JP7088361B1 - Gas barrier laminates, packaging materials, packaging and packaging articles - Google Patents

Abstract

PROBLEM TO BE SOLVED: To have excellent content resistance to wet heat treatment such as retort treatment and boiling treatment, to suppress deterioration of gas barrier property and generation of delamination even when wet heat treatment is applied, and gas barrier property to further be excellent in storage stability of contents. To provide a laminate, and packaging materials, packaging bodies and packaging articles using the same. SOLUTION: An inorganic vapor deposition layer containing an inorganic oxide, a carboxy group-containing polymer (a), polyvalent metal-containing particles (b) and a surfactant on a base material and at least one surface of the base material. A gas barrier laminated body including a coating layer containing (c) in this order is provided. In this gas barrier laminate, the maximum peak height (α) attributable to −COO— in the range of 1490 to 1659 cm-1 and the maximum peak height (α) in the range of 1660 to 1750 cm-1 in the infrared absorption spectrum of the coating layer. The ratio of the maximum peak height (β) attributable to COOH expressed by α / α + β is 0.3 or more. [Selection diagram] Fig. 1

Description

The present invention relates to gas barrier laminates, packaging materials, packaging bodies and packaging articles.

Goods such as foods, pharmaceuticals, cosmetics, pesticides, and industrial products may deteriorate in quality due to oxygen when stored for a long period of time. Therefore, films and sheets having an oxygen gas barrier property are used as packaging materials for these articles.

As such a packaging material, a material provided with an aluminum foil as a gas barrier coating layer has been widely used in the past. However, when packaging materials containing aluminum foil are used, the contents are not visible and, moreover, metal detectors cannot be used. Therefore, especially in the fields of foods and pharmaceuticals, there has been a demand for the development of transparent packaging materials having excellent gas barrier properties.

Under such a requirement, a gas barrier laminate having a layer made of PVDC by applying a coating liquid containing polyvinylidene chloride (PVDC) on a base material has been used. The layer made of PVDC is transparent and has a gas barrier property.

However, PVDC is concerned about the generation of dioxins when incinerated. Therefore, the transition from PVDC to non-chlorine materials was required. Under such a requirement, it has been proposed to use, for example, a polyvinyl alcohol (PVA) -based polymer instead of PVDC.

The layer made of PVA-based polymer has a high density due to hydrogen bonds of hydroxyl groups, and exhibits high gas barrier properties in a low humidity atmosphere. However, the layer made of PVA-based polymer has a problem that hydrogen bonds are loosened by moisture absorption in a high humidity atmosphere and the gas barrier property is greatly deteriorated. Therefore, a gas barrier laminate using a layer made of a PVA-based polymer as a gas barrier coating layer cannot often be used as a packaging material for foods containing a large amount of water, and is used as a packaging material for dried products. Was limited to.

It has been proposed to add an inorganic layered compound to the PVA-based polymer for the purpose of further improving the gas barrier property (see, for example, Patent Document 1). However, even if the inorganic layered compound is added, the water resistance of the PVA-based polymer itself is not improved, so that there still remains a problem that the gas barrier property is lowered in a high humidity atmosphere.

In order to improve the gas barrier property in a high humidity atmosphere, a coating liquid containing a PVA-based polymer and a polymer capable of forming a crosslinked structure is applied to a base material and heat-treated to cause a gas barrier laminating. It has been proposed to manufacture a body (see, for example, Patent Documents 2 and 3).

However, in order to obtain sufficient gas barrier properties with these techniques, it is necessary to heat-treat the coating liquid after coating at a high temperature, for example, 150 ° C. or higher to form a crosslinked structure. Such heat treatment causes severe deterioration of the base material, for example, when the material of the base material is a polyolefin such as Oriented polypropylene (OPP) or polyethylene (Polyethylene; PE). Therefore, there is a demand for a gas barrier laminate that can be manufactured under milder conditions and the material of the base material is limited.

As another method for forming a gas barrier coating layer, a method for exhibiting gas barrier properties by ion-crosslinking a polycarboxylic acid polymer with polyvalent metal ions has been proposed (see, for example, Patent Document 4).

This method does not require the high temperature heat treatment performed by the methods described in Patent Documents 2 and 3. Therefore, polyolefin can be used as the base material. Further, the obtained gas barrier coating layer has excellent gas barrier properties even in a high humidity atmosphere. Therefore, the gas barrier laminate containing the gas barrier coating layer can also be used for wet heat treatment such as boiling and retort.

However, when the polycarboxylic acid-based polymer and the polyvalent metal compound coexist in the coating liquid, the polycarboxylic acid-based polymer and the polyvalent metal compound react with each other in the coating liquid, and precipitation is likely to occur. If precipitation occurs in the liquid, a uniform film cannot be formed. Therefore, in this method, the gas barrier coating layer is a multilayer structure including a first aqueous layer containing a polycarboxylic acid-based resin as a main component and a second aqueous layer in which fine particles of a polyvalent metal compound are dispersed as the coating layer. To form a film.

Japanese Unexamined Patent Publication No. 6-093133 Japanese Unexamined Patent Publication No. 2000-289154 Japanese Unexamined Patent Publication No. 2000-336195 Japanese Patent No. 5278802

In the above method for exhibiting gas barrier properties by cross-linking a polycarboxylic acid polymer with polyvalent metal ions, as described above, the gas barrier coating layer is a first aqueous layer containing a polycarboxylic acid resin as a main component. And a second aqueous layer in which fine particles of the polyvalent metal compound are dispersed, and the film is formed as a multilayer structure. In this multi-layered gas barrier coating layer, the cross-linking reaction of the polycarboxylic acid-based polymer by polyvalent metal ions proceeds so much in the film forming stage (meaning before the wet heat treatment such as retort treatment and boiling treatment). Not. By performing a wet heat treatment, the polyvalent metal ions generated in the second aqueous layer are transferred to the first aqueous layer in the multi-layered gas barrier coating layer, and the polycarboxylic acid polymer is ion-crosslinked to have gas barrier properties. Is expressed.

As a result of diligent research by the present inventors, when the gas barrier coating layer is composed of the first and second aqueous layers, a wet heat treatment is performed with the actual contents filled, such as retort treatment and boiling treatment, and then. When stored for a long period of time, polyvalent metal ions in the second aqueous layer may permeate inside and react with, for example, acetic acid contained in the contents to inhibit the cross-linking reaction of the polycarboxylic acid polymer. It turned out that there was. In this case, problems such as deterioration of gas barrier property and generation of delamination may occur.

In this way, even if the contents such as foods are filled in the package and subjected to moist heat treatment such as retort treatment and boiling treatment, or then stored for a long period of time, the polyvalent metal ions in the gas barrier coating layer are the contents. It is desired to develop a gas-barrier laminate in which the deterioration of the gas barrier property and the occurrence of delamination are suppressed due to the reaction with the components of the above and the inhibition of the cross-linking reaction.

INDUSTRIAL APPLICABILITY The present invention has excellent content resistance to wet heat treatment such as retort treatment and boiling treatment, and even if wet heat treatment is performed, deterioration of gas barrier property and generation of delamination are suppressed, and gas barrier having excellent storage stability of contents. It is an object of the present invention to provide a sex laminate, and a packaging material, a packaging body, and a packaging article using the same.

According to the first aspect of the present invention, the substrate, the inorganic vapor deposition layer containing an inorganic oxide, the carboxy group-containing polymer (a), and the polyvalent metal-containing particles (b) on at least one surface of the substrate. ) And a coating layer containing the surfactant (c) in this order, ^and in the -COO- within the range of 1490 to 1659 cm ^-1 in the infrared absorption spectrum of the coating layer. Gas barrier property in which the ratio of the maximum peak height (α) attributed to α / α + β of the maximum peak height (β) attributed to −COOH in the range of 1660 to 1750 cm ^-1 is 0.3 or more. Laminates are provided.

In the embodiment of the present invention, when the gas barrier laminate is subjected to a wet heat treatment under the following conditions, the peak height ratio α / α + β in the infrared absorption spectrum of the coating layer may be 0.4 or more.
Wet heat treatment conditions: Retort treatment at 120 ° C. for 30 minutes and pressure 0.2 MPa.

Further, in the embodiment of the present invention, the coating layer may further contain the silicon-containing compound (d). The silicon-containing compound (d) is at least one selected from the group consisting of silane coupling agents represented by the following general formulas (1) and (2), hydrolysates thereof, and condensates thereof. It may be there.

Si (OR ₁ ) ₃ Z ₁ ... (1)
Si (R ₂ ) (OR ₃ ) ₂ Z ₂ ... (2)
In the general formula (1), R ₁ is an alkyl group having 1 to 6 carbon atoms, which may be the same or different, and Z ₁ is a group containing an epoxy group, and is a general formula (2). ), R ₂ is a methyl group, R ₃ is an alkyl group having 1 to 6 carbon atoms which may be the same or different, and Z ₂ is a group containing an epoxy group.

Further, in the embodiment of the present invention, the carboxy group-containing polymer (a) is at least one α, selected from the group consisting of acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid and fumaric acid. It may contain a structural unit derived from β-monoethylenically unsaturated carboxylic acid.

Further, in the embodiment of the present invention, the multivalent metal constituting the polyvalent metal-containing particles (b) may be a divalent metal.

Further, in the embodiment of the present invention, the gas barrier laminate may further include an anchor coat layer between the base material and the inorganic vapor-deposited layer.

According to the second aspect of the present invention, a packaging material containing the gas barrier laminate is provided.

According to the third aspect of the present invention, a package containing the above packaging material is provided.

According to the fourth aspect of the present invention, there is provided a packaged article containing the packaged body and the contents contained in the packaged body.

According to the present invention, the contents have excellent resistance to wet heat treatment such as retort treatment and boiling treatment, and even if the wet heat treatment is performed, deterioration of gas barrier property and generation of delamination are suppressed, and further, storage stability of the contents is improved. It becomes possible to provide an excellent gas barrier laminated body, and a packaging material, a packaging body, and a packaging article using the same.

The cross-sectional view schematically which shows the gas barrier laminated body which concerns on one Embodiment of this invention. FIG. 3 is a sectional view schematically showing a gas barrier laminated body according to another embodiment of the present invention.

Hereinafter, the present embodiment will be described with reference to the drawings. Elements having similar or similar functions are designated by the same reference numerals, and duplicate description will be omitted.

FIG. 1 is a cross-sectional view schematically showing a gas barrier laminated body according to the first embodiment of the present invention. The gas barrier laminate 10 shown in FIG. 1 includes a base material 1, an inorganic thin-film deposition layer 2 containing an inorganic oxide, and a coating layer 3.

<Coating layer>
The coating layer 3 contains the carboxy group-containing polymer (a), the polyvalent metal-containing particles (b) and the surfactant (c) described in detail below. The carboxy group-containing polymer (a) is ion-crosslinked with polyvalent metal ions derived from the polyvalent metal-containing particles (b).

The coating layer 3 has a maximum peak height (maximum absorbance) (α) belonging to −COO ⁻ in the range of 1490 to 1659 cm ^-1 in the infrared absorption spectrum and −COOH in the range of 1660 to 1750 cm ^-1 . The ratio of the maximum peak height (maximum absorbance) (β) to which it belongs is expressed by α / α + β is 0.3 or more. In the following, this α / α + β ratio will be referred to as “peak height ratio α / α + β” or simply “α / α + β ratio”.

The absorbance of the coating layer 3 is proportional to the amount of infrared active chemical species present in the coating layer 3. Therefore, the peak height ratio α / α + β is a measure of the progress of the ionic cross-linking reaction on the carboxy group-containing polymer (a) by the polyvalent metal ions derived from the polyvalent metal-containing particles (b) in the coating layer 3. ..

In the gas barrier laminate 10, the ion cross-linking reaction is proceeding with the peak height ratio α / α + β of the infrared absorption spectrum being 0.3 or more in the film forming stage before the wet heat treatment. Therefore, the gas barrier laminated body 10 has excellent content resistance to wet heat treatment such as retort treatment and boiling treatment in a state where the contents are contained, and deterioration of gas barrier properties due to the components of the contents when the contents are subjected to the wet heat treatment. The occurrence of heat treatment and delamination is suppressed, and the storage stability is also excellent.

Here, moist heat treatment is a process of heat-treating a package containing contents under conditions such as retort treatment and boiling treatment at an appropriate temperature, time, relative humidity, or pressure in a closed container. be.

For example, a case where the wet heat treatment is a retort treatment will be described. The retort treatment is generally a treatment of pressurizing and sterilizing microorganisms such as mold, yeast, and bacteria in order to store foods and the like. In the retort treatment, a packaged article, which is usually made by packaging food in a package, is sterilized under pressure for 10 to 120 minutes at a temperature of 105 to 140 ° C. under a pressure of 0.15 to 0.3 MPa. To process. The retort device includes a steam type that uses heated steam and a hot water type that uses pressurized superheated water, and these are appropriately used according to the sterilization conditions of the food or the like as the content.

Further, a case where the wet heat treatment is a boiling treatment will be described. The boil treatment is a treatment of moist heat sterilization for preserving foods and the like. In the boil treatment, although it depends on the contents, usually, a packaged article obtained by packaging the contents such as food in a package is placed under atmospheric pressure at a temperature of 60 to 100 ° C. for 10 to 120 minutes. Wet heat sterilization treatment. The boiling treatment is usually performed using a hot water tank. The boil treatment includes a batch type in which the packaged article is immersed in a hot water tank at a constant temperature and taken out after a certain period of time, and a continuous type in which the packaged article is passed through a tunnel type in the hot water tank to be sterilized.

If the wet heat treatment conditions for the packaged article are strict or the content resistance of the package is poor, the gas barrier property deteriorates due to the components of the content and delamination occurs after the wet heat treatment. As described above, in the gas barrier laminate according to the embodiment of the present invention, the ion cross-linking reaction proceeds when the peak height ratio α / α + β of the infrared absorption spectrum is 0.3 or more in the film forming stage before the wet heat treatment. However, since the content resistance is excellent, even if the wet heat treatment is performed under severe conditions from the above-mentioned wet heat treatment conditions, deterioration of the gas barrier property and occurrence of delamination due to the components of the content are suppressed.

The peak height ratio α / α + β of the coating layer 3 in the gas barrier laminate 10 before the wet heat treatment is 0.3 or more, preferably 0.4 or more, more preferably 0.5 or more as described above. be. The upper limit of the peak height ratio α / α + β is not particularly limited and is 1 or less.

Further, in the gas barrier laminate 10 according to the present embodiment, when the wet heat treatment is performed under the following conditions, the peak height α / α + β of the coating layer 3 is preferably 0.4 or more, preferably 0.6 or more. It is more preferable to have. The upper limit of the peak height ratio α / α + β of the infrared absorption spectrum after the wet heat treatment is not particularly limited and is 1 or less.
Wet heat treatment conditions: Retort treatment at 120 ° C. for 30 minutes and pressure 0.2 MPa.

[Carboxy group-containing polymer (a)]
The carboxy group-containing polymer (a) contained in the coating layer 3 is a polymer having two or more carboxy groups in the molecule, and may be hereinafter referred to as a “polycarboxylic acid-based polymer”. As described above, the carboxy group-containing polymer (a) forms an ion crosslink with the metal ion derived from the polyvalent metal-containing particles (b) described later in the coating layer 3, and exhibits excellent gas barrier properties. .. Examples of the carboxy group-containing polymer (a) include a homopolymer of a carboxy group-containing unsaturated monomer, a copolymer of two or more kinds of carboxy group-containing unsaturated monomers, and a carboxy group-containing unsaturated monomer. Typical examples are copolymers with other polymerizable monomers and polysaccharides containing a carboxy group in the molecule (also referred to as "carboxy group-containing polysaccharide" or "acidic polysaccharide").

The carboxy group includes not only a free carboxy group but also an acid anhydride group (specifically, a dicarboxylic acid anhydride group). The acid anhydride group may be partially ring-opened to form a carboxy group. Some of the carboxy groups may be neutralized with alkali. In this case, the degree of neutralization is preferably 20% or less.

Here, the "neutralization degree" is a value obtained by the following method. That is, the carboxy group can be partially neutralized by adding an alkali (ft) to the carboxy group-containing polymer (a). At this time, the ratio of the number of moles (ft) of the alkali (f) to the number of moles (at) of the carboxy group contained in the carboxy group-containing polymer (a) is the degree of neutralization.

Further, a graft polymer obtained by graft-polymerizing a carboxy group-containing unsaturated monomer to a carboxy group-free polymer such as polyolefin can also be used as the carboxy group-containing polymer (a). It is also possible to use a polymer obtained by hydrolyzing a polymer having a hydrolyzable ester group such as an alkoxycarbonyl group (for example, a methoxycarbonyl group) and converting it into a carboxy group.

As the carboxy group-containing unsaturated monomer, α, β-monoethyl unsaturated carboxylic acid is preferable. Therefore, the carboxy group-containing polymer (a) includes a homopolymer of α, β-monoethyl unsaturated carboxylic acid, a copolymer of two or more kinds of α, β-monoethyl unsaturated carboxylic acid, and a copolymer of α, β-monoethyl unsaturated carboxylic acid. It contains a copolymer of α, β-monoethyl unsaturated carboxylic acid and other polymerizable monomers. As the other polymerizable monomer, an ethylenically unsaturated monomer is typical.

Examples of the α, β-monoethylene unsaturated carboxylic acid include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; unsaturated dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid; anhydrous. Unsaturated dicarboxylic acid anhydrides such as maleic acid and itaconic acid anhydride; and mixtures of two or more of these can be mentioned. Among these, at least one α, β-monoethyl unsaturated carboxylic acid selected from the group consisting of acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, and itaconic acid is preferable, and acrylic acid and methacrylic acid are preferable. At least one α, β-monoethyl unsaturated carboxylic acid selected from the group consisting of acid and maleic acid is more preferable.

Other polymerizable monomers copolymerizable with the α, β-monoethylenically unsaturated carboxylic acid, particularly ethylenically unsaturated monomers include, for example, ethylene; propylene, 1-butene, 1-pentene, 1 -Α-olefins such as hexene and 1-octene; saturated carboxylic acid vinyl esters such as vinyl acetate; acrylic acid alkyl esters such as methyl acrylate and ethyl acrylate; methacrylic acids such as methyl methacrylate and ethyl methacrylate Alkyl esters; Chlorine-containing vinyl monomers such as vinyl chloride and vinylidene chloride; Fluorine-containing vinyl monomers such as vinyl fluoride and vinylidene fluoride; Unsaturated nitriles such as acrylonitrile and methacrylonitrile; styrene and α- Aromatic vinyl monomers such as methylstyrene; as well as itaconic acid alkyl esters can be mentioned. These ethylenically unsaturated monomers can be used alone or in combination of two or more. When the carboxy group-containing polymer is a copolymer of α, β-monoethyl unsaturated carboxylic acid and saturated carboxylic acid vinyl esters such as vinyl acetate, the copolymer is saponified to saturate carboxylic acid. A copolymer obtained by converting an acid vinyl ester unit into a vinyl alcohol unit can also be used.

Examples of the carboxy group-containing polysaccharide include acidic polysaccharides having a carboxy group in the molecule such as alginic acid, carboxymethyl cellulose, and pectin. These acidic polysaccharides can be used alone or in combination of two or more. Acidic polysaccharides can also be used in combination with (co) polymers of α, β-monoethyl unsaturated carboxylic acids.

When the carboxy group-containing polymer is a copolymer of α, β-monoethylene unsaturated carboxylic acid and other ethylenically unsaturated monomers, the gas barrier property, heat resistance and water resistance of the obtained film, and From the viewpoint of water resistance, the ratio of the number of moles of α, β-monoethyl unsaturated carboxylic acid monomer to the total number of moles of those monomers is 60 mol% or more in the polymer. It is preferably 80 mol% or more, more preferably 90 mol% or more, and particularly preferably 90 mol% or more.

The carboxy group-containing polymer (a) is excellent in gas barrier property, moisture resistance, water resistance, heat resistance and water resistance, and is easy to obtain a film having excellent gas barrier property under high humidity conditions. , A homopolymer or copolymer obtained by polymerizing only β-monoethyl unsaturated carboxylic acid is preferable. When the carboxy group-containing polymer (a) is a (co) polymer consisting of only α, β-monoethyl unsaturated carboxylic acid, preferred specific examples thereof are acrylic acid, methacrylic acid, crotonic acid, maleic acid, and fumal. It is a homopolymer, a copolymer, and a mixture of two or more thereof obtained by polymerization of at least one α, β-monoethylene unsaturated carboxylic acid selected from the group consisting of acid and itaconic acid. Among these, homopolymers and copolymers of at least one α, β-monoethyl unsaturated carboxylic acid selected from the group consisting of acrylic acid, methacrylic acid, and maleic acid are more preferable.

As the carboxy group-containing polymer (a), polyacrylic acid, polymethacrylic acid, polymaleic acid, and a mixture of two or more thereof are particularly preferable. As the acidic polysaccharide, alginic acid is preferable. Among these, polyacrylic acid is particularly preferable because it is relatively easy to obtain and it is easy to obtain a film having excellent various physical characteristics.

The number average molecular weight of the carboxy group-containing polymer (a) is not particularly limited, but the number average molecular weight is preferably in the range of 2,000 to 10,000,000 from the viewpoint of film formability and film physical characteristics. , 5,000 to 1,000,000, more preferably 10,000 to 500,000.

Here, the "number average molecular weight" is a value obtained by measurement by gel permeation chromatography (GPC). In GPC measurement, the number average molecular weight of the polymer is generally measured in terms of standard polystyrene.

[Multivalent metal-containing particles (b)]
The polyvalent metal-containing particles (b) contained in the coating layer 3 are preferably particles containing at least one type of polyvalent metal having a metal ion valence of 2 or more. The polyvalent metal-containing particles (b) may be particles made of a polyvalent metal having a metal ion valence of 2 or more, and are particles made of a polyvalent metal compound having a metal ion valence of 2 or more. It may be a mixture thereof.

Specific examples of polyvalent metals include short-period periodic table 2A metals such as beryllium, magnesium, and calcium; transition metals such as titanium, zirconium, chromium, manganese, iron, cobalt, nickel, copper, and zinc; And aluminum, but is not limited to these.

The polyvalent metal is preferably a divalent metal. Further, it is preferable that the polyvalent metal forms a compound.

Specific examples of the compound of the polyvalent metal include, but are not limited to, oxides, hydroxides, carbonates, organic acid salts, and inorganic acid salts of the polyvalent metal. Examples of the organic acid salt include acetate, oxalate, citrate, lactate, phosphate, phosphite, hypophosphite, stearate, and monoethylene unsaturated carboxylate. However, but not limited to these. Examples of the inorganic acid salt include, but are not limited to, chlorides, sulfates, and nitrates. The polyvalent metal alkyl alkoxide can also be used as the polyvalent metal compound. These polyvalent metal compounds can be used alone or in combination of two or more.

Among the polyvalent metal compounds, compounds of beryllium, magnesium, calcium, copper, cobalt, nickel, zinc, aluminum, and zirconium are preferable from the viewpoint of gas barrier properties of the gas barrier laminate 10, and berylium, magnesium, calcium, copper, etc. Compounds of divalent metals such as zinc, cobalt, and nickel are more preferred.

Preferred divalent metal compounds include, for example, oxides such as zinc oxide, magnesium oxide, copper oxide, nickel oxide, and cobalt oxide; carbonates such as calcium carbonate; organics such as calcium lactate, zinc lactate, and calcium acrylate. Examples include, but are not limited to, alkoxides such as acid salts; as well as magnesium methoxydos.

The polyvalent metal or the polyvalent metal compound is used as particles. The polyvalent metal particles (b) include the dispersion stability of the coating liquid (hereinafter, referred to as “coating liquid for forming the coating layer” or simply “coating liquid”) used for forming the coating layer 3 described later, and the dispersion stability. Gas barrier properties From the viewpoint of gas barrier properties, those having an average particle size in the coating liquid in the range of 10 nm to 10 μm (or 10,000 nm) are preferably used. The polyvalent metal particles (b) are more preferably in the range of 12 nm to 1 μm (or 1,000 nm), and further preferably in the range of 15 nm to 500 nm, as the average particle size in the coating liquid. It is particularly preferably in the range of 15 nm to 50 nm.

If the average particle size of the polyvalent metal-containing particles (b) is too large, the uniformity of the film thickness of the coating layer 3, the flatness of the surface, the ionic cross-linking reactivity with the carboxy group-containing polymer (a), and the like are insufficient. It is easy to become. If the average particle size of the polyvalent metal-containing particles (b) is too small, the ionic cross-linking reaction with the carboxy group-containing polymer (a) may proceed at an early stage. Further, if the average particle size of the polyvalent metal-containing particles (b) is too small, it may be difficult to uniformly disperse the polyvalent metal-containing particles (b) in the coating liquid.

The average particle size of the polyvalent metal-containing particles (b) can be measured by measuring and counting using a scanning electron microscope or a transmission electron microscope when the sample is a dry solid. .. The average particle size of the polyvalent metal-containing particles (b) in the coating liquid can be measured by a light scattering method. 2001)].

The polyvalent metal-containing particles in the coating liquid exist as primary particles, secondary particles, or a mixture thereof, but in many cases, it is presumed that they exist as secondary particles in view of the average particle size.

[Surfactant (c)]
The coating layer 3 contains a surfactant (c) in order to enhance the dispersibility of the polyvalent metal-containing particles (b). Surfactants are compounds that have both hydrophilic and lipophilic groups in the molecule. Surfactants include anionic, cationic, and amphoteric ionic and nonionic surfactants. Any surfactant may be used in the coating layer 3.

The anionic surfactant includes, for example, a carboxylic acid type, a sulfonic acid type, a sulfate ester type, and a phosphoric acid ester type. Examples of the carboxylic acid type anionic surfactant include an aliphatic monocarboxylate, a polyoxyethylene alkyl ether carboxylate, an N-acylsarcosate, and an N-acylglutamate. Examples of the sulfonic acid type anionic surfactant include dialkyl sulfosuccinate, alkane sulfonate, alpha olefin sulfonate, linear alkyl benzene sulfonate, alkyl (branched chain) benzene sulfonate, and naphthalene sulfonic acid. Included are salt-formaldehyde condensates, alkylnaphthalene sulfonates, and N-methyl-N-acyltaurate. Examples of the sulfate ester type anionic surfactant include alkyl sulfates, polyoxyethylene alkyl ether sulfates, and oil and fat sulfates. Examples of the phosphoric acid ester type anionic surfactant include an alkyl phosphate type, a polyoxyethylene alkyl ether phosphate, and a polyoxyethylene alkyl phenyl ether phosphate.

Examples of the cationic surfactant (c) include an alkylamine salt type and a quaternary ammonium salt type. Examples of the alkylamine salt type cationic surfactant include monoalkylamine salts, dialkylamine salts, and trialkylamine salts. Examples of the quaternary ammonium salt type cationic surfactant include halogenated (chloride, bromide or iodide) alkyltrimethylammonium salt and alkylbenzalkonium chloride.

The amphoteric tenside includes, for example, a carboxybetaine type, a derivative type of 2-alkylimidazoline, a glycine type, and an amine oxide type. Examples of the carboxybetaine type amphoteric tenside agent include alkyl betaine and fatty acid amide propyl betaine. Examples of the amphoteric surfactant of the derivative form of 2-alkylimidazolin include 2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium betaine. Examples of the glycine-type amphoteric surfactant include alkyl or dialkyldiethylenetriaminoacetic acid. Examples of the amino oxide type amphoteric surfactant include alkylamine oxides.

Nonionic surfactants include, for example, ester type, ether type, ester ether type, and alkanolamide type. Examples of the ester-type nonionic surfactant include glycerin fatty acid ester, sorbitan fatty acid ester, and sucrose fatty acid ester. Examples of the ether type nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, and polyoxyethylene polyoxypropylene glycol. Examples of the ester ether type nonionic surfactant include fatty acid polyethylene glycol and fatty acid polyoxyethylene sorbitan. Examples of the alkanolamide type nonionic surfactant include fatty acid alkanolamide.

Surfactants having a polymer skeleton, such as styrene-acrylic acid copolymers, can also be used.

Among these surfactants, anionic surfactants such as phosphate esters and surfactants having a polymer skeleton such as styrene-acrylic acid copolymers are preferable.

[Silicon-containing compound (d)]
The coating layer 3 preferably contains the silicon-containing compound (d) in order to increase the peel strength. The silicon-containing compound (d) is derived from a silane coupling agent represented by the following general formula (1), a silane coupling agent represented by the following general formula (2), hydrolysates thereof, and condensates thereof. At least one compound selected from the group consisting of.
Si (OR ₁ ) ₃ Z ₁ ... (1)
Si (R ₂ ) (OR ₃ ) ₂ Z ₂ ... (2)
In the general formula (1), R ₁ is an alkyl group having 1 to 6 carbon atoms, which may be the same or different, and Z 1 is a group containing an epoxy group. Then, in the general formula (2), R ₂ is a methyl group, R ₃ is an alkyl group having 1 to 6 carbon atoms which may be the same or different, and Z ₂ is an epoxy group. It is a group contained.

The silane coupling agent easily undergoes hydrolysis and also easily undergoes a condensation reaction in the presence of an acid or alkali. Therefore, in the coating layer 3, the silicon-containing compound (d) is contained only in the form of the silane coupling agent represented by the general formula (1) or (2), only in the form of its hydrolyzate, or its condensate. It rarely exists only in the form of. That is, in the coating layer 3, the silicon-containing compound (d) is usually at least one of the silane coupling agent represented by the general formula (1) and the silane coupling agent represented by the general formula (2), and the silane coupling agent thereof. It is mixed as a mixture of the hydrolyzate and its condensate.

Each of R ₁ and R ₃ in the general formulas (1) and (2) may be an alkyl group having 1 to 6 carbon atoms, and is preferably a methyl group or an ethyl group. Each of Z ₁ and Z ₂ may be a group containing an epoxy group, and may be, for example, an organic group having a glycidyloxy group.

Specific examples of the silane coupling agent represented by the general formula (1) or (2) include 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 3-. Examples thereof include glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane, and 3-glycidoxypropylmethyldimethoxysilane and 3-glycidoxypropyltri. Propyl methoxysilane is preferred. As the silane coupling agent, one kind or two or more kinds may be used.

The hydrolyzate of the silane coupling agent represented by the general formula (1) or (2) may be a partial hydrolyzate, a complete hydrolyzate, or a mixture thereof. good.

The condensate that the coating layer 3 can contain as at least a part of the silicon-containing compound (d) is a hydrolyzed condensate of a silane coupling agent represented by the general formula (1) and a silane represented by the general formula (2). Hydrolyzed condensate of coupling agent and condensate of hydrolyzed product of silane coupling agent represented by general formula (1) and hydrolyzed product of silane coupling agent represented by general formula (2). 2 or more. These hydrolyzed condensates are produced by the following reactions. That is, first, the silane coupling agent is hydrolyzed. As a result, the silane coupling agent becomes a hydrolyzate by substituting one or more of the alkoxy groups contained in the molecule with the hydroxyl group. Subsequently, by condensing these hydrolysates, a compound in which silicon atoms (Si) are bonded via oxygen is formed. By repeating this condensation, a hydrolyzed condensate is obtained.

〔composition〕
The coating layer 3 preferably contains the carboxy group-containing polymer (a) and the polyvalent metal-containing particles (b) in the following compounding ratios. That is, the product of the number of moles of the polyvalent metal contained in the polyvalent metal-containing particles (b) and the number of _valences with respect to the number of moles (at) of the carboxy group contained in the carboxy group-containing polymer (a). The ratio of b _t ) (( _bt ) / ₍ at)) (hereinafter, also referred to as equivalent ratio) is preferably 0.4 or more. This ratio is more preferably 0.8 or more, and particularly preferably 1.0 or more. The upper limit of this ratio is usually 10.0 or less, preferably 2.0 or less. If this ratio is made too small, various properties such as gas barrier property, heat resistance and water vapor resistance of the gas barrier layered body 10 tend to be deteriorated.

The above equivalent ratio can be obtained, for example, as follows. The case where the carboxy group-containing polymer (a) is polyacrylic acid and the polyvalent metal compound particles (b) are magnesium oxide will be described as an example.

Polyacrylic acid has a molecular weight of 72 in a monomer unit and has one carboxy group per monomer molecule. Therefore, the amount of carboxy groups in 100 g of polyacrylic acid is 1.39 mol. The above equivalent ratio of 1.0 in the coating solution containing 100 g of polyacrylic acid means that the coating layer 3 contains 1.39 mol of magnesium oxide in an amount that neutralizes the carboxy group. Means that you are. Therefore, in order to make the above equivalent ratio in the coating layer 3 containing 100 g of polyacrylic acid 0.6, magnesium oxide in an amount that neutralizes 0.834 mol of carboxy groups should be added to the coating layer 3. Just do it. Here, the valence of magnesium is divalent, and the molecular weight of magnesium oxide is 40. Therefore, in order to set the above equivalent ratio in the coating layer 3 containing 100 g of polyacrylic acid to 0.6, 16.68 g (0.417 mol) of magnesium oxide may be added to the coating layer 3.

The surfactant (c) is used in an amount sufficient to stably disperse the polyvalent metal-containing particles in the coating liquid. Therefore, when the blending amount is explained as the concentration in the coating liquid for forming a coating layer, it is usually 0.0001 to 70% by mass, preferably 0.001 to 60% by mass, more preferably 0.1 in the coating liquid. It shall be in the range of 50% by mass.

Without the addition of the surfactant (c), it becomes difficult to disperse the polyvalent metal-containing particles (b) in the coating liquid so that their average particle size is sufficiently small. As a result, it becomes difficult to obtain a coating liquid in which the multivalent metal-containing particles (b) are uniformly dispersed. In that case, it becomes difficult to obtain a coating layer 3 having a uniform film thickness in the coating layer 3 obtained by applying a coating liquid on the inorganic thin-film deposition layer 2 and drying it.

The coating layer 3 contains the silicon-containing compound (d) in the molar number of carboxy groups (at) contained in the carboxy group-containing polymer (a) from the viewpoint of achieving both high gas barrier properties and transparency in the gas barrier laminate 10. ), The molar ratio (dt) / (at) of the number of moles (dt) of the silicon-containing compound (d) is preferably 0.15% or more and 6.10% or less. Here, (dt) in the molar ratio (dt) / (at) is the number of moles of the silicon-containing compound (d) converted into a silane coupling agent.

When the amount of the silicon-containing compound (d) added is too small and the molar ratio (dt) / (at) is lower than 0.15%, the peel strength of the gas barrier laminate 10 tends to decrease. Therefore, careful handling is required to prevent delamination, which leads to a decrease in productivity.

From the above viewpoint, the molar ratio (dt) / (at) of the number of moles (dt) of the silicon-containing compound (d) to the number of moles (at) of the carboxy group contained in the carboxy group-containing polymer (a) is 0. It is preferably 3% or more, more preferably 0.46% or more, and particularly preferably 0.61% or more.

On the other hand, when the amount of the silicon-containing compound (d) added is too large and the molar ratio (dt) / (at) is higher than 6.10%, the transparency of the gas barrier laminate 10 tends to decrease. Further, the silicon-containing compound (d) does not have a gas barrier property. Therefore, when the molar ratio (dt) / (at) is higher than 6.10%, not only the transparency of the laminate is lowered, but also the gas barrier property tends to be lowered.

From the above viewpoint, the molar ratio (dt) / (at) of the number of moles (dt) of the silicon-containing compound (d) to the number of moles (at) of the carboxy group contained in the carboxy group-containing polymer (a) is 4. It is preferably 57% or less, more preferably 3.66% or less, and particularly preferably 2.13% or less.

The film thickness of the coating layer 3 is 230 nm or more and 600 nm or less from the viewpoint of achieving both transparency and gas barrier properties. Here, the film thickness of the coating layer 3 is specifically a film thickness measured by a method for measuring the film thickness of the coating layer, which will be described later. The film thickness of the coating layer 3 is preferably 250 nm or more and 500 nm or less, and more preferably 300 nm or more and 450 nm or less.

<Inorganic vapor deposition layer>
The gas barrier laminate 10 according to the present embodiment includes an inorganic thin-film deposition layer 2 between the base material 1 and the coating layer 3. As a result, the gas barrier property of the gas barrier layered body 10 provided with the coating layer 3 can be further enhanced, and both transparency and a high degree of gas barrier property can be achieved at the same time.

The inorganic vapor deposition layer 2 contains an inorganic oxide. Examples of the inorganic oxide include aluminum oxide, silicon oxide, magnesium oxide, tin oxide and the like. Among these, aluminum oxide, silicon oxide, magnesium oxide, or a mixture of any two or more thereof is preferable from the viewpoint of achieving both transparency and gas barrier property.

The thickness of the inorganic thin-film deposition layer 2 may be, for example, in the range of 5 to 100 nm, and may be in the range of 10 to 50 nm. It is preferable that the thickness of the inorganic thin-film layer 2 is 5 nm or more from the viewpoint of forming a uniform thin film. If the thin film as the gas barrier material is uniform, the functions required for the gas barrier material can be sufficiently fulfilled. It is preferable that the thickness of the inorganic thin-film layer 2 is 100 nm or less from the viewpoint of the flexibility of the thin film. If the gas barrier material has poor flexibility, cracks may occur due to external factors such as bending and pulling.

<Base material>
The base material 1 included in the gas barrier laminate 10 according to the present embodiment is not particularly limited, and various types can be used. The material constituting the base material 1 is not particularly limited, and various types can be used, and examples thereof include plastic and paper.

The base material 1 may be a single layer made of a single material, or may be a multilayer made of a plurality of materials. An example of a multi-layered substrate is a film made of plastic laminated on paper.

Among the above-mentioned materials, plastic is preferable as the material constituting the base material 1 because it can be molded into various shapes and its use is further expanded by imparting gas barrier properties.

The plastic is not particularly limited, but for example, a polyolefin resin such as polyethylene and polypropylene; a polyester resin such as polyethylene terephthalate, polyethylene-2,6-naphthalate, polybutylene terephthalate, and a copolymer thereof; nylon-6. , Nylon-66, Nylon-12, Metaxylylene adipamide, and polyamide-based resins such as copolymers thereof; styrene-based resins such as polystyrene, styrene-butadiene copolymer, and styrene-butadiene-acrylonitrile copolymer. Resin; poly (meth) acrylic acid ester; polyacrylonitrile; polyvinyl acetate; ethylene-vinyl acetate copolymer; ethylene-vinyl alcohol copolymer; polycarbonate; polyarylate; regenerated cellulose; polyimide; polyetherimide; polysulphon; Polymer sulphon; polyether ketones; and ionomer resins can be mentioned.

When the gas barrier laminate is used as a food packaging material, the base material 1 is preferably made of polyethylene, polypropylene, polyethylene terephthalate, nylon-6 or nylon-66.

As the plastic constituting the base material 1, one type may be used alone, or two or more types may be blended and used.

Additives may be blended in the plastic. The additive can be appropriately selected from known additives such as pigments, antioxidants, antistatic agents, ultraviolet absorbers, and lubricants, depending on the intended use. As the additive, one type may be used alone, or two or more types may be used in combination.

The form of the base material 1 is not particularly limited, and examples thereof include films, sheets, cups, trays, tubes, and bottles. Among these, the film is preferable.

When the base material 1 is a film, this film may be a stretched film or an unstretched film.

The thickness of the film is not particularly limited, but it is preferably in the range of 1 to 200 μm, preferably in the range of 5 to 100 μm, from the viewpoint of the mechanical strength and processability of the obtained gas barrier laminate. More preferred.

Radical activity by plasma treatment, corona treatment, ozone treatment, flame treatment, or ultraviolet (UV) or electron beam so that the coating liquid can be applied to the surface of the base material 1 without being repelled by the base material. It may have been subjected to a chemical treatment or the like. The treatment method is appropriately selected depending on the type of the base material.

[Other layers]
If necessary, the gas barrier laminate according to the present embodiment may further include one or more layers other than the base material 1, the inorganic vapor deposition layer 2, and the coating layer 3.

For example, the gas barrier laminate according to the present embodiment may include only the above-mentioned coating layer 3 as the gas barrier coating layer, but in addition to the coating layer 3, another one or more layers may be further added. It may be included. For example, a layer made of an inorganic compound such as aluminum oxide, silicon oxide, and aluminum may be formed on the surface of the base material by a sputtering method, an ion plating method, or the like.

Further, the gas barrier laminate according to the present embodiment has an object of improving the adhesion between layers or allowing the coating liquid for forming a coating layer to be applied to the inorganic vapor deposition layer without being repelled by the base material 1. An anchor coat layer may be further provided between the inorganic thin-film layer 2 or between the inorganic thin-film layer 2 and the coating layer 3.

FIG. 2 is a cross-sectional view schematically showing a gas barrier laminate according to a second embodiment of the present invention. The gas barrier laminate 20 shown in FIG. 2 further includes an anchor coat layer 4 between the base material 1 and the inorganic vapor deposition layer 2 with respect to the gas barrier laminate 10 according to the first embodiment described above.

The anchor coat layer 4 can be formed by a conventional method using a known anchor coat liquid. Examples of the anchor coating liquid include those containing resins such as polyurethane resin, acrylic resin, melamine resin, polyester resin, phenol resin, amino resin, and fluororesin.

In addition to the resin, the anchor coating liquid may further contain an isocyanate compound for the purpose of improving adhesion and heat resistance. The isocyanate compound may be any compound having one or more isocyanate groups in the molecule, and examples thereof include hexamethylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, and tolylene diisocyanate.
The anchor coating liquid may further contain a liquid medium for dissolving or dispersing the resin or the isocyanate compound.

The thickness of the anchor coat layer 4 is not particularly limited. The thickness of the anchor coat layer 4 may be, for example, in the range of 0.01 to 2 μm, and may be in the range of 0.05 to 1 μm. If the film thickness is less than 0.01 μm, it is very thin, so that the performance as an anchor coat layer may not be fully exhibited. On the other hand, it is preferable that the film thickness is 2 μm or less from the viewpoint of flexibility. When flexibility is reduced, external factors can cause cracks in the anchor coat layer.

The gas-barrier laminated body according to the present embodiment further includes another layer laminated via an adhesive on the coating layer 3 or on the surface of the base material 1 or the inorganic vapor-deposited layer 2, if necessary. It may be provided, and may be further provided with another layer formed by extruding and laminating the adhesive resin.

The other layer to be laminated can be appropriately selected according to the purpose of imparting strength, imparting sealing property, imparting easy-opening property at the time of sealing, imparting design property, imparting light blocking property, imparting moisture resistance, and the like, and in particular. Although not limited, for example, the base material may be made of the same material as the above-mentioned plastic. In addition, paper, aluminum foil, or the like may be used.

The thickness of the other layer to be laminated is preferably in the range of 1 to 1000 μm, more preferably in the range of 5 to 500 μm, still more preferably in the range of 5 to 200 μm, and 5 to 200 μm. It is particularly preferable that it is within the range of 150 μm.
The other layers to be laminated may be one type or two or more types.

The gas barrier laminate according to the present embodiment may further include a printing layer, if necessary. The printed layer may be formed on the coat layer provided on the substrate, or may be formed on the surface of the substrate on which the coat layer is not provided. Further, when another layer is laminated, it may be formed on the other layer to be laminated.

[Manufacturing method of gas barrier laminate]
The gas barrier laminate according to the present embodiment can be produced by a production method including a step of forming an inorganic vapor deposition layer and a step of forming a coating layer using the coating liquid for forming a coating layer shown below. This manufacturing method can further include, if necessary, a step of forming another layer such as an anchor coat layer and / or a step of forming a printed layer.

As an example of the method for producing the gas barrier laminate according to the present embodiment, the method for producing the gas barrier laminate 20 shown in FIG. 2 will be described below.

In the method for producing the gas barrier laminate 20, the anchor coat layer 4 is formed on the base material 1. The anchor coat layer 4 can be formed by applying the above-mentioned anchor coat liquid onto the base material 1 and drying the formed coating film. The method of applying the anchor coating liquid is not particularly limited, and a well-known printing method such as an offset printing method, a gravure printing method, or a silk screen printing method, or a well-known coating method such as a roll coat, a knife edge coat, or a gravure coat is used. Can be carried out. By drying the formed coating film, removal and curing of the solvent proceed, and the anchor coat layer 4 is formed.

In the method for producing the gas barrier laminated body 20, the inorganic thin-film deposition layer 2 is formed on the anchor coat layer 4. As a method for forming the inorganic vapor deposition layer 2, various methods such as a vacuum deposition method, a sputtering method, an ion plating method, and a chemical vapor deposition (CVD) method are known, and any method is used. Although it may be used, it is generally formed by a vacuum deposition method.
Examples of the heating means of the vacuum vapor deposition apparatus by the vacuum vapor deposition method include an electron beam heating method, a resistance heating method, an induction heating method, and the like, and any of them may be used.
It is also possible to use a plasma assist method or an ion beam assist method in order to improve the adhesion of the inorganic thin-film layer 2 to the anchor coat layer 4 and the denseness of the inorganic vapor-film layer 2.
Further, in order to increase the transparency of the inorganic thin-film vapor deposition layer 2, reaction vapor deposition may be performed by blowing oxygen gas or the like during the vapor deposition.

In the method for producing the gas barrier laminate 20, the coating layer 3 is formed on the inorganic vapor deposition layer 2. The coating layer 3 can be formed by applying a coating liquid for forming a coating layer prepared by the method described below on the inorganic vapor-filmed layer 2 and drying the formed coating film.

-Method of preparing a coating liquid for forming a coating layer In the coating liquid for forming a coating layer, an organic solvent (e) is used as a solvent or a dispersion medium. That is, this coating liquid contains a carboxy group-containing polymer (a), polyvalent metal-containing particles (b), a surfactant (c) and an organic solvent, and the polyvalent metal-containing particles (b) are dispersed. It is a dispersion liquid. The coating liquid for forming a coating layer preferably further contains the silicon-containing compound (d) in one form. Hereinafter, the preparation method when the coating for forming the coating layer contains the silicon-containing compound (d) which is an optional component will be described.

The organic solvent (e) is used in an amount sufficient to uniformly dissolve the carboxy group-containing polymer (a) and uniformly disperse the polyvalent metal-containing particles. Therefore, as the organic solvent, a solvent that dissolves the carboxy group-containing polymer but does not substantially dissolve the polyvalent metal compound and can disperse it in the form of particles is used.

Further, as the organic solvent (e), a polar organic solvent that dissolves the carboxy group-containing polymer (a) is generally used, but a polar group (an atomic group having a hetero atom or a hetero atom) is used together with the polar organic solvent. An organic solvent having no polarity may be used in combination.

Examples of the organic solvent (e) that can be preferably used include alcohols such as methanol, ethanol, isopropanol, n-propanol, and n-butanol; dimethylsulfoxide, N, N-dimethylacetamide, N, N-dimethylformamide, N. Examples include polar organic solvents such as -methyl-2-pyrrolidone, tetramethylurea, hexamethylphosphoric acid triamide, and γ-butyrolactone.

As the organic solvent (e), in addition to the above-mentioned polar organic solvent, hydrocarbons such as benzene, toluene, xylene, hexane, heptane, and octane; ketones such as acetone and methyl ethyl ketone; halogenated hydrocarbons such as dichloromethane. ; Esters such as methyl acetate; and ethers such as diethyl ether can be appropriately used. Hydrocarbons such as benzene, which do not have a polar group, are generally used in combination with a polar organic solvent.

The above coating liquid may contain only the organic solvent (e) as the solvent or the dispersion medium, but may further contain water. By containing water, the solubility of the carboxy group-containing polymer (a) can be improved, and the coatability and workability of the coating liquid can be improved. The water content of this coating liquid may be 100 ppm or more, 1,000 ppm or more, 1,500 ppm or more, or 2,000 ppm or more in terms of mass fraction. ..

The water content of this coating liquid is preferably 50,000 ppm or less, more preferably 10,000 ppm or less, still more preferably 5,000 ppm or less in terms of mass fraction.

To prepare a coating solution for forming a coating layer, on the other hand, the carboxy group-containing polymer (a) is uniformly dissolved in the organic solvent (e), and then the silicon-containing compound (d) is added thereto to carboxy. Prepare a group-containing polymer solution.

Then, on the other hand, a dispersion liquid is prepared by mixing the polyvalent metal-containing particles (b), the surfactant (c), and the organic solvent (e) and subjecting them to a dispersion treatment as necessary. The dispersion treatment is performed so that the average particle size of the polyvalent metal-containing particles (b) becomes a predetermined value. When the average particle size of the polyvalent metal-containing particles (b) in the mixed solution before the dispersion treatment is 10 μm or less, the dispersion treatment may not be performed, but it is preferable to perform the dispersion treatment even in that case. By performing the dispersion treatment, the aggregation of the multivalent metal-containing particles (b) is dissolved, the coating liquid is stabilized, and the transparency of the gas barrier laminate obtained by applying the coating liquid is enhanced. Furthermore, when the coating liquid is applied and the coating film is dried, crosslink formation between the carboxy group-containing polymer (a) and the polyvalent metal ions derived from the polyvalent metal-containing particles (b) is likely to proceed. Therefore, it is easy to obtain a gas barrier laminate having good gas barrier properties.

Examples of the dispersion treatment method include a method using a high-speed stirrer, a homogenizer, a ball mill, or a bead mill. In particular, when dispersion is performed using a ball mill or a bead mill, dispersion can be performed with high efficiency, and therefore a coating liquid having a stable dispersion state can be obtained in a relatively short time. In this case, the diameter of the ball or bead is preferably small, preferably 0.1 to 1 mm.

A coating liquid can be prepared by mixing the carboxy group-containing polymer solution prepared as described above with the dispersion liquid of the polyvalent metal-containing particles (b). In the above-mentioned preparation method, the silicon-containing compound (d) was added to the carboxyl group-containing polymer solution in advance, but the silicon-containing compound (d) was not added to the obtained solution for the carboxyl group-containing polymer, for example, carboxy. The silicon-containing compound (d) may be mixed when the group-containing polymer solution and the dispersion liquid of the polyvalent metal-containing particles (b) are mixed.

The coating liquid has a total concentration of components other than the organic solvent (e) of preferably 0.1 to 60% by mass, more preferably 0.5 to 25% by mass, and particularly preferably 1 to 20% by mass. It is preferable that it is within the range in order to obtain a coating film and a coating layer having a desired film thickness with high workability.

The above coating liquid may contain other polymers, thickeners, stabilizers, UV absorbers, antiblocking agents, softeners, inorganic layered compounds (eg, montmorillonite), and colorants (dye, as needed). Various additives such as (pigment) can be contained.

The method for applying the coating liquid is not particularly limited, but for example, a reverse roll coater such as an air knife coater, a direct gravure coater, a gravure offset, an arc gravure coater, a top feed reverse coater, a bottom feed reverse coater, and a nozzle feed reverse coater. A method of coating using a five-roll coater, a lip coater, a bar coater, a bar reverse coater, and a die coater can be mentioned.

The method for drying the coating film is not particularly limited, but for example, a method by natural drying, a method of drying in an oven set to a predetermined temperature, and a dryer attached to the coater, such as an arch dryer, a floating dryer, and a drum. A method using a dryer, an infrared dryer, or the like can be mentioned.

The drying conditions can be appropriately selected depending on the drying method and the like. For example, in the method of drying in an oven, the drying temperature is preferably in the range of 40 to 150 ° C, more preferably in the range of 45 to 150 ° C, and in the range of 50 to 140 ° C. It is particularly preferable to have. The drying time varies depending on the drying temperature, but is preferably in the range of 0.5 seconds to 10 minutes, more preferably in the range of 1 second to 5 minutes, and in the range of 1 second to 1 minute. It is especially preferable to be inside.

It is presumed that the carboxy group-containing polymer (a) contained in the coating film reacts with the polyvalent metal-containing particles (b) during or after drying to introduce an ionic crosslinked structure. In order for the ionic cross-linking reaction to proceed sufficiently, the dried film is preferably placed in an atmosphere of relative humidity in the range of preferably 20% or more, more preferably 40 to 100%, preferably 5 to 200 ° C., more preferably. It is preferably aged for about 1 second to 10 days under a temperature condition in the range of 20 to 150 ° C.

Since the gas barrier laminate thus obtained is ion-crosslinked, it is excellent in moisture resistance, water resistance, heat resistance and water resistance, and water vapor resistance. The gas barrier laminate is excellent not only in low humidity conditions but also in high humidity conditions. The gas barrier laminate preferably has an oxygen permeability measured under the conditions of a temperature of 30 ° C. and a relative humidity of 70% in accordance with the method described in JIS K-7126 B method (isopressure method) and ASTM D3985. Is 10 cm3 / (m2, day, MPa) or less.

<Packaging materials, packaging bodies and packaging articles>
The packaging material according to the present embodiment includes the above-mentioned gas barrier laminate. This packaging material is used, for example, in the manufacture of a package for packaging an article.

The package according to the present embodiment includes the above-mentioned packaging material.
This package may be made of the above-mentioned packaging material, or may include the above-mentioned packaging material and other members. In the former case, the packaging body is, for example, a bag-shaped molding of the above-mentioned packaging material. In the latter case, the packaging body is, for example, a container including the above-mentioned packaging material as a lid and a bottomed tubular container body.

In this package, the above-mentioned packaging material may be a molded product. As described above, this molded product may be a container such as a bag or a part of a container such as a lid. Specific examples of the package or a part thereof include bag-making products, pouches with spouts, laminated tubes, infusion bags, container lids, and paper containers.

There is no particular limitation on the applicable use of this package. This package can be used for packaging various articles.

The packaged article according to the present embodiment includes the above-mentioned packaged body and the contents contained therein.

As described above, the above gas barrier laminate has excellent gas barrier properties and transparency. Therefore, the packaging materials and packaging bodies containing the gas barrier laminate are used as packaging materials and packaging bodies for articles that are easily deteriorated by the influence of oxygen, steam, etc., respectively, and particularly food packaging materials and food packaging. It is preferably used as a body. These packaging materials and packaging bodies can also be preferably used as packaging materials and packaging bodies for packaging chemicals such as pesticides and pharmaceuticals, medical devices, mechanical parts, and industrial materials such as precision materials, respectively.

When the above-mentioned gas barrier laminate is subjected to heat sterilization treatment such as boiling treatment and retort treatment, the gas barrier property and interlayer adhesion do not deteriorate, and on the contrary, they tend to increase. Therefore, these packaging materials and packaging bodies may be heat sterilization packaging materials and heat sterilization packaging bodies, respectively.

The heat sterilization packaging material and the heat sterilization package are used for packaging articles that are heat sterilized after packaging.
Examples of articles that are heat sterilized after packaging include foods such as curry, stew, soup, sauce, and processed livestock meat.

Examples of the heat sterilization treatment include boiling treatment and retort treatment. The boil treatment and retort treatment are as described above.

Specific examples of the present invention will be described below.
<Preparation of coating liquid for coating layer formation>
The coating liquid for the coating layer used in each Example and each Comparative Example was prepared by the following method.
(Example 1: Coating liquid 1)
The carboxy group-containing polymer was dissolved in isopropanol by heating. As the carboxy group-containing polymer, polyacrylic acid (PAA) (Julimer (registered trademark) AC-10LP manufactured by Toagosei Co., Ltd., number average molecular weight 50,000) was used. As described above, a polyacrylic acid solution containing polyacrylic acid at a concentration of 10% by mass was prepared.

1.8 g of a polyether phosphoric acid ester (Disparon (registered trademark) DA-375 manufactured by Kusumoto Kasei Co., Ltd., solid content 100% by mass) was dissolved in 26.2 g of isopropanol. Next, 12 g of zinc oxide (FINEX® (registered trademark) -30 manufactured by Sakai Chemical Industry Co., Ltd.) having an average primary particle diameter of 35 nm was added thereto and stirred. The obtained liquid was dispersed and treated with a planetary ball mill (P-7 manufactured by Fritsch) for 1 hour. Zirconia beads having a diameter of 0.2 mm were used for this dispersion treatment. Then, beads were sieved from this liquid to obtain a dispersion liquid (ZnO dispersion liquid) containing zinc oxide at a concentration of 30% by mass.

Next, 50.00 g of a polyacrylic acid (PAA) solution, 4.71 g of a zinc oxide dispersion liquid, and 9.29 g of isopropanol were mixed to prepare a coating liquid 1. In this coating liquid 1, the equivalent ratio of the product of the number of moles of zinc contained in zinc oxide and the valence ( _bt ) to the number of moles (at) of the carboxyl group contained in polyacrylic acid ( _PAA ) _bt / at was _0.5 .

(Example 2: Coating liquid 2)
Coating by the same method as the coating liquid 1 except that the addition amounts of the zinc oxide dispersion liquid (ZnO dispersion liquid) and the isopropanol were changed to the addition amounts shown in Table 1 with respect to the above-mentioned preparation method of the coating liquid 1. Liquid 2 was prepared.

(Example 3: Coating liquid 3)
In contrast to the method for preparing the coating liquid 1 described above, in the step of mixing the polyacrylic acid solution, the zinc oxide dispersion and the isopropanol, a silane coupling agent (SC agent) as a silicon-containing compound (KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd.) , 3-Glycydoxypropyltrimethoxysilane) The coating liquid 3 was prepared by the same method as that of the coating liquid 1 except that 0.10 g was added.

(Example 4: Coating liquid 4)
In contrast to the method for preparing the coating liquid 2 described above, in the step of mixing the polyacrylic acid solution, the zinc oxide dispersion and the isopropanol, a silane coupling agent (SC agent) as a silicon-containing compound (KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd.) , 3-Glycydoxypropyltrimethoxysilane) The coating liquid 4 was prepared by the same method as the coating liquid 2 except that 0.1 g was added.

(Example C1: Coating liquid C1)
The coating liquid C1 was prepared by the same method as the coating liquid 3 except that the addition amounts of the zinc oxide dispersion liquid and isopropanol were changed to the addition amounts shown in Table 1 with respect to the above-mentioned preparation method of the coating liquid 3. ..

(Example C2: Coating liquid C2)
The zinc oxide dispersion was diluted with isopropanol according to the formulation shown in Table 1 to prepare a coating liquid C2.

<Manufacturing of gas barrier laminate>
(Preparation of anchor coat liquid)
In a diluting solvent (ethyl acetate), 5 parts by mass of an acrylic polyol was mixed with 1 part by mass of γ-isocyanatepropyltrimethoxysilane and stirred. Then, toluene diisocyanate (TDI) was added as an isocyanate compound so that the amount of NCO groups was equal to that of the OH groups of the acrylic polyol. Anchor coat liquid 1 was obtained by diluting the obtained mixed solution to a concentration of 2% by mass with the above-mentioned diluting solvent.
As the acrylic polyol, GS-5756 manufactured by Mitsubishi Rayon Co., Ltd. was used.

[Example 1]
Anchor coating liquid 1 is applied to one surface of a biaxially stretched polypropylene film (manufactured by Mitsui Chemicals Tocello Co., Ltd., trade name: ME-1, thickness 20 μm) so that the thickness after drying becomes 0.2 μm. An anchor coat layer was formed by coating with a coater and drying at 60 ° C. for 1 minute.

Alumina was vapor-deposited on the anchor coat layer to form an inorganic thin-film film having a thickness of 20 nm.

The coating liquid 1 was applied onto the inorganic thin-film deposition layer using a bar coater (wire bar). This coating film was dried in an oven at 50 ° C. for 1 minute to form a coating film having a film thickness of 400 nm. The laminated body 1 was obtained as described above.

The coating layer was separated from the obtained laminate 1, and the peak height ratio α / α + β of the infrared absorption spectrum was measured by the method described later. Further, the peak intensity of the infrared absorption spectrum was similarly measured for the coating layer after the film-forming laminated body 1 was subjected to a wet heat treatment under the following conditions.
Wet heat treatment conditions: Retort treatment at 120 ° C. for 30 minutes and pressure 0.2 MPa.

[Examples 2 to 4, Comparative Example 1]
Laminates 2 to 4 and C1 were produced by the same method as in Example 1 except that the coating liquid 1 used for forming the coating layer was changed to the coating liquid shown in Table 2. Similar to the laminated body 1, the peak intensities of the infrared absorption spectra of the coating layer were measured before and after the wet heat treatment for these laminated bodies.

[Comparative Example 2]
The laminated body C2 was produced by the same method as in Example 1 except that the coating liquids C1 and C2 were used to form the coating layer with respect to Example 1 to form the two coating layers. That is, the coating liquid C1 was applied onto the inorganic thin-film vapor deposition layer using a bar coater (wire bar), and the obtained coating film was dried in an oven at 50 ° C. for 1 minute to form a first coating film. Next, the coating liquid C2 was similarly applied onto the first coating layer and dried under the same conditions to form the second coating layer. Similar to the laminate 1, for the laminate C2, the peak intensities of the infrared absorption spectra of the first coating layer and the second coating layer were measured before and after the wet heat treatment.

<Measurement of infrared absorption spectrum>
The coating layer was separated from each of the laminates before and after the wet heat treatment to obtain a solid substance of the coating layer. The solid matter of this coating layer was measured by a total reflection measurement method (ATR) by a Fourier transform infrared spectroscope (FT-IR: manufactured by Nippon Spectroscopy (FT / IR-4600)) to obtain an infrared absorption spectrum. From the obtained infrared absorption spectrum, the maximum peak height (maximum absorbance) (α) belonging to -COO ^- in the range of 1490 to 1659 cm ^-1 and -COOH in the range of 1660 to 1750 cm ^-1 are attributed. The ratio α / α + β for the maximum peak height (maximum absorbance) (β) was determined.

<Content resistance>
Each laminate was folded and the three sides were heat-bonded to prepare a bag. This bag was filled with 150 g of water, 4% by mass acetic acid, or 6% by mass acetic acid as the contents, and the remaining side was sealed by heat adhesion to prepare a four-way seal bag filled with the contents. .. The obtained 4-way seal bag was subjected to a wet heat treatment under the conditions of 120 ° C., 30 minutes and 0.2 MPa. Oxygen permeability, laminate strength, and storage stability were measured / evaluated for each sample after this wet heat treatment by the method described below. The results are shown in Table 2.

<Oxygen Transmission Rate (OTR)>
The oxygen permeability (OTR) of each sample was measured using an oxygen permeation tester OX-TRAN (registered trademark) 2/20 manufactured by Modern Control under the conditions of a temperature of 30 ° C. and a relative humidity of 70%. The measurement method was based on JIS K-7126 B method (isopressure method) and ASTM D3985, and the measured values were expressed in units of cc / m ² / day / atm.

<Laminate strength>
Unstretched polypropylene with a thickness of 30 μm via a polyester urethane adhesive (trade name: Takelac A-969, Takenate A-5; manufactured by Mitsui Chemicals, Inc.) on the surface of each sample on the coating layer side by dry lamination processing. A film CPP (casted polypropylene) (trade name: CPP GLC, manufactured by Mitsui Chemicals Tohcello Co., Ltd.) was laminated. This was cured at 50 ° C. for 48 hours to obtain a laminated film. This laminated film is cut into strips with a width of 15 mm, and the laminated film is peeled from the CCP by 90 ° at a speed of 300 mm / min using a Tensilon tensile tester (trade name: Tensilon RTC-1250, manufactured by Orientec). T-type peeling) was performed, and the laminate strength (N / 15 mm) was measured.

<Storage stability>
Each sample was stored for 1 month in an environment of a temperature of 40 ° C. and a humidity of 90%, and then the oxygen permeability (OTR) and the laminating strength were measured by the above method.

As can be seen from Table 2, the gas barrier laminates of Examples 1 to 4 have no deterioration due to the components of the contents due to the wet heat treatment, and all of the contents resistance, the gas barrier property, the delamination resistance and the storage stability. It turns out that it is excellent.

The present invention is not limited to the above embodiment, and can be variously modified at the implementation stage without departing from the gist thereof. In addition, each embodiment may be carried out in combination as appropriate, in which case the combined effect can be obtained. Further, the above-described embodiment includes various inventions, and various inventions can be extracted by a combination selected from a plurality of disclosed constituent requirements. For example, even if some constituent elements are deleted from all the constituent elements shown in the embodiment, if the problem can be solved and the effect is obtained, the configuration in which the constituent elements are deleted can be extracted as an invention.

1 ... Substrate 2 ... Inorganic vapor deposition layer 3 ... Coating layer 4 ... Anchor coat layer 10, 20 ... Gas barrier laminate

Claims (12)

An inorganic vapor-deposited layer containing an inorganic oxide, a carboxy group-containing polymer (a), polyvalent metal-containing particles (b), and a surfactant (c) are placed on the base material and at least one surface of the base material. A gas-barrier laminate comprising a coating layer in this order, the maximum peak height (α) attributable to −COO ⁻ in the range of 1490 to 1659 cm ^-1 in the infrared absorption spectrum of the coating layer. The ratio of the maximum peak height (β) attributable to −COOH in the range of 1660 to 1750 cm ^-1 expressed by α / α + β is 0.3 or more, and the polyvalent metal-containing particles (b). A gas barrier laminated body in which the average particle size in the coating liquid for forming the coating layer is in the range of 12 nm to 1 μm . The coating layer further contains a silicon-containing compound (d), and the silicon-containing compound (d) is a silane coupling agent represented by the following general formulas (1) and (2), hydrolysates thereof, and these. The gas barrier laminate according to claim 1, which is at least one selected from the group consisting of the condensates of the above.
Si (OR ₁ ) ₃ Z ₁ ... (1)
Si (R ₂ ) (OR ₃ ) ₂ Z ₂ ... (2)
In the general formula (1), R ₁ is an alkyl group having 1 to 6 carbon atoms, which may be the same or different, and Z ₁ is a group containing an epoxy group, and is a general formula (2). ), R ₂ is a methyl group, R ₃ is an alkyl group having 1 to 6 carbon atoms which may be the same or different, and Z ₂ is a group containing an epoxy group. The carboxy group-containing polymer (a) is at least one α, β-monoethyl unsaturated carboxylic acid selected from the group consisting of acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid and fumaric acid. The gas barrier laminate according to claim 1 or 2, which comprises a structural unit derived from. The gas barrier laminate according to any one of claims 1 to 3, wherein the polyvalent metal constituting the polyvalent metal-containing particles (b) is a divalent metal. The gas barrier laminate according to any one of claims 1 to 4, further comprising an anchor coat layer between the base material and the inorganic thin-film deposition layer. The gas barrier laminate according to any one of claims 1 to 5 , wherein the surfactant (c) is a phosphoric acid ester or a styrene-acrylic acid copolymer. The gas barrier laminate according to any one of claims 1 to 6 , wherein the ratio represented by α / α + β after retort treatment at 120 ° C. for 30 minutes and a pressure of 0.2 MPa is 0.4 or more. .. The gas barrier laminate according to any one of claims 1 to 7 , which is used as a packaging material for foods containing an acetic acid component. A packaging material containing the gas barrier laminate according to any one of claims 1 to 8 . A package containing the packaging material according to claim 9 . A packaged article including the package according to claim 10 and the contents contained in the package. The packaged article according to claim 11 , wherein the content contains an acetic acid component.

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