Gas-barrier laminate and packaging material

Abstract

Provided are: a gas-barrier laminate comprising (A) a (A) layer comprising a substrate having an inorganic layer formed on at least one surface thereof and (B) a (B) layer containing a water-soluble polymer, wherein in the (A) layer, the surface where the inorganic layer is formed has a static contact angle with water at 25°C of 20-80 degrees and / or the surface where the inorganic layer is formed has a surface free energy of 41-75 mN / m; and a packaging material. The inorganic layer in the (A) layer is preferably formed by vapor deposition or sputtering and is preferably formed from one or more inorganic substances selected from the group consisting of aluminum oxide, silicon oxide, aluminum, zinc oxide, and magnesium oxide.

Description

Gas barrier laminate and packaging material

[0001] The present invention relates to a gas barrier laminate and a packaging material obtained by using the gas barrier laminate.

[0002] Packaging materials used for packaging food, daily necessities, pharmaceuticals, etc. require properties such as strength, crack resistance, and gas barrier properties to protect the contents from impacts during distribution, deterioration due to oxygen and moisture, etc. Examples of laminated films with gas barrier properties include a gas barrier laminate film having a first layer formed from a vapor-deposited layer of an inorganic compound such as aluminum oxide, and a second layer formed from a gas barrier coating formed by applying a coating agent primarily containing a water-soluble polymer and an aqueous solution containing at least one of (a) one or more alkoxides and / or their hydrolysates, or (C) tin chloride, or a water / alcohol mixed solution, followed by heating and drying (see, for example, Patent Document 1). However, because it is difficult to achieve the required functions with a single material, laminates formed by bonding different polymer materials together are widely used as packaging materials. In order to provide the gas barrier film disclosed in Patent Document 1 with all the functions required for a packaging material to be distributed, it is often used as a packaging material by, for example, laminating a heat-sealable thermoplastic resin layer or a printed layer on the gas barrier coating layer or on the substrate 2, or by laminating a plurality of resins via adhesive layers (see paragraph 0029 of Patent Document 1).

[0003] In recent years, however, there has been a growing demand for packaging materials that are not only functional but also recyclable. There are voices arguing that laminated films made of different resins that are solely functional reduce the quality of recycled plastics, and so there are high hopes for packaging materials that are made of only the same resin, such as olefin-based resins, as recyclable packaging materials.

[0004] As a gas barrier film composed solely of an olefin-based resin, for example, a gas barrier film has been disclosed that comprises a first substrate polyolefin film layer, a second substrate polyolefin film layer, and a polyolefin film sealant layer, in that order, in which the polyolefin film of the first substrate layer or the second substrate layer has an inorganic oxide layer on at least one surface, and exhibits a specific heat shrinkage rate, thereby providing a laminate that can withstand high-temperature retort processing when made into a packaging bag, even when the film is primarily composed of a polyolefin-based film (see, for example, Patent Document 2). Here, Patent Document 2 describes that, in order to improve the adhesion of olefin-based resins, which have poor adhesion, it is preferable to provide an anchor coating agent such as a polyester-based polyurethane resin or a polyether-based polyurethane resin between the polyolefin film and the inorganic oxide layer (see paragraphs 0022-0023 of Patent Document 2). However, this method requires a step of applying the anchor coating agent before providing the inorganic oxide layer on the polyolefin film, and therefore is not suitable for obtaining recyclable packaging materials with gas barrier properties by combining, for example, a general-purpose plastic film such as an olefin film having an inorganic oxide layer.

[0005] Japanese Patent No. 2790054 Japanese Patent Application Laid-Open No. 2021-20391

[0006] When a coating agent is laminated on an inorganic oxide layer formed on the surface of an olefin or other plastic film, good adhesion may not be obtained. This is thought to be due in part to the fact that, after an inorganic oxide layer is formed on the surface of an olefin or other plastic film, the film is usually wound into a roll and stored. During storage, additives such as antioxidants contained in the olefin or other plastic film bleed onto the film surface opposite the inorganic oxide layer, contaminating the inorganic oxide layer that comes into contact with the film when it is wound up. Therefore, the object of the present invention is to provide a gas barrier laminate and packaging material that maintain good adhesion and gas barrier properties even when combined with a general-purpose olefin or other plastic film having an inorganic oxide layer, and are suitable for obtaining a recyclable packaging material.

[0007] That is, the present invention provides a gas barrier laminate comprising: (A) Layer (A) consisting of a substrate having an inorganic layer formed on at least one surface thereof; and (B) Layer (B) comprising a water-soluble polymer, wherein the surface of Layer (A) on which the inorganic layer is formed has a static contact angle with water at 25°C of 20 degrees or more and 80 degrees or less, and / or the surface free energy of the surface on which the inorganic layer is formed is 41 mN / m or more and 75 mN / m or less.

[0008] The present invention also provides a packaging material comprising the gas barrier laminate described above.

[0009] The present invention also provides a method for producing the gas barrier laminate described above, which comprises carrying out, in this order, Step 1 of subjecting Layer (A) made of a base material having an inorganic layer formed on at least one surface thereof to a corona treatment, ozone treatment, plasma treatment, ultraviolet irradiation treatment or excimer UV treatment, and Step 2 of providing Layer (B) containing a water-soluble polymer on Layer (A).

[0010] The present invention can provide a gas barrier laminate that maintains good adhesion and gas barrier properties even when combined with a plastic film such as an olefin film having a general-purpose inorganic oxide layer, and is also suitable for obtaining a recyclable packaging material.

[0011] (A) Layer Composed of a Substrate Having an Inorganic Layer Formed on at Least One Surface) The gas barrier laminate of the present invention has (A) a layer (hereinafter sometimes referred to as layer (A)) composed of a substrate having an inorganic layer formed on at least one surface. The substrate used in layer (A) is not particularly limited in terms of material, manufacturing method, or shape as long as the effects of the present invention are obtained, but a film (sometimes referred to as a sheet, but referred to as a film in the present invention) is often used. Examples of materials for these substrates include olefin-based resins such as polyethylene (PE), polypropylene (PP), cyclic olefin polymer (COP), and cyclic olefin copolymer (COC), polyester, acrylic, polycarbonate, cellulose ester, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), nylon (NY), and materials containing biomass-derived components. In particular, any film composed of a thermoplastic resin primarily composed of an olefin-based resin can be used without any particular limitations. Specific examples of olefin resins include polyethylenes such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene, polypropylene (PP), ethylene-propylene copolymers, α-olefin polymers, ethylene-vinyl acetate copolymers, ethylene-vinyl alcohol copolymers, ethylene-acrylic acid copolymers, ethylene-methyl methacrylate copolymers, ethylene-ethyl acrylate copolymers, cyclic olefin resins, ionomer resins, and polymethylpentene; and modified olefin resins obtained by modifying olefin resins with acrylic acid, methacrylic acid, maleic anhydride, fumaric acid, or other unsaturated carboxylic acids. Among these, olefin resins such as polyethylene (PE), polypropylene (PP), cyclic olefin polymers (COP), and cyclic olefin copolymers (COC) are preferably used because the effects of the present invention are most pronounced, with polyethylene (PE) and polypropylene (PP) being most preferred.

[0012] Examples of film names include polyethylene terephthalate (PET) film, polystyrene film, polyamide film, polyacrylonitrile film, polyethylene film (LLDPE: low-density polyethylene film, HDPE: high-density polyethylene film, MDOPE: uniaxially oriented polyethylene film, OPE: biaxially oriented polyethylene film), polyolefin films such as polypropylene film (CPP: unoriented polypropylene film, OPP: biaxially oriented polypropylene film), polyvinyl alcohol film, ethylene-vinyl alcohol copolymer film, etc., for food packaging. It is also preferable to use biomass films formed from materials containing biomass-derived components. Biomass films are sold by various companies, and sheets such as those listed in the list of biomass-certified products listed by the Japan Organics Resources Association, a general incorporated foundation, can be used.

[0013] The substrate used in Layer (A) is not particularly limited, and may be a substrate with a thickness typically used for packaging foods, daily necessities, pharmaceuticals, etc. From the viewpoint of formability and transparency, a film having a thickness in the range of 1 μm to 500 μm is sufficient, preferably 1 μm to 300 μm, and more preferably 1 μm to 100 μm. A thickness below 1 μm may result in insufficient strength, while a thickness above 500 μm may result in excessive rigidity, making processing difficult. The method for producing these substrates is not particularly limited, and they may be produced using various film-forming methods such as melt extrusion molding, solution casting molding, and calendar molding. These may also be further subjected to biaxial or uniaxial stretching. Furthermore, films that have been subjected to various surface treatments may also be used as needed.

[0014] The layer (A) is a layer having a substrate layer with an inorganic layer formed on at least one side thereof, and the inorganic layer is formed on a part or the entire surface of at least one side of the substrate. The inorganic substance forming the inorganic layer is not particularly limited as long as the effects of the present invention can be obtained, but it is preferable to use one or more selected from metals and metal oxides such as aluminum oxide, silicon oxide, aluminum, zinc oxide, magnesium oxide, calcium oxide, and zirconium oxide, and it is particularly preferable to use one or more selected from aluminum oxide, silicon oxide, aluminum, zinc oxide, and magnesium oxide because they exhibit good barrier properties.

[0015] In the layer (A) of the present invention, the method for forming the inorganic layer is not particularly limited as long as the effects of the present invention can be obtained. However, the inorganic layer can be formed by a vapor deposition process, a sputtering process, a CVD process, or a coating process, and it is particularly preferable to use a vapor deposition process or a sputtering process because the inorganic layer can be formed uniformly.

[0016] The thickness of the inorganic layer may be within a range that allows the effects of the present invention to be obtained, but is preferably in the range of 1 to 100 nm, and more preferably in the range of 3 to 80 nm.

[0017] The (A) layer may be provided with an anchor coat layer for the purpose of enhancing adhesion of the inorganic layer to the substrate layer. The anchor coat layer can be obtained by applying an anchor coating liquid to the substrate layer and drying it. Known anchor coating liquids may be used, such as anchor coating agents primarily composed of acrylic resins, urethane resins, vinyl alcohol resins, ethylene vinyl alcohol resins, or other resins, or curable anchor coating agents that also contain an isocyanate or epoxy curing agent. The thickness of the anchor coat layer may be within a range that achieves the effects of the present invention, but is preferably in the range of 0.001 to 0.5 μm, and more preferably in the range of 0.01 to 0.4 μm. It is preferable to form the inorganic layer after providing the anchor coat layer.

[0018] The (A) layer in the present invention is characterized in that the surface on which the inorganic layer is formed has a static contact angle with water of 20 degrees or more and 80 degrees or less at 25°C, and / or a surface free energy of 41 mN / m or more and 75 mN / m or less. A surface having such characteristics is a surface that is highly wettable with water, in other words, a highly hydrophilic surface. Therefore, by setting the static contact angle and / or surface free energy of the surface within the above ranges, adhesion to the water-soluble polymer contained in the (B) layer is improved.

[0019] The upper limit of the static contact angle of the surface on which the inorganic layer is formed may be 80 degrees or less, preferably 70 degrees or less, more preferably 60 degrees or less, and even more preferably 50 degrees or less. The lower limit of the static contact angle may be 20 degrees or more, but preferably 23 degrees or more.

[0020] On the other hand, the lower limit of the surface free energy of the surface on which the inorganic layer is formed may be 41 mN / m or more, preferably 45 mN / m or more, more preferably 48 mN / m or more, and more preferably 50 mN / m or more, and the upper limit of the surface free energy may be 75 mN / m or less, preferably 73 mN / m or less.

[0021] The (A) layer can be easily obtained by subjecting the inorganic layer that has been subjected to the vapor deposition or sputtering treatment to a surface hydrophilization treatment. Examples of surface hydrophilization treatments include corona treatment, ozone treatment, plasma treatment, ultraviolet irradiation treatment (hereinafter referred to as UV treatment), ion treatment, radiation treatment, excimer UV treatment, ozone water treatment, flame treatment, and itro treatment, as described in Practical Surface Modification Technology Handbook (1993), edited by the Materials Technology Research Association. Among these, corona treatment, ozone treatment, plasma treatment, ultraviolet irradiation treatment, and excimer UV treatment are more preferred. These treatments can be used alone or in combination of two or more.

[0022] (Corona Treatment) Corona treatment is a method of surface modification using corona discharge excited by applying a high voltage AC to a pair of electrodes under atmospheric pressure. The discharge amount in the corona treatment is not particularly limited, but is preferably about 10 to 200 W / m2 / min, and more preferably about 20 to 150 W / m2 / min.

[0023] (Ozone Treatment, Ozone Water Treatment) Ozone treatment is a method of converting oxygen in the air into ozone by ultraviolet (UV) irradiation and then modifying the surface in an ozone-containing atmosphere. A low-pressure mercury lamp is preferred as the UV light source. Low-pressure mercury lamps have an emission spectrum at wavelengths around 185 nm and 254 nm, and are known to generate ozone with light having a wavelength around 185 nm and decompose the ozone with light having a wavelength around 254 nm to generate active oxygen. Therefore, by using a low-pressure mercury lamp, the inner surface can be efficiently hydrophilized. The gas that generates ozone may be any gas containing oxygen, such as oxygen gas or dry air. The pressure of the atmosphere used in the ozone treatment may be either reduced pressure or atmospheric pressure. The duration of the ozone treatment (UV irradiation time) is not particularly limited, but is preferably approximately 10 to 300 seconds, and more preferably approximately 20 to 180 seconds. When the surface modification treatment is carried out by an ozone aqueous solution treatment, the ozone concentration is preferably 5 ppm or more, and more preferably 15 ppm or more, by blowing ozone into an aqueous solution such as ordinary water or hydrogen peroxide water.

[0024] (Plasma Treatment) Plasma treatment is a method of surface modification using plasma generated by the ionization of gases through electrical discharge. Examples of treatment gases include nitrogen gas, argon gas, oxygen gas, helium gas, water, neon gas, xenon gas, carbon dioxide gas, hydrogen, and mixtures of these. Examples of electrical discharge include, but are not limited to, corona discharge (high-pressure, low-temperature plasma), arc discharge (high-pressure, high-temperature plasma), and glow discharge (low-pressure, low-temperature plasma). Of these, glow discharge is preferred because it causes less thermal and electrical damage to the substrate.

[0025] (UV Treatment) UV treatment (optical surface treatment) is a method of surface modification by directly irradiating the inner surface with ultraviolet (UV) rays with wavelengths of 300 nm or less, including excimer UV. As a UV light source, a low-pressure mercury lamp using synthetic quartz, which has a high transmittance of UV rays, particularly short wavelengths, is used. However, to prevent the generation of ozone, it is preferable to cut ultraviolet rays with a wavelength of 185 nm.

[0026] If the static contact angle and / or surface free energy of the surface on which the inorganic layer is formed is within a desired range before the hydrophilization treatment is carried out, the hydrophilization treatment may be omitted.

[0027] From the viewpoint of recycling, it is preferable that the layer structure is as simple as possible, but from the viewpoint of distribution of the packaging material, printing is often required to indicate the contents of the packaging material or a description or name of the product. Printing is often also performed on the substrate.

[0028] (Printed Layer) The printed layer is a layer on which characters, figures, symbols, and other desired designs are printed. The printing method and printing ink are not particularly limited, and known printing methods and printing inks can be used. Printing inks using methods such as gravure printing, flexographic printing, lithographic offset printing, and inkjet recording printing are often used for the film used as the substrate. Printing inks that combine these printing methods with methods of curing using active energy rays such as ultraviolet (UV), LED, and electron beam (EB), or methods of curing using heat, are also used. Depending on the solvent used, inks may be referred to as aqueous inks or organic solvent-based inks.

[0029] Specific examples include gravure printing ink and flexographic printing ink (in some industries, gravure printing ink and flexographic printing ink are sometimes referred to as liquid printing ink), ultraviolet-curable ink for lithographic offset printing, electron-beam-curable ink for lithographic offset printing, ultraviolet-curable ink for inkjet recording and printing, and electron-beam-curable ink for inkjet recording and printing.

[0030] The position at which the printed layer printed using these inks is provided is arbitrary, and it may be provided on the first substrate, or a substrate on which a separate printed layer is provided may be one of the constituent components of the laminate of the present invention, and the position is arbitrary. The ink may contain a resin, a colorant, and a solvent as essential components, or it may be a so-called clear ink that contains a resin and a solvent but does not substantially contain a colorant. Below, we will explain the liquid printing inks that are most commonly used for printing on films.

[0031] The resin used in the liquid printing ink is not particularly limited and includes, for example, acrylic resin, polyester resin, styrene resin, styrene-maleic acid resin, maleic acid resin, polyamide resin, polyurethane resin, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-acrylic copolymer resin, ethylene-vinyl acetate copolymer resin, vinyl acetate resin, polyvinyl chloride resin, chlorinated polypropylene resin, cellulose-based resin, epoxy resin, alkyd resin, rosin-based resin, rosin-modified maleic acid resin, ketone resin, cyclized rubber, chlorinated rubber, butyral, petroleum resin, etc., and one or more of these can be used in combination. Preferably, at least one or two or more selected from polyurethane resin, vinyl chloride-vinyl acetate copolymer resin, and cellulose-based resin are used.

[0032] Colorants used in liquid printing inks include inorganic pigments such as titanium oxide, red iron oxide, antimony red, cadmium red, cadmium yellow, cobalt blue, Prussian blue, ultramarine, carbon black, and graphite; organic pigments such as soluble azo pigments, insoluble azo pigments, azo lake pigments, condensed azo pigments, copper phthalocyanine pigments, and condensed polycyclic pigments; and extender pigments such as calcium carbonate, kaolin clay, barium sulfate, aluminum hydroxide, and talc.

[0033] Liquid printing inks for film printing are often organic solvent-based inks. The organic solvent used preferably does not contain an aromatic hydrocarbon organic solvent. More specific examples include alcohol-based organic solvents such as methanol, ethanol, n-propanol, isopropanol, and butanol; ketone-based organic solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ester-based organic solvents such as methyl acetate, ethyl acetate, propyl acetate, and butyl acetate; aliphatic hydrocarbon-based organic solvents such as n-hexane, n-heptane, and n-octane; and alicyclic hydrocarbon-based organic solvents such as cyclohexane, methylcyclohexane, ethylcyclohexane, cycloheptane, and cyclooctane. These may be used alone or in combination of two or more.

[0034] (Layer (B) Comprising Water-Soluble Polymer (B)) The gas barrier laminate of the present invention has a layer (B) comprising a water-soluble polymer (B) (hereinafter, may be referred to as layer (B)). The layer (B) may be laminated so that at least a portion of the layer (B) is in direct contact with the inorganic layer of the layer (A), and another layer such as layer (C) described below may be present between the layer (B) and layer (A).

[0035] The water-soluble polymer contained in the layer (B) is not particularly limited as long as the effects of the present invention can be obtained, and examples thereof include one or more water-soluble polymers such as vinyl alcohol polymers such as polyvinyl alcohol, ethylene-vinyl alcohol polymers, vinylpyrrolidone polymers, carboxyl group-containing resins such as (meth)acrylic acid polymers, salts of resins having carboxyl groups, polyvinyl butyral, starch, methyl cellulose, carboxymethyl cellulose, sodium alginate, etc. Among these, it is preferable to use one or more selected from vinyl alcohol polymers, ethylene-vinyl alcohol polymers, vinylpyrrolidone polymers, polyvinyl butyral, (meth)acrylic acid polymers, and ammonium salts of acrylic acid polymers, because they provide suitable gas barrier properties.

[0036] The vinyl alcohol polymer may be a modified polyvinyl alcohol having a reactive functional group other than a hydroxyl group, such as an acetoacetyl group, a carboxyl group, an anionic carboxyl group, a sulfonic acid group, an anionic sulfonic acid group, etc. These may be used alone or in combination of two or more.

[0037] Examples of vinyl alcohol polymers include hydrolysates of vinyl ester homopolymers or copolymers, and compounds obtained by reacting hydrolysates of vinyl ester homopolymers or copolymers with aldehydes or ketones to form acetals. Examples of vinyl alcohol polymers having a reactive functional group other than a hydroxyl group include hydrolysates of copolymers of vinyl esters and monomers having a reactive functional group, and compounds obtained by modifying (denaturing) the hydroxyl or acetyl group of a hydrolysate of a vinyl ester homopolymer or copolymer using a compound having a reactive functional group by a known method.

[0038] Examples of vinyl esters include vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl versatate, vinyl caproate, vinyl caprylate, vinyl laurate, vinyl palmitate, vinyl stearate, vinyl oleate, vinyl benzoate, and vinyl acetoacetate, and these can be used alone or in combination of two or more. Vinyl acetate is preferred.

[0039] Examples of polymerizable compounds copolymerizable with vinyl esters include ethylene, propene, 1-butene, isobutylene, 1,3-butadiene, isopropenyl acetate, 2-propenyl acetate, styrene, α-methylstyrene, vinyl chloride, acrylonitrile, maleic anhydride, methyl acrylate, methyl methacrylate, N-vinyl-N-methylformamide, vinylacetamide, N-vinylformamide, N-(hydroxymethyl)-N-vinylformamide, hydroxyethyl acrylate, methyl vinyl ketone, diacetone acrylamide, and diacetone acrylamide. Examples of suitable acrylates include acrylate, diacetone methacrylamide, acrolein, formylstyrene, vinyl methyl ketone, vinyl ethyl ketone, vinyl isobutyl ketone, diacetone acrylate, diacetone methacrylate, acetonitrile acrylate, 2-hydroxypropyl acrylate acetoacetate, butanediol acrylate acetate, vinyl sulfonic acid, acrylamide tert-butyl sulfonic acid, orthostyrene sulfonic acid, metastyrene sulfonic acid, and parastyrene sulfonic acid, and these may be used alone or in combination of two or more. Of these, ethylene, isopropenyl acetate, and 2-propenyl acetate are preferred.

[0040] When a vinyl ester and a polymerizable compound are used in combination, the amounts used can be adjusted as appropriate. From the viewpoint of gas barrier properties, however, the amount of the polymerizable compound blended is preferably kept to 60 mol % or less, and more preferably 25 mol % or less, of the total amount of the vinyl ester and the polymerizable compound.

[0041] The degree of polymerization of the vinyl ester polymer, which is the precursor of the vinyl alcohol polymer, is not particularly limited, but is, for example, 500 to 10,000, more preferably 800 to 6,000, and even more preferably 1,000 to 3,000. This makes it possible to obtain a coating agent that has an excellent balance between gas barrier properties and coatability.

[0042] The vinyl alcohol polymer preferably has a saponification degree of 90% or more, more preferably 95% or more, because it has excellent gas barrier properties. It may also be 100%. The saponification degree can be measured by FTIR using, for example, a Nicolet 5700 FTIR spectrometer controlled by OMNIC software.

[0043] When a vinyl alcohol polymer is acetalized, examples of the aldehyde used for acetalization include aliphatic aldehydes such as formaldehyde, acetaldehyde, propylaldehyde, butylaldehyde, octylaldehyde, and dodecylaldehyde; alicyclic aldehydes such as cyclohexanecarbaldehyde; aromatic aldehydes such as benzaldehyde, naphthaldehyde, anthraldehyde, phenylacetaldehyde, tolualdehyde, dimethylbenzaldehyde, cuminaldehyde, and benzylaldehyde; unsaturated aldehydes such as cyclohexene aldehyde, dimethylcyclohexene aldehyde, and acrolein; aldehydes having a heterocycle such as furfural and 5-methylfurfural; hemiacetals of glucose, glucosamine, and the like; and aldehydes having an amino group such as 4-aminobutyraldehyde. Examples of ketones include aliphatic ketones such as 2-propanone, methyl ethyl ketone, 3-pentanone, and 2-hexanone; aliphatic alicyclic ketones such as cyclopentanone and cyclohexanone; and aromatic ketones such as acetophenone and benzophenone. These can be used alone or in combination of two or more.

[0044] As the acid catalyst used in the acetalization, conventionally known organic or inorganic acids such as acetic acid, paratoluenesulfonic acid, nitric acid, sulfuric acid, and hydrochloric acid can be used.

[0045] The vinyl alcohol polymer is preferably one obtained by acetalizing a precursor having a saponification degree of 95% or more.

[0046] Examples of methods for modifying the hydroxyl or acetyl groups of a hydrolyzed vinyl ester homopolymer or copolymer include a method of directly reacting gaseous or liquid diketene, a method of preliminarily adsorbing and occluding an organic acid such as acetic acid and then reacting gaseous or liquid diketene with this under an inert gas atmosphere, or a method of spraying a mixture of an organic acid and diketene to react with diketene (reaction generation step), followed by washing and removing unreacted diketene with an alcohol having 1 to 3 carbon atoms (washing step), and then drying under specified conditions (drying step), and a method of reacting a hydrolyzed vinyl ester homopolymer or copolymer with an acetoacetic ester to perform transesterification. This allows acetoacetyl groups to be introduced into a vinyl alcohol-based polymer.

[0047] In the resin having a carboxyl group (sometimes referred to as a carboxylic acid group) used in the present invention, the carboxyl group may include a carboxylic acid anhydride.

[0048] The resin having a carboxyl group is not particularly limited in terms of its resin skeleton, and any known resin can be used, with carboxyl group-containing vinyl resins being preferred.

[0049] (Carboxyl Group-Containing Vinyl Resin) Examples of the carboxyl group-containing vinyl resin include polymers of polymerizable unsaturated monomers having a carboxyl group. Examples of the polymerizable unsaturated monomer having a carboxyl group include unsaturated carboxylic acids such as (meth)acrylic acid, 2-carboxyethyl (meth)acrylate, crotonic acid, itaconic acid, maleic acid, and fumaric acid; monoesters (half esters) of various unsaturated dicarboxylic acids such as monomethyl itaconate, mono-n-butyl itaconate, monomethyl maleate, mono-n-butyl maleate, monomethyl fumarate, and mono-n-butyl fumarate with saturated monohydric alcohols; monovinyl esters of various saturated dicarboxylic acids such as monovinyl adipate and monovinyl succinate; addition reaction products of various anhydrides of saturated polycarboxylic acids such as succinic anhydride, glutaric anhydride, phthalic anhydride, and trimellitic anhydride with various hydroxyl group-containing vinyl monomers; and further various monomers obtainable by addition reaction of the above-mentioned various carboxyl group-containing monomers with lactones.

[0050] The resin having a carboxyl group used in the present invention may be a homopolymer of the above-mentioned polymerizable unsaturated monomer having a carboxyl group, or a copolymer using a plurality of polymerizable unsaturated monomers having a carboxyl group, or a copolymer of a polymerizable unsaturated monomer having a carboxyl group and another copolymerizable monomer.

[0051] Examples of the monomer copolymerizable with the polymerizable unsaturated monomer having a carboxyl group include the following.

[0052] (1) (meth)acrylic acid esters having an alkyl group having 1 to 22 carbon atoms, such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, hexyl (meth)acrylate, hepsyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, tetradecyl (meth)acrylate, hexadecyl (meth)acrylate, stearyl (meth)acrylate, octadecyl (meth)acrylate, and docosyl (meth)acrylate;

[0053] (2) (meth)acrylic acid esters having an alicyclic alkyl group, such as cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, and dicyclopentenyloxyethyl (meth)acrylate; (3) (meth)acrylic acid esters having an aromatic ring, such as benzoyloxyethyl (meth)acrylate, benzyl (meth)acrylate, phenylethyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, and 2-hydroxy-3-phenoxypropyl (meth)acrylate;

[0054] (4) Acrylic acid esters having a hydroxyalkyl group, such as hydroxyethyl (meth)acrylate; hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, glycerol (meth)acrylate; (meth)acrylic acid esters having a polyalkylene glycol group, such as lactone-modified hydroxyethyl (meth)acrylate, polyethylene glycol (meth)acrylate, and polypropylene glycol (meth)acrylate;

[0055] (5) Unsaturated dicarboxylic acid esters such as dimethyl fumarate, diethyl fumarate, dibutyl fumarate, dimethyl itaconate, dibutyl itaconate, methyl ethyl fumarate, methyl butyl fumarate, and methyl ethyl itaconate; (6) Styrene derivatives such as styrene, α-methylstyrene, and chlorostyrene; (7) Diene compounds such as butadiene, isoprene, piperylene, and dimethylbutadiene; (8) Vinyl halides and vinylidene halides such as vinyl chloride and vinyl bromide; (9) Unsaturated ketones such as methyl vinyl ketone and butyl vinyl ketone; (10) Vinyl esters such as vinyl acetate and vinyl butyrate; (11) Vinyl ethers such as methyl vinyl ether and butyl vinyl ether; (12) Vinyl cyanides such as acrylonitrile, methacrylonitrile, and vinylidene cyanide; (13) Acrylamide and its alkyd-substituted amides; (14) N-substituted maleimides such as N-phenylmaleimide and N-cyclohexylmaleimide;

[0056] (15) Fluorine-containing α-olefins such as vinyl fluoride, vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, bromotrifluoroethylene, pentafluoropropylene, or hexafluoropropylene; or (per)fluoroalkyl perfluorovinyl ethers in which the (per)fluoroalkyl group has 1 to 18 carbon atoms, such as trifluoromethyl trifluorovinyl ether, pentafluoroethyl trifluorovinyl ether, or heptafluoropropyl trifluorovinyl ether; fluorine-containing ethylenically unsaturated monomers such as (per)fluoroalkyl (meth)acrylates in which the (per)fluoroalkyl group has 1 to 18 carbon atoms, such as 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, 1H,1H,5H-octafluoropentyl (meth)acrylate, 1H,1H,2H,2H-heptadecafluorodecyl (meth)acrylate, or perfluoroethyloxyethyl (meth)acrylate;

[0057] (16) silyl group-containing (meth)acrylates such as γ-methacryloxypropyltrimethoxysilane; and (17) N,N-dialkylaminoalkyl (meth)acrylates such as N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, and N,N-diethylaminopropyl (meth)acrylate. These polymerizable unsaturated monomers may be used alone or in combination of two or more.

[0058] The resin having a carboxyl group can be obtained by polymerization (copolymerization) using a known, commonly used method, and the copolymerization form is not particularly limited. It can be produced by addition polymerization in the presence of a catalyst (polymerization initiator), and may be any of a random copolymer, a block copolymer, a graft copolymer, etc. Furthermore, known polymerization methods such as bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization can be used as the copolymerization method.

[0059] (Acid Value) For resins having carboxyl groups, an acid value of 50 to 1000 mgKOH / g is preferred because it improves barrier performance. An acid value of 80 to 900 mgKOH / g is particularly preferred. If the acid value is 80 mgKOH / g or higher, ionic bonding will progress sufficiently and high barrier performance will be obtained.

[0060] (Method for Measuring Acid Value) The acid value is the number of milligrams of potassium hydroxide required to neutralize the acid content present in 1 g of sample. Specifically, the acid value can be measured by dissolving a weighed sample in an appropriate solvent in which the sample is soluble, for example, a solvent with a volume ratio of toluene / methanol = 70 / 30, adding several drops of a 1% phenolphthalein alcohol solution, adding a 0.1 mol / L potassium hydroxide alcohol solution thereto, and checking the point of discoloration, and can be calculated using the following formula:

[0061] Acid value measurement method-1 Acid value (mg KOH / g) = (V x F x 5.61) / S V: Amount (mL) of 0.1 mol / L potassium hydroxide alcohol solution used F: Potency of 0.1 mol / L potassium hydroxide alcohol solution S: Amount (g) of sample collected 5.61: Amount (mg) of potassium hydroxide equivalent in 1 mL of 0.1 mol / L potassium hydroxide alcohol solution

[0062] When the sample is a resin solution, the resin acid value (mgKOH / g) can be calculated using the following formula.

[0063] Resin acid value (mg KOH / g) = Acid value of resin solution (mg KOH / g) / NV (%) × 100 NV: Non-volatile content (%)

[0064] If the sample has low solubility in an organic solvent and precipitates, making measurement difficult, the acid value can also be measured by the following method.

[0065] Acid value measurement method-2 The acid value (mg KOH / g-resin) is a value calculated using the following formula using an FT-IR (FT-IR4200 manufactured by JASCO Corporation) and the coefficient (f) obtained from a calibration curve prepared using a chloroform solution of maleic anhydride, the absorbance (I) of the stretching peak of the anhydride ring of maleic anhydride (1780 cm-1) in the maleic anhydride-modified polyolefin solution, and the absorbance (II) of the stretching peak of the carbonyl group of maleic acid (1720 cm-1). Acid value (mg KOH / g-resin) = [(absorbance (I) x (f) x 2 x molecular weight of potassium hydroxide x 1000 (mg) + absorbance (II) x (f) x molecular weight of potassium hydroxide x 1000 (mg)) / molecular weight of maleic anhydride] Molecular weight of maleic anhydride: 98.06, molecular weight of potassium hydroxide: 56.11

[0066] (Molecular Weight of Resin Having Carboxyl Group) In the present invention, the resin having a carboxyl group used preferably has a weight average molecular weight in the range of 1,000 to 10,000,000, more preferably in the range of 3,000 to 5,000,000, and even more preferably in the range of 5,000 to 1,000,000.

[0067] The salt of the resin having a carboxyl group may be any resin that has been neutralized with a common base, and is preferably an ammonium salt neutralized with ammonium. Whether the resin has been neutralized can be determined by pH, and the pH of a 15% aqueous solution of the resin having a carboxyl group is preferably 7.0 to 9.0.

[0068] The ammonium used for neutralization is not particularly limited, but for example, a commonly available 30% aqueous ammonia solution can be used.

[0069] Among the resins having a carboxyl group, polyacrylic acid, which is a homopolymer of (meth)acrylic acid, and ammonium salts of polyacrylic acid are preferred.

[0070] (Metal Alkoxide and / or Hydrolysate Thereof) The (B) layer may contain a metal alkoxide and / or a hydrolysate thereof. The metal alkoxide and / or hydrolysate thereof to be used is not particularly limited as long as the effects of the present invention can be obtained, but a metal alkoxide and / or a hydrolysate thereof having one or more metal species selected from silicon, aluminum, titanium, and zirconia as the metal species is preferred, and a metal alkoxide and / or a hydrolysate thereof having one or more metal species selected from silicon and aluminum as the metal species is more preferred in terms of improving gas barrier properties.

[0071] These metal alkoxides and / or their hydrolysates are those in which the hydroxyl group of the hydroxide of the metal species is -OCH ３ , -OC ２ H ５ , -OC ３ H ７ , -OC ｎ H ２ｎ＋１ The metal alkoxide and its hydrolysate may be one or more compounds selected from metal alkoxides substituted with alkoxyl groups represented by the formula (I) and (II), and hydrolysates thereof. As the metal alkoxide and its hydrolysate used in the present invention, alkoxysilanes such as tetraethoxysilane (TEOS), tetramethoxysilane, tetraproxisilane, tetrabutoxysilane, etc. can be used, and one or more metal alkoxides and / or hydrolysates thereof selected from tetraethoxysilane and tetramethoxysilane are particularly preferred because they provide good gas barrier properties.

[0072] The water-soluble polymer and the metal alkoxide and / or hydrolyzate thereof are preferably blended so that the solid content ratio is in the range of 70:30 to 15:85, more preferably in the range of 60:40 to 20:80, and most preferably in the range of 50:50 to 25:75.

[0073] (Polyvalent Metal Compound) The (B) layer may contain a polyvalent metal compound. The polyvalent metal compound used is preferably a divalent metal compound. Examples of the divalent metal compound include zinc compounds, magnesium compounds, calcium compounds, manganese compounds, iron compounds, cobalt compounds, nickel compounds, and copper compounds, and zinc compounds, magnesium compounds, and calcium compounds are particularly preferred. These metal compounds may be used alone or in combination of two or more.

[0074] The divalent metal compound is preferably an oxide, hydroxide, or carbonate of a divalent metal, and may be a mixture of these. Specific examples of the divalent metal compound include zinc oxide, magnesium oxide, and calcium oxide, and particularly preferably zinc oxide and magnesium oxide.

[0075] The divalent metal compound is preferably in the form of particles. More preferably, it is fine particles having an average particle size of 10 nm or more and 500 nm or less. Particularly preferably, it is fine particles having an average particle size of 20 nm to 300 nm. The average particle size here can be measured using a dynamic light scattering particle size distribution analyzer, for example, LB-500 (manufactured by Horiba, Ltd.).

[0076] The polyvalent metal compound is preferably used together with the ammonium salt of the resin having a carboxyl group, and is preferably contained in an amount of 0.1 to 2.3 chemical equivalents relative to the carboxyl group. It is preferably contained in an amount of 0.2 to 1.5 chemical equivalents, and more preferably 0.3 to 1.2 chemical equivalents. If the amount is less than 0.1 equivalent, crosslinking of the resin having a carboxyl group by the metal ions of the polyvalent metal compound is insufficient, resulting in poor gas barrier properties. If the amount is more than 2.3 equivalents, the liquid stability of the coating material is poor.

[0077] In the present invention, the chemical equivalent is calculated and referred to as follows. For example, the molecular weight of a unit of ammonium polyacrylate, which is a resin having a carboxyl group, is 89. Normally, for every two molecules of ammonium polyacrylate (twice the molecular weight of 89), one molecule of zinc oxide (molecular weight 81.4), a polyvalent metal compound, contributes to the reaction and forms a salt. A formulation in which the weight of ammonium polyacrylate and the weight of zinc oxide are mixed in a ratio of 178 / 81.4 = 100 / 45.7 is referred to as mixing one equivalent of zinc oxide.

[0078] (Method for producing layer (B)) The layer (B) can be obtained by preparing a coating material in which the water-soluble polymer and, if necessary, a metal alkoxide and / or its hydrolysate or a polyvalent metal compound are dissolved or dispersed in an aqueous solvent, applying the coating material onto the inorganic layer of the layer (A), and drying and solidifying the coating material.

[0079] The aqueous solvent may be water or a water-soluble organic solvent such as methanol, ethanol, isopropanol, or 1-propanol, and a mixture of water and the water-soluble organic solvent is more preferred. Dissolution or dispersion can be carried out by a known method.

[0080] The method for applying the prepared coating material is not particularly limited, and any known and commonly used coating method can be used, such as spraying, spin coating, dipping, roll coating, blade coating, doctor roll coating, doctor blade coating, curtain coating, slit coating, screen printing, inkjet printing, and dispensing, with roll coating using a gravure coater being particularly preferred because it allows for the formation of a good coating film.

[0081] The amount of coating of the mixed coating material is not particularly limited as long as the effects of the present invention can be obtained, but is preferably 0.05 to 1.0 g / m ２ It is preferable to coat the coating amount in an amount of 0.1 to 0.5 g / m ２ It is preferable to coat the coating in an amount of 0.2 to 0.4 g / m because a good coating film is formed. ２ It is particularly preferred that the coating amount is

[0082] The (B) layer is preferably dried after coating in a drying step, which may be performed at room temperature or by forced drying using an oven or the like, under reduced pressure, or by blowing air.

[0083] The layer (B) may contain additives other than those mentioned above, such as a silane coupling agent or a wetting agent such as a surfactant, within the range in which the effects of the present invention can be obtained.

[0084] (Method for producing gas barrier laminate) The gas barrier laminate of the present invention can be obtained by carrying out, in this order, step 1 of subjecting the inorganic layer of layer (A) made of a substrate having an inorganic layer formed on at least one surface thereof to corona treatment, ozone treatment, plasma treatment, ultraviolet irradiation treatment, or excimer UV treatment, and step 2 of providing layer (B) containing a water-soluble polymer on layer (A).

[0085] The layer (A) consisting of a substrate having an inorganic layer formed on at least one surface thereof can be obtained by forming a layer of an inorganic material such as aluminum oxide, silicon oxide, aluminum, zinc oxide, or magnesium oxide on the substrate such as an olefin by a method such as vapor deposition or sputtering, as described above.

[0086] The corona treatment, ozone treatment, plasma treatment, ultraviolet irradiation treatment, or excimer UV treatment to be performed on the inorganic layer of the layer (A) may also be performed by the method described above.

[0087] Step 2 of providing a (B) layer containing a water-soluble polymer on the (A) layer that has been subjected to the above treatment can be carried out by the above-mentioned method for producing the (B) layer.

[0088] (Other Layers) In addition to the (A) layer and the (B) layer, the gas barrier laminate of the present invention may be further composed of various layers, such as a (C) layer containing 50 mass % or more of an organometallic compound containing a Group 4 element as the metal species (C), a (D) layer containing a polyvalent metal compound, a resin layer that is a base material used in the (A) layer but does not have an inorganic layer formed thereon, or a layer made of a material other than the above (second base material layer), a printed layer, a functional coating layer, an adhesive layer, etc.

[0089] (C) Layer Containing 50% by Mass or More of an Organometallic Compound Having a Group 4 Element as a Metal Species) In the present invention, a layer containing 50% by mass or more of an organometallic compound having a Group 4 element as a metal species (hereinafter, this layer may be referred to as layer (C)) may be provided between layer (A) and layer (B) so as to be in contact with the surface of layer (A) on which the inorganic layer is formed.

[0090] In the organometallic compound used in the present invention, the metal species of the Group 4 element is specifically titanium, zirconium, hafnium, or rutherfordium. Of these, titanium or zirconium is preferred.

[0091] Examples of organometallic compounds containing these Group 4 elements as metal species include metal alkoxides and / or their oligomers and / or their hydrolysates, metal acylates, metal complexes, coupling agents, etc. These organometallic compounds may be used alone or in combination of two or more.

[0092] The metal alkoxide and / or its oligomer and / or its hydrolyzate may be a metal alkoxide in which the hydroxyl group of the hydroxide of the metal species is -OC ３ H ７ , -OC ４ H ９ , -OCH ２ CH(C ２ H ５ ) C ４ H ９ , -OCH(CH ３ ) ２ , -OC ｎ H ２ｎ＋１The metal alkoxide and hydrolysate thereof used in the present invention may be one or more compounds selected from metal alkoxides substituted with alkoxyl groups represented by the formula (I) and (II), and hydrolysates thereof. Examples of the metal alkoxide and hydrolysate thereof used in the present invention include tetraisopropyl titanate, tetra-normal-butyl titanate, butyl titanate dimer, tetraoctyl titanate, butyl titanate oligomer, tetraisopropyl zirconate, tetra-normal-butyl zirconate, and the like. Particularly preferred are one or more metal alkoxides and / or hydrolysates thereof selected from tetra-normal-butyl titanate and tetra-normal-butyl zirconate.

[0093] Specific examples of metal acylates that can be used include titanium isostearate, zirconium isoctylate, and zirconium stearate.

[0094] Metal complexes, which are sometimes referred to as chelating agents, include, for example, titanium tetraalkylates such as titanium tetrapropylate and titanium tetrabutylate, titanium alkylacetoacetates such as titanium bis(acetylacetate)dipropylate, and zirconium tetraalkylates such as zirconium tetrabutylate.

[0095] Examples of coupling agents include titanium coupling agents such as isopropyl triisostearoyl titanate, isopropyl trioctanoyl titanate, isopropyl dimethacrylisostearoyl titanate, isopropyl isostearoyl diacryl titanate, isopropyl tris(dioctyl pyrophosphate) titanate, tetraoctyl bis(ditridecyl phosphite) titanate, tetra(2,2-diallyloxymethyl-1-butyl)bis(ditridecyl)phosphite titanate, bis(dioctyl pyrophosphate)oxyacetate titanate, and bis(dioctyl pyrophosphate)ethylene titanate. Examples of zirconium coupling agents include zirconium acetate, ammonium zirconium carbonate, and zirconium fluoride.

[0096] In the present invention, the lower limit of the content of the organometallic compound containing a Group 4 element as the metal species relative to the total solid content of Layer (C) is preferably 50 mass%, 55 mass%, or 60 mass%, and the upper limit of the content is preferably 100 mass%, relative to the total solid content.

[0097] The (C) layer can be obtained, for example, by a coating method. The coating method is not particularly limited, and any known and commonly used coating method can be used. Examples include spraying, spin coating, dipping, roll coating, blade coating, doctor roll coating, doctor blade coating, curtain coating, slit coating, screen printing, inkjet coating, and dispensing.

[0098] When Layer C is obtained by a coating method, a solvent can be used to improve coating suitability. The solvent is preferably an organic solvent, and examples thereof include alcohol-based organic solvents such as ethanol, n-propanol, isopropyl alcohol, and butanol; ketone-based organic solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ester-based organic solvents such as methyl acetate, ethyl acetate, propyl acetate, and butyl acetate; aliphatic hydrocarbon-based organic solvents such as n-hexane, n-heptane, and n-octane; and alicyclic hydrocarbon-based organic solvents such as cyclohexane, methylcyclohexane, ethylcyclohexane, cycloheptane, and cyclooctane, and these can be used alone or in combination of two or more.

[0099] The coating amount of the organometallic compound containing a Group 4 element as the metal species is not particularly limited as long as the effects of the present invention can be obtained, but is preferably 0.001 to 0.5 g / m in terms of solid content. ２ It is preferable to coat the film in an amount of 0.003 to 0.2 g / m because good barrier properties can be obtained. ２ It is particularly preferred that the coating amount is

[0100] It is preferable to provide a drying step for the (C) layer after coating. The drying step may be drying at room temperature or forced drying using an oven or the like, under reduced pressure, or by blowing air.

[0101] As described above, Layer (C) in the present invention contains an organometallic compound having a Group 4 element as the metal species in an amount of 50 mass % or more relative to the total solid content. However, additives such as a stabilizer, a resin serving as a binder component, a coupling agent, a plasticizer, a dispersant, a surfactant, a stabilizer, a thickener, an antifoaming agent, a wetting agent, a curing agent, an antiblocking agent, a lubricant, a preservative, and an inorganic filler may be blended within a range in which the effects of the present invention can be obtained.

[0102] In particular, when the (C) layer is obtained by coating method using metal alkoxides and / or their oligomers and / or their hydrolysates as the organometallic compound, it is preferable to contain a stabilizer.As the stabilizer, diketones such as acetylacetone, dehydroacetic acid, benzoylacetone, ethyl acetoacetate, diacetyl, etc., carboxylic acids such as acetic acid, hydroxycarboxylic acids such as citric acid, malic acid, tartaric acid, mandelic acid, lactic acid, glycolic acid, hydroxyisobutyric acid, hydroxycarbonyls such as hydroxyacetone, acetoin, etc., cellosolves such as methoxyethanol, dimethoxyethane, etc., glycols such as ethylene glycol, substituted glycols, pentaethylene glycol, hydrazones such as acetolhydrazone, acetoinhydrazone, imines such as diethanolamine, monoketones such as acetone, etc., can be used, and among them, it is preferable to select from acetylacetone, benzoylacetone, citric acid, malic acid, mandelic acid, and acetone.In addition, acetone also functions as a solvent as mentioned above.

[0103] The stabilizer is preferably contained in the range of 5 to 45% of the solid content of the layer (C), and most preferably in the range of 7 to 40%.

[0104] Furthermore, by containing a resin that serves as a binder component, it is possible to improve coating suitability. Examples of binder resins include polyvinyl butyral resins, polyvinyl acetal resins such as polyvinyl acetal resins, acrylic resins, polyester resins, styrene resins, styrene-maleic acid resins, maleic acid resins, polyamide resins, polyurethane resins, vinyl chloride-vinyl acetate copolymer resins, vinyl chloride-acrylic copolymer resins, ethylene-vinyl acetate copolymer resins, vinyl acetate resins, polyvinyl chloride resins, chlorinated polypropylene resins, cellulose-based resins, epoxy resins, alkyd resins, rosin-based resins, rosin-modified maleic acid resins, ketone resins, cyclized rubber, chlorinated rubber, butyral, and petroleum resins.

[0105] The binder resin is preferably contained in the range of 0% to 40% of the solid content of Layer (C), and most preferably in the range of 0% to 35%.

[0106] The coupling agent may be any known or commonly used one, such as a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, or an aluminum coupling agent.

[0107] As the silane coupling agent, any known or commonly used one may be used, and examples thereof include epoxy group-containing silane coupling agents such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; amino group-containing silane coupling agents such as 3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, and N-phenyl-γ-aminopropyltrimethoxysilane; (meth)acryloyl group-containing silane coupling agents such as 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltriethoxysilane; and isocyanate group-containing silane coupling agents such as 3-isocyanatepropyltriethoxysilane.

[0108] Examples of aluminum coupling agents include acetoalkoxy aluminum diisopropylate, aluminum diisopropoxymonoethyl acetoacetate, aluminum trisethyl acetoacetate, and aluminum trisacetylacetonate.

[0109] Examples of silane compounds include alkoxysilanes, silazanes, and siloxanes. Examples of alkoxysilanes include methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, 1,6-bis(trimethoxysilyl)hexane, and trifluoropropyltrimethoxysilane. Examples of silazanes include hexamethyldisilazane. Examples of siloxanes include hydrolyzable group-containing siloxanes.

[0110] The coupling agent is preferably contained in the range of 0% to 40% of the solid content of Layer (C), and most preferably in the range of 0% to 35%.

[0111] In the present invention, when the (C) layer is provided, the (C) layer and the (B) layer are preferably combined to form a strong film by a polycondensation reaction using a sol-gel method. Various catalysts and solvents may be added as necessary, and heating and drying may be performed.

[0112] In the present invention, when the (C) layer is present, the (B) layer is preferably provided so as to be in contact with the (C) layer. The method for this is not particularly limited, and may be a commonly used method, such as a method in which the (C) layer is formed on the (A) layer by coating, and then the (B) layer is continuously formed by coating, or a method in which the (C) layer is formed on the (A) layer by coating, and then the film is temporarily wound up, and then unwound, and then the (B) layer is formed on the (C) layer by coating.

[0113] (Layer (D) Containing Polyvalent Metal Compound) The gas barrier film of the present invention may further include a layer (D) containing a polyvalent metal compound, which layer may be provided adjacent to the layer (B) containing the water-soluble polymer. Here, "adjacent" means that there is at least a portion where the layer (B) and the layer (D) are in direct contact with each other.

[0114] The polyvalent metal compound contained in the (D) layer is a divalent or higher metal compound that is mixed with a resin or the like to form the (D) layer. Examples of such polyvalent metal compounds include zinc compounds, magnesium compounds, calcium compounds, manganese compounds, iron compounds, cobalt compounds, nickel compounds, and copper compounds, with zinc compounds, magnesium compounds, and calcium compounds being particularly preferred. These metal compounds may be used alone or in combination of two or more.

[0115] The polyvalent metal compound that may be used in the present invention is preferably an oxide, hydroxide, or carbonate of a divalent metal, or a mixture thereof. Of these divalent metal compounds, zinc oxide, magnesium oxide, and calcium oxide are preferred, with zinc oxide and magnesium oxide being particularly preferred.

[0116] The polyvalent metal compound is preferably in the form of particles. More preferably, it is fine particles having an average particle size of 10 nm or more and 500 nm or less. Particularly preferably, it is fine particles having an average particle size of 20 nm to 300 nm. The average particle size here is measured using a dynamic light scattering particle size distribution analyzer, for example, an LB-500 (manufactured by Horiba, Ltd.).

[0117] The polyvalent metal compound is preferably contained in the layer (D) containing the polyvalent metal compound in an amount of 40 to 90 parts by mass, and particularly preferably in an amount of 60 to 80 parts by mass, since this improves the gas barrier properties.

[0118] In addition to the polyvalent metal compound, a resin is added to the polyvalent metal compound-containing layer (D) to stabilize the coating of the polyvalent metal compound. Specific examples include cellulose-based resins, ethyl cellulose resins, carboxymethyl cellulose resins, polyester resins, epoxy resins, carboxyl group-containing resins, salts of resins having carboxyl groups, methacrylic resins, polyamide-based resins, polyether polyurethane polyol resins, polyester polyol resins, polyurethane polyol resins, styrene resins, styrene-maleic acid resins, vinyl chloride-vinyl acetate copolymer resins, vinyl chloride-acrylic copolymer resins, ethylene-vinyl acetate copolymer resins, vinyl acetate resins, polyvinyl chloride resins, chlorinated polypropylene resins, alkyd resins, rosin-based resins, rosin-modified maleic acid resins, ketone resins, cyclized rubbers, chlorinated rubbers, butyral, and petroleum resins. These resins may be used alone or in combination. Among these, ethyl cellulose resins, polyether polyurethane polyol resins, polyester polyol resins, polyurethane polyol resins, acrylic resins, maleic acid resins, and salts of acrylic resins are preferred.

[0119] The resin is preferably contained in the resin layer (B) containing a polyvalent metal compound in an amount of 5 to 70 parts by mass, and a range of 10 to 50 parts by mass is particularly preferred because the resin layer (B) has good coatability.

[0120] In the present invention, when the (D) layer is present, the (B) layer is preferably provided so as to be in contact with the (D) layer. The method for this is not particularly limited, and may be a commonly used method, such as a method in which the (B) layer is formed on the (A) layer by coating, and then the (D) layer is continuously formed by coating, or a method in which the (B) layer is formed on the (A) layer by coating, and then the film is temporarily wound up, and then unwound, and then the (D) layer is formed on the (B) layer by coating.

[0121]

[0063] Specific embodiments of the layer structure of the gas barrier laminate of the present invention are shown below, but the present invention is not limited to these, and any laminate may be used as long as it combines a second substrate layer, a printed layer, a functional coating layer, an adhesive layer, and an ink layer, as described below, so long as the effects of the present invention are not impaired. Layer (A) (substrate / inorganic layer) / Layer (B) / Adhesive layer / Second substrate layer Layer (A) (substrate / inorganic layer) / Layer (B) / Layer (D) / Adhesive layer / Second substrate layer Layer (A) (substrate / inorganic layer) / Layer (C) / Layer (B) / Adhesive layer / Second substrate layer Layer (A) (substrate / inorganic layer) / Layer (C) / Layer (B) / Layer (D) / Adhesive layer / Second substrate layer Layer (A) (substrate / inorganic layer) / Layer (B) / Layer (C) / Adhesive layer / Second substrate layer Layer (A) (substrate / inorganic layer) / Layer (D) / Layer (B) / Adhesive layer / Second substrate layer Layer (A) (substrate / inorganic layer) / Layer (D) / Layer (B) / Layer (C) / Adhesive layer / Second substrate layer In such an embodiment, when a printed layer or a functional coating layer is provided, it can be provided on any of the surface of Layer (A) opposite to the inorganic layer, the surface of Layer (A) with the inorganic layer, or the surface of the adhesive layer opposite to the second substrate layer.

[0122] Second substrate layer / adhesive layer / (A) layer (substrate / inorganic layer) / (B) layer Second substrate layer / adhesive layer / (A) layer (substrate / inorganic layer) / (B) layer / (D) layer Second substrate layer / adhesive layer / (A) layer (substrate / inorganic layer) / (C) layer / (B) layer Second substrate layer / adhesive layer / (A) layer (substrate / inorganic layer) / (C) layer / (B) layer / (D) layer Second substrate layer / adhesive layer / (A) layer (substrate / inorganic layer) / (B) layer / (C) layer Second substrate layer / adhesive layer / (A) layer (substrate / inorganic layer) / (D) layer / (B) layer Second substrate layer / adhesive layer / (A) layer (substrate / inorganic layer) / (D) layer / (B) layer Second substrate layer / adhesive layer / (A) layer (substrate / inorganic layer) / (D) layer / (B) layer / (C) layer In such an embodiment, when a printed layer or a functional coating layer is provided, it can be provided either on the surface of Layer (A) opposite to the inorganic layer or on the surface of Layer (A) on which the inorganic layer is provided.

[0123] Second substrate layer / adhesive layer / (A) layer (substrate / inorganic layer) / (B) layer / adhesive layer / second substrate layer Second substrate layer / adhesive layer / (A) layer (substrate / inorganic layer) / (B) layer / (D) layer / adhesive layer / second substrate layer Second substrate layer / adhesive layer / (A) layer (substrate / inorganic layer) / (C) layer / (B) layer / adhesive layer / second substrate layer Second substrate layer / adhesive layer / (A) layer (substrate / inorganic layer) / (C) layer / (B) layer / (D) layer / adhesive layer / second substrate layer Second substrate layer / adhesive layer / (A) layer (substrate / inorganic layer) / (B) layer / (C) layer / adhesive layer / second substrate layer Second substrate layer / adhesive layer / (A) layer (substrate / inorganic layer) / (D) layer / (B) layer / adhesive layer / second substrate layer Examples of such a structure include second substrate layer / adhesive layer / (A) layer (substrate / inorganic layer) / (D) layer / (B) layer / (C) layer / adhesive layer / second substrate layer. In such an embodiment, when a printed layer or a functional coating layer is provided, it can be provided on the surface of (A) layer opposite to the inorganic layer, on the surface of the inorganic layer of (A), or on the surface of the adhesive layer opposite to the second substrate layer.

[0124] (Second substrate layer) In the present invention, the substrate used in the layer (A) but not having an inorganic layer formed thereon can be, as described in the layer (A), for example, olefin resins such as polyethylene (PE), polypropylene (PP), cyclic olefin polymer (COP), cyclic olefin copolymer (COC), polyester, acrylic, polycarbonate, cellulose ester, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), nylon (NY), or materials containing biomass-derived components.In particular, any film made of a thermoplastic resin mainly composed of an olefin resin can be used without any particular limitation. Specific examples of olefin resins include polyethylenes such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene, polypropylene, ethylene-propylene copolymers, α-olefin polymers, ethylene-vinyl acetate copolymers, ethylene-vinyl alcohol copolymers, ethylene-acrylic acid copolymers, ethylene-methyl methacrylate copolymers, ethylene-ethyl acrylate copolymers, cyclic olefin resins, ionomer resins, and polymethylpentene; and modified olefin resins obtained by modifying olefin resins with acrylic acid, methacrylic acid, maleic anhydride, fumaric acid, or other unsaturated carboxylic acids. Among these, olefin resins such as polyethylene (PE), polypropylene (PP), cyclic olefin polymers (COP), and cyclic olefin copolymers (COC) are preferably used because the effects of the present invention are most pronounced, with polyethylene (PE) and polypropylene (PP) being most preferred.

[0125] Examples of film names include polyethylene terephthalate (PET) film, polystyrene film, polyamide film, polyacrylonitrile film, polyethylene film (LLDPE: low-density polyethylene film, HDPE: high-density polyethylene film, MDOPE: uniaxially oriented polyethylene film, OPE: biaxially oriented polyethylene film), polyolefin films such as polypropylene film (CPP: unoriented polypropylene film, OPP: biaxially oriented polypropylene film), polyvinyl alcohol film, ethylene-vinyl alcohol copolymer film, etc., for food packaging. It is also preferable to use biomass films formed from materials containing biomass-derived components. Biomass films are sold by various companies, and sheets such as those listed in the list of biomass-certified products listed by the Japan Organics Resources Association, a general incorporated foundation, can be used.

[0126] The substrate may also be, for example, wood, metal, metal oxide, a resin film other than the resin shown in layer (A), paper, silicon, modified silicon, or a substrate obtained by bonding different materials. The shape of the substrate is not particularly limited, and may be any shape depending on the purpose, such as a flat plate, a sheet, or a three-dimensional shape having curvature entirely or partially. There are also no limitations on the hardness, thickness, etc. of the substrate. When the laminate according to the present invention is used as a packaging material, paper, plastic, metal, metal oxide, etc. may be used as the substrate.

[0127] (Printed Layer) From the viewpoint of recycling, it is preferable that the layer structure is as simple as possible, but from the viewpoint of distribution of the packaging material, printing is often required to display the contents of the packaging material or a description or name of the product. Liquid inks such as gravure printing inks and flexographic printing inks are often used as printing inks for this purpose.

[0128] The printed layer is a layer on which letters, figures, symbols, and other desired designs are printed using liquid ink or the like. The laminate may be provided at any position. In this specification, liquid ink is a general term for solvent-based inks used in gravure printing or flexographic printing. Liquid inks may contain resin, colorant, and solvent as essential components, or may be so-called clear inks that contain resin and solvent but are substantially free of colorant.

[0129] The resin used in the liquid ink is not particularly limited and may include, for example, acrylic resin, polyester resin, styrene resin, styrene-maleic acid resin, maleic acid resin, polyamide resin, polyurethane resin, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-acrylic copolymer resin, ethylene-vinyl acetate copolymer resin, vinyl acetate resin, polyvinyl chloride resin, chlorinated polypropylene resin, cellulose-based resin, epoxy resin, alkyd resin, rosin-based resin, rosin-modified maleic acid resin, ketone resin, cyclized rubber, chlorinated rubber, butyral, petroleum resin, etc., and one or more of these may be used in combination. Preferably, at least one or two or more selected from polyurethane resin, vinyl chloride-vinyl acetate copolymer resin, and cellulose-based resin are used.

[0130] Colorants used in liquid inks include inorganic pigments such as titanium oxide, red iron oxide, antimony red, cadmium red, cadmium yellow, cobalt blue, Prussian blue, ultramarine, carbon black, and graphite; organic pigments such as soluble azo pigments, insoluble azo pigments, azo lake pigments, condensed azo pigments, copper phthalocyanine pigments, and condensed polycyclic pigments; and extender pigments such as calcium carbonate, kaolin clay, barium sulfate, aluminum hydroxide, and talc.

[0131] The organic solvent used in the liquid ink preferably does not contain an aromatic hydrocarbon organic solvent. More specific examples include alcohol organic solvents such as methanol, ethanol, n-propanol, isopropyl alcohol, and butanol; ketone organic solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ester organic solvents such as methyl acetate, ethyl acetate, propyl acetate, and butyl acetate; aliphatic hydrocarbon organic solvents such as n-hexane, n-heptane, and n-octane; and alicyclic hydrocarbon organic solvents such as cyclohexane, methylcyclohexane, ethylcyclohexane, cycloheptane, and cyclooctane, and these can be used alone or in combination of two or more.

[0132] (Functional Coating Layer) Examples of functional coating layers include coating agents containing various additives. Examples of additives include modifiers, coupling agents, silane compounds, phosphate compounds, organic fillers, inorganic fillers, stabilizers (antioxidants, heat stabilizers, ultraviolet absorbers, etc.), plasticizers, antistatic agents, lubricants, antiblocking agents, colorants, nucleating agents, oxygen scavengers (compounds with oxygen scavenging function), and tackifiers. These various additives may be used alone or in combination of two or more.

[0133] The modifier may be any known or commonly used one, and for example, various compounds such as diols, amine compounds, carbodiimides, and isocyanates may be added.

[0134] The coupling agent may be any known or commonly used one, such as a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, or an aluminum coupling agent.

[0135] As the silane coupling agent, any known or commonly used one may be used, and examples thereof include epoxy group-containing silane coupling agents such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; amino group-containing silane coupling agents such as 3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, and N-phenyl-γ-aminopropyltrimethoxysilane; (meth)acryloyl group-containing silane coupling agents such as 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltriethoxysilane; and isocyanate group-containing silane coupling agents such as 3-isocyanatepropyltriethoxysilane.

[0136] Examples of titanium coupling agents include isopropyl triisostearoyl titanate, isopropyl trioctanoyl titanate, isopropyl dimethacrylisostearoyl titanate, isopropyl isostearoyl diacryl titanate, isopropyl tris(dioctyl pyrophosphate) titanate, tetraoctyl bis(ditridecyl phosphite) titanate, tetra(2,2-diallyloxymethyl-1-butyl)bis(ditridecyl)phosphite titanate, bis(dioctyl pyrophosphate)oxyacetate titanate, and bis(dioctyl pyrophosphate)ethylene titanate.

[0137] Examples of zirconium coupling agents include zirconium acetate, ammonium zirconium carbonate, and zirconium fluoride.

[0138] Examples of aluminum coupling agents include acetoalkoxy aluminum diisopropylate, aluminum diisopropoxymonoethyl acetoacetate, aluminum trisethyl acetoacetate, and aluminum trisacetylacetonate.

[0139] Examples of silane compounds include alkoxysilanes, silazanes, and siloxanes. Examples of alkoxysilanes include methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, 1,6-bis(trimethoxysilyl)hexane, and trifluoropropyltrimethoxysilane. Examples of silazanes include hexamethyldisilazane. Examples of siloxanes include hydrolyzable group-containing siloxanes.

[0140] Among the additives, inorganic fillers include inorganic substances such as metals, metal oxides, resins, and minerals, as well as composites thereof. Specific examples of inorganic fillers include silica, alumina, titanium, zirconia, copper, iron, silver, mica, talc, aluminum flakes, glass flakes, and clay minerals.

[0141] Examples of compounds having an oxygen-scavenging function include low-molecular-weight organic compounds that react with oxygen, such as hindered phenol compounds, vitamin C, vitamin E, organic phosphorus compounds, gallic acid, and pyrogallol, and transition metal compounds, such as cobalt, manganese, nickel, iron, and copper.

[0142] Examples of tackifiers include xylene resins, terpene resins, phenolic resins, and rosin resins. Addition of a tackifier can improve adhesion to various substrates immediately after application. The amount of tackifier added is preferably 0.01 to 5 parts by mass per 100 parts by mass of the total amount of the resin composition.

[0143] (Adhesive Layer) The adhesive layer can be an adhesive that can be used in a general-purpose lamination method, particularly for laminating the gas barrier laminate of the present invention to a second substrate, etc. Examples of lamination methods include dry lamination, wet lamination, non-solvent lamination, and extrusion lamination. Examples of adhesives that can be used in dry lamination include one-component or two-component curing or non-curing vinyl, (meth)acrylic, polyamide, polyester, polyether, polyurethane, epoxy, rubber, and other solvent-based, aqueous, or emulsion adhesives. Examples of two-component curing adhesives that can be used include two-component curing adhesives containing a polyol and an isocyanate compound. Examples of coating methods for the lamination adhesive include direct gravure roll coating, gravure offset roll coating, kiss coating, reverse roll coating, Fountain coating, transfer roll coating, and other methods.

[0144] Various types of adhesives can also be used, and it is preferable to use a pressure-sensitive adhesive. Examples of pressure-sensitive adhesives include rubber-based adhesives obtained by dissolving polyisobutylene rubber, butyl rubber, or mixtures thereof in organic solvents such as benzene, toluene, xylene, and hexane, or these rubber-based adhesives blended with tackifiers such as abiethylene acid rosin ester, terpene-phenol copolymer, and terpene-indene copolymer, and acrylic-based adhesives obtained by dissolving an acrylic copolymer having a glass transition temperature of −20° C. or lower, such as a 2-ethylhexyl acrylate-n-butyl acrylate copolymer or a 2-ethylhexyl acrylate-ethyl acrylate-methyl methacrylate copolymer, in an organic solvent.

[0145] (Types of Gas Components That Can Be Blocked from Permeating) The gas that can be blocked by the gas barrier laminate of the present invention is mainly oxygen, but other examples include inert gases such as carbon dioxide, nitrogen, and argon, alcohols such as methanol, ethanol, and propanol, phenols such as phenol and cresol, and aroma components made of low molecular weight compounds, such as the smells of soy sauce, sauces, miso, limonene, menthol, methyl salicylate, coffee, and cocoa.

[0146] (Packaging Material) The gas barrier laminate of the present invention can be used as a multilayer packaging material for the purpose of protecting foods, medicines, etc. When used as a multilayer packaging material, the layer structure can be changed depending on the contents, usage environment, and usage form. In addition, the packaging of the present invention may be appropriately provided with an easy-open treatment or resealable means.

[0147] The contents to be filled in the packaging material of the present invention include, for example, foods such as rice crackers, bean snacks, nuts, biscuits, cookies, wafer snacks, marshmallows, pies, semi-dried cakes, candy, snacks, and other confectioneries; bread, snack noodles, instant noodles, dried noodles, pasta, aseptically packaged cooked rice, porridge, porridge, packaged rice cakes, and cereal foods, as well as agricultural processed products such as pickles, boiled beans, natto, miso, frozen tofu, tofu, nametake mushrooms, konjac, processed wild vegetables, jams, peanut cream, salads, frozen vegetables, and processed potatoes; livestock processed products such as ham, bacon, sausages, processed chicken, and corned beef; and fish. Examples of such foods include meat ham and sausage, processed seafood products such as kamaboko, nori seaweed, tsukudani (simmered food in soy sauce), bonito flakes, salted fish, smoked salmon, and spicy mentaiko, fruit pulp such as peaches, mandarin oranges, pineapples, apples, pears, and cherries, vegetables such as corn, asparagus, mushrooms, onions, carrots, radishes, and potatoes, prepared foods such as frozen and chilled prepared foods including hamburgers, meatballs, fried seafood, gyoza, and croquettes, dairy products such as butter, margarine, cheese, cream, instant creamy powder, and infant formula, liquid seasonings, retort curry, and pet food.

[0148] In addition, the present invention can also be used as a packaging material for various non-food products, such as cigarettes, disposable body warmers, medicines such as infusion packs, liquid laundry detergent, liquid kitchen detergent, liquid bath detergent, liquid bath soap, liquid shampoo, liquid conditioner, cosmetics such as lotion and emulsion, vacuum insulation materials, batteries, etc.

[0149] The present invention will be described in more detail below with reference to specific synthesis examples and examples, but the present invention is not limited to these examples. In the following examples, "parts" and "%" represent "parts by mass" and "% by mass", respectively, unless otherwise specified.

[0150] (Measurement Methods and Evaluation Methods) (Evaluation Item 1: Static Contact Angle) A 1.5 μL water droplet was dropped on the surface of the (A) layer on which the inorganic layer was formed, and the static contact angle of the water droplet at 25° C. was measured using a contact angle meter (DMo-701). The static contact angle is measured in degrees.

[0151] (Evaluation Item 2: Surface Free Energy) The static contact angles of water and diiodomethane were measured in the same manner as described above, and the surface free energy was calculated using the Owens-Wendt-Kaelble method. The unit of surface free energy is mN / m.

[0152] (Evaluation item 3: Adhesion) Cellotape (registered trademark) (Nichiban, 12 mm width) was applied to layer (B) of the prepared gas barrier laminate, and the appearance of the coating film when quickly peeled off was visually evaluated using the following three-point scale. (Evaluation criteria) ◯: 70% or more of the printed film remained on the film. △: 30% or more but less than 70% of the printed film remained on the film. ×: Less than 30% of the printed film remained.

[0153] (Evaluation Item 4: Lamination Strength) The prepared packaging material was cut into 15 mm widths in a direction parallel to the adhesive coating direction. The long-axis end of the packaging material (the end cut into 15 mm widths) was then peeled between a biaxially oriented polypropylene film (hereinafter sometimes referred to as OPP film) and a non-oriented polypropylene film (hereinafter sometimes referred to as CPP film). The two peeled layers were each fixed to an Autograph AGS-X manufactured by Shimadzu Corporation, and peeled using a T-peel method at an ambient temperature of 25°C and a peel speed of 300 mm / min to measure the tensile strength. The tensile strength measured here was used as the laminate strength of the laminate of each Example and Comparative Example. The adhesive strength is measured in units of N / 15 mm.

[0154] (Evaluation Item 5: Gas Barrier Property (Oxygen Permeability)) Oxygen permeability was measured in accordance with JIS-K7126-2:2006 "Plastics - Films and Sheets - Gas Permeability Test Methods - Part 2: Constant Pressure Method" using an oxygen permeability measuring device OX-TRAN2 / 21 manufactured by Mocon Co., Ltd., in an atmosphere of temperature 23°C and humidity 0% RH, and in an atmosphere of temperature 23°C and humidity 90% RH. RH represents relative humidity. The unit of oxygen permeability is cc / day·atm·m. ２ is.

[0155] (Preparation of Layer (A)) An anchor coating solution prepared by blending an acrylic coating agent (GAC-013S, DIC Corporation) and a polyisocyanate curing agent (KR-90, DIC Corporation) in a mixing ratio of 5:1 was applied to a biaxially stretched polypropylene film (OPP film FOR, Futamura Chemical Co., Ltd., thickness 20 μm) by gravure coating to a dry film thickness of approximately 0.05 μm, and then dried to obtain an anchor coat layer. Thereafter, metallic aluminum was vapor-deposited in a vacuum vapor deposition apparatus using an electron beam heating system, and oxygen gas was introduced. In this way, an (A) layer was formed having an anchor coat layer on the OPP film and an aluminum oxide vapor-deposited inorganic layer with a thickness of 20 nm thereon.

[0156] (Corona Treatment) The surface of the inorganic layer of Layer (A) was subjected to corona treatment using a corona discharge treatment machine manufactured by Kasuga Electric Co., Ltd., with the output and speed adjusted to achieve a predetermined irradiation dose. The irradiation dose is as shown in the table below.

[0157] (Ozone Treatment) The surface of the inorganic layer of Layer (A) was subjected to ozone cleaning treatment for a predetermined time using a UV-ozone cleaning device (OC-250315 / 6X-D+A) manufactured by Iwasaki Electric Co., Ltd. The time is as shown in the table below.

[0158] (Plasma Treatment) The surface of the inorganic layer of Layer (A) was subjected to plasma treatment using a multipurpose plasma surface treatment device (POEM) manufactured by Shinko Seiki Co., Ltd., at atmospheric pressure, an oxygen flow rate of 100 ml / min, a power of 400 W, and a distance of 10 mm between the light source and Layer (A) for a predetermined period of time as shown in the table below.

[0159] (Preparation of Coating Solution (b-1) for (B Layer)) Polyvinyl alcohol (PVA) (PVA60-98, Kuraray Co., Ltd., fully saponified PVA) was dissolved in a mixed solvent of water / isopropyl alcohol (IPA) = 98 / 2 (mass ratio) to prepare a PVA solution with a solid content of 5%. Next, tetraethoxysilane (Si(OC ２ H ５ ) 4, hereinafter referred to as "TEOS." KBE-04, Shin-Etsu Chemical Co., Ltd.) was added with 0.1N hydrochloric acid and stirred for 30 minutes to hydrolyze it to a solid content of 3% (SiO ２ The PVA solution and the TEOS hydrolyzed solution were mixed in a solid mass ratio of PVA / TEOS (SiO ２ The coating liquid (b-1) was prepared by mixing them so that the ratio of the components (based on the weight ratio) was 30 / 70.

[0160] (Preparation of Coating Solution (b-2) for (B Layer)) Polyacrylic acid (PAA) (A-10H, Toagosei Co., Ltd.) was diluted with water to a solids concentration of 5% to prepare a PAA solution. Next, 0.1N hydrochloric acid was added to TEOS, and the mixture was stirred for 30 minutes to hydrolyze the solution to a solids concentration of 3% (SiO ２ The PAA solution and the TEOS hydrolyzed solution were mixed at a solid mass ratio of PAA / TEOS (SiO２ The coating liquid (b-2) was prepared by mixing them so that the ratio of the components (based on the weight ratio) was 30 / 70.

[0161] (Preparation of Coating Solution (b-3) for (B Layer)) Modified polyvinyl alcohol (modified PVA) (25-88KL, Kuraray Co., Ltd.) was dissolved in a mixed solvent of water / isopropyl alcohol (IPA) = 98 / 2 (mass ratio) to prepare a modified PVA solution to a solids concentration of 5%. Next, 0.1N hydrochloric acid was added to TEOS, and the mixture was stirred for 30 minutes to hydrolyze the PVA to a solids concentration of 3% (SiO ２ The modified PVA solution and the TEOS hydrolyzed solution were mixed in a solid mass ratio of modified PVA / TEOS (SiO ２ The coating liquid (b-3) was prepared by mixing them so that the ratio of the total weight of the components (calculated as 1 / 2) was 30 / 70.

[0162] (Preparation of Polyvalent Metal Compound Dispersion Liquid (z-1)) For the polyvalent metal compound dispersion liquid, 30 parts of ZnO (FINEX-50, manufactured by Sakai Chemical Industry Co., Ltd.) having a primary particle size of 20 nm, 3.8 parts of an aqueous solution of ammonium polyacrylate (A-30SL, manufactured by Toagosei Co., Ltd.), and 62.5 parts of water were mixed, and the mixture was dispersed in a bead mill (manufactured by Kotobuki Co., Ltd.: Ultra Aspek Mill UAM-015) using zirconia beads having a diameter of 0.3 mm for 1 hour. The beads were then sieved to obtain a polyvalent metal compound dispersion liquid (z-1) having a solids concentration of 31.5%.

[0163] (Preparation of Polyvalent Metal Compound Dispersion Liquid (z-2)) For the polyvalent metal compound dispersion liquid, 24 parts of ZnO (FINEX-50, manufactured by Sakai Chemical Industry Co., Ltd.) having a primary particle size of 20 nm and 76 parts of methyl ethyl ketone (MEK) were mixed, and the mixture was dispersed in a bead mill using zirconia beads having a diameter of 0.3 mm for 1 hour. The beads were then sieved to obtain a polyvalent metal compound dispersion liquid (z-2) having a solids concentration of 24%.

[0164] (Preparation of Coating Liquid (b-4) for (Layer B)) 68.8 parts of water, 20.0 parts of isopropyl alcohol (IPA), 10.7 parts of an aqueous solution of ammonium polyacrylate (A-30, Toagosei Co., Ltd.), and 0.7 parts of a polyvalent metal compound dispersion liquid (z-1) were added and stirred for 1 hour to obtain a coating agent (b-4).

[0165] (Preparation of Coating Liquid (b-5) for (Layer B) and (Layer D)) 68.3 parts of water, 18.7 parts of isopropyl alcohol (IPA), 10.7 parts of an aqueous solution of ammonium polyacrylate (A-30, Toagosei Co., Ltd.), and 2.3 parts of the polyvalent metal compound dispersion liquid (z-1) were added and stirred for 1 hour to obtain a coating agent (b-5).

[0166] (Preparation of Coating Liquid (b-6) for (Layer B)) 62.2 parts of water, 23.0 parts of isopropyl alcohol (IPA), 10.0 parts of an aqueous solution of ammonium polyacrylate (A-30, Toagosei Co., Ltd.), and 4.8 parts of the polyvalent metal compound dispersion liquid (z-1) were added and stirred for 1 hour to obtain a coating agent (b-6).

[0167] (Preparation of Coating Liquid (b-7) for (Layer B) and (Layer D)) 65.0 parts of water, 17.0 parts of isopropyl alcohol (IPA), 9.0 parts of an aqueous solution of ammonium polyacrylate (A-30, Toagosei Co., Ltd.), and 9.0 parts of a polyvalent metal compound dispersion liquid (z-1) were added and stirred for 1 hour to obtain a coating agent (b-7).

[0168] (Preparation of Coating Liquid (b-8) for (Layer B)) 68.5 parts of water, 18.0 parts of isopropyl alcohol (IPA), 11.0 parts of an aqueous solution of ammonium polyacrylate (A-30, Toagosei Co., Ltd.), 2.3 parts of a polyvalent metal compound dispersion liquid (z-1), and 0.2 parts of glycerin (Kanto Chemical Co., Ltd.) were added and stirred for 1 hour to obtain a coating agent (b-8).

[0169] (Preparation of Coating Liquid (b-9) for (Layer B)) Polyacrylic acid (PAA) (A-10H, Toagosei Co., Ltd.) was diluted with water to a solids concentration of 3% to obtain a coating agent (b-9).

[0170] (Preparation of Coating Liquid (b-10) for (Layer B)) Polyacrylic acid (PAA) (AC-10L, Toagosei Co., Ltd.) was diluted with water to a solids concentration of 3% to obtain a coating agent (b-10).

[0171] (Preparation of Coating Liquid (b-11) for (Layer B)) Polyacrylic acid (PAA) (AC-10P, Toagosei Co., Ltd.) was diluted with water to a solids concentration of 3% to obtain a coating agent (b-11).

[0172] (Preparation of Coating Liquid (d-1) for (Layer D)) 39 parts of polyvalent metal compound dispersion liquid (z-2), 1 part of polyether polyurethane polyol resin solution A, and 60 parts of methyl ethyl ketone (MEK) were added and stirred for 1 hour to obtain a coating agent (d-1). The polyether polyurethane polyol resin solution A used was obtained as follows. A reaction vessel equipped with a stirrer, a nitrogen gas inlet tube, and a rectifying tube was charged with 213.7 parts of bifunctional polypropylene glycol (hereinafter sometimes abbreviated as PPG) having a molecular weight of 400, 225.2 parts of bifunctional PPG having a molecular weight of 700, 69.0 parts of bifunctional PPG having a molecular weight of 2000, and 41.1 parts of trifunctional PPG having a molecular weight of 430, and 152.6 parts of tolylene diisocyanate was added while stirring. After the temperature reached 90°C, 306.0 parts of ethyl acetate was added, and the reaction temperature was maintained at 90°C to obtain a synthesis. It was confirmed that the NCO (%) was 0.1% or less and the viscosity measured with a Brookfield viscometer was within the range of 2000 to 3000 mPa, yielding a polyether polyurethane polyol resin solution A.

[0173] (Example 1) (Preparation of gas barrier laminate) Corona treatment was performed at 100 W / (m ２ Onto the (A) layer, which had been subjected to irradiation at an amount of 1000 W / min), the coating liquid (b-1) was applied using a bar coater #3, and the coating liquid was dried for 1 minute in a hot air dryer set at 80°C to form the (B) layer, thereby preparing a gas barrier laminate.

[0174] (Preparation of Packaging Material) DiCdry LX-830 and KW-75 (both manufactured by DIC Corporation) were blended in a blending ratio of 10 / 1.5, and ethyl acetate was added to give a non-volatile content of 25% to obtain an adhesive. The adhesive was then applied to layer (B) of the prepared gas barrier laminate using a bar coater #8, and the dilution solvent was evaporated using a dryer set at a temperature of 50°C. The adhesive was then laminated to a non-oriented polypropylene film (CPP film, Toyobo Co., Ltd., P1128). Aging was carried out at 40°C for 3 days to obtain a packaging material [layer (A) (substrate: OPP film) / layer (B) / adhesive / CPP film].

[0175] Examples 2 to 40 The same procedures as in Example 1 were carried out, except that the surface treatment method for the inorganic layer of Layer (A) in Example 1 and Layer (B) were changed as shown in Tables 1 to 8, to obtain gas barrier laminates and packaging materials of Examples 2 to 40, respectively.

[0176] The evaluation results are shown in Tables 1 to 8.

[0177]

[0178]

[0179]

[0180]

[0181]

[0182]

[0183]

[0184]

[0185] (Example 41) (Preparation of gas barrier laminate) Corona treatment was performed at 100 W / (m ２ Onto the (A) layer, which had been subjected to irradiation at an irradiation dose of 1000 kJ / min), coating liquid (b-9) was applied using bar coater #3 and dried for 1 minute in a hot air dryer set at 80°C to form a (B) layer. Thereafter, coating liquid (b-5) was applied using bar coater #3 and dried for 1 minute in a hot air dryer set at 80°C to form a (D) layer, which was a gas barrier laminate.

[0186] (Preparation of Packaging Material) DiCdry LX-830 and KW-75 (both manufactured by DIC Corporation) were blended in a blending ratio of 10 / 1.5, and ethyl acetate was added so that the nonvolatile content was 25% to obtain an adhesive. The adhesive was then applied to layer (D) of the prepared gas barrier laminate using a bar coater #8, and the dilution solvent was evaporated using a dryer set at a temperature of 50°C. The adhesive was then laminated to a non-oriented polypropylene film (CPP film, Toyobo Co., Ltd., P1128). Aging was performed at 40°C for 3 days to obtain a packaging material [layer (A) (substrate: OPP film) / layer (B) / layer (D) / adhesive / CPP film].

[0187] Examples 42 to 65 The same method as in Example 42 was carried out, except that the surface treatment method for the inorganic layer of the (A) layer in Example 41 and the (B) layer and the (D) layer were changed as shown in Tables 9 to 13, to obtain gas barrier laminates and packaging materials of Examples 42 to 65, respectively.

[0188]

[0189]

[0190]

[0191]

[0192]

[0193] (Comparative Examples 1 to 14) Gas barrier laminates and packaging materials of Comparative Examples 1 to 14 were obtained in the same manner as in Example 1, except that the surface treatment of the inorganic layer of Layer (A) and Layer (B) were changed as shown in the table.

[0194] The evaluation results are shown in Tables 14 to 16.

[0195]

[0196]

[0197]

[0198] In Examples 1 to 65, gas barrier laminates with good adhesion, laminate strength, and gas barrier properties were produced. On the other hand, in Comparative Examples 1 to 14, which did not satisfy the requirements of the present invention, sufficient adhesion, laminate strength, and gas barrier properties were not obtained. Since each Example and Comparative Example had a common CPP film configuration, the differences in adhesion, laminate strength, and gas barrier properties observed between the Examples and Comparative Examples are presumably due to differences in the configurations of the laminate and packaging material. From the above results, it was confirmed that the gas barrier laminates and packaging materials having the configurations of the present invention have good adhesion, laminate strength, and gas barrier properties.

Claims

1. A gas barrier laminate comprising: (A) layer (A) made of a substrate having an inorganic layer formed on at least one surface thereof; and (B) layer (B) containing a water-soluble polymer, wherein in said layer (A), the surface on which the inorganic layer is formed has a static contact angle with water at 25°C of 20 degrees or more and 80 degrees or less, and / or the surface free energy of the surface on which the inorganic layer is formed is 41 mN / m or more and 75 mN / m or less.

2. The gas barrier laminate according to claim 1, wherein the inorganic layer in the layer (A) is formed by either a vapor deposition treatment or a sputtering treatment.

3. The gas barrier laminate according to claim 1, wherein the inorganic layer in the layer (A) is formed from one or more inorganic substances selected from the group consisting of aluminum oxide, silicon oxide, aluminum, zinc oxide and magnesium oxide.

4. The gas barrier laminate according to claim 1, wherein in the layer (A), the inorganic layer has been subjected to corona treatment, ozone treatment, plasma treatment, ultraviolet irradiation treatment or excimer UV treatment.

5. The gas barrier laminate according to claim 1, wherein the water-soluble polymer in the layer (B) is one or more water-soluble polymers selected from the group consisting of vinyl alcohol polymers, ethylene-vinyl alcohol polymers, vinylpyrrolidone polymers, acrylamide polymers, (meth)acrylic acid polymers, and salts of acrylic acid polymers.

6. The gas barrier laminate according to claim 1, wherein the layer (B) contains a metal alkoxide and / or a hydrolysate thereof.

7. A packaging material comprising the gas barrier laminate according to any one of claims 1 to 6.

8. The packaging material according to claim 7, which is obtained by laminating the gas barrier laminate according to any one of claims 1 to 6 and a second substrate with an adhesive.

9. A method for producing a gas barrier laminate according to any one of claims 1 to 6, comprising carrying out, in this order, step 1 of subjecting the inorganic layer of layer (A) made of a substrate having an inorganic layer formed on at least one surface thereof to corona treatment, ozone treatment, plasma treatment, ultraviolet irradiation treatment, or excimer UV treatment, and step 2 of providing layer (B) containing a water-soluble polymer on layer (A).

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