Hydrogenated copolymer, pellet, resin composition, and tire

Abstract

To provide a hydrogenated copolymer capable of achieving superior processability and fuel-saving performance when formulated into a resin composition, while exhibiting excellent handling properties when used alone.SOLUTION: A hydrogenated copolymer comprises: a hydrogenated block copolymer (X) having at least one polybutadiene block (A) with a vinyl group content of 20 mass% or less; and a polymer (Y) including structural units derived from an aromatic vinyl compound and / or structural units derived from a conjugated diene compound, wherein the ratio of the number average molecular weight of the hydrogenated block copolymer (X) to the number average molecular weight of the polymer (Y) is 2.5 or more and 30 or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a hydrogenated copolymer, a pellet, a resin composition, and a tire. [Background technology]

[0002] Liquid rubber is a highly viscous fluid that is fluid at room temperature, making it difficult to handle, and there have been problems such as the time and effort required to adjust the concentration of the liquid rubber to a desired value in a resin composition using it, and the need for dedicated equipment to supply the highly viscous fluid. To address this, a method has been implemented in which the liquid rubber is handled by filling it into a melting bag, but this has had problems such as increased costs due to filling into the melting bag and the melting bag breaking during transportation.

[0003] To solve the above problems, it has been proposed to prepare a masterbatch of liquid rubber. For example, Patent Documents 1 to 3 describe the preparation of a masterbatch of liquid rubber by removing the solvent from a mixture of a block copolymer, liquid rubber, and a solvent. Patent Document 4 also discloses a method of preparing a masterbatch of liquid rubber by mixing the block copolymer and liquid rubber in an extruder. However, when a liquid rubber masterbatch is used in a tire tread, the styrene block contained in the block copolymer reduces the fuel economy of the composition, which is a problem. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2009-530473 [Patent Document 2] Special Publication No. 2009-530474 [Patent Document 3] Special Publication No. 2009-542822 [Patent Document 4] WO2023 / 127895A1 Summary of the Invention

[0005] As a result of intensive investigations to solve the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by a hydrogenated copolymer comprising a hydrogenated block copolymer (X) having at least one polybutadiene block (A) having a vinyl group content of 20% by mass or less, and a polymer (Y) which contains structural units derived from an aromatic vinyl compound and / or structural units derived from a conjugated diene compound and which has a number average molecular weight smaller than that of the hydrogenated block copolymer (X), and in which the value of number average molecular weight of the hydrogenated block copolymer (X) / number average molecular weight (Y) is 2.5 or more and 30 or less, and have thereby completed the present invention. [Means for solving the problem]

[0006] That is, the present invention includes the following embodiments. [1] a hydrogenated block copolymer (X) having at least one polybutadiene block (A) having a vinyl group content of 20% by mass or less; a polymer (Y) containing structural units derived from an aromatic vinyl compound and / or structural units derived from a conjugated diene compound; Including, A hydrogenated copolymer in which the ratio of the number average molecular weight of the hydrogenated block copolymer (X) to the number average molecular weight of the polymer (Y) is 2.5 or more and 30 or less. [2] The hydrogenated copolymer according to [1], wherein the hydrogenation rate of the hydrogenated block copolymer (X) is 80% or more. [3] In the hydrogenated block copolymer (X), other than the polybutadiene block (A), When the mass fraction of the structural units derived from a conjugated diene compound having a 1,2 or 3,4 vinyl bond relative to the entire hydrogenated block copolymer (X) is a mass %, the mass fraction of the structural units derived from an aromatic vinyl compound randomly copolymerized with the conjugated diene relative to the entire hydrogenated block copolymer (X) is b mass %, and the mass fraction of the structural units derived from a conjugated diene compound having a 1,4 bond of the polybutadiene block (A) relative to the entire hydrogenated block copolymer (X) is c mass %; The hydrogenated copolymer according to [1] or [2], wherein a+bc is −15% by mass or more and 40% by mass or less. [4] The hydrogenated copolymer according to any one of [1] to [3], wherein the mass ratio of the hydrogenated block copolymer (X) to the polymer (Y) is 40:60 to 80:20. [5] The hydrogenated copolymer according to any one of [1] to [4], wherein the hydrogenated block copolymer (X) has a number average molecular weight of 70,000 to 250,000. [6] The hydrogenated copolymer according to any one of [1] to [5], wherein the number average molecular weight of the polymer (Y) is 4,000 or more and 35,000 or less. [7] The hydrogenated copolymer according to any one of [1] to [6], wherein the polybutadiene block (A) accounts for 5% or more and less than 50% by mass of the entire hydrogenated block copolymer (X). [8] Pellets of the hydrogenated copolymer according to any one of [1] to [7]. [9] A resin composition comprising the hydrogenated copolymer according to any one of [1] to [7], a styrene-butadiene rubber, and one solid rubber component selected from the group consisting of natural rubber and butadiene rubber.

[10] The resin composition according to [9], further comprising a filler.

[11] The resin composition according to [9] or

[10] , further comprising a silane coupling agent.

[12] A tire comprising the resin composition according to any one of [9] to

[11] . [Effects of the Invention]

[0007] According to the present invention, a hydrogenated copolymer can be obtained which has excellent processability and fuel economy when made into a resin composition and also has excellent handleability when used alone. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described in detail. In this embodiment, the naming of each monomer unit constituting a polymer follows the naming of the monomer from which the monomer unit is derived. For example, a "vinyl aromatic monomer unit" refers to a structural unit of a polymer resulting from the polymerization of a vinyl aromatic compound monomer, and has a molecular structure in which two carbon atoms of a substituted ethylene group derived from a substituted vinyl group serve as bonding sites. Furthermore, a "conjugated diene monomer unit" refers to a structural unit of a polymer resulting from the polymerization of a conjugated diene monomer, and has a molecular structure in which two carbon atoms of an olefin derived from the conjugated diene monomer serve as bonding sites.

[0009] ≪Hydrogenated copolymer≫ The hydrogenated copolymer of this embodiment comprises a hydrogenated block copolymer (X) (hereinafter also referred to simply as (X)) having at least one polybutadiene block (A) with a vinyl group content of 20% by mass or less, and a polymer (Y) (hereinafter also referred to simply as (Y)) containing structural units derived from an aromatic vinyl compound and / or structural units derived from a conjugated diene compound, wherein the value of the number average molecular weight of the hydrogenated block copolymer (X) divided by the number average molecular weight of the polymer (Y) is 2.5 or more and 30 or less. In the hydrogenated copolymer of this embodiment, the vinyl group content of the polybutadiene block (A) is 20% by mass or less, based on the mass of the polybutadiene block (A). When the vinyl group content is 20% by mass or more, the hydrogenated copolymer itself has excellent handleability and the resin composition obtained by the hydrogenated copolymer has excellent fuel economy. The content of vinyl groups in the polybutadiene block (A) is preferably 1 to 20% by mass, more preferably 3 to 17% by mass, and even more preferably 5 to 15% by mass. In this embodiment, the total amount of 1,2-vinyl bonds and 3,4-vinyl bonds (however, when 1,3-butadiene is used as the conjugated diene, the amount of 1,2-vinyl bonds) is defined as the "amount of vinyl bonds." The vinyl bond content based on the conjugated diene monomer units in the copolymer before hydrogenation can be determined using an infrared spectrophotometer (Hampton method).

[0010] In this embodiment, the conjugated diene monomer is a diolefin having one pair of conjugated double bonds, such as 1,3-butadiene, 2-methyl-1,3-butadiene (i.e., isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, and 1,3-hexadiene. 1,3-butadiene and isoprene are particularly preferred. These may be used singly or in combination of two or more. Examples of vinyl aromatic monomers include styrene, α-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylethylene, N,N-dimethyl-p-aminoethylstyrene, and N,N-diethyl-p-aminoethylstyrene, and these may be used singly or in combination of two or more.

[0011] In the hydrogenated copolymer of this embodiment, the value of the number average molecular weight of the hydrogenated block copolymer (X) / the number average molecular weight of the hydrogenated block copolymer (Y) is 2.5 or more and 30 or less. When the value of the number average molecular weight of the hydrogenated block copolymer (X) / the number average molecular weight of the hydrogenated block copolymer (Y) is 2.5 or more, the processability of the resin composition is excellent, and when it is 30 or less, the handleability of the hydrogenated copolymer itself is excellent. The value of the number average molecular weight of the hydrogenated block copolymer (X) / the number average molecular weight of (Y) is preferably 2.5 or more and 30 or less, more preferably 4.5 or more and 28 or less, and even more preferably 7 or more and 26 or less. The molecular weight of the hydrogenated copolymer is a number average molecular weight determined by gel permeation chromatography (GPC) using a calibration curve (prepared using the peak molecular weight of the standard polystyrene) determined from the measurement of commercially available standard polystyrene.

[0012] In the hydrogenated copolymer of this embodiment, the hydrogenated block copolymer (X) preferably has a hydrogenation rate of 80% or more. More specifically, it is preferred that 80% or more of the double bonds based on the conjugated diene monomer units of the hydrogenated block copolymer (X) are hydrogenated. When the hydrogenated block copolymer (X) has a hydrogenation rate of 80% or more, excellent handleability is exhibited. The hydrogenation rate of the hydrogenated block copolymer (X) is preferably 80% or more, more preferably 85% or more, even more preferably 92% or more, and particularly preferably 95% or more. The hydrogenation rate of the hydrogenated block copolymer (X) can be determined using a nuclear magnetic resonance (NMR) spectrometer.

[0013] In the hydrogenated copolymer of the present embodiment, other than the polybutadiene block (A) of the hydrogenated block copolymer (X), when the mass fraction of structural units derived from a conjugated diene compound having a 1,2 or 3,4 vinyl bond relative to the entire hydrogenated block copolymer (X) is a mass %, the mass fraction of structural units derived from an aromatic vinyl compound randomly copolymerized with a conjugated diene relative to the entire hydrogenated block copolymer (X) is b mass %, and the mass fraction of structural units derived from a conjugated diene compound having a 1,4 bond in the polybutadiene block (A) relative to the entire hydrogenated block copolymer (X) is c mass %, it is preferable that a+bc be −15% by mass or more and 40% by mass or less. When a + bc is -15% by mass or more, precipitation of the hydrogenated block copolymer (X) from the reaction solvent can be prevented in the production process of the hydrogenated block copolymer (X). When a + bc is 40% by mass or less, the abrasion resistance of the resin composition can be improved. Furthermore, the range of a + bc is preferably -15% by mass or more and 40% by mass or less, more preferably -10% by mass or more and 35% by mass or less, even more preferably -5% by mass or more and 30% by mass or less, and particularly preferably -5% by mass or more and 30% by mass or less. The value of a can be controlled within the above range by adjusting the content of the polybutadiene block (A), the amount of the vinyl bond amount adjuster, and the polymerization temperature. It can be calculated by measuring the mass fraction of the structural units derived from the conjugated diene compound having a vinyl bond in the entire X and the structural units derived from the conjugated diene compound having a vinyl bond in the polybutadiene block (A) by NMR and calculating the difference between the two. The value of b can be controlled within the above range by adjusting the amount of vinyl aromatic compound fed during polymerization, the amount of vinyl bond amount adjuster, and the polymerization temperature, and can be measured by nuclear magnetic resonance (NMR). The value of c can be controlled within the above range by adjusting the content of the polybutadiene block (A), the amount of vinyl bond amount adjuster during polymerization of the polybutadiene block (A), and the polymerization temperature. It can be calculated from the amount of conjugated diene compound fed during polymerization and the mass fraction of the structural units derived from the conjugated diene compound having a vinyl bond in the polybutadiene block (A).

[0014] In the hydrogenated copolymer of this embodiment, the mass ratio of the hydrogenated block copolymer (X) to the polymer (Y) is desirably 40:60 to 80:20. When the mass ratio of the hydrogenated block copolymer (X) to the polymer (Y) is 40:60 or more, the hydrogenated copolymer itself is easy to handle, and when it is 80:20 or less, the processability when made into a resin composition is excellent. The mass ratio of the hydrogenated block copolymer (X) to the polymer (Y) is preferably 40:60 to 80:20, more preferably 50:50 to 75:25, and even more preferably 60:40 to 70:30. The mass ratio of the hydrogenated block copolymers (X) and (Y) can be controlled by the mixing ratio of the hydrogenated block copolymer (X) and the polymer (Y), and can be determined by measuring by gel permeation chromatography (GPC) and determining the ratio of the area values ​​of the peaks derived from the hydrogenated block copolymer (X) and the polymer (Y).

[0015] In the hydrogenated copolymer of this embodiment, the number average molecular weight of the hydrogenated block copolymer (X) is preferably 70,000 to 250,000. When the number average molecular weight of the hydrogenated block copolymer (X) is 70,000 or more, the hydrogenated copolymer of this embodiment exhibits excellent handleability, and a resin composition containing the hydrogenated copolymer of this embodiment has high fuel economy (low RR). Furthermore, when the number average molecular weight of the hydrogenated block copolymer (X) is 250,000 or less, a resin composition containing the hydrogenated copolymer of this embodiment exhibits good processability. The number average molecular weight of the hydrogenated block copolymer (X) is preferably 70,000 to 250,000, more preferably 80,000 to 150,000.

[0016] In the hydrogenated copolymer of this embodiment, the number average molecular weight of the polymer (Y) is preferably 4,000 or more and 35,000 or less. When the number average molecular weight of the polymer (Y) is 4,000 or more, the hydrogenated copolymer of this embodiment exhibits excellent handleability, and a resin composition containing the hydrogenated copolymer of this embodiment exhibits high fuel economy (low RR). Furthermore, when the number average molecular weight of the polymer (Y) is 35,000 or less, a resin composition containing the hydrogenated copolymer of this embodiment exhibits good processability. The number average molecular weights of the hydrogenated block copolymer (X) and the polymer (Y) can be controlled within the above-mentioned ranges by adjusting the amounts of monomers and initiators added during the polymerization process, the polymerization time, and the polymerization temperature, and can be measured by gel permeation chromatography (GPC).

[0017] In the hydrogenated copolymer of this embodiment, the mass ratio of the polybutadiene block (A) of the hydrogenated block copolymer (X) to the entire hydrogenated block copolymer (X) is preferably 5% by mass or more but less than 50% by mass. When the mass ratio of the polybutadiene block (A) to the entire hydrogenated block copolymer (X) is 5% or more, the hydrogenated copolymer of this embodiment exhibits excellent handleability. This is because the presence of a sufficient amount of crystalline polybutadiene block (A) functions as a hard block of the hydrogenated block copolymer (X), suppressing stickiness and cold flow when pelletized. Furthermore, when the mass ratio of the polybutadiene block (A) to the entire hydrogenated block copolymer (X) is less than 50% by mass, precipitation of the hydrogenated block copolymer (X) from the reaction solvent during the production process of the hydrogenated block copolymer (X) due to excessive crystallinity of the hydrogenated block copolymer (X) can be prevented. As a result, problems associated with pipe clogging and non-uniformity of the solution can be prevented. The mass ratio of the polybutadiene block (A) to the entire hydrogenated block copolymer (X) is preferably 5% by mass or more and less than 50% by mass, more preferably 7% by mass or more and less than 40% by mass, and particularly preferably 8% by mass or more and less than 30% by mass. The mass ratio of the polybutadiene block (A) to the entire hydrogenated block copolymer (X) can be controlled within the above-mentioned range by adjusting the feed amount of the conjugated diene compound during polymerization, and can be measured by a nuclear magnetic resonance (NMR) spectrometer.

[0018] (Method for producing hydrogenated copolymer) Examples of methods for producing the hydrogenated copolymer include, but are not limited to, methods described in JP-B Nos. 36-19286, 43-17979, 46-32415, 49-36957, 48-2423, 48-4106, 51-49567, and JP-A No. 59-166518.

[0019] The copolymer before hydrogenation of the hydrogenated copolymer can be obtained, for example, by a method of carrying out living anionic polymerization using a predetermined monomer in a hydrocarbon solvent using a polymerization initiator such as an organic alkali metal compound, but this is not limited thereto.

[0020] Examples of hydrocarbon solvents include, but are not limited to, aliphatic hydrocarbons such as n-butane, isobutane, n-pentane, n-hexane, n-heptane, and n-octane; alicyclic hydrocarbons such as cyclohexane, cycloheptane, and methylcycloheptane; and aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene.

[0021] As the polymerization initiator, an organic alkali metal compound that is generally known to have anionic polymerization activity for conjugated diene compounds and vinyl aromatic compounds can be used. Examples of the alkali metal include aliphatic hydrocarbon alkali metal compounds having 1 to 20 carbon atoms, aromatic hydrocarbon alkali metal compounds having 1 to 20 carbon atoms, and organic amino alkali metal compounds having 1 to 20 carbon atoms. Examples of the alkali metal contained in the polymerization initiator include, but are not limited to, lithium, sodium, potassium, etc. One or more types of alkali metals may be contained in one molecule.

[0022] Examples of the polymerization initiator include, but are not limited to, n-propyllithium, n-butyllithium, sec-butyllithium, tert-butyllithium, n-pentyllithium, n-hexyllithium, benzyllithium, phenyllithium, tolyllithium, a reaction product of diisopropenylbenzene and sec-butyllithium, and a reaction product of divinylbenzene, sec-butyllithium, and a small amount of 1,3-butadiene. Further, 1-(t-butoxy)propyllithium disclosed in U.S. Patent No. 5,708,092 and lithium compounds into which one to several molecules of isoprene monomer are inserted to improve solubility, siloxy group-containing alkyllithiums such as 1-(t-butyldimethylsiloxy)hexyllithium disclosed in British Patent No. 2,241,239, amino group-containing alkyllithiums disclosed in U.S. Patent No. 5,527,753, and aminolithiums such as diisopropylamide lithium and hexamethyldisilazide lithium can also be used as the polymerization initiator.

[0023] When a conjugated diene compound and a vinyl aromatic compound are copolymerized using an organic alkali metal compound as a polymerization initiator, a tertiary amine compound or an ether compound can be added as a vinyl bond amount adjuster to adjust the content of vinyl bonds (1,2-bonds or 3,4-bonds) resulting from the conjugated diene monomer units incorporated into the block copolymer and to adjust the random copolymerization property of the conjugated diene compound and the vinyl aromatic compound. The tertiary amine compound is not particularly limited, but examples thereof include compounds represented by the following formula: R1R2R3N (In the formula, R1, R2, and R3 are hydrocarbon groups having 1 to 20 carbon atoms or hydrocarbon groups having a tertiary amino group.)

[0024] Examples of such tertiary amine compounds include, but are not limited to, trimethylamine, triethylamine, tributylamine, N,N-dimethylaniline, N-ethylpiperidine, N-methylpyrrolidine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetraethylethylenediamine, 1,2-dipiperidinoethane, trimethylaminoethylpiperazine, N,N,N',N'',N''-pentamethylethylenetriamine, and N,N'-dioctyl-p-phenylenediamine. Of these, N,N,N',N'-tetramethylethylenediamine is preferred.

[0025] As the ether compound, a linear ether compound or a cyclic ether compound can be used. Examples of linear ether compounds include, but are not limited to, dialkyl ether compounds of ethylene glycol such as dimethyl ether, diethyl ether, diphenyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and ethylene glycol dibutyl ether; and dialkyl ether compounds of diethylene glycol such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and diethylene glycol dibutyl ether. Furthermore, examples of cyclic ether compounds include, but are not limited to, tetrahydrofuran, dioxane, 2,5-dimethyloxolane, 2,2,5,5-tetramethyloxolane, 2,2-bis(2-oxolanyl)propane, and alkyl ethers of furfuryl alcohol.

[0026] The amount of the tertiary amine compound or ether compound used is preferably 0.1 to 4 (mol / 1 mol of alkali metal), more preferably 0.2 to 3 (mol / 1 mol of alkali metal), relative to the amount of the organic alkali metal compound polymerization initiator.

[0027] In the copolymer production process, sodium alkoxide may be present during copolymerization. Examples of sodium alkoxides include, but are not limited to, compounds represented by the following formula: Sodium alkoxides having an alkyl group with 3 to 6 carbon atoms are particularly preferred, with sodium t-butoxide and sodium t-pentoxide being more preferred. NaOR (wherein R is an alkyl group having 2 to 12 carbon atoms) The amount of sodium alkoxide used in the copolymer polymerization step is preferably 0.01 or more and less than 0.1 (molar ratio), more preferably 0.01 or more and less than 0.08 (molar ratio), even more preferably 0.03 or more and less than 0.08 (molar ratio), and particularly preferably 0.04 or more and less than 0.06 (molar ratio), relative to the vinyl bond amount adjuster (tertiary amine compound or ether compound). When the amount of sodium alkoxide is within this range, it tends to be possible to produce, at a high productivity, a block copolymer having a polymer block containing a conjugated diene monomer unit with a high vinyl bond content and a polymer block mainly composed of a vinyl aromatic monomer unit with a narrow molecular weight distribution, and having a narrow molecular weight distribution and high strength.

[0028] The method for copolymerizing a conjugated diene compound and a vinyl aromatic compound using an organic alkali metal compound as a polymerization initiator is not particularly limited, and may be batch polymerization, continuous polymerization, or a combination thereof. The polymerization temperature is not particularly limited, but is usually 0 to 180°C, and preferably 30 to 150°C. The time required for polymerization varies depending on the conditions, but is usually within 48 hours, preferably 0.1 to 10 hours. It is also preferable to carry out the polymerization in an atmosphere of an inert gas such as nitrogen gas. The polymerization pressure is not particularly limited as long as it is within a pressure range sufficient to maintain the monomer and solvent in a liquid phase within the above-mentioned polymerization temperature range.

[0029] Furthermore, at the end of the polymerization, a required amount of a coupling agent having two or more functional groups may be added to carry out a coupling reaction. The coupling agent having two or more functional groups is not particularly limited, and known agents can be used. Examples of bifunctional coupling agents include, but are not limited to, dihalogen compounds such as dimethyldichlorosilane and dimethyldibromosilane, acid esters such as methyl benzoate, ethyl benzoate, phenyl benzoate, and phthalates. Examples of polyfunctional coupling agents having three or more functional groups include, but are not limited to, trivalent or higher polyalcohols, epoxidized soybean oil, polyvalent epoxy compounds such as diglycidyl bisphenol A, halogenated silicon compounds represented by the formula R1(4-n)SiXn (wherein R1 is a hydrocarbon group having 1 to 20 carbon atoms, X is a halogen, and n is an integer of 3 or 4), and halogenated tin compounds. Examples of halogenated silicon compounds include, but are not limited to, methylsilyl trichloride, t-butylsilyl trichloride, silicon tetrachloride, and brominated versions of these compounds. Examples of the tin halide compound include, but are not limited to, polyvalent halogen compounds such as methyltin trichloride, t-butyltin trichloride, and tin tetrachloride. Dimethyl carbonate and diethyl carbonate can also be used.

[0030] The copolymer may be one obtained by subjecting the living terminal of the copolymer obtained by the above-mentioned method to an addition reaction with a modifier that generates a functional group-containing atomic group. Examples of functional group-containing atomic groups include, but are not limited to, atomic groups containing at least one functional group selected from the group consisting of a hydroxyl group, a carbonyl group, a thiocarbonyl group, an acid halide group, an acid anhydride group, a carboxyl group, a thiocarboxylate group, an aldehyde group, a thioaldehyde group, a carboxylic acid ester group, an amide group, a sulfonic acid group, a sulfonate ester group, a phosphoric acid group, a phosphoric acid ester group, an amino group, an imino group, a nitrile group, a pyridyl group, a quinoline group, an epoxy group, a thioepoxy group, a sulfide group, an isocyanate group, an isothiocyanate group, a silicon halide group, a silanol group, an alkoxy silicon group, a tin halide group, an alkoxy tin group, and a phenyl tin group.

[0031] Examples of the modifying agent having a functional group-containing atomic group include, but are not limited to, tetraglycidyl meta-xylenediamine, tetraglycidyl-1,3-bisaminomethylcyclohexane, ε-caprolactone, δ-valerolactone, 4-methoxybenzophenone, γ-glycidoxyethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyldimethylphenoxysilane, bis(γ-glycidoxypropyl)methylpropoxysilane, 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, N,N'-dimethylpropyleneurea, and N-methylpyrrolidone. The amount of the modifier added is preferably 0.01 to 40 parts by mass, more preferably 0.1 to 20 parts by mass, and even more preferably 0.3 to 10 parts by mass, relative to 100 parts by mass of the hydrogenated copolymer before modification. The temperature for the addition reaction of the modifying agent is preferably 0 to 150°C, more preferably 20 to 120°C. The time required for the modification reaction varies depending on the modification reaction conditions, but is preferably within 24 hours, more preferably 0.1 to 10 hours.

[0032] The copolymer may be one in which the double bonds of the conjugated diene monomer units are hydrogenated. The hydrogenation catalyst used in the hydrogenation step is not particularly limited, and for example, the hydrogenation catalysts described in JP-B-42-8704, JP-B-43-6636, JP-B-63-4841, JP-B-1-37970, JP-B-1-53851, JP-B-2-9041, etc. can be used. Preferred hydrogenation catalysts include titanocene compounds and / or mixtures with reducing organometallic compounds.

[0033] Examples of titanocene compounds include, but are not limited to, compounds described in JP-A-8-109219, and specific examples thereof include compounds having at least one ligand having a (substituted) cyclopentadienyl structure, an indenyl structure, and a fluorenyl structure, such as biscyclopentadienyltitanium dichloride and monopentamethylcyclopentadienyltitanium trichloride. Examples of reducing organometallic compounds include, but are not limited to, organic alkali metal compounds such as organolithium compounds, organomagnesium compounds, organoaluminum compounds, organoboron compounds, and organozinc compounds.

[0034] The reaction temperature for the hydrogenation reaction is usually 0 to 200°C, preferably 30 to 150°C. The pressure of hydrogen used in the hydrogenation reaction is preferably 0.1 to 30 MPa, more preferably 0.2 to 10 MPa, and even more preferably 0.3 to 5 MPa. The reaction time for the hydrogenation reaction is usually 3 minutes to 10 hours, preferably 10 minutes to 5 hours. The hydrogenation reaction can be carried out by a batch process, a continuous process, or a combination thereof. After the hydrogenation reaction is completed, the catalyst residue may be removed from the reaction solution, if necessary.

[0035] Methods for separating the copolymer and the solvent after hydrogenation include, but are not limited to, a method in which a polar solvent that is a poor solvent for the hydrogenated block copolymer, such as acetone or alcohol, is added to a solution of the hydrogenated copolymer to precipitate and recover the hydrogenated copolymer; a method in which the solution of the hydrogenated copolymer is poured into hot water with stirring and the solvent is removed by steam stripping to recover the copolymer; and a method in which the solvent is distilled off by directly heating the solution of the hydrogenated copolymer. The hydrogenated copolymer may contain an antioxidant on its surface and / or inside by, for example, adding the antioxidant during the production process. The following antioxidant may also be added to the resin composition of the present embodiment, which will be described later.

[0036] Examples of antioxidants include, but are not limited to, phenol-based antioxidants, phosphorus-based antioxidants, sulfur-based antioxidants, and amine-based antioxidants. Specifically, 2,6-di-t-butyl-4-methylphenol, n-octadecyl-3-(4'-hydroxy-3',5'-di-t-butyl-phenyl)propionate, tetrakis-[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane], tris-(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate, 4,4'-butylidene-bis-(3-methyl-6-t-butylphenol), 3,9-bis[2-{3-(3-t-butyl-4-hydroxy-5-methyl phenyl)propionyloxy}-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane, triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis-[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)1,3,5-triazine, pentaerythrityl-tetrakis[3 -(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,2-thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], N,N'-hexamethylenebis(3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), 3,5-di-t-butyl-4-hydroxybenzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, bis(3,5-di-t-butyl-4 -hydroxybenzylphosphonic acid ethyl) calcium and polyethylene wax (50%) mixture, octylated diphenylamine, 2,4-bis[(octylthio)methyl]-o-cresol, isooctyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, butylic acid, 3,3-bis(3-t-butyl-4-hydroxyphenyl)ethylene ester, 1,1,3-tris-(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate, 2-t-butyl-6-(3'-t-butyl-5'-methyl-2'-hydroxybenzyl)-4-methylphenyl-acrylate, and 2-[1-(2-hydroxy-3,5-di-t-pentylphenyl)-ethyl]-4,6-di-t-pentylphenyl acrylate.

[0037] <Hydrogenated copolymer pellets> The pellets of this embodiment are pellets of the hydrogenated copolymer of this embodiment. Pellets of the hydrogenated copolymer of this embodiment can be obtained, for example, by cutting the hydrogenated copolymer immediately after melt-kneading with a cutter or the like. The cutting method is not particularly limited, and examples thereof include a hot cut method, a strand cut method, and an underwater cut method. By forming the copolymer into pellets, measurement and transportation become easier and handling becomes easier compared to liquid or powder forms.

[0038] The size and shape of the hydrogenated copolymer pellets are not particularly limited, and they may be in the form of crumbs or powder. If necessary, a pellet anti-blocking agent may be blended into the pellets of the hydrogenated copolymer in order to prevent blocking between the pellets. Examples of pellet blocking inhibitors include, but are not limited to, calcium stearate, magnesium stearate, zinc stearate, polyethylene, polypropylene, ethylene bisstearylamide, talc, and amorphous silica. The amount of the pellet anti-blocking agent to be added is preferably 500 to 10,000 ppm, more preferably 1,000 to 5,000 ppm, relative to the block copolymer. The pellet anti-blocking agent is preferably added in a state where it is attached to the pellet surface, but may also be contained to some extent inside the pellet. (Resin composition)

[0039] The resin composition of this embodiment includes the hydrogenated copolymer of this embodiment and at least one solid rubber component selected from the group consisting of styrene-butadiene rubber, natural rubber, and butadiene rubber.

[0040] According to the above-mentioned constitution, a resin composition can be obtained which is excellent in fuel economy, wet grip properties, abrasion resistance, and processability, and which has a high level of balance of these properties.

[0041] Examples of solid rubber components include natural rubber (NR), styrene-butadiene rubber (SBR), butadiene rubber, synthetic polyisoprene rubber, epoxidized natural rubber, and polybutadiene rubber. Specific examples include high-cis polybutadiene rubber, nitrile-hydrogenated butadiene rubber (HNBR), hydrogenated SBR, ethylene propylene diene monomer rubber, ethylene propylene rubber, maleic acid-modified ethylene propylene rubber, butyl rubber, isobutylene-aromatic vinyl or diene monomer copolymer, brominated NR, chlorinated NR, brominated isobutylene-p-methylstyrene copolymer, chloroprene rubber, epichlorohydrin homopolymer rubber, and epi Examples of suitable elastomers include chlorohydrin-ethylene oxide or allyl glycidyl ether copolymer rubber, epichlorohydrin-ethylene oxide-allyl glycidyl ether terpolymer rubber, chlorosulfonated polyethylene, chlorinated polyethylene, maleic acid-modified chlorinated polyethylene, methyl vinyl silicone rubber, dimethyl silicone rubber, methyl phenyl vinyl silicone rubber, polysulfide rubber, vinylidene fluoride rubber, tetrafluoroethylene-propylene rubber, fluorinated silicone rubber, fluorinated phosphagen rubber, thermoplastic olefin elastomer, polyester elastomer, urethane elastomer, and polyamide elastomer. The solid rubber component may be coupled, star-branched, branched, or functionalized with a coupling agent and / or a star-branching or functionalizing agent.

[0042] In the resin composition of the present embodiment, the solid rubber component preferably has a functionalized end group from the viewpoint of improving affinity with fillers such as carbon black and / or silica, which will be described later. The functionalization can be carried out by using a coupling agent or a star-branching agent, and also includes coupling with carbon black as a filler, for example, functional groups containing C-Sn bonds, aminated functional groups such as benzophenone, silanol functional groups, and silanol-terminated polysiloxane functional groups, alkoxysilane groups, and polyether groups as end groups.

[0043] (Optional resin component) The resin composition of the present embodiment may contain any other resin component in addition to the solid rubber component described above. When the composition of the present embodiment contains any resin component other than the solid rubber component, the amount thereof is preferably less than 25 parts by mass of the resin component per 100 parts by mass of the solid rubber component, more preferably less than 20 parts by mass, even more preferably less than 15 parts by mass, even more preferably less than 10 parts by mass, and still more preferably less than 5 parts by mass. For example, a preferred embodiment is one in which the amount is 0.5 to 5 parts by mass, and particularly preferably 0 part by mass.

[0044] Other optional resin components that may be used include, for example, cyclopentadiene homopolymer or copolymer resins (referred to as CPD), dicyclopentadiene homopolymer or copolymer resins (referred to as DCPD or (D)CPD), terpene homopolymer or copolymer resins, rosin-derived resins, rosin / rosin esters, pinene homopolymer or copolymer resins, C5 fraction homopolymer or copolymer resins, C9 fraction homopolymer or copolymer resins, α-methylstyrene homopolymer or copolymer resins, and combinations thereof, as well as substituted or unsubstituted versions of these resins. The optional resin component is preferably a (D) CPD / vinyl aromatic copolymer resin, a (D) CPD / terpene copolymer resin, a terpene / phenol copolymer resin, a (D) CPD / pinene copolymer resin, a pinene / phenol copolymer resin, a (D) CPD / C5 fraction copolymer resin, a (D) CPD / C9 fraction copolymer resin, a terpene / vinyl aromatic copolymer resin, a terpene / phenol copolymer resin, a pinene / vinyl aromatic copolymer resin, a pinene / phenol resin, a C5 fraction / vinyl aromatic copolymer resin, and combinations thereof. In particular, terpene resins, rosin esters, and oligoester resins are preferred.

[0045] (Optional plasticizer component) The rubber composition of the present embodiment may further contain an optional plasticizer component. The term "plasticizer" (also referred to as process oil) refers to petroleum-derived process oil and synthetic plasticizers that extend the solid rubber component described above and improve the processability of the resin composition of this embodiment. The plasticizer is not limited to the following, but examples thereof include fatty acid esters, hydrocarbon process oils, tall oil pitch, modified tall oil pitch, and combinations thereof. The amount of the plasticizer is preferably 0 to 35 parts by mass, more preferably 5 to 25 parts by mass, and even more preferably less than 20 parts by mass, per 100 parts by mass of the solid rubber component. More preferably, the plasticizer is a modified tall oil pitch selected from the group consisting of pitch esters, decarbonated tall oil pitch, tall oil pitch soap, heat-treated tall oil pitch, and heat- and catalytically-treated tall oil pitch. Plasticizers include both extender oils contained in the solid rubber component and process oils added during mixing. Suitable process oils include aromatic oils, paraffinic oils, naphthenic oils, low PCA oils such as MES, TDAE, and heavy naphthenic oils, as well as vegetable oils such as sunflower oil, soybean oil, and safflower oil. Examples of low PCA oils include those with a polycyclic aromatic content of less than 3% by weight. Suitable vegetable oils include soybean oil, sunflower oil, and rapeseed oil in the form of esters containing some degree of unsaturation.

[0046] In the resin composition of the present embodiment, the total content of the optional resin and plasticizer described above is preferably 70 parts by mass or less, more preferably 65 parts by mass or less, and more preferably 60 parts by mass or less, per 100 parts by mass of the solid rubber component. This provides the effect of reducing the processability and hardness of the resin composition.

[0047] (coupling agent) The resin composition of the present embodiment may further contain a coupling agent, and preferably further contains a silane coupling agent. Coupling agents are substances that can promote stable chemical and / or physical interactions between two species that would not otherwise interact, for example, between a filler such as silica and a solid rubber component. The coupling agent may be premixed or reacted with the filler particles or added to the rubber mix during the rubber / silica processing, ie, mixing, stage. Coupling agents include, but are not limited to, sulfur-based coupling agents, organic peroxide-based coupling agents, inorganic coupling agents, polyamine coupling agents, resin coupling agents, sulfur compound-based coupling agents, oxime-nitrosamine-based coupling agents, and sulfur. At least difunctional coupling agents are preferred. Examples of such coupling agents include organosilanes or polyorganosiloxanes. Silane sulfides, silane polysulfides, and combinations thereof are particularly preferred. The amount of the coupling agent added is preferably 1 to 20 parts by mass, more preferably 1 to 10 parts by mass, and even more preferably 3 to 15 parts by mass, per 100 parts by mass of the solid rubber component.

[0048] (filler) The resin composition of the present embodiment preferably further contains a filler. The resin composition of the present embodiment preferably further contains 50 to 200 parts by mass of a filler per 100 parts by mass of the solid rubber component. Examples of fillers include, but are not limited to, calcium carbonate, carbon nanotubes, clay, mica, silica, silicates, talc, titanium dioxide, alumina, zinc oxide, starch, wood flour, carbon black, or mixtures thereof, each having an average particle size of 0.0001 μm to 100 μm. Other fillers include, but are not limited to, granular fillers such as ultra-high molecular weight polyethylene (UHMWPE), granular polymer gels, and plasticized starch composite fillers known in the art. The filler may be surface treated, for example, a silica material coated or reacted with a terpene-derived silane, such as the alkoxyterpene epoxy silanes disclosed in U.S. Pat. No. 4,738,892. The filler may also be treated in the presence of a functional moiety such as at least one of an organosilane, an organotitanate, or an organozirconate. Specifically, prior to being incorporated into the resin composition, the filler may first be surface-treated with a coupling agent such as an aminosilane, hexamethyldisilazane (HMDS), or vinyltriethoxysilane, or may be physically coated or covered with a resin. The resin composition of this embodiment may further contain 5 to 100 parts by mass of carbon black per 100 parts by mass of the solid rubber component. The iodine adsorption capacity of carbon black is usually in the range of 9 to 145 g / kg, and the DBP value is in the range of 34 to 150 cm3 / 100 g. The resin composition of the present embodiment preferably contains 5 to 125 parts by mass, more preferably 20 to 60 parts by mass, even more preferably 30 to 50 parts by mass, and still more preferably 40 to 45 parts by mass of the filler per 100 parts by mass of the solid rubber component.

[0049] (Crosslinking agent) The solid rubber component in the resin composition of the present embodiment may be crosslinked by adding a curing agent such as sulfur, metals, metal oxides such as zinc oxide, peroxides, organometallic compounds, radical initiators, fatty acids, and other materials common in the art. Zinc oxide is added, for example, in an amount of about 5 parts by weight per 100 parts by weight of the solid rubber component to form a zinc halide, which then acts as a catalyst for vulcanization of the rubber compound. Known curing methods can be used, including peroxide curing systems, resin curing systems, and crosslinking of polymers by heat or radiation. Accelerators, activators, and retarders can also be used in the curing process. The amount of the crosslinking agent added is preferably 0.3 to 10 parts by mass, more preferably 0.5 to 5.0 parts by mass, and even more preferably 0.5 to 3 parts by mass, based on 100 parts by mass of the solid rubber component.

[0050] (Other additives) The resin composition of the present embodiment may contain various additives known in the art, such as curing aids such as sulfur donors, accelerators, activators, and retarders, processing additives, pigments, fatty acids, zinc oxide, waxes, antioxidants, antiozonants, and peptizers, etc. The amount of these other additives is preferably 10 parts by mass or less per 100 parts by mass of the solid rubber component.

[0051] (Method for molding resin composition) The rubber compositions of the present embodiments can be molded by methods known to those skilled in the rubber mixing art. For example, the components of the rubber composition are typically mixed in two stages, that is, at least one non-productive stage followed by a productive mix stage. The final curative, e.g., sulfur vulcanizing agent, is typically mixed in what is conventionally called the "productive" mix stage, which is conducted at a lower temperature than the mixing temperature in the preceding non-productive mix stages, i.e., the final temperature reached. The rubber composition may be subjected to a thermomechanical mixing process, which generally involves mechanical processing in a mixer or extruder for a time suitable to create a temperature environment of 140°C to 190°C. The appropriate duration of the thermomechanical processing varies depending on the operating conditions and the volume and properties of the components, but the thermomechanical processing is preferably carried out for, for example, 1 to 20 minutes.

[0052] (Application) Specific applications of the polymer composition according to this embodiment include tire applications such as tire treads, undertreads, carcasses, sidewalls, and bead portions; sealing materials such as packings, gaskets, weatherstrips, and O-rings; interior and exterior skin materials for various vehicles such as automobiles, ships, aircraft, and railways; building materials; vibration-proof rubbers for industrial machinery and equipment; various hoses and hose covers such as diaphragms, rolls, radiator hoses, and air hoses; belts such as power transmission belts; linings; dust boots; medical device materials; fenders; insulating materials for electric wires; and other industrial products. In particular, crosslinked polymers obtained using the resin composition according to this embodiment are suitable for tire applications. The tire of the present embodiment contains the resin composition of the present embodiment. The crosslinked polymer obtained using the resin composition of this embodiment has an excellent balance of rigidity, abrasion resistance, and viscoelastic properties, and is therefore suitable as a material for tire treads and sidewalls. [Example]

[0053] Hereinafter, the present embodiment will be described in more detail with reference to specific examples and comparative examples, but the present invention is not limited to the following examples. First, the evaluation methods and methods for measuring physical properties applied to the examples and comparative examples are described below.

[0054] [Method for identifying copolymer structure and method for measuring physical properties] (Content of total vinyl aromatic monomer units in copolymer) The content of all vinyl aromatic monomer units in the block copolymer was measured by the following method. Using the block copolymer before hydrogenation, the content (mass%) of all vinyl aromatic monomer units in the block copolymer was calculated from the absorption intensity at 262 nm using an ultraviolet spectrophotometer (Shimadzu Corporation, UV-2450). Since the content of all vinyl aromatic monomer units does not change significantly before and after hydrogenation, the content of all vinyl aromatic monomer units (styrene monomer units) obtained for the block copolymer before hydrogenation was used as the content of all vinyl aromatic monomer units (total styrene content) of the block copolymer.

[0055] (Random vinyl aromatic monomer unit content in aromatic vinyl-conjugated diene random block) The content of vinyl aromatic monomer units randomly copolymerized with conjugated diene monomer units in the copolymer was measured by the following method. The copolymer was used as a measurement sample and subjected to proton nuclear magnetic resonance ( 1 By H-NMR (Joel ResonABCE ECS400), polymer block B, which is mainly composed of vinyl aromatic monomer units, and polymer block C, which is composed of vinyl aromatic monomer units and conjugated diene monomer units, were distinguished. Deuterated chloroform was used as the solvent, with a sample concentration of 50 mg / mL, an observation frequency of 400 MHz, tetramethylsilane as the chemical shift standard, a pulse delay of 2.904 seconds, 256 scans, and a measurement temperature of 23°C. Random and block aromatics were calculated from the integral value per 1H of each bond type based on the integrated intensity of the signals assigned to aromatics. The total styrene content was then calculated as described above, and the percentage content was calculated. The vinyl aromatic monomer unit content of block B was calculated by subtracting the vinyl aromatic monomer unit content in block C from the total vinyl aromatic monomer unit content.

[0056] (vinyl bond content) The vinyl bond amount of the copolymer before hydrogenation, excluding polymer blocks A and A, was measured by the following method. The polymers sampled at each step of the copolymer polymerization process before hydrogenation and the polymers sampled after the completion of polymerization were analyzed by proton nuclear magnetic resonance ( 1 The vinyl bond content (1,2-bond content) was measured by 1 H-NMR. Deuterated chloroform was used as the solvent, the sample concentration was 50 mg / mL, the observation frequency was 400 MHz, tetramethylsilane was used as the chemical shift standard, the pulse delay was 2.904 seconds, the number of scans was 64, the pulse width was 45°, and the measurement temperature was 26°C. The amount of vinyl bonds was calculated from the integral per 1H of each bond type calculated from the integrals of the signals assigned to 1,4-bonds and 1,2-bonds, and then calculated from the ratio of 1,2-bonds to the total of 1,4-bonds and 1,2-bonds.

[0057] (Number average molecular weight of hydrogenated copolymer) The number average molecular weight of the hydrogenated copolymer was measured by the following method. Measurement was performed using GPC (apparatus: Tosoh HLC8220, column: TSKgel SuperH-RC x 2). Tetrahydrofuran was used as the solvent. Measurement was performed at a temperature of 35°C. A calibration curve prepared using commercially available standard polystyrene was used to determine the number average molecular weight converted into polystyrene.

[0058] (Hydrogenation rate of hydrogenated copolymer (hydrogenation rate)) The hydrogenation rate of the hydrogenated copolymer was measured by the following method. The hydrogenation rate of the block copolymer was measured using a nuclear magnetic resonance spectrometer (BRUKER, DPX-400). Using the hydrogenated copolymer, which is the copolymer after hydrogenation, proton nuclear magnetic resonance ( 1 Specifically, the integral values ​​of the signals at 4.5 to 5.5 ppm derived from the residual double bonds and the signals attributable to the hydrogenated conjugated dienes were calculated, and the ratio thereof was calculated.

[0059] [Production of Rubber Composition] The components were mixed using the materials and methods described below to obtain a rubber composition.

[0060] Styrene-butadiene rubber (SBR (XB120 manufactured by Asahi Kasei Corporation): 70 parts by mass) Butadiene rubber (BR (brand name "BR150" manufactured by Ube Industries): 30 parts by mass Polymers of Production Examples 1 to 16 and Comparative Production Examples 1 to 7: 20 parts by mass Silica (product name "Ultrasil 7000GR" manufactured by Evonik Degussa, nitrogen adsorption specific surface area 170m 2 / g):75.0 parts by mass Silane coupling agent (manufactured by Evonik Degussa, "Si75", bis(triethoxysilylpropyl) disulfide): 6.0 parts by mass Carbon black (Tokai Carbon Co., Ltd., Seast KH (N339)): 5.0 parts by mass Softener (SRAE oil (manufactured by JX Nippon Oil & Energy Corporation, product name "PF30")): 32 parts by mass ·Zinc white: 2.5 parts by mass Stearic acid: 2.0 parts by weight Wax, Sunnock: 1.5 parts by weight Antioxidant (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine): 2.0 parts by mass ·Sulfur: 2.2 parts by mass Vulcanization accelerator 1 (N-cyclohexyl-2-benzothiazylsulfinamide): 1.7 parts by mass Vulcanization accelerator 2 (diphenyl guanidine): 2.0 parts by mass

[0061] (Kneading method) Using an internal mixer (capacity: 0.5 L) equipped with a temperature control device, the materials other than sulfur and vulcanization accelerator were mixed in the first stage of mixing under the conditions of a filling rate of 65% and a rotor rotation speed of 50 to 90 rpm. At this time, the temperature of the internal mixer was controlled, and the discharge temperature was 150 to 160°C to obtain a compound. Next, in the second stage of mixing, the mixture obtained above was cooled to room temperature and then mixed again to improve the dispersion of the reinforcing filler. In this case, the discharge temperature of the mixture was also adjusted to 150 to 160°C by controlling the temperature of the mixer. After cooling, in the third stage of kneading, a vulcanization accelerator and sulfur were added and kneaded using an open roll set at 70°C to obtain an unvulcanized rubber composition. Thereafter, the rubber composition was molded and vulcanized in a vulcanization press at 160°C for a predetermined vulcanization time to obtain a vulcanized rubber composition. The vulcanization time was set to a value obtained by adding 5 minutes to the 90% vulcanization time of the unvulcanized rubber composition. The vulcanized rubber compositions were evaluated by the following methods.

[0062] [Evaluation of physical properties of rubber composition] (Wet grip performance (tan δ at 0°C)) The resin compositions of the examples and comparative examples were measured using a viscoelasticity tester "ARES" manufactured by Rheometrics Scientific at 0°C, a frequency of 10 Hz, and a strain of 1% in torsion mode, and the tan δ was used as an index of wet grip properties. The measurement result of the resin composition of Comparative Example 7 was standardized as 100, and a higher value was evaluated as indicating better performance. A value of more than 100 was evaluated as having excellent wet grip properties.

[0063] (Fuel economy (tan δ at 50°C)) The resin compositions of the examples and comparative examples were measured in torsional mode using a viscoelasticity tester "ARES" manufactured by Rheometrics Scientific at 50°C, a frequency of 10 Hz, and a strain of 1%, and the tan δ was used as an index of fuel economy. The values ​​are expressed as an index, with the measured value of Comparative Example 7 being set at 100, and the larger the index, the smaller the adverse effect on the viscoelasticity (RR) and the better the result. Values ​​of 96 or higher were evaluated as having excellent fuel economy.

[0064] (Processability (compound Mooney viscosity)) Each resin composition before vulcanization was used as a measurement sample, and the Mooney viscosity ML1+4 was measured in accordance with JIS K6300-1:2013 using an L rotor under the conditions of 1 minute of preheating, 4 minutes of rotor operation time, and a temperature of 100°C. In Table 2 below, the values ​​are shown as an index, with the measured value of Comparative Example 7 set as the standard, and a larger index indicates better processability. Values ​​of 90 or higher were evaluated as having excellent processability.

[0065] (wear resistance) The abrasion resistance of the resin compositions of the examples and comparative examples was measured according to the DIN abrasion test method of JIS K6246-2 using a DIN abrasion tester (manufactured by Ueshima Seisakusho Co., Ltd.) The measurement result of Comparative Example 7 was standardized as 100, and a higher value was evaluated as indicating better performance. A value exceeding 100 was evaluated as having excellent abrasion resistance.

[0066] (Handling) The hydrogenated copolymers of Production Examples 1 to 16 and Comparative Production Examples 1 to 7 were melt-kneaded in a twin-screw extruder and pelletized using an underwater pelletizer. Those that could be pelletized were rated as A, those that could be pelletized but were very sticky and fused together immediately after cutting were rated as B, and those that could not be pelletized were rated as C. Those that received an A or B rating were evaluated as having excellent handleability.

[0067] (Presence or absence of precipitation during the production process) The solutions of the hydrogenated copolymers of Production Examples 1 to 16 and Comparative Production Examples 1 to 7 were taken out and cooled to 20° C. At this time, the polymer components that separated and precipitated from the solution were evaluated as B, and those that did not were evaluated as A.

[0068] [Production of hydrogenated copolymer] (Preparation of hydrogenation catalyst) The hydrogenation catalyst used in the hydrogenation reaction of the block copolymer was prepared by the following method. A nitrogen-purged reaction vessel was charged with 1 liter of dried and purified cyclohexane, and 100 mmol of biscyclopentadienyltitanium dichloride was added. With sufficient stirring, an n-hexane solution containing 200 mmol of trimethylaluminum was added, and the mixture was allowed to react at room temperature for approximately 3 days to obtain a hydrogenation catalyst.

[0069] (Production Examples 1 to 9, Comparative Production Examples 1 to 7) As Production Examples 1 to 9 and Comparative Production Examples 1 to 7, block copolymers (SBC-1) to (SBC-16) were prepared as follows.

[0070] <Production Example 1> Batch polymerization was carried out using a tank-type reactor (internal volume: 10 L) equipped with a stirrer and a jacket to polymerize a hydrogenated block copolymer (X). First, a cyclohexane solution containing 30 parts by mass of butadiene (concentration: 20% by mass) was added. Next, 0.069 parts by mass of n-butyllithium relative to 100 parts by mass of the total monomers and 0.05 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Next, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and the internal temperature of the reactor was adjusted to 55° C. Next, a cyclohexane solution containing 10 parts by mass of styrene and a cyclohexane solution containing 40 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 55° C., and polymerization was carried out. Next, a cyclohexane solution containing 20 parts by mass of styrene (concentration: 20% by mass) was added, and polymerization was carried out at 70° C. for 1 hour. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the entire amount of the hydrogenated block copolymer (X) was withdrawn, and then polymer (Y) was polymerized. First, a cyclohexane solution containing 20 parts by mass of styrene (concentration: 20% by mass) was added. Next, 0.91 parts by mass of n-butyllithium per 100 parts by mass of the total monomers, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium, and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and polymerization was carried out at 60°C for 20 minutes. Next, a cyclohexane solution containing 20 parts by mass of styrene and a cyclohexane solution containing 60 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 55°C, to carry out polymerization. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the cyclohexane solutions of X and Y were mixed so that the mass ratio of X to Y was 70:30. Finally, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by mass of the hydrogenated copolymer, and the cyclohexane was removed by vacuum drying to obtain a hydrogenated copolymer. Table 1 shows the physical properties of the obtained hydrogenated copolymer.

[0071] <Production Example 2> Batch polymerization was carried out using a tank-type reactor (internal volume: 10 L) equipped with a stirrer and a jacket to polymerize a hydrogenated block copolymer (X). First, a cyclohexane solution containing 30 parts by mass of butadiene (concentration: 20% by mass) was added. Next, 0.23 parts by mass of n-butyllithium per 100 parts by mass of the total monomers and 0.05 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Next, 0.7 mol of N,N,N',N'-tetramethylethylenediamine was added per 1 mol of n-butyllithium, and the internal temperature of the reactor was adjusted to 70° C. Next, a cyclohexane solution containing 10 parts by mass of styrene and a cyclohexane solution containing 60 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 65° C., and polymerization was carried out. Next, 0.5 moles of dimethyldichlorosilane was added per mole of n-butyllithium, and the mixture was reacted at 70° C. for 1 hour, and methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the entire amount of the hydrogenated block copolymer (X) was withdrawn, and then polymer (Y) was polymerized. First, a cyclohexane solution containing 20 parts by mass of styrene (concentration 20% by mass) and a cyclohexane solution containing 80 parts by mass of butadiene (concentration 20% by mass) were added. Next, 1.07 parts by mass of n-butyllithium per 100 parts by mass of the total monomers, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium, and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and polymerization was carried out at 55°C for 60 minutes. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the cyclohexane solutions of X and Y were mixed so that the mass ratio of X to Y was 70:30. Finally, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by mass of the hydrogenated copolymer, and the cyclohexane was removed by vacuum drying to obtain a hydrogenated copolymer. Table 1 shows the physical properties of the obtained hydrogenated copolymer.

[0072] <Production Example 3> Batch polymerization was carried out using a tank-type reactor (internal volume: 10 L) equipped with a stirrer and a jacket to polymerize a hydrogenated block copolymer (X). First, a cyclohexane solution containing 48 parts by mass of butadiene (concentration: 20% by mass) was added. Next, 0.21 parts by mass of n-butyllithium per 100 parts by mass of the total monomers and 0.05 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Next, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and the internal temperature of the reactor was adjusted to 55° C. Next, a cyclohexane solution containing 10 parts by mass of styrene and a cyclohexane solution containing 42 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 55° C., and polymerization was carried out. Next, 0.5 moles of dimethyldichlorosilane was added per mole of n-butyllithium, and the mixture was reacted at 70° C. for 1 hour, and methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the resulting copolymer in an amount of 30 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 82%. Next, the entire amount of the hydrogenated block copolymer (X) was withdrawn, and then polymer (Y) was polymerized. First, a cyclohexane solution containing 20 parts by mass of styrene (concentration 20% by mass) and a cyclohexane solution containing 80 parts by mass of butadiene (concentration 20% by mass) were added. Next, 1.07 parts by mass of n-butyllithium per 100 parts by mass of the total monomers, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium, and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and polymerization was carried out at 55°C for 60 minutes. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the resulting copolymer in an amount of 30 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 82%. Next, the cyclohexane solutions of X and Y were mixed so that the mass ratio of X to Y was 70:30. Finally, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by mass of the hydrogenated copolymer, and the cyclohexane was removed by vacuum drying to obtain a hydrogenated copolymer. Table 1 shows the physical properties of the obtained hydrogenated copolymer.

[0073] <Production Example 4> Batch polymerization was carried out using a tank-type reactor (internal volume: 10 L) equipped with a stirrer and a jacket to polymerize a hydrogenated block copolymer (X). First, a cyclohexane solution containing 52 parts by mass of butadiene (concentration: 20% by mass) was added. Next, 0.069 parts by mass of n-butyllithium relative to 100 parts by mass of the total monomers and 0.05 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Next, 0.9 mol of N,N,N',N'-tetramethylethylenediamine was added per 1 mol of n-butyllithium, and the internal temperature of the reactor was adjusted to 60° C. Next, a cyclohexane solution containing 10 parts by mass of styrene and a cyclohexane solution containing 18 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 60° C., and polymerization was carried out. Next, a cyclohexane solution containing 20 parts by mass of styrene (concentration: 20% by mass) was added, and polymerization was carried out at 70° C. for 1 hour. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the entire amount of the hydrogenated block copolymer (X) was withdrawn, and then polymer (Y) was polymerized. First, a cyclohexane solution containing 20 parts by mass of styrene (concentration 20% by mass) and a cyclohexane solution containing 80 parts by mass of butadiene (concentration 20% by mass) were added. Next, 1.07 parts by mass of n-butyllithium per 100 parts by mass of the total monomers, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium, and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and polymerization was carried out at 55°C for 60 minutes. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the cyclohexane solutions of X and Y were mixed so that the mass ratio of X to Y was 70:30. Finally, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by mass of the hydrogenated copolymer, and the cyclohexane was removed by vacuum drying to obtain a hydrogenated copolymer. Table 1 shows the physical properties of the obtained hydrogenated copolymer.

[0074] <Production Example 5> Batch polymerization was carried out using a tank-type reactor (internal volume: 10 L) equipped with a stirrer and a jacket to polymerize a hydrogenated block copolymer (X). First, a cyclohexane solution containing 4 parts by mass of butadiene (concentration: 20% by mass) was added. Next, 0.21 parts by mass of n-butyllithium per 100 parts by mass of the total monomers and 0.05 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Next, 0.25 mol of N,N,N',N'-tetramethylethylenediamine was added per 1 mol of n-butyllithium, and the internal temperature of the reactor was adjusted to 70° C. Next, a cyclohexane solution containing 20 parts by mass of styrene and a cyclohexane solution containing 76 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 70° C., and polymerization was carried out. Next, 0.5 moles of dimethyldichlorosilane was added per mole of n-butyllithium, and the mixture was reacted at 70° C. for 1 hour, and methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the entire amount of the hydrogenated block copolymer (X) was withdrawn, and then polymer (Y) was polymerized. First, a cyclohexane solution containing 20 parts by mass of styrene (concentration 20% by mass) and a cyclohexane solution containing 80 parts by mass of butadiene (concentration 20% by mass) were added. Next, 1.07 parts by mass of n-butyllithium per 100 parts by mass of the total monomers, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium, and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and polymerization was carried out at 55°C for 60 minutes. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the cyclohexane solutions of X and Y were mixed so that the mass ratio of X to Y was 70:30. Finally, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by mass of the hydrogenated copolymer, and the cyclohexane was removed by vacuum drying to obtain a hydrogenated copolymer. Table 1 shows the physical properties of the obtained hydrogenated copolymer.

[0075] <Production Example 6> Batch polymerization was carried out using a tank-type reactor (internal volume: 10 L) equipped with a stirrer and a jacket to polymerize a hydrogenated block copolymer (X). First, a cyclohexane solution containing 48 parts by mass of butadiene (concentration: 20% by mass) was added. Next, 0.21 parts by mass of n-butyllithium per 100 parts by mass of the total monomers and 0.05 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Next, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and the internal temperature of the reactor was adjusted to 55° C. Next, a cyclohexane solution containing 10 parts by mass of styrene and a cyclohexane solution containing 42 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 55° C., and polymerization was carried out. Next, 0.5 moles of dimethyldichlorosilane was added per mole of n-butyllithium, and the mixture was reacted at 70° C. for 1 hour, and methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the resulting copolymer in an amount of 30 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 75%. Next, the entire amount of the hydrogenated block copolymer (X) was withdrawn, and then polymer (Y) was polymerized. First, a cyclohexane solution containing 20 parts by mass of styrene (concentration 20% by mass) and a cyclohexane solution containing 80 parts by mass of butadiene (concentration 20% by mass) were added. Next, 1.07 parts by mass of n-butyllithium per 100 parts by mass of the total monomers, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium, and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and polymerization was carried out at 55°C for 60 minutes. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the resulting copolymer in an amount of 30 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 75%. Next, the cyclohexane solutions of X and Y were mixed so that the mass ratio of X to Y was 70:30. Finally, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by mass of the hydrogenated copolymer, and the cyclohexane was removed by vacuum drying to obtain a hydrogenated copolymer. Table 1 shows the physical properties of the obtained hydrogenated copolymer.

[0076] <Production Example 7> Batch polymerization was carried out using a tank-type reactor (internal volume: 10 L) equipped with a stirrer and a jacket to polymerize a hydrogenated block copolymer (X). First, a cyclohexane solution containing 20 parts by mass of butadiene (concentration: 20% by mass) was added. Next, 0.19 parts by mass of n-butyllithium relative to 100 parts by mass of the total monomers and 0.05 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Next, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and the internal temperature of the reactor was adjusted to 55° C. Next, a cyclohexane solution containing 30 parts by mass of styrene and a cyclohexane solution containing 50 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 55° C., and polymerization was carried out. Next, 0.5 moles of dimethyldichlorosilane was added per mole of n-butyllithium, and the mixture was reacted at 70° C. for 1 hour, and methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the resulting copolymer in an amount of 30 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out under a hydrogen pressure of 0.7 MPa at a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the entire amount of the hydrogenated block copolymer (X) was withdrawn, and then polymer (Y) was polymerized. First, a cyclohexane solution containing 20 parts by mass of styrene (concentration 20% by mass) and a cyclohexane solution containing 80 parts by mass of butadiene (concentration 20% by mass) were added. Next, 1.07 parts by mass of n-butyllithium per 100 parts by mass of the total monomers, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium, and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and polymerization was carried out at 55°C for 60 minutes. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the resulting copolymer in an amount of 30 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out under a hydrogen pressure of 0.7 MPa at a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the cyclohexane solutions of X and Y were mixed so that the mass ratio of X to Y was 70:30. Finally, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by mass of the hydrogenated copolymer, and the cyclohexane was removed by vacuum drying to obtain a hydrogenated copolymer. Table 1 shows the physical properties of the obtained hydrogenated copolymer.

[0077] <Production Example 8> Batch polymerization was carried out using a tank-type reactor (internal volume: 10 L) equipped with a stirrer and a jacket to polymerize a hydrogenated block copolymer (X). First, a cyclohexane solution containing 40 parts by mass of butadiene (concentration: 20% by mass) was added. Next, 0.25 parts by mass of n-butyllithium per 100 parts by mass of the total monomers and 0.05 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Next, 0.4 mol of N,N,N',N'-tetramethylethylenediamine was added per 1 mol of n-butyllithium, and the internal temperature of the reactor was adjusted to 70° C. Next, a cyclohexane solution containing 60 parts by mass of butadiene (concentration: 20% by mass) was supplied at a constant flow rate while maintaining the internal temperature at 70° C., and polymerization was carried out. Next, 0.5 moles of dimethyldichlorosilane was added per mole of n-butyllithium, and the mixture was reacted at 70° C. for 1 hour, and methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the resulting copolymer in an amount of 30 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out under a hydrogen pressure of 0.7 MPa at a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the entire amount of the hydrogenated block copolymer (X) was withdrawn, and then polymer (Y) was polymerized. First, a cyclohexane solution containing 20 parts by mass of styrene (concentration 20% by mass) and a cyclohexane solution containing 80 parts by mass of butadiene (concentration 20% by mass) were added. Next, 1.07 parts by mass of n-butyllithium per 100 parts by mass of the total monomers, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium, and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and polymerization was carried out at 55°C for 60 minutes. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the resulting copolymer in an amount of 30 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out under a hydrogen pressure of 0.7 MPa at a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the cyclohexane solutions of X and Y were mixed so that the mass ratio of X to Y was 70:30. Finally, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by mass of the hydrogenated copolymer, and the cyclohexane was removed by vacuum drying to obtain a hydrogenated copolymer. Table 1 shows the physical properties of the obtained hydrogenated copolymer.

[0078] <Production Example 9> Batch polymerization was carried out using a tank-type reactor (internal volume: 10 L) equipped with a stirrer and a jacket to polymerize a hydrogenated block copolymer (X). First, a cyclohexane solution containing 30 parts by mass of butadiene (concentration: 20% by mass) was added. Next, 0.086 parts by mass of n-butyllithium relative to 100 parts by mass of the total monomers and 0.05 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Next, 0.5 mol of N,N,N',N'-tetramethylethylenediamine was added per 1 mol of n-butyllithium, and the internal temperature of the reactor was adjusted to 70° C. Next, a cyclohexane solution containing 60 parts by mass of butadiene (concentration: 20% by mass) was supplied at a constant flow rate while maintaining the internal temperature at 70° C., and polymerization was carried out. Next, 0.5 moles of dimethyldichlorosilane was added per mole of n-butyllithium, and the mixture was reacted at 70° C. for 1 hour, and methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the resulting copolymer in an amount of 30 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out under a hydrogen pressure of 0.7 MPa at a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the entire amount of the hydrogenated block copolymer (X) was withdrawn, and then polymer (Y) was polymerized. First, a cyclohexane solution containing 20 parts by mass of styrene (concentration 20% by mass) and a cyclohexane solution containing 80 parts by mass of butadiene (concentration 20% by mass) were added. Next, 1.07 parts by mass of n-butyllithium per 100 parts by mass of the total monomers, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium, and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and polymerization was carried out at 55°C for 60 minutes. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the resulting copolymer in an amount of 30 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out under a hydrogen pressure of 0.7 MPa at a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the cyclohexane solutions of X and Y were mixed so that the mass ratio of X to Y was 70:30. Finally, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by mass of the hydrogenated copolymer, and the cyclohexane was removed by vacuum drying to obtain a hydrogenated copolymer. Table 1 shows the physical properties of the obtained hydrogenated copolymer.

[0079] <Production Example 10> Batch polymerization was carried out using a tank-type reactor (internal volume: 10 L) equipped with a stirrer and a jacket to polymerize a hydrogenated block copolymer (X). First, a cyclohexane solution containing 30 parts by mass of butadiene (concentration: 20% by mass) was added. Next, 0.16 parts by mass of n-butyllithium per 100 parts by mass of the total monomers and 0.05 moles of N,N,N',N'-tetramethylethylenediamine per mole of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Next, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and the internal temperature of the reactor was adjusted to 55° C. Next, a cyclohexane solution containing 10 parts by mass of styrene and a cyclohexane solution containing 40 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 55° C., and polymerization was carried out. Next, a cyclohexane solution containing 20 parts by mass of styrene (concentration: 20% by mass) was added, and polymerization was carried out at 70° C. for 1 hour. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the entire amount of the hydrogenated block copolymer (X) was withdrawn, and then polymer (Y) was polymerized. First, a cyclohexane solution containing 20 parts by mass of styrene (concentration: 20% by mass) was added. Next, 0.91 parts by mass of n-butyllithium per 100 parts by mass of the total monomers, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium, and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and polymerization was carried out at 60°C for 20 minutes. Next, a cyclohexane solution containing 20 parts by mass of styrene and a cyclohexane solution containing 60 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 55° C., and polymerization was then carried out. Methanol was then added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the cyclohexane solutions of X and Y were mixed so that the mass ratio of X to Y was 70:30. Finally, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by mass of the hydrogenated copolymer, and the cyclohexane was removed by vacuum drying to obtain a hydrogenated copolymer. Table 1 shows the physical properties of the obtained hydrogenated copolymer.

[0080] <Production Example 11> Batch polymerization was carried out using a tank-type reactor (internal volume: 10 L) equipped with a stirrer and a jacket to polymerize a hydrogenated block copolymer (X). First, a cyclohexane solution containing 30 parts by mass of butadiene (concentration: 20% by mass) was added. Next, 0.069 parts by mass of n-butyllithium relative to 100 parts by mass of the total monomers and 0.05 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Next, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and the internal temperature of the reactor was adjusted to 55° C. Next, a cyclohexane solution containing 10 parts by mass of styrene and a cyclohexane solution containing 40 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 55° C., and polymerization was carried out. Next, a cyclohexane solution containing 20 parts by mass of styrene (concentration: 20% by mass) was added, and polymerization was carried out at 70° C. for 1 hour. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the entire amount of the hydrogenated block copolymer (X) was withdrawn, and then polymer (Y) was polymerized. First, a cyclohexane solution containing 20 parts by mass of styrene (concentration: 20% by mass) was added. Next, 3.2 parts by mass of n-butyllithium per 100 parts by mass of the total monomers, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium, and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and polymerization was carried out at 60°C for 20 minutes. Next, a cyclohexane solution containing 20 parts by mass of styrene and a cyclohexane solution containing 60 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 55°C, to carry out polymerization. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the cyclohexane solutions of X and Y were mixed so that the mass ratio of X to Y was 70:30. Finally, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by mass of the hydrogenated copolymer, and the cyclohexane was removed by vacuum drying to obtain a hydrogenated copolymer. Table 1 shows the physical properties of the obtained hydrogenated copolymer.

[0081] <Production Example 12> Batch polymerization was carried out using a tank-type reactor (internal volume: 10 L) equipped with a stirrer and a jacket to polymerize a hydrogenated block copolymer (X). First, a cyclohexane solution containing 30 parts by mass of butadiene (concentration: 20% by mass) was added. Next, 0.069 parts by mass of n-butyllithium relative to 100 parts by mass of the total monomers and 0.05 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Next, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and the internal temperature of the reactor was adjusted to 55° C. Next, a cyclohexane solution containing 10 parts by mass of styrene and a cyclohexane solution containing 40 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 55° C., and polymerization was carried out. Next, a cyclohexane solution containing 20 parts by mass of styrene (concentration: 20% by mass) was added, and polymerization was carried out at 70° C. for 1 hour. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the entire amount of the hydrogenated block copolymer (X) was withdrawn, and then polymer (Y) was polymerized. First, a cyclohexane solution containing 20 parts by mass of styrene (concentration: 20% by mass) was added. Next, 2.1 parts by mass of n-butyllithium per 100 parts by mass of the total monomers, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium, and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and polymerization was carried out at 60°C for 20 minutes. Next, a cyclohexane solution containing 20 parts by mass of styrene and a cyclohexane solution containing 60 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 55°C, to carry out polymerization. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the cyclohexane solutions of X and Y were mixed so that the mass ratio of X to Y was 70:30. Finally, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by mass of the hydrogenated copolymer, and the cyclohexane was removed by vacuum drying to obtain a hydrogenated copolymer. Table 1 shows the physical properties of the obtained hydrogenated copolymer.

[0082] <Production Example 13> Batch polymerization was carried out using a tank-type reactor (internal volume: 10 L) equipped with a stirrer and a jacket to polymerize a hydrogenated block copolymer (X). First, a cyclohexane solution containing 30 parts by mass of butadiene (concentration: 20% by mass) was added. Next, 0.069 parts by mass of n-butyllithium relative to 100 parts by mass of the total monomers and 0.05 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Next, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and the internal temperature of the reactor was adjusted to 55° C. Next, a cyclohexane solution containing 10 parts by mass of styrene and a cyclohexane solution containing 40 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 55° C., and polymerization was carried out. Next, a cyclohexane solution containing 20 parts by mass of styrene (concentration: 20% by mass) was added, and polymerization was carried out at 70° C. for 1 hour. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the entire amount of the hydrogenated block copolymer (X) was withdrawn, and then polymer (Y) was polymerized. First, a cyclohexane solution containing 20 parts by mass of styrene (concentration: 20% by mass) was added. Next, 0.256 parts by mass of n-butyllithium per 100 parts by mass of the total monomers, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium, and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and polymerization was carried out at 60°C for 20 minutes. Next, a cyclohexane solution containing 20 parts by mass of styrene and a cyclohexane solution containing 60 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 55°C, to carry out polymerization. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the cyclohexane solutions of X and Y were mixed so that the mass ratio of X to Y was 70:30. Finally, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by mass of the hydrogenated copolymer, and the cyclohexane was removed by vacuum drying to obtain a hydrogenated copolymer. Table 1 shows the physical properties of the obtained hydrogenated copolymer.

[0083] <Production Example 14> Batch polymerization was carried out using a tank-type reactor (internal volume: 10 L) equipped with a stirrer and a jacket to polymerize a hydrogenated block copolymer (X). First, a cyclohexane solution containing 30 parts by mass of butadiene (concentration: 20% by mass) was added. Next, 0.069 parts by mass of n-butyllithium relative to 100 parts by mass of the total monomers and 0.05 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Next, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and the internal temperature of the reactor was adjusted to 55° C. Next, a cyclohexane solution containing 10 parts by mass of styrene and a cyclohexane solution containing 40 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 55° C., and polymerization was carried out. Next, a cyclohexane solution containing 20 parts by mass of styrene (concentration: 20% by mass) was added, and polymerization was carried out at 70° C. for 1 hour. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the entire amount of the hydrogenated block copolymer (X) was withdrawn, and then polymer (Y) was polymerized. First, a cyclohexane solution containing 20 parts by mass of styrene (concentration: 20% by mass) was added. Next, 0.237 parts by mass of n-butyllithium per 100 parts by mass of the total monomers, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium, and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and polymerization was carried out at 60°C for 20 minutes. Next, a cyclohexane solution containing 20 parts by mass of styrene and a cyclohexane solution containing 60 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 55°C, to carry out polymerization. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the cyclohexane solutions of X and Y were mixed so that the mass ratio of X to Y was 70:30. Finally, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by mass of the hydrogenated copolymer, and the cyclohexane was removed by vacuum drying to obtain a hydrogenated copolymer. Table 1 shows the physical properties of the obtained hydrogenated copolymer.

[0084] <Production Example 15> Batch polymerization was carried out using a tank-type reactor (internal volume: 10 L) equipped with a stirrer and a jacket to polymerize a hydrogenated block copolymer (X). First, a cyclohexane solution containing 30 parts by mass of butadiene (concentration: 20% by mass) was added. Next, 0.12 parts by mass of n-butyllithium per 100 parts by mass of the total monomers and 0.05 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Next, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and the internal temperature of the reactor was adjusted to 55° C. Next, a cyclohexane solution containing 10 parts by mass of styrene and a cyclohexane solution containing 40 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 55° C., and polymerization was carried out. Next, a cyclohexane solution containing 20 parts by mass of styrene (concentration: 20% by mass) was added, and polymerization was carried out at 70° C. for 1 hour. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the entire amount of the hydrogenated block copolymer (X) was withdrawn, and then polymer (Y) was polymerized. First, a cyclohexane solution containing 20 parts by mass of styrene (concentration: 20% by mass) was added. Next, 0.29 parts by mass of n-butyllithium per 100 parts by mass of the total monomers, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium, and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and polymerization was carried out at 60°C for 20 minutes. Next, a cyclohexane solution containing 20 parts by mass of styrene and a cyclohexane solution containing 60 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 55°C, to carry out polymerization. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the cyclohexane solutions of X and Y were mixed so that the mass ratio of X to Y was 70:30. Finally, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by mass of the hydrogenated copolymer, and the cyclohexane was removed by vacuum drying to obtain a hydrogenated copolymer. Table 1 shows the physical properties of the obtained hydrogenated copolymer.

[0085] <Production Example 16> Batch polymerization was carried out using a tank-type reactor (internal volume: 10 L) equipped with a stirrer and a jacket to polymerize a hydrogenated block copolymer (X). First, a cyclohexane solution containing 30 parts by mass of butadiene (concentration: 20% by mass) was added. Next, 0.12 parts by mass of n-butyllithium per 100 parts by mass of the total monomers and 0.05 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Next, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and the internal temperature of the reactor was adjusted to 55° C. Next, a cyclohexane solution containing 10 parts by mass of styrene and a cyclohexane solution containing 40 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 55° C., and polymerization was carried out. Next, a cyclohexane solution containing 20 parts by mass of styrene (concentration: 20% by mass) was added, and polymerization was carried out at 70° C. for 1 hour. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the entire amount of the hydrogenated block copolymer (X) was withdrawn, and then polymer (Y) was polymerized. First, a cyclohexane solution containing 20 parts by mass of styrene (concentration: 20% by mass) was added. Next, 0.27 parts by mass of n-butyllithium per 100 parts by mass of the total monomers, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium, and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and polymerization was carried out at 60°C for 20 minutes. Next, a cyclohexane solution containing 20 parts by mass of styrene and a cyclohexane solution containing 60 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 55°C, to carry out polymerization. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the cyclohexane solutions of X and Y were mixed so that the mass ratio of X to Y was 70:30. Finally, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by mass of the hydrogenated copolymer, and the cyclohexane was removed by vacuum drying to obtain a hydrogenated copolymer. Table 1 shows the physical properties of the obtained hydrogenated copolymer.

[0086] <Production Example 17> Batch polymerization was carried out using a tank-type reactor (internal volume: 10 L) equipped with a stirrer and a jacket to polymerize a hydrogenated block copolymer (X). First, a cyclohexane solution containing 30 parts by mass of butadiene (concentration: 20% by mass) was added. Next, 0.23 parts by mass of n-butyllithium per 100 parts by mass of the total monomers and 0.05 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Next, 0.7 mol of N,N,N',N'-tetramethylethylenediamine was added per 1 mol of n-butyllithium, and the internal temperature of the reactor was adjusted to 70° C. Next, a cyclohexane solution containing 10 parts by mass of styrene and a cyclohexane solution containing 60 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 65° C., and polymerization was carried out. Next, 0.5 moles of dimethyldichlorosilane was added per mole of n-butyllithium, and the mixture was reacted at 70° C. for 1 hour, and methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the entire amount of the hydrogenated block copolymer (X) was withdrawn, and then polymer (Y) was polymerized. First, a cyclohexane solution containing 20 parts by mass of styrene (concentration 20% by mass) and a cyclohexane solution containing 80 parts by mass of butadiene (concentration 20% by mass) were added. Next, 1.07 parts by mass of n-butyllithium per 100 parts by mass of the total monomers, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium, and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and polymerization was carried out at 55°C for 60 minutes. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the cyclohexane solutions of X and Y were mixed so that the mass ratio of X to Y was 80:20. Finally, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by mass of the hydrogenated copolymer, and the cyclohexane was removed by vacuum drying to obtain a hydrogenated copolymer. Table 1 shows the physical properties of the obtained hydrogenated copolymer.

[0087] <Production Example 18> Batch polymerization was carried out using a tank-type reactor (internal volume: 10 L) equipped with a stirrer and a jacket to polymerize a hydrogenated block copolymer (X). First, a cyclohexane solution containing 30 parts by mass of butadiene (concentration: 20% by mass) was added. Next, 0.23 parts by mass of n-butyllithium per 100 parts by mass of the total monomers and 0.05 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Next, 0.7 mol of N,N,N',N'-tetramethylethylenediamine was added per 1 mol of n-butyllithium, and the internal temperature of the reactor was adjusted to 70° C. Next, a cyclohexane solution containing 10 parts by mass of styrene and a cyclohexane solution containing 60 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 65° C., and polymerization was carried out. Next, 0.5 moles of dimethyldichlorosilane was added per mole of n-butyllithium, and the mixture was reacted at 70° C. for 1 hour, and methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the entire amount of the hydrogenated block copolymer (X) was withdrawn, and then polymer (Y) was polymerized. First, a cyclohexane solution containing 20 parts by mass of styrene (concentration 20% by mass) and a cyclohexane solution containing 80 parts by mass of butadiene (concentration 20% by mass) were added. Next, 1.07 parts by mass of n-butyllithium per 100 parts by mass of the total monomers, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium, and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and polymerization was carried out at 55°C for 60 minutes. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the cyclohexane solutions of X and Y were mixed so that the mass ratio of X to Y was 30:70. Finally, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by mass of the hydrogenated copolymer, and the cyclohexane was removed by vacuum drying to obtain a hydrogenated copolymer. Table 1 shows the physical properties of the obtained hydrogenated copolymer.

[0088] <Comparative Manufacturing Example 1> Batch polymerization was carried out using a tank-type reactor (internal volume: 10 L) equipped with a stirrer and a jacket to polymerize a hydrogenated block copolymer (X). First, a cyclohexane solution containing 30 parts by mass of styrene (concentration: 20% by mass) was added. Next, 0.060 parts by mass of n-butyllithium relative to 100 parts by mass of the total monomers and 0.05 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Next, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and the internal temperature of the reactor was adjusted to 55° C. Next, a cyclohexane solution containing 10 parts by mass of styrene and a cyclohexane solution containing 40 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 55° C., and polymerization was carried out. Next, a cyclohexane solution containing 20 parts by mass of styrene (concentration: 20% by mass) was added, and polymerization was carried out at 70° C. for 1 hour. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the entire amount of the hydrogenated block copolymer (X) was withdrawn, and then polymer (Y) was polymerized. First, a cyclohexane solution containing 20 parts by mass of styrene (concentration: 20% by mass) was added. Next, 0.91 parts by mass of n-butyllithium per 100 parts by mass of the total monomers, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium, and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and polymerization was carried out at 60°C for 20 minutes. Next, a cyclohexane solution containing 20 parts by mass of styrene and a cyclohexane solution containing 60 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 55°C, to carry out polymerization. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the cyclohexane solutions of X and Y were mixed so that the mass ratio of X to Y was 70:30. Finally, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by mass of the hydrogenated copolymer, and the cyclohexane was removed by vacuum drying to obtain a hydrogenated copolymer. Table 1 shows the physical properties of the obtained hydrogenated copolymer.

[0089] <Comparative Manufacturing Example 2> Batch polymerization was carried out using a tank-type reactor (internal volume: 10 L) equipped with a stirrer and a jacket to polymerize a hydrogenated block copolymer (X). First, a cyclohexane solution containing 30 parts by mass of butadiene (concentration: 20% by mass) was added. Next, 0.23 parts by mass of n-butyllithium per 100 parts by mass of the total monomers and 0.15 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Next, 0.7 mol of N,N,N',N'-tetramethylethylenediamine was added per 1 mol of n-butyllithium, and the internal temperature of the reactor was adjusted to 70° C. Next, a cyclohexane solution containing 10 parts by mass of styrene and a cyclohexane solution containing 60 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 65° C., and polymerization was carried out. Next, a cyclohexane solution containing 20 parts by mass of styrene (concentration: 20% by mass) was added, and polymerization was carried out at 70° C. for 1 hour. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the entire amount of the hydrogenated block copolymer (X) was withdrawn, and then polymer (Y) was polymerized. First, a cyclohexane solution containing 20 parts by mass of styrene (concentration: 20% by mass) was added. Next, 0.91 parts by mass of n-butyllithium per 100 parts by mass of the total monomers, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium, and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and polymerization was carried out at 60°C for 20 minutes. Next, a cyclohexane solution containing 20 parts by mass of styrene and a cyclohexane solution containing 60 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 55°C, to carry out polymerization. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the cyclohexane solutions of X and Y were mixed so that the mass ratio of X to Y was 70:30. Finally, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by mass of the hydrogenated copolymer, and the cyclohexane was removed by vacuum drying to obtain a hydrogenated copolymer. Table 1 shows the physical properties of the obtained hydrogenated copolymer.

[0090] <Comparative Manufacturing Example 3> Batch polymerization was carried out using a tank-type reactor (internal volume: 10 L) equipped with a stirrer and a jacket to polymerize a hydrogenated block copolymer (X). First, a cyclohexane solution containing 30 parts by mass of butadiene (concentration: 20% by mass) was added. Next, 0.23 parts by mass of n-butyllithium per 100 parts by mass of the total monomers and 0.05 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Next, 0.7 mol of N,N,N',N'-tetramethylethylenediamine was added per 1 mol of n-butyllithium, and the internal temperature of the reactor was adjusted to 70° C. Next, a cyclohexane solution containing 10 parts by mass of styrene and a cyclohexane solution containing 60 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 65° C., and polymerization was carried out. Next, 0.5 moles of dimethyldichlorosilane was added per mole of n-butyllithium, and the mixture was reacted at 70° C. for 1 hour, and methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the entire amount of the hydrogenated block copolymer (X) was withdrawn, and then polymer (Y) was polymerized. First, a cyclohexane solution containing 20 parts by mass of styrene (concentration 20% by mass) and a cyclohexane solution containing 80 parts by mass of butadiene (concentration 20% by mass) were added. Next, 0.23 parts by mass of n-butyllithium per 100 parts by mass of the total monomers, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium, and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and polymerization was carried out at 55°C for 60 minutes. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the cyclohexane solutions of X and Y were mixed so that the mass ratio of X to Y was 70:30. Finally, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by mass of the hydrogenated copolymer, and the cyclohexane was removed by vacuum drying to obtain a hydrogenated copolymer. Table 1 shows the physical properties of the obtained hydrogenated copolymer.

[0091] <Comparative Manufacturing Example 4> Batch polymerization was carried out using a tank-type reactor (internal volume: 10 L) equipped with a stirrer and a jacket to polymerize a hydrogenated block copolymer (X). First, a cyclohexane solution containing 30 parts by mass of butadiene (concentration: 20% by mass) was added. Next, 0.14 parts by mass of n-butyllithium relative to 100 parts by mass of the total monomers and 0.05 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Next, 0.7 mol of N,N,N',N'-tetramethylethylenediamine was added per 1 mol of n-butyllithium, and the internal temperature of the reactor was adjusted to 70° C. Next, a cyclohexane solution containing 10 parts by mass of styrene and a cyclohexane solution containing 60 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 65° C., and polymerization was carried out. Next, 0.5 moles of dimethyldichlorosilane was added per mole of n-butyllithium, and the mixture was reacted at 70° C. for 1 hour, and methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the entire amount of the hydrogenated block copolymer (X) was withdrawn, and then polymer (Y) was polymerized. First, a cyclohexane solution containing 20 parts by mass of styrene (concentration 20% by mass) and a cyclohexane solution containing 80 parts by mass of butadiene (concentration 20% by mass) were added. Next, 0.21 parts by mass of n-butyllithium per 100 parts by mass of the total monomers, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium, and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and polymerization was carried out at 55°C for 60 minutes. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Next, the cyclohexane solutions of X and Y were mixed so that the mass ratio of X to Y was 70:30. Finally, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by mass of the hydrogenated copolymer, and the cyclohexane was removed by vacuum drying to obtain a hydrogenated copolymer. Table 1 shows the physical properties of the obtained hydrogenated copolymer.

[0092] <Comparative Manufacturing Example 5> Batch polymerization was carried out using a tank-type reactor (internal volume: 10 L) equipped with a stirrer and a jacket to polymerize a hydrogenated block copolymer (X). First, a cyclohexane solution containing 30 parts by mass of butadiene (concentration: 20% by mass) was added. Next, 0.060 parts by mass of n-butyllithium relative to 100 parts by mass of the total monomers and 0.05 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Next, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and the internal temperature of the reactor was adjusted to 55° C. Next, a cyclohexane solution containing 10 parts by mass of styrene and a cyclohexane solution containing 40 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 55° C., and polymerization was carried out. Next, a cyclohexane solution containing 20 parts by mass of styrene (concentration: 20% by mass) was added, and polymerization was carried out at 70° C. for 1 hour. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Finally, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by mass of the hydrogenated copolymer, and the cyclohexane was removed by vacuum drying to obtain a hydrogenated copolymer. Table 1 shows the physical properties of the obtained hydrogenated copolymer.

[0093] <Comparative Manufacturing Example 6> Batch polymerization was carried out using a tank reactor (internal volume: 10 L) equipped with a stirrer and a jacket to polymerize copolymer (Y). First, a cyclohexane solution containing 20 parts by mass of styrene (concentration: 20% by mass) was added. Next, 0.91 parts by mass of n-butyllithium per 100 parts by mass of the total monomers, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium, and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and polymerization was carried out at 60°C for 20 minutes. Next, a cyclohexane solution containing 20 parts by mass of styrene and a cyclohexane solution containing 60 parts by mass of butadiene (concentration: 20% by mass) were supplied at a constant flow rate while maintaining the internal temperature at 55°C, to carry out polymerization. Thereafter, methanol was added to terminate the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained copolymer in an amount of 50 ppm (Ti basis) per 100 parts by mass of the copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. At this time, the hydrogenation rate of the double bonds in the conjugated diene moiety was 99%. Finally, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by mass of the hydrogenated copolymer, and the cyclohexane was removed by vacuum drying to obtain a hydrogenated copolymer. Table 1 shows the physical properties of the obtained hydrogenated copolymer.

[0094] <Comparative Manufacturing Example 7> Batch polymerization was carried out using a tank reactor (internal volume: 10 L) equipped with a stirrer and a jacket to polymerize copolymer (Y). First, a cyclohexane solution containing 100 parts by mass of butadiene (concentration: 20% by mass) was added. Next, 1.5 parts by mass of n-butyllithium per 100 parts by mass of the total monomers, 1.2 mol of N,N,N',N'-tetramethylethylenediamine per 1 mol of n-butyllithium, and 0.05 mol of sodium amylate per 1 mol of n-butyllithium were added, and polymerization was carried out at 55°C for 20 minutes. Thereafter, methanol was added to terminate the polymerization reaction. Finally, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by mass of the hydrogenated copolymer, and the cyclohexane was removed by vacuum drying to obtain a hydrogenated copolymer. Table 1 shows the physical properties of the obtained hydrogenated copolymer.

[0095] [Table 1]

[0096] [Table 2]

[0097] [Table 3]

Claims

1. a hydrogenated block copolymer (X) having at least one polybutadiene block (A) having a vinyl group content of 20% by mass or less; a polymer (Y) containing a structural unit derived from an aromatic vinyl compound and / or a structural unit derived from a conjugated diene compound; Including, The hydrogenated copolymer has a value of the number average molecular weight of the hydrogenated block copolymer (X) / the number average molecular weight of the polymer (Y) of 2.5 or more and 30 or less.

2. 2. The hydrogenated copolymer according to claim 1, wherein the hydrogenation rate of the hydrogenated block copolymer (X) is 80% or more.

3. In the hydrogenated block copolymer (X), other than the polybutadiene block (A), When the mass fraction of the structural units derived from a conjugated diene compound having a 1,2 or 3,4 vinyl bond relative to the entire hydrogenated block copolymer (X) is a %, the mass fraction of the structural units derived from an aromatic vinyl compound randomly copolymerized with a conjugated diene relative to the entire hydrogenated block copolymer (X) is b %, and the mass fraction of the structural units derived from a conjugated diene compound having a 1,4 bond of the polybutadiene block (A) relative to the entire hydrogenated block copolymer (X) is c %, 2. The hydrogenated copolymer according to claim 1, wherein a+b−c is −15% by mass or more and 40% by mass or less.

4. 2. The hydrogenated copolymer according to claim 1, wherein the mass ratio of the hydrogenated block copolymer (X) to the polymer (Y) is 40:60 to 80:

20.

5. The hydrogenated copolymer according to claim 1, wherein the number average molecular weight of the hydrogenated block copolymer (X) is from 70,000 to 250,000.

6. The hydrogenated copolymer according to claim 1, wherein the number average molecular weight of the polymer (Y) is from 4,000 to 35,000.

7. 2. The hydrogenated copolymer according to claim 1, wherein the polybutadiene block (A) accounts for 5% or more and less than 50% by mass of the entire hydrogenated block copolymer (X).

8. Pellets of the hydrogenated copolymer according to any one of claims 1 to 7.

9. A resin composition comprising the hydrogenated copolymer according to claim 1 and at least one solid rubber component selected from the group consisting of styrene-butadiene rubber, natural rubber, and butadiene rubber.

10. The resin composition according to claim 9, further comprising a filler.

11. The resin composition according to claim 9, further comprising a silane coupling agent.

12. A tire comprising the resin composition according to claim 9.

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