JP2005029727A - Thermoplastic polymer composition, molding, and laminated structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic polymer composition having good flexibility, good in barrier property to gasses, organic liquids, etc., and adhering to polyolefin resin. <P>SOLUTION: This thermoplastic polymer composition comprises an ethylene/vinyl alcohol copolymer (A), a block copolymer (B) mainly comprising a polymer block of a vinyl aromatic monomer and a conjugated diene polymer block which may be hydrogenated, a softening agent (C) for rubber, a modified elastomer (D) having a functional group which can react with the ethylene/vinyl alcohol copolymer (A), and a polyolefin resin (E1). Further, this thermoplastic polymer composition contains 3-50 pts.mass ethylene /vinyl alcohol copolymer (A), 10-80 pts.mass block copolymer (B), 0-60 pts.mass softening agent (C) for rubber, 3-50 pts.mass modified elastomer (D), and 3-30 pts.mass polyolefin resin (E1) to 100 pts.mass of the total of (A), (B), (C), and (D). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention has a thermoplastic polymer composition having good flexibility, excellent barrier properties against gases and organic liquids and adhering to a polyolefin-based resin, a molded article comprising the polymer composition, and the weight The present invention relates to a multilayer structure having a layer made of a combined 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, a hydrogenated vinyl aromatic compound-conjugated diene compound block copolymer (hereinafter abbreviated as “hydrogenated block copolymer”) contains a rubber softener. Since its flexibility is improved and it has excellent rubber elasticity and molding processability, its use amount has increased in recent years.

  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, or organic liquids such as gasoline and oil, and such gases or organics. Actually, it is extremely difficult to apply to a sheet, a film, a packaging for food and drink, a container, a packing for a container, a tube, a hose and the like that require a liquid blocking property.

  On the other hand, the ethylene-vinyl alcohol copolymer has a high barrier property against gases, organic liquids, etc., and may generate harmful gases during incineration such as vinylidene chloride resin and vinyl chloride resin. Therefore, it has been developed for various uses such as food packaging materials. However, since the ethylene-vinyl alcohol copolymer is inferior in flexibility, it cannot be applied to applications in which a thermoplastic elastomer is used and a barrier is required.

  Therefore, as a material having both barrier property against gas, organic liquid, etc. and flexibility, ethylene-vinyl alcohol copolymer and another soft resin are mixed under melting conditions, and the barrier property against gas, organic liquid, etc. Attempts have been made to obtain a material having both flexibility (see Patent Document 1). However, since the compatibility between the ethylene-vinyl alcohol copolymer and the soft resin is poor, the mechanical properties are inferior, and the ethylene-vinyl alcohol copolymer does not adhere to the polyolefin resin. Further, for the purpose of improving the compatibility between the ethylene-vinyl alcohol copolymer and the soft resin, the ethylene-vinyl alcohol copolymer and the soft resin modified with the epoxy compound are mixed under melting conditions, Attempts have been made to obtain a material excellent in oil resistance (see Patent Document 2).

  However, flexibility and adhesiveness to polyolefin resins are insufficient. In addition, a proposal has been made to add a styrene-based elastomer modified with maleic anhydride for the purpose of improving the compatibility between the ethylene-vinyl alcohol copolymer and polypropylene and improving the appearance defect of the molded product (Patent Document). 3). In this case, although it has adhesiveness to polyolefin, it is hard and does not show rubber elasticity, so it cannot be used as a thermoplastic elastomer.

Japanese Patent Laid-Open No. 10-110086 JP-A-7-207097 Japanese Patent No. 2612034

  An object of the present invention is to provide a thermoplastic polymer composition that is flexible, has a barrier property against gases and organic liquids, and adheres to a polyolefin resin. Another object of the present invention is to provide a molded article comprising the thermoplastic polymer composition and a multilayer structure having a layer comprising the polymer composition.

  As a result of intensive studies, the present inventors have found that a thermoplastic polymer composition comprising an ethylene-vinyl alcohol copolymer, a specific block copolymer, a rubber softener, a specific modified elastomer, and a polyolefin resin is flexible. The present invention has been completed by finding that it satisfies the properties, barrier properties, and adhesion to polyolefin resins.

  That is, the present invention relates to a block copolymer (B) mainly comprising an ethylene-vinyl alcohol copolymer (A), a vinyl aromatic monomer polymer block and a conjugated diene polymer block which may be hydrogenated, and a rubber. A softening agent (C), a modified elastomer (D) having a functional group capable of reacting with the ethylene-vinyl alcohol copolymer (A), and a polyolefin resin (E1), comprising an ethylene-vinyl alcohol copolymer (A ), Block copolymer (B), rubber softener (C), and modified elastomer (D) in total 100 parts by mass, ethylene-vinyl alcohol copolymer (A) 3 to 50 parts by mass, block 10-80 parts by mass of copolymer (B), 0-60 parts by mass of rubber softener (C), 3-50 parts by mass of modified elastomer (D) and polyolefin Fin-based resin (E1) is a thermoplastic polymer composition comprising 3 to 30 parts by weight.

  At this time, it is preferable that the said thermoplastic polymer composition contains 10-60 mass parts of rubber | gum softeners (C). It is also preferred that the functional group of the modified elastomer (D) is a functional group derived from an α, β-unsaturated carboxylic acid and / or a derivative thereof. It is also preferred that the polyolefin resin (E1) is a propylene polymer. It is also preferred that the polyolefin resin (E1) contains a functional group derived from an α, β-unsaturated carboxylic acid and / or a derivative thereof.

  A molded article made of the thermoplastic polymer composition is a preferred embodiment of the present invention. A multilayer structure having a layer made of the thermoplastic polymer composition and a layer made of a polyolefin resin (E2) is also a preferred embodiment of the present invention. At this time, it is preferable that the layer made of the thermoplastic polymer composition and the layer made of the polyolefin resin (E2) are directly bonded to each other. It is also preferable that the polyolefin resin (E2) is polypropylene. Moreover, the packing for containers which consists of such a multilayer structure is a suitable embodiment of this invention.

  Since the thermoplastic polymer composition of the present invention is flexible and has excellent barrier properties against gases, organic liquids, etc., sheets, films, food and beverage packaging materials, containers, container packings, and tubes that require these properties It can be used effectively in applications such as hoses, and when laminated with a polyolefin resin, it can be bonded without using an adhesive.

The present invention is described in detail below. The thermoplastic polymer composition of the present invention is mainly composed of ethylene units (—CH ₂ CH ₂ —) and vinyl alcohol units (—CH ₂ —CH (OH)) as components that exhibit good barrier properties against gases, organic liquids and the like. -) And an ethylene-vinyl alcohol copolymer (A).

  The ethylene unit content of the ethylene-vinyl alcohol copolymer (A) is preferably 10 to 99 mol% from the viewpoint of high barrier property against gas, organic liquid and the like and good moldability. It is more preferably 20 to 75 mol%, and further preferably 25 to 60 mol%.

  As will be described later, the ethylene-vinyl alcohol copolymer (A) is typically an ethylene-fatty acid vinyl ester copolymer saponified product. In this case, the saponification degree of the fatty acid vinyl ester unit is obtained. In view of the high barrier properties and thermal stability of the ethylene-vinyl alcohol copolymer, it is preferably 50 mol% or more, more preferably 90 mol% or more, and 95 mol% or more. Is more preferable, and 98 mol% or more is particularly preferable.

  The melt flow rate (measured by the method described in ASTM D1238 under the conditions of a temperature of 210 ° C. and a load of 2.16 kg) of the ethylene-vinyl alcohol copolymer (A) is 0 from the viewpoint of good moldability. 0.1 to 100 g / 10 min is preferable, 0.5 to 50 g / 10 min is more preferable, and 1 to 20 g / 10 min is particularly preferable.

  Further, the intrinsic viscosity of the ethylene-vinyl alcohol copolymer (A) is preferably 0.1 to 5 dl / g at a temperature of 30 ° C. in a mixed solvent of 85% by mass of phenol and 15% by mass of water, More preferably, it is 0.2-2 dl / g.

  The ethylene-vinyl alcohol copolymer (A) can be produced according to a conventional method. For example, a radical polymerization initiator such as benzoyl peroxide or azobisisobutyronitrile is added under pressure in an organic solvent such as methanol, t-butyl alcohol, or dimethyl sulfoxide with a monomer mainly composed of ethylene and a fatty acid vinyl ester. And an ethylene-fatty acid vinyl ester copolymer can be obtained by polymerization, and then it can be produced by saponification in the presence of an acid catalyst or an alkali catalyst. Here, as the fatty acid vinyl ester, for example, vinyl acetate vinyl ester, propionic acid vinyl ester, versatic acid vinyl ester, pivalic acid vinyl ester, valeric acid vinyl ester, capric acid vinyl ester and the like can be used. Of these, vinyl acetate is preferred.

  The ethylene-vinyl alcohol copolymer (A) may have other structural units other than those described above as long as it is a small amount (preferably, 10 mol% or less based on the total structural monomer units). . Other structural units include α-olefins such as propylene, isobutylene, 4-methylpentene-1, 1-hexene, 1-octene; vinyl acetate, vinyl propionate, vinyl vinyl versatate, vinyl pivalate, Carboxylic acid vinyl esters such as valeric acid vinyl ester, capric acid vinyl ester, and benzoic acid vinyl ester; unsaturated carboxylic acids such as itaconic acid, methacrylic acid, acrylic acid, and maleic anhydride or derivatives thereof (eg, salts, esters, nitriles) And units derived from vinylsilane compounds such as vinyltrimethoxysilane; unsaturated sulfonic acids or salts thereof; N-methylpyrrolidone; and the like. The ethylene-vinyl alcohol copolymer may have a functional group such as an alkylthio group at the terminal.

  The ethylene-vinyl alcohol copolymer (A) used in the present invention may contain 0.3 to 40 mol% of the following structural unit (I) in addition to the ethylene unit and the vinyl alcohol unit. Use of such a modified ethylene-vinyl alcohol copolymer is preferable because a thermoplastic polymer composition having excellent flexibility can be obtained.

Wherein R ¹ , R ² , R ³ and R ⁴ are a hydrogen atom, an aliphatic hydrocarbon group having 1 to 10 carbon atoms (for example, an alkyl group, an alkenyl group, etc.), or an alicyclic group having 3 to 10 carbon atoms. Represents a hydrocarbon group having a formula (for example, a cycloalkyl group, a cycloalkenyl group, etc.), an aromatic hydrocarbon group having 6 to 10 carbon atoms (for example, a phenyl group, etc.) R ¹ , R ² , R ^3, and R ⁴ are R ³ and R ⁴ may be bonded (except when R ³ and R ⁴ are both hydrogen atoms), and R ¹ may be the same or different. , R ² , R ^3, and R ⁴ may be substituted with a substituent such as a hydroxyl group, a carboxyl group, or a halogen atom when they are groups other than hydrogen atoms.

  The method for producing the modified ethylene-vinyl alcohol copolymer containing the structural unit (I) is as described in WO 02/092643 pamphlet. For example, by reacting an ethylene-vinyl alcohol copolymer with a monovalent epoxy compound having a number average molecular weight of 500 or less, such as 1,2-epoxybutane, 2,3-epoxybutane, epoxypropane, epoxyethane, and glycidol. Can be manufactured. Here, the reaction between the ethylene-vinyl alcohol copolymer and the monovalent epoxy compound having a number average molecular weight of 500 or less can be carried out by any method such as a melt reaction using an extruder or a reaction in a solution.

  The thermoplastic polymer composition of the present invention contains a block copolymer (B) mainly composed of a vinyl aromatic monomer polymer block and a conjugated diene polymer block which may be hydrogenated. Here, unlike the modified elastomer (D) described below, the block copolymer (B) does not have a functional group capable of reacting with the ethylene-vinyl alcohol copolymer (A). Those having no functional group are less expensive than those having a functional group, and are preferably used in combination with the modified elastomer (D). The block copolymer (B) has excellent compatibility with the polyolefin resin (E1), particularly polypropylene.

  The block copolymer (B) is a diblock structure represented by a-b, where a vinyl aromatic monomer polymer block is represented by a and a conjugated diene polymer block is represented by b, a-b-a Alternatively, a triblock structure represented by b-a-b, a tetrablock structure represented by ab-a-b, or a polyblock structure in which five or more of a and b are linearly bonded. be able to. Among them, a triblock structure represented by a-b-a is preferable from the viewpoint that the resulting thermoplastic polymer composition has good flexibility and mechanical properties.

  Examples of the vinyl aromatic monomer used for forming the vinyl aromatic monomer polymer block constituting the block copolymer (B) together with the conjugated diene polymer block include styrene, α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, t-butylstyrene, 2,4-dimethylstyrene, 2,4,6-trimethylstyrene, monofluorostyrene, difluorostyrene, monochlorostyrene, dichlorostyrene, methoxy Examples thereof include vinyl aromatic compounds such as styrene, vinyl naphthalene, vinyl anthracene, indene, and acetonaphthylene. The vinyl aromatic monomer polymer block may have a structural unit composed of only one kind of the above-described vinyl aromatic compound, or may have a structural unit composed of two or more kinds. Among them, the vinyl aromatic monomer polymer block is preferably mainly composed of structural units derived from styrene.

  The vinyl aromatic monomer polymer block has a structural unit such as 1-butene, pentene, hexene, butadiene, isoprene, methyl vinyl ether and the like, together with a structural unit composed of a vinyl aromatic compound, if necessary, and other copolymerizable monomers. The proportion of structural units composed of other copolymerizable monomers may be 30% by mass or less based on the mass of the vinyl aromatic monomer polymer block. More preferably, it is 10 mass% or less.

  Examples of the conjugated diene compound used for forming the conjugated diene polymer block constituting the block copolymer (B) together with the vinyl aromatic monomer polymer block include isoprene, butadiene, hexadiene, 2,3-dimethyl-1,3. -Butadiene, 1,3-pentadiene and the like. The conjugated diene polymer block may be composed of one or more of these conjugated diene compounds. When the conjugated diene polymer block has a structural unit derived from two or more kinds of conjugated diene compounds, their bonding form is random, tapered, partially blocky, or a combination of two or more thereof. Either may be sufficient.

  Among them, the conjugated diene polymer block is a polyisoprene block composed of monomer units mainly composed of isoprene units or a hydrogenated polyisoprene block obtained by hydrogenating a part or all of unsaturated bonds thereof; mainly composed of butadiene units. A polybutadiene block composed of monomer units or a hydrogenated polybutadiene block in which some or all of the unsaturated bonds thereof are hydrogenated; or an isoprene / butadiene copolymer block composed of monomer units mainly composed of isoprene units and butadiene units A hydrogenated isoprene / butadiene copolymer block in which some or all of the saturated bonds are hydrogenated is preferable.

In the above-described polyisoprene block that can be a constituent block of a conjugated diene polymer block, the unit derived from isoprene is a 2-methyl-2-butene-1,4-diyl group [—CH ₂ — before hydrogenation. C (CH ₃ ) ═CH—CH ₂ —; 1,4-bonded isoprene unit], isopropenylethylene group [—CH (C (CH ₃ ) ═CH ₂ ) —CH ₂ —; Isoprene unit] and 1-methyl-1-vinylethylene group [—C (CH ₃ ) (CH═CH ₂ ) —CH ₂ —; 1,2-bonded isoprene unit]. The ratio of each unit is not particularly limited.

In the above-mentioned polybutadiene block which can be a constituent block of the conjugated diene polymer block, 70 to 20 mol%, particularly 65 to 40 mol% of the butadiene unit is 2-butene-1,4-diyl group before hydrogenation. (—CH ₂ —CH═CH—CH ₂ —; 1,4-bonded butadiene unit), and 30 to 80 mol%, particularly 35 to 60 mol% is a vinylethylene group [—CH (CH═CH ₂ ) —. CH _2- ; 1,2-bonded butadiene unit] is preferable.

  In the above-described isoprene / butadiene copolymer block that can be a building block of a conjugated diene polymer block, before hydrogenation, the units derived from isoprene are 2-methyl-2-butene-1,4-diyl group, isopropenyl. It consists of at least one group selected from the group consisting of an ethylene group and 1-methyl-1-vinylethylene group, and the unit derived from butadiene is a 2-butene-1,4-diyl group and / or vinylethylene. The ratio of each unit is not particularly limited. In the isoprene / butadiene copolymer block, the arrangement of isoprene units and butadiene units may be any of random, block, and tapered block. In the isoprene / butadiene copolymer block, the molar ratio of isoprene unit: butadiene unit is preferably 1: 9 to 9: 1, and more preferably 3: 7 to 7: 3.

  The block copolymer (B) mainly composed of a vinyl aromatic monomer polymer block and a conjugated diene polymer block is a conjugated diene from the viewpoint that the heat resistance and weather resistance of the thermoplastic polymer composition are good. It is preferable that some or all of the unsaturated double bonds in the polymer block are hydrogenated (hereinafter sometimes referred to as “hydrogenation”). The hydrogenation rate of the conjugated diene polymer block at that time is preferably 50 mol% or more, more preferably 60 mol% or more, and further preferably 80 mol% or more.

  In the block copolymer (B), the molecular weight of the vinyl aromatic monomer polymer block and the molecular weight of each conjugated diene polymer block are not particularly limited, but the number of vinyl aromatic monomer polymer blocks in the state before hydrogenation. The mechanical property of the thermoplastic polymer composition is that the average molecular weight is in the range of 1,000 to 100,000 and the number average molecular weight of the conjugated diene polymer block is in the range of 10,000 to 500,000. It is preferable from the viewpoints of characteristics and moldability. In addition, the number average molecular weight as used in this specification says the value calculated | required from the standard polystyrene calibration curve by the gel permeation chromatography (GPC) method.

  The block copolymer (B) 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.

  The thermoplastic polymer composition of the present invention preferably contains a rubber softener (C) as a component for softening or plasticizing the conjugated diene polymer block of the block copolymer (B). There is no restriction | limiting in particular as such a rubber softener (C), Although the rubber softener generally mix | blended with rubber | gum can be used, Among these, paraffinic oil can be used preferably. In general, oil used as process oil or the like is a mixture of components having an aromatic ring such as a benzene ring or naphthene ring, paraffin components (chain hydrocarbons), etc., and the number of carbon atoms constituting the paraffin chain is What occupies 50 mass% or more of the total carbon number of oil is called “paraffin oil”. As the rubber softener (C) used in the present invention, paraffin oil having an aromatic ring content of 5% by mass or less is preferably used.

The kinematic viscosity at 40 ° C. of the paraffinic oil is preferably 20 × 10 ^{−6 to} 800 × 10 ⁻⁶ m ² / sec, and is preferably 50 × 10 ⁻⁶ to 600 × 10 ⁻⁶ m ² / sec. Is more preferable. The pour point is preferably −40 to 0 ° C., and more preferably −30 to 0 ° C. Furthermore, the flash point is preferably 200 to 400 ° C, more preferably 250 to 350 ° C.

  Further, the thermoplastic polymer composition of the present invention is a thermoplastic modified elastomer having a functional group capable of reacting with the ethylene-vinyl alcohol copolymer (A) as a component for improving the barrier property against gas and organic liquid. (D) is contained. The modified elastomer (D) has a function of improving the compatibility between the ethylene-vinyl alcohol copolymer (A), the block copolymer (B) and the polyolefin resin (E1), while providing flexibility. It also has a function to improve. Such a modified elastomer (D) is not particularly limited as long as it is a thermoplastic elastomer and has a functional group capable of reacting with the ethylene-vinyl alcohol copolymer (A). An addition polymer comprising a single addition polymerizable monomer and having a functional group capable of reacting with the ethylene-vinyl alcohol copolymer (A), a random addition polymer comprising a plurality of addition polymerizable monomers and ethylene- Those having a functional group capable of reacting with the vinyl alcohol copolymer (A), a block addition polymer comprising a plurality of addition polymerizable monomers, and having a functional group capable of reacting with the ethylene-vinyl alcohol copolymer (A) Things can be used.

  Examples of the modified elastomer (D) include block copolymers or random copolymers mainly composed of a vinyl aromatic monomer polymer block and a conjugated diene polymer block, EPM, EPDM, polyisoprene and hydrogenated products thereof, or polybutadiene and Examples of the hydrogenated product include those having a functional group capable of reacting with the ethylene-vinyl alcohol copolymer (A). Among these, the modified elastomer (D) is a block polymer mainly composed of a vinyl aromatic monomer polymer block and a conjugated diene polymer block, and a functional group capable of reacting with the ethylene-vinyl alcohol copolymer (A). It is preferable that it is what has. Here, the vinyl aromatic monomer polymer block and the conjugated diene polymer block constituting the block polymer are formed from the various vinyl aromatic monomer polymer blocks and the conjugated diene polymer block described above with respect to the block copolymer (B). In particular, it is preferable that the vinyl aromatic monomer polymer block and the conjugated diene polymer block constituting the block polymer are formed of the same block as the block copolymer (B). It is preferable from the viewpoint of obtaining the capacity.

  Further, as described above, the functional group capable of reacting with the ethylene-vinyl alcohol copolymer (A) of the modified elastomer (D) is derived from α, β-unsaturated carboxylic acid and / or a derivative thereof as a preferred embodiment. Can be mentioned. α, β-unsaturated carboxylic acid and / or derivatives thereof include α, β-unsaturated monocarboxylic acids such as acrylic acid and methacrylic acid; α, β- such as maleic acid, succinic acid, itaconic acid, and phthalic acid. Unsaturated dicarboxylic acid; α, β-unsaturated monocarboxylic acid ester such as glycidyl acrylate, glycidyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate; α, such as maleic anhydride, succinic anhydride, itaconic anhydride, phthalic anhydride, etc. β-unsaturated dicarboxylic acid anhydrides can be mentioned, among which α, β-unsaturated dicarboxylic acid anhydrides such as maleic anhydride, succinic anhydride, itaconic anhydride, phthalic anhydride, etc., especially maleic anhydride Acid is preferred.

  There is no particular limitation on the method for producing a modified elastomer (D) by introducing an α, β-unsaturated carboxylic acid and / or derivative thereof into a thermoplastic elastomer. For example, a vinyl aromatic monomer polymer block and a conjugated diene polymer are used. Examples thereof include a method of radical addition to a block copolymer composed of blocks.

  Specific examples of suitable modified elastomers (D) include EPM containing α, β-unsaturated carboxylic acid and / or a derivative thereof, EPDM containing α, β-unsaturated carboxylic acid and / or a derivative thereof, Examples thereof include a block polymer mainly composed of a vinyl aromatic monomer polymer block and a conjugated diene polymer block and containing an α, β-unsaturated carboxylic acid and / or a derivative thereof. Among these, the modified elastomer (D) is a block polymer mainly composed of a vinyl aromatic monomer polymer block and a conjugated diene polymer block and containing an α, β-unsaturated carboxylic acid and / or a derivative thereof. Is more preferable in that the resulting thermoplastic polymer composition has excellent mechanical performance.

  Examples of the polyolefin resin (E1) used in the thermoplastic polymer composition of the present invention include an ethylene polymer and a propylene polymer, and one or more of these can be used.

  Examples of the ethylene polymer preferably used as the polyolefin resin (E1) include, for example, ethylene homopolymers such as high density polyethylene, medium density polyethylene, and low density polyethylene, propylene, 1-butene, 1-hexene, 1- Copolymers with α-olefins having 2 to 10 carbon atoms such as heptene, 1-octene, 4-methyl-1-pentene, ethylene polymers containing α, β-unsaturated carboxylic acids and / or derivatives thereof Etc. Among these, an ethylene homopolymer is a gas and an organic liquid blocking property, so that an ethylene polymer containing an α, β-unsaturated carboxylic acid and / or a derivative thereof is an ethylene-vinyl alcohol copolymer (A). It is more preferably used in terms of improving compatibility.

  Examples of the propylene polymer preferably used as the polyolefin resin (E1) include propylene homopolymer, ethylene-propylene random copolymer, ethylene-propylene block copolymer, 1-butene, 1-hexene, Propylene containing a copolymer with an α-olefin having 3 to 10 carbon atoms such as 1-heptene, 1-octene, 4-methyl-1-pentene, α, β-unsaturated carboxylic acid and / or a derivative thereof A polymer etc. can be mentioned. Of these, propylene homopolymers are compatible with ethylene-vinyl alcohol copolymers because propylene homopolymers are gas and organic liquid barrier properties, and propylene polymers containing α, β-unsaturated carboxylic acids and / or their derivatives are compatible. It is more preferably used in terms of improving the properties.

  Among these, it is preferable to use a propylene polymer as the polyolefin resin (E1). This is because the propylene polymer is often excellent in compatibility with the block copolymer (B) mainly composed of a vinyl aromatic monomer polymer block and a conjugated diene polymer block which may be hydrogenated. Because. Particularly suitable propylene polymers include propylene homopolymers and propylene polymers containing α, β-unsaturated carboxylic acids and / or derivatives thereof.

  Although not limited at all, the polyolefin-based resin can be produced by, for example, coordination polymerization, radical polymerization, anion polymerization using a Ziegler-Natta catalyst or a metallocene catalyst.

  Examples of the α, β-unsaturated carboxylic acid and / or derivative thereof in the olefin polymer containing the α, β-unsaturated carboxylic acid and / or derivative thereof include α, β- such as acrylic acid and methacrylic acid. Unsaturated monocarboxylic acids; α, β-unsaturated dicarboxylic acids such as maleic acid, succinic acid, itaconic acid and phthalic acid; α, β-unsaturated monocarboxylic acids such as glycidyl acrylate, glycidyl methacrylate, hydroxyethyl acrylate and hydroxyethyl methacrylate Carboxylic acid ester; α, β-unsaturated dicarboxylic acid anhydrides such as maleic anhydride, succinic anhydride, itaconic anhydride, phthalic anhydride and the like can be mentioned, among which maleic anhydride, succinic anhydride, Α, β-unsaturated dicarboxylic anhydrides such as itaconic anhydride and phthalic anhydride, particularly maleic anhydride, are preferred. That's right.

  The thermoplastic polymer composition of the present invention is based on a total of 100 parts by mass of the ethylene-vinyl alcohol copolymer (A), the block copolymer (B), the rubber softener (C) and the modified elastomer (D). The ethylene-vinyl alcohol copolymer (A) is 3 to 50 parts by mass, the block copolymer (B) is 10 to 80 parts by mass, the rubber softener (C) is 0 to 60 parts by mass, and the modified elastomer ( 3) to 50 parts by mass of D) and 3 to 30 parts by mass of polyolefin resin (E1).

  The content of the ethylene-vinyl alcohol copolymer (A) is 100 in total of the ethylene-vinyl alcohol copolymer (A), the block copolymer (B), the rubber softener (C) and the modified elastomer (D). It is 3-50 mass parts with respect to a mass part. When the blending ratio of the ethylene-vinyl alcohol copolymer (A) is less than 3 parts by mass, the barrier property against gas or organic liquid is insufficient, and preferably 5 parts by mass or more. Moreover, when it exceeds 50 mass parts, there exists a problem that a softness | flexibility falls, Preferably it is 40 mass parts or less.

  The content of the block copolymer (B) is 100 parts by mass in total of the ethylene-vinyl alcohol copolymer (A), the block copolymer (B), the rubber softener (C) and the modified elastomer (D). On the other hand, it is 10-80 mass parts. When the blending ratio of the block copolymer (B) is less than 10 parts by mass, the rubber elasticity and flexibility are lowered, and the retention of the rubber softener (C) is also reduced, preferably 15 parts by mass. That's it. When the amount exceeds 80 parts by mass, the amount of each component of the ethylene-vinyl alcohol copolymer (A), the rubber softener (C), and the modified elastomer (D) is reduced. There is a problem that the balance between the barrier property against the mechanical properties and the mechanical properties is deteriorated, and is preferably 60 parts by mass or less.

  The content of the rubber softener (C) is 100 parts by mass in total of the ethylene-vinyl alcohol copolymer (A), the block copolymer (B), the rubber softener (C) and the modified elastomer (D). On the other hand, it is 0-60 mass parts. The rubber softener (C) may not be blended, but in order to obtain more excellent flexibility, blending is preferable, and the blending amount in that case is 10 to 60 parts by mass. Is preferred. In particular, when the molecular weight of the block copolymer (B) is relatively high, it is desirable to add a rubber softener (C). When the blending ratio of the rubber softener (C) is less than 10 parts by mass, the flexibility may be insufficient, and is preferably 15 parts by mass or more. On the other hand, when it exceeds 60 parts by mass, the rubber softener (C) tends to bleed, and is preferably 50 parts by mass or less.

  The content of the modified elastomer (D) is 100 parts by mass in total of the ethylene-vinyl alcohol copolymer (A), the block copolymer (B), the rubber softener (C) and the modified elastomer (D). 3 to 50 parts by mass. When the blending ratio of the modified elastomer (D) is less than 3 parts by mass, the effect of improving the compatibility between the ethylene-vinyl alcohol copolymer and other components is not manifested, leading to a decrease in mechanical properties and the like. Is 5 parts by mass or more. Moreover, when it exceeds 50 mass parts, there exists a possibility of showing skin irritation derived from a modified group, and it is 40 mass parts or less suitably.

  The content of the polyolefin resin (E1) is 100 parts by mass in total of the ethylene-vinyl alcohol copolymer (A), the block copolymer (B), the rubber softener (C) and the modified elastomer (D). And 3 to 30 parts by mass. When the blending ratio of the polyolefin-based resin (E1) is less than 3 parts by mass, the adhesiveness with the layer made of the polyolefin-based resin is insufficient when the multilayer structure is formed, and preferably 5 parts by mass or more. is there. Moreover, when it exceeds 30 mass parts, a softness | flexibility becomes inadequate and it is 20 mass parts or less suitably.

  The method for producing the thermoplastic polymer composition of the present invention is not particularly limited, and ethylene-vinyl alcohol copolymer (A), block copolymer (B), rubber softener (C), and modified elastomer (D). The polyolefin resin (E1) may be any method as long as it can be uniformly mixed, and can usually be produced by melt-kneading the 5 or 4 components together with other components as required. In that case, as an apparatus to be used, for example, a single-screw extruder, a twin-screw extruder, a kneader, a Banbury mixer, etc. can be mentioned, and in a range of about 160 to 280 ° C., it is melted for about 30 seconds to 10 minutes. By kneading, the thermoplastic polymer composition of the present invention can be obtained.

  The thermoplastic polymer composition obtained as described above contains ethylene in a matrix comprising a block copolymer (B), a rubber softener (C), a modified elastomer (D), and a polyolefin resin (E1). When the vinyl alcohol copolymer (A) has a particle diameter of 0.1 μm to 200 μm and a layered structure, the barrier property and flexibility are further improved in a balanced manner. In this case, the particles of the ethylene-vinyl alcohol copolymer (A) dispersed in layers preferably have an L / D of 5 or more when the major axis of the particles is L and the minor axis is D. More preferably, it is 10 or more.

  In addition to the components described above, 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, xylene group-containing polyamide; Polyester resins such as polyethylene terephthalate and polybutylene terephthalate; Acrylic resins such as polymethyl acrylate and polymethyl methacrylate; Poly Polyoxymethylene resins such as oxymethylene homopolymers and polyoxymethylene copolymers; styrene homopolymers, acrylonitrile / styrene resins, acrylonitrile / butadiene / Polystyrene resin, natural rubber, synthetic isoprene rubber, liquid polyisoprene rubber and hydrogenated products thereof, chloroprene rubber, acrylic rubber, butyl rubber, acrylonitrile butadiene rubber, epichlorohydrin rubber, silicone rubber, fluorine Examples thereof include rubber; urethane rubber; polyurethane elastomer; polyamide elastomer; polyester elastomer; soft vinyl chloride resin.

  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 that does not impair the barrier property to the gas, organic liquid, etc. of the thermoplastic polymer composition. Generally, the ethylene-vinyl alcohol copolymer (A) The total amount of the block copolymer (B), the rubber softener (C), the modified elastomer (D), and the polyolefin resin (E1) is preferably 50 parts by mass or less.

  In addition to the above-described components, the thermoplastic polymer composition of the present invention includes a crosslinking agent, a crosslinking aid, a lubricant, a light stabilizer, a flame retardant, an antistatic agent, silicone oil, an antiblocking agent, if necessary. You may contain 1 type, or 2 or more types of other components, such as a ultraviolet absorber, antioxidant, a mold release agent, a foaming agent, and a fragrance | flavor.

  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 moisture resistance and mechanical properties into the molded product.

  In the multilayer structure comprising at least one layer made of the thermoplastic polymer composition of the present invention and at least one layer made of another material, the other material is used for required characteristics, intended use, etc. Appropriate ones may be selected accordingly. Examples of the other materials include 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. Heat of polymer (EVA), ethylene-vinyl alcohol copolymer (EVOH), ethylene-acrylic acid ester copolymer (EEA), polystyrene (PS), vinyl chloride resin (PVC), vinylidene chloride resin (PVDC), etc. Examples thereof include a plastic polymer.

  Among the multilayer structures, a multilayer structure having a layer made of a thermoplastic polymer composition and a layer made of a polyolefin resin (E2) is a preferred embodiment. This is because the thermoplastic polymer composition of the present invention is excellent in adhesiveness with the polyolefin resin (E2). As the polyolefin resin (E2), the same ones as those used as the above-mentioned polyolefin resin (E1) can be used. Among them, a propylene resin, particularly a propylene homopolymer is preferably used. Also. In the multilayer structure, since it is possible to adhere without interposing an adhesive layer between a layer made of the thermoplastic polymer composition of the present invention and a base material layer made of a polyolefin-based resin or the like, In a preferred embodiment, the layer made of the thermoplastic polymer composition and the layer made of the polyolefin resin (E2) are directly bonded to each other.

  Moreover, you may interpose an adhesive bond layer between the layer which consists of the said thermoplastic polymer composition, 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. Examples of the adhesive used in the adhesive layer include acid anhydride-modified products of diene polymers; acid anhydride-modified products of polyolefins; polymer polyols (for example, glycol compounds such as ethylene glycol and propylene glycol, and adipic acid) Polyester polyol obtained by polycondensation of a dibasic acid, a partially saponified product of a copolymer of vinyl acetate and vinyl chloride, and a polyisocyanate compound (for example, a glycol compound such as 1,6-hexamethylene glycol) A reaction product of a molar ratio of 1 to 2 with a diisocyanate compound such as 2,4-tolylene diisocyanate; a molar ratio of a triol compound such as trimethylolpropane and a diisocyanate compound such as 2,4-tolylene diisocyanate of 1: 3 A mixture with a reaction product or the like can be used. For forming the laminated structure, a known method such as co-extrusion, co-injection, or extrusion coating can be used.

  Since the molded article made of the thermoplastic polymer composition of the present invention has both excellent flexibility and excellent barrier properties against many gases, organic liquids, etc., daily necessities and packaging that require these properties It can be used as materials, machine parts, medicine plugs and the like. Examples of applications in which the features of the polymer composition of the present invention are particularly effective include food and beverage packaging materials, containers, and container packings. In a molded article for use in these applications, the polymer composition only needs to form at least one layer, and has a single-layer structure composed of the polymer composition, and the thermoplastic polymer composition. It can be appropriately selected from those having a laminated structure of at least one layer made of a material 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, the molded article made of the polymer composition of the present invention can be melted and reused when discarded.

  Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. Also, using the thermoplastic polymer composition pellets obtained in the following examples and comparative examples, molded articles (test pieces) were prepared as follows, and their physical properties, that is, oxygen permeability coefficient, hardness, etc. The peel strength of the laminated structure was measured as follows.

(1) Measurement of oxygen transmission coefficient:
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 film-like test pieces having a thickness of 100 μm. The oxygen permeability coefficient (cc · 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 the conditions of a temperature of 35 ° C. and a humidity of 0% RH.

(2) Hardness measurement:
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-like test piece having a thickness of 2 mm. The A hardness was measured according to JIS-K6253.

(3) Measurement of peel strength:
Polypropylene (“Grand Polypro J106W” manufactured by Sumitomo Mitsui Polyolefin Co., Ltd.) is used with an injection molding machine (“IS-80” manufactured by Nissei Plastic Industry Co., Ltd .; 80 ton injection molding machine), cylinder temperature 220 ° C. Injection molding was performed at a temperature of 40 ° C. to form a flat plate having a thickness of 1 mm. This was placed in a flat plate mold (dimensions: length × width × thickness = 200 mm × 200 mm × 2 mm) and injected there using the thermoplastic resin composition pellets produced in (1) above. Using a molding machine (“IS-80” manufactured by Nissei Plastic Industry Co., Ltd .; 80-ton injection molding machine), injection molding was performed under the conditions of a cylinder temperature of 200 ° C. and a mold temperature of 40 ° C. A laminate structure (dimensions: length × width × thickness = 200 mm × 200 mm × 2 mm) in which a layer of the thermoplastic resin composition was laminated on the surface of was prepared. A test piece for measuring peel strength (dimension: length × width × thickness = 150 mm × 25 mm × 2 mm) was cut out from the laminated structure thus obtained, and the “180 ° peel” described in JIS-K6854 was used. The peel strength was measured according to “Test”.

  In addition, the ethylene-vinyl alcohol copolymer (A), block copolymer (B), rubber softener (C), modified elastomer (D), and polyolefin resin (E1) used in the following examples and comparative examples The contents of) are as follows.

[Ethylene-vinyl alcohol copolymer (A)]
"Eval EP-G110" manufactured by Kuraray Co., Ltd .:
Ethylene content 47 mol%, melt flow rate 14 g / 10 min (190 ° C, 2.16 kg load), melting point 160 ° C

[Block copolymer (B-1)]
Triblock copolymer comprising polystyrene block-hydrogenated isoprene / butadiene copolymer block-polystyrene block:
Styrene unit content 30% by mass, number average molecular weight 200,000
[Block copolymer (B-2)]
Triblock copolymer comprising polystyrene block-hydrogenated polyisoprene block-polystyrene block:
Styrene unit content 30% by mass, number average molecular weight 60,000

[Rubber softener (C)]
“PW-380” manufactured by Idemitsu Kosan Co., Ltd .:
Paraffin oil, kinematic viscosity 381.6 × 10 ⁻⁶ m ² / sec (40 ° C.), pour point −15 ° C.

[Modified Elastomer (D)]
Triblock copolymer composed of polystyrene block-hydrogenated polybutadiene block-polystyrene block and modified with maleic anhydride:
Styrene unit content 30% by mass, number average molecular weight = 100,000, acid value 2 mg CH ₃ ONa / g

[Polyolefin resin (E-1)]
“Grand Polypro J106W” manufactured by Sumitomo Mitsui Polyolefin Co., Ltd .:
Homopolypropylene, melt flow rate 15 g / 10 min (230 ° C., 2.16 kg load)
[Polyolefin resin (E-2)]
“Admer QF551” manufactured by Mitsui Chemicals, Inc .:
Maleic anhydride-modified polypropylene, melt flow rate 5.7 g / 10 min (230 ° C., 2.16 kg load), melting point 135 ° C.

Examples 1-7
The ratio shown in Table 1 below for the ethylene-vinyl alcohol copolymer (A), block copolymer (B), rubber softener (C), modified elastomer (D) and polyolefin resin (E1). And then pre-mixed with a twin-screw extruder (“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. Each pellet of a thermoplastic polymer composition was produced.

  Using the pellets of the obtained thermoplastic polymer composition, a press film and a molded article (test piece) were produced by the above-described method, and the oxygen transmission coefficient and peel strength were measured by the above-described method. It was as shown in Table 1.

Comparative Examples 1-4
After pre-mixing the ethylene-vinyl alcohol copolymer (A), block copolymer (B), rubber softener (C) and modified elastomer (D) in the proportions shown in Table 2 below, biaxial extrusion Machine (Krupp Werner & Pfleiderer "ZSK-25WLE"), melt kneading under conditions of cylinder temperature 200 ° C and screw rotation speed 350rpm, extruding and cutting to produce pellets of thermoplastic polymer composition, respectively did. Using the obtained thermoplastic polymer composition pellets, a press film and a molded article (test piece) were produced by the method described above, and the oxygen transmission coefficient, hardness and peel strength were measured by the method described above. It was as shown in Table 2 below.

Based on the results in Table 1, ethylene-vinyl alcohol copolymer (A), block copolymer (B), rubber softener (C), modified elastomer (D), and polyolefin resin (E1) were used. Manufactured using the thermoplastic polymer compositions of Examples 1 to 6, or the ethylene-vinyl alcohol copolymer (A), the block copolymer (B), the modified elastomer (D) and the polyolefin resin (E1). When the thermoplastic polymer composition of Example 7 was used, the gas permeability was good as indicated by the oxygen permeability coefficient of about 1300 to about 17000 ml · 20 μm / m ² · day · atm, and the hardness was 56 A to 90A was flexible and the peel strength with respect to polypropylene was 19 to 103 N / 25 mm.

  Moreover, from the result of Table 2, the comparative examples 1-3 which consist of an ethylene-vinyl alcohol copolymer (A), a block copolymer (B), a softener for rubber (C), and a modified addition polymer (D). The thermoplastic polymer composition or the thermoplastic polymer composition of Comparative Example 4 consisting of an ethylene-vinyl alcohol copolymer (A), a block copolymer (B) and a modified addition polymer (D) is flexible. Although it is excellent in gas barrier property, it turns out that the adhesiveness to polyolefin resin is not favorable.

Claims (10)

Block copolymer (B) mainly comprising an ethylene-vinyl alcohol copolymer (A), a vinyl aromatic monomer polymer block and an optionally hydrogenated conjugated diene polymer block, a rubber softener (C) , A modified elastomer (D) having a functional group capable of reacting with the ethylene-vinyl alcohol copolymer (A), and a polyolefin resin (E1). The ethylene-vinyl alcohol copolymer (A), block copolymer 3 to 50 parts by mass of an ethylene-vinyl alcohol copolymer (A) and a block copolymer (B) with respect to 100 parts by mass in total of the blend (B), the rubber softener (C) and the modified elastomer (D). ) 10-80 parts by mass, rubber softener (C) 0-60 parts by mass, modified elastomer (D) 3-50 parts by mass and polyolefin resin (E1) The thermoplastic polymer composition comprising 3 to 30 parts by weight. The thermoplastic polymer composition according to claim 1, comprising 10 to 60 parts by mass of a rubber softener (C). The thermoplastic polymer composition according to claim 1 or 2, wherein the functional group of the modified elastomer (D) is a functional group derived from an α, β-unsaturated carboxylic acid and / or a derivative thereof. The thermoplastic polymer composition according to any one of claims 1 to 3, wherein the polyolefin resin (E1) is a propylene polymer. The thermoplastic polymer composition according to any one of claims 1 to 4, wherein the polyolefin resin (E1) contains a functional group derived from an α, β-unsaturated carboxylic acid and / or a derivative thereof. The molded article which consists of a thermoplastic polymer composition in any one of Claims 1-5. The multilayer structure which has a layer which consists of a thermoplastic polymer composition in any one of Claims 1-5, and a layer which consists of polyolefin resin (E2). The multilayer structure according to claim 6, wherein the layer made of the thermoplastic polymer composition and the layer made of the polyolefin resin (E2) are directly bonded to each other. The multilayer structure according to claim 7 or 8, wherein the polyolefin resin (E2) is polypropylene. The packing for containers which consists of a multilayer structure in any one of Claims 7-9.