Gas barrier coating agent, laminate, and method for producing the same

Abstract

To provide a gas barrier coating agent and a laminate, exhibiting superior gas barrier performance even under high humidity conditions, and possessing transparency, water-rub resistance, and substrate adhesion.SOLUTION: The present invention provides a gas barrier coating agent comprising: a compound (A) including an amino group and a hydroxyl group; a compound (B) including an anionic hydrophilic group and an ethylenically unsaturated double bond and having a molecular weight of 50 or more and less than 300; and a metal salt (C) that includes, as a ligand, a compound including an anionic hydrophilic group and an ethylenically unsaturated double bond and having a molecular weight of 50 or more and less than 300, wherein the compound (A) has an amine value of 30 to 600 mgKOH / g and a hydroxyl value of 400 to 1300 mgKOH / g.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a gas barrier coating agent, a laminate, and a method for producing the same.

Background Art

[0002] Packaging materials used for packaging foods, pharmaceuticals, etc. are required to prevent the deterioration of the contents. The deterioration of the contents is mainly caused by oxygen permeating through the packaging material or other gases that react with the contents. Therefore, packaging materials used for packaging foods, pharmaceuticals, etc. are required to have a property of not permeating gases such as oxygen, so-called gas barrier properties. In particular, in food packaging, it is expected that extending the shelf life and expiration date will lead to a reduction in waste generated in large quantities from general households, supermarkets, convenience stores, and other commercial facilities (Non-Patent Document 1).

[0003] To impart barrier properties to packaging materials, it is effective to use inorganic materials containing metals such as aluminum, alumina, silica, etc. as barrier layers. Specifically, a laminate configured by laminating an aluminum foil is used, or a method of forming an inorganic layer on a plastic film substrate by a vacuum process such as CVD or vapor deposition is used to ensure high gas barrier properties. However, the step of laminating an aluminum foil is desired to be eliminated from the viewpoints of energy saving and recyclability. On the other hand, in a configuration including an inorganic layer, there are problems such as resistance due to defects such as cracks.

[0004] In response to such problems, gas barrier films composed of relatively highly gas-barrier and flexible gas-barrier polymers, and laminates using such films as base films, have been proposed. Conventionally, polymers containing hydrogen-bonding groups in the molecule, such as poly(meth)acrylic acid, ethylene-vinyl alcohol copolymers, vinylamine-vinyl alcohol copolymers, or mixtures thereof, have been used as oxygen barrier polymers (Patent Documents 1 to 3). However, gas barrier materials made of these polymers have very excellent oxygen barrier properties under dry conditions, but under high humidity conditions, there are problems such as a significant decrease in oxygen barrier properties due to their hydrophilicity, and the films have poor resistance to water friction and resistance to hot water. Naturally, it is practically difficult to use such a film with low water resistance as the outermost layer (top coat) of a packaging material.

[0005] To solve these problems, it is known to incorporate a polyvalent metal compound into the base material itself, or to laminate a polycarboxylic acid-based polymer layer and a polyvalent metal compound-containing layer adjacent to each other on the base material, and to form a polyvalent metal salt of the polycarboxylic acid-based polymer by an interlayer reaction (Patent Documents 4 and 5). The gas barrier packaging material thus obtained has been shown to have high oxygen gas barrier properties even under high humidity. However, the gas barrier packaging materials described in Patent Documents 4 and 5 above require heat treatment at 150°C or higher, immersion treatment with a crosslinking agent, or retort treatment, resulting in a decrease in productivity. Furthermore, in order to achieve high barrier properties, it is necessary to form a layer containing a polyvalent metal salt in an insoluble state at a high concentration, and there is a problem such as a decrease in transparency.

Prior Art Documents

Non-Patent Documents

[0006]

Non-Patent Document 1

Patent Documents

[0007]

Patent Document 1

[0008] Even when using general-purpose base materials such as polyethylene terephthalate (PET) films, polypropylene (OPP, CPP) films, and paper, by coating on the base material and curing by irradiation with active energy rays such as ultraviolet rays and electron beams, it exhibits excellent gas barrier properties even under high humidity, and further provides a gas barrier coating agent capable of producing a laminate having transparency, water friction resistance, and substrate adhesion. [Means for Solving the Problems

[0009] As a result of intensive studies to solve the above problems, the present inventor has found that the above problems can be solved by a gas barrier coating agent for packaging materials containing a compound (A) having an amino group and a hydroxyl group, a compound (B) having an anionic hydrophilic group and an ethylenically unsaturated double bond and having a molecular weight of 50 or more and less than 300, and a metal salt (C) having a compound having an anionic hydrophilic group and an ethylenically unsaturated double bond and having a molecular weight of 50 or more and less than 300 as a ligand, and has reached the present invention.

[0010] That is, the present invention relates to a gas barrier coating agent containing a compound (A) having an amino group and a hydroxyl group, a compound (B) having an anionic hydrophilic group and an ethylenically unsaturated double bond and having a molecular weight of 50 or more and less than 300, and a metal salt (C) having a compound having an anionic hydrophilic group and an ethylenically unsaturated double bond and having a molecular weight of 50 or more and less than 300 as a ligand, wherein the amine value of the compound (A) is 30 to 600 mgKOH / g and the hydroxyl value is 400 to 1300 mgKOH / g.

[0011] The present invention also relates to the above-mentioned gas barrier coating agent in which the compound (A) having an amino group and a hydroxyl group contains a vinylamine-vinyl alcohol copolymer.

[0012] The present invention also relates to the above-mentioned gas barrier coating agent in which the central metal of the metal salt (C) contains at least one selected from the group consisting of zinc, calcium, magnesium, and aluminum.

[0013] The present invention also relates to the above-mentioned gas barrier coating agent in which the content of the compound (A) having an amino group and a hydroxyl group is 20 to 70% by mass in 100% by mass of the solid content of the gas barrier coating agent, the content of the compound (B) is 3 to 60% by mass, and the content of the metal salt (C) is 10 to 70% by mass. The present invention also relates to the above-mentioned gas barrier coating agent.

[0014] The present invention also relates to the above-mentioned gas barrier coating agent for packaging materials.

[0015] The present invention also relates to a laminate having a gas barrier layer formed on a substrate using the above-mentioned gas barrier coating agent for packaging materials.

[0016] The present invention also relates to a method for producing a laminate having a step of coating a gas barrier coating agent on a substrate and a step of irradiating the coated article with ultraviolet rays or electron beams. The present invention relates to a method for manufacturing a laminate, which is a gas barrier coating agent comprising a compound (A) having an amino group and a hydroxyl group, a compound (B) having an anionic hydrophilic group and an ethylenically unsaturated double bond with a molecular weight of 50 or more and less than 300, and a metal salt (C) having a compound with an anionic hydrophilic group and an ethylenically unsaturated double bond with a molecular weight of 50 or more and less than 300 as a ligand, wherein the amine value of the compound (A) is 30 to 600 mgKOH / g and the hydroxyl value is 400 to 1300 mgKOH / g.

Effects of the Invention

[0017] According to the present invention, even when using general-purpose base materials such as polyethylene terephthalate (PET) films, polypropylene (OPP, CPP) films, and paper, by applying them on the base material and curing them by irradiation with active energy rays such as ultraviolet rays and electron beams, a gas barrier coating agent can be provided that exhibits excellent gas barrier properties even under high humidity conditions and can further produce a laminate having transparency, water friction resistance, and base material adhesion.

Modes for Carrying Out the Invention

[0018] Examples will be given below to explain the embodiments of the present invention in detail. However, the matters described below are examples or representative examples of the embodiments of the present invention, and the present invention is not limited to these contents unless it exceeds the gist thereof.

[0019] The gas barrier coating agent of the present invention is characterized by containing a compound (A) having an amino group and a hydroxyl group, a compound (B) having an anionic hydrophilic group and an ethylenically unsaturated double bond with a molecular weight of 50 or more and less than 300, and a metal salt (C) having a compound with an anionic hydrophilic group and an ethylenically unsaturated double bond with a molecular weight of 50 or more and less than 300 as a ligand, and can be preferably used for packaging materials.

[0020] [Compound (A) having an amino group and a hydroxyl group] Since the compound (A) having the amino group and the hydroxyl group has a plurality of hydrogen-bonding functional groups in the molecule, it is likely to exhibit excellent oxygen barrier properties. Further, if it is a high molecular weight substance, it is suitable as a binder resin in that it can impart coating suitability, wettability to a substrate, adhesiveness, and flexibility that does not crack even when bent.

[0021] Generally, the term "amino group" refers to a primary amine, but the amino group in the present invention may be in the state of a secondary or tertiary amine in which the hydrogen atom bonded to the nitrogen atom is substituted with an alkyl group, an aryl group, etc., and may be in the state of a quaternary ammonium salt in part. On the other hand, it is known that the more substituents there are, the higher the ability to trap and stabilize radicals generated by electron beam or UV irradiation, and the more likely it is to cause curing inhibition. Therefore, the use of a primary amine compound is desirable.

[0022] For the compound (A) having an amino group and a hydroxyl group, the functional group values for exhibiting excellent curability and oxygen barrier properties are preferably an amine value of 30 to 600 mgKOH / g and a hydroxyl value of 400 to 1300 mgKOH / g, more preferably an amine value of 30 to 550 mgKOH / g and a hydroxyl value of 500 to 1300 mgKOH / g, and even more preferably an amine value of 30 to 500 mgKOH / g and a hydroxyl value of 600 to 1300 mgKOH / g.

[0023] The amine value can be measured by the following method. The amine value is measured by a known titration method according to JIS K0070:1992. That is, a sample (compound (A)) is accurately weighed at 0.5 to 2 g (sample amount: S g, solid content: Z%), and 30 mL of neutral ethanol (BDG neutral) is added to the accurately weighed sample and dissolved. If the solubility of the sample is low, ion-exchanged water may be added as appropriate. The obtained solution is titrated with a 0.2 mol / L ethanolic hydrochloric acid solution (titer: f). The point at which the color of the solution changes from green to yellow is taken as the end point, and using the titration amount (A mL) at this time, the amine value is determined by the following (Formula 1). (Formula 1) Amine value = (A × f × 0.2 × 56.106) / (S × Z / 100)

[0024] The hydroxyl value can be calculated from the following (Formula 2) based on the structure of the polymer (Compound (A)). (Formula 2) Hydroxyl value = 56106 × A / M A: The number of hydroxyl groups in the polymer constituent unit M: The molecular weight of the polymer constituent unit

[0025] As the compound (A) having an amino group and a hydroxyl group, a vinylamine-vinyl alcohol copolymer is preferred from the viewpoint that the molecular structure and composition ratio that can achieve both a relatively high amine value and a sufficient high hydroxyl value can be controlled in the synthesis process.

[0026] The vinylamine-vinyl alcohol copolymer can be obtained by hydrolyzing a copolymer of N-vinylformamide or N-vinylacetamide and a vinyl carboxylate ester, etc. From the viewpoints of availability of raw materials and ease of hydrolysis, it is preferable to hydrolyze a copolymer of N-vinylformamide and vinyl acetate. The copolymerization method can be carried out by known methods such as bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, etc. Considering the ease of controlling the reaction, solution polymerization, suspension polymerization, and emulsion polymerization are preferred. In addition, an oil-in-water type emulsion may be formed and emulsion polymerization or suspension polymerization may be carried out (Japanese Patent Application Laid-Open No. 2004-315792, Japanese Patent Application Laid-Open No. 2002-069124).

[0027] From the viewpoint of satisfying the appropriate solid content and viscosity of the coating solution and the cured physical properties of the coating film, the number average molecular weight of the vinylamine-vinyl alcohol copolymer in the present invention is preferably 1000 to 200000, more preferably 5000 to 100000, and even more preferably 10000 to 70000. Also, from the viewpoints of the above-mentioned curing inhibition and the stability of the aqueous solution, there is an appropriate value for the amine value, and the molar fraction of amino groups and hydroxyl groups (amino group: hydroxyl group) in the vinylamine-vinyl alcohol copolymer is preferably 5:95 to 40:60, and more preferably 10:90 to 30:70.

[0028] The number average molecular weight can be measured by the following method. The number average molecular weight is calculated by aqueous GPC (gel permeation chromatography) measurement. The measurement is carried out, for example, under the following conditions. Measuring device: Agilent 1260 Infinity II GPC / SEC system Column: OHpak SB-800 HQ Solvent: water / methanol = 5 / 5 vol% + 50 mM lithium chloride Standard substance: polyethylene oxide / polyethylene glycol

[0029] [Compound having an anionic hydrophilic group and an ethylenically unsaturated double bond] The compound having an anionic hydrophilic group and an ethylenically unsaturated double bond used in the present invention contains a compound (B) having a molecular weight of 50 or more and less than 300. The anionic hydrophilic group refers to a functional group in which more than half of the hydrogen ions are dissociated in water at pH 7, and examples thereof include a carboxyl group, a sulfonic acid group, a phosphonic acid group, a phosphinic acid group, and a phosphate group. All of them have hydrogen bonding properties, thereby complementing the oxygen barrier properties of the compound having the amino group and the hydroxyl group. Further, since it is a monomer containing an ethylenically unsaturated double bond, improvement in coating film strength, improvement in water resistance, and suppression of a decrease in oxygen barrier properties under high humidity can be achieved by crosslinking by thermal polymerization, photopolymerization, electron beam, or the like. Examples of the compound having the amino group and the hydroxyl group include a vinylamine-vinyl alcohol copolymer, which is preferably modified by an ionic bond with an anionic monomer and serves as a reactive binder.

[0030] The compound having an anionic hydrophilic group and an ethylenically unsaturated double bond used in the present invention has a molecular weight of 50 or more and less than 300, and from the viewpoints of molecular mobility and reactivity derived from steric hindrance, a molecular weight of 50 or more and less than 200 is preferable, and a molecular weight of 50 or more and less than 120 is more preferable. Further, from the viewpoint of radical polymerization reactivity, as the compound having an ethylenically unsaturated double bond, a (meth)acrylic acid or a (meth)acrylate compound is preferable, and (meth)acrylic acid is most preferable.

[0031] Specific examples of the compound (B) include acrylic acid, methacrylic acid, cinnamic acid, crotonic acid, senecioic acid, tiglic acid, sorbic acid, itaconic acid, maleic acid, angelic acid, aconitic acid, citraconic acid, mesaconic acid, 3-cyclopentene-1-carboxylic acid, 2-methyl-4-pentenoic acid, 2-amino-4-pentenoic acid, 2-hydroxy-3-butenoic acid, trans-2-pentenoic acid, trans-3-hexenedioic acid, sulfoalkyl (meth)acrylate, 2-acrylamido-2-methylpropanesulfonic acid, 2-methacryloyloxyethyl acid phosphate, vinylsulfonic acid, styrenesulfonic acid, vinylphosphonic acid, cinnamylphosphonic acid, etc. Acrylic acid and methacrylic acid are more preferred, and acrylic acid is particularly preferred in terms of properties such as gas barrier properties and cost. The above compounds can be used alone or in combination of two or more.

[0032] [Metal salt] The metal salt used in the present invention contains a metal salt (C) having, as a ligand, a compound having an anionic hydrophilic group and an ethylenically unsaturated double bond and having a molecular weight of 50 or more and less than 300. Examples of the central metal of the metal salt (C) include divalent or higher polyvalent metals such as magnesium (Mg), calcium (Ca), barium (Ba), zinc (Zn), copper (Cu), cobalt (Co), nickel (Ni), aluminum (Al), and iron (Fe). Among the above, zinc, calcium, magnesium, and aluminum are preferred. The metal salt using a divalent or higher metal, when used simultaneously with a compound having an amino group and a hydroxyl group of the binder resin and a compound containing an anionic hydrophilic group and an ethylenically unsaturated double bond, makes the crosslinking by thermal polymerization, photopolymerization, electron beam, etc. denser and improves the curability. Thereby, the intrusion of water and water vapor into the coating film is suppressed, and the water resistance and gas barrier properties under high humidity are improved. The type of the metal salt may be used alone or in combination of two or more. In addition, a compound having an anionic hydrophilic group and an ethylenically unsaturated double bond as a ligand and having a molecular weight of 50 or more and less than 300 is synonymous with the aforementioned compound (B), and the compound as a ligand of the metal salt (C) and the aforementioned compound (B) may be the same or different.

[0033] Examples of the metal salt (C) include calcium acrylate, magnesium acrylate, zinc acrylate, aluminum acrylate, zinc 2-acrylamido-2-methylpropanesulfonate, and the like.

[0034] By using a gas barrier coating agent containing the compound (A), compound (B), and metal salt (C) having the above amino group and hydroxyl group to form a cured coating film (gas barrier layer), oxygen barrier properties, substrate adhesion, and water resistance can be realized at a high level. As the content ratio of each component, in 100% by mass of the solid content of the gas barrier coating agent, the content ratio (% by mass) of the compound (A) having an amino group and a hydroxyl group is preferably 20 to 70% by mass, more preferably 30 to 60% by mass. The content ratio (% by mass) of the compound (B) is preferably 3 to 60% by mass, more preferably 4 to 60% by mass, and even more preferably 5 to 50% by mass. The content ratio (% by mass) of the metal salt (C) is preferably 10 to 70% by mass, more preferably 15 to 60% by mass, and even more preferably 20 to 50% by mass. The content ratio (% by mass) of the compound (B) may be 10 to 60% by mass, 15 to 60% by mass, or 20 to 50% by mass. The content ratio (% by mass) of the metal salt (C) is preferably 10 to 70% by mass, more preferably 15 to 60% by mass, and even more preferably 20 to 50% by mass.

[0035] [Solvent] The gas barrier coating agent of the present invention preferably contains a solvent. It is preferable to use water as the solvent to form an aqueous composition, but in order to improve the wettability to the substrate or to achieve uniform dissolution or dispersion of each component, a small amount of an organic solvent (for example, alcohols) may be added within a range that does not inhibit the polymerization reaction.

[0036] [Initiator] Since the gas barrier coating agent of the present invention has an ethylenically unsaturated double bond as a polymerizable group, a method of obtaining a cured coating film by crosslinking reaction by ultraviolet irradiation or electron beam irradiation is preferable. Electron beam irradiation is more preferable because it is possible to perform a crosslinking reaction without using a polymerization initiator, but a polymerization initiator can also be contained if necessary. As the polymerization initiator, a photopolymerization initiator and a thermal polymerization initiator are typical. A photopolymerization initiator and a thermal polymerization initiator may be used in combination. As the thermal polymerization initiator, an azo compound or a peroxide activated by irradiation with ionizing radiation may be used.

[0037] The polymerization reaction after applying the gas barrier coating agent to the substrate may be carried out after sufficiently distilling off the solvent in an oven, or may be carried out in a wet state before drying. When irradiating ultraviolet rays on the wet coating film, it is preferable to contain a photopolymerization initiator in the gas barrier coating agent. A photopolymerization initiator is sometimes simply called a photoinitiator or a sensitizer. Examples of the photopolymerization initiator include acetophenones, benzophenones, Michler's ketones, benzyles, benzoins, benzoin ethers, benzyldimethyl ketals, thioxanthones, and mixtures of two or more of these.

[0038] Preferable specific examples of the photopolymerization initiator include acetophenones such as acetophenone, 2,2 - diethoxyacetophenone, m - chloroacetophenone, p - tert - butyltrichloroacetophenone, 4 - dialkylacetophenone, 1 - [4 - (2 - hydroxyethoxy)phenyl] - 2 - hydroxy - 2 - methylpropan - 1 - one; benzophenones such as benzophenone; Michler's ketones such as Michler's ketone; benzyles such as benzyl and benzyl methyl ether; benzoins such as benzoin and 2 - methylbenzoin; benzoin methyl ether, benzoin ethyl ether, benzoin iso Benzoin ethers such as ropyl ether and benzoin butyl ether; Benzyldimethyl ketals such as benzyldimethyl ketal; Thioxanthones such as thioxanthone; Carbonyl compounds such as propiophenone, anthraquinone, acetoin, butyroin, tolualoin, benzoyl benzoate, α-acyloxime ester; and the like can be mentioned. can be mentioned.

[0039] As the photopolymerization initiator, in addition to the above carbonyl compounds, sulfur compounds such as tetramethylthiuram disulfide ide, tetraethylthiuram disulfide, tetramethylthiuram monosulfide, thioxanthone, 2-chlorothioxanthone, etc.; azo compounds such as azobisisobutyronitrile, azobis-2,4-dimethylvaleronitrile, etc.; peroxides such as benzoyl peroxide, di-tert-butyl peroxide, etc. can be mentioned.

[0040] When these photopolymerization initiators are added to the gas barrier coating agent, they are usually added in a proportion of 0.001 to 10% by mass, preferably 0.01 to 5% by mass, based on the polymerizable compound containing the compound (B). The photopolymerization initiator is not necessarily added, but when performing polymerization by irradiation with ultraviolet rays, it is preferable to add a photopolymerization initiator to enhance the polymerization efficiency. When using a hydrogen abstraction type photopolymerization initiator such as benzophenone, a part of the α,β-unsaturated carboxylic acid monomer is grafted onto the plastic film used as the base material, and the interlayer adhesion between the base material and the ion crosslinked polycarboxylic acid polymer film layer can be enhanced. Other general-purpose additives such as other sensitizers and light stabilizers may be added together with the photopolymerization initiator.

[0041] When heating the wet coating film to perform thermal polymerization, it thermally dissociates to function as an initiator It is preferable to use a thermal polymerization initiator that exhibits heat. Examples of the thermal polymerization initiator include persulfates such as potassium persulfate and ammonium persulfate; azo-based polymerization initiators such as 2,2′-azobis〔2-methyl-N-(2-hydroxyethyl)propionamide〕, 2,2′-azobis[2-methyl-N-〔1,1-bis(hydroxymethyl)ethyl〕propionamide], 2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile), 4,4′-azobis(4-cyanovaleric acid), 2,2′-azobis(methyl isobutyrate), 1,2′-azobis(N,N′-dimethylenebis(isobutylamidine)dihydrochloride, 2,2′-azobis[2-methyl-N-(2-hydroxyethyl)-propionamide, 1,1′-azobis(cyclohexane-1-carbonitrile); hydroperoxides such as tert-alkyl hydroperoxide; peroxides such as di-tert-butyl peroxide, dicumyl peroxide, lauroyl peroxide, benzoyl peroxide, tert-butyl peroxy-2-ethylhexanoate, tert-hexyl peroxy-2-ethylhexanoate, tert-butyl peroxypivalate, di-isopropyl peroxydicarbonate, di-tert-butyl peroxyisophthalate, 1,1′, 3,3′-tetramethylbutyl peroxy-2-ethylhexanoate, tert-butyl peroxybutyrate. When using a thermal polymerization initiator, it is usually added in a proportion of 0.001 to 10% by mass, preferably 0.01 to 5% by mass, based on the solid content of the gas barrier coating agent.

[0042] [Sensitizer] In the gas barrier coating agent of the present invention, a sensitizer can be used in combination with a photoinitiator. Examples of the sensitizer include amine-based sensitizers, anthracene-based sensitizers, thioxanthone-based sensitizers, and the like. The sensitizers can be used alone or in combination of two or more.

[0043] Examples of amine-based sensitizers include trimethylamine, methyldiethanolamine, triethanolamine, p - diethylaminoacetophenone, ethyl p - dimethylaminobenzoate, isoamyl p - dimethylaminobenzoate, ethyl 4 - dimethylaminobenzoate, N,N - dimethylbenzylamine, 4’ - bis(diethylamino)benzophenone, and the like.

[0044] Examples of anthracene - based sensitizers include 9,10 - dibutoxyanthracene, 9,10 - diethoxyanthracene, 9,10 - dipropoxyanthracene, 9,10 - bis(2 - ethylhexyloxy)anthracene, and the like.

[0045] Examples of thioxanthone - based sensitizers include thioxanthone - based sensitizers such as 2,4 - diethylthioxanthone, 2 - isopropylthioxanthone, 4 - isopropylthioxanthone, and the like. Representative examples of commercially available products include EPA (manufactured by Nippon Kayaku Co., Ltd.) for amine - based sensitizers, DBA and DEA (manufactured by Kawasaki Kasei Kogyo Co., Ltd.) for anthracene - based sensitizers, and DETX and ITX (manufactured by Lambson) for thioxanthone - based sensitizers. The sensitizer is preferably a thioxanthone - based sensitizer or the like.

[0046] [Resin] The gas barrier coating agent in the present invention can contain a non-polymerizable resin to such an extent that it does not impair the performance such as gas barrier properties and water resistance, and an aqueous resin is preferred. By including a non-polymerizable resin in the gas barrier coating agent, the flexibility of the coated article, the wettability to the substrate, and the curing shrinkage of the coating film generated during curing are alleviated to suppress the curling of the substrate, and furthermore, the adhesion to the substrate may be improved. Examples of the resin include acrylic resin, epoxy resin, polyurethane resin, polyurethane-urea resin, (modified) styrene maleic anhydride copolymer, (modified) vinyl chloride-vinyl acetate copolymer, (modified) vinyl chloride-vinyl acetate-maleic anhydride copolymer, ketone aldehyde resin, polyester resin, polypropylene resin, polylactic acid resin, cellulose acetate resin, cellulose acetate butyrate resin, esterified cellulose resin, butyral resin, etc. These resins can be used alone or in combination of two or more kinds.

[0047] [Crosslinking agent] The gas barrier coating agent in the present invention may use a water-soluble or water-dispersible crosslinking agent for the purpose of improving the gas barrier properties and water resistance under high humidity, and a crosslinking agent that can react with functional groups such as hydroxyl groups, carboxyl groups, and amino groups in the molecules of the compounds contained in the gas barrier coating agent is preferred. Representative examples of the crosslinking agent that can react with the above functional groups include compounds having an isocyanate group, an epoxy group, a carbodiimide group, an oxazoline group, etc., and metal chelates such as titanium and zirconium may also be used. These can be used alone or in combination of two or more.

[0048] Specific examples of the crosslinking agent include Duranate WB40-100 and Duranate WT20-100 of the water-dispersible isocyanate manufactured by Asahi Kasei Corporation, Denacol EX-313 and Denacol EX-321 of the water-soluble polyfunctional epoxy compound manufactured by Nagase ChemteX Corporation, Carbodilite E-02 and Carbodilite E-05 of the carbodiimide compound manufactured by Nisshinbo Holdings, Inc., WS-500 and K2020E of the oxazoline compound manufactured by Nippon Shokubai Co., Ltd., Orgatix TC-300 and TC-310 of the titanium chelate manufactured by Matsumoto Fine Chemical Co., Ltd., ZC-126 and ZC-300 of the zirconium chelate manufactured by Matsumoto Fine Chemical Co., Ltd., and the like.

[0049] The gas barrier coating agent in the present invention can contain other additives as necessary. Examples of the other additives include surface modifiers, ultraviolet absorbers, antioxidants, polymerization inhibitors, waxes, inorganic compounds, and the like.

[0050] [Surface modifier] The surface modifier is a material having a surface modification function such as leveling property and anti-cratering. Examples of the material having a surface modification function include silicone-based surface modifiers such as polyether-modified polydimethylsiloxane having an acrylic group, polyether-modified dimethylsiloxane, polyester-modified dimethylsiloxane having an acrylic group, polyether-modified polydimethylsiloxane, polyester-modified polydimethylsiloxane, and aralkyl-modified polymethylalkylsiloxane. Other examples include acrylic-based surface modifiers, fluorine-based surface modifiers, and acetylene glycol-based surface modifiers. These can be used alone or in combination of two or more, and are preferably 0.001% by mass or more and 2.0% by mass or less, more preferably 0.01% by mass or more and 1.0% by mass or less, based on 100% by mass of the total of components (A) to (C).

[0051] [Ultraviolet absorber] Ultraviolet absorbers are used for the purpose of preventing the degradation of laminates caused by ultraviolet rays emitted from sunlight or lighting. For example, benzophenone-based, benzotriazole-based, triazine-based, etc. can be mentioned, and many water-dispersible products are on the market for water-based applications. These can be used alone or in combination of two or more kinds, and it is preferably 0.001% by mass or more and 1.0% by mass or less with respect to the total 100% by mass of components (A) to (C).

[0052] [Antioxidant] Antioxidants are used for the purpose of preventing degradation in the same manner as the above ultraviolet absorbers, and examples include hindered phenol-based antioxidants and hindered amine-based antioxidants. These can be used alone or in combination of two or more kinds, and it is preferably 0.001% by mass or more and 0.5% by mass or less with respect to the total 100% by mass of components (A) to (C).

[0053] [Polymerization inhibitor] In the gas barrier coating agent of the present invention, a polymerization inhibitor may be used from the viewpoint of improving storage stability. The polymerization inhibitor can be appropriately selected from known ones. Examples of the polymerization inhibitor include hindered phenols, hindered amines, quinones, nitrosoamines, phenothiazines, piperidine-1-oxyls, and the like. When using a polymerization inhibitor, its content ratio is preferably 0.001% by mass or more and 0.2% by mass or less with respect to the total 100% by mass of components (A) to (C) from the viewpoint of achieving both storage stability and photocurability.

[0054] [Wax] When the gas barrier coating agent of the present invention is aqueous, the wax is preferably an aqueous dispersion, that is, an emulsion. Examples of the wax emulsion include wax emulsions containing polyolefin wax, paraffin wax, Sasol wax, and the like. The polyolefin wax is a polymer or copolymer mainly composed of an olefin monomer. The paraffin wax is a petroleum wax composed of a mixture of chain saturated hydrocarbons having 20 to 30 carbon atoms. The Sasol wax is a synthetic wax composed of substantially saturated linear hydrocarbons produced from carbon monoxide and hydrogen as raw materials by the Fischer-Tropsch method. A wax emulsion containing one or more selected from polyolefin wax and paraffin wax is preferred, and a wax emulsion containing polyolefin wax is more preferred. The wax emulsions containing the above waxes can be used alone or in combination of two or more.

[0055] [Inorganic compound] The gas barrier coating agent of the present invention may further contain an inorganic compound for the purpose of imparting higher gas barrier properties. As the form of the inorganic compound, it is preferably plate-like which is likely to exhibit a labyrinth effect, but it cannot be said to be optimal in general from the viewpoints of coatability and stability over time, and it may be spherical or amorphous. Examples of the plate-like inorganic compound preferably used in the present invention include hydrous silicates (phyllosilicate minerals, etc.), kaolinite-serpentine group clay minerals (halloysite, kaolinite, endellite, dickite, nacrite, etc., antigorite, chrysotile, etc.), pyrophyllite-talc group (pyrophyllite, talc, kerolite, etc.), smectite group clay minerals (montmorillonite, beidellite, nontronite, saponite, hectorite, sauconite, stibnite, etc.), vermiculite group clay minerals (vermiculite, etc.), mica or mica group clay minerals (mica such as muscovite and phlogopite, margarite, tetrasilicic mica, teniolite, etc.), chlorite group (cookeite, sudoite, clinochlore, chamosite, nimite, etc.), hydrotalcite, plate-like barium sulfate, boehmite, and aluminum polyphosphate. These minerals may be natural clay minerals or synthetic clay minerals.

[0056] <Method for producing gas barrier coating agent> The gas barrier coating agent of the present invention only needs to contain a compound (A) having the above-mentioned amino group and hydroxyl group, a compound (B) having an anionic hydrophilic group and an ethylenically unsaturated double bond and having a molecular weight of 50 or more and less than 300, and a metal salt (C) having a compound having an anionic hydrophilic group and an ethylenically unsaturated double bond and having a molecular weight of 50 or more and less than 300 as a ligand, and the production method is not particularly limited. Specific production methods include a method of mixing each raw material and water and dissolving it over time with a roller mixer, a method of preparing a coating agent by stirring with a stirrer such as a homodisper, etc. Any method may be used as long as a uniform solution without lumps can be obtained, but from the above viewpoints, the compound (A) having an amino group and a hydroxyl group and the metal salt (C) are preferably prepared in a water-soluble state or a dispersed state at an arbitrary ratio and then mixed. Further, when the compound (A) having an amino group and a hydroxyl group is solubilized in water, if a compound (B) having an anionic hydrophilic group is required, it is necessary to mix and dissolve it first and then mix it with an aqueous solution of the metal salt (C). In addition, when additives are blended, it is desirable to dilute them with water or alcohol, etc. from the viewpoint of preventing shock during addition and then use them.

[0057] <Gas barrier laminate> The gas barrier laminate of the present invention has a gas barrier layer formed by coating and, if necessary, curing the gas barrier coating agent of the present invention on one side or both sides of a base material, and can be suitably used for packaging material applications. [Base material] The base material or film base material is selected from the group consisting of a resin sheet, paper, and an aluminum sheet (aluminum foil). For example, as the resin sheet, there are resin sheets formed from resins such as polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polycarbonate resins, polyarylate resins, acrylic resins, polyphenylene sulfide resins, polystyrene resins, vinyl resins, vinyl chloride resins, polyimide resins, epoxy resins, polyolefin resins such as polyethylene, polypropylene, and polynorbornene. Further, it may be a laminate in which a metal is laminated on these sheets. For example, it may be a laminate in which a metal is laminated on a polyethylene terephthalate (PET) sheet. Among the above base materials, polypropylene, polyethylene terephthalate, polyethylene, etc. are preferable because a laminated sheet having good stretchability, translucency, and rigidity can be obtained. The base material may contain one or more optional components as long as the effects of the present invention are not impaired. The base material used in the present invention may contain an ultraviolet absorber, an antioxidant, an antistatic agent, a surfactant, a pigment, a fluorescent brightening agent, etc. The base material may contain inorganic particles containing silica, calcium carbonate, titanium oxide, etc., or organic particles containing an acrylic resin or a styrene resin, etc.

[0058] [Coating Method of Gas Barrier Coating Agent] The coating method of the gas barrier coating agent includes printing methods, is not particularly limited, and known coating methods can be utilized. Examples of coating methods include wire bar coating method, die coat coating method, cast coating method, slot coating method, omega coating method, spiral coating method, control seam coating method, slot coating method, dot coating method, hot melt applicator coating method, hot melt coater coating method, blade coat coating method, dip coating method, gravure coat coating method, microgravure coating method, curtain spray coating method, bead coating method, hot melt roll coater coating method, spin coating method. Examples of printing methods include inkjet printing method, spray printing method, roll coat printing method, doctor roll printing method, doctor blade printing method, curtain coat printing method, slit coat printing method, screen printing method, reverse printing method, push coat printing method, slit coater printing method, etc. After the oxygen barrier laminate is coated on the substrate by these methods, for the purpose of removing the solvent or promoting crosslinking, it may be heated and dried or dried under reduced pressure as necessary. The drying conditions are not particularly limited as long as the substrate does not deteriorate, depending on the film thickness, substrate, and the selected organic solvent, but preferably hot air heating at about 40 to 200 °C is used.

[0059] The thickness of the gas barrier coating agent (coated object) is not particularly limited, but it is preferably a thin film for the purpose of suppressing crack generation during bending, etc. In the dry state, 0.1 to 200 μm is preferable, 0.5 to 20 μm is more preferable, and 1.0 to 10.0 μm is even more preferable. Also, the gas barrier coating agent layer formed here may be laminated in one layer or multiple layers on one side or both sides of the substrate. When providing multiple gas barrier coating layers, their compositions may be the same or different. For example, after coating the gas barrier coating agent on one side of the substrate, through a drying process, the same water vapor barrier layer may be formed in the same manner to form two layers, or a different gas barrier coating agent may be formed to form three layers.

[0060] [Method for Curing Gas Barrier Coating Agent Layer] For the gas barrier coating agent of the present invention, after being printed by various coating methods, the method of obtaining a cured coating film by passing through an electron beam irradiator is most preferable. In the case of electron beam irradiation, the irradiation dose varies depending on the film thickness and the required degree of curing. However, if the film thickness is 10 μm or less, it is desired to irradiate at 10 to 100 kGy at an acceleration voltage of 80 to 150 kV, preferably at 30 to 80 kGy at an acceleration voltage of 100 to 120 kV. After electron beam irradiation, heating can be performed as necessary to promote curing.

[0061] In addition to electron beam curing, the method of obtaining a cured coating film by ultraviolet irradiation is also suitable for the gas barrier coating agent of the present invention. When using the ultraviolet irradiation method, it is necessary to add a photopolymerization initiator, a photosensitizer, etc. as described above to the gas barrier coating agent. As the ultraviolet irradiation means, for example, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, an excimer laser lamp, a xenon lamp, an ultraviolet light-emitting diode (UV-LED), etc. can be used.

[0062] Among the ultraviolet irradiation means, UV-LED has characteristics such as a narrow wavelength range of the irradiated ultraviolet light and easy miniaturization. Therefore, the irradiation wavelength and usage method of the UV-LED can be adjusted arbitrarily to some extent according to the characteristics of the photopolymerization initiator in the gas barrier coating agent. The peak wavelength of the UV-LED to be used is preferably 280 to 420 nm, and particularly preferably 320 to 400 nm.

[0063] Also, when using an ultraviolet irradiation means other than UV-LED (ultraviolet lamp) as the ultraviolet irradiation means, from the viewpoint of efficiently emitting ultraviolet light in the UV-A region and allowing the irradiation light to reach sufficiently inside the ink film, a metal halide lamp is preferably used. In addition, it can also be used in combination with the above-mentioned UV-LED.

[0064] The maximum illuminance of ultraviolet light is preferably 80 mW / cm 2 or more, and 120 mW / cm2 It is more preferable that it is as described above. Further, the integrated light quantity during irradiation varies depending on the types and contents of the polymerizable monomer and the photoinitiator, etc., but it is preferably 100 mJ / cm 2 or more, more preferably 150 mJ / cm 2 or more, and even more preferably 200 mJ / cm 2 or more.

[0065] When the gas barrier coating agent of the present invention uses an electron beam or ultraviolet curing method, it is normal to obtain a cured coating film through a solvent drying process from the coating process and then an electron beam or ultraviolet irradiation process. However, when the binder resin used has a high molecular weight, since the molecular mobility is restricted, the crosslinking degree may be improved by prioritizing the polymerization reaction in the wet state. That is, in the solvent drying process, it is sufficient to stop at pre-drying to the extent that some solvent remains, perform electron beam or ultraviolet irradiation, and then perform a complete drying process to obtain a higher-degree crosslinked coating film, and there is a possibility that the barrier property and water resistance are improved.

[0066] In addition to the base material and the gas barrier coating agent layer, an arbitrary organic layer or inorganic layer can be provided in the gas barrier laminate, and examples of the arbitrary layer include an anchor coat layer, a printing ink layer, a top coat layer, or an overcoat layer. These layers can include one layer or a plurality of layers. The arbitrary layer is not particularly limited, but it may be formed directly on the base material layer, or may be formed via the gas barrier coating agent layer. For example, from the viewpoint of protecting the oxygen barrier composition layer or improving the abrasion resistance, a protective layer and an adhesive layer may be provided on the gas barrier coating agent layer as necessary. Further, the anchor coat layer is preferably formed between the gas barrier coating agent layer and the base material layer, and the top coat layer is preferably formed on the gas barrier coating agent layer formed via the base material. The thickness of the laminate when an arbitrary layer is provided is not particularly limited, but in the dry state, it is preferably 0.1 to 200 μm, more preferably 0.5 to 20 μm, and even more preferably 1.0 to 10.0 μm.

[0067] The method for laminating the organic layer or the inorganic layer is not particularly limited. For example, it may be laminated by a wet process such as coating, or may be laminated by stacking from above with a film, extrusion, or lamination. It may also be a laminate including a layer formed by a vacuum process such as vapor deposition or CVD. Examples of the material for the organic layer include polyvinyl alcohol, polyolefins (such as polyethylene, polypropylene, poly-4-methyl-1-pentene, and polybutene), cyclic olefin polymers, polyesters (such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate), polyamides (such as nylon-6, nylon-66, and polymetaxylylene adipamide), polyphenylene sulfide, polyethyleneimine, and polyimide. These may be used alone or in combination of two or more. Examples of the material for the inorganic layer include metals and semimetals such as chromium, zinc, cobalt, aluminum, tin, and silicon, or oxides, nitrides, oxynitrides, sulfides, and phosphides of the aforementioned metals and semimetals such as silica, alumina, titanium oxide, zinc oxide, silicon nitride. These may be used alone or in combination of two or more. When one or more layers of oxygen barrier composition layers and one or more layers of organic layers or inorganic layers are included on one or both sides of the substrate, the lamination order thereof is arbitrary.

[0068] Further, the laminate of the present invention may further have a heat-sealable heat-fusion layer as needed. By having a heat-fusion layer, the laminate can be sealed by heat-sealing and can be preferably used for packaging material applications.

[0069] The laminate of the present invention can be used as a multilayer packaging material for protecting foods, pharmaceuticals, etc. When used as a multilayer packaging material, the layer structure can vary depending on the content, use environment, and use form. The use is not particularly limited, but since foods, daily necessities, electronic materials, medical uses, etc. require high barrier properties, the laminate of the present invention can be preferably used.

Example

[0070] Hereinafter, specific examples of the present invention will be described together with comparative examples. However, the present invention is not limited to the following examples. In the following examples and comparative examples, "parts" and "%" represent "parts by mass" and "mass%", respectively. Further, in the following examples and comparative examples, "parts" and "%" represent "parts by mass" and "mass%", respectively.

[0071] <Compound (A) having an amino group and a hydroxyl group> (Production of vinylamine-vinyl alcohol copolymer) Referring to the production example of JP-A-2004-315792, resin powder of the following vinylamine-vinyl alcohol copolymer was obtained through a polymerization reaction, a hydrolysis reaction, and a purification step. The amine value, hydroxyl value, and number average molecular weight of the vinylamine-vinyl alcohol copolymer were determined by the above-described method. The specific calculation method of the hydroxyl value is as follows. Copolymer 1 is a copolymer containing 10.2 mol% of vinylamine units and 89.8 mol% of vinyl alcohol units. The content ratio (mol%) of the monomer units was calculated using the masses and molecular weights of N-vinylformamide and vinyl acetate used in the polymerization. The molecular weight (M) of the polymer constituent units contained in Copolymer 1 can be determined as the weighted average value of vinylamine units (molecular weight 43.07) and vinyl alcohol units (molecular weight 44.05), and is 43.95. The number (A) of hydroxyl groups of the polymer constituent units is 0.898 because the content rate of vinyl alcohol units having one hydroxyl group is 89.8 mol%. Therefore, the hydroxyl value of Copolymer 1 is (Equation 2) hydroxyl value = 56106 × 0.898 (A) / 43.95 (M), and is 1146 mgKOH / g. Copolymers 2 and 3 were also determined by the same calculation. Copolymer 1: Amine value 130 mgKOH / g, hydroxyl value 1146 mgKOH / g, number average molecular weight 22000 Copolymer 2: Amine value 213 mgKOH / g, hydroxyl value 1065 mgKOH / g, number average molecular weight 32000 Copolymer 3: Amine value 300 mgKOH / g, hydroxyl value 980 mgKOH / g, number average molecular weight 27000

[0072] <Preparation of Aqueous Solution of Metal Salt (C)> [Aqueous Solution of Calcium Acrylate] 10 parts of calcium hydroxide powder (manufactured by Fujifilm Wako Pure Chemical Corporation, special grade, 0.135 mol ) and 64 parts of ion-exchanged water were placed in a 225 ml mayonnaise bottle and gently mixed with a homodisper so that no lumps were formed. While stirring, 20 parts (0.278 mol) of acrylic acid were gradually added dropwise so that the temperature in the system did not exceed 50 °C due to the exothermic reaction. The addition of acrylic acid changed the state from a turbid dispersion to a transparent liquid, and stirring was continued for about 10 minutes to complete the reaction. After filtering through a #200 filter cloth, ion-exchanged water was added so that the solid content became 30.0%, and an aqueous solution of calcium acrylate was obtained. The molecular weight of acrylic acid is 72.1 g / mol.

[0073] [Aqueous Solution of Magnesium Acrylate] 10 parts of magnesium hydroxide powder (manufactured by Fujifilm Wako Pure Chemical Corporation, special grade, 0.171 mol) and 74 parts of ion-exchanged water were placed in a 225 ml mayonnaise bottle and gently mixed with a homodisper so that no lumps were formed . While stirring, 25 parts (0.347 mol) of acrylic acid were gradually added dropwise so that the temperature in the system did not exceed 50 °C due to the exothermic reaction. The addition of acrylic acid changed the state from a turbid dispersion to a transparent liquid, and stirring was continued for about 10 minutes to complete the reaction. After filtering through a #200 mesh filter cloth, it was adjusted so that the solid content became 30.0%, and an aqueous solution of magnesium acrylate was obtained.

[0074] [Aqueous Solution of Zinc Acrylate] 10 parts of zinc oxide powder (manufactured by Fujifilm Wako Pure Chemical Corporation, special grade, 0.123 mol) and ion 60 parts of ion-exchanged water were placed in a 225 ml mayonnaise bottle and gently mixed with a homodisper so that no lumps were formed. While stirring, 18.2 parts (0.253 mol) of acrylic acid were gradually added dropwise so that the temperature in the system did not exceed 50 °C due to the exothermic reaction. The addition of acrylic acid changed the turbid dispersion state to a transparent liquid, and stirring was continued for about 10 minutes to complete the reaction. After filtering through a #200 mesh filter cloth, it was adjusted so that the solid content was 30.0% to obtain an aqueous zinc acrylate solution.

[0075] [Zinc 2-acrylamido-2-methylpropanesulfonate aqueous solution] 5.0 parts of zinc oxide powder (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., special grade, 0.061 mol) and 60 parts of ion-exchanged water were placed in a 225 ml mayonnaise bottle and gently mixed with a homodisper so that no lumps were formed. While stirring, 25.7 parts (0.124 mol) of 2-acrylamido-2-methylpropanesulfonic acid were gradually added dropwise so that the temperature in the system did not exceed 50 °C due to the exothermic reaction. The addition of 2-acrylamido-2-methylpropanesulfonic acid changed the turbid dispersion state to a transparent liquid, and stirring was continued for about 10 minutes to complete the reaction. After filtering through a #200 mesh filter cloth, it was adjusted so that the solid content was 30.0% to obtain an aqueous solution of 2-acrylamido-2-methylpropanesulfonic acid zinc. The molecular weight of 2-acrylamido-2-methylpropanesulfonic acid is 207.3 g / mol. acrylamido-2-methylpropanesulfonic acid zinc aqueous solution was obtained.

[0076] [Aqueous polyurethane solution] A 2000 ml four-necked flask equipped with a reflux condenser, a dropping funnel, a gas inlet tube, a stirrer, and a thermometer was charged with 240 parts of PTG-2000SN (polytetramethylene glycol with a number average molecular weight of 2000, manufactured by Hodogaya Chemical Co., Ltd.), 24 parts of PEG2000 (polyethylene glycol with a number average molecular weight of 2000), 35 parts of dimethylolbutanoic acid (manufactured by Haichem Co., Ltd.), 75 parts of isophorone diisocyanate (manufactured by Evonik Degussa Japan Co., Ltd.), and 94 parts of MEK (methyl ethyl ketone). The flask was purged with dry nitrogen, and while stirring, the temperature was gradually raised to 85 °C and reacted for 5 hours. Next, while cooling, a mixed solution of 8.9 parts of 28% aqueous ammonia, 900 parts of ion-exchanged water, and 119 parts of isopropyl alcohol was gradually added dropwise to the above solvent-type polyurethane resin and neutralized to make it water-soluble. Thereafter, the solvent was distilled off under reduced pressure, and the distilled-off fraction was replaced with ion-exchanged water to obtain an aqueous polyurethane resin solution (PU-1) with a solid content of 24%. PU-1 had a structural unit derived from polyethylene glycol of 6.4%, a weight average molecular weight of 30,000, a glass transition temperature of -80 °C, and an acid value of 35 mg KOH / g.

[0077] <Preparation of Gas Barrier Coating Agent> [Example 1] 10 parts of the powder of copolymer 1 and 50 parts of ion-exchanged water were placed in a 225 ml mayonnaise bottle. After covering the bottle, it was stirred and mixed with a roller mixer for 20 minutes. It was heated in an oven at 95 °C for 1 hour to sufficiently dissolve the crystals, and then the insoluble matter was removed with a filter cloth. 10 parts of acrylic acid and 66.7 parts (solid content 20 parts) of 30% aqueous calcium acrylate solution were added to the filtered aqueous solution, and a transparent viscous gas barrier coating agent was obtained by stirring and mixing with a roller mixer for 20 minutes.

[0078] [Examples 2 to 13, 15 to 17] A gas barrier coating agent was obtained in the same manner as in Example 1, except that the compounds and compounding amounts shown in Table 1 were changed.

[0079] [Example 14] 10 parts of copolymer 3, 60 parts of ion-exchanged water, and 10 parts of acrylic acid were placed in a 225 ml mayonnaise bottle, capped, and stirred and mixed with a roller mixer for 20 minutes. After heating in an oven at 95 °C for 1 hour to dissolve the crystals sufficiently, the remaining insoluble matter was removed using a filter cloth. To the filtered aqueous solution, 10 parts (solid content 3 parts) of an aqueous zinc acrylate solution, 2 parts of aluminum acrylate powder (manufactured by Asada Chemical Industry Co., Ltd.), and 30 parts of glass beads (5 μm) were added, and shaking and stirring were carried out for 1 hour with a wet media disperser Scan dex to complete the dispersion. The glass beads were removed by a filter cloth to obtain a gas barrier coating agent.

[0080] [Comparative Examples 1 - 4] A coating agent was obtained by the same operation as in Example 1, except that the compounds and compounding amounts described in Table 1 were changed.

[0081] [Comparative Example 5] 33.3 parts of polyethyleneimine (P-1000, manufactured by Nippon Shokubai Co., Ltd., solid content 30%, amine value 18 mmol / g), 5 parts of ion-exchanged water, and 15 parts of acrylic acid were placed in a 225 ml mayonnaise bottle and stirred with a roller mixer. 66.7 parts of a 30% aqueous zinc acrylate solution was added, and the mixture was stirred again with a roller mixer for 30 minutes to obtain a coating agent.

[0082] [Comparative Example 6] 41.7 parts of an aqueous polyurethane (PU-1, solid content 24%), 20 parts of ion-exchanged water, and 12.5 parts of Carbodilite E-02 (manufactured by Nisshinbo Industries, Inc., solid content 40%) were placed and stirred and mixed with a homodisper to obtain a coating agent.

[0083] [Comparative Example 7] 10 parts of polyacrylic acid (manufactured by Wako Pure Chemical Industries, Ltd., average molecular weight 25,000), 40 parts of ion-exchanged water, and 5 parts of Denacol EX-313 (manufactured by Nagase ChemteX Corporation) were placed and stirred and mixed with a homodisper to obtain a coating agent.

[0084]

Table 1

[0085]

Table 2

[0086] The abbreviations and properties of the raw materials described in Tables 1 and 2 are as follows. The compounding amounts of the compounds described in the tables represent solid amounts.

[0087] (Compound (A) having an amino group and a hydroxyl group) Copolymer 1: Amine value 130 mg KOH / g, hydroxyl value 1146 mg KOH / g, number average molecular weight 22000 Copolymer 2: Amine value 213 mg KOH / g, hydroxyl value 1065 mg KOH / g, number average molecular weight 32000 Copolymer 3: Amine value 300 mg KOH / g, hydroxyl value 980 mg KOH / g, number average molecular weight 27000

[0088] (Compound having an anionic hydrophilic group and an ethylenically unsaturated double bond) · Acrylic acid: Manufactured by Fujifilm Wako Pure Chemical Corporation, molecular weight 72.1 g / mol · Methacrylic acid: Manufactured by Fujifilm Wako Pure Chemical Corporation, molecular weight 86.1 g / mol · AAmSA (2 - acrylamido - 2 - methylpropanesulfonic acid): Manufactured by Fujifilm Wako Pure Chemical Corporation, 207.3 g / mol · Light Ester P - 1M: 2 - methacryloyloxyethyl acid phosphate, manufactured by Kyoei Chemical Co., Ltd., molecular weight 210 g / mol Company Chemical Co., Ltd., molecular weight 210 g / mol · Light Ester P - 2M: 2 - methacryloyloxyethyl acid phosphate, manufactured by Kyoei Chemical Co., Ltd., molecular weight 322 g / mol Company Chemical Co., Ltd., molecular weight 322 g / mol ※ The molecular weights of Light Ester P - 1M and Light Ester P - 2M are calculated from the chemical structures of the main components

[0089] (Metal salt (C)) · Calcium acrylate: 30% aqueous calcium acrylate solution adjusted as described above · Magnesium acrylate: 30% aqueous magnesium acrylate solution adjusted as described above · Zinc acrylate: 30% aqueous zinc acrylate solution adjusted as described above · Zinc AAmSA: 30% aqueous zinc 2-acrylamido-2-methylpropanesulfonate solution adjusted as described above · Aluminum acrylate: White powder, manufactured by Wako Pure Chemical Industries, Ltd.

[0090] (Resin (D)) · EVOH: Ethylene-vinyl alcohol copolymer AQ-4104 (manufactured by Kuraray Co., Ltd.) · Polyethyleneimine (P-1000): Manufactured by Nippon Shokubai Co., Ltd., solid content 30%, amine value 18 mmol / g (= 1010 mgKOH / g) · Polyacrylic acid: Manufactured by Fuji Film Wako Pure Chemical Industries, Ltd., average molecular weight 25,000 · Aqueous polyurethane (PU-1): Aqueous polyether-based polyurethane resin, solid content 24%, average molecular weight 30,000, acid value 35 mgKOH / g

[0091] (Crosslinking agent (E)) · Carbodiite E-02: Carbodiimide crosslinking agent, manufactured by Nisshinbo Industries, Inc., carbodiimide equivalent 445 g / eq., solid content 40% · Denacol EX-313: Glycerol polyglycidyl ether (epoxy crosslinking agent), manufactured by Nagase ChemteX Corporation, epoxy equivalent 141 g / eq.

[0092] [Preparation of laminate] In Examples 1 to 19 and Comparative Examples 1 to 7, the prepared samples were coated on a PET substrate (E-5102 manufactured by Toyobo Co., Ltd., film thickness 25 μm) using a Mayer bar. The Mayer bar number was selected so that the coating film thickness would be within 3 to 5 μm when measured at multiple locations. After coating, the coated article was placed in a drying oven at 75°C for 3 minutes to distill off the solvent, and then cured using an electron beam irradiator EC250 / 15 / 180L manufactured by Iwasaki Electric Co., Ltd. at an acceleration voltage of 130 kV and an electron beam dose of 70 kGy. As described in Tables 1 and 2, a laminate was produced and used as a coating film physical property evaluation sample.

[0093] <Oxygen Permeability Measurement> For the laminates obtained in Examples 1 to 19 and Comparative Examples 1 to 7, the oxygen permeability was measured under the conditions of a temperature of 23°C and a relative humidity of 65% RH and a temperature of 23°C and a relative humidity of 90% RH. The measurement of the oxygen permeability was carried out by the isobaric method in accordance with JIS K7126 using an oxygen permeability measuring device OX-TRAN2 / 22 manufactured by MOCON. The measurement area of the laminate set in the measurement cell was 50 cm 2 . As the oxygen barrier property required for a general packaging material, if the oxygen permeability is less than 1 cc / m 2 ·day·atm under the conditions of a temperature of 23°C and a relative humidity of 65% RH, it has sufficient performance. In addition, it can be said to be excellent enough to suppress the decrease in the barrier property under high humidity conditions. Under the above conditions, a barrier film with an oxygen permeability of 20 cc / m 2 ·day·atm or more has low reproducibility of the oxygen permeability, so it was marked as OVER. The oxygen permeability measurement values under normal humidity and high humidity were evaluated according to the following criteria, and the evaluation results are described in Tables 1 and 2. <Oxygen Permeability under Normal Humidity> A: Excellent Less than 1.0 cc / m 2 ·day·atm B: Good 1.0 cc / m or more and less than 5.0 cc / m 2 ·day·atm 2 ·day·atm C: Practical level 5.0 cc / m or more and less than 20.0 cc / m 2 ·day·atm 2 ·day·atm D: Poor 20.0 cc / m or more2 ·day·atm or more <Oxygen permeability under high humidity> A: Excellent 3.0 cc / m 2 ·day·atm less than B: Good 3.0 cc / m 2 ·day·atm or more 10.0 cc / m 2 ·day·atm less than C: Practical level 10.0 cc / m 2 ·day·atm or more 20.0 cc / m 2 ·day·atm less than D: Poor 20.0 cc / m 2 ·day·atm or more

[0094] <Water resistance and friction resistance> Using the laminates obtained in Examples 1 to 19 and Comparative Examples 1 to 6, the water resistance and friction resistance were evaluated. From the uncoated substrate part to the coated part, it was rubbed a certain number of times from one side with a cotton swab sufficiently wetted with water, and the degree of dissolution at the coated end, the degree of swelling of the rubbed part, and the abrasion condition of the coating film surface were visually evaluated. The scores were judged according to the following criteria and are shown in Tables 1 and 2. (Evaluation criteria) A: Excellent No change in appearance even after rubbing more than 200 times B: Good Appearance changes such as swelling and abrasion of the coating film surface occur after rubbing 200 times C: Practical level End dissolution occurs between more than 100 times and less than 200 times D: Poor Dissolution occurs at the end or throughout the rubbed part within less than 100 times, exposing the substrate

[0095] <Adhesion to substrate> Using the laminates obtained in Examples 1 to 19 and Comparative Examples 1 to 7, the adhesion to the substrate was evaluated. The measurement was carried out using an adhesive tape (cellophane tape (width 12 mm) manufactured by Nichiban Co., Ltd.). When the tape was stuck on the coated surface and peeled off at an angle of 180 degrees, the area percentage of the coating film remaining on the coated substrate side was evaluated according to the following criteria, and the evaluation results are shown in Tables 1 and 2. (Evaluation criteria) A: Excellent No peeling B: Good peeling (less than 40%) C: Practically usable level with peeling (40% or more and less than 90%) D: Poor peeling (90% or more)

[0096] <haze> Regarding the transparency of the laminates obtained in Examples 1 to 18 and Comparative Examples 1 to 7, the haze value was evaluated using a spectroscopic haze meter SH7000 (manufactured by Nippon Denshoku Industries Co., Ltd.) according to the following criteria, and the evaluation results are shown in Tables 1 and 2. (Evaluation Criteria) A: Excellent. The haze value is less than 3.0%. B: Good. The haze value is 3.0% or more and less than 6.0%. C: Practical level. The haze value is 6.0% or more and less than 10.0%. D: Poor. The haze value is 10.0% or more.

[0097] As shown in Table 1, the coated articles of the coating agents in the examples not only showed excellent oxygen barrier properties under mild humidity conditions of 23°C and 65% RH, but also were shown to be able to suppress the decrease in barrier properties under high humidity of 23°C and 90% RH. In addition, high levels of substrate adhesion, transparency, and water resistance were achieved, and it was shown that top coating of packaging materials was also possible.< / haze>

Claims

1. A gas barrier coating agent comprising a compound (A) having an amino group and a hydroxyl group, a compound (B) having an anionic hydrophilic group and an ethylenically unsaturated double bond and having a molecular weight of 50 or more and less than 300, and a metal salt (C) having, as a ligand, a compound having an anionic hydrophilic group and an ethylenically unsaturated double bond and having a molecular weight of 50 or more and less than 300, wherein the amine value of the compound (A) is 30 to 600 mgKOH / g and the hydroxyl value is 400 to 1300 mgKOH / g.

2. The gas barrier coating agent according to claim 1, wherein the compound (A) having an amino group and a hydroxyl group contains a vinylamine-vinyl alcohol copolymer.

3. The gas barrier coating agent according to claim 1, wherein the central metal of the metal salt (C) contains at least one selected from the group consisting of zinc, calcium, magnesium, and aluminum.

4. In 100% by mass of the solid content of the gas barrier coating agent, the content of the compound (A) is 20 to 70% by mass, the content of the compound (B) is 3 to 60% by mass, and the content of the metal salt (C) is 10 to 70% by mass. The gas barrier coating agent according to claim 1.

5. The gas barrier coating agent according to claim 1, which is for a packaging material.

6. A laminate having a gas barrier layer formed by using the gas barrier coating agent according to any one of claims 1 to 5 on a substrate.

7. A method for producing a laminate, comprising a step of applying a gas barrier coating agent to a substrate to obtain a coated article, and a step of irradiating the coated article with ultraviolet rays or electron beams to form a gas barrier layer on the substrate, wherein the gas barrier coating agent contains a compound (A) having an amino group and a hydroxyl group, a compound (B) having an anionic hydrophilic group and an ethylenically unsaturated double bond and having a molecular weight of 50 or more and less than 300, and a metal salt (C) having, as a ligand, a compound having an anionic hydrophilic group and an ethylenically unsaturated double bond and having a molecular weight of 50 or more and less than 300, and the amine value of the compound (A) is 30 to 600 mgKOH / g and the hydroxyl value is 400 to 1300 mgKOH / g.

Images