Gas barrier laminate, coating liquid for producing the same, packaging material, packaging body, and packaged article

Abstract

According to an embodiment of the present invention, a coating liquid for producing a gas barrier laminate is provided, which contains a carboxyl group-containing polymer (a), polyvalent metal-containing particles (b), a surfactant (c), a specific silicon-containing compound (d), and an organic solvent (e). In the coating liquid, the product of the number of moles and the valence of the polyvalent metal contained in the polyvalent metal-containing particles (b) is (b). t ) relative to the molar number (a) of the carboxyl groups contained in the carboxyl group-containing polymer (a) t ) equivalent ratio b t / a t is 0.45 or more and 0.9 or less, and the molar number (d t ) relative to the molar number of the above carboxyl groups (a t ) molar ratio d t / a t It is not less than 0.7% and not more than 7.5%.

Description

Technical Field

[0001] The present invention relates to a gas barrier laminate, a coating liquid for producing the same, a packaging material, a packaging body, and a packaged article. Background Art

[0002] When storing food, medicines, cosmetics, pesticides, and industrial products for a long time, their quality may deteriorate due to oxygen. Therefore, films or sheets with oxygen barrier properties are used as packaging materials for these items.

[0003] Conventionally, aluminum foil with a gas barrier coating has been widely used as such packaging materials. However, packaging materials containing aluminum foil make it impossible to visually identify the contents and are not suitable for use with metal detectors. Therefore, in the food and pharmaceutical sectors, in particular, there is a demand for transparent packaging materials with excellent gas barrier properties.

[0004] In response to such demands, a gas barrier laminate having a layer made of polyvinylidene chloride (PVDC) formed by coating a coating liquid containing PVDC on a substrate is used. The layer made of PVDC is transparent and has gas barrier properties.

[0005] However, PVDC can generate dioxins when incinerated. Consequently, there is a demand to shift from PVDC to non-chlorine-based materials. In response to this demand, for example, the use of polyvinyl alcohol (PVA)-based polymers as a replacement for PVDC has been proposed.

[0006] Layers composed of PVA polymers achieve high density through hydrogen bonding of hydroxyl groups, exhibiting high gas barrier properties in low-humidity atmospheres. However, layers composed of PVA polymers in high-humidity atmospheres suffer from moisture absorption, weakening hydrogen bonds and significantly reducing gas barrier properties. Consequently, gas barrier laminates using layers composed of PVA polymers as gas barrier coatings are often unsuitable for packaging materials for foods containing high amounts of water, and their applications are limited to packaging materials for dry items.

[0007] In order to further improve the gas barrier properties, it has been proposed to add inorganic layered compounds to PVA-based polymers (for example, see Patent Document 1). However, even with the addition of inorganic layered compounds, the water resistance of the PVA-based polymer itself is not improved, and thus the gas barrier properties are still reduced in high humidity atmospheres.

[0008] In order to improve the gas barrier properties in a high humidity atmosphere, a method has been proposed for producing a gas barrier laminate by coating a substrate with a coating liquid containing a PVA-based polymer and a polymer that can form a cross-linked structure therewith and then heat-treating the coating liquid (for example, see Patent Documents 2 and 3).

[0009] However, to achieve sufficient gas barrier properties, these technologies require post-application heat treatment at high temperatures, such as 150°C or higher, to form a crosslinked structure. For example, if the substrate is made of a polyolefin such as polypropylene (OPP) or polyethylene (PE), such heat treatment can cause rapid degradation of the substrate. Consequently, the substrate material is limited, and there is a need for a gas barrier laminate that can be manufactured under milder conditions.

[0010] As a method for forming a gas barrier coating layer, there has also been proposed a method of forming a layer containing a polycarboxylic acid polymer such as polyacrylic acid and ionically crosslinking the polycarboxylic acid polymer with polyvalent metal ions (for example, see Patent Document 4).

[0011] This method eliminates the need for high-temperature heat treatment required by the methods described in Patent Documents 2 and 3. Therefore, polyolefins can be used as substrates. Furthermore, the resulting gas-barrier coating layer exhibits excellent gas-barrier properties even in high-humidity atmospheres. Therefore, a gas-barrier laminate containing this gas-barrier coating layer can also be used for heat sterilization treatments such as boiling or retorting.

[0012] However, when a polycarboxylic acid polymer and a polyvalent metal compound coexist in a coating liquid, the polycarboxylic acid polymer and the polyvalent metal compound tend to react in the coating liquid, forming a precipitate. When precipitates form in the liquid, a uniform film cannot be formed. Therefore, in this method, when forming the gas barrier coating layer, a layer containing the polycarboxylic acid polymer and a layer containing the polyvalent metal compound are formed separately. Therefore, when using this method, the number of steps required to achieve a two-layer structure for the gas barrier coating increases.

[0013] Patent Document 5 discloses a gas barrier film containing a polycarboxylic acid polymer and polyvalent metal compound particles in the same gas barrier coating layer. This proposal proposes a coating solution for forming the gas barrier coating layer, comprising a polycarboxylic acid polymer, polyvalent metal compound particles, a surfactant, and an organic solvent, with a water content of 1000 ppm or less. This coating solution, with a water content of 1000 ppm or less, suppresses the reaction between the polycarboxylic acid polymer and the polyvalent metal compound.

[0014] This document describes that the use of the aforementioned coating solution can form a film with excellent gas barrier properties under high-humidity conditions. However, the gas barrier properties of a laminate formed by applying this coating solution may be reduced under more severe conditions, specifically, after exposure to high-temperature, high-humidity, or high-temperature, high-pressure atmospheres such as boiling or retorting, and when subjected to physical stress (abuse) such as bending.

[0015] Prior art literature

[0016] Patent Literature

[0017] Patent Document 1: Japanese Patent Application Laid-Open No. 6-093133

[0018] Patent Document 2: Japanese Patent Application Laid-Open No. 2000-289154

[0019] Patent Document 3: Japanese Patent Application Laid-Open No. 2000-336195

[0020] Patent Document 4: International Publication No. 2003 / 091317

[0021] Patent Document 5: Japanese Patent Application Laid-Open No. 2005-126528 Summary of the Invention

[0022] Problems to be solved by the present invention

[0023] The object of the present invention is to provide a gas barrier laminate having excellent abuse resistance that can withstand treatment in high-temperature and high-humidity environments or high-temperature and high-pressure environments such as retorting and boiling treatments, and can maintain a high degree of gas barrier properties even when subjected to abuse such as bending, as well as a coating liquid for its production, a packaging material, a packaging body, and a packaged article.

[0024] Means for solving problems

[0025] According to a first aspect of the present invention, there is provided a coating liquid for producing a gas barrier laminate, comprising: a carboxyl group-containing polymer (a), polyvalent metal-containing particles (b), a surfactant (c), a silicon-containing compound (d), and an organic solvent (e), wherein 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), their hydrolyzates, and their condensates, and the product of the number of moles and the valence of the polyvalent metal contained in the polyvalent metal-containing particles (b) (b) is 1: t ) relative to the molar number (a) of the carboxyl groups contained in the carboxyl group-containing polymer (a) t ) equivalent ratio b t / a t is 0.45 or more and 0.9 or less, and the molar number (d t ) relative to the molar number of the above carboxyl groups (a t ) molar ratio d t / a t The molar ratio d t / a t d in t It is the number of moles of the silicon-containing compound (d) converted into the silane coupling agent.

[0026] Si(OR1)3Z1···(1)

[0027] Si(R2)(OR3)2Z2···(2)

[0028] In the general formula (1), R1 may be the same or different and is an alkyl group having 1 to 6 carbon atoms, and Z1 is a group containing an epoxy group. In the general formula (2), R2 is a methyl group, R3 may be the same or different and is an alkyl group having 1 to 6 carbon atoms, and Z2 is a group containing an epoxy group.

[0029] According to the second aspect of the present invention, there is provided the coating liquid according to the first aspect, wherein the carboxyl group-containing polymer (a) comprises at least one constituent unit derived from at least one α,β-monoethylenically unsaturated carboxylic acid selected from the group consisting of acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid and fumaric acid.

[0030] According to a third aspect of the present invention, there is provided the coating solution according to the first or second aspect, wherein the polyvalent metal contained in the polyvalent metal-containing particles (b) is a divalent metal.

[0031] According to a fourth aspect of the present invention, there is provided a gas barrier laminate comprising, in order, a substrate, an inorganic vapor-deposited layer containing an inorganic oxide on at least one main surface of the substrate, and a coating layer, wherein the coating layer contains a carboxyl group-containing polymer (a), polyvalent metal-containing particles (b), a surfactant (c), and a silicon-containing compound (d), wherein 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), their hydrolyzates, and their condensates, and the product of the number of moles and the valence of the polyvalent metal contained in the polyvalent metal-containing particles (b) (b) is 1. t ) relative to the molar number (a) of the carboxyl groups contained in the carboxyl group-containing polymer (a) t ) of the equivalent ratio b t / a t is 0.45 or more and 0.9 or less, and the molar number (d t ) relative to the molar number of the above carboxyl groups (a t ) molar ratio d t / a t The molar ratio d t / a t d in t It is the number of moles of the silicon-containing compound (d) converted into the silane coupling agent.

[0032] Si(OR1)3Z1···(1)

[0033] Si(R2)(OR3)2Z2···(2)

[0034] In the general formula (1), R1 may be the same or different and is an alkyl group having 1 to 6 carbon atoms, and Z1 is a group containing an epoxy group. In the general formula (2), R2 is a methyl group, R3 may be the same or different and is an alkyl group having 1 to 6 carbon atoms, and Z2 is a group containing an epoxy group.

[0035] According to the fifth aspect of the present invention, there is provided the gas barrier laminate according to the fourth aspect, wherein the carboxyl group-containing polymer (a) comprises at least one structural unit derived from at least one α,β-monoethylenically unsaturated carboxylic acid selected from the group consisting of acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, and fumaric acid.

[0036] According to a sixth aspect of the present invention, there is provided the gas barrier laminate according to the fourth or fifth aspect, wherein the polyvalent metal contained in the polyvalent metal-containing particles (b) is a divalent metal.

[0037] According to a seventh aspect of the present invention, there is provided the gas barrier laminate according to any one of the fourth to sixth aspects, wherein the coating layer has a thickness of 230 nm to 600 nm.

[0038] According to an eighth aspect of the present invention, there is provided the gas barrier laminate according to any one of the fourth to seventh aspects, further comprising an anchor coating layer between the substrate and the inorganic vapor-deposited layer.

[0039] According to a ninth aspect of the present invention, there is provided a packaging material comprising the gas barrier laminate according to any one of the fourth to eighth aspects.

[0040] According to a tenth aspect of the present invention, there is provided a packaging body comprising the packaging material according to the ninth aspect.

[0041] According to an eleventh aspect of the present invention, there is provided a packaged article comprising the package according to the tenth aspect and contents contained in the package.

[0042] Effects of the present invention

[0043] According to the present invention, there can be provided a gas barrier laminate having excellent abuse resistance that can withstand treatment in high temperature and high humidity or high temperature and high pressure environments such as retorting and boiling treatments, and can maintain a high degree of gas barrier properties even when subjected to abuse such as bending, a coating liquid for its manufacture, a packaging material, a packaging body, and a packaged article. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] [ Figure 1 ] is a cross-sectional view schematically showing a gas barrier layered product according to one embodiment of the present invention.

[0045] [ Figure 2] is a cross-sectional view schematically showing a gas barrier laminate according to another embodiment of the present invention. DETAILED DESCRIPTION

[0046] Hereinafter, the present embodiment will be described with reference to the accompanying drawings. It should be noted that elements having the same or similar functions are denoted by the same reference numerals, and redundant descriptions will be omitted.

[0047] <Coating Liquid for Producing Gas Barrier Laminate>

[0048] The coating liquid for producing a gas barrier laminate according to an embodiment of the present invention (hereinafter referred to as "the coating liquid according to the present embodiment" or simply "the coating liquid") is suitable for forming a coating layer of a gas barrier laminate, for example, Figure 1 or Figure 2 The covering layer 3 in the gas barrier laminates 10 and 20 shown. Hereinafter, a layer obtained by drying a coating film composed of the coating liquid according to the present embodiment may be referred to as a "covering layer derived from the coating liquid" or simply as a "covering layer".

[0049] The coating liquid according to this embodiment contains a carboxyl group-containing polymer (a), polyvalent metal-containing particles (b), a surfactant (c), a silicon-containing compound (d), and an organic solvent (e). In this embodiment, the polyvalent metal-containing particles (b) are contained in the coating liquid at the following mixing ratio: the product of the number of moles of the polyvalent metal contained in the polyvalent metal-containing particles (b) and the valence (b) t ) relative to the molar number of carboxyl groups contained in the carboxyl group-containing polymer (a) (a t ) of the equivalent ratio b t / a t The coating liquid contains the silicon-containing compound (d) at the following mixing ratio: the number of moles of the silicon-containing compound (d) (d t ) relative to the molar number of the above carboxyl groups (a t ) molar ratio d t / a t It is not less than 0.7% and not more than 7.5%.

[0050] [Carboxyl group-containing polymer (a)]

[0051] The carboxyl group-containing polymer contained in the coating liquid involved in this embodiment is a polymer having two or more carboxyl groups in the molecule, and is sometimes referred to as a "polycarboxylic acid polymer." Representative examples of carboxyl group-containing polymers include homopolymers of carboxyl group-containing unsaturated monomers, copolymers of two or more carboxyl group-containing unsaturated monomers, copolymers of carboxyl group-containing unsaturated monomers and other polymerizable monomers, and polysaccharides containing carboxyl groups in the molecule (also referred to as "carboxyl group-containing polysaccharides" or "acidic polysaccharides").

[0052] Carboxyl groups include not only free carboxyl groups but also acid anhydride groups (specifically, dicarboxylic anhydride groups). Acid anhydride groups can partially open their rings to become carboxyl groups. Some of the carboxyl groups can be neutralized with a base. In this case, the degree of neutralization is preferably 20% or less.

[0053] Here, the "neutralization degree" is a value obtained by the following method. That is, by adding a base (f) to the carboxyl group-containing polymer (a), the carboxyl groups can be partially neutralized. In this case, the ratio of the number of moles (Ft) of the base (F) to the number of moles (At) of carboxyl groups contained in the carboxyl group-containing polymer (a) is the neutralization degree.

[0054] Alternatively, a graft polymer obtained by graft-polymerizing a carboxyl-containing unsaturated monomer onto a carboxyl-free polymer such as a polyolefin may be used as the carboxyl-containing polymer. Alternatively, a polymer obtained by hydrolyzing a hydrolyzable ester group such as an alkoxycarbonyl group (e.g., a methoxycarbonyl group) to convert the hydrolyzed polymer into a carboxyl group may be used.

[0055] The carboxyl group-containing unsaturated monomer is preferably an α,β-monoethylenically unsaturated carboxylic acid. Therefore, the carboxyl group-containing polymer includes homopolymers of α,β-monoethylenically unsaturated carboxylic acids, copolymers of two or more α,β-monoethylenically unsaturated carboxylic acids, and copolymers of α,β-monoethylenically unsaturated carboxylic acids and other polymerizable monomers. Representative examples of other polymerizable monomers include ethylenically unsaturated monomers.

[0056] Examples of α,β-monoethylenically unsaturated carboxylic acids 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; unsaturated dicarboxylic anhydrides such as maleic anhydride and itaconic anhydride; and mixtures of two or more thereof. Among these, at least one α,β-monoethylenically unsaturated carboxylic acid selected from the group consisting of acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, and itaconic acid is preferred, and at least one α,β-monoethylenically unsaturated carboxylic acid selected from the group consisting of acrylic acid, methacrylic acid, and maleic acid is more preferred.

[0057] Examples of other polymerizable monomers copolymerizable with α,β-monoethylenically unsaturated carboxylic acids, particularly ethylenically unsaturated monomers, include: ethylene; α-olefins such as propylene, 1-butene, 1-pentene, 1-hexene, and 1-octene; saturated carboxylic acid vinyl esters such as vinyl acetate; alkyl acrylates such as methyl acrylate and ethyl acrylate; alkyl methacrylates such as methyl methacrylate and ethyl methacrylate; vinyl chloride-containing 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; aromatic vinyl monomers such as styrene and α-methylstyrene; and alkyl itaconic acid esters. These ethylenically unsaturated monomers can be used alone or in combination of two or more. Furthermore, when the carboxyl group-containing polymer is a copolymer of an α,β-monoethylenically unsaturated carboxylic acid and a saturated carboxylic acid vinyl ester such as vinyl acetate, a copolymer obtained by saponifying the copolymer to convert the saturated carboxylic acid vinyl ester units into vinyl alcohol units can also be used.

[0058] Examples of carboxyl-containing polysaccharides include acidic polysaccharides having carboxyl groups in their molecules, such as alginic acid, carboxymethyl cellulose, and pectin. These acidic polysaccharides can be used alone or in combination of two or more. Furthermore, acidic polysaccharides can be used in combination with (co)polymers of α,β-monoethylenically unsaturated carboxylic acids.

[0059] When the carboxyl group-containing polymer is a copolymer of an α,β-monoethylenically unsaturated carboxylic acid and other ethylenically unsaturated monomers, from the viewpoint of the gas barrier properties, hot water resistance, and water vapor resistance of the resulting film, the ratio of the number of moles of the α,β-monoethylenically unsaturated carboxylic acid monomer to the total number of moles of these monomers in the copolymer is preferably 60 mol% or more, more preferably 80 mol% or more, and particularly preferably 90 mol% or more.

[0060] From the viewpoint of being easy to obtain a film having excellent gas barrier properties, moisture resistance, water resistance, hot water resistance and water vapor resistance, and excellent gas barrier properties under high humidity environments, the carboxyl group-containing polymer is preferably a homopolymer or copolymer obtained by polymerization of only α, β-monoethylenically unsaturated carboxylic acids. In the case where the carboxyl group-containing polymer is a (co)polymer consisting only of α, β-monoethylenically unsaturated carboxylic acids, preferred specific examples thereof are: homopolymers, copolymers, and mixtures of two or more thereof obtained by polymerization of at least one α, β-monoethylenically unsaturated carboxylic acid selected from the group consisting of acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, and itaconic acid. Among these, homopolymers and copolymers of at least one α, β-monoethylenically unsaturated carboxylic acid selected from the group consisting of acrylic acid, methacrylic acid, and maleic acid are more preferably selected.

[0061] As the carboxyl-containing polymer, particularly preferred are polyacrylic acid, polymethacrylic acid, polymaleic acid, and mixtures of two or more thereof. As the acidic polysaccharide, preferred is alginic acid. Among these, from the viewpoint of being easier to obtain and easily obtaining the film of various excellent physical properties, particularly preferred is polyacrylic acid.

[0062] The number average molecular weight of the carboxyl group-containing polymer is not particularly limited, but is preferably in the range of 2,000 to 10,000,000, more preferably in the range of 5,000 to 1,000,000, and further preferably in the range of 10,000 to 500,000 from the viewpoint of film formability and film properties.

[0063] Here, the "number average molecular weight" is a value measured by gel permeation chromatography (GPC). In GPC measurement, the number average molecular weight of a polymer is usually measured in terms of standard polystyrene.

[0064] [Polyvalent metal-containing particles (b)]

[0065] The polyvalent metal-containing particles contained in the coating liquid according to this embodiment are particles containing one or more polyvalent metals having a metal ion valence of 2 or greater. The polyvalent metal-containing particles may be particles composed of a polyvalent metal having a metal ion valence of 2 or greater, particles composed of a compound of a polyvalent metal having a metal ion valence of 2 or greater, or a mixture thereof.

[0066] Specific examples of polyvalent metals include, but are not limited to, metals of Group 2A of the short-period periodic table, such as beryllium, magnesium, and calcium; transition metals, such as titanium, zirconium, chromium, manganese, iron, cobalt, nickel, copper, and zinc; and aluminum.

[0067] The polyvalent metal is preferably a divalent metal. In addition, the polyvalent metal preferably forms a compound.

[0068] Specific examples of polyvalent metal compounds include, but are not limited to, polyvalent metal oxides, hydroxides, carbonates, organic acid salts, and inorganic acid salts. Examples of organic acid salts include, but are not limited to, acetates, oxalates, citrates, lactates, phosphates, phosphites, hypophosphites, stearates, and monoethylenically unsaturated carboxylates. Examples of inorganic acid salts include, but are not limited to, chlorides, sulfates, and nitrates. Polyvalent metal alkyl alcohol salts may also be used as the polyvalent metal compound. These polyvalent metal compounds may be used individually or in combination of two or more.

[0069] Among the polyvalent metal compounds, compounds of beryllium, magnesium, calcium, copper, cobalt, nickel, zinc, aluminum, and zirconium are preferred from the viewpoint of dispersion stability of the coating liquid and gas barrier properties of the laminate formed from the coating liquid, and compounds of divalent metals such as beryllium, magnesium, calcium, copper, zinc, cobalt, and nickel are more preferred.

[0070] Preferred divalent metal compounds include, but are not limited to, oxides such as zinc oxide, magnesium oxide, copper oxide, nickel oxide, and cobalt oxide; carbonates such as calcium carbonate; organic acid salts such as calcium lactate, zinc lactate, and calcium acrylate; and alkoxides such as magnesium methoxide.

[0071] The polyvalent metal or polyvalent metal compound is used in the form of particles, and maintains its particle shape even in the coating liquid. From the perspective of dispersion stability of the coating liquid and the gas barrier properties of a laminate formed from the coating liquid, the average particle size of the polyvalent metal-containing particles, as measured in the coating liquid, is preferably in the range of 10 nm to 10 μm (or 10,000 nm), more preferably in the range of 12 nm to 1 μm (or 1,000 nm), further preferably in the range of 15 nm to 500 nm, and particularly preferably in the range of 15 nm to 50 nm.

[0072] When the average grain diameter of the particle that contains the polyvalent metal in the coating fluid is too large, the uniformity of the film thickness of the coating that obtains, the flatness on the surface, and the ionic crosslinking reactivity of carboxyl-containing polymers etc. easily become insufficient.When the average grain diameter of the particle that contains the polyvalent metal is too small, might carry out early with the ionic crosslinking reaction of carboxyl-containing polymers.In addition, particle diameter is difficult to evenly disperse in coating fluid less than the ultrafine particle of 10nm.

[0073] When the sample is a dried solid, the average particle size of the polyvalent metal-containing particles can be measured and counted using a scanning electron microscope or a transmission electron microscope. The average particle size of the polyvalent metal-containing particles in the coating solution can be measured by a light scattering method [Reference: "Microparticle Engineering System," Vol. 1, pp. 362-365, Fuji Techno System (2001)].

[0074] The polyvalent metal-containing particles in the coating liquid exist in the form of primary particles, secondary particles, or a mixture thereof. However, based on the average particle diameter, it is presumed that they exist in the form of secondary particles in most cases.

[0075] [Surfactant (c)]

[0076] To improve the dispersibility of the polyvalent metal-containing particles, a surfactant is used in the coating solution of this embodiment. A surfactant is a compound having both a hydrophilic group and a lipophilic group within its molecule. Surfactants include anionic, cationic, and amphoteric surfactants, as well as nonionic surfactants. Any surfactant can be used in the coating solution.

[0077] Examples of anionic surfactants include carboxylic acid type, sulfonic acid type, sulfate type, and phosphate type. Examples of carboxylic acid type anionic surfactants include aliphatic monocarboxylates, polyoxyethylene alkyl ether carboxylates, N-acyl sarcosinates, and N-acyl glutamates. Examples of sulfonic acid type anionic surfactants include dialkyl sulfosuccinates, alkyl sulfonates, α-olefin sulfonates, linear alkylbenzene sulfonates, alkyl (branched) benzene sulfonates, naphthalenesulfonate-formaldehyde condensates, alkylnaphthalenesulfonates, and N-methyl-N-acyltaurates. Examples of sulfate type anionic surfactants include alkyl sulfates, polyoxyethylene alkyl ether sulfates, and oil sulfates. Examples of phosphate type anionic surfactants include alkyl phosphates, polyoxyethylene alkyl ether phosphates, and polyoxyethylene alkylphenyl ether phosphates.

[0078] Examples of cationic surfactants include alkylamine salts and quaternary ammonium salts. Examples of alkylamine salt-type cationic surfactants include monoalkylamine salts, dialkylamine salts, and trialkylamine salts. Examples of quaternary ammonium salt-type cationic surfactants include halogenated (chlorinated, brominated, or iodinated) alkyltrimethylammonium salts and alkylbenzalkonium chloride.

[0079] Examples of amphoteric surfactants include carboxybetaine-type, 2-alkylimidazoline derivative-type, glycine-type, and amine oxide-type. Examples of carboxybetaine-type amphoteric surfactants include alkyl betaines and fatty acid amide propyl betaines. Examples of 2-alkylimidazoline derivative-type amphoteric surfactants include 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaines. Examples of glycine-type amphoteric surfactants include alkyl or dialkyl diethylenetriaminoacetic acid. Examples of amine oxide-type amphoteric surfactants include alkyl amine oxides.

[0080] Examples of nonionic surfactants include ester-type, ether-type, ester-ether-type, and alkanolamide-type surfactants. Examples of ester-type nonionic surfactants include glycerol fatty acid esters, sorbitan fatty acid esters, and sucrose fatty acid esters. Examples of ether-type nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, and polyoxyethylene polyoxypropylene glycols. Examples of ester-ether-type nonionic surfactants include fatty acid polyethylene glycols and fatty acid polyoxyethylene sorbitan. Examples of alkanolamide-type nonionic surfactants include fatty acid alkanolamides.

[0081] Surfactants having a polymer skeleton such as styrene-acrylic acid copolymers can also be used.

[0082] Among these surfactants, anionic surfactants such as phosphate esters and surfactants having a polymer skeleton such as styrene-acrylic acid copolymers are preferred.

[0083] [Silicon-containing compound (d)]

[0084] In order to improve the peel strength of the coating layer, the coating solution according to this embodiment contains a silicon-containing compound (d). The silicon-containing compound (d) contained in the coating solution is at least one compound selected from the group consisting of a silane coupling agent represented by the following general formula (1), a silane coupling agent represented by the following general formula (2), their hydrolyzates, and their condensates.

[0085] Si(OR1)3Z1···(1)

[0086] Si(R2)(OR3)2Z2···(2)

[0087] In the general formula (1), R1, which may be the same or different, is an alkyl group having 1 to 6 carbon atoms, and Z1 is a group containing an epoxy group. Furthermore, in the general formula (2), R2 is a methyl group, R3, which may be the same or different, is an alkyl group having 1 to 6 carbon atoms, and Z2 is a group containing an epoxy group.

[0088] Silane coupling agents are easily hydrolyzed and easily undergo condensation reactions in the presence of acids or bases. Therefore, in the above-mentioned coating liquid, it is rare for the silicon-containing compound to exist only in the form of the silane coupling agent represented by general formula (1) or (2), only in the form of its hydrolyzate, or only in the form of its condensate. That is, in the coating liquid involved in this embodiment, the silicon-containing compound is usually present in the form of a mixture of at least one of the silane coupling agent represented by general formula (1) and the silane coupling agent represented by general formula (2), their hydrolyzate, and their condensate.

[0089] R1 in the general formula (1) and R3 in the general formula (2) may each be an alkyl group having 1 to 6 carbon atoms, preferably a methyl group or an ethyl group. Z1 in the general formula (1) and Z2 in the general formula (2) may each be a group containing an epoxy group.

[0090] Specific examples of the silane coupling agent represented by general formula (1) or (2) include 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane, with 3-glycidoxypropylmethyldimethoxysilane and 3-glycidoxypropyltrimethoxysilane being preferred. The silane coupling agent may be used alone or in combination of two or more.

[0091] 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.

[0092] The coating liquid involved in this embodiment contains a condensate as at least a part of the silicon-containing compound, which is a hydrolysis condensate of a silane coupling agent represented by the general formula (1), a hydrolysis condensate of a silane coupling agent represented by the general formula (2), and a condensate of a hydrolysis product of a silane coupling agent represented by the general formula (1) and a hydrolysis product of a silane coupling agent represented by the general formula (2). These hydrolysis condensates are produced by the following reaction. That is, first, the silane coupling agent is hydrolyzed. As a result, one or more alkoxy groups contained in the molecules of the silane coupling agent are replaced by hydroxyl groups to form a hydrolysis product. Then, by condensing these hydrolysis products, a compound in which silicon atoms (Si) are bonded via oxygen is formed. By repeating this condensation, a hydrolysis condensate is obtained.

[0093] [Organic solvent (e)]

[0094] In the coating liquid that present embodiment relates to, use organic solvent as solvent or dispersion medium.As organic solvent, usually use the polar organic solvent that dissolves carboxyl-containing polymer, but also can use together with polar organic solvent the organic solvent that does not have polar group (heteroatoms or have heteroatomic atomic group).

[0095] Examples of preferably usable organic solvents include alcohols such as methanol, ethanol, isopropanol, n-propanol, and n-butanol; and polar organic solvents such as dimethyl sulfoxide, N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidone, tetramethylurea, hexamethylphosphoric acid triamide, and γ-butyrolactone.

[0096] In addition to the polar organic solvents listed above, 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 also be used as appropriate. Hydrocarbons such as benzene, which do not have polar groups, are often used in combination with polar organic solvents.

[0097] The coating solution involved in this embodiment may contain only an organic solvent as a solvent or dispersion medium, but may also contain water. By containing water, the solubility of the carboxyl group-containing polymer can be increased, and the coating and handling properties of the coating solution can be improved. The water content of the coating solution can be 100 ppm or more, 1,000 ppm or more, 1,500 ppm or more, or 2,000 ppm or more, by mass fraction.

[0098] The water content of the coating liquid according to the present embodiment is preferably 50,000 ppm or less, more preferably 10,000 ppm or less, and even more preferably 5,000 ppm or less, in terms of mass fraction.

[0099] 〔composition〕

[0100] The coating liquid involved in this embodiment is a dispersion containing a carboxyl group-containing polymer (a), polyvalent metal-containing particles (b), a surfactant (c), a silicon-containing compound (d) and an organic solvent (e), and in which the polyvalent metal-containing particles (b) are dispersed.

[0101] Equivalent ratio of carboxyl group-containing polymer (a) to polyvalent metal-containing particles (b)

[0102] In the coating liquid according to the present embodiment, the polyvalent metal-containing particles (b) are contained in an equivalent ratio of 0.45 to 0.9 relative to the carboxyl group-containing polymer (a). Here, the equivalent ratio of the polyvalent metal-containing particles (b) to the carboxyl group-containing polymer (a) refers to the product of the number of moles of the polyvalent metal contained in the polyvalent metal-containing particles (b) and the valence (b t ) relative to the molar number of carboxyl groups contained in the carboxyl group-containing polymer (a) (a t ) than (b t ) / (a t ).

[0103] In this embodiment, the equivalence ratio b t / a t The equivalent ratio b is 0.45 or more and 0.9 or less, preferably 0.5 or more and 0.8 or less, and more preferably 0.6 or more and 0.7 or less. t / a tWithin the above range, crosslinking between the carboxyl group-containing polymer (a) and the polyvalent metal ions contained in the polyvalent metal-containing particles (b) proceeds appropriately, resulting in a coating layer from the coating liquid that is neither too soft nor too hard. As a result, the abuse resistance of the gas barrier laminate is improved.

[0104] Equivalent ratio b of the carboxyl group-containing polymer (a) to the polyvalent metal-containing particles (b) t / a t For example, it can be determined as follows: The following description will be given of an example in which the carboxyl group-containing polymer (a) is polyacrylic acid and the polyvalent metal-containing particles (b) are magnesium oxide.

[0105] The molecular weight of the monomer unit of polyacrylic acid is 72, and each monomer molecule has one carboxyl group. Therefore, the amount of carboxyl groups in 100 g of polyacrylic acid is 1.39 mol. The above equivalent ratio b in the coating solution containing 100 g of polyacrylic acid is t / a t 1.0 means that the coating solution contains magnesium oxide in an amount sufficient to neutralize 1.39 mol of carboxyl groups. t / a t To make the equivalent ratio b in the coating solution containing 100 g of polyacrylic acid equal to 0.6, it is sufficient to add magnesium oxide in an amount that neutralizes 0.834 mol of carboxyl groups. Here, the valence of magnesium is 2 and the molecular weight of magnesium oxide is 40. t / a t To achieve 0.6, 16.68 g (0.417 mol) of magnesium oxide may be added to the coating liquid.

[0106] The molar ratio of the carboxyl group-containing polymer (a) to the silicon-containing compound (d)

[0107] In the coating liquid according to the present embodiment, the silicon-containing compound (d) is contained in a mixing ratio of 0.7% to 7.5% with respect to the molar ratio of the carboxyl group-containing polymer (a). Here, the molar ratio of the silicon-containing compound (d) to the carboxyl group-containing polymer (a) refers to the number of moles of the silicon-containing compound (d). t ) relative to the molar number of carboxyl groups contained in the carboxyl group-containing polymer (a) (a t ) molar ratio d t / a t At this molar ratio d t / a t In, d t is the number of moles of the silicon-containing compound (d) converted into a silane coupling agent. t The equivalent ratio b of the carboxyl group-containing polymer (a) and the polyvalent metal-containing particles (b) is t / a in att The number of moles is calculated using the same method.

[0108] In this embodiment, the molar ratio d t / a t The content of the silicon-containing compound (d) is preferably 0.7% to 7.5%, preferably 0.9% to 6.1%, and more preferably 2% to 5%. If the amount of the silicon-containing compound (d) added is too small, the adhesion of the coating layer decreases, and the abuse resistance decreases. On the other hand, if the amount of the silicon-containing compound (d) added is too large, the silicon-containing compound itself becomes a foreign matter, and the oxygen barrier properties deteriorate.

[0109] The surfactant (c) is used in an amount sufficient to stably disperse the polyvalent metal-containing particles (b). The concentration of the surfactant (c) in the coating liquid is generally in the range of 0.0001 to 70% by mass, preferably in the range of 0.001 to 60% by mass, and more preferably in the range of 0.1 to 50% by mass.

[0110] Without the addition of the surfactant (c), it is difficult to disperse the polyvalent metal-containing particles (b) in the coating solution so that their average particle size is sufficiently small. As a result, it is difficult to obtain a coating solution in which the polyvalent metal-containing particles (b) are uniformly dispersed, and when applied to a substrate, it is difficult to form a coating film with a uniform film thickness.

[0111] [Method for producing coating liquid]

[0112] In order to prepare the coating liquid, on one hand, the carboxyl group-containing polymer (a) is uniformly dissolved in the organic solvent (e), and then the silicon-containing compound (d) is added thereto to prepare a carboxyl group-containing polymer solution.

[0113] Then, on the other hand, the particles (b) containing a polyvalent metal, a surfactant (c), and an organic solvent (e) are mixed and dispersed as needed to prepare a dispersion liquid. The dispersion treatment is carried out in a manner such that the average particle size of the particles (b) containing a polyvalent metal becomes a predetermined value. In the case where the average particle size of the particles (b) containing a polyvalent metal in the mixed solution before the dispersion treatment is less than 10 μm, the dispersion treatment may not be carried out, but even in this case, the dispersion treatment is preferably carried out. By carrying out the dispersion treatment, the aggregation of the particles (b) containing a polyvalent metal can be released, the coating liquid can be stabilized, and the transparency of the gas barrier laminate obtained by applying the coating liquid is improved. In addition, when the coating liquid is applied and the coating film is dried, the cross-linking formation of the carboxyl group-containing polymer (a) and the polyvalent metal ions is easily carried out, thereby easily obtaining a gas barrier laminate having good gas barrier properties.

[0114] Examples of dispersion methods include those using a high-speed stirrer, homogenizer, ball mill, or bead mill. Using a ball mill or bead mill is particularly effective, allowing for efficient dispersion and a stable dispersion to be obtained in a relatively short time. In this case, the diameter of the balls or beads can be very small, preferably 0.1 to 1 mm.

[0115] By mixing the above-mentioned prepared carboxyl-containing polymer solution with the dispersion liquid containing the particle of polyvalent metal, coating fluid can be made.It should be noted that, silicon-containing compound (d) can be omitted from carboxyl-containing polymer solution.In this case, for example, when mixing carboxyl-containing polymer solution and the dispersion liquid containing the particle (b) of polyvalent metal, silicon-containing compound (d) is mixed together.

[0116] In the coating liquid involved in this embodiment, the total concentration of components other than the organic solvent is preferably in the range of 0.1 to 60 mass %, more preferably in the range of 0.5 to 25 mass %, and particularly preferably in the range of 1 to 20 mass %, which is preferred in terms of obtaining a coating film and a covering layer of the desired film thickness with high operability.

[0117] The coating solution according to this embodiment may contain various additives such as other polymers, thickeners, stabilizers, ultraviolet absorbers, anti-blocking agents, softeners, inorganic layered compounds (such as montmorillonite), and colorants (dyes, pigments), as needed.

[0118] <Gas Barrier Laminate>

[0119] The gas barrier laminate according to the present embodiment includes a substrate, an inorganic deposited layer containing an inorganic oxide on at least one main surface of the substrate, and a covering layer, wherein the covering layer is a coating layer derived from the above-mentioned coating solution. Figure 1 1 is a cross-sectional view schematically showing a gas barrier laminate according to the present embodiment. The gas barrier laminate 10 includes a substrate 1 , an inorganic vapor-deposited layer 2 containing an inorganic oxide, and a covering layer 3 .

[0120] 〔Base material〕

[0121] The substrate in the gas barrier layered product is not particularly limited, and various substrates can be used. The material constituting the substrate is not particularly limited, and various materials can be used, for example, plastic or paper.

[0122] The substrate may be a single layer composed of a single material or a multilayer composed of a plurality of materials. An example of a multilayer substrate includes a substrate in which a film composed of plastic is laminated on paper.

[0123] As the material constituting the substrate, among the above materials, plastic is preferred from the viewpoint of being able to be molded into various shapes and further expanding its applications by imparting gas barrier properties.

[0124] The plastic is not particularly limited, and examples thereof include: polyolefin resins such as polyethylene and polypropylene; polyester resins such as polyethylene terephthalate, polyethylene 2,6-naphthalate, polybutylene terephthalate, and copolymers thereof; polyamide resins such as nylon-6, nylon-66, nylon-12, meta-xylylenediamine adipamide, and copolymers thereof; styrene resins such as polystyrene, styrene-butadiene copolymer, and styrene-butadiene-acrylonitrile copolymer; poly(meth)acrylate; polyacrylonitrile; polyvinyl acetate; ethylene-vinyl acetate copolymer; ethylene-vinyl alcohol copolymer; polycarbonate; polyarylate; regenerated cellulose; polyimide; polyetherimide; polysulfone; polyethersulfone; polyetherketone; and ionomer resin.

[0125] When the gas barrier laminate is used for food packaging materials, the substrate is preferably composed of polyethylene, polypropylene, polyethylene terephthalate, nylon 6, or nylon 66.

[0126] As the plastic constituting the base material, one kind may be used alone, or two or more kinds may be used in combination.

[0127] Plastics may also be formulated with additives. As additives, they may be appropriately selected from known additives such as pigments, antioxidants, antistatic agents, ultraviolet absorbers, and lubricants according to the intended use. As additives, one may be used alone or two or more may be used in combination.

[0128] The form of the substrate is not particularly limited, and examples thereof include films, sheets, cups, trays, tubes, and bottles. Among these, films are preferred. When the substrate is a film, the film may be a stretched film or an unstretched film.

[0129] The thickness of the substrate is not particularly limited, but is preferably in the range of 1 to 200 μm, more preferably in the range of 5 to 100 μm, from the viewpoint of mechanical strength and processability of the resulting gas barrier laminate.

[0130] In order to allow the coating liquid to be applied to the surface of the substrate without being repelled by the substrate, the surface of the substrate may be subjected to plasma treatment, corona treatment, ozone treatment, flame treatment, or radical activation treatment using ultraviolet (UV) or electron beams, etc. The treatment method may be appropriately selected depending on the type of substrate.

[0131] 〔Inorganic vapor deposition layer〕

[0132] The gas barrier laminate according to this embodiment includes an inorganic vapor-deposited layer between the substrate and the covering layer. This can further improve the gas barrier properties of the gas barrier laminate including the covering layer.

[0133] The inorganic deposited layer contains an inorganic oxide. Examples of the inorganic oxide include aluminum oxide, silicon oxide, magnesium oxide, and tin oxide. Among these, aluminum oxide, silicon oxide, magnesium oxide, or a mixture of two or more thereof is preferred from the perspective of both transparency and gas barrier properties.

[0134] The thickness of the inorganic deposited layer can be, for example, in the range of 5 to 100 nm, or 10 to 50 nm. From the perspective of forming a uniform thin film, the thickness of the inorganic deposited layer is preferably 5 nm or greater. A uniform thin film serving as a gas barrier material can fully demonstrate the required function of the gas barrier material. From the perspective of film flexibility, the thickness of the inorganic deposited layer is preferably 100 nm or less. If the gas barrier material has poor flexibility, cracks may form due to external factors such as bending and stretching.

[0135] 〔Coating layer〕

[0136] The coating layer is formed by the above-mentioned coating liquid, specifically, by coating the above-mentioned coating liquid on the inorganic vapor-deposited layer and drying the coating film. As mentioned above, in the coating layer, the equivalent ratio of the polyvalent metal-containing particles (b) to the carboxyl group-containing polymer (a) is t / a t , and the molar ratio d of the silicon-containing compound (d) to the carboxyl-containing polymer (a) t / a t The gas barrier laminate according to this embodiment, by comprising a coating layer formed from the coating liquid, exhibits excellent abuse resistance, capable of withstanding treatments such as retorting and boiling in high-temperature, high-humidity, or high-temperature, high-pressure environments, and maintaining a high degree of gas barrier properties even after subsequent abuse such as bending.

[0137] From the viewpoint of gas barrier properties and abuse resistance after high temperature and high pressure treatment, the thickness of the coating layer is preferably 230 nm to 600 nm, more preferably 270 nm to 520 nm, and even more preferably 300 nm to 450 nm.

[0138] [Other layers]

[0139] The gas barrier laminate according to the present embodiment may further include one or more layers other than the substrate, the inorganic vapor-deposited layer, and the covering layer, as necessary.

[0140] For example, the gas barrier laminate according to this embodiment may include only the above-mentioned covering layer as a gas barrier coating, or may include one or more other layers in addition to the covering layer. For example, a layer composed of an inorganic compound such as aluminum oxide, silicon oxide, and aluminum may be formed on the surface of the substrate by sputtering or ion plating.

[0141] In addition, in order to improve the adhesion between layers, or to apply the coating liquid for forming the coating layer without being repelled by the inorganic vapor-deposited layer, the gas barrier laminate involved in this embodiment may further have an anchor coating between the substrate and the inorganic vapor-deposited layer, or between the inorganic vapor-deposited layer and the coating layer.

[0142] Figure 2 : is a cross-sectional view schematically showing a gas barrier laminate according to another embodiment of the present invention. Figure 1 The gas barrier laminate 10 shown, Figure 2 The gas barrier laminate 20 shown further includes an anchor coating layer 4 between the substrate 1 and the inorganic vapor-deposited layer 2 .

[0143] The anchor coating layer can be formed by a conventional method using a known anchor coating liquid. Examples of the anchor coating liquid include coating liquids containing resins such as polyurethane resins, acrylic resins, melamine resins, polyester resins, phenolic resins, amino resins, and fluororesins.

[0144] In order to improve adhesion and hot water resistance, the anchor coating liquid may further contain an isocyanate compound in addition to the resin. The isocyanate compound may contain one or more isocyanate groups in the molecule, and examples thereof include hexamethylene diisocyanate, xylylenediisocyanate, isophorone diisocyanate, and toluene diisocyanate.

[0145] The anchor coating liquid may further contain a liquid medium for dissolving or dispersing the resin and the isocyanate compound.

[0146] The thickness of the anchor coating is not particularly limited. For example, the thickness of the anchor coating can be in the range of 0.01 to 2 μm, or 0.05 to 1 μm. A thickness less than 0.01 μm is too thin and may not fully demonstrate its performance as an anchor coating. On the other hand, from the perspective of flexibility, the thickness is preferably 2 μm or less. Reduced flexibility may cause cracks in the anchor coating due to external factors.

[0147] If necessary, the gas barrier laminate according to the present embodiment may further include another layer laminated via an adhesive on the covering layer or on the surface of the substrate or inorganic vapor-deposited layer, or may further include another layer formed by extrusion lamination of an adhesive resin.

[0148] The other layers to be laminated can be appropriately selected based on the purpose of imparting strength, imparting sealing properties, imparting easy opening when sealed, imparting design, imparting light shielding properties, and imparting moisture resistance, and are not particularly limited. For example, the same materials as the plastics mentioned above for the substrate can be used. In addition, paper or aluminum foil can also be used.

[0149] The thickness of the other laminated layers is preferably in the range of 1 to 1000 μm, more preferably in the range of 5 to 500 μm, further preferably in the range of 5 to 200 μm, particularly preferably in the range of 5 to 150 μm.

[0150] The other layers to be laminated may be one type or two or more types.

[0151] The gas barrier laminate according to this embodiment may further include a printed layer as needed. The printed layer may be formed on a coating layer provided on a substrate, or on a surface of a substrate not provided with a coating layer. Furthermore, when other layers are laminated, the printed layer may be formed on the other laminated layers.

[0152] [Method for producing gas barrier laminate]

[0153] The gas barrier laminate according to this embodiment can be produced by a production method comprising the steps of forming an inorganic vapor-deposited layer and forming a coating layer using the coating solution. The production method may further comprise the steps of forming other layers such as an anchor coating layer and / or forming a printed layer, as required.

[0154] As an example of a method for producing a gas barrier laminate according to this embodiment, Figure 2 A method for producing the gas barrier laminate 20 shown in FIG.

[0155] In the method for producing the gas barrier laminate 20, the anchor coating layer 4 is formed on the substrate 1. The anchor coating layer 4 can be formed by applying the anchor coating liquid described above to the substrate 1 and drying the resulting coating. The method for applying the anchor coating liquid is not particularly limited; known printing methods such as offset printing, gravure printing, and screen printing, or known coating methods such as roll coating, knife edge coating, and gravure coating can be used. The resulting coating film is dried to remove the solvent and solidify, thereby forming the anchor coating layer 4.

[0156] In the method for producing the gas barrier laminate 20, the inorganic deposited layer 2 is formed on the anchor coating layer 4. Various methods are known for forming the inorganic deposited layer 2, such as vacuum deposition, sputtering, ion plating, and chemical vapor deposition (CVD). Any method can be used, but vacuum deposition is typically used.

[0157] Examples of heating means for a vacuum deposition apparatus utilizing a vacuum deposition method include electron beam heating, resistance heating, and induction heating, and any of these can be used.

[0158] Furthermore, in order to improve the adhesion of the inorganic vapor deposited layer 2 to the anchor coat layer 4 and the density of the inorganic vapor deposited layer 2 , a plasma-assisted method or an ion beam-assisted method may be used.

[0159] Furthermore, when vapor deposition is performed in order to improve the transparency of the inorganic vapor-deposited layer 2 , reactive vapor deposition by blowing in oxygen or the like may be performed.

[0160] In the method for producing the gas barrier laminate 20, the covering layer 3 is formed on the inorganic vapor-deposited layer 2. The covering layer 3 can be formed by applying the above-mentioned coating liquid on the inorganic vapor-deposited layer 2 and drying the formed coating film.

[0161] The coating method of the coating liquid is not particularly limited, and examples thereof include methods of coating using an air knife coater, a direct gravure coater, a gravure offset press, an arc gravure coater, a top feed reverse coater, a bottom feed reverse coater, a nozzle feed reverse coater, a reverse roll coater, a 5-roll coater, a lip coater, a rod coater, a rod reverse coater, and a die coater.

[0162] The method for drying the coating film is not particularly limited, and examples thereof include natural drying, drying in an oven set to a predetermined temperature, and using a dryer attached to a coater, such as an arch dryer, a floating dryer, a drum dryer, or an infrared dryer.

[0163] Drying conditions can be appropriately selected depending on the drying method, etc. For example, in the case of oven drying, the drying temperature is preferably in the range of 40 to 150°C, more preferably in the range of 45 to 150°C, and particularly preferably in the range of 50 to 140°C. 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 particularly preferably in the range of 1 second to 1 minute.

[0164] It is presumed that during or after drying, the carboxyl group-containing polymer (a) contained in the coating film reacts with the polyvalent metal-containing particles (b), thereby introducing an ionically crosslinked structure. To fully promote the ion crosslinking reaction, the dried film is preferably aged in an atmosphere having a relative humidity of preferably 20% or higher, more preferably in the range of 40 to 100%, and at a temperature of preferably 5 to 200°C, more preferably 20 to 150°C, for a period of about 1 second to 10 days.

[0165] The resulting gas barrier laminate is ionically crosslinked, resulting in excellent resistance to moisture, water, hot water, and water vapor. Furthermore, the gas barrier laminate exhibits excellent gas barrier properties even after treatment in high-temperature, high-humidity, or high-temperature, high-pressure environments, such as retorting and boiling. Furthermore, it exhibits excellent abuse resistance, maintaining high gas barrier properties even after being subjected to abuse such as bending after such treatment.

[0166] <Packaging Materials, Packages, and Packaged Items>

[0167] The packaging material according to the present embodiment includes the above-mentioned gas barrier layered product and is used, for example, to produce a package for packaging articles.

[0168] The packaging body according to the present embodiment includes the above-mentioned packaging material.

[0169] The packaging body may be composed solely of the aforementioned packaging material, or may include the aforementioned packaging material and other components. In the former case, the packaging body is, for example, formed by shaping the aforementioned packaging material into a bag. In the latter case, the packaging body is, for example, a container comprising the aforementioned packaging material as a lid and a bottomed cylindrical container body.

[0170] In this packaging body, the packaging material may be a molded article. As mentioned above, the molded article may be a container such as a bag, or a portion of a container such as a lid. Specific examples of the packaging body or its portion include manufactured bags, spouted bags, laminated tubes, infusion bags, container lids, and paper containers.

[0171] The application of the packaging body is not particularly limited and the packaging body can be used for packaging various articles.

[0172] The packaged article according to the present embodiment includes the above-mentioned package and contents accommodated therein.

[0173] As described above, the gas barrier laminates of this embodiment exhibit excellent gas barrier properties and abuse resistance even after high-temperature, high-humidity treatments such as boiling and retorting, or high-temperature, high-pressure treatments. Therefore, packaging materials and packaging bodies comprising these gas barrier laminates are particularly suitable for use as packaging materials and packaging bodies for items susceptible to degradation by oxygen, water vapor, and the like, and are particularly suitable for use as food packaging materials and packaging bodies. These packaging materials and packaging bodies are also particularly suitable for use as packaging materials and packaging bodies for packaging pesticides, pharmaceuticals, medical devices, machine parts, and industrial materials such as precision materials.

[0174] The gas barrier properties and interlayer adhesion of the above-mentioned gas barrier laminates do not deteriorate but tend to improve when subjected to heat sterilization treatments such as boiling and retorting. Therefore, these packaging materials and packaging bodies can be packaging materials and packaging bodies for heat sterilization, respectively.

[0175] Heat sterilization packaging materials and heat sterilization packaging bodies are used to package items that are heat sterilized after packaging.

[0176] Examples of items that are heat-sterilized after packaging include foods such as curry, stew, soup, sauce, and processed meat products.

[0177] Examples of heat sterilization treatment include boiling treatment and retort treatment.

[0178] Boiling is a moist heat sterilization process for preserving food, etc. During boiling, packaged items, such as food, are sterilized in packaging at a temperature of 60 to 100°C under atmospheric pressure for 10 to 120 minutes, depending on the contents. Boiling is typically performed in a hot water tank. There are two types of boiling: a batch method, where the packaged items are immersed in a hot water tank at a constant temperature and removed after a certain period of time; and a continuous method, where the packaged items are sterilized by passing them through a hot water tank in a tunnel-like manner.

[0179] Retort sterilization is a process that sterilizes microorganisms such as mold, yeast, and bacteria by applying heat and pressure to preserve food. Retort sterilization involves applying heat and pressure to packaged food, typically at a pressure of 0.15 to 0.3 MPa and a temperature of 105 to 140°C for 10 to 120 minutes. Retort systems include steam-based systems that utilize heated steam and hot-water systems that utilize pressurized superheated water. These systems are used based on the sterilization requirements for the food contents.

[0180] Example

[0181] Specific examples of the present invention are described below.

[0182] <Preparation of coating solution>

[0183] (Comparative Example 1: Coating Liquid 1-1)

[0184] The carboxyl group-containing polymer was dissolved by heating in isopropyl alcohol. As the carboxyl group-containing polymer, polyacrylic acid (PAA) (Jurymer (registered trademark) AC-10LP manufactured by Toagosei (strain), number average molecular weight 50,000) was used. By the above method, a polyacrylic acid solution containing 10% by mass of polyacrylic acid was prepared.

[0185] 1.8 g of polyether phosphate (Disparlon (registered trademark) DA-375 manufactured by Kusumoto Chemicals, 100% solid content by mass) was dissolved in 26.2 g of isopropyl alcohol. Subsequently, 12 g of zinc oxide having an average primary particle diameter of 35 nm (FINEX (registered trademark) -30 manufactured by Sakai Chemical Industry, Ltd.) was added thereto and stirred. The resulting liquid was dispersed for 1 hour using a planetary ball mill (P-7 manufactured by Fritsch). Zirconia microbeads having a diameter of 0.2 mm were used for this dispersion. The microbeads were then sieved out from the liquid to obtain a dispersion containing zinc oxide at a concentration of 30% by mass.

[0186] Next, 50.00 g of polyacrylic acid (PAA) solution, 3.77 g of zinc oxide dispersion, 0.10 g of silane coupling agent (SC agent) as a silicon-containing compound (KBM-403, 3-glycidoxypropyltrimethoxysilane manufactured by Shin-Etsu Chemical Co., Ltd.), and 22.86 g of isopropyl alcohol were mixed to prepare coating liquid 1-1. In this coating liquid 1-1, the product of the number of moles of zinc contained in zinc oxide and the valence (b t ) relative to the molar number of carboxyl groups contained in polyacrylic acid (PAA) (a t ) of the equivalent ratio b t / a t is 0.4, the molar number of SC agent (d t ) relative to the molar number of carboxyl groups contained in polyacrylic acid (PAA) (a t ) molar ratio d t / a t It is 0.6%.

[0187] (Comparative Examples 2 to 4: Coating Liquids 1-2 to 1-4)

[0188] Coating solutions 1-2 to 1-4 were prepared in the same manner as for coating solution 1-1, except that the amount of the SC agent added was changed to the amount shown in Table 1. t / at and molar ratio d t / a t As shown in Table 1.

[0189] (Comparative Example 5: Coating Liquid 2-1)

[0190] Coating liquid 2-1 was prepared by the same method as that for coating liquid 1-1 except that the amount of zinc oxide dispersion added was changed to 4.71 g and the amount of isopropyl alcohol added was changed to 25.45 g. t / a t is 0.5, the molar ratio d t / a t It is 0.6%.

[0191] (Examples 1-2, Comparative Example 6: Coating Liquids 2-2 to 2-4)

[0192] Coating solutions 2-2 to 2-4 were prepared in the same manner as for coating solution 2-1, except that the amount of the SC agent added was changed to the amount shown in Table 1. t / a t and molar ratio d t / a t As shown in Table 1.

[0193] (Comparative Example 7: Coating Liquid 3-1)

[0194] Coating liquid 3-1 was prepared by the same method as that for coating liquid 1-1 except that the amount of zinc oxide dispersion added was changed to 7.54 g and the amount of isopropyl alcohol added was changed to 33.22 g. t / a t is 0.8, the molar ratio d t / a t It is 0.6%.

[0195] (Examples 3 to 4, Comparative Example 8: Coating Liquids 3-2 to 3-4)

[0196] Coating solutions 3-2 to 3-4 were prepared in the same manner as for coating solution 3-1, except that the amount of the SC agent added was changed to the amount shown in Table 1. t / a t and molar ratio d t / a t As shown in Table 1.

[0197] (Comparative Example 9: Coating Liquid 4-1)

[0198] Coating liquid 4-1 was prepared by the same method as that for coating liquid 1-1 except that the amount of zinc oxide dispersion added was changed to 9.42 g and the amount of isopropyl alcohol added was changed to 38.40 g. t / a t is 1.0, the molar ratio d t / a t It is 0.6%.

[0199] (Comparative Examples 10 to 12: Coating Liquids 4-2 to 4-4)

[0200] Coating solutions 4-2 to 4-4 were prepared in the same manner as for coating solution 4-1, except that the amount of the SC agent added was changed to the amount shown in Table 1. t / a t and molar ratio d t / a t As shown in Table 1.

[0201] [Table 1]

[0202]

[0203] <Manufacturing of Gas Barrier Laminate>

[0204] (Preparation of anchor coating solution)

[0205] In a diluent solvent (ethyl acetate), 5 parts by mass of acrylic polyol was mixed with 1 part by mass of γ-isocyanatepropyltrimethoxysilane and stirred. Toluene diisocyanate (TDI) was then added as an isocyanate compound to provide an equal number of NCO groups to the OH groups of the acrylic polyol. The resulting mixed solution was diluted with the aforementioned diluent solvent to a concentration of 2% by mass, thereby obtaining anchor coating solution 1.

[0206] As the acrylic polyol, GS-5756 manufactured by Mitsubishi Rayon Co., Ltd. was used.

[0207] (Example 101)

[0208] Anchor coating liquid 1 was applied to one surface of a biaxially stretched polypropylene film (Mitsui Chemicals Tohcello, Inc., trade name: ME-1, thickness 20 μm) using a bar coater to a thickness of 0.2 μm after drying, and dried at 150° C. for 1 minute to form an anchor coating layer.

[0209] On the anchor coat layer, silicon was evaporated using a vacuum evaporation device using electron beam heating, and oxygen gas was introduced therein to deposit silicon oxide (SiO) to form an inorganic vapor deposition layer with a thickness of 20 nm.

[0210] Coating solution 2-2 was applied to the inorganic deposited layer using a rod coater (wire bar machine). The coating was dried in an oven at 50°C for 1 minute to form a coating layer with a thickness of 400 nm. In this manner, a laminate 1 was obtained. The thickness of the coating layer was measured by the method described below.

[0211] [Examples 102 to 104]

[0212] Laminates 2, 3, and 4 were produced by the same method as for the laminate 1 of Example 101, except that the coating liquid 2-2 was changed to the coating liquids 2-3, 3-2, and 3-3, respectively.

[0213] [Examples 105-106]

[0214] Laminates 5 and 6 were produced by the same method as for the laminate 3 of Example 103, except that the film thickness of the coating layer was changed from 400 nm to 230 nm or 600 nm, respectively.

[0215] [Comparative Examples 101 to 112]

[0216] Laminates 1C to 12C were produced by the same method as for the laminate 1 of Example 101, except that the coating liquid 2-2 was changed to coating liquids 1-1 to 1-4, 2-1, 2-4, 3-1, 3-4, and 4-1 to 4-4, respectively.

[0217] <Measurement of Film Thickness of Coating Layer>

[0218] Each obtained laminate was embedded with an embedding resin, and a cross section was exposed using a microtome. The cross section of the laminate was observed using a scanning electron microscope (SEM). Based on the obtained SEM image, the thickness of the coating layer in the flat portion was measured at 10 locations and the average value was taken as the coating layer thickness.

[0219] <Evaluation>

[0220] [Oxygen permeability after retorting]

[0221] Each obtained laminate was cut into a size of 20 cm x 20 cm and subjected to retort treatment at 0.2 MPa and 120°C for 30 minutes using a hot water immersion retort. The oxygen permeability of each sample after retort treatment was measured using an oxygen permeability tester OX-TRAN (registered trademark) 2 / 20 manufactured by Modern Control Co., Ltd. at a temperature of 30°C and a relative humidity of 70%. The measurement method was based on JIS K-7126B method (isobaric method) and ASTM D3985, and the measured value is expressed in cc / m 2 / day / atm. The oxygen permeability is 10cc / m 2 / day / atm or less is rated as A, and will exceed 10cc / m 2 / day / atm is evaluated as B. When the oxygen permeability is 10cc / m 2 When the pressure drop is less than 100 % / day / atm, the laminate has the desired gas barrier properties after high temperature, high pressure and high temperature, high humidity treatment.

[0222] [Oxygen permeability after retorting and bending abuse test]

[0223] Each laminate after the retort test was bent five times using a Gelbo bend tester manufactured by Tester Sangyo Co., Ltd. as specified in MIL B131 (ASTM F 392). The oxygen permeability of each laminate after the abuse test was measured using the same conditions and method as above. The oxygen permeability was set to 10 cc / m 2 / day / atm or less is rated as A, and will exceed 10cc / m 2 / day / atm is evaluated as B. When the oxygen permeability is 10cc / m 2 When the temperature is less than 100 °C / day / atm, the laminate can withstand treatment in high-temperature, high-humidity, and high-temperature, high-pressure environments, and can maintain high gas barrier properties even after being abused, indicating excellent abuse resistance. These results are shown in Table 2.

[0224] [Table 2]

[0225]

[0226] As shown in Table 2, it can be seen that the laminates 1 to 6 (Examples 101 to 106) according to this embodiment not only have excellent gas barrier properties after high temperature, high humidity and high temperature, high pressure treatment, but also have excellent abuse resistance, maintaining high gas barrier properties even after being subjected to abuse such as bending.

[0227] It should be noted that the present invention is not limited to the above-mentioned embodiments, and various modifications can be made during the implementation stage without departing from the main purpose thereof. In addition, the various embodiments can also be implemented in appropriate combination, in which case the combined effect can be obtained. In addition, the above-mentioned embodiments include various inventions, and various inventions can be extracted by combining the components selected from the disclosed multiple components. For example, in the case where the problem can be solved and the effect can be obtained even if several components are deleted from all the components shown in the embodiment, the structure from which the components are deleted can be extracted as an invention.

[0228] Explanation of symbols

[0229] 1. Substrate

[0230] 2···Inorganic vapor deposition layer

[0231] 3···Coating layer

[0232] 4···Anchor coating

[0233] 10, 20···Gas barrier laminate

Claims

1. A coating liquid for producing a gas barrier laminate, comprising: a carboxyl group-containing polymer (a), polyvalent metal-containing particles (b), a surfactant (c), a silicon-containing compound (d), and an organic solvent (e). 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), their hydrolyzates, and their condensates. The product of the number of moles and the valence of the polyvalent metal contained in the polyvalent metal-containing particles (b) (b t ) relative to the molar number of carboxyl groups contained in the carboxyl group-containing polymer (a) (a t ) equivalent ratio b t / a t is 0.45 or more and 0.9 or less, and the molar number (d t ) relative to the molar number of the carboxyl group (a t ) molar ratio d t / a t 0.7% to 7.5%, of which: The molar ratio d t / a t d in t is the number of moles obtained by converting the silicon-containing compound (d) into a silane coupling agent, Si(OR1)3Z1···(1) Si(R2)(OR3)2Z2···(2) In the general formula (1), R1 may be the same or different and is an alkyl group having 1 to 6 carbon atoms, Z1 is a group containing an epoxy group, In the general formula (2), R2 is a methyl group, R3, which may be the same or different, is an alkyl group having 1 to 6 carbon atoms, and Z2 is a group containing an epoxy group.

2. The coating solution according to claim 1, wherein The carboxyl group-containing polymer (a) contains at least a structural unit derived from at least one α,β-monoethylenically unsaturated carboxylic acid selected from the group consisting of acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, and fumaric acid.

3. The coating solution according to claim 1 or 2, wherein The polyvalent metal contained in the polyvalent metal-containing particles (b) is a divalent metal.

4. A gas barrier laminate comprising, in this order, a substrate, an inorganic vapor-deposited layer containing an inorganic oxide on at least one main surface of the substrate, and a coating layer. The coating layer contains: a carboxyl group-containing polymer (a), particles containing a polyvalent metal (b), a surfactant (c), and a 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), their hydrolyzates, and their condensates. The product of the number of moles and the valence of the polyvalent metal contained in the polyvalent metal-containing particles (b) (b t ) relative to the molar number of carboxyl groups contained in the carboxyl group-containing polymer (a) (a t ) of the equivalent ratio b t / a t is 0.45 or more and 0.9 or less, and the molar number (d t ) relative to the molar number of the carboxyl group (a t ) molar ratio d t / a t 0.7% to 7.5%, of which: The molar ratio d t / a t d in t is the number of moles obtained by converting the silicon-containing compound (d) into a silane coupling agent, Si(OR1)3Z1···(1) Si(R2)(OR3)2Z2···(2) In the general formula (1), R1 may be the same or different and is an alkyl group having 1 to 6 carbon atoms, Z1 is a group containing an epoxy group, In the general formula (2), R2 is a methyl group, R3, which may be the same or different, is an alkyl group having 1 to 6 carbon atoms, and Z2 is a group containing an epoxy group. The gas barrier laminate according to claim 4 , wherein The carboxyl group-containing polymer (a) contains at least a structural unit derived from at least one α,β-monoethylenically 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 4 or 5, wherein The polyvalent metal contained in the polyvalent metal-containing particles (b) is a divalent metal.

7. The gas barrier laminate according to claim 4 or 5, wherein The coating layer has a thickness of 230 nm to 600 nm.

8. The gas barrier laminate according to claim 4 or 5, An anchor coating layer is further provided between the substrate and the inorganic vapor-deposited layer. 9 . A packaging material comprising the gas barrier laminate according to claim 4 .

10. A packaging body comprising the packaging material according to claim 9. 11 . A packaged article comprising the package according to claim 10 and contents contained in the package.

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