JP2017008308A - Elastic material, film and unwoven fabric - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an elastic member excellent in elastic recovery property, a film and an unwoven fabric consisting of the elastic member.SOLUTION: There is provided an elastic member by molding a thermoplastic elastomer composition containing a hydrogenated block copolymer (I), where the hydrogenated block copolymer (I) is a hydrogenated article 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 a structural unit (b1) derived from farnesene of 1 to 100 mass% and a structural unit (b2) derived from conjugated diene other than farnesene of 99 to 0 mass% and has mass ratio of the polymer block (a) and the polymer block (b), [(a)/(b)] of 1/99 to 70/30, where 50 mol% or more of carbon-carbon double bond in the polymer block (b) is hydrogenated, and hysteresis loss ratio in 1 cycle of deformation and recover, where a test piece obtained by punching strip shape pieces with width of 25 mm and length of 150 mm from a sheet with thickness of 0.5 mm by compression molding the thermoplastic elastomer composition at 240°C and 10 MPa load for 3 minutes is elongated 100% at a temperature of 23°C and contracted, is 20% or less.SELECTED DRAWING: None

Description

  The present invention relates to a stretchable member that is formed by molding a thermoplastic elastomer composition and has excellent elastic recovery properties, and a film and a nonwoven fabric made of the stretchable member. More specifically, the present invention relates to a hydrogenated block copolymer obtained by hydrogenating a polymer block containing a structural unit derived from an aromatic vinyl compound and a block copolymer containing a polymer block containing a structural unit derived from farnesene. It is related with the elastic member which shape | molds the thermoplastic elastomer composition containing this, and is excellent in elastic recoverability, and the film and nonwoven fabric which consist of the said elastic member.

Among hydrogenated block copolymers, hydrogenated styrene-based thermoplastic elastomers are thermoplastic elastomers that are excellent in weather resistance, heat resistance, impact resistance, flexibility, and elastic recovery. Compositions containing hydrogenated block copolymers provide excellent mechanical strength, flexibility, weather resistance, ozone resistance, thermal stability, transparency, automotive, household appliances, medical supplies, construction supplies It is used in a wide range of fields such as toys, daily goods, and miscellaneous goods.
For example, Patent Document 1 discloses that a mixed monomer of isoprene and butadiene is copolymerized with styrene for the purpose of improving low-temperature characteristics, impact resistance, permanent distortion, and mechanical strength of hydrogenated styrene thermoplastic elastomer. A hydrogenated block copolymer is disclosed.

In utilizing the excellent properties of hydrogenated styrene-based thermoplastic elastomers, a method of mixing with a plasticizer or various thermoplastic resins has been proposed.
For example, Patent Document 2 discloses a composition comprising 20 to 80% by weight of an elastomeric block copolymer, 5 to 60% by weight of process oil, and 3 to 60% by weight of vinylarene resin.
Patent Document 3 discloses 52-60 wt.% Of a block polymer having at least two polystyrene end blocks and a central block of a hydrogenated polymerized diene having a vinyl content of 45 wt.% Or less, 19-28 wt.% Of oil. A composition comprising 13 to 22% by weight of polystyrene is disclosed.
In Patent Document 4, 35 to 50 parts by mass of a hydrogenated block copolymer having an aromatic vinyl content of 35 to 45% by mass and a weight average molecular weight of 70,000 to 120,000, and a rubber softening agent 30 to 30%. A composition comprising 5 to 25 parts by mass of a polystyrene resin having 50 parts by mass and a weight average molecular weight of 100,000 to 400,000 is disclosed.

Patent Document 5 has at least two blocks composed of an aromatic vinyl compound and at least one hydrogenated polymer block composed of a conjugated diene compound and having a hydrogenation rate of 50% or more, and the aromatic vinyl compound The softening agent is 0 to 120 parts by weight, and the polyethylene is 0 to 80 parts by weight with respect to 100 parts by weight of the hydrogenated block copolymer having a block consisting of 10 to 40% by weight and a number average molecular weight of 50,000 to 140,000. The composition contained in the ratio of a mass part and 0-80 mass parts of polystyrene is disclosed.
In Patent Document 6, two or more polymer blocks containing a structural unit derived from an aromatic vinyl compound and one or more polymer blocks containing a structural unit derived from isoprene and 1,3-butadiene are used. A composition comprising a hydrogenated block copolymer obtained by hydrogenating a block copolymer having a crystallization peak temperature (Tc) of −3 to 15 ° C. and a polystyrene resin is disclosed.

Japanese Patent Laid-Open No. 3-188114 Special table 2003-509565 gazette Special table 2003-509564 gazette International Publication No. 2007/119390 International Publication No. 2002/098976 International Publication No. 2012/111644

  However, the hydrogenated block copolymer disclosed in Patent Document 1 and the thermoplastic elastomer composition disclosed in Patent Documents 2 to 6 are not sufficiently elastic and have room for further improvement. It was.

  This invention is made | formed in view of the said situation, Comprising: It is related with the elastic member which is excellent in elastic recoverability, the film and nonwoven fabric which consist of the said elastic member.

  As a result of intensive studies by the present inventors, it has been found that a specific hydrogenated block copolymer can solve the above-mentioned problems, leading to the present invention.

That is, the present invention relates to the following [1] to [3].
[1] A stretchable member formed by molding a thermoplastic elastomer composition containing a hydrogenated block copolymer (I), wherein the hydrogenated block copolymer (I) is derived from an aromatic vinyl compound. A polymer block (a) containing a structural unit, a heavy unit 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. A block block having a mass ratio [(a) / (b)] of 1/99 to 70/30 of the polymer block (a) and the polymer block (b). A hydrogenated product of a polymer (P), which is a carbon-carbon double bond derived from farnesene present in the block copolymer (P) and a carbon-carbon double bond derived from a conjugated diene other than farnesene. 50 of total ol% or more is hydrogenated, and the thermoplastic elastomer composition is compression-molded at 240 ° C. and 10 MPa load for 3 minutes, from a 0.5 mm thick sheet having a width of 25 mm and a length of 150 mm. A stretchable member having a hysteresis loss rate of 20% or less in one cycle of deformation and recovery in which a test piece obtained by punching into a shape is stretched 100% at a temperature of 23 ° C. and then contracted.
[2] A film comprising the stretchable member according to [1].
[3] A nonwoven fabric comprising the stretchable member according to [1].

  ADVANTAGE OF THE INVENTION According to this invention, the film and nonwoven fabric which consist of an elastic member excellent in elastic recoverability, and the said elastic member can be provided.

[1] Stretchable member The stretchable member according to the present embodiment is a stretchable member formed by molding a thermoplastic elastomer composition containing the hydrogenated block copolymer (I), and the hydrogenated block. The copolymer (I) contains 1 to 100% by mass of a polymer block (a) containing a structural unit derived from an aromatic vinyl compound and a structural unit (b1) derived from farnesene, and is derived from a conjugated diene other than farnesene. A polymer block (b) containing 99 to 0% by mass of the structural unit (b2), and the mass ratio of the polymer block (a) to the polymer block (b) [(a) / (b) ] Is a hydrogenated product of the block copolymer (P) having a ratio of 1/99 to 70/30, and the carbon-carbon double bond in the polymer block (b) is hydrogenated in an amount of 50 mol% or more. The thermoplastic elastomer A test piece obtained by punching a tomer composition into a strip having a width of 25 mm and a length of 150 mm from a sheet having a thickness of 0.5 mm obtained by compression molding at 240 ° C. under a 10 MPa load for 3 minutes was obtained at a temperature of 23 ° C. It is a stretchable member having a hysteresis loss rate of 20% or less in one cycle of deformation and recovery after being stretched by%.

[Thermoplastic elastomer composition]
The thermoplastic elastomer composition according to the present embodiment contains a hydrogenated block copolymer (I).
The thermoplastic elastomer composition may contain an optional component other than the hydrogenated block copolymer (I). Examples of the optional component include polystyrene resin (II) and softener (III).

<Hydrogenated block copolymer (I)>
The hydrogenated block copolymer (I) according to the present embodiment contains 1 to 100% by mass of a polymer block (a) containing a structural unit derived from an aromatic vinyl compound and a structural unit (b1) derived from farnesene. And a polymer block (b) containing 99 to 0% by mass of a structural unit (b2) derived from a conjugated diene other than farnesene, and the mass of the polymer block (a) and the polymer block (b) A hydrogenated product of a block copolymer (P) having a ratio [(a) / (b)] of 1/99 to 70/30, the carbon-carbon double bond in the polymer block (b) Is hydrogenated in an amount of 50 mol% or more.

The polymer block (a) includes a structural unit derived from an aromatic vinyl compound.
Examples of the aromatic vinyl compound 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- Examples thereof include vinyl naphthalene, vinyl anthracene, N, N-diethyl-4-aminoethyl styrene, vinyl pyridine, 4-methoxy styrene, monochlorostyrene, dichlorostyrene and divinylbenzene. These aromatic vinyl compounds may be used alone or in combination of two or more. Of these, styrene, α-methylstyrene, and 4-methylstyrene are more preferable, and styrene is more preferable.

The polymer block (a) may contain, in addition to the structural unit derived from the aromatic vinyl compound, other structural units as a trace unit or impurity unit to the extent that the effects of the present invention are not impaired. Preferably not.
The content of other structural units in the polymer block (a) is preferably 10% by mass or less, more preferably 5% by mass or less, and still more preferably 1% by mass or less.
The content of the structural unit derived from the aromatic vinyl compound in the polymer block (a) is preferably 90% by mass or more, more preferably 95% by mass or more, and further preferably 99% by mass or more.

  The peak top molecular weight (Mp) of the polymer block (a) is preferably 1,000 to 200,000, more preferably 5,000 to 150,000, and 6,000 to 100,000 from the viewpoint of moldability. Is more preferable, and 7,000 to 60,000 is even more preferable. In addition, the peak top molecular weight (Mp) in this specification means the value measured by the method described in the Example mentioned later.

  The polymer block (b) contains 1 to 100% by mass of farnesene-derived structural units (b1) and 99 to 0% by mass of structural units (b2) derived from conjugated dienes other than farnesene. The structural unit (b1) may be either α-farnesene or a β-farnesene-derived structural unit represented by the following formula (I). However, from the viewpoint of ease of production of the block copolymer (P), β- A structural unit derived from farnesene is preferred. Note that α-farnesene and β-farnesene may be used in combination.

  As the conjugated diene constituting the structural unit (b2) derived from a conjugated diene other than farnesene, for example, 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 and chloroprene. . These may be used alone or in combination of two or more. Among these, at least one selected from butadiene, isoprene and myrcene is more preferable, butadiene and / or isoprene is more preferable, and butadiene is most preferable.

The polymer block (b) contains 1 to 100% by mass of farnesene-derived structural units (b1) and 99 to 0% by mass of structural units (b2) derived from conjugated dienes other than farnesene. Here, “containing 0 mass% of the structural unit (b2)” means that the structural unit (b2) is not contained.
When the content ((b1) / (b)) of the structural unit (b1) derived from farnesene in the polymer block (b) is less than 1% by mass, an elastic member excellent in elastic recovery can be obtained. Can not. The content of the structural unit (b1) in the polymer block (b) is preferably 30 to 100% by mass, more preferably 45 to 100% by mass, further preferably 50 to 100% by mass, and more preferably 55 to 100% by mass. More preferably, for example, 100% by mass (the polymer block (b) is composed only of the structural unit (b1)) is preferable.
When the polymer block (b) contains a structural unit (b2) derived from a conjugated diene other than farnesene, the content of the structural unit (b2) is preferably 70% by mass or less, more preferably 55% by mass or less. Preferably, 50 mass% or less is still more preferable, and 45 mass% or less is still more preferable. From the viewpoint of improving the strength, the content of the structural unit (b2) is preferably 5% by mass or more, more preferably 10% by mass or more, further preferably 15% by mass or more, and further more preferably 20% by mass or more. preferable.
The total content of the structural unit (b1) and the structural unit (b2) in the polymer block (b) is preferably 80% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, and 99% by mass. % Or more is more preferable, and 100 mass% is still more preferable.

In the block copolymer (P), the content of the structural unit (b1) derived from farnesene is less than 1% by mass in addition to the polymer block (a) and the polymer block (b). The polymer block (c) whose content of the structural unit (b2) derived from the conjugated diene is 1 to 100% by mass may be included.
The farnesene which is a component derived from these structural units (b1) and the conjugated diene which is a component derived from (b2) are as described above.

By including the polymer block (c) in addition to the polymer block (b) described above, there is an advantage of excellent molding processability.
Here, “the content of the structural unit (b1) derived from farnesene is less than 1% by mass” in the polymer block (c) means that the content of the structural unit (b1) is 0% by mass, that is, the structural unit ( The case of not containing b1) is also included. The structural unit (b1) is preferably 0% by mass.
The content of the structural unit (b2) 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 still more preferably 99% by mass. % And 100% by mass, and still more preferably 100% by mass.
The total content of the structural unit (b1) and the structural unit (b2) in the polymer block (c) is preferably 80% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, and 99% by mass. % Or more is more preferable, and 100 mass% is still more preferable.

The hydrogenated block copolymer (I) is a hydrogenated product of a block copolymer (P) containing at least one polymer block (a) and one polymer block (b).
The hydrogenated block copolymer (I) is preferably a hydrogenated product of a block copolymer (P) containing two or more polymer blocks (a) and one or more polymer blocks (b). .
The bonding form of the plurality of polymer blocks is not particularly limited, and may be linear, branched, radial, or a combination of two or more thereof. Especially, the form which each block couple | bonded linearly is preferable.

When the hydrogenated block copolymer (I) includes a polymer block (a) and a polymer block (b), when the polymer block (a) is represented by a and the polymer block (b) is represented by b, A bond form represented by (ab) _l , a- (ba) _m or b- (ab) _n is preferred. In addition, said l, m, and n represent an integer greater than or equal to 1 each independently.
As the bonding form, a pentablock copolymer represented by bb-a-b or a triblock copolymer represented by ab-a from the viewpoint of elastic recovery and molding processability Is preferable, and a pentablock copolymer represented by b-a-b-a-b is more preferable.
When the block copolymer (P) has two or more polymer blocks (a) or two or more polymer blocks (b), each polymer block is a polymer comprising the same structural unit. It may be a block or a polymer block composed of different structural units. For example, in the two polymer blocks (a) in the triblock copolymer represented by [a-ba], each aromatic vinyl compound may be the same or different in type. Good.

When the hydrogenated block copolymer (I) includes a polymer block (a), a polymer block (b), and a polymer block (c), the polymer block (a) is a and the polymer block (b) is b, when the polymer block (c) is represented by c, a pentablock copolymer represented by b-a-c-a-b, a tetrablock copolymer represented by b-a-c-a A coalescence is preferable, and a pentablock copolymer represented by b-ac-a-b is more preferable.
When the block copolymer (P) has two or more polymer blocks (a), two or more polymer blocks (b), or two or more (c), the respective polymer blocks These may be polymer blocks composed of the same structural unit or polymer blocks composed of different structural units.

  The mass ratio [(a) / (b)] of the polymer block (a) and the polymer block (b) in the block copolymer (P) is from 1/99 to 70/30. Within the range, a stretchable member excellent in elastic recovery can be obtained. From this viewpoint, the mass ratio [(a) / (b)] of the polymer block (a) and the polymer block (b) is preferably 1/99 to 60/40, and preferably 10/90 to 55/45. More preferably, 10 / 90-50 / 50 is still more preferable, and 15 / 85-50 / 50 is still more preferable. The mass ratio [(a) / (b)] may be, for example, 15/85 to 40/60, or 20/80 to 40/60.

  When the block copolymer (P) has a polymer block (c), the mass ratio of the polymer block (b) in the block copolymer (P) and the polymer (a) to the polymer block (c) [ (A) / ((b) + (c))] is preferably 1/99 to 70/30. Within the range, a stretchable member excellent in elastic recovery can be obtained. From this viewpoint, the mass ratio [(a) / ((b) + (c))] is more preferably 1/99 to 60/40, still more preferably 10/90 to 40/60, and 10/90 to 30/70 is still more preferable, and 15/85 to 25/75 is still more preferable.

When the block copolymer (P) has a polymer block (c), the structural unit (b1) in the total amount of the polymer block (b) and the polymer block (c) in the block copolymer (P). The content [(b1) / ((b) + (c))] is preferably 30 to 99% by mass. Within the range, a stretchable member excellent in elastic recovery can be obtained. From this viewpoint, the mass ratio [(b1) / ((b) + (c))] is preferably 30 to 90% by mass, more preferably 40 to 80% by mass, and still more preferably 45 to 70% by mass, 50-70 mass% is still more preferable.
Here, the structural unit (b1) in the mass ratio [(b1) / ((b) + (c))] is composed of the structural unit (b1) contained in the polymer block (b) and the polymer block (c ) Is the total amount with the structural unit (b1) contained therein.

  The total content of the polymer block (a), the polymer block (b) and the polymer block (c) in the block copolymer (P) is preferably 80% by mass or more, more preferably 90% by mass or more. 95 mass% or more is more preferable, 99 mass% or more is further more preferable, and 100 mass% is still more preferable.

  The peak top molecular weight (Mp) of the hydrogenated block copolymer (I) is preferably 4,000 to 500,000, more preferably 9,000 to 450,000, and more preferably 30,000 to 400 from the viewpoint of moldability. Is more preferable, and 50,000 to 380,000 is still more preferable. In addition, the peak top molecular weight (Mp) in this specification means the value measured by the method described in the Example mentioned later.

  1-4 is preferable, as for molecular weight distribution (Mw / Mn) of hydrogenated block copolymer (I), 1-3 are more preferable, and 1-2 are still more preferable. When the molecular weight distribution is within the above range, the viscosity variation of the hydrogenated block copolymer (I) is small and easy to handle.

The block copolymer (P) is composed of the above-mentioned polymer block (a), polymer block (b) and polymer block (c), and other monomers as long as the effects of the present invention are not impaired. The polymer block (d) may be contained.
Examples of such other monomers include propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1- Unsaturated hydrocarbon compounds such as tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene; acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate , Acrylonitrile, methacrylonitrile, maleic acid, fumaric acid, crotonic acid, itaconic acid, 2-acryloylethanesulfonic acid, 2-methacryloylethanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, 2-methacrylamide-2 -Methylpropane sulfonic acid, vinyl sulfonic acid, vinegar Functional group-containing unsaturated compounds such as vinyl acid and methyl vinyl ether; These may be used alone or in combination of two or more.
When the block copolymer (P) has a polymer block (d), the content thereof is preferably 50% by mass or less, more preferably 40% by mass or less, further preferably 30% by mass or less, and more preferably 10% by mass or less. More preferably, 5 mass% or less is still more preferable.

  For example, the hydrogenated block copolymer (I) according to one aspect is a hydrogen of a block copolymer (P) including the polymer block (a), the polymer block (b), and the polymer block (c). In the polymer block (c), the content of (b1) is less than 1% by mass, and the content of the structural unit (b2) derived from a conjugated diene other than farnesene is 1 to 100% by mass. It is a certain polymer block, and the mass ratio of the polymer block (a) to the total amount of the polymer block (b) and the polymer block (c) [(a) / ((b) + (c ))] Is 1/99 to 70/30, and the hydrogenated block copolymer (I) comprises at least two polymer blocks (a), at least one polymer block (b), And at least one polymer block (c) And at least one of said polymer block (b) is a hydrogenated product of a block copolymer present at the end (P).

Here, the polymer block consisting only of poly (β-farnesene) is F, the polymer block consisting only of polystyrene is St, the polymer block consisting only of polyisoprene is Ip, the polymer block consisting only of polybutadiene is Bd, β -A polymer block consisting only of farnesene and isoprene is expressed as F / Ip, and a polymer block consisting only of β-farnesene and butadiene is expressed as F / Bd.
In this case, a hydrogenated product of a pentablock copolymer (F-St-Bd-St-F) in which F, St, Bd, St, F are combined in this order, and F, St, Ip, St, F Are preferably hydrogenated products of pentablock copolymers (F-St-Ip-St-F) formed by bonding in this order.

Moreover, the hydrogenated block copolymer (I) which concerns on another aspect is a hydrogenated triblock copolymer which has a block in order of a polymer block (a), a polymer block (b), and a polymer block (a). is there.
For example, a hydrogenated triblock copolymer (St-F-St) in which St, F, and St are bonded in this order, and a triblock copolymer in which St, F / Ip, and St are bonded in this order Hydrogenated product of (St- (F / Ip) -St), hydrogenated product of triblock copolymer (St- (F / Bd) -St) in which St, F / Bd, St are combined in this order Is preferred.

[Production Method of Hydrogenated Block Copolymer (I)]
The hydrogenated block copolymer (I) comprises, for example, a polymerization step for obtaining the block copolymer (P) by anionic polymerization, and a carbon-carbon double bond derived from farnesene present in the block copolymer (P). And a carbon-carbon double bond derived from a conjugated diene other than farnesene can be suitably produced.

<Polymerization process>
The block copolymer (P) can be produced by a solution polymerization method or a method described in JP-A-2012-502135, JP-A-2012-502136. Among them, the solution polymerization method is preferable, and known methods such as an ion polymerization method such as anion polymerization and cation polymerization, and a radical polymerization method can be applied. Of these, the anionic polymerization method is preferred. In the anionic polymerization method, an aromatic vinyl compound, farnesene and / or conjugated dienes other than farnesene are sequentially added in the presence of a solvent, an anionic polymerization initiator, and, if necessary, a Lewis base, to form a 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 earth metals and lanthanoid rare earth metals. Among them, an alkali metal and a compound containing an alkali metal are preferable, and an organic alkali metal compound is more preferable.

Examples of the organic alkali metal compound include methyl lithium, ethyl lithium, n-butyl lithium, sec-butyl lithium, t-butyl lithium, hexyl lithium, phenyl lithium, stilbene lithium, dilithiomethane, dilithionaphthalene, 1,4-dilithiobutane. Organic lithium compounds such as 1,4-dilithio-2-ethylcyclohexane and 1,3,5-trilithiobenzene; sodium naphthalene, potassium naphthalene and the like. Among these, an organic lithium compound is preferable, n-butyl lithium and sec-butyl lithium are more preferable, and sec-butyl lithium is particularly preferable. The organic alkali metal compound may be used as an organic alkali metal amide by reacting with a secondary amine such as diisopropylamine, dibutylamine, dihexylamine, and dibenzylamine.
The amount of the organic alkali metal compound used for the polymerization varies depending on the molecular weight of the block copolymer (P), but is usually 0.01 to 3 with respect to the total amount of the aromatic vinyl compound, farnesene and conjugated dienes other than farnesene. It is the range of mass%.

  The solvent is not particularly limited as long as it does not adversely affect the anionic polymerization reaction. For example, saturated aliphatic hydrocarbons such as n-pentane, isopentane, n-hexane, n-heptane and isooctane; cyclopentane, cyclohexane and methylcyclopentane And saturated alicyclic hydrocarbons; aromatic hydrocarbons such as benzene, toluene and xylene. These may be used alone or in combination of two or more. There is no restriction | limiting in particular in the usage-amount of a solvent.

  The Lewis base has a role of controlling the microstructure in the structural unit derived from farnesene and the structural unit derived from conjugated dienes other than farnesene. Examples of the Lewis base include ether compounds such as dibutyl ether, diethyl ether, tetrahydrofuran, dioxane, and ethylene glycol diethyl ether; pyridine; tertiary amines such as N, N, N ′, N′-tetramethylethylenediamine and trimethylamine; potassium Examples include alkali metal alkoxides such as t-butoxide; phosphine compounds. When using a Lewis base, it is preferable that the quantity is 0.01-1000 molar equivalent normally with respect to 1 mol of anionic polymerization initiators normally.

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 polymerization reaction may be carried out batchwise or continuously. Each monomer is continuously or intermittently supplied into the polymerization reaction solution so that the amount of aromatic vinyl compound, farnesene and / or conjugated diene other than farnesene in the polymerization reaction system falls within a specific range, Or a block copolymer (P) can be manufactured by superposing | polymerizing sequentially so that each monomer may become a specific ratio in a polymerization reaction liquid.
The polymerization reaction can be stopped by adding an alcohol such as methanol or isopropanol as a polymerization terminator. The block copolymer (P) is obtained by pouring the obtained polymerization reaction liquid into a poor solvent such as methanol to precipitate the block copolymer (P), or washing the polymerization reaction liquid with water, separating, and drying. Can be isolated.

In the main polymerization step, an unmodified block copolymer (P) may be obtained as described above, but before the hydrogenation step described later, a functional group is introduced into the block copolymer (P). A modified block copolymer (P) may be obtained, or a functional block may be introduced at the time of the hydrogenated block copolymer (I) to obtain a modified block copolymer. Examples of functional groups that can be introduced include amino groups, alkoxysilyl groups, hydroxyl groups, epoxy groups, carboxyl groups, carbonyl groups, mercapto groups, isocyanate groups, and acid anhydrides.
Examples of the modification method of the block copolymer (P) include, for example, tin tetrachloride, tetrachlorosilane, dimethyldichlorosilane, dimethyldiethoxysilane, and tetramethoxysilane that can react with a polymerization active terminal before adding a polymerization terminator. , Tetraethoxysilane, 3-aminopropyltriethoxysilane, tetraglycidyl-1,3-bisaminomethylcyclohexane, 2,4-tolylene diisocyanate, 4,4′-bis (diethylamino) benzophenone, N-vinylpyrrolidone, etc. Examples thereof include a method of adding a modifying agent or other modifying agents described in JP2011-132298A. In addition, maleic anhydride or the like can be grafted onto the isolated copolymer.
The position where the functional group is introduced may be the polymerization terminal of the block copolymer (P) or the side chain. Moreover, the said functional group may be used individually by 1 type or in combination of 2 or more types. It is preferable that the modifier is usually in the range of 0.01 to 10 molar equivalents relative to the anionic polymerization initiator.

<Hydrogenation process>
The hydrogenated block copolymer (I) can be obtained by subjecting the block copolymer (P) obtained by the above method or the modified block copolymer (P) to a hydrogenation step. A known method can be used for the hydrogenation. For example, in a solution in which the block copolymer (P) is dissolved in a solvent that does not affect the hydrogenation reaction, a Ziegler catalyst; nickel, platinum, palladium, ruthenium supported on carbon, silica, diatomaceous earth, etc. Rhodium metal catalyst: An organic metal complex having cobalt, nickel, palladium, rhodium or ruthenium metal is present as a hydrogenation catalyst to carry out a hydrogenation reaction. In the hydrogenation step, the hydrogenation reaction may be performed by adding a hydrogenation catalyst to the polymerization reaction solution containing the block copolymer (P) obtained by the method for producing the block copolymer (P). . In the present invention, palladium carbon in which palladium is supported on carbon is preferable.
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.

The total hydrogenation rate of the carbon-carbon double bond derived from the farnesene present in the polymer block (b) and the polymer block (c) and the carbon-carbon double bond derived from a conjugated diene other than farnesene is: From the viewpoint of obtaining a stretchable member having excellent elastic recovery, it is 50 to 100 mol%. The hydrogenation rate is preferably 70 to 100 mol%, more preferably 80 to 100 mol%, and still more preferably 90 to 100 mol%.
The hydrogenation rate can be calculated by measuring ¹ H-NMR of the block copolymer (P) and the hydrogenated block copolymer (I) after hydrogenation.

<Polystyrene resin (II)>
The thermoplastic elastomer composition according to the present embodiment may contain a polystyrene resin (II) in addition to the hydrogenated block copolymer (I). By containing the polystyrene resin (II), the strength of the stretchable member is improved.
The weight average molecular weight of the polystyrene resin (II) is preferably 100,000 to 400,000, more preferably 120,000 to 350,000, still more preferably 150,000 to 300,000. When the weight average molecular weight of the polystyrene resin (II) is 100,000 or more, heat resistance is improved, and when it is 400,000 or less, molding processability is improved.

  When the thermoplastic elastomer composition according to the present embodiment contains a polystyrene resin (II), the content thereof is 1 to 100 parts by mass of the hydrogenated block copolymer (I), and the polystyrene resin (II) is 1 to 1. A range of 70 parts by weight is preferred. When the polystyrene resin (II) is within this range, the strength of the thermoplastic elastomer composition is further improved. From this viewpoint, the content of the polystyrene resin (II) is more preferably 1 to 50 parts by mass, still more preferably 5 to 50 parts by mass, and still more preferably 100 parts by mass of the hydrogenated block copolymer (I). Preferably it is 10-50 mass parts, Most preferably, it is 15-50 mass parts.

<Softener (III)>
The thermoplastic elastomer composition of the present invention may further contain a softening agent (III). As the softener (III), softeners generally used for rubber and plastics can be used. For example, paraffinic, naphthenic, and aromatic process oils; phthalic acid derivatives such as dioctyl phthalate and dibutyl phthalate; white oil; mineral oil; liquid co-oligomer of ethylene and α-olefin; liquid paraffin; polybutene; low molecular weight poly Isobutylene: liquid polybutadiene, liquid polyisoprene, liquid polyisoprene / butadiene copolymer, liquid styrene / butadiene copolymer, liquid polydiene such as liquid styrene / isoprene copolymer, and hydrogenated products thereof. Among these, from the viewpoint of compatibility with the hydrogenated block copolymer (I), paraffinic process oil; liquid co-oligomer of ethylene and α-olefin; liquid paraffin; low molecular weight polyisobutylene and hydrogenated product thereof are preferable. A hydrogenated product of paraffinic process oil is more preferable.
As the softening agent (III), one kind may be used alone, or two or more kinds may be used in combination.

  When the thermoplastic elastomer composition according to the present embodiment contains the softening agent (III), the content of the softening agent (III) is 1 to 100 parts by mass of the hydrogenated block copolymer (I). A range of 150 parts by weight is preferred. When the softening agent (III) is within this range, the flexibility and moldability of the thermoplastic elastomer composition are further improved. From this viewpoint, the content of the softening agent (III) is more preferably 5 to 150 parts by mass, still more preferably 10 to 150 parts by mass, and still more preferably 100 parts by mass of the hydrogenated block copolymer (I). Preferably it is 15-120 mass parts.

[Other hydrogenated block copolymers]
The thermoplastic elastomer composition according to the present embodiment may contain other hydrogenated block copolymers other than the hydrogenated block copolymer (I).
As other hydrogenated block copolymer other than the hydrogenated block copolymer (I), for example, a block copolymer containing the polymer block (a) and the polymer block (c) is hydrogenated. And hydrogenated block copolymers. In addition, suitable aspects, such as a polymer block (a), polymer block (c), and a hydrogenation rate in other hydrogenated block copolymers, each polymer block in hydrogenated block copolymer (I) and This is the same as the preferred embodiment of the hydrogenation rate.
When the thermoplastic elastomer composition contains other hydrogenated block copolymer, the content thereof is preferably 100 parts by mass or less with respect to 100 parts by mass of the hydrogenated block copolymer (I).

<Other optional components>
The thermoplastic elastomer composition according to the present embodiment is within a range that does not impair the effects of the present invention, and if necessary, other thermoplastic polymer, inorganic filler, tackifier resin, antioxidant, lubricant, Light stabilizers, processing aids, colorants such as pigments and dyes, flame retardants, antistatic agents, matting agents, silicone oils, antiblocking agents, UV absorbers, mold release agents, foaming agents, antibacterial agents, fungicides An agent and a fragrance may be contained.
When other thermoplastic polymer is contained, the content thereof is preferably 100 parts by mass or less, more preferably 50 parts by mass or less, more preferably 100 parts by mass with respect to 100 parts by mass of the hydrogenated block copolymer (I). It is 20 mass parts or less, More preferably, it is 10 mass parts or less.

The inorganic filler can be contained for the purpose of improving the physical properties such as heat resistance and weather resistance of the thermoplastic elastomer composition of the present invention, adjusting the hardness, and improving the economy as an extender. Examples of the inorganic filler include calcium carbonate, talc, magnesium hydroxide, aluminum hydroxide, mica, clay, natural silicic acid, synthetic silicic acid, titanium oxide, carbon black, barium sulfate, glass balloon, and glass fiber. It is done. An inorganic filler may be used individually by 1 type, and may be used in combination of 2 or more type.
When the inorganic filler is contained, the content thereof is preferably in a range that does not impair the flexibility of the thermoplastic elastomer composition, and preferably 100 parts by weight of the hydrogenated block copolymer (I). 100 parts by mass or less, more preferably 70 parts by mass or less, still more preferably 30 parts by mass or less, and particularly preferably 10 parts by mass or less.

  The total amount of hydrogenated block copolymer (I), polystyrene resin (II), and softener (III) in the total amount of resin components of the thermoplastic elastomer composition according to the present embodiment is preferably 50 masses. % Or more, more preferably 60% by mass or more, still more preferably 80% by mass or more, still more preferably 90% by mass or more, and particularly preferably 95% by mass or more.

  The method for producing the thermoplastic elastomer composition of the present invention is not particularly limited, and the hydrogenated block copolymer (I) and, if necessary, the polystyrene resin (II), the softening agent (III), and other components are uniformly distributed. Any method that can be mixed may be used, and a melt-kneading method is preferably used. The melt kneading can be performed using a melt kneading apparatus such as a single screw extruder, a twin screw extruder, a kneader, a batch mixer, a roller, a Banbury mixer, and preferably by melt kneading at 170 to 270 ° C. The thermoplastic elastomer composition of the present invention can be obtained.

<Physical properties of thermoplastic elastomer composition>
The thermoplastic elastomer composition according to the present embodiment is a strip having a width of 25 mm and a length of 150 mm formed by compression molding the thermoplastic elastomer composition at 240 ° C. under a 10 MPa load for 3 minutes. The test piece obtained by punching into a shape is stretched 100% at a temperature of 23 ° C., and then contracted and shrunk, and the hysteresis loss rate in one cycle of recovery (hysteresis loss rate in the first cycle) is 20% or less. Therefore, the stretchable member formed by molding the physical properties of the thermoplastic elastomer composition is excellent in elastic recovery. The hysteresis loss rate is preferably 19% or less, more preferably 17% or less, and still more preferably 16% or less.

  From the same viewpoint, the second cycle of deformation and recovery when the test piece was stretched 100% at a speed of 100 mm / min at a temperature of 23 ° C. and then contracted at a speed of 100 mm / min for 2 cycles. The hysteresis loss rate is preferably 15% or less, more preferably 14% or less, still more preferably 13% or less, and still more preferably 12% or less.

Moreover, when the elastic member is expanded and contracted a plurality of times, it may be preferable that there is no significant change in the hysteresis loss rate. For example, when the elastic member is used for gathering a diaper, it is preferable that the feeling of use does not change greatly before and after the diaper is put on. From this viewpoint, the ratio (L ₂ / L ₁ ) of the hysteresis loss rate (L ₂ ) in the second cycle to the hysteresis loss rate (L ₁ ) in the first cycle is preferably 0.40 or more, more preferably 0 .50 or more, more preferably 0.60 or more, and still more preferably 0.70 or more.

  Furthermore, in the measurement of the hysteresis loss rate in the first cycle of the test piece, the tensile stress (100% modulus) when the test piece is stretched 100% at a temperature of 23 ° C. is from the viewpoint of the strength of the stretchable member. Preferably it is 0.02 MPa or more, More preferably, it is 0.05 MPa or more, More preferably, it is 0.10 MPa or more.

[2] Form of stretchable member The form of the stretchable material according to the present embodiment is not particularly limited, and may be a form suitable for each according to the application, usage form, and the like. For example, the stretchable material is preferably in the form of a film, a nonwoven fabric, a strand, or a strip.
In the case of a film made of the aforementioned stretchable material, its thickness and width are not particularly limited and can be appropriately selected. In general, the thickness of the film is preferably about 15 μm to 200 μm.
Even in the case of the nonwoven fabric made of the aforementioned stretchable material, the fineness of the fibers constituting the nonwoven fabric, the basis weight of the nonwoven fabric, etc. can be made suitable for each application. In general, in a nonwoven fabric-like stretchable material, the fibers constituting the nonwoven fabric are preferably long fibers having a uniform fineness because of excellent mechanical properties. Moreover, it is preferable from points, such as a handleability, that the fabric weight of this nonwoven fabric is about 5-300 g / m < ² >. The average fiber diameter of the nonwoven fabric is preferably 1 to 30 μm, more preferably 5 to 20 μm.

Further, when the stretchable material is a strand, the cross section can be in the form of a linear body, a string body, or the like having a circular, elliptical, square, or other cross sectional shape. Even when the stretchable material is a belt-like body, its thickness and width are not particularly limited and can be appropriately selected. In general, the thickness of the strip is preferably about 200 μm to 2 mm. And also when a stretchable material is a nonwoven fabric, the fineness of the fiber which comprises a nonwoven fabric, the fabric weight of a nonwoven fabric, etc. can be made suitable for each use. In general, in a nonwoven fabric-like stretchable material, the fibers constituting the nonwoven fabric are preferably long fibers having a uniform fineness because of excellent mechanical properties. Moreover, it is preferable from points, such as a handleability, that the fabric weight of this nonwoven fabric is about 5-200 g / m < ² >.

The method for forming the thermoplastic elastomer composition described above into a stretchable material can be appropriately selected according to the form of the stretchable material. For example, when the stretchable material is in the form of a film, a strand, or a nonwoven fabric. A molding method generally used when molding a thermoplastic polymer material into a film, a strand or a nonwoven fabric is suitably employed.
For example, when forming into a film and a strand, it can shape | mold into a film shape or a strand shape, respectively using a single screw or a biaxial extruder.
In addition, as a method for shaping into a nonwoven fabric, for example, a melt-blown nonwoven fabric is manufactured by melt spinning a thermoplastic elastomer composition with a normal melt-blown nonwoven fabric production apparatus and forming a fiber web on the collection surface of the fiber group. can do. A nonwoven fabric stretchable material can also be produced by a spunbond method.
The stretchable material according to the present embodiment can be used as a stretchable member as it is, but at least one stretchable fabric selected from an extensible fabric and a pleated fabric that can stretch in at least one direction; Laminating and adhering improves shape stability, for sanitary materials such as disposable diapers, toilet training pants, sanitary goods, and medical materials such as base materials for compresses, elastic tape, surgical bandages, and surgical clothes A necessary and complicated form of the elastic member can be obtained.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples. In addition, β-farnesene (purity 97.6% by mass Amiris, Inc., manufactured by Incorporated) was purified by 3Å molecular sieve and distilled in a nitrogen atmosphere, so that gingivalene, bisabolene, farnesene epoxide, farnesol isomerism This was used in the following polymerization, except for hydrocarbon impurities such as dimer, E, E-farnesol, squalene, ergosterol and several kinds of dimers of farnesene.

Each component used for an Example and a comparative example is as follows.
<Hydrogenated block copolymer (I)>
Hydrogenated block copolymers (I-1) to (I-9) of Production Examples 1 to 9 described later
<Hydrogenated block copolymer (I ')>
Hydrogenated block copolymers (I′-1) to (I′-8) of Production Examples 10 to 17 described later

<Polystyrene resin (II)>
GPPS (trade name: 679, manufactured by PS Japan, MFR: 18 g / 10 min, weight average molecular weight: 199,000)

<Softener (III)>
Hydrogenated paraffin process oil (trade name: Diana Process Oil PW-90, manufactured by Idemitsu Kosan Co., Ltd., kinematic viscosity at 40 ° C .: 95.54 mm ² / s)

Moreover, the detail of each measuring method in a manufacture example is as follows.
(1) Measurement of molecular weight distribution and peak top molecular weight (Mp), etc. The peak top molecular weight (Mp) and molecular weight distribution (Mw / Mn) of hydrogenated block copolymer and styrene block are determined by GPC (gel permeation chromatography). It calculated | required by the standard polystyrene conversion molecular weight, and calculated the peak top molecular weight (Mp) from the position of the vertex of the peak of molecular weight distribution. The measuring apparatus and conditions are as follows.
・ Device: GPC device “GPC8020” manufactured by Tosoh Corporation
Separation column: “TSKgel G4000HXL” manufactured by Tosoh Corporation
Detector: “RI-8020” manufactured by Tosoh Corporation
・ Eluent: Tetrahydrofuran ・ Eluent flow rate: 1.0 ml / min ・ Sample concentration: 5 mg / 10 ml
-Column temperature: 40 ° C

(2) Method of measuring hydrogenation rate In each of the examples and comparative examples, the block copolymer before hydrogenation and the block copolymer after hydrogenation (hydrogenated block copolymer) were dissolved in deuterated chloroform solvent, respectively. ¹ H-NMR was measured at 50 ° C. using “Lambda-500” manufactured by JEOL Ltd. The hydrogenation rate of the polymer blocks (b) and (c) in the hydrogenated block copolymer (I) is a proton possessed by a carbon-carbon double bond appearing at 4.5 to 6.0 ppm in the obtained spectrum. It calculated from the following peak by the following formula.
Hydrogenation rate (mol%) = {1− (number of moles of carbon-carbon double bonds contained per mole of block copolymer after hydrogenation) / (per mole of block copolymer before hydrogenation) Number of moles of carbon-carbon double bonds contained)} × 100

(3) Method for Measuring Hysteresis Loss Rate and 100% Modulus Thickness of the hydrogenated block copolymers and thermoplastic elastomer compositions obtained in Examples and Comparative Examples by compression molding at 240 ° C. under a 10 MPa load for 3 minutes. An approximately 0.5 mm sheet was obtained. From the obtained sheet, a strip-shaped test piece having a width of 25 mm and a length of 150 mm was used as a punching test piece. However, when evaluating the hysteresis loss rate and 100% modulus of the melt blown nonwoven fabric, the nonwoven fabric once produced was remelted into a sheet shape, and a punched test piece having the above size was produced from the obtained sheet.
Using a tensile tester “3345 model” manufactured by Instron Co., Ltd., it is stretched 100% at a test speed of 100 mm / min at a distance between grips of 40 mm and a test temperature of 23 ° C., and then reduced to 0% at a test speed of 100 mm / min. This operation was performed for 2 cycles.
The maximum tensile stress at the time of 100% elongation at the first cycle at that time was taken as 100% modulus.
Also, 100% extension energy [A1 (100% going)] for the first cycle, 100% extension energy [B1 (100% return)] for the first cycle, 100% extension energy [A2 (outbound) for the second cycle 100%)], 100% return energy [B2 (return 100%)] was measured. The hysteresis loss rate at the first cycle and the hysteresis loss rate at the second cycle were obtained by the following formula and used as an index of elastic recovery. In addition, it shows that it is excellent in elastic recoverability, so that the following value is low.
Hysteresis loss rate in the first cycle (L ₁ ) = [(A1−B1) / A1] × 100
Hysteresis loss rate in the second cycle (L ₂ ) = [(A2−B2) / A2] × 100

(4) Fabric weight of nonwoven fabric (g / m ² )
According to JIS L 1906, three sample pieces measuring 20 cm in length and 20 cm in width were sampled from 1 m of nonwoven fabric width, the mass of each sample piece was measured with an electronic balance, and the average value of the three points was 400 cm in area of the test piece. ^By dividing by ² , the mass per unit area was calculated and used as the basis weight of the nonwoven fabric.

(5) Average fiber diameter of nonwoven fabric (μm)
An arbitrary value in the nonwoven fabric was magnified by 300 times with a scanning electron microscope, and an average value of values obtained by measuring 50 fiber diameters was defined as an average fiber diameter.

(6) Melt blow moldability evaluation method Using the hydrogenated block copolymers and thermoplastic elastomer compositions obtained in the examples and comparative examples, a melt blown nonwoven fabric was prepared by the method described later, and according to the results, The melt blow moldability was evaluated in the following three stages.
○: A good nonwoven fabric is obtained, and the productivity is excellent.
(Triangle | delta): Although a nonwoven fabric is obtained, many fluffs generate | occur | produce and productivity is poor.
X: A nonwoven fabric cannot be obtained.

<Hydrogenated block copolymer (I)>
[Production Example 1]
A pressure-resistant container purged with nitrogen and dried was charged with 50.0 kg of cyclohexane as a solvent and 36.9 g of sec-butyllithium (10.5 mass% cyclohexane solution) as an anionic polymerization initiator (3.9 g of sec-butyllithium). The temperature was raised to 50 ° C., 1.87 kg of styrene (1) was added and polymerized for 1 hour, then 8.75 kg of β-farnesene was added and polymerized for 2 hours, and 1.87 kg of styrene (2) was further added. In addition, polymerization was performed for 1 hour to obtain a reaction solution containing a polystyrene-poly (β-farnesene) -polystyrene triblock copolymer. To this reaction solution, 5% by mass of palladium carbon (palladium supported amount: 5% by mass) as a hydrogenation catalyst was added to the block copolymer, and the reaction was performed for 10 hours under conditions of a hydrogen pressure of 2 MPa and 150 ° C. . After allowing to cool and release the pressure, palladium carbon is removed by filtration, the filtrate is concentrated, and further dried under vacuum to obtain a hydrogenated polystyrene-poly (β-farnesene) -polystyrene triblock copolymer (hereinafter referred to as water). A block copolymer (referred to as I-1)) was obtained. The above-described evaluation was performed on the hydrogenated block copolymer (I-1). The results are shown in Table 1.

[Production Examples 2 to 4]
Hydrogenated block copolymers (I-2) to (I-4) were produced in the same manner as in Production Example 1 except that the composition described in Table 1 was followed. The obtained hydrogenated block copolymers (I-2) to (I-4) were evaluated as described above. The results are shown in Table 1.

[Production Example 5]
A pressure-resistant container purged with nitrogen and dried was charged with 50.0 kg of cyclohexane as a solvent and 58.9 g of sec-butyllithium (10.5 mass% cyclohexane solution) as an anionic polymerization initiator (sec-butyllithium 6.2 g). The temperature was raised to 50 ° C., 1.32 kg of styrene (1) was added and polymerized for 1 hour, and subsequently, a mixture of 3.09 kg of β-farnesene and 3.09 kg of isoprene was added for polymerization for 2 hours. (2) A reaction liquid containing polystyrene-poly (β-farnesene / isoprene) -polystyrene triblock copolymer was obtained by adding 1.32 kg and polymerizing for 1 hour. To this reaction solution, 5% by mass of palladium carbon (palladium supported amount: 5% by mass) as a hydrogenation catalyst was added to the block copolymer, and the reaction was performed for 10 hours under conditions of a hydrogen pressure of 2 MPa and 150 ° C. . After standing to cool and release the pressure, palladium carbon is removed by filtration, the filtrate is concentrated, and further dried under vacuum to obtain a hydrogenated polystyrene-poly (β-farnesene / isoprene) -polystyrene triblock copolymer (hereinafter referred to as “polyhydride”). Hydrogenated block copolymer (I-5)) was obtained. The above-described evaluation was performed on the hydrogenated block copolymer (I-5). The results are shown in Table 1.

[Production Example 6]
Hydrogenation of polystyrene-poly (β-farnesene / butadiene) -polystyrene triblock copolymer in the same manner as in Production Example 1 except that butadiene was used instead of isoprene and the formulation shown in Table 1 was followed. Product (hereinafter referred to as hydrogenated block copolymer (I-6)) was produced. The above-mentioned evaluation was performed about the obtained hydrogenated block copolymer (I-6). The results are shown in Table 1.

[Production Example 7]
Hydrogenated product of polystyrene-poly (β-farnesene) -polystyrene triblock copolymer in the same manner as in Production Example 1 except that the conditions of the hydrogenation step were changed so as to achieve the hydrogenation rates shown in Table 1. (Hereinafter referred to as hydrogenated block copolymer (I-7)) was produced. The above-mentioned evaluation was performed about the obtained hydrogenated block copolymer (I-7). The results are shown in Table 1.

[Production Example 8]
In a pressure vessel that has been purged with nitrogen and dried, 50.0 kg of cyclohexane as a solvent, 190.5 g of sec-butyl lithium (10.5 mass% cyclohexane solution) as an anionic polymerization initiator (20.0 g of sec-butyl lithium), Lewis After adding 400.0 g of tetrahydrofuran as a base and raising the temperature to 50 ° C., 6.34 kg of β-farnesene was added, followed by polymerization for 2 hours, followed by addition of 2.50 kg of styrene (1) and polymerization for 1 hour. 3.66 kg of butadiene was added and polymerization was performed for 1 hour. Subsequently, 20.0 g of dichlorodimethylsilane as a coupling agent was added to the polymerization reaction solution and reacted for 1 hour, so that a poly (β-farnesene) -polystyrene-polybutadiene-polystyrene-poly (β-farnesene) pentablock copolymer was obtained. A reaction solution containing was obtained. To this reaction solution, 5% by mass of palladium carbon (palladium supported amount: 5% by mass) as a hydrogenation catalyst was added to the block copolymer, and the reaction was performed for 10 hours under conditions of a hydrogen pressure of 2 MPa and 150 ° C. . After allowing to cool and release the pressure, the palladium carbon is removed by filtration, the filtrate is concentrated, and further dried under vacuum, so that poly (β-farnesene) -polystyrene-polybutadiene-polystyrene-poly (β-farnesene) pentablock copolymer A combined hydrogenated product (hereinafter referred to as hydrogenated block copolymer (I-8)) was obtained. With respect to the hydrogenated block copolymer (I-8), the above physical properties were measured. The results are shown in Table 1.

[Production Example 9]
Poly (β-farnesene) -polystyrene-polyisoprene-polystyrene--in the same manner as in Production Example 8 except that isoprene was used in place of butadiene, the use of tetrahydrofuran was omitted, and the formulation shown in Table 1 was followed. A hydrogenated product of poly (β-farnesene) pentablock copolymer (hereinafter referred to as hydrogenated block copolymer (I-9)) was produced. The above-mentioned evaluation was performed about the obtained hydrogenated block copolymer (I-9). The results are shown in Table 1.

<Hydrogenated block copolymer (I ')>
[Production Example 10]
A hydrogenated block copolymer (I′-1) was produced in the same manner as in Production Example 1, except that the composition described in Table 2 was followed. The obtained hydrogenated block copolymer (I′-1) was evaluated as described above. The results are shown in Table 2.
[Production Examples 11 and 12]
Hydrogenated block copolymers (I′-2) and (I′-3) were prepared in the same manner as in Production Example 10 except that isoprene was blended instead of β-farnesene and the blending described in Table 2 was followed. Manufactured. The obtained hydrogenated block copolymers (I′-2) and (I′-3) were evaluated as described above. The results are shown in Table 2.
[Production Example 13]
A hydrogenated block copolymer (I′-4) was prepared in the same manner as in Production Example 10 except that butadiene was blended in place of β-farnesene, tetrahydrofuran was mixed with cyclohexane as a solvent, and the blend described in Table 2 was followed. ) Was manufactured. The above-mentioned evaluation was performed about the obtained hydrogenated block copolymer (I'-4). The results are shown in Table 2.
[Production Examples 14 to 17]
Hydrogenated block copolymers (I′-5) to (I ′) in the same manner as in Production Example 10 except that a mixture of isoprene and butadiene was blended instead of β-farnesene and the blending described in Table 2 was followed. -8) was produced. The obtained hydrogenated block copolymers (I′-5) to (I′-8) were evaluated as described above. The results are shown in Table 2.

[Examples 1-8 and Comparative Examples 1-8]
Each hydrogenated block copolymer described in Table 3 was used as a thermoplastic elastomer composition.
Each thermoplastic elastomer composition was compression molded at 240 ° C. under a 10 MPa load for 3 minutes to obtain a sheet (stretchable member or film) having a thickness of about 0.5 mm. The physical properties of the obtained sheet were evaluated as described above. The results are shown in Table 3.

[Examples 9 to 15 and Comparative Examples 9 to 16]
Each component shown in Table 4 was melt-kneaded at a ratio shown in Table 4 using a batch mixer at 230 ° C. and a screw rotation speed of 200 rpm to prepare a thermoplastic elastomer composition.
The obtained thermoplastic elastomer composition was compression-molded at 240 ° C. under a 10 MPa load for 3 minutes to obtain a sheet (elastic member or film) having a thickness of about 0.5 mm. The physical properties of the obtained sheet were evaluated as described above. The results are shown in Table 4.

[Examples 16 to 19 and Comparative Examples 17 to 18]
(1) Preparation of thermoplastic elastomer composition The components shown in Table 5 were melt-kneaded at a ratio shown in Table 5 using a batch mixer under the conditions of 230 ° C and a screw rotation speed of 200 rpm to produce a thermoplastic elastomer composition. A product was made.
(2) Production of melt blown non-woven fabric The thermoplastic elastomer composition described in Table 5 was melted with a 40 mmφ single screw extruder and then fed into a die at 300 ° C. Using a melt blown spinning machine with 0.3mmφ orifices arranged at 1mm pitch and slits for jetting heated gas on both sides, polymer is discharged at a discharge rate of 0.3g / min per hole and heated to 300 ° C The air was refined by spraying with a hot air amount of 2.8 Nm ³ / min per 1 m width. This was collected on a wire mesh belt installed 15 cm below the nozzle and taken up by a rear take-up machine to obtain a nonwoven fabric (elastic member). The obtained nonwoven fabric had a basis weight of 150 g / m ² and a filament diameter (average fiber diameter) of 9 μm.
(3) Evaluation The melt-blown nonwoven fabric described above was remelted at 240 ° C., and then compression molded for 3 minutes under a 10 MPa load to obtain a sheet having a thickness of about 0.5 mm. The physical properties of the obtained sheet were evaluated as described above. The results are shown in Table 5.

The elastic member according to the example has a hysteresis loss rate (L ₁ ) of the first cycle of 20% or less, and is excellent in elastic recovery. Also, stretchable member according to embodiments, second cycle hysteresis loss rate _{(L 2)} is low, also higher these ratios _(L 2 / L _1).
On the other hand, the elastic member according to the comparative example has a hysteresis loss rate (1) at the first cycle of more than 20%, and the elastic recoverability is inferior to the elastic member according to the example.

Claims (15)

An elastic member formed by molding a thermoplastic elastomer composition containing the hydrogenated block copolymer (I),
The hydrogenated block copolymer (I) contains 1 to 100% by mass of a polymer block (a) containing a structural unit derived from an aromatic vinyl compound and a structural unit (b1) derived from farnesene, and other than farnesene. A polymer block (b) containing 99 to 0% by mass of a structural unit (b2) derived from a conjugated diene, and a mass ratio of the polymer block (a) and the polymer block (b) [(a) / (B)] is a hydrogenated product of the block copolymer (P) having a ratio of 1/99 to 70/30, and is carbon-carbon derived from farnesene present in the block copolymer (P). 50 mol% or more of the total of carbon-carbon double bonds derived from conjugated dienes other than heavy bonds and farnesene is hydrogenated,
A test piece obtained by punching the thermoplastic elastomer composition into a strip having a width of 25 mm and a length of 150 mm from a sheet having a thickness of 0.5 mm formed by compression molding at 240 ° C. under a load of 10 MPa for 3 minutes is used. A stretchable member having a hysteresis loss rate of 20% or less in one cycle of deformation and recovery after stretching 100% at 100C and then shrinking.   The elastic member of Claim 1 which contains 1-50 mass parts of polystyrene resins (II) with respect to 100 mass parts of said hydrogenated block copolymers (I).   The elastic member according to claim 1 or 2, comprising 1 to 150 parts by mass of the softening agent (III) with respect to 100 parts by mass of the hydrogenated block copolymer (I).   When the test piece was stretched 100% at a speed of 100 mm / min at a temperature of 23 ° C. and then contracted at a speed of 100 mm / min for 2 cycles, the hysteresis loss rate of the second cycle of deformation and recovery was as follows. The elastic member according to any one of claims 1 to 3, which is 15% or less. 5. The ratio (L ₂ / L ₁ ) of the hysteresis loss rate (L ₂ ) in the second cycle to the hysteresis loss rate (L ₁ ) in the first cycle is 0.40 or more. Elastic member.   The peak top molecular weight (Mp) calculated | required by the gel permeation chromatography of the said hydrogenated block copolymer (I) in standard polystyrene conversion is 4,000-500,000, It is in any one of Claims 1-5. Elastic member.   The stretchable member according to any one of claims 1 to 6, wherein the aromatic vinyl compound is styrene.   The stretchable member according to any one of claims 1 to 7, wherein the farnesene is β-farnesene.   The stretchable member according to any one of claims 1 to 8, wherein the conjugated diene other than the farnesene is at least one selected from isoprene, butadiene, and myrcene.   The elastic member in any one of Claims 1-9 whose molecular weight distribution (Mw / Mn) of the said hydrogenated block copolymer (I) is 1-4.   In the hydrogenated block copolymer (I), carbon-carbon double bonds derived from farnesene present in the block copolymer (P) and carbon-carbon double bonds derived from conjugated dienes other than farnesene. The stretchable member according to any one of claims 1 to 10, wherein the total hydrogenation rate is 70 mol% or more.   The hydrogenated block copolymer (I) is a hydrogenated triblock copolymer having blocks in the order of a polymer block (a), a polymer block (b), and a polymer block (a). The elastic member in any one of -11.   The elastic member in any one of Claims 1-12 in which the said polymer block (b) consists only of a structural unit (b1) derived from farnesene.   The film which consists of an elastic member in any one of Claims 1-13.   The nonwoven fabric which consists of an elastic member in any one of Claims 1-13.