JP3333784B2 - Aqueous composition and laminate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an aqueous dispersion of an ethylene-vinyl alcohol copolymer and a water-swellable phyllosilicate.
The aqueous composition containing the salt was applied aqueous composition
After having dried coating layer, the laminate your excellent gas barrier properties for use in packaging films and containers such as food, etc.
And a method for producing the laminate .

[0002]

2. Description of the Related Art Saponified ethylene-vinyl ester copolymers, in particular, ethylene-vinyl alcohol copolymers (abbreviated as EVOH) obtained by saponifying ethylene-vinyl acetate copolymer, have a gas barrier property against oxygen and the like. Fragrance and oil resistance
Because of its excellent chemical resistance, it is suitable for use in packaging films in various packaging fields, especially for molded products such as food packaging films, sheets and containers, and for protective coating of metal surfaces, paper, wood, etc. It is attracting attention as a material.

[0003] In particular, high gas barrier properties are required for films, sheets, laminates, hollow containers, and the like for food packaging, which require prevention of oxidation of contents or retention of aroma. Further, a coating material for preventing bleeding of a plasticizer is required for a PVC wallpaper, a PVC leather, a sheet and the like made of soft vinyl chloride. Therefore, it is widely practiced to provide EVOH having excellent gas barrier properties, fragrance retention properties, and oil / chemical resistance in the inner layer, the outer layer, or the intermediate layer to satisfy these required performances to a high degree.

In general, as a method of forming an EVOH layer, a method by melt extrusion or injection molding, a method of laminating an EVOH film, and the like are widely practiced.
On the other hand, a method has been proposed in which an EVOH solution or an aqueous dispersion is applied and dried. This method attracts attention because a relatively thin film can be formed and a film can be easily formed even on a complicated shape such as a hollow container.

However, in the method of applying an EVOH solution, it is basically difficult to use a solution having a high concentration because of high viscosity, and the solvent is an organic solvent such as dimethyl sulfoxide or a mixed solvent of a large amount of alcohol and water. In addition, there is a problem that the working environment is deteriorated due to the evaporation of the organic solvent in the process of forming the film and an apparatus for recovering the organic solvent is required. In contrast, EVOH
The method of applying the aqueous dispersion of (1) is expected because it is considered to be advantageous from the viewpoint of the above working environment and economy because the solvent is aqueous.

[0006] As an aqueous dispersion of EVOH, conventional EOH
VOH emulsified and dispersed in the presence of a normal surfactant or a normal polymer protective colloid, for example, polyethylene oxide, carboxymethylcellulose, hydroxyethylcellulose, polyvinyl alcohol and the like, are disclosed in JP-A-54-101844 and JP-A-56-101. 61430 and the like. However, there is no description about blending an inorganic filler.

[0007]

The present invention is to challenge it to solve], which has been made in order to solve the shortcomings of the prior art as described above, excellent stability during storage or use, yet capable of high concentration EVOH aqueous composition, and the aqueous composition
Gas barrier properties with a coating layer dried after application ,
In particular an object to provide a laminate <br/> excellent in gas barrier property under high humidity.

[0008]

The above objects are achieved by providing an aqueous composition comprising an aqueous EVOH dispersion and a water-swellable phyllosilicate .

Hereinafter, the present invention will be described specifically. In the present invention, the EVOH aqueous dispersion includes an aqueous dispersion using EVOH as a dispersoid and EVOH having an ionic group as a dispersion stabilizer, and an aqueous dispersion using EVOH having an ionic group as a dispersoid. Then, water <br/> dispersions that are used in the present invention, the EVOH as dispersoid is described aqueous dispersion and the dispersion stabilizer EVOH having ionic groups.

The ionic group of the EVOH having an ionic group used as a dispersion stabilizer includes a group which dissociates in water and exhibits ionicity, that is, an anionic group, a chaotic group and an amphoteric group. Anionic groups are preferred from the viewpoint of the dispersion stabilizing effect.

Examples of the anionic group include groups such as sulfonic acid, sulfonate, sulfate, sulfate, phosphoric acid, phosphate, carboxylic acid, and carboxylate, and these acids and bases are simultaneously contained. May be. Sulfonic acid or carboxylic acid or its base is preferable in terms of excellent dispersion stabilizing effect, and sulfonic acid or its base is particularly preferable.

Examples of the cationic group include amines and salts thereof, quaternary ammonium salts, phosphonium salts and sulfonium salts. In particular, quaternary ammonium salts are preferred because of their high dispersion stabilizing effect. Examples of the amphoteric group include aminocarboxylates (betaine type), aminosulfonates (sulfobetaine type), and aminosulfate salts (sulfate betaine type).

The content of the ionic group is appropriately selected within the range of the dispersion stabilizing effect. From the viewpoint of the dispersion stabilizing effect, the content of the ionic group is 0.04 to the EVOH component unit in the ion-modified EVOH.
5 to 50 mol% is desirable. More preferably 0.1 to
30 mol%, in particular 0.2 to 15 mol%, even 0.2
-10 mol% is desirable. If it is less than 0.05 mol%, the dispersion stabilizing effect is small, and if it exceeds 50 mol%, the water resistance and gas barrier properties of the film obtained by applying and drying the aqueous dispersion are unpreferable. Ion-modified EVOH
Other units containing no ionic group may be included therein as long as the dispersion stabilizing effect is not significantly impaired.

The composition of the EVOH component in the ion-modified EVOH preferably has an ethylene content of 10 to 70 mol% and a degree of saponification of 80 mol% (the degree of saponification in the present invention indicates the degree of saponification of vinyl ester units). . A preferred range of the ethylene content is 12 mol% or more, more preferably 1 mol% or more.
It is at least 5 mol%, and more preferably at least 20 mol%. The upper limit is preferably at most 65 mol%, more preferably at most 60 mol%. The preferred degree of saponification is 90 mol% or more, and more preferably 95 mol% or more. Dispersoid E
The ethylene content and the degree of saponification of VOH will be described later, but a substance close to that is desirable from the viewpoint of the particle dispersion stabilizing effect. More preferably, substantially the same ethylene content and degree of saponification are desired. The degree of polymerization of the ion-modified EVOH is not particularly limited, but is preferably 100 or more from the viewpoint of the dispersion stabilizing effect. The upper limit of the degree of polymerization is not particularly limited. However, if the degree is too large, the degree of polymerization is usually 2000 or less because the solution viscosity is high and the dispersing performance is lowered. Here, the degree of polymerization of the ion-modified EVOH is determined from the intrinsic viscosity measured at 30 ° C. in a water / phenol-based mixed solvent (weight ratio 15/85) containing 1 mol / l ammonium thiocyanate.

The vinyl ester can be copolymerized with ethylene such as vinyl formate, vinyl acetate, vinyl propionate, vinyl benzoate, vinyl trifluoroacetate, vinyl pivalate and the like. Convertible monomers can be used, but vinyl acetate is particularly preferred.

Regarding the structure of the ion-modified EVOH, those in which ionic groups are randomly introduced are preferably used, and there is no particular limitation on the production method.

For example, a method in which a monomer containing an ionic group is radically copolymerized with ethylene and a vinyl ester, and then the vinyl ester unit in the obtained copolymer is saponified to be converted into a vinyl alcohol unit. A method in which an ionic group-containing component is introduced through an addition reaction of an ionic group-containing component, or a method in which an ionic group-containing component is added to an ethylene-vinyl ester copolymer, followed by saponifying a vinyl ester unit in the copolymer to form a vinyl alcohol. Examples of the method include conversion into units. Methods such as polymerization, saponification and addition reaction can be carried out by known methods.

As the ionic group-containing monomer copolymerized with ethylene and vinyl ester, those capable of radical homopolymerization or radical copolymerization having an ionic group or a group convertible to an ionic group can be used. An example is shown below.

O Anionic group-containing monomer Sulfonate anionic group-containing monomer includes 2-
(Meth) acrylamide sulfonate monomers such as sodium (meth) acrylamide-2-methylpropane sulfonate, styrene sulfonate monomers such as potassium styrene sulfonate, allylic sulfonate monomers such as sodium allyl sulfonate; In addition, vinyl sulfonates such as sodium vinyl sulfonate, ammonium salts of these salts, and acid monomers thereof. Esters of these sulfonic acids can also be used by converting the esters into their salts or acids after polymerization.

Examples of the carboxylic acid anionic group-containing monomer include mono-, di-, and polycarboxylic vinyl monomers such as acrylic acid, methacrylic acid, maleic anhydride, itaconic acid, and fumaric acid, and alkali metal salts and ammonium salts thereof. Can be These esters can also be used after the polymerization since the ester group can be converted into a base.

O Cationic group-containing monomer Amino group-containing (meth) acrylamide monomer such as aminopropylacrylamide or methacrylamide, amino group-containing (meth) acrylate such as aminoethyl acrylate or methacrylate or a salt thereof has good polymerizability. preferable. Particularly, the quaternary salt is preferable because the coloring of the polymer is small. For example, trimethylacrylamidopropyl ammonium chloride, triethyl methacryloyl ethyl ammonium bromide, and the like.

[0022] These monomers can be used alone or also can be used in combination.

Examples of the addition reaction to EVOH include Michael addition reaction of an ionic group-containing vinyl monomer to its hydroxyl group, acetalization or ketalization with an ionic group-containing aldehyde or ketone, addition of an ionic group-containing epoxy compound, Addition of carboxylic anhydride, esterification with sulfuric acid and the like can be mentioned. In addition, introduction by a radical addition reaction of an ionic group-containing monomer having low radical homopolymerizability such as maleic anhydride may be mentioned.

Further, an ethylene-vinyl ester copolymer is produced by subjecting an ionic group-containing monomer having low radical homopolymerizability such as maleic anhydride to a radical addition reaction, followed by saponification to convert vinyl ester units into vinyl alcohol. It is also possible.

EVOH, a dispersoid polymer, comprises ethylene and vinyl acetate, vinyl formate, vinyl propionate,
Vinyl benzoate, vinyl trifluoride acetate, vinyl esters such as vinyl pivalate, especially ethylene-vinyl alcohol copolymer obtained by copolymerization and saponification with vinyl acetate, ethylene content is 15 to 65 mol%, It is preferable that the degree of saponification is 90 mol% or more. If the ethylene content is less than 15 mol%, the stability of the aqueous dispersion becomes poor, and if it exceeds 65 mol%, the gas barrier properties become poor, which is not preferable.

The ethylene content is preferably from 20 to 55 mol% from the viewpoint of the stability of the aqueous dispersion and the gas barrier properties. If the saponification degree is less than 90 mol%, the gas barrier property becomes insufficient, so that it is necessary to use one having 90 mol% or more. The higher the degree of saponification, the higher the gas barrier property, preferably 95 mol% or more, more preferably 97 mol% or more.

The degree of polymerization of the dispersoid EVOH is usually extremely low because the strength of the formed film is unfavorably low.
0 or more, preferably 700 or more are used. The higher the degree of polymerization, the more advantageous it is to apply and use as an aqueous dispersion, and it is usually possible to use up to about 5,000.
Here, the polymerization degree of the dispersoid is determined from the intrinsic viscosity measured at 30 ° C. in a water / phenol-based mixed solvent (weight ratio 15/85). If necessary, a copolymerizable monomer other than ethylene and vinyl ester may be copolymerized in an amount of 5 mol% or less.

The amount of the ion-modified EVOH used as a dispersion stabilizer is appropriately selected in consideration of the type and content of the ionic group, but is preferably 2 to 2 parts per 100 parts by weight of the dispersoid EVOH.
00 parts by weight, preferably 3 to 100 parts by weight, more preferably 5 to 50 parts by weight. If the amount is small, the dispersion stability becomes poor, and if it is too large, the gas barrier properties of the formed film may become extremely insufficient, which is not preferable.

The method of dispersing EVOH as a dispersoid using ion-modified EVOH as a dispersion stabilizer is not limited, and a known method can be used.

For example, a solution of EVOH, which is a dispersoid, is brought into contact with water, which is a non-solvent for EVOH, in the presence of ion-modified EVOH, which is a dispersion stabilizer, to agitate the EVOH particles.
An aqueous dispersion can be obtained by precipitating as fine particles of not more than 2 μm, preferably not more than 2 μm, optimally not more than 1 μm, and then removing the solvent. Here, the diameter of the fine particles is a number average particle diameter.

The solid concentration is preferably 10% by weight.
Or more, more preferably 15% by weight or more, and most preferably 20% by weight.
% By weight or more. The upper limit of the solid concentration is not particularly limited. However, if the concentration is too high, the storage stability of the aqueous dispersion may be slightly poor.
It is preferably at most 50% by weight, more preferably at most 40% by weight.

As the solvent, for example, methyl alcohol,
Monohydric alcohols such as ethyl alcohol, propyl alcohol and butyl alcohol, dihydric alcohols such as ethylene glycol and propylene glycol, and trihydric alcohols such as glycerin
Polyhydric alcohols, phenols, phenols such as cresol, ethylenediamine, amines such as trimethylenediamine, dimethylsulfoxide, dimethylacetamide,
N-methylpyrrolidone or the like, or a hydrate thereof may be used alone or in combination of two or more. Particularly preferred solvents are alcohol-water mixed solvents such as water-methyl alcohol, water-normal propyl alcohol, water-isopropyl alcohol and the like.

The ion-modified EVOH is a dispersoid, EVO
Although it can coexist in a solution of H, non-solvent water, or both, it is preferable to coexist in a solution of EVOH.

The organic solvent in the solvent can be removed by an appropriate method such as an evaporation method, an extraction method, or a dialysis method. Although it is desirable that the degree of removal is high, a small proportion of the organic solvent may be left in consideration of economy.

As another method, after dissolving EVOH as a dispersoid and ion-modified EVOH as a dispersion stabilizer in a solvent system that dissolves at high temperature but becomes insoluble at low temperature,
A method in which the solution is cooled to precipitate and disperse as fine particles can also be adopted. Thereafter, by replacing the solvent with water, an aqueous dispersion can be obtained.

As the solvent system that dissolves at a high temperature and precipitates at a low temperature, the above-mentioned solvents alone or a mixed solvent with water can be used.

As still another method, ion-modified EVO
A method is also possible in which a solution of EVOH in which H is coexisted is brought into contact with a non-solvent or cooled, and particles precipitated and dispersed are separated by filtration, and the particles are dispersed in water in the coexistence of ion-modified EVOH.

In the present invention, an aqueous dispersion is preferably prepared by mixing a dispersoid EVOH and an EVOH having an ionic group of a dispersion stabilizer in a common solvent, for example, a mixed solvent of water-alcohol with stirring at a temperature of Dissolve at 50-75 ° C to form a solution, then cool (temperature -10-30 ° C)
VOH particles are precipitated and dispersed (emulsified), and then under reduced pressure (temperature of 10 to 30 ° C., pressure of 10 to 150 mmH).
The alcohol was removed in g), by further removing a desired amount of water, a method can be exemplified to obtain an aqueous dispersion of the desired solids concentration.

As described above, the EVOH having an ionic group includes an EVO into which an ionic group is randomly introduced.
H is preferred, but EVOH having an ionic group at the terminal and optionally a crosslinkable group can also be used. Here, EVOH having an ionic group at the terminal is
For example, a compound containing an active group such as an alcohol, aldehyde or thiol having a sulfonic acid group or a salt thereof, a carboxylic acid group or a salt thereof, an ammonium group or the like coexists as a chain transfer agent, and copolymerizes ethylene and a vinyl ester. A method of saponifying a vinyl ester unit, and a sulfonic acid group or a salt thereof at the terminal of EVOH;
It is produced by a method of introducing a compound containing a carboxylic acid group or a salt thereof, an ammonium group or the like by a chemical reaction. Among these methods, a method for economically and efficiently introducing an ionic group at the terminal to obtain EVOH exhibiting excellent stability and the like as an aqueous emulsion dispersion includes a sulfonic acid group or a salt thereof, Preferred is a method in which ethylene and vinyl ester are copolymerized in the presence of a thiol containing an acid group or a salt thereof, an ammonium group, and the like, and then saponified.

Next, an aqueous dispersion containing EVOH having an ionic group as a dispersoid, which is another suitable aqueous dispersion used in the present invention, will be described. In this case, as the EVOH having an ionic group, in particular, the EVOH into which the ionic group is randomly introduced, one having a sulfonic acid group or its base as the above-mentioned ionic group is preferable. When EVOH having these ionic groups is used as a dispersoid,
Suitable ethylene content, saponification degree and polymerization degree are the same as the ethylene content, saponification degree and polymerization degree of EVOH used as the above-mentioned dispersoid.

In the present invention, EVO having an ionic group used as the above-mentioned dispersion stabilizer or dispersoid is used.
As H, a block or graft copolymer of an EVOH component and a component having an ionic group can also be used. In addition to the above-described EVOH aqueous dispersion, an aqueous dispersion using a block or graft copolymer of an EVOH component and a polyvinyl alcohol component as a dispersion stabilizer or dispersoid, a block or graft copolymer of an EVOH component and a polyether component Aqueous dispersions containing as a dispersion stabilizer or dispersoid can also be used.

The aqueous dispersion thus obtained is swelled with water .
Obtained by allowed to blend a Junsei phyllosilicate
By drying after applying the aqueous composition, a film having excellent gas barrier properties under high humidity can be obtained .
The water-swellable phyllosilicates may be e pressurized during manufacture of the EVOH aqueous dispersion, or may be e pressurized after manufacture. A typical structure of the water-swellable phyllosilicate is a layered overlap of [sheet-like structure of Si-O tetrahedron] and [octahedral sheet of Al-O or Mg-O] as one unit. (Hereinafter, referred to as flakes). The size of the flake, which is one unit of the water-swellable phyllosilicate, is approximately 1 μm or less in average particle size, and the interval between flakes (bottom surface interval y) is approximately 20 Å or less. The swellability of the water-swellable phyllosilicate referred to in the present invention refers to the property of coordinating, absorbing and swelling water between the flakes, and in some cases, dispersing the flakes or a part thereof to form a colloid.

The water-swellable phyllosilicate salt raw materials are clay minerals such as smectite and vermiculite, and synthetic mica. Specific examples of the former smectite include montmorillonite, beidellite, nontronite,
Examples include saponite, hectorite, sauconite, and stevensite. These may be natural or synthetic. Among these, smectite, especially montmorillonite is preferred.
Further, in obtaining an aqueous composition comprising an aqueous dispersion of EVOH and the phyllosilicate, the phyllosilicate is preferably in a colloidal state of an aqueous sol. Further, the phyllosilicate may be used alone, or two or more kinds may be mixed.

The method for obtaining the aqueous composition comprising the EVOH aqueous dispersion and the phyllosilicate is not particularly limited. However, as described above, even if the flakes of the phyllosilicate are at least partially separated and dispersed. It is important to disperse in the form of fine particles obtained by applying the aqueous composition obtained by mixing and drying, and to obtain a film obtained by applying and drying the phyllosilicic acid by observation with an optical microscope (magnification: 10 times). It is preferable that salt aggregates or local aggregates are dispersed in the ion-modified EVOH in a state where almost no salt is assumed.

As a method for obtaining the above-mentioned dispersion state, for example, a method in which an aqueous dispersion of a phyllosilicate obtained by mixing a water-swellable phyllosilicate in the presence of water and an aqueous dispersion of an EVOH, are mixed under stirring. When preparing an aqueous dispersion, use is made of a mixture of the aqueous dispersion and a phyllosilicate. Further, by removing a desired amount of water, an aqueous composition having a desired solid content can be obtained.

[0046] The EVOH aqueous dispersion in the aqueous composition of the present invention the mixing ratio of (resin solids) and water-swellable phyllosilicate (solids), solid content 99 of the aqueous dispersion.
Water swellable phyllosilicate 0.0 to 95-3% by weight
5 to 97% by weight, preferably 0.1 to 80% by weight,
More preferably, it is selected from the range of 1 to 50% by weight. water
If the proportion of the swellable phyllosilicate is less than 0.05% by weight, the effect of improving the gas barrier properties of the coating layer obtained by applying and drying the aqueous composition is not preferred. On the other hand, if it exceeds 97% by weight, the strength of the coating layer is undesirably reduced.

The aqueous composition of the present invention may contain an alkali metal compound such as sodium hydroxide, sodium chloride, sodium acetate, sodium sulfate, sodium nitrate, calcium hydroxide, calcium chloride, calcium acetate, calcium sulfate for the purpose of decreasing the viscosity. , An alkaline earth metal compound such as calcium nitrate, and other electrolytes from 0.01 to
0.5% by weight (based on the polymer) may be added. The formulation is
It may be before or after dispersing the EVOH into fine particles.

The aqueous composition of the present invention is particularly useful as a coating material for forming a film having excellent gas barrier properties on a substrate. However, the aqueous composition can be used for other applications by taking advantage of its excellent mechanical and chemical properties. For example, it can be used in a wide range such as fine powder by spray drying and a binder or a vehicle of a paint or an adhesive.

It is possible to add an ordinary surfactant or protective colloid to the aqueous composition of the present invention, if necessary, as long as the object of the present invention is not hindered. Further, an aqueous dispersion of another resin, a stabilizer against light or heat, a pigment, a lubricant, a fungicide, a film-forming aid, and the like can be added. The dispersion stabilizer of the present invention is most suitable as the above-mentioned dispersion stabilizer for EVOH, but other organic materials (resins)
And also as a dispersion stabilizer for inorganic materials.

The aqueous composition of the present invention can be applied to the surface of a substrate by discharging from a casting head, roll coating, air knife coating, gravure roll coating, or the like.
Optional means such as doctor roll coating, doctor knife coating, curtain flow coating, spraying, dipping, and brush coating are exemplified. The substrate coated in this way is dried and
Examples of the heat treatment method include a dry heat treatment method such as an infrared irradiation method and a hot air drying method. These infrared irradiation, hot air drying, etc. may be used alone,
Also, they can be used in combination. The temperature for drying and heat treatment is preferably from 30 to 180 ° C, and the lower limit is preferably at least 50 ° C, most preferably at least 80 ° C.
The drying and heat treatment time is preferably from 5 seconds to 10 minutes, more preferably from 1 to 5 minutes. Conditions during drying and heat treatment,
For example, it is free to increase or decrease the temperature, for example, to process at a low temperature at first and gradually increase the temperature. By performing such drying and heat treatment, a film having excellent gas barrier properties is formed on the substrate surface.

It is preferable to apply and dry an adhesive in advance on the surface of the substrate by a dry lamination method or the like, that is, to perform anchor coating. The adhesive for dry lamination is not particularly limited as long as the interlayer adhesive strength is sufficient. For example, polyurethane-based and polyester-based adhesives for dry lamination are mentioned. Further, the surface of the base material may be subjected to a corona discharge treatment, a sputtering treatment, a high-frequency treatment, a fire treatment, a chromic acid treatment, a solvent etching treatment, or a combination of these surface treatments.

The following are examples of the substrate. A thermoplastic resin film, for example, a biaxially stretched film containing a propylene homopolymer as a main component, a ε-caprolactam homopolymer and a diamine component such as hexamethylenediamine and meta-xylylenediamine and adipic acid can be obtained as main raw materials. A biaxially oriented film mainly composed of nylon, a biaxially oriented film mainly composed of polyester obtained using ethylene glycol and terephthalic acid or naphthalenedicarboxylic acid as a main material, and a carbonic acid derivative such as bisphenol A and phosgene obtained as a main material A biaxially stretched film of polyvinylidene chloride obtained by copolymerizing vinyl chloride, acrylonitrile, (meth) acrylic acid ester, etc., and a homopolymer of styrene and styrene. Raw material and butadiene, acrylonitrile, biaxially oriented film of polystyrene by copolymerizing like, include rolling or biaxially oriented high density polyethylene film or the like.

In addition, various molded products (sheets, cups, bottles, etc.) other than the above-mentioned films are also suitable, and fiber aggregates (paper, nonwoven fabric, woven fabric, fibrous casing, etc.) and inorganic substances (cement, etc.) ), Metal, polyvinyl chloride resin wallpaper, photographic paper and the like.

The thickness of the film after application, drying and heat treatment of the aqueous composition of the present invention is preferably 0.5 to 15 μm, more preferably 1 to 10 μm, and most preferably 2 to 6 μm. is there.

Further, there is no particular limitation on the structure of the laminate including the substrate and the film-forming layer comprising the aqueous composition of the present invention, which is obtained by the above-mentioned method. be able to. These methods include, for example, an extrusion lamination method and a dry lamination method.

In laminating these layers, an ordinary method of laminating an adhesive resin layer between layers is adopted. The adhesive resin is not particularly limited as long as it does not cause delamination at a practical stage. For example, an unsaturated carboxylic acid or an anhydride thereof may be an olefin polymer (eg, polyethylene, polypropylene,
A modified olefin polymer containing a carboxyl group, which is obtained by chemically (for example, addition of a olefin or grafting reaction) a polyolefin such as polybutene or a copolymer mainly composed of an olefin. Specifically, one selected from maleic anhydride graft-modified polyethylene, maleic anhydride graft-modified polypropylene, maleic anhydride graft-modified ethylene-ethyl acrylate copolymer, maleic anhydride graft-modified ethylene-vinyl acetate copolymer or A mixture of the two is mentioned. Further, glycidyl acrylate, a polymerizable unsaturated compound having a glycidyl group such as glycidyl methacrylate, a polymerizable unsaturated compound having a methacryloxypropyltrimethoxysilane group, a glycidyl group, a modified olefin polymer such as an alkoxysilane group. Can be These functional groups may be used in combination. Specifically, glycidyl-modified polyethylene, glycidyl-modified polypropylene, glycidyl-modified ethylene-ethyl acrylate copolymer, glycidyl-modified ethylene-vinyl acetate copolymer, alkoxysilane-modified polyethylene, alkoxysilane-modified polypropylene, alkoxysilane-modified ethylene-vinyl acetate One type or a mixture of two types selected from copolymers may be mentioned. In addition, a polyester resin containing a polyvalent carboxylic acid, a polyhydric alcohol, or a hydroxycarboxylic acid as a component is also exemplified as the adhesive resin.

When the dry lamination method is used,
The same adhesive for dry lamination as described above can be used and is not particularly limited.

Containers (bags, cups, tubes, trays, bottles, etc.) composed of the laminates (films, sheets, etc.) produced by these methods are used for general food packaging,
It is very suitable for pharmaceutical packaging and retort food packaging.

Hereinafter, the present invention will be described with reference to Examples.
The present invention is not limited by this.

[0060]

【Example】

Example 1 An ion-modified EVOH having an ethylene content of 33 mol%, a saponification degree of 99.6 mol%, and a polymerization degree of 800, in which sodium 2-acrylamido-2-methylpropanesulfonate was randomly copolymerized with EVOH at 1.2 mol%, was used. 10% by weight
50% by weight of a mixed solvent containing 50/50 (weight ratio) of water / methyl alcohol (hereinafter referred to simply as "parts") is used as an ethylene content of 32.
Mol EV, 28 parts of normal EVOH having a saponification degree of 99.5 mol% and a polymerization degree of 1000, 100 parts of water and methyl alcohol 1
The resulting mixture was added to and mixed with 00 parts and dissolved by heating at 65 ° C. while stirring.

This solution was cooled to 10 ° C. with stirring to precipitate particles, thereby obtaining a dispersion. The average particle size was 0.7 μm. Then, the dispersion was evaporated under reduced pressure at 20 ° C. with stirring to remove methyl alcohol. Even in the process of distilling off methyl alcohol, particles were hardly observed to aggregate, and an aqueous dispersion having an average particle diameter of 0.7 μm and a solid concentration of 26% was obtained. The storage stability was also good, and almost no aggregation was observed in a storage test at 40 ° C. for 10 days.

On the other hand, 3 parts of montmorillonite (Kunimine Kogyo Co., Ltd., Kunipia-F) was added to a container equipped with a stirrer so as to form an aqueous dispersion having a concentration of 1% by weight, followed by stirring to prepare a montmorillonite colloid. did.

Next, the aqueous dispersion of montmorillonite colloid was added with stirring to obtain an aqueous composition.
The storage stability was good. Using this aqueous composition as a substrate, a biaxially oriented polypropylene film (film thickness 20 μm,
Urethane-based anchor coating agent (Toyo Morton Co., Ltd. AD335A) is applied to the primer-treated surface of Tokyo Cellophane Paper Co., Ltd.
/ CAT10) was applied by an air knife coating method, and dried and heat-treated at 110 ° C. for 5 minutes to obtain a multilayer film. Subsequently, the multilayer film (EV
Oxygen barrier properties (Moden with an OH layer thickness of 3 μm)
When OX-TRAN 10 / 50A manufactured by Control Corporation was used and the measurement conditions were 20 ° C. and 85% RH, the oxygen permeation amount was 8.1 cc / m ² · day · atm.
Showed good barrier properties as a food packaging material (hereinafter, measurement conditions and units of oxygen permeation amount are the same).
In addition, an optical microscope observation (magnification: 10 times) of the surface and cross section of the layer coated and dried with the aqueous composition did not reveal any aggregates or local aggregates of montmorillonite.

Example 2 0.3 mol% of potassium 2-acrylamido-2-methylpropanesulfonate was randomly copolymerized with EVOH. Water having an ethylene content of 22 mol%, a saponification degree of 99.6 mol% and a polymerization degree of 600 was used. / Ethylene alcohol = 40/6
50 parts of a mixed solvent (concentration: 10%) with an ethylene content of 27
The mixture was added to 140 parts of a mixed solvent (concentration: 10%) of ordinary EVOH having a water / ethyl alcohol ratio of 40/60 (concentration: 10%) having a molar ratio of 99.4 mol% and a degree of polymerization of 900, and dissolved by heating at 70 ° C. with stirring.

This solution was cooled to 8 ° C. with stirring to precipitate particles, thereby obtaining a dispersion. The average particle size was 0.5 μm. Then, the dispersion was evaporated under reduced pressure at 25 ° C. with stirring to remove ethyl alcohol. Average particle size 0.5μ
m, an aqueous dispersion having a solid content of 23% was obtained.

Next, 1.7 parts of montmorillonite (Kunimine Kogyo Co., Ltd., Kunipia-F) was added to a container equipped with a stirrer so as to form an aqueous dispersion having a concentration of 1% by weight, followed by stirring. The colloid was adjusted. And
A montmorillonite colloid was added to the aqueous dispersion under stirring to obtain an aqueous composition. The storage stability was good.

Example 3 0.8 mol% of sodium allyl sulfonate was copolymerized randomly with EVOH to give an ethylene-modified EV having an ethylene content of 25 mol%, a saponification degree of 99.3 mol% and a polymerization degree of 400.
A solution prepared by dissolving 1900 parts of water in 250 parts of OH was prepared. A high-speed stirrer is immersed in this solution at 5000 rpm.
While stirring, ethylene content 27 mol%, saponification degree 9
9.6 mol% of normal EVOH having a degree of polymerization of 1100 was added to water /
The solution was dropped into 5000 parts of a 10% concentration solution dissolved in a 30/70 mixed solvent of isopropyl alcohol to precipitate particles to obtain a dispersion. The average particle size was 0.9 μm.

Next, this dispersion was evaporated under reduced pressure at 20 ° C. to distill off isopropyl alcohol.
An aqueous dispersion having a solid content of 21 μm was obtained. It was a stable aqueous dispersion with almost no particle enlargement during the vacuum distillation process.

Subsequently, in the same manner as in Example 1, an aqueous composition containing a colloid of montmorillonite (a 1% by weight aqueous dispersion using 65 parts) was obtained, and a similar multilayer film was prepared. Measurement and observation were performed. Oxygen permeation rate is 6.3 cc / m ² · day · atm, showing good barrier properties as a food packaging material. In addition, when the aqueous composition is applied and dried, the montmorillonite aggregates or local lumps are formed. Nothing was found.

Example 4 Sodium 2-methacrylamido-2-methylpropanesulfonate was added and introduced by Michael addition reaction of EVOH to a hydroxyl group. The ethylene content was 33 mol%, the saponification degree was 99.6 mol%, and the polymerization degree was 1000. Using 300 parts of EVOH as a dispersion stabilizer, an ordinary EVOH 1 having an ethylene content of 33 mol%, a saponification degree of 99.5 mol% and a polymerization degree of 1010 is used.
000 parts and 10,000 parts of a mixed solvent of water / methyl alcohol = 100/100 were mixed and dissolved by heating.

The solution was cooled to 15 ° C. with stirring to precipitate particles, thereby obtaining a dispersion. Then, the dispersion was evaporated under reduced pressure to remove methyl alcohol. An aqueous dispersion having an average particle diameter of 0.8 μm and a solid concentration of 22% was obtained.

Subsequently, in the same manner as in Example 1, an aqueous composition containing a colloid of montmorillonite (a 1% by weight aqueous dispersion using 110 parts) was obtained, and a similar multilayer film was prepared. , Was observed. The oxygen permeation amount is 11.6 cc / m ² · day · atm, showing good barrier properties as a food packaging material. The coated and dried layer of the aqueous composition has a montmorillonite aggregate or a local lump. Nothing was found.

Example 5 An aqueous composition containing a montmorillonite colloid was prepared in the same manner as in Example 1 except that ion-modified EVOH in which sodium itaconate was randomly copolymerized with EVOH at 5.8 mol% was used. Then, the same multilayer film was prepared, and measured and observed. Oxygen permeation is 1
At 0.1 cc / m ² · day · atm, it shows good barrier properties as a food packaging material, and the aqueous composition is coated and dried, and no montmorillonite aggregates or local lumps are found in the layer. Did not.

Comparative Example 1 A multilayer film was prepared and measured in the same manner as in Example 1 except that the montmorillonite colloid was not blended. Oxygen permeation rate is 18.0 cc / m
^{It was 2} * day * atm, and the gas barrier property was lower than that of Example 1.

Example 6 0.5 mol% of sodium 2-acrylamido-2-methylpropanesulfonate was randomly copolymerized with EVOH. An ion having an ethylene content of 34 mol%, a saponification degree of 99.4 mol%, and a polymerization degree of 1100. 50 parts of denatured EVOH
The mixture was added to and mixed with 600 parts of a mixed solvent of methyl alcohol = 30/70, and dissolved by heating at 65.degree.

This solution was cooled to 10 ° C. with stirring to precipitate particles, thereby obtaining a dispersion. Average particle size is 0.6 μm
Met. Then, the dispersion was evaporated under reduced pressure with stirring to distill off methyl alcohol. In the process of distilling off methyl alcohol, particles are hardly aggregated and stable, and the ion-modified EVOH having an average particle diameter of 0.6 μm and a solid concentration of 27% is used.
Was obtained. Also has good shelf stability, 40 ° C
No aggregation was observed even in the standing test for 10 days.

On the other hand, 5 parts of montmorillonite (Kunimine Kogyo Co., Ltd., Kunipia-F) was added to a container equipped with a stirrer so as to form an aqueous dispersion having a concentration of 1% by weight, followed by stirring to prepare a montmorillonite colloid. did.

Next, a colloid of montmorillonite was added to the aqueous dispersion of the ion-modified EVOH with stirring to obtain an aqueous composition. The storage stability was good. A coating obtained by applying a urethane-based anchor coating agent (AD335A / CAT10, Toyo Morton Co., Ltd.) to a primer-treated surface of a biaxially stretched polypropylene film (thickness: 20 μm, Tokyo Cellophane Paper Co., Ltd.) using this aqueous composition as a base material Use and apply by air knife coating method 110 ℃,
After drying and heat treatment for 5 minutes, a multilayer film was obtained. The oxygen permeation amount was 8.7 cc / m ² · day · atm, indicating good barrier properties as a food packaging material (hereinafter, the measurement conditions and units of the oxygen permeation amount are the same). In addition, an optical microscope observation (magnification: 10 times) of the surface and cross section of the layer coated and dried with the aqueous composition did not reveal any aggregates or local aggregates of montmorillonite.

Example 7 Potassium 2-acrylamido-2-methylpropanesulfonate was randomly copolymerized to 1.2 mol% with respect to EVOH to obtain an ion having an ethylene content of 48 mol%, a saponification degree of 99.2 mol%, and a polymerization degree of 800. 50 parts of modified EVOH was added to and mixed with 600 parts of a mixed solvent of water / isopropyl alcohol = 30/70, and dissolved by heating at 70 ° C. with stirring.

This solution was cooled to 5 ° C. with stirring to precipitate particles, thereby obtaining a dispersion. The average particle size was 0.7 μm. Then, the dispersion was evaporated under reduced pressure with stirring to remove isopropyl alcohol. Even in the process of distilling off isopropyl alcohol, almost no aggregation of particles was observed, and an aqueous dispersion of ion-modified EVOH having an average particle diameter of 0.7 μm and a solid concentration of 23% was obtained.

Next, 5 parts of montmorillonite (Kunimine Industry Co., Ltd., Kunipia-F) was placed in a container equipped with a stirrer at a concentration of 1%.
Water was added so as to obtain a weight percent aqueous dispersion, followed by stirring to prepare a montmorillonite colloid. Then, a montmorillonite colloid was added to the aqueous dispersion of the ion-modified EVOH with stirring to obtain an aqueous composition. The storage stability was good.

Example 8 Sodium allyl sulfonate was randomly copolymerized with EVOH at 0.6 mol%, and an ion-modified EV having an ethylene content of 28 mol%, a saponification degree of 99.7 mol% and a polymerization degree of 700 was used.
50 parts of OH in water / isopropyl alcohol = 40/60
Was added to and mixed with 500 parts of a mixed solvent of the above, and dissolved by heating at 75 ° C. with stirring. While stirring this solution in 200 parts of a mixed solvent of water / isopropyl alcohol = 20/80 at 20 ° C. with a high-speed stirrer, particles were precipitated to obtain a dispersion. The average particle size was 0.9 μm.

Next, this dispersion was evaporated under reduced pressure at 20 ° C. to distill off isopropyl alcohol.
An aqueous dispersion of ion-modified EVOH having a thickness of 20 μm and a solid concentration of 20% was obtained. It was a stable aqueous dispersion with almost no particle enlargement during the vacuum distillation process.

Subsequently, an aqueous composition containing a colloid of montmorillonite was obtained in the same manner as in Example 6, and a similar multilayer film was formed, followed by measurement and observation. Oxygen permeation rate is 6.5 cc / m ² · day · atm, showing good barrier properties as a food packaging material. In addition, when the aqueous composition is applied and dried, montmorillonite aggregates or local lumps are formed. Nothing was found.

Example 9 1.0 mol% of sodium 2-methacrylamido-2-methylpropanesulfonate was introduced into EVOH by a Michael addition reaction to a hydroxyl group of EVOH, ethylene content was 34 mol%, and saponification degree was 99.5. Mol%, degree of polymerization 100
50 parts of ion-modified EVOH was added to and mixed with 400 parts of a mixed solvent of water / ethyl alcohol = 50/50, and dissolved by heating at 70 ° C. with stirring. This solution was dispersed and ethyl alcohol was distilled off in the same manner as in Example 6 to obtain an ion-modified EVO having an average particle diameter of 0.8 μm and a solid concentration of 22%.
An aqueous dispersion of H was obtained.

Subsequently, an aqueous composition containing a colloid of montmorillonite was obtained in the same manner as in Example 6, and a similar multilayer film was formed, followed by measurement and observation. Oxygen permeation rate is 12.0 cc / m ² · day · atm, showing good barrier properties as a food packaging material. The coated and dried layer of the aqueous composition has a montmorillonite aggregate or a local lump Nothing was found.

Example 10 An aqueous composition containing a colloid of montmorillonite was prepared in the same manner as in Example 6, except that ion-modified EVOH in which sodium itaconate was randomly copolymerized with EVOH at 0.6 mol% was used. Then, the same multilayer film was prepared, and measured and observed. Oxygen permeation is 1
At 0.0 cc / m ² · day · atm, it shows good barrier properties as a food packaging material, and the coated and dried layer of the aqueous composition shows no aggregates or local aggregates of montmorillonite. Did not.

[0088]

As described above, according to the present invention, an aqueous composition having a high solid content with excellent stability during use can be obtained, and since it is aqueous, there is no problem such as environmental pollution. It has advantages, and the film formed by coating and drying on various substrates shows excellent gas barrier properties, especially gas barrier properties under high humidity, fragrance retention, oil and chemical resistance, and is suitable for various packaging Useful.

──────────────────────────────────────────────────の Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 23/00-23/36 C08L 29/00-29/14 C08K 3/00-13/08 B32B 27 / 18

Claims (4)

(57) [Claims] 1. An ethylene content of 10 having an ionic group.
Aqueous solution comprising a saponified modified ethylene-vinyl ester copolymer having a saponification degree of 80 to 70 mol% and a dispersant of an ethylene-vinyl alcohol copolymer having an ethylene content of 15 to 65 mol%. Dispersion and water swelling
Aqueous composition comprising a phyllosilicate . 2. An ethylene content having an ionic group of 15 to 15.
An aqueous composition comprising a 65 mol% aqueous dispersion of an ethylene-vinyl alcohol copolymer and a water-swellable phyllosilicate . On at least one surface of wherein the substrate according to claim 1 or 2
A laminate obtained by applying the aqueous composition described in 1 above, followed by drying. On at least one surface of 4. A substrate according to claim 1 or
After applying the aqueous composition according to 2, preparation of the laminate, characterized in Rukoto was dried to form a film layer.