JP2003268183A - Resin composition and its applications - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition with an outstanding barrier property, especially in a highly moist environment, to provide a film, a laminate and a container made thereof. <P>SOLUTION: The resin composition comprises a vinyl alcohol polymer and a plurality of inorganic layer structure compounds with a specific mean particle diameter. The film, the laminate and the container which contain at least one layer comprised of the composition are provided. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a vinyl alcohol polymer (hereinafter sometimes abbreviated as PVA polymer).
The present invention also relates to a vinyl alcohol-based polymer composition which is composed of a plurality of inorganic layered compounds having a specific average particle diameter and has excellent barrier properties, and uses thereof.

[0002]

2. Description of the Related Art Although the functions required of packaging materials are diverse, the barrier property against various gases (gas barrier property) is an important function that determines the storability of packaged contents. The gas barrier property is becoming more and more important due to the diversification of packaging technology, the regulation of additives and the change of taste. The deterioration factors of the packaged contents, particularly the food, include oxygen, light, heat, moisture, etc. Among them, oxygen is the main deterioration factor. In addition, barrier materials having barrier properties against not only oxygen gas but also various gases, organic solvent vapors, fragrances, etc. are effective for rust prevention, deodorization, and sublimation prevention, and are useful in many fields such as food, cosmetics, agricultural chemicals, and medical treatment. Are used in confectionery bags, skipjack packs, retort pouches, carbon dioxide beverage containers, and the like. However, the gas barrier properties of resins generally used for packaging materials are low, and the performance as a barrier material used for the above purpose was not sufficient.

On the other hand, a technique for dispersing a filler, particularly a layered inorganic compound in a resin for the purpose of improving the gas barrier property of the resin is widely known, and is disclosed in, for example, JP-A-64-43554. Is a saponified ethylene-vinyl acetate copolymer (hereinafter sometimes abbreviated as EVOH)
Describes a method of dispersing mica and talc.
However, the resin composition obtained by such a method has a drawback that the dispersibility of the inorganic layered compound in the resin is poor and the transparency of the resin is significantly deteriorated.

In order to overcome this drawback, various attempts have been made to use an inorganic layered compound such as a layered silicate having a property of swelling or cleaving in a dispersion medium, particularly in water, as an inorganic layered compound. As a method for dispersing an inorganic layered compound in a polyamide, JP-A-62-74957 discloses a method of swelling an inorganic layered compound with a monomer and then polymerizing the monomer. Also, EVOH
As a method of dispersing the inorganic layered compound in the composition
In 39392, JP-A-5-86241, and JP-A-6-57066, an inorganic layered compound is mixed and dispersed in EVOH in a state where it is swollen and cleaved in an aqueous solvent (water-methanol solvent). The method is shown.
However, the method of polymerizing after swelling the inorganic layered compound with a monomer of polyamide is a very excellent method in improving the dispersibility of the inorganic layered compound, on the other hand, in the method, the viscosity is obtained by dispersing the inorganic layered compound. Therefore, it is practically limited to those containing an extremely low concentration of the inorganic layered compound. In addition, since the polyamide itself is not so excellent in the barrier property, the polyamide-based barrier material obtained by dispersing the inorganic layered compound by the method has a problem that the barrier property is inferior to that of EVOH alone. There is. In addition, when the inorganic layered compound is swollen and cleaved in an aqueous solvent, E
Regarding the method of mixing and dispersing in VOH, it is very difficult to secure sufficient dispersibility and it is difficult to stably exhibit the performance when montmorillonite or the like which has been conventionally used as an inorganic layered compound is used. I have a problem.

In addition to the above, Japanese Unexamined Patent Publication No. 7-70357 discloses a method of compounding a hydrophobic resin with an inorganic layered compound having a specific particle size and an aspect ratio.
Since the hydrophobic resin itself is not so excellent in the barrier property, there is a problem that the barrier property of the composite obtained by the method is still insufficient. Furthermore, as a method of improving the barrier properties of a resin by compounding a water-soluble resin such as a PVA-based polymer with an inorganic layered compound, a method of applying the compound to a film having a specific surface composition (JP-A-9- 1
11017) and a method using a specific inorganic layered compound (JP 2001-105543 A, JP 2001-114966 A, JP 2001-214 A).
No. 020) has been proposed. However, although the barrier property of the resin is improved by this method, the barrier property may be insufficient unless heat treatment at high temperature is performed, and a material that is easy to manufacture and has a high gas barrier property is desired. .

[0006]

DISCLOSURE OF THE INVENTION The present invention solves the above problems and provides a resin composition having remarkably excellent barrier properties, particularly excellent barrier properties in a high humidity environment, and uses of the resin composition. The purpose is to provide.

[0007]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have surprisingly found that a PVA-based polymer and a plurality of inorganic layered layers having a specific average particle size are used. The present invention has been achieved by finding that the combination of compounds exhibits extremely excellent performance and can achieve the object of the present invention.

That is, the first invention of the present invention is PVA.
A resin composition comprising a polymer and a plurality of inorganic layered compounds having a specific average particle diameter.

The second invention of the present invention is a film, a laminate and a container having at least one layer comprising the above resin composition.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. The inorganic layered compound (B) constituting the resin composition of the present invention is a sheet in which atoms are strongly bonded by covalent bonds or the like and are densely arranged, and are substantially parallel to each other due to weak force such as Van der Waals force or electrostatic force. It is an inorganic compound with a stacked structure. Examples of such an inorganic layered compound include mica, talc, montmorillonite, smectite, kaolinite, vermiculite, and the like, which may be naturally produced or synthesized.

Among these inorganic layered compounds, those which swell or cleave upon immersion in an organic solvent or an inorganic solvent (collectively referred to as swellable inorganic compounds in the present specification) have excellent barrier properties and water resistance. It is preferably used for expressing Here, swelling means that when the inorganic layered compound is dipped in a large excess of an organic solvent or an inorganic solvent, the distance between layers as seen by an X-ray diffraction method is widened, and cleaving is a case where the same operation is performed. , The peak showing the distance between layers is
It is one that behaves as it becomes smaller or disappears. Examples of the swelling inorganic compound include vermiculite, montmorillonite, smectite, swelling synthetic fluoromica-based minerals in which lithium, sodium and the like are intercalated between layers. In addition, when mixed with a water-soluble resin, among such swellable inorganic compounds, a swellable inorganic compound having a property of swelling or cleaving with water (hereinafter referred to as water swelling property) is most preferably used. Examples of such water-swellable inorganic compounds include water-swellable vermiculite, water-swellable montmorillonite, water-swellable synthetic fluoromica minerals, and water-swellable synthetic smectites.

Further, in the present invention, it is an essential requirement to use at least two kinds of inorganic layered compounds having a specific average particle diameter. The average particle diameter of the inorganic layered compound as used herein means, before mixing with the PVA-based resin, water, an organic solvent or a dispersion liquid in which the inorganic layered compound is dispersed in a mixed solvent of water and an organic solvent is prepared, It is the average value of the particle diameter of the dispersoid measured in a state where the inorganic layered compound is swollen or cleaved by the solvent in the dispersion liquid. Specifically, the volume-based particle size distribution of the dispersoid particles contained in the dispersion of the inorganic layered compound is measured with a laser diffraction / scattering particle size distribution measuring device, and the median diameter corresponding to 50% in volume ratio is measured. The average particle size is used. The inorganic layered compound (B) is composed of an inorganic layered compound (C) having an average particle size of 0.01 to 5 μm and an inorganic layered compound (D) having an average particle size of 1.5 to 10 μm. As the inorganic layered compound (C) and the inorganic layered compound (D), any of those belonging to the above-mentioned inorganic layered compound (B) can be used as long as they have a specific average particle diameter which is a constituent feature of the present invention. However, a swellable inorganic compound is preferable, and a water-swellable inorganic compound having a cleavability in a water solvent is more preferable. A combination in which the inorganic layered compound (C) is composed of water-swellable montmorillonite and water-swellable synthetic smectite and the inorganic layered compound (D) is composed of water-swellable fluoromica-based mineral is particularly preferable from the viewpoint of barrier properties.

The water-swellable montmorillonite used in the present invention has 0.15 sodium atoms per 4 Si atoms.
Or more, preferably 0.2 or more, more preferably 0.
The ratio is 25 or more, and optimally 0.3 or more. Such montmorillonite can be obtained, for example, by dispersing the raw material montmorillonite in an aqueous solution of sodium oxalate, sodium carbonate, etc., collecting only the supernatant of the dispersion, and drying.

The swellable fluoromica-based mineral used in the present invention is typically obtained by heat-treating a mixture of talc and sodium and / or lithium silicofluoride or fluoride. As a specific method thereof, for example, the method disclosed in Japanese Patent Laid-Open No. 2-149415 can be mentioned. That is, it is a method in which talc is used as a starting material and sodium ions and / or lithium ions are intercalated into the starting material to obtain a swellable fluoromica-based mineral. In this method, a swellable fluoromica-based mineral is obtained by mixing talc with sodium and / or lithium silicofluoride or fluoride and heat-treating in a magnetic crucible at about 700 to 1200 ° C for a short time. As the swellable fluoromica-based mineral used in the present invention, those produced by this method are particularly preferable.

In the present invention, it is essential that the difference in average particle diameter between the inorganic layered compound (C) and the inorganic layered compound (D) is 1.4 μm or more, and 1.7 μm.
It is more preferably at least m, and even more preferably at least 2.0 μm. Difference in average particle size is 1.4 μm
When it is smaller, the effect of improving the barrier property by using two or more inorganic layered compounds having a specific average particle diameter is small. The difference in average particle diameter between the inorganic layered compound (C) and the inorganic layered compound (D) is preferably 8 μm or less, more preferably 7 μm or less, and further preferably 6 μm or less. When the difference in average particle diameter is larger than 8 μm, the surface smoothness of a molded product such as a film made of the resin composition of the present invention is impaired, and the effect of improving the barrier property may be small.

Further, in the present invention, the compounding ratio (C) of the inorganic layered compound (C) and the inorganic layered compound (D) /
(D) has a weight ratio of 90/10 to 5/95, and 85 /
15 to 10/90 is more preferable, and 80/20 to 15 /
85 is more preferred. When the compounding ratio (C) / (D) is out of the above range, the effect of improving the barrier property, which is the object of the present invention, is not sufficient.

Next, the vinyl alcohol polymer (A) (hereinafter sometimes abbreviated as PVA polymer (A)) constituting the resin composition of the present invention will be described. The PVA-based polymer (A) in the present invention refers to a polymer obtained by saponifying a polymer containing 40 mol% or more of vinyl ester units represented by vinyl acetate as a constituent of the main chain. In this case, a vinyl ester other than vinyl acetate, for example, a vinyl ester such as vinyl propionate or vinyl pivalate may be used in place of vinyl acetate.

Further, the degree of saponification of the PVA polymer (A) in the present invention is saponified with respect to the ester group existing before saponification, from the viewpoint that the barrier property of the obtained resin composition can be more highly drawn out. In terms of the molar ratio of the ester group, 90% or more is preferable, 95% or more is more preferable, 97% or more is further preferable, and 98% or more is the most preferable.

Examples of the comonomer component used in an amount of 60 mol% or less in addition to vinyl ester include various compounds having a double bond in the molecule such as ethylene, propylene, butylene and unsaturated carboxylic acid. Among them, α-olefins having 4 or less carbon atoms are preferable, and ethylene is particularly preferably used because it improves the moisture resistance and moldability of the obtained resin composition and gives a resin composition having excellent properties. A PVA-based polymer obtained by copolymerizing ethylene in the range of 0.5 to 60 mol% is preferable because it shows stable and good barrier property in a wide humidity range, and ethylene is 3
The PVA-based polymer copolymerized in the range of ˜50 to 50 mol% is more preferable, and since it can be used by being dissolved in a solvent containing water as a main component, PVA copolymerized in the range of 4.5 to 15 mol% with ethylene. Most preferred are polymers.

Further, in the resin composition of the present invention, other types of polymers such as polyamide, polyester, polyethylene, polypropylene, copolymers of ethylene and propylene, polystyrene, polyisoprene, polymethylmethacrylate, etc. are used within the range not impairing the object of the present invention. , Polyethylene glycol and the like can be added to the PVA polymer (A).

The viscosity average degree of polymerization (hereinafter abbreviated as the degree of polymerization) of the PVA polymer (A) in the present invention is not particularly limited, but a resin composition comprising the PVA polymer (A) is used. From the viewpoint of mechanical properties and workability in molding the composition, the degree of polymerization after saponification is 200 to 240.
The range of 0 is preferable, the range of 300 to 2000 is more preferable, and the range of 400 to 1500 is most preferable.

When the PVA polymer (A) is water-soluble, its polymerization degree P is measured according to JIS-K6726.
That is, after re-saponifying and purifying the PVA-based polymer,
It is determined by the following formula from the intrinsic viscosity [η] measured in water at 30 ° C. P = ([η] × 10 ³ /8.29) ^{(1 / 0.62)}

The PVA polymer (A) in the present invention is
It is preferable to contain an alkali metal. The content ratio of the alkali metal based on 100 parts by weight of the PVA polymer (A) is 0.0003 in terms of sodium of the alkali metal.
1 part by weight, preferably 0.0003 to 0.8 part by weight, more preferably 0.0005 to 0.6 part by weight, and 0.1.
001-0.5 weight part is especially preferable. Examples of the alkali metal include potassium and sodium,
They exist mainly as salts of lower fatty acids such as acetic acid and propionic acid. In addition, the alkali metal is PV
Also included are the alkali metals present in the additives of the A-based polymer (A). When the content ratio of the alkali metal to 100 parts by weight of the PVA polymer (A) is less than 0.0003 parts by weight, the water solubility of the PVA polymer (A) when used as an aqueous solution Tends to decrease.
On the other hand, if the amount exceeds 1 part by weight, the crystallinity of the PVA-based polymer may decrease, and the barrier property against gas and water vapor of the resin composition of the present invention tends to decrease.

Further, in the present invention, the addition of a crosslinking agent to the PVA polymer (A) also gives favorable results such as improvement in water resistance and mechanical properties of the resin composition of the present invention. It is preferably carried out. As such a cross-linking agent, any known cross-linking agent used for PVA-based polymers is preferably used, and a boron compound such as boric acid, a zirconium salt, a titanium compound such as titanium tetralactate, an epoxy group and / or Examples thereof include compounds having a plurality of isocyanate groups. The cross-linking agent is added to the resin or the resin solution in the saponification step before saponification of the vinyl ester polymer and the saponification step of the PVA polymer, or to the inorganic layered compound or its dispersion. , PVA-based polymer and inorganic layered compound are added at the time of mixing in an extruder, and are used at any process step in the process for producing the resin composition of the present invention. Further, the cross-linking agent is added to a solution or dispersion of the composition prepared for applying the resin composition of the present invention to a substrate, or is applied to and impregnated into a film, a laminate and a container after molding. As described above, it can be used at any process step in the process of manufacturing a film, a laminate and a container made of the resin composition of the present invention.

There are no particular restrictions on the amount of the inorganic layered compound (B) compounded in the resin composition of the present invention.
0.01-10 with respect to 100 parts by weight of the polymer (A).
0 part by weight is preferable, 0.5 to 80 parts by weight is more preferable, 1 to 70 parts by weight is further preferable, and 3 to 50 parts by weight is particularly preferable. If the amount is less than 0.01 parts by weight, the effect of improving the barrier property, which is the object of the present invention, is not sufficient, and if it exceeds 100 parts by weight, the toughness of the resin composition is greatly reduced.
It is not preferable because the viscosity of the solution or dispersion of the resin composition becomes large, film formation becomes difficult, and pinholes are easily generated in the molded product of the resin composition.

As the method for producing the resin composition of the present invention and the solution or dispersion thereof, any known method of dispersing an inorganic compound in a PVA polymer can be applied. For example, after polymerizing a vinyl ester-based monomer and optionally other monomers, the inorganic layered compound (B)
Is added, followed by saponification, concentration and drying to obtain a resin composition comprising the PVA-based polymer (A) and the inorganic layered compound (B), or the PVA-based polymer (A) after the saponification and the inorganic layered A method in which the compound (B) is supplied all at once to the extruder, and the inorganic layered compound (B) is dispersed in the PVA-based polymer (A) by the shearing force of the extruder to obtain a resin composition, and further, a solvent. , A PVA polymer (A) and an inorganic layered compound (B) are collectively charged and kneaded with a homogenizer or the like to obtain a solution or dispersion of the resin composition.

Regarding the method for adding the inorganic layered compound (C) and the inorganic layered compound (D), the inorganic layered compound (C) and the inorganic layered layer can be added in any step of adding the inorganic layered compound (B) in the above production method. Examples thereof include a method of adding a mixture of both compounds (D) in advance, or a method of adding the inorganic layered compound (C) and the inorganic layered compound (D) separately. Here, the inorganic layered compound (C) and the inorganic layered compound (D) may be added in the same step or may be added in different steps.

The resin composition of the present invention can be used as a molded product having a barrier property by injection molding or the like, but it is most preferably used as a film, a laminate or a container. When the resin composition of the present invention is used as a molded article, it is of course possible to use it as a single layer, but to impart a function such as heat welding, to protect against mechanical action from the outside, and to improve handleability, Preferably laminated with another material such as another film and paper,
It is also preferable to provide a printing layer for improving the design.

As the method for molding the film, laminate and container, any known molding method for molding the resin composition into the film, laminate and container can be applied. The optimum molding method is slightly different depending on the molecular composition of the PVA polymer (A) and the types and compositions of the PVA polymer (A) and the inorganic layered compound (B) in the resin composition. Melt extrusion molding from a material, blow molding, by a hot melt molding method such as inflation molding, or water as a solvent or a dispersion medium, a casting method from a solution or dispersion of a resin composition using an organic solvent or a mixed solvent thereof, Dipping method, gravure coating method,
A single-layer film and container made of the resin composition of the present invention can be obtained by a molding method such as a blade coating method, a calendar coating method or a spray coating method. Further, by simultaneously forming and laminating a base material layer and a layer composed of the resin composition of the present invention by the above-mentioned molding method, or by successively forming and laminating a base material layer and a layer composed of the resin composition of the present invention. It is possible to obtain a multilayer film, a laminate and a container having at least one layer composed of the resin composition of the present invention on a substrate. Here, when the base material layer and the layer made of the resin composition of the present invention are sequentially formed and laminated, after forming the base material layer first, the layer made of the resin composition of the present invention is formed on the base material layer. May be laminated, and after forming a layer made of the resin composition of the present invention, a base material layer may be laminated thereon, or a layer made of the base material layer and the resin composition of the present invention may be formed. After forming each separately,
You may laminate | stack each of those layers.

The substrate used for the film, laminate and container of the present invention is not particularly limited, but polyolefin resins such as polyethylene and polypropylene; polyethylene terephthalate (hereinafter sometimes abbreviated as PET), polyethylene iso Polyester resins represented by phthalate, polyethylene 2,6-naphthalate, polybutylene terephthalate and copolymers thereof; polyether resins represented by polyoxymethylene; nylon-6, nylon-6,6, poly Polyamide resins represented by meth-xylene adipamide; vinyl resins other than polyolefin resins represented by polystyrene, poly (meth) acrylic acid ester, polyacrylonitrile, polyvinyl acetate and their copolymers; Nay System resin; cellophane, cellulose resins typified acetate; more polyimide, polyetherimide, polyphenylene sulfide,
Examples include molded products made of various resins such as polyether sulfone, polysulfone, polyether ketone, and fluorine-containing polymer, as well as copolymers, mixtures, and composites.

Here, as the substrate used for the film, laminate and container of the present invention, an unstretched film made of a simple substance, a copolymer, a mixture or a complex of the various resins described above, or a uniaxial direction or an orthogonal direction. An oriented film stretched in the biaxial direction is preferably used. Among them, biaxially stretched polypropylene, polyester, films such as polyamide are preferable in terms of heat-resistant dimensional stability and mechanical strength, and moldability and economy.
Further, from the viewpoint of transparency, heat resistance and mechanical strength, a polyester film containing polyethylene terephthalate as a main component is particularly preferable.

The thickness of the above-mentioned film is not particularly limited, but it is usually 1 to 250 μm, and 3 as a packaging material.
It is particularly preferable that the thickness is ˜50 μm. Further, the base film may be a simple substance or a composite multilayer film, and the composite method and the number of layers in the multilayer film are arbitrary.

Furthermore, the single-layer or multi-layer film of the present invention can be improved in various properties such as its barrier property and mechanical strength by adding a stretching operation.
Examples of the stretching operation include uniaxial stretching, sequential or simultaneous biaxial stretching, and the like. The stretching ratio in such stretching operation is 2 to 15 times, more preferably 7 to 15 times the film area after stretching with respect to the film area before stretching.
11 times is recommended.

Paper is also included in the laminate of the present invention. When the laminate of the present invention is paper, the base paper used for the base material is not particularly limited, and any material generally used as paper can be preferably used depending on the purpose. It is preferable to use glassine paper and semi-glassine paper as the base paper which is the base material, since the resin composition of the present invention exhibits a high degree of barrier property and recyclability even when the layer is thin. The thickness of the base paper for the base material is not particularly limited, and may be 0.1 to 1000 μm if necessary.
m, preferably 1 to 500 μm, optimally 3 to 300 μm
It can be appropriately selected within the range of m.

Further, various materials conventionally used by being laminated on paper can be further laminated on the above paper to be used as processed paper. For example, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, etc. may be used to impart heat sealability to the above paper, and thermosetting resin or biaxially stretched PET may be used to impart scratch resistance.
A polyamide or the like can be laminated to impart pinhole resistance, and a water-soluble polymer compound can be laminated to impart water sticking property. In addition, polypropylene or vapor-deposited PE can be used to impart high moisture resistance.
It is effective to stack T and the like. Furthermore, it is also preferable to provide a plurality of the above layers, if necessary.

In the above various films, laminates and containers, the thickness of the layer comprising the resin composition of the present invention is not particularly limited, but the average thickness is 0.1 to 100 μm.
m is preferable, 0.3 to 50 μm is preferable, and 0.5 to
30 μm is particularly preferable. If it is 0.1 μm or less, the barrier property may be insufficient even in a film, a laminate and a container having a layer made of the resin composition of the present invention.
When it exceeds 0 μm, the elastic modulus becomes high and the handling property as a film and a laminate becomes poor.

In forming the film, laminate and container of the present invention, when the resin composition of the present invention is laminated on a substrate, a corona treatment or other surface activation treatment on the substrate or a known method is used. A known method for improving the adhesiveness to the substrate, such as performing anchor treatment using an anchor treatment agent, is appropriately adopted.

When the resin composition of the present invention and its solution or dispersion are used as a coating agent,
The conditions of drying and heat treatment at the time of coating depend on the conditions such as coating thickness and equipment, but it is usually preferable to select from the range of about 70 to 170 ° C. The drying and heat treatment may be performed in one step, or the drying step and the heat treatment step may be performed in separate steps. When it is performed in a separate process, the drying process is performed at a temperature of 70
It is preferable that the temperature is 90 to 170 ° C. in the heat treatment step at 90 ° C., and the time is 5 seconds to 10 minutes in each step.

When the container of the present invention is a container formed by molding paper having at least one layer comprising the resin composition of the present invention, the final shape of the paper container is not particularly limited, Various existing forms, for example, gable top containers, pillow bags, standing pouches, paper drums, boxes, trays, etc. are exemplified. In this case, the entire container does not have to be a container using the paper shown in the present invention, and a part thereof is made visible for various reasons such as making the contents visible or improving the design. Other materials can be used.

[0040]

EXAMPLES The present invention will now be described in detail with reference to examples, but the present invention is not limited to these examples. In the text,% means% by weight unless otherwise specified, and each property was measured by the following method. The resins and the inorganic layered compounds in the following examples were vacuum dried at 80 ° C. for 12 hours or more and used, unless otherwise specified.

[Measurement of average particle diameter] A laser diffraction / scattering type particle size distribution measuring apparatus LA910 (manufactured by Horiba Ltd.) was used to measure the volume-based particle size distribution of particles considered to be dispersed inorganic compounds, and the volume was measured. The median diameter corresponding to 50% in percentage was taken as the average particle diameter.

[Oxygen permeability] MODERN CONTR
OLS INC. Oxygen transmission rate measuring device MOCONOX
-TRAN2 / 20 type was used according to the method described in JIS K7126 (isobaric method) under the conditions of 20 ° C and 85% RH. In the present invention, the oxygen permeability of the film is the amount of oxygen permeation (ml / m ² · day · atm) measured at an arbitrary film thickness for a film composed of a single layer
Is converted to the amount of oxygen permeation at a film thickness of 1 μm (ml ・ μ
m / m ² · day · atm). In the case of laminated paper, the amount of oxygen permeation measured with the laminated paper (ml /
m ² · day · atm), and in the case of a container, it is represented by the amount of oxygen permeation per container (ml / container · day · atm) measured in the form of the sample container.

[Bending resistance test] Using a Gelbo flex tester (manufactured by Rigaku Kogyo Co., Ltd.), a 12-inch x 8-inch test piece was formed into a cylindrical shape having a diameter of 3.5 inches, and both ends were gripped, and the initial state was obtained. Gripping interval 7 inches, gripping interval 1 at maximum bending
Inch, the first 3.5 inch of the stroke adds a twist of 440 degrees, and the subsequent 2.5 inch is a reciprocating reciprocating motion of linear horizontal motion at a speed of 40 times / minute,
After repeating this reciprocating motion 100 times under the conditions of 20 ° C. and 65% RH, the oxygen permeability was measured.

[Haze] A part of the sample film was cut off, silicone oil was applied, and the haze value was measured according to ASTM D1003-6 using HR-100 manufactured by Murakami Color Research Laboratory.

Example 1 1) Preparation of resin solution As PVA-based polymer (A), saponification degree 99.2 mol%,
Ethylene-containing PVA (PVA-1) having an ethylene content of 9 mol%, a degree of polymerization of 550, and a sodium content of 0.05% was dissolved in warm water to prepare a solution having a concentration of 15%. This is called resin solution A.

2) Preparation of Inorganic Layered Compound Dispersion Natural montmorillonite (Kunimine Industries Co., Ltd .; Kunipia F) was dispersed as an inorganic layered compound (C) in water to a concentration of 3%, and a household mixer was used. The mixture was stirred for 30 minutes to prepare an inorganic layered compound dispersion liquid. This is referred to as an inorganic layered compound dispersion liquid C. The average particle size of the montmorillonite in the dispersion C was 0.9 μm. In addition, a swelling fluoromica-based mineral (manufactured by Coop Chemical Co .; Somasif ME-100) as an inorganic layered compound (D) had a concentration of 6%.
The resulting mixture was dispersed in water so that it was stirred for 30 minutes using a household mixer to prepare an inorganic layered compound dispersion liquid. This is referred to as an inorganic layered compound dispersion liquid D. The average particle size of the swelling fluoromica-based mineral of the dispersion D was 4.1 μm.

3) Preparation of coat film 100 parts by weight of resin solution A and inorganic layered compound dispersion C3
7.5 parts by weight, inorganic layered compound dispersion D43.75 parts by weight, and water 27.1 parts by weight were mixed and stirred for 3 minutes using a home mixer to prepare a coating solution having a solid content concentration of 9%. The weight ratio (A) / (B) of the PVA polymer (A) and the inorganic layered compound (B) in the coating liquid was 100/2.
5, and the weight ratio (C) / (D) of the inorganic layered compound (C) and the inorganic layered compound (D) is 30/70.
Stretched polypropylene film (Tokyo Cellophane Paper Co., Ltd.)
Manufactured by Toyo Morton Co., Ltd. AD335A / C
The coating solution is applied onto the product coated with AT10) using a bar coater and dried at 70 ° C. for 5 minutes, and then 1
Heat treatment was performed at 10 ° C. for 2 minutes to obtain a coated film. The coat layer of the film had a thickness of 7.6 μm. In the following, stretched polypropylene is abbreviated as OPP.

4) Measurement When the oxygen permeability of the film obtained above was measured, it was 2.3 ml · μm / m ² · day · atm and the internal haze was 3.8%. The oxygen permeability after the flex resistance test was 2.4 ml · μm / m ² · day · atm.

Example 2 The PVA polymer (A) was changed to an ethylene-containing PVA (PVA-2) having a saponification degree of 98.9 mol%, an ethylene content of 6 mol%, a polymerization degree of 1000, and a sodium content of 0.0015%. Then, by changing the stirring time of the mixer, the average particle diameter of the montmorillonite (Kunipia F) of the inorganic layered compound (C) is 2.2 μm, and the swelling fluoromica-based mineral (Somasif ME-100) of the inorganic layered compound (D) is used. Having an average particle diameter of 6.3 μm, and the weight ratio of the PVA polymer (A) and the inorganic layered compound (B) in the coating liquid (A) /
A film was prepared in the same manner as in Example 1 except that (B) was changed to 100/40 and the weight ratio of the inorganic layered compound (C) and the inorganic layered compound (D) was changed to 50/50.
Various performances similar to those in Example 1 were measured. Oxygen permeability is 2.
8 ml · μm / m ² · day · atm, internal haze 7.2%, oxygen permeability after bending resistance test 3.3 ml · μ
It was m / m ² · day · atm.

Comparative Example 1 A film was prepared in the same manner as in Example 1 except that the natural layered compound (D) was natural montmorillonite (Kunipia F, average particle size 0.9 μm), and various performances similar to those in Example 1 were obtained. Was measured. Oxygen permeability is 50 ml ・ μm / m ²・ da
y · atm, the internal haze was 2.4%, and the oxygen permeability after the bending resistance test was 50 ml · μm / m ² · day · atm.

Comparative Example 2 A film was prepared in the same manner as in Example 1 except that the swellable fluoromica-based mineral (Somasif ME-100, average particle size 4.1 μm) was used as the inorganic layered compound (C). 1
Various performances similar to those were measured. Oxygen permeability is 17 ml · μ
m / m ² · day · atm, internal haze 4.6%, oxygen permeability after flex resistance test is 18 ml · μm / m ² · da
It was y • atm. When only one type of inorganic layered compound is used (Comparative Example 1 and Comparative Example 2), two or more types of inorganic layered compounds having a specific average particle diameter of the present invention are used (Example 1). It can be seen that the oxygen barrier property is significantly reduced as compared with.

Example 3 Inorganic layered compound (C) was replaced with natural montmorillonite (Kunipia F, average particle size 1.2 μm), inorganic layered compound (D).
A swellable fluoromica-based mineral (Somasif ME-100,
A film was prepared in the same manner as in Example 1 except that the average particle diameter was 3.5 μm) and the weight ratio of the inorganic layered compound (C) to the inorganic layered compound (D) was changed to 82/18.
Various performances similar to those were measured. Oxygen permeability is 15 ml · μ
m / m ² · day · atm, internal haze 2.8%, oxygen permeability after bending resistance test is 15 ml · μm / m ² · da
It was y • atm.

Comparative Example 3 A film was prepared in the same manner as in Example 3 except that the inorganic lamellar compound (C) was changed to natural montmorillonite (Kunipia F, average particle size 2.2 μm), and various properties similar to those in Example 1 were obtained. The performance was measured. Oxygen permeability is 51 ml ・ μm / m ²・
day · atm, internal haze is 2.7%, oxygen permeability after bending resistance test is 51 ml · μm / m ² · day · atm
Met. The oxygen permeability of the film of Comparative Example 3 in which the difference in average particle size between the inorganic layered compound (C) and the inorganic layered compound (D) was 1.3 μm was 51 ml · μm / m ^2.
・ Day · atm, and the oxygen permeability of Example 3 in which the difference in average particle diameter between the inorganic layered compound (C) and the inorganic layered compound (D) was 2.3 μm was 15 ml · μm / m ^2.
-The oxygen barrier property was lower than that of day-atm.

Example 4 As a dispersion of the inorganic layered compound (C), a dispersion of natural montmorillonite (Kunipia F) (average particle size 0.5 μm)
m) and natural montmorillonite (manufactured by Kunimine Industries Co., Ltd .;
A mixture of Kunipia W) dispersion (average particle size 0.1 μm) was used so that the weight ratio based on solid content was 50/50, and the inorganic layered compound (C) and the inorganic layered compound (D) were mixed. The same test as in Example 3 was conducted except that the weight ratio was 16/84. Oxygen permeability is 4.5ml ・ μm /
m ² · day · atm, internal haze 4.2%, oxygen permeability after flex resistance test 4.5 ml · μm / m ² · day
・ It was atm.

Example 5 Example 1 except that PVA-2 was used as the PVA polymer (A) and natural montmorillonite (Kunipia F, average particle size 2.2 μm) was used as the inorganic layered compound (C).
The same test was performed. Oxygen permeability is 6.1 ml ・ μm
/ M ² · day · atm, internal haze 4.0%, oxygen permeability after flex resistance test is 6.2 ml · μm / m ² · da
It was y • atm.

Example 6 PVA polymer (A) having a saponification degree of 99.6 mol%,
Ethylene-containing PVA with an ethylene content of 3 mol%, a degree of polymerization of 1800, and a sodium content of 0.005% (PVA-3)
The same test as in Example 2 was carried out except that a synthetic smectite (manufactured by Kunimine Industry Co., Ltd .; Smecton SA, average particle size 0.1 μm) was used as the inorganic layered compound (C). Oxygen permeability is 8.4 ml · μm / m ² · day
-Atm, the internal haze was 7.4%, and the oxygen permeability after the bending resistance test was 13 ml-μm / m ² -day-atm.

Example 7 As a PVA polymer (A), a saponification degree of 98.5 mol%,
Ethylene-containing PVA (PVA-4) having an ethylene content of 6 mol%, a degree of polymerization of 800, a sodium content of 0.11%, and a vinylmethoxysilane content of 0.15 mol% was used as an inorganic layered compound (C) of natural montmorillonite (Kunipia). F, average particle diameter 4.2 μm, swellable fluoromica-based mineral (Somasif ME-100, as inorganic layered compound (D))
The same test as in Example 1 was performed except that the average particle diameter was 1.9 μm). Oxygen permeability is 4.6 ml ・ μm / m
² · day · atm, internal haze 3.9%, oxygen permeability after bending resistance test is 4.6 ml · μm / m ² · day ·
It was atm.

Example 8 The saponification degree of the PVA polymer (A) was 97.7 mol%,
Using ethylene-containing PVA (PVA-5) having an ethylene content of 11 mol%, a degree of polymerization of 370, and a sodium content of 0.16%, the weight ratio of the PVA-based polymer (A) and the inorganic layered compound (B) in the coating solution ( A) / (B) is 100/9
The same test as in Example 1 was carried out except that Oxygen permeability is 3.5 ml · μm / m ² · day · atm, internal haze is 2.6%, oxygen permeability after bending test is 4.3 m
It was 1 · μm / m ² · day · atm.

Example 9 PVA polymer (A) solution as saponification degree 99.5 mol%, ethylene content 44 mol%, sodium content 0.0
A solution of 03% ethylene-containing PVA (manufactured by Kuraray Co., Ltd .; Eval EP-E105) (PVA-6) in a water / n-propanol mixed solvent (n-propanol 70%), an inorganic layered compound (C) As a dispersion of water / n-
A dispersion liquid of natural montmorillonite (Kunipia F, average particle diameter 1.2 μm) using a propanol mixed solvent (n-propanol 70%) as a dispersion medium, and a water / n-propanol mixed solvent (as a dispersion liquid of the inorganic layered compound (D) ( Swelling fluoromica-based mineral (Somasif ME-100, average particle diameter 3.5 μ) with n-propanol 70% as a dispersion medium.
m) using the dispersion liquid, the weight ratio of the PVA polymer (A) and the inorganic layered compound (B) in the coating liquid (A) /
The same test as in Example 1 was conducted except that (B) was set to 100/75. Oxygen permeability is 0.9ml ・ μm / m ²・ d
It was ay · atm and had an extremely excellent barrier property. On the other hand, the internal haze was 13% and the transparency was slightly inferior.

Example 10 A PVA polymer (A) having a saponification degree of 98.8 mol%,
PVA with a degree of polymerization of 530 and a sodium content of 0.05%
Using (PVA-7), the same test as in Example 3 was performed except that the weight ratio of the inorganic layered compound (C) and the inorganic layered compound (D) was changed to 9/91. Oxygen permeability is 31 ml
・ Μm / m ²・ day ・ atm, internal haze is 4.5
%, Oxygen permeability after flex resistance test is 33 ml · μm / m ²
・ It was day ・ atm.

Example 11 A PVA polymer (A) having a saponification degree of 95.8 mol%,
An ethylene-containing PVA (PVA-8) having an ethylene content of 64 mol%, a polymerization degree of 510 (calculated from an intrinsic viscosity measured with a water-containing phenol solution), and a sodium content of 0.003% was used, and a PVA-based polymer (A ) And the inorganic layered compound (B) in a weight ratio (A) / (B) of 100/2.
The same test as in Example 9 was performed, except that the weight ratio of the inorganic layered compound (C) to the inorganic layered compound (D) was changed to 88/12. Oxygen permeability is 13 ml ・ μm / m ²・
day · atm, internal haze is 2.9%, oxygen permeability after bending resistance test is 13 ml · μm / m ² · day · atm
Met.

Comparative Example 4 Inorganic layered compound (C) (natural montmorillonite Kunipia F, average particle size 2.2 μm) and inorganic layered compound (D) (Somasif ME-100, average particle size 4.1).
The same test as in Example 2 was carried out except that silica (Mizukasi Chemical Co., Ltd., Mizukasil, average particle size 2.2 μm) and silica (Mizawazawa Chemical Co .; Mizukasil, average particle size 6.3 μm) were used instead of (μm). It was Oxygen permeability is 450ml ・ μ
m / m ² · day · atm, internal haze 15%, oxygen permeability after bending resistance test is 630 ml · μm / m ² · da
It was y • atm.

Comparative Example 5 Instead of the inorganic layered compound (D) (swelling fluoromica mineral Somasif ME-100, average particle diameter 4.1 μm), silica (manufactured by Mizusawa Chemical Co .; Mizukasil, average particle diameter 6.3) was used.
The same test as in Example 2 was performed except that (.mu.m) was used. Oxygen permeability is 55ml ・ μm / m ²・ day ・ at
m, the internal haze was 11%, and the oxygen permeability after the bending resistance test was 140 ml · μm / m ² · day · atm. Compared with the film of Example 2 using the inorganic layered compound, the films of Comparative Example 4 and Comparative Example 5 using the inorganic non-layered compound had significantly reduced barrier properties.

Comparative Example 6 Instead of natural montmorillonite (Kunipia F, average particle size 0.9 μm) as the inorganic layered compound (C), synthetic smectite (manufactured by Kunimine Industry Co., Ltd .; Smecton SA, average particle size 0.008 μm) was used. The same test as in Example 1 was carried out except that it was used. Oxygen permeability is 16ml ・ μm / m
² · day · atm, internal haze 3.7%, oxygen permeability after bending resistance test is 16 ml · μm / m ² · day · a
It was tm.

Comparative Example 7 Inorganic layered compound (C) was replaced with natural montmorillonite (Kunipia F, average particle size 6.2 μm), inorganic layered compound (D).
A swellable fluoromica-based mineral (Somasif ME-100,
The same test as in Example 6 was performed except that the average particle size was changed to 8.5 μm. Oxygen permeability is 37 ml ・ μm / m ²
・ Day ・ atm, internal haze 14%, oxygen permeability after bending resistance test is 76 ml ・ μm / m ²・ day ・ atm
Met.

Comparative Example 8 As the inorganic layered compound (D), natural montmorillonite (Kunipia F, average particle diameter 1.3 μm) was used in place of the swelling fluoromica-based mineral (Somasif ME-100, average particle diameter 4.1 μm). The same test as in Example 1 was carried out except that it was used. Oxygen permeability is 31 ml · μm / m ² · da
y · atm, internal haze was 2.0%, and oxygen permeability after the flex resistance test was 32 ml · μm / m ² · day · atm.

Comparative Example 9 The same test as in Example 7 was conducted except that a swellable fluoromica-based mineral (Somasif ME-100, average particle diameter 12 μm) was used as the inorganic layered compound (D). Oxygen permeability is 60 ml · μm / m ² · day · atm, internal haze is 13%, oxygen permeability after bending resistance test is 1000 ml ·
It was at least μm / m ² · day · atm. The films of Comparative Examples 6 and 7 in which the average particle size of the inorganic layered compound (C) is outside the range specified by the present invention, and the average particle size of the inorganic layered compound (D) are specified by the present invention. The films of Comparative Examples 8 and 9 out of the range had lower barrier properties as compared with the films of Control Examples 1, 6, 6 and 1.

Comparative Example 10 The weight ratio (A) / (B) of the PVA polymer (A) and the inorganic layered compound (B) in the coating liquid was set to 100/10,
The same test as in Example 1 was performed except that the weight ratio of the inorganic layered compound (C) and the inorganic layered compound (D) was changed to 3/97. Oxygen permeability is 27ml ・ μm / m ²・ day ・
The internal haze was 2.1%, and the oxygen permeability after the bending resistance test was 27 ml · μm / m ² · day · atm.

Comparative Example 11 The same test as in Example 8 was carried out except that the weight ratio of the inorganic layered compound (C) and the inorganic layered compound (D) was changed to 95/5. Oxygen permeability is 60ml ・ μm / m ²・ day ・
The internal haze was 2.0%, and the oxygen permeability after the flex resistance test was 60 ml · μm / m ² · day · atm. The films of Comparative Example 10 and Comparative Example 11 in which the weight ratio of the inorganic layered compound (C) and the inorganic layered compound (D) were out of the range defined by the present invention were the films of Comparative Examples 1 and 8. The barrier property is lower than that of the film.

Example 12 Canadian Susu consisting of 80 parts NBK and 20 parts LBK
230 ml of tundard freeness pulp slurry
On the other hand, based on the pulp in an absolutely dry state, it was used as a sizing agent.
Size (Arakawa Chemical Industry; Size Pine E (TM))
After 0.4% and sulfuric acid band 2.4% were added and fixed,
Paper making with a Fourdrinier paper machine, basis weight 200 g / m ^Two, Moisture 12%
I got the base paper. The coating used in Example 1 was coated on one side of the base paper.
Coating solution using a bar coater and 5 minutes at 70 ℃
After drying, heat treatment at 110 ℃ for 2 minutes to coat
Got the paper. At this time, the coating amount of the coating liquid is based on the solid content.
4.1 g / m^TwoMet. The oxygen permeability of this laminated paper is
0.7 ml / m^Two・ It was day ・ atm.

Comparative Example 12 A coated paper was prepared in the same manner as in Example 12 except that the coating liquid used in Comparative Example 1 was changed, and the coating amount of the coating liquid was 4.1 g / m ² (based on solid content). A laminated paper was obtained. The oxygen permeability measured in the same manner as in Example 12 was 21 ml / m ^2.
-Day-atm, the oxygen barrier property was significantly inferior to the laminated paper of Example 12.

Example 13 A high density polyethylene (hereinafter abbreviated as HDPE) film having a thickness of 60 μm was laminated on the coated surface of the laminated paper obtained in Example 12 using an isocyanate adhesive. The four sides of the paper were adhered by heat sealing to obtain a 30 × 30 cm rectangular container having the HDPE layer as the innermost layer. The oxygen permeability of this container was measured and found to be 0.9 ml / co
It was ntainer / day / atm.

Comparative Example 13 A container was prepared in the same manner as in Example 13 except that the laminated paper obtained in Comparative Example 12 was used. The oxygen permeability of the container is 27.
ml / container · day · atm, Example 13
The oxygen barrier property was significantly inferior to that of the container.

[0074]

[Table 1]

[0075]

According to the present invention, it is possible to obtain a resin composition having excellent barrier properties against various substances typified by oxygen gas, especially in a high humidity environment. Also,
Films, laminates and containers made of the resin composition of the present invention are also excellent in flex resistance, and are suitably used as packaging materials and containers having excellent barrier properties in many fields such as foods, cosmetics, agricultural chemicals and medicine. Therefore, the quality of the contents can be prevented from changing over a long period of time as compared with the conventional products.

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08K 3/34 C08K 3/34 F term (reference) 3E086 AC22 AD01 AD02 AD05 AD08 BA02 BA04 BA14 BA24 BA33 BA35 BB01 BB05 BB22 BB85 CA01 CA28 CA29 DA08 4F071 AA15X AA20X AA21X AA29 AA29X AB30 AE17 AH05 BA06 BB02 BC02 4F100 AA00A AK01B AK07B AK21A AK51 AK69A AK69K BA02 CA23A DA01 DE02A EH46 EJ65J GB01 DJ01B01 GB01 JD00 GB06 GB00 GB01 GB16 GB16 GB16 GB16 GB16 GB16 GB16 GB16 GB16 GB16 GB16 GB16 GB16 GB16 GB16 GB16 GB16

Claims (6)

[Claims] 1. A vinyl alcohol-based polymer (A) and an inorganic layered compound (B), wherein (1) the inorganic layered compound (B) has an average particle diameter of 0.01 to 5.
Inorganic layered compound (C) with an average particle size of 1.5 to
10 μm of inorganic layered compound (D); (2) difference in average particle size of inorganic layered compound (C) and inorganic layered compound (D) is 1.4 μm or more; (3) inorganic layered compound (C) and inorganic The weight ratio (C) / (D) of the layered compound (D) is 90/10 to 5/9.
5; A resin composition characterized in that 2. The resin composition according to claim 1, wherein the inorganic layered compound (C) is a swellable montmorillonite or a swellable synthetic smectite, and the inorganic layered compound (D) is a swellable fluoromica-based mineral. 3. The resin composition according to claim 1, wherein the vinyl alcohol polymer (A) is a vinyl alcohol polymer containing 0.5 to 60 mol% of an α-olefin unit having 4 or less carbon atoms. . 4. A film having at least one layer comprising the resin composition according to claim 1. 5. A laminate having at least one layer comprising the resin composition according to any one of claims 1 to 3. 6. A container having at least one layer comprising the resin composition according to claim 1.