JP2023042643A - Gas barrier laminate - Google Patents

Abstract

To provide a gas barrier laminate that has improved water-wetted peel strength while maintaining good gas barrier property.SOLUTION: Provided is a laminate, which is a gas barrier laminate having a substrate, a first layer and a second layer in this order, and in which the first layer contains an amino group-containing resin and the amount of amino group in the first layer is 0.3 mmol/g or more, and the second layer contains a resin that contains at least one functional group selected from the group consisting of a hydroxy group, a carboxy group, an amino group and a sulfo group, and an inorganic laminar compound.SELECTED DRAWING: None

Description

The present invention relates to a gas barrier laminate and a method for producing the gas barrier laminate.

For example, packaging materials for foods, cosmetics, and the like are required to have a characteristic of suppressing the permeation of gases such as water vapor and oxygen, that is, gas barrier properties, in order to prevent their deterioration. A laminate having a gas barrier layer formed on a substrate using polyvinyl alcohol or a derivative thereof is known as a packaging material having high gas barrier properties. Here, the "gas barrier layer" means a layer used for suppressing permeation of gas.

Patent Document 1 describes a gas barrier layer comprising a polyvinylamine-polyvinylalcohol copolymer. Further, Patent Document 2 describes a laminate including a substrate and a coating film formed from a coating liquid containing a hydroxyl group-containing resin such as a vinylamine-vinyl alcohol copolymer, an inorganic stratiform compound, and a liquid medium. It is

Patent No. 5669738 WO2021/095755

Patent Document 1 describes that a gas barrier layer containing a polyvinylamine-polyvinyl alcohol copolymer described in the same document exhibits good oxygen barrier properties. However, according to the study of the present inventors, it has been found that the gas barrier properties of the gas barrier layer described in Patent Document 1 are not sufficient. In addition, although the laminate as described in Patent Document 2 exhibits good gas barrier properties, the adhesiveness between the gas barrier layer and the substrate in the presence of water (hereinafter also referred to as "peeling strength with water") is poor. We found that there is room for improvement.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a gas barrier laminate having improved wet peel strength while maintaining good gas barrier properties.

The present inventors arrived at the present invention as a result of intensive studies in order to solve the above problems. That is, the present invention provides the following preferred aspects.

[1] A gas barrier laminate comprising a substrate, a first layer and a second layer in this order,
The first layer contains an amino group-containing resin, the amount of amino groups in the first layer is 0.3 mmol / g or more,
A laminate, wherein the second layer comprises a resin containing at least one functional group selected from the group consisting of a hydroxyl group, a carboxyl group, an amino group and a sulfo group, and an inorganic stratiform compound.
[2] The laminate according to [1], wherein the content of the inorganic stratiform compound in the second layer is 1 to 50% by mass with respect to the total mass of the second layer.
[3] The laminate according to [1] or [2], wherein the resin contained in the second layer contains at least one functional group selected from the group consisting of hydroxy groups and amino groups.
[4] The laminate according to any one of [1] to [3], wherein the resin contained in the second layer contains a resin containing a hydroxy group.
[5] The laminate according to any one of [1] to [4], wherein the hydroxy group-containing resin contained in the second layer is a vinyl alcohol resin.
[6] The laminate according to any one of [1] to [5], wherein the resin containing a hydroxyl group contained in the second layer includes a resin containing an amino group in addition to the hydroxyl group.
[7] The amount of amino groups (mmol/g) in the first layer is higher than the amount of amino groups (mmol/g) in the second layer, according to any one of [1] to [6] laminate.
[8] The laminate according to any one of [1] to [7], wherein the first layer contains, in addition to the amino group-containing resin, a resin containing a hydroxyl group and not containing an amino group.
[9] The laminate according to [8], wherein the resin containing a hydroxyl group but not containing an amino group contained in the first layer is a vinyl alcohol resin containing no amino group.
[10] The laminate according to any one of [1] to [9], wherein the amino group-containing resin contained in the first layer contains a resin containing hydroxy groups in addition to amino groups.
[11] The laminate according to any one of [1] to [10], wherein the amino group-containing resin contained in the first layer contains a vinylamine-vinyl alcohol copolymer.
[12] The laminate according to any one of [1] to [11], wherein the content of the inorganic stratiform compound in the first layer is 50% by mass or less with respect to the total mass of the first layer.
[13] The first layer and/or the second layer further comprises at least one additive selected from the group consisting of a cross-linking agent, an ultraviolet absorber, an antioxidant, a surfactant and an antirust agent. A laminate according to any one of claims 1 to 12.
[14] The laminate according to [13], wherein the additive includes a cross-linking agent.
[15] The laminate according to [14], wherein the cross-linking agent has an epoxy group.
[16] A step of forming a first layer containing an amino group-containing resin on a substrate, and at least one selected from the group consisting of a hydroxy group, a carboxy group, an amino group and a sulfo group on the first layer and a step of forming a second layer containing an inorganic layered compound.

ADVANTAGE OF THE INVENTION According to this invention, the gas-barrier laminated body which the wet peeling strength improved can be provided, maintaining favorable gas-barrier property.

FIG. 1 is an image diagram of a method for measuring peel strength with water.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail. The scope of the present invention is not limited to the embodiments described here, and various modifications can be made without departing from the gist of the present invention.

[Gas barrier laminate]
The gas barrier laminate of the present invention comprises a substrate, a first layer and a second layer in this order, the first layer comprising an amino group-containing resin, and the amount of amino groups in the first layer being 0.3 mmol. / g or more. The present inventors have found that when a first layer having a high amino group concentration is formed between a base material and a second layer acting as a gas barrier layer, the resulting gas barrier laminate maintains the gas barrier property while maintaining the water barrier property. It was found that the adhesive peel strength can be improved. It is believed that this is because the first layer has a high amino group concentration and therefore acts not only as a gas barrier layer but also as a primer layer. In this specification, the term "gas barrier property" refers to the property of suppressing permeation of gases such as oxygen and water vapor, and the term "gas barrier laminate" refers to a laminate including a gas barrier layer. In this specification, the term "wet peel strength" refers to the peel strength between the substrate and the gas barrier layer including the first layer and the second layer in the gas barrier laminate measured in the presence of water.

<First Layer>
The first layer contains an amino group-containing resin, and the amount of amino groups in the first layer is 0.3 mmol/g or more. Since the amount of amino groups in the first layer is 0.3 mmol/g or more, the gas barrier laminate of the present invention can improve the wet peel strength while maintaining good gas barrier properties. On the other hand, when the amount of amino groups in the first layer is less than 0.3 mmol/g, the wet peel strength tends to decrease.

The amount of amino groups in the first layer is preferably 0.5 mmol/g or more, more preferably 0.8 mmol/g or more, still more preferably 1.0 mmol/g or more, still more preferably 1.5 mmol/g or more. , particularly preferably 1.8 mmol/g or more, particularly more preferably 2.0 mmol/g or more. When the amount of amino groups is at least the above lower limit, the reaction between the amino groups in the first layer and functional groups such as carbonyl groups, aldehyde groups, carboxyl groups, and ester groups that may exist on the surface of the substrate proceeds. Since the adhesiveness or adhesiveness between the first layer and the substrate is enhanced, the gas barrier property and water peel strength of the gas barrier laminate are easily improved. In addition, the amount of amino groups in the first layer is preferably 10 mmol/g or less, more preferably 8.0 mmol/g or less, still more preferably 5.0 mmol/g or less, still more preferably 3.0 mmol/g or less. is.
The amount of amino groups in the first layer can be adjusted by the amount of amino groups (mmol/g) in the amino group-containing resin contained in the first layer and the ratio of the amino group-containing resin contained in the first layer. .
The amino group amount (mmol/g) in the first layer can be calculated by performing ¹ H NMR measurement of the amino group amount (mmol/g) in the amino group-containing resin contained in the first layer. It can be calculated by the method described in Examples.

(Amino group-containing resin)
The amino group-containing resin is not particularly limited as long as it contains an amino group. For example, vinylamine-vinyl alcohol copolymer; polyethyleneimine; vinylbenzenetrimethylammonium chloride; , di- or trialkylammonium salts, N-methylaminoethyl acrylate, N,N-dimethylaminoethyl methacrylate, N,N-dimethylaminomethyl-N-acrylamide, N,N-dimethylaminoethyl-N-acrylamide, etc. Homopolymers and copolymers thereof and the like are included. These amino group-containing resins can be used alone or in combination of two or more. The amino group may be unsubstituted or substituted with an alkyl group or the like.

In one embodiment of the present invention, the amino group-containing resin preferably contains a resin containing a hydroxy group in addition to an amino group, and more preferably contains an amino group, from the viewpoint of easily improving gas barrier properties and water peel strength. It contains a vinyl alcohol-based resin, more preferably a vinylamine-vinyl alcohol copolymer. The vinylamine-vinyl alcohol copolymer may be a random copolymer or a block copolymer, but is preferably a random copolymer from the viewpoint of manufacturability and cost.

In one embodiment of the present invention, the amount of amino groups in the resin containing hydroxy groups in addition to amino groups is preferably 0.3 mmol/g or more, more preferably 0.5 mmol/g or more, still more preferably 0.5 mmol/g or more. It is 8 mmol/g or more, still more preferably 1.0 mmol/g or more, particularly preferably 1.5 mmol/g or more, even more preferably 1.8 mmol/g or more, and most preferably 2.0 mmol/g or more. When the amount of amino groups is at least the above lower limit, the amount of amino groups in the first layer is likely to be increased, and the gas barrier property and water peel strength of the gas barrier laminate are likely to be improved. In addition, the amount of amino groups in the resin containing hydroxy groups in addition to amino groups is preferably 10 mmol/g or less, more preferably 8.0 mmol/g or less, still more preferably 5.0 mmol/g or less, and even more preferably is 3.0 mmol/g or less. Incidentally, the amount of amino groups in the resin can be measured by ¹ H NMR measurement.

In one embodiment of the present invention, the amount of hydroxy groups in the resin containing hydroxy groups in addition to amino groups is preferably 1 mmol/g or more, more preferably 5 mmol/g or more, still more preferably 10 mmol/g or more, and More preferably, it is 15 mmol/g or more. When the amount of hydroxy groups is equal to or more than the above lower limit, a crystal structure is likely to be formed by hydrogen bonding in the first layer, and gas barrier properties are likely to be improved. Also, the amount of hydroxy groups is preferably 50 mmol/g or less, more preferably 40 mmol/g or less, even more preferably 30 mmol/g or less, still more preferably 25 mmol/g or less. When the amount of hydroxy groups is equal to or less than the above upper limit, it is easy to suppress a decrease in the surface activity of the resin containing hydroxy groups in addition to amino groups, and it is easy to increase compatibility with hydrophobic materials. Incidentally, the amount of hydroxy groups in the resin can be measured by ¹ H NMR measurement.

In one embodiment of the present invention, the saponification degree of the amino group-containing vinyl alcohol resin is preferably It is 80% or more, more preferably 90% or more, still more preferably 95% or more, particularly preferably 98% or more, and may be 100% or less.

In one embodiment of the present invention, when the amino group-containing resin contains a resin containing a hydroxy group in addition to the amino group, hydroxy groups in addition to the amino group with respect to the total mass of the amino group-containing resin contained in the first layer is preferably 60% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, and even more preferably 95 mass % or more, particularly preferably 99 mass % or more. Moreover, the content may be preferably 100% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less.

In another embodiment of the present invention, the amino group-containing resin may contain a resin containing an amino group and not containing a hydroxy group, from the viewpoint of easily improving peel strength, particularly peel strength with water. The resin containing an amino group and not containing a hydroxy group has at least one of a primary amine, a secondary amine, or a tertiary amine in its main chain, side chain, or terminal and has a hydroxy group. Examples include polyethylenimine, polyvinylamine, polyallylamine, polydiallylamine, polyvinylamidine, and polylysine. Among these resins, polyethyleneimine and polydiallylamine, which are classified as main chain amines, and polyvinylamine and polyallylamine, which are classified as side chain amines, are preferable. Among these resins, polyethyleneimine, polyvinylamine, and polyallylamine are preferable from the viewpoint of availability.

In one embodiment of the present invention, the amount of amino groups in the resin containing amino groups and not containing hydroxy groups is preferably 0.3 mmol/g or more, more preferably 0.5 mmol/g or more, and still more preferably 0 0.8 mmol/g or more, still more preferably 1.0 mmol/g or more, particularly preferably 1.5 mmol/g or more, even more preferably 1.8 mmol/g or more, particularly preferably 2.0 mmol/g or more. When the amount of amino groups is at least the above lower limit, the amount of amino groups in the first layer is likely to be increased, and the gas barrier property and water peel strength of the gas barrier laminate are likely to be improved. In addition, the amount of amino groups in the resin containing an amino group and not containing a hydroxy group is preferably 10 mmol/g or less, more preferably 8.0 mmol/g or less, still more preferably 5.0 mmol/g or less, and even more preferably 5.0 mmol/g or less. Preferably, it is 3.0 mmol/g or less.

In one embodiment of the present invention, when the amino group-containing resin contains an amino group-containing resin that does not contain a hydroxy group, the amino group-containing hydroxy group-containing resin relative to the total mass of the amino group-containing resin contained in the first layer is The content of the resin that does not contain is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 20% by mass or more, and particularly preferably It is 50% by mass or more. Also, the content is preferably 99% by mass or less, more preferably 80% by mass or less, and even more preferably 60% by mass or less.

In one embodiment of the present invention, the amino group-containing resin contained in the first layer may contain both a resin containing a hydroxy group in addition to an amino group and a resin containing an amino group but not a hydroxy group. , only one of which may be included. When the amino group-containing resin contains both a resin containing a hydroxy group in addition to an amino group and a resin containing an amino group but not a hydroxy group, the content ratio [resin containing a hydroxy group in addition to an amino group] : [resin containing an amino group and not containing a hydroxy group] (mass ratio) is preferably 99:1 to 1:99, more preferably 80:20 to 20:80, further preferably 70:30 to 30: 70 may be used.

In one embodiment of the present invention, the number average molecular weight of the amino group-containing resin is preferably 5,000 or more, more preferably 10,000 or more, still more preferably 12,000 or more, still more preferably 15,000 or more. preferably 100,000 or less, more preferably 50,000 or less, still more preferably 40,000 or less, and even more preferably 30,000 or less. The number average molecular weight of the amino group-containing resin can be measured by gel permeation chromatography (GPC), for example, by the method described in Examples.

In one embodiment of the present invention, the amount of amino groups in the entire amino group-containing resin contained in the first layer is preferably 0.3 mmol/g or more, more preferably 0.5 mmol/g or more, still more preferably 0.5 mmol/g or more. It is 8 mmol/g or more, still more preferably 1.0 mmol/g or more, particularly preferably 1.5 mmol/g or more, even more preferably 1.8 mmol/g or more, and most preferably 2.0 mmol/g or more. When the amount of amino groups is at least the above lower limit, the amount of amino groups in the first layer is likely to be increased, and the gas barrier property and water peel strength of the gas barrier laminate are likely to be improved. In addition, the amount of amino groups in the amino group-containing resin contained in the first layer is preferably 10 mmol/g or less, more preferably 8.0 mmol/g or less, still more preferably 5.0 mmol/g or less, and even more preferably is 3.0 mmol/g or less.

In one embodiment of the present invention, the content of the amino group-containing resin in the first layer is preferably 20% by mass or more, more preferably 50% by mass or more, based on the total mass of the first layer. It is preferably 65% by mass or more, still more preferably 80% by mass or more, particularly preferably 90% by mass or more, and preferably 100% by mass or less.

(Amino group-free resin)
In one embodiment of the present invention, the first layer may contain a resin containing no amino group (amino group-free resin) in addition to the amino group-containing resin. Examples of amino group-free resins that can be contained in the first layer include vinyl alcohol resins that do not contain amino groups, such as polyvinyl alcohol, (meth)acrylic acid-vinyl alcohol copolymer, and ethylene-vinyl alcohol copolymer. etc. These resins may be used alone or in combination of two or more. Among these resins, the amino group-free resin is preferably a resin containing a hydroxyl group but not an amino group, more preferably a vinyl alcohol resin containing no amino group, and still more preferably vinyl alcohol. .

In one embodiment of the present invention, the amount of hydroxy groups in the resin containing hydroxy groups and not containing amino groups is preferably 1 mmol/g or more, more preferably 5 mmol/g or more, still more preferably 10 mmol/g or more, and More preferably, it is 15 mmol/g or more. When the amount of hydroxy groups is equal to or more than the above lower limit, a crystal structure is likely to be formed by hydrogen bonding in the first layer, and gas barrier properties are likely to be improved. Also, the amount of hydroxy groups is preferably 50 mmol/g or less, more preferably 40 mmol/g or less, even more preferably 30 mmol/g or less, still more preferably 25 mmol/g or less. When the amount of hydroxy groups is equal to or less than the above upper limit, it is easy to suppress a decrease in surface activity, and it is easy to improve compatibility with a hydrophobic material.

In one embodiment of the present invention, the degree of saponification of the vinyl alcohol resin containing no amino group is preferably 80% or higher, more preferably 90% or higher, still more preferably 95% or higher, and particularly preferably 98% or higher. , 100% or less.

In one embodiment of the present invention, the amino group-free resin preferably has a number average molecular weight of 10,000 or more, more preferably 30,000 or more, still more preferably 50,000 or more, and preferably 150,000 or more. 000 or less, more preferably 100,000 or less, and even more preferably 70,000 or less. The number average molecular weight of the amino group-free resin can be measured by gel permeation chromatography (GPC), for example, by the method described in Examples.

In one embodiment of the present invention, the total amount of the resins (amino group-containing resin and amino group-free resin) contained in the first layer is preferably 50% by mass or more with respect to the total mass of the first layer, More preferably 60% by mass or more, still more preferably 70% by mass or more, even more preferably 80% by mass or more, particularly preferably 90% by mass or more, and usually 100% by mass or less.

In one embodiment of the present invention, the content of the amino group-containing resin in the resin contained in the first layer is preferably 20% by mass or more, more than It is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, particularly preferably 90% by mass or more, and usually 100% by mass or less.

In one embodiment of the present invention, the amount of amino groups in the resin contained in the first layer is preferably 0.5 mmol/g or more, preferably 0.8 mmol/g or more, more preferably 1.0 mmol/g or more. , more preferably 1.5 mmol/g or more, still more preferably 1.8 mmol/g or more, and particularly preferably 2.0 mmol/g or more. When the amount of amino groups is at least the above lower limit, the amount of amino groups in the first layer is likely to be increased, and the gas barrier property and water peel strength of the gas barrier laminate are likely to be improved. In addition, the amino group content is preferably 10 mmol/g or less, more preferably 8.0 mmol/g or less, even more preferably 5.0 mmol/g or less, still more preferably 3.0 mmol/g or less.

(Inorganic layered compound)
In one embodiment of the present invention, the first layer may further contain an inorganic stratiform compound from the viewpoint of easily improving gas barrier properties. The inorganic stratiform compound that may be contained in the first layer is not particularly limited, and may be, for example, the same as the inorganic stratiform compound contained in the second layer described below, including preferred embodiments.

In one embodiment of the present invention, the content of the inorganic layered compound in the first layer is preferably 0.1% by mass or more with respect to the total mass of the first layer, from the viewpoint of easily improving the gas barrier property. More preferably 1% by mass or more, still more preferably 5% by mass or more, even more preferably 10% by mass or more, and particularly preferably 15% by mass or more.
In one embodiment of the present invention, the content of the inorganic stratiform compound in the first layer is preferably 50% with respect to the total mass of the first layer from the viewpoint of easily improving the peel strength with water. % by mass or less, more preferably 35% by mass or less, still more preferably 20% by mass or less, even more preferably 10% by mass or less, particularly preferably 5% by mass or less, and particularly more preferably 1% by mass or less, The first layer may be substantially free of inorganic stratiform compounds.

(Additive)
In one embodiment of the present invention, the first layer may further comprise at least one additive selected from the group consisting of cross-linking agents, UV absorbers, antioxidants, surfactants and rust inhibitors. The additive is preferably a cross-linking agent, a surfactant and/or an antirust agent, and more preferably contains at least a cross-linking agent, from the viewpoint of easily improving gas barrier properties and wet peel strength.

The cross-linking agent may be an organic cross-linking agent or an inorganic cross-linking agent, but is preferably an organic cross-linking agent. Examples of the organic cross-linking agent include polyfunctional monomers having a functional group capable of reacting with the amino group of the amino group-containing resin and/or the hydroxyl group optionally contained in the amino group-containing resin, such as epoxy group, vinyl group, (meth) Polyfunctional monomers having at least two functional groups selected from the group consisting of acrylic groups, aldehyde groups, isocyanate groups and/or allyl groups are included. Examples of the polyfunctional monomer include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, resorcinol diglycidyl ether, 1,6-hexanediol diglycidyl ether, sorbitol polyglycidyl ether, and glycerol polyglycidyl ether. Compounds having an epoxy group such as ether, diglycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, pentaerythritol polyglycidyl ether; compounds having a vinyl group such as divinylbenzene; trimethylolpropane triacrylate, 1,6-hexanediol Diacrylate, 1,9-nonanediol diacrylate, 1,10-decanediol diacrylate, trimethylolpropane trimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, 1,10-decane Compounds having (meth) acrylic groups such as diol dimethacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, cyanoethyl acrylate; compounds having These cross-linking agents may be used alone or in combination of two or more. Among these cross-linking agents, the cross-linking agent is preferably a compound having an epoxy group, more preferably a bifunctional epoxy compound, a polyfunctional (trifunctional or more) epoxy compound, and still more preferably a bifunctional epoxy compound.

In one embodiment of the present invention, the epoxy equivalent weight of the compound having an epoxy group may be preferably 50-1000 g/equivalent, more preferably 100-500 g/equivalent, still more preferably 150-400 g/equivalent.

The content of the cross-linking agent in the first layer is preferably 0.5% by mass or more, more preferably 1% by mass, relative to the total mass of the first layer, from the viewpoint of easily improving the wet peel strength. Above, more preferably 3% by mass or more, still more preferably 5% by mass or more, and particularly preferably 8% by mass or more. Also, the content is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less.

Examples of the ultraviolet absorber include at least one compound selected from the group consisting of benzophenone-based compounds, salicylate-based compounds, benzotriazole-based compounds, and triazine-based compounds. Ultraviolet absorbers can be used alone or in combination of two or more. As used herein, a "based compound" refers to a derivative of the compound to which the "based compound" is attached. For example, a "benzophenone-based compound" refers to a compound having benzophenone as a parent skeleton and a substituent attached to the benzophenone.

Examples of antioxidants include phenol-based antioxidants, sulfur-based antioxidants, phosphorus-based antioxidants, and the like.

Examples of rust preventives include azoles, inorganic acids, organic acids, and the like. Inorganic acids and organic acids may each be a salt. Azoles include imidazole, benzimidazole, 2-mercaptobenzimidazole, benzotriazole and the like.
Inorganic acids include boric acid, nitrous acid, phosphonic acid and the like.

Surfactants include, for example, anionic surfactants, cationic surfactants, zwitterionic surfactants and nonionic surfactants.

In one embodiment of the present invention, the total amount of additives contained in the first layer is preferably 0.1 to 30% by mass, more preferably 1 to 20% by mass, based on the total mass of the first layer. , more preferably 5 to 15% by mass.

In one embodiment of the present invention, the amount of sodium (Na) in the first layer is preferably 2500 ppm or less, more preferably 1500 ppm or less, and still more preferably 1000 ppm or less with respect to the total mass of the first layer. you can When the amount of Na in the first layer is equal to or less than the above upper limit, it is easy to obtain a gas barrier laminate with excellent gas barrier properties. The lower limit of the amount of Na is not particularly limited, and may be 0 ppm or more. The amount of Na in the first layer can be adjusted by the amount of Na in the first coating liquid forming the first layer. For example, the amount of Na in the first coating liquid can be adjusted by a cation exchange treatment or the like. can be reduced. Also, the amount of Na in the first layer can be measured by inductively coupled plasma emission spectrometry using an ICP emission spectrometer.

<Second layer>
The second layer contains a resin containing at least one functional group selected from the group consisting of a hydroxy group, a carboxyl group, an amino group and a sulfo group (hereinafter also referred to as "resin A") and an inorganic layered compound.

(Resin A)
Resin A is not particularly limited as long as it contains at least one functional group selected from the group consisting of a hydroxy group, a carboxy group, an amino group and a sulfo group. The amino group may be unsubstituted or substituted with an alkyl group or the like. Moreover, all of the carboxy group, amino group and sulfo group may be in the form of a salt.
Resin A may be a homopolymer or a copolymer, and the copolymer may be a block copolymer, alternating copolymer, random copolymer, and combinations thereof. Resin A contained in the second layer has at least one functional group selected from the group consisting of a hydroxy group, a carboxyl group, an amino group and a sulfo group. It can improve the peel strength.

Examples of the resin having at least one functional group selected from the group consisting of a hydroxy group, a carboxyl group and an amino group include polyvinyl alcohol (PVA), vinylamine-vinyl alcohol copolymer, (meth)acrylic acid-vinyl alcohol. Copolymers, ethylene-vinyl alcohol copolymers (EVOH), polyacrylic acid, polymethacrylic acid, polysaccharides, derivatives thereof, and the like. Examples of resins having a sulfo group include derivatives obtained by substituting a sulfo group for a hydroxy group in a resin having a hydroxy group such as polyvinyl alcohol. These resins can be used alone or in combination of two or more. Among these resins, the resin A preferably has at least one functional group selected from the group consisting of a hydroxy group and an amino group from the viewpoint of easily improving gas barrier properties and film durability.

In one embodiment of the present invention, the resin A preferably contains a resin containing a hydroxy group (hydroxy group-containing resin), and the hydroxy group-containing resin is polyvinyl alcohol, (meth)acrylic acid-vinyl alcohol copolymer. , ethylene-vinyl alcohol copolymer, vinylamine-vinyl alcohol copolymer and the like.

In one embodiment of the present invention, the hydroxy group-containing resin may contain a resin containing an amino group in addition to the hydroxy group. Examples of resins containing amino groups in addition to hydroxy groups include vinyl alcohol resins containing amino groups, and vinylamine-vinyl alcohol copolymers are preferred. The vinylamine-vinyl alcohol copolymer may be a random copolymer or a block copolymer, but is preferably a random copolymer from the viewpoint of manufacturability and cost.
In one embodiment of the present invention, the hydroxy group-containing resin includes only a resin containing an amino group in addition to a hydroxy group, a resin containing an amino group in addition to a hydroxy group, and a resin containing no amino group. A hydroxy group-containing resin may be included.

In one embodiment of the present invention, the amount of amino groups in Resin A is preferably 0.3 mmol/g or more, more preferably 0.5 mmol/g or more, still more preferably 0.8 mmol/g or more, and even more preferably It is 1.0 mmol/g or more, particularly preferably 1.5 mmol/g or more, particularly more preferably 1.8 mmol/g or more, and particularly preferably 2.0 mmol/g or more. When the amount of amino groups is at least the above lower limit, the amount of amino groups in the second layer is likely to be increased, and as a result, the gas barrier properties and water peel strength of the gas barrier laminate are likely to be improved. Further, the amount of amino groups in Resin A is preferably 10 mmol/g or less, more preferably 8.0 mmol/g or less, still more preferably 5.0 mmol/g or less, still more preferably 3.0 mmol/g or less. .

In one embodiment of the present invention, the number average molecular weight of Resin A is preferably 500 or more, more preferably 800 or more, and still more preferably 1,000 or more, from the viewpoint of easily improving gas barrier properties and film durability. , preferably 200,000 or less, more preferably 100,000 or less, and even more preferably 50,000 or less. The number average molecular weight of resin A can be measured by gel permeation chromatography (GPC), for example, by the method described in the Examples.

In one embodiment of the present invention, the content of resin A in the second layer is preferably 30% by mass or more, more preferably 40% by mass or more, and still more preferably 50% by mass or more, more preferably 60% by mass or more, particularly preferably 65% by mass or more, and preferably 90% by mass or less, more preferably 85% by mass or less, and still more preferably 80% by mass or less .

In one embodiment of the present invention, the content of the hydroxy group-containing resin in the resin A is preferably 60% by mass or more, more preferably 80% by mass, based on the total mass of the resin A contained in the second layer. Above, more preferably 90% by mass or more, still more preferably 95% by mass or more. The upper limit of the content is not particularly limited, and may be, for example, 100% by mass or less.

In one embodiment of the present invention, the content of the resin containing an amino group in addition to the hydroxyl group in the resin A is preferably 50% by mass or more with respect to the total mass of the resin A contained in the second layer. , more preferably 60% by mass or more, and still more preferably 80% by mass or more. The upper limit of the content is not particularly limited, and may be, for example, 100% by mass or less.

In one embodiment of the present invention, the amount of amino groups in the second layer is preferably 0 mmol/g or more, more preferably 0.3 mmol/g or more, still more preferably 0.5 mmol/g or more, still more preferably It is 0.8 mmol/g or more, particularly preferably 1.0 mmol/g or more, particularly more preferably 1.2 mmol/g or more, and even more preferably 1.5 mmol/g or more. When the amount of amino groups is at least the above lower limit, the gas barrier property and water peel strength of the gas barrier laminate are likely to be improved. Further, the amount of amino groups in the second layer is preferably 3.0 mmol/g or less, more preferably 2.5 mmol/g or less, still more preferably 2.0 mmol/g or less, still more preferably 1.8 mmol/g. g or less.
The amount of amino groups in the second layer is the amount of amino groups in the resin containing amino groups that can be contained in the second layer (mmol / g) and the resin containing amino groups that can be contained in the second layer can be adjusted by the ratio of
The amino group amount (mmol/g) in the second layer is calculated by performing ¹ H NMR measurement of the amino group amount (mmol/g) in the resin containing amino groups that can be contained in the second layer. For example, it can be calculated by the method described in Examples.

(Inorganic layered compound)
Since the second layer contains the inorganic stratiform compound, the gas barrier laminate of the present invention can maintain high gas barrier properties. The inorganic layered compounds can be used alone or in combination of two or more. In the present invention, the inorganic layered compound refers to an inorganic compound in which unit crystal layers are stacked to form a layered structure. A layered structure refers to a structure in which planes in which atoms are strongly bonded by covalent bonds or the like and arranged densely are stacked almost parallel due to a weak bonding force such as van der Waals.

Examples of the inorganic layered compound include clay minerals, and the clay minerals can be used singly or in combination of two or more. Clay minerals include, for example, kaolinite, dickite, nacrite, halloysite, antigorite, chrysotile, pyrophyllite, montmorillonite, beidellite, nontronite, saponite, sauconite, stevensite, hectorite, tetrasilic mica, sodium teniolite, muscovite, margarite, talc, vermiculite, phlogopite, xanthophyllite, chlorite, hydrotalcite and the like. The clay mineral may be improved in dispersibility and the like by treatment with an organic substance (for example, ion exchange, etc.).

In one embodiment of the present invention, the inorganic layered compound is preferably a smectite group clay mineral from the viewpoints of high aspect ratio, easy improvement of gas barrier properties, and availability. Examples of smectite clay minerals include montmorillonite, beidellite, nontronite, saponite, sauconite, stevensite, and hectorite, with montmorillonite being more preferred.

In one embodiment of the present invention, the thickness of the unit crystal layer of the layered inorganic compound is preferably 0.5 to 3.0 nm, more preferably 0.8 to 2.0 nm, still more preferably 1.0 to 1.0 nm. 5 nm. The thickness of the unit crystal layer can be measured by a powder X-ray diffraction method or the like.

In one embodiment of the present invention, the average particle size of the inorganic layered compound is preferably 0.1-20 μm, more preferably 0.2-10 μm, and even more preferably 0.3-5 μm. When the average particle size of the inorganic layered compound is within the above range, it is easy to obtain a gas barrier laminate with good gas barrier properties and transparency. The average particle diameter of the inorganic layered compound is a volume-based median diameter (D50), which can be measured with a laser diffraction scattering particle size distribution analyzer.

In one embodiment of the present invention, the aspect ratio of the inorganic layered compound (average particle diameter of the inorganic layered compound/thickness of the unit crystal layer of the inorganic layered compound) is preferably 50 to 5000, more preferably 100 to 4000, and more preferably 100 to 4000. Preferably it is 200-3000. When the aspect ratio is at least the above lower limit, the gas barrier properties are likely to be improved. Moreover, when the aspect ratio is equal to or less than the above upper limit, it is easy to improve manufacturability and economic efficiency.

In one embodiment of the present invention, the content of the inorganic stratiform compound in the second layer is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably, based on the total mass of the second layer. is 10% by mass or more, more preferably 15% by mass or more, and particularly preferably 20% by mass or more. In addition, the content is preferably 50% by mass or less, more preferably 45% by mass or less, still more preferably 40% by mass or less, and even more preferably 35% by mass or less. When the content of the inorganic stratiform compound in the second layer is at least the above lower limit, the gas barrier properties are likely to be improved, and when it is at most the above upper limit, the wet peel strength is likely to be improved.

(Additive)
In one embodiment of the present invention, the second layer may further comprise at least one additive selected from the group consisting of cross-linking agents, UV absorbers, antioxidants, surfactants and rust inhibitors. Examples of the additive include the same additives as those that can be contained in the first layer, and preferred embodiments are also the same as those that can be contained in the first layer.

The content of the cross-linking agent in the second layer is preferably 0.5% by mass or more, more preferably 1% by mass, relative to the total mass of the second layer, from the viewpoint of easily improving the wet peel strength. Above, more preferably 3% by mass or more, still more preferably 5% by mass or more, and particularly preferably 8% by mass or more. Also, the content is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less.

In one embodiment of the present invention, the total amount of additives contained in the second layer is preferably 0.1 to 30% by weight, more preferably 1 to 20% by weight, based on the total weight of the second layer. , more preferably 5 to 15% by mass.

In one embodiment of the present invention, the amount of sodium (Na) in the second layer is preferably 2500 ppm or less, more preferably 1500 ppm or less, still more preferably 1000 ppm or less, relative to the total mass of the second layer. you can When the amount of Na in the second layer is equal to or less than the above upper limit, it is easy to obtain a gas barrier laminate with excellent gas barrier properties. The lower limit of the amount of Na is not particularly limited, and may be, for example, 0 ppm or more. The amount of Na in the second layer can be adjusted by the amount of Na in the second coating liquid forming the second layer. For example, the amount of Na in the second coating liquid can be adjusted by cation exchange treatment or the like. can be reduced. Also, the amount of Na in the second layer can be measured by inductively coupled plasma emission spectrometry using an ICP emission spectrometer.

<Base material>
The gas barrier laminate of the present invention includes a substrate. The substrate is not particularly limited, and examples thereof include polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyolefins such as polyethylene and polypropylene, polystyrene, polyamide, polyvinyl chloride, polycarbonate, polyacrylonitrile, and polyimide. These substrates can be used alone or in combination of two or more. In one embodiment of the invention, the preferred substrate is polyolefin, more preferably polypropylene.

In one embodiment of the present invention, it is preferred that the substrate surface that is in direct contact with the first layer or indirectly via another layer has a functional group capable of reacting with an amino group. When a functional group capable of reacting with an amino group is present on the surface of the base material, the functional group capable of reacting with the amino group on the surface of the base material easily reacts with the amino group of the first layer to form a bond. Since the adhesiveness or adhesiveness between the first layer and the substrate is enhanced, the wet peel strength of the gas barrier laminate is likely to be improved. A carbonyl group, an aldehyde group, a carboxyl group, an ester group, etc. are mentioned as a functional group which can react with an amino group. In one embodiment of the present invention, the substrate may be one in which a functional group capable of reacting with an amino group is imparted to the surface of the substrate by surface treatment such as corona treatment.

<Gas barrier laminate>
The gas barrier laminate of the present invention includes a substrate, a first layer and a second layer in this order. The first layer in the gas barrier laminate contains an amino group-containing resin, the amount of amino groups in the first layer is 0.3 mmol/g or more, and the second layer contains hydroxy groups, carboxy groups, and amino groups. and a sulfo group. Therefore, the gas barrier laminate of the present invention can achieve both high gas barrier properties and high wet peel strength.

In one embodiment of the present invention, the amino group content (mmol/g) in the first layer is preferably higher than the amino group content (mmol/g) in the second layer. When the amount of amino groups per 1 g of the first layer is higher than the amount of amino groups per 1 g of the second layer, gas barrier properties and wet peel strength are likely to be improved.

In one embodiment of the present invention, the resin A contained in the second layer contains a structural unit having the same structure as at least one of the structural units constituting the amino group-containing resin contained in the first layer. is preferred. For example, when the amino group-containing resin contained in the first layer is a vinylamine-vinyl alcohol copolymer and the resin A contained in the second layer is polyvinyl alcohol, the polyvinyl alcohol is a vinylamine-vinyl alcohol copolymer. Since the polyvinyl alcohol contained in the second layer contains a vinyl alcohol unit that is one of the vinylamine unit and the vinyl alcohol unit that constitute the coalescence, the polyvinyl alcohol contained in the second layer is the vinylamine-vinyl alcohol copolymer contained in the first layer. It can be said that it contains a structural unit having the same structure as at least one of the constituent structural units. When the resin A contained in the second layer contains a structural unit having the same structure as at least one of the structural units constituting the amino group-containing resin contained in the first layer, the amino group-containing resin constituting the first layer The compatibility between the resin and the resin A constituting the second layer is enhanced, and the interface between the first layer and the second layer becomes difficult to form. Easy to improve.
In one embodiment of the present invention, the amino group-containing resin contained in the first layer and the resin A contained in the second layer constitute at least vinyl alcohol units from the viewpoint of easily improving gas barrier properties and water peel strength. It preferably contains a vinyl alcohol resin as a unit, and more preferably both the amino group-containing resin contained in the first layer and the resin A contained in the second layer are vinyl alcohol resins.

In one embodiment of the present invention, the thickness of the first layer is preferably 0.001-10 μm, more preferably 0.01-1 μm, even more preferably 0.05-0.5 μm, even more preferably 0 0.08 to 0.2 μm.
In one embodiment of the present invention, the thickness of the second layer is preferably 0.001-10 μm, more preferably 0.01-5 μm, even more preferably 0.05-1 μm, even more preferably 0.1 ~0.5 μm.
In one embodiment of the invention, the thickness of the first layer is preferably less than the thickness of the second layer.

In one embodiment of the invention, the thickness of the substrate is preferably 5-50 μm, more preferably 10-40 μm, even more preferably 15-30 μm. When the gas barrier laminate includes two or more base materials, the thickness of the base material represents the thickness of each base material.

In one embodiment of the present invention, the thickness of the gas barrier laminate of the present invention is preferably 5-60 μm, more preferably 10-40 μm, still more preferably 15-30 μm.

In one embodiment of the present invention, other layers such as an adhesive layer and a primer layer may be present between each layer of the substrate, the first layer and the second layer, but the gas barrier laminate From the viewpoint of easily improving the wet peel strength, it is preferable that the substrate and the first layer are in direct contact, and that the first layer and the second layer are in direct contact. That is, in one embodiment of the present invention, the gas barrier laminate of the present invention comprises only a base material, a first layer and a second layer, and the base material, the first layer and the second layer are arranged in this order. It is preferably laminated.

The gas barrier laminate of the present invention has good gas barrier properties. In one embodiment of the present invention, the gas barrier laminate of the present invention preferably has an oxygen permeability of 100 cc/(m ² ·day·atm) or less, more preferably 70 cc/(m ² ·day·atm) or less, still more preferably 50 cc/(m ² ·day·atm) or less. Since the lower the oxygen permeability, the better the gas barrier property of the gas barrier laminate, the lower limit is not particularly limited, and may be, for example, 0 cc/(m ² ·day·atm) or more.

The wet peel strength of the gas barrier laminate of the present invention is preferably 0.4 N/15 mm or more, more preferably 0.6 N/15 mm or more, still more preferably 1 N/15 mm or more, still more preferably 1.5 N/15 mm or more, Especially preferably, it is 2 N/15 mm or more. The upper limit of the wet peel strength is not particularly limited, and may be, for example, 10 N/15 mm or less. The wet peel strength of the gas barrier laminate can be measured by conducting a peel test of the gas barrier laminate while applying water to the peel surface so that water is always present on the peel surface. can be measured by

[Method for producing gas barrier laminate]
The gas barrier laminate of the present invention comprises a step of forming a first layer containing an amino group-containing resin on a substrate (first layer forming step), and and a resin having at least one functional group selected from the group consisting of a sulfo group, and a step of forming a second layer containing an inorganic stratiform compound (second layer forming step)
It can be produced by a method including Accordingly, the present invention also includes a method for manufacturing a gas barrier laminate.

<First layer forming step>
The first layer forming step is a step of forming the first layer on the base material by applying the first coating liquid on the base material and drying the coating film.

(First coating liquid)
The first coating liquid contains an amino group-containing resin and a liquid medium, and optionally an amino group-free resin, an inorganic layered compound and additives. The first layer in the gas barrier laminate of the present invention is formed by removing the liquid medium from the coating film of the first coating liquid by drying. For example, amino group-containing resins, amino group-free resins, inorganic layered compounds and additives, the description of each component in the <First layer> section applies similarly. In addition, regarding the content of each component in the first coating liquid relative to the solid content of the first coating liquid, the content of each component relative to the total mass of the first layer in the section <First layer> The statements apply equally. The solid content of the first coating liquid represents all components of the first coating liquid excluding the liquid medium.

The liquid medium preferably includes water and a liquid organic medium. As used herein, the term “liquid medium” means a medium that is liquid at 25° C. and 1 atmosphere, and the term “liquid organic medium” means an organic compound that is liquid at 25° C. and 1 atmosphere.

Examples of liquid organic media include monohydric alcohol, glycol, dimethylformamide, dimethylsulfoxide, and acetone. A liquid organic medium can be used individually or in combination of 2 or more types. Examples of monohydric alcohols include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol and the like.

When the liquid medium contains a liquid organic medium, the content of the liquid organic medium is preferably 1 to 70 parts by mass, more preferably 5 to 60 parts by mass, and still more preferably 10 parts by mass with respect to 100 parts by mass of the liquid medium. ~50 parts by mass.

In one embodiment of the present invention, the liquid medium preferably contains water and at least one monohydric alcohol selected from the group consisting of methanol, ethanol, 1-propanol, 2-propanol and 1-butanol, More preferably, it contains water and ethanol. When the liquid medium contains water and a monohydric alcohol, the total amount of the monohydric alcohol contained in the liquid medium is preferably 1 to 70 parts by mass, more preferably 5 to 60 parts by mass, still more preferably 10 to 50 parts by mass.

In one embodiment of the present invention, the content of the liquid medium is preferably 90 to 99.5% by mass, more preferably 91 to 99% by mass, more preferably 92 to 98% by mass. Therefore, with respect to the total mass of the first coating liquid, the solid content of the first coating liquid is preferably 0.5 to 10% by mass, more preferably 1 to 9% by mass, further preferably 2 to 10% by mass. 8% by mass. When the content of the liquid medium and the solid content of the first coating liquid are within the above ranges, gas barrier properties and film-forming properties are likely to be improved.

The first coating liquid can be prepared by mixing and stirring the above amino group-containing resin and liquid medium, and optionally the amino group-free resin, inorganic layered compound and additives. The mixing order and mixing method of each component are not particularly limited, and can be prepared, for example, by the following methods (1) to (3).
(1) A method of preparing a solution of an amino group-containing resin and a non-amino group-containing resin by mixing an amino group-containing resin, a liquid medium, and optionally an amino group-free resin and stirring with heating. When the first coating liquid contains an inorganic stratiform compound and/or an additive, the inorganic stratiform compound and/or the additive is added to the obtained resin solution, and the inorganic stratiform compound and/or the additive is added by stirring. A method of dispersing an agent in the resin solution.
(2) When the first coating liquid contains an inorganic layered compound and/or an additive, the inorganic layered compound and/or the additive are mixed with a liquid medium and stirred to remove the inorganic layered compound and/or the additive. A method of preparing a dispersion containing and mixing and stirring the obtained dispersion with a resin solution prepared separately in the same manner as in method (1) above.
(3) When the first coating liquid contains an inorganic layered compound and/or an additive, a dispersion liquid containing an inorganic layered compound and/or an additive is prepared in the same manner as in method (2) above, and obtained A method of adding an amino group-containing resin and optionally an amino group-free resin to a dispersion and stirring with heating to dissolve the amino group-containing resin and the amino group-free resin in the liquid medium in the dispersion.

The temperature at which the amino group-containing resin and the amino group-free resin are dissolved in the liquid medium or the liquid medium in the dispersion containing the inorganic layered compound and/or additives is preferably 50 to 100°C, more preferably 60°C. 100° C., the stirring speed is preferably 300 to 5,000 rpm, more preferably 500 to 3,000 rpm, and the peripheral stirring speed is preferably 1 to 8 m/min, more preferably 2 to 6 m. /min, and the stirring time is preferably 10 to 120 minutes, more preferably 20 to 110 minutes.

The temperature at which the inorganic layered compound and/or additive is dispersed in the liquid medium or the solution of the amino group-containing resin and the amino group-free resin is preferably 20 to 100°C, more preferably 30 to 80°C, The stirring speed is preferably 500 to 5,000 rpm, more preferably 1,000 to 5,000 rpm, and the stirring peripheral speed is preferably 1 to 20 m/min, more preferably 2 to 15 m/min. , the stirring time is preferably 10 to 150 minutes, more preferably 20 to 120 minutes.

When the first coating liquid contains an inorganic layered compound, it is preferable to subject the dispersion containing the inorganic layered compound to a high-pressure dispersion treatment using a high-pressure dispersion apparatus in order to improve the dispersibility of the inorganic layered compound. Examples of the high-pressure dispersion treatment include an ultrahigh-pressure homogenizer manufactured by Microfluidics Corporation, a nanomizer manufactured by Nanomizer, a Manton-Gaulin type high-pressure disperser, and a homogenizer manufactured by Izumi Food Machinery. Here, the high-pressure dispersion treatment is a treatment for applying high shear and/or high pressure to the dispersion liquid by passing the dispersion liquid through a plurality of narrow tubes at high speed.

The capillary diameter of the high-pressure disperser is preferably between 1 and 1,000 μm. The pressure of the high-pressure dispersion treatment is preferably 500-2,000 kgf/cm ² , more preferably 1,000-1,800 kgf/cm ² . The temperature during the high pressure dispersion treatment is preferably 10 to 50°C, more preferably 15 to 45°C.

In one embodiment of the present invention, in preparing the first coating liquid, it is preferable to perform a cation exchange treatment to reduce the amount of Na in the first coating liquid. Cation exchange treatment can be performed with a cation exchange resin.
Examples of cation exchange resins include resins into which functional groups having cation exchange ability have been introduced. Cation exchange resins can be classified according to the acidity of the functional groups. Specifically, the cation exchange resin can be classified into a strongly acidic cation exchange resin having a sulfo group or the like as a functional group, or a weakly acidic cation exchange resin having a carboxy group or the like as a functional group. Examples of resins into which functional groups having cation exchange ability are introduced include styrene-based resins, acrylic-based resins, and methacrylic-based resins. Cation exchange resins are classified into gel type and macroporous type depending on the difference in resin structure such as the degree of cross-linking and porosity. The cation exchange resin that can be used in the preparation of the first coating liquid is not particularly limited, and commercial products may be used. Examples of commercially available products include "Duolite C255LFH" manufactured by Rohm and Haas, "Diaion SK1B" manufactured by Mitsubishi Chemical, and "Amberlite IR120B" manufactured by Dow Chemical. The amount of cation exchange resin used and the time of cation exchange treatment can be appropriately adjusted according to the target amount of Na.

(Coating and drying)
The method of applying the first coating liquid onto the substrate is not particularly limited, and may be a batch method or a continuous method. For example, gravure such as direct gravure and reverse gravure. roll coating method, double roll beat coating method, bottom feed triple reverse coating method, doctor knife method, die coating method, bar coating method, dipping method, spray coating method, curtain coating method, spin coating method, flexo coating method, screen coating method, method using a brush or a writing brush, and the like.

Although the method for drying the coating film formed on the substrate by applying the first coating liquid is not particularly limited, it is preferable to use a drying furnace or a heater to heat the coating film. The drying temperature is preferably 50 to 150° C., more preferably 60 to 150° C., further preferably 70 to 140° C. The drying time is preferably 0.1 to 120 seconds, more preferably 0.2 to 100 seconds, More preferably, it is 0.5 to 70 seconds. Drying is preferably carried out in an atmospheric atmosphere of normal pressure.

<Second layer forming step>
In the second layer forming step, a second coating liquid is applied on the first layer formed in the first layer forming step, and the coating film is dried to form a second layer on the first layer. is a step of forming a layer of

(Second coating liquid)
The second coating liquid contains resin A, an inorganic stratiform compound, a liquid medium, and, if necessary, additives. The second layer in the gas barrier laminate of the present invention is formed by removing the liquid medium from the coating film of the second coating liquid by drying. , for example, resin A, inorganic stratiform compound and additives, the description of each component in the <Second layer> section applies similarly. In addition, regarding the content of each component in the second coating liquid relative to the solid content of the second coating liquid, the content of each component relative to the total mass of the second layer in the section <Second layer> The statements apply equally. The solid content of the second coating liquid represents all components of the second coating liquid excluding the liquid medium.

The liquid medium contained in the second coating liquid may be the same as the liquid medium contained in the first coating liquid. The statements regarding the liquid medium contained in the liquid apply analogously.

In one embodiment of the present invention, the content of the liquid medium is preferably 90 to 99.5% by mass, more preferably 91 to 99% by mass, more preferably 91 to 99% by mass, more preferably 92 to 98% by mass. Therefore, with respect to the total mass of the second coating liquid, the solid content of the second coating liquid is preferably 0.5 to 10% by mass, more preferably 1 to 9% by mass, further preferably 2 to 8% by mass. When the content of the liquid medium and the solid content of the second coating liquid are within the above ranges, gas barrier properties and film-forming properties are likely to be improved.

The second coating liquid can be prepared by mixing and stirring the resin A, the inorganic stratiform compound, the liquid medium, and, if necessary, additives. The mixing order and mixing method of each component are not particularly limited, and can be prepared, for example, by the following methods (1') to (3').
(1′) Resin A and a liquid medium are mixed and stirred while heating to prepare a solution of Resin A, and an inorganic layered compound and optional additives are added to the obtained resin solution and stirred. A method of dispersing an inorganic layered compound and/or an additive in the resin solution.
(2') An inorganic layered compound and optional additives are mixed with a liquid medium and stirred to prepare a dispersion containing the inorganic layered compound, and the obtained dispersion is treated in the same manner as in method (1') above. A method of mixing and stirring with a separately prepared solution of resin A.
(3′) A dispersion containing an inorganic layered compound is prepared in the same manner as in method (2′) above, and resin A is added to the obtained dispersion and stirred with heating to obtain resin A as described above. A method of dissolving in a liquid medium in a dispersion.

The temperature at which the resin A is dissolved in the liquid medium or the dispersion containing the inorganic stratiform compound is preferably 50 to 100° C., more preferably 60 to 100° C., and the stirring speed is preferably 300 to 5.5° C. 000 rpm, more preferably 500 to 3,000 rpm, the peripheral speed of stirring is preferably 1 to 8 m/min, more preferably 2 to 6 m/min, and the stirring time is preferably 10 to 120 minutes, more preferably is 20-110 minutes.

The temperature at which the inorganic stratiform compound and optional additives are dispersed in the liquid medium or the solution of resin A is preferably 20 to 100°C, more preferably 30 to 80°C, and the stirring speed is preferably 500. 5,000 rpm, more preferably 1,000 to 5,000 rpm, the peripheral speed of stirring is preferably 1 to 20 m/min, more preferably 2 to 15 m/min, and the stirring time is preferably 10 to 150 minutes, more preferably 20 to 120 minutes.

In order to improve the dispersibility of the inorganic stratiform compound, it is preferable to perform a high-pressure dispersion treatment of the dispersion liquid containing the inorganic stratiform compound using a high-pressure dispersion apparatus. Regarding the high-pressure dispersion treatment, the description regarding the high-pressure dispersion treatment in the section (First Coating Liquid) is similarly applicable.

In one embodiment of the present invention, it is preferable to reduce the amount of Na in the second coating liquid by performing a cation exchange treatment in the preparation of the second coating liquid. Regarding the cation exchange treatment, the description regarding the cation exchange treatment in the section (First Coating Liquid) applies similarly.

(Coating and drying)
The method of applying the second coating liquid on the first layer and the drying method of the coating film formed on the first layer by applying the second coating liquid are not particularly limited. It can be carried out by the same method as the method of applying the first coating liquid in the layer forming step and the method of drying the coating film formed from the first coating liquid.

INDUSTRIAL APPLICABILITY The gas barrier laminate of the present invention has good gas barrier properties and high water peel strength, and is therefore useful as a packaging material for foods, cosmetics, and the like.

EXAMPLES The present invention will be described in more detail below based on examples and comparative examples, but the present invention is not limited to the following examples.

[1. material〕
Raw materials used in Examples and Comparative Examples are shown below.

<Resin>
NVF: vinylamine-vinyl alcohol copolymer (“Ultiloc 5003” manufactured by Sekisui Specialty Chemicals America, L.L.C., random copolymer, amount of amino groups in NVF: 2.3 mmol/g, hydroxy groups in NVF amount: 20 mmol / g, number average molecular weight: 20,000, degree of saponification: 99.0%)
PVA1: polyvinyl alcohol ("RS2117" manufactured by Kuraray Co., Ltd., number average molecular weight: 190,000, degree of saponification: 99.6%)
PVA2: Polyvinyl alcohol ("Poval 105" manufactured by Kuraray Co., Ltd., number average molecular weight: 65,000, degree of saponification: 98.5%)

<Inorganic layered compound>
High-purity montmorillonite ("Kunipia G" manufactured by Kunimine Industries, unit crystal layer thickness a: 1.2156 nm, average grain size: 560 nm, aspect ratio: 460)

<Liquid medium>
Ion-exchanged water (specific electrical conductivity: 0.7 μs/cm or less)
ethanol

<Additive>
Cross-linking agent: bifunctional epoxy compound (“Denacol EX-920” manufactured by Nagase ChemteX Corporation, epoxy equivalent: 176 g/equivalent)

[2. Measurement method and evaluation method]
The raw materials used in Examples and Comparative Examples and the properties of the obtained gas barrier laminates were measured and evaluated as follows.

<Hydroxy Group Amount and Amino Group Amount in NVF>
(1) The monomer ratio of the precursor vinyl acetate-N-vinylformamide copolymer was measured by ¹ H NMR.
(2) A vinyl acetate-N-vinylformamide copolymer was hydrolyzed to produce a vinylamine-vinyl alcohol copolymer.
(3) The residual amounts of vinyl acetate and N-vinylformamide were measured by ¹ H NMR.
(4) The residual amount (mol) of vinyl acetate and N-formaldehyde was converted to 1 g of NVF, and the amount of hydroxy groups (mmol/g) and the amount of amino groups (mmol/g) in NVF were calculated.
(Measuring device and conditions)
¹ H NMR apparatus (400 MHz): "Bruker Avance 400" manufactured by Bruker
Solvent: DMSO- _d6
Sample concentration: 1% by mass
Measurement temperature: 25°C
Accumulated times: 16 times D1 (delay between pulses): 0.1 second

<Number average molecular weight of resin>
The number average molecular weights of NVF and PVA were determined by gel permeation chromatography (GPC) with the following equipment and conditions. The results are as above.
(equipment and conditions)
GPC device: "Viscotek TDA305" manufactured by Malvern
Column: SOLDEX "SB804X2+802.5"
Sample solution: aqueous solution containing measurement sample (concentration 1% by mass), NaNO ₃ (pH adjuster, concentration 0.05M) and sodium azide (antifungal agent, concentration 0.00077M) Detector temperature: 30°C
Column temperature: 30°C

<Oxygen Permeability of Gas Barrier Laminate>
The gas barrier properties of the gas barrier laminates obtained in Examples and Comparative Examples were evaluated by oxygen permeability. The oxygen permeability was measured under conditions of 23° C. and 75% RH in accordance with JIS K7126-2-2006 using an oxygen permeability measuring device (“OX-TRANML” manufactured by MOCON). Table 1 shows the results.

<Measurement of peel strength with water>
A urethane-based adhesive (manufactured by Toyo-Morton Co., Ltd.) was applied to the coating film of the uppermost layer of the gas barrier laminates obtained in Examples and Comparative Examples, and dried in a hot air oven at 80°C for 20 minutes. A layer was formed (adhesive layer thickness: 16 μm). A non-stretched polypropylene film (“P1111” manufactured by Toyobo Co., Ltd.) with a thickness of 50 μm as a sealant is attached to this adhesive layer by a dry lamination method, and aged at 40 ° C. for 1 day to obtain “base material / first layer/second layer/adhesive layer/sealant)", "substrate/first layer/adhesive layer/sealant)" or "substrate/second layer/adhesive layer/sealant)" A laminate for peel strength evaluation having a laminate structure was obtained.
Cut the obtained laminate for peel strength evaluation into strips with a width of 15 mm, and part of the obtained strip-shaped laminate for peel strength evaluation is manually peeled off by 5 mm or more so that the base material or sealant does not break. let me After several drops of water were dropped on the peeled interface with a pipette or a syringe, the base material and the sealant were closed and the water was permeated for 2 seconds. Thereafter, the sealant and the base material of the laminate for peel strength evaluation were sandwiched with chucks of a testing machine, with the base material side that had been peeled off in advance facing down and the sealant side facing up. In addition, if the adhesion is strong and it is not possible to pre-peel as described above, do not pre-peel. sandwiched between the chucks. The peel strength between the base material and the sealant was measured at 23 ° C. according to the test method specified in Japanese Industrial Standards JIS-K6854-3: 1999 "Adhesives-Peel adhesion strength test method-Part 3: T-type peel". , 50% RH and tensile speed were measured at 300 mm/min using a small desktop tester ("EZ-LX" manufactured by Shimadzu Corporation). The measurement was carried out while dripping water onto the peeled surface using a pipette or syringe so that water was always present on the peeled surface (so that a pool of water was present at the interface). FIG. 1 shows an image diagram during the measurement.
Table 1 shows the results. In addition, when the base material or the sealant was broken and the peel strength could not be measured, it is described as "broken".

<Example 1>
1. Preparation of First Coating Liquid 110 g of ion-exchanged water and 30 g of NVF were added to a polypropylene container, and the temperature was raised to 90° C. while stirring the mixture of ion-exchanged water and NVF at 1,000 rpm. After heating, the mixture was stirred at 90° C. and 1,000 rpm for 60 minutes to dissolve NVF in water. The resulting resin solution was cooled to 60° C. or below. After cooling, 77 g of ethanol was added to the resin solution over 5 minutes while stirring at 60° C. or less and 1,000 rpm, and further stirred at 1,000 rpm for 10 minutes to obtain solution (A). This solution (A) was diluted with a diluent (water/ethanol = 2/1 (mass ratio)) so that the solid content was 1.3% by mass to obtain a first coating liquid. .
The content of NVF in the first coating liquid (100% by mass) was 1.3% by mass, and the content of the liquid medium (water and ethanol) was 98.7% by mass. The amount of ethanol was 33.3 parts by mass with respect to 100 parts by mass of the liquid medium.

2. Preparation of Second Coating Liquid A solution (A) was obtained in the same manner as the first coating liquid.
Next, 15 g of montmorillonite was added to 360 g of ion-exchanged water, and the mixture was stirred at room temperature and 3,500 rpm for 30 minutes to obtain dispersion liquid (B).
The solution (A) and the dispersion (B) are placed in a polypropylene container, and the ratio of the resin in the solution (A) and the inorganic layered compound in the dispersion (B) is resin/inorganic layered compound = 60/40 (mass ratio). A mixture of solution (A) and dispersion (B) was stirred at room temperature and 3,500 rpm for 60 minutes. After that, 5 g of ion-exchanged water and 153 g of ethanol were added to the mixture over 15 minutes, and the mixture was stirred at room temperature for 10 minutes to obtain a dispersion liquid (C).
The resulting dispersion (C) was subjected to high-pressure dispersion treatment using a high-pressure dispersing device (Microfluidics Corporation "Ultra-High Pressure Homogenizer M110-E/H", capillary diameter: 100 μm) under conditions of 30° C. and 1250 kgf/cm ^{2 .} to obtain a dispersion (D).
A cation exchange resin (Duolite C255LFH (manufactured by Rohm and Haas Japan) in an amount of 3.0 parts by mass per 100 parts by mass of the obtained dispersion (D) was added to the dispersion (D), Cation exchange was then carried out, and then the cation exchange resin was removed from the dispersion (D) by filtration to obtain a dispersion (E).The content of NVF in the dispersion (E) (100% by mass) The content of montmorillonite was 2.0% by mass, the content of the liquid medium (water and ethanol) was 94.0% by mass, and 100 parts by mass of the liquid medium. This dispersion (E) was diluted with a diluent (water/ethanol = 2/1 (mass ratio)) to a solid content of 4.0 mass%. to obtain a second coating liquid.
The content of NVF in the second coating liquid (100% by mass) is 2.7% by mass, the content of montmorillonite is 1.3% by mass, and the content of the liquid medium (water and ethanol) is It was 96.0% by mass. The amount of ethanol was 33.3 parts by mass with respect to 100 parts by mass of the liquid medium.

3. Preparation of Gas Barrier Laminate A first coating liquid was applied to the corona-treated surface of a 20 μm-thick biaxially oriented polypropylene film (hereinafter referred to as “OPP”) (“FOA” manufactured by Futamura Chemical Co., Ltd.) using a bar coater. , dried in a hot air oven at 100 ° C. for 1 minute to form a first layer on the substrate, a laminate of substrate / first layer (thickness of the first layer: 0.1 μm) got Next, the second coating liquid is applied and dried on the first layer in the same manner as the first coating liquid, and the substrate / first layer / second layer (second layer A gas barrier laminate having a thickness of 0.2 μm was produced. In addition, drying was performed in the air atmosphere of a normal pressure.

<Example 2>
In the preparation of the dispersion liquid (C) in the second coating liquid, except that the solution (A) and the dispersion liquid (B) were mixed so that NVF/inorganic layered compound = 67/33 (mass ratio), A gas barrier laminate was produced in the same manner as in Example 1.

<Example 3>
A gas barrier laminate was produced in the same manner as in Example 2, except that the thickness of the second layer was 0.4 μm.

<Example 4>
A gas barrier laminate was produced in the same manner as in Example 2, except that PVA1 was used instead of NVF in the second coating liquid and that the dispersion (D) was not ion-exchanged.

<Example 5>
A gas barrier laminate was produced in the same manner as in Example 2, except that PVA1 was used instead of NVF in the second coating liquid.

<Example 6>
In the preparation of the first coating liquid, the dispersion liquid (B) was mixed with the solution (A) so that NVF/inorganic layered compound = 70/30 (mass ratio), and the obtained solution (A) and Gas barrier lamination in the same manner as in Example 2, except that the mixture with the dispersion (B) was subjected to high-pressure dispersion treatment and cation exchange in the same manner as in the preparation of the dispersion (D) and the dispersion (E). made the body.

<Example 7>
In the preparation of the first coating liquid, the dispersion liquid (B) was mixed with the solution (A) so that NVF/inorganic layered compound = 67/33 (mass ratio), and the obtained solution (A) and The mixture with dispersion (B) was subjected to high-pressure dispersion treatment and cation exchange in the same manner as in the preparation of dispersion (D) and dispersion (E), and dispersion in the second coating liquid In the preparation of the liquid (C), the gas barrier was prepared in the same manner as in Example 1, except that the solution (A) and the dispersion liquid (B) were mixed so that NVF/inorganic layered compound = 70/30 (mass ratio). A laminate was produced.

<Example 8>
In the preparation of the first coating liquid, the dispersion liquid (B) was mixed with the solution (A) so that NVF/inorganic layered compound = 60/40 (mass ratio), and the obtained solution (A) and A gas barrier laminate in the same manner as in Example 2 except that the mixture with dispersion (B) was subjected to high-pressure dispersion treatment and cation exchange in the same manner as in the preparation of dispersion (D) and dispersion (E). was made.

<Example 9>
In the preparation of the first coating liquid, the dispersion liquid (B) was mixed with the solution (A) so that NVF/inorganic layered compound = 50/50 (mass ratio), and the resulting solution (A) and A gas barrier laminate in the same manner as in Example 2 except that the mixture with dispersion (B) was subjected to high-pressure dispersion treatment and cation exchange in the same manner as in the preparation of dispersion (D) and dispersion (E). was made.

<Example 10>
A gas barrier laminate was produced in the same manner as in Example 2, except that NVF and PVA2 were mixed so that NVF/PVA2 = 80/20 (mass ratio) in the preparation of solution (A) in the first coating liquid. bottom.

<Example 11>
A gas barrier laminate was produced in the same manner as in Example 4, except that NVF and PVA2 were mixed so that NVF/PVA2 = 70/30 (mass ratio) in the preparation of solution (A) in the first coating liquid. bottom.

<Example 12>
A gas barrier laminate was produced in the same manner as in Example 4, except that NVF and PVA2 were mixed so that NVF/PVA2 = 50/50 (mass ratio) in the preparation of solution (A) in the first coating liquid. bottom.

<Example 13>
A gas barrier laminate was produced in the same manner as in Example 2, except that NVF and PVA2 were mixed so that NVF/PVA2 = 20/80 (mass ratio) in the preparation of solution (A) in the first coating liquid. bottom.

<Example 14>
In the first coating liquid, in the same manner as in Example 2, except that the cross-linking agent (EX-920) was added to the solution (A) so that NVF/cross-linking agent = 90/10 (mass ratio). A gas barrier laminate was produced.

<Example 15>
In the preparation of the dispersion (C) in the second coating liquid, the solution (A), the dispersion (B) and the cross-linking agent (EX-920) were mixed with NVF/inorganic layered compound/cross-linking agent = 61/30/9 ( A gas barrier laminate was produced in the same manner as in Example 14, except that the components were mixed so as to satisfy the mass ratio.

<Comparative Example 1>
A gas barrier laminate was produced in the same manner as in Example 2, except that the first layer was not formed between the substrate and the second layer.

<Comparative Example 2>
In the preparation of the dispersion (C) in the second coating liquid, the solution (A) and the dispersion (B) were mixed so that NVF/inorganic layered compound = 80/20 (mass ratio), and A gas barrier laminate was produced in the same manner as in Comparative Example 1, except that the thickness of the second layer was 0.1 μm.

<Comparative Example 3>
A gas barrier laminate was produced in the same manner as in Example 4, except that the first layer was not formed between the substrate and the second layer.

<Comparative Example 4>
A gas barrier laminate was produced in the same manner as in Example 1, except that the second layer was not formed on the first layer.

<Comparative Example 5>
Gas barrier in the same manner as in Example 1, except that PVA2 was used instead of NVF in the preparation of solution (A) in the first coating liquid, and the second layer was not formed on the first layer. A laminate was produced.

<Comparative Example 6>
A gas barrier laminate was produced in the same manner as in Comparative Example 4, except that NVF and PVA2 were mixed so that NVF/PVA2 = 10/90 (mass ratio) in the preparation of solution (A) in the first coating liquid. bottom.

<Comparative Example 7>
In the preparation of the solution (A) in the first layer, instead of NVF, a urethane-based primer (manufactured by Toyo Morton Co., Ltd., main agent: EL-510-1-17K (polyester), 83% by mass, and a curing agent: CAT A gas barrier laminate was produced in the same manner as in Example 1, except that -RT87 (polyisocyanate-based, 17% by mass) was used and the second layer was not formed on the first layer.

<Comparative Example 8>
In the preparation of the solution (A) in the first layer, instead of NVF, a urethane-based primer (manufactured by Toyo Morton Co., Ltd., main agent: EL-510-1-17K (polyester), 83% by mass, and a curing agent: CAT A gas barrier laminate was produced in the same manner as in Example 2, except that -RT87 (polyisocyanate-based, 17% by mass) was used.

Table 1 shows the measurement results and evaluation results of Examples and Comparative Examples. In addition, "cissing" in the table refers to a coating film defect (surface defect ) occurred, indicating that the gas barrier laminate could not be obtained or that each evaluation could not be performed.

As shown in Table 1, it was confirmed that the gas barrier laminates obtained in Examples had lower oxygen permeability, higher gas barrier properties, and higher water peel strength than Comparative Examples.

Claims (16)

A gas barrier laminate comprising a substrate, a first layer and a second layer in this order,
The first layer contains an amino group-containing resin, the amount of amino groups in the first layer is 0.3 mmol / g or more,
A laminate, wherein the second layer comprises a resin containing at least one functional group selected from the group consisting of a hydroxyl group, a carboxyl group, an amino group and a sulfo group, and an inorganic stratiform compound. 2. The laminate according to claim 1, wherein the content of the inorganic stratiform compound in the second layer is 1 to 50% by mass with respect to the total mass of the second layer. 3. The laminate according to claim 1, wherein the resin contained in the second layer contains at least one functional group selected from the group consisting of hydroxy groups and amino groups. 4. The laminate according to any one of claims 1 to 3, wherein the resin contained in the second layer contains a resin containing a hydroxy group. 5. The laminate according to any one of claims 1 to 4, wherein the resin containing a hydroxy group contained in the second layer is a vinyl alcohol resin. 6. The laminate according to any one of claims 1 to 5, wherein the resin containing a hydroxy group contained in the second layer includes a resin containing an amino group in addition to the hydroxy group. The laminate according to any one of claims 1 to 6, wherein the amount of amino groups (mmol/g) in the first layer is higher than the amount (mmol/g) of amino groups in the second layer. 8. The laminate according to any one of claims 1 to 7, wherein the first layer contains, in addition to the amino group-containing resin, a resin containing a hydroxyl group and not containing an amino group. 9. The laminate according to claim 8, wherein the resin containing a hydroxyl group but not containing an amino group contained in the first layer is a vinyl alcohol resin containing no amino group. 10. The laminate according to any one of claims 1 to 9, wherein the amino group-containing resin contained in the first layer contains a resin containing a hydroxy group in addition to an amino group. The laminate according to any one of claims 1 to 10, wherein the amino group-containing resin contained in the first layer contains a vinylamine-vinyl alcohol copolymer. The laminate according to any one of claims 1 to 11, wherein the content of the inorganic stratiform compound in the first layer is 50% by mass or less with respect to the total mass of the first layer. 1. The first layer and/or the second layer further comprises at least one additive selected from the group consisting of a cross-linking agent, an ultraviolet absorber, an antioxidant, a surfactant and an antirust agent. 13. The laminate according to any one of 12. 14. The laminate of claim 13, wherein said additive comprises a cross-linking agent. 15. The laminate according to claim 14, wherein said cross-linking agent has an epoxy group. A step of forming a first layer containing an amino group-containing resin on a substrate, and at least one functional group selected from the group consisting of a hydroxy group, a carboxy group, an amino group and a sulfo group on the first layer and a step of forming a second layer containing an inorganic stratiform compound.

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