laminate

Abstract

A laminate having a resin layer containing both a vinyl alcohol polymer and a layered inorganic material is provided, and the interlayer adhesion is high. The laminate has a substrate, a resin layer (1) and a resin layer (2), the resin layer (1) and the resin layer (2) being adjacent to each other, the resin layer (1) containing a water-dispersible polymer and polymer (1), the resin layer (2) containing a vinyl alcohol polymer (2) and a layered inorganic material (2), wherein the polymer (1) is selected from at least one of vinyl alcohol polymers (1) and urethane polymers.

Description

Technical Field

[0001] This invention relates to laminates. Background Technology

[0002] Paper packaging materials have long been used for packaging food, medical products, electronic components, and the like. Patent Document 1 describes an oil-resistant paper made by coating a paper substrate with a coating agent containing a carboxyl-containing polyvinyl alcohol polymer. However, the gas barrier properties (especially water vapor barrier and oxygen barrier properties) of the oil-resistant paper in Patent Document 1 are insufficient. Patent Documents 2 and 3 describe paper packaging materials with improved gas barrier properties, in which a water vapor barrier layer, a gas barrier layer, and a sealing layer are laminated on a paper substrate, and the gas barrier layer contains a vinyl alcohol polymer (hereinafter also referred to as "PVOH").

[0003] Existing technical documents Patent documents Patent Document 1: International Publication No. 2022 / 202997 Patent Document 2: Japanese Patent Application Publication No. 2020-163675 Patent document 3: Japanese Patent Application Publication No. 2021-20398. Summary of the Invention

[0004] The problem that the invention aims to solve In laminates with gas barrier layers, etc., to improve oxygen barrier properties, it is advisable to include layered inorganic materials in the gas barrier layer. However, according to the inventors' research, a gas barrier layer containing both vinyl alcohol polymers and layered inorganic materials has the inconvenience of insufficient adhesion to adjacent resin layers. When the interlayer adhesion of the laminate is insufficient, interlayer delamination can occur during use and processing, potentially leading to a decrease in barrier properties.

[0005] The present invention was made to solve the aforementioned problems, and its purpose is to provide a laminate having a resin layer containing both a vinyl alcohol polymer and a layered inorganic material, and having high interlayer adhesion.

[0006] means for solving problems The aforementioned problem can be solved by providing any of the following: [1] A laminate having a substrate, a resin layer (1) and a resin layer (2), the resin layer (1) being adjacent to the resin layer (2), the resin layer (1) containing a water-dispersible polymer and a polymer (1), the resin layer (2) containing a vinyl alcohol polymer (2) and a layered inorganic substance (2), wherein the polymer (1) is selected from at least one of vinyl alcohol polymers (1) and urethane polymers; [2] According to the laminate of [1], wherein the water-dispersible polymer is selected from at least one of olefin polymers and styrene polymers; [3] According to the laminate described in [1] or [2], wherein the viscosity-uniform degree of polymerization of the vinyl alcohol polymer (1) is 200 or more and 5000 or less; [4] The laminate according to any one of [1] to [3], wherein the degree of saponification of the vinyl alcohol polymer (1) is 70 mol% or more and 100 mol% or less; [5] The laminate according to any one of [1] to [4], wherein the content of polymer (1) in the resin layer (1) is 0.1 parts by mass or more and less than 50 parts by mass relative to 100 parts by mass of the water-dispersible polymer; [6] The laminate according to any one of [1] to [5], wherein the resin layer (1) further contains a layered inorganic material (1) with an aspect ratio of 500 or more. [7] According to the laminate of [6], the content of the layered inorganic matter (1) in the resin layer (1) is more than 1 part by mass and less than 50 parts by mass relative to 100 parts by mass of the water-dispersible polymer. [8] The laminate according to any one of [1] to [7], wherein the resin layer (1) further contains a cationic polymer; [9] The laminate according to any one of [1] to [8], wherein the aspect ratio of the layered inorganic material (2) is 500 or more;

[10] The laminate according to any one of [1] to [9], wherein the content of the layered inorganic matter (2) in the resin layer (2) is more than 1 part by mass and less than 30 parts by mass relative to 100 parts by mass of the vinyl alcohol polymer (2);

[11] The laminate according to any one of [1] to

[10] , wherein a sealing layer containing at least one polymer (3) selected from olefin polymers and styrene polymers is the outermost layer;

[12] The laminate according to any one of [1] to

[11] , wherein the substrate is paper.

[0007] Invention Effects According to the present invention, a laminate can be provided which is a resin layer containing both a vinyl alcohol polymer and a layered inorganic material, and has high interlayer adhesion. Detailed Implementation

[0008] <Layered Body> An embodiment of the present invention relates to a laminate having a substrate, a resin layer (1) and a resin layer (2), wherein the resin layer (1) and the resin layer (2) are adjacent to each other, the resin layer (1) contains a water-dispersible polymer and a polymer (1), the resin layer (2) contains PVOH (2) and a layered inorganic substance (2), and the polymer (1) is at least one selected from PVOH (1) and urethane polymers. One embodiment of the present invention relates to a laminate having resin layers containing both PVOH and layered inorganic matter, and exhibiting high interlayer adhesion. The reason for this is not yet clear, but it is believed that since both resin layer (1) and resin layer (2) contain PVOH, the adhesion between resin layer (1) and resin layer (2) is improved through the interaction of the PVOH. Furthermore, the improved adhesion between resin layer (1) and resin layer (2) in the laminate is considered to solve the problem of providing a laminate with high interlayer adhesion. In addition, since resin layer (2) contains both PVOH and layered inorganic matter, this laminate exhibits high oxygen barrier properties. In other words, this laminate can achieve both high oxygen barrier properties and high interlayer adhesion. Furthermore, the presence of resin layer (1) and the like also provides good water vapor barrier properties. Details of each layer will be described below.

[0009] (Substrate) The substrate can be the outermost layer on one side of a laminate. That is, no other layers may be laminated on one side of the substrate. Other layers may be laminated on both sides of the substrate. Printing, etc., can be applied to the substrate.

[0010] Furthermore, in this specification, the outermost layer refers to a layer with one surface exposed. The description of the outermost layer does not distinguish between the inner and outer surfaces of the laminate. That is, there may be two outermost layers in a laminate; for example, when the laminate is formed into a bag shape, both the innermost and outermost layers are considered outermost layers.

[0011] The material of the substrate is not particularly limited, and substrates formed from various materials can be used. Examples of substrates include resin films such as thermoplastic resin films and thermosetting resin films, fibrous aggregates such as paper and fabric, and metal foil. The resin film can be a stretched film or an unstretched film. The substrate is preferably a fibrous aggregate, and more preferably paper. The substrate can be single-layered or multi-layered. In the case of multi-layered substrates, such as multi-layered substrates formed by stacking resin films on paper, each layer can be composed of different materials.

[0012] The paper used as the base material can be ordinary paper with plant-derived pulp as the main component. It should be noted that in this specification, "main component" refers to the component with the highest content by weight. Furthermore, the paper used as the base material is also referred to as paper base material. In addition to pulp, paper base material may also contain sizing agents, fillers, paper strength enhancers, yield improvers, pH adjusters, water permeability improvers, water-resistant agents, softeners, antistatic agents, defoamers, slime control agents, dyes, pigments, etc.

[0013] Examples of paper substrates include kraft paper, bleached kraft paper, high-quality paper, medium-quality paper, alkaline paper, paperboard, cellophane, semi-cellophane, and parchment, with kraft paper or bleached kraft paper being preferred.

[0014] The preferred basis weight (mass per unit area) of the paper substrate is 20 g / m². 2 Above and 500g / m 2 The following is more preferably 30g / m 2 Above and 300g / m 2 The following is a further preferred value: 40g / m 2 Above and 200g / m 2 The following is a further preferred value: 50g / m 2 Above and 100g / m 2 the following.

[0015] The preferred density for the paper substrate is 0.5 g / cm³. 3 Above and 1.2g / cm 3 The following is more preferably 0.6 g / cm³ 3 Above and 1.0 g / cm 3 the following.

[0016] Paper substrates can be manufactured using methods already known. Alternatively, commercially available paper substrates can be used.

[0017] The average thickness of the substrate (paper substrate and other substrates) can be, for example, in the range of 1 μm or more and 1000 μm or less, in the range of 3 μm or more and 400 μm or less, in the range of 5 μm or more and 100 μm or less, or in the range of 7 μm or more and 50 μm or less.

[0018] (Resin layer (1)) The resin layer (1) contains a water-dispersible polymer and polymer (1). The resin layer (1) may be a layer with a resin content of 50% by mass or more and 100% by mass or less. The resin layer (1) may be a layer formed by coating (coating layer). The resin layer (1) may be a layer that primarily functions as a water vapor barrier.

[0019] (Water-dispersible polymer) The resin layer (1) contains a water-dispersible polymer, which provides good water vapor barrier properties. The water-dispersible polymer can be, for example, a polymer having structural units derived from hydrocarbon monomers, or a copolymer having structural units derived from hydrocarbon monomers and other structural units. Examples of hydrocarbon monomers include olefins and styrene compounds, which will be described later. The proportion of structural units derived from hydrocarbon monomers in the water-dispersible polymer relative to all structural units can be, for example, 40 mol% or more and 100 mol% or less, 50 mol% or more and 99 mol% or less, or 60 mol% or more and 95 mol% or less. The water-dispersible polymer can be a polymer that is substantially insoluble in water but can be dispersed in water. The solubility of the water-dispersible polymer in water at 20°C can be, for example, 1 g / 100 g or less, 0.1 g / 100 g or less, or 0.01 g / 100 g or less. Examples of water-dispersible polymers include olefin polymers, styrene polymers, and polyester polymers. From the viewpoint of water vapor barrier properties, the water-dispersible polymer is preferably selected from at least one of olefin polymers and styrene polymers, and more preferably from olefin polymers. The water-dispersible polymer can be the main component of the resin layer (1). One or more water-dispersible polymers can be used.

[0020] (Olefin polymers) Olefin polymers are polymers that contain olefins as monomers. As olefin polymers, they can be polymers of one or more olefins, i.e., polyolefins, or copolymers of one or more olefins with one or more monomers other than olefins.

[0021] Examples of olefins include ethylene, propylene, n-butene, and isobutene.

[0022] Other monomers besides olefins that constitute olefin polymers may include unsaturated carboxylic acid compounds, diene compounds, vinyl esters, vinyl ethers, halogenated ethylene, unsymmetrical dihalogenated ethylene, allyl compounds, etc., preferably unsaturated carboxylic acid compounds or vinyl esters, more preferably unsaturated carboxylic acid compounds.

[0023] Unsaturated carboxylic acid compounds refer to compounds formed by replacing the hydrogen atoms of unsaturated carboxylic acids and their carboxyl groups with other atoms or groups. That is, unsaturated carboxylic acid compounds include not only unsaturated carboxylic acids but also unsaturated carboxylic acid esters, unsaturated carboxylates, etc. Preferably, unsaturated carboxylic acid compounds are monomers or salts containing a carboxyl group.

[0024] As unsaturated carboxylic acid compounds, examples include unsaturated carboxylic acids such as (meth)acrylic acid, crotonic acid, cinnamic acid, itaconic acid, fumaric acid, maleic acid, and butene tricarboxylic acid; unsaturated carboxylic acid esters such as methyl (meth)acrylate, ethyl (meth)acrylate, monoethyl itaconic acid, and monobutyl fumarate; and unsaturated carboxylates such as sodium (meth)acrylate. It should be noted that "(meth)acrylic acid" refers to both acrylic acid and methacrylic acid.

[0025] Examples of vinyl esters include vinyl formate, vinyl acetate, vinyl propionate, vinyl valerate, vinyl decanoate, vinyl laurate, vinyl stearate, vinyl benzoate, vinyl neopentanoate, and vinyl tert-carbonate. Vinyl acetate is preferred.

[0026] As an olefin-based polymer, polyolefins, olefin-vinyl ester copolymers, or olefin-unsaturated carboxylic acid copolymers are preferred, with olefin-unsaturated carboxylic acid copolymers being more preferred. An olefin-vinyl ester copolymer refers to a copolymer of one or more olefins with one or more vinyl esters. An olefin-unsaturated carboxylic acid copolymer refers to a copolymer of one or more olefins with one or more unsaturated carboxylic acid compounds.

[0027] Examples of olefin-vinyl ester copolymers include ethylene-vinyl formate copolymers, ethylene-vinyl acetate copolymers, and ethylene-vinyl propionate copolymers, among which ethylene-vinyl acetate copolymers are preferred. These copolymers can be further copolymerized with other monomers capable of copolymerizing with olefins and vinyl esters.

[0028] Examples of olefin-unsaturated carboxylic acid copolymers include ethylene-(meth)acrylic acid copolymers, ethylene-(meth)acrylic acid methyl ester copolymers, ethylene-(meth)acrylic acid ethyl ester copolymers, ethylene-(meth)acrylic acid butyl ester copolymers, and ethylene-maleic acid copolymers. Olefin-unsaturated carboxylic acid copolymers are preferably copolymers of one or more olefins with one or more unsaturated carboxylic acids, i.e., olefin-unsaturated carboxylic acid copolymers (e.g., ethylene-(meth)acrylic acid copolymers, ethylene-maleic acid copolymers, etc.). Furthermore, olefin-unsaturated carboxylic acid copolymers are also preferably copolymers of ethylene and unsaturated carboxylic acid compounds. Ethylene-(meth)acrylic acid copolymers are a particularly preferred example of olefin-unsaturated carboxylic acid copolymers. These copolymers can be further copolymerized with other monomers capable of copolymerizing with olefins and unsaturated carboxylic acid compounds.

[0029] (Styrene-based polymers) Styrene-based polymers are polymers containing styrene-based compounds as monomers. Styrene-based compounds refer to styrene and compounds in which the hydrogen atoms of styrene are replaced by other atoms or other groups. Examples of styrene-based compounds include styrene, α-methylstyrene, vinyltoluene, and chlorostyrene, with styrene being preferred.

[0030] Examples of styrene-based copolymers include polystyrene, styrene-acrylic copolymers, and styrene-butadiene copolymers.

[0031] Styrene-acrylic copolymers are copolymers of the aforementioned styrene compounds and acrylic compounds. Acrylic compounds refer to compounds formed by replacing the hydrogen atoms of the carboxyl groups constituting (meth)acrylic acid with other atoms or groups. Examples of acrylic compounds include (meth)acrylic acid, (meth)acrylates, and (meth)acrylate salts. Examples of (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, and other alkyl (meth)acrylates. Examples of (meth)acrylate salts include sodium (meth)acrylate.

[0032] Examples of styrene-acrylic acid copolymers include styrene-(meth)acrylic acid copolymers, styrene-(meth)acrylate copolymers, and styrene-(meth)acrylate copolymers. Styrene-acrylic acid copolymers can be further copolymerized with other monomers.

[0033] Styrene-butadiene copolymers are copolymers of the aforementioned styrene compounds and butadiene compounds. Butadiene compounds refer to compounds formed by replacing the hydrogen atoms of butadiene with other atoms or other groups. Examples of butadiene compounds include 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, and 1,3-pentadiene, with 1,3-butadiene being preferred.

[0034] As a styrene-butadiene copolymer, a styrene-butadiene copolymer is preferred. The styrene-butadiene copolymer may be further copolymerized with other monomers.

[0035] As a styrene-based polymer, styrene-acrylic copolymers and styrene-butadiene copolymers are preferred, and styrene-acrylic copolymers are more preferred.

[0036] (Polyester polymer) Polyester polymers are polymers formed by the polymerization of one or more monomers via ester bonds. Examples of polyester polymers include polyethylene terephthalate, polybutylene terephthalate, polypropylene terephthalate, polyethylene naphthalate, polyglycolic acid, and aromatic liquid crystal polyesters.

[0037] The lower limit of the content of the water-dispersible polymer in the resin layer (1) is preferably 50% by mass, more preferably 60% by mass, and may also be 65% by mass, 70% by mass, or 80% by mass. By making the content of the water-dispersible polymer in the resin layer (1) at or above the above lower limit, the water vapor barrier properties can be further improved. On the other hand, the upper limit of this content is preferably 99.9% by mass, more preferably 99% by mass, and may also be 98% by mass, 96% by mass, 90% by mass, or 80% by mass.

[0038] (Polymer(1)) The polymer (1) is selected from at least one of PVOH (1) and urethane polymers. PVOH (1) is preferred as the polymer (1). One or more polymers (1) may be used.

[0039] (PVOH(1)) PVOH(1) is a polymer containing vinyl alcohol units (-CH2-CHOH-). PVOH(1) is usually obtained by saponification of vinyl ester polymers.

[0040] The viscosity-uniform polymerization degree of PVOH(1) is preferably 200 or more and 5000 or less. The lower limit of the viscosity-uniform polymerization degree can be 300, or 400, 500 or 800. On the other hand, the upper limit of the viscosity-uniform polymerization degree can be 3000, or 2500, 2000, 1200 or 1000.

[0041] The viscosity-uniform degree of polymerization of PVOH was determined according to JIS K 6726:1994. Specifically, the intrinsic viscosity [η] (L / g) of PVOH was measured in water at 30°C, and the viscosity-uniform degree of polymerization P was calculated using the following formula based on the intrinsic viscosity [η]. It should be noted that if the degree of saponification of PVOH is less than 99.5 mol%, the intrinsic viscosity [η] should be measured only after saponification has been completed to a degree of saponification of 99.5 mol% or higher.

[0042] P = ([η] × 10) 4 (8.29) （1 / 0.62） The lower limit of the degree of saponification of PVOH (1) is preferably 70 mol%, more preferably 80 mol%, even more preferably 90 mol%, and still more preferably 95 mol%, but can be 97 mol%, 98 mol%, or 99 mol%. When the degree of saponification of PVOH (1) is above the aforementioned lower limit, its oxygen barrier properties tend to be further improved. On the other hand, the upper limit of the aforementioned degree of saponification can be 100 mol%, or 99.9 mol%. The degree of saponification of PVOH is determined according to JIS K 6726:1994.

[0043] PVOH(1) may have monomer units derived from other monomers besides vinyl alcohol units and vinyl ester units. Examples of other monomers include α-olefins such as ethylene, propylene, n-butene, and isobutene; (meth)acrylic acid and its salts; (meth)acrylates; (meth)acrylamide; N-methyl (meth)acrylamide, N-ethyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide, diacetone (meth)acrylamide, (meth)acrylamide propanesulfonic acid and its salts, (meth)acrylamide propyl dimethylamine and its salts or quaternary salts, N-hydroxymethyl (meth)acrylamide and its derivatives, etc. (meth)acrylamide derivatives; methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, etc. Vinyl ethers such as butyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, tert-butyl vinyl ether, dodecyl vinyl ether, stearyl vinyl ether, etc.; nitrile compounds such as acrylonitrile and methacrylonitrile; halogenated vinylides such as vinyl chloride and vinyl fluoride; vinylidene halogenated vinylides such as vinylidene chloride and vinylidene fluoride; allyl acetate, allyl chloride, etc.; unsaturated dicarboxylic acids such as maleic acid, itaconic acid, fumaric acid, and their salts or esters; vinyl silyl compounds such as vinyltrimethoxysilane; isopropyl acetate; 1,4-diacetoxybutene; 3,4-diacetoxy-1-butene; vinyl formamide; vinylpyrrolidone, etc. It should be noted that in this specification, PVOH that substantially does not possess monomer units derived from other monomers besides the vinyl alcohol unit and vinyl ester unit is also referred to as polyvinyl alcohol.

[0044] As other monomers, α-olefins are preferred, and ethylene is more preferred. That is, PVOH (1) can be an α-olefin-vinyl alcohol copolymer or an ethylene-vinyl alcohol copolymer (ethylene-modified polyvinyl alcohol). By using this PVOH (1), interlayer tightness, gas barrier properties, etc. can be improved.

[0045] The lower limit of the content of α-olefin units relative to all monomer units in the α-olefin-vinyl alcohol copolymer is preferably 0.1 mol%, more preferably 0.5 mol%, and even more preferably 1 mol%, which can be 2 mol%, 3 mol%, 4 mol%, or 5 mol%. On the other hand, the upper limit of its content is preferably 20 mol%, more preferably 15 mol%, and even more preferably 13 mol%, which can be 10 mol% or 8 mol%. The lower limit of the content of ethylene units relative to all monomer units in ethylene-modified polyvinyl alcohol (hereinafter sometimes referred to as ethylene modification amount) is preferably 0.1 mol%, more preferably 0.5 mol%, and even more preferably 1 mol%, which can be 2 mol%, 3 mol%, 4 mol%, or 5 mol%. On the other hand, the upper limit of this content is preferably 20 mol%, more preferably 15 mol%, and even more preferably 13 mol%, which can be 10 mol% or 8 mol.

[0046] The total content of ethylene alcohol units, vinyl ester units and optional α-olefin units in PVOH (1) is preferably 95 mol% or more, more preferably 99 mol% or more, and can be 100 mol% relative to all monomer units.

[0047] (Carbamate polymers) Carbamate polymers are polymers containing carbamate bonds. Typically, carbamate polymers are polymers obtained by reacting polyisocyanates with polyols. Preferably, carbamate polymers contain at least one of monomer units derived from isophthalic diisocyanate and monomer units derived from hydrogenated isophthalic diisocyanate. In carbamate polymers, the total content of monomer units derived from isophthalic diisocyanate and monomer units derived from hydrogenated isophthalic diisocyanate is preferably 50 mol% or more relative to the total content of monomer units derived from polyisocyanates. Such carbamate polymers exhibit high cohesiveness through hydrogen bonding and the stacking effect of dimethyl groups, thus possessing excellent oxygen barrier properties. The above-mentioned content can be used... 1 It can be identified using well-known analytical methods such as H-NMR.

[0048] Carbamate polymers can be synthesized by known methods. For example, carbamate polymers described in International Publication No. 2015 / 016069 can be used.

[0049] Carbamate polymers can be commercially available. For example, "TAKELAC (registered trademark) W", "TAKELAC (registered trademark) WPB", "TAKELAC (registered trademark) WS" manufactured by Mitsui Chemicals Co., Ltd. can be used. More specifically, "TAKELAC (registered trademark) WPB-341" can be cited as an example.

[0050] As a lower limit for the content of polymer (1) in the resin layer (1), it is preferably 0.1 parts by mass, more preferably 0.5 parts by mass, and even more preferably 1 part by mass, relative to 100 parts by mass of the water-dispersible polymer. Sometimes, it is even more preferably 3 parts by mass, 6 parts by mass, or 8 parts by mass. By making the content of polymer (1) at or above the above lower limit, the interlayer adhesion can be further improved. On the other hand, the above content is preferably 50 parts by mass, more preferably 35 parts by mass, and even more preferably 25 parts by mass or less, 20 parts by mass or less, or 15 parts by mass or less. By making the content of polymer (1) less than or below the above upper limit, the water vapor barrier properties can be improved.

[0051] (Layered inorganic matter (1)) The resin layer (1) preferably contains a layered inorganic material (1). By containing a layered inorganic material (1) in the resin layer (1), the water vapor barrier properties can be improved. Examples of layered inorganic materials (1) include mica, talc, montmorillonite, kaolinite, vermiculite, montmorillonite, lithium montmorillonite, mica-bearing clay, acid clay, etc., with mica being preferred. The layered inorganic material can be a natural product or a synthetic product. One or more types of layered inorganic material (1) can be used.

[0052] The average particle size of the layered inorganic material (1) is preferably 1 μm or more and 50 μm or less, more preferably 4 μm or more and 30 μm or less. By setting the average particle size of the layered inorganic material (1) to the above range, the water vapor barrier properties can be further improved. The average particle size is set as the average of the diameters (longest diameters) of any 20 particles in the magnified image obtained by atomic force microscopy.

[0053] The aspect ratio of the layered inorganic material (1) can be, for example, 20 or more, 100 or more, or 300 or more, preferably 500 or more. By using a layered inorganic material with an aspect ratio of the lower limit mentioned above, the water vapor barrier properties can be further improved. The aspect ratio mentioned above can be, for example, 10000 or less, or 7000 or less, 3000 or less, or 2000 or less. The aspect ratio refers to the average length of the flattened particles relative to their average thickness. The average thickness and average length are set as the average of the thickness and length (longest diameter) of any 20 particles in a magnified image obtained by atomic force microscopy.

[0054] The content of layered inorganic matter (1) in the resin layer (1) is preferably 1 part by mass or more, more preferably 5 parts by mass or more, further preferably 10 parts by mass or more, and even more preferably 20 parts by mass or more, relative to 100 parts by mass of the water-dispersible polymer. The above content is preferably less than 50 parts by mass, more preferably 40 parts by mass or less, and even more preferably 35 parts by mass or less. By setting the content of layered inorganic matter (1) in the resin layer (1) to the above range, the water vapor barrier properties can be further improved.

[0055] (Catonic polymer) The resin layer (1) preferably contains a cationic polymer. By containing a cationic polymer in the resin layer (1), water vapor barrier properties can be further improved. A cationic polymer is a polymer having cationic groups. A cationic polymer may also be a polymer having structural units containing cationic groups.

[0056] Examples of cationic polymers include polyamines, modified polyamides (e.g., amine-modified polyamides and other cationic modified polyamides), polyamide epichlorohydrin, polyalkylene imides (e.g., polyethyleneimine), polyalkylene polyamines, polyamide amine-epimerized alcohol or formaldehyde condensation products, polyamine-epimerized alcohol or formaldehyde condensation products, polyamide polyurea-epimerized alcohol or formaldehyde condensation products, polyamine polyurea-epimerized alcohol or formaldehyde condensation products, polyamide amine polyurea-epimerized alcohol or formaldehyde condensation products, polyamide polyurea compounds, polyamine polyurea compounds, polyamide amine polyurea compounds, polyamide amine compounds, polyvinylpyridine, amino-modified acrylamide compounds, polyethyleneamine, polydiallyl dimethylammonium chloride, etc.

[0057] The cationic polymer is preferably a polyamide resin. A polyamide resin refers to a polymer having amide bonds. Examples of cationic polyamide resins include, for instance, modified polyamides, polyamide epichlorohydrin, polyamide-epimergic alcohol or formaldehyde condensation products, polyamide-polyurea-epimergic alcohol or formaldehyde condensation products, polyamide-polyurea-epimergic alcohol or formaldehyde condensation products, polyamide-polyurea compounds, polyamide-polyurea compounds, polyamide-amine compounds, etc., and more preferably modified polyamides.

[0058] Cationic polymers can be synthesized using methods already known. Commercially available cationic polymers can be used.

[0059] As the lower limit of the content of cationic polymer in the resin layer (1), it is preferably 0.1 parts by mass, more preferably 0.3 parts by mass, further preferably 0.5 parts by mass, and even more preferably 0.8 parts by mass, relative to 100 parts by mass of water-dispersible polymer. The upper limit of the aforementioned content is preferably 10 parts by mass, more preferably 5 parts by mass, further preferably 3 parts by mass, and even more preferably 2 parts by mass. By setting the content of cationic polymer in the resin layer (1) within the aforementioned range, the water vapor barrier properties, etc., can be further improved.

[0060] (Other ingredients, etc.) The resin layer (1) may further contain other components besides the water-dispersible polymer, polymer (1), layered inorganic material (1), and cationic polymer. Examples of other components include, for example, resins, dispersants, surfactants, defoamers, dyes, thickeners, etc., other than the water-dispersible polymer, polymer (1), and cationic polymer.

[0061] The total content of water-dispersible polymer, polymer (1) and any component, namely layered inorganic matter (1) and cationic polymer in the resin layer (1) can be more than 90% by mass, or more than 95% by mass, more than 99% by mass or substantially 100% by mass.

[0062] The lower limit of the mass per unit area of ​​resin layer (1) is preferably 1 g / m². 2 More preferably 3g / m 2 Further preferred is 5g / m 2 A further preferred value is 7g / m 2 By ensuring that the mass per unit area of ​​resin layer (1) is at or above the aforementioned lower limit, the water vapor barrier properties and oxygen barrier properties can be further improved. Furthermore, when resin layer (1) is the outermost layer, by ensuring that the mass per unit area of ​​resin layer (1) is at or above the aforementioned lower limit, resin layer (1) can function as a sufficiently good sealing layer. The upper limit for the mass per unit area of ​​resin layer (1) is preferably 100 g / m². 2 More preferably 40g / m 2 Further preferred is 20g / m 2 A further preferred value is 15g / m 2 By making the mass per unit area of ​​resin layer (1) 1 below the above-mentioned upper limit, it is possible to achieve thinning of the laminate, etc.

[0063] (Resin layer (2)) The resin layer (2) contains PVOH (2) and layered inorganic matter (2). The resin layer (2) can be a layer with a resin content of 50% by mass or more but less than 100% by mass. The resin layer (2) can be a layer formed by coating (coating layer). The resin layer (2) is the layer that mainly functions as an oxygen barrier.

[0064] PVOH(2) The resin layer (2) contains PVOH (2) and can provide good oxygen barrier properties. PVOH (2) can be the main component of the resin layer (2). One or more types of PVOH (2) can be used.

[0065] The PVOH (2) contained in the resin layer (2) can be an α-olefin-vinyl alcohol copolymer or an ethylene-modified polyvinyl alcohol. As PVOH (2), by using an α-olefin-vinyl alcohol copolymer, especially an ethylene-modified polyvinyl alcohol, the interlayer adhesion, oxygen barrier properties, etc. can be further improved. The specific manner of PVOH (2) is the same as that of PVOH (1) mentioned above.

[0066] The viscosity-uniform polymerization degree of PVOH (2) is preferably 200 or more and 5000 or less. The lower limit of the viscosity-uniform polymerization degree can be 300, or 400, 500 or 800. On the other hand, the upper limit of the viscosity-uniform polymerization degree can be 3000, or 2500, 2000, 1200 or 1000. By keeping the viscosity-uniform polymerization degree of PVOH (2) within the above range, the water vapor barrier properties, oxygen barrier properties, etc., can be further improved, and the coatability and the strength of the formed layer are also optimized.

[0067] The lower limit of the degree of saponification of PVOH (2) is preferably 70 mol%, more preferably 80 mol%, even more preferably 90 mol%, and even more preferably 95 mol%, and may also be 96 mol%, 97 mol%, 98 mol%, or 99 mol%. By making the degree of saponification above the above lower limit, the water vapor barrier properties, oxygen barrier properties, etc., can be further improved. On the other hand, the upper limit of the above saponification can be 100 mol%, or may be 99.9 mol%.

[0068] The lower limit of the content of α-olefin units in the α-olefin vinyl alcohol copolymer contained in the resin layer (2) relative to all monomer units is preferably 0.1 mol%, more preferably 0.5 mol%, and even more preferably 1 mol%, and may also be 2 mol%, 3 mol%, 4 mol%, or 5 mol%. On the other hand, the upper limit of this content is preferably 20 mol%, more preferably 15 mol%, and even more preferably 13 mol%, and may also be 10 mol% or 8 mol%. The lower limit of the content of ethylene units in the ethylene-modified polyvinyl alcohol contained in the resin layer (2) relative to all monomer units is preferably 0.1 mol%, more preferably 0.5 mol%, and even more preferably 1 mol%, and may also be 2 mol%, 3 mol%, 4 mol%, or 5 mol%. On the other hand, the upper limit of this content is preferably 20 mol%, more preferably 15 mol%, and even more preferably 13 mol%, and may also be 10 mol% or 8 mol.

[0069] The total content of ethylene alcohol units, vinyl ester units and any α-olefin units in PVOH (2) relative to all monomer units is preferably 95 mol% or more, more preferably 99 mol% or more, and may also be 100 mol%.

[0070] The lower limit for the PVOH (2) content in the resin layer (2) is preferably 60% by mass, more preferably 70% by mass, even more preferably 80% by mass, and even more preferably 85% by mass. By making the PVOH (2) content in the resin layer (2) at or above the above lower limit, the water vapor barrier properties, oxygen barrier properties, etc., can be improved. On the other hand, the upper limit for the PVOH (2) content in the resin layer (2) is preferably 99% by mass, but may also be 98% by mass, or may be 97% by mass, 96% by mass, or 95% by mass.

[0071] (Layered inorganic matter (2)) In one embodiment of the present invention, the laminated body contains both PVOH (2) and layered inorganic material (2) in the resin layer (2), thus exhibiting high oxygen barrier properties. The specific and preferred embodiments of the layered inorganic material (2) are the same as those of the aforementioned layered inorganic material (1). One or more types of layered inorganic material (2) may be used.

[0072] The aspect ratio of the layered inorganic material (2) can be, for example, 20 or more, 100 or more, or 300 or more, preferably 500 or more. By using a layered inorganic material with an aspect ratio of the aforementioned lower limit or more, oxygen barrier properties can be further improved. The aspect ratio can be, for example, 10,000 or less, or 7,000 or less, 3,000 or less, or 2,000 or less.

[0073] The content of layered inorganic matter (2) in the resin layer (2) relative to 100 parts by mass of PVOH (2) is preferably 1 part by mass or more, more preferably 3 parts by mass or more, even more preferably 5 parts by mass or more, and even more preferably 7 parts by mass or more. The content is preferably less than 30 parts by mass, more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less. By setting the content of layered inorganic matter (2) in the resin layer (2) to the aforementioned range, oxygen barrier properties, interlayer adhesion, etc., can be further improved.

[0074] (Other ingredients, etc.) The resin layer (2) may further contain other components besides PVOH (2) and layered inorganic matter (2). Other components may include, for example, resins other than PVOH (2), dispersants, surfactants, defoamers, dyes, preservatives, fillers, interlayer adhesives, thickeners, etc.

[0075] The total content of PVOH (2) and layered inorganic matter (2) in the resin layer (2) is preferably 90% by mass or more, more preferably 95% by mass or more or 99% by mass or more. When the total content of PVOH (2) and layered inorganic matter (2) in the resin layer (2) is above the lower limit mentioned above, the interlayer adhesion, oxygen barrier properties, etc. tend to be further improved.

[0076] The mass per unit area of ​​resin layer (2) 1 is preferably 0.3 g / m². 2 Above and 15g / m 2 The following is more preferably 0.5 g / m 2 Above and 10g / m 2 The following is a further preferred value: 1 g / m 2 Above and 6g / m 2 The following is a further preferred value of 1.5 g / m 2 Above and 4.0g / m 2 The following applies. By making the mass per unit area of ​​resin layer (2) 1 above the lower limit mentioned above, it is possible to improve water vapor barrier properties, oxygen barrier properties, etc. On the other hand, by making the mass per unit area of ​​resin layer (2) 1 below the upper limit mentioned above, it is possible to achieve thinning of the laminate, etc.

[0077] (Sealing layer) In one embodiment of the invention, the laminate preferably further comprises a sealing layer. The sealing layer is typically the outermost layer of the laminate. The outermost layer on one side of the laminate may be a sealing layer, or the outermost layers on both sides may both be sealing layers. The sealing layer may be a layer formed by coating (coating layer).

[0078] The sealing layer typically contains a polymer as its main component. The polymer used for the sealing layer is preferably a thermoplastic resin. The melting point of the polymer used for the sealing layer is preferably 50°C or higher and 150°C or lower, more preferably 70°C or higher and 110°C or lower. One or more polymers may be used.

[0079] (Polymer (3)) As the polymer used for the sealing layer, it is preferred to use at least one polymer (3) selected from olefin polymers and styrene polymers. The specific and preferred methods of these polymers (3) are the same as those of the olefin polymers and styrene polymers used as water-dispersible polymers described above. One or more polymers (3) may be used.

[0080] As the olefin-based polymer (3), olefin-vinyl ester copolymer or olefin-unsaturated carboxylic acid copolymer is preferred, more preferably olefin-unsaturated carboxylic acid copolymer, further preferably olefin-unsaturated carboxylic acid copolymer, and even more preferably ethylene-(meth)acrylic acid copolymer. As the styrene-based copolymer (3), styrene-acrylic acid copolymer is preferred.

[0081] The lower limit of the content of polymer (3) in the sealing layer is preferably 50% by mass, more preferably 60% by mass, even more preferably 70% by mass, and even more preferably 80% by mass, 85% by mass, 90% by mass, or 95% by mass. By making the content of polymer (3) above the above lower limit, heat-sealing properties can be improved. On the other hand, the upper limit of this content is preferably 100% by mass, and may also be 99% by mass or 95% by mass.

[0082] The sealing layer may contain PVOH. When the sealing layer contains PVOH, it can improve the smoothness of the sealing layer surface. In addition, when the sealing layer contains PVOH, it can also improve the water vapor barrier and oxygen barrier properties of the laminate. The specific manner in which the PVOH is contained in the sealing layer is the same as the specific manner in which PVOH (1) is described above. One or more types of PVOH can be used.

[0083] The sealing layer may further contain other components besides the aforementioned polymers. Examples of such components include waxes (paraffin, etc.), dispersants, surfactants, defoamers, dyes, and thickeners.

[0084] The mass of the sealing layer 1 per unit area is preferably 1 g / m². 2 Above and 50g / m 2 The preferred value is 2g / m 2 Above and 30g / m 2 The following is a further preferred value: 3g / m 2 Above and 20g / m 2 The following is a further preferred value: 4g / m 2 Above and 15g / m 2 The following is particularly preferred: 5g / m 2 Above and 10g / m 2 The following applies. By making the mass per unit area of ​​the sealing layer 1 above the aforementioned lower limit, sufficient heat sealing performance can be achieved, and water vapor barrier performance, oxygen barrier performance, etc., can be further improved. On the other hand, by making the mass per unit area of ​​the sealing layer 1 below the aforementioned upper limit, the laminate can be made thinner, etc.

[0085] (Other layers) In one embodiment of the present invention, the laminate may further have layers other than the substrate, resin layer (1), resin layer (2), and sealing layer. Examples of other layers include other resin layers, vapor-deposited layers, metal foil layers, etc. In one embodiment of the present invention, the laminate may not have layers other than the substrate, resin layer (1), resin layer (2), and any sealing layer. For example, the laminate may not have a vapor-deposited layer.

[0086] In one embodiment of the present invention, the laminated body exhibits excellent water vapor barrier properties and oxygen barrier properties when it has a vapor-deposited layer. The vapor-deposited layer is a layer formed by vapor deposition, and preferably a layer formed by vapor deposition of an inorganic material (inorganic vapor-deposited layer).

[0087] Examples of materials constituting the vapor-deposited layer include metals (e.g., aluminum), metal oxides (e.g., silicon oxide, aluminum oxide, magnesium oxide), metal nitrides (e.g., silicon nitride), metal oxynitrides (e.g., silicon oxynitride), and metal carbonitrides (e.g., silicon carbonitride). Furthermore, in the examples of the aforementioned inorganic materials, silicon is considered to be included within the metal. The vapor-deposited layer can be composed of organic materials or a combination of organic and inorganic materials. From the viewpoints of barrier properties and industrial productivity, aluminum, aluminum oxide, silicon oxide, magnesium oxide, or silicon nitride are preferred materials constituting the vapor-deposited layer; aluminum or aluminum oxide is more preferred; and aluminum is even more preferred.

[0088] The lower limit of the average thickness of the vapor-deposited layer is preferably 5 nm, more preferably 10 nm, further preferably 20 nm, and even more preferably 30 nm. By ensuring the average thickness of the vapor-deposited layer is above or above this lower limit, barrier properties can be improved. On the other hand, the upper limit of the average thickness of the vapor-deposited layer is preferably 200 nm, more preferably 150 nm, further preferably 100 nm, and may also be 80 nm or 60 nm. By ensuring the average thickness of the vapor-deposited layer is below or below this upper limit, cracking of the vapor-deposited layer during bending can be suppressed, and the decrease in water vapor barrier properties and oxygen barrier properties after bending can be reduced. The average thickness of the vapor-deposited layer refers to the average thickness of any 10 points in the cross-section of the vapor-deposited layer measured by an electron microscope.

[0089] (Layered structure, etc.) In a laminated body according to one embodiment of the present invention, resin layer (1) and resin layer (2) are adjacent. Resin layer (1) and resin layer (2) can be in direct contact. In this laminated body, the interlayer adhesion between resin layer (1) and resin layer (2) is high.

[0090] At least one of the resin layer (1) or resin layer (2) is preferably in contact with the substrate, and more preferably the resin layer (1) is in contact with the substrate. That is, in this laminate, it is preferred that the substrate, resin layer (1) and resin layer (2) are directly laminated in this order, or the substrate, resin layer (2) and resin layer (1) are directly laminated in this order, and more preferably the substrate, resin layer (1) and resin layer (2) are directly laminated in this order.

[0091] Furthermore, when the laminate further includes a sealing layer, the sealing layer is preferably laminated on the resin layer (2), and more preferably the substrate, resin layer (1), resin layer (2), and sealing layer are laminated in this order. In addition, in the laminate, when the resin layer (1) is located on the outermost layer, the resin layer (1) can function as a sealing layer.

[0092] In a laminated body according to one embodiment of the present invention, the substrate, resin layer (1), resin layer (2), and any sealing layer may each be a single layer or two or more layers. Preferably, in a laminated body according to one embodiment of the present invention, the substrate, resin layer (1), resin layer (2), and sealing layer are each a single layer. When any one of the substrate, resin layer (1), resin layer (2), and sealing layer is two or more layers, their composition, thickness, etc., may be the same or different. Furthermore, when any one of the resin layer (1) and resin layer (2) is two or more layers, a resin layer (1) or resin layer (2) that is not adjacent to the other resin layer (1) or resin layer (2) may exist. That is, it is sufficient that at least one set of resin layers (1) and resin layers (2) exist adjacent to each other.

[0093] As an embodiment of the laminated body described herein, the layer structure is shown below, for example. Furthermore, 1 represents resin layer (1), 2 represents resin layer (2), S represents sealing layer, and X represents other layers.

[0094] Substrate / 1 / 2 Substrate / 2 / 1 Substrate / 1 / 2 / 1 Substrate / 2 / 1 / 2 Substrate / X / 1 / 2 Substrate / X / 2 / 1 Substrate / 1 / 2 / S Substrate / 1 / 2 / X Substrate / 1 / 2 / X / S Substrate / 2 / 1 / X Substrate / 2 / 1 / X / S 2 / 1 / Substrate / 1 / 2 1 / 2 / Substrate / 2 / 1 S / 2 / 1 / Substrate / 1 / 2 / S S / substrate / 1 / 2 / S.

[0095] The laminate described in one embodiment of the present invention can be suitable for use as greaseproof paper, gas barrier paper, odor barrier paper, packaging material, etc. When the laminate has a sealing layer, it can also be used in a predetermined shape (e.g., a bag) by heat-sealing the sealing layers together. There are no particular limitations on the heat-sealing method; known methods can be used, such as hot plate heat sealers, pulse sealers, ultrasonic sealers, friction heat sealers, dielectric heating sealers, etc.

[0096] <Method for manufacturing laminates> The method for manufacturing the laminate according to one embodiment of the present invention is not particularly limited, but it is typically manufactured by coating a substrate with resin layers (1) and (2). The order in which the resin layers (1) and (2) are applied is not particularly limited, but it is preferable to apply them in the order of resin layers (1) and (2) relative to the substrate. In the case of a laminate having a sealing layer, the sealing layer can also be applied by coating. The sealing layer can also be applied by methods other than coating.

[0097] For example, resin layer (1), resin layer (2), and sealing layer can be formed by applying a coating liquid for forming each layer and allowing it to dry. Drying is not required each time each coating liquid is applied, or a simultaneous multi-layer coating method can be used. The application of each coating liquid can be carried out by existing known methods. Coating can be carried out using, for example, a scraper coater, a flexographic coater, a comma coater, a metering rod press, a two-roll sizing press, a Sym-Sizer, a bar coater, an air knife coater, a slot die coater, a gravure coater, a reverse gravure coater, a micro-gravure coater, a door roller coater, a curtain coater, etc.

[0098] There are no particular limitations on the drying method for the coating liquid; for example, a hot air dryer, an infrared dryer, a gas burner, or a heating plate can be used.

[0099] There are no particular limitations on the solvent or dispersion medium used to form the coating liquid for each layer; water, organic solvents (ethanol, isopropanol, methyl ethyl ketone, toluene, etc.) can be used, but water is preferred.

[0100] Oil-resistant paper Oil-resistant paper incorporating the laminate described in one embodiment of the present invention is also a suitable embodiment of the present invention. The oil-resistant paper described in one embodiment of the present invention can be composed of the laminate described in one embodiment of the present invention.

[0101] This greaseproof paper has excellent water vapor barrier and oxygen barrier properties. It is suitable for use as packaging material for, for example, oily foods such as potato chips and fried chicken; packaging material for wrapping butter; and cooking paper for baking bread, cakes, etc.

[0102] The oil resistance (KIT value) of the oil-resistant paper is preferably grade 5 or higher, more preferably grade 6 or higher, or grade 7 or higher. This oil resistance is set as the value measured on the surface using the KIT test based on TAPPI No. T559cm-02.

[0103] <Gas Barrier Paper> A gas barrier paper incorporating the laminate described in one embodiment of the present invention is also a suitable embodiment of the present invention. The gas barrier paper described in one embodiment of the present invention can be composed of the laminate described in one embodiment of the present invention.

[0104] This gas barrier paper exhibits excellent water vapor and oxygen barrier properties. It is suitable for use as packaging material for food, pesticides, pharmaceuticals, cosmetics, medical products, electronic components, clothing, and more.

[0105] The upper limit for the oxygen permeability of this gas barrier paper is preferably 100 cc / atm / m. 2 / day, preferably 50cc / atm / m 2 / day, further optimized to 10cc / atm / m 2 / day, further optimized to 3cc / atm / m 2 / day, 1cc / atm / m 2 / day or 0.1cc / atm / m 2 / day. Oxygen permeability is set as the value measured at 20°C and 65%RH.

[0106] Packaging Materials Packaging materials incorporating the laminated body described in one embodiment of the present invention are also a suitable embodiment of the present invention. The packaging material described in one embodiment of the present invention may be composed of the laminated body described in one embodiment of the present invention, the oil-resistant paper described in one embodiment of the present invention, or the gas barrier paper described in one embodiment of the present invention.

[0107] This packaging material exhibits excellent water vapor barrier and oxygen barrier properties. It is suitable for use as packaging for products such as food, pesticides, pharmaceuticals, cosmetics, medical products, electronic components, and clothing. Example

[0108] The present invention will be described in more detail below using examples, but the present invention is not limited to these examples at all.

[0109] (Evaluation of water vapor barrier properties) For laminates, with the coated surface as the inner side, the water vapor transmission rate (WVTR) was determined using the cup method based on JIS Z 2080 at a temperature of 40°C and a relative humidity of 90%.

[0110] (Evaluation of oxygen barrier properties) For laminates, oxygen permeability (OTR) was measured using an oxygen permeability measuring device (MOCON, OX-TRAN2 / 20) at 20°C and 65%RH.

[0111] (Evaluation of interlayer tightness) As an evaluation of interlayer adhesion, peel strength is determined by the following method.

[0112] One test piece was cut from the laminate, designated as test piece 1. Next, on the same substrate used in the examples, a dispersion of ethylene-acrylic acid copolymer (manufactured by Sumitomo Seika Co., Ltd., “ZAIKTHENE AC”) was coated at a rate of 6 g / m². 2 The coating was applied in the following manner. After coating, it was dried to form a sealing layer, and an area of ​​the same size as test piece 1 was cut out as test piece 2. Test piece 1 and test piece 2 were overlapped with their opposite outermost surfaces in contact with each other, and a hot-pressing was performed on an area equivalent to approximately half the area of ​​the test piece. The hot-pressing conditions were: temperature 150°C, pressing time 1 second, and pressure 2 kgf. For the partially molten test piece, a tensile test was performed using a tensile testing machine at a peel angle of 180° and a peel speed of 300 mm / min. The state of the peeled piece after the tensile test was observed, and the peel strength was determined according to the following criteria.

[0113] (Benchmark) A: The area of ​​the peeled portion between resin layer (1) and resin layer (2) is less than 20%.

[0114] B: The area of ​​the peeled portion between resin layer (1) and resin layer (2) is greater than 20% and less than 80%.

[0115] C: The area of ​​the peeled portion between resin layer (1) and resin layer (2) is greater than 80%.

[0116] Furthermore, it can be visually determined whether the peeling after the tensile test is of the substrate alone or has a coating layer on the substrate. In addition, the resin layer (2) has the property of reacting with iodine and turning blue. Therefore, by visual observation and utilizing the aforementioned property, it is possible to specify which layer peeling occurs between. Furthermore, the adhesion strength between the substrate and the sealing layer of test piece 2, and between the sealing layer of test piece 2 and the sealing layer of test piece 1, is considered to be sufficiently high. Therefore, for example, in the tensile tests of Examples 1 to 16 and Comparative Examples 1 to 3, where the test pieces after heat pressing have layers such as test piece 1 (substrate / resin layer (1) / resin layer (2) / sealing layer) / test piece 2 (sealing layer / substrate), peeling occurs at any point between the substrate / resin layer (1), between resin layer (1) / resin layer (2), and between resin layer (2) / sealing layer. Visually observing the peeling on the test piece 1 side after the tensile test, the peeling part consisting only of the substrate peels off between the substrate / resin layer (1). The release sheet on side 1 of the test piece is immersed in an iodine aqueous solution. The part that does not turn blue is the part that is peeled off between resin layer (1) and resin layer (2), and the part that turns blue is the part that is peeled off between resin layer (2) and sealing layer. That is, in the release sheet on side 1 of the test piece, by calculating the area of ​​the part that does not turn blue when immersed in an iodine aqueous solution in the part of the substrate with a certain coating layer, the area of ​​the part peeled off between resin layer (1) and resin layer (2) can be calculated.

[0117] The materials used in the manufacture of the laminates for the embodiments and comparative examples are shown below.

[0118] EAA: Ethylene-acrylic acid copolymer ("ZAIKTHENE AC", manufactured by Sumitomo Seika Co., Ltd.) SA: Styrene-acrylic copolymer ("Joncryl 4130", manufactured by BASF).

[0119] PVOH-1: Ethylene-modified polyvinyl alcohol with a viscosity-average polymerization degree of 950, a saponification degree of 99.3 mol%, and an ethylene modification content of 6.4 mol%. PVOH-2: Ethylene-modified polyvinyl alcohol with a viscosity-average degree of polymerization of 2,130, a saponification degree of 98.2 mol%, and an ethylene modification content of 4.1 mol%. PVOH-3: Ethylene-modified polyvinyl alcohol with a viscosity-average degree of polymerization of 380, a saponification degree of 99.0 mol%, and an ethylene modification content of 7.8 mol%. PVOH-4: Ethylene-modified polyvinyl alcohol with a viscosity-uniform polymerization degree of 500, a saponification degree of 95.8 mol%, and an ethylene modification content of 6.9 mol%. PVOH-5: Polyvinyl alcohol with a viscosity-uniform polymerization degree of 440 and a saponification degree of 98.3 mol%. PVOH-6: A vinyl alcohol polymer ("BVE8049Q", manufactured by Mitsubishi Chemical Corporation) Polyurethane: urethane polymer "Neorez R600" (manufactured by Covestro Coating Resins) Cationic polymer: Modified polyamide resin (“SPI201”, manufactured by Taoka Chemical Industry Co., Ltd.) Mica: "NTS-10NC" Made by Topy Industrial Co., Ltd. (length-to-diameter ratio 1000).

[0120] [Example 1] A coating solution (1) for forming a resin layer (1) was prepared by mixing PVOH-1, which is polymer (1), into a dispersion of an aqueous polymer, namely ethylene-acrylic acid copolymer (EAA) (manufactured by Sumitomo Seika Co., Ltd.). The content of polymer (1) in the coating solution (1) is 10 parts by mass relative to 100 parts by mass of the aqueous polymer. Furthermore, the coating solution (1) does not contain layered inorganic matter (1) or cationic polymers.

[0121] A coating solution (2) for forming a resin layer (2) was prepared by mixing mica (aspect ratio 1000; "NTS-10NC" manufactured by Topy Industrial Co., Ltd.) as a layered inorganic material (2) into an aqueous solution of PVOH-1, which is PVOH (2). The content of the layered inorganic material (2) in the coating solution (2) is 10 parts by mass relative to 100 parts by mass of PVOH (2).

[0122] A dispersion of ethylene-acrylic acid copolymer (EAA) ("ZAIKTHENE AC", manufactured by Sumitomo Seika Co., Ltd.) which is polymer (3) is prepared as a coating liquid (3) for forming a sealing layer.

[0123] The basis weight of the substrate is 80 g / m³. 2 The aforementioned coating liquid (1) was applied to bleached kraft paper using a reverse gravure coating machine, resulting in a coating weight of 10 g / m² after drying. 2 The resin layer (1) was formed by drying at 100°C for 5 minutes. The aforementioned coating liquid (2) was then applied to this resin layer (1) using a reverse gravure coating machine, resulting in a coating weight of 3 g / m² after drying. 2 The resin layer (2) was prepared by drying at 100°C for 5 minutes. Then, the aforementioned coating liquid (3) was applied to the resin layer (2) using a wire bar coater, so that the coating amount after drying was 6 g / m. 2 The material was dried at 100°C for 5 minutes to form a sealing layer. This resulted in the laminate of Example 1 (substrate / resin layer (1) / resin layer (2) / sealing layer).

[0124] The water vapor barrier property (WVTR) of the laminate obtained in Example 1 was 177 cc / m 2 / day, Oxygen Barrier Reduction (OTR) is less than 0.1 cc / atm / m 2 / day, the interlayer adhesion (peel strength) is rated as A.

[0125] [Examples 2-18, Comparative Examples 1-3, Reference Example 1] The coating liquids (1) to (3) were appropriately varied in the manner shown in Table 1, including the types of water-dispersible polymers in the resin layer (1), the types and contents of polymers (1) (relative to 100 parts by mass of water-dispersible polymers), the contents of layered inorganic matter (1) (relative to 100 parts by mass of water-dispersible polymers), the contents of cationic polymers (relative to 100 parts by mass of water-dispersible polymers), the types of PVOH (2) in the resin layer (2), the contents of layered inorganic matter (2) (relative to 100 parts by mass of PVOH (2)), and the types of polymers (3) in the sealing layer. Furthermore, “-” in Table 1 indicates that the coating liquid is not present.

[0126] In addition to the above points, the laminates (substrate / resin layer (1) / resin layer (2) / sealing layer) of Examples 2 to 18, Comparative Examples 1 to 3 and Reference Example 1 were obtained in the same manner as in Example 1.

[0127] The water vapor barrier properties (WVTR), oxygen barrier properties (OTR), and interlayer adhesion (peel strength) of the obtained laminates were evaluated. The evaluation results are shown in Table 1.

[0128] [Example 19] The coating liquids (1) to (2) were changed in the manner shown in Table 1, including the type of water-dispersible polymer in the resin layer (1), the type and content of polymer (1) (relative to 100 parts by mass of water-dispersible polymer), the content of layered inorganic matter (1) (relative to 100 parts by mass of water-dispersible polymer), the content of cationic polymer (relative to 100 parts by mass of water-dispersible polymer), and the type of PVOH (2) in the resin layer (2), the type and content of layered inorganic matter (2) (relative to 100 parts by mass of PVOH (2)).

[0129] In addition, the substrate was coated with coating liquid (2) and coating liquid (1) in sequence, but coating liquid (3) was not applied.

[0130] In addition to the above points, the laminate (substrate / resin layer (2) / resin layer (1)) of Example 19 was obtained in the same manner as in Example 1.

[0131] The water vapor barrier properties (WVTR), oxygen barrier properties (OTR), and interlayer adhesion (peel strength) of the obtained laminates were evaluated. The evaluation results are shown in Table 1.

[0132] [Table 1] .

[0133] The laminates of Examples 1-19 exhibit high interlayer tightness. Furthermore, the laminates of Examples 1-19 also exhibit high oxygen barrier properties and sufficiently high water vapor barrier properties.

[0134] On the other hand, the interlayer adhesion of the laminates in Comparative Examples 1 to 3, where the resin layer (1) does not contain PVOH, is low. Furthermore, the laminate in Reference Example 1, where the resin layer (2) does not contain layered inorganic matter (2), has low oxygen barrier properties but high interlayer adhesion. It can be confirmed that the problem of low interlayer adhesion is a significant issue when the resin layer (2) containing PVOH contains layered inorganic matter.

[0135] Industrial practicality The laminate of the present invention can be suitably used as packaging material for oil-resistant paper, gas barrier paper, odor barrier paper, etc.

Claims

1. A laminate having a substrate, a resin layer (1) and a resin layer (2), the resin layer (1) being adjacent to the resin layer (2), the resin layer (1) containing a water-dispersible polymer and a polymer (1), the resin layer (2) containing a vinyl alcohol polymer (2) and a layered inorganic substance (2), wherein the polymer (1) is selected from at least one of vinyl alcohol polymers (1) and urethane polymers.

2. The laminated body according to claim 1, wherein, The water-dispersible polymer is selected from at least one of olefin polymers and styrene polymers.

3. The laminate according to claim 1 or 2, wherein, The viscosity-average degree of polymerization of the vinyl alcohol polymer (1) is above 200 and below 5000.

4. The laminate according to claim 1 or 2, wherein, The degree of saponification of the vinyl alcohol polymer (1) is above 70 mol% and below 100 mol%.

5. The laminate according to claim 1 or 2, wherein, The content of polymer (1) in the resin layer (1) is more than 0.1 parts by mass and less than 50 parts by mass relative to 100 parts by mass of the water-dispersible polymer.

6. The laminate according to claim 1 or 2, wherein, The resin layer (1) also contains layered inorganic material (1) with an aspect ratio of 500 or more.

7. The laminate according to claim 6, wherein, The content of layered inorganic matter (1) in the resin layer (1) is more than 1 part by mass and less than 50 parts by mass relative to 100 parts by mass of the water-dispersible polymer.

8. The laminate according to claim 1 or 2, wherein, The resin layer (1) also contains cationic polymers.

9. The laminate according to claim 1 or 2, wherein, The aspect ratio of the layered inorganic material (2) is 500 or more.

10. The laminate according to claim 1 or 2, wherein, The content of layered inorganic matter (2) in the resin layer (2) is more than 1 part by mass and less than 30 parts by mass relative to 100 parts by mass of the vinyl alcohol polymer (2).

11. The laminate according to claim 1 or 2, wherein, The outermost layer is a sealing layer containing at least one polymer selected from olefin polymers and styrene polymers (3).

12. The laminate according to claim 1 or 2, wherein, The substrate is paper.