Laminate and packaging material

Abstract

To provide a gas barrier laminate applicable to packaging materials, exhibiting high gas barrier capability without including an aluminum foil, an aluminum vapor-deposited film or the like.SOLUTION: Provided is a laminate that comprises a first base material and a second base material including a gas barrier resin layer and a sealant layer having heat sealability and easy peelability, wherein the gas barrier resin layer is (A1) or (A2). Also provided is a packaging material. The gas barrier resin layer (A1) contains a water-soluble polymer having a hydroxyl group and at least one selected from silicon compounds represented by Si(OR1)4 or R2Si(OR3)3 (where OR1 and OR3 represent hydrolyzable groups, and R2 represents an organic functional group), and hydrolysates of the silicon compounds. The gas barrier resin layer (A2) contains a heteroatom compound capable of dehydrative condensation and a polymer having a carboxyl group.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a laminate having gas barrier properties and a packaging material.

Background Art

[0002] For the purpose of preventing the intrusion of gases such as moisture and oxygen from the outside air, gas barrier materials are used in various fields. For example, packaging materials used for packaging foods, beverages, etc. protect the contents from various distributions, storage such as refrigeration, and treatments such as heat sterilization, and for the purpose of long-term preservation of foods, oxygen barrier properties for preventing the intrusion of oxygen from the outside to suppress oxidation, carbon dioxide barrier properties, and barrier functions for various aroma components, etc. are required. In addition, various displays such as solar cells, liquid crystals, organic or inorganic electroluminescence (hereinafter referred to as "EL"), and electronic devices such as electronic paper generally use a glass substrate as a sealing material for protecting their internal structures and blocking oxygen and water vapor from the outside. However, for the purpose of providing a thinner, lighter, or flexible product, the use of a transparent gas barrier film based on a plastic film is being considered. (For example, see Patent Documents 1 and 2).

[0003] Recently, packaging materials and sealants are required to be recyclable at the time of disposal. As a conventional method for imparting gas barrier properties, a method of using an aluminum foil or an aluminum vapor deposition film as a part of the structure has been common. However, since aluminum reduces recyclability, a gas barrier material that does not use aluminum is required.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] An object of the present invention is to provide a gas barrier laminate applicable to packaging materials, which has high gas barrier properties without having an aluminum foil, an aluminum vapor deposition film, or the like.

Means for Solving the Problems

[0006] That is, the present invention provides a laminate including a first base material, a gas barrier resin layer, and a second base material including a sealant layer having heat sealability and easy peelability, wherein the gas barrier resin layer is (A1) or (A2). (1) A water-soluble polymer having a hydroxyl group, and a silicon compound represented by Si(OR 1 )4, or R 2 Si(OR 3 )3 (wherein OR 1 and OR 3 represent hydrolyzable groups, and R 2 represents an organic functional group), or a gas barrier resin layer (A1) containing one or more of the hydrolyzates of the silicon compound (2) A gas barrier resin layer (A2) containing a heteroatom compound having dehydrative condensability and a polymer having a carboxyl group

[0007] The present invention also provides a packaging material comprising the laminate.

Advantages of the Invention

[0008] According to the present invention, it is possible to provide a gas barrier laminate applicable to packaging materials, which has high gas barrier properties without having an aluminum foil, an aluminum vapor deposition film, or the like.

Embodiments for Carrying Out the Invention

[0009] In this specification, "~" means greater than or equal to the value before the description of "~" and less than or equal to the value after the description of "~".

[0010] (First Base Material) The first base material used in the present invention is not particularly limited, and examples include polyethylene terephthalate (PET) film, polystyrene film, polyamide film, nylon film, polyacrylonitrile film, polyethylene film (OPE: biaxially stretched polyethylene film, LLDPE: low-density polyethylene film, HDPE: high-density polyethylene film), polyolefin films such as polypropylene film (CPP: unstretched polypropylene film, OPP: biaxially stretched polypropylene film), polyvinyl alcohol film, ethylene-vinyl alcohol copolymer film, cellophane, and the like.

[0011] In addition, films laminated with inorganic vapor deposition layers such as metal oxides such as silica and alumina can also be used. Specific examples include OPE films, OPP films, PET films, and nylon films having a silica vapor deposition layer, and OPE films, OPP films, PET films, and nylon films having an alumina vapor deposition layer.

[0012] When considering a single-material package, a film made of a thermoplastic resin mainly composed of an olefin-based resin can be used as the base material. Specific examples of the olefin-based resin include polyethylene such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear (linear) low-density polyethylene, polypropylene, ethylene-propylene copolymer, α-olefin polymer, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene-acrylic acid copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl acrylate copolymer, cyclic olefin resin, ionomer resin, polyolefin resins such as polymethylpentene; and modified olefin-based resins obtained by modifying olefin-based resins with acrylic acid, methacrylic acid, maleic anhydride, fumaric acid, and other unsaturated carboxylic acids.

[0013] Also, it is preferable to use a film formed of a material containing a biomass-derived component as the film substrate. Biomass films are sold by various companies, and for example, sheets such as those listed in the biomass-certified product list described by the Japan Organic Resources Association, a general incorporated foundation, can be used.

[0014] Specifically, a well-known film is made from ethylene glycol derived from biomass. Ethylene glycol derived from biomass is made from ethanol (biomass ethanol) produced from biomass as a raw material. For example, biomass-derived ethylene glycol can be obtained by a method of producing ethylene glycol via ethylene oxide from biomass ethanol by a conventionally known method or the like. Also, commercially available biomass ethylene glycol may be used, and for example, biomass ethylene glycol commercially available from Indiaglycol Co., Ltd. can be preferably used.

[0015] Alternatively, products using biomass raw materials distinguished by the biomass plastic content defined in ISO 16620 or ASTM D6866 are also on the market. Radiocarbon 14C exists in the atmosphere at a ratio of 1 in 1012, and this ratio does not change even in atmospheric carbon dioxide. Therefore, this ratio also does not change in plants that have fixed this carbon dioxide through photosynthesis. For this reason, the carbon in plant-derived resins contains radiocarbon 14C. In contrast, the carbon in fossil fuel-derived resins contains almost no radiocarbon 14C. Therefore, by measuring the concentration of radiocarbon 14C in the resin using an accelerator mass spectrometer, the content ratio of plant-derived resin in the resin, that is, the biomass plastic content, can be determined. Examples of plant-derived low-density polyethylene that is a biomass plastic with a biomass plastic content of 80% or more, preferably 90% or more, as defined in ISO 16620 or ASTM D6866, include products with the trade names "SBC818", "SPB608", "SBF0323HC", "STN7006", "SEB853", "SPB681", etc. manufactured by Braskem, and films using these as raw materials can be preferably used.

[0016] For example, as an alternative to conventional polyolefin films using petroleum-based raw materials, biomass polyolefin films such as biomass polyethylene films containing a polyethylene-based resin made from ethylene glycol derived from biomass and biomass polyethylene - polypropylene films are also known. The polyethylene-based resin is not particularly limited except that ethylene glycol derived from the above-mentioned biomass is used as a part of the raw material, and examples include homopolymers of ethylene and copolymers of ethylene and α-olefins with ethylene as the main component (ethylene-α-olefin copolymers containing 90% by mass or more of ethylene units). These can be used alone or in combination of two or more. The α-olefin constituting the copolymer of ethylene and α-olefin is not particularly limited, and examples thereof include α-olefins having 4 to 8 carbon atoms such as 1-butene, 4-methyl-1-pentene, 1-hexene, and 1-octene. Known polyethylene resins such as low-density polyethylene resin, medium-density polyethylene resin, and linear low-density polyethylene resin can be used. Among them, from the viewpoint of making it less likely to cause damage such as perforation or breakage even when the films rub against each other, linear low-density polyethylene resin (LLDPE) (a copolymer of ethylene and 1-hexene, or a copolymer of ethylene and 1-octene) is preferable, and a linear low-density polyethylene resin having a density of 0.910 to 0.925 g / cm3 is more preferable.

[0017] The biomass film may be a laminate in which a plurality of biomass films are laminated, or may be a laminate of a conventional petroleum-based film and a biomass film.

[0018] The base material may be subjected to some surface treatment, such as physical treatment such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, flame treatment, or chemical treatment such as oxidation treatment using chemicals, or other treatments.

[0019] The base material can be produced by a conventionally known film-forming method such as an extrusion method, a casting method, a T-die method, a cutting method, an inflation method, etc. It may be an unstretched film, or may be stretched in one or two directions using a tenter method, a tubular method, etc. from the viewpoints of the strength, dimensional stability, and heat resistance of the film (1).

[0020] The base material may contain additives as required. Specifically, for the purpose of improving or modifying processability, heat resistance, weather resistance, mechanical properties, dimensional stability, antioxidant properties, slipperiness, mold release properties, flame retardancy, antifungal properties, electrical properties, strength, etc., plastic compounding agents and additives such as elastomers, lubricants, crosslinking agents, antioxidants, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, etc. can be added. The addition amount of the additive is adjusted within a range that does not affect other performances and recyclability.

[0021] The film thickness of the base material is not particularly limited and may be appropriately selected within the range of 0.1 to 300 μm from the viewpoints of moldability and transparency. Preferably, it is in the range of 0.3 to 100 μm. If it is less than 0.1 μm, the strength is insufficient, and if it exceeds 300 μm, the rigidity becomes too high and processing may become difficult.

[0022] From the viewpoint of recycling, it is preferably as simple as possible in layer structure. However, from the viewpoint of the flowability of the packaging material, printing for displaying the contents of the packaging material and the description and name of the product is often necessary. The base material is often printed as well.

[0023] (Printing layer) The printing layer is a layer on which characters, figures, symbols, and other desired patterns are printed. The printing method and printing ink are not particularly limited, and known printing methods and printing inks can be used. Printing inks that use gravure printing methods, flexographic printing methods, lithographic offset printing methods, inkjet recording printing methods, etc. are often used for the film used as the above-mentioned base material. Also, printing inks that combine these printing methods with methods of curing with active energy rays such as ultraviolet rays (UV), LEDs, electron beams (EB), etc. or methods of curing with heat are also used. Also, depending on the solvent used, it may be referred to as aqueous ink or organic solvent-based ink.

[0024] Specifically, there may be mentioned gravure printing inks, flexographic printing inks (which may be referred to as liquid inks in the industry), ultraviolet-curable inks for lithographic offset printing, electron beam-curable inks for lithographic offset printing, ultraviolet-curable inks for inkjet recording printing, electron beam-curable inks for inkjet recording printing, and the like.

[0025] The position where the printed layer printed using these inks is provided is arbitrary. It may be provided on the first substrate, or a substrate provided with a separately printed layer may be one of the components of the laminate of the present invention, and the position is arbitrary. Also, the ink may contain a resin, a colorant, and a solvent as essential components, or may be a so-called clear ink containing a resin and a solvent and substantially not containing a colorant. Hereinafter, the liquid ink most commonly used for printing on films will be described.

[0026] The resin used in the liquid ink is not particularly limited. 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. may be mentioned, and one kind or two or more kinds can be used in combination. Preferably, it is at least one kind, or two or more kinds selected from polyurethane resin, vinyl chloride-vinyl acetate copolymer resin, and cellulose-based resin.

[0027] Examples of the colorant used in the liquid ink include inorganic pigments such as titanium oxide, red lead, antimony red, cadmium red, cadmium yellow, cobalt blue, ultramarine blue, lapis lazuli, 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.

[0028] The liquid ink for film printing is often an organic solvent-based ink. It is preferable that the organic solvent used does not contain aromatic hydrocarbon-based organic solvents. More specifically, 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 can be mentioned, and one or more of them can be used in combination.

[0029] (Gas barrier resin layer) The gas barrier resin layer used in the present invention is characterized by being (A1) or (A2). (1) A gas barrier resin layer (A1) containing at least one of a water-soluble polymer having a hydroxyl group and a silicon compound represented by Si(OR 1 )4 or R 2 Si(OR 3 )3 (where OR 1 and OR 3 represent hydrolyzable groups and R 2 represents an organic functional group), or a hydrolyzate of the silicon compound (2) A gas barrier resin layer (A2) containing a heteroatom compound having dehydration condensation properties and a polymer having a carboxyl group

[0030] (Gas barrier resin layer (A1)) The gas barrier resin layer (A1) used in the present invention contains a water-soluble polymer having a hydroxyl group. Examples of the water-soluble polymer having a hydroxyl group include vinyl alcohol-based polymers, polyvinylpyrrolidone, starch, methylcellulose, carboxymethylcellulose, sodium alginate, and the like. Among them, it is preferable to use a vinyl alcohol-based polymer because it can impart good gas barrier properties.

[0031] The vinyl alcohol-based polymer is a hydrolyzate of a homopolymer or copolymer of vinyl ester (a1) and can be obtained by a known and commonly used method. Alternatively, the vinyl alcohol-based polymer can be a reaction product of a hydrolyzate of a homopolymer or copolymer of vinyl ester (a1) and an aldehyde, and can be obtained by a known and commonly used method.

[0032] Examples of vinyl ester (a1) 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, etc., and one kind or a combination of two or more kinds can be used. It is preferable to use vinyl acetate.

[0033] Examples of the polymerizable compound (a2) copolymerizable with the vinyl ester (a1) 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, vinyl acetamide, N-vinylformamide, N-(hydroxymethyl)-N-vinylformamide, hydroxyethyl acrylate, methyl vinyl ketone, and diacetone acrylamide. One or more of these can be used in combination. Among them, it is preferable to use ethylene, isopropenyl acetate, or 2-propenyl acetate.

[0034] When the vinyl ester (a1) and the polymerizable compound (a2) are used in combination, their usage amounts can be adjusted as appropriate. However, from the viewpoint of gas barrier properties, it is preferable to keep the blending amount of the polymerizable compound (a2) at 60 mol% or less of the total amount of the vinyl ester (a1) and the polymerizable compound (a2), and more preferably at 25 mol% or less.

[0035] The degree of polymerization of the vinyl ester polymer, which is a precursor of the vinyl alcohol-based polymer, is not particularly limited. As an example, it is 500 to 10,000, more preferably 800 to 6,000, and even more preferably 1,000 to 3,000. Thereby, a coating agent excellent in the balance between gas barrier properties and coating applicability can be obtained.

[0036] As aldehydes used for acetalization, there may be mentioned aliphatic aldehydes such as formaldehyde, acetaldehyde, propyl aldehyde, butyl aldehyde, octyl aldehyde, dodecyl aldehyde; alicyclic aldehydes such as cyclohexanecarbaldehyde; aromatic aldehydes such as benzaldehyde, naphthaldehyde, anthracene aldehyde, phenylacetaldehyde, tolualdehyde, dimethylbenzaldehyde, cuminaldehyde, benzyl aldehyde; unsaturated aldehydes such as cyclohexene aldehyde, dimethylcyclohexene aldehyde, acrolein; aldehydes having a heterocyclic ring such as furfural, 5-methylfurfural; hemiacetals such as glucose, glucosamine; aldehydes having an amino group such as 4-aminobutyl aldehyde, etc. Further, aliphatic ketones such as 2-propanone, methyl ethyl ketone, 3-pentanone, 2-hexanone; alicyclic ketones such as cyclopentanone, cyclohexanone; aromatic ketones such as acetophenone, benzophenone, etc. can be used singly or in combination of two or more kinds.

[0037] As the acid catalyst used in acetalization, conventionally known organic acids and inorganic acids such as acetic acid, p-toluenesulfonic acid, nitric acid, sulfuric acid, hydrochloric acid can be used.

[0038] Preferable specific examples of the vinyl alcohol-based polymer include polyvinyl alcohol, ethylene vinyl alcohol, polyvinyl butyral, etc. It may be used alone or in combination of two or more kinds. From the viewpoint of the balance between gas barrier properties and adhesion, it is more preferable to use either or both of polyvinyl alcohol and ethylene vinyl alcohol in combination.

[0039] The gas barrier resin layer (A1) used in the present invention is Si(OR 1 )4, or R 2 Si(OR 3 )3 (wherein OR 1 and OR 3 represent hydrolyzable groups, and R 2It contains a silicon compound represented by (wherein represents an organic functional group) or a hydrolyzate of the silicon compound. Examples of these silicon compounds or the hydrolyzates of the silicon compounds include tetraalkoxysilanes such as tetraethyl silicate (Si(OC2H5)4) (hereinafter sometimes referred to as TEOS), tetramethyl silicate; trialkoxysilanes such as trimethoxymethyl silane, triethoxymethyl silane, trimethoxyvinyl silane; dialkoxysilanes such as dimethoxydimethyl silane, diethoxydimethyl silane; monoalkoxysilanes such as methoxytrimethyl silane, ethoxytrimethyl silane, or their hydrolyzates or partial hydrolyzates.

[0040] TEOS is preferable in that it is relatively stable in an aqueous solvent after hydrolysis. Also, R 2 Si(OR 3 )3 contains R 2 is preferably a vinyl group, an epoxy group, an acryloyl group, a methacryloxy group, a ureido group, or an isocyanate group.

[0041] When the water-soluble polymer is a vinyl alcohol-based polymer, the ratio of the mass of the vinyl alcohol-based polymer to the mass in the total solid content of the mixed solution is preferably 20% by mass or more and 50% by mass or less, and more preferably 25% by mass or more and 40% by mass or less. When PVA is contained in an amount of 20% by mass or more, the flexibility of the coating film is maintained. Therefore, the formation of the coating film is easy. Also, when the vinyl alcohol-based polymer is contained in an amount of 50% by mass or less, it is possible to have sufficient barrier properties.

[0042] The gas barrier resin layer (A1) may contain other components other than the water-soluble polymer having the hydroxyl group, the silicon compound, or the hydrolyzate of the silicon compound. Examples of other components include other water-soluble polymers (such as sodium polyacrylate, polyethylene oxide, polyvinyl pyrrolidone, dextrin, chitosan, chitin, methyl cellulose, hydroxyethyl cellulose, etc.), fragrances, rust preventives, colorants, extenders, defoamers, ultraviolet absorbers, fluorescent brighteners, liquid paraffins, bitter components (such as sodium benzoate, etc.).

[0043] As a method for forming the gas barrier resin layer (A1), it can be formed by a known method without particular limitation. The easiest method is to apply a coating liquid (A1) (hereinafter sometimes simply referred to as the coating liquid (A1)) containing the water-soluble polymer having the hydroxyl group and one or more of the silicon compound or the hydrolyzate of the silicon compound on the first substrate by a known coating method to form a coating film. Examples of the coating method include spray method, spin coating method, dip method, roll coating method, blade coating method, doctor roll method, doctor blade method, curtain coating method, slit coating method, screen printing method, inkjet method, dispensing method, die coating method, direct gravure method, reverse gravure method, flexo method, knife coating method, dot coating method, etc.

[0044] (aqueous solvent) In order to facilitate coating, the coating liquid (A1) preferably contains an arbitrary aqueous solvent. As the aqueous solvent, water, water-soluble organic solvents soluble in water, etc. can be used. As water, pure water such as ion-exchanged water, ultrafiltration water, reverse osmosis water, distilled water, or ultrapure water can be used. From the viewpoint of long-term storage, it is preferable to use water sterilized by ultraviolet irradiation or hydrogen peroxide addition, etc. because the generation of mold or bacteria can be prevented.

[0045] Examples of the water-soluble organic solvent include glycols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, polyethylene glycol, and polypropylene glycol; diols such as butanediol, pentanediol, and hexanediol; glycol esters such as propylene glycol laurate; diethylene glycol ethers such as diethylene glycol monoethyl, diethylene glycol monobutyl, diethylene glycol monohexyl, and carbitol; glycol ethers such as cellosolve including propylene glycol ether, dipropylene glycol ether, and triethylene glycol ether; alcohols such as methanol, ethanol, isopropyl alcohol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, butyl alcohol, and pentyl alcohol; lactones such as sulfolane, esters, ketones, and γ-butyrolactone; lactams such as N-(2-hydroxyethyl)pyrrolidone; glycerin and its polyalkylene oxide adducts; and other various solvents known as water-soluble organic solvents. These water-soluble organic solvents can be used alone or in combination of two or more.

[0046] The thickness of the gas barrier resin layer (A1) is preferably selected, for example, from the range of 0.05 μm or more and 30 μm or less.

[0047] (Gas barrier resin layer (A2)) The gas barrier resin layer (A2) used in the present invention contains a heteroatom compound having dehydration condensability and a polymer having a carboxyl group.

[0048] (Heteroatom compound having dehydration condensability) The heteroatom compound having dehydration condensation property used in the present invention is a compound that causes dehydration condensation when contacted with a compound having a hydroxyl group, and is a compound having a heteroatom in its structure. Examples of these heteroatom compounds having dehydration condensation property include phosphoric acid, sulfuric acid, nitric acid, etc. These phosphoric acid, sulfuric acid, and nitric acid may be used alone or in combination of a plurality.

[0049] The addition amount of the heteroatom compound having dehydration condensation property is not particularly limited within the range where the effects of the present invention can be obtained, but it is preferably contained in the gas barrier resin layer (A2) in an amount of 10 parts by mass or less, and particularly preferably contained in an amount of 4 to 6 parts by mass because the adhesion when contacted with a compound having a hydroxyl group in the composition is further improved.

[0050] (Polymer having a carboxyl group) The polymer having a carboxyl group used in the present invention is a polymer obtained by polymerizing a polymerizable unsaturated monomer having a carboxyl group in its structure (hereinafter, the "polymerizable unsaturated monomer" is referred to as "monomer") as a polymerization raw material. Specific examples of the monomer having a carboxyl group in its structure include (meth)acrylic acid, β-carboxyethyl (meth)acrylate, etc., and (meth)acrylic acid is preferred. Further, the carboxyl group in the present invention may include a structure in which an H2O molecule is lost from two molecules of carboxylic acid such as carboxylic anhydride. In the present invention, "(meth)acrylic acid" refers to one or both of acrylic acid and methacrylic acid, and "(meth)acrylate" refers to one or both of acrylate and methacrylate.

[0051] The acid value of the polymer having a carboxyl group is not particularly limited within the range where the effects of the present invention can be obtained, but an acid value of 50 to 800 mgKOH / g is preferred because the barrier performance is improved. Further, an acid value of 80 to 800 mgKOH / g is more preferred, and a polymer having an acid value of 80 mgKOH / g or more can obtain a high barrier performance due to sufficient progress of ionic bonding.

[0052] (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 the sample. Specifically, the weighed sample is dissolved in a suitable solvent in which the sample is soluble, for example, a solvent of toluene / methanol = 70 / 30 by volume ratio. A few drops of a 1% phenolphthalein alcohol solution are added dropwise, and a 0.1 mol / L potassium hydroxide alcohol solution is added dropwise thereto, and it can be measured by a method of confirming the color change point and can be obtained by the following calculation formula.

[0053] (Acid value measurement method - 1) Acid value (mgKOH / g) = (V × F × 5.61) / S V: Amount of 0.1 mol / L potassium hydroxide alcohol solution used (mL) F: Normality of 0.1 mol / L potassium hydroxide alcohol solution S: Sampling amount of sample (g) 5.61: Equivalent amount of potassium hydroxide in 1 mL of 0.1 mol / L potassium hydroxide alcohol solution (mg)

[0054] When the sample is a resin solution, the resin acid value (mgKOH / g) can be obtained by the following calculation formula.

[0055] Resin acid value (mgKOH / g) = Acid value of resin solution (mgKOH / g) / NV(%) × 100 NV: Non-volatile content (%)

[0056] Also, when the solubility of the sample in the organic solvent is low and precipitation occurs, making measurement difficult, the acid value can also be measured by the following method.

[0057] (Acid value measurement method - 2) The acid value (mgKOH / g-resin) is a value calculated by the following formula using the coefficient (f) obtained from the calibration curve prepared with a chloroform solution of maleic anhydride using FT-IR (manufactured by JASCO Corporation, FT-IR4200), the absorbance (I) of the stretching peak (1780 cm-1) of the anhydride ring of maleic anhydride and the absorbance (II) of the stretching peak (1720 cm-1) of the carbonyl group of maleic acid in the maleic anhydride-modified polyolefin solution. Acid value (mgKOH / g-regin)=[(Absorbance (I) × (f) × 2 × Molecular weight of potassium hydroxide × 1000 (mg) + Absorbance (II) × (f) × Molecular weight of potassium hydroxide × 1000 (mg)) / Molecular weight of maleic anhydride] Molecular weight of maleic anhydride: 98.06, Molecular weight of potassium hydroxide: 56.11

[0058] The polymer having a carboxyl group used in the present invention is not particularly limited in molecular weight, but a weight average molecular weight of 300 to 1,000,000 is preferable from the viewpoint of good film formability. Particularly preferably, it is 500 to 500,000. The weight average molecular weight of the polymer having a carboxyl group used in the present invention can be calculated by measuring by the method of gel permeation chromatography (GPC).

[0059] As the polymer having a carboxyl group, the resin skeleton is not particularly limited as long as the effects of the present invention can be obtained. It may be a homopolymer of a polymerizable unsaturated monomer having a carboxyl group, or a copolymer using a plurality of polymerizable unsaturated monomers having a carboxyl group. Further, it may be a copolymer of a polymerizable unsaturated monomer having a carboxyl group and other monomers copolymerizable therewith. As the polymer having a carboxyl group used in the present invention, one or more polymers selected from the group consisting of acrylic acid, methacrylic acid, maleic acid and itaconic acid are preferable.

[0060] ((Meth)acrylic acid polymer) The (meth)acrylic acid polymer may be a polymer of a (meth)acrylic acid monomer. For example, polyethers such as ethylene glycol di(meth)acrylate, polyethylene glycol (meth)acrylates, ethylene oxide-modified 4,4-dihydroxydiphenyl sulfone di(meth)acrylate, and ethylene oxide-modified bisphenol A di(meth)acrylate; ethylene glycol diglycidyl di(meth)acrylate, ethylene oxide-modified bisphenol A diglycidyl di(meth)acrylate, etc. are used.

[0061] (Carboxyl group-containing vinyl polymer) Examples of the carboxyl group-containing vinyl polymer resin include polymers of polymerizable unsaturated monomers having a carboxyl group. Examples of the polymerizable unsaturated monomers having a carboxyl group include unsaturated carboxylic acids such as (meth)acrylic acid, 2-carboxyethyl (meth)acrylate, crotonic acid, itaconic acid, maleic acid, or 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; Mono vinyl esters of various saturated dicarboxylic acids such as monovinyl adipate or monovinyl succinate; Addition reaction products of various anhydrides of saturated polycarboxylic acids such as succinic anhydride, glutaric anhydride, phthalic anhydride, or trimellitic anhydride with various hydroxyl group-containing vinyl monomers; furthermore, various monomers obtained by subjecting various carboxyl group-containing monomers as described above to an addition reaction with lactones, etc. are included.

[0062] Examples of the monomers copolymerizable with the polymerizable unsaturated monomer having a carboxyl group include, for example, the following.

[0063] (Meth)acrylic acid esters having an alkyl group with 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, heptyl (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, docosyl (meth)acrylate;

[0064] (Meth)acrylic acid esters having an aliphatic alkyl group such as cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl oxyethyl (meth)acrylate; (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, 2-hydroxy-3-phenoxypropyl (meth)acrylate; hydroxyethyl (meth)acrylate; hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, glycerol (meth)acrylate; (meth)acrylic acid esters having a hydroxyalkyl group such as lactone-modified hydroxyethyl (meth)acrylate, polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, etc. which have a polyalkylene glycol group;

[0065] 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; styrene derivatives such as styrene, α-methylstyrene, and chlorostyrene; diene compounds such as butadiene, isoprene, piperylene, and dimethylbutadiene; vinyl halides and vinylidene halides such as vinyl chloride and vinyl bromide; unsaturated ketones such as methyl vinyl ketone and butyl vinyl ketone; vinyl esters such as vinyl acetate and vinyl butyrate; vinyl ethers such as methyl vinyl ether and butyl vinyl ether; vinyl cyanides such as acrylonitrile, methacrylonitrile, and vinylidene cyanide; acrylamide and its alkyd-substituted amides; N-substituted maleimides such as N-phenylmaleimide and N-cyclohexylmaleimide;

[0066] Fluorine-containing α-olefins such as vinyl fluoride, vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, bromotrifluoroethylene, pentafluoropropylene or hexafluoropropylene; or (per)fluoroalkyl·perfluorovinyl ethers in which the carbon number of the (per)fluoroalkyl group is 1 to 18, such as trifluoromethyl trifluorovinyl ether, pentafluoroethyl trifluorovinyl ether or heptafluoropropyl trifluorovinyl ether; (per)fluoroalkyl (meth)acrylates in which the carbon number of the (per)fluoroalkyl group is 1 to 18, 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, etc., fluorine-containing ethylenically unsaturated monomers; silyl group-containing (meth)acrylates such as γ-methacryloxypropyltrimethoxysilane; N,N-dialkylaminoalkyl (meth)acrylates such as N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate or N,N-diethylaminopropyl (meth)acrylate, etc. are mentioned.

[0067] The polymer having a carboxyl group is obtained by polymerization or copolymerization using a known method, and its polymerization form is not particularly limited. Further, it can be produced by addition polymerization in the presence of a catalyst (polymerization initiator), and it may be a polymer by any of a random copolymer, a block copolymer, a graft copolymer, etc. Also, known polymerization methods such as bulk polymerization method, solution polymerization method, suspension polymerization method, emulsion polymerization method, etc. can be used as the copolymerization method.

[0068] The gas barrier resin layer (A2) can contain a heteroatom compound having dehydrative condensability and a compound other than the polymer having a carboxyl group within the range where the effects of the present invention can be obtained. As these additional additive components, alcohols such as methanol, ethanol, propanol, butanol, hexanol, etc., solvents such as ethylene glycol, propylene glycol, glycerin, coupling agents, silane compounds, phosphoric acid compounds, organic fillers, inorganic fillers, stabilizers (antioxidants, heat stabilizers, ultraviolet absorbers, etc.), plasticizers, antistatic agents, lubricants, antiblocking agents, colorants, crystal nucleating agents, oxygen scavengers (compounds having an oxygen scavenging function), tackifiers and other additives can be used.

[0069] As a method for forming the gas barrier resin layer (A2), it can be formed in the same manner as the gas barrier resin layer (A1). As the easiest method, a coating solution (A2) containing a heteroatom compound having dehydrative condensability and a polymer having a carboxyl group (hereinafter sometimes simply referred to as the coating solution (A2)) is applied onto the first substrate by a known coating method to form a coating film. In order to facilitate coating, the coating solution (A2) preferably contains an arbitrary organic solvent.

[0070] Furthermore, it is also preferable that the gas barrier resin layer (A2) has, adjacent thereto, a resin layer (A2-2) containing a polyvalent metal compound. Here, "adjacent" means that there is at least a part where the resin layer (A) and the resin layer (A2-2) are in direct contact.

[0071] The polyvalent metal compound contained in the resin layer (A2-2) is a metal compound having a valence of 2 or more, and is mixed with a water-soluble polymer or the like to form the resin layer (A2-2). Examples of such polyvalent metal compounds include zinc compounds, magnesium compounds, calcium compounds, manganese compounds, iron compounds, cobalt compounds, nickel compounds, copper compounds, etc. Particularly preferred are zinc compounds, magnesium compounds, and calcium compounds. These metal compounds can be used alone or in combination of two or more.

[0072] As the polyvalent metal compound that may be used in the present invention, it is preferably an oxide, hydroxide, or carbonate of a divalent metal, and a mixture thereof may also be used. As these divalent metal compounds, zinc oxide, magnesium oxide, and calcium oxide are preferable, and zinc oxide and magnesium oxide are particularly preferable.

[0073] The polyvalent metal compound is preferably in particulate form. More preferably, it is fine particles with an average particle diameter of 10 nm or more and 500 nm or less. Particularly preferably, it is fine particles of 20 nm to 300 nm. The average particle diameter here is measured using a dynamic light scattering type particle size distribution measuring device, for example, LB-500 (manufactured by Horiba, Ltd.).

[0074] These polyvalent metal compounds are preferably contained in the resin layer (A2-2) containing the polyvalent metal compound in the range of 40 to 90 parts by mass, and particularly preferably in the range of 60 to 80 parts by mass because an improvement in gas barrier properties can be seen.

[0075] In addition to the polyvalent metal compound, a resin is added to the resin layer (A2-2) containing the polyvalent metal compound in order to stably coat the polyvalent metal compound. Specifically, for example, cellulose-based resins, ethyl cellulose resins, carboxymethyl cellulose resins, polyester resins, epoxy resins, acrylic resins, methacrylic resins, polyamide-based resins, etc., polyether polyurethane polyol resins, polyester polyol resins, and polyurethane polyol resins can be mentioned. These resins may be used alone or in combination of a plurality. Among them, ethyl cellulose resin, polyether polyurethane polyol resin, polyester polyol resin, and polyurethane polyol resin are preferable.

[0076] The resin is preferably contained in the resin layer (A2-2) containing the polyvalent metal compound in the range of 10 to 60 parts by mass, and particularly preferably in the range of 20 to 40 parts by mass because the coatability of the resin layer (A2-2) becomes good.

[0077] Furthermore, it is also preferable that the gas barrier resin layer (A2) has, adjacent thereto, a layer (A2-3) containing a compound selected from the group consisting of aluminum oxide, silicon oxide, and silicon nitride. In the present invention, the layer (A2-3) provided adjacent to the resin layer (A) is a layer formed by a process such as vapor deposition, sputtering, or CVD of a compound selected from the group consisting of aluminum oxide, silicon oxide, and silicon nitride. These (A2-3) layers may be formed on a base film such as a polyethylene terephthalate (PET) resin film, a polypropylene (PP) resin film, a polybutylene terephthalate (PBT) resin film, a nylon (NY) resin film, or a biomass film. As these base films, films manufactured by various known processes such as biaxially stretched films, stretched films, and non-stretched films, or films subjected to various surface treatments as necessary may be used.

[0078] (The gas barrier resin layer (A2) is appropriately selected depending on its use, but the coating amount after drying is 0.01 to 100 g / m 2 is preferable, 0.1 to 50 g / m 2 is more preferable, and 0.5 to 3 g / m 2 is particularly preferable.

[0079] (Second substrate) The laminate including the first substrate and the gas barrier resin layer can also be bonded to a second substrate using an adhesive. Alternatively, the second substrate may be formed on the laminate by an extrusion method. As the second base material, a base material composed of a sealant layer having heat sealability and easy peelability is preferable. Examples of the material for the sealant layer include polyethylene resins such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), very low-density polyethylene (VLDPE), polypropylene (CPP), ethylene-propylene copolymer, and polymethylpentene; and ethylene-based copolymers such as ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate (EMA) copolymer, ethylene-ethyl acrylate-maleic anhydride copolymer (E-EA-MAH), ethylene-acrylic acid copolymer (EAA), and ethylene-methacrylic acid copolymer (EMAA); furthermore, olefin-based resins such as ionomers of ethylene-acrylic acid copolymers and ionomers of ethylene-methacrylic acid copolymers may be mentioned, and they may be used alone or in combination of two or more.

[0080] In order to exhibit easy peelability, the sealant layer may be a mixed resin containing the olefin-based resin and a resin incompatible with the olefin-based resin. Examples of such a mixed resin include polyethylene and polypropylene, and polyethylene and polybutene. Also, in order to exhibit easy peelability, the sealant layer may contain an easily peelable thermoplastic resin. As the easily peelable thermoadhesive resin, a modified polyolefin-based resin mainly composed of ethylene-vinyl acetate copolymer can be used.

[0081] Examples of resins and films suitable for the sealant layer having heat sealability and easy peelability include, for example, DIFAREN E1901T manufactured by DIC Corporation, TAF 650C and CMPS 013C manufactured by Mitsui Chemicals Toagosei Co., Ltd., 7601A and 9501E manufactured by Toray Film Processing Co., Ltd., SMX manufactured by J Film Co., Ltd., and Aromer Film TP6 manufactured by Okamoto Co., Ltd., which can be preferably used. The film thickness of the heat seal layer can be appropriately adjusted according to the purpose, but as an example, it is preferably 1 μm or more and 100 μm or less. Also, the sealant layer is preferably unstretched.

[0082] (Adhesive) As the adhesive used when laminating the second layer to the laminate including the first base material and the gas barrier resin layer, any adhesive that can be used in a general laminating method may be used. Examples of the laminating method include methods such as dry lamination, wet lamination, non-solvent lamination, and extrusion lamination. The adhesive becomes an adhesive layer after curing or drying.

[0083] As the adhesive used in the dry lamination, for example, solvent-based, water-based, or emulsion-type adhesives such as one-component or two-component curable or non-curable types of vinyl-based, (meth)acrylic-based, polyamide-based, polyester-based, polyether-based, polyurethane-based, epoxy-based, rubber-based, and others can be used. As the two-component curable adhesive, a two-component curable adhesive of a polyol and an isocyanate compound can be used. As the coating method of the adhesive for lamination, for example, it can be applied by a direct gravure roll coating method, a gravure offset roll coating method, a kiss coating method, a reverse roll coating method, a fountain method, a transfer roll coating method, or other methods. For example, the Dick Dry series manufactured by DIC Corporation can be preferably used.

[0084] In addition, various adhesives can be used, and it is preferable to use a pressure-sensitive adhesive. Examples of the pressure-sensitive adhesive include rubber-based adhesives obtained by dissolving polyisobutylene rubber, butyl rubber, or a mixture thereof in an organic solvent such as benzene, toluene, xylene, or hexane, or those obtained by blending tackifiers such as abietic acid rosin ester, terpene-phenol copolymer, or terpene-indene copolymer with these rubber-based adhesives, or acrylic adhesives obtained by dissolving acrylic copolymers having a glass transition point of -20°C or lower, such as 2-ethylhexyl acrylate / n-butyl acrylate copolymer or 2-ethylhexyl acrylate / ethyl acrylate / methyl methacrylate copolymer, in an organic solvent.

[0085] In the adhesive, a functional adhesive may be used. For example, as an adhesive having gas barrier properties, a two-component reactive adhesive composed of a polyester polyol and an isocyanate compound, such as the series of oxygen barrier adhesive Paslim (PASLIM) manufactured by DIC Corporation, can be used. The gas barrier adhesive becomes a gas barrier adhesive layer after curing or drying. By using a gas barrier adhesive, it is preferable because the gas barrier properties of the laminate of the present invention can be further enhanced.

[0086] When the adhesive is a solvent type, the adhesive is applied to one substrate using a roll such as a gravure roll, and after the organic solvent is volatilized by heating in an oven or the like, the other substrate is laminated to obtain the laminate of the present invention. It is preferable to perform an aging treatment after lamination. The aging temperature is preferably room temperature to 80°C, and the aging time is preferably 12 to 240 hours.

[0087] When the adhesive is a solvent-free type, a fragrance-retaining adhesive preheated to about 40°C to 100°C is applied to one substrate using a roll such as a gravure roll, and then the other substrate is immediately laminated to obtain the laminate of the present invention. It is preferable to perform an aging treatment after lamination. The aging temperature is preferably room temperature to 70°C, and the aging time is preferably 6 to 240 hours.

[0088] The coating amount of the adhesive is adjusted as appropriate. In the case of a solvent type, as an example, the solid content is 1 g / m 2 or more and 10 g / m 2 or less, preferably 1 g / m 2 or more and 5 g / m 2 or less. In the case of a solvent-free type, the coating amount of the adhesive is, as an example, 1 g / m 2 or more and 10 g / m 2 or less, preferably 1 g / m 2 or more and 5 g / m 2 or less.

[0089] (Laminated Structure) Here, an example of a specific aspect of the laminate of the present invention is given. Of course, the laminate of the present invention is not limited to this aspect. (Configuration using two base materials) First base material / Gas barrier resin layer / Adhesive layer / Second base material First base material / Printing layer / Gas barrier resin layer / Adhesive layer / Second base material Printing layer / First base material / Gas barrier resin layer / Adhesive layer / Second base material First base material / Gas barrier resin layer / Gas barrier adhesive layer / Second base material First base material / Printing layer / Gas barrier resin layer / Gas barrier adhesive layer / Second base material Printing layer / First base material / Gas barrier resin layer / Gas barrier adhesive layer / Second base material

[0090] (Example 1 of the configuration using three base materials) First base material / Gas barrier resin layer / Adhesive layer / Base material used as an intermediate layer / Adhesive layer / Second base material First base material / Printing layer / Gas barrier resin layer / Adhesive layer / Base material used as an intermediate layer / Adhesive layer / Second base material Printing layer / First base material / Gas barrier resin layer / Adhesive layer / Base material used as an intermediate layer / Adhesive layer / Second base material First base material / Gas barrier resin layer / Gas barrier adhesive layer / Base material used as an intermediate layer / Adhesive layer / Second base material First base material / Printing layer / Gas barrier resin layer / Gas barrier adhesive layer / Base material used as an intermediate layer / Adhesive layer / Second base material Printing layer / First substrate / Gas barrier resin layer / Gas barrier adhesive layer / Substrate used as intermediate layer / Adhesive layer / Second substrate

[0091] (Example 2 of the structure using three substrates) When using three or more film substrates for the outermost layer, when made into a packaging material through a lamination process, it refers to the substrate on the side that touches the outside world. Substrate used as outermost layer / Adhesive layer / Gas barrier resin layer / First substrate / Adhesive layer / Second substrate Substrate used as outermost layer / Printing layer / Adhesive layer / Gas barrier resin layer / First substrate / Adhesive layer / Second substrate Printing layer / Substrate used as outermost layer / Adhesive layer / Gas barrier resin layer / First substrate / Adhesive layer / Second substrate Substrate used as outermost layer / Adhesive layer / Gas barrier resin layer / First substrate / Gas barrier adhesive layer / Second substrate Substrate used as outermost layer / Printing layer / Adhesive layer / Gas barrier resin layer / First substrate / Gas barrier adhesive layer / Second substrate Printing layer / Substrate used as outermost layer / Adhesive layer / Gas barrier resin layer / First substrate / Gas barrier adhesive layer / Second substrate

[0092] (Packaging material) The laminate of the present invention can be used as a multilayer packaging material for the purpose of protecting foods, pharmaceuticals, etc. When used as a multilayer packaging material, its layer structure can change according to the contents, usage environment, and usage form. Also, an easy-opening treatment or resealing means may be appropriately provided in the package of the present invention.

[0093] For example, as the packaging material of the present invention, taking a laminate having a sealant layer as an example, after the surfaces of the sealant layers of the laminates are overlapped facing each other, the peripheral edges thereof are heat-sealed to form a bag shape. As the bag-making method, the laminate of the present invention can be bent or overlapped so that the inner layer surfaces (the surfaces of the sealant layers) face each other, and the peripheral edges thereof can be heat-sealed in forms such as, for example, side-seal type, two-side seal type, three-side seal type, four-side seal type, envelope-pasting seal type, palm-pasting seal type, pleat-attaching seal type, flat-bottom seal type, corner-bottom seal type, gusset type, and other heat-seal types. The packaging material of the present invention can take various forms according to the contents, the use environment, and the use form. A self-standing packaging material (standing pouch) or the like is also possible. As the heat-sealing method, it can be carried out by known methods such as bar-sealing, rotary roll sealing, belt sealing, impulse sealing, high-frequency sealing, ultrasonic sealing, and the like.

[0094] When the first base material and the second base material of the laminate of the present invention do not function as a sealant layer that becomes a heat-sealing site when forming the packaging material, a sealant layer may be further added. As the sealant layer, an additional base material may be bonded with the adhesive of the present invention, or an adhesive layer made of the adhesive of the present invention may be used.

[0095] After filling the contents into the packaging material of the present invention through its opening, the opening is heat-sealed to produce a product using the packaging material of the present invention. As the contents to be filled, for example, as foods, there are confectioneries such as rice confectioneries, bean confectioneries, nuts, biscuits / cookies, wafers, marshmallows, pies, semi-cooked cakes, candies, snack confectioneries, staple foods such as bread, snack noodles, instant noodles, dried noodles, pasta, aseptic-packed rice, congee, oatmeal, packaged mochi, cereal foods, pickles, boiled beans, natto, miso, frozen bean curd, tofu, shiitake mushrooms, konjac, processed wild vegetables, jams, peanut creams, salads, frozen vegetables, processed potato products, etc., processed livestock products such as hams, bacon, sausages, processed chicken products, corned beef, etc., processed fishery products such as fish ham / sausage, fishery processed products, kamaboko, nori, tsukudani, dried bonito, salted fish, smoked salmon, spicy pollock roe, etc., fruits such as peaches, oranges, pineapples, apples, pears, cherries, etc., vegetables such as corn, asparagus, mushrooms, onions, carrots, daikon radishes, potatoes, etc., frozen prepared foods represented by hamburgers, meatballs, fried fish, gyoza, croquettes, etc., cooked foods such as chilled prepared foods, dairy products such as butter, margarine, cheese, cream, instant creamy powder, formula milk for infants, etc., food products such as liquid seasonings, retort curries, pet foods, etc.

[0096] Also, as non-foods, there are pharmaceuticals such as tobacco, disposable warmers, infusion packs, etc., liquid detergents for laundry, liquid detergents for kitchens, liquid detergents for baths, liquid soaps for baths, liquid shampoos, liquid conditioners, cosmetics such as lotions and emulsions, vacuum insulation materials, batteries, etc., and can also be used as various packaging materials.

Examples

[0097] Hereinafter, the present invention will be described in more detail with 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 "mass%" respectively unless otherwise specified.

[0098] <Manufacture of the first base material> [Production Example 1] As the film used as the first base material, an OPP film with a thickness of 16 μm was prepared. The surface of the OPP film on which the inorganic oxide vapor deposition layer was to be formed was subjected to plasma pretreatment, and then, by a reactive resistance heating method as a heating means of the vacuum vapor deposition method under the following conditions, an aluminum oxide vapor deposition film with a thickness of 15 nm was continuously formed on the plasma-treated surface. This film is called AlOxOPP. (Aluminum oxide film formation conditions): Vacuum degree: 8.1 × 10 -2 Pa

[0099] <Second base material> EP1: The easy peel film "DIFAREN E1901T with a thickness of 50 μm" manufactured by DIC Corporation was used.

[0100] <Manufacture of gas barrier resin layer A1> [Production Example 23] According to the composition shown in Table 1, the hydrolysis solution of the previously prepared composition (Y) was added to the prepared mixed solution of composition (X) and stirred to obtain a colorless and transparent gas barrier resin solution C1.

[0101]

Table 1

[0102] <Manufacture of gas barrier resin layer A2> [Production Example 3] In a flask, 30 g of polyacrylic acid with a molecular weight of 200,000 (hereinafter sometimes abbreviated as PAA) (manufactured by Toagosei Co., Ltd., Aron A-10H) was dissolved in isopropyl alcohol (hereinafter sometimes abbreviated as IPA) while stirring and boiling to obtain a PAA solution with a solid content concentration of 3%. To 100 g of this solution, a phosphoric acid aqueous solution (manufactured by Tokyo Chemical Industry Co., Ltd., solid content 86%) solution diluted with IPA to a solid content of 5% was added in an amount of 5 g to obtain a gas barrier resin solution C2.

[0103] [Production Example 4] 300 g of zinc oxide with a primary particle size of 200 nm (hereinafter sometimes abbreviated as ZnO) (manufactured by Sakai Chemical Industry Co., Ltd., FINEX-50) and 700 g of methyl ethyl ketone (hereinafter sometimes abbreviated as MEK) were mixed and dispersed in a bead mill (manufactured by Kotobuki Chemical Co., Ltd., Ultra Spec Mill UAM-015) using zirconia beads with a diameter of 0.3 mm for 1 hour. After that, the beads were separated by a sieve to obtain a ZnO solution with a solid content concentration of 30%. The primary particle size of ZnO in this dispersion was 88 nm. This solution was mixed and stirred with a 5% solid content polyester resin (product name: Baylon 500, manufactured by Toyobo Co., Ltd.) solution dissolved in MEK and an MEK solution to obtain a ZnO dispersion. The ratio during mixing was ZnO solution: 20 g, polyester resin solution: 20 g, MEK: 60 g. A polyester resin, an MEK solution, and a stir bar were previously placed in a 200 ml beaker, and the stir bar was rotated at 200 rpm. After confirming that the polyester resin and MEK were uniform, the ZnO solution was added to obtain a ZnO dispersion. The solid content was 7%. The obtained gas barrier resin solution is called C3.

[0104] <Fabrication of laminate> <Fabrication of laminate using two film substrates> [Example 1] AlOxOPP / Gas barrier resin layer C1 / Adhesive layer / EP1 The gas barrier resin solution C1 prepared above was coated on AlOxOPP by the direct gravure method. Then, heat treatment was performed at 85 °C for 60 seconds to form a gas barrier resin layer with a thickness of 300 nm (dry state). Subsequently, EP1 was laminated on the barrier coat layer of the barrier film obtained above via an adhesive having no oxygen barrier performance (Takelac A520 / Takenate A 50 (Mitsui Chemicals, Inc.)) to obtain a laminate.

[0105] [Example 2] AlOxOPP / Gas barrier resin layer C2 / Gas barrier resin layer C3 / Adhesive layer / EP1 The gas barrier resin solution C2 prepared above was coated and dried on AlOxOPP in the same manner as in Example 1, and then the gas barrier resin solution C3 was coated and dried in the same manner. On the coated surface of the obtained laminate, EP1 was laminated via an adhesive having no oxygen barrier performance (Takelac A520 / Takenate A 50 (Mitsui Chemicals, Inc.)) to obtain a laminate.

[0106] [Example 3] AlOxOPP / Gas barrier resin layer C1 / Gas barrier adhesive layer / EP1 The adhesive in Example 1 was changed to an adhesive having oxygen barrier performance (PASLIM VM001 / VM108CP, manufactured by DIC Corporation), and a laminate was produced in the same manner as in Example 1 except for this.

[0107] [Example 4] AlOxOPP / Gas barrier resin layer C2 / Gas barrier resin layer C3 / Gas barrier adhesive layer / EP1 The adhesive in Example 2 was changed to an adhesive having oxygen barrier performance (PASLIM VM001 / VM108CP, manufactured by DIC Corporation), and a laminate was produced in the same manner as in Example 1 except for this.

[0108] [Production of laminate using three film substrates] [Example 5] OPP / Adhesive layer / Gas barrier resin layer C1 / AlOxOPP / Adhesive layer / EP1 A laminate obtained by bonding the surface of the AlOxOPP film without the gas barrier resin layer coated thereon to EP1 was bonded to an OPP film (thickness: 20 μm) to produce a laminate.

[0109] [Example 6] OPP / Adhesive layer / Gas barrier resin layer C2 / Gas barrier resin layer C3 / AlOxOPP / Adhesive layer / EP1 The gas barrier resin layer C1 in Example 5 was changed to a layer coated with the gas barrier resin layer C2 and the gas barrier resin layer C3, and a laminate was produced in the same manner as in Example 5 except for this.

[0110] [Example 7] OPP / Oxygen-barrier adhesive layer / Oxygen-barrier resin layer C1 / AlOxOPP / Adhesive layer / EP1 The adhesive for laminating the OPP film and the AlOxOPP film in Example 5 was changed to an adhesive having oxygen-barrier performance (PASLIM VM001 / VM108CP, manufactured by DIC Corporation), and a laminate was produced in the same manner as in Example 5 except for this change.

[0111] [Example 8] OPP / Oxygen-barrier adhesive layer / Oxygen-barrier resin layer C2 / Oxygen-barrier resin layer C3 / AlOxOPP / Adhesive layer / EP1 The adhesive for laminating the OPP film and the AlOxOPP film in Example 6 was changed to an adhesive having oxygen-barrier performance (PASLIM VM001 / VM108CP, manufactured by DIC Corporation), and a laminate was produced in the same manner as in Example 6 except for this change.

[0112] [Comparative Example 1] In Example 1, no resin layer was coated on AlOxOPP, an adhesive was coated on AlOxOPP, and it was directly laminated with EP1 to produce a laminate.

[0113] [Comparative Example 2] The barrier resin layer in Example 1 was changed to a polyester resin having no barrier performance (Bylon 500, manufactured by Toyobo Co., Ltd.), and a laminate was produced in the same manner as in Example 1 except for this change.

[0114] [Comparative Example 3] In Example 5, no resin layer was coated on AlOxOPP, an adhesive was coated on AlOxOPP, and the laminate obtained by directly laminating it with EP1 was laminated with an OPP film (thickness: 20 μm) to produce a laminate.

[0115] [Comparative Example 4] The barrier resin layer in Example 5 was changed to a polyester resin having no barrier performance (Bylon 500, manufactured by Toyobo Co., Ltd.), and a laminate was produced in the same manner as in Example 3 except for this change.

[0116] (Measurement of oxygen permeability) For the laminates produced in the above Examples and Comparative Examples, using an oxygen permeability measuring device (manufactured by MOCON, model name: Ox-Tran 2 / 21), set so that the oxygen supply side is the base material layer surface of the barrier film, and under the measurement conditions of 23°C and 90% RH atmosphere, in accordance with JIS K7126 method, the oxygen permeability (cc / m 2 ·atm·day) was measured. The measurement results are shown in Tables 2 and 3.

[0117] (Measurement of water vapor permeability) For the laminates produced in the above Examples and Comparative Examples, using a water vapor permeability measuring device (a measuring instrument manufactured by MOCON, model name: Permatran 3 / 33), set so that the sensor side is the base material layer surface of the barrier film, and under the measurement conditions of 40°C and 100% RH atmosphere, in accordance with JIS K7129 method, the water vapor permeability (g / m 2 ·day) was measured. The measurement results are shown in Tables 2 and 3.

[0118] <Performance evaluation of the laminate> The packaging materials produced in the above Examples and Comparative Examples were made into a cylindrical shape, and the Gelbo flex test in accordance with ASTM F392 was repeated 5 times. Then, a part of the packaging material was cut out to obtain a test sample, and the oxygen permeability and water vapor permeability were measured. The following measurement results are the average values of 3 samples. Table 2 shows the evaluation results of the laminate using 2 film substrates, Table 3 shows the evaluation results of the laminate using 3 film substrates.

[0119]

Table 2

[0120] From the results in Table 2 above, Examples 1 and 2 with AlOxOPP and a gas barrier resin layer showed good gas barrier properties both in the normal state and after the gelbo flex test. Examples 3 and 4 using an adhesive with oxygen barrier performance in the adhesive layer showed even more excellent barrier properties both in the normal state and after the gelbo flex test. For Comparative Example 1 without a resin layer and Comparative Example 2 with a resin layer having no gas barrier property, the gas barrier performance in the normal state was low, and the deterioration of the barrier property after the gelbo flex test was also significant.

[0121]

Table 3

[0122] From the results in Table 3 above, Examples 5 and 6 with AlOxOPP and a gas barrier resin layer showed good gas barrier properties both in the normal state and after the gelbo flex test. Examples 7 and 8 using an adhesive with oxygen barrier performance in the adhesive layer showed even more excellent barrier properties both in the normal state and after the gelbo flex test. For Comparative Example 3 without a resin layer and Comparative Example 4 with a resin layer having no gas barrier property, the gas barrier performance in the normal state was low, and the deterioration of the barrier property after the gelbo flex test was also significant.

Claims

1. A laminate comprising a first substrate, a gas barrier resin layer, and a second substrate including a sealant layer having heat sealability and easy peelability, wherein the gas barrier resin layer is (A1) or (A2). (1) A water-soluble polymer having a hydroxyl group and Si(OR １ ) ４ , or R ２ Si(OR ３ ) ３ (However, OR １ and OR ３ represents a hydrolyzable group, R ２ represents an organic functional group), or one or more hydrolyzates of the silicon compounds. The gas barrier resin layer (A2) containing a heteroatom compound having dehydrative condensability and a polymer having a carboxyl group

2. The laminate according to claim 1, comprising the first substrate, the gas barrier resin layer, a gas barrier adhesive layer, and the second substrate.

3. The laminate according to claim 1, wherein the first substrate is an olefin resin substrate.

4. The laminate according to claim 1, wherein the first substrate and the second substrate are olefin resin substrates.

5. A packaging material comprising the laminate according to any one of claims 1 to 4.

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