Laminated film and method for manufacturing the same

Abstract

To provide a laminated film which prevents cracks on a vapor-deposited film even when stored under high humidity, is excellent in gas barrier property, and is also excellent in adhesion between a base material layer and the vapor-deposited film, and a method for manufacturing the same.SOLUTION: A laminated film includes a base material layer, a first layer stacked on at least one surface of the base material layer, and a second layer stacked on the first layer, wherein the base material layer contains a thermoplastic resin, the first layer contains a polyvinyl alcohol-based resin (A), and an inorganic laminar compound (B), the second layer is a vapor-deposited film containing at least one selected from metal and a metal oxide as a main component, and a ratio of the inorganic laminar compound (B) in the first layer is more than 0 mass% and less than 40 mass%.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to a laminated film and a method for manufacturing the same.

Background Art

[0002] Conventionally, a gas barrier film has been known in which a laminated film having gas barrier properties is formed on a base film to prevent permeation of oxygen, water vapor, etc. As such a laminated film, for example, an inorganic oxide vapor deposition film such as alumina or silica, or a resin layer such as polyvinyl alcohol (PVA) or ethylene-vinyl alcohol copolymer is used.

[0003] Since the gas barrier film can suppress deterioration of the contents due to oxygen and water vapor, it is used as a packaging material in various fields such as food, pharmaceuticals, and electronic devices. As the base material of the gas barrier film for packaging materials in this field, a stretched film having properties such as water resistance and transparency is often used. However, a laminated film in which a vapor deposition film is laminated on a stretched film has a problem that cracks are likely to occur in the vapor deposition film when stored under high humidity, thereby reducing the gas barrier properties.

[0004] For example, Patent Document 1 proposes improving the adhesion between a vapor deposition film and a multilayer base material by using a multilayer base material including a stretched polypropylene resin layer and a resin material having a polar group as a coating layer, thereby improving the gas barrier properties. Further, Patent Document 2 proposes improving the gas barrier properties by forming an alumina hydroxide region in the vicinity of the interface between a plastic film and an aluminum vapor deposition interface in a barrier film in which a base material made of a plastic film, an aluminum oxide vapor deposition film, and an organic coating layer are laminated in this order, and forming an aluminum oxide region on this alumina hydroxide region.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2021-024136 [Patent Document 2] Japanese Patent Application Laid-Open No. 2022-000345 [Summary of the Invention] [Problems to be Solved by the Invention]

[0006] Both Patent Documents 1 and 2 improve the gas barrier properties by enhancing the adhesion between the base material and the vapor deposition film, but no consideration has been given to suppressing the cracks in the vapor deposition film itself.

[0007] In view of the above circumstances, the present application has been made, and an object thereof is to provide a laminated film that does not crack in the vapor deposition film even when stored under high humidity conditions, has excellent gas barrier properties, and also has excellent adhesion between the base material layer and the vapor deposition film, and a method for producing the same. [Means for Solving the Problems]

[0008] As a result of intensive studies, the inventors of the present application have found that a laminated film, which comprises a base material layer, a first layer laminated on at least one surface of the base material layer, and a second layer laminated on the first layer, wherein the base material layer contains a thermoplastic resin, the first layer contains a polyvinyl alcohol-based resin (A) and an inorganic layered compound (B), the second layer is a vapor deposition film containing at least one selected from metals and metal oxides as a main component, and the proportion of the inorganic layered compound (B) in the first layer is more than 0% by mass and less than 40% by mass, can solve the above-described problems. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide a laminated film that does not crack in the vapor deposition film even when stored under high humidity conditions, has excellent gas barrier properties, and also has excellent adhesion between the base material layer and the vapor deposition film, and a method for producing the same. [Modes for Carrying Out the Invention]

[0010] Hereinafter, although one embodiment of the present disclosure will be described in detail, the scope of the present disclosure is not limited to the one embodiment described here, and various changes can be made without departing from the spirit of the present disclosure. Each aspect disclosed in this specification can be combined with any other features disclosed in this specification. Also, when a plurality of upper limit values and lower limit values are described for a specific parameter, any upper limit value and lower limit value among these can be combined to form a suitable numerical range. Further, the lower limit value and / or upper limit value of the numerical range described in the present disclosure are numerical values within that numerical range and may be replaced with the numerical values shown in the examples. The expression "X~Y" indicating a numerical range means "X or more and Y or less". Also, unless otherwise noted, all test temperatures are room temperature (20°C ± 5°C). When the specific description given for one embodiment also applies to other embodiments, the description may be omitted in other embodiments.

[0011] Each configuration and their combinations, etc. in each embodiment are examples, and within the scope not departing from the gist of the present disclosure, addition, omission, substitution, and other changes of the configuration can be made as appropriate. The present disclosure is not limited by the embodiments. Each aspect disclosed in this specification can be combined with any other features disclosed in this specification.

[0012] [Laminated Film] The first embodiment of the present disclosure relates to a laminated film. The first embodiment is a laminated film, and the laminated film includes a base material layer, a first layer laminated on at least one surface of the base material layer, and a second layer laminated on the first layer. The base material layer contains a thermoplastic resin, the first layer contains a polyvinyl alcohol-based resin (A) and an inorganic layered compound (B), the second layer is a vapor deposition film mainly containing at least one selected from metals and metal oxides, and the proportion of the inorganic layered compound (B) in the first layer is more than 0% by mass and less than 40% by mass. According to the laminated film according to the first embodiment, by laminating a specific first layer and a second layer on a base material layer containing a thermoplastic resin, cracks do not occur in the vapor deposition film even when stored under high humidity conditions, and high gas barrier properties can be achieved.

[0013] <Base material layer> The base material layer contains a thermoplastic resin. That is, the base material layer is composed of a resin composition containing a thermoplastic resin. Examples of the thermoplastic resin include polyolefin resins (such as polyethylene and polypropylene), polyester resins (such as polyethylene naphthalate and polyethylene terephthalate), polyamide resins (such as nylon-6 and nylon-66), polystyrene, ethylene-vinyl alcohol copolymer resins, polyvinyl chloride, polyimide, polyvinyl alcohol, polycarbonate, polyethersulfone, acrylic resins, and cellulose resins (such as triacetyl cellulose and diacetyl cellulose). These thermoplastic resins may be used alone or in combination of two or more. Among these, it is preferable that the base material layer contains a polyolefin resin, and it is more preferable that the base material layer contains a polypropylene resin.

[0014] Polypropylene-based resins are excellent in heat resistance, oil resistance, chemical resistance, strength, rigidity, etc. The polypropylene-based resin may be a homopolymer of propylene or a copolymer of propylene and other monomers. Examples of other monomers include α-olefins such as ethylene, 1-butene, 1-hexene, 1-octene, 3-methylpentene, and 4-methylpentene. The polypropylene-based resin may also be a copolymer combining two or more other monomers with propylene. When the base material layer contains the copolymer, preferably, as a monomer component, it contains 80% by mass or more of polypropylene, more preferably 90% by mass or more, still more preferably 95% by mass or more, and particularly preferably 98% by mass or more. In an embodiment where the base material layer contains only a homopolymer of propylene as the thermoplastic resin, the effects of the present disclosure can be obtained more significantly.

[0015] Also, the polypropylene-based resin may have an atactic structure, an isotactic structure, a syndiotactic structure, or a metallocene structure.

[0016] In one embodiment, the base material layer is preferably a film obtained by forming a resin composition containing a thermoplastic resin. More preferably, it is a film composed of a polyolefin-based resin, and particularly preferably a polypropylene-based resin film composed of a polypropylene-based resin. This film may be a uniaxially stretched film, a biaxially stretched film, or an unstretched film. Also, the base material layer may be composed of a single-layer film or a laminate of two or more films.

[0017] In the resin composition constituting the base material layer, known additives such as antioxidants, weather stabilizers, heat stabilizers, lubricants, crystal nucleating agents, ultraviolet absorbers, colorants, antiblocking agents, etc. can be included as long as the effects of the present disclosure are not inhibited. For example, for the purpose of improving the water vapor barrier property of the base material layer, at least one resin selected from petroleum resins and terpene resins may be blended. When the base material layer contains these resins, the total content thereof may be 1% by mass or more, 2% by mass or more, 15% by mass or less, or 10% by mass or less based on the total mass of the resin composition constituting the base material layer.

[0018] Also, for the purpose of improving the adhesion between the base material layer and the first layer, corona discharge treatment, plasma treatment, etc. may be performed on the surface of the base material layer. If necessary, corona discharge treatment or plasma treatment may be performed on the surface where the first layer is not laminated (non-coated surface side).

[0019] The thickness of the base material layer is not particularly limited and can be appropriately set according to the use of the obtained laminated film. In one embodiment, the thickness of the base material layer may be 5 μm or more, 10 μm or more, or 15 μm or more. Also, the upper limit of the thickness of the base material layer may be 100 μm or less, 90 μm or less, or 80 μm or less. In a particularly preferred embodiment, the base material layer is an OPP film with a thickness of 5 to 80 μm.

[0020] <The first layer> The first layer is laminated on at least one surface of the base material layer. The first layer may be laminated on both surfaces of the base material layer. Also, the first layer may be laminated on the surface of the base material layer that has been subjected to corona discharge treatment or plasma treatment. The first layer contains a polyvinyl alcohol-based resin (A) and an inorganic layered compound (B). That is, the first layer is composed of a resin composition containing a polyvinyl alcohol-based resin (A) (hereinafter, may also be simply referred to as "resin (A)") and an inorganic layered compound (B).

[0021] (Polyvinyl alcohol-based resin (A)) In the first embodiment, the first layer contains a polyvinyl alcohol-based resin (A). In the present disclosure, the "polyvinyl alcohol-based resin" refers to a polymer or copolymer containing monomer units derived from vinyl alcohol. Preferably, the resin (A) contains at least one selected from a polyvinyl alcohol resin (A1), a polyvinyl alcohol-based crosslinked resin (A2) containing a hydrazone bond, and an olefin-modified polyvinyl alcohol-based resin (A3).

[0022] [Polyvinyl alcohol resin (A1)] In the first embodiment, the resin (A) can contain a polyvinyl alcohol resin (A1) (hereinafter, sometimes simply referred to as "resin (A1)"). The resin (A1) is a polymer mainly containing vinyl alcohol units. Here, "main component" means containing 80 mol% or more, preferably 85 mol% or more, more preferably 90 mol% or more, and still more preferably 95 mol% or more of the component. In one embodiment, as the resin (A1), PVA with a saponification degree of 90 mol% or more is preferable, PVA with a saponification degree of 95 mol% or more is more preferable, and PVA with a saponification degree of 98 mol% or more is still more preferable. Also, the degree of polymerization of the resin (A1) is preferably 200 or more, more preferably 250 or more, and still more preferably 300 or more. Also, the upper limit of the degree of polymerization is preferably 5000 or less, more preferably 4000 or less, and still more preferably 3000 or less. If the degree of polymerization of the resin (A1) is within the above range, the water resistance and film strength of the first layer are likely to be improved. Also, cracks in the second layer (vapor deposition film) can be more effectively suppressed. In one embodiment, as the resin (A1), those with a degree of polymerization of 300 to 3000 may be used. The resin (A1) may be used alone or in combination of two or more.

[0023] In one embodiment, when the first layer contains the resin (A1), it can be arbitrarily adjusted within the range of 60% by mass or more and less than 100% by mass with respect to the total mass of the resin composition constituting the first layer. In one embodiment, the first layer may contain only the resin (A1) and the inorganic layered compound (B). When the first layer contains only the resin (A1) and the inorganic layered compound (B), the proportion of the resin (A1) in the first layer is preferably 90 to 99% by mass from the viewpoint that cracks are less likely to occur in the second layer even when stored under high humidity conditions, and the gas barrier property and the laminate strength are likely to be good.

[0024] Commercially available products may be used as the resin (A1). Examples of commercially available products include fully saponified polyvinyl alcohol resins manufactured by Kuraray Co., Ltd., product names such as "Kuraray Poval (registered trademark) 3-98", "Kuraray Poval 5-98", "Kuraray Poval 28-98", etc.

[0025] [Polyvinyl alcohol-based crosslinked resin (A2) containing a hydrazone bond] In the first embodiment, the resin (A) can include a polyvinyl alcohol-based crosslinked resin (A2) containing a hydrazone bond (hereinafter, may also be simply referred to as "resin (A2)"). The resin (A2) is a resin including a network structure in which two or more polymer chains containing vinyl alcohol units are bonded by crosslinking. In the first embodiment, the resin (A2) includes a network structure crosslinked by a hydrazone bond. By including a network structure crosslinked by a hydrazone bond, the water resistance, heat resistance, and laminate strength of the first layer are likely to be improved. Further, cracks in the second layer during storage under high humidity can be more effectively suppressed.

[0026] The crosslinked structure in the resin (A2) may be obtained by chemical crosslinking using a crosslinking agent, or may be obtained by irradiation crosslinking (physical crosslinking) such as electron beam or radiation. A crosslinked structure containing a hydrazone bond may be formed by chemical crosslinking and / or irradiation crosslinking.

[0027] In one embodiment, it is preferable that the hydrazone bond in the resin (A2) is obtained by chemical crosslinking. Such a resin (A2) can be obtained by the reaction of a polyvinyl alcohol-based resin having a reactive functional group and a crosslinking agent. Hereinafter, in the present disclosure, a polyvinyl alcohol-based resin having a reactive functional group that can react with a crosslinking agent to form the resin (A2) will be described as "modified PVA (a2)".

[0028] <modified PVA (a2)> The reactive functional group in the modified PVA (a2) preferably contains a carbonyl group. By reacting the carbonyl group present in the molecule of the modified PVA (a2) with a crosslinking agent, a network structure crosslinked by a hydrazone bond can be formed to obtain the resin (A2). That is, the resin (A2) can include a reaction product of a carbonyl group-containing polyvinyl alcohol-based resin (a2-1) and a crosslinking agent (a2-2). When the first layer mainly contains this reaction product, water resistance and heat resistance are particularly likely to be improved. In addition, since the adhesion to the base material layer is further improved, the first layer can also be directly laminated on the base material layer. Here, the "main component" means, as described above, containing 80% by mass or more, preferably 85% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more of the component.

[0029] (carbonyl group-containing polyvinyl alcohol-based resin (a2-1)) The carbonyl group-containing polyvinyl alcohol-based resin (a2-1) (hereinafter, may also be simply referred to as "resin (a2-1)") only needs to have an active carbonyl group capable of forming a hydrazone bond, and its physical properties and structure are not particularly limited. Examples of such a carbonyl group include a carbonyl group such as vinyl ketones; a diketo group such as a cetyl acetonato group; a diacetone group such as a diacetone acrylamide group. Among these, a polyvinyl alcohol resin containing a diacetone group is preferable, and a diacetone acrylamide-modified polyvinyl alcohol-based resin is more preferable. The resin (a2-1) may be obtained by carbonyl-modifying a polyvinyl alcohol-based resin (including the above resin (A1)), or may be obtained by copolymerizing a monomer having a carbonyl group. Note that the resin (a2-1) may be used alone or in combination of two or more.

[0030] As long as the effects of the present disclosure can be obtained, the content of the carbonyl group in the resin (a2-1) is not particularly limited. In one embodiment, the content of the structural unit having a carbonyl group may be 0.01 mol% or more, 0.05 mol% or more, 0.1 mol% or more, or 1.0 mol% or more with respect to the total (100 mol%) of all the structural units of the resin (a2-1). The upper limit may be 25 mol% or less, 20 mol% or less, or 15 mol% or less. The "structural unit having a carbonyl group" means, for example, a "diacetone acrylamide unit" in the case of a diacetone acrylamide-modified polyvinyl alcohol-based resin.

[0031] In one embodiment, the degree of polymerization of the resin (a2-1) may be 200 or more, 250 or more, or 300 or more. The upper limit of the degree of polymerization may be 5000 or less, 4000 or less, or 3000 or less. If the degree of polymerization of the resin (a2-1) is within the above range, the water resistance and film strength of the first layer containing the reaction product of the resin (a2-1) and the crosslinking agent are likely to be improved. In addition, cracks in the second layer (vapor deposition film) can be more effectively suppressed. In one embodiment, as the resin (a2-1), those having a degree of polymerization of 500 to 2000 may be used. In one embodiment, the saponification degree of the resin (a2-1) may be 90 mol% or more, or 95 mol% or more.

[0032] (Crosslinking agent (a2-2)) The crosslinking agent (a2-2) is not particularly limited as long as it is a compound containing a functional group having reactivity with a carbonyl group. Examples of such functional groups include a hydrazide group and an amino group. Among these, a compound containing two or more functional groups in one molecule is preferred.

[0033] For example, crosslinking agents containing a plurality of hydrazide groups include hydrazine, hydrazine hydrate, carbohydrazide, polyhydrazide compounds of polyvalent carboxylic acids, poly(meth)acrylic acid hydrazide, and the like. Further, derivatives obtained by reacting these compounds with ketones such as acetone and methyl ethyl ketone may also be used.

[0034] Among these, as the crosslinking agent (a2-2), a polyhydrazide compound of polyvalent carboxylic acid is preferably used. The polyhydrazide compound of polyvalent carboxylic acid may be a dibasic acid dihydrazide or a polyhydrazide of polyvalent carboxylic acid.

[0035] Examples of the dibasic acid dihydrazide include C2-C20 alkane dicarboxylic acid dihydrazides such as oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, pimelic acid dihydrazide, suberic acid dihydrazide, azelaic acid dihydrazide, sebacic acid dihydrazide, dodecanedioic acid dihydrazide, hexadecanoic acid dihydrazide; C4-C10 cycloalkane dicarboxylic acid dihydrazides such as cyclohexanedicarboxylic acid dihydrazide; C6-C16 arenedicarboxylic acid dihydrazides such as phthalic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide, naphthoic acid dihydrazide; heterocyclic dicarboxylic acid dihydrazides such as pyridinedicarboxylic acid dihydrazide; dibasic oxyacid dihydrazides such as malic acid dihydrazide, tartaric acid dihydrazide; iminodiacetic acid dihydrazide, and the like. Examples of the polyhydrazide of polyvalent carboxylic acid include cyclohexanetricarboxylic acid trihydrazide, benzenetricarboxylic acid trihydrazide, pyromellitic acid tetrahydrazide, citric acid trihydrazide, ethylenediaminetetraacetic acid tetrahydrazide, and the like.

[0036] The crosslinking agent (a2-2) may be a combination of two or more of the above-mentioned polyvalent carboxylic acid polyhydrazide compounds. From the viewpoint of low environmental impact, a water-soluble or water-dispersible crosslinking agent is preferred. As the water-soluble or water-dispersible crosslinking agent, among the above-mentioned C2-C20 alkanedicarboxylic acid dihydrazides, C4-C7 alkanedicarboxylic acid dihydrazides are preferred. Among these, from the viewpoint of reactivity with the resin (a2-1), adipic acid dihydrazide is preferably used.

[0037] The content of the crosslinking agent (a2-2) can be appropriately changed within the range in which the effects of the present disclosure can be obtained. By increasing the content of the crosslinking agent (a2-2), the crosslinking density of the resin (A2) can be increased. When such a resin (A2) is included, cracks in the second layer are more easily suppressed. Also, the interlayer adhesion between the base material layer and the second layer is likely to be improved, and a laminated film excellent in laminate strength is easily obtained. From these viewpoints, the content of the crosslinking agent (a2-2) is preferably 1.0% by mass or more, more preferably 5.0% by mass or more, based on the total mass of the resin composition containing the resin (a2-1). The upper limit is preferably 20.0% by mass or less, more preferably 15.0% by mass or less.

[0038] In one embodiment, when the first layer contains the resin (A2), it can be arbitrarily adjusted within the range of 60% by mass or more and less than 100% by mass of the resin (A2) with respect to the total mass of the resin composition constituting the first layer. Here, the ratio of the resin (A2) in the resin composition constituting the first layer can be the total amount of the modified PVA (a2) (preferably the resin (a2-1)) and the crosslinking agent (a2-2). In one embodiment, the first layer may contain only the resin (A2) and the inorganic layered compound (B). When the first layer contains only the resin (A2) and the inorganic layered compound (B), the ratio of the resin (A2) in the first layer is preferably 90 to 99% by mass from the viewpoint that cracks are less likely to occur in the second layer even when stored under high humidity, and the gas barrier property and laminate strength are also likely to be good. Also, the ratio of the resin (A2) may be 90 to 95% by mass, or may be 95 to 99% by mass.

[0039] [Olefin-modified polyvinyl alcohol resin (A3)] In the first embodiment, the resin (A) can include an olefin-modified polyvinyl alcohol resin (A3) (hereinafter, may be simply referred to as "resin (A3)"). The resin (A3) is a resin containing units derived from olefins and vinyl alcohol units. In one embodiment, the degree of polymerization of the resin (A3) may be 200 or more, may be 250 or more, and may be 300 or more. The upper limit of the degree of polymerization may be 5000 or less, may be 4000 or less, and may be 3000 or less. If the degree of polymerization of the resin (A3) is within the above range, the water resistance and film strength of the first layer are likely to be improved. In addition, cracks in the second layer (vapor deposition film) can be more effectively suppressed. In one embodiment, as the resin (A3), those having a degree of polymerization of 400 to 3000 may be used.

[0040] In one embodiment, the saponification degree of the resin (A3) may be 90 mol% or more, and may be 95 mol% or more.

[0041] Examples of the units derived from olefins contained in the resin (A3) include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-pentene, 4-methyl-1-pentene, etc. The resin (A3) may contain one or more of these units derived from olefins. Among these, from the viewpoint of water resistance, the resin (A3) preferably contains an ethylene-modified polyvinyl alcohol resin (a3). The content of ethylene in the ethylene-modified polyvinyl alcohol resin (a3) (hereinafter, may be simply referred to as "resin (a3)") may be 1 mol% or more, and may be 2 mol% or more with respect to the total of all constitutional units of the resin (a3) (100 mol%). The upper limit may be 15 mol% or less, and may be 12 mol% or less.

[0042] In one embodiment, when the first layer contains the resin (A3), the proportion of the resin (A3) can be arbitrarily adjusted within the range of 60% by mass or more and less than 100% by mass with respect to the total mass of the resin composition constituting the first layer. In one embodiment, the first layer may contain only the resin (A3) and the inorganic layered compound (B). When the first layer contains only the resin (A3) and the inorganic layered compound (B), the proportion of the resin (A3) in the first layer is preferably 90 to 99% by mass from the viewpoint that cracks are less likely to occur in the second layer even when stored under high humidity, and the gas barrier property and the laminate strength are also likely to be good. Further, the proportion of the resin (A3) may be 90 to 95% by mass, or may be 95 to 99% by mass.

[0043] As described above, the resin (A) can contain at least one resin selected from the resins (A1), (A2), and (A3). In a preferred embodiment, the resin (A) contains any one of the resins (A1), (A2), or (A3). In a more preferred embodiment, the resin (A) contains the resin (A1).

[0044] When the resin (A) contains two or more resins selected from the resins (A1), (A2), and (A3), the blending ratio can be arbitrarily set within a range that does not inhibit the effects of the present disclosure. For example, when the resin (A) contains the resin (A2) and the resin (A3), the proportion of the resin (A3) (resin (A3) / (resin (a2)+resin (A3))×100) with respect to the total (100% by mass) of the resin (a2) (preferably resin (a2-1)) forming the resin (A2) and the resin (A3) (preferably resin (a3)) may be 10 to 60% by mass, may be 10 to 50% by mass, may be 20 to 60% by mass, or may be 20 to 50% by mass. By mixing the resin (a2) (preferably (a2-1)) and the resin (A3) (preferably resin (a3)) at such a ratio, it becomes easier to obtain a laminated film with excellent interlayer adhesion and improved water resistance, particularly stability against hot water.

[0045] In the resin composition constituting the first layer, any modified PVA resin other than the aforementioned resin component and crosslinking agent, and known additives such as adhesives, antioxidants, colorants, heat stabilizers, etc. can be included as long as the effects of the present disclosure are not inhibited.

[0046] Examples of the optional modified PVA resin include polyvinyl alcohol-based resins containing amino groups, carboxyl groups, silanol groups, etc., and one or more of these may be blended.

[0047] The thickness of the first layer may be 0.2 μm or more, may be 0.3 μm or more, may be 0.4 μm or more, and the upper limit of the thickness may be 5.0 μm or less, may be 4.5 μm or less. The thickness of the first layer can be adjusted by the concentration and coating amount of the coating agent described later. From the viewpoint of suppressing cracks in the second layer and improving the gas barrier property during storage under high humidity, the thickness of the first layer is preferably 0.1 μm or more.

[0048] <Inorganic layered compound (B)> In the first embodiment, the first layer includes an inorganic layered compound (B) together with the aforementioned resin (A). By combining the resin (A) and the inorganic layered compound (B), cracks in the second layer during storage under high humidity can be effectively suppressed. Also, the gas barrier property and laminate strength. In the present disclosure, the "inorganic layered compound" means an inorganic compound in which unit crystal layers are stacked to form a layered structure.

[0049] The inorganic layered compound (B) preferably includes a swellable inorganic layered compound (B1). The swellable inorganic layered compound (B1) refers to an inorganic compound having a structure in which unit crystal layers are stacked and exhibiting the property of swelling or exfoliating by coordinating or absorbing a solvent (especially water) between the layers. Examples of such inorganic compounds include swellable hydrous silicates, such as smectite group clay minerals (montmorillonite, beidellite, nontronite, saponite, hectorite, sauconite, stibnite, etc.), vermiculite group clay minerals (vermiculite, etc.), kaolin-type minerals (halloysite, kaolinite, endellite, dickite, etc.), phyllosilicates (talc, pyrophyllite, mica, margarite, muscovite, phlogopite, tetrasilicic mica, teniolite, etc.), jamontite group minerals (antigorite, etc.), chlorite group minerals (chlorite, cookeite, nantait, etc.). These swellable inorganic layered compounds (B1) may be natural products or synthetic products. The laminated film according to the first embodiment may contain one kind alone or two or more kinds of the above-described swellable inorganic layered compound (B1) in the first layer. Among these swellable inorganic layered compounds (B1), it is preferable to contain smectite group clay minerals, and particularly preferably to contain montmorillonite.

[0050] From the viewpoints of crack suppression in the second layer and adhesion between the base material layer and the second layer, the swellable inorganic layered compound (B1) is preferably subjected to a micronization treatment. The micronized swellable inorganic layered compound usually has a plate-like or flat shape, but its planar shape is not particularly limited and may be amorphous or the like. From the viewpoint of more easily obtaining the crack suppression effect in the second layer, the average particle diameter (average particle diameter of the planar shape) of the micronized swellable inorganic layered compound (B1) is 0.01 to 5 μm, preferably 0.1 to 3 μm, and more preferably about 0.5 to 2 μm. The average particle diameter of the swellable inorganic layered compound (B1) can be measured by a laser diffraction method or the like.

[0051] When using a micronized swellable inorganic layered compound (B1), it is preferable that the micronization treatment is a high-pressure dispersion treatment of the swellable inorganic layered compound (B1) in a solution. Examples of the solvent include water or water-soluble solvents (such as lower alcohols like methanol and ethanol, and acetone). Usually, water is used. The treatment pressure in the high-pressure dispersion treatment is, for example, 20 MPa (about 200 kgf / cm 2 ) or higher (for example, 20 to 100 MPa), preferably about 20 to 80 MPa, and more preferably about 40 to 60 MPa. Examples of the treatment method include a method of high-pressure dispersion by swelling the swellable inorganic layered compound (B1) in a solvent and then stirring at the above-described pressure with a high-pressure homogenizer. Such high-pressure dispersion treatment is performed a plurality of times (for example, 2 to 10 times), preferably 2 to 7 times, and more preferably about 2 to 5 times.

[0052] The inventors of the present application have found that by including a specific resin (A) and an inorganic layered compound (B) in the first layer and controlling the blending amount of the inorganic layered compound (B) within a specific range, the excellent adhesion between the base material layer and the second layer is maintained while the stability against moisture is improved. That is, in the laminated film according to the first embodiment, the ratio of the inorganic layered compound (B) contained in the first layer is more than 0% by mass and less than 40% by mass with respect to the total mass of the resin composition constituting the first layer. The lower limit of the ratio of the inorganic layered compound (B) is preferably 1.0% by mass or more, more preferably 2.0% by mass or more, and even more preferably 3.0% by mass or more. Also, the upper limit of the ratio of the inorganic layered compound (B) is preferably 35% by mass or less, more preferably 30% by mass or less, even more preferably 25% by mass or less, and particularly preferably 20% by mass or less. In one embodiment, from the viewpoint of easily achieving all of crack suppression, gas barrier properties, and laminate strength of the second layer during storage under high humidity, the ratio of the inorganic layered compound (B) in the first layer may be 1.0 to 20% by mass.

[0053] <Second layer> The second layer is formed by laminating on the first layer. If necessary, another layer may be further laminated on the second layer.

[0054] The second layer is a vapor deposition film containing at least one selected from metals and metal oxides as a main component. As the metal contained in the second layer, aluminum is preferable. Examples of the metal oxide include aluminum oxide, silicon oxide, magnesium oxide, tin oxide, etc. Among these, the second layer is preferably a vapor deposition film containing at least one selected from aluminum, aluminum oxide, and silicon oxide as a main component, and particularly preferably a vapor deposition film containing aluminum or aluminum oxide as a main component. In the present disclosure, aluminum oxide may be AlO x (0 < x ≤ 1.5), and silicon oxide may be SiO x (0 < x ≤ 2.0). As long as the effects of the present disclosure are not inhibited, the second layer may contain other elements other than aluminum and silicon.

[0055] From the viewpoint of the gas barrier property of the laminated film and the suppression of cracks under high humidity conditions, the thickness of the second layer is preferably 3 nm or more, more preferably 10 nm or more, and even more preferably 30 nm or more. Also, the upper limit is preferably 300 nm or less, and more preferably 100 nm or less. The thickness of the second layer can be adjusted according to the vapor deposition conditions described later.

[0056] The second layer mainly composed of a metal and / or a metal oxide is excellent in oxygen barrier property and water vapor barrier property. The oxygen permeability of the laminated film according to the first embodiment at 20°C / 0%RH measured according to JIS K7126-2 is 1.0 cc / m 2 ·day or less is preferable, and 0.9 cc / m 2 ·day or less is more preferable. In one embodiment, the oxygen permeability of the laminated film at 20°C / 0%RH measured according to JIS K7126-2 may be 0.5 cc / m 2 ·day or less.

[0057] Also, the oxygen permeability of the laminated film according to the first embodiment at 20°C / 90%RH measured according to JIS K7126-2 is 5.0 cc / m 2·day or less is preferable. In one embodiment, the oxygen permeability under the high humidity condition is 4.0 cc / m 2 ·day or less, may be 3.0 cc / m 2 ·day or less, may be 2.0 cc / m 2 ·day or less, may be 1.0 cc / m 2 ·day or less.

[0058] Also, the water vapor permeability of the laminated film according to the first embodiment measured at 40 °C / 90% RH according to JIS K7129-2 is 3.0 g / m 2 ·day or less is preferable, 2.0 g / m 2 ·day or less is preferable, 1.5 g / m 2 ·day or less is more preferable. In one embodiment, the water vapor permeability of the laminated film measured at 40 °C / 90% RH according to JIS K7129-2 is 1.0 g / m 2 ·day or less.

[0059] An anchor coat layer may be formed between the base material layer and the first layer in the laminated film according to the first embodiment. The anchor coat layer can be formed by applying an anchor coat agent to the base material layer. The anchor coat layer is preferably formed when the first layer contains the resin (A1) and / or the resin (A3).

[0060] The anchor coat agent is not particularly limited as long as it can bond the base material layer and the first layer. For example, a urethane resin obtained by reacting an isocyanate group-containing polymer and a hydroxyl group-containing polymer; an imino group-containing polymer such as polyethyleneimine; a polyester resin; an olefin resin such as ethylene-(meth)acrylic acid copolymer; a rubber-based adhesive; known adhesive materials such as coupling agents can be appropriately selected and used. Also, two or more adhesive materials may be combined as the anchor coat agent.

[0061] In one embodiment, any of the above-described various adhesive materials may be blended as a constituent component of the first layer as an anchor coating agent. When blending the adhesive material as a constituent component of the first layer, the addition amount thereof may be 1 part by mass or more, and may be 10 parts by mass or more with respect to 100 parts by mass of the resin (A). Further, the upper limit thereof may be 20 parts by mass or less, and may be 15 parts by mass or less.

[0062] When providing an anchor coating layer between the base material layer and the first layer, the thickness of the anchor coating layer is not particularly limited. For example, the thickness of the anchor coating layer may be 0.01 μm or more, and may be 0.02 μm or more. Further, the upper limit thereof may be 3.0 μm or less, and may be 2.5 μm or less.

[0063] A preferred embodiment of the laminated film includes a base material layer, an anchor coating layer laminated on at least one surface of the base material layer, a first layer laminated on the anchor coating layer, and a second layer laminated on the first layer, wherein the first layer contains a polyvinyl alcohol resin (A1) and / or an olefin-modified polyvinyl alcohol-based resin (A3) and an inorganic layered compound (B), and the proportion of the inorganic layered compound (B) in the first layer is 1% by mass or more and less than 40% by mass, and the second layer is a vapor deposition film containing aluminum and / or aluminum oxide. Another preferred embodiment includes a base material layer, a first layer directly laminated on at least one surface of the base material layer, and a second layer laminated on the first layer, wherein the first layer contains a polyvinyl alcohol-based crosslinked resin (A2) containing a hydrazone bond and an inorganic layered compound (B), and the proportion of the inorganic layered compound (B) in the first layer is 1% by mass or more and less than 40% by mass, and the second layer is a vapor deposition film containing aluminum and / or aluminum oxide.

[0064] [Use] As described above, the laminated film according to the first embodiment does not crack in the vapor deposition film even when stored under high humidity, and also has excellent gas barrier properties. In addition, the adhesion between the base material layer and the second layer is also good. Such a laminated film can be suitably used, for example, as a film for food packaging. Preferably, it is suitably used for food packaging applications that require retort processing or the like. The laminated film according to the first embodiment also has high water resistance, so the content of volatile components such as moisture can be reduced, resulting in less outgassing during vapor deposition processing and enabling stable vapor deposition processing.

[0065] [Manufacturing method of laminated film] The second embodiment of the present disclosure relates to a manufacturing method of the laminated film according to the first embodiment. The manufacturing method according to the second embodiment includes laminating a first layer on the base material layer (step (1)), and depositing at least one selected from the metal and the metal oxide on the first layer to form the second layer (step (2)). Hereinafter, the details of the manufacturing method according to the second embodiment including steps (1) to (2) will be described.

[0066] [Step (1'): Preparation of coating agent] The manufacturing method according to the second embodiment may include preparing a coating agent (step (1')) before step (1). It is preferable to prepare coating agent (1) or coating agent (2) according to the type of resin (A) contained in the first layer.

[0067] When the resin (A) contained in the first layer contains the resin (A1) and / or the resin (A3), it is preferable to prepare a coating agent (1) containing the resin (A1) and / or the resin (A3) and the inorganic layered compound (B), and the proportion of the inorganic layered compound (B) is more than 0% by mass and less than 40% by mass. When the coating agent (1) contains a solvent described later, the proportion of the inorganic layered compound (B) in the coating agent means the proportion with respect to the total amount of the resin composition excluding the solvent. Further, the proportion of the resin (A1) and / or the resin (A3) in the coating agent (1) (the proportion with respect to the total mass of the resin composition excluding the solvent) can be adjusted to be within the preferable range described in the above-mentioned first embodiment.

[0068] On the other hand, when the resin (A) contained in the first layer contains the resin (A2), it is preferable to prepare a coating agent (2) containing a polyvinyl alcohol-based resin (a2) having a reactive functional group (modified PVA resin (a2)), a crosslinking agent (a2-2), and the inorganic layered compound (B), and the proportion of the inorganic layered compound (B) is more than 0% by mass and less than 40% by mass. The proportion of the inorganic layered compound (B) in the coating agent (2) also means the proportion with respect to the total amount of the resin composition excluding the solvent.

[0069] As the modified PVA resin (a2) contained in the coating agent (2), one or more of the above-mentioned resins can be included, and among them, it is particularly preferable to include the resin (a2-1). Also, as the crosslinking agent (a2-2) contained in the coating agent (2), one or more of the above-mentioned compounds can be blended, and a particularly preferable crosslinking agent (a2-2) is a polyvalent carboxylic acid polyhydrazide compound.

[0070] From the viewpoints of the water resistance and strength of the obtained first layer, the content of the crosslinking agent (a2-2) in the coating agent (2) may be 0.1 part by mass or more, 0.5 part by mass or more, 1.0 part by mass or more, 3.0 part by mass or more, 5.0 part by mass or more with respect to 100 parts by mass of the resin (a2). The upper limit may be 30 parts by mass or less, 20 parts by mass or less, 15 parts by mass or less, 10 parts by mass or less.

[0071] The proportion of the inorganic layered compound (B) in the coating agents (1) to (2) is more than 0% by mass and less than 40% by mass, but can be adjusted to the aforementioned preferred range.

[0072] Further, the coating agents (1) to (2) preferably contain at least one selected from water and water-soluble solvents as a solvent. As the water-soluble solvent, it is preferable to select a solvent capable of dissolving the resin (A1) and / or the resin (A3), or a solvent capable of dissolving the resin (a2) and the crosslinking agent (a2-2). As such a solvent, water or a mixed solvent of water and a water-soluble organic solvent is preferable. Examples of the water-soluble organic solvent include alcohols such as ethanol and isopropanol; cellosolves such as methyl cellosolve; carbitols; and ketones such as acetone. These may be used alone or in combination of two or more. Further, in order to enhance the stability of the coating agents (1) to (2), ammonia, amines, ketones, etc. may be further contained. Also, within a range where the effects of the present disclosure are not inhibited, the coating agents (1) to (2) may contain known additives such as adhesives, antioxidants, colorants, heat stabilizers, etc.

[0073] The coating agents (1) to (2) are prepared by mixing the above-described various components using a known mixer.

[0074] In another embodiment, a coating agent (3) containing the resin (a2) (preferably the resin (a2-1)) and the resin (A3) (preferably the resin (a3)), and the inorganic layered compound (B) can also be prepared. In this case, from the viewpoint of forming the crosslinked structure of the resin (A2) contained in the first layer, the mixing ratio of the resin (a2) and the resin (A3) may be 90:10 to 40:60, 80:20 to 50:50, or 80:20 to 60:40 in terms of mass ratio ((a2):(A3)). Note that the coating agent (3) preferably further contains a crosslinking agent (a2-2).

[0075] <Step (1): Lamination of the first layer> Step (1) is a step of laminating a first layer on a base material layer. As a method for laminating the first layer, it is preferable that the above-described coating agent is applied to the base material layer. As the base material layer to which the coating agent is applied, it is preferable to employ the above-described film. In a particularly preferred embodiment, the base material layer is a polypropylene-based resin film.

[0076] Step (1) preferably includes forming an anchor coat layer on at least one surface of the base material layer and then forming the first layer on the anchor coat layer (step (1-1)), or directly laminating the first layer on the base material layer (step (1-2)).

[0077] When the first layer contains resin (A1) and / or resin (A3) as resin (A), it is preferable to perform step (1-1). When the first layer contains resin (A2), it is preferable to perform step (1-2).

[0078] (Step (1-1)) Step (1-1) is to form an anchor coat layer on at least one surface of the base material layer and then form the first layer on the anchor coat layer. When the first layer contains resin (A1) and / or resin (A3), it is preferable to apply the above-described coating agent (1) on the surface of the anchor coat layer to form the first layer. As the anchor coat agent, the materials described in the above-described first embodiment can be preferably used. Also, the thickness of the anchor coat layer can be within the preferred range described in the above-described first embodiment. In one embodiment, before forming the anchor coat layer on the base material layer, step (1-1) may optionally subject at least one surface of the base material layer (including the surface on the side where the anchor coat layer is provided) to corona discharge treatment or plasma treatment. Also, when resin (A) contains resin (A2), a first layer containing the resin (A2) may be formed on the anchor coat layer. In this case, the above-described coating agent (2) can be applied on the anchor coat layer to form the first layer on the anchor coat layer.

[0079] (Step (1-2)) Step (1-2) is to directly laminate the first layer on the base material layer. When the first layer contains resin (A2), since the resin (A2) has excellent adhesion to the base material layer, the first layer can be directly laminated on the base material layer.

[0080] In Step (1), the coating amounts of coating agents (1) and (2) can be appropriately selected according to the size of the base material layer, the desired thickness of the first layer, etc. In either case of Step (1-1) or Step (1-2), the coating amounts of coating agents (1) and (2) may be 0.05 g / m 2 or more, and may be 0.3 g / m 2 or more. Also, the upper limit may be 5 g / m 2 or less, and may be 1 g / m 2 or less.

[0081] The method of applying coating agent (1) or (2) on the base material layer or the anchor coat layer is not particularly limited. For example, known methods and apparatuses such as gravure coating, reverse coating, doctor coating, bar coating, dip coating, etc. can be used.

[0082] After Step (1-1) or Step (1-2), it can include heat treatment for drying (Step (1-3)). The temperature of the heat treatment may be, for example, 80°C or higher, may be 90°C or higher, and may be 100°C or higher. Also, the upper limit may be 140°C or lower, and may be 120°C or lower. The time of the heat treatment can be appropriately changed according to the coating amount and temperature.

[0083] In one embodiment, after the heat treatment, an aging treatment may be further performed (step (1-4)). That is, step (1) may include heat-treating the applied coating agent (step (1-3)) and performing an aging treatment (step (1-4)) after performing step (1-1) or step (1-2). The temperature of the aging treatment may be 40°C or higher, and may be 50°C or higher. Also, the upper limit may be 60°C or lower. The time of the aging treatment may be, for example, 1 day or longer.

[0084] <Step (2): Formation of the second layer> After laminating the first layer on the base material layer, at least one selected from metals and metal oxides can be vapor-deposited on the surface of this first layer to form a second layer as a vapor-deposited film. As the metal and / or metal oxide, those described above can be adopted. The vapor deposition method is not particularly limited, and known methods and apparatuses can be used, and it may be a physical vapor deposition method (PVD) or a chemical vapor deposition method (CVD). Examples of the physical vapor deposition method include vacuum vapor deposition method, reactive vapor deposition method, sputtering method, reactive sputtering method, ion plating method, reactive ion plating method, etc. Examples of the chemical vapor deposition method include plasma CVD method, laser CVD method, etc. The vapor deposition conditions may be appropriately selected so that a second layer with a desired thickness can be obtained.

[0085] For the purpose of improving gas barrier properties, preventing cracks, etc., a protective layer may be further formed on the surface of the second layer. That is, step (2) may include forming a protective layer on the surface of the second layer (step (3)). As the protective layer, polyvinyl alcohol resin, ethylene-vinyl alcohol resin, acrylic resin, urethane resin, polyester resin, hydrolyzate of silicon alkoxide, mixture of water-soluble polymer and hydrolyzate of silicon alkoxide, etc. can be used. Particularly from the viewpoint of gas barrier properties, a mixture of a water-soluble polymer and a hydrolyzate of silicon alkoxide is preferable.

[0086] In one embodiment, a sealant layer may be further formed on the second layer or on the protective layer (step (4)). Examples of the sealant layer include the thermoplastic resin described in the base material layer above. Among these, the sealant layer may be a film made of the same polyolefin resin as the base material layer, or a film made of a polypropylene resin.

[0087] According to the manufacturing method according to the second embodiment, a laminated film that does not crack in the vapor deposition film even when stored under high humidity, has excellent gas barrier properties, and also has excellent adhesion between the base material layer and the vapor deposition film can be manufactured.

Examples

[0088] Hereinafter, the effects of the present disclosure will be clarified by examples, but the present disclosure should not be construed in a limited manner based on the description of these examples.

[0089] [Preparation of coating agent] Coating agents 1 to 19 were prepared according to the compounds and formulations shown in Tables 1 to 2. The specific preparation method is as follows. In Tables 1 to 2, the "solid content concentration" means the ratio of the resin composition (including resin (A) and inorganic layered compound (B)) in the coating agent.

[0090] [Coating agent 1] 99 parts by mass of polyvinyl alcohol resin (A1) (polyvinyl alcohol resin manufactured by Kuraray Co., Ltd., product name "Kuraray Poval 3-98") and 1 part by mass of inorganic layered compound (B) (montmorillonite, manufactured by Kunimine Industries Co., Ltd., product name "Kunipia (registered trademark)-G") were added to distilled water, and then stirred and dissolved at 90°C for 1 hour to obtain coating agent 1 (solid content concentration: 5.0% by mass).

[0091] [Coating agents 2 to 9] Coating agents 2 to 7 were obtained in the same manner as coating agent 1, except that the ratio of polyvinyl alcohol resin (A1) to inorganic layered compound (B) and the type of polyvinyl alcohol resin (A1) were as shown in Table 1.

[0092] [Coating Agent 10] 95 parts by mass of resin (a2-1) (a diacetone acrylamide-modified polyvinyl alcohol-based resin manufactured by Nippon Vinyl Poval Co., Ltd., product name "D Polymer DF-05") and 5 parts by mass of inorganic layered compound (B) (montmorillonite) were added to distilled water, and then stirred at 90 °C for 1 hour to dissolve. 5 parts by mass of crosslinking agent (a2-2) (dihydrazide adipate, manufactured by Nippon Fine Chemical Co., Ltd., product name "ADH") was added to this solution and mixed to obtain Coating Agent 10 (solid content concentration: 5.0% by mass). The proportion of the inorganic layered compound (B) in the first layer obtained with Coating Agent 10 is 4.8% by mass.

[0093] [Coating Agent 11] Coating Agent 11 was obtained in the same manner as Coating Agent 10 except that the type of resin (a2-1) was as shown in Table 1. The proportion of the inorganic layered compound (B) in the first layer obtained with Coating Agent 11 is 4.8% by mass.

[0094] [Coating Agent 12] 95 parts by mass of olefin-modified polyvinyl alcohol-based resin (A3) (ethylene-modified polyvinyl alcohol-based resin manufactured by Kuraray Co., Ltd., product name "Exceval (registered trademark) HR-3010") and 1 part by mass of inorganic layered compound (B) (montmorillonite, manufactured by Kunimine Industries Co., Ltd., product name "Kunipia (registered trademark)-G") were added to distilled water, and then stirred at 90 °C for 1 hour to dissolve, thereby obtaining Coating Agent 12 (solid content concentration: 5.0% by mass).

[0095] [Coating Agent 13] Coating Agent 13 was obtained in the same manner as Coating Agent 12 except that the type of resin (A3) was as shown in Table 1.

[0096] [Coating Agents 14 - 19] Coating Agents 14 - 17 were obtained in the same manner as the above Coating Agents 1, 9, 10, 12 except that the inorganic layered compound (B) was not blended. Further, coating agents 18 to 19 were obtained in the same manner as the above coating agent 1, except that the ratio of the inorganic layered compound (B) was as shown in Table 2.

[0097]

Table 1

[0098]

Table 2

[0099] The details of the compounds described in Tables 1 to 2 are as follows. (Resin (A1)) · 3-28: Fully saponified polyvinyl alcohol resin manufactured by Kuraray Co., Ltd., saponification degree: 98 to 99 mol%, 4% viscosity: 3.2 to 3.8 mPa / s (20 °C), degree of polymerization 300. · 5-98: Fully saponified polyvinyl alcohol resin manufactured by Kuraray Co., Ltd., saponification degree: 98 to 99 mol%, 4% viscosity: 5.2 to 6.0 mPa / s (20 °C), degree of polymerization 500. · 28-98: Fully saponified polyvinyl alcohol resin manufactured by Kuraray Co., Ltd., saponification degree: 98 to 99 mol%, 4% viscosity: 25.0 to 31.0 mPa / s (20 °C), degree of polymerization 2800. (Resin (A2): Resin (a2-1)) · DF-05: Diacetoneacrylamide-modified polyvinyl alcohol-based resin manufactured by Nippon Vinyl Alcohol & Poval Co., Ltd., saponification degree: 98 to 99 mol%, 4% viscosity: 6 ± 2 mPa / s, degree of polymerization: 500 · DF-17: Diacetoneacrylamide-modified polyvinyl alcohol-based resin manufactured by Nippon Vinyl Alcohol & Poval Co., Ltd., saponification degree: 98 to 99 mol%, 4% viscosity: 23 ± 3 mPa / s, degree of polymerization: 1700. (Resin (A3)) · HR-3010: Ethylene-modified polyvinyl alcohol-based resin manufactured by Kuraray Co., Ltd., saponification degree: 99 to 99.4 mol%, 4% viscosity: 12.0 to 16.0 mPa / s (20 °C), degree of polymerization 1000. · AQ-4104: Ethylene-modified polyvinyl alcohol-based resin manufactured by Kuraray Co., Ltd., saponification degree: 98 - 99 mol%, 4% viscosity: 3.5 - 4.5 mPa / s (20 °C), degree of polymerization 400. (Inorganic layered compound (B)) · Montmorillonite: Manufactured by Kunimine Industries Co., Ltd., product name "Kunipia - G". (Inorganic compound (B’)) · Silica: Manufactured by Fuji Silysia Chemical Ltd., product name "Silicia (registered trademark) 320". (Crosslinking agent (a2 - 2)) · ADH: Adipic acid dihydrazide manufactured by Nippon Fine Chemical Co., Ltd.

[0100] [Manufacture of laminated film] [Example 1] As the base material layer, a corona-discharge-treated biaxially oriented polypropylene film (thickness 20 μm) was prepared. On the corona-discharge-treated surface of this base material layer, an anchor coat agent (manufactured by Mitsui Chemicals, Inc., product name "A310 / A - 3") was applied in an amount of 0.2 g / m 2 after drying and dried to form an anchor coat layer. On this anchor coat layer, Coating Agent 1 was applied in an amount of 0.5 g / m 2 after drying (the thickness of the first layer is 0.4 μm) and dried at 100 °C for 1 minute to form the first layer. Next, aluminum (Al) was deposited on the surface of the first layer by physical vapor deposition (PVD method) to form a second layer (thickness 40 nm), thereby obtaining the laminated film of Example 1.

[0101] [Examples 2 - 9, 12 - 13] A laminated film was prepared in the same manner as in Example 1, except that the types of coating agents were as shown in Table 3.

[0102] [Example 10] As the base material layer, a corona-discharge-treated biaxially oriented polypropylene film (thickness 20 μm) was prepared. Coating Agent 10 was directly applied on this base material layer in an amount of 0.5 g / m 2It was applied in an amount to result in (the thickness of the first layer being 0.4 μm), and dried at 100°C for 1 minute to form the first layer. Next, aluminum (Al) was vapor-deposited on the surface of the first layer by physical vapor deposition (PVD method) to form a second layer (thickness 40 nm), thereby obtaining the laminated film of Example 10.

[0103] [Example 11] A laminated film was prepared in the same manner as in Example 10, except that the type of the coating agent was as shown in Table 3.

[0104] [Example 14] As the base material layer, a corona-discharge-treated biaxially stretched polypropylene film (thickness 20 μm) was prepared. On the corona-discharge-treated surface of this base material layer, an anchor coating agent (manufactured by Mitsui Chemicals, Inc., product name "A310 / A-3") was applied in an amount to result in 0.2 g / m after drying and dried to form an anchor coating layer. On this anchor coating layer, Coating Agent 1 was applied in an amount to result in 0.4 g / m after drying (the thickness of the first layer is 0.3 μm), and dried at 100°C for 1 minute to form the first layer. Next, aluminum oxide (AlOx) was vapor-deposited on the surface of the first layer by physical vapor deposition (PVD method) to form a second layer (thickness 40 nm), thereby obtaining the laminated film of Example 14. 2 2

[0105] [Examples 15 to 22, 25 to 26] A laminated film was prepared in the same manner as in Example 14, except that the type of the coating agent was as shown in Table 4.

[0106] [Example 23] As the base material layer, a corona-discharge-treated biaxially stretched polypropylene film (thickness 20 μm) was prepared. Coating Agent 10 was directly applied on this base material layer in an amount to result in 0.4 g / m after drying. 2 ​​It was applied in an amount such that (the thickness of the first layer was 0.3 μm), and dried at 100 °C for 1 minute to form the first layer. Next, aluminum oxide (AlOx) was deposited on the surface of the first layer by physical vapor deposition (PVD method) to form a second layer (thickness 40 nm), thereby obtaining the laminated film of Example 23.

[0107] [Example 24] A laminated film was prepared in the same manner as in Example 23, except that the type of coating agent was as shown in Table 4.

[0108] [Comparative Examples 1 - 6] Laminated films of Comparative Examples 1 - 2, 4 - 6 were prepared in the same manner as in Example 1, except that the type of coating agent was as shown in Table 5. Also, a laminated film of Comparative Example 3 was prepared in the same manner as in Example 10, except that the type of coating agent was as shown in Table 5.

[0109] Regarding the laminated films obtained in each example, the presence or absence of cracks in the second layer, gas barrier properties (oxygen permeability and water vapor permeability), and laminate strength were evaluated as follows when stored under high humidity conditions.

[0110] <Crack Evaluation of the Second Layer> The laminated films of each example were stored for 1 week under the conditions of a temperature of 40 °C and a relative humidity of 90% RH. Regarding the laminated films after storage, visually observe the appearance change of the vapor deposition film (second layer), and those in which no cracks and deformations were observed in the second layer were rated as "qualified", and those in which cracks and / or deformations occurred in the second layer were rated as "unqualified". The results are shown in Tables 3 - 5.

[0111] <Gas Barrier Property (Oxygen Permeability 1 (Dry Condition))> Regarding the laminated films of each example, the gas barrier property (oxygen permeability 1) was evaluated. Specifically, in accordance with JIS K7126 - 2, using an oxygen permeability measuring device (manufactured by MOCON, product name "OX - TRA N2 / 20"), the oxygen permeability (unit: cc / m 2 ·day) was measured. The measurement conditions were 20 °C and a relative humidity of 0% RH. The results are shown in Tables 3 - 5.

[0112] <Gas barrier property (oxygen permeability 2 (under high humidity conditions))> For each laminated film of the examples, the gas barrier property (oxygen permeability 2) was evaluated. Specifically, in accordance with JIS K7126-2, using an oxygen permeability measuring device (manufactured by MOCON, product name "OX-TRA N2 / 20"), the oxygen permeability (unit: cc / m 2 ·day) was measured. The measurement conditions were 20°C and a relative humidity of 90%RH. The results are shown in Tables 3 to 5.

[0113] <Gas barrier property (water vapor permeability)> For each laminated film of the examples, the gas barrier property (water vapor permeability) was evaluated. Specifically, in accordance with JIS K7129-2, using a water vapor permeability measuring device (manufactured by MOCON, product name "PERMATRAN"), the water vapor permeability (unit: g / m 2 ·day) was measured. The measurement conditions were 40°C and a relative humidity of 90%RH. The results are shown in Tables 3 to 5.

[0114] <Lamination strength> For each laminated film of the examples, after applying an adhesive (manufactured by Mitsui Chemicals, Inc., product name "A310 / A-3") to the surface of the second layer, it was dry-laminated with an unstretched polypropylene film (manufactured by Futamura Chemical Co., Ltd., product name "FRTK-G", thickness 70 μm). After aging the obtained laminated film at 40°C for 3 days, it was cut into 15 mm widths, and the peel strength between the laminated film and the unstretched polypropylene film was measured using a tensile testing machine (manufactured by ORIENTEC, product name "RTC-1210") under the conditions of a temperature of 23°C and a relative humidity of 50%RH. The measurement was performed by the T-peel method. The results are shown in Tables 3 to 5.

[0115]

Table 3

[0116]

Table 4

[0117] [Table 5]

[0118] In Tables 3 to 5, "OPP" means a biaxially oriented polypropylene film, "Al" means an aluminum vapor-deposited film, and "AlOx" means an aluminum oxide vapor-deposited film.

[0119] As shown in Tables 3 to 5, in the laminated films of Examples 1 to 26, cracks in the second layer were suppressed even after storage under high humidity for one week. Furthermore, the oxygen permeability (dry condition and high humidity condition) and the water vapor permeability were also low, and the gas barrier property was excellent. Furthermore, the laminate strength also showed a high value. On the other hand, in the laminated films of Comparative Examples 1 to 4 that did not contain the inorganic layered compound (B), and in the laminated film of Comparative Example 6 that contained silica in the first layer, although the gas barrier property and the laminate strength were relatively good, cracks occurred in the second layer during storage under high humidity. Therefore, it is expected that the gas barrier property of the packages (for example, food packaging films) containing the laminated films of Comparative Examples 1 to 4 and 6 will deteriorate with time during long-term storage. In addition, the laminated film of Comparative Example 5 containing 40% by mass of the inorganic layered compound (B) in the first layer had a low laminate strength. From these results, it was confirmed that the laminated film according to the first embodiment does not generate cracks in the vapor-deposited film even when stored under high humidity, has excellent gas barrier properties, and also has excellent adhesion between the base material layer and the vapor-deposited film.

[0120] A non-limiting list of exemplary embodiments and combinations of exemplary embodiments of the present disclosure is described below. [1] A laminated film, wherein the laminated film comprises a base material layer, a first layer laminated on at least one surface of the base material layer, and a second layer laminated on the first layer, wherein the base material layer contains a thermoplastic resin, wherein the first layer contains a polyvinyl alcohol-based resin (A) and an inorganic layered compound (B), The second layer is a vapor deposition film containing at least one selected from metals and metal oxides as a main component, A laminated film in which the proportion of the inorganic layered compound (B) in the first layer is more than 0% by mass and less than 40% by mass. [2] The laminated film according to [1], wherein the base material layer contains a polyolefin resin. [3] The laminated film according to [1] or [2], wherein the polyvinyl alcohol resin (A) contains at least one resin selected from a polyvinyl alcohol resin (A1), a polyvinyl alcohol-based crosslinked resin (A2) containing a hydrazone bond, and an olefin-modified polyvinyl alcohol resin (A3). [4] The laminated film according to any one of [1] to [3], wherein the second layer is a vapor deposition film containing at least one selected from aluminum, aluminum oxide, and silicon oxide as a main component. [5] The laminated film according to any one of [1] to [4], wherein the inorganic layered compound (B) contains montmorillonite. [6] The oxygen permeability of the laminated film at 20 ° C. / 90% RH measured according to JIS K7126-2 is 2.0 cc / m 2 ·day or less. The laminated film according to any one of [1] to [5]. [7] The water vapor permeability of the laminated film at 40 ° C. / 90% RH measured according to JIS K7129-2 is 2.0 g / m 2 ·day or less. The laminated film according to any one of [1] to [6]. [8] The laminated film according to any one of [1] to [7], which is a film for food packaging. [9] A method for producing the laminated film according to any one of [1] to [8], laminating the first layer on the base material layer; and forming the second layer by vapor-depositing at least one selected from the metal and the metal oxide on the first layer.

[10] Laminating the first layer on the base material layer is After forming an anchor coat layer on at least one surface of the base material layer, forming the first layer on the anchor coat layer, or The manufacturing method according to [9], comprising laminating the first layer directly on the base material layer.

Claims

1. A laminated film, wherein the laminated film comprises a base material layer, a first layer laminated on at least one surface of the base material layer, and a second layer laminated on the first layer, wherein the base material layer contains a thermoplastic resin, wherein the first layer contains a polyvinyl alcohol-based resin (A) and an inorganic layered compound (B), wherein the second layer is a vapor deposition film containing at least one selected from metals and metal oxides as a main component, and wherein the proportion of the inorganic layered compound (B) in the first layer is more than 0% by mass and less than 40% by mass. A laminated film.

2. The laminated film according to Claim 1, wherein the base material layer contains a polyolefin-based resin.

3. The laminated film according to Claim 1 or 2, wherein the polyvinyl alcohol-based resin (A) contains at least one resin selected from a polyvinyl alcohol resin (A1), a polyvinyl alcohol-based crosslinked resin (A2) containing a hydrazone bond, and an olefin-modified polyvinyl alcohol-based resin (A3).

4. The laminated film according to Claim 1 or 2, wherein the second layer is a vapor deposition film containing at least one selected from aluminum, aluminum oxide, and silicon oxide as a main component.

5. The laminated film according to Claim 1 or 2, wherein the inorganic layered compound (B) contains montmorillonite.

6. The oxygen permeability of the laminated film at 20°C / 90% RH measured according to JIS K7126-2 is 2.0 cc / m ２ ・day or less, the laminated film according to claim 1 or 2.

7. The water vapor transmission rate of the laminated film at 40°C / 90% RH measured according to JIS K7129-2 is 2.0 g / m ２ ・day or less, the laminated film according to claim 1 or 2.

8. The laminated film according to Claim 1 or 2, which is a film for food packaging.

9. A method for producing the laminated film according to Claim 1 or 2, comprising laminating the first layer on the base material layer, and forming the second layer by vapor-depositing at least one selected from the metal and the metal oxide on the first layer. A manufacturing method.

10. Laminating the first layer on the base material layer includes forming an anchor coat layer on at least one surface of the base material layer and then forming the first layer on the anchor coat layer, or directly laminating the first layer on the base material layer. The manufacturing method according to Claim 9.

Images