Rubber composition for passenger car tires and passenger car tires

Abstract

To provide a rubber composition for a passenger car tire and a passenger car tire which can improve performances such as wet grip performance and fracture strength required for a tire while reducing use of a raw material derived from a fossil fuel in consideration of environment.SOLUTION: A rubber composition for a passenger car tire contains 30% or more of a pMC (percent Modern Carbon) measured according to ASTM D 6866-10 of a component based on butadiene and aromatic vinyl, has a content of a unit derived from the butadiene of 80-100 mass% in 100 mass% of the unit of the total rubber components, has a content of a unit derived from the aromatic vinyl of 0-20 mass% in 100 mass% of the unit of the total rubber components, and contains 10-100 pts.mass of the resin with respect to 100 pts.mass of the rubber component.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a rubber composition for a passenger car tire and a passenger car tire. [Background technology]

[0002] In response to environmental and resource depletion issues, various efforts have been made to reduce the use of petroleum resources. For example, a technology using biomass-derived polybutadiene rubber is known (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-051617 Summary of the Invention [Problem to be solved by the invention]

[0004] However, as a result of investigations by the present inventors, it has become clear that there is room for improvement in terms of providing a rubber composition for tires that reduces the use of raw materials derived from fossil fuels in consideration of the environment, while also improving the performance required for tires, such as wet grip performance and breaking strength. The present invention aims to solve the above-mentioned problems and to provide a rubber composition for passenger car tires, which can reduce the use of raw materials derived from fossil fuels in consideration of the environment, while also improving performance required for tires, such as wet grip performance and breaking strength, and a passenger car tire. [Means for solving the problem]

[0005] The present invention relates to a rubber composition having a pMC (percent modern carbon) of 30% or more as measured in accordance with ASTM D6866-10 of components based on butadiene and aromatic vinyl, The content of units derived from butadiene is 80 to 100% by mass based on 100% by mass of all units of the rubber component, the content of units derived from aromatic vinyl is 0 to 20% by mass based on 100% by mass of all units of the rubber component, The present invention relates to a rubber composition for passenger car tires, which contains 10 to 100 parts by mass of a resin per 100 parts by mass of a rubber component.

[0006] The pMC (percent modern carbon) of the entire rubber component measured in accordance with ASTM D6866-10 is 30% or more, The content of units derived from butadiene is 80 to 99% by mass based on 100% by mass of all units of the rubber component, the content of units derived from aromatic vinyl is 0 to 19% by mass based on 100% by mass of all units of the rubber component, The content of units derived from isoprene is preferably 1 to 10% by mass based on 100% by mass of all units in the rubber component.

[0007] The butadiene is preferably obtained by a catalytic reaction from at least one biomass-derived component selected from the group consisting of biomass-derived alkyl alcohols, allyl alcohols, alkenes, aldehydes, and unsaturated carboxylic acids.

[0008] The alkyl alcohol is preferably at least one selected from the group consisting of ethanol, butanol, and butanediol.

[0009] The butanol is preferably produced by at least one species 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 a gene associated with the mevalonate pathway, a gene associated with the MEP / DOXP pathway, a gene encoding butyryl-CoA dehydrogenase, a gene encoding butyraldehyde dehydrogenase, and a gene encoding butanol dehydrogenase has been introduced.

[0010] The allyl alcohol is preferably crotyl alcohol and / or 3-buten-2-ol.

[0011] The alkenes are preferably butene and / or ethylene.

[0012] The aldehyde is preferably acetaldehyde.

[0013] The unsaturated carboxylic acids are preferably tiglic acid and / or angelic acid.

[0014] The butadiene is preferably produced directly from biomass by at least one selected from the group consisting of microorganisms, plants, animals, and tissue cultures thereof.

[0015] The butadiene is preferably converted from at least one selected from the group consisting of sugars, hemiterpenes, and amino acids.

[0016] The amino acid is preferably at least one selected from the group consisting of valine, leucine, isoleucine, and arginine.

[0017] The enzyme that converts hemiterpenes and / or amino acids into butadiene is preferably at least one selected from the group consisting of HMG-CoA reductase, diphosphomevalonate decarboxylase, and amino acid decarboxylase.

[0018] The ethylene is preferably converted from biomass by fermentation using at least one selected from the group consisting of microorganisms, plants, animals, and tissue cultures thereof.

[0019] The ethylene-producing microorganisms, plants, animals, and tissue cultures thereof are preferably those into which a gene encoding ACC synthase has been introduced and / or modified.

[0020] The ethylene is preferably obtained by a catalytic reaction using carbon dioxide as a raw material.

[0021] The content of units in which the double bond is of cis type in the units derived from butadiene is preferably 5 to 100% by mass based on 100% by mass of the units of the entire rubber component.

[0022] The aromatic vinyl is preferably produced directly from biomass by at least one selected from the group consisting of microorganisms, plants, animals, and tissue cultures thereof.

[0023] The aromatic vinyl is preferably one converted from cinnamic acid derived from biomass.

[0024] The plant preferably belongs to at least one family selected from the group consisting of Hamamelidaceae, Styraxaceae, Apocynaceae, Solanaceae, Carrot family, and Theaceae family.

[0025] It is preferable that the microorganism belongs to at least one genus selected from the group consisting of Fusarium, Penicillium, Pichia, Candida, Debaryomyces, Torulopsis, Saccharomyces, Bacillus, Escherichia, Streptomyces, and Pseudomonas.

[0026] Preferably, the microorganism is a non-genetically modified microorganism.

[0027] It is preferable that the microorganism and / or plant be engineered to highly express phenylalanine ammonia-lyase.

[0028] It is preferable that the microorganism and / or plant be engineered to highly express cinnamic acid decarboxylase (phenylacrylic acid decarboxylase).

[0029] Preferably, the microorganism and / or plant is one that has been engineered to highly express phenolic acid decarboxylase.

[0030] The aromatic vinyl is preferably obtained from biomass-derived cinnamic acid by metabolism in a plant.

[0031] The aromatic vinyl is preferably obtained by microbial fermentation of biomass-derived cinnamic acid.

[0032] The aromatic vinyl is preferably obtained by catalytic reaction of cinnamic acid derived from biomass.

[0033] The aromatic vinyl is preferably styrene.

[0034] It is preferable that the copolymer contains an aromatic vinyl / butadiene copolymer in which the content of units derived from aromatic vinyl is 10% by mass or less.

[0035] The content of natural rubber in 100% by mass of the rubber component is preferably 0.1 to 10% by mass.

[0036] It is preferable that the 0°C tan δ is 0.18 to 1.60 and the Tg is -85°C to -5°C.

[0037] The resin is preferably at least one selected from the group consisting of terpene-based resins and rosin-based resins.

[0038] The resin is preferably at least one selected from the group consisting of cyclopentadiene resins, C5 resins, C5 / C9 resins, and C9 resins.

[0039] The resin is preferably an aromatic resin.

[0040] Preferably, the resin is modified with a polar functional group that interacts with silica.

[0041] It is preferable to contain silica derived from rice husks.

[0042] The rubber composition preferably contains rubber powder.

[0043] The rubber composition preferably contains 80 parts by mass or more of silica per 100 parts by mass of the rubber component.

[0044] The rubber composition preferably contains 50 parts by mass or more of resin per 100 parts by mass of the rubber component.

[0045] The present invention also relates to a passenger vehicle tire having tire components using the rubber composition.

[0046] The tire component is preferably a tread. [Effects of the Invention]

[0047] The present invention relates to a rubber composition for passenger car tires, which has a pMC (percent modern carbon) of 30% or more of components based on butadiene and aromatic vinyl, measured in accordance with ASTM D6866-10, and which contains 80 to 100% by mass of units derived from butadiene, based on 100% by mass of all units in the rubber component, and 0 to 20% by mass of units derived from aromatic vinyl, based on 100% by mass of all units in the rubber component, and which contains 10 to 100 parts by mass of resin, based on 100 parts by mass of the rubber component. Therefore, the rubber composition is environmentally friendly and reduces the use of raw materials derived from fossil fuels, while also improving performance required for tires, such as wet grip performance and breaking strength. [Brief explanation of the drawings]

[0048] [Figure 1] FIG. 1 is a schematic diagram showing a simplified apparatus used for producing butadiene. [Figure 2] FIG. 1 is a diagram showing a schematic diagram of the prepared plasmid. DETAILED DESCRIPTION OF THE INVENTION

[0049] The rubber composition for passenger car tires of the present invention has a pMC (percent modern carbon) of 30% or more of components based on butadiene and aromatic vinyl, measured in accordance with ASTM D6866-10, a content of units derived from butadiene of 80 to 100% by mass based on 100% by mass of all units in the rubber component, a content of units derived from aromatic vinyl of 0 to 20% by mass based on 100% by mass of all units in the rubber component, and contains 10 to 100 parts by mass of resin per 100 parts by mass of the rubber component. This allows for environmentally friendly reduction in the use of fossil fuel-derived raw materials, while also improving performance required for tires, such as wet grip performance and breaking strength.

[0050] The reason why the rubber composition exhibits the above-mentioned effects is presumed to be as follows. The rubber component used in the rubber composition is a rubber component having a pMC of 30% or more of components based on butadiene and aromatic vinyl, and a content of units derived from butadiene of 80 to 100% by mass of 100% by mass of all units in the rubber component, i.e., a rubber component having a pMC of 30% or more of components based on butadiene and aromatic vinyl, i.e., a high biomass ratio of components based on butadiene and aromatic vinyl, and a high content of units derived from butadiene. By using such a rubber component, it becomes possible to reduce the use of raw materials derived from fossil fuels in an environmentally friendly manner. Furthermore, by combining a rubber component with a high biomass ratio of components based on butadiene and aromatic vinyl, and a high content of units derived from butadiene, with a resin, the overall performance of wet grip performance and breaking strength (expressed as the sum of the two indices of wet grip performance and breaking strength) can be synergistically improved. Although the details are not clear, it is speculated that the rubber component contains rubber that uses biomass-derived butadiene, and that the biomass-derived butadiene and aromatic vinyl contain trace amounts of impurities that are different from those derived from petroleum resources. These impurities interact with the resin, reinforcing the resin domains, resulting in a synergistic effect.

[0051] pMC is the modern standard reference 14 of sample against C concentration 14 In this specification, this value is used as an index showing the biomass ratio of the compound (rubber). The significance of this value will be described below.

[0052] 1 mole of carbon atoms (6.02 × 10 23 ) contains approximately 6.02 × 10 atoms, which is about one trillionth of the number of ordinary carbon atoms. 11 pieces 14 C exists. 14 C is called a radioactive isotope, and its half-life is 5,730 years, and it decreases regularly. It takes 226,000 years for all of it to decay. Therefore, in fossil fuels such as coal, oil, and natural gas, which are thought to have been absorbed and fixed by plants and other organisms more than 226,000 years ago, C was also included in these when it was first fixed. 14 All C elements have decayed. Therefore, in the 21st century, fossil fuels such as coal, oil, and natural gas contain 14 Therefore, chemicals produced from these fossil fuels do not contain any C element. 14 It does not contain any C elements.

[0053] on the other hand, 14 C is produced continuously by nuclear reactions in the atmosphere caused by cosmic rays, and this balances with the decrease due to radioactive decay. In the Earth's atmospheric environment, 14 Therefore, the amount of carbon derived from biomass resources currently circulating in the environment is constant. 14 As mentioned above, the C concentration is approximately 1 × 10 -12 The value is approximately mol%. Therefore, by using the difference between these values, it is possible to calculate the ratio (biomass ratio) of compounds derived from natural resources (compounds derived from biomass resources) in a certain compound (rubber).

[0054] this 14C is typically measured using accelerator mass spectrometry based on a tandem accelerator. 13 C concentration ( 13 C / 12 C). 14 C concentration ( 14 C / 12 C) is measured. 14 The modern standard reference for the C concentration is the carbon circulating in nature as of 1950. 14 The specific standard substance used is the oxalic acid standard provided by NIST (National Institute of Standards and Technology). The specific activity of carbon in this oxalic acid (per gram of carbon) is 14 The radioactivity of C is separated into carbon isotopes, 13 The standard value is the value corrected for decay from 1950 to the measurement date. 14 The ratio of this value to the value of the actually measured sample is the pMC value used in the present invention.

[0055] Therefore, if rubber is made from 100% biomass (natural) derived materials, it will show a value of approximately 110 pMC, although there may be regional differences (currently, under normal conditions, it is often not 100). On the other hand, for chemical substances derived from petroleum and other fossil fuels, 14 When the carbon concentration is measured, it will be approximately 0 pMC (for example, 0.3 pMC), which corresponds to the biomass ratio of 0% mentioned above.

[0056] From the above, it is preferable in terms of environmental protection to use materials such as rubbers with high pMC values, that is, materials such as rubbers with high biomass ratios, in rubber compositions for passenger car tires.

[0057] (rubber component) In the rubber composition for passenger car tires, the pMC (percent modern carbon) (this value indicates the biomass ratio of the butadiene- and aromatic vinyl-based components contained in the rubber component) measured in accordance with ASTM D6866-10 is 30% or more, preferably 40% or more, more preferably 50% or more, even more preferably 60% or more, particularly preferably 70% or more, most preferably 80% or more, even most preferably 90% or more, and even most preferably 100% or more, with no particular upper limit. A higher pMC is preferable because it provides more optimal effects. As mentioned above, the pMC can be calculated as a ratio to a standard substance, and therefore can take a value exceeding 100%. In this specification, the pMC of the butadiene and aromatic vinyl based components contained in the rubber component means the pMC of the entire butadiene based components and aromatic vinyl based components contained in the rubber component. In this specification, a butadiene-based component means a structural unit in a polymer constituted based on butadiene as a monomer, and an aromatic vinyl-based component means a structural unit in a polymer constituted based on aromatic vinyl as a monomer.

[0058] In the rubber composition for passenger car tires, the pMC (percent modern carbon) (this value indicates the biomass ratio of the butadiene-based component) of the butadiene-based component contained in the rubber component, measured in accordance with ASTM D6866-10, is preferably 30% or more, more preferably 40% or more, even more preferably 50% or more, particularly preferably 60% or more, most preferably 70% or more, even most preferably 80% or more, even most preferably 90% or more, and particularly most preferably 100% or more, with no particular upper limit. A higher pMC is preferable because the effects can be more effectively obtained. As mentioned above, the pMC can take a value exceeding 100% due to the nature of the calculation being based on a ratio to a standard substance.

[0059] In the rubber composition for passenger car tires, the pMC (percent modern carbon) (this value indicates the biomass ratio of the entire rubber component) measured in accordance with ASTM D6866-10 of the entire rubber component is preferably 30% or more, more preferably 40% or more, even more preferably 50% or more, particularly preferably 60% or more, most preferably 70% or more, even most preferably 80% or more, even most preferably 90% or more, and particularly most preferably 100% or more, with no particular upper limit. A higher pMC is preferable because the effects can be more suitably obtained. As mentioned above, since the pMC is calculated as a ratio to a standard substance, it can take a value exceeding 100%.

[0060] In this specification, the pMC of each component is a value obtained by measurement in accordance with ASTM D6866-10, and specifically, can be measured by the method described in the Examples. As described in the examples, the amount of each component such as rubber 14 To analyze the C concentration, it is first necessary to pre-treat each component, such as rubber. Specifically, the carbon contained in each component, such as rubber, is oxidized and converted into carbon dioxide. The resulting carbon dioxide must then be separated from water and nitrogen, reduced, and converted into graphite, which is solid carbon. Then, the resulting graphite is charged with Cs. + The carbon ions are accelerated using a tandem accelerator, and the negative ions are converted to positive ions. 12 C 3+ , 13 C 3+ , 14 C 3+ Separating the traveling orbit of 14 C 3+ can be measured by an electrostatic analyzer. In this specification, biomass is also referred to as biomass resources.

[0061] In order to set the pMC of each of the butadiene, aromatic vinyl-based component, and butadiene-based component within the above range, for example, a polymer synthesized using biomass-derived butadiene or biomass-derived aromatic vinyl (e.g., biomass-derived styrene) as a monomer component may be used. In order to set the pMC of the entire rubber component within the above range, in addition to the above-mentioned methods, natural rubber may be used or a polymer synthesized using a biomass-derived monomer component (for example, biomass-derived isoprene) as a monomer component may be used.

[0062] Previously, the raw materials for rubber compositions for tires (rubber monomers, fillers, resins, etc.) required large-scale manufacturing equipment, and were often produced in large factories in specific regions, resulting in the use of a lot of energy for storing and transporting raw materials and products. Bio-based materials, on the other hand, can often be made from raw materials derived from local agricultural and forestry sources, and can often be manufactured on a small scale with the right technologies, such as microbial fermentation and catalytic reactions. By utilizing local products and waste, there is no need for the energy required to transport and store raw materials from long distances. Furthermore, long-distance transportation of the manufactured materials to tire factories and subsequent storage are often unnecessary, resulting in comprehensive environmentally friendly tire manufacturing.

[0063] Furthermore, when producing a rubber composition, the ratio of the biomass-derived monomer component and the petroleum-derived monomer component can be appropriately selected in accordance with overall environmental requirements such as the supply status of biomass resources, the supply status of petroleum resources (e.g., petroleum-resource-derived monomer components), and / or market demands (e.g., competing trends with demand for biomass resources as food), and the biomass-derived monomer component or the biomass-derived monomer component and the petroleum-resource-derived monomer component can be polymerized in the appropriately selected ratio to polymerize biomass-derived rubber, thereby making it possible to produce biomass-derived rubber with performance equivalent to that of conventional synthetic rubber.

[0064] In this specification, the rubber component is a component that contributes to crosslinking, and generally has a weight average molecular weight (Mw) of 10,000 or more.

[0065] The weight average molecular weight of the rubber component is preferably 50,000 or more, more preferably 150,000 or more, and even more preferably 200,000 or more, and is preferably 2,000,000 or less, more preferably 1,500,000 or less, and even more preferably 1,300,000 or less. Within the above ranges, the effect tends to be more favorable.

[0066] In this specification, the weight average molecular weight (Mw) and number average molecular weight (Mn) can be determined in terms of standard polystyrene based on measurements obtained using a gel permeation chromatograph (GPC) (GPC-8000 series, manufactured by Tosoh Corporation; detector: differential refractometer; column: TSKGEL SUPERMULTIPORE HZ-M, manufactured by Tosoh Corporation).

[0067] In the rubber composition for passenger car tires, the content of units derived from butadiene is 80 to 100% by mass, based on 100% by mass of all units in the rubber component. The lower limit 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. Within the above ranges, the effect tends to be more favorably obtained.

[0068] In the rubber composition for passenger car tires, the content of units derived from aromatic vinyl is 0 to 20% by mass, based on 100% by mass of all rubber component units. The lower limit is preferably 1% by mass or more, more preferably 3% by mass or more, and the upper limit is preferably 19% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, and particularly preferably 8% by mass or less. Within the above ranges, the effect tends to be more favorably obtained.

[0069] In the rubber composition for passenger car tires, the content of units derived from isoprene is preferably 1 to 10% by mass, based on 100% by mass of all units in the rubber component. The lower limit is preferably 1% by mass or more, more preferably 3% by mass or more, and the upper limit is preferably 7% by mass or less. Within the above ranges, better effects tend to be obtained.

[0070] In the rubber composition for passenger car tires, the content of units in which the double bond in the butadiene-derived unit is cis-type is preferably 5 to 100% by mass, based on 100% by mass of the units in the total rubber component. The lower limit is preferably 10% by mass or more, more preferably 30% by mass or more, even more preferably 50% 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, and even most preferably 90% by mass or more, and the upper limit is preferably 99% by mass or less. Within the above range, the effect tends to be more favorably obtained.

[0071] In this specification, the term "unit" refers to a structural unit of a polymer. A butadiene-derived unit refers to a structural unit in a polymer formed based on the butadiene monomer, an aromatic vinyl-derived unit refers to a structural unit in a polymer formed based on the aromatic vinyl monomer, and an isoprene-derived unit refers to a structural unit in a polymer formed based on the isoprene monomer (including the isoprene unit in natural rubber). In this specification, the content of each unit is measured by NMR.

[0072] In order to set the content of the units in the rubber composition within the above range, for example, butadiene rubber (BR), aromatic vinyl / butadiene copolymer (e.g., styrene butadiene rubber (SBR)), and isoprene-based rubber may be used in appropriate combination.

[0073] The BR is not particularly limited, and can be a high-cis BR, a low-cis BR, a BR containing syndiotactic polybutadiene crystals, etc. Commercially available products include those from Ube Industries, Ltd., JSR Corporation, Asahi Kasei Corporation, and Zeon Corporation. These can be used alone or in combination of two or more.

[0074] The cis amount (cis content) of BR is preferably 30% by mass or more, more preferably 50% by mass or more, even more preferably 70% by mass or more, and particularly preferably 90% by mass or more, with no particular upper limit. Within this range, better effects tend to be obtained. The cis content of BR can be measured by NMR.

[0075] In 100% by mass of the rubber component, the BR content is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more, and particularly preferably 90% by mass or more, and is preferably 100% by mass or less, more preferably 99% by mass or less, and even more preferably 97% by mass or less. Within the above ranges, the effects tend to be more favorably obtained.

[0076] The aromatic vinyl / butadiene copolymer (e.g., SBR) is not particularly limited, and examples thereof include emulsion-polymerized aromatic vinyl / butadiene copolymers (e.g., emulsion-polymerized styrene-butadiene rubber (E-SBR)), solution-polymerized aromatic vinyl / butadiene copolymers (e.g., solution-polymerized styrene-butadiene rubber (S-SBR)), etc. Commercially available products include those from 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.

[0077] Examples of aromatic vinyl (aromatic vinyl monomer) include styrene, vinylnaphthalene, and divinylnaphthalene. These may be used alone or in combination of two or more. Among these, styrene (particularly biomass-derived styrene) is preferred. That is, SBR is preferred as the aromatic vinyl / butadiene copolymer. The styrene may have a substituent.

[0078] 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, and preferably 60% by mass or less, more preferably 50% by mass or less, even more preferably 40% by mass or less, particularly preferably 30% by mass or less, most preferably 20% by mass or less, and most preferably 10% by mass or less. When it is within the above range, the effect tends to be better obtained. In this specification, the aromatic vinyl content (preferably styrene content) of the rubber is 1 It is calculated by H-NMR measurement.

[0079] In 100% by mass of the rubber component, the content of the aromatic vinyl / butadiene copolymer (preferably SBR) is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, particularly preferably 15% by mass or more, and is preferably 20% by mass or less. Within the above range, the effect tends to be more favorably obtained.

[0080] Examples of isoprene-based rubbers include natural rubber (NR), isoprene rubber (IR), modified NR, modified NR, and modified IR. NRs such as SIR20, RSS#3, and TSR20 are commonly used in the tire industry. IRs are not particularly limited, and examples of IRs such as IR2200 are commonly used in the tire industry. Modified NRs include deproteinized natural rubber (DPNR) and highly purified natural rubber (UPNR). Modified NRs include epoxidized natural rubber (ENR), hydrogenated natural rubber (HNR), and grafted natural rubber. Modified IRs include epoxidized isoprene rubber, hydrogenated isoprene rubber, and grafted isoprene rubber. These may be used alone or in combination of two or more. NR is preferred.

[0081] The content of isoprene-based 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, and even more preferably 3% by mass or more, and is preferably 10% by mass or less, more preferably 7% by mass or less. Within the above ranges, better effects tend to be obtained.

[0082] Usable rubber components other than BR, aromatic vinyl / butadiene copolymer (e.g., SBR), and isoprene-based rubber include diene-based 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.

[0083] The rubber component may be modified to introduce a functional group that interacts 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 imido 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, and an epoxy group. These functional groups may have a substituent. These may be used alone or in combination of two or more. Among these, 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.

[0084] Specific examples of the compound (modifier) ​​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.

[0085] In order to set the pMC of each of the butadiene, aromatic vinyl-based component, and butadiene-based component within the above range, as described above, for example, a polymer synthesized using biomass-derived butadiene or biomass-derived aromatic vinyl (e.g., biomass-derived styrene) as a monomer component may be used. Specifically, biomass-derived polybutadiene rubber (BBR) synthesized from biomass-derived butadiene, or a 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. Biomass-derived polybutadiene rubber (BBR) and biomass-derived aromatic vinyl / butadiene copolymer (for example, biomass-derived styrene butadiene rubber (BSBR)) include not only rubber obtained by polymerizing butadiene and the like according to conventional methods, but also rubber obtained by reactions involving microorganisms, plants, animals, and tissue cultures of these (hereinafter also referred to as microorganisms, etc.) or enzymatic reactions.

[0086] Furthermore, the biomass-derived rubber may be any rubber obtained by polymerizing aromatic vinyl or butadiene as monomer components so as to satisfy the pMC, and at least one of the aromatic vinyl and butadiene must be derived from biomass (biomass-derived monomer components), but it is preferable that both the aromatic vinyl and butadiene are biomass-derived monomer components.

[0087] Furthermore, as long as the pMC is satisfied, a biomass-derived monomer component and a petroleum-derived monomer component may be used in combination. That is, biomass-derived butadiene may be used in combination with a butadiene other than biomass-derived butadiene (petroleum-derived butadiene). Similarly, biomass-derived aromatic vinyl may be used in combination with an aromatic vinyl other than biomass-derived aromatic vinyl (petroleum-derived aromatic vinyl).

[0088] Furthermore, the biomass-derived rubber may contain structural units derived from other monomer components (copolymerizable monomer components such as monoterpenes (e.g., myrcene)) other than aromatic vinyl and butadiene, as long as the pMC is satisfied.

[0089] The proportion of the biomass-derived monomer components in 100 mol% of the monomer components constituting the biomass-derived rubber is preferably 50 mol% or more, more preferably 70 mol% or more, even more preferably 80 mol% or more, particularly preferably 90 mol% or more, and most preferably 95 mol% or more, and may be 100 mol%.

[0090] The rubber composition preferably contains, as the biomass-derived rubber, a butadiene rubber obtained by polymerizing biomass-derived butadiene (biomass butadiene rubber (BBR)).

[0091] ((Method for preparing biomass-derived rubber)) Next, before describing a method for preparing biomass-derived rubber from biomass, the biomass in this specification will first be described.

[0092] In this specification, biomass (biomass resources) means carbon-neutral organic resources derived from living organisms, and specifically includes those converted and stored in forms such as starch and cellulose, the bodies of animals that grow by eating plants, and products made by processing plant or animal bodies, and is a resource excluding fossil resources.

[0093] The biomass resource may be edible or non-edible and is not particularly limited. From the viewpoint of not competing with food and effectively utilizing resources, it is preferable to use non-edible raw materials.

[0094] Specific examples of biomass resources include cellulosic crops (pulp, kenaf, wheat straw, rice straw, waste paper, papermaking residues, etc.), wood, charcoal, compost, natural rubber, cotton, sugarcane, soybean lees, oils and fats (rapeseed oil, cottonseed oil, soybean oil, coconut oil, castor oil, etc.), carbohydrate crops (corn, potatoes, wheat, rice, rice husks, rice bran, used rice, cassava, sago palm, etc.), bagasse, buckwheat, soybeans, essential oils (pine oil, orange oil, eucalyptus oil, etc.), pulp black liquor, food waste, vegetable oil cakes, fishery residues, livestock excrement, food waste, algae, and wastewater sludge.

[0095] Biomass resources may also be processed products (i.e., biomass-derived substances). Examples of processing methods include known methods such as biological processing methods that utilize the activity 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 pulverization, compression, microwave treatment, and electromagnetic wave treatment.

[0096] The biomass resource may also be a substance extracted and purified from the biomass resource or a biomass resource that has been subjected to the above-mentioned treatment (i.e., a biomass-derived substance). For example, it may be a sugar, protein, amino acid, fatty acid, fatty acid ester, or the like purified from the biomass resource.

[0097] The sugars are not particularly limited as long as they are derived from biomass, and examples include sucrose, glucose, trehalose, fructose, lactose, galactose, xylose, allose, talose, gulose, altrose, mannose, idose, arabinose, apiose, maltose, cellulose, starch, chitin, and the like.

[0098] The protein is not particularly limited as long as it is derived from biomass and is a compound formed by linking amino acids (preferably L-amino acids), and also includes oligopeptides such as dipeptides.

[0099] The amino acid is not particularly limited as long as it is an organic compound derived from biomass and has both an amino group and a carboxyl group, and examples thereof include valine, leucine, isoleucine, arginine, lysine, asparagine, glutamine, phenylalanine, etc. Among these, valine, leucine, isoleucine, arginine, and phenylalanine are preferred. Note that the amino acid may be either L-type or D-type, but L-type is preferred because it is abundant in nature and can be easily used as a biomass resource.

[0100] The fatty acid is not particularly limited as long as it is derived from biomass, and examples thereof include butyric acid, oleic acid, linoleic acid, palmitic acid, and stearic acid.

[0101] The fatty acid ester is not particularly limited as long as it is derived from biomass, and examples thereof include animal-derived fats, vegetable oils, modified biomass-derived fats and oils, and the like.

[0102] Biomass resources may contain a mixture of various materials and impurities, but for efficient conversion, it is preferable that the sugar content in 100% by mass of biomass be 20% by mass or more, more preferably 30% by mass or more, and even more preferably 50% by mass or more. In another embodiment, for efficient conversion, it is preferable that the total content of amino acids and proteins in 100% by mass of biomass be 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more. In yet another embodiment, it is preferable that the total content of fatty acids and fatty acid esters in 100% by mass of biomass be 10% by mass or more.

[0103] Next, a method for preparing biomass-derived rubber from biomass will be described. Below, as a representative example, a case where the biomass-derived rubber is BSBR will be specifically described. As mentioned above, in this specification, BSBR includes not only BSBR obtained by polymerizing biomass-derived butadiene and styrene according to conventional methods, but also BSBR obtained by reactions using microorganisms or enzyme reactions.

[0104] (((Method for preparing butadiene))) First, a method for preparing butadiene from a biomass resource will be described, but the method for preparing butadiene is not limited to the method described below.

[0105] There are various methods for preparing butadiene from biomass resources, and they are not particularly limited. For example, there are biological treatment methods in which butadiene is obtained directly from biomass resources using at least one selected from the group consisting of microorganisms, plants, animals, and tissue cultures thereof; methods in which butadiene is obtained by subjecting biomass resources to the aforementioned chemical treatment methods; methods in which butadiene is obtained by subjecting biomass resources to the aforementioned physical treatment methods; methods in which biomass resources are converted into butadiene by in vitro enzymatic reactions, etc.; and methods that combine these methods. It should be noted that the microorganisms, plants, and animals that convert biomass resources into butadiene may or may not be genetically engineered.

[0106] The method for directly converting biomass resources into butadiene using microorganisms or the like is not particularly limited, but it can be carried out using an in vivo pathway that converts amino acids into alkyl alcohols and / or hemiterpenes.

[0107] Preferred amino acids are valine, leucine, isoleucine, and arginine, and preferred hemiterpenes are tiglic acid and / or angelic acid.

[0108] A preferred example is a method for obtaining butadiene from amino acids and / or hemiterpenes by introducing and / or modifying a gene encoding an enzyme having decarboxylase activity and / or a gene encoding an enzyme having reductase activity into a microorganism, a plant, an animal, or a tissue culture thereof.

[0109] Enzymes having decarboxylase activity include, for example, diphosphomevalonate decarboxylase (EC 4.1.1.33) and various amino acid decarboxylases, and enzymes having reductase activity include HMG-CoA reductase and 12-oxophytodienoic acid reductase (EC 1.3.1.42).

[0110] A preferred example of producing butadiene by fermentation through an in vivo reaction via an amino acid is a production method in which various decarboxylases act on tiglic acid and / or angelic acid, which are in vivo synthesized from isoleucine along a natural metabolic pathway possessed by microorganisms, etc. In addition, butadiene can be obtained by a decarboxylase reaction using various fatty acid derivatives produced during the metabolism of amino acids.

[0111] The amino acids necessary for obtaining butadiene may be added directly to the medium, but a preferred example is to use the biosynthesized amino acids biosynthesized in vivo by fermenting crushed plant matter, livestock waste, etc. In this case, butadiene rubber is converted from sugars and / or proteins.

[0112] While typical fermentation methods for producing alcohols and alkenes mainly use sugars as biomass resources, this production method is useful because it has a high potential for effectively utilizing biomass resources, mainly amino acids and proteins.

[0113] Another method that can be preferably used for preparing butadiene from biomass resources is to obtain an intermediate capable of synthesizing butadiene from biomass resources using at least one selected from the group consisting of microorganisms, plants, animals, and tissue cultures thereof, and then subject the obtained intermediate to the chemical treatment method such as a catalytic reaction, the physical treatment method, the in vitro enzymatic reaction, or a combination of these methods to obtain butadiene (a diene such as butadiene).

[0114] Examples of intermediates that can be used to synthesize butadiene include alkyl alcohols, allylic alcohols, alkenes, aldehydes, and unsaturated carboxylic acids.

[0115] The alkyl alcohols are not particularly limited as long as they are derived from biomass, and are preferably ethanol, butanol, or butanediol, more preferably butanol or butanediol. Note that the butanol may be 1-butanol, 2-butanol, or a mixture thereof.

[0116] Various methods are known for producing ethanol (biomass-derived ethanol is also called bioethanol) and butanol (biomass-derived butanol is also called biobutanol) from biomass resources by fermentation using microorganisms. Common methods include ethanol fermentation using yeast to obtain bioethanol from biomass resources (e.g., sugarcane or glucose), and acetone-butanol fermentation (ABE fermentation) using fermentative fungi to obtain biobutanol from biomass resources (e.g., glucose). ABE fermentation produces a mixed solvent of butanol, acetone, and other components, which can be distilled to obtain biobutanol. Furthermore, butanol can also be obtained directly from bioethanol via catalytic reaction or via acetaldehyde.

[0117] The microorganisms that perform ABE fermentation are not particularly limited as long as they are capable of performing ABE fermentation, and examples include microorganisms belonging to the genera Escherichia, Zymomonas, Candida, Saccharomyces, Pichia, Streptomyces, Bacillus, Lactobacillus, Corynebacterium, Clostridium, and Saccharomyces. These can be used in any form, such as wild-type strains, mutant strains, or recombinant strains derived by genetic engineering techniques such as cell fusion or genetic manipulation. Among these, microorganisms belonging to the genus Clostridium are preferred, with Clostridium acetobutylicum, Clostridium beijerinckii, Clostridium saccharobutylicum, and Clostridium saccharoperbutylacetonicum being more preferred.

[0118] A preferred example of a method for producing biobutanol is a method of obtaining butanol by fermentation using 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 a gene associated with the mevalonate pathway, a gene associated with the MEP / DOXP pathway, a gene encoding butyryl-CoA dehydrogenase, a gene encoding butyraldehyde dehydrogenase, and a gene encoding butanol dehydrogenase has been introduced (e.g., JP 2010-508017 A).

[0119] Furthermore, ethanol and butanol produced by fermentation from biomass resources are commercially available as bioethanol and biobutanol (for example, biobutanol manufactured by DuPont).

[0120] In addition, various methods have been developed for directly producing butanediol as a raw material for bioplastics through fermentation (e.g., Syu MJ, Appl Microbial Biotechnol 55:10-18 (2001); Qin et al., Chinese J Chem Eng 14(1):132-136 (2006); JP-A 2011-522563; JP-A 62-285779; JP-A 2010-115116, etc.), and bio-derived butanediol can be easily used. Furthermore, butanediol can also be produced by converting biomass-derived succinic acid, fumaric acid, furfural, etc.

[0121] The microorganism that performs butanediol fermentation is not particularly limited as long as it is capable of butanediol fermentation, and examples thereof include microorganisms belonging to the genera Escherichia, Zymomonas, Candida, Saccharomyces, Pichia, Streptomyces, Bacillus, Lactobacillus, Corynebacterium, Clostridium, Klebsiella, and Saccharomyces. These microorganisms can be used in any form, such as wild-type strains, mutant strains, or recombinant strains derived by genetic engineering techniques such as cell fusion or genetic manipulation. Among these, microorganisms belonging to the genera Bacillus, Clostridium, and Crypsiella are preferred, and Clostridium autoethanogenum, Bacillus polymyxa, Bacillus subtilis, Bacillus pumilus, Bacillus macerans, Bacillus licheniformis, Bacillus megaterium, and Klebsiella pneumoniae are more preferred.

[0122] The alkyl alcohols can be converted into butadiene by the biological treatment method such as fermentation, the chemical treatment method such as catalytic reaction, the physical treatment method, the in vitro enzymatic reaction, a combination of these methods, or the like.

[0123] Known methods for directly converting alkyl alcohols to butadiene include converting ethanol and / or butanol to butadiene using a dehydration / dehydrogenation catalyst such as hydroxyapatite, Ta / SiO2, alumina, or zeolite.

[0124] 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 because they can be easily converted to butadiene.

[0125] Crotyl alcohol and 3-buten-2-ol can be obtained directly from biomass resources by fermentation using microorganisms or by reducing biomass-derived crotonic acid or its derivatives. Crotyl alcohol can also be obtained from biomass-derived butanediol using zeolite, alumina, cerium oxide, or other catalysts (see, for example, JP 2004-306011 A).

[0126] Examples of methods for converting allyl alcohols to butadiene include a method in which crotyl alcohol is converted to butadiene by dehydration using a commonly known catalytic reduction catalyst such as zeolite or alumina.

[0127] The alkene is not particularly limited as long as it is derived from biomass, and ethylene and butene (also known as butylene) are preferred, with ethylene being more preferred.

[0128] Examples of methods for producing biomass-derived ethylene and butene include a method of converting bioethanol into ethylene using a dehydration catalyst such as alumina or zeolite or high-temperature treatment, and a method of converting biobutanol into butene using a dehydration catalyst such as alumina or zeolite or high-temperature treatment.

[0129] The alkenes (ethylene, butene) can also be obtained directly from biomass resources by fermentation using at least one selected from the group consisting of microorganisms, plants, animals, and tissue cultures thereof.

[0130] In terms of production efficiency, it is preferable that the microorganisms, plants, animals, and tissue cultures thereof that perform ethylene fermentation be those into which a gene encoding an enzyme having ACC synthase (ethylene synthase) activity has been introduced and / or modified, but this is not a limitation.

[0131] Although different from the biomass resource-derived ethylene, from the viewpoint of carbon neutrality, 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 ethylene may be produced by, for example, the method described in JP 2019-154435 A.

[0132] The microorganisms, plants, animals, and tissue cultures thereof that perform butene fermentation are preferably those into which a gene encoding an enzyme having diphosphomevalonate decarboxylase (EC 4.1.1.33) activity has been introduced and / or modified (for example, JP 2011-526489 A), but are not limited to this.

[0133] Examples of the method for converting alkenes to butadiene include a method for converting butene into butadiene using alumina, zeolite, or the like, and a method for partially converting ethylene into acetaldehyde using an oxidation catalyst such as palladium chloride or palladium acetate, and then subjecting the acetaldehyde to a dehydration reaction with the remaining ethylene using a dehydration catalyst such as alumina or zeolite to obtain butadiene.

[0134] The aldehyde is not particularly limited as long as it is derived from biomass, and acetaldehyde is preferred.

[0135] Acetaldehyde may be obtained directly from biomass resources by fermentation using microorganisms or by converting biomass-derived ethylene into acetaldehyde using an oxidation catalyst such as palladium chloride.

[0136] The method for converting the aldehydes into butadiene includes, for example, a method of subjecting the aldehydes to a dehydration reaction with ethylene.

[0137] The unsaturated carboxylic acids are not particularly limited as long as they are derived from biomass, and tiglic acid and angelic acid are preferred.

[0138] Tiglic acid and angelic acid may be obtained directly from biomass resources by fermentation using microorganisms, etc. Specifically, tiglic acid and angelic acid can be synthesized in vivo from isoleucine through natural metabolic pathways possessed by microorganisms, etc. Alternatively, they may be purified from cypress oil, etc.

[0139] Examples of the method for converting the unsaturated carboxylic acids into butadiene include a method of converting tiglic acid or angelic acid by allowing various decarboxylases to act on the acid, and a method of converting the acid by allowing a metal catalyst such as palladium, zeolite, alumina, or the like to act on the acid.

[0140] Butadiene can be obtained from biomass resources by the above-mentioned method or the like.

[0141] (((Method of Preparing Styrene))) Next, a method for preparing styrene from a biomass resource will be described, but the method for preparing styrene is not limited to the method described below. When an aromatic vinyl other than styrene is used, it is sufficient to synthesize the aromatic vinyl other than styrene by a known method, but the method is not limited to this.

[0142] Various methods for preparing styrene from biomass resources can be used, and are not particularly limited. Examples include biological treatment methods in which styrene is obtained directly from biomass resources using at least one species selected from the group consisting of microorganisms, plants, animals, and tissue cultures thereof (particularly, microorganisms, plants, and tissue cultures thereof); methods in which styrene is obtained by subjecting biomass resources to the aforementioned chemical treatment methods; methods in which styrene is obtained by subjecting biomass resources to the aforementioned physical treatment methods; methods in which biomass resources are converted to styrene by in vitro enzymatic reactions, etc.; and methods combining these methods. Among these, biological treatment methods are preferred. In this production method, sugars used as carbon sources in the culture medium are mainly used as biomass resources. The microorganisms, plants, and animals that convert biomass resources into styrene may or may not be genetically engineered.

[0143] The method for directly converting biomass resources into styrene using microorganisms or the like (biological treatment method) is not particularly limited, but can be carried out by utilizing the in vivo pathway for biosynthesis of styrene from phenylalanine via cinnamic acid.

[0144] Phenylanine is a substance biosynthesized via the shikimic acid pathway present in most microorganisms and plants, and an in vivo pathway for biosynthesis of styrene from phenylalanine via cinnamic acid is known. Therefore, by utilizing these in vivo pathways present in microorganisms, etc., styrene can be obtained directly from biomass resources using at least one species selected from the group consisting of microorganisms, plants, animals, and tissue cultures thereof (particularly, microorganisms, plants, and tissue cultures thereof).

[0145] From the viewpoint of efficient styrene production, it is preferable that the microorganisms, plants, animals, and tissue cultures thereof (particularly, the microorganisms, plants, and tissue cultures thereof) be engineered to highly express phenylalanine ammonia-lyase, cinnamic acid decarboxylase (phenylacrylic acid decarboxylase), and / or phenolic acid decarboxylase (particularly, ferulic acid decarboxylase).

[0146] Similarly, because styrene can be produced efficiently, microorganisms, plants, animals, and tissue cultures thereof (particularly, microorganisms, plants, and tissue cultures thereof) are preferably modified to promote (overproduce) phenylalanine, which is considered to be a substrate in the styrene biosynthetic pathway.

[0147] Specifically, it is preferable that the microorganisms, plants, animals, and tissue cultures thereof (particularly the microorganisms, plants, and tissue cultures thereof) be engineered to highly express enzymes and / or feedback inhibitory enzymes involved in the shikimate pathway.

[0148] More specifically, it is preferred that the microorganisms, plants, animals, and tissue cultures thereof (particularly the microorganisms, plants, and tissue cultures thereof) are those in which an enzyme involved in the shikimic acid pathway is highly expressed, that an enzyme involved in the L-phenylalanine biosynthetic pathway is desensitized to feedback inhibition by L-phenylalanine, and / or that an enzyme from which feedback inhibition has been desensitized is highly expressed.

[0149] Enzymes involved in the shikimate pathway include, but are not limited to, arogenate dehydratase, prephenate aminotransferase, prephenate dehydratase, chorismate mutase, and the like.

[0150] It is preferable to add phenylalanine and / or cinnamic acid (preferably biomass-derived phenylalanine and / or cinnamic acid) to a culture medium (including soil for cultivating plants) for cultivating microorganisms and the like, because this allows for efficient production of styrene. Styrene can be produced efficiently by adding these compounds, which are located upstream in the in vivo pathway for styrene biosynthesis. The phenylalanine and cinnamic acid to be added can be prepared by culturing microorganisms and the like.

[0151] Microorganisms capable of directly converting biomass resources into styrene are not particularly limited, and examples include microorganisms belonging to the genus Fusarium, Penicillium, Pichia, Candida, Debaryomyces, Torulopsis, Saccharomyces, Bacillus, Escherichia, Streptomyces, Pseudomonas, etc. These can be used in any form, such as wild-type strains, mutant strains, or recombinant strains derived by genetic engineering techniques such as cell fusion or gene manipulation.

[0152] Microorganisms belonging to the genus Fusarium are not particularly limited, but F. oxysporum, F. roseum, F. aquasductuum, F. fujikuroi, F. solani, F. graminearum, F. asiaticum, F. culmorum, etc. are preferred in terms of styrene conversion efficiency, with F. oxysporum being more preferred.

[0153] Microorganisms belonging to the genus Penicillium are not particularly limited, but 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, and the like are preferred from the viewpoint of styrene conversion efficiency, with P. citrinum, P. oxalicum, and P. camamberti being more preferred, and P. citrinum being even more preferred.

[0154] Microorganisms belonging to the genus Pichia are not particularly limited, but Pichia carsonii, Pichia anomala, Pichia pastoris, Pichia farinosa, Pichia membranifaciens, Pichia angusta, etc. are preferred in terms of styrene conversion efficiency, with Pichia carsonii being more preferred.

[0155] Microorganisms belonging to the genus Candida are not particularly limited, but C. famata, C. etchellsii, C. versatilis, C. stellata, etc. are preferred in terms of styrene conversion efficiency, with C. famata being more preferred.

[0156] The microorganism belonging to the genus Debaryomyces is not particularly limited, but Debaryomyces hansenii is preferred in terms of styrene conversion efficiency.

[0157] Microorganisms belonging to the genus Torulopsis are not particularly limited.

[0158] The microorganism belonging to the genus Saccharomyces is not particularly limited, but S. cerevisiae, S. bayanus, S. boulardii, etc. are preferred in terms of styrene conversion efficiency.

[0159] Microorganisms belonging to the genus Bacillus are not particularly limited, but B. subtilis, B. thuringiensis, B. coagulans, B. licheniformis, B. megaterium, etc. are preferred from the viewpoint of styrene conversion efficiency, with B. subtilis being more preferred.

[0160] Microorganisms belonging to the genus Escherichia are not particularly limited, but E. albertii, E. blattae, E. coli, E. fergusonii, E. hermannii, E. vulneris, etc. are preferred in terms of styrene conversion efficiency, with E. coli being more preferred.

[0161] Microorganisms belonging to the genus Streptomyces are not particularly limited, but S. griseus, S. kanamyceticus, S. peucetius, S. galilaeus, S. parvulus, S. antibioticus, S. lividans, S. maritimus, etc. are preferred in terms of styrene conversion efficiency.

[0162] Microorganisms belonging to the genus Pseudomonas are not particularly limited, but P. aeruginosa, P. syringae pv. Japonica, P. meliae, P. putida, and the like are preferred from the viewpoint of styrene conversion efficiency, with P. putida, P. putida IH-2000, and P. putida S12 being more preferred, and P. putida IH-2000 and P. putida S12 being even more preferred.

[0163] As the microorganisms capable of directly converting biomass resources into styrene, microorganisms belonging to the genus Penicillium and Escherichia are preferred, and P. citrinum and transformed E. coli are more preferred.

[0164] Plants capable of directly converting biomass resources into styrene are not particularly limited, and examples include plants belonging to the Hamamelidaceae, Styraxaceae, Apocynaceae, Solanaceae, Carrot family, Theaceae, etc. These can be used in any form, such as wild-type strains, mutant strains, or recombinant strains induced by genetic engineering techniques such as cell fusion or gene manipulation.

[0165] The plant (tree) belonging to the Hamamelidaceae family is not particularly limited, but from the viewpoint of styrene production efficiency, a plant (tree) belonging to the genus Liquidambar is preferred, and among them, Liquidambar formosana, Liquidambar styraciflua, and Liquidambar orientalis are more preferred, Liquidambar formosana and Liquidambar orientalis are even more preferred, and Liquidambar orientalis is particularly preferred.

[0166] The plant (tree) belonging to the Styraxaceae family is not particularly limited, but from the viewpoint of styrene production efficiency, a plant (tree) belonging to the genus Styrax is preferred, and among them, Styrax officinalis, Styrax japonica, and Styrax benzoin Dryander are more preferred, with Styrax being even more preferred.

[0167] Plants belonging to the Apocynaceae family are not particularly limited, but from the viewpoint of the efficiency of styrene production, plants belonging to the genus Catharanthus, Oleander, Vinca, Periwinkle, and Rubber Vine are preferred, and plants belonging to the genus Catharanthus (particularly Catharanthus roseus) are more preferred.

[0168] Plants belonging to the Solanaceae family are not particularly limited, but are preferably plants of the genus Nicotiana from the viewpoint of the efficiency of styrene production, with N. tabacum and N. rustica being more preferred.

[0169] The plant belonging to the Carrot family is not particularly limited, but plants belonging to the genus Carrot are preferred from the viewpoint of the efficiency of styrene production.

[0170] Plants belonging to the Theaceae family are not particularly limited, but plants belonging to the genera Camellia, Sakaki and Sasamia are preferred from the viewpoint of the efficiency of styrene production.

[0171] As plants capable of directly converting biomass resources into styrene, plants belonging to the Hamamelidaceae, Styraxaceae, and Apocynaceae families are preferred, plants belonging to the genera Liquidambar, Styrax, and Catharanthus roseus are more preferred, sweetgum, Levantostrac, Styrax japonica, and Catharanthus roseus are even more preferred, and sweetgum, Styrax japonica, and Catharanthus roseus are particularly preferred.

[0172] When the plant is a tree, the method for obtaining styrene from the tree is not particularly limited, but a method in which the resin (sap) exuded by wounding the trunk is purified is preferred from the viewpoint of efficiency. Alternatively, styrene can be obtained by crushing the bark, trunk, branches, roots, leaves, etc. of the tree, extracting with an appropriate solvent, heating, and / or irradiating with ultrasound to obtain volatile components, and then purifying the volatile components.

[0173] When the plant is not a tree, it is difficult to obtain styrene as a resin. However, styrene can be obtained by crushing the plant tissue (e.g., stems, leaves, roots, flowers, etc.), extracting with an appropriate solvent, heating, and / or irradiating with ultrasound to obtain volatile components, and then purifying the volatile components.

[0174] Styrene can also be obtained by culturing tissues of the above plants and extracting volatile components from the cultured tissues by extraction with an appropriate solvent, heating, and / or ultrasonic irradiation.

[0175] Although the plant tissue to be cultured is not particularly limited, callus induced from plant tissue explants is preferred because styrene can be obtained efficiently. That is, it is preferred to induce callus from plant tissue explants and then culture the induced callus.

[0176] The method for inducing callus is not particularly limited, and examples include a method of inducing callus by culturing plant tissue fragments (e.g., buds, leaves, stems, etc.) in a medium containing a plant growth hormone (e.g., an auxin-based plant hormone (e.g., dichlorophenoxyacetic acid) and / or a cytokinin-based plant hormone (e.g., benzyladenine)).

[0177] Another preferred method for preparing styrene from biomass resources involves obtaining an intermediate (particularly, phenylalanine and / or cinnamic acid) capable of synthesizing styrene from a biomass resource using at least one selected from the group consisting of microorganisms, plants, animals, and tissue cultures thereof (particularly, microorganisms, plants, and tissue cultures thereof), and then subjecting the obtained intermediate (particularly, phenylalanine and / or cinnamic acid) to the aforementioned biological treatment method, the aforementioned chemical treatment method such as catalytic reaction, the aforementioned physical treatment method, the aforementioned in vitro enzymatic reaction, or a combination of these methods to obtain styrene. Among these, the method of subjecting the obtained intermediate (particularly, phenylalanine and / or cinnamic acid) to the aforementioned biological treatment method is preferred. The microorganisms, plants, and animals that convert the intermediate into styrene may or may not be genetically engineered.

[0178] As a method for obtaining styrene by subjecting the obtained intermediate (particularly, phenylalanine and / or cinnamic acid) to the biological treatment method, for example, as described above, phenylalanine and / or cinnamic acid may be added to a culture medium (including soil for growing plants) for cultivating the microorganisms, etc., and the microorganisms, etc. may be cultured in the culture medium. As a result, styrene is biosynthesized by the microorganisms, etc., from the added phenylalanine and / or cinnamic acid.

[0179] Examples of the method for obtaining styrene by subjecting the obtained intermediate phenylalanine to the above-mentioned chemical treatment method such as catalytic reaction include a method in which styrene is obtained by converting phenylalanine into cinnamic acid through the action of an ammonia lyase such as phenylalanine ammonia lyase, followed by decarboxylation using a decarboxylase, a transition metal catalyst, zeolite, or the like; and a method in which styrene is obtained by directly treating phenylalanine at high temperature using zeolite, alumina, or the like.

[0180] Examples of the method for obtaining styrene by subjecting the obtained intermediate cinnamic acid to the above-mentioned chemical treatment method such as catalytic reaction include a method in which styrene is obtained by decarboxylation reaction using a metal catalyst using a transition metal or the like, zeolite, alumina, or the like at high temperature.

[0181] Styrene can be obtained from biomass resources by the above-mentioned method or the like.

[0182] (((Polymerization method))) The method for polymerizing styrene-butadiene rubber (biomass styrene-butadiene rubber (BSBR)) from butadiene and styrene obtained from biomass resources by the above-mentioned method or the like is similar to the method for polymerizing styrene-butadiene rubber from butadiene and styrene derived from petroleum resources, which is well known to those skilled in the art, and is not particularly limited. Similarly, the method for polymerizing butadiene rubber (biomass butadiene rubber (BBR)) from butadiene obtained from biomass resources by the above-mentioned method or the like is similar to the method for polymerizing butadiene rubber from butadiene derived from petroleum resources, which is a method known to those skilled in the art, and is not particularly limited.

[0183] Suitable butadienes obtained from biomass resources include butadienes derived from alkyl alcohols (preferably ethanol and butanol (more preferably butanol)), butadienes derived from alkenes (preferably ethylene), and butadienes derived from unsaturated carboxylic acids (preferably tiglic acid). It is also suitable to use a combination of these butadienes.

[0184] Suitable styrene obtained from biomass resources includes styrene obtained from plants (preferably plants belonging to the Hamamelidaceae, Styraxaceae, and Apocynaceae families, more preferably plants belonging to the genus Liquidambar, Styrax rostrata, and Catharanthus roseus, and even more preferably Sweetgum, Styrax roseus, and Catharanthus roseus), and styrene obtained from microorganisms (preferably microorganisms belonging to the genus Penicillium or Escherichia, more preferably P. citrinum or transformed E. coli). It is also suitable to use a combination of these styrenes.

[0185] The molecular weight, branching and microstructure of the resulting BBR or BSBR can be selected as desired according to the desired tire performance by changing the polymerization conditions according to known methods.

[0186] On the other hand, there are currently some plans for biomass industrial complexes that focus on bioethanol, bioethylene, etc., but bioethanol and bioethylene are produced primarily from sugars and / or cellulose as biomass resources, and do not effectively utilize other biomass resources such as proteins, lipids, and amino acids. Furthermore, sugars compete with food, and overharvesting of cellulose leads to deforestation, so the situation may not necessarily be environmentally friendly.

[0187] Therefore, in response to comprehensive environmental needs, such as the supply status of various biomass resources, the supply status of petroleum resources, and market demands (e.g., competition between biomass resources and demand for food), it is preferable to use multiple biomass-derived monomer components as the biomass-derived monomer component, use a biomass-derived monomer component in combination with a petroleum-derived monomer component, or adjust the use ratio of these monomer components to an optimal ratio. This allows for effective utilization of a wide range of biomass resources, such as sugars, proteins, and lipids, without relying on a single type of biomass resource, thereby stabilizing the supply of biomass-derived rubber and taking environmental considerations into account during production. For example, biomass-derived butadiene can be obtained using various substrates, including bioethanol, biobutanol, and terpenes. Furthermore, biomass-derived styrene can be obtained using various plants and microorganisms.

[0188] When multiple biomass-derived monomer components are used, it is preferable to use monomer components derived from different biomass sources, i.e., monomer components obtained from different biomass resources. Specifically, it is preferable to use a mixture of butadienes derived from multiple biomass sources of different origins as the biomass-derived butadiene, and / or to use a mixture of styrenes derived from multiple biomass sources of different origins as the biomass-derived styrene. This allows for effective use of multiple biomass resources, and more appropriately meets the above-mentioned overall environmental demands.

[0189] In addition to the above-mentioned artificial polymerization method, polymerization may also be carried out in vivo or using enzymes derived from living organisms as a method for obtaining BBR and BSBR from biomass resources.

[0190] 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, even more preferably 60% by mass or more, particularly preferably 80% by mass or more, and may be 100% by mass. When it is within the above range, the effect tends to be more favorably obtained.

[0191] (Compounding agents other than rubber components) The rubber composition contains a resin. Examples of resins include cyclopentadiene resins, terpene resins, rosin resins, aromatic resins, C5 resins, C9 resins, C5 / C9 resins, coumarone-indene resins (including simple coumarone and indene resins), olefin resins, polyurethane resins, and acrylic resins. These may be used alone or in combination of two or more. They may also be hydrogenated (hydrogenated resins). 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 the functional groups that interact with fillers such as silica described above are used in the same preferred embodiments.

[0192] Among these, cyclopentadiene resins, terpene resins, rosin resins, aromatic resins, C5 resins, C9 resins, and C5 / C9 resins are preferred because they provide the desired effect. It is also preferable that the resin is at least one selected from the group consisting of terpene resins and rosin resins. These resins are naturally derived, and therefore can further reduce the environmental impact and improve tire performance such as grip performance on dry roads. 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, which can improve the overall performance of wear resistance and fuel economy (expressed as the sum of two indices of wear resistance and fuel economy), and can further improve the overall performance of wear resistance and fuel economy, particularly when silica is added at a high content. It is also preferable that the resin is an aromatic resin, which not only allows for more suitable effects to be obtained but also allows for a balanced improvement in grip performance, abrasion resistance, and rubber strength. The resin is most preferably a rosin-based resin.

[0193] The cyclopentadiene resin is a polymer containing a cyclopentadiene monomer as a constituent monomer, and examples thereof include a homopolymer obtained by polymerizing one type of cyclopentadiene monomer alone, a copolymer obtained by copolymerizing two or more types of cyclopentadiene monomers, and a copolymer of a cyclopentadiene monomer and another monomer copolymerizable therewith. These may be used alone or in combination of two or more types.

[0194] Examples of cyclopentadiene-based monomers include cyclopentadiene, dicyclopentadiene, and tricyclopentadiene. These may be used alone or in combination of two or more. Among these, dicyclopentadiene is preferred.

[0195] The cyclopentadiene-based resin is preferably a polymer (DCPD-based resin) containing dicyclopentadiene (DCPD) as a constituent monomer, because this tends to produce better effects. Alternatively, the cyclopentadiene-based resin may be a copolymer of DCPD and an aromatic monomer, or a copolymer of DCPD and a C9 fraction (vinyl toluene, indene, etc.) (DCPD-C9 resin). In this specification, a polymer containing a cyclopentadiene-based monomer and an aromatic-based monomer as constituent monomers, such as DCPD-C9 resin, is treated as a cyclopentadiene-based resin, not an aromatic-based resin.

[0196] Examples of terpene resins that can be used include polyterpene resins obtained by polymerizing terpene compounds and aromatic modified terpene resins obtained by polymerizing terpene compounds and aromatic compounds. Hydrogenated versions of these resins can also be used. These resins can be used alone or in combination of two or more.

[0197] Polyterpene resin is a resin obtained by polymerizing terpene compounds. Terpene compounds are (C5H8) n The hydrocarbons and their oxygen-containing derivatives are represented by the following composition: monoterpenes (C 10 H 16 ), sesquiterpenes (C 15 H 24 ), diterpenes (C 20 H 32 ), and examples thereof include α-pinene, β-pinene, dipentene, limonene, myrcene, alloocimene, ocimene, α-phellandrene, α-terpinene, γ-terpinene, terpinolene, 1,8-cineole, 1,4-cineole, α-terpineol, β-terpineol, γ-terpineol, etc. These may be used alone or in combination of two or more.

[0198] Examples of polyterpene resins include pinene resins, limonene resins, dipentene resins, and pinene / limonene resins, which are made from the above-mentioned terpene compounds. These may be used alone or in combination of two or more. Among these, pinene resins are preferred. Pinene resins usually contain both α-pinene and β-pinene, which are isomers, but are classified into β-pinene resins containing β-pinene as the main component and α-pinene resins containing α-pinene as the main component, depending on the components contained.

[0199] Examples of aromatic modified terpene resins include terpene phenol resins made from terpene compounds and phenolic compounds, and terpene styrene resins made from terpene compounds and styrene compounds. Terpene phenol styrene resins made from terpene compounds, phenolic compounds, and styrene compounds can also be used. These may be used alone or in combination of two or more. In this specification, polymers containing terpene compounds and phenolic compounds as constituent monomers, such as aromatic modified terpene resins, are treated as terpene resins rather than aromatic resins.

[0200] As the terpene resin, polyterpene resin is preferred, and β-pinene resin is more preferred, because better effects tend to be obtained.

[0201] Examples of rosin-based resins include gum rosin, which is obtained by processing pine resin and contains as its main component resin acids such as abietic acid and pimaric acid, natural rosin resins (polymerized rosins) such as wood rosin and tall oil rosin, hydrogenated rosin resin, maleic acid-modified rosin resin, rosin-modified phenolic resin, rosin glycerin ester, disproportionated rosin resin, etc. These may be used alone or in combination of two or more.

[0202] Aromatic resins are polymers containing aromatic monomers as constituent monomers, and examples thereof include homopolymers obtained by polymerizing one type of aromatic monomer alone, copolymers obtained by copolymerizing two or more types of aromatic monomers, and copolymers of an aromatic monomer and another monomer copolymerizable therewith. These may be used alone or in combination of two or more types.

[0203] 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, and p-chlorostyrene; phenol-based monomers such as phenol, alkylphenol, and alkoxyphenol; and naphthol-based monomers such as naphthol, alkylnaphthol, and alkoxynaphthol. These may be used alone or in combination of two or more. Among these, styrene-based monomers are preferred, and styrene and α-methylstyrene are more preferred.

[0204] The aromatic resin is preferably a polymer containing α-methylstyrene as a constituent monomer (α-methylstyrene resin), and more preferably a copolymer of α-methylstyrene and styrene, because these tend to produce better effects.

[0205] C5 resins are polymers containing structural units of hydrocarbons having 5 carbon atoms and their polymers (dimers, etc.). Examples of hydrocarbons having 5 carbon atoms and their polymers include isoprene, pentane, and cyclopentadiene. Specific examples of C5 resins include copolymers of isoprene and pentane. C5 resins also include aliphatic petroleum resins obtained by (co)polymerizing C5 fractions obtained by thermal cracking of naphtha in the petrochemical industry. C5 fractions include olefinic hydrocarbons such as 1-pentene, 2-pentene, and 2-methyl-1-butene, and diolefinic hydrocarbons such as 2-methyl-1,3-butadiene, 1,2-pentadiene, and 1,3-pentadiene. These may be used alone or in combination of two or more. In this specification, a polymer containing cyclopentadiene as a constituent monomer is referred to as a cyclopentadiene-based resin.

[0206] A C9 resin is a polymer containing structural units of a hydrocarbon having 9 carbon atoms and its polymers (dimers, etc.). Examples of the hydrocarbon having 9 carbon atoms and its polymers (dimers, etc.) include indene, methylstyrene, vinyltoluene, etc. Specific examples of C9 resins include solid polymers obtained by (co)polymerizing a C9 fraction using a Friedel-Crafts catalyst or the like, such as a copolymer containing indene as the main component, a copolymer containing methylindene as the main component, a copolymer containing α-methylstyrene as the main component, and a copolymer containing vinyltoluene as the main component. These may be used alone or in combination of two or more types. In this specification, a polymer containing methylstyrene as a constituent monomer is considered to be an aromatic resin.

[0207] Examples of the C5 / C9 resin include a mixture of the C5 resin and the C9 resin, a copolymer of a C5 fraction and a C9 fraction, etc. These may be used alone or in combination of two or more. The C5 resin is preferably an aliphatic resin, and the C9 resin is preferably an alicyclic resin.

[0208] The softening point of the resin is preferably 30° C. or higher, more preferably 60° C. or higher, and even more preferably 80° C. or higher, and is preferably 160° C. or lower, and more preferably 140° C. or lower. Within the above ranges, the effect tends to be more favorably obtained. In this specification, the softening point of a polymer (resin, polymer, etc.) is the temperature at which the ball drops when the softening point specified in JIS K 6220-1:2001 is measured using a ring and ball softening point tester.

[0209] Commercially available resins include those manufactured by Maruzen Petrochemical Co., Ltd., Sumitomo Bakelite Co., Ltd., Yasuhara Chemical Co., Ltd., Tosoh Corporation, Rutgers Chemicals, BASF, Arizona Chemical Company, Nitto Chemical Co., Ltd., Nippon Shokubai Co., Ltd., ENEOS Corporation, Arakawa Chemical Industries, Ltd., Taoka Chemical Co., Ltd., and ExxonMobil Corporation.

[0210] The resin content is 10 to 100 parts by mass per 100 parts by mass of the rubber component. It is preferably 20 parts by mass or more, more preferably 30 parts by mass or more, even more preferably 40 parts by mass or more, particularly preferably 50 parts by mass or more, and 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, and even more preferably 80 parts by mass or less. Within the above ranges, the effect tends to be better obtained.

[0211] The rubber composition preferably contains silica. Examples of silica include dry-process silica (anhydrous silica) and wet-process silica (hydrated silica). Among these, wet-process silica is preferred because it has a large number of silanol groups. Commercially available products include those from Degussa, Rhodia, Tosoh Silica Co., Ltd., Solvay Japan, and Tokuyama Corporation. These may be used alone or in combination of two or more.

[0212] The silica is preferably silica derived from rice husks (also called rice husk silica). The first benefit of using rice husk silica is that it effectively utilizes rice husks, which are industrial waste, making it favorable from an environmental perspective. The second benefit is that the raw material can be procured locally. Recycling rice husks, a waste product of rice, which is produced in large quantities around the world as a staple food, is an important issue. By incorporating rice husk silica, waste can be reduced. Furthermore, since rice husks are produced in many places, they can be procured near tire manufacturing plants, which has the advantage of reducing the energy required for transportation and storage. The third effect is that the incorporation of rice husk silica improves tire physical properties such as wet grip performance compared to conventional industrially produced wet silica. The reason for this is unclear, but it is thought that trace amounts of carbon black and other components that may be present in rice husk-derived silica contribute to improving affinity with other components, or that they change the viscoelasticity in the area related to wet grip performance more than when silica is used alone.

[0213] The rice husk silica may be rice husk charcoal powder obtained by carbonizing rice husks by heating, or may be precipitated silica produced by a wet process using an aqueous alkali silicate solution prepared by extracting rice husk ash, which is generated when rice husks are burned as fuel in a biomass boiler, with an alkali. These may be used alone or in combination of two or more.

[0214] The method for producing 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 in a kiln. The rice husk charcoal powder can be obtained by pulverizing the rice husk charcoal obtained in this manner using a known pulverizer (for example, a ball mill), and then sorting and classifying the charcoal into particles having a predetermined particle size range. Precipitated silica can be produced from rice husks by the method described in JP-A-2019-38728. It is particularly preferable that the rice husk silica is produced in an area close to a tire manufacturing plant.

[0215] The nitrogen adsorption specific surface area (N2SA) of the silica is preferably 50 m 2 / g or more, more preferably 100m 2 / g or more, more preferably 150m 2 The upper limit of the N2SA of silica is not particularly limited, but is preferably 350 m 2 / g or less, more preferably 250m 2 / g or less, more preferably 230m 2 / g or less, particularly preferably 200m 2 Within this range, there is a tendency for the effect to be better obtained. The N2SA of silica is a value measured by the BET method in accordance with ASTM D3037-93.

[0216] The content of silica is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, even more preferably 30 parts by mass or more, particularly preferably 50 parts by mass or more, most preferably 70 parts by mass or more, further most preferably 80 parts by mass or more, even most preferably 100 parts by mass or more, and particularly most preferably 110 parts by mass or more, per 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, even more preferably 180 parts by mass or less, and particularly preferably 150 parts by mass or less. Within the above range, the effect tends to be more favorably obtained.

[0217] In the rubber composition, the resin content / silica content ratio is preferably 0.1 or more, more preferably 0.2 or more, even more preferably 0.3 or more, particularly preferably 0.4 or more, and most preferably 0.5 or more, and is preferably 1.5 or less, more preferably 1.2 or less, even more preferably 0.9 or less, particularly preferably 0.8 or less, and most preferably 0.7 or less. Within the above ranges, the effect tends to be more favorable. In this relationship, the resin content and silica content are the contents (unit: parts by mass) relative to 100 parts by mass of the rubber component.

[0218] Silica is preferably used in combination with a silane coupling agent. The silane coupling agent is not particularly limited, and examples thereof include bis(3-triethoxysilylpropyl)tetrasulfide, bis(2-triethoxysilylethyl)tetrasulfide, bis(4-triethoxysilylbutyl)tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, bis(2-trimethoxysilylethyl)tetrasulfide, bis(2-triethoxysilylethyl)trisulfide, bis(4-trimethoxysilylbutyl)trisulfide, bis(3-triethoxysilylpropyl)disulfide, bis(2-triethoxysilylethyl)disulfide, bis(4-triethoxysilylbutyl)disulfide, bis(3-trimethoxysilylpropyl)disulfide, bis(2-trimethoxysilylethyl)disulfide, bis(4-trimethoxysilylbutyl)disulfide, bis(3-trimethoxysilylpropyl)disulfide, bis(2-trimethoxysilylethyl)disulfide, bis(4-trimethoxysilylbutyl)disulfide, 3-trimethoxysilylpropyl sulfide-based compounds such as propyl-N,N-dimethylthiocarbamoyl tetrasulfide, 2-triethoxysilylethyl-N,N-dimethylthiocarbamoyl tetrasulfide, and 3-triethoxysilylpropyl methacrylate monosulfide; mercapto-based compounds such as 3-mercaptopropyltrimethoxysilane and 2-mercaptoethyltriethoxysilane; vinyl-based compounds such as vinyltriethoxysilane and vinyltrimethoxysilane; amino-based compounds such as 3-aminopropyltriethoxysilane and 3-aminopropyltrimethoxysilane; glycidoxy-based compounds such as γ-glycidoxypropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane; nitro-based compounds such as 3-nitropropyltrimethoxysilane and 3-nitropropyltriethoxysilane; and chloro-based compounds such as 3-chloropropyltrimethoxysilane and 3-chloropropyltriethoxysilane. Commercially available products include those from Degussa, Momentive, Shin-Etsu Silicones, Tokyo Chemical Industry Co., Ltd., Azmax Corporation, and Dow Corning Toray Co., Ltd. These may be used alone or in combination of two or more. Of these, sulfide-based silane coupling agents are preferred.

[0219] The content of the silane coupling agent is preferably 3 parts by mass or more, more preferably 6 parts by mass or more, and even more preferably 8 parts by mass or more, relative to 100 parts by mass of silica, and is preferably 15 parts by mass or less, more preferably 12 parts by mass or less, and even more preferably 10 parts by mass or less. Within the above ranges, the effect tends to be more favorable.

[0220] 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, and N762. Commercially available products that can be used include those from Asahi Carbon Co., Ltd., Cabot Japan Co., Ltd., Tokai Carbon Co., Ltd., Mitsubishi Chemical Corporation, Lion Corporation, Shin-Nichika Carbon Co., Ltd., Columbia Carbon Co., Ltd., and the like. These may be used alone, or two or more types may be used in combination.

[0221] The nitrogen adsorption specific surface area (N2SA) of carbon black is 50m 2 / g or more is preferable, and 70m 2 / g or more is more preferable, and 90m 2 / g or more is more preferable. 2 / g or less is preferable, and 150m 2 / g or less is more preferable, and 130m 2 Within this range, the effect tends to be better. The nitrogen adsorption specific surface area of ​​carbon black can be determined according to JIS K6217-2:2001.

[0222] The amount of carbon black per 100 parts by mass of the rubber component is preferably 1 part by mass or more, more preferably 3 parts by mass or more, and even more preferably 5 parts by mass or more, and is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 10 parts by mass or less. Within the above ranges, the effect tends to be more favorably obtained.

[0223] The silica content is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, particularly preferably 90% by mass or more, and most preferably 95% by mass or more, with the upper limit being 100% by mass, but preferably 98% by mass or less, based on a total content of silica and carbon black of 100% by mass. Within this range, better effects tend to be obtained.

[0224] The rubber composition preferably contains rubber powder. The rubber powder may be used alone or in combination of two or more kinds.

[0225] The rubber powder preferably contains 10 parts by mass or more of carbon black and 13 to 20 parts by mass of silica per 100 parts by mass of the rubber component. The carbon black and silica are the same as those used in the rubber composition, and are used in the same preferred form.

[0226] In the rubber crumb, the content of carbon black is preferably 15 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, and particularly preferably 40 parts by mass or more, per 100 parts by mass of the rubber component, and although there is no particular upper limit, it is preferably 80 parts by mass or less, more preferably 60 parts by mass or less, and even more preferably 50 parts by mass or less. Within the above range, better effects tend to be obtained.

[0227] In the rubber crumb, the content of silica per 100 parts by mass of the rubber component is preferably 18 parts by mass or less, and preferably 15 parts by mass or more. Within this range, the effect tends to be more favorable.

[0228] The compounding ingredients used in the rubber powder are the same as those used in the rubber composition in the same preferred embodiments.

[0229] In the rubber crumb, the content of units derived from isoprene is preferably 40% by mass or more, more preferably 50% by mass or more, and even more preferably 60% by mass or more, based on 100% by mass of all units in the rubber component. The upper limit is not particularly limited, but is preferably 95% by mass or less, more preferably 90% by mass or less, even more preferably 80% by mass or less, and particularly preferably 70% by mass or less. Within the above range, the effect tends to be more favorably obtained. In this case, the content of butadiene-derived units in the rubber powder is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, and particularly preferably 30% by mass or more, based on 100% by mass of units in the total rubber component, and is preferably 60% by mass or less, more preferably 50% by mass or less, and even more preferably 40% by mass or less. Within the above ranges, better effects tend to be obtained.

[0230] The rubber crumb preferably contains 1 to 40% by mass of butadiene rubber (high-cis BR) having a cis content of 90% by mass or more, based on 100% by mass of the rubber component. The lower limit is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and particularly preferably 20% by mass or more, and the upper limit is preferably 35% by mass or less, more preferably 30% by mass or less. Within the above ranges, better effects tend to be obtained.

[0231] The rubber powder may be prepared, for example, by kneading and vulcanizing the rubber composition B containing the above-mentioned components according to the above-mentioned method, and pulverizing the resulting vulcanized rubber composition as needed.

[0232] The volume average particle diameter of the rubber powder is preferably 1000 μm or less. The volume average particle diameter is preferably 500 μm or less, more preferably 200 μm or less, and even more preferably 100 μm or less. The smaller the volume average particle diameter, the better, so there is no particular lower limit. Within the above range, better effects tend to be obtained. In this specification, the volume average particle size is measured by a laser diffraction particle size distribution measuring device, for example, "CAPA500" manufactured by Horiba, Ltd.

[0233] The 60-mesh sieve residue of the crumbly rubber is preferably less than 1% by mass, more preferably 0.5% by mass or less, and even more preferably 0.1% by mass or less, with no particular lower limit. Within this range, better effects tend to be obtained. The 80-mesh sieve residue of the crumbly rubber is preferably less than 10% by mass, more preferably 1% by mass or less, and even more preferably 0.5% by mass or less, with no particular lower limit. Within this range, better effects tend to be obtained. In this specification, the sieve residue is measured in accordance with ASTM D5644-01.

[0234] The acetone extractable content of the rubber powder, as determined by the acetone extraction method, is preferably 12% by mass or less, more preferably 11% by mass or less, even more preferably 10% by mass or less, and is preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 3% by mass or more. When the content is within the above range, better effects tend to be obtained. In this specification, the acetone extractables in the rubber crumb refers to the acetone extractables (%) determined by the acetone extraction method in accordance with JIS K6350.

[0235] In the rubber composition, the content of rubber powder is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and even more preferably 3 parts by mass or more, per 100 parts by mass of the rubber component, and is preferably 200 parts by mass or less, more preferably 150 parts by mass or less, even 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, even most preferably 10 parts by mass or less, and especially most preferably 5 parts by mass or less. Within the above ranges, the effect tends to be better obtained.

[0236] The rubber composition may contain a liquid plasticizer (a plasticizer that is in a liquid state at room temperature (25° C.)). Liquid plasticizers (plasticizers that are liquid at room temperature (25°C)) are not particularly limited, and examples include oils and liquid polymers (liquid diene polymers, etc.). These may be used alone or in combination of two or more. Of these, oils are preferred.

[0237] Examples of oils include process oils, vegetable oils, and mixtures thereof. Examples of process oils that can be used include paraffin-based process oils, aromatic process oils, and naphthenic process oils. Examples of vegetable oils include castor oil, cottonseed oil, linseed oil, rapeseed oil, soybean oil, palm oil, coconut oil, peanut oil, rosin, pine oil, pine tar, tall oil, corn oil, rice bran oil, safflower oil, sesame oil, olive oil, sunflower oil, palm kernel oil, camellia oil, jojoba oil, macadamia nut oil, and tung oil. Commercially available products include those from Idemitsu Kosan Co., Ltd., Sankyo Yuka Kogyo Co., Ltd., Japan Energy Corporation, Oriso, H&R, Toyokuni Oil Mills, Showa Shell Sekiyu K.K., Fuji Kosan Co., Ltd., and Nisshin Oillio Group, Ltd. These oils may be used alone or in combination. Among these, process oils (paraffin-based process oils, aromatic process oils, naphthenic process oils, etc.) and vegetable oils are preferred, and aromatic process oils are more preferred.

[0238] Examples of liquid diene polymers include liquid styrene-butadiene copolymers (liquid SBR), liquid butadiene polymers (liquid BR), liquid isoprene polymers (liquid IR), liquid styrene-isoprene copolymers (liquid SIR), liquid styrene-butadiene-styrene block copolymers (liquid SBS block polymers), liquid styrene-isoprene-styrene block copolymers (liquid SIS block polymers), liquid farnesene polymers, and liquid farnesene-butadiene copolymers, which are liquid at 25°C. These may be modified at the ends or main chains with polar groups. Hydrogenated versions of these polymers can also be used. These may be used alone or in combination.

[0239] 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, even more preferably 50 parts by mass or less, and particularly preferably 30 parts by mass or less. Within the above range, the effect tends to be more favorably obtained. The content of the liquid plasticizer (preferably oil) also includes the oil contained in the oil-extended rubber.

[0240] The rubber composition may contain an antioxidant. Examples of the antioxidant include naphthylamine-based antioxidants such as phenyl-α-naphthylamine; diphenylamine-based antioxidants such as octylated diphenylamine and 4,4'-bis(α,α'-dimethylbenzyl)diphenylamine; N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, and N,N'-di-2-naphthyl-p-phenylenediamine. Examples of suitable antioxidants include p-phenylenediamine-based antioxidants such as quinoline; quinoline-based antioxidants such as polymers of 2,2,4-trimethyl-1,2-dihydroquinoline; monophenol-based antioxidants such as 2,6-di-t-butyl-4-methylphenol and styrenated phenol; and bis-, tris-, and polyphenol-based antioxidants such as tetrakis-[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane. Commercially available products include those from Seiko Chemical Co., Ltd., Sumitomo Chemical Co., Ltd., Ouchi Shinko Chemical Industry Co., Ltd., and Flexis. These antioxidants may be used alone or in combination. Among these, p-phenylenediamine-based antioxidants and quinoline-based antioxidants are preferred, and the combined use of p-phenylenediamine-based antioxidants and quinoline-based antioxidants is even more preferred.

[0241] The content of the antioxidant is preferably 1 part by mass or more, more preferably 1.5 parts by mass or more, and even more preferably 2 parts by mass or more, per 100 parts by mass of the rubber component, and is preferably 12 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 8 parts by mass or less. Within the above ranges, the effect tends to be more favorably obtained.

[0242] The rubber composition may contain a wax. The wax is not particularly limited, and examples thereof include petroleum waxes such as paraffin wax and microcrystalline wax; natural waxes such as vegetable wax and animal wax; and synthetic waxes such as polymers of ethylene, propylene, etc. Commercially available products include those from Ouchi Shinko Chemical Industry Co., Ltd., Nippon Seiro Co., Ltd., Seiko Chemical Co., Ltd., etc. These may be used alone or in combination of two or more.

[0243] The amount of wax per 100 parts by mass of the rubber component is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and is preferably 10 parts by mass or less, more preferably 6 parts by mass or less. Within the above ranges, better effects tend to be obtained.

[0244] The rubber composition may contain stearic acid. As the stearic acid, conventionally known ones can be used, and commercially available products that can be used include products from NOF Corporation, Kao Corporation, Fujifilm Wako Pure Chemical Industries, Ltd., Chiba Fatty Acid Co., Ltd., etc. These may be used alone or in combination of two or more.

[0245] The amount of stearic acid per 100 parts by mass of the rubber component is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and is preferably 10 parts by mass or less, more preferably 6 parts by mass or less. Within the above ranges, the effect tends to be more favorably obtained.

[0246] The rubber composition may contain zinc oxide. As the zinc oxide, conventionally known ones can be used, and commercially available products include those available from Mitsui Mining & Smelting Co., Ltd., Toho Zinc Co., Ltd., Hakusui Tech Co., Ltd., Seido Chemical Industry Co., Ltd., Sakai Chemical Industry Co., Ltd., etc. These may be used alone or in combination of two or more.

[0247] The amount of zinc oxide per 100 parts by mass of the rubber component is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and is preferably 10 parts by mass or less, more preferably 6 parts by mass or less. Within the above ranges, the effect tends to be more favorably obtained.

[0248] The rubber composition preferably contains sulfur. Examples of sulfur include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersible sulfur, and soluble sulfur, which are commonly used as crosslinking agents in the rubber industry. Commercially available products include those from Tsurumi Chemical Industry Co., Ltd., Karuizawa Sulfur Co., Ltd., Shikoku Chemical Industry Co., Ltd., Flexis Corporation, Nippon Kanzuri Kogyo Co., Ltd., and Hosoi Chemical Industry Co., Ltd. These may be used alone or in combination of two or more.

[0249] The amount of sulfur per 100 parts by mass of the rubber component is preferably 0.3 parts by mass or more, more preferably 0.5 parts by mass or more, and even more preferably 0.8 parts by mass or more, and is preferably 8 parts by mass or less, and more preferably 5 parts by mass or less. Within the above range, the effect tends to be more favorably obtained.

[0250] The rubber composition preferably contains a vulcanization accelerator. Examples of vulcanization accelerators include thiazole-based vulcanization accelerators such as 2-mercaptobenzothiazole and di-2-benzothiazolyl disulfide; 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-benzothiazyl sulfenamide (CBS), N-tert-butyl-2-benzothiazolyl sulfenamide (TBBS), N-oxyethylene-2-benzothiazole sulfenamide, and N,N'-diisopropyl-2-benzothiazole sulfenamide; and guanidine-based vulcanization accelerators such as diphenylguanidine, di-orthotolylguanidine, and orthotolylbiguanidine. Commercially available products include those from Sumitomo Chemical Co., Ltd. and Ouchi Shinko Chemical Industry Co., Ltd. These may be used alone or in combination. Of these, sulfenamide vulcanization accelerators and guanidine vulcanization accelerators are preferred, and it is more preferred to use a sulfenamide vulcanization accelerator and a guanidine vulcanization accelerator in combination.

[0251] The content of the vulcanization accelerator is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and even more preferably 3 parts by mass or more, per 100 parts by mass of the rubber component, and is preferably 8 parts by mass or less, more preferably 6 parts by mass or less, and even more preferably 5.5 parts by mass or less. Within the above ranges, the effect tends to be more favorably obtained.

[0252] 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 per 100 parts by mass of the rubber component.

[0253] The rubber composition can be produced, for example, by kneading the components using a rubber kneading device such as an open roll or a Banbury mixer, followed by vulcanization.

[0254] As for kneading conditions, in the base kneading step in which additives other than the vulcanizing agent and vulcanization accelerator are kneaded, the kneading temperature is usually 100 to 180°C, preferably 120 to 170°C. In the finish kneading step in which the vulcanizing agent and vulcanization accelerator are kneaded, the kneading temperature is usually 120°C or lower, preferably 80 to 110°C. Furthermore, the composition kneaded with the vulcanizing agent and vulcanization accelerator is usually subjected to a vulcanization treatment such as press vulcanization. The vulcanization temperature is usually 140 to 190°C, preferably 150 to 185°C. The vulcanization time is usually 5 to 15 minutes.

[0255] The rubber composition (after vulcanization) preferably has a 0° C. tan δ of 0.18 to 1.60. When the tan δ is within this range, the effect tends to be more favorable. In this specification, 0°C tan δ of a rubber composition (after vulcanization) is a loss tangent measured under conditions of 0°C, initial strain of 10%, dynamic strain of 2%, and frequency of 10 Hz.

[0256] The rubber composition (after vulcanization) preferably has a glass transition temperature (Tg) of −85° C. to −5° C. If it is within this range, the effect tends to be more favorable. In this specification, the Tg of the rubber composition (after vulcanization) can be measured by the method described in the Examples. When multiple Tgs are observed, the preferred Tg range refers to the higher Tg.

[0257] The rubber composition can be used (as a rubber composition for a tire) for tire components such as a tread (cap tread), sidewall, base tread, undertread, shoulder, clinch, bead apex, breaker cushion rubber, carcass cord covering rubber, insulation, chafer, inner liner, and the like, as well as a side reinforcing layer of a run-flat tire. It is particularly suitable for use in a tread. In the case of a tread composed of a cap tread and a base tread, it is more suitable for use in the cap tread.

[0258] The tire (pneumatic tire, etc.) of the present invention is manufactured by a conventional method using the rubber composition. That is, the rubber composition, to which various additives are optionally added, is extruded in an unvulcanized state to match the shapes of the tire components (particularly the tread (cap tread)), molded in a conventional method on a tire building machine, and laminated together with other tire components to form an unvulcanized tire, which is then heated and pressurized in a vulcanizer to manufacture the tire.

[0259] It is sufficient that at least a part of the tire component (for example, the tread) of the tire is made of the rubber composition, and the entire tire component may be made of the rubber composition.

[0260] The tire is a passenger tire. In this specification, a passenger car tire refers to a tire that is intended to be mounted on a four-wheeled vehicle and has a maximum load capacity (as 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, and even more preferably 700 kg or less, with no particular lower limit.

[0261] The tires are suitably used as winter tires (studless tires, snow tires, studded tires), all-season tires, summer tires, run-flat tires, and the like. [Example]

[0262] The present invention will be specifically described based on examples, but the present invention is not limited to these examples.

[0263] The butadiene, styrene, butadiene rubber, and styrene-butadiene rubber obtained in the following production examples were evaluated by the following methods.

[0264] (Butadiene, styrene, butadiene rubber, styrene butadiene rubber pMC) The pMC of butadiene, styrene, styrene-butadiene rubber, etc. was measured in accordance with ASTM D6866-10 by the following method. The sample (butadiene, styrene, butadiene rubber, or styrene-butadiene rubber) was burned to generate carbon dioxide (CO2), which was then purified in a vacuum line. Next, the purified carbon dioxide was reduced with hydrogen using iron as a catalyst to generate graphite (C). The resulting graphite was then packed into a cathode with an inner diameter of 1 mm using a hand press, which was then fitted into a wheel and used in a measurement device (a tandem accelerator-based 14 The measurement was performed using a dedicated C-AMS device (manufactured by NEC). 14 C concentration, 13 The C concentration was measured, and the pMC (%), which indicates the biomass ratio, was calculated using oxalic acid provided by the National Institute of Standards (NIST) as a standard sample. 13 Correction was performed using C concentration values.

[0265] (Cis content of butadiene rubber) The cis content was measured using a BRUKER AV400 NMR instrument and data analysis software TOP SPIN2.1.

[0266] (styrene content of styrene butadiene rubber) The styrene content was measured using a BRUKER AV400 NMR device and data analysis software TOP SPIN2.1.

[0267] (Rubber weight average molecular weight (Mw), molecular weight distribution (Mw / Mn)) 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).The molecular weight distribution (Mw / Mn) of the polymer was calculated from the measured Mw and Mn. (1) Equipment: Tosoh HLC-8020 (2) Separation column: Tosoh GMH-XL (two columns in series) (3) Measurement temperature: 40℃ (4) Carrier: Tetrahydrofuran (5)Flow rate: 0.6mL / min (6) Injection volume: 5μL (7) Detector: Differential refraction (8) Molecular weight standard: Standard polystyrene

[0268] Production Example 1 (Production of butadiene from butanol) <Production of biobutanol> A 300 ml fermenter (DASGIP) was filled with 250 ml of 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 (ATCC 824) was inoculated under anaerobic conditions. The culture temperature was maintained at 35°C, and the pH was adjusted to 5.5 using NH4OH solution. Anaerobic conditions were maintained throughout the culture, and the shaking speed was maintained at 300 rpm. After 5 days of culture, the culture broth was distilled and separated using a conventional ion exchange resin method to obtain biobutanol (1-butanol).

[0269] <Production of butadiene from biobutanol> Using the apparatus shown in Figure 1, biomass-derived butadiene was synthesized using the biobutanol (1-butanol) obtained in <Production of biobutanol> as a raw material.

[0270] The apparatus used (see FIG. 1 ) was equipped with an alcohol inlet pipe (raw material inlet pipe) 21, a heater (electric furnace) 22 for vaporizing the introduced alcohol, a dehydration column 23 for dehydrating the alcohol, a cooling device 24 for cooling the product obtained by 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 reaction product. The dehydration column 23 was packed with 10 g of aluminum oxide (Merck Co., Ltd., product number 101095100) as a catalyst.

[0271] 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 zeolite (silica / alumina ratio: 40) was added to the solution for impregnation and left overnight. The solution was then dried in an oven at 100°C to obtain a precursor. This precursor was placed in a ceramic container and calcined in the presence of air at 700°C for 3 hours to obtain a chromium-supported zeolite catalyst containing 10% by mass of chromium. Then, the second-stage reaction column 26 was packed with 10 g of the chromium-supported zeolite catalyst.

[0272] Nitrogen gas was supplied to the dehydration column 23 through a gas inlet pipe (not shown). The nitrogen gas supply rate was 1 / hr in terms of LHSV. After the dehydration column 23 was heated to a predetermined temperature using a heater 22, a predetermined amount of biobutanol was supplied through the alcohol inlet pipe 21. The reaction conditions were: reaction temperature: 500°C, reaction pressure: atmospheric pressure, and a molar ratio of biobutanol to nitrogen (biobutanol / nitrogen): 50 / 50. The reaction time was 2 hours. The product was collected in a cooling device (product trap) 24 connected to the dehydration column 23, and water was separated.

[0273] The second-stage reaction column 26 was heated to 500°C. The cooling device (product trap) 27 was cooled to -20°C. A preheated mixed gas (a 1:1:1 mixture of the butene mixture obtained in the first-stage dehydration reaction, nitrogen, and air) was introduced through the cooling device (product trap) 24 at a feed rate of 1 / hr in terms of LHSV, and the resulting reaction mixture was separated and purified by the method described in JP-A-60-115532, yielding biomass-derived butadiene in an 8% yield. The pMC value, which indicates the biomass ratio of the resulting butadiene (biomass-derived butadiene), was 105%.

[0274] Production Example 2 (Producing butadiene from bioethanol) Using the apparatus shown in Figure 1, biomass-derived butadiene was synthesized using commercially available bioethanol by a known method of converting ethanol into 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 pMC value, which indicates the biomass ratio of the obtained butadiene (biomass-derived butadiene), was 108%.

[0275] Production Example 3 (Production of butadiene from bioethylene) Palladium acetate 0.5mmol / L, 0.3mol / L Na3H3PMo9V3O 40 The catalyst prepared by dissolving in ethanol was introduced into the second-stage reaction column 26 of the apparatus shown in Figure 1, and the apparatus was purged with argon. Biomass-derived ethylene (a prototype product made from corn-derived bioethanol) was then introduced into the column. The reaction was carried out for 1 hour at 150 °C and 0.5 MPaG while circulating the catalyst solution through the circulation line 28. 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.) soaked in bioethanol was added, and the reaction was carried out for 5 hours at 400 °C. The reaction mixture was analyzed by GC / MS to confirm the production of butadiene. The pMC value, which indicates the biomass ratio of the obtained butadiene (biomass-derived butadiene), was 109%.

[0276] Production Example 4 (Production of butadiene from tiglic acid) 500 mg of tiglic acid (an intermediate in the formation of amino acids in the body) separated and purified from cinnamon 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 product was analyzed by GC / MS to confirm the production of butadiene. The pMC value, which indicates the biomass ratio of the resulting butadiene (biomass-derived butadiene), was 108%.

[0277] The biomass-derived butadienes obtained in Production Examples 1 to 4 were measured using an NMR apparatus AV400 manufactured by BRUKER (data analysis software TOP SPIN2.1), and it was confirmed that these butadienes were 1,3-butadienes.

[0278] Production Example 5 (Production of styrene from trees belonging to the Hamamelidaceae family) The bark of a sweetgum (Liquidambar styraciflua) was partially peeled off, and a total of 620 g of the exuded resin was immersed in toluene. After leaving it for half a day, the toluene solution was filtered and distilled, and 2.4 g of a fraction at 130-160°C was collected. The obtained fraction was separated and purified by HPLC, yielding 0.8 g of styrene. The pMC value, which indicates the biomass ratio of the obtained styrene (biomass-derived styrene), was 109%. In addition, 1 kg of peeled bark was treated in the same way to obtain 0.8 g of styrene. The pMC value, which indicates the biomass ratio of the obtained styrene (biomass-derived styrene), was 109%.

[0279] Production Example 6 (Production of styrene from trees belonging to the Styrax family) 610 g of resin from Styrax japonica was treated in the same manner as in Production Example 5 to obtain 0.1 g of styrene. The pMC value, which indicates the biomass ratio of the obtained styrene (biomass-derived styrene), was 109%.

[0280] Production Example 7 (Production of styrene by plant tissue culture) Catharanthus roseus shoots were excised and immersed in 70% ethanol solution, followed by approximately 0.5% sodium hypochlorite solution, and then washed with sterile water. The washed tissue pieces (shoots) were placed on MS medium supplemented with 1.0 mg / L dichlorophenoxyacetic acid and 1.0 mg / L benzyladenine. Callus formation was achieved by culturing these at 25°C for 5 weeks. Next, 10 g of the callus was transplanted into 20 ml of a medium prepared by adding 50 mg of biomass-derived cinnamic acid, 1.0 mg / l of dichlorophenoxyacetic acid, 1.0 mg / l of benzyladenine, and 3% sucrose to Gamborg B5 liquid medium (Gamborg O.L., Miller R. A., Ojima K., Experimental Cell Research, 50, 151 - 158 (1968)). This was cultured for 12 days while shaking at a culture temperature of 25°C, in the dark, and at a rotation speed of 100 rpm. The cultured tissue was taken out, washed with water, dried, and then the frozen and ground product was extracted with hexane. The extract was separated and purified by HPLC to obtain 6 mg of styrene. The value of pMC indicating the biomass ratio of the obtained styrene (biomass-derived styrene) was 109%. In addition, biomass-derived cinnamic acid was prepared by further purifying cinnamic acid derived from the herb (Seseli gummiferum) sold for aroma use by high performance liquid chromatography.

[0281] Production Example 8 (Production of styrene by non-genetically modified microorganisms) 24 g of potato dextrose agar powder (manufactured by Sigma-Aldrich) was dissolved in 1000 mL of purified water and autoclaved at 121°C for 20 minutes. Chloramphenicol was added to a final concentration of 100 mg / L before use. Penicillium citrinum (ATCC 9849) was inoculated into the medium and statically cultured at 25°C under sealed conditions for 2 weeks. Then, hexane was added to the culture vessel and shaken, and the hexane layer was separated and analyzed by GC / MS to confirm the production of styrene. The value of pMC indicating the biomass ratio of the obtained styrene (biomass-derived styrene) was 109%.

[0282] Production Example 9 (Production of styrene by genetically recombinant Escherichia coli) <Preparation of <encP gene (gene encoding phenylalanine ammonia lyase) fragment and construction of <encP expression plasmid>> The actinomycete Streptomyces maritimus encP gene (1572 bp from the start codon to the stop codon (GenBank accession number: AF254925, nucleotide numbers 16269 - 17840)) was prepared as an artificial gene, and the DNA inserted into the SmaI site of the cloning vector pUC19 plasmid was used as a template for PCR. PCR was performed using an upstream primer containing an NdeI site at the 5'-end (SEQ ID NO: 1) and a downstream primer containing a BamHI site at the 5'-end (SEQ ID NO: 2), and the reaction solution was purified with a QIAprep PCR Purification Kit (Qiagen) to obtain a DNA fragment E (NdeI-encP-BamHI: 1592 bp) of the encP gene containing novel restriction enzyme sites at both ends. By general recombinant DNA procedures, the DNA fragment E treated with NdeI and BamHI restriction enzymes was ligated into the NdeI - BamHI site of the pET11a vector (Novagen), transformed into E. coli DH-5α competent cells, seeded on an LB agar medium containing 50 μg / mL of ampicillin, and cultured overnight at 37°C. The E. coli colonies formed on the agar medium were cultured with shaking overnight at 37°C in 5 mL of an LB liquid medium containing 50 μg / mL of ampicillin, and plasmids were extracted from the obtained E. coli using a QIAprep Spin Miniprep Kit (Qiagen). A plasmid confirmed by DNA sequence analysis to have the DNA sequence of GenBank accession number AF254925 inserted into the target site of the pET11a vector was designated as the encP expression plasmid pET11-encP (the plasmid shown in Fig. 2(a)).

[0283] <Isolation of the FDC1 gene (gene encoding ferulic acid decarboxylase)> Genomic DNA was purified from the budding yeast Saccharomyces cerevisiae using Yeast Geno-DNA-Template (Geno Technology, Inc), and this was used as the template for the first round of PCR. PCR was performed using the upstream primer (SEQ ID NO: 3) and the downstream primer (SEQ ID NO: 4), and the reaction solution was purified using the QIAprep PCR purification Kit (Qiagen), and the resulting DNA was used as the template for the second round of PCR. The second round of PCR was performed using the upstream primer containing a BspHI site at the 5'-end (SEQ ID NO: 5) and the downstream primer containing a HindIII site at the 5'-end (SEQ ID NO: 6), and the reaction solution was purified using the QIAprep PCR purification Kit (Qiagen) to obtain a DNA fragment F of the FDC1 gene (BspHI-FDC1-HindIII: 1525 bp) with novel restriction enzyme sites added to both ends.

[0284] <Isolation of the PAD1 gene (gene encoding cinnamate decarboxylase (phenylacrylic acid decarboxylase))> Using the above-mentioned Saccharomyces cerevisiae genome as a template, PCR was performed using the upstream primer (SEQ ID NO: 7) and the downstream primer (SEQ ID NO: 8), and the reaction solution was purified using the PCR purification Kit (Qiagen), and the resulting DNA was used as the template for the second round of PCR. The second round of PCR was performed using the upstream primer containing an NdeI site at the 5'-end (SEQ ID NO: 9) and the downstream primer containing an XhoI site at the 5'-end (SEQ ID NO: 10), and the reaction solution was purified using the QIAprep PCR purification Kit (Qiagen) to obtain a DNA fragment P of the PAD1 gene (NdeI-PAD1-XhoI: 746 bp) with novel restriction enzyme sites added to both ends.

[0285] <Construction of the FDC1 / PAD1 co-expression plasmid> The FDC1 gene DNA fragment F was inserted into the multiple cloning site-1 (MCS-1) of pRSFDuet-1 (Novagen), and the PAD1 gene DNA fragment P was inserted into the multiple cloning site-2 (MCS-2) by the following procedure. Using standard recombinant DNA procedures, DNA fragment F was treated with BspHI and HindIII restriction enzymes and inserted into the NcoI and HindIII sites in the multiple cloning site-1 of the pRSFDuet-1 vector (Novagen). pRSF-FDC1 was constructed using the same procedures as for constructing pET11-encP, except that ampicillin in the agar and liquid media was changed to kanamycin. Similarly, DNA fragment P treated with NdeI and XhoI restriction enzymes was inserted into the NdeI and XhoI sites of pRSF-FDC1 (derived from MCS-2 of the original vector pRSFDuet-1), and the constructed plasmid was named pRSF-FDC1-PAD1 (the plasmid shown in Figure 2(b)).

[0286] <Preparation of transformants> pET11-encP and pRSF-FDC1-PAD1 were simultaneously transformed into Escherichia coli BL21(DE3) competent cells, which were then plated on LB agar medium containing 35 μg / mL ampicillin and 20 μg / mL kanamycin. The cells were then cultured overnight at 30°C, and the formation of E. coli colonies on the agar medium was confirmed.

[0287] <Production of styrene by transformants> A colony of E. coli transformed with pET11-encP and pRSF-FDC1-PAD1 was inoculated into 1 mL of LB liquid medium containing 35 μg / mL ampicillin and 20 μg / mL kanamycin and cultured overnight at 30°C with shaking to prepare a preculture. 100 μL of the preculture was inoculated into 50 mL of LB liquid medium containing 35 μg / mL ampicillin and 20 μg / mL kanamycin in a 300 mL Meyer flask and cultured at 30°C with shaking for 15 hours. The absorbance (A600) of the culture at 600 nm was measured every 30 minutes, and the culture was continued under the same conditions. When the A600 reached 0.8, 25 μL of 1 M isopropyl-β-thiogalactopyranoside (IPTG) (final concentration: 0.5 mM) was added to induce protein expression, and the culture was continued for another 8 hours.

[0288] <Measurement of styrene production in culture medium> The culture medium was centrifuged, and hexane was added to the supernatant and vigorously stirred. After centrifugation, the hexane layer was separated and analyzed by GC / MS to confirm the production of styrene. The amount of styrene produced was 140 mg / L. The pMC value, which indicates the biomass ratio of the obtained styrene (biomass-derived styrene), was 109%.

[0289] The biomass-derived styrenes obtained in Production Examples 5 to 9 were measured using an NMR apparatus AV400 manufactured by BRUKER (data analysis software TOP SPIN2.1), and it was confirmed that these styrenes were styrenes.

[0290] Production Example 10 (Production of Biomass Butadiene Rubber (BioBR1)) 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: In-house production Potassium rosinate soap: Harima Chemicals Co., Ltd. Fatty acid sodium soap: Fujifilm Wako Pure Chemical Industries, Ltd. Potassium chloride: Fujifilm Wako Pure Chemical Industries, Ltd. Sodium naphthalenesulfonate formalin condensate: Kao Corporation t-Dodecyl mercaptan: tert-Dodecyl mercaptan (chain transfer agent) manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Sodium hydrosulfide: Fujifilm Wako Pure Chemical Industries, Ltd. FeSO4: Ferric sulfate manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. EDTA: Sodium ethylenediaminetetraacetate manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Rongalit: Sodium formaldehyde sulfoxylate manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Polymerization initiator: Paramenthane hydroperoxide manufactured by NOF Corporation Polymerization terminator: N,N-diethylhydroxylamine manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. 2,6-di-t-butyl-p-cresol: Sumilizer BHT manufactured by Sumitomo Chemical Co., Ltd. <Synthesis of butadiene rubber> A 50-liter stainless steel polymerization reactor was washed, dried, and purged with dry nitrogen. Then, 5,000 g of 1,3-butadiene, 5.74 g of t-dodecyl mercaptan, 9,688 g of emulsifier (a mixture of ion-exchanged water, potassium rosinate soap, sodium fatty acid soap, potassium chloride, and sodium naphthalenesulfonate formalin condensate), 6.3 ml (1.8 M) of sodium hydrosulfide, 6.3 ml each of activators (FeSO4 / EDTA / Rongalit), and 6.3 ml (2.3 M) of polymerization initiator were added, and 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 mixture was allowed to react for 30 minutes. The contents of the polymerization reaction vessel were then removed, and 10 g of 2,6-di-t-butyl-p-cresol was added. After evaporating most of the water, the mixture was dried under reduced pressure at 55°C for 12 hours to obtain a biobutadiene polymer (biomass butadiene rubber (BioBR1)). The pMC, which indicates the biomass ratio of the obtained BioBR, was 105%.

[0291] Production Example 11 (Production of Biomass Butadiene Rubber (BioBR2)) A butadiene rubber (biomass-derived rubber) was synthesized in the same manner as in Production Example 10, except that the biomass-derived butadiene (1,3-butadiene) obtained in Production Example 1 was used as the monomer component, and a biobutadiene polymer (biomass butadiene rubber (BioBR2); pMC, which indicates the biomass ratio of the obtained BioBR, was 105%) was obtained.

[0292] Production Example 12 (Production of Biomass Butadiene Rubber (BioBR3)) A butadiene rubber (biomass-derived rubber) was synthesized in the same manner as in Production Example 10, except that the biomass-derived butadiene (1,3-butadiene) obtained in Production Example 2 was used as the monomer component, and a biobutadiene polymer (biomass butadiene rubber (BioBR3); pMC, which indicates the biomass ratio of the obtained BioBR, was 108%) was obtained.

[0293] Production Example 13 (Production of Biomass Butadiene Rubber (BioBR4)) A butadiene rubber (biomass-derived rubber) was synthesized in the same manner as in Production Example 10, except that the biomass-derived butadiene (1,3-butadiene) obtained in Production Example 3 was used as the monomer component, and a biobutadiene polymer (biomass butadiene rubber (BioBR4); pMC, which indicates the biomass ratio of the obtained BioBR, was 109%) was obtained.

[0294] Production Example 14 (Production of Biomass Butadiene Rubber (BioBR5)) A butadiene rubber (biomass-derived rubber) was synthesized in the same manner as in Production Example 10, except that the biomass-derived butadiene (1,3-butadiene) obtained in Production Example 4 was used as the monomer component, and a biobutadiene polymer (biomass butadiene rubber (BioBR5); pMC, which indicates the biomass ratio of the obtained BioBR, was 108%) was obtained.

[0295] Production Example 15 (Production of Biomass Styrene Butadiene Rubber (Bio-SBR)) Bio-SBR (biomass-derived rubber) was synthesized using a mixture of biomass-derived butadiene (1,3-butadiene) obtained in Production Examples 1 to 4 as the biomass-derived butadiene and a mixture of biomass-derived styrene obtained in Production Examples 5 to 9 as the biomass-derived styrene as the monomer components. The chemicals used are as follows: Water: Distilled water Emulsifier (1): Rosin acid soap manufactured by Harima Chemical Co., Ltd. Emulsifier (2): Fatty acid soap manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Electrolyte: Sodium phosphate manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Molecular weight modifier: tert-dodecyl mercaptan manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Radical initiator: Paramenthane hydroperoxide manufactured by NOF Corporation SFS: Sodium formaldehyde sulfoxylate manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. EDTA: Sodium ethylenediaminetetraacetate manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Catalyst: Ferric sulfate manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Polymerization terminator: N,N'-dimethyldithiocarbamate manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Alcohol: Methanol and ethanol manufactured by Kanto Chemical Co., Ltd. Formic acid: Formic acid manufactured by Kanto Chemical Co., Ltd. <Synthesis of styrene butadiene rubber> A pressure-resistant reactor equipped with a stirrer was charged with 200 g of water, 4.5 g of emulsifier (1), 0.15 g of emulsifier (2), 0.8 g of electrolyte, 25 g of styrene, 75 g of butadiene, and 0.2 g of molecular weight modifier. The reactor temperature was adjusted to 5°C, and an aqueous solution containing 0.1 g of radical initiator and 0.15 g of SFS, and an aqueous solution containing 0.07 g of EDTA and 0.05 g of catalyst were added to the reactor to initiate polymerization. Five hours after the start of polymerization, 0.2 g of polymerization terminator was added to terminate the reaction, yielding a latex. Unreacted monomers were removed from the obtained latex by steam distillation. The latex was then added to alcohol and coagulated while adjusting the pH to 3 to 5 with formic acid, yielding a crumb-like biostyrene butadiene polymer. The polymer was dried in a vacuum dryer at 40°C to obtain a solid rubber (biomass styrene butadiene rubber (bio-SBR) with a pMC (biomass ratio) of 108%).

[0296] The various chemicals used in the examples and comparative examples will be explained below. Bio-SBR: SBR prepared in Production Example 15 (Mw / Mn: 3.2, styrene content: 8% by mass) BR: BR150B manufactured by Ube Industries, Ltd. (cis content: 97% by mass, vinyl content: 1% by mass) Bio BR1 to 5: BR1 to 5 prepared in Production Examples 10 to 14 (cis content: 98% by mass, Mw: 400,000, Mw / Mn: 4.2) NR:TSR20(NR) Rubber powder: PolyDyne 200 manufactured by Lehigh TECHNOLOGIES (containing 46 parts by mass of carbon black and 15 to 18 parts by mass of silica per 100 parts by mass of rubber component, with 65% by mass of isoprene-derived units and 35% by mass of butadiene-derived units out of 100% by mass of all rubber component units, containing 26% by mass of high-cis BR (cis content: 97% by mass) out of 100% by mass of rubber component, volume average particle size: 53 μm, 60-mesh sieve residue: 0.1% by mass, 80-mesh sieve residue: 0.1% by mass, acetone extractables: 7.2% by mass) Carbon black: Diablack N220 (N2SA: 111m) manufactured by Mitsubishi Chemical Corporation 2 / g) Silica: Ultrasil VN3 (N2SA: 175 ml) manufactured by Evonik Degussa 2 / g) Rice husk silica: Rice husk silica (N2SA: 175 ml) produced by the method described in JP 2019-38728 A 2 / g) Oil: Diana Process AH-24 (aromatic process oil) manufactured by Idemitsu Kosan Co., Ltd. Silane coupling agent: Si266 (bis(3-triethoxysilylpropyl) disulfide) manufactured by Evonik Degussa Resin 1: Sylvatraxx 4401 (α-methylstyrene resin (copolymer of α-methylstyrene and styrene), softening point: 85°C) manufactured by Arizona Chemical Company Resin 2: Sylvatraxx 4150 manufactured by Arizona Chemical Company (β-pinene resin, β-pinene content: 98% by mass or more, softening point: 115°C) Resin 3: Pine Crystal KR-85 (rosin-based resin, softening point: 80-87°C) manufactured by Arakawa Chemical Industries, Ltd. Resin 4: Marucaretz M-890A (dicyclopentadiene resin, softening point: 105°C) manufactured by Maruzen Petrochemical Co., Ltd. Resin 5: ECR-373 manufactured by ExxonMobil Corporation (a copolymer of C5 fraction and C9 fraction (C5 / C9 resin), softening point: 86°C) Zinc oxide: Zinc oxide No. 1 manufactured by Mitsui Mining & Smelting Co., Ltd. Stearic acid: NOF Corporation's "Tsubaki" stearic acid Antioxidant 1: Nocrac 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 (powdered sulfur containing 5% oil by mass) manufactured by Hosoi Chemical Industry Co., Ltd. Vulcanization accelerator 1: Noccela CZ (N-cyclohexyl-2-benzothiazolyl sulfenamide) manufactured by Ouchi Shinko Chemical Industry Co., Ltd. Vulcanization accelerator 2: Noccela D (diphenyl guanidine) manufactured by Ouchi Shinko Chemical Industry Co., Ltd.

[0297] Examples and Comparative Examples According to the formulation shown in Tables 1 and 2, materials other than sulfur and vulcanization accelerator were kneaded for 5 minutes at 150°C using a 1.7 L Banbury mixer to obtain a kneaded mixture. Next, sulfur and vulcanization accelerator were added to the obtained kneaded mixture, and the mixture was kneaded for 5 minutes at 80°C 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 laminated together with other tire components to form an unvulcanized tire. This was press-vulcanized for 12 minutes at 150°C to produce a test tire (size: 195 / 65R15).

[0298] The unvulcanized rubber compositions and test tires obtained were subjected to the following evaluations, and the results are shown in Tables 1 and 2. The reference example in Table 1 was designated Comparative Example 1-1, and the reference example in Table 2 was designated Comparative Example 2-1.

[0299] (tanδ) A test specimen was cut out from the cap tread of the test tire. Then, the 0°C tan δ of the test specimen (vulcanized rubber composition) was measured using a viscoelasticity spectrometer VES manufactured by Iwamoto Seisakusho Co., Ltd. The measurement conditions are as follows. The results are expressed as an index, with the reference example being set at 100, along with the actual measured value. The larger the index, the better the wet grip performance. An index of 45 or more was judged to be good. Measurement temperature: 0°C, initial strain: 10%, dynamic strain: 2%, frequency: 10Hz

[0300] (glass transition temperature (Tg)) A test specimen was cut out from the cap tread of the test tire, and the glass transition temperature (Tg) of the test specimen (vulcanized rubber composition) was measured at a heating rate of 10°C / min using an automatic differential scanning calorimeter (DSC-60A) manufactured by Shimadzu Corporation in accordance with JIS-K7121 (2012).

[0301] (processability) The obtained unvulcanized rubber composition was measured in accordance with JIS K 6300-1 "Unvulcanized rubber - Physical properties - Part 1: Determination of viscosity and scorch time using a Mooney viscometer" using a Mooney viscosity tester. The small rotor was rotated at a temperature of 130°C, which had been preheated for 1 minute, and the Mooney viscosity (ML 1+4 / 130℃ ) was measured. The measurement results for the reference example were set at 100, and the Mooney viscosity of each formulation was expressed as an index using the following calculation formula. A larger index indicates a lower Mooney viscosity and better processability. (ML1+4 index) = (Mooney viscosity of the reference example) / (Mooney viscosity of each compound) × 100

[0302] (Hardness (Hs)) A test specimen was cut out from the cap tread of the test tire. Then, in accordance with JIS K6253 "Testing Method for Hardness of Vulcanized and Thermoplastic Rubber," the Hs of the test specimen 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. An index of 60 or more was considered to be good.

[0303] (Tensile test) Test specimens were cut out from the cap tread of the test tire. Then, No. 3 dumbbell-shaped test specimens were prepared from the obtained test specimens based on JIS K6251 (2010), and tensile tests were carried out using the test specimens at 23°C to measure the tensile strength at break (TB) and 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. A TB index of 60 or more was considered to be good.

[0304] [Table 1]

[0305] [Table 2]

[0306] Tables 1 and 2 show that examples in which the pMC (percent modern carbon) of components based on butadiene and aromatic vinyl, measured in accordance with ASTM D6866-10, is 30% or more, the content of units derived from butadiene is 80 to 100% by mass out of 100% by mass of units in the total rubber component, the content of units derived from aromatic vinyl is 0 to 20% by mass out of 100% by mass of units in the total rubber component, and the resin is contained in an amount of 10 to 100 parts by mass per 100 parts by mass of the rubber component, are environmentally friendly and reduce the use of raw materials derived from fossil fuels, while also improving performance required for tires, such as wet grip performance and breaking strength.

[0307] Comparing Example 1-1 and Comparative Examples 1-1 to 1-3, it was found that by using a rubber component with a high biomass ratio of components based on butadiene and aromatic vinyl and a high content of units derived from butadiene in combination with a resin, the overall performance of wet grip performance and breaking strength (expressed as the sum of the two indices of wet grip performance and breaking strength) can be synergistically improved. [Explanation of symbols]

[0308] 21 Alcohol inlet pipe (raw material inlet pipe) 22 Heating device (electric furnace) 23 Dehydration reaction column 24 Cooling device 25 Heating device 26 Second-stage reaction column 27 Cooling device 28 Circulation Line

[0309] (Sequence listing free text) SEQ ID NO: 1: upstream primer (encP-U-Nde) SEQ ID NO: 2: downstream primer (encP-L-Bam) SEQ ID NO: 3: upstream primer (FDC1-gU) SEQ ID NO: 4: downstream primer (FDC1-gL) SEQ ID NO: 5: upstream primer (FDC1-nU-BspHI) SEQ ID NO: 6: downstream primer (FDC1-nL-Hind) SEQ ID NO: 7: Upstream primer (PAD1-gU) SEQ ID NO: 8: downstream primer (PAD1-gL) SEQ ID NO: 9: upstream primer (PAD1-nU-Nde) SEQ ID NO: 10: downstream primer (PAD1-nL-Xho)

Claims

1. The percent modern carbon (pMC) of the butadiene and aromatic vinyl-based components measured in accordance with ASTM D6866-10 is 30% or more; the content of units derived from butadiene is 80 to 100% by mass based on 100% by mass of all units of the rubber component, the content of units derived from aromatic vinyl is 0 to 20% by mass based on 100% by mass of all units of the rubber component, The rubber composition contains 40 to 80 parts by mass of a resin per 100 parts by mass of the rubber component, A rubber composition for passenger car tires comprising 50 to 150 parts by mass of silica per 100 parts by mass of a rubber component.

2. The percent modern carbon (pMC) of the entire rubber component measured in accordance with ASTM D6866-10 is 30% or more, the content of units derived from butadiene is 80 to 99% by mass based on 100% by mass of all units of the rubber component, the content of units derived from aromatic vinyl is 0 to 19% by mass based on 100% by mass of all units of the rubber component, 2. The rubber composition for passenger car tires according to claim 1, wherein the content of units derived from isoprene is 1 to 10 mass % based on 100 mass % of all units in the rubber component.

3. 3. The rubber composition for passenger car tires according to claim 1, wherein the aromatic vinyl is styrene.

4. 4. The rubber composition for passenger car tires according to claim 1, comprising an aromatic vinyl / butadiene copolymer having a content of units derived from aromatic vinyl of 10% by mass or less.

5. 5. The rubber composition for passenger car tires according to claim 1, wherein the content of the natural rubber is 0.1 to 10 mass% based on 100 mass% of the rubber component.

6. 6. The rubber composition for passenger car tires according to claim 1, wherein 0°C tan δ is 0.18 to 1.60 and Tg is -85°C to -5°C.

7. 7. The rubber composition for passenger car tires according to claim 1, wherein the resin is at least one selected from the group consisting of terpene-based resins and rosin-based resins.

8. The rubber composition for passenger car tires according to any one of claims 1 to 6, wherein the resin is at least one selected from the group consisting of cyclopentadiene-based resins, C5-based resins, C5 / C9-based resins, and C9-based resins.

9. 7. The rubber composition for passenger car tires according to claim 1, wherein the resin is an aromatic resin.

10. 10. The rubber composition for passenger car tires according to claim 1, wherein the resin is modified with a polar functional group that interacts with silica.

11. The rubber composition for passenger car tires according to any one of claims 1 to 10, which contains silica derived from rice husks.

12. The rubber composition for passenger car tires according to any one of claims 1 to 11, which contains rubber powder.

13. 13. The rubber composition for passenger car tires according to claim 1, wherein the content of silica per 100 parts by mass of the rubber component is 80 to 150 parts by mass.

14. The rubber composition for passenger car tires according to any one of claims 1 to 13, wherein the content of the resin per 100 parts by mass of the rubber component is 50 to 80 parts by mass.

15. A passenger car tire having a tire component using the rubber composition according to any one of claims 1 to 14.

16. 16. The passenger tire of claim 15, wherein the tire component is a tread.

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