JP4615357B2 - Thermoplastic polymer composition, molded article and multilayer structure excellent in barrier property - Google Patents

Description

  The present invention relates to a thermoplastic polymer composition having good molding processability, flexibility, rubber elasticity, and excellent gas barrier properties, a molded article comprising the thermoplastic polymer composition, and the thermoplastic polymer. It relates to the use of the composition.

  In recent years, thermoplastic elastomers, which are soft materials with rubber elasticity and do not require a vulcanization process and can be processed and recycled in the same way as thermoplastic resins, are automotive parts, home appliance parts, electric wire coatings, medical parts It is widely used in fields such as miscellaneous goods and footwear. Among such thermoplastic elastomers, the hydrogenated vinyl aromatic compound-conjugated diene compound block copolymer is excellent in rubber elasticity, flexibility, and molding processability. ing.

  However, in general, thermoplastic elastomers such as the above-mentioned hydrogenated block copolymers have poor barrier properties against gases such as oxygen, nitrogen, and carbon dioxide, and sheets and films that require such barrier properties. Actually, it is extremely difficult to apply to packaging materials for food and drink, containers, packing for containers, tubes, hoses and the like.

Therefore, butyl rubber is usually used for applications that require gas barrier properties, rubber elasticity, and flexibility. However, in order to generate rubber elasticity in a molded product using butyl rubber, a complicated vulcanization process is required after molding.
Therefore, the present applicant has conducted intensive studies to find a polymer material excellent in rubber elasticity, flexibility, and gas barrier properties without requiring a vulcanization step. The present applicant has compared the ethylene-vinyl alcohol copolymer having a high barrier property against gas, organic liquid, etc., and the hydrogenated product of the above-mentioned vinyl aromatic compound-conjugated diene compound block copolymer. We focused on vinyl aromatic compound-isobutylene compound block copolymer, which is excellent in gas barrier properties. As a result, in the polymer composition in which the vinyl aromatic compound-isobutylene compound block copolymer is a substantial matrix and the ethylene-vinyl alcohol copolymer is in a substantially dispersed particle state, the barrier property, rubber elasticity And found that the flexibility is satisfied (Patent Document 1).
Also, a vinyl aromatic compound-conjugated diene compound having a functional group selected from the group consisting of boron-containing groups in a matrix of an ethylene-vinyl alcohol copolymer having a high barrier property against gases, organic liquids, etc. It has been found that a polymer composition in which a block copolymer or a hydrogenated product thereof is dispersed can compensate for the disadvantages of an ethylene-vinyl alcohol copolymer having excellent gas barrier properties and poor flexibility. (Patent Document 2).

The present applicant has a polymer block composed of vinyl aromatic monomer units limited by means for solving the problems described later, and a polymer block composed of isoprene or butadiene units and optionally hydrogenated. A technique similar to a thermoplastic polymer composition comprising a block copolymer and an acrylic resin has been proposed (Patent Documents 3 and 4). These will be described later. Further, Patent Document 5 and Non-Patent Documents 1 to 3 are cited in the best mode for carrying out the invention described later.
Japanese Patent Laid-Open No. 10-110086 JP 2002-338772 A JP-A-5-295216 JP 2004-2657 A JP 2003-73434 A Macromolecules, 2, 453-458, 1969 Kautschuk Gummi Kunststoff, 37, 377-379, 1984 Polym. Bull. 12, pp. 71-77, 1984

The polymer composition disclosed in Patent Document 1 has a problem of high production costs. This is because in order to synthesize a polymer block composed of the isobutylene monomer unit, it is necessary to produce the polymer block in an extremely low temperature environment, which requires refrigeration costs. In addition, there is a concern that the use of a halogen-based solvent places a large burden on the environment, and further, the use of a Lewis acid as a metal catalyst tends to leave metal residues.
The polymer composition disclosed in Patent Document 2 is superior in flexibility as compared to an ethylene-vinyl alcohol copolymer having poor flexibility, but further improvement in flexibility is desired. By the way.

  The present invention has been made in view of the above-mentioned background. The object of the present invention is to provide the following thermoplastic polymer composition, a molded article comprising the thermoplastic polymer composition, and the thermoplastic resin. It is to provide a multilayer structure having a layer composed of a polymer composition. That is, although it is inferior to the gas barrier property compared with a vinyl aromatic compound-isobutylene compound block copolymer, the production cost can be reduced, there is less concern about metal residues, and the vinyl aromatic has a low environmental impact in the production process. A compound-hydrogenated conjugated diene compound block copolymer is used to provide a thermoplastic polymer composition having excellent flexibility and rubber elasticity and excellent gas barrier properties.

  The present inventors have repeatedly studied to achieve the above object. As a result, the vinyl aromatic compound-isobutylene compound block copolymer is generally inferior in gas barrier properties but is advantageous in terms of production cost, and the vinyl aromatic compound-conjugated which may be hydrogenated. It has been found that the object of the present invention can be achieved in the following compositions in which conditions are set in a composite manner using a diene compound block copolymer, and the present invention has been completed.

The thermoplastic polymer composition according to the present invention is a hydrogenated polymer comprising a vinyl aromatic monomer polymer block (a) and a total ratio of 1,2-bonds and 3,4-bonds of 30 [mol%] or more. which may have been ing mainly from the good isoprene and / or consisting of butadiene units a conjugated diene polymer block or a conjugated diene copolymer block (b). A block copolymer having an oxygen permeability coefficient of 60000 [(ml · 20 μm) / (m ² · day · atm)] or less measured using a gas permeability measuring device under conditions of a temperature of 35 ° C. and a humidity of 0% RH ( in a), but the oxygen permeability contains 3000 and ^{[(ml · 20μm) / (} m 2 · day · atm)] or less of the acrylic resin (B) as the main component. When at least the content of the vinyl aromatic monomer polymer block (a) in the block copolymer (A) exceeds 16% by mass, a rubber softener (C) is added, and the vinyl When the content of the aromatic monomer polymer block (a) exceeds 16% by mass, the content of the softening agent for rubber (C) is as follows: the block copolymer (A), the acrylic resin (B) and 10 parts by mass or more and 24 parts by mass or less with respect to 100 parts by mass of the total mass of the softener for rubber (C), and the vinyl aromatic monomer polymer block (a) in the block copolymer (A). When the content is 16% by mass or less, the rubber softener (C) is not added, or 1 part of the rubber softener (C) is added to 100 parts by weight of the block copolymer (A). Part to 200 parts by weight, and the acrylic tree The content of (B) is 40 parts by mass or more and 60 parts by mass with respect to 100 parts by mass of the total mass of the block copolymer (A), the acrylic resin (B), and the rubber softener (C). Not more than part by mass. Further, in a matrix consisting of at least the block copolymer component (A), the acrylic resin (B) component is present in the form of substantially dispersed phase, Op the oxygen permeability coefficient of the dispersed phase, the When the weight fraction of the dispersed phase is Wp, the oxygen permeability coefficient of the matrix is Om, and the weight fraction of the matrix is Wm, the following formula 1 is satisfied.
<Equation 1> Op × Wp + Om × Wm <25000

  According to the thermoplastic polymer composition of the present invention, hydrogenation mainly comprising isoprene and / or butadiene units in which the total ratio of 1,2-bonds and 3,4-bonds is 30 [mol%] or more. Since the conjugated diene polymer block which may be included is included, the oxygen permeability coefficient can be reduced as compared with the conventional vinyl aromatic compound-conjugated diene compound block copolymer and a hydrogenated product thereof. Further, an acrylic resin having a small oxygen permeability coefficient (advantageous to gas blocking property) is finely dispersed in the matrix containing at least the block copolymer (A) as a constituent component, and the above formula 1 is satisfied. As a result, the oxygen permeability coefficient of the entire thermoplastic polymer composition can be greatly reduced without impairing the flexibility and elasticity of the block copolymer (A). As a result, it is possible to provide a thermoplastic polymer composition having good moldability, rubber elasticity and flexibility, and having excellent barrier properties against liquids and gases.

In addition, in the said patent document 3, this applicant is abba structure (a: the block which consists of an aromatic vinyl monomer, b: the block which consists of isoprene and / or butadiene) with respect to acrylic resin. And a thermoplastic resin composition containing a hydrogenation product of a ternary block copolymer having a specific number average molecular weight in a specific blending ratio. As a result, surface properties such as surface hardness, weather resistance, transparency, etc. possessed by the acrylic resin can be maintained, and properties such as flexibility and low temperature properties can be combined. However, this invention does not reach the present invention in terms of gas barrier properties and flexibility.
Moreover, in the said patent document 4, the polymer block of the specific weight average molecular weight which has a polymer block which mainly has (alpha) -methylstyrene, and a polymer block which may consist of a conjugated diene or isobutylene and may be hydrogenated, A thermoplastic resin composition in which an acrylic resin and a softening agent are set to a specific blending ratio is proposed. Thereby, it was possible to combine various physical properties such as molding processability, scratch resistance, abrasion resistance, flexibility, mechanical strength, rubber elasticity, and transparency. However, it does not reach the present invention in terms of gas barrier properties.

Further, preferred examples of the thermoplastic polymer composition rubber softener to be added as required to the product (C) of the present invention, it may be mentioned polybutene, or polyisobutylene.

  Moreover, as a suitable example of the said vinyl aromatic monomer polymer block in the thermoplastic polymer composition of this invention, the polymer block which has an alpha-methylstyrene unit as a main can be mentioned. By using a poly α-methylstyrene block having a high glass transition temperature (Tg) among vinyl aromatic monomer polymer blocks, it is possible to satisfy low compression set at high temperature in addition to the above-mentioned properties. it can.

  The molded article of the present invention is composed of the thermoplastic polymer composition described above. Furthermore, the present invention is a multilayer molded article having a layer made of the thermoplastic polymer composition, a tube having at least one layer made of the thermoplastic polymer composition, and a container packing.

  According to the present invention, a thermoplastic polymer composition, which is excellent in molding processability, flexibility, rubber elasticity, liquid and gas barrier properties, has a simple manufacturing process, and can reduce manufacturing costs. Product and a multilayer structure having a layer made of this thermoplastic polymer composition can be provided.

Hereinafter, the present invention will be described in detail. The thermoplastic polymer composition according to the present invention contains a block copolymer (A) described below as a matrix component and an acrylic resin (B) described later as a dispersed phase component. In the thermoplastic polymer composition according to the present invention, the oxygen permeability coefficient of the dispersed phase is Op, the weight fraction of the dispersed phase is Wp, the oxygen permeability coefficient of the matrix is Om, and the weight fraction of the matrix is Wm. Sometimes, the following formula 1 is satisfied.
<Equation 1> Op × Wp + Om × Wm <25000

(Block Copolymer (A)) The block copolymer (A) used in the thermoplastic polymer composition according to the present invention is a polymer block (i) mainly composed of vinyl aromatic monomer units (hereinafter referred to as “vinyl”). Abbreviated as “aromatic monomer polymer block (i)”), and a hydrogenated isoprene having a total ratio of 1,2-bond and 3,4-bond of 30 [mol%] or more and / or Or a polymer block or copolymer block (ii) mainly composed of butadiene units (hereinafter abbreviated as “conjugated diene polymer block (ii)”), having an oxygen permeability coefficient of 60000 [(ml · 20 μm) / ^{(m 2 · day · atm)} ] (6.8 × 10 3 [(fm · 20μm) / (Pa · s)] That is, 60000 × 0.113 [(fm · 20μm) / (Pa · s) ) Are as follows.

  As long as the vinyl aromatic monomer polymer block (i) and the conjugated diene polymer block (ii) are bonded to each other, the block copolymer (A) is not limited in the bonding type, and is linear or branched. , Radial, or a combination of two or more of them. Among them, the bond type of the vinyl aromatic monomer polymer block (i) and the conjugated diene polymer block (ii) is preferably linear, and examples thereof include a vinyl aromatic monomer polymer block ( When i) is represented by a and the conjugated diene polymer block (ii) is represented by b, a diblock copolymer represented by ab, a triblock copolymer represented by aba, a A tetrablock copolymer represented by -b-a-b or a multiblock copolymer structure in which 5 or more of a and b are linearly bonded can be employed. Among these, a triblock copolymer (abba) is preferably used from the viewpoints of flexibility and mechanical properties of the resulting thermoplastic polymer composition.

  Examples of the vinyl aromatic monomer used for forming the vinyl aromatic monomer polymer block (i) constituting the block copolymer (A) include styrene, α-methylstyrene, β-methylstyrene, and o-methylstyrene. , M-methylstyrene, p-methylstyrene, t-butylstyrene, 2,4-dimethylstyrene, 2,4,6-trimethylstyrene, monofluorostyrene, difluorostyrene, monochlorostyrene, dichlorostyrene, methoxystyrene, vinylnaphthalene Vinyl aromatic compounds such as vinyl anthracene, indene and acetonaphthylene. The vinyl aromatic monomer polymer block (i) may have a structural unit composed of only one kind of the vinyl aromatic compound described above, or may have a structural unit composed of two or more kinds. Among them, the vinyl aromatic monomer polymer block (i) is preferably mainly composed of structural units derived from styrene. Among them, it is more preferable that the main unit is a structural unit derived from α-methylstyrene. The reason will be described later.

  The vinyl aromatic monomer polymer block (i) includes a structural unit composed of a vinyl aromatic compound and other copolymerizable monomers as necessary, for example, 1-butene, pentene, hexene, butadiene, isoprene, methyl vinyl ether. A small amount of structural units such as In this case, the proportion of the structural unit composed of another copolymerizable monomer is preferably 30 [mass%] or less based on the mass of the vinyl aromatic monomer polymer block (i), and preferably 10 [mass%]. The following is more preferable.

The conjugated diene compound used for forming the conjugated diene polymer block (ii) constituting the block copolymer (A) together with the vinyl aromatic monomer polymer block (i) is mainly composed of (1) mainly an isoprene unit. A hydrogenated polyisoprene block composed of a monomer unit comprising a hydrogenated polyisoprene block or a part or all of its unsaturated bonds (hereinafter sometimes referred to as “hydrogenation”), and (2) a monomer mainly composed of a butadiene unit. A polybutadiene block comprising units, a hydrogenated polybutadiene block in which a part or all of the unsaturated bonds thereof are hydrogenated, or (3) an isoprene / butadiene copolymer block comprising monomer units mainly composed of isoprene units and butadiene units, or Hydrogenated isoprene in which some or all of the unsaturated bonds are hydrogenated. / Butadiene copolymer block, and the total content of 3,4-bonds and 1,2-bonds in the above (1), (2), and (3) is 30 [mol%] or more, preferably It consists of 40 [mol%] or more structural units. Among them, a hydrogenated polyisoprene block or a hydrogenated isoprene / butadiene copolymer block containing 40 [% by mass] or more of isoprene units from the viewpoint of good gas barrier properties of the thermoplastic polymer composition. Is preferred.
In the isoprene / butadiene copolymer block, the arrangement of isoprene units and butadiene units may be any of random, block, and tapered block.

  The conjugated diene polymer block (ii) has other copolymerizable monomers, for example, hexadiene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene and the like as necessary. May be. When the conjugated diene polymer block (ii) has a structural unit derived from two or more kinds of conjugated diene compounds, the bonding form thereof is random, tapered, partially blocked, or two or more kinds thereof. Any of combinations may be used.

The unsaturated double bond in the conjugated diene polymer block (ii) is preferably partially or entirely hydrogenated. This is because hydrogen shielding makes the gas barrier property, heat resistance and weather resistance of the thermoplastic polymer composition good. The hydrogenation rate of the conjugated diene polymer block (ii) is preferably 50 [mol%] or more, and preferably 60 [mol%] or more from the viewpoints of barrier properties against heat, heat resistance, and weather resistance. Is more preferable, and it is more preferable that it is 80 [mol%] or more. The hydrogenation rate of the unsaturated double bond derived from the conjugated diene unit in the hydrogenated block copolymer (A) is determined by iodine titration method, infrared spectroscopic measurement, nuclear magnetic resonance spectrum ( ¹ H-NMR It can be calculated using analytical means such as (spectrum) measurement.

In the block copolymer (A), the mass ratio of the vinyl aromatic monomer polymer block (i) and the conjugated diene polymer block (ii) is determined from the viewpoints of flexibility, mechanical properties, and molding processability of the obtained molded product. Therefore, it is preferable that vinyl aromatic monomer polymer block (i): conjugated diene polymer block (ii) = 5: 95 to 40:60, and vinyl aromatic monomer polymer block (i): conjugated diene polymer. More preferably, the block (ii) = 10: 90 to 30:70.
In the block copolymer (A), the molecular weight of the vinyl aromatic monomer polymer block (i) and the molecular weight of the conjugated diene polymer block (ii) are not particularly limited, but in the state before hydrogenation, the vinyl aromatic The number average molecular weight Mn of the monomer polymer block (i) is in the range of 1,000 to 100,000, and the number average molecular weight of the conjugated diene polymer block (ii) is in the range of 10,000 to 500,000. It is preferable from the viewpoints of the mechanical properties and molding processability of the thermoplastic polymer composition.
The number average molecular weight here refers to a value obtained from a standard polystyrene calibration curve by gel permeation chromatography (GPC).

  The block copolymer (A) can be produced, for example, by an ion polymerization method such as anionic polymerization or cationic polymerization, a single site polymerization method, or a radical polymerization method. For example, in the case of the anionic polymerization method, a vinyl aromatic compound and a conjugated diene compound are sequentially polymerized in an inert organic solvent such as n-hexane or cyclohexane in the presence of an anionic polymerization initiator such as an alkyl lithium compound. The block copolymer (preferably a triblock copolymer) having a molecular structure and a number average molecular weight is produced, and then an active hydrogen compound such as alcohols, carboxylic acids or water is added to stop the polymerization. can do.

  By the way, with the recent progress of industrial technology, the demand for using a thermoplastic elastomer at a high temperature tends to increase in the market, and development of a thermoplastic elastomer excellent in high temperature characteristics is strongly desired. High temperature characteristics are particularly required in application fields such as automobile parts, electrical / electronic parts, films / sheets, and medical materials. As a result of extensive studies by the present inventors, as the vinyl aromatic monomer polymer block (i) constituting the block copolymer (A) of the thermoplastic polymer composition according to the present invention, α-methylstyrene units are used. From the above, it was found that the low compression set in the vicinity of 70 [° C.] can be satisfied by using the main component. By adopting α-methylstyrene as the vinyl aromatic monomer, it is considered that the glass transition temperature Tg can be improved and low compression set can be realized.

  Examples of the synthesis of the vinyl aromatic monomer polymer block (i) mainly composed of α-methylstyrene units include the following. (1) After polymerization of a conjugated diene using a dianionic initiator such as 1,4-dilithio-1,1,4,4-tetraphenylbutane in a tetrahydrofuran solvent, α-under conditions of −78 [° C.] A method of sequentially polymerizing methylstyrene to obtain a triblock copolymer represented by aba (see Non-Patent Document 1), (2) α-methylstyrene in sec-butyl in a nonpolar solvent such as cyclohexane After polymerization with an anionic polymerization initiator such as lithium, conjugated dienes are polymerized, and then coupling agents such as tetrachlorosilane and diphenyldichlorosilane (α, α'-dichloro-p-xylene, phenyl benzoate, etc. (Ab) a method of obtaining an nX type block copolymer (see Non-Patent Documents 2 and 3), 3) In a nonpolar solvent, an organolithium compound is used as an initiator, and in the presence of a polar compound having a concentration of 0.1 to 10 [% by mass] at a temperature of −30 to 30 [° C.], 5 to 50 [ Mass%] of α-methylstyrene is polymerized, and the resulting living polymer is polymerized with conjugated diene, and then a coupling agent is added to obtain an aba block copolymer (patent) Reference 5). Among these, the method (3) is particularly preferable from the viewpoint of productivity.

  Hereinafter, the synthesis method (3) will be described in detail. Examples of the organic lithium compound used as the initiator include monolithium compounds such as n-butyllithium, sec-butyllithium and tert-butyllithium, and dilithium compounds such as tetraethylenedilithium. These compounds may be used alone or in combination of two or more.

  The solvent used in the polymerization of α-methylstyrene is a nonpolar solvent, such as aliphatic hydrocarbons such as cyclohexane, methylcyclohexane, n-hexane, n-heptane, aromatic hydrocarbons such as benzene, toluene, xylene, etc. Can be mentioned. These nonpolar solvents may be used alone or in combination of two or more.

A polar compound is a compound that does not have a functional group (hydroxyl group, carbonyl group, etc.) that reacts with anion species, and has a hetero atom such as an oxygen atom or nitrogen atom in the molecule. For example, diethyl ether, monoglyme, tetramethylethylenediamine , Dimethoxyethane, tetrahydrofuran and the like. These polar compounds may be used alone or in combination of two or more.
The concentration of the polar compound in the reaction system is 0.1 to 0.1 from the viewpoint of controlling the total ratio of 1,2-bonds and 3,4-bonds in the conjugated diene polymer block portion when polymerizing the conjugated diene. It is preferably in the range of 10 [mass%], more preferably in the range of 0.5 to 3 [mass%]. In order to set the total ratio of 1,2-bond and 3,4 bond to 30 mol% or more, for example, about 1 to 10 [mass%] of a polar solvent such as tetrahydrofuran is used with respect to the total amount of the nonpolar solvent used in the polymerization. It can be achieved by coexisting to the extent.

  The α-methylstyrene concentration in the reaction system is preferably in the range of 5 to 50 [mass%], preferably in the range of 25 to 40 [mass%], from the viewpoint of the viscosity of the reaction solution in the late polymerization stage. More preferred.

  The temperature condition during polymerization of α-methylstyrene is preferably in the range of −30 to 30 ° C., more preferably −20 to 10 [° C. from the viewpoints of polymerization rate of α-methylstyrene, living property, and the like. [° C.], more preferably −15 to 0 [° C.]. By setting the polymerization temperature to 30 [° C.] or less, the ratio of the living polymer to be deactivated is reduced, the mixture of homopoly α-methylstyrene is suppressed in the resulting block copolymer, and the physical properties are impaired. Absent. Further, by setting the polymerization temperature to −30 [° C.] or higher, the reaction solution can be stirred without increasing the viscosity in the latter stage of polymerization of α-methylstyrene, and the cost required to maintain the low temperature state may be increased. This is economically preferable.

  In the above method, as long as the characteristics of the α-methylstyrene polymer block are not impaired, another vinyl aromatic compound may coexist at the time of polymerization of α-methylstyrene, and this may be copolymerized with α-methylstyrene. . Examples of the vinyl aromatic compound include styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, 2,4-dimethyl styrene, vinyl naphthalene, and vinyl anthracene. A vinyl aromatic compound may be used independently and may be used in mixture of 2 or more types.

  Living poly α-methylstyryl lithium is produced by polymerization of α-methylstyrene using an organolithium compound as an initiator, and then a conjugated diene is polymerized thereto. Isoprene or / and butadiene are used as the conjugated diene. Other conjugated dienes such as 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene and the like may be included as necessary.

  The conjugated diene is subjected to polymerization by being added to the reaction system. The method for adding the conjugated diene to the reaction system is not particularly limited, and the conjugated diene may be added directly to the living poly α-methylstyryllithium solution or diluted with a solvent. The method of diluting a conjugated diene into a solvent is to add the conjugated diene and then dilute with the solvent, or add the conjugated diene and the solvent at the same time, or add the conjugated diene after diluting with the solvent. Good. Suitably, an amount of conjugated diene corresponding to 1 to 100 [mol equivalent], preferably 5 to 50 [mol equivalent] is added to the living poly α-methylstyryllithium and polymerized to form a conjugated diene block (hereinafter referred to as “diene block”). , This may be referred to as polymer block b1), and the living active terminal is variably modified, then diluted with a solvent, and then charged with the remaining conjugated diene, at a temperature above 30 ° C., preferably A method in which a polymerization reaction is carried out in a temperature range of 40 to 80 [° C.] to further form a conjugated diene block (hereinafter, this may be referred to as polymer block b2) is recommended. When changing the active terminal of living poly α-methylstyryllithium, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, vinylnaphthalene, vinyl instead of conjugated diene Vinyl aromatic compounds such as anthracene and 1,1-diphenylethylene may be used.

  Examples of the solvent that can be used for dilution include aliphatic hydrocarbons such as cyclohexane, methylcyclohexane, n-hexane, and n-heptane, and aromatic hydrocarbons such as benzene, toluene, and xylene. . These solvents may be used alone or in combination of two or more.

  For example, a polyfunctional coupling agent is added to a living polymer of a block copolymer comprising an α-methylstyrene polymer block and a conjugated diene polymer block obtained by copolymerizing a conjugated diene with living poly α-methylstyryl lithium. By reacting, a triblock or radial teleblock type block copolymer (A) can be produced. The block copolymer in this case is a mixture containing diblock, triblock, and radial teleblock block copolymers at an arbitrary ratio, which is obtained by adjusting the amount of the polyfunctional coupling agent used. May be. Examples of multifunctional coupling agents include phenyl benzoate, methyl benzoate, ethyl benzoate, ethyl acetate, methyl acetate, methyl pivalate, phenyl pivalate, ethyl pivalate, α, α′-dichloro-o-xylene, α, α′-dichloro-m-xylene, α, α′-dichloro-p-xylene, bis (chloromethyl) ether, dibromomethane, diiodomethane, dimethyl phthalate, dichlorodimethylsilane, dichlorodiphenylsilane, trichloromethylsilane, Examples include tetrachlorosilane and divinylbenzene. In addition, what is necessary is just to adjust suitably the usage-amount of a polyfunctional coupling agent according to the number average molecular weight of a block copolymer (A), and there is no restriction | limiting in a strict meaning.

  A triblock or radial teleblock type block copolymer (A) obtained by reacting a living polymer of a block copolymer comprising an α-methylstyrene polymer block and a conjugated diene polymer block with a polyfunctional coupling agent ) Is hydrogenated (hydrogenated), an active hydrogen compound such as alcohols, carboxylic acids, or water is added as necessary to stop the coupling reaction. By hydrogenation in the presence of a hydrogenation catalyst in an active organic solvent, a hydrogenated block copolymer (A) can be obtained.

  In addition, when hydrogenating a block copolymer (A) comprising an α-methylstyrene polymer block and a conjugated diene polymer block, alcohols are formed after polymerizing the conjugated diene to living poly α-methylstyryl lithium. Then, an active hydrogen compound such as carboxylic acids and water is added to stop the polymerization reaction, and hydrogenated in the presence of a hydrogenation catalyst in an inert organic solvent according to a known method to be described later, a hydrogenated block It can be set as a copolymer (A).

  Polyfunctional living copolymer of unhydrogenated block copolymer consisting of α-methylstyrene polymer block and conjugated diene polymer block, or block copolymer consisting of α-methylstyrene polymer block and conjugated diene polymer block An unhydrogenated triblock or radial teleblock block copolymer (both included in the block copolymer (A) used in the present invention) obtained by reacting a reactive coupling agent is produced Without replacing the solvent used in the above, it can be directly subjected to hydrogenation.

  In the hydrogenation reaction, Raney nickel; a heterogeneous catalyst in which a metal such as Pt, Pd, Ru, Rh, Ni is supported on a carrier such as carbon, alumina, diatomaceous earth; a transition metal compound (nickel octylate, nickel naphthenate, Ziegler-based catalyst comprising a combination of nickel acetylacetonate, cobalt octylate, cobalt naphthenate, cobalt acetylacetonate, etc.) and an organoaluminum compound or organolithium compound such as triethylaluminum or triisobutylaluminum; titanium, zirconium, hafnium In the presence of a hydrogenation catalyst such as a metallocene catalyst comprising a combination of a bis (cyclopentadienyl) compound of a transition metal such as lithium and sodium, potassium, aluminum, zinc or magnesium. Normal, reaction temperature 20 to 100 [° C.], can be performed under conditions of a range of hydrogen pressure 0.1 to 10 [MPa].

  As the block copolymer (A) used in the present invention, those obtained by the above method are preferably used. In particular, an organic lithium compound is used as an initiator in a nonpolar solvent, and 0.1 to 10 [mass%] In the presence of a polar compound at a concentration of α-methylstyrene at a temperature of −30 to 30 [° C.] at a temperature of −30 to 30 [° C.], the living poly α- A polymer block b1 is formed by adding 1 to 100 [mol equivalent] conjugated diene to methylstyryllithium and polymerizing the living active terminal, and then the reaction system is heated to a temperature exceeding 30 [° C]. It is desirable that the polymer is obtained by adding a conjugated diene and polymerizing to form a polymer block b2, from the viewpoint of excellent low-temperature characteristics of the block copolymer. That is, in this case, the polymer block b is composed of the polymer block b1 and the polymer block b2.

  The block copolymer (A) is not limited to a linear or branched structure as its structure, but among them, a block copolymer having at least one (a-b1-b2) structure is preferred, and a- b1-b2-b2-b1-a type copolymer, ab1-b2-b2-b1-a type copolymer and ab1-b2 type copolymer mixture, (a-b1-b2) nX And a type copolymer (X represents a coupling agent residue, n is an integer of 2 or more).

The number average molecular weight of the polymer block a in the block copolymer (A) is preferably in the range of 1,000 to 50,000, and more preferably in the range of 2,000 to 40,000.
The number average molecular weight of the polymer block b1 in the block copolymer (A) is preferably in the range of 1,000 to 30,000, more preferably in the range of 2,000 to 25,000. It is preferable that the total ratio of 1,2-bonds and 3,4-bonds of the conjugated diene units constituting the polymer block b1 is more than 70 [mol%].
Further, the number average molecular weight of the polymer block b2 in the block copolymer (A) is preferably in the range of 25,000 to 190,000, more preferably in the range of 30,000 to 100,000. The total ratio of 1,2-bonds and 3,4-bonds of the conjugated diene units constituting the polymer block b2 is preferably 70 [mol%] or less, preferably 5 [mol%] or more and 65 [ mol%] or less is more preferable. More preferably, it is the range of 20 [mol%] or more and 60 [mol%] or less. However, the ratio of the total of 1,2-bonds and 3,4-bonds of conjugated diene units constituting b1 and b2 needs to be 30 [mol%] or more. Thereby, an oxygen permeation coefficient can be reduced as compared with a conventional vinyl aromatic compound-conjugated diene compound block copolymer and a hydrogenated product thereof. More preferably, it is 40 [mol%] or more.

(Acrylic resin (B)) The acrylic resin (B) used in the thermoplastic polymer composition according to the present invention has an oxygen permeability coefficient of 3000 [(ml · 20 μm) / (m ² · day · atm)]. The following are polymers of methyl methacrylate alone or copolymers obtained by copolymerizing methyl methacrylate with other copolymerizable monomers.
Examples of copolymer components that can be used include acrylic acid, metal acrylate, methyl acrylate, ethyl acrylate, n-butyl acrylate, s-butyl acrylate, t-butyl acrylate, and 2-ethylhexyl acrylate. Acid esters; methacrylic acid, metal methacrylate, ethyl methacrylate, n-butyl methacrylate, s-butyl methacrylate, t-butyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, cyclohexyl methacrylate, etc. Methacrylic acid esters; Acetic acid esters such as vinyl acetate; Aromatic vinyl compounds such as styrene, α-methylstyrene and p-methylstyrene; Maleic anhydride, maleic acid mono- and dialkyl esters; N-phenylmaleimide and the like Maleimides It is below.
When these are copolymerized with methyl methacrylate, one type may be used or two or more types may be used in combination. The ratio of the monomer having copolymerizability to methyl methacrylate is preferably a ratio that does not significantly change the properties of the acrylic resin, preferably 30 [mass%] or less, and 20 [mass%]. The following is more preferable.

  The acrylic resin (B) can be produced by a general polymerization technique such as solution polymerization, emulsion polymerization, suspension polymerization, and the production method is not particularly limited.

  (Thermoplastic polymer composition) The thermoplastic polymer composition according to the present invention comprises a rubber softener as a component for softening or plasticizing the conjugated diene polymer block (ii) of the block copolymer (A). (C) can be contained. The rubber softener (C) is not particularly limited, and rubber softeners generally blended in rubber can be used. Among them, the thermoplastic polymer composition can be used. Polybutene and polyisobutylene are preferably used from the viewpoint of good gas barrier properties. These may be used alone or in combination of two or more.

  When the rubber softener (C) is included, the thermoplastic polymer composition can be improved in flexibility. The softening agent for rubber (C) is preferably 1 part by mass or more and 200 parts by mass or less, and more preferably 150 parts by mass or less with respect to 100 parts by mass of the block copolymer (A). This is because when the amount exceeds 200 parts by mass, bleeding out of the rubber softener tends to occur.

  The method for producing the thermoplastic polymer composition of the present invention is not particularly limited as long as it can uniformly mix the block copolymer (A), the acrylic resin (B), and the rubber softener (C). Any method may be used. Usually, the three components can be produced by melt-kneading together with other components as required. In that case, as an apparatus to be used, a single screw extruder, a twin screw extruder, a kneader, a Banbury mixer, etc. can be mentioned, for example, in the range of about 160-280 [degreeC], about 30 seconds-10 minutes. The thermoplastic polymer composition of the present invention can be obtained by melt-kneading.

  The thermoplastic polymer composition obtained as described above contains an acrylic resin (B) in a block copolymer (A) or a matrix composed of a block copolymer (A) and a rubber softener (C). ) Is prepared to have a structure dispersed with a particle diameter of 0.05 [μm] to 100 [μm]. In the thermoplastic polymer composition of the present invention, the block copolymer (A), or the block copolymer (A) and the rubber softener (C) constitute a matrix, and the acrylic resin (B) is dispersed particles. The formation of the layer can be confirmed by observing with a transmission electron microscope, for example. In addition, unless it is contrary to the meaning of this invention, you may contain other components other than a block copolymer (A) and a rubber softener (C) as a matrix component.

Moreover, the compounding ratio with a matrix component and a dispersed phase component shall be the compounding ratio which satisfies the following number 1.
<Equation 1> Op × Wp + Om × Wm <25000
Here, Op is the oxygen permeation coefficient of the dispersed phase mainly composed of the acrylic resin (B), Wp is the weight fraction of the dispersed phase component mainly composed of the acrylic resin (B), and Om is the oxygen permeation of the matrix. The coefficient, Wm, is the weight fraction of the matrix component.

  According to the present invention, since the acrylic resin (B) is dispersed in the matrix containing at least the block copolymer (A) and satisfies the above formula 1, the block copolymer (A) It is possible to improve the gas barrier property of the entire thermoplastic polymer composition without impairing the flexibility and rubber elasticity. Further, by using a poly α-methylstyrene block as the vinyl aromatic monomer polymer block (i), in addition to the above properties, it has excellent compression set at high temperatures and good rubber elasticity at high temperatures. be able to.

  In addition to the above components, the thermoplastic polymer composition of the present invention may contain other polymers as necessary within a range that does not substantially impair the effects of the present invention. Examples of other polymers that can be blended include polyphenylene ether resins; polyamide 6, polyamide 6 · 6, polyamide 6 · 10, polyamide 11, polyamide 12, polyamide 6 · 12, polyhexamethylenediamine terephthalamide, polyhexa Polyamide resins such as methylenediamine isophthalamide, polynonamethylenediamine terephthalamide, and xylene group-containing polyamides; Polyester resins such as polyethylene terephthalate and polybutylene terephthalate; Polyoxymethylenes such as polyoxymethylene homopolymers and polyoxymethylene copolymers Resin; Styrene homopolymer, styrene resin such as acrylonitrile / styrene resin, acrylonitrile / butadiene / styrene resin; polycarbonate resin; natural rubber; Synthetic isoprene rubber; Chloroprene rubber; Acrylic rubber; Butyl rubber; Acrylonitrile butadiene rubber; Epichlorohydrin rubber; Silicone rubber; Fluorine rubber; Urethane rubber; Polyurethane elastomer; Polyamide elastomer; Polyester elastomer; Vinyl chloride resin; Examples thereof include resins.

Furthermore, the thermoplastic polymer composition of the present invention may contain an inorganic filler, a dye / pigment or the like as necessary for the purpose of reinforcement, weight increase, coloring, and the like. Examples of inorganic fillers and dyes include calcium carbonate, talc, clay, synthetic silicon, titanium oxide, carbon black, and barium sulfate. The blending amount of the inorganic filler and the dye / pigment is preferably within a range in which the barrier property to the gas, organic liquid, etc. of the thermoplastic polymer composition is not impaired. Generally, the block copolymer (A), acrylic type It is preferable that it is 50 mass parts or less with respect to 100 mass parts of resin (B) and a rubber | gum softener (C) in total.

  In addition to the above-described components, the thermoplastic polymer composition of the present invention includes a lubricant, a light stabilizer, a flame retardant, an antistatic agent, silicone oil, an antiblocking agent, an ultraviolet absorber, and an antioxidant as necessary. In addition, one or more of other components such as a mold release agent, a foaming agent, and a fragrance may be contained.

  Since the thermoplastic polymer composition of the present invention has thermoplasticity, it can be molded using a normal molding method or molding processing apparatus used for general thermoplastic polymers. As the molding method, for example, any method such as injection molding, extrusion molding, compression molding, blow molding, calendar molding, or vacuum molding can be employed. Molded articles comprising the polymer composition of the present invention produced by such a method include pipes, sheets, films, disks, rings, bags, bottles, strings, fibers, etc. A wide variety of shapes are included, and laminated structures or composite structures with other materials are also included. By adopting a laminated structure with other materials, it is possible to introduce the properties of other materials such as mechanical properties into the molded product.

  The thermoplastic polymer composition of the present invention can be applied to a multilayer structure composed of at least one layer made of the thermoplastic polymer composition and at least one layer made of another material. The other material may be selected appropriately according to required characteristics, intended use, and the like. For example, polyolefin (eg, high density polyethylene, medium density polyethylene, low density polyethylene, linear low density polyethylene, ethylene-propylene copolymer, polypropylene, etc.), ionomer, ethylene-vinyl acetate copolymer (EVA), ethylene -Thermoplastic polymers such as vinyl alcohol copolymer (EVOH), ethylene-acrylic acid ester copolymer (EEA), polystyrene (PS), vinyl chloride resin (PVC), vinylidene chloride resin (PVDC), etc. Can do.

Among the multilayer structures, a multilayer structure having a layer made of the thermoplastic polymer composition according to the present invention and a layer made of a polyolefin resin is a preferred embodiment. This is because the thermoplastic polymer composition of the present invention is excellent in adhesiveness with a polyolefin resin. As the polyolefin resin, a propylene resin, particularly a homopolymer of propylene is preferably used.
Further, in the multilayer structure, it is adhered by a heating means without interposing an adhesive layer between the layer made of the thermoplastic polymer composition of the present invention and the base material layer made of polyolefin resin or the like. Is possible. Therefore, it is a preferred embodiment that the layer made of the thermoplastic polymer composition according to the present invention and the layer made of polyolefin resin are directly bonded to each other.

  Moreover, you may interpose an adhesive bond layer between the layer which consists of a thermoplastic polymer composition based on this invention, and the base material layer which consists of another raw material. By interposing the adhesive layer, the layer made of the thermoplastic polymer composition of the present invention and the base material layer made of another material can be joined and integrated more firmly.

Since the molded article comprising the thermoplastic polymer composition of the present invention has both excellent flexibility and excellent barrier properties against many gases, liquids, etc., daily necessities and packaging materials that require these properties Can be used as mechanical parts, medicine plugs, etc. Examples of applications in which the features of the thermoplastic polymer composition of the present invention are particularly effective include food and beverage packaging materials, containers, and container packings. In the molded article for use in these applications, the thermoplastic polymer composition only needs to form at least one layer. The thermoplastic polymer composition has a single-layer structure composed of the thermoplastic polymer composition, and the thermal polymer. It can be appropriately selected from those having a laminated structure of at least one layer made of a plastic polymer composition and at least one layer made of another material.
When the other material is a polyolefin-based resin, both are firmly bonded without using an adhesive. In the above food and beverage packaging material, container, and container packing, the permeation of oxygen gas in the atmosphere and the permeation of volatile components of the contents can be prevented, and thus the long-term storage stability of the contents is excellent. In particular, a multilayer structure having a layer made of the thermoplastic polymer composition of the present invention and a layer made of a polyolefin resin is useful as a packing for containers. In addition, a molded article made of the thermoplastic polymer composition of the present invention also has an excellent effect that it can be reused after being melted.

EXAMPLES Hereinafter, although an Example etc. demonstrate this invention concretely, this invention is not limited at all by it. Also, using the thermoplastic polymer composition pellets obtained in the following examples and comparative examples, molded articles (test pieces) were produced as follows, and their physical properties, that is, oxygen permeability coefficient, compression Permanent strain, hardness, rubber elasticity, morphology, and adhesion of the laminated structure were measured or evaluated.

(1) Measurement of oxygen transmission coefficient:
The pellets of the thermoplastic polymer composition produced in the following examples and comparative examples were compression-molded under heating by a compression molding machine to produce a film-like test piece having a thickness of 100 [μm], and using them, oxygen was used. The permeability coefficient [(ml · 20 μm) / (m ² · day · atm)] was measured. The oxygen permeability coefficient was measured using a gas permeability measuring device (“GTR-10” manufactured by Yanagimoto Seisakusho) under conditions of a temperature of 35 [° C.] and a humidity of 0 [% RH].

(2) Measurement of flexibility (hardness):
Using the pellets of the thermoplastic polymer composition produced in the following examples and comparative examples, the pellets were compression-molded by heating with a compression molding machine to produce a sheet-shaped test piece having a thickness of 2 [mm]. Using these, a constant pressure loader for a rubber hardness meter (A type analog hardness meter was attached to “CL-150” manufactured by Kobunshi Keiki, and Shore A hardness was measured in accordance with ISO-48.

(3) Measurement of tensile properties:
Using the pellets of the thermoplastic polymer composition produced in the following examples and comparative examples, the pellets were compression-molded under heating by a compression molding machine to produce a sheet-shaped test piece having a thickness of 1 [mm]. These were used to measure tensile physical properties according to JIS K6251.

(4) Measurement of compression set:
Using the sheet-like test piece made of the thermoplastic polymer composition produced in the following examples and comparative examples, the compression set after being left for 22 hours at a measurement temperature of 70 ° C. according to JIS K6262 It was measured.

(5) Morphological observation:
Using the thermoplastic polymer composition pellets produced in the following examples and comparative examples, ultra-thin sections having a thickness of 100 nm or less were prepared, stained with ruthenium tetroxide vapor, and then used with a transmission electron microscope. The morphology was observed. The case where the block copolymer (A) formed a matrix was marked with ◯, and the case where the block copolymer (A) was not formed was marked with ×.

(6) Adhesiveness:
A thermoplastic polymer composition produced in the following Examples and Comparative Examples on which a polypropylene sheet having a thickness of 1 [mm] is placed in a mold of length × width × thickness = 100 × 50 × 2 [mm]. A sheet having a thickness of 1 [mm] was placed and molded by heating with a compression molding machine to obtain a multilayer molded product having a thickness of 2 [mm] or less. The case where the sheet | seat which consists of a thermoplastic polymer composition cannot be peeled from a polypropylene sheet was set as (circle), and the case where it can peel off was set as x.

  The contents of the block copolymer (A), acrylic resin (B), and rubber softener (C) used in the following examples and comparative examples are as follows.

First, the manufacturing method of the block copolymer (A-1 to A-4) applicable to the polymer composition of an Example and the block copolymer (5) applied as a comparative example is demonstrated.
[Block copolymer (A-1)]
In a pressure-resistant vessel equipped with a stirrer sufficiently substituted with nitrogen, 5000 parts by mass of cyclohexane, 100 parts by mass of styrene monomer, and 18.1 parts by mass of 1.3 [mol%] cyclohexane solution of sec-butyllithium were added, Polymerization was carried out at 50 [° C.] for 60 minutes. Thereafter, the temperature in the container was cooled to 40 [° C.] or less, and then 28.13 parts by mass of tetrahydrofuran, 525 parts by mass of isobrene monomer, and 525 parts by mass of butadiene monomer were added and polymerization was performed for 90 minutes. Furthermore, after adding 100 mass parts of styrene monomers and superposing | polymerizing for 60 minutes, methanol was added and superposition | polymerization was stopped and the polystyrene-isoprene / butadiene copolymer-polystyrene type | mold triblock copolymer was obtained. A cyclohexane solution of the triblock copolymer was prepared and charged in a pressure-resistant vessel that had been sufficiently purged with nitrogen, and then at 80 [° C.] in a hydrogen atmosphere using a Ni / Al-based Ziegler-based hydrogenation catalyst. Hydrogenation reaction was performed for 5 hours. And the hydrogenated product of polystyrene-isoprene / butadiene copolymer-polystyrene type triblock copolymer [Mn = 120,000; ratio of each polymer block = 8/84/8 (mass ratio); 3,4- Bond and 1,2-bond content 53 [mol%]; Diene block hydrogenation rate = 93 [mol%]] was obtained.

[Block copolymer (A-2)]
In a pressure-resistant vessel equipped with a stirrer sufficiently purged with nitrogen, 4000 parts by mass of cyclohexane, 100 parts by mass of styrene monomer, and 13.33 parts by mass of a 1.3 [mol%] cyclohexane solution of sec-butyllithium were added, Polymerization was carried out at 50 [° C.] for 60 minutes. Thereafter, the temperature in the container was cooled to 40 [° C.] or less, and then 23.5 parts by mass of tetrahydrofuran and 800 parts by mass of isobrene monomer were added and polymerization was performed for 90 minutes. Furthermore, after adding 100 mass parts of styrene monomers and superposing | polymerizing for 60 minutes, methanol was added and superposition | polymerization was stopped and the polystyrene-polyisoprene-polystyrene type | mold triblock copolymer was obtained. A cyclohexane solution of the triblock copolymer was prepared and charged into a pressure-resistant vessel that had been sufficiently purged with nitrogen, and then at 80 [° C.] in a hydrogen atmosphere using a Ni / Al Ziegler hydrogenation catalyst. The hydrogenation reaction was carried out for 5 hours. And a hydrogenated product of polystyrene-polyisoprene-polystyrene type triblock copolymer [Mn = 100,000; ratio of each polymer block = 10/80/10 (mass ratio); 3,4-bond and 1, 2-bond content 57 [mol%]; hydrogenation rate of diene block = 90 [mol%] was obtained.

[Block copolymer (A-3)]
With reference to the polymerization method described in Patent Document 5, the following block copolymer (A-3) was obtained. That is, poly α-methylstyrene-isoprene / butadiene copolymer-poly α-methylstyrene type triblock copolymer hydrogenated product [Mn = 120,000; ratio of each polymer block = 8/84/8 ( (Mass ratio); 3,4-bond and 1,2-bond content 55 [mol%]; hydrogenation rate of diene block = 94 [mol%]].
[Block copolymer (A-4)]
With reference to the polymerization method described in Patent Document 5, the following block copolymer (A-4) was obtained. That is, poly α-methylstyrene-polyisoprene-polyα-methylstyrene is a hydrogenated product of a type triblock copolymer [Mn = 110,000; ratio of each polymer block = 10/80/10 (mass ratio) 3,4-bond and 1,2-bond content 57 [mol%]; Diene block hydrogenation rate = 92 [mol%]].

[Block copolymer (5)]
2700 parts by mass of cyclohexane, 100 parts by mass of styrene monomer, and 18.89 parts by mass of a 1.3 [mol%] cyclohexane solution of sec-butyllithium were added into a pressure-resistant vessel with a stirrer that had been sufficiently purged with nitrogen, Polymerization was carried out at 50 [° C.] for 60 minutes. Thereafter, 467 parts by mass of isobrene monomer was added and polymerization was carried out for 90 minutes. Furthermore, after adding 100 mass parts of styrene monomers and superposing | polymerizing for 60 minutes, methanol was added and superposition | polymerization was stopped and the polystyrene-polyisoprene-polystyrene type | mold triblock copolymer was obtained. A cyclohexane solution of the triblock copolymer was prepared and charged into a pressure-resistant vessel that had been sufficiently purged with nitrogen, and then at 80 [° C.] in a hydrogen atmosphere using a Ni / Al Ziegler hydrogenation catalyst. The hydrogenation reaction was carried out for 5 hours. And a hydrogenated product of polystyrene-polyisoprene-polystyrene type triblock copolymer [Mn = 60,000; ratio of each polymer block = 15/70/15 (mass ratio); 3,4-bond and 1, 2- Bond content 6 [mol%]; Hydrogenation rate of diene block = 98 [mol%]] was obtained.

[Acrylic resin (B)]
A polymerization vessel equipped with a reflux condenser is charged with 500 parts of pure water, and then a mixed solution of 425 parts of methyl methacrylate, 55 parts of methyl acrylate, 2.5 parts of lauryl peroxide, and 4 parts of lauryl mercaptan is charged with nitrogen while stirring. After replacing the atmosphere, the temperature was raised to 80 [° C.] and polymerized for 2 hours, then at 95 [° C.] for 1 hour, washed with water and dried to obtain a bead-like polymer. When this bead polymer was measured by GPC, the number average molecular weight and molecular weight distribution in terms of polystyrene were 18,400 and 2.1, respectively.

[Rubber softener (C-1)]
“Nisseki Polybutene HV-100” manufactured by Nippon Petrochemical Co., Ltd .:
Polybutene, kinematic viscosity 220 × 10 ⁻⁶ [m ² / s] (100 [° C.]), pour point −7.5 [° C.]
[Rubber softener (C-2)]
“Nisseki Polybutene HV-300” manufactured by Nippon Petrochemical Co., Ltd .:
Polybutene, kinematic viscosity 590 × 10 ⁻⁶ [m ² / s] (100 [° C.]), pour point 0 [° C.]

<< Examples 1 to 11 >>
The above-mentioned block copolymer (A), acrylic resin (B), and rubber softener (C) in the proportions shown in Table 1 below are twin screw extruders (“ZSK-25WLE” manufactured by Krupp Werner & Pfleiderer) ), Melt-kneaded under conditions of a cylinder temperature of 200 [° C.] and a screw rotation speed of 350 [rpm], extruded, and cut to produce thermoplastic polymer composition pellets.

Using the obtained thermoplastic polymer composition pellets, a press film and a molded article (test piece) are produced by the above-described method, and its oxygen transmission coefficient, compression set, hardness, tensile physical properties, morphology and adhesiveness. Was measured by the above method, and was as shown in Table 2 below.

<< Comparative Examples 1-3 >>
The above-mentioned block copolymer (A), acrylic resin (B), and rubber softener (C) were mixed in the ratio shown in Table 3 below in a twin screw extruder (“ZSK-25WLE” manufactured by Krupp Werner & Pfleiderer). The mixture was melt-kneaded under conditions of a cylinder temperature of 200 [° C.] and a screw rotation speed of 350 rpm, extruded, and cut to produce thermoplastic polymer composition pellets. Using the obtained thermoplastic polymer composition pellets, a press film and a molded article (test piece) were produced by the above method, and the oxygen permeability coefficient, hardness, morphology, and adhesion were measured by the above method. However, it was as shown in Table 4 below.

≪Reference Examples 1-13≫
The block copolymer (A), the acrylic resin (B), and the ratio of the block copolymer (A) and the rubber softener (C) shown in Table 5 are formed into a press film by the above-described method. When the oxygen permeability coefficient was measured by the above method, it was as shown in Table 5 below.

From the results of Table 2 above, the block copolymer (A) comprising the vinyl aromatic monomer polymer block (i) according to this example and the conjugated diene polymer block (ii) according to this example, A block copolymer (A) component or a block copolymer (A) component and a rubber softener (C) are substantially a matrix containing the acrylic resin (B) according to the embodiment as a main component. When the thermoplastic polymer composition of Examples 1 to 11 in which the acrylic resin (B) component is substantially present in a dispersed phase and satisfies the above formula 1, the Shore A hardness is 38A to 78A. The oxygen permeability coefficient was about 10,000 to about 19000 [(ml · 20 μm) / (m ² · day · atm)]. That is, it has excellent flexibility and rubber elasticity, and also has a gas barrier property. Furthermore, it turns out that adhesiveness with a polypropylene is also favorable.

  Furthermore, in the examples of Examples 7 to 10 using a poly α-methylstyrene block as the vinyl aromatic monomer polymer block (i), the compression set value at 70 ° C. was 21 to 50%. It was. On the other hand, in the example of Example 11 in which no poly α-methylstyrene block was used, the compression set value at 70 [° C.] was 96 [%]. By using a poly α-methylstyrene block as the vinyl aromatic monomer polymer block (i), in addition to the above properties such as flexibility, rubber elasticity, gas barrier property, and adhesion to polypropylene, It was found that low compression set, that is, excellent rubber elasticity at high temperature. By adopting a poly α-methylstyrene block as the vinyl aromatic monomer polymer block (i), it was possible to improve the glass transition temperature Tg. ing.

On the other hand, in the thermoplastic polymer composition of Comparative Example 1, the block copolymer (5) has an oxygen permeability coefficient of 60000 [(ml · 20 μm) / (m ² · day · atm)] or less. In addition, the block copolymer (5) is inferior in gas barrier property because the total proportion of 1,2 and 3,4 bonds of the block copolymer (5) does not satisfy the range of 30 mol% or more. I understand that.

In the thermoplastic polymer composition of Comparative Example 2, the oxygen permeability coefficient of the block copolymer (A-2) satisfies the condition of 60000 [(ml · 20 μm) / (m ² · day · atm)] or less. The gas barrier property is excellent. However, it is inferior in flexibility. This is because the block copolymer (A) and the rubber softener (C) do not have a matrix component and the acrylic resin (B) does not have a dispersed layer.
Although the thermoplastic polymer composition of Comparative Example 3 is excellent in flexibility, the oxygen permeability coefficient exceeds 20000 [(ml · 20 μm) / (m ² · day · atm)], and has a gas barrier property. Inferior. The block copolymer (A-2) has an oxygen permeability coefficient of 60000 [ml · 20 μm / (m ² · day · atm)] or less, but the value of Op × Wp + Om × Wm is 25000. This is because the blending ratio exceeds.

The thermoplastic polymer composition of Comparative Example 4 satisfies the condition that the oxygen permeability coefficient of the block copolymer (A-2) is 6000 [(ml · 20 μm) / (m ² · day · atm)] or less. Therefore, the barrier property against gas is excellent. However, it is inferior in flexibility. This is because the block copolymer (A) and the rubber softener (C) do not have a matrix component and the acrylic resin (B) does not have a dispersed layer.
Although the thermoplastic polymer composition of Comparative Example 5 is excellent in flexibility, the oxygen permeability coefficient exceeds 20000 [(ml · 20 μm) / (m ² · day · atm)] and is inferior in gas barrier properties. . The block copolymer (A-2) satisfies the condition that the oxygen permeability coefficient is 60000 [ml · 20 μm / (m ² · day · atm)] or less, but the value of Op × Wp + Om × Wm is 25000. This is because the blending ratio exceeds.

Claims (10)

From the vinyl aromatic monomer polymer block (a) and optionally hydrogenated isoprene and / or butadiene units in which the total ratio of 1,2-bonds and 3,4-bonds is 30 [mol%] or more. The oxygen permeability coefficient measured mainly under the conditions of a temperature of 35 ° C. and a humidity of 0% RH using a gas permeability measuring device is 60000 [( (), which comprises a conjugated diene polymer block or a conjugated diene copolymer block (b). ml · 20 μm) / (m ² · day · atm)] the following block copolymer (A),
The oxygen permeability coefficient contains 3000 and ^{[(ml · 20μm) / (} m 2 · day · atm)] or less of the acrylic resin (B) as the main component,
When the content of the vinyl aromatic monomer polymer block (a) in at least the block copolymer (A) exceeds 16% by mass, a rubber softener (C) is added,
When the content of the vinyl aromatic monomer polymer block (a) exceeds 16% by mass, the content of the softener for rubber (C) is as follows: the block copolymer (A), the acrylic resin (B ) And the rubber softener (C) for a total mass of 100 parts by mass of 10 to 24 parts by mass,
When the content of the vinyl aromatic monomer polymer block (a) in the block copolymer (A) is 16% by mass or less, the rubber softener (C) is not added, or the block copolymer The rubber softener (C) is 1 part by mass or more and 200 parts by mass or less with respect to 100 parts by mass of the polymer (A).
Content of this acrylic resin (B) is 40 mass with respect to 100 mass parts of total mass of this block copolymer (A), this acrylic resin (B), and this rubber softener (C). Part to 60 parts by weight,
And in the matrix consisting of at least the block copolymer (A) component, the acrylic resin (B) component is present in a substantially dispersed phase state,
Op The oxygen permeability coefficient of the dispersed phase, the weight fraction of the dispersed phase Wp, Om the oxygen permeability of the matrix, the weight fraction of the matrix is taken as Wm, satisfies the following equation (1) A thermoplastic polymer composition.
<Equation 1> Op × Wp + Om × Wm <25000 The thermoplastic polymer composition according to claim 1, wherein
The block copolymer (A) is a triblock copolymer having the (a)-(b)-(a) structure comprising the vinyl aromatic monomer polymer block (a) and the conjugated diene copolymer block (b). Mainly consisting of polymers,
Hydrogenation ratio of the conjugated diene copolymer block (b) is a thermoplastic polymer composition characterized der Rukoto 80% or more. In the thermoplastic polymer composition according to claim 1 or 2 ,
The thermoplastic polymer composition, wherein the rubber softener (C) comprises polybutene or polyisobutylene. The thermoplastic polymer composition according to claim 1, 2, or 3,
Shore A hardness is 30 or more and 90 or less,
A thermoplastic polymer composition having an oxygen permeability coefficient of 20000 [(ml · 20 μm) / (m ² · day · atm)] or less. In the thermoplastic polymer composition according to any one of claims 1 to 4,
The thermoplastic polymer composition, wherein the vinyl aromatic monomer polymer block is a polymer block mainly composed of α-methylstyrene units. The thermoplastic polymer composition according to claim 5, wherein
The compression set measured at a measurement temperature of 70 ° C. according to JIS K6262 is 75.
[%] Thermoplastic polymer composition which is equal to or less than   The molded article which consists of a thermoplastic polymer composition of any one of Claims 1-6. The multilayer molded article which has a layer which consists of a layer which consists of a thermoplastic polymer composition of any one of Claims 1-6, and another material. A tube having at least one layer made of the thermoplastic polymer composition according to any one of claims 1 to 6. The packing for containers which has at least 1 layer which consists of a thermoplastic polymer composition of any one of Claims 1-6.