JP2007313758A - Gas barrier laminated film, gas barrier multi-layer film, and method for manufacturing them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To ensure high gas barrier properties by avoiding heat treatment at a high temperature and to improve simultaneously productivity, coating properties and other performances such as water resistance in a gas barrier laminated film utilizing both a polycarboxylic acid polymer and a water-soluble polyvalent metal salt. <P>SOLUTION: The gas barrier laminated film characterized in that a layer comprising the polycarboxylic acid polymer is formed without heat treatment on at least one face of a plastic film substrate, and a layer comprising the water-soluble polyvalent metal salt and a water-based resin is formed in adjoining with the layer comprising the polycarboxylic acid polymer, and the polycarboxylic acid polymer is ion-crosslinked at the carboxyl groups by shifting polyvalent metal ions in the water-soluble polyvalent metal salt, and a method for manufacturing it, are provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a gas barrier laminate film, a gas barrier multilayer film, and a method for producing the same, and more particularly, as a packaging material for foods and drinks, pharmaceuticals, and electronic parts that are susceptible to deterioration due to the influence of oxygen, or high-temperature hydrothermal treatment. The present invention relates to a gas barrier laminated film and a gas barrier multilayer film useful as packaging materials for required articles, and methods for producing them.

Plastic films and plastic laminated films are widely used in the form of films and containers as packaging materials in various fields such as food and drink, cosmetics, pharmaceuticals, and electronic devices. As one of the enhancement of their functions, gas barrier properties ( Permeability of oxygen gas and water vapor) is very important.
In packaging materials, oxygen gas causes deterioration due to oxidative degradation of packaged foods and beverages and accelerated growth of microorganisms, evaporation of moisture reduces the quality and flavor of stored food, and dissipation of readily volatile components is an important component of pharmaceuticals. In addition, oxygen gas may lead to deterioration and deterioration of stored electronic equipment and precision equipment, etc., so shielding of oxygen gas entering from the outside or dissipating moisture and easily volatile components of stored goods to the outside Conventionally, gas barrier properties have been very important for deterrence and the like.

  However, plastic general-purpose films generally have low gas barrier properties. Polyvinyl chloride and polyvinylidene chloride have relatively high gas barrier properties, but environmental pollution problems during incineration cannot be avoided. As a material to be obtained, a laminated film of polyalcohol resin such as polyvinyl alcohol is inexpensive and has no environmental problems and has a high gas barrier property in a low humidity atmosphere, but due to its hydroxyl group, the gas barrier property is drastically increased in a high humidity atmosphere. It drops and cannot be used for packaging foods and drinks containing moisture. A copolymer of vinyl alcohol and ethylene is known as a polymer with improved gas barrier properties under high humidity, but a high ethylene content is required to improve gas barrier properties under high humidity. Such a polymer is hardly soluble in water, and processing such as molding and coating becomes difficult.

Therefore, as an advanced improvement technology that increases gas barrier properties, polyalcohol-based resins such as polyvinyl alcohol are used in combination with polycarboxylic acid-based polymers such as (meth) acrylic acid resins, and they are resistant to ester bonds by heat treatment. A number of gas barrier films having improved wettability and gas barrier properties and methods for producing the same have been disclosed (for example, see Patent Document 1).
In addition, a number of gas barrier films and laminated films in which the gas barrier property is further enhanced by using a metal compound in combination with the resin material of the gas barrier film and utilizing metal ion crosslinking of carboxylic acid groups in addition to ester crosslinking are also disclosed. (For example, see Patent Documents 2 and 3).
In these methods, the gas barrier property under a highly humid atmosphere is remarkably enhanced. However, since a heat treatment process for a considerable time at a high temperature is required, a large amount of energy is consumed and the film substrate and the gas barrier resin are thermally deteriorated. Problems such as alteration and deformation are derived, and if the heat treatment process is performed at a low temperature in order to avoid such problems, a long process is required and productivity is lowered.
For this reason, although the manufacturing method of the gas barrier film which relaxes a heat treatment process using polyvinyl alcohol and an ethylene-maleic acid copolymer etc. together is proposed (for example, refer to patent documents 4), high temperature heat treatment is still possible. It is inevitable and the gas barrier property is not sufficiently enhanced.

Furthermore, as a gas barrier film improvement from a new resin material, a polycarboxylic acid polymer and a polyvalent metal compound are used in combination without using a polyalcohol resin and a polycarboxylic acid polymer in combination. A gas barrier film material (see Patent Document 5), in which a metal compound layer is provided on an acid polymer layer or a film made of a mixture of a polycarboxylic acid polymer and a metal compound is used, at least one surface of a substrate Discloses a gas barrier laminate (see Patent Document 6) in which a carboxylic acid resin layer and a polyvalent metal compound-containing layer containing a binder resin and a surfactant are disposed adjacent to each other, and these are heat-treated at high temperature. Because it does not need.
However, when the gas barrier laminate film described in Patent Document 5 is exposed to low-temperature water for a long time, the polycarboxylic acid is prior to metal ion crosslinking in the polycarboxylic acid polymer. The polymer may swell with moisture, and as a result, the transparency of the film may be lost or the gas barrier property may be lowered.
In addition, a gas barrier film (see Patent Document 7) in which a metal layer is provided by vapor deposition or the like on a thermoplastic resin film having a defined carboxylic acid concentration on the surface, and a gas barrier property by a specific crosslinking agent such as polyacrylic acid and an isocyanate compound A film (see Patent Document 8) and the like are also presented, but all of them are subjected to a high-temperature heat treatment. In addition, a gas barrier laminate in which a polycarboxylic acid polymer layer is formed on a film substrate, and a laminated film coated with a solution of a polyvalent metal compound is allowed to crosslink in the presence of moisture without heat treatment. A method for producing a film is also disclosed (see Patent Document 9). However, since the film is allowed to crosslink without being subjected to a heat treatment step, it takes a long time for ionic crosslinking and the productivity is very low.

  In the above, the flow of technological improvements in gas barrier films or gas barrier laminated films as packaging materials has been outlined. Even if the gas barrier properties, which are the main issues, are gradually improved, high-temperature heat treatment problems, productivity, or product appearance It is difficult to improve other performances such as water resistance and water resistance, and a gas barrier packaging material that sufficiently improves these problems has not yet been found.

JP-A-6-220221 (summary) JP-A-10-237180 (abstract, claim 15 in claims, and paragraphs 0039,0062,0066) JP 2000-931 A (summary) JP 2000-323204 A (summary) International application publication pamphlet WO03 / 091317 (summary of cover page and claims 2,22 on pages 89, 91) International Application Publication WO2005 / 037534 (summary of cover page and claims 1,16 on pages 32, 34) Japanese Patent Laid-Open No. 7-314612 (Abstract, Claim 1 of Claim, and Paragraph 0051) JP 2001-310425 A (Claims 2 and 6 of the claims) JP 2005-125893 A (Abstract and paragraph 0014)

  In view of the flow of technical improvements relating to gas barrier films as packaging materials outlined in paragraphs 0002 to 0006 as background art, the improvement of gas barrier properties is achieved by improving the gas barrier resin material, in particular, polyalcohol-based resins and polycarboxylic acids. Achieved sufficiently in gas barrier laminated films that use acid polymers and metal compounds in combination, and have improved gas barrier properties by utilizing ester bond crosslinking by heat treatment and metal ion crosslinking of carboxylic acid groups. However, such a gas barrier resin material requires a heat treatment at a high temperature, and the burden of cost and energy is large. In addition, in various improvement proposals, incidental problems such as the necessity of heat treatment at high temperatures, low productivity, poor appearance of the product and poor coating properties of the coating solution are also included. However, the present invention avoids the problem of high-temperature heat treatment, ensures high gas barrier properties, and improves as much as possible incidental problems such as productivity or product appearance. This is an object of the invention.

  In order to realize the solution of the above-mentioned problems, the inventors of the present invention have the types of resin materials in the gas barrier film, the steps in ester crosslinking and ionic crosslinking, the types and application methods of ionic crosslinking agents, and further the heat treatment conditions. In the process of this, the method of relaxation and the layered configuration of each material and the coating method are considered from multiple viewpoints, and trials and demonstrations are repeated, and in the process, polycarboxylic acid polymer and polyvalent metal As a method for imparting ions as a cross-linking agent in a gas barrier resin material using the above compound, heat treatment is performed such that a coating liquid containing a water-soluble polyvalent metal salt and an aqueous resin is applied so as to be adjacent to the polycarboxylic acid polymer layer. A method that does not perform the process was adopted. By this method, improvement in coatability and product appearance were achieved. Further, it has been found that a coating liquid containing a water-soluble polyvalent metal salt and a water-based resin can accelerate the onset of gas barrier properties mainly by using water as a solvent, leading to the creation of the present invention.

Specifically, a combination of a water-soluble polyvalent metal salt and a polycarboxylic acid polymer was selected as the gas barrier resin material. The selection made it possible to quickly crosslink the carboxyl group of the polycarboxylic acid polymer with metal ions and to exhibit high gas barrier properties. Since heat treatment is not performed, problems associated with heat treatment are not derived.
Furthermore, water-soluble polyvalent metal salts are combined with water-based resins in order to ensure transparency of the product film and uniformity of the coating surface (no repelling of the coating agent) and to achieve high water resistance. It is essential to use it.

As a method for producing the gas barrier laminate film of the present invention, in a laminate film formed by applying a polycarboxylic acid polymer coating solution to at least one surface of a plastic film substrate, a coating solution containing a polycarboxylic acid polymer is used. A coating solution containing a water-soluble polyvalent metal salt and a water-based resin is applied adjacent to the layer formed from the above, and these coating layers are dried without heat treatment to form a layer.
In order to solve the above-mentioned problems of the present invention, the main configuration described in the above paragraph is proved to be rational and significant, as demonstrated by contrast between Examples and Comparative Examples described later. ing.

In the present invention, more specifically, the polycarboxylic acid polymer has an oxygen permeability coefficient specified, and is obtained by polymerizing at least one unsaturated acid selected from the group of acrylic acid, methacrylic acid, maleic acid, and itaconic acid. A homopolymer or a copolymer thereof or a mixture thereof. Further, preferably, a layer formed from a coating liquid containing a polycarboxylic acid polymer via an anchor coat layer on a film substrate, or a layer formed from a coating liquid containing a water-soluble polyvalent metal salt and an aqueous resin. Are stacked.
The water-soluble polyvalent metal salt is mainly calcium or zinc acetate, lactate, or chloride, and the water-based resin is not reactive with the polyvalent metal ion or has low reactivity, and the water-based resin is Preferably, it is any one of a water-based polyurethane resin, a water-based polyisocyanate resin, a water-based acrylic resin, a water-based alkyd resin, and a water-based fluororesin, or the water-based resin is an oxazoline group-containing resin, and a polycarboxylic acid-based polymer is used. It is also possible to use an embodiment in which a polyalcohol resin is used in combination with the coating liquid to be included, and these are applied to the film substrate as a mixed solution, and the polyalcohol resin is mainly composed of polyvinyl alcohol resin, polyethylene glycol resin, starch, saccharides. Either or a mixture thereof is used.

  As a feature of the configuration of the present invention, a layer formed from a coating liquid containing a polycarboxylic acid polymer is disposed on a film base, and a water-soluble polyvalent metal salt and an aqueous resin are further disposed adjacent to the layer. In order to form a gas barrier layer on a film substrate, a layer formed from a coating liquid containing the film is provided, and is not subjected to heat treatment in these steps, and exhibits a gas barrier property. In addition, a polycarboxylic acid polymer and a water-soluble polyvalent metal salt are exclusively used, and the carboxyl group of the carboxylic acid polymer is crosslinked by metal ions. Even in a mode in which a polycarboxylic acid polymer and a polyalcohol resin are used in combination, it is not necessary to form an ester bridge, so there is no need for a heat treatment, and there is no heat treatment process for a considerable time at a high temperature. The conventional problems such as deformation, shrinkage and thermal deterioration of the gas barrier resin layer as well as alteration and coloring of the gas barrier resin layer are solved, and it becomes possible to use a film base material having low heat resistance, and a large amount of energy is not required. The manufacturing process is shortened, the economic efficiency of the manufacturing process is increased, and the environmental load due to energy consumption is also reduced.

  Further, in the present invention, a coating solution containing a water-soluble polyvalent metal salt and a water-based resin is applied adjacent to a layer formed from a coating solution containing a polycarboxylic acid polymer, and these coating layers are heat-treated. Without drying, and the polycarboxylic acid polymer is ionically cross-linked at the carboxyl group by migration of polyvalent metal ions in the water-soluble polyvalent metal salt, whereby a gas barrier laminate film is produced. Compared with the immersion method of metal ion aqueous solution etc., production line speed is fast and production can be performed efficiently and economically. Ii) From coating liquid containing polycarboxylic acid polymer to layer formed without heat treatment The transition of the polyvalent metal ions is fast even at normal temperature, the gas barrier property is rapidly developed by ionic crosslinking, and iii) the aqueous resin is used in the aqueous solution of the polyvalent metal salt. Transparency Shinagaikan high, salt deposition on the product surface is also suppressed, there is no cissing of the coating liquid, and a property that.

By the way, when each of the prior art patent documents described in paragraphs 0002 to 0007 is scrutinized, Patent Document 5 discloses that a polycarboxylic acid polymer is not used in combination with a polyalcohol resin and a polycarboxylic acid polymer. A gas barrier film material in which only a polyvalent metal compound is used in combination and a metal compound layer is provided on a polycarboxylic acid polymer layer is disclosed. Patent Document 6 discloses a carboxylic acid resin layer on at least one surface of a substrate. And a gas barrier laminate in which a polyvalent metal compound-containing layer containing a binder resin and a surfactant is disposed adjacent to each other is disclosed, and in Patent Document 9, a polycarboxylic acid polymer layer is formed on a film substrate. In addition, a method for producing a gas barrier laminate film is disclosed in which a laminate film coated with a solution of a polyvalent metal compound is left to stand in the presence of moisture without performing heat treatment. However, each of them shows a specific configuration in which a coating solution containing a water-soluble polyvalent metal salt and an aqueous resin is applied adjacent to a layer formed from the coating solution containing a polycarboxylic acid polymer in the present invention. It is not a thing.
Furthermore, JP 2004-34616 A, which is not described in paragraph 0007, describes that a polymer layer containing a polyvalent metal compound and polyester and polyisocyanate is provided adjacent to the gas barrier polymer layer. (Refer to claims 1 and 10 of the claims), i) as a gas barrier resin, a polyalcohol-based polymer and a polycarboxylic acid-based polymer are used in combination, and ii) a polyvalent metal compound is a water-soluble polyvalent metal. Iii) It is unclear whether the polymer containing polyester and polyisocyanate is water-based, and iv) a heat treatment step is essential (see paragraph 0051), so the invention described in this document is the present invention. It is substantially different from the invention.
International publication pamphlet WO 2004/096540 not described in paragraph 0007 describes that a mixed aqueous solution of polyvinyl alcohol and calcium acetate is applied adjacent to the polycarboxylic acid polymer layer (see page 21). See Example 5), i) always use a heat-shrinkable film as the substrate (see claim 1 on page 31), ii) water-soluble in the coating solution of polyvalent metal compound and resin The polyvalent metal salt and the water-based resin are not limited (see page 11). On the other hand, the present invention is specific to the water-soluble polyvalent metal salt and the water-based resin and exhibits the specific effects detailed in paragraph 0014. Therefore, the description in this document does not suggest the present invention.
In the above-mentioned Patent Document 6, a polycarboxylic acid resin layer and a polyvalent metal compound-containing layer containing an aqueous binder resin and a surfactant are disposed adjacent to each other (claims 1 and 32 on page 32). (See Preparation Example 7 on page 25), i) a surfactant must be used (see claim 1 on page 32), and ii) an inorganic compound (zinc oxide) is used as the polyvalent metal compound. (See Preparation Example 7 on page 25), the description in this document does not suggest the present invention.

  In the above, the background of the creation of the present invention, the characteristics of the configuration and the differences from the prior art, etc. have been outlined, so here the overview of the present invention is overviewed and the entire configuration is clearly described. The invention is composed of the following invention unit groups. The inventions of [1] and [10] are used as basic inventions, and other inventions embody the basic inventions or form the embodiments. . (The invention group as a whole is collectively referred to as “the present invention”.)

[1] A layer (a) formed from a coating liquid (A) containing a polycarboxylic acid polymer on at least one surface of the plastic film substrate without heat treatment, a water-soluble polyvalent metal salt and an aqueous resin The layer (b) formed from the coating liquid (B) containing, and the layer (a) formed from the coating liquid (A) and the layer (b) formed from the coating liquid (B) are mutually A gas barrier laminate film, wherein at least a pair of laminate units adjacent to each other is formed.
[2] When the polycarboxylic acid polymer is formed into a film alone, the oxygen permeability coefficient at 30 ° C. and 0% relative humidity is 1,000 cm ³ (STP) · μm / (m ² · day · MPa) The gas barrier laminate film according to [1], which is as follows.
[3] A layer (a) formed from a coating liquid (A) containing a polycarboxylic acid-based polymer without heat treatment via an anchor coat layer on a film substrate, or a water-soluble polyvalent metal salt and an aqueous system The gas barrier laminate film according to [1] or [2], wherein a layer (b) formed from a coating liquid (B) containing a resin is laminated.
[4] The polycarboxylic acid polymer is a homopolymer obtained by polymerizing at least one unsaturated acid selected from the group of acrylic acid, methacrylic acid, maleic acid, and itaconic acid, a copolymer thereof, or a mixture thereof. The gas barrier laminate film according to any one of [1] to [3], wherein
[5] The water-soluble polyvalent metal salt is calcium or zinc acetate, lactate or chloride, and the aqueous resin is an aqueous polyurethane resin, an aqueous polyisocyanate resin, an aqueous acrylic resin, an aqueous alkyd resin, or an aqueous fluororesin. The gas barrier laminated film according to any one of [1] to [4], wherein the water-based resin is an oxazoline group-containing resin.
[6] The gas barrier according to any one of [1] to [5], wherein the water-soluble polyvalent metal salt is zinc acetate or calcium acetate, and the aqueous resin is an aqueous polyurethane resin or an aqueous polyisocyanate resin. Laminated film.
[7] The layer (a) formed from the coating liquid (A) containing a polycarboxylic acid polymer without heat treatment contains a polyalcohol resin, [1] to [1] [6] The gas barrier laminate film according to any one of [6].
[8] The gas barrier laminate film according to any one of [1] to [7], and a plastic film laminated on at least one surface of the gas barrier laminate film via an adhesive layer or directly. Gas barrier multilayer film.
[9] A packaging material comprising the gas barrier laminate film according to [1] to [7].
[10] A coating liquid (A) containing a polycarboxylic acid polymer is applied to at least one surface of a plastic film substrate, and the coating liquid (A) containing a polycarboxylic acid polymer is not subjected to heat treatment. Adjacent to the layer (a) to be formed, a coating liquid (B) containing a water-soluble polyvalent metal salt and an aqueous resin is applied, and these coating layers are dried. Production method.
[11] An anchor coating agent is applied to the film substrate and dried, and then a coating liquid (A) containing a polycarboxylic acid polymer is applied, and heat treatment is performed from the coating liquid (A) containing the polycarboxylic acid polymer. The coating liquid (B) containing a water-soluble polyvalent metal salt and an aqueous resin is applied adjacent to the layer (a) formed without drying, and these coating layers are dried, [10 ] The manufacturing method of the gas-barrier laminated | multilayer film in].
[12] When the polycarboxylic acid polymer is formed into a film alone, the oxygen permeability coefficient at 30 ° C. and 0% relative humidity is 1,000 cm ³ (STP) · μm / (m ² · day · MPa) A homopolymer obtained by polymerizing at least one unsaturated acid selected from the group of acrylic acid, methacrylic acid, maleic acid, and itaconic acid, a copolymer thereof, or a mixture thereof, and a water-soluble polyvalent metal The method for producing a gas barrier laminate film according to [10] or [11], wherein the salt is zinc acetate or calcium acetate, and the aqueous resin is an aqueous polyurethane resin or an aqueous polyisocyanate resin.
[13] A coating liquid (A) containing a polycarboxylic acid polymer is applied to at least one surface of a plastic film substrate, and the coating liquid (A) containing a polycarboxylic acid polymer is not subjected to heat treatment. Adjacent to the layer (a) to be formed, a coating solution (B) containing a water-soluble polyvalent metal salt and a water-based resin is applied, and these coating layers are dried to any one of [10] to [12] A gas barrier multilayer film obtained by laminating a plastic film on at least one surface of the gas barrier film through an adhesive layer or directly after obtaining the gas barrier multilayer film in For producing a porous multilayer film.

  In the present invention, a coating solution containing a water-soluble polyvalent metal salt and a water-based resin is applied adjacent to a layer formed from a coating solution containing a polycarboxylic acid-based polymer without heat treatment, and these coatings are applied. The layer is dried, and the polyvalent metal ions in the water-soluble polyvalent metal salt migrate to the layer formed from the coating liquid containing the polycarboxylic acid polymer, so that the polycarboxylic acid polymer is Since the gas barrier laminate film is produced by ionic crosslinking, i) the production line speed is higher than that of the immersion method of the metal ion aqueous solution, and the production can be carried out efficiently and economically. Ii) polycarboxylic acid Migration of polyvalent metal ions to a layer formed from a coating solution containing a polymer is fast even at room temperature, and gas barrier properties are rapidly developed by ionic crosslinking, and iii) water solubility of the polyvalent metal salt Since aqueous resin is used in a high transparency of the product appearance, salt deposition on the product surface is also suppressed, there is no cissing of the coating liquid.

  Although the outline of the present invention has been described above along the basic configuration and features of the present invention as means for solving the problems of the present invention, the embodiments of the invention of the present invention group described above will be described below. The gas barrier laminate film and the production method thereof will be specifically described in detail.

1. Gas Barrier Laminate Film (1) Basic Structure of Laminate Film The main gas barrier laminate film of the present invention is subjected to heat treatment from a coating liquid (A) containing a polycarboxylic acid polymer on at least one surface of a plastic film substrate. A layer formed from the coating liquid (B) containing a water-soluble polyvalent metal salt and a water-based resin is provided adjacent to the layer (a) formed without the coating.
By migration of metal ions in water-soluble polyvalent metal salt to polycarboxylic acid polymer layer, polycarboxylic acid polymer can be cross-linked with each other by polyvalent metal ions without being subjected to high temperature heat treatment. And gas barrier properties are exhibited.
The layer (a) formed from the coating liquid (A) containing the polycarboxylic acid polymer is formed on one surface of the film substrate, but is formed on both surfaces if it is necessary to further improve the gas barrier properties. You can also The water-soluble polyvalent metal salt is applied as a mixed solution with an aqueous resin, so that the water-soluble polyvalent metal is adjacent to the layer (a) formed from the coating liquid (A) containing the polycarboxylic acid polymer. It is formed as a layer (b) formed from a coating liquid (B) containing a salt and an aqueous resin.
The basic layer structure of the gas barrier laminate film is shown as a schematic cross-sectional view in FIGS. 1 and 2, and a layer (b) formed from a coating liquid (B) containing a water-soluble polyvalent metal salt and an aqueous resin. (1 in the figure) is formed adjacent to the layer (a) (2 in the figure) formed from the coating liquid (A) containing a polycarboxylic acid polymer, and the layer (a) is an anchor coat. It is laminated | stacked on a base film (4 in a figure) via the (undercoat) layer (3 in a figure) or directly.

(2) Layer (a) formed from coating solution (A) containing polycarboxylic acid polymer
In the present invention, the layer (a) formed from the coating liquid (A) containing the polycarboxylic acid polymer is coated with the coating liquid (A) containing the polycarboxylic acid polymer and dried. The polycarboxylic acid of the layer (a) is formed in the layer (b), and the polycarboxylic acid in the layer (b) formed from the coating liquid (B) containing the water-soluble polyvalent metal salt and the water-based resin disposed adjacent to the polycarboxylic acid. The carboxyl groups are ionically cross-linked by the valent metal ions, and the gas barrier properties are improved.

i) Polycarboxylic acid-based polymer The number-average molecular weight of the polycarboxylic acid-based polymer is not particularly limited, but is in the range of 2,000 to 10,000,000 from the viewpoint of coating suitability and stability of the coating liquid. More preferably, it is in the range of 5,000 to 4,000,000, and most preferably 20,000 to 1,500,000. At this time, polycarboxylic acid polymers having different molecular weights may be mixed and used.
The polycarboxylic acid-based polymer has an oxygen permeability coefficient of 1,000 cm ³ (STP) · μm / () measured for a single film-like product under dry conditions (30 ° C., relative humidity 0%). m ² · day · MPa) or less, more preferably 500 cm ³ (STP) · μm / (m ² · day · MPa) or less, most preferably 100 cm ³ (STP) · μm / (m ² · day · MPa). )
Here, the oxygen transmission coefficient can be obtained by the following method, for example. When a laminated film in which a polycarboxylic acid polymer layer having a thickness of 1 μm is formed on a plastic film substrate and the oxygen permeability of the used plastic film substrate is known, the oxygen permeability of the laminated film is If the oxygen permeability of the plastic film alone used as the substrate is 1/10 or less, the measured value of the oxygen permeability of the laminated film is regarded as the oxygen permeability of the polycarboxylic acid polymer layer alone. be able to. And since the obtained value is the oxygen permeability of the polycarboxylic acid polymer having a thickness of 1 μm, it can be converted into an oxygen permeability coefficient by multiplying the value by 1 μm.
The oxygen permeability of the film was measured under conditions of a temperature of 30 ° C. and a relative humidity of 0% using an oxygen permeability tester OXTRAN 2/20 manufactured by Modern Control. A measuring method is based on JIS K-7126 B method (isobaric method) and ASTM D3985-81, and a measured value is a unit cm < ³ > (STP) * micrometer / (m < ² > * day * MPa). Here, (STP) means a standard condition (0 ° C. · 1 atm) for defining the volume of oxygen.

ii) Specific Examples of Polycarboxylic Acid Polymers As the polycarboxylic acid polymer used in the present invention, an existing polycarboxylic acid polymer can be used, but an existing polycarboxylic acid polymer is a molecule. A generic term for polymers having two or more carboxyl groups.
Specifically, a polymer of α, β-monoethylenically unsaturated carboxylic acid as a polymerizable monomer, a copolymer of the monomer and another ethylenically unsaturated monomer, and alginic acid Examples thereof include acidic polysaccharides having a carboxyl group in the molecule such as carboxymethylcellulose and pectin.
These polycarboxylic acid polymers can be used alone or as a mixture of at least two polycarboxylic acid polymers.
Here, representative examples of the α, β-monoethylenically unsaturated carboxylic acid include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Further, as the copolymerizable therewith monomers, ethylenically unsaturated carboxylic acid vinyl esters, alkyl acrylates, alkyl methacrylates, alkyl itaconates, acrylonitrile, vinyl chloride, vinylidene chloride, vinyl fluoride, fluoride Vinylidene, styrene, acrylamide and the like are also used. In the case where the polycarboxylic acid polymer is a copolymer of an α, β-monoethylenically unsaturated carboxylic acid and a saturated carboxylic acid vinyl ester such as vinyl acetate, further saponification is performed to obtain a saturated vinyl carboxylate. The ester moiety can be converted to vinyl alcohol for use.

When the polycarboxylic acid polymer used in the present invention is a copolymer of an α, β-monoethylenically unsaturated carboxylic acid and another ethylenically unsaturated monomer, the gas barrier property of the resulting film From the viewpoint of resistance to high temperature steam and hot water, the copolymer composition is preferably such that the α, β-monoethylenically unsaturated carboxylic acid monomer composition is 60 mol% or more. More preferably 80 mol% or more, still more preferably 90 mol% or more, and most preferably 100 mol%, that is, the polycarboxylic acid polymer is a polymer composed only of α, β-monoethylenically unsaturated carboxylic acid. Most preferred.
Further, when the polycarboxylic acid polymer is composed of only α, β-monoethylenically unsaturated carboxylic acid, preferred specific examples thereof are acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, croton. Examples thereof include at least one polymerizable monomer selected from the group consisting of acids, and mixtures thereof. Preferably, a polymer or copolymer obtained by polymerization of at least one polymerizable monomer selected from acrylic acid, methacrylic acid, maleic acid, and itaconic acid, or a mixture thereof can be used. More preferably, polyacrylic acid, polymethacrylic acid, polymaleic acid, polyitaconic acid, and mixtures thereof are used.
In the case where the polycarboxylic acid polymer is an acidic polysaccharide other than the α, β-monoethylenically unsaturated carboxylic acid monomer, for example, alginic acid can be preferably used.

iii) Metal addition to polycarboxylic acid polymer The polycarboxylic acid polymer used in the present invention may be a monovalent alkali metal compound or a polyvalent metal compound.
Examples of the monovalent alkali metal compound added to the polycarboxylic acid polymer include sodium, lithium, potassium, cesium, rubidium, francium oxide, hydroxide, carbonate, inorganic acid salt, and organic acid salt. Can be mentioned. Polyvalent metal compounds include alkaline earth metals such as beryllium, magnesium and calcium, transition metals such as titanium, zirconium, chromium, manganese, iron, copper, cobalt, nickel and zinc, and oxides and hydroxides of aluminum. , Carbonates, inorganic acid salts, organic acid salts, other ammonium complexes, secondary to quaternary amine complexes and their carbonates, organic acid salts, alkyl alkoxides, and the like.
In the case of adding a monovalent alkali metal compound to the polycarboxylic acid polymer, the composition of the monovalent alkali metal compound is based on the carboxyl group of the polycarboxylic acid polymer in terms of coating suitability and coating solution stability. It is preferably 0.01 to 0.35 chemical equivalent.
In the case of adding a polyvalent metal compound to the polycarboxylic acid polymer, the composition of the polyvalent metal compound is 0. 0 with respect to the carboxyl group of the polycarboxylic acid polymer in terms of coating suitability and coating solution stability. It is preferably 05 to 0.25 chemical equivalent.
In addition, when the monovalent alkali metal compound and the polyvalent metal compound are added to the polycarboxylic acid polymer, the composition of the monovalent alkali metal compound is a polyvalent metal with respect to the carboxyl group of the polycarboxylic acid polymer. It is preferably 0.01 to 0.35 chemical equivalent from the viewpoint of compound solubility and gas barrier properties, and the polyvalent metal compound is 0.05 to 0.75 chemical equivalent from the viewpoint of coating solution stability. Is preferred.

iv) Addition of polyalcohol resin to polycarboxylic acid polymer In the present invention, a polyalcohol resin may be added to the polycarboxylic acid polymer. The polyalcohol-based resin used in the present invention is an alcohol-based polymer having two or more hydroxyl groups in the molecule, and includes polyvinyl alcohol, saccharides and starches.
Polyvinyl alcohol preferably has a saponification degree of 95% or more, more preferably 98% or more, and a number average polymerization degree of usually 300 to 1,500.
Monosaccharides, oligosaccharides and polysaccharides are used as the saccharides. These saccharides include sugar alcohols, various substitutes and derivatives, and cyclic oligosaccharides such as cyclodextrins. These saccharides are preferably soluble in water.
Starches are contained in polysaccharides, but starches used in the present invention include raw starches such as wheat starch, corn starch, waxy corn starch, potato starch, tapioca starch, rice starch, and sago starch (unmodified starch). Besides, there are various processed starches. Examples of the modified starch include physically modified starch, enzyme-modified starch, chemically decomposed modified starch, chemically modified starch, and grafted starch obtained by graft polymerization of monomers on starch. Among these starches, processed starch that is soluble in water, such as roasted dextrin and reduced starch saccharified product obtained by alcoholizing the reducing terminal thereof, is preferable. The starches may be hydrated, and these starches can be used alone or in combination of two or more.

v) Coating liquid containing polycarboxylic acid polymer A coating liquid (A) containing a polycarboxylic acid polymer is obtained by dissolving a polycarboxylic acid polymer in a solvent. As the solvent, water or alcohols can be used, but water is preferably used from the viewpoint of environmental burden and the solubility of the polycarboxylic acid polymer.
The proportion of the solvent and the polycarboxylic acid polymer is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 20 parts by mass with respect to 100 parts by mass of the solvent, from the viewpoints of coating suitability and coating solution stability. 1 to 10 parts by mass is preferable.
As described in paragraphs 0025 to 0026, a monovalent alkali metal compound and a polyvalent metal compound, or a polyalcohol resin may be added to the coating liquid (A) containing a polycarboxylic acid polymer.

vi) Thickness of the layer formed from the coating liquid containing the polycarboxylic acid polymer The thickness of the layer (a) formed from the coating liquid (A) containing the polycarboxylic acid polymer is not particularly limited. From the viewpoint of productivity and productivity, it is preferably in the range of 0.01 to 10 μm. More preferably, it is 0.05-5 micrometers, Most preferably, it is the range of 0.05-1 micrometer.

(3) Layer (b) formed from a coating liquid (B) containing a water-soluble polyvalent metal salt and an aqueous resin
i) Action of water-soluble polyvalent metal salt In the present invention, a divalent or higher valent metal salt is used as the polyvalent metal salt, and the surface of the layer in which the metal ion dissolved in the aqueous solution contains a polycarboxylic acid polymer. From the inside to the inside, two or more carboxyl groups of the polycarboxylic acid polymer are ionically crosslinked by ionic bonds.
Due to the ionic crosslinking, the inside of the layer containing the polycarboxylic acid polymer becomes dense, and the permeation of oxygen gas through the layer is suppressed to improve the gas barrier property.

ii) Water-soluble polyvalent metal salt Examples of the metal of the water-soluble polyvalent metal salt include alkaline earth metals such as beryllium, magnesium and calcium, titanium, zirconium, chromium, manganese, iron, cobalt, nickel, copper and zinc. A transition metal, aluminum, etc. can be mentioned.
Examples of the water-soluble polyvalent metal salt in the present invention include inorganic acid salts, organic acid salts, ammonium complexes, secondary to quaternary amine complexes, carbonates, organic acid salts, and alkyl alkoxides of the above metals. . As the inorganic acid salt, chloride, sulfate, and nitrate are preferable, and as the organic acid salt, formate, acetate, oxalate, citrate, and lactate are preferable.
From the viewpoints of gas barrier properties and water solubility, alkaline earth metals and copper, zinc and inorganic acid salts and organic acid salts are more preferably used, and most preferably calcium, zinc chloride, acetate, and lactic acid. Salt is used.
In particular, in the present invention, the water-soluble polyvalent metal salt has a solubility in water at 25 ° C. of 5 g / 100 g of water or more from the viewpoint of the necessity of mixing with an aqueous resin described later and the gas barrier property of the film. Preferably used. The range is more preferably 7 g / 100 g or more, most preferably 10 g / 100 g or more. If the solubility in water is low, a uniform coating solution containing sufficient metal ions cannot be obtained as a coating solution (B) containing a water-soluble polyvalent metal salt and an aqueous resin, and the coating solution (B) is applied. The gas barrier property of the gas barrier laminate film obtained in this way becomes insufficient.
These water-soluble polyvalent metal salts can be used alone or as a mixture of at least two water-soluble metal salts.

iii) Action of aqueous resin In the present invention, in order to form a layer containing a water-soluble polyvalent metal salt, a mixed aqueous solution of the water-soluble polyvalent metal salt and an aqueous resin as an incidental resin is used.
Since an aqueous resin is used in an aqueous solution of a water-soluble polyvalent metal salt, the appearance of the product is highly transparent, salt precipitation on the product surface is suppressed, and no repelling of the coating solution occurs.
The reactivity between the water-based resin and the polycarboxylic acid-based polymer is absent or gradual, and the water-based resin needs to proceed the reaction between the polyvalent metal salt and the polycarboxylic acid-based polymer moderately and promptly. is there. Thereby, the gel production | generation by reaction of a polycarboxylic acid type polymer and a polyvalent metal salt can be suppressed, and a coating surface can be kept favorable.
These aqueous resins are capable of forming a film having hot water resistance after the resin is cured.

iv) Type of water-based resin As the water-based resin, any resin can be used as long as a water-soluble polyvalent metal salt and a water-based resin are mixed and a stable coating liquid can be obtained without forming a precipitate.
As the type of water-based resin, water-based polyurethane resin, water-based isocyanate resin, water-based acrylic resin, water-based alkyd resin, water-based fluororesin and oxazoline resin are preferably used.
Specifically, examples of the water-based polyurethane resin include emulsion-type polyurethane resin, water-based urethane resin composed of water-based polyester polyol and water-dispersed polyisocyanate, and the like. Examples of water-based acrylic resins include thermosetting acrylic emulsions and self-crosslinking acrylic emulsions. Also, a curing agent such as polyisocyanate can be used.
On the surface of a layer containing a water-soluble polyvalent metal salt and an aqueous resin, the polyvalent metal salt may be deposited in the order of nm (nanometer), but the aqueous resin fills the space between the precipitates, Is estimated to be smooth.

v) Coating liquid containing water-soluble polyvalent metal salt and aqueous resin The coating liquid (B) containing water-soluble polyvalent metal salt and aqueous resin is obtained by dissolving water-soluble polyvalent metal salt and aqueous resin in a solvent. Can do. As the solvent, water or alcohols can be used, but water is preferably used from the viewpoint of environmental burden and the solubility of the polyvalent metal salt.
The ratio of the water-soluble polyvalent metal salt in the coating liquid is preferably 5 to 30 parts by mass, more preferably 7 to 25 parts by mass with respect to 100 parts by mass of the coating liquid from the viewpoint of gas barrier properties and solubility of the polyvalent metal salt. Preferably, 8-20 mass parts is the most preferable.
The ratio of the water-based resin in the coating liquid is preferably 0.1 to 70 parts by mass, more preferably 0.5 to 65 parts by mass with respect to 100 parts by mass of the coating liquid from the viewpoint of gas barrier properties and coating suitability. 60 parts by mass is most preferred.
The coating liquid (B) containing a water-soluble polyvalent metal salt and a water-based resin can be used after adding a monovalent metal. By adding a monovalent metal, the ionization behavior of the polycarboxylic acid polymer can be controlled, and more effective crosslinking with metal ions may be possible.

vi) Thickness of the layer formed from the coating liquid containing the water-soluble polyvalent metal salt and the aqueous resin The thickness of the layer (b) formed from the coating liquid (B) containing the water-soluble polyvalent metal salt and the aqueous resin is: Although not particularly limited, it is preferably in the range of 0.01 to 10 μm from the viewpoint of gas barrier properties and productivity. More preferably, it is 0.05-5 micrometers, Most preferably, it is the range of 0.05-1 micrometer.

(4) Film base material i) Form of use In the present invention, the film base material is not particularly limited, but a transparent thermoplastic resin is preferably used.
Specifically, a film-like base material formed by general-purpose means such as extrusion molding, injection molding, blow molding, stretch blow molding, or cast molding is used. The film substrate may be composed of a single layer, or may be composed of a plurality of layers by lamination such as simultaneous melt extrusion.
The form is basically a film form, but may be a sheet form or a container form such as a bottle or a tray.
Since the present invention is not subjected to heat treatment at a high temperature, there is no fear of curling, shrinking, deformation or alteration of the film substrate, and a film substrate having low heat resistance can also be used.

ii) Types of resin The thermoplastic resin constituting the plastic film substrate includes olefin resin, polyester, polyamide, styrene (co) polymer, vinyl chloride (co) polymer, acrylic (co) polymer. Various materials such as polycarbonate can be used. Olefin resins, polyesters, and polyamides are preferable from the viewpoint of economy and physical properties of packaging materials.
As the olefin resin, various polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-butene-copolymer and the like are preferably used, and as the polyester, polyethylene terephthalate, polybutylene terephthalate, polyethylene terephthalate / isophthalate are used. As the polyamide, nylon 6, nylon 6,6, nylon 6,10, metaxylylene adipamide polymer or the like is used.
These thermoplastic resins may be used alone or in combination of two or more.

(5) Anchor coat layer In the present invention, the anchor coat layer is an undercoat layer as a layer (a) containing a film substrate and a polycarboxylic acid polymer, and a layer containing a water-soluble polyvalent metal salt and an aqueous resin. In order to improve the bondability with (b), it is preferably used but not essential.

i) Types of anchor coating agents As materials for the anchor coating layer, various polymer materials such as urethane, polyester, acrylic, and epoxy are used, and urethane coating agents containing a polyol component and a polyisocyanate are used. Is preferred.
The polyol component in the urethane-based coating agent is preferably a polyester-based polyol, and examples of the polyester-based polyol include polyester-based polyols obtained by reacting a polyvalent carboxylic acid or the like with glycols. As polyisocyanates, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate Etc. are exemplified.

ii) Thickness of anchor coat layer The thickness of the anchor coat layer can be appropriately determined, but is preferably 0.01 to 10 μm, more preferably 0.05 to 5 μm, and particularly preferably 0. 0.05 to 1 μm. If the thickness is less than 0.01 μm, the bondability is insufficient, and if it exceeds 10 μm, the productivity decreases.

(6) Additives In the present invention, physical properties are further enhanced or various physical properties are added to a coating liquid containing a film substrate or a polycarboxylic acid polymer and a coating liquid containing a water-soluble polyvalent metal salt and an aqueous resin. Ordinary additives may be added for the purpose. As various additives, for example, antioxidants, dyes, pigments, heat stabilizers, light stabilizers, fillers, and the like can be used.

(7) Performance of gas barrier laminate film The gas barrier laminate film of the present invention is a film excellent in gas barrier properties such as oxygen even under high humidity. Therefore, the oxygen permeability of the gas barrier laminate film of the present invention at 20 ° C. and 80% relative humidity is preferably 1,000 cm ³ (STP) / (m ² · day · MPa) or less, more preferably 500 cm ³ (STP). ) / (M ² · day · MPa) or less, more preferably 100 cm ³ (STP) · / (m ² · day · MPa) or less. Any film having such a value of oxygen permeability can be suitably used as a film for a gas barrier material.
The oxygen permeability of the film was measured using an oxygen permeability tester OXTRAN 2/20 manufactured by Modern Control under the conditions of a temperature of 20 ° C. and a relative humidity of 80%. The measuring method is based on JIS K-7126 B method (isobaric method) and ASTM D3985-81, and the measured value is unit cm ³ (STP) / (m ² · day · MPa).

(8) Use of gas barrier laminate film The gas barrier laminate film of the present invention is basically used as a gas barrier packaging film for foods and drinks, cosmetics, pharmaceuticals, electronic devices, precision instruments, etc. It is also useful as a packaging material for various types of packaging materials such as sheets and pouches, and particularly for gas barrier heat sterilization by trays and cups.

2. Production of Gas Barrier Laminate Film (1) Basic Production Method of Gas Barrier Laminate Film The production method of the gas barrier laminate film as the second main component of the present invention is applied to at least one surface of the plastic film substrate as necessary. In a laminated film formed by applying and drying a coating liquid (A) containing a polycarboxylic acid polymer on both sides, a layer formed without heat treatment from the coating liquid (A) containing a polycarboxylic acid polymer Adjacent to (a), a coating liquid (B) containing a water-soluble polyvalent metal salt and an aqueous resin is applied, and these coating layers are dried without heat treatment, so that the water-soluble polyvalent metal salt and the aqueous system are dried. The basic constitution is that the polycarboxylic acid polymer is ionically cross-linked at the carboxyl group by the intercalation of polyvalent metal ions in the layer (b) formed from the coating liquid (B) containing the resin.

(2) Manufacturing Process The manufacturing process of the present invention is illustrated in FIG. 3 as a schematic diagram of the manufacturing process. Explaining along FIG. 3, the film substrate 5 wound in a roll shape is continuously fed out, and if necessary, an anchor coat agent is applied by a coater 6 to form an anchor coat layer, and then passed through a drying furnace 7. The solvent is removed by drying, and then the coating liquid (A) containing the polycarboxylic acid polymer is applied by the coater 8 to form the layer (a) from the coating liquid (A) containing the polycarboxylic acid polymer, The solvent is removed by passing through a drying oven 7 again, and then the coating liquid (B) containing the water-soluble polyvalent metal salt and the aqueous resin is applied by the coater 9, and the water-soluble polyvalent metal salt and the aqueous resin are applied. A layer (b) is formed from the coating liquid (B) that is included, and is further dried by passing through a drying oven 7 to remove the solvent, and a layer containing an anchor coat layer and a polycarboxylic acid polymer on the film substrate, and water Layer containing functional polyvalent metal salt and water-based resin As gas barrier laminate film 10 that is, the winding on winding roll product.

(3) Application and drying of anchor coating agent i) Application of anchor coating agent The anchor coating layer is made of various polymer materials such as urethane-based, polyester-based, acrylic-based, and epoxy-based when dried, and more preferably 0.01 to 10 μm. It is applied to a thickness of 0.05 to 5 μm, particularly preferably 0.05 to 1 μm.
A coating device is not specifically limited, Various normal coating devices are used. A dipping method, a spray method, a coater or a printing machine is used as a method or apparatus for applying a solution comprising an anchor coating agent and a solvent onto a substrate. Coating methods include direct gravure method, reverse gravure method, kiss reverse method, offset gravure method, etc. Can be used.
In order to further improve the bondability, a physical preliminary treatment such as corona discharge, plasma treatment, or intro treatment may be applied to the coated surface of the film base in advance.

ii) Drying Drying is carried out in a drying furnace, and the drying conditions may be in a range where the solvent can be removed. For example, the drying temperature may be in the range of 20 to 160 ° C., and the drying time is 0.5 seconds. It is preferable that it is 10 minutes or less.
The method of evaporating and drying the solvent after applying the solution comprising the anchor coating agent and the solvent onto the substrate is not limited to a drying furnace. A method using natural drying, a method of drying in an oven set to a predetermined temperature, and a dryer attached to the coater, for example, an arch dryer, a floating dryer, a drum dryer, an infrared dryer and the like can also be used.

(4) Application of coating liquid (A) containing polycarboxylic acid polymer and drying i) Application of coating liquid (A) containing polycarboxylic acid polymer Including the polycarboxylic acid polymer described in paragraph 0027 The coating liquid (A) preferably has a dry thickness in the range of 0.01 to 10 μm. More preferably, it is applied in the range of 0.05 to 5 μm, particularly preferably 0.05 to 1 μm.
A coating device is not specifically limited, Various normal coating devices are used. As a specific method or apparatus, a dipping method, a spray method, a coater or a printing machine is used. Coating methods include direct gravure method, reverse gravure method, kiss reverse method, offset gravure method, etc. Can be used.

ii) Drying of the coating liquid (A) containing the polycarboxylic acid polymer The drying is preferably carried in a drying furnace, and the drying conditions are not particularly limited because they depend on the resin or solvent used. A method using natural drying, a method of drying in an oven set to a predetermined temperature, and a dryer attached to the coater, for example, an arch dryer, a floating dryer, a drum dryer, an infrared dryer and the like can also be used.
The drying temperature after applying the coating liquid (A) containing the polycarboxylic acid polymer may be a temperature at which the solvent can be removed, and is preferably in the range of 20 to 160 ° C. More preferably, it is the range of 30-150 degreeC, Most preferably, it is the range of 45-130 degreeC. If it is less than 20 ° C., it takes too much time for drying, which is not suitable for industrial production. When the temperature exceeds 160 ° C., the base material is limited such that a heat-resistant base material must be used.

Similarly to the above, the drying time is not particularly limited, but is preferably 1 second or more and 60 minutes or less. More preferably, it is 1 second or more and 20 minutes or less, and most preferably 3 seconds or more and 10 minutes or less. If it is less than 1 second, solvent removal of the coating liquid (A) containing the polycarboxylic acid polymer is insufficient, and if it exceeds 60 minutes, it takes too much processing time, which is not suitable for industrial production.
In particular, in the present invention, the optimum condition for drying the coating liquid (A) containing the polycarboxylic acid polymer is that the carboxyl group in the polycarboxylic acid is a dehydration reaction, a decarbonylation reaction, or a polyalcohol resin. This is a condition that does not cause the esterification reaction. If a dehydration reaction, decarbonylation reaction, or esterification reaction occurs during the drying process, the water resistance of the layer containing the polycarboxylic acid polymer will increase too much, and the migration of polyvalent metal ions will take a long time. Moreover, in order to shorten the processing time, it is necessary to increase the processing temperature, which is not preferable.

  From the above, the drying temperature that does not give the above water resistance is preferably in the range of 45 to 100 ° C. In the drying temperature range of 45 to 100 ° C., the drying time is not particularly limited, but is preferably within 10 minutes in consideration of industrial production. More preferably, it is within 5 minutes, and most preferably within 3 minutes.

(5) Application and drying of coating liquid (B) containing water-soluble polyvalent metal salt and aqueous resin In the present invention, the layer (a) formed from the coating liquid (A) containing a polycarboxylic acid polymer is used. A layer (b) formed from a coating liquid (B) containing a water-soluble polyvalent metal salt and a water-based resin is disposed so as to be adjacent to each other. When the coating liquid (B) is applied so as to be in contact with the layer (a), the carboxyl group is quickly cross-linked by the polyvalent metal ions, and high gas barrier properties are exhibited.

i) Application of coating liquid (B) containing water-soluble polyvalent metal salt and water-based resin The coating liquid (B) containing the water-soluble polyvalent metal salt and water-based resin described in paragraph 0033 has a thickness of 0 when dried. It is preferably in the range of 0.01 to 10 μm. More preferably, it is applied in a range of 0.05 to 5 μm, particularly preferably 0.05 to 1 μm.
A coating device is not specifically limited, Various normal coating devices are used. As a specific method or apparatus, a coater or a printing machine is used. As the coating method, direct gravure method, reverse gravure method, kiss reverse method, offset gravure method, etc., as the coater, gravure coater, reverse gravure coater, air knife coater, bar coater, comma coater, die coater, etc. can be used it can.

ii) Drying of coating liquid (B) containing water-soluble polyvalent metal salt and water-based resin Drying is preferably carried out by transporting in a drying furnace, and the drying conditions are not particularly limited because they depend on the resin or solvent used. A method using natural drying, a method of drying in an oven set to a predetermined temperature, and a dryer attached to the coater, for example, an arch dryer, a floating dryer, a drum dryer, an infrared dryer and the like can also be used.
The drying temperature after application may be any temperature that can remove the solvent, and is preferably in the range of 20 to 160 ° C. More preferably, it is the range of 30-150 degreeC, Most preferably, it is the range of 45-130 degreeC. If it is less than 20 ° C., it takes too much time for drying, which is not suitable for industrial production. When the temperature exceeds 160 ° C., the base material is limited such that a heat-resistant base material must be used.

  Similarly to the above, the drying time is not particularly limited, but is preferably 1 second or more and 60 minutes or less. More preferably, it is 1 second or more and 20 minutes or less, and most preferably 3 seconds or more and 10 minutes or less. If it is less than 1 second, solvent removal is insufficient, and if it exceeds 60 minutes, it takes too much processing time, which is not suitable for industrial production.

3. Layer constitution of gas barrier laminate film The gas barrier laminate film of the present invention comprises a layer (a) formed from a coating liquid (A) containing a polycarboxylic acid polymer on at least one surface of a plastic film substrate, and a water-soluble layer. The layer (b) formed from the coating liquid (B) containing the functional polyvalent metal salt and the water-based resin is disposed adjacently. As the lamination form of these layers, from the one side of the base film, (a) / (b), (b) / (a), (a) / (b) / (a), (b) The aspect laminated | stacked in the order of / (a) / (b) can be illustrated.
These structural units consisting of the layer (a) and the layer (b) are arranged on one side or both sides of the base film. An anchor coat layer is preferably provided between the base film and these layers in order to improve the adhesion between the base film and these layers, but it is not essential.

4). Gas barrier multilayer film The gas barrier multilayer film of the present invention has a structure in which a plastic film is further laminated on at least one surface of the gas barrier laminate film described above.
Such a plastic film is intended for imparting strength improvement, sealing properties, easy opening of seals, design properties, light shielding properties, moisture resistance, etc., and is appropriately selected according to the purpose of use. . Although the material is not particularly limited, the same material as the plastic in the base film described in Paragraph 0036 is used. Such plastic films can be used singly or by laminating a plurality of them.
As a method of laminating the plastic film, it can be laminated via an adhesive or directly. Specifically, as a laminating method, a normal laminating method can be suitably used, and a dry laminating method, a wet laminating method, or an extrusion laminating method can be exemplified.

  In the following, while disclosing examples of the present invention and contrasting comparative examples, the present invention will be illustrated in more detail, the structure of the present invention will be further clarified, and each requirement of the structure of the present invention will be rationalized. Demonstrate gender and significance and excellence over the prior art.

[Methods for evaluating various physical properties of laminated film]
1. Evaluation of repellency at the time of coating in the coating liquid (B) containing a water-soluble polyvalent metal salt and an aqueous resin A coating liquid containing a polycarboxylic acid polymer on the anchor coat layer formed on the base film ( A film in which the layer (a) was formed from A) was produced. Moreover, the film which formed the layer (a) directly from the coating liquid (A) containing a polycarboxylic acid-type polymer was formed, without forming an anchor coat layer on a base film.
Further, a coating liquid (B) containing a water-soluble polyvalent metal salt and an aqueous resin was applied on the layer (a), and the state of the coated surface at that time was observed.
Those in which the coating liquid (B) was applied satisfactorily were accepted, and those in which film repelling was observed were evaluated as unacceptable.
2. Appearance evaluation In the same manner as described above, an anchor coat layer was formed on a base film, and a film in which a layer (a) was formed from a coating liquid (A) containing a polycarboxylic acid polymer was produced.
Moreover, the film which formed the layer (a) directly from the coating liquid (A) containing a polycarboxylic acid-type polymer was formed, without forming an anchor coat layer on a base film.
Further, a coating liquid (B) containing a water-soluble polyvalent metal salt and an aqueous resin was applied on the layer (a), and the appearance of the coated surface at that time was observed.
A transparent film after drying was regarded as good, and a film where salt precipitation or whitening occurred was evaluated as poor.
3. Haze after immersion in water In order to evaluate the water resistance of the coating layer, a gas barrier laminate film was prepared and then left in cold water at 20 ° C. for 24 hours, and the haze of this film was measured. The haze was measured using a turbidimeter NDH2000 manufactured by Nippon Denka Kogyo Co., Ltd. The measuring method was based on JIS K7136 (Plastic-Determination of haze of transparent material).
4). Film Oxygen Permeation After Water Soaking In order to evaluate the water resistance of the coating layer, a gas barrier laminate film was prepared, and then left in cold water at 20 ° C. for 10 minutes, and the oxygen permeability of this film was measured.
The oxygen permeability was measured under the conditions of a temperature of 20 ° C. and a relative humidity of 80% using an oxygen permeability tester OXTRAN 2/20 manufactured by Modern Control. The measuring method is based on JIS K-7126 B method (isobaric method) and ASTM D3985-81, and the measured value is unit cm ³ (STP) / (m ² · day · MPa). Here, (STP) means a standard condition (0 ° C. · 1 atm) for defining the volume of oxygen.
5). Appearance evaluation after retorting A gas barrier laminate film was provided with a sealing layer to form a multilayer film, which was then formed into a bag shape to prepare a pouch. The pouch was filled with water and retorted at 121 ° C. for 40 minutes. The retort method is a hot water storage type retort. The appearance of the pouch after the retort was evaluated, and a pouch with a good pouch state was judged as “good”, and when a problem such as occurrence of peeling (delamination) or whitening occurred was judged as “bad”.
6). Film oxygen permeability after retorting A pouch was made of a gas barrier multilayer film. The pouch was filled with water and retorted at 121 ° C. for 40 minutes. The retort method is a hot water storage type retort. The oxygen permeability of the film after retorting was based on the above method 4.

[Composition of coating liquid]
Each composition of coating liquid (A) containing polycarboxylic acid polymer

Each composition of coating liquid (B) containing water-soluble polyvalent metal salt and water-based resin

[Coating liquid 1]
A polyacrylic acid aqueous solution (manufactured by Toagosei Co., Ltd., polyacrylic acid (PAA) aqueous solution Aron A-10H, number average molecular weight 200,000, 25% by weight concentration) was diluted with distilled water, and a 5% by weight aqueous solution of polyacrylic acid (coating) Liquid 1) was prepared.
[Coating liquid 2]
In said coating liquid 1, 0.02 chemical equivalent sodium hydroxide was added as an alkali metal with respect to the carboxyl group of polyacrylic acid, and it was made to melt | dissolve completely, and the coating liquid 2 was prepared.
[Coating liquid 3]
In the above coating solution 1, 0.2 chemical equivalent of zinc oxide was added to the carboxyl group of polyacrylic acid and stirred at room temperature for 2 days to prepare coating solution 3.
[Coating liquid 4]
In the above coating solution 1, 0.1 chemical equivalent of sodium hydroxide as alkali metal and 0.3 chemical equivalent of zinc oxide as polyvalent metal were added to the carboxyl group of polyacrylic acid and stirred at room temperature for 2 days. Coating solution 4 was prepared.
[Coating fluid 5]
Zinc acetate (Zinc acetate manufactured by Wako Pure Chemical Industries, Ltd .: solubility 40 g / water 100 g · 25 ° C.) was diluted with distilled water to prepare a 20 wt% aqueous solution of zinc acetate. Emulsion-type water-based polyurethane resin (acrylate copolymer / hexamethylene diisocyanate (main agent Liofol A6018-21 / curing agent Hardener UR58889-21) manufactured by Henkel) was mixed at a ratio of main agent / curing agent (weight ratio) = 50/4, and water-based resin mixed A liquid was prepared. A coating solution 5 was prepared by mixing a 20 wt% aqueous zinc acetate solution and an aqueous resin mixture at a weight ratio of 50/50.
[Coating liquid 6]
Calcium acetate (calcium acetate manufactured by Wako Pure Chemical Industries, Ltd .: solubility 35 g / water 100 g, 25 ° C.) was diluted with distilled water to prepare a 20 wt% aqueous solution of calcium acetate. Emulsion-type water-based polyurethane resin (acrylate copolymer / hexamethylene diisocyanate (main agent Liofol A6018-21 / curing agent Hardener UR 5889-21) manufactured by Henkel) was mixed at a ratio of main agent / curing agent (weight ratio) = 50/4, and water-based resin mixed A liquid was prepared. A 20 wt% calcium acetate aqueous solution and an aqueous resin mixture were mixed at a weight ratio of 50/50 to prepare a coating solution 6.
[Coating liquid 7]
Zinc acetate (Zinc acetate manufactured by Wako Pure Chemical Industries, Ltd .: solubility 40 g / water 100 g · 25 ° C.) was diluted with distilled water to prepare a 20 wt% aqueous solution of zinc acetate. An oxazoline group-containing aqueous resin (Epocross, manufactured by Nippon Shokubai Co., Ltd.) was mixed with this zinc acetate aqueous solution at a weight ratio of 50/50 with a 20% by weight zinc acetate aqueous solution to prepare a coating solution 7.
[Coating liquid 8]
Zinc acetate (Zinc acetate manufactured by Wako Pure Chemical Industries, Ltd .: solubility 40 g / water 100 g · 25 ° C.) was diluted with distilled water to prepare a 1 wt% aqueous solution of zinc acetate. Emulsion-type water-based polyurethane resin (acrylate copolymer / hexamethylene diisocyanate (main agent Liofol A6018-21 / hardener Hardener UR5889-21) manufactured by Henkel) was mixed at a ratio of main agent / hardener (weight ratio) = 50/4, and water-based resin mixed A liquid was prepared. A 1 wt% aqueous zinc acetate solution and an aqueous resin mixture were mixed at a weight ratio of 50/50 to prepare a coating solution 8.
[Coating liquid 9]
Zinc acetate (Zinc acetate manufactured by Wako Pure Chemical Industries, Ltd .: solubility 40 g / water 100 g · 25 ° C.) was diluted with distilled water to prepare a 10 wt% aqueous solution of zinc acetate. Emulsion-type water-based polyurethane resin (acrylate copolymer / hexamethylene diisocyanate (main agent Liofol A6018-21 / hardener Hardener UR5889-21) manufactured by Henkel) was mixed at a ratio of main agent / hardener (weight ratio) = 50/4, and water-based resin mixed A liquid was prepared. A 10 wt% aqueous zinc acetate solution and an aqueous resin mixture were mixed at a weight ratio of 99.9 / 0.1 to prepare a coating solution 9.
[Coating liquid 10]
A zinc oxide fine particle toluene dispersion (Zinc oxide dispersion paint ZR133, manufactured by Sumitomo Osaka Cement Co., Ltd.) was used as the coating liquid 10. (For reference, the solubility of zinc oxide in water is 0.042 mg / water 100 g · 18 ° C.)

[Performance evaluation of gas barrier film]
Example 1
On a corona-treated surface of a biaxially stretched polyethylene terephthalate film (Toray Co., Ltd. Lumirror P-60, 12 μm thick, inner corona treatment, hereinafter referred to as “PET”), a bar coater (K303PROFER manufactured by RK PRINT-COAT INSTRUMENT) was applied. A commercially available adhesive for anchor coat (Dick Dry LX747 hardener KX75 solvent: ethyl acetate) manufactured by Dainippon Ink & Chemicals, Inc. was applied and dried. The thickness of the obtained anchor coat layer was 0.1 μm. Next, the coating liquid 1 was applied onto the anchor coat layer as a coating liquid (A) containing a polycarboxylic acid polymer using the bar coater and dried. The thickness of this coating layer was 0.3 μm. Further, the coating liquid 5 is applied as a coating liquid (B) containing a water-soluble polyvalent metal salt and an aqueous resin on the layer formed from the coating liquid (A) containing the dried polycarboxylic acid polymer. Used to coat and dry. The thickness of this coating layer was 0.3 μm. Thus, [PET (12 μm) / anchor coat layer (0.1 μm) / layer containing polycarboxylic acid polymer (0.3 μm) / (layer containing water-soluble polyvalent metal salt and aqueous resin (0.3 μm) ] Was formed.
(Example 2)
The same operation as in Example 1 was performed except that the anchor coat layer was omitted.
(Example 3)
It implemented similarly to Example 1 except having used the coating liquid 2 as a coating liquid (A) containing a polycarboxylic acid-type polymer.
Example 4
It implemented similarly to Example 1 except having used the coating liquid 3 as a coating liquid (A) containing a polycarboxylic acid-type polymer.
(Example 5)
It implemented similarly to Example 1 except having used the coating liquid 4 as a coating liquid (A) containing a polycarboxylic acid-type polymer.
(Example 6)
Biaxially stretched 6 nylon film as substrate (Emblem ON by Unitika Ltd.)
BC 15 μm thick Internal corona treatment; hereinafter referred to as “OPA”. ) Was carried out in the same manner as in Example 1 except that.
(Example 7)
The same as in Example 1 except that the coating liquid 2 was used as the coating liquid (A) containing the polycarboxylic acid polymer, and the coating liquid 6 was used as the coating liquid (B) containing the water-soluble polyvalent metal salt and the water-based resin. Implemented.
(Example 8)
The same as Example 1 except that the coating liquid 2 was used as the coating liquid (A) containing the polycarboxylic acid-based polymer and the coating liquid 7 was used as the coating liquid (B) containing the water-soluble polyvalent metal salt and the water-based resin. Implemented.

(Comparative Example 1)
It implemented similarly to Example 1 except having used the coating liquid 8 as a coating liquid (B) containing water-soluble polyvalent metal salt and aqueous resin.
(Comparative Example 2)
It implemented similarly to Example 2 except having used the coating liquid 8 as a coating liquid (B) containing water-soluble polyvalent metal salt and aqueous resin.
(Comparative Example 3)
It carried out similarly to the comparative example 1 except having used the coating liquid 2 as a coating liquid (A) containing a polycarboxylic acid-type polymer.
(Comparative Example 4)
It carried out similarly to the comparative example 1 except having used the coating liquid 9 as a coating liquid (B) containing water-soluble polyvalent metal salt and aqueous resin.
(Comparative Example 5)
The same as Comparative Example 3, except that the biaxially stretched 6 nylon film used in Example 6 was used as the substrate, and the coating liquid 9 was used as the coating liquid (B) containing the water-soluble polyvalent metal salt and the aqueous resin. Implemented.
(Comparative Example 6)
It implemented similarly to the comparative example 1 except having used the coating liquid 10 as a coating liquid (B) containing water-soluble polyvalent metal salt and aqueous resin.
(Comparative Example 7)
The same operation as in Example 1 was carried out except that the coating liquid (B) containing a water-soluble polyvalent metal salt and an aqueous resin was not applied.

[Performance evaluation of gas barrier multilayer film]
Example 9
Using a bar coater (K303PROFER manufactured by RK PRINT-COAT INSTRUMENT) on the corona-treated surface of a biaxially stretched polyethylene terephthalate film (PET manufactured by Toray Industries, Inc.), a commercially available adhesive for anchor coat (Dainippon Ink & Chemicals, Inc.) Co., Ltd. Dick Dry LX747 curing agent KX75 solvent: ethyl acetate) was applied and dried. The thickness of the obtained anchor coat layer was 0.1 μm. Next, the coating liquid 1 was applied as a coating liquid (A) containing a polycarboxylic acid polymer on the anchor coat layer using the bar coater and dried. The thickness of this coating layer was 0.3 μm. Further, on the layer formed from the coating liquid (A) containing the dried polycarboxylic acid polymer, the coating liquid 5 is used as the coating liquid (B) containing the water-soluble polyvalent metal and the water-based resin. Applied and dried. The thickness of this coating layer was 0.3 μm. Thus, [PET (12 μm) / anchor coat layer (0.1 μm) / layer containing polycarboxylic acid polymer (0.3 μm) / layer containing water-soluble polyvalent metal salt and water-based resin (0.3 μm)] A gas barrier laminate film was formed. Further, a urethane adhesive (TM250 / curing agent CAT-RT86 solvent: ethyl acetate) manufactured by Toyo Morton Co., Ltd. was applied on the coating layer, and a polypropylene film (Toray Industries, Inc. Treffan NO ZK93K, thickness 60 μm or less). , “CPP”) was laminated to obtain a gas barrier multilayer film.

(Example 10)
Using a bar coater (K303PROFER manufactured by RK PRINT-COAT INSTRUMENT) on the corona-treated surface of a biaxially stretched polyethylene terephthalate film (PET manufactured by Toray Industries, Inc.), a commercially available adhesive for anchor coat (Dainippon Ink & Chemicals, Inc.) Co., Ltd. Dick Dry LX747 curing agent KX75 solvent: ethyl acetate) was applied and dried. The thickness of the obtained anchor coat layer was 0.1 μm. Next, the coating liquid 1 was applied as a coating liquid (A) containing a polycarboxylic acid polymer on the anchor coat layer using the bar coater and dried. The thickness of this coating layer was 0.3 μm. Further, on the layer formed from the coating liquid (A) containing the dried polycarboxylic acid polymer, the coating liquid 5 is used as the coating liquid (B) containing the water-soluble polyvalent metal and the water-based resin. Applied and dried. The thickness of this coating layer was 0.3 μm. Thus, [PET (12 μm) / anchor coat layer (0.1 μm) / layer containing polycarboxylic acid polymer (0.3 μm) / layer containing water-soluble polyvalent metal salt and water-based resin (0.3 μm)] The gas barrier film was formed. Further, a urethane adhesive (TM250 / curing agent CAT-RT86 solvent: ethyl acetate) manufactured by Toyo Morton Co., Ltd. was applied on the coating layer, and corona treatment of the biaxially stretched 6 nylon film used in Example 6 was performed. Laminated to the surface. Furthermore, the urethane adhesive was applied thereon, and an unstretched polypropylene film (CPP manufactured by Toray Industries, Inc.) was laminated to obtain a gas barrier multilayer film.
(Example 11)
Unstretched linear low-density polyethylene film (Tosero Co., Ltd. T instead of CPP
UX-TCS thickness 50 μm: hereinafter referred to as “LLDPE”. ) Was used in the same manner as in Example 10.

(Comparative Example 8)
It implemented similarly to Example 9 except having used what was produced in the comparative example 1 as a gas-barrier laminated | multilayer film.
(Comparative Example 9)
It implemented similarly to Example 11 except having used what was produced in the comparative example 1 as a gas-barrier laminated | multilayer film.
(Comparative Example 10)
It implemented similarly to Example 10 except having used what was produced in the comparative example 2 as a gas-barrier laminated | multilayer film.
(Comparative Example 11)
It implemented similarly to Example 10 except having used what was produced in the comparative example 4 as a gas-barrier laminated | multilayer film.
(Comparative Example 12)
It implemented similarly to Example 10 except having used what was produced in the comparative example 7 as a gas-barrier laminated | multilayer film.

[Consideration of results of Examples and Comparative Examples]
By contrasting Examples 1 to 8 and Comparative Examples 1 to 7 in Tables 1 to 3, the gas barrier laminate film of the present invention has excellent gas barrier properties, high transparency (low haze value), and coating. It is clear that the properties and the appearance are good, but in Comparative Examples 1 to 7 that do not satisfy the requirements of the configuration of the present invention, the gas barrier properties and other performances are inferior.
Specifically, in Comparative Examples 1 to 3, the amount of zinc acetate used is too small, and the oxygen permeability after water immersion is too high. In Comparative Examples 4 and 5, since the amount of water-based resin used is too small and hardly used, the coatability and product appearance are poor, and the oxygen permeability after water immersion is too high. In Comparative Example 6, since an inorganic metal compound (zinc oxide) is used and no water-based resin is used, the transparency after water immersion is low, and the oxygen permeability after water immersion is high. In Comparative Example 7, the layer (b) composed of the coating liquid (B) containing a water-soluble polyvalent metal and an aqueous resin is not formed by coating, and naturally the oxygen permeability after water immersion is too high.

In the performance evaluation after retorting in Table 4, in Examples 9 to 11, the appearance after retorting and the film oxygen permeability after retorting are also good.
In Comparative Examples 8 to 11, since the amount of zinc acetate and the amount of aqueous resin are too small or not used, the appearance after retorting and the film oxygen permeability after retorting are inferior. In Comparative Example 12, since the layer containing the water-soluble polyvalent metal and the water-based resin is not formed by coating, the appearance after retorting and the film oxygen permeability after retorting are inferior.

  From the comparison and consideration of each of the above examples and comparative examples, it is clarified that the configuration of the present invention has sufficient rationality and significance and has superiority to the prior art.

It is a cross-sectional schematic diagram which illustrates the layer structure of the gas barrier laminated film of this invention. It is a cross-sectional schematic diagram which illustrates the layer structure of the gas barrier laminated film of this invention. It is a schematic diagram which illustrates the manufacturing process of the gas barrier laminated film of this invention.

Explanation of symbols

1: Layer (b) formed from a coating liquid (B) containing a water-soluble polyvalent metal salt and an aqueous resin
2: Layer (a) formed from the coating liquid (A) containing a polycarboxylic acid polymer
3: Anchor coat layer 4: Base film 5: Unwinding part of base film 6: Coating part of anchor coat layer 7: Drying furnace
8: Coating part of coating liquid (A) containing polycarboxylic acid polymer 9: Coating part of coating liquid (B) containing water-soluble polyvalent metal salt and water-based resin 10: Winding of gas barrier laminate film Part

Claims (13)

On at least one surface of the plastic film substrate, a layer (a) formed from the coating solution (A) containing a polycarboxylic acid polymer without heat treatment, and a coating containing a water-soluble polyvalent metal salt and an aqueous resin. A layer (b) formed from the liquid (B), and at least the layer (a) formed from the coating liquid (A) and the layer (b) formed from the coating liquid (B) are adjacent to each other A gas barrier laminate film comprising a pair of laminate units. When the polycarboxylic acid polymer is formed into a film alone, the oxygen permeability coefficient at 30 ° C. and 0% relative humidity is 1,000 cm ³ (STP) · μm / (m ² · day · MPa) or less. The gas barrier laminate film according to claim 1, wherein Layer (a) formed without heat treatment from coating liquid (A) containing polycarboxylic acid polymer via anchor coat layer on film base, or water-soluble polyvalent metal salt and water-based resin The layer (b) formed from a coating liquid (B) is laminated | stacked, The gas barrier laminated film described in Claim 1 or Claim 2 characterized by the above-mentioned. The polycarboxylic acid polymer is a homopolymer obtained by polymerizing at least one unsaturated acid selected from the group of acrylic acid, methacrylic acid, maleic acid, and itaconic acid, a copolymer thereof, or a mixture thereof. The gas barrier laminate film according to any one of claims 1 to 3, wherein the gas barrier laminate film is characterized. The water-soluble polyvalent metal salt is calcium or zinc acetate, lactate or chloride, and the water-based resin is any one of water-based polyurethane resin, water-based polyisocyanate resin, water-based acrylic resin, water-based alkyd resin and water-based fluororesin. The gas barrier laminate film according to any one of claims 1 to 4, wherein the water-based resin is an oxazoline group-containing resin. The gas barrier according to any one of claims 1 to 5, wherein the water-soluble polyvalent metal salt is zinc acetate or calcium acetate, and the aqueous resin is an aqueous polyurethane resin or an aqueous polyisocyanate resin. Laminated film. The polyalcohol-based resin is contained in the layer (a) formed from the coating liquid (A) containing the polycarboxylic acid-based polymer without heat treatment. A gas barrier laminate film described in any of the above. A gas barrier laminate film according to any one of claims 1 to 7 and a plastic film laminated on at least one surface of the gas barrier laminate film via an adhesive layer or directly. Gas barrier multilayer film. A packaging material comprising the gas barrier laminate film according to claim 1. The coating liquid (A) containing the polycarboxylic acid polymer is applied to at least one surface of the plastic film substrate, and the coating liquid (A) containing the polycarboxylic acid polymer is formed without heat treatment. A method for producing a gas barrier laminate film, wherein a coating liquid (B) containing a water-soluble polyvalent metal salt and a water-based resin is applied adjacent to the layer (a), and these coating layers are dried. The anchor coating agent is applied to the film substrate and dried, and then the coating liquid (A) containing the polycarboxylic acid polymer is applied, and the coating liquid (A) containing the polycarboxylic acid polymer is not subjected to heat treatment. The coating liquid (B) containing a water-soluble polyvalent metal salt and an aqueous resin is applied adjacent to the layer (a) to be formed, and these coating layers are dried. For producing a laminated gas barrier film. When the polycarboxylic acid polymer is formed into a film alone, the oxygen transmission coefficient at 30 ° C. and 0% relative humidity is 1,000 cm ³ (STP) · μm / (m ² · day · MPa) or less. A homopolymer obtained by polymerizing at least one unsaturated acid selected from the group of acrylic acid, methacrylic acid, maleic acid, and itaconic acid, a copolymer thereof, or a mixture thereof, and the water-soluble polyvalent metal salt is The method for producing a gas barrier laminate film according to claim 10 or 11, wherein the method is zinc acetate or calcium acetate, and the aqueous resin is an aqueous polyurethane resin or an aqueous polyisocyanate resin. The coating liquid (A) containing the polycarboxylic acid polymer is applied to at least one surface of the plastic film substrate, and the coating liquid (A) containing the polycarboxylic acid polymer is formed without heat treatment. Adjacent to the layer (a), a coating liquid (B) containing a water-soluble polyvalent metal salt and an aqueous resin is applied, and these coating layers are dried to be described in any one of claims 10 to 12. A gas barrier, characterized in that a gas barrier multilayer film is obtained by laminating a plastic film on at least one surface of the gas barrier film after the gas barrier laminate film is obtained via an adhesive layer or directly. For producing a porous multilayer film.

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