JPH101579A - Polymer composition and its use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polymer composition improved in flexibility without detriment to excellent barrier properties to gas, organic liquids, etc., by compounding an ethylene/vinyl alcohol copolymer and a specified isobutylene block copolymer so as to form a specified state of phases. SOLUTION: This composition mainly comprises an ethylene/vinyl alcohol copolymer (called EVOH hereinafter) (A) and a block copolymer (B) containing polymer blocks comprising mainly aromatic vinyl monomer units and polymer blocks comprising mainly isobutylene units, wherein the component A is present substantially in a state of matrix while the component B is present substantially in a state of dispersed particles. The formulation ratio in weight of component A to component B is preferably (99:1) to (25:75). The ethylene unit content of the EVOH is preferably 10-99mol%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer composition comprising an ethylene-vinyl alcohol copolymer and a specific block copolymer, a molded article comprising the polymer composition, and use of the polymer composition. About. According to the polymer composition of the present invention, it is possible to make use of the excellent barrier property against gas, organic liquid, and the like, which are advantages of the ethylene-vinyl alcohol copolymer, and to improve the drawback of insufficient flexibility.

[0002]

2. Description of the Related Art Ethylene-vinyl alcohol copolymers have high barrier properties against many gases, organic liquids and the like, and are harmful to incineration disposal such as vinylidene chloride resin and vinyl chloride resin. Since it does not generate gas, it is being developed for various uses. That is, in addition to food packaging materials that utilize a high degree of gas barrier properties (gas barrier properties) and the like, applications to gasoline tanks for automobiles and the like that utilize high levels of organic liquid barrier properties are being implemented or studied. However, ethylene-vinyl alcohol copolymers are inferior in flexibility and are generally used in the form of a composition or a laminate with a soft resin such as polyolefin.

[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. In many cases, the inherent barrier properties of the ethylene-vinyl alcohol copolymer are greatly impaired. 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 still be lacking depending on the application.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is as follows.
An ethylene-vinyl alcohol-based copolymer composition that utilizes the advantages of an ethylene-vinyl alcohol-based copolymer, such as gas and organic liquids, and that has the disadvantage of improving the lack of flexibility. Is to provide. Secondly, an object of the present invention is to provide a molded article in which the above excellent properties are effectively exhibited. Also,
Thirdly, an object of the present invention is to provide various uses of the composition in which the above excellent properties are effectively exhibited.

[0005]

Means for Solving the Problems As a result of intensive studies, the first object of the present invention is to provide both an ethylene-vinyl alcohol copolymer and a specific isobutylene block copolymer in a specific state. The second and third objects are achieved by providing a polymer composition containing:
It has been found that this can be achieved by utilizing the polymer composition, and the present invention has been completed.

That is, according to the present invention, the first object is to provide (A) an ethylene-vinyl alcohol copolymer and (B) a polymer block (b1) mainly composed of a vinyl aromatic monomer unit. A block copolymer mainly comprising a polymer block (b2) comprising an isobutylene unit, wherein the component (A) is substantially present in a matrix state, and the component (B) is substantially in a state of dispersed particles. This is achieved by providing a polymer composition characterized by being present in:

According to the present invention, the second object is to provide a molded article made of the polymer composition, and at least one layer made of the polymer composition and at least one layer made of another material. This is achieved by providing molded articles each having a laminated structure.

According to the present invention, the third object is attained by providing the following uses (1) to (9).

(1) A packaging material for food and drink having at least one layer comprising the polymer composition.

(2) A container having at least one layer made of the polymer composition.

(3) A bag-in-box having an inner bag having at least one layer comprising the polymer composition.

(4) Packing for containers having at least one layer made of the polymer composition.

(5) A medical infusion bag having at least one layer made of the polymer composition.

(6) An organic liquid storage tank having at least one layer made of the polymer composition.

(7) An organic liquid transport pipe having at least one layer made of the polymer composition.

(8) A heating hot water pipe having at least one layer made of the polymer composition.

(9) A resin wallpaper having at least one layer comprising the polymer composition.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

The polymer composition of the present invention mainly comprises the above components (A) and (B).

In the present invention, the ethylene-vinyl alcohol copolymer (hereinafter referred to as "EVOH") as the component (A) is mainly composed of ethylene units (-CH ₂ CH _2- ).
And a vinyl alcohol unit (—CH ₂ —CH (OH) —). E used in the present invention
The VOH is not particularly limited, and includes, for example, known ones used in molding applications. However, the content of ethylene units in EVOH is preferably from 10 to 99 mol%, and more preferably from 20 to 65 mol%, from the viewpoint of high barrier properties against gas, organic liquid, and the like and good moldability. Is more preferable, and 25
The content is more preferably from 60 to 60 mol%, particularly preferably from 25 to 50 mol%. EVOH is typically a saponified ethylene-fatty acid vinyl ester copolymer as described later, but in the case of a saponified ethylene-fatty acid vinyl ester copolymer, the saponification degree of the fatty acid vinyl ester unit is From the viewpoint of high barrier property and thermal stability of the obtained EVOH to gas, organic liquid, etc., it is preferably at least 50 mol%, more preferably at least 90 mol%, and preferably at least 95 mol%. More preferably, it is particularly preferably 98 mol% or more.
The melt flow rate of EVOH (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 set at 0.1 from the viewpoint of good moldability.
It is preferably from 1 to 100 g / 10 min, and from 0.5 to
More preferably 50 g / 10 min, 1 to 20 g
/ 10 minutes is particularly preferable. The intrinsic viscosity of EVOH is 85% by weight of phenol and 15% by weight of water.
0.1 to 5 dl at a temperature of 30 ° C. in a mixed solvent of
/ G, more preferably 0.2 to 2 dl / g.

EVOH may have other structural units in addition to ethylene units and vinyl alcohol units, as long as the amount is small (preferably 10 mol% or less based on all structural units). Other structural units include α-olefins such as propylene, isobutylene, 4-methylpentene-1, 1-hexene, and 1-octene; vinyl acetate, vinyl propionate, 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) Amides and anhydrides); vinylsilane compounds such as vinyltrimethoxysilane; unsaturated sulfonic acids or salts thereof; and units derived from N-methylpyrrolidone and the like. EVOH may have a functional group such as an alkylthio group at the terminal.

The method for producing EVOH is not particularly limited. For example, an ethylene-fatty acid vinyl ester copolymer is produced according to a known method, and then saponified to produce EVOH. can do. 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. Is preferred. In the saponification of the ethylene-fatty acid vinyl ester copolymer, an acid catalyst or an alkali catalyst can be used.

The component (B) includes a polymer block (b1) mainly composed of vinyl aromatic monomer units and a polymer block (b) mainly composed of isobutylene units.
2) (hereinafter referred to as “b1 / b2”).
Referred to as "block copolymer").

The vinyl aromatic monomer unit which is a main constituent unit of the polymer block (b1) is a unit derived from a vinyl aromatic monomer by addition polymerization. Examples of the vinyl aromatic monomer include styrene, α-methylstyrene, 2-methylstyrene, 4-methylstyrene, 4-propylstyrene, 4-t-butylstyrene,
4-cyclohexylstyrene, 4-dodecylstyrene,
2-ethyl-4-benzylstyrene, 4- (phenylbutyl) styrene, 2,4,6-trimethylstyrene, monofluorostyrene, difluorostyrene, monochlorostyrene, dichlorostyrene, methoxystyrene, t-
Styrenes such as butoxystyrene; vinyl group-containing aromatic compounds such as vinyl naphthalenes such as 1-vinylnaphthalene and 2-vinylnaphthalene; and vinylene group-containing aromatic compounds such as indene and acenaphthylene. The number of vinyl aromatic monomer units constituting the polymer block (b1) may be only one, or may be two or more. However, among them, it is particularly preferable that the polymer block (b1) is composed of a unit derived from styrene.

The polymer block (b1) preferably has a number average molecular weight of 2,500 to 400,000,
More preferably, it is 5,000 to 200,000. The number average molecular weight of the polymer block (b1) is 2500 or more,
In particular, when the molecular weight is 5,000 or more, the mechanical properties of the b1 / b2 block copolymer become good, and the composition with the component (A) also has good mechanical properties. on the other hand,
The number average molecular weight of the polymer block (b1) is 400,000
B1 / b2 below, especially below 200,000
The melt viscosity of the block copolymer does not become too high;
Mixing with the components becomes easy, and the moldability and processability of the obtained polymer composition are also improved.

The isobutylene unit which is the main constituent unit of the polymer block (b2) in the b1 / b2 block copolymer is a unit derived from isobutylene by addition polymerization (-C (CH ₃ ) ₂ -CH _2- ). is there. The number average molecular weight of the polymer block (b2) is 10,000 to 400,000
It is preferred that When the number average molecular weight of the polymer block (b2) is 10,000 or more, the blockability of the b1 / b2 block copolymer with respect to gas, organic liquid, and the like is particularly good, and the composition with the component (A) is also effective. The blocking properties are particularly good. On the other hand, the polymer block (b2)
Is less than 400,000, b1 / b
The fluidity of the two-block copolymer is good, and the polymer composition with the component (A) has good moldability and workability.

At least one polymer block (b1)
And a b1 / b2 block copolymer having at least one polymer block (b2) have a number average molecular weight of 2
000 to 500,000, preferably 300
It is more preferable that the number be from 00 to 400,000. b1 /
When the number average molecular weight of the b2 block copolymer is 20,000 or more, especially 30,000 or more, mechanical properties such as strength and elongation of the b1 / b2 block copolymer, and thus the polymer composition with the component (A). Is good. On the other hand, b
The number average molecular weight of the 1 / b2 block copolymer is 50,000
When the value is 0 or less, especially 400,000 or less, b1 / b
The fluidity of the two-block copolymer is good, and the moldability and processability of the polymer composition with the component (A) are good. b1
/ B The polymer block (b) in the two-block copolymer
The ratio between 1) and the polymer block (b2) depends on the b1 / b2 block copolymer, the number average molecular weight of the polymer block (b1), the number average molecular weight of the polymer block (b2), and the like.
Generally, based on the weight of the b1 / b2 block copolymer, the proportion of the polymer block (b1) is 5 to 80% by weight, and the proportion of the polymer block (b2) is 95 to 20%.
%, More preferably 10 to 75% by weight of the polymer block (b1), and more preferably 90 to 25% by weight of the polymer block (b2). The proportion of the polymer block (b1) is 5% by weight or more,
In particular, when the content is 10% by weight or more, the mechanical properties such as the strength of the b1 / b2 block copolymer and thus the polymer composition with the component (A) are improved, while the ratio of the polymer block (b1) is improved. Is 80% by weight or less, especially 75% by weight or less, the melt viscosity does not become too high, and the moldability and processability of the polymer composition with the component (A) are improved. The weight percentage of the polymer block (b1) is b1 /
b2 block copolymer is composed of a plurality of polymer blocks (b
In the case of having 1), it is the sum of the weight% of each polymer block (b1). Similarly, the polymer block (b)
When the b1 / b2 block copolymer has a plurality of polymer blocks (b2), the weight% of 2) is the sum of the weight% of each polymer block (b2).

The b1 / b2 block copolymer only has to have at least one polymer block (b1) and at least one polymer block (b2) in the molecule, and the structure is not particularly limited. Not done. For example, b1 / b2
The block copolymer may have any of a straight-chain, two or more branched-chain or star-shaped molecular chain forms. In addition, as a typical example of the b1 / b2 block copolymer, a copolymer having a molecular chain having a structure represented by the following formula (I) or (II) can be given.

[0029]

Embedded image Q- [C (R ¹ ) (R ² )-(b2-b1) m- (b2) k-] n (I) Q- [C (R ¹ ) (R ² )-(b1- b2) m- (b1) k-] n (II)

(In the above formulas (I) and (II), Q is n
And b1 represents a polymer block (b1)
And b2 represents a polymer block (b2), R ¹ and R ² each represent an alkyl group or an aralkyl group having 1 to 20 carbon atoms, k represents 0 or 1, and m and n each represent 1 or more. Represents an integer. However, m is preferably 1. )

Further, the b1 / b2 block copolymer has a content within the range not impairing the performance of the polymer composition of the present invention.
The functional group may be introduced by any method. Examples of functional groups that can be introduced include a hydroxyl group, an amino group, an alkylamino group, an epoxy group, an ether group (eg, an alkoxyl group), a carboxyl group, an ester group (eg, an alkoxycarbonyl group, an acyloxyl group), and an amide group ( Examples include a carbamoyl group, an alkylcarbamoyl group, an acylamino group), and a group having a dicarboxylic anhydride structure (eg, a maleic anhydride residue).

The method for producing the b1 / b2 block copolymer is not particularly limited. For example, according to a usual method,
Using a polymerization initiator system, in an inert solvent, a polymerization operation of a monomer mainly composed of a vinyl aromatic monomer and a polymerization operation of a monomer mainly composed of isobutylene are performed stepwise in an arbitrary order, and further, if desired. And a compound having a functional group. Examples of the polymerization initiator system in that case include a mixed system of a Lewis acid and an organic compound capable of generating a cationic polymerization active species by the Lewis acid. As the Lewis acid, titanium tetrachloride, tin tetrachloride, boron trichloride, aluminum chloride and the like can be used. Examples of the organic compound capable of generating a cationic polymerization active species with a Lewis acid include, for example, bis (1-methoxy-1-methylethyl)
Benzene, bis (1-acetoxy-1-methylethyl)
Benzene, bis (1-chloro-1-methylethyl) benzene and the like can be used. Further, together with the above-mentioned Lewis acid and organic compound, if necessary, for example, N, N
-Amides such as dimethylacetamide, esters such as ethyl acetate, pyridines, amines and the like may be used as stabilizers for polymerization active species. Organic solvents such as hexane, cyclohexane, methylcyclohexane, methyl chloride, and methylene chloride can be used as the inert solvent for polymerization.

The linear b1 / b2 block copolymer is:
For example, (1) an organic compound having one functional group capable of forming a Lewis acid and a cationic polymerization active species in a molecule is used as a polymerization initiator system, and a monomer mainly composed of isobutylene is added to the reaction system. A polymer block (b2) by polymerization to form a polymer block (b2) and then polymerizing a monomer mainly composed of a vinyl aromatic monomer to form a polymer block (b1); (2) Lewis acid and First, a monomer mainly composed of isobutylene is polymerized to form a polymer block (b2) using an organic compound having two functional groups capable of generating a cationic polymerization active species in a molecule. It is manufactured by a method of adding a monomer mainly composed of a vinyl aromatic monomer and performing polymerization to form a polymer block (b1). Can. Also, star-shaped b1
/ B2 block copolymer is prepared by first using, as a polymerization initiator system, an organic compound having at least three functional groups capable of generating a Lewis acid and a cationically polymerizable active species in a molecule, and starting with a monomer mainly composed of isobutylene. Are polymerized to form a polymer block (b2), and then a monomer mainly composed of a vinyl aromatic monomer is added to carry out polymerization to form a polymer block (b1).

In the polymer composition of the present invention, (A)
Two or more types of EVOH may be used as a component, and two or more types of b1 / b2 block copolymers may be used as a component (B).

In the polymer composition of the present invention, substantially,
The component (A) constitutes a matrix phase, and the component (B) constitutes a dispersed particle phase. Since the polymer composition has a matrix phase mainly composed of the component (A), an extremely high barrier property against gases, organic liquids, and the like inherently contained in the component (A) is effectively exhibited. .
The polymer composition contains the component (A) having excellent flexibility and good gas barrier properties in the matrix phase of the component (A) as a dispersed particle phase. The flexibility is remarkably improved as compared with the case where the component (A) is used alone, while maintaining the excellent barrier property of the above-mentioned high degree.

In the polymer composition of the present invention, the fact that the component (A) substantially constitutes a matrix phase and the component (B) constitutes a dispersed particle phase can be determined, for example, by the following method. It can be confirmed by observing with an electron microscope. The shape and the like of the sample are not necessarily limited. For example, a sheet having a thickness of 1 mm is formed from the polymer composition by hot press molding, and sufficiently cooled by immersion in liquid nitrogen under normal pressure. After that, the sample was taken out, rapidly broken, and the broken sample was immersed in a 50 times or more weight of toluene at a temperature of 20 ° C. for 1 minute to etch the fractured surface without causing physical damage (( B) The components are dissolved and removed), dried, and then ion sputtering is performed. Observation of the fracture surface thus treated with a scanning electron microscope shows that adjacent holes (dents) are not substantially connected to each other (ie,
By observing the state (substantially independent), it can be confirmed that the component (A) substantially constitutes a matrix phase and the component (B) substantially constitutes a dispersed particle phase. In the polymer composition of the present invention, the particle diameter of the dispersed particles mainly composed of the component (B) is not particularly limited, but is prepared by melt-kneading the polymer composition and then hot pressing. After using a sheet having a thickness of 1 mm as a sample and subjecting it to the same cooling, breaking, etching, drying and ion sputtering as described above,
Average value of major axis (Ls = (Σn · L) / (Σn) obtained when measuring the major axis for about 1000 holes formed by etching based on scanning electron microscope observation
(Where n represents the number of pores having a long diameter L)), it is generally preferred that the thickness be in the range of 0.01 to 100 μm. When the polymer composition of the present invention takes the form of a thin layer in a molded article, the maximum value of the length in the thickness direction of the layer in the dispersed particles mainly composed of the component (B) is substantially The thickness should be set to be smaller than the thickness of the layer, preferably １ ／ or less of the thickness of the layer, more preferably 1/10 or less.

The quantitative ratio of the component (A) to the component (B) in the polymer composition of the present invention is such that the component (A) and the component (B) substantially constitute the matrix phase and the dispersed particle phase, respectively. Although it is not particularly limited as long as it is particularly excellent overall in terms of barrier properties against gas and liquid and flexibility, the weight ratio of component (A) / component (B) is generally 99/1 to 1/99. Preferably it is in the range of 25/75.

The polymer composition of the present invention has the above-mentioned (A)
In addition to the component and the component (B), if necessary, other polymers and additives may be contained as long as the effects of the present invention are not substantially impaired. Examples of other polymers that can be blended include EPR (ethylene-propylene rubber), EPD
M (ethylene-propylene-diene rubber), NR (natural rubber), isoprene rubber, butadiene rubber, IIR
(Butyl rubber); and resins such as polyethylene, polypropylene, polybutene, polyisobutylene, polyamide, and polyester. Examples of additives include mineral oils or softeners for improving fluidity during molding; inorganic powder fillers; fibrous fillers such as glass fibers and metal fibers; heat stabilizers; Light stabilizers; adhesives; tackifiers; antistatic agents; foaming agents and the like. These other polymers or additives may be contained in the matrix phase or in the dispersed phase. For example, phosphoric acid, pyrophosphoric acid, phosphorous acid,
Oxalic acid, succinic acid, adipic acid, tartaric acid, citric acid,
When a partial salt of an acid or a polybasic acid such as sodium dihydrogen phosphate, potassium dihydrogen phosphate, and acetic acid is contained in the EVOH matrix phase, the melt kneading for the production of the polymer composition or Gelation of EVOH during melt molding of the polymer composition may be suppressed, and deterioration of color tone may be prevented.

Although the method for preparing the polymer composition of the present invention is not particularly limited, predetermined amounts of the components (A) and (B) are
It is preferably prepared by sufficiently mixing or kneading under melting conditions together with other polymers or additives, if desired. At this time, it is desirable to experimentally appropriately select the melt viscosity of each component in advance so that the component (A) and the component (B) can substantially form a matrix phase and a dispersed particle phase, respectively. Mixing or kneading under the melting conditions, for example, kneader ruder, extruder,
It can be performed using a known mixing device or kneading device such as a mixing roll or a Banbury mixer. The temperature at the time of mixing or kneading is preferably adjusted as appropriate according to the melting point of the component (A) to be used, but is usually 110 to 110.
What is necessary is just to adopt the temperature in the temperature range of 300 degreeC.

The polymer composition of the present invention can be used as a molding material in an arbitrary form such as a pellet or a powder. 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, press 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 molds, pipes, sheets, films, disks, rings, bags, bottles, strings, and fibrous materials. A variety of shapes, such as objects, are included, as well as those in the form of a laminated structure or a composite structure with other materials. By adopting a laminated structure with other materials,
It is possible to improve the moisture resistance, mechanical properties and the like of the molded product.

In a molded article having a laminated structure of at least one layer made of the polymer composition of the present invention and at least one layer made of another material, the other material has the required characteristics and is expected. What is necessary is just to select a suitable thing suitably according to a use etc. 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.), ionomers, ethylene-vinyl acetate copolymers. Examples thereof include thermoplastic polymers such as polymer (EVA), ethylene-acrylate 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 polymer composition of the present invention and a base material layer made of another material. By interposing the adhesive layer, the two layers on both sides thereof 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). A polyester polyol obtained by polycondensation with a dibasic acid of the above; a partially saponified product of a copolymer of vinyl acetate and vinyl chloride, etc.) and a polyisocyanate compound (for example, a glycol compound such as 1,6-hexamethylene glycol). A reaction product having a molar ratio of 1: 2 with a diisocyanate compound such as 2,4-tolylene diisocyanate; a molar ratio of 1: 3 between a triol compound such as trimethylolpropane and a diisocyanate compound such as 2,4-tolylene diisocyanate. A reaction product). In addition, a known method such as co-extrusion, co-injection, and extrusion coating may be used for forming a laminated structure.

The molded article comprising the polymer composition of the present invention is
Since it has both high barrier properties against many gases and organic liquids and good 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 exerted include packaging materials for food and drink, containers,
Inner bags for bag-in-box, packing for containers, infusion bags for medical use, tanks for storing organic liquid, pipes for transporting organic liquid, hot water pipes for heating (hot water pipes for floor heating, etc.), resin wallpaper, 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 It can be appropriately selected from those having a laminated structure of at least one layer of at least one layer and at least one layer of another material. The above-mentioned food and beverage packaging materials, containers, bag-in-box inner bags, container packing, and medical infusion bags can prevent the transmission of oxygen gas in the atmosphere and the transmission of volatile components of the contents. Has excellent long-term storage properties. The above-described organic liquid storage tank and organic liquid transport pipe can seal an organic liquid such as aliphatic hydrocarbons, ketones, and gasoline and the vapor thereof, and thus have the same functions as metal tanks and pipes. Compared with metal parts, the weight can be reduced, and the degree of freedom in the shape that can be taken is high because of the ease of molding. In the above-described heating hot water pipe, deterioration due to penetration of hot water and occurrence of stress cracks are suppressed even in long-term use, and thus hot water leakage can be prevented. Further, in the above resin wallpaper, by taking a laminated structure of a layer made of the polymer composition of the present invention and a base layer made of a soft resin such as a vinyl chloride resin, the plasticizer in the soft resin is applied to the wallpaper surface. Bleed-out can be prevented, and as a result, the occurrence of surface contamination can be prevented.

The scrap of the molded article comprising the polymer composition of the present invention can be reused by melting and, if necessary, adding the component (A) and / or the component (B). .

[0044]

EXAMPLES The present invention will be specifically described below with reference to examples and the like, but the present invention is not limited thereto.

In the following synthesis examples, the number average molecular weight of the block copolymer was determined by GPC (gel permeation chromatography), and the number average molecular weight of each block in the block copolymer was determined by It was determined based on GPC of polyisobutylene as a synthetic intermediate, and the content of styrene units in the block copolymer was ¹ H
-Determined by NMR.

<Synthesis Example 1> A mixed solvent consisting of 1060 parts by weight of methylene chloride and 920 parts by weight of methylcyclohexane, and 2.7 parts by weight of titanium tetrachloride and 1,4 parts by weight in a reactor equipped with a stirrer and purged with nitrogen. A polymerization initiator system comprising 0.91 parts by weight of -bis (1-methoxy-1-methylethyl) benzene was charged, and 150 parts by weight of isobutylene was charged and polymerized for 4 hours under cooling at -65 ° C. -6
Under cooling at 5 ° C, dimethylacetamide 0.08
Parts by weight and 38 parts by weight of styrene were added, and the mixture was further polymerized for 4 hours. The obtained reaction mixture was reprecipitated in methanol to produce a styrene-isobutylene-styrene triblock copolymer (i). Table 1 shows the number average molecular weight of the obtained triblock copolymer (i), the number average molecular weight of each block, and the styrene content.

<Synthesis Examples 2 and 3> Styrene, isobutylene and 1,4-bis (1-methoxy-1-methylethyl) benzene were prepared in the same manner as in Synthesis Example 1 except that the proportion of benzene was changed. -Isobutylene-styrene triblock copolymers (ii) and (iii) were produced respectively. Table 1 below shows the number average molecular weight of these triblock copolymers, the number average molecular weight of each block, and the styrene content.

[0048]

[Table 1]

<Examples 1 to 5> The triblock copolymer (i), (ii) or (iii) and EVOH (“EVAL EP-H101” or “EVAL EP-E105” manufactured by Kuraray Co., Ltd.) The mixture was mixed at a ratio shown in Table 2 below, melt-kneaded at 200 ° C. with a small twin-screw extruder, and extruded and cut to produce polymer composition pellets. The pellets were subjected to hot press molding by a press molding machine to produce sheet-like test pieces having a thickness of 1 mm and 100 μm, and the hardness (JIS D) and the oxygen permeability coefficient were measured using these test pieces. Hardness is JIS K7
215 was measured. The oxygen permeability coefficient is measured by a gas permeability measuring device ("GTR-10" manufactured by Yanagimoto Seisakusho).
Was performed under the conditions of an oxygen pressure of 3.5 kg / cm ² , a temperature of 35 ° C., and a humidity of 0% RH. Further, using the above-mentioned pellets, in accordance with the above-mentioned procedure, a hot-pressed sheet was formed by a press-forming machine into a sheet having a thickness of 1 mm, cooled with liquid nitrogen, broken, and the cut surface was etched with toluene for 1 minute. After drying and ion-sputtering, observation with a scanning electron microscope (S-2150 manufactured by Hitachi, Ltd.) confirmed that the triblock copolymer was dispersed in the EVOH matrix in the form of particles. The major axis was measured for about 1000 holes formed by dissolving and removing the triblock copolymer by etching, and based on the measured value, the average value of the major axis (Ls = (Σn · L)
/ (Σn) (where n represents the number of holes having a long diameter L). Table 2 shows the obtained measurement results.

<Comparative Examples 1 to 3> Polyamide ("UBE nylon 1013B" manufactured by Ube Industries, Ltd.) alone and EVOH ("EVAL EP-E105" manufactured by Kuraray Co., Ltd.) were used instead of the polymer composition sheet. Polymer composition with isoprene-styrene based block copolymer (SEPS) (“Septon 2002” manufactured by Kuraray Co., Ltd.) and EVOH (Eval EP-E10 manufactured by Kuraray Co., Ltd.)
The hardness and the oxygen permeability coefficient were measured in the same manner as in Example 1 except that each of the sheets 5)) was used alone. Table 2 shows the obtained measurement results.

[0051]

[Table 2]

From Table 2 above, the polymer compositions of the present invention of Examples 1 to 5 have an oxygen permeability coefficient of 30 cc.20 μm / m 2.
Excellent gas barrier properties as shown below ²・ day ・ atm,
In addition, it is understood that the flexibility is good as shown in JIS D hardness of 50 to 80. On the other hand, in the case of the polyamide of Comparative Example 1, the oxygen transmission coefficient was 2%.
It can be seen that the gas barrier property is insufficient as indicated by the value of 50 cc · 20 μm / m ² · day · atm, and that the flexibility is slightly insufficient as indicated by the value of 84 in JIS D hardness.
In the case of the polymer composition of EVOH and the isoprene-styrene block copolymer of Comparative Example 2, the gas barrier property was 3200 cc · 20 μm / m ² · day · atm as shown in the oxygen permeability coefficient. It turns out to be insufficient. Further, in the case of EVOH alone in Comparative Example 3, it can be seen that the flexibility is insufficient as indicated by 88 in JIS D hardness.

Example 6 Pellets were produced using the same polymer composition as that obtained in Example 2, and the pellets were mixed under a nitrogen stream in a three-layer, five-layer coextrusion apparatus (for a polymer composition). (Set temperature of the extruder: 230 ° C.) to produce a multilayer film of three types and five layers. The layer constitution of the film is, from one side, in the order of high-density polyethylene layer / adhesive layer / polymer composition layer / adhesive layer / high-density polyethylene layer, and the thickness of each layer is Both are about 60 μm in the high-density polyethylene layer, and about 10 μm in both adhesive layers (maleic acid-modified polyethylene; “Admer NF-500” manufactured by Mitsui Petrochemical Co., Ltd.)
The thickness was about 10 μm in the polymer composition layer. The obtained film was subjected to a bending test using a gelbo flex tester. The first through-hole (pinhole) was generated when the number of times of bending exceeded 300 times.

<Comparative Example 4> EV instead of the polymer composition
OH (“EVAL EP-H101” manufactured by Kuraray Co., Ltd.)
Coextruded in the same manner as in Example 6 except for using singly, and a high-density polyethylene layer (thickness: about 60 μm) / adhesive layer (thickness: about 10 μm) / EVOH layer (thickness: about 10 μm)
μm) / adhesive layer (thickness: about 10 μm) / high-density polyethylene layer (thickness: about 60 μm)
A multilayer film of layers was made. A bending test was performed in the same manner as in Example 6 except that the obtained film was used. The first through-hole (pinhole) when the number of bending exceeds 50
There has occurred.

From the comparison between Example 6 and Comparative Example 4,
It can be seen that the film having a layer of the polymer composition of Example 6 according to the present invention has significantly improved bending resistance as compared with the film having a layer of EVOH of Comparative Example 4 other than the present invention. .

<Example 7> In the same manner as in Example 6, the same polymer composition, high-density polyethylene and adhesive resin as those obtained in Example 2 were co-extruded to form a high-density polyethylene layer (thickness). Thickness: approx. 60 μm) / adhesive layer (thickness: approx. 1)
0 μm) / polymer composition layer (thickness: about 10 μm) / adhesive layer (thickness: about 10 μm) / high-density polyethylene layer (thickness: about 60 μm) Was prepared. The obtained film was simultaneously biaxially stretched using a pantograph-type biaxial stretching machine at a temperature of 70 ° C. and a stretching ratio of 3 × 3. The obtained stretched film was free from cracks, spots, and uneven thickness, and had good appearance and transparency. The stretched film was conditioned at 20 ° C. and 100% RH, and its oxygen permeability coefficient was measured using a gas permeation measuring device (GTR-30 manufactured by Yanagimoto Seisakusho).
・ It was 20 μm / m ²・ day ・ atm. From the above, it can be seen that the stretched film of this example has excellent gas barrier properties under wet conditions.

<Example 8> In the same manner as in Example 6, the same polymer composition, high-density polyethylene and adhesive resin as those obtained in Example 2 were co-extruded to form a high-density polyethylene layer (thickness). Thickness: approx. 60 μm) / adhesive layer (thickness: approx. 1)
0 μm) / polymer composition layer (thickness: about 10 μm) / adhesive layer (thickness: about 10 μm) / high-density polyethylene layer (thickness: about 60 μm) Was prepared. This film is cut into a rectangular shape having a predetermined size, and two opposing sides are thermocompression-bonded with a heat sealer to form a cylinder, and one end of the cylindrical film is thermocompression-bonded with a heat sealer to form a bag-like product (food packaging). Material). This bag was filled with commercially available miso, and the mouth of the bag was thermocompressed with a heat sealer and sealed. After storing the packed miso at room temperature for 3 months, the mouth of the bag was opened to check the color tone and aroma of the contents, but no change was observed.

<Example 9> The same polymer composition, high-density polyethylene and adhesive as those obtained in Example 2 were prepared in the same manner as in Example 6, except that the conditions such as the die lip thickness were changed. Resin is co-extruded and a high density polyethylene layer (thickness: about 150 μm) / adhesive layer (thickness: about 20 μm)
m) / polymer composition layer (thickness: about 20 μm) / adhesive layer (thickness: about 20 μm) / high-density polyethylene layer (thickness:
A multilayer sheet of three types and five layers having a layer configuration of about 150 μm) was produced. This sheet was cut into a disc shape, and used as a packing (packing for containers). A glass bottle filled with orange juice was covered with a metal crown and sealed in a conventional manner. After storing the sealed orange juice at room temperature for 3 months, the crown was opened to check the color tone and aroma of the contents, but no change was observed.

<Example 10> In the same manner as in Example 8, using the same polymer composition as obtained in Example 2, a high-density polyethylene layer (thickness: about 60 µm) / adhesive layer ( Thickness: about 10 μm) / Polymer composition layer (thickness: about 10 μm)
μm) / adhesive layer (thickness: about 10 μm) / high-density polyethylene layer (thickness: about 60 μm)
A bag consisting of a multilayer film of layers was produced. The bag was filled with the solution for infusion, and the mouth of the bag was thermocompressed with a heat sealer and sealed. This sealed solution for infusion is 10 ° C
For 3 months, no change was found in the content, gas chromatographic analysis, color tone, odor, etc. From the above, it is understood that the above polymer composition is useful as a material for a medical infusion bag.

Example 11 Pellets were produced using the same polymer composition as that obtained in Example 2, and the pellets were subjected to a three-layer, five-layer co-extrusion multilayer direct blow apparatus (polymer) under a nitrogen stream. (Set temperature of extruder for composition: 230 ° C)
And 5 types of multi-layer hollow molded products (cylindrical body,
A molded article having an inner volume of about 1.5 liters, comprising a cylindrical neck portion provided continuously at one end of the body portion and a bottom portion provided continuously at the other end of the body portion, was produced. The layer configuration of the hollow molded article is, in order from the outer surface, a high-density polyethylene layer / adhesive layer / polymer composition layer / adhesive layer / high-density polyethylene layer. Is approximately 850 μm for both high-density polyethylene layers and both adhesive layers (maleic acid-modified polyethylene;
"Admer NF-50" manufactured by Mitsui Petrochemical Industries, Ltd.
0 ") was about 100 μm, and about 100 μm in the polymer composition layer. The hollow molded article was free from cracks, spots, and uneven thickness, and had good appearance and transparency. After filling the obtained hollow molded product with 1.0 liter of gasoline and sealing it tightly, place it in a dark place at 40 ° C. and 65% RH.
It was left still for a year. No gasoline odor leak occurred during standing. Thereafter, the cap was opened and gasoline was withdrawn, and the state of the hollow molded article was observed. No abnormalities such as cracks and deterioration were found. In addition, the amount of gasoline recovered was examined, but virtually no loss was observed during storage. From these facts, it is understood that the hollow molded article having the layer composed of the above polymer composition is useful as a container for organic liquid, a tank for storing organic liquid, and a pipe for transporting organic liquid.

Example 12 The same polymer composition, high-density polyethylene and adhesive resin as those obtained in Example 2 were co-extruded from an annular die into a pipe to form a high-density polyethylene layer (thickness). Thickness: about 3 mm) / adhesive layer (thickness:
About 0.5 mm) / polymer composition layer (thickness: about 0.5 m)
m) / adhesive layer (thickness: about 0.5 mm) / high-density polyethylene layer (thickness: about 3 mm) to produce a multilayer pipe of three types and five layers (diameter: about 5 cm). This pipe was cut to a predetermined length and used as a hot water pipe for heating for one year. During that time, no hot water leakage due to cracking or the like was observed. This shows that the pipe having the layer composed of the above polymer composition is useful as a heating hot water pipe.

Example 13 Pellets were produced using the same polymer composition as obtained in Example 2, and the pellets were subjected to a twin-screw extruder equipped with a T-die at 230 ° C. under a nitrogen stream. And extruded at a screw rotation speed of 200 rpm, and further uniaxially stretched at 70 ° C. at a stretching ratio of 3 to obtain a film having a thickness of 15 μm. One side of this film is coated with a main agent AD- having a solid concentration of 20% by weight.
The two-component urethane adhesive (manufactured by Toyo Morton) composed of 585 and the curing agent CAT-10 was mixed at a weight ratio of the base agent to the curing agent of 17: 1, and the coating amount (solid content basis) was obtained. After coating with a gravure coater to ² g / m ² and drying at 110 ° C. for 1 minute,
One side of a 0.3 mm thick flexible polyvinyl chloride sheet containing 38% by weight of a plasticizer (di-2-ethylhexyl phthalate) is laminated and integrated by a drain lamination method at a temperature of 110 ° C. through the coating surface. It has become. When a part of the obtained laminated sheet was subjected to a T-type peeling test, the polyvinyl chloride sheet layer was broken, and thus it was found that the laminated sheet had sufficient adhesive strength. A rigid polyvinyl chloride plate (without adding a plasticizer) having a side length of 6 cm and a thickness of 2 mm is placed in close contact with the surface of the laminated sheet on the polymer composition film layer side, and the rigid polyvinyl chloride plate Was left at 70 ° C. for 50 hours with a load of 2 kg applied. Thereafter, the weight of the rigid polyvinyl chloride plate and the surface condition of the laminated sheet on the polymer composition film layer side were examined, but no change in weight and no sticky surface were observed. From these, it was confirmed that there was no oozing out of the plasticizer on the surface of the laminated sheet on the polymer composition film layer side. The surface of the laminated sheet on the polymer composition film layer side was rubbed with a wet cloth, but no damage was found on the surface. From the above, it can be seen that the laminated sheet having the layer composed of the above polymer composition is useful as a resin wallpaper.

[0063]

As described above, the polymer composition of the present invention can maintain excellent barrier properties against many gases, organic liquids, etc., which are advantages of an ethylene-vinyl alcohol copolymer, at a high level.
The disadvantage of lack of flexibility is improved. Therefore,
The polymer composition is a food or beverage packaging material required for these properties, a container, a bag-in-box inner bag, a container packing, a medical infusion bag, an organic liquid storage tank, an organic liquid transport pipe, It is effectively used in applications such as heating hot water pipes and resin wallpaper.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication location C08J 5/00 CEX C08J 5/00 CEX C08L 53/00 LLY C08L 53/00 LLY

Claims (12)

[Claims] (A) an ethylene-vinyl alcohol copolymer, (B) a polymer block (b1) mainly composed of vinyl aromatic monomer units and (B2) a polymer block (b2) mainly composed of isobutylene units. A polymer composition mainly comprising a block copolymer, wherein the component (A) is substantially present in the form of a matrix, and the component (B) is substantially present in the form of dispersed particles. . 2. A molded article comprising the polymer composition according to claim 1. 3. A molded article having a laminated structure of at least one layer made of the polymer composition according to claim 1 and at least one layer made of another material. 4. A packaging material for food and drink having at least one layer comprising the polymer composition according to claim 1. 5. A container having at least one layer comprising the polymer composition according to claim 1. 6. A bag-in-box having an inner bag having at least one layer comprising the polymer composition according to claim 1. 7. A container packing having at least one layer comprising the polymer composition according to claim 1. 8. A medical infusion bag having at least one layer comprising the polymer composition according to claim 1. 9. An organic liquid storage tank having at least one layer comprising the polymer composition according to claim 1. 10. An organic liquid transport pipe having at least one layer comprising the polymer composition according to claim 1. 11. A heating hot water pipe having at least one layer comprising the polymer composition according to claim 1. 12. A resin wallpaper having at least one layer comprising the polymer composition according to claim 1.