carboxyl group, a nitrile group, a pyridyl group, an alkoxy group, a hydroxyl group, an oxy group, an epoxy group, etc. These functional groups may have substituents. These may be used alone or in combination of two or more. Among them, an amino group (preferably an amino group in which a hydrogen atom of the amino group is substituted with an alkyl group having 1 to 6 carbon atoms), an alkoxy group (preferably an alkoxy group having 1 to 6 carbon atoms), and an alkoxysilyl group (preferably an alkoxysilyl group having 1 to 6 carbon atoms) are preferred.

[0043] Specific examples of the compound (modifying agent) having the functional group include 2-dimethylaminoethyltrimethoxysilane, 3-dimethylaminopropyltrimethoxysilane, 2-dimethylaminoethyltriethoxysilane, 3-dimethylaminopropyltriethoxysilane, 2-diethylaminoethyltrimethoxysilane, 3-diethylaminopropyltrimethoxysilane, 2-diethylaminoethyltriethoxysilane, 3-diethylaminopropyltriethoxysilane, etc. These may be used alone or in combination of two or more.

[0044] In the rubber composition A phase, it is preferable that the rubber component contains a unit derived from at least one biomass-derived component selected from the group consisting of butadiene, aromatic vinyl, and ethylene. Thereby, the use of fossil fuel-derived raw materials can be reduced in consideration of the environment.

[0045] In the A phase of the rubber composition, the pMC (percent Modern Carbon) measured in accordance with ASTM D6866-10 for the components based on butadiene, aromatic vinyl, and ethylene contained in the rubber component (this value indicates the biomass ratio of the components based on butadiene, aromatic vinyl, and ethylene) is 30% or more, preferably 40% or more, more preferably 50% or more, still more preferably 60% or more, particularly preferably 70% or more, most preferably 80% or more, even most preferably 90% or more, and still most preferably 100% or more, and the upper limit is not particularly limited. For the reason that the effect can be obtained more preferably, the higher the pMC, the more preferable. As described above, due to the property of being calculated as a ratio to the reference substance, a value exceeding 100% can be obtained. In the present specification, the pMC of the components based on butadiene, aromatic vinyl, and ethylene contained in the rubber component means the pMC of the entire components based on butadiene, aromatic vinyl, and ethylene contained in the rubber component. In the present specification, the component based on butadiene means a structural unit in a polymer composed based on the monomer butadiene, the component based on aromatic vinyl means a structural unit in a polymer composed based on the monomer aromatic vinyl, and the component based on ethylene means a structural unit in a polymer composed based on the monomer ethylene.

[0046] In the A phase of the rubber composition, the pMC (percent Modern Carbon) measured in accordance with ASTM D6866-10 for the component based on butadiene contained in the rubber component (this value indicates the biomass ratio of the component based on butadiene) is preferably 30% or more, more preferably 40% or more, still more preferably 50% or more, particularly preferably 60% or more, most preferably 70% or more, even most preferably 80% or more, and still most preferably 90% or more, and particularly most preferably 100% or more, and the upper limit is not particularly limited. For the reason that the effect can be obtained more preferably, the higher the pMC, the more preferable. As described above, due to the property of being calculated as a ratio to the reference substance, a value exceeding 100% can be obtained.

[0047] In the rubber composition A phase, the pMC (percent Modern Carbon) measured in accordance with ASTM D6866-10 for the entire rubber component (this value indicates the biomass ratio of the entire rubber component) is preferably 30% or more, more preferably 40% or more, still more preferably 50% or more, particularly preferably 60% or more, most preferably 70% or more, even most preferably 80% or more, still most preferably 90% or more, particularly most preferably 100% or more, and the upper limit is not particularly limited. The higher the pMC, the more preferable it is because the effect can be obtained more suitably. Note that, as described above, due to the property of being calculated as a ratio to the standard substance, a value exceeding 100% can be obtained.

[0048] In this specification, the pMC of each component is a value obtained by measuring in accordance with ASTM D6866-10, and specifically, it can be measured by the method described in the examples. As described in the examples, for each component such as rubber 14 In order to analyze the C concentration of each component such as rubber, first, pretreatment of each component such as rubber is required. Specifically, the carbon contained in each component such as rubber is oxidized and all converted into carbon dioxide. Further, it is necessary to separate the obtained carbon dioxide from water and nitrogen, and reduce the carbon dioxide to convert it into graphite, which is solid carbon. Then, positive ions such as Cs + are irradiated to the obtained graphite to generate negative carbon ions, the carbon ions are accelerated using a tandem accelerator, the charge is converted from negative ions to positive ions, and 12 C 3+ , 13 C 3+ , 14 C 3+ the orbits of the progress are separated, and 14 C 3+ can be measured by an electrostatic analyzer. In this specification, biomass is also referred to as biomass resources.

[0049] pMC is the 14The ratio of the sample to the C concentration, and in this specification, this value is used as an index indicating the biomass ratio of the compound (rubber). The significance of this value will be described below. 14

[0050] In one mole (6.02×10 23 atoms) of carbon atoms, there are approximately 6.02×10 11 atoms of 14 C, which is about one trillionth of normal carbon atoms. 14 14 [ 14 C is called a radioactive isotope, and its half-life is 5730 years and it decreases regularly. It takes 226,000 years for all of these to decay. Therefore, after carbon dioxide in the atmosphere is taken up and fixed by plants, etc., in fossil fuels such as coal, oil, and natural gas where more than 226,000 years are considered to have passed, all of the 14 14 [ 14 C element that was also contained in them at the time of fixation has decayed. Therefore, in the 21st century, fossil fuels such as coal, oil, and natural gas do not contain any 14 14 [ 14 C element. Therefore, chemical substances produced from these fossil fuels also do not contain any 14 14 [ 14 C element.

[0051] On the other hand, 14 14 [ 14 C is constantly generated by nuclear reactions of cosmic rays in the atmosphere, and the balance between its decrease due to radioactive decay results in a constant amount of 14 14 [ 14 C in the earth's atmospheric environment. Therefore, the 14 14 [ 14 C concentration of substances derived from biomass resources that are circulating in the current environment is about 1×10 -12 -12 [ -12 mol% with respect to the entire C atoms as described above. Therefore, by utilizing the difference between these values, the ratio (biomass ratio) of compounds derived from natural resources (compounds derived from biomass resources) in a certain compound (rubber) can be calculated.

[0052] This 14 14 [ 14 C is generally measured as follows. Using accelerator mass spectrometry based on a tandem accelerator, 13 13 [ 13 C concentration ( 13 13 [ 13 C / 12 12 [ 12 C),14 Measurement of the C concentration ( 14 C / 12 C) is performed. In the measurement, 14 As a modern standard reference for the concentration of C, the 14 C concentration in the circulating carbon in nature in 1950 is adopted. As a specific standard substance, the oxalic acid standard provided by NIST (National Institute of Standards and Technology) is used. The specific radioactivity of carbon in this oxalic acid (the radioactivity intensity of 14 C per gram of carbon) is separated for each carbon isotope, 13 For 14 C, it is corrected to a constant value, and the value obtained by performing decay correction from 1950 AD to the measurement date is used as the value of the standard

[0053] Therefore, if the rubber is made of a substance derived from 100% biomass (natural system), although there are regional differences, etc., it will show a value of approximately 110 pMC (currently, in the normal state, it often does not reach 100). On the other hand, for chemical substances derived from fossil fuels such as petroleum, when the 14 C concentration is measured, it will show approximately 0 pMC (for example, 0.3 pMC). This value corresponds to a biomass ratio of 0% mentioned above.

[0054] From the above, using materials such as rubber with a high pMC value, that is, materials such as rubber with a high biomass ratio, in the rubber composition is suitable from the perspective of environmental protection.

[0055] In order to make the pMC of each component such as butadiene, components based on aromatic vinyl, and components based on butadiene within the above range, for example, polymers synthesized using biomass-derived butadiene and biomass-derived aromatic vinyl (for example, biomass-derived styrene) as monomer components can be used. In order to make the pMC of the entire rubber component fall within the above range, in addition to the above method, natural rubber may be used, or a polymer synthesized using a monomer component derived from biomass (for example, isoprene derived from biomass) as the monomer component may be used.

[0056] The materials (rubber monomers, fillers, resins, etc.) for conventional tire rubber compositions require large-scale manufacturing equipment, so many are produced in large factories in specific regions, and a large amount of energy is used for the storage and transportation of raw materials and products. On the other hand, bio-derived materials can mostly use raw materials from regional agricultural and forestry products. Many of them can be produced on a small scale as long as there are technologies such as microbial fermentation and catalytic reactions. Utilization of regional products and waste eliminates the need for energy to transport and store raw materials from far away. Furthermore, in many cases, there is no need for long-distance transportation of the produced materials to the tire factory and subsequent storage, and an overall environmentally friendly effect can be obtained in tire manufacturing.

[0057] The selection of materials is preferably to combine materials produced by the optimal manufacturing method in the situation at that time according to the business model shown in, for example, Japanese Patent Application Laid-Open No. 2014-115867.

[0058] In addition, according to the comprehensive environmental demands such as the supply situation of biomass resources, the supply situation of petroleum resources (for example, monomer components derived from petroleum resources), and / or market requirements (for example, the competition trend with the demand for biomass resources as food), the ratio of monomer components derived from biomass and monomer components derived from petroleum resources is appropriately selected, and at the appropriately selected ratio, a monomer component derived from biomass or a monomer component derived from biomass and a monomer component derived from petroleum resources are polymerized to polymerize biomass-derived rubber, whereby biomass-derived rubber with the same performance as that when using conventional synthetic rubber can be produced.

[0059] In order to make each pMC of the components based on butadiene, aromatic vinyl, and butadiene-based components fall within the above range, as described above, for example, a polymer synthesized using biomass-derived butadiene and biomass-derived aromatic vinyl (e.g., biomass-derived styrene) as monomer components may be used. Specifically, biomass-derived polybutadiene rubber (BBR) synthesized from biomass-derived butadiene, and biomass-derived aromatic vinyl / butadiene copolymer (e.g., biomass-derived styrene butadiene rubber (BSBR)) synthesized from biomass-derived butadiene and biomass-derived aromatic vinyl (e.g., biomass-derived styrene) may be used. Note that biomass-derived polybutadiene rubber (BBR) and biomass-derived aromatic vinyl / butadiene copolymer (e.g., biomass-derived styrene butadiene rubber (BSBR)) include not only rubbers polymerized from butadiene and the like according to the conventional method, but also rubbers obtained by reactions of microorganisms, plants, animals, and tissue cultures thereof (hereinafter also referred to as microorganisms, etc.) and enzyme reactions.

[0060] Also, the biomass-derived rubber may be any rubber obtained by polymerizing aromatic vinyl or butadiene as monomer components so as to satisfy the above pMC, and at least one of aromatic vinyl and butadiene needs to be biomass-derived (biomass-derived monomer component), but it is preferable that both aromatic vinyl and butadiene are biomass-derived monomer components.

[0061] Also, within the range that satisfies the above pMC, a biomass-derived monomer component and a petroleum resource-derived monomer component may be used in combination. That is, biomass-derived butadiene may be used in combination with butadiene other than biomass-derived butadiene (petroleum resource-derived butadiene). Similarly, biomass-derived aromatic vinyl may be used in combination with aromatic vinyl other than biomass-derived aromatic vinyl (petroleum resource-derived aromatic vinyl).

[0062] In addition, as long as the biomass-derived rubber satisfies the above pMC, it may contain structural units derived from monomer components other than aromatic vinyl and butadiene (monomer components copolymerizable with monoterpenes (such as myrcene, etc.)).

[0063] The proportion of the biomass-derived monomer component in 100 mol% of the monomer components constituting the biomass-derived rubber is preferably 50 mol% or more, more preferably 70 mol% or more, still more preferably 80 mol% or more, particularly preferably 90 mol% or more, and most preferably 95 mol% or more, and may be 100 mol%.

[0064] The A phase of the rubber composition preferably contains a butadiene rubber (biomass butadiene rubber (BBR)) obtained by polymerizing biomass-derived butadiene as the biomass-derived rubber. Since the biomass-derived butadiene contains ultra-trace impurities different from those derived from petroleum resources, it is presumed that these impurities interact with other components (especially resins), and the domains of other components (especially resins) are reinforced, so that the effect can be more preferably obtained.

[0065] ((Method for Preparing Biomass-Derived Rubber)) Next, before explaining the method for preparing biomass-derived rubber from biomass, first, the biomass in this specification will be explained.

[0066] In this specification, biomass (biomass resources) means carbon-neutral organic resources derived from organisms. Specifically, it includes those stored in the form of starch, cellulose, etc., the bodies of animals that grow by eating plants, and products made by processing plant or animal bodies, etc., and is a resource excluding fossil resources.

[0067] The biomass resources may be edible or inedible, and are not particularly limited. From the perspective of effective utilization of resources without competing with food, it is preferable to use inedible raw materials.

[0068] Specific examples of biomass resources include, for example, cellulosic crops (pulp, kenaf, wheat straw, rice straw, waste paper, paper-making residues, etc.), wood, charcoal, compost, natural rubber, cotton, sugarcane, okara, oils and fats (rapeseed oil, cottonseed oil, soybean oil, coconut oil, castor oil, etc.), carbohydrate crops (corn, tubers, wheat, rice, rice husks, rice bran, old rice, cassava, sago palm, etc.), bagasse, buckwheat, soybeans, essential oils (pine root oil, orange oil, eucalyptus oil, etc.), pulp black liquor, food waste, vegetable oil cake, fishery residues, livestock excrement, food waste, algae, sewage sludge, and the like.

[0069] As biomass resources, those obtained by processing these (i.e., biomass-derived substances) may also be used. Examples of the processing methods include known methods such as biological processing methods that utilize the functions of microorganisms, plants, animals, and tissue cultures thereof; chemical processing methods that utilize acids, alkalis, catalysts, thermal energy, light energy, etc.; and physical processing methods such as micronization, compression, microwave treatment, and electromagnetic wave treatment.

[0070] In addition, as biomass resources, those extracted and purified from the above-mentioned biomass resources or the processed biomass resources (i.e., biomass-derived substances) may also be used. For example, saccharides, proteins, amino acids, fatty acids, fatty acid esters, etc. purified from biomass resources may be used.

[0071] The saccharides are not particularly limited as long as they are derived from biomass, and examples thereof include sucrose, glucose, trehalose, fructose, lactose, galactose, xylose, allose, talose, gulose, altrose, mannose, idose, arabinose, apiose, maltose, cellulose, starch, chitin, and the like.

[0072] The protein is not particularly limited as long as it is a compound formed by linking amino acids (preferably L-amino acids) derived from biomass, and includes oligopeptides such as dipeptides.

[0073] The amino acid is not particularly limited as long as it is an organic compound derived from biomass and has both functional groups of an amino group and a carboxyl group. Examples include valine, leucine, isoleucine, arginine, lysine, asparagine, glutamine, phenylalanine, etc. Among them, valine, leucine, isoleucine, arginine, and phenylalanine are preferred. The amino acid may be of the L-form or the D-form, but the L-form is preferred because of its large abundance in nature and ease of use as a biomass resource.

[0074] The fatty acid is not particularly limited as long as it is derived from biomass. Examples include butyric acid, oleic acid, linoleic acid, palmitic acid, stearic acid, etc.

[0075] The fatty acid ester is not particularly limited as long as it is derived from biomass. Examples include animal-derived fats, vegetable oils, modified biomass-derived oils and fats, etc.

[0076] As the biomass resource, various materials and impurities may be mixed, but for efficient conversion, it is preferable that the content of saccharides in 100% by mass of the biomass is 20% by mass or more, more preferably 30% by mass or more, and still more preferably 50% by mass or more. In another form, for efficient conversion, it is preferable that the total content of amino acids and proteins in 100% by mass of the biomass is 10% by mass or more, more preferably 20% by mass or more, and still more preferably 30% by mass or more. In yet another form, for efficient conversion, it is preferable that the total content of fatty acids and fatty acid esters in 100% by mass of the biomass is 10% by mass or more.

[0077] Next, a method for preparing biomass-derived rubber from biomass will be described. Hereinafter, as a representative example, the case where the biomass-derived rubber is BSBR will be specifically described. As described above, in this specification, BSBR includes not only BSBR polymerized from biomass-derived butadiene and styrene according to the conventional method, but also BSBR obtained by reactions by microorganisms or the like or enzymatic reactions.

[0078] ((Method for preparing butadiene)) First, a method for preparing butadiene from biomass resources will be described. However, the method for preparing butadiene is not limited to the method described below.

[0079] As the method for preparing butadiene from biomass resources, various methods can be mentioned and it is not particularly limited. For example, a biological treatment method of directly obtaining butadiene from biomass resources by at least one selected from the group consisting of microorganisms, plants, animals, and tissue cultures thereof; a method of obtaining butadiene by subjecting the biomass resources to the chemical treatment method; a method of obtaining butadiene by subjecting the biomass resources to the physical treatment method; a method of converting biomass resources into butadiene by an in vitro enzyme reaction or the like; a method of combining these methods, etc. can be mentioned. In addition, the microorganisms, plants, and animals that convert biomass resources into butadiene may or may not be genetically engineered.

[0080] The direct conversion method from biomass resources to butadiene using microorganisms or the like is not particularly limited, but it is possible to use an in vivo pathway that converts an amino acid into alkyl alcohols and / or hemiterpenes.

[0081] As the amino acid, valine, leucine, isoleucine, and arginine are preferable. Also, as the hemiterpenes, tiglic acid and / or angelic acid are preferable.

[0082] Preferable examples include a method of introducing and / or modifying a gene encoding an enzyme having decarboxylase activity and / or a gene encoding an enzyme having reductase activity into microorganisms, plants, animals, and tissue cultures thereof to obtain butadiene from amino acids and / or hemiterpenes.

[0083] Examples of enzymes having decarboxylase activity include, for example, diphosphomevalonate decarboxylase (E.C. 4.1.1.33), various amino acid decarboxylases. Examples of enzymes having reductase activity include HMG-CoA reductase, 12-oxophytodienoic acid reductase (E.C. 1.3.1.42), etc.

[0084] Preferable examples of producing butadiene by fermentation through in vivo reactions via amino acids include a method of producing tiglic acid and / or angelic acid biosynthesized in vivo along the natural metabolic pathway of microorganisms or the like from isoleucine and then allowing various decarboxylases to act thereon. Alternatively, butadiene can be obtained by a decarboxylase reaction using various fatty acid derivatives produced during the metabolism of amino acids.

[0085] The amino acids necessary for obtaining butadiene may be directly added to the medium, but preferably, examples include biosynthesizing amino acids in vivo by fermentation of plant pulverized products, livestock waste, etc. and using the biosynthesized amino acids. In this case, butadiene rubber will be converted from saccharides and / or proteins.

[0086] In general, methods for producing alcohols and alkenes by fermentation mainly utilize saccharides as biomass resources. In contrast, in this production method, it is highly likely that biomass resources centered on amino acids and proteins can also be effectively utilized, so it is useful.

[0087] As another method for preparing butadiene from biomass resources, at least one selected from the group consisting of microorganisms, plants, animals, and tissue cultures thereof is used to obtain an intermediate capable of synthesizing butadiene from the biomass resources, and the obtained intermediate is subjected to the above chemical treatment methods such as catalytic reactions, the above physical treatment methods, the above in vitro enzyme reactions, methods of combining these methods, etc. to obtain butadiene (dienes such as butadiene). This method is also preferably used.

[0088] Examples of intermediates capable of synthesizing butadiene include alkyl alcohols, allyl alcohols, alkenes, aldehydes, unsaturated carboxylic acids, etc.

[0089] The alkyl alcohols are not particularly limited as long as they are derived from biomass, and ethanol, butanol, and butanediol are preferred, with butanol and butanediol being more preferred. Note that butanol may be 1-butanol, 2-butanol, or a mixture thereof.

[0090] As methods for producing ethanol (ethanol derived from biomass resources is also referred to as bioethanol) or butanol (butanol derived from biomass resources is also referred to as biobutanol) by fermentation using microorganisms or the like, various known methods are available. For example, a method of obtaining bioethanol from biomass resources (such as sugarcane or glucose) by ethanol fermentation with yeast, and a method of obtaining biobutanol from biomass resources (such as glucose) by acetone-butanol fermentation (ABE fermentation) with fermentative fungi are common. In the case of ABE fermentation, a mixed solvent of butanol, acetone, etc. is obtained, and biobutanol can be obtained by distilling this. Furthermore, butanol can also be obtained directly from bioethanol by a catalytic reaction or via acetaldehyde.

[0091] The microorganism that performs ABE fermentation is not particularly limited as long as it is capable of performing ABE fermentation. For example, it includes microorganisms belonging to the genus Escherichia, Zymomonas, Candida, Saccharomyces, Pichia, Streptomyces, Bacillus, Lactobacillus, Corynebacterium, Clostridium, Saccharomyces, etc. These can be used in any form such as wild strains, mutant strains, or recombinant strains induced by genetic engineering techniques such as cell fusion or genetic manipulation. Among them, microorganisms belonging to the genus Clostridium are preferred, and Clostridium acetobutylicum, Clostridium beijerinckii, Clostridium saccharobutylicum, and Clostridium saccharoperbutylacetonicum are more preferred.

[0092] As a preferred example of a method for producing biobutanol, for example, a method for obtaining butanol by fermentation with at least one selected from the group consisting of microorganisms, plants, animals, and tissue cultures thereof into which at least one gene selected from the group consisting of genes related to the mevalonic acid pathway, genes related to the MEP / DOXP pathway, genes encoding butyryl-CoA dehydrogenase, genes encoding butyraldehyde dehydrogenase, and genes encoding butanol dehydrogenase has been introduced (for example, Japanese Patent Application Laid-Open No. 2010-508017).

[0093] In addition, ethanol and butanol produced by fermentation from biomass resources are also commercially distributed as bioethanol and biobutanol (for example, biobutanol manufactured by DuPont).

[0094] In addition, butanediol can be directly produced by various fermentations as a raw material for bioplastics (for example, Syu MJ, Appl Microbial Biotechnol 55:10-18(2001), Qin et al., Chinese J Chem Eng 14(1):132-136(2006), JP-T-2011-522563, JP-A-62-285779, JP-A-2010-115116, etc.), and can be easily used as bio-derived butanediol. Further, butanediol may be produced by converting biomass-derived succinic acid, fumaric acid, furfural, etc.

[0095] The microorganism that performs the butanediol fermentation is not particularly limited as long as it is a microorganism capable of performing butanediol fermentation. For example, microorganisms belonging to the genus Escherichia, Zymomonas, Candida, Saccharomyces, Pichia, Streptomyces, Bacillus, Lactobacillus, Corynebacterium, Clostridium, Klebsiella, Saccharomyces, etc. can be mentioned. These can be used in any form such as wild strains, mutant strains, or recombinant strains induced by genetic engineering techniques such as cell fusion or genetic manipulation. Among them, microorganisms belonging to the genus Bacillus, Clostridium, and Klebsiella are preferred, and Clostridium autoethanogenum, Bacillus polymyxa, Bacillus subtilis, Bacillus pumilus, Bacillus macerans, Bacillus licheniformis, Bacillus megaterium, Klebsiella pneumoniae are more preferred.

[0096] From the alkyl alcohols, they can be converted into butadiene by subjecting them to the biological treatment method such as fermentation, the chemical treatment method such as catalytic reaction, the physical treatment method, the in vitro enzymatic reaction, the method of combining these methods, and the like.

[0097] As a method for directly converting alkyl alcohols into butadiene, for example, a method of converting ethanol and / or butanol into butadiene using a dehydration and dehydrogenation catalyst such as hydroxyapatite, Ta / SiO2, alumina, or zeolite is known.

[0098] The allyl alcohols are not particularly limited as long as they are derived from biomass, and crotyl alcohol and 3-buten-2-ol are preferred in view of the ease of conversion into butadiene.

[0099] Crotyl alcohol and 3-buten-2-ol may be directly obtained from biomass resources by fermentation of microorganisms or the like, or may be obtained by reducing crotonic acid or its derivatives derived from biomass. It is also possible to obtain crotyl alcohol using butanediol derived from biomass as a catalyst such as zeolite, alumina, or cerium oxide (for example, Japanese Patent Application Laid-Open No. 2004-306011).

[0100] As a method for converting allyl alcohols into butadiene, for example, a method of converting crotyl alcohol into butadiene by dehydration using a generally known catalytic reduction catalyst such as zeolite or alumina can be mentioned.

[0101] The alkenes are not particularly limited as long as they are derived from biomass, and ethylene and butene (also known as butylene) are preferred, and ethylene is more preferred.

[0102] As a method for producing ethylene and butene derived from biomass, for example, a method of converting bioethanol into ethylene by using a dehydration catalyst such as alumina or zeolite or by high-temperature treatment, a method of converting biobutanol into butene by using a dehydration catalyst such as alumina or zeolite or by high-temperature treatment, and the like can be mentioned.

[0103] In addition, the alkenes (ethylene, butene) can also be directly obtained from biomass resources by fermentation using at least one selected from the group consisting of microorganisms, plants, animals, and tissue cultures thereof.

[0104] From the viewpoint of production efficiency, it is preferable that the microorganisms, plants, animals, and tissue cultures thereof for performing the ethylene fermentation have a gene encoding an enzyme having ACC synthase (ethylene synthase) activity introduced and / or modified, but this is not the only case.

[0105] The ethylene may be obtained by a catalytic reaction using carbon dioxide as a raw material. The method for producing ethylene by a catalytic reaction using carbon dioxide as a raw material is not particularly limited, and for example, it may be produced by the method described in JP-A-2019-154435.

[0106] From the viewpoint of production efficiency, it is preferable that the microorganisms, plants, animals, and tissue cultures thereof for performing the butene fermentation have a gene encoding an enzyme having diphosphomevalonate decarboxylase (E.C. 4.1.1.33) activity introduced and / or modified (for example, JP-T-2011-526489), but this is not the only case.

[0107] Examples of the method for converting the alkenes to butadiene include a method of converting butene to butadiene using alumina, zeolite, etc., and a method of obtaining butadiene by partially converting ethylene to acetaldehyde using an oxidation catalyst such as palladium chloride and palladium acetate and then performing a dehydration reaction with the remaining ethylene using a dehydration catalyst such as alumina and zeolite.

[0108] The aldehydes are not particularly limited as long as they are derived from biomass, and acetaldehyde is preferable.

[0109] Acetaldehyde may be obtained directly from biomass resources by fermentation with microorganisms or the like, or may be obtained by converting ethylene derived from biomass into acetaldehyde using an oxidation catalyst such as palladium chloride.

[0110] Examples of the method for converting the aldehydes into butadiene include a method of performing a dehydration reaction with ethylene.

[0111] The unsaturated carboxylic acids are not particularly limited as long as they are derived from biomass, and tiglic acid and angelic acid are preferred.

[0112] Tiglic acid and angelic acid may be obtained directly from biomass resources by fermentation with microorganisms or the like. Specifically, tiglic acid and angelic acid can be biosynthesized in vivo from isoleucine through the natural metabolic pathways of microorganisms or the like. They may also be purified from oils such as croton oil.

[0113] Examples of the method for converting the unsaturated carboxylic acids into butadiene include a method of converting tiglic acid or angelic acid by the action of various decarboxylases, and a method of converting them by the action of a metal catalyst such as palladium, zeolite, alumina, or the like.

[0114] Butadiene can be obtained from biomass resources by the above methods and the like.

[0115] (((Method for preparing styrene))) Next, a method for preparing styrene from biomass resources will be described. However, the method for preparing styrene is not limited to the method described below. When using aromatic vinyl other than styrene, styrene may be further synthesized into aromatic vinyl other than styrene by a known method.

[0116] As methods for preparing styrene from biomass resources, various methods can be mentioned and are not particularly limited. For example, a biological treatment method of directly obtaining styrene from biomass resources by at least one selected from the group consisting of microorganisms, plants, animals, and tissue cultures thereof (particularly, microorganisms, plants, and tissue cultures thereof); a method of obtaining styrene by subjecting the biomass resources to the chemical treatment method; a method of obtaining styrene by subjecting the biomass resources to the physical treatment method; a method of converting biomass resources into styrene by in vitro enzyme reactions, etc.; a method of combining these methods, etc. Among them, the biological treatment method is preferable. In this production method, mainly saccharides used as a carbon source in the medium are utilized as the biomass resources. Note that the microorganisms, plants, and animals that convert biomass resources into styrene may or may not be genetically engineered.

[0117] The direct conversion method (biological treatment method) from biomass resources to styrene using microorganisms, etc. is not particularly limited, but it can be carried out by utilizing the in vivo pathway of biosynthesizing styrene via cinnamic acid from phenylalanine.

[0118] Phenylalanine is a substance biosynthesized by the shikimic acid pathway possessed by most microorganisms and plants, and an in vivo pathway in which styrene is biosynthesized via cinnamic acid from this phenylalanine is known. Therefore, by utilizing these in vivo pathways possessed by microorganisms, etc., at least one selected from the group consisting of microorganisms, plants, animals, and tissue cultures thereof (particularly, microorganisms, plants, and tissue cultures thereof) can directly obtain styrene from biomass resources.

[0119] Microorganisms, plants, animals, and tissue cultures thereof (particularly, microorganisms, plants, and tissue cultures thereof) are preferably those that have been engineered to highly express phenylalanine ammonia-lyase, cinnamic acid decarboxylase (phenylacrylic acid decarboxylase), and / or phenolic acid decarboxylase (particularly, ferulic acid decarboxylase) in terms of efficiently producing styrene.

[0120] Also, similarly, for the reason that styrene can be efficiently produced, microorganisms, plants, animals, and tissue cultures thereof (particularly, microorganisms, plants, and tissue cultures thereof) are preferably modified to promote (overproduce) the production of phenylalanine, which is considered a substrate of the styrene biosynthetic pathway.

[0121] Specifically, microorganisms, plants, animals, and tissue cultures thereof (particularly, microorganisms, plants, and tissue cultures thereof) are preferably those that have been engineered to highly express enzymes involved in the shikimate pathway and / or feedback inhibition enzymes.

[0122] More specifically, microorganisms, plants, animals, and tissue cultures thereof (particularly, microorganisms, plants, and tissue cultures thereof) are preferably those in which enzymes involved in the shikimate pathway are highly expressed, feedback inhibition by L-phenylalanine is released in enzymes involved in the L-phenylalanine biosynthetic pathway, and / or enzymes with released feedback inhibition are highly expressed.

[0123] Enzymes involved in the shikimate pathway are not particularly limited, and examples include allogenic acid dehydratase, prephenic acid aminotransferase, prephenic acid dehydratase, chorismic acid mutase, and the like.

[0124] Since styrene can be efficiently produced, it is preferable to add phenylalanine and / or cinnamic acid (preferably phenylalanine and / or cinnamic acid derived from biomass) to a medium for culturing microorganisms etc. (including soil for cultivating plants). By adding these compounds located upstream of the in vivo pathway for biosynthesis of styrene, styrene can be efficiently produced. Note that the phenylalanine and cinnamic acid to be added can be prepared by culturing microorganisms etc.

[0125] Although not particularly limited, examples of microorganisms capable of directly converting biomass resources into styrene include microorganisms belonging to the genera Fusarium, Penicillium, Pichia, Candida, Debaryomyces, Torulopsis, Saccharomyces, Bacillus, Escherichia, Streptomyces, Pseudomonas, etc. These can be used in any form such as wild strains, mutant strains, or recombinant strains induced by genetic engineering techniques such as cell fusion or gene manipulation.

[0126] Although not particularly limited, examples of microorganisms belonging to the genus Fusarium include F. oxysporum, F. roseum, F. aquasductuum, F. fujikuroi, F. solani, F. graminearum, F. asiaticum, F. culmorum, etc., which are preferable from the viewpoint of styrene conversion efficiency, and F. oxysporum is more preferable.

[0127] Examples of microorganisms belonging to the genus Penicillium include, but are not particularly limited to, P. citrinum, P. oxalicum, P. glabrum, P. chrysogenum, P. digitatum, P. camemberti, P. islandicum, P. verrucosum, P. cyclopium, P. commune, P. citro-viride, P. rugulosum, P. italicum, P. expansum, P. marneffei, P. griseofluvum, P. galaucum, P. roqueforti, P. camamberti, P. natatum, P. gladioli, etc. Among them, P. citrinum, P. oxalicum, and P. camamberti are preferred from the viewpoint of styrene conversion efficiency, with P. citrinum being more preferred and P. citrinum being even more preferred.

[0128] Examples of microorganisms belonging to the genus Pichia include, but are not particularly limited to, Pichia carsonii, Pichia anomala, Pichia pastoris, Pichia farinosa, Pichia membranifaciens, Pichia angusta, etc. Among them, Pichia carsonii is preferred from the viewpoint of styrene conversion efficiency, and Pichia carsonii is more preferred.

[0129] Examples of microorganisms belonging to the genus Candida include, but are not particularly limited to, C. famata, C. etchellsii, C. versatilis, C. stellata, etc. Among them, C. famata is preferred from the viewpoint of styrene conversion efficiency, and C. famata is more preferred.

[0130] Examples of microorganisms belonging to the genus Debaryomyces include, but are not particularly limited to, Debaryomyces hansenii, which is preferred from the viewpoint of styrene conversion efficiency.

[0131] Examples of microorganisms belonging to the genus Torulopsis are not particularly limited.

[0132] Examples of microorganisms belonging to the genus Saccharomyces include, but are not particularly limited to, S. cerevisiae, S. bayanus, S. boulardii, etc., which are preferred in terms of styrene conversion efficiency.

[0133] Examples of microorganisms belonging to the genus Bacillus include, but are not particularly limited to, B. subtilis, B. thuringiensis, B. coagulans, B. licheniformis, B. megaterium, etc., which are preferred in terms of styrene conversion efficiency, and B. subtilis is more preferred.

[0134] Examples of microorganisms belonging to the genus Escherichia include, but are not particularly limited to, E. albertii, E. blattae, E. coli, E. fergusonii, E. hermannii, E. vulneris, etc., which are preferred in terms of styrene conversion efficiency, and E. coli is more preferred.

[0135] Examples of microorganisms belonging to the genus Streptomyces include, but are not particularly limited to, S. griseus, S. kanamyceticus, S. peucetius, S. galilaeus, S. parvulus, S. antibioticus, S. lividans, S. maritimus, etc., which are preferred in terms of styrene conversion efficiency.

[0136] Examples of microorganisms belonging to the genus Pseudomonas include, but are not particularly limited to, P. aeruginosa, P. syringae pv. Japonica, P. meliae, P. putida, etc., which are preferred in terms of styrene conversion efficiency, and P. putida, P. putida IH - 2000, P. putida S12 are more preferred, and P. putida IH - 2000, P. putida S12 are even more preferred.

[0137] Examples of microorganisms capable of directly converting biomass resources into styrene include microorganisms belonging to the genus Penicillium and the genus Escherichia, and P. citrinum and transformed E. coli are more preferred.

[0138] Although there is no particular limitation on plants that can directly convert biomass resources into styrene, examples include plants belonging to the Anacardiaceae, Styracaceae, Styracaceae, Solanaceae, Apiaceae, Theaceae, etc. These can be used in any form of strain, such as wild strains, mutant strains, or recombinant strains induced by genetic engineering techniques such as cell fusion or genetic manipulation.

[0139] Although there is no particular limitation on plants (trees) belonging to the Anacardiaceae, from the perspective of styrene production efficiency, plants (trees) belonging to the genus Liquidambar are preferred. Among them, Liquidambar formosana, Liquidambar styraciflua, and Liquidambar orientalis are more preferred, Liquidambar styraciflua and Liquidambar orientalis are even more preferred, and Liquidambar styraciflua is particularly preferred.

[0140] Although there is no particular limitation on plants (trees) belonging to the Styracaceae, from the perspective of styrene production efficiency, plants (trees) belonging to the genus Styrax are preferred. Among them, Styrax officinalis, Styrax japonica, and Styrax benzoin Dryander are more preferred, and Styrax japonica is even more preferred.

[0141] Although there is no particular limitation on plants belonging to the Styracaceae, from the perspective of styrene production efficiency, plants belonging to the genera Dianthus, Styrax, Calystegia, Aristolochia, and Quisqualis are preferred, and plants belonging to the genus Dianthus (especially Dianthus) are more preferred.

[0142] Although there is no particular limitation on plants belonging to the Solanaceae, plants of the genus Nicotiana are preferred from the perspective of styrene production efficiency, and N. tabacum and N. rustica are more preferred.

[0143] Although there is no particular limitation on plants belonging to the Apiaceae, plants belonging to the genus Daucus are preferred from the perspective of styrene production efficiency.

[0144] Although the plants belonging to the Camellia family are not particularly limited, plants belonging to the Camellia genus, the Rhododendron genus, or the Stewartia genus are preferred from the viewpoint of the efficiency of styrene production.

[0145] As plants capable of directly converting biomass resources into styrene, plants belonging to the Euphorbiaceae family, the Pittosporaceae family, or the Styracaceae family are preferred, plants belonging to the Euphorbia genus, the Pittosporum genus, or the Stellaria genus are more preferred, Euphorbia cotinifolia, Leucophyllum frutescens, Pittosporum tobira, or Stellaria media are even more preferred, and Euphorbia cotinifolia, Pittosporum tobira, or Stellaria media are particularly preferred.

[0146] When the plant is a tree, the method for obtaining styrene from the tree is not particularly limited, but the method of obtaining it by purifying the resin (sap) exuded by damaging the tree trunk is preferred in terms of efficiency. Also, it can be obtained by pulverizing the bark, trunk, branches, roots, leaves, etc. of the tree, obtaining volatile components by extraction with an appropriate solvent, heating, and / or ultrasonic irradiation, etc., and then purifying.

[0147] When the plant is not a tree, it is difficult to obtain styrene as a resin, but styrene can be obtained by pulverizing the plant tissue (for example, stems, leaves, roots, flowers, etc.), obtaining volatile components by extraction with an appropriate solvent, heating, and / or ultrasonic irradiation, etc., and then purifying.

[0148] Also, it is possible to obtain styrene by culturing the tissue of the plant and obtaining volatile components from the cultured tissue by extraction with an appropriate solvent, heating, and / or ultrasonic irradiation, etc.

[0149] The tissue of the plant to be cultured is not particularly limited, but callus induced from a plant tissue piece is preferred because styrene can be obtained efficiently. That is, it is preferable to induce callus from a plant tissue piece and culture the induced callus.

[0150] The method for inducing callus is not particularly limited. For example, a method of inducing callus by culturing a tissue piece of a plant (such as a bud, leaf, stem, etc.) in a medium containing a plant growth hormone (such as an auxin plant hormone (such as dichlorophenoxyacetic acid) and / or a cytokinin plant hormone (such as benzyladenine)) can be mentioned.

[0151] As another method for preparing styrene from biomass resources, at least one selected from the group consisting of microorganisms, plants, animals, and tissue cultures thereof (particularly, microorganisms, plants, and tissue cultures thereof) can be used to obtain an intermediate capable of synthesizing styrene (particularly, phenylalanine and / or cinnamic acid) from the biomass resources. Then, for the obtained intermediate (particularly, phenylalanine and / or cinnamic acid), a method of obtaining styrene by subjecting it to the above biological treatment method, chemical treatment methods such as catalytic reactions, the above physical treatment method, the in vitro enzyme reaction, a method of combining these methods, etc. is also preferably used. Among them, a method of subjecting the obtained intermediate (particularly, phenylalanine and / or cinnamic acid) to the above biological treatment method is preferred. Note that the microorganisms, plants, and animals that convert the intermediate to styrene may or may not be genetically engineered.

[0152] As a method of obtaining styrene by subjecting the obtained intermediate (particularly, phenylalanine and / or cinnamic acid) to the above biological treatment method, for example, as described above, phenylalanine and / or cinnamic acid can be added to the medium for culturing the above microorganisms, etc. (including the soil for cultivating plants), and the above microorganisms, etc. can be cultured in this medium. Thereby, styrene is biosynthesized from the added phenylalanine and / or cinnamic acid by the above microorganisms, etc.

[0153] As a method for obtaining styrene by subjecting the obtained intermediate phenylalanine to the above chemical treatment method such as a catalytic reaction, for example, a method of obtaining styrene by converting it to cinnamic acid by the action of an ammonia lyase such as phenylalanine ammonia lyase and then decarboxylating it using a decarboxylase, a transition metal catalyst, zeolite, etc., a method of obtaining styrene by subjecting it to high-temperature treatment directly using zeolite, alumina, etc. can be mentioned.

[0154] As a method for obtaining styrene by subjecting the obtained intermediate cinnamic acid to the above chemical treatment method such as a catalytic reaction, for example, a method of obtaining styrene by a decarboxylation reaction by allowing a metal catalyst using a transition metal, zeolite, alumina, etc. to act at a high temperature can be mentioned.

[0155] Styrene can be obtained from biomass resources by the above methods and the like.

[0156] (((Polymerization method))) A method for polymerizing styrene-butadiene rubber (biomass styrene-butadiene rubber (BSBR)) from butadiene and styrene obtained from biomass resources by the above methods and the like is a method known to those skilled in the art, which is the same as the method for polymerizing styrene-butadiene rubber from butadiene and styrene derived from petroleum resources and is not particularly limited. Similarly, a method for polymerizing butadiene rubber (biomass butadiene rubber (BBR)) from butadiene obtained from biomass resources by the above methods and the like is a method known to those skilled in the art, which is the same as the method for polymerizing butadiene rubber from butadiene derived from petroleum resources and is not particularly limited.

[0157] As the butadiene obtained from biomass resources, butadiene derived from alkyl alcohols (preferably ethanol, butanol (more preferably butanol)), butadiene derived from alkenes (preferably ethylene), and butadiene derived from unsaturated carboxylic acids (preferably tiglic acid) can be preferably used. It is also preferable to use a combination of these butadienes.

[0158] As the styrene obtained from biomass resources, styrene obtained from plants (preferably plants belonging to the Anacardiaceae, Euphorbiaceae, or Burseraceae families, more preferably plants belonging to the Rhus, Euphorbia, or Portulaca genera, still more preferably Toxicodendron succedaneum, Euphorbia antiquorum, or Portulaca oleracea), and styrene obtained from microorganisms (preferably microorganisms belonging to the Penicillium or Escherichia genera, more preferably P. citrinum or transformed E. coli) can be suitably used. It is also suitable to use these styrenes in combination.

[0159] The molecular weight, branching, and microstructure of the obtained BBR and BSBR can be arbitrarily selected by changing the polymerization conditions according to known methods in accordance with the performance requirements of the desired tire.

[0160] On the other hand, currently, there are some plans for biomass combinats centered around bioethanol, bioethylene, etc. However, bioethanol and bioethylene are mainly produced using saccharides and / or celluloses as biomass resources, and other biomass resources such as proteins, lipids, and amino acids cannot be effectively utilized. Furthermore, competition with food due to saccharides and illegal harvesting of cellulose leading to deforestation may occur, and situations that are not necessarily environmentally friendly can also arise.

[0161] Therefore, in response to the comprehensive environmental demands such as the supply situation of various biomass resources, the supply situation of petroleum resources, and market requirements (for example, the competition trend with the demand for biomass resources as food), as the monomer component derived from biomass, it is preferable to use a plurality of monomer components derived from biomass, or to use a monomer component derived from biomass and a monomer component derived from petroleum resources in combination, or to adjust the usage ratio of these monomer components to an optimal ratio for use. Thereby, without relying on a single type of biomass resource, a wide range of biomass resources such as sugars, proteins, and lipids can be effectively utilized, and the supply of biomass-derived rubber can be stabilized, and consideration for the environment according to the situation during production can be carried out. For example, biomass-derived butadiene can be obtained using various substrates such as bioethanol, biobutanol, and terpenes. Also, biomass-derived styrene can be obtained using various plants and microorganisms.

[0162] When using a plurality of monomer components derived from biomass, it is preferable to use monomer components derived from different biomass, that is, monomer components obtained from different biomass resources. Specifically, as the biomass-derived butadiene, it is preferable to use a mixture of a plurality of biomass-derived butadienes with different origins, and / or as the biomass-derived styrene, it is preferable to use a mixture of a plurality of biomass-derived styrenes with different origins. Thereby, a plurality of biomass resources can be effectively utilized, and can preferably respond to the above-mentioned comprehensive environmental demands.

[0163] Also, as another preferable example of converting BBR from butadiene obtained from biomass resources and BSBR from butadiene and styrene obtained from biomass resources, there is a method using an enzymatic reaction. Some enzymes (long-chain prenyl chain elongation enzymes) contained in rubber latex are known to have the effect of promoting the polymerization reaction of dienes, and polymerization can be carried out in vivo or in vitro using these enzymes.

[0164] The long-chain prenyl chain elongation enzyme is not particularly limited, and known ones can be used.

[0165] As a method for directly obtaining BBR and BSBR from biomass resources, for example, by culturing (tissue culturing) at least one selected from the group consisting of microorganisms, plants, animals, and tissue cultures thereof having a diene polymerization ability, a method of directly converting from biomass resources to BBR and BSBR, in a medium added with butadiene (preferably butadiene obtained from biomass resources) and styrene (preferably styrene obtained from biomass resources), culturing at least one selected from the group consisting of microorganisms, plants, animals, and tissue cultures thereof, and polymerizing BBR and BSBR, etc. can be mentioned.

[0166] Examples of the microorganisms, etc. having a diene polymerization ability include plants such as Pará rubber tree, Indian rubber tree, dandelion, fig, nageshi, Japanese knotweed, guayule, sabojira, and tochū, and their tissue cultures.

[0167] When culturing microorganisms, etc., usually, saccharides such as glucose are used as a carbon source, so all the compounds produced by microorganisms, etc. correspond to substances derived from biomass resources.

[0168] In the rubber composition A phase, the content of the biomass-derived rubber (preferably BBR) in 100% by mass of the rubber component is preferably 20% by mass or more, more preferably 40% by mass or more, still more preferably 60% by mass or more, particularly preferably 80% by mass or more, and may be 100% by mass. When within the above range, the effect tends to be obtained more favorably.

[0169] (Compounders other than the rubber component) The rubber composition A phase preferably contains a resin. Examples of the resin include cyclopentadiene resins, terpene resins, rosin resins, aromatic resins, C5 resins, C9 resins, C5 / C9 resins, coumarone-indene resins (including coumarone and indene monomer resins), olefin resins, polyurethane resins, acrylic resins, etc. These may be used alone or in combination of two or more. Also, they may be hydrogenated products (hydrogenated resins). Further, it is also preferable that the resin is modified with a polar functional group that interacts with silica. As the polar functional group that interacts with silica, the same groups as those of the functional groups that interact with fillers such as silica described above are used in the same preferred embodiments.

[0170] Among them, cyclopentadiene resins, terpene resins, rosin resins, aromatic resins, C5 resins, C9 resins, and C5 / C9 resins are preferable because the effects can be more suitably obtained. Also, it is preferable that the resin is at least one selected from the group consisting of terpene resins and rosin resins. Since these resins are naturally derived resins, the environmental load can be further reduced, and the tire performance such as the grip performance on a dry road surface can be improved. Also, it is also preferable that the resin is at least one selected from the group consisting of cyclopentadiene resins, C5 resins, C5 / C9 resins, and C9 resins. Thereby, the comprehensive performance of wear resistance and low fuel consumption (represented by the sum of two indexes of wear resistance and low fuel consumption) can be improved, and particularly when a high content of silica is used, the comprehensive performance of wear resistance and low fuel consumption can be further improved. Also, it is preferable that the resin is an aromatic resin. Thereby, not only can the effects be more suitably obtained, but also the grip performance, wear resistance, and rubber strength can be improved in a well-balanced manner. As the resin, an aromatic resin is most preferable.

[0171] Cyclopentadiene-based resins are polymers containing cyclopentadiene-based monomers as constituent monomers. For example, there are homopolymers obtained by polymerizing one type of cyclopentadiene-based monomer alone, copolymers obtained by copolymerizing two or more cyclopentadiene-based monomers, and copolymers of cyclopentadiene-based monomers and other monomers copolymerizable therewith. These may be used alone or in combination of two or more.

[0172] Examples of cyclopentadiene-based monomers include cyclopentadiene, dicyclopentadiene, tricyclopentadiene, etc. These may be used alone or in combination of two or more. Among them, dicyclopentadiene is preferred.

[0173] Due to the tendency to obtain better effects, cyclopentadiene-based resins are preferably polymers (DCPD-based resins) containing dicyclopentadiene (DCPD) as a constituent monomer, and may also be copolymers of DCPD and aromatic monomers, or copolymers of DCPD and C9 fraction (vinyltoluene, indene, etc.) (DCPD-C9 resins). In this specification, polymers containing cyclopentadiene-based monomers and aromatic monomers as constituent monomers, such as DCPD-C9 resins, are not aromatic resins but are treated as cyclopentadiene-based resins.

[0174] As terpene-based resins, polyterpene resins obtained by polymerizing terpene compounds, aromatic modified terpene resins obtained by polymerizing terpene compounds and aromatic compounds, etc. can be used. Also, hydrogenated products thereof can be used. These may be used alone or in combination of two or more.

[0175] Polyterpene resins are resins obtained by polymerizing terpene compounds. Terpene compounds are hydrocarbons represented by the composition of (C5H8) n and their oxygen-containing derivatives, monoterpenes (C 10 H 16 ), sesquiterpenes (C 15 H24 )), compounds having a terpene with a basic skeleton classified into diterpenes (C 20 H 32 ), etc. Examples include α-pinene, β-pinene, dipentene, limonene, myrcene, allo-ocimene, ocimene, α-farnesene, α-terpinene, γ-terpinene, terpinolene, 1,8-cineole, 1,4-cineole, α-terpineol, β-terpineol, γ-terpineol, etc. These may be used alone or in combination of two or more.

[0176] Examples of polyterpene resins include pinene resins, limonene resins, dipentene resins, pinene / limonene resins, etc. using the above-mentioned terpene compounds as raw materials. These may be used alone or in combination of two or more. Among them, pinene resins are preferred. Pinene resins usually contain both α-pinene and β-pinene, which are in an isomeric relationship, but depending on the components contained, they are classified into β-pinene resins with β-pinene as the main component and α-pinene resins with α-pinene as the main component.

[0177] Examples of aromatic-modified terpene resins include terpene phenol resins using terpene compounds and phenolic compounds as raw materials, terpene styrene resins using terpene compounds and styrene-based compounds as raw materials, etc. Also, terpene phenol styrene resins using terpene compounds, phenolic compounds, and styrene-based compounds as raw materials can be used. These may be used alone or in combination of two or more. In addition, in this specification, polymers containing terpene compounds and phenolic compounds as constituent monomers, such as aromatic-modified terpene resins, are not aromatic resins but are treated as terpene resins.

[0178] For the reason that the effects tend to be obtained more favorably, as the terpene resin, polyterpene resin is preferred, and β-pinene resin is more preferred.

[0179] Examples of rosin-based resins include natural rosin resins (polymerized rosin) such as gum rosin, wood rosin, and tall oil rosin, which are mainly composed of resin acids such as abietic acid and pimaric acid obtained by processing pine resin, hydrogenated rosin resins, maleic acid-modified rosin resins, rosin-modified phenolic resins, rosin glycerin esters, disproportionated rosin resins, etc. These may be used alone or in combination of two or more.

[0180] Aromatic resins are polymers containing aromatic monomers as constituent monomers. For example, there are homopolymers obtained by polymerizing one type of aromatic monomer alone, copolymers obtained by copolymerizing two or more aromatic monomers, and copolymers of aromatic monomers and other monomers copolymerizable therewith. These may be used alone or in combination of two or more.

[0181] Examples of aromatic monomers include styrene-based monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-methoxystyrene, p-tert-butylstyrene, p-phenylstyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene; phenol-based monomers such as phenol, alkylphenol, alkoxyphenol; naphthol-based monomers such as naphthol, alkylnaphthol, alkoxynaphthol; etc. These may be used alone or in combination of two or more. Among them, styrene-based monomers are preferred, and styrene and α-methylstyrene are more preferred.

[0182] For the reason that the effect tends to be obtained more favorably, aromatic resins are preferably polymers containing α-methylstyrene as a constituent monomer (α-methylstyrene-based resins), and more preferably copolymers of α-methylstyrene and styrene.

[0183] The C5 resin is a polymer containing hydrocarbon units with 5 carbon atoms and its multimers (dimers, etc.). Examples of hydrocarbons with 5 carbon atoms and their multimers include isoprene, pentane, cyclopentadiene, etc. Specific examples of C5 resins include copolymers of isoprene and pentane. Also, as C5 resins, aliphatic petroleum resins obtained by (co)polymerizing C5 fractions obtained by thermal decomposition of naphtha in the petrochemical industry are included. The C5 fraction contains olefinic hydrocarbons such as 1-pentene, 2-pentene, 2-methyl-1-butene, and diolefinic hydrocarbons such as 2-methyl-1,3-butadiene, 1,2-pentadiene, 1,3-pentadiene, etc. These may be used alone or in combination of two or more. In this specification, polymers containing cyclopentadiene as a constituent monomer are treated as cyclopentadiene-based resins.

[0184] The C9 resin is a polymer containing hydrocarbon units with 9 carbon atoms and its multimers (dimers, etc.). Examples of hydrocarbons with 9 carbon atoms and their multimers (dimers, etc.) include indene, methylstyrene, vinyltoluene, etc. Specific examples of C9 resins include solid polymers obtained by (co)polymerizing C9 fractions using Friedel-Crafts type catalysts, etc., such as copolymers mainly composed of indene, copolymers mainly composed of methylindene, copolymers mainly composed of α-methylstyrene, copolymers mainly composed of vinyltoluene, etc. These may be used alone or in combination of two or more. In this specification, polymers containing methylstyrene as a constituent monomer are treated as aromatic resins.

[0185] Examples of C5 / C9 resins include mixtures of the above C5 resins and C9 resins, copolymers of C5 fractions and C9 fractions, etc. These may be used alone or in combination of two or more. Preferably, the C5 resin is aliphatic and the C9 resin is alicyclic.

[0186] The softening point of the resin is preferably 30°C or higher, more preferably 60°C or higher, still more preferably 80°C or higher, and is preferably 160°C or lower, more preferably 140°C or lower. When within the above range, the effect tends to be obtained more favorably. In this specification, the softening point of a polymer (such as a resin or a polymer) is the temperature at which the ball drops when measured with a ring and ball type softening point measuring device according to the softening point defined in JIS K 6220-1:2001.

[0187] As commercially available products of the above resin, for example, products of Maruzen Petrochemical Co., Ltd., Sumitomo Bakelite Co., Ltd., Yasuhara Chemical Co., Ltd., Tosoh Corporation, Rutgers Chemicals, BASF, Arizona Chemical, Nippon Paint Co., Ltd., Nippon Shokubai Co., Ltd., ENEOS Corporation, Arakawa Chemical Industries, Ltd., Tago Chemical Industry Co., Ltd., ExxonMobil, etc. can be used.

[0188] In the rubber composition A phase, the content of the resin is preferably 5 to 100 parts by mass with respect to 100 parts by mass of the rubber component. The content of the resin is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, still more preferably 30 parts by mass or more, particularly preferably 40 parts by mass or more, most preferably 50 parts by mass or more, and even most preferably 60 parts by mass or more, and is preferably 90 parts by mass or less, more preferably 85 parts by mass or less, still more preferably 80 parts by mass or less. When within the above range, the effect tends to be obtained more favorably.

[0189] The rubber composition A phase preferably contains silica. Examples of silica include dry-process silica (anhydrous silica), wet-process silica (hydrous silica), etc. Among them, wet-process silica is preferred because it has many silanol groups. As commercially available products, products of Degussa, Rhodia, Tosoh Silica Corporation, Solvay Japan Co., Ltd., Tokuyama Corporation, etc. can be used. These may be used alone or in combination of two or more.

[0190] The silica is preferably silica derived from rice husks (also referred to as rice husk silica). The first effect of using rice husk silica is the effective utilization of rice husks, which become industrial waste, and is preferable from the aspect of environmental response. The second effect is that local procurement of raw materials becomes possible. Recycling rice husks, which are waste from rice produced in large quantities around the world as a staple food, is an important issue. However, by blending it as rice husk silica, it can reduce waste. Moreover, since it is produced in many places, there is an advantage that less energy for transportation and storage is required by procuring it near tire manufacturing factories. The third effect is that by blending rice husk silica, tire physical properties such as low fuel consumption are improved compared to ordinary wet silica that has been industrially produced conventionally. The reason for this is not clear, but it is thought to be due to components such as carbon black that may be contained in trace amounts in silica derived from rice husks contributing to an improved affinity with other components, and changing the viscoelasticity in the region related to low fuel consumption compared to the case of a single silica component.

[0191] Rice husk silica may be powder of rice husk charcoal obtained by carbonizing rice husks by heating, or precipitated silica produced by a wet method using an aqueous alkali silicate solution prepared by extracting rice husk ash generated when rice husks are burned in a biomass boiler using rice husks as fuel with an alkali. These may be used alone or in combination of two or more.

[0192] The manufacturing method of rice husk charcoal is not particularly limited, and various known methods can be used. For example, rice husk charcoal can be obtained by pyrolyzing rice husks by steaming them using a kiln. The rice husk charcoal powder can be obtained by pulverizing the rice husk charcoal thus obtained using a known pulverizer (for example, a ball mill) and selecting and classifying it within a predetermined particle size range. The method for manufacturing precipitated silica from rice husks can be manufactured by the method described in Japanese Patent Application Laid-Open No. 2019-38728. It is preferable that the rice husk silica is produced particularly in an area close to a tire production factory.

[0193] The nitrogen adsorption specific surface area (N2SA) of silica is preferably 50 m 2 / g or more, more preferably 100 m 2 / g or more, still more preferably 150 m 2 / g or more. Also, the upper limit of the N2SA of silica is not particularly limited, but is preferably 350 m 2 / g or less, more preferably 250 m 2 / g or less, still more preferably 230 m 2 / g or less, particularly preferably 200 m 2 / g or less. When within the above range, the effect tends to be obtained more favorably. Note that the N2SA of silica is a value measured by the BET method in accordance with ASTM D3037-93.

[0194] In the rubber composition A phase, the content of silica is 100 parts by mass or more, preferably 110 parts by mass or more, based on 100 parts by mass of the rubber component. The upper limit of the content is preferably 300 parts by mass or less, more preferably 200 parts by mass or less, still more preferably 180 parts by mass or less, particularly preferably 150 parts by mass or less. When within the above range, the effect tends to be obtained more favorably.

[0195] In the rubber composition A phase, the resin content / silica content is preferably 0.1 or more, more preferably 0.2 or more, still more preferably 0.3 or more, particularly preferably 0.4 or more, and preferably 1.5 or less, more preferably 1.2 or less, still more preferably 0.9 or less, particularly preferably 0.8 or less, most preferably 0.7 or less, even most preferably 0.6 or less. When within the above range, the effect tends to be obtained more favorably. Note that in this relationship, the resin content and the silica content are the contents (unit: parts by mass) based on 100 parts by mass of the rubber component.

[0196] Silica is preferably used in combination with a silane coupling agent. The silane coupling agent is not particularly limited. For example, bis(3-triethoxysilylpropyl)tetrasulfide, bis(2-triethoxysilylethyl)tetrasulfide, bis(4-triethoxysilylbutyl)tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, bis(2-trimethoxysilylethyl)tetrasulfide, bis(2-triethoxysilylethyl)trisulfide, bis(4-trimethoxysilylbutyl)trisulfide, bis(3-triethoxysilylpropyl)disulfide, bis(2-triethoxysilylethyl)disulfide, bis(4-triethoxysilylbutyl)disulfide, bis(3-trimethoxysilylpropyl)disulfide, bis(2-trimethoxysilylethyl)disulfide, bis(4-trimethoxysilylbutyl)disulfide, 3-trimethoxysilylpropyl-N,N-dimethylthiocarbamoyl tetrasulfide, 2-triethoxysilylethyl-N,N-dimethylthiocarbamoyl tetrasulfide, 3-triethoxysilylpropyl methacrylate monosulfide, etc. of sulfide series; 3-mercaptopropyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, etc. of mercapto series; vinyltriethoxysilane, vinyltrimethoxysilane, etc. of vinyl series; 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, etc. of amino series; γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, etc. of glycidoxy series; 3-nitropropyltrimethoxysilane, 3-nitropropyltriethoxysilane, etc. of nitro series; 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, etc. of chloro series can be mentioned. As commercially available products, for example, products of Degussa, Momentive, Shin-Etsu Silicone Co., Ltd., Tokyo Chemical Industry Co., Ltd., Azmax Co., Ltd., Toray Dow Corning Co., Ltd., etc. can be used. These may be used alone or in combination of two or more. Among them, sulfide-based silane coupling agents are preferred.

[0197] In the A phase of the rubber composition, the content of the silane coupling agent is preferably 3 parts by mass or more, more preferably 6 parts by mass or more, still more preferably 8 parts by mass or more, and preferably 15 parts by mass or less, more preferably 12 parts by mass or less, still more preferably 10 parts by mass or less, based on 100 parts by mass of silica. When within the above range, the effect tends to be obtained more favorably.

[0198] The A phase of the rubber composition preferably contains carbon black. The carbon black is not particularly limited, and examples thereof include N134, N110, N220, N234, N219, N339, N330, N326, N351, N550, N762, etc. As commercially available products, products of Asahi Carbon Co., Ltd., Cabot Japan Co., Ltd., Tokai Carbon Co., Ltd., Mitsubishi Chemical Corporation, Lion Corporation, Shin Nippon Chemical Carbon Co., Ltd., Columbian Carbon Co., etc. can be used. These may be used alone or in combination of two or more.

[0199] The nitrogen adsorption specific surface area (N2SA) of the carbon black is preferably 50 m 2 / g or more, more preferably 70 m 2 / g or more, still more preferably 90 m 2 / g or more. Also, the N2SA is preferably 200 m 2 / g or less, more preferably 150 m 2 / g or less, still more preferably 130 m 2 / g or less. When within the above range, the effect tends to be obtained more favorably. Note that the nitrogen adsorption specific surface area of the carbon black is determined according to JIS K6217-2:2001.

[0200] In the A phase of the rubber composition, the content of the carbon black is preferably 1 part by mass or more, more preferably 3 parts by mass or more, still more preferably 5 parts by mass or more, and 10 parts by mass or less, based on 100 parts by mass of the rubber component. When within the above range, the effect tends to be obtained more favorably.

[0201] In the A phase of the rubber composition, in the total content of 100% by mass of silica and carbon black, the content of silica is preferably 60% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, particularly preferably 90% by mass or more, and most preferably 95% by mass or more. The upper limit may be 100% by mass, but is preferably 98% by mass or less. When it is within the above range, the effect tends to be obtained more favorably.

[0202] The A phase of the rubber composition preferably contains a liquid plasticizer (a plasticizer in a liquid state at normal temperature (25°C)). The liquid plasticizer (a plasticizer in a liquid state at normal temperature (25°C)) is not particularly limited, and examples include oils and liquid polymers (such as liquid diene polymers). These may be used alone or in combination of two or more. Among them, oil is preferred.

[0203] Examples of the oil include process oil, vegetable oil, or a mixture thereof. As the process oil, for example, paraffinic process oil, aromatic process oil, naphthenic process oil, etc. can be used. Examples of the 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, tung oil, etc. As commercially available products, products of Idemitsu Kosan Co., Ltd., Sankyo Yuka Kogyo Co., Ltd., Japan Energy Corporation, Orisoy Co., Ltd., H&R Co., Ltd., Toyokuni Seiyu Co., Ltd., Showa Shell Sekiyu K.K., Fuji Kogyo Co., Ltd., Nisshin Oillio Group Co., Ltd., etc. can be used. These may be used alone or in combination of two or more. Among them, process oil (such as paraffinic process oil, aromatic process oil, naphthenic process oil, etc.) and vegetable oil are preferred, and aromatic process oil is more preferred.

[0204] Examples of the liquid diene polymer include a liquid styrene-butadiene copolymer (liquid SBR), a liquid butadiene polymer (liquid BR), a liquid isoprene polymer (liquid IR), a liquid styrene-isoprene copolymer (liquid SIR), a liquid styrene-butadiene-styrene block copolymer (liquid SBS block polymer), a liquid styrene-isoprene-styrene block copolymer (liquid SIS block polymer), a liquid farnesene polymer, a liquid farnesene-butadiene copolymer, etc., which are in a liquid state at 25°C. These may have their terminals or main chains modified with polar groups. Also, hydrogenated products thereof can be used. These may be used alone or in combination of two or more.

[0205] In the A phase of the rubber composition, the content of the liquid plasticizer (preferably oil) is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, based on 100 parts by mass of the rubber component. The upper limit of the content is preferably 100 parts by mass or less, more preferably 70 parts by mass or less, still more preferably 50 parts by mass or less, and particularly preferably 30 parts by mass or less. When within the above range, the effect tends to be obtained more favorably. Note that the content of the liquid plasticizer (preferably oil) includes the oil contained in the oil-extended rubber.

[0206] The A phase of the rubber composition may contain an antioxidant. Examples of the anti-aging agent include naphthylamine-based anti-aging agents such as phenyl-α-naphthylamine; diphenylamine-based anti-aging agents such as octylated diphenylamine and 4,4′-bis(α,α′-dimethylbenzyl)diphenylamine; p-phenylenediamine-based anti-aging agents such as N-isopropyl-N′-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine, and N,N′-di-2-naphthyl-p-phenylenediamine; quinoline-based anti-aging agents such as polymers of 2,2,4-trimethyl-1,2-dihydroquinoline; monophenol-based anti-aging agents such as 2,6-di-t-butyl-4-methylphenol and styrenated phenol; bis, tris, polyphenol-based anti-aging agents such as tetrakis-[methylene-3-(3′,5′-di-t-butyl-4′-hydroxyphenyl)propionate]methane, etc. As commercial products, products of Seiko Chemical Co., Ltd., Sumitomo Chemical Co., Ltd., Ouchi Shinsei Chemical Industry Co., Ltd., Flexsys Co., etc. can be used. These may be used alone or in combination of two or more. Among them, p-phenylenediamine-based anti-aging agents and quinoline-based anti-aging agents are preferred, and it is more preferred to use p-phenylenediamine-based anti-aging agents and quinoline-based anti-aging agents in combination.

[0207] In the A phase of the rubber composition, the content of the anti-aging agent is preferably 1 part by mass or more, more preferably 1.5 parts by mass or more, still more preferably 2 parts by mass or more, and preferably 12 parts by mass or less, more preferably 10 parts by mass or less, still more preferably 8 parts by mass or less, based on 100 parts by mass of the rubber component. When within the above range, the effect tends to be obtained more favorably.

[0208] The A phase of the rubber composition may contain wax. The wax is not particularly limited, and examples include petroleum waxes such as paraffin wax and microcrystalline wax; natural waxes such as plant waxes and animal waxes; synthetic waxes such as polymers of ethylene, propylene, etc. As commercially available products, products of Ouchi Shinko Chemical Industry Co., Ltd., Nippon Seiro Co., Ltd., Seiko Chemical Co., Ltd., etc. can be used. These may be used alone or in combination of two or more.

[0209] In the rubber composition A phase, the content of the wax is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and preferably 10 parts by mass or less, more preferably 6 parts by mass or less, based on 100 parts by mass of the rubber component. When within the above range, the effect tends to be obtained more favorably.

[0210] The rubber composition A phase may contain stearic acid. As the stearic acid, conventionally known ones can be used. As commercially available products, products of NOF Corporation, Kao Corporation, Fujifilm Wako Pure Chemical Corporation, Chiba Fatty Acids Co., Ltd., etc. can be used. These may be used alone or in combination of two or more.

[0211] In the rubber composition A phase, the content of stearic acid is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and preferably 10 parts by mass or less, more preferably 6 parts by mass or less, based on 100 parts by mass of the rubber component. When within the above range, the effect tends to be obtained more favorably.

[0212] The rubber composition A phase may contain zinc oxide. As the zinc oxide, conventionally known ones can be used. As commercially available products, products of Mitsui Mining & Smelting Co., Ltd., Toho Zinc Co., Ltd., Hakusuitech Co., Ltd., Shoindo Chemical Industry Co., Ltd., Sakai Chemical Industry Co., Ltd., etc. can be used. These may be used alone or in combination of two or more.

[0213] In the A phase of the rubber composition, the content of zinc oxide is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and preferably 10 parts by mass or less, more preferably 6 parts by mass or less, based on 100 parts by mass of the rubber component. When it is within the above range, the effect tends to be obtained more favorably.

[0214] The A phase of the rubber composition preferably contains sulfur. Examples of sulfur include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersed sulfur, soluble sulfur, etc., which are generally used as crosslinking agents in the rubber industry. As commercially available products, products of Tsukimi Chemical Industry Co., Ltd., Karuizawa Sulfur Co., Ltd., Shikoku Kasei Kogyo Co., Ltd., Flexsys, Nippon Karyu Kogyo Co., Ltd., Hosoi Chemical Industry Co., Ltd., etc. can be used. These may be used alone or in combination of two or more.

[0215] In the A phase of the rubber composition, the content of sulfur is preferably 0.3 part by mass or more, more preferably 0.5 part by mass or more, still more preferably 0.8 part by mass or more, and preferably 8 parts by mass or less, more preferably 5 parts by mass or less, based on 100 parts by mass of the rubber component. When it is within the above range, the effect tends to be obtained more favorably.

[0216] The A phase of the rubber composition preferably contains a vulcanization accelerator. As vulcanization accelerators, there are thiazole-based vulcanization accelerators such as 2-mercaptobenzothiazole and di-2-benzothiazolyldisulfide; thiuram-based vulcanization accelerators such as tetramethylthiuram disulfide (TMTD) and tetrakis(2-ethylhexyl)thiuram disulfide (TOT-N); sulfenamide-based vulcanization accelerators such as N-cyclohexyl-2-benzothiazylsulfenamide (CBS), N-tert-butyl-2-benzothiazolylsulfenamide (TBBS), N-oxyethylene-2-benzothiazole sulfenamide, and N,N'-diisopropyl-2-benzothiazole sulfenamide; and guanidine-based vulcanization accelerators such as diphenylguanidine, diorthotolylguanidine, and orthotolylbiguanidine. As commercially available products, products of Sumitomo Chemical Co., Ltd., Ouchi Shinsei Chemical Industry Co., Ltd., etc. can be used. These may be used alone or in combination of two or more. Among them, sulfenamide-based vulcanization accelerators and guanidine-based vulcanization accelerators are preferred, and it is more preferred to use them in combination.

[0217] In the A phase of the rubber composition, the content of the vulcanization accelerator is preferably 1 part by mass or more, more preferably 2 parts by mass or more, still more preferably 3 parts by mass or more, and preferably 8 parts by mass or less, more preferably 6 parts by mass or less, still more preferably 5.5 parts by mass or less, based on 100 parts by mass of the rubber component. When within the above range, the effect tends to be obtained more favorably.

[0218] In addition to the above components, the rubber composition may further contain additives commonly used in the tire industry, such as organic peroxides; fillers such as calcium carbonate, talc, alumina, clay, aluminum hydroxide, mica, etc. The content of these additives is preferably 0.1 to 200 parts by mass based on 100 parts by mass of the rubber component.

[0219] The rubber composition can be produced, for example, by kneading the respective components using a rubber kneading device such as an open roll or a Banbury mixer, and then vulcanizing.

[0220] As for the kneading conditions, in the base kneading step of kneading additives other than the vulcanizing agent and the vulcanization accelerator, the kneading temperature is usually 100 to 180°C, preferably 120 to 170°C. In the finishing kneading step of kneading the vulcanizing agent and the vulcanization accelerator, the kneading temperature is usually 120°C or lower, preferably 80 to 110°C. Further, the composition kneaded with the vulcanizing agent and the vulcanization accelerator is usually subjected to a vulcanization treatment such as press vulcanization. As the vulcanization temperature, it is usually 140 to 190°C, preferably 150 to 185°C. The vulcanization time is usually 5 to 15 minutes.

[0221] (Rubber powder (rubber composition B phase)) The rubber composition A phase preferably further contains rubber powder. The rubber powder may be used alone or in combination of two or more. When the rubber composition A further contains rubber powder, in the rubber composition A, the rubber powder exists independently as the rubber composition B, and the rubber composition A phase and the rubber composition B phase having boundaries independent of each other are obtained. A cap tread in which the rubber composition B phase is divided into the rubber composition A phase and exists independently in the rubber composition A phase is preferably obtained. Thus, it is preferable that the rubber composition B phase is rubber powder. Further, the cap tread of the passenger car tire of the present invention also has a rubber component and rubber powder, contains 100 parts by mass or more of silica and 10 parts by mass or less of carbon black with respect to 100 parts by mass of the rubber component, and the rubber powder contains 10 parts by mass or more of carbon black and 13 to 20 parts by mass of silica with respect to 100 parts by mass of the rubber component contained in the rubber powder. It is a cap tread of a passenger car tire.

[0222] In the rubber composition B phase, 10 parts by mass or more of carbon black and 13 to 20 parts by mass of silica are contained with respect to 100 parts by mass of the rubber component. As the carbon black and silica, the same ones as those in the rubber composition A are used in the same preferable embodiments.

[0223] In the B phase of the rubber composition, the content of carbon black is preferably 15 parts by mass or more, more preferably 20 parts by mass or more, still more preferably 30 parts by mass or more, particularly preferably 40 parts by mass or more, based on 100 parts by mass of the rubber component. The upper limit is not particularly limited, but is preferably 80 parts by mass or less, more preferably 60 parts by mass or less, still more preferably 50 parts by mass or less. When within the above range, the effect tends to be obtained more favorably.

[0224] In the B phase of the rubber composition, the content of silica is preferably 18 parts by mass or less and preferably 15 parts by mass or more, based on 100 parts by mass of the rubber component. When within the above range, the effect tends to be obtained more favorably.

[0225] The compounding agents used in the B phase of the rubber composition are those similar to the above rubber composition A and are used in similar preferred embodiments.

[0226] In the B phase of the rubber composition, the content of units derived from isoprene is preferably 40% by mass or more, more preferably 50% by mass or more, still more preferably 60% by mass or more, in 100% by mass of the units of all rubber components. The upper limit is not particularly limited, but is preferably 95% by mass or less, more preferably 90% by mass or less, still more preferably 80% by mass or less, particularly preferably 70% by mass or less. When within the above range, the effect tends to be obtained more favorably. In this case, in the B phase of the rubber composition, the content of units derived from butadiene is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 20% by mass or more, particularly preferably 30% by mass or more, in 100% by mass of the units of all rubber components, and is preferably 60% by mass or less, more preferably 50% by mass or less, still more preferably 40% by mass or less. When within the above range, the effect tends to be obtained more favorably.

[0227] In the B phase of the rubber composition, it is preferable to contain 1 to 40% by mass of butadiene rubber (high cis BR) having a cis content of 90% by mass or more in 100% by mass of the rubber component. The lower limit is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 15% by mass or more, and particularly preferably 20% by mass or more. The upper limit is preferably 35% by mass or less, more preferably 30% by mass or less. When within the above range, the effect tends to be obtained more favorably.

[0228] As a method for preparing the rubber powder, for example, the rubber composition B containing each of the above components may be kneaded and vulcanized according to the above method or the like, and the obtained vulcanized rubber composition may be pulverized as necessary.

[0229] The volume average particle diameter of the B phase (rubber powder) of the rubber composition is preferably 1000 μm or less. The volume average particle diameter is preferably 500 μm or less, more preferably 200 μm or less, still more preferably 100 μm or less. Since the smaller the better, the lower limit is not particularly limited. When within the above range, the effect tends to be obtained more favorably. In the present specification, the volume average particle diameter is measured by a laser diffraction particle size distribution measuring device, and can be measured using, for example, "CAPA500" manufactured by Horiba, Ltd.

[0230] The residue on a 60-mesh sieve of the B phase (rubber powder) of the rubber composition is preferably less than 1% by mass, more preferably 0.5% by mass or less, still more preferably 0.1% by mass or less, and the lower limit is not particularly limited. When within the above range, the effect tends to be obtained more favorably. Also, the residue on an 80-mesh sieve of the B phase (rubber powder) of the rubber composition is preferably less than 10% by mass, more preferably 1% by mass or less, still more preferably 0.5% by mass or less, and the lower limit is not particularly limited. When within the above range, the effect tends to be obtained more favorably. In the present specification, the residue on a sieve is measured according to ASTM D5644-01.

[0231] The acetone extract content of the rubber composition B phase (rubber powder), as determined by the acetone extraction method, is preferably 12% by mass or less, more preferably 11% by mass or less, still more preferably 10% by mass or less, and preferably 1% by mass or more, more preferably 2% by mass or more, still more preferably 3% by mass or more. When within the above range, the effect tends to be better obtained. In this specification, the acetone extract content in the rubber composition B phase (rubber powder) refers to the acetone extract content (%) determined by the acetone extraction method in accordance with JIS K6350.

[0232] In the rubber composition A phase, the content of the rubber composition B phase (rubber powder) is preferably 1 part by mass or more, more preferably 2 parts by mass or more, still more preferably 3 parts by mass or more, and preferably 200 parts by mass or less, more preferably 150 parts by mass or less, still more preferably 100 parts by mass or less, particularly preferably 50 parts by mass or less, most preferably 30 parts by mass or less, even most preferably 15 parts by mass or less, still most preferably 10 parts by mass or less, and particularly most preferably 5 parts by mass or less, based on 100 parts by mass of the rubber component. When within the above range, the effect tends to be better obtained.

[0233] The rubber composition can be used for a tread (cap tread). In the case of a tread composed of a cap tread and a base tread, it can be preferably used for the cap tread.

[0234] In 100% by mass of the cap tread rubber, the content of the rubber composition A phase is preferably 40 to 99% by mass. The content is preferably 60% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, and preferably 99% by mass or less. When within the above range, the effect tends to be better obtained.

[0235] The tire (pneumatic tire, etc.) of the present invention is manufactured by a normal method using the rubber composition. That is, a rubber composition blended with various additives as required is extruded in an unvulcanized stage according to the shape of each member of the tire (especially the tread (cap tread)), molded by a normal method on a tire molding machine, bonded together with other tire members to form an unvulcanized tire, and then the tire can be manufactured by heating and pressurizing in a vulcanizer.

[0236] Note that at least a part of the tire member (for example, the tread) of the tire may be composed of the rubber composition, or all of it may be composed of the rubber composition.

[0237] The tire is a passenger car tire. In this specification, a passenger car tire is a tire assumed to be mounted on a four-wheel driving automobile, and means a tire having a maximum load capacity (indicated by JATMA, ETRTO, etc.) of 1000 kg or less. Here, the maximum load capacity is preferably 900 kg or less, more preferably 800 kg or less, still more preferably 700 kg or less, and the lower limit is not particularly limited.

[0238] The tire is preferably used as a winter tire (studless tire, snow tire, stud tire), all-season tire, summer tire, run-flat tire, etc.

Example

[0239] The present invention will be specifically described based on the examples, but the present invention is not limited to these only.

[0240] The butadiene and butadiene rubber obtained in the following production example were evaluated by the following method.

[0241] (pMC of butadiene, butadiene rubber) The pMC of butadiene, styrene, styrene-butadiene rubber, etc. was measured according to ASTM D6866-10 by the following method. A sample (butadiene, styrene, butadiene rubber, or styrene-butadiene rubber) was burned to generate carbon dioxide (CO2), and the carbon dioxide was purified using a vacuum line. Next, the purified carbon dioxide was reduced with hydrogen using iron as a catalyst to produce graphite (C). Then, the obtained graphite was packed into a cathode with an inner diameter of 1 mm using a hand press, fitted into a wheel, and mounted on a measuring device (a 14 C-AMS dedicated device (manufactured by NEC Corporation)). Using this measuring device, 14 the 14C concentration, 13 the 13C concentration were measured, and pMC (%) indicating the biomass ratio was calculated using oxalic acid provided by the National Institute of Standards and Technology (NIST) as a standard sample. When calculating pMC, 13 correction was performed based on the 14C concentration value.

[0242] (Cis content of butadiene rubber) The cis content was measured using an NMR device AV400 manufactured by BRUKER and data analysis software TOP SPIN 2.1.

[0243] (Weight-average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of rubber) The weight-average molecular weight (Mw) and number-average molecular weight (Mn) were measured by gel permeation chromatography (GPC) under the following conditions (1) to (8). Then, the molecular weight distribution (Mw / Mn) of the polymer was determined from the measured Mw and Mn. (1) Device: HLC-8020 manufactured by Tosoh Corporation (2) Separation column: GMH-XL (two in series) manufactured by Tosoh Corporation (3) Measurement temperature: 40 °C (4) Carrier: Tetrahydrofuran (5) Flow rate: 0.6 mL / min (6) Injection volume: 5 μL (7) Detector: Differential refraction (8) Molecular weight standard: Standard polystyrene

[0244] Production Example 1 (Production of butadiene from butanol) <Production of biobutanol> A 300 ml fermenter (DASGIP) was filled with 250 ml of the synthetic medium (containing sugars) described by Soni et al (Soni et al, 1987, Appl. Microbiol. Biotechnol. 27: 1-5) and sparged with nitrogen for 30 minutes. Clostridium acetobutylicum (ATCC824) was inoculated therein under anaerobic conditions. The culture temperature was maintained at a constant 35 °C, and the pH was adjusted to 5.5 using an NH4OH solution. During the culture, anaerobic conditions were maintained, and the shaking speed was maintained at 300 rpm. After culturing for 5 days, the culture broth was distilled and separated by the well-known ion exchange resin method to obtain bio-butanol (1-butanol).

[0245] <Production of butadiene from bio-butanol> Using the apparatus shown in Figure 1, bio-mass-derived butadiene was synthesized using bio-butanol (1-butanol) obtained by <Production of bio-butanol> as a raw material.

[0246] An apparatus (see Figure 1) comprising an alcohol introduction pipe (raw material introduction pipe) 21, a heating device (electric furnace) 22 for vaporizing the introduced alcohol, a dehydration reaction column 23 for subjecting the alcohol to a dehydration reaction, a cooling device 24 for cooling the product obtained in the dehydration reaction to remove water from the purified alkene mixture, a heating device 25 for vaporizing the alkene, a second-stage reaction column 26 for further dehydrogenating the alkene to synthesize butadiene, and a cooling device 27 for recovering the generated reaction product was used. The dehydration reaction column 23 was filled with 10 g of aluminum oxide (101095100 manufactured by Merck & Co., Inc.) as a catalyst.

[0247] The catalyst for the second-stage dehydrogenation reaction was prepared as follows. 5.8 g of chromium nitrate was dissolved in ion-exchanged water, and 6 g of SSZ-35 type zeolite (silica / alumina ratio: 40) was added thereto and impregnated, and left overnight. Thereafter, it was dried in an oven at 100 °C to obtain a precursor. This precursor was placed in a ceramic container and calcined at 700 °C for 3 hours in the presence of air to obtain a chromium-supported zeolite catalyst containing 10% by mass of chromium. Then, 10 g of the chromium-supported zeolite catalyst was charged into the second-stage reaction column 26.

[0248] Nitrogen gas was supplied to the dehydration reaction column 23 through a gas introduction pipe (not shown). The supply rate of nitrogen gas was 1 / hr in terms of LHSV. After heating the dehydration reaction column 23 to a predetermined temperature by the heating device 22, a predetermined amount of bio-butanol was supplied from the alcohol introduction pipe 21. The reaction conditions were as follows: reaction temperature: 500 °C, reaction pressure: normal pressure, molar ratio of bio-butanol to nitrogen (bio-butanol / nitrogen): 50 / 50. The reaction time was 2 hours. The product was collected in a cooling device (product trap) 24 connected to the dehydration reaction column 23, and water was separated.

[0249] The second-stage reaction column 26 was heated to 500 °C. The cooling device (product trap) 27 was cooled to -20 °C. Through the cooling device (product trap) 24, a preheated mixed gas (butene mixture / nitrogen / air obtained from the first-stage dehydration reaction in a ratio of 1:1:1) was introduced at a supply rate of 1 / hr in terms of LHSV, and the obtained reaction mixture was separated and purified by the method described in JP-A-60-115532 to obtain biomass-derived butadiene in a yield of 8%. The value of pMC indicating the biomass ratio of the obtained butadiene (biomass-derived butadiene) was 105%.

[0250] Production Example 2 (Production of butadiene from bio-ethanol) Using the apparatus of Fig. 1, biomass-derived butadiene was synthesized using commercially available bio-ethanol by a known method for converting ethanol to butadiene (Kirshenbaum, I. (1978). Butadiene. In M. Grayson (Ed.), Encyclopedia of Chemical Technology, 3rd ed., vol. 4, pp. 313 - 337. New York: John Wiley & Sons.). The value of pMC indicating the biomass ratio of the obtained butadiene (biomass-derived butadiene) was 108%.

[0251] Production Example 3 (Production of Butadiene from Bioethylene) A catalyst prepared by dissolving 0.5 mmol / L of palladium acetate in 0.3 mol / L of Na3H3PMo9V3O 40 was introduced into the second-stage reaction column 26 of the apparatus shown in Fig. 1, and the apparatus was purged with argon. Bio-derived ethylene (prototype, product from corn-derived bioethanol) was introduced thereinto. The reaction was carried out for 1 hour while circulating the catalyst solution through the circulation line 28 under the conditions of 150 °C and 0.5 MpaG. After removing the catalyst solution through the drain of the cooling device 27, an alumina catalyst (alumina KHA-46 manufactured by Sumitomo Chemical Co., Ltd.) immersed in bioethanol was charged and reacted at 400 °C for 5 hours. The production of butadiene was confirmed by analyzing the reaction mixture by GC / MS. The value of pMC indicating the biomass ratio of the obtained butadiene (bio-derived butadiene) was 109%.

[0252] Production Example 4 (Production of Butadiene from Tiglic Acid) 500 mg of tiglic acid (an intermediate via in vivo amino acids) separated and purified from hazelnut oil, 30 mg of tetrakistriphenylphosphine palladium(0), and 10 mg of triethylboron were placed in an autoclave filled with argon and reacted at 200 °C for 1 hour. The production of butadiene was confirmed by analyzing the product by GC / MS. The value of pMC indicating the biomass ratio of the obtained butadiene (bio-derived butadiene) was 108%.

[0253] When the bio-derived butadiene obtained in Production Examples 1 to 4 was measured using an NMR apparatus AV400 manufactured by BRUKER (data analysis software TOP SPIN 2.1), it was confirmed that these butadienes were 1,3-butadiene.

[0254] Production Example 5 (Production of Biomass Butadiene Rubber (Bio-BR)) As the biomass-derived butadiene, a mixture of the biomass-derived butadiene (1,3-butadiene) obtained in Production Examples 1 to 4 was used as a monomer component to synthesize butadiene rubber (biomass-derived rubber). The chemicals used are as follows. Ion-exchanged water: manufactured by the company Potassium rosinate soap: manufactured by Harima Kasei Co., Ltd. Sodium fatty acid soap: manufactured by Fujifilm Wako Pure Chemical Corporation Potassium chloride: manufactured by Fujifilm Wako Pure Chemical Corporation Sodium naphthalenesulfonate formalin condensate: manufactured by Kao Corporation t-Dodecyl mercaptan: tert-dodecyl mercaptan (chain transfer agent) manufactured by Fujifilm Wako Pure Chemical Corporation Sodium hydrosulfide: manufactured by Fujifilm Wako Pure Chemical Corporation FeSO4: ferric sulfate manufactured by Fujifilm Wako Pure Chemical Corporation EDTA: sodium ethylenediaminetetraacetate manufactured by Fujifilm Wako Pure Chemical Corporation Rongalit: sodium formaldehyde sulfoxylate manufactured by Fujifilm Wako Pure Chemical Corporation Polymerization initiator: paramethane hydroperoxide manufactured by NOF Corporation Polymerization terminator: N,N-diethylhydroxylamine manufactured by Fujifilm Wako Pure Chemical Corporation 2,6-Di-t-butyl-p-cresol: Sumilizer BHT manufactured by Sumitomo Chemical Co., Ltd. <Synthesis of butadiene rubber> A stainless-steel polymerization reactor with an internal volume of 50 liters was washed, dried, and purged with dry nitrogen. Then, 5000 g of 1,3-butadiene, 5.74 g of t-dodecyl mercaptan, 9688 g of an emulsifier (a mixture of ion-exchanged water, potassium rosinate soap, sodium fatty acid soap, potassium chloride, and a sodium naphthalene sulfonate formalin condensate), 6.3 ml (1.8 M) of sodium hydrosulfide, 6.3 ml each of an activator (FeSO4 / EDTA / rongalite), and 6.3 ml (2.3 M) of a polymerization initiator were added. Polymerization was carried out at 10 °C for 3 hours with stirring. After the polymerization was completed, 2.9 g of N,N-diethylhydroxylamine was added, and the reaction was carried out for 30 minutes. The content of the polymerization reaction vessel was taken out, 10 g of 2,6-di-t-butyl-p-cresol was added, and most of the water was evaporated. Then, it was dried under reduced pressure at 55 °C for 12 hours to obtain a biobutadiene polymer (biomass butadiene rubber (bioBR), and pMC indicating the biomass ratio of the obtained bioBR was 105%).

[0255] The following describes various chemicals used in the examples and comparative examples. NR: TSR20 (NR) BioBR: BR prepared in Production Example 5 above (cis content: 98% by mass, Mw: 400,000, Mw / Mn: 4.2) Rubber powder 1: PolyDyne40 manufactured by Lehigh TECHNOLOGIES (containing 51 parts by mass of carbon black and 7 - 10 parts by mass of silica based on 100 parts by mass of the rubber component. In 100% by mass of the units of the total rubber component, the content of units derived from isoprene is 66% by mass, and the content of units derived from butadiene is 34% by mass. It contains 26% by mass of high-cis BR (cis content: 97% by mass) in 100% by mass of the rubber component, volume average particle diameter: 281 μm, residue on a 60-mesh sieve: 1% by mass or less, residue on an 80-mesh sieve: 0.1% by mass, acetone extract: 6.1% by mass) Rubber powder 2: PolyDyne60 manufactured by Lehigh TECHNOLOGIES (containing 54 parts by mass of carbon black and 8 - 11 parts by mass of silica per 100 parts by mass of rubber component. In 100 mass% of the total rubber component units, the content of units derived from isoprene is 86 mass%, the content of units derived from butadiene is 14 mass%. It contains 14 mass% of high - cis BR (cis content: 97 mass%) in 100 mass% of the rubber component, volume - average particle diameter: 131μm, residue on 60 - mesh sieve: 0.1 mass%, residue on 80 - mesh sieve: 0.1 mass%, acetone extract: 6.3 mass%) Rubber powder 3: PolyDyne80 manufactured by Lehigh TECHNOLOGIES (containing 54 parts by mass of carbon black and 9 - 12 parts by mass of silica per 100 parts by mass of rubber component. In 100 mass% of the total rubber component units, the content of units derived from isoprene is 40 mass%, the content of units derived from butadiene is 10 mass%. It contains 10 mass% of high - cis BR (cis content: 97 mass%) in 100 mass% of the rubber component, volume - average particle diameter: 114μm, residue on 60 - mesh sieve: 0.1 mass%, residue on 80 - mesh sieve: 0.1 mass%, acetone extract: 6.5 mass%) Rubber powder 4: PolyDyne140 manufactured by Lehigh TECHNOLOGIES (containing 46 parts by mass of carbon black and 15 - 18 parts by mass of silica per 100 parts by mass of rubber component. In 100 mass% of the total rubber component units, the content of units derived from isoprene is 42 mass%, the content of units derived from butadiene is 11 mass%. It contains 11 mass% of high - cis BR (cis content: 97 mass%) in 100 mass% of the rubber component, volume - average particle diameter: 64μm, residue on 60 - mesh sieve: 0.1 mass% or less, residue on 80 - mesh sieve: 0.1 mass% or less, acetone extract: 7.5 mass%) Rubber powder 5: PolyDyne 200 manufactured by Lehigh TECHNOLOGIES (containing 46 parts by mass of carbon black and 15 - 18 parts by mass of silica based on 100 parts by mass of the rubber component, content of units derived from isoprene in 100 mass% of the unit of all rubber components: 65 mass%, content of units derived from butadiene: 35 mass%, containing 26 mass% of high - cis BR (cis content: 97 mass%) in 100 mass% of the rubber component, volume - average particle diameter: 53μm, residue on 60 - mesh sieve: 0.1 mass%, residue on 80 - mesh sieve: 0.1 mass%, acetone extract: 7.2 mass%) Carbon black: Diablack N220 manufactured by Mitsubishi Chemical Corporation (N2SA: 111m 2 / g) Silica: Ultrasil VN3 manufactured by Evonik Degussa (N2SA: 175m 2 / g) Rice husk silica: Rice husk silica manufactured by the method described in JP - A - 2019 - 38728 (N2SA: 175m 2 / g) Oil: Diana Process AH - 24 manufactured by Idemitsu Kosan Co., Ltd. (aromatic process oil) Silane coupling agent: Si266 manufactured by Evonik Degussa (bis(3 - triethoxysilylpropyl) disulfide) Resin 1: Sylvatraxx 4401 manufactured by Arizona Chemical Company (α - methylstyrene - based resin (copolymer of α - methylstyrene and styrene), softening point: 85℃) Resin 2: Sylvatraxx 4150 manufactured by Arizona Chemical Company (β - pinene resin, β - pinene content: 98 mass% or more, softening point: 115℃) Resin 3: Pine Crystal KR - 85 manufactured by Arakawa Chemical Industries, Ltd. (rosin - based resin, softening point: 80 - 87℃) Resin 4: Marca Retz M - 890A manufactured by Maruzen Petrochemical Co., Ltd. (dicyclopentadiene - based resin, softening point: 105℃) Resin 5: ECR - 373 manufactured by ExxonMobil (copolymer of C5 fraction and C9 fraction (C5 / C9 - based resin), softening point: 86℃) Zinc oxide: Zinc white No. 1 manufactured by Mitsui Mining & Smelting Co., Ltd. Stearic acid: Stearic acid "Tsubaki" manufactured by NOF Corporation Antioxidant 1: Nocrack 6C (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine) manufactured by Ouchi Shinko Chemical Industry Co., Ltd. Antioxidant 2: Nonflex RD (poly(2,2,4-trimethyl-1,2-dihydroquinoline)) manufactured by Seiko Chemical Co., Ltd. Sulfur: HK-200-5 (powder sulfur containing 5% by mass of oil) manufactured by Hosoi Chemical Industry Co., Ltd. Vulcanization accelerator 1: Noxeller CZ (N-cyclohexyl-2-benzothiazolylsulfenamide) manufactured by Ouchi Shinko Chemical Industry Co., Ltd. Vulcanization accelerator 2: Noxeller D (diphenylguanidine) manufactured by Ouchi Shinko Chemical Industry Co., Ltd.

[0256] (Examples and Comparative Examples) According to the formulation contents shown in Tables 1 to 2, using a 1.7 L Banbury mixer, materials other than sulfur and vulcanization accelerators were kneaded at 150 °C for 5 minutes to obtain a kneaded product. Next, sulfur and vulcanization accelerators were added to the obtained kneaded product, and it was kneaded at 80 °C for 5 minutes using an open roll to obtain an unvulcanized rubber composition. The obtained unvulcanized rubber composition was molded into the shape of a cap tread and bonded together with other tire members to form an unvulcanized tire, which was press-vulcanized at 150 °C for 12 minutes to manufacture a test tire (size: 195 / 65R15).

[0257] Using the obtained unvulcanized rubber composition and test tire, the following evaluations were conducted, and the results are shown in Tables 1 to 2. Note that the reference example in Table 1 was taken as Comparative Example 1-1, and the reference example in Table 2 was taken as Comparative Example 2-1.

[0258] (Dimensional Stability) Using an extruder, the obtained unvulcanized rubber composition was extruded, the obtained extrudate was cut in the thickness direction, and the variation in cross-sectional area was calculated as the coefficient of variation (CV value) and shown as an index with the reference example set to 100. The larger the numerical value, the higher the effect of suppressing shrinkage generation, and it can be judged that the dimensions are stable due to more uniform heat treatment.

[0259] (Hardness (Hs)) A test piece was cut out from the cap tread of the test tire. Then, in accordance with "Testing Method for Hardness of Vulcanized Rubber and Thermoplastic Rubber" of JIS K6253, the Hs of the test piece was measured using a Type A durometer (measurement temperature: 25°C). The results were expressed as an index with the reference example being 100. The larger the index, the higher the hardness.

[0260] (Tensile Test) A test piece was cut out from the cap tread of the test tire. Then, based on JIS K6251 (2010), a No. 3 dumbbell-shaped test piece was prepared from the obtained test piece, and a tensile test was carried out at 23°C using this test piece to measure the tensile strength at break (TB) and the elongation at break (EB). The results were expressed as an index with the reference example being 100. The larger the index, the higher the breaking strength.

[0261] (tanδ) A test piece was cut out from the cap tread of the test tire. Then, using a viscoelastic spectrometer VES manufactured by Iwamoto Seisakusho Co., Ltd., the 30°C tanδ of the test piece (vulcanized rubber composition) was measured. The measurement conditions are as follows. The results were expressed as an index with the reference example being 100. The larger the index, the better the low fuel consumption performance. When the index is 99 or more, it was judged that the low fuel consumption performance is excellent. Measurement temperature: 30°C, initial strain: 10%, dynamic strain: 2%, frequency: 10 Hz

[0262]

Table 1

[0263]

Table 2

[0264] From Tables 1 to 2, it was found that the cap tread of the example having a rubber composition A phase and a rubber composition B phase with boundaries independent of each other, in the rubber composition A phase, containing 100 parts by mass or more of silica and 10 parts by mass or less of carbon black with respect to 100 parts by mass of the rubber component, and in the rubber composition B phase, containing 10 parts by mass or more of carbon black and 13 to 20 parts by mass of silica with respect to 100 parts by mass of the rubber component, and the rubber composition B phase being divided into the rubber composition A phase and existing independently in the rubber composition A phase, can improve the comprehensive performance of low fuel consumption and fracture strength while having good dimensional stability.

[0265] From the comparison between Examples 1-2 and Comparative Examples 1-1, 1-5, 1-6, and the comparison between Examples 2-2 and Comparative Examples 2-1, 2-5, 2-6, it was found that by the independent existence of a rubber composition B phase (for example, rubber powder) with a specific formulation in the rubber composition A phase with a high silica content, specifically, by the dispersion of a rubber composition B phase (for example, rubber powder) with a specific formulation in the rubber composition A phase with a high silica content, the comprehensive performance (represented by the sum of two indices of low fuel consumption and fracture strength) of low fuel consumption and fracture strength can be synergistically improved while having good dimensional stability.

Explanation of Symbols

[0266] 21 Alcohol introduction pipe (raw material introduction pipe) 22 Heating device (electric furnace) 23 Column for dehydration reaction 24 Cooling device 25 Heating device 26 Second-stage reaction column 27 Cooling device 28 Circulation line

Claims

1. A rubber composition has a rubber composition A phase and a rubber composition B phase that have boundaries independent of each other. In the rubber composition A phase, 100 to 300 parts by mass of silica and 1 to 10 parts by mass of carbon black are contained per 100 parts by mass of the rubber component. In the rubber composition A phase, 50 to 100 parts by mass of resin are contained per 100 parts by mass of the rubber component. In the rubber composition B phase, 10 to 80 parts by mass of carbon black and 13 to 20 parts by mass of silica are contained per 100 parts by mass of the rubber component. The rubber composition B phase is divided into the rubber composition A phase and exists independently in the rubber composition A phase as a cap tread of a passenger car tire.

2. The cap tread according to claim 1, wherein the volume average particle diameter of the rubber composition B phase is 1000 μm or less.

3. The cap tread according to claim 1 or 2, wherein in the rubber composition A phase, the content of units derived from isoprene is 50 to 90% by mass in 100% by mass of the units of the total rubber component.

4. The cap tread according to claim 1 or 2, wherein in the rubber composition A phase, the content of units derived from isoprene is 1 to 10% by mass in 100% by mass of the units of the total rubber component.

5. The cap tread according to any one of claims 1 to 4, wherein the content of the rubber composition A phase is 40 to 99% by mass in 100% by mass of the cap tread rubber.

6. The cap tread according to any one of claims 1 to 5, wherein in the rubber composition A phase, the rubber component contains units derived from at least one biomass-derived component selected from the group consisting of butadiene, aromatic vinyl, and ethylene.

7. The cap tread according to any one of claims 1 to 6, wherein the resin is at least one selected from the group consisting of terpene resins and rosin resins.

8. The cap tread according to any one of claims 1 to 6, wherein the resin is at least one selected from the group consisting of cyclopentadiene resins, C5 resins, C5 / C9 resins, and C9 resins.

9. The cap tread according to any one of claims 1 to 6, wherein the resin is an aromatic resin.

10. The cap tread according to any one of claims 1 to 9, wherein the resin is modified with a polar functional group that interacts with silica.

11. The cap tread according to any one of claims 1 to 10, wherein in the rubber composition A phase, silica derived from rice husks is included.

12. The cap tread according to any one of claims 1 to 11, wherein in the B phase of the rubber composition, the content of units derived from isoprene is 50 to 95% by mass based on 100% by mass of the units of all rubber components.

13. The cap tread according to any one of claims 1 to 12, wherein in the B phase of the rubber composition, 1 to 40% by mass of butadiene rubber having a cis content of 90% by mass or more is contained based on 100% by mass of the rubber components.

14. The cap tread according to any one of claims 1 to 13, wherein the B phase of the rubber composition is rubber powder.

15. A passenger car tire having the cap tread according to any one of claims 1 to 14.

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