Resin Composition and Molded Body

Abstract

Provided are: a resin composition from which a molded body having excellent dry gripping properties and wet gripping properties can be formed; and a molded body using said resin composition.　This resin composition comprising an ethylene-vinyl acetate copolymer (I) and a hydrogenated block copolymer (II) is characterized in that: the hydrogenated block copolymer (II) is a hydrogenated product of a block copolymer (P) which contains a polymer block (A) containing an aromatic vinyl compound-derived structural unit, and a polymer block (B) containing 1-100 mass% of a farnesene-derived structural unit (b1) and 99-0 mass% of a structural unit (b2) derived from conjugated diene other than farnesene, wherein the hydrogenation rate of a carbon-carbon double bond in a conjugated diene-derived structural unit in the block copolymer (P) is at least 70 mol%; and in said resin composition, the content of the ethylene-vinyl acetate copolymer (I) is 40-95 mass%, and the content of the hydrogenated block copolymer (II) is 5-60 mass%.

Description

Technical Field

[0001] The present invention relates to a resin composition containing at least an ethylene-vinyl acetate copolymer and a hydrogenated block copolymer having a structural unit derived from farnesene, and a molded article using the resin composition.

Background Art

[0002] Rubber compositions obtained by mixing various rubbers with thermoplastic elastomers such as styrene-based elastomers and olefin-based elastomers are used in a wide range of fields such as shoe soles for footwear, various tires, building materials such as packings, and mechanical parts because of their excellent mechanical properties and flexibility. However, rubber compositions containing thermoplastic elastomers become slippery when moisture adheres thereto, which causes problems particularly in applications such as shoe soles for footwear and various tires because of the high risk involved.

[0003] Therefore, studies have been conducted to improve the wet grip property of rubber compositions containing thermoplastic elastomers and rubber components. For example, resin compositions have been proposed in which the number average molecular weight of a thermoplastic elastomer or the glass transition temperature of a rubber component is specified, or a tackifier resin or a hydrogenated block copolymer is contained (for example, Patent Documents 1 to 8). In addition, resin compositions containing a hydrogenated block copolymer containing a polymer block containing a structural unit derived from farnesene have been proposed (for example, Patent Document 9).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

Patent Document 8

Patent Document 9

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, with the technologies disclosed in Patent Documents 1 to 8, it is impossible to obtain a resin composition having an excellent balance between dry grip properties and wet grip properties, and further improvement is required. Note that Patent Documents 1 to 8 do not describe block copolymers containing a polymer block derived from an aromatic vinyl compound and a polymer block containing a structural unit derived from farnesene, and hydrogenated products thereof. In addition, although the resin composition disclosed in Patent Document 9 has an excellent balance between dry grip properties and wet grip properties, further improvement is required.

[0006] Therefore, an object of the present invention is to provide a resin composition capable of providing a molded article excellent in dry grip properties and wet grip properties, and a molded article using the resin composition.

Means for Solving the Problems

[0007] As a result of intensive studies in view of the above problems, the present inventors have found that the above problems can be solved by using an ethylene-vinyl acetate copolymer and a specific hydrogenated block copolymer in specific blending amounts.

[0008] That is, the present invention relates to the following [1] to

[11] . [1] A resin composition containing an ethylene-vinyl acetate copolymer (I) and a hydrogenated block copolymer (II), wherein the hydrogenated block copolymer (II) is a hydrogenated product of a block copolymer (P) containing a polymer block (A) containing structural units derived from an aromatic vinyl compound and a polymer block (B) containing 1 to 100% by mass of structural units (b1) derived from farnesene and 99 to 0% by mass of structural units (b2) derived from a conjugated diene other than farnesene, and the hydrogenation rate of the carbon-carbon double bonds in the structural units derived from the conjugated diene in the block copolymer (P) is 70 mol% or more, The resin composition is characterized in that the content of the ethylene-vinyl acetate copolymer (I) in the resin composition is 40 to 95% by mass, and the content of the hydrogenated block copolymer (II) is 5 to 60% by mass. [2] The resin composition according to [1], having a biomass content of 4 to 70% by mass. [3] The resin composition according to [1] or [2], wherein the content of the structural units derived from vinyl acetate in the ethylene-vinyl acetate copolymer (I) is 5 to 60% by mass. [4] The resin composition according to any one of [1] to [3], wherein the aromatic vinyl compound is styrene. [5] The resin composition according to any one of [1] to [4], wherein the conjugated diene other than farnesene is at least one selected from butadiene, isoprene, and myrcene. [6] The resin composition according to any one of [1] to [5], wherein the mass ratio [(A) / (B)] of the polymer block (A) to the polymer block (B) is 10 / 90 to 40 / 60. [7] The resin composition according to any one of [1] to [6], wherein the hydrogenated block copolymer (II) further has a polymer block (C) consisting only of structural units derived from a conjugated diene other than farnesene. [8] The SP value of the ethylene-vinyl acetate copolymer (I) is 4.0 to 10.0 (cal / cm 3 ) 1 / 2 and the SP value of the hydrogenated block copolymer (II) is 6.0 to 10.0 (cal / cm 3 )1 / 2 The resin composition according to any one of [1] to [7] above. [9] The resin composition according to any one of [1] to [8] above, wherein the peak top molecular weight of the hydrogenated block copolymer (II) is 50,000 to 500,000.

[10] The resin composition according to any one of [1] to [9] above, wherein the peak top molecular weight of the polymer block (A) is 5,000 to 100,000.

[11] A molded article using at least a part of the resin composition according to any one of [1] to

[10] above. [Advantages of the Invention]

[0009] According to the present invention, there can be provided a resin composition capable of giving a molded article excellent in dry grip property and wet grip property, and a molded article using the resin composition. [Embodiments for Carrying Out the Invention]

[0010] [Resin Composition] The resin composition of the present invention is a resin composition containing an ethylene-vinyl acetate copolymer (I) and a hydrogenated block copolymer (II), wherein the hydrogenated block copolymer (II) is a polymer block (A) containing a structural unit derived from an aromatic vinyl compound, and a polymer block (B) containing 1 to 100% by mass of a structural unit (b1) derived from farnesene and 99 to 0% by mass of a structural unit (b2) derived from a conjugated diene other than farnesene, and is a hydrogenated product of a block copolymer (P), and the hydrogenation rate of the carbon-carbon double bond in the structural unit derived from the conjugated diene in the block copolymer (P) is 70 mol% or more, and the content of the ethylene-vinyl acetate copolymer (I) in the resin composition is 40 to 95% by mass, and the content of the hydrogenated block copolymer (II) is 5 to 60% by mass. According to the resin composition of the present invention, since the ethylene-vinyl acetate copolymer (I) and the hydrogenated block copolymer (II) are used in specific blending amounts, when this is made into a molded article, a molded article excellent in dry grip property and wet grip property can be obtained.

[0011] <Ethylene-vinyl acetate copolymer (I)> As the ethylene-vinyl acetate copolymer (I) used in the present invention, the content ratio (VA ratio) of the structural unit derived from vinyl acetate in the copolymer is preferably 5 to 60% by mass, more preferably 5 to 55% by mass, and still more preferably 10 to 50% by mass. When the content ratio of the structural unit derived from vinyl acetate in the ethylene-vinyl acetate copolymer is within the above range, it is easy to obtain a molded article excellent in dry grip property and wet grip property.

[0012] The SP value of the ethylene-vinyl acetate copolymer (I) is preferably 4.0 to 10.0 (cal / cm 3 ) 1 / 2 more preferably 5.0 to 9.5 (cal / cm 3 ) 1 / 2 even more preferably 6.0 to 9.0 (cal / cm 3 ) 1 / 2 and still more preferably 7.0 to 9.0 (cal / cm 3 ) 1 / 2 and even more preferably. When the SP value of the ethylene-vinyl acetate copolymer (I) is within the above range, it is easy to improve the compatibility with the hydrogenated block copolymer (II), and the dry grip property and wet grip property of the molded article can be improved. In the present invention, the SP value (solubility parameter) is calculated based on the estimation method of D.W. Van Krevelen, and the estimation method is calculated based on the cohesive energy density and the molar molecular volume (D.W. Van Krevelen, Klaas te Nijenhuis, "Properties of Polymers, Fourth Edition" Elsevier Science, 2009).

[0013] The MFR (melt flow rate) of the ethylene-vinyl acetate copolymer (I) at a temperature of 190 °C and a load of 2.16 kg is preferably from 0.5 to 20.0 g / 10 min, more preferably from 1.0 to 15.0 g / 10 min, and even more preferably from 1.2 to 10.0 g / 10 min. When the MFR is within the above range, the foaming property becomes good.

[0014] In addition, the ethylene-vinyl acetate copolymer (I) used in the present invention includes, in addition to ethylene and vinyl acetate, a copolymer containing vinyl alcohol formed by hydrolyzing a part of vinyl acetate, which is also included in the ethylene-vinyl acetate copolymer (I) of the present application. In this case, the vinyl acetate content is defined as the total amount of vinyl acetate and vinyl alcohol in the copolymer, and the vinyl acetate content is defined.

[0015] Commercially available products of the ethylene-vinyl acetate copolymer (I) that can be used in the present invention include, for example, "Evaflex" (trade name, registered trademark) manufactured by Mitsui Dow Polychemical Co., Ltd., "Ultra Sen" (trade name, registered trademark) manufactured by Tosoh Corporation, "UBE Polyethylene" (trade name, registered trademark) manufactured by Ube Industries, Ltd., "Suntech" (trade name, registered trademark) manufactured by Asahi Kasei Chemicals Corporation, "Ethylene Vinyl Acetate Copolymer NUC" (brand name) manufactured by NUC Corporation, and the like.

[0016] <Hydrogenated block copolymer (II)> The hydrogenated block copolymer (II) used in the present invention is a hydrogenated product of a block copolymer (P) containing a polymer block (A) containing a structural unit derived from an aromatic vinyl compound and a polymer block (B) containing 1 to 100% by mass of a structural unit (b1) derived from farnesene and 99 to 0% by mass of a structural unit (b2) derived from a conjugated diene other than farnesene, and is a hydrogenated product in which the hydrogenation rate of the carbon-carbon double bond in the structural unit derived from the conjugated diene in the block copolymer (P) is 70 mol% or more. In the present invention, by using the hydrogenated block copolymer, a resin composition capable of providing a molded article excellent in dry grip property and wet grip property can be obtained.

[0017] [Polymer block (A)] Examples of the aromatic vinyl compound constituting the polymer block (A) include styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-propylstyrene, 4-t-butylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, 2,4,6-trimethylstyrene, 2-ethyl-4-benzylstyrene, 4-(phenylbutyl)styrene, 1-vinylnaphthalene, 2-vinylnaphthalene, vinylanthracene, N,N-diethyl-4-aminoethylstyrene, vinylpyridine, 4-methoxystyrene, monochlorostyrene, dichlorostyrene, and divinylbenzene. These aromatic vinyl compounds may be used alone or in combination of two or more. Among these, styrene, α-methylstyrene, and 4-methylstyrene are more preferable, and styrene is even more preferable.

[0018] The peak top molecular weight (Mp) of the polymer block (A) is preferably from 5,000 to 100,000, more preferably from 6,000 to 75,000, and even more preferably from 7,000 to 50,000. When the peak top molecular weight (Mp) of the polymer block (A) composed of structural units derived from styrene is within the above range, a resin composition can be obtained that gives a molded article excellent in dry grip properties and wet grip properties while improving the handleability during production. In addition, the peak top molecular weight (Mp) in this specification means the value measured by the method described in the examples below. In addition, all of the "peak top molecular weights" described in this specification and the claims are peak top molecular weights in terms of standard polystyrene determined by gel permeation chromatography (GPC) measurement, and more specifically, values measured according to the method described in the examples.

[0019] The peak top molecular weight of each polymer block of the block copolymer (P) can be determined by measuring the sampled liquid each time the polymerization of each polymer block is completed in the production process. For example, when synthesizing a triblock copolymer having an a1-b-a2 structure by sequentially polymerizing a1, b, and a2 in this order, the peak top molecular weight of the first polymer block a1 can be determined by subjecting the liquid sampled when the polymerization of a1 is completed to GPC measurement. Further, the peak top molecular weight of the polymer block b can be determined by subjecting the liquid sampled when the polymerization of b is completed to GPC measurement to obtain the peak top molecular weight of the diblock copolymer having an a1-b structure, and subtracting the peak top molecular weight of the polymer block a1 from that value. Furthermore, the peak top molecular weight of the polymer block a2 can be determined by subjecting the liquid sampled when the polymerization of a2 is completed to GPC measurement to obtain the peak top molecular weight of the triblock copolymer having an a1-b-a2 structure, and subtracting the peak top molecular weight of the diblock copolymer having an a1-b structure from that value.

[0020] [Polymer block (B)] The polymer block (B) contains 1 to 100% by mass of a structural unit (b1) derived from farnesene and 99 to 0% by mass of a structural unit (b2) derived from a conjugated diene other than farnesene. The farnesene constituting the structural unit (b1) derived from farnesene may be either α-farnesene or β-farnesene represented by the following formula (I), but from the viewpoint of ease of production of the hydrogenated block copolymer, it is preferable to use β-farnesene. Note that α-farnesene and β-farnesene may be used in combination.

[0021] [Chemical formula]

[0022] Examples of the conjugated diene that constitutes the structural unit (b2) derived from a conjugated diene other than farnesene include butadiene, isoprene, 2,3-dimethylbutadiene, 2-phenyl-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 1,3-octadiene, 1,3-cyclohexadiene, 2-methyl-1,3-octadiene, 1,3,7-octatriene, myrcene, farnesene, chloroprene, and the like. These may be used alone or in combination of two or more. Among these, it is preferably at least one selected from butadiene, isoprene, and myrcene.

[0023] The polymer block (B) in the present invention contains 1 to 100% by mass of the structural unit (b1) derived from farnesene and 99 to 0% by mass of the structural unit (b2) derived from a conjugated diene other than farnesene. When the content of each structural unit is within the above range, the dry grip property and wet grip property of the obtained molded body are improved. From this viewpoint, the content of the structural unit (b1) derived from farnesene is more preferably 30 to 100% by mass, still more preferably 50 to 100% by mass, and even more preferably 70 to 100% by mass. On the other hand, the content of the structural unit (b2) derived from a conjugated diene other than farnesene is more preferably 0 to 70% by mass, still more preferably 0 to 50% by mass, and even more preferably 0 to 30% by mass.

[0024] The mass ratio [(A) / (B)] of the polymer block (A) to the polymer block (B) is preferably 10 / 90 to 40 / 60. When the content of the polymer block (A) is at least the lower limit value, a hydrogenated block copolymer excellent in flexibility and moldability can be obtained. On the other hand, when the mass ratio is at most the upper limit value, the compatibility and moldability with the ethylene-vinyl acetate copolymer (I) are improved. From this viewpoint, the mass ratio [(A) / (B)] of the polymer block (A) to the polymer block (B) is more preferably 15 / 85 to 30 / 70, and still more preferably 15 / 85 to 35 / 65.

[0025] [Polymer block (C)] The hydrogenated block copolymer (II) obtained by hydrogenating the block copolymer (P) preferably contains, in addition to the aforementioned polymer blocks (A) and (B), a polymer block (C) containing structural units derived from conjugated dienes other than farnesene. In the polymer block (C) in the present invention, the content of the structural units derived from farnesene is preferably less than 1% by mass, and the content of the structural units derived from conjugated dienes other than farnesene is preferably 1 to 100% by mass. Examples of the conjugated dienes other than farnesene that constitute the polymer block (C) are the same as those of the conjugated dienes other than farnesene that constitute the aforementioned polymer block (B). Among them, isoprene, butadiene, and myrcene are preferable as the conjugated dienes that constitute the polymer block (C), and isoprene and butadiene are more preferable.

[0026] The content of the structural units derived from conjugated dienes other than farnesene in the polymer block (C) is preferably 60 to 100% by mass, more preferably 80 to 100% by mass, still more preferably 90 to 100% by mass, and even more preferably substantially 100% by mass, that is, consisting only of the structural units derived from conjugated dienes other than farnesene. In addition, the content of the structural units derived from farnesene in the polymer block (C) is preferably 0% by mass. Further, the polymer block (C) may contain other structural units other than the structural units derived from farnesene and the structural units derived from conjugated dienes other than farnesene. Examples of the monomers constituting such other structural units include unsaturated hydrocarbon compounds such as propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene; functional group-containing unsaturated compounds such as acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, acrylonitrile, methacrylonitrile, maleic acid, fumaric acid, crotonic acid, itaconic acid, 2-acryloylethane sulfonic acid, 2-methacryloylethane sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, 2-methacrylamido-2-methylpropane sulfonic acid, vinyl sulfonic acid, vinyl acetate, methyl vinyl ether; and the like.

[0027] In the polymer block (C), the total content of the structural units derived from farnesene and the structural units derived from conjugated dienes other than farnesene is preferably 60% by mass or more, more preferably 80% by mass or more, and still more preferably 100% by mass.

[0028] 〔Bonding form〕 The hydrogenated block copolymer (II) is a hydrogenated product of a block copolymer (P) containing at least one polymer block (A) and at least one polymer block (B), and may contain a polymer block (C) as necessary. The bonding forms of the polymer block (A), the polymer block (B), and the polymer block (C) are not particularly limited, and may be linear, branched, radial, or a combination of two or more thereof. Among them, a form in which each block is linearly bonded is preferable. When the polymer block (A) is represented by a, the polymer block (B) is represented by b, and the polymer block (C) is represented by c, (a-b) l , a-(b-a) m , b-(a-b) n , bonding forms represented by b-a-c-a-b and a-b-a are preferable. Note that l, m, and n each independently represent an integer of 1 or more. In addition, when the block copolymer (P) has two or more polymer blocks (A) or two or more polymer blocks (B), each polymer block may be a polymer block composed of the same structural unit or a polymer block composed of different structural units. For example, in the two polymer blocks (A) in the triblock copolymer represented by [a-b-a], the aromatic vinyl compounds may be the same or different in type.

[0029] The hydrogenated block copolymer (II) may be one in which the same type of block polymers are linearly bonded via a bifunctional coupling agent or the like. For example, the copolymer represented by b-a-c-a-b may be a copolymer in which the copolymers represented by b-a-c are coupled to form a copolymer represented by b-a-c-x-c-a-b (x represents a coupling residue). In this case, the portion represented by c-x-c is regarded as one block c. Examples of the coupling agent include alkoxysilane compounds such as diethoxydimethylsilane, trimethoxymethylsilane, triethoxymethylsilane, tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, tetrakis(2-ethylhexyloxy)silane, bis(triethoxysilyl)ethane, 3-aminopropyltriethoxysilane; divinylbenzene; polyvalent epoxy compounds such as epoxidized 1,2-polybutadiene, epoxidized soybean oil, tetraglycidyl-1,3-bis(aminomethyl)cyclohexane; and halides such as tin tetrachloride, tetrachlorosilane, trichlorosilane, trichloromethylsilane, dichlorodimethylsilane, dibromodimethylsilane.

[0030] The peak top molecular weight (Mp) of the hydrogenated block copolymer (II) is preferably from 50,000 to 500,000, more preferably from 70,000 to 400,000, still more preferably from 90,000 to 300,000, and even more preferably from 100,000 to 250,000, from the viewpoint of improving the moldability. The peak top molecular weight (Mp) in this specification means the value measured by the method described in the examples below.

[0031] The molecular weight distribution (Mw / Mn) of the hydrogenated block copolymer (II) is preferably from 1.00 to 4.00, more preferably from 1.00 to 3.00, and still more preferably from 1.00 to 2.00. When the molecular weight distribution is within the above range, the variation in the viscosity of the hydrogenated block copolymer (II) is small and it is easy to handle.

[0032] <Method for producing hydrogenated block copolymer (II)> The hydrogenated block copolymer (II) can be preferably produced, for example, by a polymerization step of obtaining a block copolymer (P) by anionic polymerization and a step of hydrogenating the carbon-carbon double bonds in the polymer block (B) and the polymer block (C) in the block copolymer (P). 〔Polymerization step〕 The block copolymer (P) can be produced by a solution polymerization method or the methods described in JP-T-2012-502135 and JP-T-2012-502136. Among them, the solution polymerization method is preferable, and for example, known methods such as ionic polymerization methods such as anionic polymerization and cationic polymerization, and radical polymerization methods can be applied. Among them, the anionic polymerization method is preferable. As the anionic polymerization method, an aromatic vinyl compound, farnesene, and / or a conjugated diene other than farnesene are sequentially added in the presence of a solvent, an anionic polymerization initiator, and, if necessary, a Lewis base to obtain the block copolymer (P). Examples of the anionic polymerization initiator include alkali metals such as lithium, sodium, and potassium; alkaline earth metals such as beryllium, magnesium, calcium, strontium, and barium; lanthanoid rare earth metals such as lanthanum and neodymium; and compounds containing the alkali metals, alkaline earth metals, or lanthanoid rare earth metals. Among them, alkali metals and compounds containing alkali metals are preferred, and organic alkali metal compounds are more preferred.

[0033] Examples of the organic alkali metal compound include organic lithium compounds such as methyllithium, ethyllithium, n-butyllithium, sec-butyllithium, t-butyllithium, hexyllithium, phenyllithium, stilbenelithium, dilithiomethane, dilithionaphthalene, 1,4-dithiobutane, 1,4-dithio-2-ethylcyclohexane, and 1,3,5-trilithiobenzene; and sodium naphthalene, potassium naphthalene, etc. Among them, organic lithium compounds are preferred, n-butyllithium and sec-butyllithium are more preferred, and sec-butyllithium is particularly preferred. Note that the organic alkali metal compound may be reacted with a secondary amine such as diisopropylamine, dibutylamine, dihexylamine, or dibenzylamine and used as an organic alkali metal amide. The amount of the organic alkali metal compound used in the polymerization varies depending on the molecular weight of the block copolymer (P), but is usually in the range of 0.01 to 3% by mass based on the total amount of the aromatic vinyl compound, farnesene, and conjugated diene other than farnesene.

[0034] The solvent is not particularly limited as long as it does not adversely affect the anionic polymerization reaction. Examples include saturated aliphatic hydrocarbons such as n-pentane, isopentane, n-hexane, n-heptane, and isooctane; saturated alicyclic hydrocarbons such as cyclopentane, cyclohexane, and methylcyclopentane; and aromatic hydrocarbons such as benzene, toluene, and xylene. These may be used alone or in combination of two or more. There is no particular limitation on the amount of the solvent used.

[0035] The Lewis base has a role in controlling the microstructure in the structural unit derived from farnesene and the structural unit derived from conjugated dienes other than farnesene. Examples of such Lewis bases include ether compounds such as dibutyl ether, diethyl ether, tetrahydrofuran, dioxane, ethylene glycol diethyl ether, ditetrahydrofuryl propane; pyridine; tertiary amines such as N,N,N’,N’-tetramethylethylenediamine, trimethylamine; alkali metal alkoxides such as potassium t-butoxide; phosphine compounds and the like. When using a Lewis base, its amount is usually preferably in the range of 0.01 to 1000 molar equivalents relative to 1 mole of the anionic polymerization initiator.

[0036] The temperature of the polymerization reaction is usually in the range of -80 to 150 °C, preferably 0 to 100 °C, more preferably 10 to 90 °C. The form of the polymerization reaction may be batch or continuous. The block copolymer (P) can be produced by continuously or intermittently feeding each monomer into the polymerization reaction solution so that the abundance of the aromatic vinyl compound, farnesene and / or conjugated dienes other than farnesene in the polymerization reaction system is within a specific range, or by sequentially polymerizing each monomer in the polymerization reaction solution so that they have a specific ratio. The polymerization reaction can be stopped by adding an alcohol such as methanol or isopropanol as a polymerization terminator. The obtained polymerization reaction solution is poured into a poor solvent such as methanol to precipitate the block copolymer (P), or the polymerization reaction solution is washed with water, separated, and dried to isolate the block copolymer (P).

[0037] In this polymerization step, an unmodified block copolymer (P) may be obtained as described above, but before the subsequent hydrogenation step, a functional group may be introduced into the block copolymer (P) to obtain a modified block copolymer (P). Examples of the functional groups that can be introduced include an amino group, an alkoxysilyl group, a hydroxyl group, an epoxy group, a carboxy group, a carbonyl group, a mercapto group, an isocyanate group, a chloro group, an acid anhydride, and the like. Examples of the method for modifying the block copolymer (P) include, for example, before adding a polymerization terminator, tin tetrachloride, tetrachlorosilane, dichlorodimethylsilane, dimethyldiethoxysilane, tetramethoxysilane, tetraethoxysilane, 3-aminopropyltriethoxysilane, tetraglycidyl-1,3-bis(aminomethyl)cyclohexane, 2,4-tolylene diisocyanate, 4,4'-bis(diethylamino)benzophenone, N-vinylpyrrolidone and other modifiers that can react with the polymerization active terminal, or the method of adding other modifiers described in JP-A-2011-132298. Further, it is also possible to use a graft copolymerized maleic anhydride or the like to the copolymer after isolation. The position where the functional group is introduced may be the polymerization terminal or the side chain of the block copolymer (P). Further, the above functional groups may be used alone or in combination of two or more. The above modifier is preferably in the range of usually 0.01 to 10 molar equivalents with respect to the anionic polymerization initiator.

[0038] 〔Hydrogenation step〕 By subjecting the block copolymer (P) or the modified block copolymer (P) obtained by the above method to a hydrogenation step, a hydrogenated block copolymer (II) can be obtained. As the hydrogenation method, a known method can be used. For example, in a solution obtained by dissolving the block copolymer (P) in a solvent that does not affect the hydrogenation reaction, a Ziegler catalyst; a nickel, platinum, palladium, ruthenium or rhodium metal catalyst supported on carbon, silica, diatomaceous earth, etc.; an organometallic complex having a cobalt, nickel, palladium, rhodium or ruthenium metal, etc. are present as a hydrogenation catalyst to carry out a hydrogenation reaction. In the hydrogenation step, a hydrogenation catalyst may be added to the polymerization reaction solution containing the block copolymer (P) obtained by the above-described method for producing the block copolymer (P) to carry out a hydrogenation reaction. In the present invention, palladium carbon in which palladium is supported on carbon is preferred. In the hydrogenation reaction, the hydrogen pressure is preferably 0.1 to 20 MPa, the reaction temperature is preferably 100 to 200 ° C, and the reaction time is preferably 1 to 20 hours.

[0039] From the viewpoint of obtaining a thermoplastic elastomer composition excellent in flexibility and moldability, the hydrogenation ratio of the carbon-carbon double bond in the hydrogenated block copolymer (II) is preferably 70 to 100 mol%, more preferably 80 to 100 mol%, still more preferably 85 to 100 mol%, and even more preferably 90 to 100 mol%. The hydrogenation ratio can be calculated by measuring the 1 1H-NMR of the block copolymer (P) and the hydrogenated block copolymer (II) after hydrogenation.

[0040] The SP value of the hydrogenated block copolymer (II) is preferably 6.0 to 10.0 (cal / cm 3 ) 1 / 2 and more preferably 7.0 to 9.5 (cal / cm 3 ) 1 / 2 and still more preferably 8.0 to 9.0 (cal / cm 3 ) 1 / 2 When the SP value of the hydrogenated block copolymer (II) is within the above range, the compatibility with the ethylene-vinyl acetate copolymer (I) is improved, and the dry grip property and wet grip property of the obtained molded article are improved.

[0041] <Content of ethylene-vinyl acetate copolymer (I) and hydrogenated block copolymer (II)> The content of the ethylene-vinyl acetate copolymer (I) in the resin composition is 40 to 95% by mass, and the content of the hydrogenated block copolymer (II) is 5 to 60% by mass. In the present invention, since the contents of the ethylene-vinyl acetate copolymer (I) and the hydrogenated block copolymer (II) are in the above ranges, a resin composition capable of providing a molded article having excellent dry grip property and wet grip property can be obtained. From the viewpoint of improving the dry grip property and wet grip property of the molded article, the content of the ethylene-vinyl acetate copolymer (I) in the resin composition is preferably 40 to 95% by mass, and more preferably 45 to 95% by mass. On the other hand, from the same viewpoint, the content of the hydrogenated block copolymer (II) is preferably 5 to 60% by mass, more preferably 5 to 55% by mass.

[0042] In the resin composition of the present invention, the total content of the ethylene-vinyl acetate copolymer (I) and the hydrogenated block copolymer (II) is preferably 50 to 95% by mass, more preferably 70 to 95% by mass, and even more preferably 80 to 95% by mass from the viewpoint of more easily improving the slipperiness and abrasion resistance of the resulting molded article and also improving the balance of flexibility and processability.

[0043] <Optional component> [Other resins] The resin composition of the present invention may contain a resin other than the ethylene-vinyl acetate copolymer (I) and the hydrogenated block copolymer (II). Examples of the resin other than the ethylene-vinyl acetate copolymer (I) and the hydrogenated block copolymer (II) include a thermoplastic elastomer resin or a polyolefin resin. Examples of the thermoplastic elastomer include a styrene-based elastomer, an olefin-based elastomer, a diene-based elastomer, a polyvinyl chloride-based thermoplastic elastomer, a chlorinated polyethylene-based thermoplastic elastomer, a polyurethane-based thermoplastic elastomer, a polyester-based thermoplastic elastomer, a polyamide-based thermoplastic elastomer, a fluororesin-based thermoplastic elastomer, and the like. Examples of the polyolefin resin include polyethylene such as linear low-density polyethylene and high-density polyethylene. Among these, linear low-density polyethylene is preferred from the viewpoint of improving compatibility with the ethylene-vinyl acetate copolymer (I).

[0044] Examples of the olefin-based elastomer include polyisobutylene, an ethylene-propylene copolymer, an ethylene-propylene-diene terpolymer, and a thermoplastic elastomer in which ethylene-propylene rubber (EPDM, EPM) is finely dispersed in polypropylene (PP). Examples of commercially available products of the thermoplastic elastomer and the polyolefin resin include ENGAGE8480 (polyolefin elastomer, manufactured by Dow Chemical Company) and STN7006 (bio LDPE, manufactured by Braskem).

[0045] When the resin composition of the present invention contains other resins, the content thereof is preferably 5 to 80 parts by mass, more preferably 10 to 75 parts by mass, and still more preferably 15 to 70 parts by mass with respect to 100 parts by mass in total of the ethylene-vinyl acetate copolymer (I) and the hydrogenated block copolymer (II). When the content of the other resin is within the above range, in addition to improving the dry grip property and the wet grip property, the abrasion resistance and flexibility can be improved.

[0046] [Crosslinking agent] The resin composition of the present invention preferably contains a crosslinking agent. The crosslinking agent is preferably one that undergoes a crosslinking reaction only with the carbon-carbon double bond or its α-methylene in the structural unit derived from a conjugated diene. Here, α-methylene refers to the methylene adjacent to the carbon-carbon double bond. By containing such a crosslinking agent, only the carbon-carbon double bond or the α-methylene of the carbon-carbon double bond in the block copolymer (II) is crosslinked, and it is possible to maintain excellent flexibility while being difficult to slip and having excellent abrasion resistance.

[0047] Examples of the crosslinking agent include radical generators, sulfur, and sulfur-containing compounds. From the viewpoint of improving the abrasion resistance of the molded body and the like, a radical generator is more preferable. Examples of the radical generator include organic peroxides such as dicumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, 1,3-bis(t-butylperoxyisopropyl)benzene, α,α'-bis(t-butylperoxy)diisopropylbenzene, 3,3,5-trimethylcyclohexane, n-butyl-4,4-bis(t-butylperoxy)valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, t-butyl peroxybenzoate, t-butyl peroxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, t-butyl cumyl peroxide, etc. These may be used alone or in combination of two or more. Examples of commercially available products of the radical generator include Percumyl D-40 (dicumyl peroxide, purity 40% by mass, manufactured by NOF Corporation), etc.

[0048] Sulfur can be used without particular limitation, and for example, any of fine sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, etc. may be used. Examples of the sulfur-containing compound include sulfur monochloride, sulfur dichloride, disulfide compounds, triazine thiols, etc. Examples of the crosslinking agent include phenolic resins such as alkylphenol resins and brominated alkylphenol resins; combinations such as p-quinonedioxime and lead dioxide, p,p'-dibenzoylquinonedioxime and lead sesquioxide, etc. can also be used.

[0049] When the resin composition of the present invention contains a crosslinking agent, the content thereof is preferably 0.1 to 15 parts by mass, more preferably 0.5 to 10 parts by mass, and still more preferably 1.0 to 8 parts by mass with respect to 100 parts by mass in total of the ethylene-vinyl acetate copolymer (I) and the hydrogenated block copolymer (II). When the content of the crosslinking agent is within the above range, it becomes possible to improve the abrasion resistance and the hardness of the obtained molded article.

[0050] [Crosslinking accelerator] The resin composition of the present invention may contain a crosslinking accelerator. Examples of the crosslinking accelerator include thiazoles such as N,N-diisopropyl-2-benzothiazole-sulfenamide, 2-mercaptobenzothiazole, di-2-benzothiazolyldisulfide, 2-(4-morpholinodithio)benzothiazole; guanidines such as diphenylguanidine and triphenylguanidine; aldehyde-amine reaction products or aldehyde-ammonia reaction products such as butyraldehyde-aniline reaction product and hexamethylenetetramine-acetaldehyde reaction product; imidazolines such as 2-mercaptoimidazoline; thioureas such as thiocarbanilide, diethylurea, dibutylthiourea, trimethylthiourea, diorthotolylthiourea; thiuram mono- or polysulfides such as tetramethylthiuram monosulfide, tetramethylthiuram disulfide, pentamethylenethiuram tetrasulfide; thiocarbamates such as zinc dimethyldithiocarbamate, zinc ethylphenyldithiocarbamate, sodium dimethyldithiocarbamate, selenium dimethyldithiocarbamate, tellurium diethyldithiocarbamate; xanthates such as zinc dibutylxanthate, etc. These crosslinking accelerators may be used alone or in combination of two or more. The content of the crosslinking accelerator is preferably 0.05 to 15 parts by mass, more preferably 0.1 to 5 parts by mass, and still more preferably 0.5 to 4 parts by mass with respect to 100 parts by mass in total of the ethylene-vinyl acetate copolymer (I) and the block copolymer (II).

[0051] [Crosslinking aid] The resin composition of the present invention may further contain a crosslinking aid. Examples of the crosslinking aid include fatty acids such as stearic acid, metal oxides such as zinc white, and fatty acid metal salts such as zinc stearate. These may be used alone or in combination of two or more. When the crosslinking aid is contained, its content is preferably 0.1 to 15 parts by mass, more preferably 1 to 10 parts by mass, based on 100 parts by mass in total of the ethylene-vinyl acetate copolymer (I) and the hydrogenated block copolymer (II).

[0052] 〔Filler〕 The resin composition of the present invention may contain fillers other than the above-mentioned silica. As the filler, an inorganic filler and / or an organic filler can be used. Preferred examples of the inorganic filler preferably include silicate compounds and metal oxides. The silicate compound is preferably at least one silicate compound selected from the group consisting of kaolin, talc, clay, pyrophyllite, mica, montmorillonite, bentonite, wollastonite, sepiolite, zonotrite, zeolite, diatomaceous earth, and halloysite. The metal oxide is at least one metal oxide selected from the group consisting of titanium oxide, iron oxide, magnesium oxide, aluminum oxide, cerium oxide, antimony oxide, tin oxide, lead oxide, chromium oxide, cobalt oxide, tungsten oxide, and copper oxide.

[0053] In addition, preferred examples of the organic filler include particulate organic fillers and / or fibrous organic fillers. Preferred examples of the particulate organic filler include at least one organic filler selected from the group consisting of urethane fine particles, acrylic fine particles, styrene fine particles, acrylic / styrene-based fine particles, styrene olefin fine particles, fluorine-based fine particles, polyethylene-based fine particles, and silicone fine particles. From the viewpoint of the moldability of the resin composition, the preferred average particle diameter of the particulate organic filler is 2 to 50 μm. The average particle diameter can be measured by the laser diffraction method in accordance with JIS Z 8825-1.

[0054] As the fibrous organic filler, various organic fibers can be used. For example, 6-nylon fiber, 6,6-nylon fiber, 4,6-nylon fiber, aromatic polyamide fiber, para-aramid fiber, meta-aramid fiber, polyethylene terephthalate (PET) fiber, polyethylene naphthalate (PEN) fiber, polyparaphenylene benzoxazole (PBO) fiber, PVA-based fiber (vinylon), polyarylene sulfide-based fiber, 2,6-hydroxy naphthoic acid·para-hydroxybenzoic acid fiber (vectran), polyethylene (PE) fiber, polypropylene (PP) fiber, polylactic acid (PLA) fiber, polybutylene succinate (PBS) fiber, polyethylene succinate fiber, syndiotactic-1,2-polybutadiene (SPB) fiber, polyvinyl chloride (PVC) fiber and other synthetic fibers, cotton, hemp, rayon, cellulose fiber and other natural (regenerated) fibers are preferably exemplified.

[0055] When the resin composition of the present invention contains a filler, the content is preferably 1 to 50 parts by mass, more preferably 2 to 20 parts by mass, based on 100 parts by mass of the total content of the ethylene-vinyl acetate copolymer (I) and the block copolymer (II).

[0056] 〔Softening agent〕 The resin composition of the present invention may contain a softening agent as long as the effects of the invention are not impaired. In addition, process oils such as paraffinic, naphthenic and aromatic oils, mineral oils, oil-based softening agents such as white oil are preferably not contained in the resin composition because there is a risk that the oil will ooze out over time when formed into a molded body. Examples of the softening agent that can be contained include phthalic acid derivatives such as dioctyl phthalate and dibutyl phthalate; liquid co-oligomers of ethylene and α-olefin; liquid paraffin; polybutene; low molecular weight polyisobutylene; liquid polybutadiene, liquid polyisoprene, liquid polyisoprene / butadiene copolymer, liquid styrene / butadiene copolymer, liquid styrene / isoprene copolymer and other liquid poly-dienes and their hydrogenated products. When contained, the content of the softening agent is preferably 30% by mass or less, more preferably 20% by mass or less, still more preferably 0% by mass, that is, it is preferably not contained, in the above resin composition.

[0057] 〔Other Additives〕 In the resin composition of the present embodiment, other additives other than those described above, for example, heat aging inhibitors, antioxidants, light stabilizers, antistatic agents, mold release agents, flame retardants, foaming agents, pigments, dyes, brightening agents, etc. can be added within a range that does not impair the effects of the present invention. These additives may be used alone or in combination of two or more.

[0058] <Biomass Content> The biomass content of the resin composition of the present invention is preferably 4 to 70% by mass, more preferably 10 to 60% by mass, still more preferably 15 to 50% by mass. When the biomass content is within the above range, it is possible to obtain a molded article excellent in dry grip property and wet grip property while using an environmentally friendly material and further suppressing the manufacturing cost. In this specification, the biomass content means a value measured in accordance with ASTM D6866, and specifically, it can be measured according to the method described in the examples.

[0059] <Manufacturing Method of Resin Composition> The manufacturing method of the resin composition can be, for example, melt-kneading each component except the crosslinking agent added as necessary, then adding the crosslinking agent, and crosslinking by the crosslinking method described later. There is no particular limitation on the method of melt-kneading each component except the crosslinking agent. Examples of the method include simultaneously supplying the ethylene-vinyl acetate copolymer (I), the hydrogenated block copolymer (II), and other optional components to a kneading device such as a single-screw extruder, a multi-screw extruder, a Banbury mixer, a Brabender mixer, an open roll, a heating roll, various kneaders, etc. and melt-kneading them. Also, a method of supplying the ethylene-vinyl acetate copolymer (I), the hydrogenated block copolymer (II), and other optional components from separate inlets and melt-kneading them, or a method of previously melt-kneading the hydrogenated block copolymer (II) with some optional components such as silica and a silane coupling agent and then melt-kneading the melt-kneaded product with other optional components may be used. The temperature during melt-kneading can usually be arbitrarily selected within the range of 20 to 270°C.

[0060] As a crosslinking method, after the above melt-kneading, a crosslinking agent and, if necessary, a crosslinking accelerator are added, and crosslinking is carried out using a crosslinking mold at a crosslinking temperature of usually about 120 to 200°C, preferably 140 to 200°C, a crosslinking pressure of usually about 0.5 to 10 MPa, and usually maintained for about 1 minute to 2 hours.

[0061] [Molded article] The molded article of the present invention is obtained using the above resin composition and is excellent in dry grip property and wet grip property. Specifically, the static friction coefficient of the molded article measured according to ASTM D-1894 is preferably 1.5 or more, more preferably 2.0 or more under dry conditions. Also, under wet conditions, it is preferably 0.7 or more, more preferably 0.9 or more. The dry conditions and wet conditions mean the measurement conditions described in the examples below.

[0062] The shape of the molded article of the present invention may be any as long as it is a molded article that can be manufactured using the above-described resin composition. For example, it can be molded into various shapes such as pellets, films, sheets, plates, pipes, tubes, rod-shaped bodies, granular bodies, etc. The manufacturing method of this molded article is not particularly limited, and it can be molded by various conventional molding methods, for example, injection molding, blow molding, press molding, extrusion molding, calender molding, etc. The above-described resin composition can particularly preferably obtain a press-molded article. Since the above molded article is expected to be difficult to slip and excellent in abrasion resistance, it can be used for molded articles that require these properties. In particular, it can be preferably used as a molded article such as a shoe sole using at least a part of the resin composition of the present embodiment. Specifically, shoe soles for footwear such as hiking boots, sandals, safety shoes, mountaineering boots, marathon shoes, underground socks, and boots; sports goods such as underwater goggles, snorkels, ski boots, and ski and snowboards; writing utensils such as pens and scissors, tools such as drivers, pliers, and wrenches, and electric tools, water-related supplies such as toothbrushes and kitchen supplies (such as knives and spatulas), instruments used for sports and fitness such as golf clubs, ski stocks, bicycles, and bikes, and various grips such as knives; parts of household appliances such as refrigerators, vacuum cleaners, and waterproof bodies (such as mobile phones); automotive supplies such as side moldings, rack and pinion boots, suspension boots, constant velocity joint boots, weather strips, mat guards, floor mats, armrests, belt line moldings, flash mounts, and interior and exterior automotive parts (such as gears and knobs); office equipment such as copy machine feed rollers and take-up rollers; parts used for furniture such as sofas and chair seats; rubber parts such as switch covers, stoppers, casters, and foot rubbers; building materials such as coated plywood and coated steel plates, etc. can be preferably used. Note that the molded article of the present invention is excellent in dry grip performance and wet grip performance even if it does not have a silica-containing layer containing silica on the surface of the molded article.

Examples

[0063] Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited thereto. β-Farnesene (purity 97.6% by mass, manufactured by Amyris, Inc.) was purified with 3 Å molecular sieves and distilled under a nitrogen atmosphere to remove hydrocarbon impurities such as zingiberene, bisabolene, farnesene epoxide, farnesol isomers, E,E-farnesol, squalene, ergosterol, and several dimers of farnesene, and was used in the following polymerization.

[0064] <Ethylene-vinyl acetate copolymer (I)> · EV460 (VA = 19% by mass, MFR = 2.5 g / 10 min at a temperature of 190 °C and a load of 2.16 kg, SP value = 8.30 (cal / cm 3 ) 1 / 2 , manufactured by Mitsui Dow Polychemical Co., Ltd.) · EV45LX (VA = 46% by mass, MFR = 2.5 g / 10 min at a temperature of 190 °C and a load of 2.16 kg, SP value = 8.60 (cal / cm 3 ) 1 / 2 , manufactured by Mitsui Dow Polychemical Co., Ltd.)

[0065] <Hydrogenated block copolymer (II)> · Hydrogenated block copolymer (II-1) The hydrogenated block copolymer (II-1) of Production Example 1 described below · Hydrogenated block copolymer (II-2) The hydrogenated block copolymer (II-2) of Production Example 2 described below

[0066] <Unhydrogenated block copolymer (P’)> The unhydrogenated block copolymer (P’) of Production Example 3 described below

[0067] <Other resins> · ENGAGE8480 (polyolefin elastomer, manufactured by Dow Chemical Company) · STN7006 (bio LDPE, manufactured by Braskem)

[0068] <Crosslinking agent> · Percumyl D-40 (purity 40% by mass, manufactured by Nippon Oil Corporation) <Crosslinking aid> · Zinc oxide: One type of zinc oxide, manufactured by Sakai Chemical Industry Co., Ltd. · Stearic acid: Lunac S-20, manufactured by Kao Corporation

[0069] [Measurement method] Details of each measurement method for the polymer obtained in the production example are as follows. (1) Measurement of peak top molecular weight and molecular weight distribution The peak top molecular weight of the hydrogenated block copolymer, the peak top molecular weight (Mp) of the styrene block, and the molecular weight distribution (Mw / Mn) were determined in terms of standard polystyrene equivalent molecular weight by GPC (gel permeation chromatography), and the peak top molecular weight (Mp) was determined from the position of the peak top of the molecular weight distribution peak. The measuring apparatus and conditions are as follows. · Apparatus: GPC apparatus "HLC-8320GPC" manufactured by Tosoh Corporation · Separation column: Column "TSKgel SuperHZ4000" manufactured by Tosoh Corporation · Eluent: Tetrahydrofuran · Eluent flow rate: 0.7 mL / min · Sample concentration: 5 mg / 10 mL · Column temperature: 40 °C

[0070] (2) Measurement method of hydrogenation rate The block copolymer (P) and the hydrogenated block copolymer (II) were each dissolved in a deuterated chloroform solvent, and 1H-NMR was measured at 50 °C using "Lambda-500" manufactured by JEOL Ltd. 1 1H-NMR was measured. The hydrogenation rate of the carbon-carbon double bond in the structural unit derived from the conjugated diene in the hydrogenated block copolymer (II) was calculated by the following formula from the peak of the proton possessed by the carbon-carbon double bond appearing at 4.5 - 6.0 ppm in the obtained spectrum. Hydrogenation rate (mol%) = {1 - (number of moles of carbon-carbon double bonds contained per mole of hydrogenated block copolymer (II)) / (number of moles of carbon-carbon double bonds contained per mole of block copolymer (P))} × 100

[0071] [Production Example 1] Hydrogenated block copolymer (II-1) 50.0 kg of cyclohexane as a solvent, 0.1905 kg of sec-butyllithium (10.5 mass% cyclohexane solution) as an anionic polymerization initiator, and 0.40 kg of tetrahydrofuran as a Lewis base were charged into a pressure-resistant container that was purged with nitrogen and dried. After heating to 50°C, 6.34 kg of β-farnesene was added and polymerization was carried out for 2 hours. Subsequently, 2.50 kg of styrene (1) was added and polymerized for 1 hour, and further 3.66 kg of butadiene was added and polymerization was carried out for 1 hour. Subsequently, 0.02 kg of dichlorodimethylsilane as a coupling agent was added to this polymerization reaction solution and reacted for 1 hour to obtain a reaction solution containing poly(β-farnesene)-polystyrene-polybutadiene-polystyrene-poly(β-farnesene) pentablock copolymer (P-1). To this reaction solution, 5 mass% of palladium carbon (palladium loading: 5 mass%) as a hydrogenation catalyst was added based on the block copolymer (P-1), and the reaction was carried out at a hydrogen pressure of 2 MPa and 150°C for 10 hours. After cooling and depressurizing, palladium carbon was removed by filtration, the filtrate was concentrated, and further vacuum dried to obtain a hydrogenated product (II-1) of poly(β-farnesene)-polystyrene-polybutadiene-polystyrene-poly(β-farnesene) pentablock copolymer (hereinafter referred to as "hydrogenated block copolymer (II-1)"). The biomass content measured in accordance with ASTM D6866 of the obtained hydrogenated block copolymer (I-1) was 50 mass%. For the obtained hydrogenated block copolymer (II-1), the above physical properties were measured. The results are shown in Table 1.

[0072] [Production Example 2] Hydrogenated block copolymer (II-2) Into a nitrogen-substituted and dried pressure-resistant container, 50.0 kg of cyclohexane as a solvent and 0.0413 kg of sec-butyllithium (10.5 mass% cyclohexane solution) as an anionic polymerization initiator were charged. After heating to 50 °C, 1.12 kg of styrene (1) was added and polymerization was carried out for 1 hour. Subsequently, 10.25 kg of β-farnesene was added and polymerization was carried out for 2 hours. Further, 1.12 kg of styrene (2) was added and polymerization was carried out for 1 hour to obtain a reaction solution containing a polystyrene-poly(β-farnesene)-polystyrene triblock copolymer (P-2). To this reaction solution, 5 mass% of palladium carbon (palladium loading: 5 mass%) as a hydrogenation catalyst was added based on the block copolymer (P-2), and the reaction was carried out at a hydrogen pressure of 2 MPa and 150 °C for 10 hours. After cooling and depressurizing, palladium carbon was removed by filtration, the filtrate was concentrated, and further vacuum dried to obtain a hydrogenated product of the polystyrene-poly(β-farnesene)-polystyrene triblock copolymer (hereinafter referred to as "hydrogenated block copolymer (I-2)"). The biomass content measured in accordance with ASTM D6866 of the obtained hydrogenated block copolymer (II-2) was 82 mass%. The above physical properties of the hydrogenated block copolymer (II-2) were measured. The results are shown in Table 1.

[0073] [Production Example 3] Unhydrogenated block copolymer (P’) Into a nitrogen-substituted and dried pressure-resistant container, 50.0 kg of cyclohexane as a solvent and 0.073 kg of sec-butyllithium (10.5 mass% cyclohexane solution) as an anionic polymerization initiator were charged. After heating to 50 °C, 1.25 kg of styrene (1) was added and polymerization was carried out for 1 hour. 0.27 kg of tetrahydrofuran as a Lewis base was added, and subsequently, 10.00 kg of isoprene was added and polymerization was carried out for 2 hours. Further, 1.25 kg of styrene (2) was added and polymerization was carried out for 1 hour to obtain a reaction solution containing a styrene-isoprene-styrene triblock copolymer (P’). The polymerization reaction was terminated by adding 200 mL of methanol to this reaction solution. The resulting mixture was washed with water and then reprecipitated into a large amount of methanol to obtain a styrene-isoprene-styrene triblock copolymer (hereinafter also referred to as "unhydrogenated block copolymer (P')"). Regarding the unhydrogenated block copolymer (P'), the above physical properties were measured. The results are shown in Table 1.

[0074]

Table 1

[0075] *1: Represents the mass ratio of polymer block (A) to polymer block (B). *2: Represents the content (mass %) of the structural unit (b1) derived from farnesene in polymer block (B). *3: Represents the content (mass %) of the structural unit (b1) derived from farnesene in polymer block (B) and polymer block (C). *4: F-St-Bd-St-F represents a poly(β-farnesene)-polystyrene-polybutadiene-polystyrene-poly(β-farnesene) pentablock copolymer. St-F-St represents a polystyrene-poly(β-farnesene)-polystyrene triblock copolymer. St-Ip-St represents a polystyrene-polyisoprene-polystyrene triblock copolymer. *4: The hydrogenation rate of the hydrogenated block copolymer (II) represents the hydrogenation rate of the carbon-carbon double bond in the structural unit derived from conjugated diene in the block copolymer (P).

[0076] <Examples 1 to 9, Comparative Examples 1 to 6> (1) Melt kneading (manufacture of resin composition) According to the compounding ratios (parts by mass) described in Table 3, the components were charged into a Brabender mixer (product name: Plastograph EC50cc mixer, manufactured by Brabender) in the order and under the conditions shown in Table 2, and melt-kneaded (Steps 1 and 2). Thereafter, the melt-kneaded product was taken out of the Brabender mixer (Step 3). Next, this melt-kneaded product was charged into the Brabender again, kneaded (Step 4), and then a crosslinking agent was added and re-kneaded (Step 5) to obtain a resin composition. (2) Molding (Manufacture of Molded Body) The obtained resin composition was press-molded (at 170 °C for 7 to 10 minutes) to obtain a crosslinked sheet (thickness: 0.5 mm). The physical properties of the obtained sheet were evaluated based on the following evaluation methods. The results are shown in Table 3.

[0077]

Table 2

[0078] <Evaluation Method> 〔Coefficient of Static Friction〕 (1) Dry In accordance with ASTM D-1894, the coefficient of static friction of the surfaces of the sheets obtained in the examples and comparative examples was measured. A test piece measuring 110 mm in length, 63.5 mm in width, and 0.5 mm in thickness was cut out from the above sheet, wound around a cell (weight: 200 g, 63.5 mm × 63.5 mm), and fixed to an autograph head so that the test piece stage of the friction coefficient measuring device was horizontal. The material of the friction table was aluminum, and the coefficient of static friction was measured at a tensile speed of 150 mm / min. The higher the value of the coefficient of static friction, the greater the frictional force, the more difficult it is to slip, and the better the dry grip property.

[0079] (2) Wet The coefficient of static friction was measured in the same manner as in (1) Dry above, except that 1 cc of distilled water was dropped onto the friction table. The higher the value of the coefficient of static friction, the greater the frictional force, the more difficult it is to slip, and the better the wet grip property.

[0080] <Degree of Biomass> Degree of Biomass (mass %) =(MI ×X I / 100)+(M II ×X II / 100) (In the above formula, M I is the mass ratio (mass %) of the ethylene-vinyl acetate copolymer (I) to the total mass of the ethylene-vinyl acetate copolymer (I) and the hydrogenated block copolymer (II), M II is the mass ratio (mass %) of the hydrogenated block copolymer (II) to the total mass of the ethylene-vinyl acetate copolymer (I) and the hydrogenated block copolymer (II). X I (%) is the biomass content of the ethylene-vinyl acetate copolymer (I), X II (%) is the biomass content of the hydrogenated block copolymer (II). The biomass content is measured in accordance with ASTM D6866.)

[0081]

Table 3

[0082] As can be seen from the results in Table 3, according to the resin composition of the present invention, a molded article excellent in dry grip property and wet grip property can be obtained.

Claims

1. A resin composition containing an ethylene-vinyl acetate copolymer (I) and a hydrogenated block copolymer (II), wherein the hydrogenated block copolymer (II) is a hydrogenated product of a block copolymer (P) containing a polymer block (A) containing structural units derived from an aromatic vinyl compound and a polymer block (B) containing 1 to 100% by mass of structural units derived from farnesene and 99 to 0% by mass of structural units derived from a conjugated diene other than farnesene, and the hydrogenation rate of the carbon-carbon double bond in the structural units derived from the conjugated diene in the block copolymer (P) is 70 mol% or more, the peak top molecular weight of the hydrogenated block copolymer (II) is 50,000 to 500,000, the content of the ethylene-vinyl acetate copolymer (I) in the resin composition is 40 to 95% by mass, and the content of the hydrogenated block copolymer (II) is 5 to 60% by mass. A resin composition characterized by the above.

2. The resin composition according to claim 1, having a biomass content of 4 to 70% by mass.

3. The resin composition according to claim 1 or 2, wherein the content of the structural units derived from vinyl acetate in the ethylene-vinyl acetate copolymer (I) is 5 to 60% by mass.

4. The resin composition according to any one of claims 1 to 3, wherein the aromatic vinyl compound is styrene.

5. The resin composition according to any one of claims 1 to 4, wherein the conjugated diene other than farnesene is at least one selected from butadiene, isoprene, and myrcene.

6. The resin composition according to any one of claims 1 to 5, wherein the mass ratio [(A) / (B)] of the polymer block (A) to the polymer block (B) is 10 / 90 to 40 / 60.

7. The resin composition according to any one of claims 1 to 6, wherein the hydrogenated block copolymer (II) further has a polymer block (C) consisting only of structural units derived from a conjugated diene other than farnesene.

8. The SP value of the ethylene-vinyl acetate copolymer (I) is 4.0 to 10.0 (cal / cm 3 ). 1 / 2 and the SP value of the hydrogenated block copolymer (II) is 6.0 to 10.0 (cal / cm 3 ). 1 / 2 The resin composition according to any one of claims 1 to 7.

9. The resin composition according to any one of claims 1 to 8, wherein the peak top molecular weight of the polymer block (A) is 5,000 to 100,000.

10. A molded article using at least a part of the resin composition according to any one of claims 1 to 9.

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