JP2003238758A - Thermoplastic polymer composition having excellent gas- barrier properties - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a thermoplastic polymer composition excellent both in barrier properties against a gas, organic liquid, or the like, and in flexibility. <P>SOLUTION: This thermoplastic polymer composition is obtained by dynamically crosslinking, in a molten condition, 100 pts.mass of (I) an ethylene-vinyl alcohol copolymer, 5-900 pts.mass of (II) at least one kind of a block addition copolymer selected from the group consisting of a block copolymer and a hydrogenated product thereof, the block copolymer comprising (A) a polymer block composed of an aromatic vinyl compound unit having 1 mass% or more of a methylstyrene derivative unit wherein at least one methyl group is bonded to a benzene ring, and (B) a polymer block composed of a conjugated diene compound unit, and 0.05-20 pts.mass of (III) a bismaleimide compound per 100 pts.mass of the component (II). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a thermoplastic polymer composition comprising an ethylene-vinyl alcohol copolymer and a specific addition polymerization block copolymer crosslinked with a bismaleimide compound, and the polymer. The present invention relates to a molded article composed of a composition and uses of the polymer composition. INDUSTRIAL APPLICABILITY The thermoplastic polymer composition of the present invention is excellent in both barrier properties against gas and organic liquids and flexibility, and is therefore useful as a sheet, a film, a packaging material for food and drink, a container, a container packing, and the like.

[0002]

2. Description of the Related Art Ethylene-vinyl alcohol copolymers have a high degree of blocking properties against gases and organic liquids, and moreover, do not emit harmful gases such as vinylidene chloride resin and vinyl chloride resin during incineration. Since it does not occur, it is used for various purposes such as food packaging. However, since the ethylene-vinyl alcohol-based copolymer is inferior in flexibility, it is 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.

The ethylene-vinyl alcohol copolymer and other resins usually have a low affinity and poor compatibility, so that a composition obtained by blending a soft resin with the ethylene-vinyl alcohol copolymer is used. In the case of products, compatibility between flexibility and barrier properties is insufficient. In a laminate obtained by laminating a soft resin layer on an ethylene-vinyl alcohol copolymer layer, the flexibility is improved as compared with the ethylene-vinyl alcohol copolymer layer alone. , Depending on the application, it may still lack flexibility. In addition, the adhesive force between the layer of the ethylene-vinyl alcohol copolymer and the layer of the soft resin is often insufficient, which may cause a problem such as delamination.

[0004]

The object of the present invention is to provide a gas, which is an advantage of ethylene-vinyl alcohol copolymers,
Utilizing a high level of barrier properties against organic liquids, and
By improving its shortcoming of lack of flexibility,
It is intended to provide a thermoplastic polymer composition having both excellent barrier properties and flexibility.

[0005]

Means for Solving the Problems As a result of earnest studies, the present inventors have found that an ethylene-vinyl alcohol copolymer, a specific addition polymerization block copolymer and a bismaleimide compound are dynamically added under melting conditions. By the cross-linking treatment, the addition-polymerization block copolymer cross-linked with the bismaleimide compound is dispersed in the ethylene-vinyl alcohol-based copolymer, and a thermoplastic polymer composition capable of achieving both barrier property and flexibility. It was found that a product was obtained, and the present invention was completed.

That is, the present invention comprises 100 parts by mass of an ethylene-vinyl alcohol copolymer (I) and an aromatic vinyl compound unit having 1% by mass or more of a methylstyrene derivative unit having at least one methyl group bonded to a benzene ring. Block copolymer having a polymer block (A) and a polymer block (B) comprising a conjugated diene compound unit, and at least one addition polymerization block copolymer (II) selected from hydrogenated products thereof 5 to 900 parts by mass, and 0.05 to 20 parts by mass of the bismaleimide compound (III) with respect to 100 parts by mass of the component (II), a thermoplastic polymer obtained by dynamically crosslinking under melting conditions. It is a united composition.

The present invention is also a molded article and a sheet or film made of the above-mentioned thermoplastic polymer composition.

Furthermore, the present invention has a laminated structure having a layer made of the above-mentioned thermoplastic polymer composition and a layer made of another material, and at least one layer made of the above-mentioned thermoplastic polymer composition. It is a packaging material for food and drink, containers, and packing for containers.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

The ethylene-vinyl alcohol copolymer (I) in the present invention is mainly composed of ethylene units (--CH
₂ CH ₂ -) and vinyl alcohol units _(-CH 2 -CH
(OH)-). The ethylene-vinyl alcohol-based 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 copolymer is preferably 10 to 99 mol% from the viewpoint of high barrier properties against gas, organic liquids, etc. and good moldability. It is more preferably 20 to 75 mol%, further preferably 25 to 60 mol%, and particularly preferably 25 to 50 mol%. As will be described later, the ethylene-vinyl alcohol-based copolymer is typically an saponified ethylene-fatty acid vinyl ester-based copolymer, but in the case of an saponified ethylene-fatty acid vinyl ester-based copolymer, a fatty acid vinyl is used. The degree of saponification of the ester unit is preferably 50 mol% or more, and more preferably 90 mol% or more from the viewpoints of high barrier properties and high thermal stability of the obtained ethylene-vinyl alcohol copolymer. It is more preferably 95 mol% or more, still more preferably 98 mol% or more. The melt flow rate of the ethylene-vinyl alcohol-based 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 in terms of good moldability. ˜100 g / 10 min, preferably 0.5 to 50 g / 10 min, more 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.
˜5 dl / g is preferable, and 0.2 to 2 dl /
More preferably, it is g.

In the ethylene-vinyl alcohol copolymer, in addition to the ethylene unit and the vinyl alcohol unit, a small amount (preferably 10 mol% based on all the constituent units).
The following may be included in 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 their derivatives (eg salts, esters, nitriles, amides,
(Anhydride, etc.); vinylsilane compounds such as vinyltrimethoxysilane; unsaturated sulfonic acids or salts thereof; N-methylpyrrolidone; Further, the ethylene-vinyl alcohol copolymer may have a functional group such as an alkylthio group at the terminal.

The method for producing the ethylene-vinyl alcohol-based copolymer is not particularly limited, and for example, an ethylene-fatty acid vinyl ester-based copolymer is produced according to a known method, which is then subjected to The ethylene-vinyl alcohol-based copolymer can be produced by the conversion. The ethylene-fatty acid vinyl ester-based copolymer may be obtained by, for example, adding a monomer mainly composed of ethylene and a fatty acid vinyl ester in an organic solvent such as methanol, t-butyl alcohol, or dimethyl sulfoxide under pressure to benzoyl peroxide and azobis. It is obtained by polymerizing with a radical polymerization initiator such as isobutyronitrile. As the fatty acid vinyl ester, vinyl acetate, 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. preferable. An acid catalyst or an alkali catalyst can be used for the saponification of the ethylene-fatty acid vinyl ester copolymer.

The addition polymerization block copolymer (II) used in the thermoplastic polymer composition of the present invention comprises a polymer block (A) mainly composed of an aromatic vinyl compound unit and a polymer block mainly composed of a conjugated diene compound unit. A block copolymer having a united block (B) and at least one addition polymerization block copolymer selected from hydrogenated products thereof, wherein the polymer block (A) has at least one benzene ring. It has a methylstyrene derivative unit bonded with a methyl group in an amount of 1% by mass or more based on the total mass of all polymer blocks (A).

Examples of the methyl styrene derivative (hereinafter sometimes referred to as "methyl styrene derivative") unit in which at least one methyl group is bonded to the benzene ring constituting the polymer block (A) include, for example, o-methyl styrene,
m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, 3,5-dimethylstyrene, 2,4
A unit composed of 6-trimethylstyrene or the like can be mentioned, and among them, a unit composed of p-methylstyrene or 2,4,6-trimethylstyrene is preferable because of its excellent reactivity. Examples of aromatic vinyl compound units other than methylstyrene derivative units include styrene, α-methylstyrene, β-methylstyrene, t-butylstyrene, monofluorostyrene, difluorostyrene, monochlorostyrene, dichlorostyrene, methoxystyrene. , Vinyl naphthalene, vinyl anthracene,
Examples thereof include units composed of indene, acetonaphthylene, etc., and among them, units composed of styrene are preferable.

In the addition polymerization block copolymer (II), the polymer block (A) corresponds to a hard block,
The methyl group bonded to the benzene ring in the methylstyrene derivative unit in the polymer block (A) is a bismaleimide compound (II) due to a dynamic crosslinking reaction under melting conditions.
It has a function of reacting with I) to introduce a cross-linkage into the hard block composed of the polymer block (A). The ratio of the methylstyrene derivative unit in the polymer block (A) is 1 with respect to the total mass of all the polymer blocks (A).
It is preferably at least 10% by mass, more preferably at least 40% by mass, and all units may be methylstyrene derivative units. When the proportion of the methylstyrene derivative unit is less than 1% by mass, crosslinking bond is not introduced into the polymer block (A), and the obtained thermoplastic polymer composition has poor flexibility. The bonding form of the methylstyrene derivative unit and the other aromatic vinyl compound unit in the polymer block (A) may be any form such as a random form, a block form, and a taper block form.

The polymer block (A) may have a small amount of a structural unit composed of an aromatic vinyl compound containing a methylstyrene derivative and, if necessary, a structural unit composed of another copolymerizable monomer. In that case, the ratio of the structural unit composed of the other copolymerizable monomer is preferably 30% by mass or less based on the mass of the polymer block (A),
It is more preferably 10% by mass or less. Examples of the other copolymerizable monomer in that case include ion-polymerizable monomers such as 1-butene, pentene, hexene, butadiene, isoprene, and methyl vinyl ether.

The addition polymerization block copolymer (II) used in the present invention contains a methylstyrene derivative unit in addition to the above-mentioned polymer block (A) composed of an aromatic vinyl compound unit containing a methylstyrene derivative unit. It may have a polymer block composed of aromatic vinyl compound units.

As the conjugated diene compound constituting the polymer block (B) in the addition polymerization block copolymer (II), isoprene, butadiene, hexadiene, 2,
Examples thereof include 3-dimethyl-1,3-butadiene and 1,3-pentadiene. Polymer block (B)
May be composed of only one kind of these conjugated diene compounds, or may be composed of two or more kinds thereof. When the polymer block (B) has a structural unit derived from two or more kinds of conjugated diene compounds, their bonding form is random, tapered, partially block-shaped, or a combination of two or more kinds thereof. Can be

Among them, the polymer block (B) is
Polyisoprene block consisting of monomer unit mainly composed of isoprene unit or hydrogenated polyisoprene block in which a part or all of unsaturated bond thereof is hydrogenated; polybutadiene block consisting of monomer unit mainly composed of butadiene unit or unsaturated thereof Hydrogenated polybutadiene block in which some or all of the bonds are hydrogenated; or isoprene / butadiene copolymer block composed of isoprene units and monomer units mainly composed of butadiene units, or some or all of their unsaturated bonds are hydrogenated It is preferably a hydrogenated isoprene / butadiene copolymer block. In particular, the polymer block (B) is more preferably a hydrogenated block of the above polyisoprene block, polybutadiene block or isoprene / butadiene copolymer block.

As a building block of the polymer block (B)
In the above polyisoprene block, the hydrogen
Before addition, the unit derived from isoprene is 2-methyl
-2-butene-1,4-diyl group [-CH₂-C (C
H₃) = CH-CH₂-; 1,4-bonded isoprene single
Position], an isopropenylethylene group [—CH (C (C
H ₃) = CH₂) -CH₂-; 3,4-bonded isoprene
Unit] and 1-methyl-1-vinylethylene group [-C
(CH₃) (CH = CH₂) -CH₂-; 1,2-bonded
At least 1 selected from the group consisting of isoprene units]
It is composed of seed groups, and the proportion of each unit is not particularly limited.
Yes.

In the above-mentioned polybutadiene block which can be a constituent block of the polymer block (B), 70 to 20 mol% of the butadiene unit is added before the hydrogenation,
In particular 65-40 mol% of 2-butene-1,4-diyl group _{(-CH 2 -CH = CH-CH} 2 -; 1,4- bound butadiene units), and 30 to 80 mol%, particularly 35 to 60
Mol% is a vinyl ethylene group [-CH (CH = CH) -C
H ₂ −; 1,2-bond butadiene unit] is preferable. When the 1,4-bond amount in the polybutadiene block is within the above range of 70 to 20 mol%, the rubber physical properties will be good.

In the above-mentioned isoprene / butadiene copolymer block which can be a constituent block of the polymer block (B), the unit derived from isoprene is 2-methyl-2-butene-1,4-diyl before hydrogenation. Group, an isopropenylethylene group and at least one group selected from the group consisting of 1-methyl-1-vinylethylene group, and the unit derived from butadiene is a 2-butene-1,4-diyl group and And / or vinyl ethylene 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 may be any of random, block, and tapered block shapes. In the isoprene / butadiene copolymer block, the isoprene unit:
The molar ratio of butadiene units is preferably 1: 9 to 9: 1, and more preferably 3: 7 to 7: 3.

The addition-polymerization block copolymer (II) has an unsaturated double bond in the polymer block (B) from the viewpoint that the resulting thermoplastic polymer composition has good heat resistance and weather resistance. It is preferable that a part or all of the above is hydrogenated (hereinafter sometimes referred to as “hydrogenated”). At that time, the hydrogenation rate of the conjugated diene polymer block was 60 mol%.
It is preferably not less than 80 mol%, more preferably not less than 80 mol%, further preferably 100 mol%. Particularly, when the hydrogenation rate is close to 100 mol%, the ratio of the reaction between the polymer block (B) and the bismaleimide compound (III) in the dynamic crosslinking treatment is lowered, and the polymer block (A) and the bismaleimide are reduced. It is preferable in that the selectivity with which a crosslink is introduced into the hard block is increased by reacting with the compound (III).

The molecular weight of the addition polymerization block copolymer (II) is not particularly limited, but the number average molecular weight of the polymer block (A) is 2,500 to 5,000 in the state before hydrogenation and before dynamic crosslinking treatment. 75,000, preferably 5,000-5
The number average molecular weight of the polymer block (B) is in the range of 10,000 to 300,000, preferably 30,000 to 250,000. (II) The total number average molecular weight is 1
2,500 to 2,000,000, preferably 50,0
It is preferable that it is in the range of 0 to 1,000,000 from the viewpoints of mechanical properties, molding processability and the like of the thermoplastic polymer composition obtained. The number average molecular weight (Mn) of the addition polymerization block copolymer (II) as used in the present specification is
The value obtained from the standard polystyrene calibration curve by the gel permeation chromatography (GPC) method.
Further, the bonding form of the polymer block (A) and the polymer block (B) is a diblock copolymer represented by AB,
It is not particularly limited among triblock copolymers represented by ABA or BAB, and multiblock copolymers having tetrablock or more, but among them, triblocks represented by ABA. Copolymers are preferable because the efficiency of physical property improvement by introducing cross-linking is high and the resulting thermoplastic polymer composition has excellent flexibility and rubber properties.

Although not limited thereto, the addition polymerization block copolymer (II) may be produced by a known polymerization method such as an ionic polymerization method such as anionic polymerization or cationic polymerization, or a radical polymerization method. You can

The bismaleimide compound (II used in the present invention
I) is at least methylstyrene in the polymer blocks constituting the addition-polymerization block copolymer (II), which reacts with at least the methyl group bonded to the benzene ring during the dynamic crosslinking treatment under melting conditions. It is not particularly limited as long as it can form a crosslink in the polymer block (A) having a derivative unit, and it is appropriately selected depending on the reactivity and the like according to the treatment temperature and treatment time of the dynamic crosslinking treatment. be able to. Examples of such bismaleimide compound (III) include, for example, N, N'-m-phenylene bismaleimide, N, N'-p-phenylene bismaleimide,
N, N'-p-phenylene (1-methyl) bismaleimide, N, N'-2,7-naphthene bismaleimide, N,
N'-m-naphthene bismaleimide, N, N'-m-phenylene-4-methyl bismaleimide, N, N'-m-
Examples thereof include phenylene (4-ethyl) bismaleimide and toluylene bismaleimide, and among these, N, N'-m-phenylene bismaleimide is preferable. These bismaleimide compounds (III) may be used alone or in combination of two or more.

The mixing ratio of the above components (I) to (III) in the thermoplastic polymer composition of the present invention is 100 parts by weight of the ethylene-vinyl alcohol copolymer (I) and 100 parts by weight of the component (I). To the addition polymerization block copolymer (II) 5 to 900 parts by mass, preferably 40 to 800 parts by mass, and the bismaleimide compound (III) 0.05 to 20 parts by mass with respect to 100 parts by mass of the component (II). Parts, preferably 0.1 to 10 parts by mass.

When the addition amount of the block copolymer (II) is less than 5 parts by mass based on 100 parts by mass of the ethylene-vinyl alcohol copolymer (I), a thermoplastic polymer composition is obtained. Inferior in flexibility, 9
If it exceeds 100 parts by mass, the gas barrier properties will be poor.

Further, addition polymerization type block copolymers (II)
Based on 100 parts by mass, the bismaleimide compound (III)
If the compounding amount of is less than 0.05 parts by mass, the resulting thermoplastic polymer composition has poor gas barrier properties,
If it exceeds 20 parts by mass, the surface appearance of the molded article made of the composition will be inferior.

The thermoplastic polymer composition of the present invention can be obtained by dynamically crosslinking the above-mentioned components (I) to (III) under melting conditions. In this step, the ethylene-vinyl alcohol copolymer (I) and the addition polymerization block copolymer (II) are melt-kneaded to disperse finely and uniformly, and at least addition polymerization is carried out with the bismaleimide compound (III). The cross-linking is caused between the polymer blocks (A) in the system block copolymer (II). For the melt kneading, any device may be used as long as it is a melt kneading device capable of uniformly mixing the respective 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 continuously operated.

The thermoplastic polymer composition of the present invention can be manufactured through the following processing steps as a specific example. That is, the ethylene-vinyl alcohol-based copolymer (I) and the addition polymerization-based block copolymer (II) are mixed and put into the hopper of the extruder. A part of the ethylene-vinyl alcohol copolymer (I) may be added in the middle of the extruder. The bismaleimide compound (III) is
It may be added from the beginning together with the ethylene-vinyl alcohol copolymer (I) and the addition polymerization block copolymer (II), or may be added in the middle of the extruder. Further, two or more extruders may be used and the melt kneading may be sequentially performed stepwise. The melt-kneading temperature is preferably about 160 to 280 ° C, more preferably 200 to 240 ° C. The melt-kneading time is preferably about 30 seconds to 5 minutes.

The thermoplastic polymer composition obtained as described above has a bismaleimide compound (II) in the matrix of the ethylene-vinyl alcohol copolymer (I).
I) cross-linked addition polymerization block copolymer (I
I) has a dispersed structure, and the dispersed particle diameter of the crosslinked addition-polymerization block copolymer is 0.1
The thickness is preferably ˜50 μm, more preferably 0.1 to 30 μm.

Further, the thermoplastic polymer composition of the present invention may contain a paraffinic oil in order to make it more flexible. Generally, an 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 number of carbon atoms constituting the paraffin chain is Those that account for 50% by mass or more of the total carbon number of oil are called "paraffin oil". As the paraffinic oil used in the thermoplastic polymer composition of the present invention, any paraffinic oil can be used, but the content of the component having an aromatic ring is 5% by mass or less. Those of are preferably used.

The amount of paraffin oil blended is 200 with respect to 100 parts by mass of the addition polymerization block copolymer (II).
It is preferably less than or equal to parts by mass. The kinematic viscosity of paraffin oil at 40 ° C. is 20 × 10 ^{−6 to} 800 × 1.
It is preferably 0 ⁻⁶ m ² / sec, and 50 × 10 ⁻⁶ or more.
It is more preferably 600 × 10 ⁻⁶ m ² / sec. The pour point is preferably -40 to 0 ° C, and -3
It is more preferably 0 to 0 ° C. Furthermore, the flash point is
It is preferably 200 to 400 ° C, and 250 to 350
More preferably, it is ° C. The paraffinic oil may be melt-kneaded after impregnating the addition polymerization block copolymer (II) during the production of the thermoplastic polymer composition, or may be added during the melt-kneading. However, the impregnation and the intermediate addition may be used together.

The thermoplastic polymer composition of the present invention may contain, in addition to the above-mentioned components, other polymers, if necessary, within a range not substantially impairing the effects of the present invention. .
Examples of other polymers that may be blended include polyethylene,
Resins such as polypropylene, polyamide and polyester can be used.

Further, the thermoplastic polymer composition of the present invention may contain an inorganic filler, a dye or pigment, etc., if necessary, for the purpose of reinforcement, weight increase, coloring or the like. Examples of the inorganic fillers and dyes and pigments include calcium carbonate, talc, clay, synthetic silicon, titanium oxide, carbon black, barium sulfate and the like. The blending amount of the inorganic filler and the dye / pigment is the gas of the thermoplastic polymer composition,
It is preferable that the barrier property against organic liquids is not impaired, and generally, with respect to a total of 100 parts by mass of the ethylene-vinyl alcohol copolymer (I) and the addition polymerization block copolymer (II). It is preferably 50 parts by mass or less.

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

The thermoplastic polymer composition of the present invention can be used as a molding material in any form such as pellets and powder. Furthermore, since the polymer composition of the present invention has thermoplasticity, it can be molded by using the usual molding method and molding apparatus used for general thermoplastic polymers. As the molding method, for example, any method such as injection molding, extrusion molding, compression molding, blow molding, calender molding, and vacuum molding can be adopted. Molded articles comprising the polymer composition of the present invention produced by such a method include various types such as pipes, sheets, films, discs, rings, bags, bottles, strings and fibrous substances. Various 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 characteristics possessed by other materials such as moisture resistance and mechanical properties into the molded product.

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 required properties An appropriate one may be selected according to the intended use. Examples of other materials include polyolefins (eg, high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, ethylene-propylene copolymer, polypropylene, etc.), ionomers, ethylene-vinyl acetate copolymers. Examples thereof include thermoplastic polymers such as polymer (EVA), ethylene-acrylic acid ester copolymer (EEA), polystyrene (PS), vinyl chloride resin (PVC) and vinylidene chloride resin (PVDC).

In the molded article having the laminated structure, an adhesive layer may be interposed between a layer made of the thermoplastic polymer composition of the present invention and a 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 acid anhydride modified products of diene-based polymers; acid anhydride modified products of polyolefins; polymer polyols (eg, glycol compounds such as ethylene glycol and propylene glycol, and adipic acid). A polyester polyol obtained by polycondensation of a dibasic acid of 1; a partially saponified product of a copolymer of vinyl acetate and vinyl chloride) and a 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 It is possible to use, for example, a mixture with a compound such as a reaction product having a molar ratio of 1: 3). A known method such as co-extrusion, co-injection, and extrusion coating can be used for forming the laminated structure.

Molded articles comprising the polymer composition of the present invention are
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 which require these properties. Examples of applications in which the characteristics of the polymer composition of the present invention are particularly effectively exhibited 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 only needs to form at least one layer, and has a single-layer structure composed of the polymer composition, and the polymer composition. It can be appropriately selected from those having a laminated structure of at least one layer made of and another layer made of another material.
The packaging material for food and drink, the container, and the container packing described above are excellent in long-term storability of the contents because the permeation of oxygen gas in the atmosphere and the permeation of volatile components of the contents can be prevented.

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

[0043]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. Further, using the pellets of the thermoplastic polymer composition 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, elasticity The modulus, 100% modulus, tensile strength at break, tensile elongation at break, and average dispersed particle diameter were measured as follows.

(1) Measurement of oxygen permeability 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 obtain the thickness. A sheet-like test piece having a thickness of 100 μm was prepared, and the oxygen permeation coefficient was measured using these. The oxygen permeability coefficient was measured using a gas permeability measuring device ("GTR-10" manufactured by Yanagimoto Seisakusho), and the oxygen pressure was 0.34 MPa,
It was performed under the conditions of a temperature of 35 ° C. and a humidity of 0% RH.

(2) Measurement of elastic modulus: 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 have a thickness of 1 mm. And the sheet. From this, a strip-shaped test piece with a width of 5 mm was prepared, and dynamic viscoelasticity measurement by tension was performed.
The elastic modulus at room temperature was obtained. The dynamic viscoelasticity is measured by a viscoelasticity analysis measuring device (“DVE-V” manufactured by Rheology Co., Ltd.
4 ”) was used under the condition of a frequency of 1 Hz.

(3) Measurement of Tensile Breaking Strength, Tensile Breaking Elongation and 100% Modulus: A 15 ton injection molding machine using the pellets of the thermoplastic polymer composition produced in the following Examples, Comparative Examples or Reference Examples. [ROB manufactured by FANUC
OSHOT-α15 "], and a cylinder temperature of 21
Molded under conditions of 0 ℃, mold temperature 40 ℃, thickness 2mm,
A dumbbell having a width of 5 mm was manufactured. Using the dumbbell test piece thus obtained, using an autograph (manufactured by Shimadzu Corp.), in accordance with JIS-K6301, 500.
Tensile strength at break, tensile elongation at break and 100% modulus were measured under conditions of mm / min.

(4) Addition polymerization type block copolymer (II)
Measurement of the average dispersed particle size of: The cut surface of each of the thermoplastic polymer compositions produced in the following Examples and Comparative Examples was electron-stained and observed by a scanning electron microscope. In addition, in Table 2 below, those in which the addition polymerization block copolymer (II) is not a dispersed phase but a matrix phase or a co-continuous phase, or a single phase is indicated by "-". It was

The contents of the ethylene-vinyl alcohol copolymer (I), the addition polymerization block copolymer (II) and the bismaleimide compound (III) used in the following Examples and Comparative Examples are as follows. Is.

[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.

[Addition-polymerization block copolymer (II)] ○ Addition-polymerization block copolymer (II-1): poly-p-methylstyrene block / hydrogenated polybutadiene block /
Tri-block copolymer consisting of poly-p-methylstyrene block; Mn = 80,000; ratio of each polymer block = 17.5 / 65 / 17.5 (unit: mass%); hydrogenation rate of polybutadiene block = 99 mol %. ○ Addition polymerization type block copolymer (II-2): poly p-methylstyrene block / polystyrene block / hydrogenated polybutadiene block / polystyrene block / polyp
-Pentablock copolymer consisting of methylstyrene block; Mn = 80,000; ratio of each polymer block = 5
/12.5/65/12.5/5 (unit: mass%); Hydrogenation rate of polybutadiene block = 99 mol%.

[Bismaleimide compound (III)] N,
N'-m-phenylene bismaleimide: "Barnock PM" manufactured by Ouchi Shinko Chemical Industry Co., Ltd.

Examples 1 to 6 (1) The above-mentioned ethylene-vinyl alcohol copolymer (I), addition polymerization block copolymer (II) and bismaleimide compound (III) were cross-linked with a crosslinking aid ( Dibenzothiazyl disulfide) at a ratio shown in Table 1 below, followed by twin screw extruder (Krupp Werne).
"ZSK-25WL" manufactured by r & Pfleiderer
E)), and melt-kneaded under the conditions of a cylinder temperature of 200 ° C. and a screw rotation speed of 350 rpm, extruded and cut to produce pellets of the thermoplastic polymer composition. (2) Using the pellets of the thermoplastic polymer composition obtained in (1) above, a press film and a molded product (test piece) are produced by the above-mentioned method, and the oxygen permeability coefficient, 23
Elastic modulus at ℃, tensile breaking strength, tensile breaking elongation and 10
When the 0% modulus was measured by the above method, it was as shown in Table 1 below.

[0053]

[Table 1]

Comparative Examples 1 and 2 (1) The above-mentioned ethylene-vinyl alcohol copolymer (I) and addition polymerization block copolymer (II)
After premixing in the ratio shown in Table 2 below, the twin screw extruder (Krup was used) without adding the bismaleimide compound (III).
Made by p Werner & Pfleiderer "ZSK
-25WLE "), and melt-kneaded under the conditions of a cylinder temperature of 200 ° C and a screw rotation speed of 350 rpm, extruded and cut to produce pellets of the thermoplastic polymer composition. (2) Using the pellets of the thermoplastic polymer composition obtained in (1) above, a press film and a molded product (test piece) are manufactured by the above-described method, and the oxygen permeability coefficient, elastic modulus, and tensile rupture thereof are produced. When the strength, the tensile elongation at break and the 100% modulus were measured by the methods described above, the results are shown in Table 2 below.

Comparative Examples 3 to 5 (1) Ethylene-vinyl alcohol copolymer (I)
Alternatively, a press film and a molded product (test piece) were manufactured by the above-mentioned method using the pellets of the addition polymerization block copolymer (II) alone. (2) When the oxygen permeability coefficient, elastic modulus tensile breaking strength, tensile breaking elongation and 100% modulus were measured by the above-mentioned methods, the results are shown in Table 2 below.

[0056]

[Table 2]

From the results shown in Table 1 above, Examples 1 to 6 prepared using ethylene-vinyl alcohol copolymer (I), addition polymerization block copolymer (II) and bismaleimide compound (III). When the thermoplastic polymer composition is used, the oxygen permeability coefficient is 22 to 2550 ml · 20.
μm / m ² · day · atm (2.5 to 290 fm · 2
It can be seen that, as shown by the value of 0 μm / Pa · s), a high-quality molded product having a good gas barrier property and excellent in various physical properties such as mechanical properties, flexibility and elasticity can be obtained smoothly.

From the results in Table 2 above, Comparative Example 1 containing the ethylene-vinyl alcohol copolymer (I) and the addition polymerization block copolymer (II) and not adding the bismaleimide compound (III) It can be seen that when the thermoplastic polymer composition No. 2 is used, the gas barrier property is inferior and the mechanical properties are not sufficiently good.

[0059]

EFFECT OF THE INVENTION The thermoplastic polymer composition of the present invention has excellent barrier properties against gas, organic liquids and the like, and also has good flexibility, and therefore, packaging materials for foods and drinks, containers for which these properties are required. , It is effectively used in applications such as container packing.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08J 5/18 CEQ C08J 5/18 CEQ CEX CEX C08K 5/3415 C08K 5/3415 C08L 23/26 C08L 23 / 26 53/02 53/02 F-term (reference) 3E084 HA01 HC03 3E086 AB01 AD01 AD04 BA02 BA04 BA15 BB01 BB90 CA01 CA11 4F071 AA12X AA15X AA22X AA29X AA75 AA78 AC19 AE02 BC01 BC05 BC01 BC02 BC01 BC02 BC01 BC02 BC01 BC02 BC01 BC02 BC01 JD02 4J002 BB22W BE03W BP01X EU026 FD146 GC00 GG01 GG02 GM00

Claims (9)

[Claims] 1. An ethylene-vinyl alcohol-based copolymer (I) (100 parts by mass), and 1% by mass of a methylstyrene derivative unit having at least one methyl group bonded to a benzene ring.
At least one addition polymerization selected from a block copolymer having a polymer block (A) having the above aromatic vinyl compound unit and a polymer block (B) having a conjugated diene compound unit, and a hydrogenated product thereof. 5 to 900 parts by mass of the block copolymer (II), and the component (I
I) 100 parts by mass of bismaleimide compound (II
I) A thermoplastic polymer composition obtained by dynamically cross-linking 0.05 to 20 parts by mass under melting conditions. 2. A crosslinked addition polymerization block copolymer (II) having a particle diameter of 0.1 to 50 μm dispersed in a matrix of the ethylene-vinyl alcohol copolymer (I). The thermoplastic polymer composition according to 1. 3. The thermoplastic polymer composition according to claim 1, wherein at least the polymer block (A) among the polymer blocks constituting the addition-polymerization block copolymer (II) is crosslinked. . 4. A molded article made of the thermoplastic polymer composition according to claim 1. 5. A sheet or film made of the thermoplastic polymer composition according to claim 1. 6. A laminated structure having a layer made of the thermoplastic polymer composition according to claim 1 and a layer made of another material. 7. A packaging material for food and drink which has at least one layer comprising the thermoplastic polymer composition according to any one of claims 1 to 3. 8. A container having at least one layer made of the thermoplastic polymer composition according to claim 1. 9. A packing for a container having at least one layer of the thermoplastic polymer composition according to claim 1.