JP2002338772A - Thermoplastic gas-barrier polymer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic polymer composition which is excellent in softness and in capability for stopping a gas, an organic liquid, etc. SOLUTION: This thermoplastic polymer composition is prepared by subjecting an ethylene/vinyl alcohol copolymer, an elastomer haying at least one kind of functional group selected from the group consisting of a boronic acid group and boron-containing groups each convertible into a boronic acid group in the presence of water, and optionally a cross-linking agent to a dynamic cross-linking treatment under melting conditions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a gas-barrier thermoplastic polymer composition comprising an ethylene-vinyl alcohol copolymer and a crosslinked elastomer, and to the use of the polymer composition. The thermoplastic polymer composition of the present invention is excellent in both flexibility and barrier properties against gases, organic liquids, etc., sheets, films, food and beverage packaging materials,
It is useful as a container, packing for containers, and the like.

[0002]

2. Description of the Related Art Ethylene-vinyl alcohol copolymers have a high level of barrier properties against gases, organic liquids, etc. and, at the same time, remove harmful gases such as vinylidene chloride resin and vinyl chloride resin during incineration. Since it does not occur, it has been developed for various uses such as food packaging materials. However, ethylene-vinyl alcohol copolymers are inferior in flexibility, and are known to be used in the form of a composition with a soft resin such as polyolefin (see JP-A-4-164947) or a laminate. ing.

[0003] Since ethylene-vinyl alcohol copolymers and other resins usually have low affinity and poor compatibility, a composition obtained by blending a soft resin with an ethylene-vinyl alcohol copolymer is usually used. With a product, the compatibility between flexibility and barrier properties is insufficient. Further, in a laminate obtained by laminating a layer of a soft resin with respect to a layer of an ethylene-vinyl alcohol-based copolymer, flexibility is improved as compared with the ethylene-vinyl alcohol-based copolymer alone. However, flexibility may be insufficient depending on the application.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a gas, which is an advantage of an ethylene-vinyl alcohol copolymer,
Utilizing high barrier properties against organic liquids, etc., and
By improving the disadvantage of lack of flexibility,
An object of the present invention is to provide a thermoplastic polymer composition excellent in both barrier properties and flexibility.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that an ethylene-vinyl alcohol-based copolymer and an elastomer having a specific functional group are dynamically cross-linked under melting conditions to obtain a cross-linked polymer. The inventors have found that the obtained elastomer is dispersed in an ethylene-vinyl alcohol copolymer to obtain a thermoplastic polymer composition capable of achieving both barrier properties and flexibility, and have completed the present invention.

That is, the present invention provides at least 100 parts by mass of an ethylene-vinyl alcohol copolymer (I), and at least one selected from the group consisting of a boronic acid group and a boron-containing group which can be converted to a boronic acid group in the presence of water. This is a thermoplastic polymer composition obtained by subjecting a mixture containing 5 to 900 parts by mass of an elastomer (II) having one kind of functional group to a dynamic crosslinking treatment under melting conditions.

Further, the present invention is a molded article and a sheet or film comprising the above-mentioned thermoplastic polymer composition.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

The ethylene-vinyl alcohol copolymer (I) in the present invention is mainly composed of ethylene units (-CH
₂ CH ₂ —) and a vinyl alcohol unit (—CH ₂ —CH
(OH)-). The ethylene-vinyl alcohol copolymer used in the present invention is not particularly limited, and examples thereof include known ones used in molding applications. However, the content of ethylene units in the ethylene-vinyl alcohol-based copolymer is preferably from 10 to 99 mol% from the viewpoint of high barrier properties against gases, organic liquids and the like and good moldability. It is more preferably from 20 to 75 mol%, further preferably from 25 to 60 mol%, particularly preferably from 25 to 50 mol%. The ethylene-vinyl alcohol-based copolymer is typically a saponified ethylene-fatty acid vinyl ester-based copolymer, as will be described later. The degree of saponification of the ester unit is preferably at least 50 mol%, more preferably at least 90 mol%, from the viewpoint of high barrier properties and high thermal stability of the obtained ethylene-vinyl alcohol copolymer. It is more preferably at least 95 mol%, particularly preferably at least 98 mol%. The melt flow rate of the ethylene-vinyl alcohol copolymer (measured by the method described in ASTM D1238 under the conditions of a temperature of 210 ° C. and a load of 2.16 kg) is 0.1% from the viewpoint of good moldability. To 100 g / 10 min, more preferably 0.5 to 50 g / 10 min, and particularly preferably 1 to 20 g / 10 min. The intrinsic viscosity of the ethylene-vinyl alcohol copolymer is 85% by mass of phenol and 1% of water.
0.1% at a temperature of 30 ° C. in a mixed solvent of 5% by mass.
To 5 dl / g, preferably 0.2 to 2 dl / g.
g is more preferable.

In the ethylene-vinyl alcohol copolymer, a small amount (preferably, 10 mol% based on all the constituent units) is added to the ethylene unit and the vinyl alcohol unit.
If it is the following), it may have other structural units. Other structural units include propylene, isobutylene, 4-
Α-olefins such as methylpentene-1, 1-hexene and 1-octene; vinyl acetate, vinyl propionate, vinyl versatate, vinyl pivalate, vinyl valerate, vinyl caprate, vinyl benzoate Carboxylic acid vinyl esters such as esters; itaconic acid, methacrylic acid,
Unsaturated carboxylic acids such as acrylic acid and maleic anhydride or derivatives thereof (eg, salts, esters, nitriles, amides,
Anhydrides and the like); vinylsilane compounds such as vinyltrimethoxysilane; unsaturated sulfonic acids or salts thereof; and units derived from N-methylpyrrolidone and the like. In addition, ethylene-vinyl alcohol-based copolymer,
The terminal may have a functional group such as an alkylthio group.

The method for producing the ethylene-vinyl alcohol-based copolymer is not particularly limited. For example, an ethylene-fatty acid vinyl ester-based copolymer is produced according to a known method. Thus, an ethylene-vinyl alcohol copolymer can be produced. Ethylene-fatty acid vinyl ester-based copolymer is, for example, a monomer mainly composed of ethylene and a fatty acid vinyl ester, in an organic solvent such as methanol, t-butyl alcohol, and dimethyl sulfoxide, under pressure, under pressure, benzoyl peroxide, azobis It is obtained by polymerization using a radical polymerization initiator such as isobutyronitrile. As the fatty acid vinyl ester, vinyl acetate, vinyl propionate, vinyl versatate, vinyl pivalate, vinyl valerate, vinyl caprate and the like can be used. preferable. For saponification of the ethylene-fatty acid vinyl ester copolymer, an acid catalyst or an alkali catalyst can be used.

The elastomer (II) [hereinafter sometimes referred to as the elastomer (II)] used in the thermoplastic polymer composition of the present invention is converted into a boronic acid group in the presence of a boronic acid group and water in the molecule. An elastomer (II) having at least one functional group selected from the group consisting of boron-containing groups that can be converted to a boronic acid group in the presence of water and a boronic acid group in the presence of water. Having at least one functional group selected from the group consisting of a styrene elastomer, an olefin elastomer, a synthetic rubber,
Natural rubber or the like can be used.

Among these, examples of the styrene-based elastomer include a block copolymer mainly comprising a vinyl aromatic compound polymer block and a conjugated diene polymer block. Examples of the vinyl aromatic compound used to form the vinyl aromatic compound polymer block constituting the block copolymer include styrene and α-
Methylstyrene, β-methylstyrene, o-, m-, p
-Methylstyrene, t-butylstyrene, 2,4-dimethylstyrene, 2,4,6-trimethylstyrene, monofluorostyrene, difluorostyrene, monochlorostyrene, dichlorostyrene, methoxystyrene, vinylnaphthalene, vinylanthracene, indene, acetonaphthylene And the like. The vinyl aromatic compound polymer block is one of the above-mentioned vinyl aromatic compounds.
It may have a structural unit consisting of only one kind, or may have a structural unit consisting of two or more kinds. Among them, the vinyl aromatic compound polymer block is preferably mainly composed of structural units derived from styrene.

The vinyl aromatic compound polymer block may have, if necessary, a small amount of a structural unit composed of another copolymerizable monomer together with a structural unit composed of a vinyl aromatic compound. Is preferably not more than 30% by mass based on the mass of the vinyl aromatic compound polymer block.
It is more preferable that the content is not more than mass%. In this case, examples of other copolymerizable monomer units include, for example, monomer units such as 1-butene, pentene, hexene, butadiene, isoprene, and methyl vinyl ether.

The conjugated diene compound used for forming the conjugated diene polymer block in the block copolymer mainly comprising a vinyl aromatic compound polymer block and a conjugated diene polymer block includes 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 kind of these conjugated diene compounds or may be composed of two or more kinds. 2 conjugated diene polymer blocks
When having a structural unit derived from more than one type of conjugated diene compound, their bonding form is random, tapered,
It may be partly block-shaped or a combination of two or more of them.

Among them, in the conjugated diene polymer block, a polyisoprene block composed of monomer units mainly composed of isoprene units or a part or all of unsaturated bonds thereof is hydrogenated (hereinafter sometimes referred to as “hydrogenated”).
Hydrogenated polyisoprene block; polybutadiene block composed of monomer units mainly composed of butadiene units or hydrogenated polybutadiene blocks partially or wholly hydrogenated with unsaturated bonds; or mainly composed of isoprene units and butadiene units It is preferable that the isoprene / butadiene copolymer block composed of monomer units or a hydrogenated isoprene / butadiene copolymer block in which some or all of the unsaturated bonds are hydrogenated.

In the above polyisoprene block which can be a constituent block of the conjugated diene polymer block, before hydrogenation, the unit derived from isoprene has a 2-methyl-2-butene-1,4-diyl group [- CH ₂ -C
(CH ₃ ) ＝ CH—CH ₂ —; 1,4-bonded isoprene unit], isopropenylethylene group [—CH (C (C
H ₃ ) = CH ₂ ) —CH ₂ —; a 3,4-bonded isoprene unit] and a 1-methyl-1-vinylethylene group [−
C (CH ₃ ) (CH ＝ CH ₂ ) —CH ₂ —; 1,2-bonded isoprene unit], and 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, before hydrogenation, 70 to 20 mol%, particularly 65 to 40 mol%, of the butadiene unit is 2-butene-1,4. - diyl group _{(-CH 2 -CH = CH-CH} 2 -; 1,4- bound butadiene units), and 30 to 80 mol%, in particular 35
６０60 mol% is a vinylethylene group [—CH (CH ＝ CH
Preferably a 1,2-bond butadiene unit]; - _{2) -CH 2.}

In the above-mentioned isoprene / butadiene copolymer block which can be a constituent block of the conjugated diene polymer block, before hydrogenation, the unit derived from isoprene has a 2-methyl-2-butene-1,4-diyl group. , An isopropenylethylene group and a 1-methyl-1-vinylethylene group, and at least one group selected from the group consisting of
It comprises a butene-1,4-diyl group and / or a vinylethylene group, and the ratio of each unit is not particularly limited. In the isoprene / butadiene copolymer block, the arrangement of isoprene units and butadiene units is random,
The shape may be any of a block shape and a tapered block shape. In the isoprene / butadiene copolymer block, the molar ratio of isoprene unit: butadiene unit is preferably 1: 9 to 9: 1, and preferably is 3: 7 to
The ratio is more preferably 7: 3.

The block copolymer composed mainly of a vinyl aromatic compound polymer block and a conjugated diene polymer block has a good conjugated diene content because the thermoplastic polymer composition has good heat resistance and weather resistance. It is preferable that some or all of the unsaturated double bonds in the polymer block are hydrogenated. At that time, the hydrogenation rate of the conjugated diene polymer block is preferably 50 mol% or more, more preferably 60 mol% or more, and further preferably 80 mol% or more.

In the block copolymer, the molecular weight of the vinyl aromatic compound polymer block and the molecular weight of the conjugated diene polymer block are not particularly limited, but the number average molecular weight of the vinyl aromatic compound polymer block before hydrogenation is not limited. The molecular weight is in the range of 2,500 to 75,000, and the number average molecular weight of the conjugated diene polymer block is 10,000.
And the number average molecular weight of the entire block copolymer is 12,500 to 2,000,000.
0, more preferably 30,000 to 1,000,000
It is preferable in terms of the mechanical properties, moldability and the like of the thermoplastic polymer composition to be obtained. In addition, the number average molecular weight referred to in the present specification refers to a value determined from a standard polystyrene calibration curve by gel permeation chromatography (GPC).

Although not limited, the block copolymer can be produced by, for example, an ionic polymerization method such as anionic polymerization or cationic polymerization, a single-site polymerization method, a radical polymerization method, or the like. In the case of using an anionic polymerization method, for example, using an alkyl lithium compound or the like as a polymerization initiator, in an inert organic solvent such as n-hexane or cyclohexane, successively polymerizing a vinyl aromatic compound, a conjugated diene compound, or the like, The diblock copolymer having a molecular structure and molecular weight of, a triblock copolymer and the like, and then produced by stopping the polymerization by adding an active hydrogen compound such as alcohols, carboxylic acids, and water. it can.

In the present invention, the elastomer (II)
Examples of olefin-based elastomers that can be used as polyethylene include polyethylene, polypropylene, ethylene-propylene copolymer (EPM), polybutene, and poly (3-
Methyl-1-pentene), an ethylene-propylene-nonconjugated diene copolymer (EPDM), an ethylene-α-olefin copolymer using a metallocene-based polymerization catalyst, and the like.

Further, synthetic rubbers that can be used as the elastomer (II) include polybutadiene, polyisoprene, butyl rubber, styrene-butadiene random copolymer, styrene-isoprene random copolymer,
Acrylonitrile-butadiene copolymer, polychloroprene and the like can be mentioned. Natural rubber may be used as the elastomer (II), and the double bond contained in the synthetic rubber or the natural rubber may be hydrogenated.

As the elastomer (II), at least one selected from the group consisting of a boron-containing group which is excellent in flexibility and is capable of being converted to a boronic acid group in the presence of a boronic acid group and water is used as the thermoplastic polymer composition. Styrene-based elastomers are preferred among the above, because it is easy to introduce one type of functional group, and a block copolymer mainly composed of a vinyl aromatic compound polymer block and a conjugated diene polymer block is more preferred.

In the present invention, the boronic acid group which can be contained in the elastomer (II) is represented by the following formula (Formula 1).

[0027]

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The boron-containing group (hereinafter abbreviated as boron-containing group) which can be converted into a boronic acid group in the presence of water which can be contained in the elastomer (II) includes the elastomer (II) of the present invention. Water, water and organic solvents (toluene,
Xylene, acetone, etc.) or a mixed liquid of 5% boric acid aqueous solution and the above organic solvent, when hydrolyzed under the conditions of a reaction time of 10 minutes to 2 hours and a reaction temperature of room temperature to 150 ° C. Any boron-containing group that can be converted into a boronic acid group may be used, and typical examples thereof include a boronic ester group represented by the following general formula (Chemical Formula 2) and a boronic ester group represented by the following General Formula (Chemical Formula 3) Examples thereof include a boronic anhydride group and a group formed of a boronate represented by the following general formula (Formula 4).

[0029]

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In the formula, X and Y represent a hydrogen atom, an aliphatic hydrocarbon group (such as a linear or branched alkyl group or alkenyl group having 1 to 20 carbon atoms), and an alicyclic hydrocarbon group (cyclo Alkyl group, cycloalkenyl group, etc.), aromatic hydrocarbon group (phenyl group, biphenyl group, etc.)
X and Y may be the same group or different. Further, X and Y may be bonded. Where X and Y
Are excluded when both are hydrogen atoms. ]

[0031]

Embedded image

[0032]

Embedded image

[0033] ^{[wherein, R 1, R 2, R} 3 represents the X, Y and similar hydrogen atom, an aliphatic hydrocarbon group, alicyclic hydrocarbon group, an aromatic hydrocarbon ^{group, R} 1, R ² and R ³ may be the same group or different. Also M
Represents an alkali metal or an alkaline earth metal. [In addition, X, Y, and R ¹ , R ² , and R ³ may have other groups such as a hydroxyl group, a carboxyl group, and a halogen atom. ]

Specific examples of the boronic ester groups, boronic anhydride groups and boronic acid bases represented by the general formulas (Chemical Formula 2) to (Chemical Formula 4) include boronic acid dimethyl ester, boronic acid diethyl ester, and boronic acid. Acid dibutyl ester group, boronic acid dicyclohexyl group, boronic acid ethylene glycol ester, boronic acid propylene glycol ester group (boronic acid 1,2-propanediol ester group, boronic acid 1,3-propanediol ester group), neopentyl boronate Boronic ester groups such as ester group, boronic acid catechol ester group, boronic acid glycerin ester group, boronic acid trimethylolethane ester group, boronic acid trimethylolethane ester group, and boronic acid diethanolamine ester group; boronic anhydride group; boron Alkali metal salts of acids , And alkali earth metal bases such as boronic acid. Among the boronic acid groups that can be contained in the elastomer (II) or the boron-containing groups that can be converted to boronic acid groups in the presence of water, the thermoplastic polymer composition of the present invention has excellent flexibility, 5- and 6-membered cyclic boronic esters are preferred. Examples of such cyclic boronic esters include boronic acid ethylene glycol esters and boronic acid propylene glycol esters.
6-membered ring esters such as boronic acid trimethylene glycol ester, boronic acid 1,3-butanediol ester and boronic acid glycerin ester;

The total amount of boronic acid groups and / or boron-containing groups contained in the elastomer (II) in the present invention is not particularly limited, but is preferably from 100 to 2000 μeq / g, and more preferably from 150 to 1500 μeq / g. More preferred.

The method for producing an elastomer (II) having at least one functional group selected from the group consisting of a boronic acid group and a boron-containing group which can be converted into a boronic acid group in the presence of water in the present invention includes, for example, It can be produced by the following method.

The hydrogenated product of a styrene-diene-based block copolymer having a boronic acid group or a boron-containing group which can be converted into a boronic acid group by the presence of water can be obtained from a styrene having a carbon-carbon double bond under a nitrogen atmosphere. By reacting a hydrogenated product of a diene-based block copolymer with a borane complex and a trialkyl borate to obtain a hydrogenated product of a styrene-diene-based block copolymer having a dialkyl boronate group, It is obtained by reacting water or alcohols. In this production method, if an olefin polymer having a double bond at a terminal is used as a raw material, an olefin polymer having a boronic acid group at the terminal or a boron-containing group that can be converted into a boronic acid group by the presence of water is obtained. When a styrene-diene-based block copolymer having a double bond in the side chain or main chain is used as a raw material, a boronic acid group or a boron-containing group that can be converted to a boronic acid group by the presence of water is provided in the side chain. A styrene-diene-based block copolymer is obtained.

As the borane complex, borane-tetrahydrofuran complex, borane-dimethylsulfide complex, borane-pyridine complex, borane-trimethylamine complex, borane-triethylamine complex and the like are preferable. Among these, a borane-dimethyl sulfide complex, a borane-trimethylamine complex, and a borane-triethylamine complex are more preferable. As trialkyl borate,
Preferred are lower alkyl borate esters such as trimethyl borate, triethyl borate, tripropyl borate and tributyl borate. It is not necessary to use a solvent, but if used, hexane, heptane, octane,
Saturated hydrocarbon solvents such as decane, dodecane, cyclohexane, ethylcyclohexane and decalin are preferred.

The thermoplastic polymer composition of the present invention comprises an ethylene-vinyl alcohol copolymer (I) and a boron-containing group which can be converted to a boronic acid group in the presence of a boronic acid group and water. The mixture containing the selected elastomer (II) having at least one kind of functional group can be obtained by subjecting the mixture to dynamic crosslinking under melting conditions. By reacting with a part of the hydroxyl groups of the alcohol-based copolymer (I) or reacting with the functional groups of the elastomer (II), at least the elastomer (I)
I) is crosslinked, resulting in a structure in which crosslinked particles of the elastomer (II) are dispersed in a matrix of the ethylene-vinyl alcohol copolymer (I).

Further, in order to facilitate the control of the degree of crosslinking of the elastomer (II), it is possible to convert the boron-containing group into a boronic acid group in the presence of an ethylene-vinyl alcohol copolymer (I), a boronic acid group and water. It is preferable that a crosslinking agent (III) is used in combination with the elastomer (II) having at least one functional group selected from the group consisting of the containing groups, and the crosslinking is performed dynamically under melting conditions.

The crosslinking agent (III) used in the present invention is not particularly limited as long as it is a crosslinking agent which reacts with the functional group of the elastomer (II). From the viewpoint of excellent reactivity with a boron-containing group that can be converted into a group, a compound having four or more hydroxyl groups in the molecule is preferable. Examples of such a compound include pentaerythritol, inositol, glucose, heptose, and lactose. And the like. Among them, the hydroxyl group is at least 1-position of the carbon skeleton and 2
More preferred are inositol, glucose, heptose, lactose, and the like, which are cyclic compounds at the 3- and / or 3-positions.

In the present invention, the mixing ratio of the above components (I) and (II) is based on 100 parts by mass of the ethylene-vinyl alcohol copolymer (I) and the elastomer (I).
I) 5 to 900 parts by mass, preferably 30 to 500 parts by mass, and when the crosslinking agent (III) is used, the component (I)
The amount is not more than 30 parts by mass, preferably 0.05 to 30 parts by mass for 100 parts by mass of the crosslinking agent (III).

If the amount of the elastomer (II) is less than 5 parts by mass per 100 parts by mass of the ethylene-vinyl alcohol copolymer (I), the flexibility of the obtained thermoplastic polymer composition is inferior. If the amount exceeds 900 parts by mass, the gas barrier property becomes inferior.

When the amount of the crosslinking agent (III) is 30 parts by mass or less based on 100 parts by mass of the elastomer (II), the obtained thermoplastic polymer composition has a gas barrier property and a surface appearance of a molded article. Will be excellent.

The thermoplastic polymer composition of the present invention is prepared by using the above-mentioned ethylene-vinyl alcohol-based copolymer (I), elastomer (II) and optionally a crosslinking agent (III) in combination under a melting condition. It is obtained by subjecting to a cross-linking treatment. In this step, the ethylene-vinyl alcohol copolymer (I) and the elastomer (II) are melt-kneaded and finely and uniformly dispersed to form cross-linking between functional groups of the elastomer (II). Consists of
For the melt kneading, any device may be used as long as it is a melt kneading device capable of uniformly mixing the components, and as such a melt kneading device, for example, a single screw extruder, a twin screw extruder, Examples thereof include a kneader and a Banbury mixer. Among them, it is preferable to use a twin-screw extruder which has a large shearing force during kneading and can be operated continuously.

The thermoplastic polymer composition of the present invention can be produced through the following processing steps as specific examples. That is, the ethylene-vinyl alcohol copolymer (I) and the elastomer (II) are mixed and charged into a hopper of an extruder. Part of the ethylene-vinyl alcohol copolymer (I) may be added in the middle of the extruder. The crosslinking agent (III) may be added together with the ethylene-vinyl alcohol-based copolymer (I) and the elastomer (II) from the beginning, or may be added in the middle of the extruder. Further, two or more extruders may be used and melt-kneaded in a stepwise manner. Melt kneading temperature is about 160-280
C., preferably from 200.degree. C. to 240.degree. The melt-kneading time is preferably about 30 seconds to 5 minutes.

The thermoplastic polymer composition obtained as described above has a structure in which a crosslinked elastomer (II) is dispersed in a matrix of an ethylene-vinyl alcohol copolymer (I). The dispersed particle diameter of the crosslinked elastomer is 0.1 μm to 30 μm in diameter.
m, more preferably 0.1 μm to 10 μm.

Further, the thermoplastic polymer composition of the present invention may contain a process oil for further softening. Generally, oil used as a process oil is a mixture of a component having an aromatic ring such as a benzene ring and a naphthene ring, a paraffin component (chain hydrocarbon), and the like. The oil that occupies 50% by mass or more of the total carbon number of the process oil is called "paraffin oil". As the process oil used in the thermoplastic polymer composition of the present invention, those referred to as paraffin oil are preferably used, and among those, the content of the component having an aromatic ring is preferably 5% by mass or less. Used.

The amount of the paraffinic oil is preferably 200 parts by mass or less, more preferably 5 to 100 parts by mass, per 100 parts by mass of the elastomer (II). The kinematic viscosity of paraffin oil at 40 ° C.
It is preferably 20 × 10 ^{−6 to} 800 × 10 ⁻⁶ m ² / sec, more preferably 50 × 10 ⁻⁶ to 600 × 10 ⁻⁶ m ² / sec. The pour point is between -40 and 0
C., preferably -30 to 0 C. Further, the flash point is preferably from 200 to 400 ° C, more preferably from 250 to 350 ° C. The paraffinic oil may be subjected to dynamic crosslinking treatment after impregnating the elastomer (II) during the production of the thermoplastic polymer composition, or may be added during the course of the dynamic crosslinking treatment. Alternatively, impregnation and intermediate addition may be used in combination.

The thermoplastic polymer composition of the present invention may contain, if necessary, other polymers in addition to the above-mentioned components as long as the effects of the present invention are not substantially impaired. .
Examples of other polymers that can be compounded include polyethylene,
Resins such as polypropylene, polyamide, and polyester are included.

Further, the thermoplastic polymer composition of the present invention may contain an inorganic filler, a dye and a pigment, if necessary, for the purpose of reinforcing, increasing the amount, coloring and the like. Examples of the inorganic filler and dye / pigment include calcium carbonate, talc, clay, synthetic silicon, titanium oxide, carbon black, barium sulfate, and the like. The amount of the inorganic filler or dye / pigment is determined by the gas of the thermoplastic polymer composition,
It is preferable that the barrier property against an organic liquid or the like is not impaired, and it is generally 50 parts by mass or less based on a total of 100 parts by mass of the ethylene-vinyl alcohol copolymer (I) and the elastomer (II). Is preferred.

Further, the thermoplastic polymer composition of the present invention comprises:
In addition to the above components, if necessary, a crosslinking aid, a lubricant, a light stabilizer, a flame retardant, an antistatic agent, a silicone oil, an antiblocking agent, an ultraviolet absorber, an antioxidant, a release agent, a foaming agent, and a fragrance And other components may be contained.

The thermoplastic polymer composition of the present invention can be used as a molding material in an arbitrary form such as a pellet or powder. Further, since the polymer composition of the present invention has thermoplasticity, it can be molded using a usual molding method or molding apparatus used for a general thermoplastic polymer. As the molding method, for example, any method such as injection molding, extrusion molding, compression molding, blow molding, calender molding, vacuum molding and the like can be adopted. Molded articles comprising the polymer composition of the present invention produced by such a method include pipes, sheets,
Films, disks, rings, bags, bottles, strings,
A wide variety of shapes such as fibrous materials are included, and a laminated structure or a composite structure with another material is 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 article.

In a molded article having a laminated structure of 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 has the required properties, An appropriate one may be selected according to the intended use. Examples of the other material include polyolefins (eg, high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, ethylene-propylene copolymer, polypropylene, etc.), ionomer resins, ethylene-vinyl acetate Thermoplastic polymers such as copolymer (EVA), ethylene-acrylate copolymer (EEA), polystyrene (PS), vinyl chloride resin (PVC), and vinylidene chloride resin (PVDC) can be used.

In the molded article having the laminated structure, an adhesive layer may be interposed between the layer made of the thermoplastic polymer composition of the present invention and the base material layer made of another material. By interposing the adhesive layer, the layer made of the thermoplastic polymer composition of the present invention on both sides thereof and the base material layer made of another material can be firmly joined and integrated. Examples of the adhesive used in the adhesive layer include modified acid anhydrides of diene polymers; modified acid anhydrides of polyolefins; and high molecular polyols (for example, glycol compounds such as ethylene glycol and propylene glycol and adipic acid). Polyester polyol obtained by polycondensation with dibasic acid of the above; partially saponified copolymer of vinyl acetate and vinyl chloride, etc.) and polyisocyanate compound (for example, 1,6)
A reaction product of a glycol compound such as hexamethylene glycol and a diisocyanate compound such as 2,4-tolylene diisocyanate in a molar ratio of 1: 2; a triol compound such as trimethylolpropane and a diisocyanate such as 2,4-tolylene diisocyanate And a reaction product having a molar ratio of 1 to 3 with a compound). For forming the laminated structure, known methods such as co-extrusion, co-injection, and extrusion coating may be used.

The molded article comprising the polymer composition of the present invention
Since it has both excellent barrier properties against many gases and organic liquids and excellent flexibility, it can be used as daily necessities, packaging materials, machine parts, and the like that require these properties. Examples of applications in which the features of the polymer composition of the present invention are particularly effectively exerted include packaging materials for food and drink, containers, packing for containers, and the like. In a molded article for use in these applications, the polymer composition may form at least one layer, and may have a single-layer structure composed of the polymer composition, and may be composed of the polymer composition. It can be appropriately selected from those having a laminated structure of at least one layer and at least one layer made of another material. The above-mentioned packaging materials for foods and drinks, containers, and packing for containers can prevent permeation of oxygen gas in the atmosphere and permeation of volatile components of the contents, so that the contents are excellent in long-term preservability.

The molded article comprising the polymer composition of the present invention can be melted and reused at the time of disposal.

[0058]

EXAMPLES The present invention will be described below in more detail with reference to examples and the like, but the present invention is not limited thereto. Further, using the pellets of the thermoplastic polymer compositions obtained in the following Examples and Comparative Examples, molded articles (test pieces) were prepared as follows, and their physical properties, ie, oxygen permeability coefficient, elasticity, The modulus, 100% modulus, tensile strength at break, tensile elongation at break, and elastomer dispersed particle diameter were measured as follows.

(1) Measurement of Oxygen Permeability Coefficient: Using 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 obtain a thickness. A sheet-shaped test piece of 100 μm was prepared,
Using these, the oxygen permeability coefficient was measured. The measurement of the oxygen permeability coefficient is performed using a gas permeability measuring device ("Yanagimoto Seisakusho" GT
R-10 "), oxygen pressure 0.34 MPa, temperature 3
The test was performed under the conditions of 5 ° C. and 0% RH.

(2) Measurement of elastic modulus: Using the pellets of the thermoplastic polymer compositions produced in the following Examples and Comparative Examples, the pellets were compression-molded with a compression molding machine under heating to a thickness of 1 mm. Was prepared, a strip having a width of 5 mm was prepared, and dynamic viscoelasticity was measured by tension. The dynamic viscoelasticity was measured using a viscoelasticity analyzer (“DVE-V4” manufactured by Rheology) at a frequency of 1 Hz.

(3) Measurement of tensile strength at break, tensile elongation at break, and 100% modulus: 15 ton injection molding machine using pellets of thermoplastic polymer composition produced in the following Examples, Comparative Examples or Reference Examples [ROB manufactured by FANUC
OSHOT-α15 "] and the cylinder temperature 21
Molded under the condition of 0 ° C. and mold temperature of 40 ° C., thickness 2 mm,
A dumbbell-shaped test piece having a width of 5 mm was manufactured. Using a test piece obtained in this way, using an autograph (manufactured by Shimadzu Corporation), 500 according to JIS-K6301
The tensile strength at break, tensile elongation at break and 100% modulus were measured under the condition of mm / min.

(4) Measurement of the average dispersed particle diameter of the elastomer: The cut surface of the thermoplastic polymer compositions produced in the following Examples and Comparative Examples was electronically dyed, and observed by a scanning electron microscope. In Table 2 below, those in which the elastomer is not a dispersed phase but a matrix phase, or a single phase are indicated by "-".

The contents of the ethylene-vinyl alcohol copolymer (I), the elastomer (II-2), and the crosslinking agent (III) used in the following Examples and Comparative Examples are as follows. In addition, what was manufactured according to the manufacturing example shown below was used for the elastomer (II-1).

[Ethylene-vinyl alcohol copolymer (I)] Saponified ethylene-vinyl acetate copolymer having an ethylene unit content of 47 mol%: "EVAL EP-G110A" manufactured by Kuraray Co., Ltd.

[Production Example of Elastomer (II-1)] A styrene-hydrogenated butadiene-styrene block copolymer (number average molecular weight: 100400, styrene unit content: 18% by mass, hydrogenation ratio: 97 mol%) was charged into an inlet. Was supplied to a twin-screw extruder at a rate of 7 kg / hour while replacing with 1 L / min of nitrogen. Next, a liquid mixture of borane-triethylamine complex (TEAB) and 1,3-butanediol borate (BBD) (TEAB / BBD = 29) was supplied from the liquid feeder 1.
/ 71, mass ratio) at a rate of 0.6 kg / hour and 1,3-butanediol from the liquid feeder 2 at a rate of 0.4 kg / hour, and were continuously kneaded. During kneading, the gauge of vent 1 and vent 2 was about 2.7 kPa (20 mm).
The pressure was adjusted to show Hg). As a result, an elastomer containing a 1,3-butanediol boronic acid ester group was obtained at a rate of 7 kg / hour from the discharge port. The ¹ H-NMR spectrum of the elastomer was measured, and the amount of the boronic acid 1,3-butanediol ester group added was determined from the intensity ratio of the hydrogen atoms close to the boron atoms, and was 210 μeq / g.

[Elastomer (II-2)] Styrene-hydrogenated butadiene-styrene block copolymer containing no functional group (number average molecular weight 97000, styrene unit content 18% by mass, hydrogenation rate 98 mol%)

[Crosslinking agent (III)] Inositol: manufactured by Wako Pure Chemical Industries

<< Examples 1 to 3 >> (1) A half of the above-mentioned ethylene-vinyl alcohol copolymer (I) was mixed with a twin-screw extruder (Krupp Werne).
r & Pfleiderer “ZSK-25WL”
E ") and feed from the main feeder and cylinder temperature 20
The mixture is melt-kneaded under the conditions of 0 ° C. and a screw rotation number of 350 rpm, and a preliminary mixture of the elastomer (II-1) and the remaining ethylene-vinyl alcohol copolymer (I) is charged from a side feeder and melt-kneaded. A dynamic cross-linking treatment was performed, extruded and cut to produce pellets of the thermoplastic polymer composition. (2) Using the pellets of the thermoplastic polymer composition obtained in the above (1), a press film and a molded product (test piece) are produced by the method described above, and the oxygen permeability coefficient of the molded product is 20
Modulus at 10 ° C, tensile strength at break, tensile elongation at break and 10
The 0% modulus was measured by the method described above and was as shown in Table 1 below.

Examples 4 to 7 (1) The above-mentioned ethylene-vinyl alcohol copolymer (I), elastomer (II-1) and crosslinking agent (II)
I) was premixed in the proportions shown in Table 1 below and then twin-screw extruder (Krupp Werner & Pfleid)
ERER “ZSK-25WLE”), cylinder temperature 200 ° C and screw rotation speed 350 rpm
m, performing a dynamic crosslinking treatment by melt-kneading under the conditions of
The pellets were extruded and cut to produce pellets of the thermoplastic polymer composition. In Example 7, "PW-380" manufactured by Idemitsu Kosan Co., Ltd. was used as the process oil (IV). (2) Using the pellets of the thermoplastic polymer composition obtained in the above (1), a press film and a molded product (test piece) are produced by the method described above, and the oxygen permeability coefficient of the molded product is 20
Modulus at 10 ° C, tensile strength at break, tensile elongation at break and 10
The 0% modulus was measured by the method described above and was as shown in Table 1 below.

[0070]

[Table 1]

Comparative Example 1 (1) The above ethylene-vinyl alcohol copolymer (I) and elastomer (II-2) were prepared according to the following Table 2.
After pre-mixing at the ratio shown in Table 2, the twin screw extruder (Krupp Werner & Pfl) was added without adding the crosslinking agent (III).
Eiderer “ZSK-25WLE”), cylinder temperature 200 ° C and screw rotation speed 3
The mixture was melt-kneaded under the conditions of 50 rpm, extruded, and cut to produce pellets of the thermoplastic polymer composition. (2) Using the pellets of the thermoplastic polymer composition obtained in the above (1), a press film and a molded article (test piece) are produced by the above-mentioned method, and the oxygen permeability coefficient, the elastic modulus, and the tensile rupture thereof are obtained. The strength, tensile elongation at break and 100% modulus were measured by the methods described above, and were as shown in Table 2 below.

<< Comparative Examples 2 and 3 >> (1) Using the pellets shown in Table 2 below alone, press films and molded articles (test pieces) were produced by the above-described methods. (2) The oxygen transmission coefficient, modulus of elasticity, tensile breaking strength, tensile breaking elongation, and 100% modulus were measured by the methods described above.

[0073]

[Table 2]

From the results shown in Table 1, the ethylene-vinyl alcohol copolymer (I) and the elastomer (II-1)
The thermoplastic polymer compositions of Examples 1 to 3 produced by using the above, ethylene-vinyl alcohol copolymer (I), elastomer (II-1) and crosslinking agent (III)
When using the thermoplastic polymer compositions of Examples 4 to 7 manufactured using
・ 20 μm / m ²・ day ・ atm (1.8 to 250f
m / Pa · s), the gas barrier properties are good, and it can be seen that a high quality molded article excellent in various physical properties such as mechanical properties, flexibility and elasticity can be obtained smoothly.

From the results shown in Table 2 above, when the thermoplastic polymer composition of Comparative Example 1 comprising the ethylene-vinyl alcohol copolymer (I) and the elastomer (II-2) containing no functional group was used, 4500 in oxygen permeability coefficient
0ml ・ 20μm / m ²・ day ・ atm (5100f
m / Pa · s), it is inferior in gas barrier properties, and is not sufficiently satisfactory in terms of mechanical properties.

[0076]

The thermoplastic polymer composition of the present invention has excellent barrier properties against gases, organic liquids, and the like, and also has good flexibility. It is effectively used in applications such as packing for containers.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 23/26 C08L 23/26 53/02 53/02 101/02 101/02 F-term (Reference) 4F070 AA05 AA06 AA07 AA08 AA09 AA13 AA15 AA26 AA28 AB01 AB08 AB16 AC36 AE08 GA06 GB08 4F071 AA10 AA11 AA12 AA12X AA13 AA13X AA15 AA15X AA20 AA22 AA22X AA28 AA28X AA03 A03 A05 AB A03 A03 A04 A05 AB A03 B EC056 FD010 FD146 GG01 GG02

Claims (8)

[Claims] 1. 100 parts by mass of an ethylene-vinyl alcohol copolymer (I) and at least one member selected from the group consisting of a boronic acid group and a boron-containing group which can be converted to a boronic acid group in the presence of water. A thermoplastic polymer composition obtained by dynamically cross-linking a mixture containing 5 to 900 parts by mass of an elastomer (II) having a functional group under melting conditions. 2. The mixture before dynamic crosslinking treatment further comprises 30 parts by mass of a crosslinking agent (III) capable of reacting with a functional group of the elastomer (II) per 100 parts by mass of the elastomer (II). The thermoplastic polymer composition according to claim 1, which contains: 3. The thermoplastic polymer composition according to claim 2, wherein the crosslinking agent (III) is a compound having four or more hydroxyl groups in a molecule. 4. The method according to claim 1, wherein the functional group of the elastomer (II) is
The thermoplastic polymer composition according to any one of claims 1 to 3, which is a boronic acid cyclic ester group. 5. The elastomer according to claim 1, wherein the elastomer (II) is a block copolymer comprising a vinyl aromatic compound polymer block and a conjugated diene polymer block or a hydrogenated product thereof. A thermoplastic polymer composition. 6. An elastomer (II) crosslinked in a matrix of an ethylene-vinyl alcohol copolymer (I).
The thermoplastic polymer composition according to any one of claims 1 to 5, wherein the thermoplastic polymer composition has a structure in which particles have a particle diameter of 0.1 µm to 30 µm. 7. A molded article comprising the thermoplastic polymer composition according to claim 1. 8. A sheet or film comprising the thermoplastic polymer composition according to claim 1.