Block copolymer, resin composition, and cured product

Abstract

To provide a block copolymer excellent in high-temperature characteristics and strength.SOLUTION: The block copolymer has a polymer block mainly composed of at least one vinyl aromatic monomer unit and a polymer block mainly composed of at least one conjugated diene monomer unit, and satisfies the following conditions (1) to (4): (1) The vinyl aromatic compound forming the vinyl aromatic monomer unit is α-methylstyrene having an alkyl group on the benzene ring. (2) the content of the polymer block mainly comprising a vinyl aromatic monomer unit is from 10% by mass to 50% by mass; (3) The content of the polymer block mainly comprising a conjugated diene monomer unit is from 90 mass% to 50 mass%. (4) The peak molecular weight (Mp) of the block copolymer is 40,000 or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a block copolymer, a resin composition, and a cured product thereof. [Background technology]

[0002] Block copolymers, which have polymer blocks (restrained phases) at both ends of a polymer chain with a glass transition temperature (Tg) higher than room temperature and a polymer block (rubber phase) with a Tg lower than room temperature interposed therebetween, have been widely known as thermoplastic elastomers. Among these, block copolymers of conjugated diene compounds and vinyl aromatic compounds have elasticity at room temperature similar to that of natural or synthetic rubber, and processability at high temperatures similar to that of thermoplastic resins. Therefore, they have been widely used in a variety of fields, including plastic modifiers, automobile parts, medical molded products, asphalt modifiers, footwear, molded products such as food containers, packaging materials, adhesive sheets, and home appliance and industrial parts (see Patent Document 1).

[0003] In recent years, there has been a demand for longer product life in order to reduce environmental impact, and materials with higher strength are in demand. On the other hand, in order to realize a sustainable society, there is a demand for the use of renewable resources, and the use of plant-derived raw materials is being considered. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2000 / 015680 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the styrene-based thermoplastic elastomer disclosed in Patent Document 1 has a problem in that the Tg of the styrene polymer block, which is the constrained phase, is approximately 100°C, and the performance as an elastomer is significantly reduced under high temperature conditions exceeding this temperature.

[0006] Therefore, an object of the present invention is to provide a block copolymer that utilizes an α-methylstyrene derivative, which is a plant-derived raw material, has a constrained phase with a high Tg, and is excellent in high-temperature properties and strength. [Means for solving the problem]

[0007] As a result of extensive research to solve the above-mentioned problems of the conventional art, the present inventors have found that the above-mentioned problems can be solved by a block copolymer having a specific structure, which is composed of vinyl aromatic monomer units and conjugated diene monomer units, and which has a peak molecular weight and a vinyl aromatic compound content within a predetermined range, and have thereby completed the present invention. That is, the present invention is as follows.

[0008] [1] at least one polymer block based on vinyl aromatic monomer units; at least one polymer block mainly composed of conjugated diene monomer units; , and The following conditions (1) to (4) are met: Block copolymer. <Condition (1)> The vinyl aromatic compound forming the vinyl aromatic monomer unit has the structure shown in the following formula (1).

[0009] [ka]

[0010] In formula (1), R1 represents an alkyl group.

[0011] <Condition (2)> The content of the polymer block mainly composed of vinyl aromatic monomer units is The content is 10% by mass to 50% by mass. <Condition (3)> The content of the polymer block mainly composed of conjugated diene monomer units is The content is 90% by mass to 50% by mass. <Condition (4)> The peak molecular weight (Mp) of the block copolymer is 40,000 or more.

[0012] [2] The vinyl aromatic compound is p-methyl-α-methylstyrene; The block copolymer described in [1] above. [3] The number average molecular weight of the polymer block mainly composed of vinyl aromatic monomer units is Between 8,000 and 40,000 The block copolymer according to [1] or [2] above. [4] The glass transition temperature (Tg) of the block copolymer derived from the polymer block mainly composed of vinyl aromatic monomer units is 110°C or higher. The block copolymer according to any one of [1] to [3] above. [5] the polymer block mainly composed of conjugated diene monomer units is hydrogenated; The block copolymer according to any one of [1] to [4] above. [6] A resin composition comprising the block copolymer according to any one of [1] to [5] above. [7] A cured product of the resin composition described in [6] above. [Effects of the Invention]

[0013] According to the present invention, a block copolymer having excellent high-temperature properties and strength can be obtained. [Brief explanation of the drawings]

[0014] [Figure 1]1 shows the relationship between polymerization time and polymerization conversion rate in Production Examples 1 to 3. [Figure 2] The GPC charts of Production Examples 2 and 3 are shown below. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. It should be noted that the following embodiments are merely examples for explaining the present invention, and are not intended to limit the present invention to the following content, and the present invention can be implemented in various modified forms within the scope of its gist.

[0016] [Block copolymer] The block copolymer of this embodiment is at least one polymer block based on vinyl aromatic monomer units; at least one polymer block mainly composed of conjugated diene monomer units; , and The following conditions (1) to (4) are met.

[0017] <Condition (1)> The vinyl aromatic compound forming the vinyl aromatic monomer unit has the structure shown in the following formula (1).

[0018] [ka]

[0019] In formula (1), R1 represents an alkyl group.

[0020] <Condition (2)> The content of the polymer block mainly composed of vinyl aromatic monomer units is The content is 10% by mass to 50% by mass. <Condition (3)> The content of the polymer block mainly composed of conjugated diene monomer units is The content is 90% by mass to 50% by mass. <Condition (4)> The peak molecular weight (Mp) of the block copolymer is 40,000 or more.

[0021] By having the above structure, a block copolymer having excellent high-temperature properties and strength can be obtained. In this specification, when a polymerized monomer is incorporated into a constituent element of a polymer, it is referred to as a "monomer unit," and when it is in the state of a monomer before becoming a constituent element of a polymer, it is referred to as a "compound."

[0022] (Polymer block mainly composed of vinyl aromatic monomer units) The block copolymer of this embodiment has at least one polymer block (hereinafter, sometimes referred to as polymer block A) mainly composed of vinyl aromatic monomer units (the above-mentioned condition (1)). The vinyl aromatic compound forming the vinyl aromatic monomer unit has a structure represented by the following formula (1). In this specification, the term "mainly composed of" means that the vinyl aromatic monomer unit is contained in an amount of 70% by mass or more and 100% by mass or less in the target polymer block.

[0023] [ka]

[0024] As in the structure of formula (1), by having a methyl group at the α-position, the glass transition temperature of the constrained phase of the block copolymer of this embodiment increases, and the high-temperature properties tend to be excellent. Furthermore, the presence of an alkyl group on the benzene ring makes crosslinking possible by a radical reaction in the constrained phase, and tends to result in a cured product with high strength. Examples of vinyl aromatic compounds having the structure of formula (1) include, but are not limited to, m-methyl-α-methylstyrene, o-methyl-α-methylstyrene, p-methyl-α-methylstyrene, m-ethyl-α-methylstyrene, o-ethyl-α-methylstyrene, p-ethyl-α-methylstyrene, m-isopropyl-α-methylstyrene, o-isopropyl-α-methylstyrene, and p-isopropyl-α-methylstyrene. Among these, p-methyl-α-methylstyrene is preferred from the viewpoints of availability and productivity. These may be used alone or in combination of two or more.

[0025] In the block copolymer of this embodiment, the content of the polymer block A is 10% by mass or more (condition (2)). The content of the polymer block A is preferably 15% by mass or more, and more preferably 20% by mass or more. When the content of the polymer block A is within the above range, the block copolymer of this embodiment tends to exhibit good high-temperature properties. Furthermore, in the block copolymer of this embodiment, the content of polymer block A is 50% by mass or less (condition (2)). The content of polymer block A is preferably 45% by mass or less, and more preferably 40% by mass or less. When the content of the polymer block A is within the above range, the block copolymer of the present embodiment exhibits rubber elasticity and tends to have improved strength. The content of polymer block A in the block copolymer of this embodiment can be measured by proton nuclear magnetic resonance (H-NMR) method. Specifically, it can be measured by the method described in the examples below. The content of polymer block A in the block copolymer of this embodiment can be controlled within the above numerical range by adjusting the amount of vinyl aromatic compound added in the polymerization step.

[0026] The number average molecular weight of the polymer block A is preferably 8,000 or more, more preferably 9,000 or more, and even more preferably 10,000 or more. When the number average molecular weight of the polymer block A is within the above range, the block copolymer of this embodiment tends to exhibit a high glass transition temperature and good high-temperature properties. In addition, in the block copolymer of this embodiment, the number average molecular weight of the polymer block A is preferably 40,000 or less, more preferably 35,000 or less, and even more preferably 30,000 or less. When the content of polymer block A is within the above range, the block copolymer of this embodiment tends to have a reduced modulus of elasticity and a lower hardness. The number average molecular weight of the polymer block A in the block copolymer can be measured by gel permeation chromatography (hereinafter referred to as GPC) using standard polystyrene as a calibration curve. Specifically, it can be measured by the method described in the Examples below. The number average molecular weight of the polymer block A in the block copolymer can be controlled within the above numerical range by adjusting conditions such as the amount of aromatic compound added and the amount of polymerization initiator added in the polymerization step.

[0027] (Polymer block mainly composed of conjugated diene monomer units) The block copolymer of this embodiment has at least one polymer block (hereinafter, sometimes referred to as polymer block B) mainly composed of conjugated diene monomer units. In this specification, the term "mainly composed of" means that the conjugated diene monomer unit is contained in an amount of 70% by mass or more and 100% by mass or less in the target polymer block.

[0028] The conjugated diene compound constituting the block copolymer of the present embodiment may be any diolefin having a conjugated double bond, and may include, but is not limited to, 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, farnesene, and the like. Among these, 1,3-butadiene and isoprene are preferred from the viewpoints of availability and productivity. These may be used alone or in combination of two or more.

[0029] In the block copolymer of the present embodiment, the content of the polymer block B is 50% by mass or more (condition (3)), preferably 55% by mass or more, and more preferably 60% by mass or more. When the content of polymer block B is within the above range, the block copolymer of the present embodiment exhibits rubber elasticity and tends to have improved strength. In the block copolymer of the present embodiment, the content of the polymer block B is 90% by mass or less (condition (3)), preferably 85% by mass or less, and more preferably 80% by mass or less. When the content of polymer block B is within the above range, the block copolymer of this embodiment tends to exhibit good high-temperature properties. The content of polymer block B in the block copolymer can be measured by proton nuclear magnetic resonance (H-NMR) method, specifically by the method described in the examples below. The content of the polymer block B in the block copolymer can be controlled within the above-mentioned range by adjusting the amount of the conjugated diene compound added in the polymerization step.

[0030] The number average molecular weight of the polymer block B mainly composed of conjugated diene monomer units in the block copolymer of this embodiment is preferably 25,000 or more, more preferably 35,000 or more, and even more preferably 45,000 or more. When the number average molecular weight of the polymer block B is within the above range, the block copolymer of this embodiment tends to exhibit good elongation. The number average molecular weight of the polymer block B in the block copolymer of this embodiment can be measured by gel permeation chromatography (hereinafter referred to as GPC) using standard polystyrene as a calibration curve. Specifically, it can be measured by the method described in the Examples below. The number average molecular weight of the polymer block B in the block copolymer of this embodiment can be controlled within the above-mentioned range by adjusting conditions such as the amount of conjugated diene compound added and the amount of polymerization initiator added in the polymerization step. The number average molecular weight of the polymer block B mainly composed of conjugated diene monomer units in the block copolymer of this embodiment is preferably 200,000 or less, more preferably 180,000 or less, and even more preferably 150,000 or less. When the number average molecular weight of the polymer block B is within the above range, the block copolymer of this embodiment tends to exhibit good processability. The number average molecular weight of the polymer block B in the block copolymer of this embodiment can be measured by gel permeation chromatography (hereinafter referred to as GPC) using standard polystyrene as a calibration curve. Specifically, it can be measured by the method described in the Examples below. The number average molecular weight of the polymer block B in the block copolymer of this embodiment can be controlled within the above-mentioned range by adjusting conditions such as the amount of conjugated diene compound added and the amount of polymerization initiator added in the polymerization step.

[0031] (Peak molecular weight of block copolymer) The block copolymer of this embodiment has a peak molecular weight (Mp) of 40000 or more. The peak molecular weight (Mp) is preferably 45000 or more, more preferably 50000 or more, and even more preferably 60000 or more. When the peak molecular weight (Mp) of the block copolymer of this embodiment is in the above-mentioned range, the block copolymer of this embodiment tends to exhibit good elongation. The peak molecular weight (Mp) of the block copolymer can be measured by gel permeation chromatography (hereinafter referred to as GPC) using standard polystyrene as a calibration curve. Specifically, it can be measured by the method described in the Examples below. The peak molecular weight (Mp) of the block copolymer of this embodiment can be controlled within the above-mentioned range by adjusting conditions such as the amounts of the vinyl aromatic compound and the conjugated diene compound added in the polymerization step and the amount of the polymerization initiator added. The block copolymer of this embodiment preferably has a peak molecular weight (Mp) of 250,000 or less, more preferably 200,000 or more, and even more preferably 170,000 or more. When the peak molecular weight (Mp) of the block copolymer of this embodiment is in the above-mentioned range, the block copolymer of this embodiment tends to exhibit good processability. The peak molecular weight (Mp) of the block copolymer can be measured by gel permeation chromatography (hereinafter referred to as GPC) using standard polystyrene as a calibration curve. Specifically, it can be measured by the method described in the Examples below. The peak molecular weight (Mp) of the block copolymer of this embodiment can be controlled within the above-mentioned range by adjusting conditions such as the amounts of the vinyl aromatic compound and the conjugated diene compound added in the polymerization step and the amount of the polymerization initiator added.

[0032] (Hydrogenation rate) In the block copolymer of the present embodiment, the polymer block mainly composed of conjugated diene monomer units is preferably hydrogenated, with the hydrogenation rate being preferably 30% or more, more preferably 40% or more, even more preferably 50% or more, and even more preferably 60%. When the block copolymer of the present embodiment is hydrogenated, the glass transition temperature tends to increase and the high-temperature properties tend to be improved. The hydrogenation rate can be controlled, for example, by the amount of catalyst used during hydrogenation, and the hydrogenation rate can be controlled, for example, by the amount of catalyst used during hydrogenation, the amount of hydrogen fed, the pressure, the temperature, etc. The hydrogenation rate of the double bonds in the polymer block mainly composed of conjugated diene monomer units in the block copolymer of this embodiment can be measured by a nuclear magnetic resonance (NMR) spectrometer.

[0033] (vinyl bond content) The vinyl bond content in the polymer block B mainly composed of conjugated diene monomer units in the block copolymer of this embodiment is preferably 15% or more and 90% or less, more preferably 20% or more and 80% or less, even more preferably 25% or more and 70% or less, and even more preferably 30% or more and 60% or less. When the amount of vinyl bonds in the polymer block B mainly composed of conjugated diene monomer units in the block copolymer of this embodiment is 15% or more and 90% or less, the block copolymer tends to exhibit good elasticity. The amount of vinyl bonds in the polymer block B mainly composed of conjugated diene monomer units in the block copolymer of this embodiment can be measured by a nuclear magnetic resonance (NMR) spectrometer.

[0034] (Glass transition temperature in viscoelasticity of block copolymers) The block copolymer of the present embodiment has a glass transition temperature derived from the polymer block A mainly composed of vinyl aromatic monomer units, which is measured by viscoelasticity measurement (1 Hz) of preferably 110°C or higher, more preferably 115°C or higher, and even more preferably 120°C or higher. When the glass transition point derived from the polymer block A mainly composed of vinyl aromatic monomer units in the block copolymer of this embodiment is 110° C. or higher, the high-temperature properties tend to be improved. In the block copolymer of this embodiment, the glass transition temperature (Tg) derived from the polymer block A mainly composed of vinyl aromatic monomer units can be controlled within the above-mentioned range by the molecular weight of the polymer block A.

[0035] (Molecular weight distribution of block copolymer) The molecular weight distribution (Mw / Mn) of the block copolymer of this embodiment is preferably 1.01 to 10.0, more preferably 1.01 to 9.0, and even more preferably 1.01 to 8.0. When the molecular weight distribution is within the above range, better molding processability tends to be obtained. The shape of the molecular weight distribution of the block copolymer of the present embodiment measured by GPC is not particularly limited, and the block copolymer may have a polymodal molecular weight distribution with two or more peaks, or a monomodal molecular weight distribution with one peak. The weight-average molecular weight (Mw) and molecular weight distribution [Mw / Mn; the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn)] of the block copolymer of this embodiment can be determined by using the molecular weight of the peak in a chromatogram measured by GPC according to the method described in the Examples below, and a calibration curve (prepared using the peak molecular weight of the standard polystyrene) obtained from the measurement of commercially available standard polystyrene.

[0036] [Method for producing block copolymer] Examples of methods for producing the block copolymer of the present embodiment include, but are not limited to, methods described in JP-B-36-19286, JP-B-43-17979, JP-B-46-32415, JP-B-49-36957, JP-B-48-2423, JP-B-48-4106, JP-B-51-49567, and JP-A-59-166518.

[0037] The block copolymer before hydrogenation can be obtained by, but not limited to, a method of living anionic polymerization using predetermined monomers in a hydrocarbon solvent using a polymerization initiator such as an organic alkali metal compound. The hydrocarbon solvent is not particularly limited, and examples thereof include 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.

[0038] 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. For example, there may be mentioned 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. The alkali metal contained in the polymerization initiator is not limited to the following, but examples thereof include lithium, sodium, and potassium. One or more types of alkali metals may be contained in one molecule. 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. Furthermore, 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, diisopropylamide lithium, hexamethyldisilazide lithium and other aminolithiums can also be used.

[0039] The amount of the lithium compound used as a polymerization initiator depends on the molecular weight of the target block copolymer, but is preferably 0.005 to 6.4 parts by mass, more preferably 0.005 to 2.6 parts by mass, per 100 parts by mass of the monomer.

[0040] 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 to adjust the content of vinyl bonds (1,2-bonds or 3,4-bonds) resulting from the conjugated diene compound incorporated into the block copolymer or to adjust the random copolymerization property of the conjugated diene compound and the vinyl aromatic compound.

[0041] 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.) Examples of such 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.

[0042] As the ether compound, a linear ether compound or a cyclic ether compound can be used. Examples of the linear ether compound include 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. Examples of cyclic ether compounds include tetrahydrofuran, dioxane, 2,5-dimethyloxolane, 2,2,5,5-tetramethyloxolane, 2,2-bis(2-oxolanyl)propane, and alkyl ethers of furfuryl alcohol.

[0043] 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.

[0044] In the process for producing the block copolymer of this embodiment, sodium alkoxide may be present during copolymerization. The sodium alkoxide is, for example, a compound represented by the following formula, but is not limited to the following: In particular, sodium alkoxides having an alkyl group with 3 to 6 carbon atoms are preferred, and sodium t-butoxide and sodium t-pentoxide are more preferred. NaOR (wherein R is an alkyl group having 2 to 12 carbon atoms). The amount of sodium alkoxide used in the polymerization step of the block copolymer of this embodiment 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 still more 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 narrow molecular weight distribution and a polymer block B mainly composed of conjugated diene monomer units with a high vinyl bond content and a polymer block A mainly composed of vinyl aromatic monomer units with a narrow molecular weight distribution.

[0045] 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.

[0046] In the polymerization step of the block copolymer of this embodiment, the concentration of the vinyl aromatic compound in the reaction system is preferably in the range of 5 to 50% by mass, more preferably in the range of 25 to 40% by mass. When the concentration of the vinyl aromatic compound in the reaction system is 5% by mass or more, the vinyl aromatic compound tends to be polymerized at a high conversion rate. Furthermore, when the concentration of the vinyl aromatic compound is 50% by mass or less, it is possible to prevent the reaction solution from becoming highly viscous and difficult to stir in the later stage of polymerization of the vinyl aromatic compound.

[0047] The temperature conditions for the polymerization step of the block copolymer of this embodiment are preferably within the range of -30°C to 30°C, more preferably -20°C to 10°C, and even more preferably -17°C to 0°C, from the viewpoints of the ceiling temperature of the vinyl aromatic compound (the temperature at which the polymerization reaction reaches equilibrium and substantially stops proceeding), the polymerization rate of the vinyl aromatic compound, the living property, etc. By setting the polymerization temperature to 30°C or lower, the vinyl aromatic compound tends to be polymerized at a high conversion rate, and the rate at which the resulting living polymer is deactivated tends to be reduced. Furthermore, by setting the polymerization temperature to -30°C or higher, the reaction solution can be prevented from becoming highly viscous and difficult to stir in the later stage of polymerization of the vinyl aromatic compound of this embodiment, and the cost required for maintaining a low temperature tends to be reduced.

[0048] Furthermore, in the process for producing the block copolymer of this embodiment, a required amount of a coupling agent having two or more functional groups may be added at the end of the polymerization 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 α,α'-dichloroparaxylene, dimethyldichlorosilane, and dimethyldibromosilane, and acid esters such as methyl benzoate, ethyl benzoate, phenyl benzoate, and phthalates. Examples of polyfunctional coupling agents with three or more functional groups include, but are not limited to, 1,1,1,2,2-pentachloroethane, perchloroethane, pentachlorobenzene, perchlorobenzene, octabromodiphenyl ether, decabromodiphenyl ether, trivalent or higher polyalcohols, epoxidized soybean oil, polyfunctional epoxy compounds such as diglycidyl bisphenol A, difunctional to hexafunctional epoxy group-containing compounds, carboxylic acid esters, polyvinyl compounds such as divinylbenzene, and compounds of the formula R1 (4-n) Six n (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.

[0049] The block copolymer of this embodiment may be obtained by subjecting the living terminal of the block copolymer obtained by the method described above 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.

[0050] Examples of modifying agents 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 modifying agent added is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, and even more preferably 0.3 to 10 parts by mass, relative to 100 parts by mass of the block 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.

[0051] The block copolymer of the present embodiment may be subjected to a hydrogenation step after the above-described polymerization step or the above-described modification step. The hydrogenation catalyst used to produce the block copolymer of the present embodiment 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 a mixture of a titanocene compound and / or a reducing organometallic compound, and a palladium carbon catalyst. 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. 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 15 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.

[0052] If necessary, catalyst residues may be removed from the reaction solution after the hydrogenation step. The catalyst residue contains remaining metal compounds. Examples of the remaining metal compounds include compounds of metals contained in the polymerization initiator and the hydrogenation catalyst, oxides of each atom such as titanium oxide, amorphous titanium oxide, orthotitanic acid, metatitanic acid, titanium hydroxide, nickel hydroxide, nickel monoxide, lithium oxide, lithium hydroxide, cobalt oxide, and cobalt hydroxide, and composite oxides of each atom with a different metal such as lithium titanate, barium titanate, strontium titanate, nickel titanate, nickel titanate, nickel-iron oxide, and palladium carbon.

[0053] The method for reducing the amount of residual metal in the block copolymer of this embodiment can be any conventional method, and is not particularly limited. For example, a method of adding water and carbon dioxide gas after the hydrogenation reaction of the block copolymer to neutralize the hydrogenation catalyst residue, or a method of adding water, carbon dioxide gas, and an acid to neutralize the hydrogenation catalyst residue, can be used. Specifically, the method described in Japanese Patent Application No. 2014-557427 can be applied. Even when these metal removal methods are used, water containing hydroxides of metal compounds is typically mixed in during the desolvation process of the block copolymer, resulting in a metal content of approximately 1 to 15 ppm. Therefore, it is preferable to remove at least 20% of the amount of metal added to the block copolymer, more preferably at least 30%, even more preferably at least 40%, even more preferably at least 50%, and even more preferably at least 60%.

[0054] In addition, the amount of residual metal in the block copolymer can also be reduced by reducing the amounts of polymerization initiator and hydrogenation catalyst added, but reducing the amount of polymerization initiator increases the molecular weight of the block copolymer, and if the molecular weight falls outside the preferred range described above, the heat resistance of the cured product tends to decrease. Furthermore, when performing a hydrogenation reaction, reducing the amount of hydrogenation catalyst increases the hydrogenation reaction time and the hydrogenation reaction temperature, which tends to significantly reduce productivity.

[0055] Methods for separating the block copolymer from the solvent include, but are not limited to, a method in which a polar solvent that is a poor solvent for the block copolymer, such as acetone or alcohol, is added to a solution of the block copolymer to precipitate and recover the block copolymer; a method in which the solution of the block copolymer is poured into hot water with stirring and the solvent is removed by steam stripping to recover the block copolymer; and a method in which the solvent is distilled off by directly heating the solution of the block copolymer.

[0056] The block copolymer may contain an antioxidant on its surface and / or within it, for example, by adding the antioxidant during manufacture. The following antioxidant may also be added to the resin composition of the present embodiment, which will be described later.

[0057] 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.

[0058] The polymerization terminator is not particularly limited, but examples thereof include water, alcohols such as methanol, ethanol, isopropanol, 2-ethylhexanol, heptanol, and mixtures thereof.

[0059] The block copolymer of this embodiment may be pelletized. Examples of the pelletizing method include a method in which the block copolymer of the present embodiment is extruded in the form of a strand from a single-screw or twin-screw extruder and then cut in water with a rotary blade installed in front of a die; a method in which the hydrogenated copolymer is extruded in the form of a strand from a single-screw or twin-screw extruder, cooled with water or air, and then cut with a strand cutter; and a method in which the copolymer is melt-mixed using an open roll or Banbury mixer, then formed into a sheet using a roll, and the sheet is further cut into strips and then cut into cubic pellets using a pelletizer. The size and shape of the pellets of the block copolymer of this embodiment are not particularly limited. If necessary, the block copolymer of this embodiment may be blended with a pellet anti-blocking agent in the pellets to prevent pellet blocking. 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 6000 ppm, more preferably 1000 to 5000 ppm, relative to the block copolymer of this embodiment. 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.

[0060] [Resin composition] The resin composition of the present embodiment contains the block copolymer of the present embodiment described above. The content of the block copolymer is preferably 5 parts by mass or more and 60 parts by mass or less, more preferably 7 parts by mass or more and 55 parts by mass or less, and even more preferably 10 parts by mass or more and 50 parts by mass or less, relative to 100 parts by mass of the resin solid content of the resin composition of this embodiment. The resin composition of the present embodiment may contain, in addition to the block copolymer of the present embodiment described above, a thermoplastic resin, a thermosetting resin, a filler, an oil, and the like.

[0061] [Cured product] The cured product of this embodiment is a cured product of the resin composition of this embodiment, and is obtained by subjecting the resin composition of this embodiment to a curing reaction at any temperature and for any time. The concept encompasses not only a completely cured product, but also a form in which only a portion of the resin composition is cured and contains uncured components (semi-cured). [Example]

[0062] Hereinafter, the present embodiment will be described in 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.

[0063] [Method for measuring polymerization conversion rate] The polymerization conversion of p-methyl-α-methyl-styrene (AMMS) was measured by proton nuclear magnetic resonance ( 1 H-NMR was used for the measurement. Using the block copolymer before hydrogenation, proton nuclear magnetic resonance ( 1H-NMR was used for the measurement. The measurement equipment used was a JNM-LA400 (manufactured by JEOL), the solvent was deuterated chloroform, 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 polymerization conversion of p-methyl-α-methyl-styrene was calculated using the decrease in the integrated value of the peak derived from the vinyl bond of the vinyl aromatic compound in the range of 5.2 to 5.4 ppm in the spectrum.

[0064] [Method for identifying block copolymer structure and method for measuring physical properties] ((1) Vinyl aromatic monomer unit (AMMS or styrene) content of block copolymer) Using the block copolymer before hydrogenation, proton nuclear magnetic resonance ( 1 H-NMR was used for the measurement. The measurement equipment used was a JNM-LA400 (manufactured by JEOL), the solvent was deuterated chloroform, 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 content of vinyl aromatic compounds was calculated using the integrated value of the total vinyl aromatic signals in the spectrum from 6.2 to 7.5 ppm.

[0065] ((2) Amount of vinyl bonds in block copolymer) Using the block copolymer before hydrogenation, proton nuclear magnetic resonance ( 1 The vinyl bond content was measured by H-NMR. The measurement conditions and the method of processing the measurement data were the same as those in (1) above. The amount of vinyl bonds is calculated by calculating the integral per 1H of each bond type from the integral values ​​of the signals assigned to 1,4-bonds and 1,2-bonds, and dividing the integral value of 1,2-bonds by the sum of the integral values ​​of 1,4-bonds and 1,2-bonds (1,2-bonds in the case of butadiene, and 3,4-bonds in the case of isoprene).

[0066] ((3) Number-average molecular weight of polymer block mainly composed of vinyl aromatic monomer units) The number-average molecular weight of the polymer block mainly composed of vinyl aromatic monomer units was measured by sampling a portion of the polymerization solution after the completion of the polymerization of p-methyl-α-methyl-styrene and styrene and using GPC (pump: JASCO PU-2080, detector: JASCO RI-2031, column: Shodex KF-805L x 2). Tetrahydrofuran was used as the solvent. The measurement was carried out at a temperature of 40° C. The polystyrene-equivalent number average molecular weight was determined using a calibration curve prepared using commercially available standard polystyrenes with known number average molecular weights.

[0067] ((4) Peak molecular weight of block copolymer (Mp)) The peak molecular weight of the block copolymer was measured using GPC under the same conditions as in (3) above.

[0068] ((5) Molecular weight of polymer block mainly composed of conjugated diene monomer units) The molecular weight of the polymer block mainly composed of conjugated diene monomer units was calculated by the following formula. Formula: (Molecular weight of polymer block mainly composed of conjugated diene monomer units) = (peak molecular weight of block copolymer) -(molecular weight of polymer block mainly composed of vinyl aromatic monomer units) x 2

[0069] ((6) Double bond hydrogenation rate) The hydrogenation rate of the block copolymer after hydrogenation was measured using a nuclear magnetic resonance spectrometer (BRUKER, DPX-400). The hydrogenated block copolymer was used for proton nuclear magnetic resonance ( 1 H-NMR). Specifically, the integral values ​​of the signals at 4.5 to 5.5 ppm derived from the residual double bonds and the signals at 4.5 to 5.5 ppm derived from the hydrogenated conjugated dienes were calculated, and the ratio thereof was calculated.

[0070] (7) Hardness of Block Copolymer The instantaneous hardness was measured using a durometer type A in accordance with JIS K6253.

[0071] (8) Elastic modulus, breaking strength, and breaking elongation of block copolymers by tensile testing The elastic modulus, breaking strength and breaking elongation of the block copolymer were measured by carrying out a tensile test under the following conditions. First, the block copolymer was molded into a sheet with a thickness of 2 mm, and then a dumbbell piece with a parallel section width of 3 mm was prepared. The measurement was carried out at a pulling speed of 100 mm / min and a chuck distance of 30 mm.

[0072] ((9) Glass transition temperature derived from polymer blocks mainly composed of aromatic vinyl monomer units) The dynamic viscoelasticity spectrum was measured by the following method, and the glass transition temperature derived from the polymer block mainly composed of aromatic vinyl monomer units was determined from the tan δ peak on the high temperature side. First, block copolymers H1, H6, and H9, which will be described later, were molded into sheets of 2 mm in thickness, which were then cut into a size of 10 mm in width and 35 mm in length to prepare measurement samples. The measurement sample was set in the torsion type geometry of the ARES device (manufactured by TA Instruments Corporation, trade name), and measurements were performed under the following conditions: effective measurement length 25 mm, strain 0.5%, frequency 1 Hz, measurement range from -100°C to 200°C, and heating rate 3°C / min.

[0073] ((10) Tensile test after curing) Block copolymers H1, H6, and H9, which will be described later, were each dissolved in toluene to prepare a 30% by mass solution, to which 0.5 equivalents of Perbutyl P (NOF Corporation) relative to the block copolymer was added. The solution was applied to a Teflon (registered trademark) sheet and cured for 90 minutes at 200° C. The resulting film was peeled off from the Teflon sheet to obtain a film with a thickness of 0.1 μm. The obtained film was molded into a No. 1 dumbbell according to JIS K 6251, and a tensile test was carried out at a pulling rate of 1 mm to measure the modulus of elasticity and breaking strength.

[0074] [Preparation of homopolymer of p-methyl-α-methyl-styrene] In the following Production Examples 1 to 3, a homopolymer of p-methyl-α-methyl-styrene was produced, and the polymerization conversion rate and GPC measurement were carried out to verify the effect of adding sodium t-pentoxide.

[0075] <Production Example 1: (Polymer without sodium t-pentoxide added)> In a 100 mL flask that had been thoroughly purged with nitrogen, 37 mL of methylcyclohexane, 2 mL of tetralin, and 25 mL of p-methyl-α-methyl-styrene were added and stirred at -15°C. Thereafter, 0.5 parts by mass of sec-butyllithium relative to 100 parts by mass of the monomer and 3 equivalents of THF relative to the sec-butyllithium were added, and polymerization was carried out at -15°C for 1 hour. At this time, the polymerization solution was sampled 15 minutes and 30 minutes after the addition of sec-butyllithium, and the polymerization conversion was measured.

[0076] <Production Example 2: (Polymer with 0.1 equivalent of sodium t-pentoxide added)> In a 100 mL flask that had been thoroughly purged with nitrogen, 37 mL of methylcyclohexane, 2 mL of tetralin, and 25 mL of p-methyl-α-methyl-styrene were added and stirred at -15°C. Thereafter, 0.5 parts by mass of sec-butyllithium per 100 parts by mass of the monomer, 3 equivalents of THF per sec-butyllithium, and 0.1 equivalents of sodium t-pentoxide per sec-butyllithium were added, and polymerization was carried out at -15°C for 1 hour. At this time, the polymerization solution was sampled 15 minutes and 30 minutes after the addition of sec-butyllithium, and the polymerization conversion was measured.

[0077] <Production Example 3: (Polymer with 0.2 equivalents of sodium t-pentoxide added)> In a 100 mL flask that had been thoroughly purged with nitrogen, 37 mL of methylcyclohexane, 2 mL of tetralin, and 25 mL of p-methyl-α-methyl-styrene were added and stirred at -15°C. Thereafter, 0.5 parts by mass of sec-butyllithium per 100 parts by mass of the monomer, 3 equivalents of THF per sec-butyllithium, and 0.2 equivalents of sodium t-pentoxide per sec-butyllithium were added, and polymerization was carried out at -15°C for 1 hour. At this time, the polymerization solution was sampled 15 minutes and 30 minutes after the addition of sec-butyllithium, and the polymerization conversion was measured.

[0078] Plots of the polymerization conversion rates of the polymers of the samples of Production Examples 1 to 3 and GPC charts of Production Examples 2 and 3 are shown in FIG. 1 and FIG. 2, respectively.

[0079] Figure 1 shows that sodium t-pentoxide is useful in increasing the polymerization rate of p-methyl-α-methyl-styrene. Figure 2 shows GPC curves of samples taken 15 minutes, 30 minutes, and 1 hour after the addition of sec-butyllithium in Production Examples 2 and 3. It was found that in Production Example 3, the peaks broadened as the polymerization time increased. This indicates that an increased amount of the additive tends to impair polymerization controllability. MW(PS) indicates the molecular weight in terms of polystyrene.

[0080] <Production Example 4: Polymer at polymerization temperature of -15°C> In a 100 mL flask that had been thoroughly purged with nitrogen, 37 mL of methylcyclohexane, 2 mL of tetralin, and 25 mL of p-methyl-α-methyl-styrene were added and stirred at -15°C. Thereafter, 0.5 parts by mass of sec-butyllithium relative to 100 parts by mass of the monomer and 3 equivalents of THF relative to the sec-butyllithium were added, and polymerization was carried out for 20 hours at −15° C. The polymerization conversion rate was measured and found to be 93%.

[0081] <Production Example 5: Polymer at polymerization temperature of 0°C> In a 100 mL flask that had been thoroughly purged with nitrogen, 37 mL of methylcyclohexane, 2 mL of tetralin, and 25 mL of p-methyl-α-methyl-styrene were added and stirred at -15°C. Thereafter, 0.5 parts by mass of sec-butyllithium relative to 100 parts by mass of the monomer and 3 equivalents of THF relative to the sec-butyllithium were added, and polymerization was carried out for 20 hours at 0° C. The polymerization conversion rate was measured and found to be 82%.

[0082] <Production Example 6: Polymer at polymerization temperature of 15°C> In a 100 mL flask that had been thoroughly purged with nitrogen, 37 mL of methylcyclohexane, 2 mL of tetralin, and 25 mL of p-methyl-α-methyl-styrene were added and stirred at -15°C. Thereafter, 0.5 parts by mass of sec-butyllithium relative to 100 parts by mass of the monomer and 3 equivalents of THE relative to the sec-butyllithium were added, and polymerization was carried out for 20 hours at 15° C. The polymerization conversion rate was measured and found to be 56%.

[0083] From the results of Production Examples 4 to 6, it was found that the polymerization conversion rate of p-methyl-α-methyl-styrene tends to improve as the polymerization temperature decreases.

[0084] [Production of Block Copolymer] A block copolymer was produced under the following conditions. In the following block copolymers, (H1) in <Production Example 8> was referred to as [Example 1], (H6) in <Production Example 18> was referred to as [Example 2], and (H9) in <Production Example 26> was referred to as [Comparative Example 1].

[0085] <Production Example 7> In a 500 mL flask that had been thoroughly purged with nitrogen, 26 mL of methylcyclohexane, 0.54 mL of tetralin, and 16 mL of p-methyl-α-methyl-styrene were added and stirred at -15°C. Thereafter, 1.8 mL of sec-butyllithium (1.2 mol / L) and 3 equivalents of THF relative to the sec-butyllithium were added, and polymerization was carried out at −15° C. for 6 hours. Subsequently, 138 mL of methylcyclohexane and 20 equivalents of THF relative to sec-butyllithium were added, and 25.7 mL of isoprene was added, followed by polymerization at 40° C. for 20 minutes. Subsequently, 0.5 equivalents of α,α'-dichloroparaxylene (200 mmol / L) relative to the sec-butyllithium was added, and the mixture was stirred at 40°C for 10 minutes. The block copolymer (B1) obtained as described above had a p-methyl-α-methyl-styrene content of 44% by mass, a p-methyl-α-methyl-styrene block molecular weight of 7,100, an isoprene block molecular weight of 30,800, a peak top molecular weight of 45,000, and a vinyl bond content of 83%.

[0086] <Production Example 8: Example 1> In an autoclave that had been thoroughly purged with nitrogen, 15 g of the block copolymer (B1) was dissolved in 135 mL of THF. Subsequently, a palladium carbon catalyst (type NX) was added in an amount equal to that of the polymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.99 MPa and a temperature of 180°C. The hydrogenation rate of the resulting block copolymer (H1) was 84%.

[0087] <Production Example 9> In a 500 mL flask that had been thoroughly purged with nitrogen, 16.4 mL of methylcyclohexane and 10.2 mL of p-methyl-α-methyl-styrene were added and stirred at -15°C. Thereafter, 1.2 mL of sec-butyllithium (1.2 mol / L) and 3 equivalents of THF relative to the sec-butyllithium were added, and polymerization was carried out at -15°C for 6 hours. Subsequently, 168 mL of methylcyclohexane and 49.2 mL of isoprene were added, and polymerization was carried out at 40°C for 30 minutes. Subsequently, 0.5 equivalents of α,α'-dichloroparaxylene (200 mmol / L) relative to the sec-butyllithium was added, and the mixture was stirred at 40°C for 10 minutes. The block copolymer (B2) obtained as described above had a p-methyl-α-methyl-styrene content of 18% by mass, a p-methyl-α-methyl-styrene block molecular weight of 6,500, an isoprene block molecular weight of 74,000, a peak top molecular weight of 87,000, and a vinyl bond content of 28%.

[0088] <Production Example 10> In an autoclave whose atmosphere had been thoroughly purged with nitrogen, 15 g of the block copolymer (B2) was dissolved in 135 mL of THF. Subsequently, a palladium carbon catalyst (type NX) was added in an amount equal to that of the polymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.99 MPa and a temperature of 180°C. The hydrogenation rate of the resulting block copolymer (H2) was 58%.

[0089] <Production Example 11> In a 500 mL flask that had been thoroughly purged with nitrogen, 16.4 mL of methylcyclohexane and 10.2 mL of p-methyl-α-methyl-styrene were added and stirred at -15°C. Thereafter, 1.2 mL of sec-butyllithium (1.2 mol / L) and 3 equivalents of THF relative to the sec-butyllithium were added, and polymerization was carried out at −15° C. for 17 hours. Subsequently, 156 mL of methylcyclohexane and 35 mL of isoprene were added, and polymerization was carried out at 40°C for 30 minutes. Subsequently, 0.5 equivalents of α,α'-dichloroparaxylene (200 mmol / L) relative to the sec-butyllithium was added, and the mixture was stirred at 40°C for 10 minutes. The block copolymer (B3) obtained as described above had a p-methyl-α-methyl-styrene content of 25% by mass, a p-methyl-α-methyl-styrene block molecular weight of 6,500, an isoprene block molecular weight of 71,000, a peak top molecular weight of 84,000, and a vinyl bond content of 33%.

[0090] <Production Example 12> In an autoclave that had been thoroughly purged with nitrogen, 15 g of the block copolymer (B3) was dissolved in 135 mL of THF. Subsequently, 2 equivalents of a palladium carbon catalyst (type NX) relative to the polymer were added, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.99 MPa and a temperature of 180°C. The hydrogenation rate of the resulting block copolymer (H3) was 44%.

[0091] <Production Example 13> In an autoclave that had been thoroughly purged with nitrogen, 15 g of the block copolymer (H3) was dissolved in 135 mL of THF. Subsequently, a palladium carbon catalyst (type NX) was added in an amount equal to that of the polymer, and the hydrogenation reaction was carried out again at a hydrogen pressure of 0.99 MPa and a temperature of 180°C. The hydrogenation rate of the resulting block copolymer (H4) was 70%.

[0092] <Production Example 14> In a 500 mL flask that had been thoroughly purged with nitrogen, 20.1 mL of methylcyclohexane and 13.1 mL of p-methyl-α-methyl-styrene were added and stirred at -15°C. Thereafter, 1.5 mL of sec-butyllithium (1.2 mol / L) and 3 equivalents of THF relative to the sec-butyllithium were added, and polymerization was carried out at -15°C for 6 hours. Subsequently, 168 mL of methylcyclohexane, 45 mL of isoprene, and 17 equivalents of THF relative to sec-butyllithium were added, and polymerization was carried out at 40° C. for 30 minutes. Subsequently, 0.5 equivalents of α,α'-dichloroparaxylene (200 mmol / L) relative to the sec-butyllithium was added, and the mixture was stirred at 40°C for 10 minutes. The block copolymer (B4) obtained as described above had a p-methyl-α-methyl-styrene content of 25% by mass, a p-methyl-α-methyl-styrene block molecular weight of 6,600, an isoprene block molecular weight of 53,800, a peak top molecular weight of 67,000, and a vinyl bond content of 60%.

[0093] <Production Example 15> In an autoclave that had been thoroughly purged with nitrogen, 15 g of the block copolymer (B4) was dissolved in 135 mL of THF. Subsequently, a palladium carbon catalyst (type NX) was added in an amount equal to that of the polymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.99 MPa and a temperature of 180°C. The hydrogenation rate of the resulting block copolymer (H5) was 70%.

[0094] <Production Example 16> In a 500 mL flask that had been thoroughly purged with nitrogen, 20.1 mL of methylcyclohexane and 13.1 mL of p-methyl-α-methyl-styrene were added and stirred at -15°C. Thereafter, 1.5 mL of sec-butyllithium (1.2 mol / L) and 3 equivalents of THF relative to the sec-butyllithium were added, and polymerization was carried out at -15°C for 6 hours. Subsequently, 168 mL of methylcyclohexane, 45 mL of isoprene, and 37 equivalents of THF relative to sec-butyllithium were added, and polymerization was carried out at 40° C. for 30 minutes. Subsequently, 0.5 equivalents of α,α'-dichloroparaxylene (200 mmol / L) relative to the sec-butyllithium was added, and the mixture was stirred at 40°C for 10 minutes. The block copolymer (B5) obtained as described above had a p-methyl-α-methyl-styrene content of 24 mass%, a p-methyl-α-methyl-styrene block molecular weight of 6,400, an isoprene block molecular weight of 48,200, a peak top molecular weight of 61,000, and a vinyl bond content of 71%.

[0095] <Production Example 17> In a 500 mL flask that had been thoroughly purged with nitrogen, 18 mL of methylcyclohexane and 14.5 mL of p-methyl-α-methyl-styrene were added, and the mixture was stirred at -15°C. Thereafter, 1.2 mL of sec-butyllithium (1.2 mol / L) and 3 equivalents of THF relative to the sec-butyllithium were added, and polymerization was carried out at -15°C for 6 hours. Subsequently, 138 mL of methylcyclohexane and 32 mL of isoprene were added, and polymerization was carried out at 40°C for 30 minutes. Subsequently, 0.5 equivalents of α,α'-dichloroparaxylene (200 mmol / L) relative to the sec-butyllithium was added, and the mixture was stirred at 40°C for 10 minutes. The block copolymer (B6) obtained as described above had a p-methyl-α-methyl-styrene content of 32 mass%, a p-methyl-α-methyl-styrene block molecular weight of 10,300, an isoprene block molecular weight of 66,400, a peak top molecular weight of 87,000, and a vinyl bond content of 34%.

[0096] <Production Example 18: Example 2> In an autoclave whose atmosphere had been thoroughly purged with nitrogen, 15 g of the block copolymer (B6) was dissolved in 135 mL of THF. Subsequently, 2 equivalents of a palladium carbon catalyst (type NX) relative to the polymer were added, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.99 MPa and a temperature of 180°C. The hydrogenation rate of the resulting block copolymer (H6) was 45%.

[0097] <Production Example 19> In an autoclave that had been thoroughly purged with nitrogen, 15 g of the block copolymer (H6) was dissolved in 135 mL of THF. Subsequently, a palladium carbon catalyst (type NX) was added in an amount equal to that of the polymer, and the hydrogenation reaction was carried out again at a hydrogen pressure of 0.99 MPa and a temperature of 180°C. The hydrogenation rate of the resulting block copolymer (H7) was 70%.

[0098] <Production Example 20> In a 500 mL flask that had been thoroughly purged with nitrogen, 29.3 mL of methylcyclohexane and 17.4 mL of p-methyl-α-methyl-styrene were added, and the mixture was stirred at -15°C. Thereafter, 1 mL of sec-butyllithium (1.2 mol / L) and 3 equivalents of THF relative to the sec-butyllithium were added, and polymerization was carried out at −15° C. for 17 hours. Subsequently, 164 mL of methylcyclohexane and 38.4 mL of isoprene were added, and polymerization was carried out at 40°C for 30 minutes. Subsequently, 0.5 equivalents of α,α'-dichloroparaxylene (200 mmol / L) relative to the sec-butyllithium was added, and the mixture was stirred at 40°C for 10 minutes. The block copolymer (B7) obtained as described above had a p-methyl-α-methyl-styrene content of 32 mass%, a p-methyl-α-methyl-styrene block molecular weight of 10,300, an isoprene block molecular weight of 87,400, a peak top molecular weight of 108,000, and a vinyl bond content of 30%.

[0099] <Production Example 21: Example 3> In a 500 mL flask that had been thoroughly purged with nitrogen, 21.6 mL of methylcyclohexane and 13.1 mL of p-methyl-α-methyl-styrene were added and stirred at -15°C. Thereafter, 1 mL of sec-butyllithium (1.2 mol / L) and 3 equivalents of THF relative to the sec-butyllithium were added, and polymerization was carried out at −15° C. for 17 hours. Subsequently, 162 mL of methylcyclohexane and 42 mL of isoprene were added, and polymerization was carried out at 40°C for 30 minutes. Subsequently, 0.5 equivalents of α,α'-dichloroparaxylene (200 mmol / L) relative to the sec-butyllithium was added, and the mixture was stirred at 40°C for 10 minutes. The block copolymer (B8) obtained as described above had a p-methyl-α-methyl-styrene content of 27% by mass, a p-methyl-α-methyl-styrene block molecular weight of 11,000, an isoprene block molecular weight of 117,000, a peak top molecular weight of 139,000, and a vinyl bond content of 31%.

[0100] <Production Example 22> In a 500 mL flask that had been thoroughly purged with nitrogen, 160 mL of methylcyclohexane and 10.2 mL of styrene were added and stirred at -15°C. Thereafter, 1.2 mL of sec-butyllithium (1.2 mol / L) and 3 equivalents of THF relative to the sec-butyllithium were added, and polymerization was carried out at 40° C. for 1 hour. Subsequently, 49.2 mL of isoprene was added, and polymerization was carried out at 40°C for 30 minutes. Subsequently, 0.5 equivalents of α,α'-dichloroparaxylene (200 mmol / L) relative to the sec-butyllithium was added, and the mixture was stirred at 40°C for 10 minutes. The block copolymer (B9) obtained as described above had a styrene content of 18% by mass, a styrene block molecular weight of 6,400, an isoprene block molecular weight of 76,200, a peak top molecular weight of 89,000, and a vinyl bond content of 30%.

[0101] <Production Example 23> In a 500 mL flask that had been thoroughly purged with nitrogen, 160 mL of methylcyclohexane and 10.2 mL of styrene were added and stirred at -15°C. Thereafter, 1.2 mL of sec-butyllithium (1.2 mol / L) and 3 equivalents of THF relative to the sec-butyllithium were added, and polymerization was carried out at 40° C. for 1 hour. Subsequently, 35 mL of isoprene was added, and polymerization was carried out at 40°C for 30 minutes. Subsequently, 0.5 equivalents of α,α'-dichloroparaxylene (200 mmol / L) relative to the sec-butyllithium was added, and the mixture was stirred at 40°C for 10 minutes. The block copolymer (B10) obtained as described above had a styrene content of 27% by mass, a styrene block molecular weight of 6,500, an isoprene block molecular weight of 71,000, a peak top molecular weight of 84,000, and a vinyl bond content of 21%.

[0102] <Production Example: 24> In an autoclave that had been thoroughly purged with nitrogen, 15 g of the block copolymer (B10) was dissolved in 135 mL of THF. Subsequently, palladium carbon catalyst (type NX) was added in an amount of 2 equivalents relative to the polymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.99 MPa and a temperature of 150°C. The hydrogenation rate of the resulting block copolymer (H8) was 70%.

[0103] <Production Example 25> In a 500 mL flask that had been thoroughly purged with nitrogen, 150 mL of methylcyclohexane and 14.5 mL of styrene were added and stirred at -15°C. Thereafter, 1.2 mL of sec-butyllithium (1.2 mol / L) and 3 equivalents of THF relative to the sec-butyllithium were added, and polymerization was carried out at 40° C. for 1 hour. Subsequently, 32 mL of isoprene was added, and polymerization was carried out at 40°C for 30 minutes. Subsequently, 0.5 equivalents of α,α'-dichloroparaxylene (200 mmol / L) relative to the sec-butyllithium was added, and the mixture was stirred at 40°C for 10 minutes. The block copolymer (B11) obtained as described above had a styrene content of 32% by mass, a styrene block molecular weight of 10,000, an isoprene block molecular weight of 68,000, a peak top molecular weight of 88,000, and a vinyl bond content of 30%.

[0104] <Production Example 26: Comparative Example 1> In an autoclave whose atmosphere had been thoroughly purged with nitrogen, 15 g of the block copolymer (B11) was dissolved in 135 mL of THF. Subsequently, 2 equivalents of a palladium carbon catalyst (type NX) relative to the polymer were added, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.99 MPa and a temperature of 180°C. The hydrogenation rate of the resulting block copolymer (H9) was 70%.

[0105] <Production Example 27> In a 500 mL flask that had been thoroughly purged with nitrogen, 150 mL of methylcyclohexane and 14.5 mL of styrene were added and stirred at -15°C. Thereafter, 1.2 mL of sec-butyllithium (1.2 mol / L) and 3 equivalents of THF relative to the sec-butyllithium were added, and polymerization was carried out at 40° C. for 1 hour. Subsequently, 32 mL of isoprene was added, and polymerization was carried out at 60°C for 30 minutes. Subsequently, 0.5 equivalents of α,α'-dichloroparaxylene (200 mmol / L) relative to the sec-butyllithium was added, and the mixture was stirred at 60°C for 10 minutes. The block copolymer (B12) obtained as described above had a styrene content of 33% by mass, a styrene block molecular weight of 10,000, an isoprene block molecular weight of 68,000, a peak top molecular weight of 88,000, and a vinyl bond content of 6%.

[0106] [Table 1]

[0107] [Table 2]

[0108] [Table 3]

[0109] As shown in Tables 1 to 3, it was found that the block copolymer using p-methyl-α-methyl-styrene has a higher glass transition point than the block copolymer using styrene, and is superior in high-temperature properties. Furthermore, it was found that the block copolymer using p-methyl-α-methyl-styrene exhibited higher modulus and strength upon curing than the block copolymer using styrene. [Industrial Applicability]

[0110] The block copolymer of the present invention has industrial applicability as a plastic modifier, automobile parts, medical molded products, asphalt modifier, footwear, molded products such as food containers, packaging materials, adhesive sheets, and materials for home appliances and industrial parts.

Claims

1. at least one polymer block based on vinyl aromatic monomer units; at least one polymer block mainly composed of conjugated diene monomer units; , and The following conditions (1) to (4) are met: Block copolymer. <Condition (1)> The vinyl aromatic compound forming the vinyl aromatic monomer unit has a structure represented by the following formula (1). 【Chemistry 1】 (In formula (1), R １ represents an alkyl group.) <Condition (2)> The content of the polymer block mainly composed of vinyl aromatic monomer units is It is 10% by mass to 50% by mass. <Condition (3)> The content of the polymer block mainly composed of conjugated diene monomer units is It is 90% by mass to 50% by mass. <Condition (4)> The peak molecular weight (Mp) of the block copolymer is 40,000 or more.

2. The vinyl aromatic compound is p-methyl-α-methylstyrene. The block copolymer of claim 1 .

3. The number average molecular weight of the polymer block mainly composed of vinyl aromatic monomer units is 8,000 or more and 40,000 or less, The block copolymer of claim 1 .

4. the glass transition temperature (Tg) of the block copolymer derived from the polymer block mainly composed of vinyl aromatic monomer units is 110°C or higher; The block copolymer of claim 1 .

5. the polymer block mainly composed of conjugated diene monomer units is hydrogenated; The block copolymer of claim 1 .

6. A resin composition comprising the block copolymer according to claim 1 .

7. A cured product of the resin composition according to claim 6.

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