Barrier film, laminate and packaging container

Abstract

To provide a barrier film having a stretched polyolefin film and a vapor-deposited film, which is excellent in adhesion of the vapor-deposited film, and gas barrier property.SOLUTION: A barrier film includes at least a stretched film of a polyolefin film, an anchor coat layer, and a vapor-deposited film, in this order in a lamination direction, wherein the polyolefin film is a polyethylene film or a polypropylene film, the polyolefin film and its stretched film each have a first surface and a second surface facing the first surface, the anchor coat layer contains a resin material having a polar group, the anchor coat layer is provided on at least a second surface in the stretched film, and the vapor-deposited film is provided on the anchor coat layer.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a barrier film, a laminate, and a packaging container. [Background technology]

[0002] Packaging containers are used to store contents such as liquids and powders, etc. Packaging containers are made using a laminate including a base material and a heat-sealable layer (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-55156 Summary of the Invention [Problem to be solved by the invention]

[0004] The present inventors have investigated the production of packaging containers using laminates comprising stretched polyolefin films as substrates. However, because stretched polyolefin films have poor gas barrier properties, such packaging containers do not have sufficient gas barrier properties. Therefore, the present inventors have investigated the use of a barrier film comprising a vapor-deposited film on a stretched polyolefin film as a substrate, but the adhesion between the stretched polyolefin film and the vapor-deposited film is insufficient, and the barrier film still sometimes does not have sufficient gas barrier properties. An object of the present disclosure is to provide a barrier film comprising a stretched polyolefin film and a vapor-deposited film, which has excellent adhesion to the vapor-deposited film and excellent gas barrier properties. [Means for solving the problem]

[0005] One embodiment of the barrier film of the present disclosure comprises at least a stretched polyolefin film, an anchor coat layer, and a vapor-deposited film, in this order in the stacking direction, wherein the polyolefin film is a polyethylene film or a polypropylene film, and the polyolefin film and the stretched polyolefin film each have a first surface and a second surface opposite to the first surface, the anchor coat layer contains a resin material having a polar group, the anchor coat layer is provided on at least the second surface of the stretched film, and the vapor-deposited film is provided on the anchor coat layer. [Effects of the Invention]

[0006] According to the present disclosure, there is provided a barrier film comprising a stretched polyolefin film and a vapor-deposited film, which has excellent adhesion to the vapor-deposited film and excellent gas barrier properties. The barrier film is useful, for example, as a substrate for packaging materials for producing packaging containers with excellent gas barrier properties. [Brief explanation of the drawings]

[0007] [Figure 1A] FIG. 1A is a schematic cross-sectional view showing one embodiment of a barrier film. [Figure 1B] FIG. 1B is a schematic cross-sectional view showing one embodiment of a barrier film. [Figure 1C] FIG. 1C is a schematic cross-sectional view showing one embodiment of a barrier film. [Figure 2] FIG. 2 is a schematic cross-sectional view showing one embodiment of the laminate. [Figure 3] FIG. 3 is a schematic cross-sectional view showing one embodiment of the laminate. [Figure 4] FIG. 4 is a schematic cross-sectional view showing one embodiment of the laminate. [Figure 5] FIG. 5 is a perspective view showing one embodiment of a tube container comprising a tube container body including a laminate and a cap. [Figure 6] FIG. 6 is a cross-sectional view taken along line AA in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present disclosure will be described in detail. For clarity of explanation, the drawings may show the width, thickness, shape, etc. of each layer more schematically than in the embodiments, but these are merely examples and do not limit the interpretation of the present disclosure. In this specification and each drawing, elements similar to those already described with reference to the previous drawings are designated by the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0009] In this specification, when multiple upper limit candidates and multiple lower limit candidates are listed for a certain parameter, the numerical range of the parameter may be constructed by combining any one upper limit candidate with any one lower limit candidate. Examples of such parameters include physical properties, component content, and layer thickness. As an example, the following statement will be explained: "Parameter B is preferably A1 or greater, more preferably A2 or greater, and even more preferably A3 or greater. Parameter B is preferably A4 or less, more preferably A5 or less, and even more preferably A6 or less." In this example, the numerical range of parameter B may be A1 or greater and A4 or less, A1 or greater and A5 or less, A1 or greater and A6 or less, A2 or greater and A4 or less, A2 or greater and A5 or less, A2 or greater and A6 or less, A3 or greater and A4 or less, A3 or greater and A5 or less, or A3 or greater and A6 or less.

[0010] In this specification, polyethylene refers to a polymer in which the content of ethylene-derived structural units in all repeating structural units is greater than 50 mol%. In this polymer, the content of ethylene-derived structural units is preferably 70 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, and particularly preferably 95 mol% or more. The content is measured by NMR.

[0011] In this specification, polyethylene may be a homopolymer of ethylene or a copolymer of ethylene and an ethylenically unsaturated monomer other than ethylene. Examples of the ethylenically unsaturated monomer other than ethylene include α-olefins having 3 to 20 carbon atoms, such as propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 3-methyl-1-butene, 4-methyl-1-pentene, and 6-methyl-1-heptene; vinyl monomers, such as vinyl acetate and vinyl propionate; and (meth)acrylic acid esters, such as methyl (meth)acrylate and ethyl (meth)acrylate.

[0012] In this specification, examples of polyethylene include high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, ethylene-vinyl acetate copolymer, and ethylene-(meth)acrylic acid ester copolymer. From the viewpoint of reducing the environmental load, the polyethylene may be biomass-derived polyethylene (hereinafter also referred to as "biomass polyethylene") or mechanically or chemically recycled polyethylene (hereinafter also referred to as "recycled polyethylene").

[0013] In this specification, the density of polyethylene is as follows: The density of the high density polyethylene is preferably 0.945 g / cm 3 The upper limit of the density of high density polyethylene is, for example, 0.965 g / cm 3 and preferably 0.960 g / cm 3 The density of the medium density polyethylene is preferably 0.930 g / cm 3 Exceeds 0.945g / cm 3 The density of the low density polyethylene is preferably 0.860 g / cm or less. 3 More than 0.930g / cm 3 or less, more preferably 0.900 g / cm 3 More than 0.930g / cm 3The density of the linear low density polyethylene is preferably 0.860 g / cm 3 More than 0.930g / cm 3 or less, more preferably 0.900 g / cm 3 More than 0.930g / cm 3 In this specification, the density of polyethylene is measured in accordance with JIS K7112-2:2023 (density gradient tube method, 23°C).

[0014] Low-density polyethylene is, for example, polyethylene obtained by polymerizing ethylene using a high-pressure polymerization method (high-pressure low-density polyethylene).Linear low-density polyethylene is, for example, polyethylene obtained by polymerizing ethylene and a small amount of α-olefins using a polymerization method using a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as a metallocene catalyst.

[0015] Examples of linear low-density polyethylene include ethylene-α-olefin copolymers. Examples of the α-olefin include the above-mentioned α-olefins having from 3 to 20 carbon atoms, preferably α-olefins having from 3 to 8 carbon atoms, and more preferably α-olefins having from 4 to 8 carbon atoms. Examples of linear low-density polyethylene include ethylene-1-butene copolymer (C4-LLDPE) in which the comonomer is at least 1-butene, ethylene-1-hexene copolymer (C6-LLDPE) in which the comonomer is at least 1-hexene, and ethylene-1-octene copolymer (C8-LLDPE) in which the comonomer is at least 1-octene. In these copolymers, the comonomer is not limited to the above-mentioned comonomers, and additional comonomers may be used. For example, linear low-density polyethylene produced using a metallocene catalyst is preferred.

[0016] Polyethylenes with different densities or branches can be obtained by appropriately selecting the polymerization method. For example, it is preferable to use a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as a metallocene catalyst as the polymerization catalyst, and carry out polymerization in one or more stages by any of gas phase polymerization, slurry polymerization, solution polymerization, and high-pressure ionic polymerization.

[0017] In this specification, from the viewpoint of film formability and processability, for example, by an inflation method, the melt flow rate (MFR) of the polyethylene is preferably 0.1 g / 10 min or more, more preferably 0.2 g / 10 min or more, even more preferably 0.3 g / 10 min or more, particularly preferably 0.5 g / 10 min or more, and is preferably 30 g / 10 min or less, more preferably 20 g / 10 min or less, even more preferably 10 g / 10 min or less, particularly preferably 5 g / 10 min or less, for example, 0.1 g / 10 min or more and 30 g / 10 min or less. In the first embodiment described later, such an MFR range is preferred. In this specification, from the viewpoint of film formability and processability, for example, by a T-die casting method, the melt flow rate (MFR) of the polyethylene is preferably 0.1 g / 10 min or more, more preferably 1 g / 10 min or more, even more preferably 1.5 g / 10 min or more, and is preferably 50 g / 10 min or less, more preferably 30 g / 10 min or less, even more preferably 10 g / 10 min or less, and particularly preferably 5 g / 10 min or less, for example, 0.1 g / 10 min or more and 50 g / 10 min or less. In the second aspect described below, such an MFR range is preferred. In this specification, the MFR of polyethylene is measured by Method A in accordance with JIS K7210-1:2014 under conditions of a temperature of 190°C and a load of 2.16 kg.

[0018] In this specification, the melting point (Tm) of the polyethylene constituting the stretched film is preferably 100°C or higher, more preferably 105°C or higher, even more preferably 110°C or higher, even more preferably 115°C or higher, and particularly preferably 120°C or higher and preferably 140°C or lower, for example, 100°C or higher and 140°C or lower, from the viewpoint of the strength and heat resistance of the polyethylene film and the stretched film thereof. In this specification, the Tm of various materials is the melting peak temperature obtained by differential scanning calorimetry (DSC) in accordance with JIS K7121:2012 (using test specimens conditioned according to 3.(2) (however, a cooling rate of 10°C / min)).

[0019] In this specification, each of the components (for example, polyolefins such as polyethylene, α-olefins, and additives) appearing in the following description may be used either alone or in combination of two or more.

[0020] In this specification, "film" and "sheet" may be referred to, but "film" and "sheet" are not distinguished from each other solely on the basis of the difference in name. In this specification, "multilayer" means two or more layers. In this specification, when adjacent layers constituting a film have the same resin composition and are indistinguishable from each other, the adjacent layers may be integrated to form a single layer.

[0021] In this specification, the term "major component" in a layer refers to a component whose content in the layer is greater than 50% by mass, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and even more preferably 90% by mass or more.

[0022] [Barrier film] The barrier film of the present disclosure comprises at least A stretched polyolefin film; An anchor coat layer; a vapor-deposited film; are provided in this order in the stacking direction (hereinafter, also simply referred to as "provided in this order").

[0023] The polyolefin film has a first surface and a second surface opposite to the first surface. The stretched film has a first surface and a second surface opposite to the first surface. The first surface of the stretched film corresponds to the first surface of the polyolefin film. The second surface of the stretched film corresponds to the second surface of the polyolefin film. Examples of polyolefin films include polyethylene films and polypropylene films. The anchor coat layer is provided on at least the second surface of the stretched film.

[0024] <Polyethylene film and stretched film> The polyethylene film and its stretched film are preferably polyethylene-containing films, primarily containing polyethylene. The polyethylene film and its stretched film preferably have a layer primarily containing polyethylene as the layer constituting the second surface. Examples of polyethylene include high-density polyethylene, medium-density polyethylene, low-density polyethylene, and linear low-density polyethylene.

[0025] The polyethylene film preferably comprises, as a layer constituting its second surface, a polyethylene layer containing high-density polyethylene and a polyethylene other than the high-density polyethylene, or a polyethylene layer containing at least one polymer selected from the group consisting of high-density polyethylene and medium-density polyethylene and a polyethylene other than the polymer. The polyethylene film of the first embodiment has, as a layer constituting its second surface, a polyethylene layer containing high-density polyethylene and a polyethylene other than the high-density polyethylene. Hereinafter, the layer constituting the second surface of the polyethylene film of the first embodiment will also be referred to as the "polyethylene layer (S2)." The stretched film of the polyethylene film of the first embodiment will also be referred to as the "stretched film of the first embodiment." The polyethylene film of the second embodiment has, as a layer constituting its second surface, a polyethylene layer containing at least one polymer selected from the group consisting of high-density polyethylene and medium-density polyethylene and a polyethylene other than said polymer (hereinafter also referred to as "other polyethylene"), or a polyethylene layer containing high-density polyethylene and medium-density polyethylene (hereinafter also referred to as "polyethylene layer (1)"). A stretched film of the polyethylene film of the second embodiment is also referred to as "stretched film of the second embodiment". Such a stretched polyethylene film has, for example, high heat resistance, specifically, excellent resistance to heating during drying and heat sealing when forming the anchor coat layer, and excellent resistance to vapor deposition when vapor deposition is performed, and also excellent adhesion to the anchor coat layer.

[0026] Unless otherwise specified, the matters described below are common to the first and second embodiments.

[0027] In the first embodiment, examples of the polyethylene other than high-density polyethylene include medium-density polyethylene, linear low-density polyethylene, and low-density polyethylene. Among these, medium-density polyethylene and linear low-density polyethylene are preferred. In one embodiment, the polyethylene layer (S2) preferably contains high-density polyethylene and medium-density polyethylene. Stretched films of such polyethylene films have, for example, high impact resistance, and can be used to produce packaging containers with excellent tear resistance using the laminate described below. Furthermore, stretched films of such polyethylene films have, for example, high rigidity, and specifically, can increase the conveying speed of the stretched film when vapor deposition is performed, thereby improving productivity. In one embodiment, the polyethylene layer (S2) preferably contains high-density polyethylene and linear low-density polyethylene. Such a polyethylene film has excellent stretchability, for example. A stretched film of such a polyethylene film tends to have higher adhesion to an anchor coat layer, for example.

[0028] The other polyethylene in the second embodiment may be, for example, at least one selected from the group consisting of linear low-density polyethylene and high-pressure low-density polyethylene. It may be linear low-density polyethylene, high-pressure low-density polyethylene, or a mixture of linear low-density polyethylene and high-pressure low-density polyethylene. Among these, linear low-density polyethylene is preferred. The polyethylene layer (1) preferably contains high-density polyethylene and linear high-density polyethylene. Such polyethylene films have excellent stretchability, for example. Stretched films of such polyethylene films have high impact resistance, and can be used with the laminates described below to produce packaging containers with excellent rupture resistance. Furthermore, stretched films of such polyethylene films have high rigidity, and specifically, the conveying speed of the stretched film can be increased during vapor deposition, thereby improving productivity.

[0029] The above-mentioned stretched film has excellent adhesion to the anchor coat layer. The reason for this is unclear, but is presumed to be due to the following reasons. When forming an anchor coat layer on the second surface of a polyethylene film or a stretched film thereof, a surface treatment such as corona treatment may be performed on the second surface as a pretreatment. A layer containing high-density polyethylene and other polyethylenes such as medium-density polyethylene and a stretched layer thereof tends to have a higher surface treatment efficiency (e.g., polar group introduction rate) than a layer containing only high-density polyethylene as the polyethylene and a stretched layer thereof. For this reason, a layer containing high-density polyethylene and other polyethylenes such as medium-density polyethylene and a stretched layer thereof has excellent adhesion to the anchor coat layer after surface treatment.

[0030] High-density polyethylenes include, for example, ethylene homopolymers and ethylene-α-olefin copolymers. Examples of α-olefins include the aforementioned α-olefins having from 3 to 20 carbon atoms, with α-olefins having from 3 to 8 carbon atoms being preferred, and α-olefins having from 4 to 8 carbon atoms being more preferred. Examples of ethylene-α-olefin copolymers include ethylene-1-butene copolymers (C4-HDPE) in which the comonomer is at least 1-butene, ethylene-1-hexene copolymers (C6-HDPE) in which the comonomer is at least 1-hexene, and ethylene-1-octene copolymers (C8-HDPE) in which the comonomer is at least 1-octene. These copolymers are not limited to the above-mentioned comonomers, and additional comonomers may also be used. For example, high-density polyethylenes produced using a metallocene catalyst are preferred.

[0031] Examples of medium-density polyethylene include ethylene homopolymers and ethylene-α-olefin copolymers. Examples of α-olefins include the aforementioned α-olefins having from 3 to 20 carbon atoms, with α-olefins having from 3 to 8 carbon atoms being preferred, and α-olefins having from 4 to 8 carbon atoms being more preferred. Examples of ethylene-α-olefin copolymers include ethylene-1-butene copolymers (C4-MDPE) in which the comonomer is at least 1-butene, ethylene-1-hexene copolymers (C6-MDPE) in which the comonomer is at least 1-hexene, and ethylene-1-octene copolymers (C8-MDPE) in which the comonomer is at least 1-octene. These copolymers are not limited to the above-mentioned comonomers, and additional comonomers may also be used. For example, medium-density polyethylenes produced using a metallocene catalyst are preferred.

[0032] The high-density polyethylene may be, for example, an ethylene homopolymer, an ethylene-α-olefin copolymer, or a mixture thereof. The medium-density polyethylene may be, for example, an ethylene homopolymer, an ethylene-α-olefin copolymer, or a mixture thereof.

[0033] In the second aspect, the high-density polyethylene and the medium-density polyethylene are preferably the above-mentioned ethylene-α-olefin copolymers. Polyethylene films containing such high-density polyethylene and / or medium-density polyethylene exhibit, for example, excellent biaxial stretchability, particularly excellent stretchability in the width direction. This is presumably because the side chains derived from the α-olefins prevent the film from tearing during stretching. The ethylene-α-olefin copolymer is preferably a polyethylene obtained by polymerizing ethylene and a small amount of α-olefins using a polymerization method using a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as a metallocene catalyst, and more preferably a polyethylene produced using a metallocene catalyst. The density of the high density polyethylene is preferably 0.945 g / cm 3 Exceeds 0.960g / cm 3 The density of the medium density polyethylene is preferably 0.930 g / cm or less. 3 Exceeds 0.945g / cm 3 The density can be adjusted, for example, by the amount of structural units derived from the α-olefin, which is the comonomer in the ethylene-α-olefin copolymer, introduced.

[0034] The polyethylene layer (S2) may contain, for example, a mixture of high-density polyethylene and a polyethylene other than the high-density polyethylene as a main component, or a mixture of high-density polyethylene and medium-density polyethylene or linear low-density polyethylene as a main component. The fact that the main component is the mixture means that the content of the mixture in the polyethylene layer (S2) is more than 50% by mass, and the content is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and still more preferably 90% by mass or more.

[0035] From the viewpoint of heat resistance, the content of high-density polyethylene in the polyethylene layer (S2) is preferably 10% by mass or more, more preferably 15% by mass or more, even more preferably 20% by mass or more, and particularly preferably 25% by mass or more. From the viewpoint of formability and adhesion of the anchor coat layer, the content of high-density polyethylene in the polyethylene layer (S2) is preferably 90% by mass or less, more preferably 85% by mass or less, even more preferably 80% by mass or less, still more preferably 75% by mass or less, and particularly preferably 60% by mass or less, 50% by mass or less, or 40% by mass or less.

[0036] When the content of high-density polyethylene is low, the surface treatment tends to further improve the adhesion between the second surface of the stretched film and the anchor coat layer. This is presumably because, for example, high-density polyethylene is highly crystalline, and surface treatments such as corona treatments may not be able to sufficiently introduce polar groups into the high-density polyethylene. However, when the content of high-density polyethylene is low, the polar groups can be sufficiently introduced into the polyethylene by surface treatments such as corona treatment. Furthermore, when the content of high-density polyethylene is low, the appearance, surface smoothness, and transparency of the film tend to be excellent.

[0037] The content of medium-density polyethylene or linear low-density polyethylene in the polyethylene layer (S2) is preferably 10% by mass or more, more preferably 15% by mass or more, even more preferably 20% by mass or more, still more preferably 25% by mass or more, particularly preferably 40% by mass or more, 50% by mass or more, or 60% by mass or more, from the viewpoint of formability and adhesion of the anchor coat layer. The content of medium-density polyethylene or linear low-density polyethylene in the polyethylene layer (S2) is preferably 90% by mass or less, more preferably 85% by mass or less, even more preferably 80% by mass or less, particularly preferably 75% by mass or less, from the viewpoint of heat resistance.

[0038] The polyethylene content in the polyethylene layer (S2) is preferably 80% by mass or more, more preferably 85% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more.

[0039] The polyethylene layer (S2) may contain a resin material other than polyethylene, such as polyolefins other than polyethylene, polyesters, polyamides, (meth)acrylic resins, vinyl resins, cellulose resins, and ionomer resins.

[0040] The polyethylene layer (S2) may contain additives such as crosslinking agents, antioxidants, UV absorbers, light stabilizers, antiblocking agents, slip agents, fillers, reinforcing agents, antistatic agents, compatibilizers, pigments, and modifying resins.

[0041] In one embodiment, the stretched film is a stretched film of a monolayer polyethylene film consisting of a polyethylene layer (S2). In one embodiment, the stretched film is a stretched film of a polyethylene film comprising one or more polyethylene layers and a polyethylene layer (S2).

[0042] The polyethylene layer contains polyethylene as a main component. Examples of preferred polyethylene include high-density polyethylene, medium-density polyethylene, low-density polyethylene, and linear low-density polyethylene. The polyethylene content in the polyethylene layer is preferably 80% by mass or more, more preferably 85% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more. The polyethylene layer may have the same composition as the polyethylene layer (S2). The polyethylene layer may contain the above-mentioned resin material other than polyethylene. The polyethylene layer may contain the additive.

[0043] The polyethylene layer (1) may contain, for example, a mixture of at least one polyethylene selected from the group consisting of high-density polyethylene and medium-density polyethylene and another polyethylene as a main component. The polyethylene layer (1) may contain, for example, a mixture of high-density polyethylene and medium-density polyethylene as a main component. The polyethylene layer (1) may contain, for example, a mixture of high-density polyethylene and another polyethylene as a main component, a mixture of medium-density polyethylene and another polyethylene as a main component, or a mixture of high-density polyethylene, medium-density polyethylene, and another polyethylene as a main component. The main component being the above mixture means that the content of the above mixture in the polyethylene layer (1) is more than 50% by mass, and the content is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and still more preferably 90% by mass or more. The high-density polyethylene may be, for example, an ethylene homopolymer, an ethylene-α-olefin copolymer, or a mixture thereof. The medium-density polyethylene may be, for example, an ethylene homopolymer, an ethylene-α-olefin copolymer, or a mixture thereof.

[0044] From the viewpoint of heat resistance, the total content of high-density polyethylene and medium-density polyethylene in the polyethylene layer (1) is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, and may be 30% by mass or more, 35% by mass or more, or 40% by mass or more. The total content of high-density polyethylene and medium-density polyethylene in the polyethylene layer (1) is preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less, from the viewpoint of biaxial stretchability and, when the polyethylene layer (1) is a layer constituting the second surface of the polyethylene film, from the viewpoint of formability and adhesion of an anchor coat layer, and may be 70% by mass or less, 65% by mass or less, or 60% by mass or less. The total content of high-density polyethylene and medium-density polyethylene in the polyethylene layer (1) is, for example, 10% by mass or more and 90% by mass or less, and preferably 20% by mass or more and 60% by mass or less.

[0045] This section describes the case where the polyethylene layer (1) constitutes the second surface of the polyethylene film. When the total content of the high-density polyethylene and the medium-density polyethylene is low, the adhesion between the second surface of the stretched film and the anchor coat layer tends to be improved by the surface treatment described below. This is presumably because, for example, high-density polyethylene has high crystallinity, and it may be difficult to sufficiently introduce polar groups into high-density polyethylene by surface treatment such as corona treatment. When the total content is low, polar groups can be sufficiently introduced into the polyethylene by surface treatment such as corona treatment. Furthermore, when the content is low, the appearance, surface smoothness, and transparency of the film tend to be excellent.

[0046] From the viewpoint of biaxial stretchability and, when the polyethylene layer (1) is a layer constituting the second surface of the polyethylene film, from the viewpoint of formability and adhesion of an anchor coat layer, the polyethylene layer (1) preferably further contains a linear low-density polyethylene in addition to at least one polyethylene selected from the group consisting of high-density polyethylene and medium-density polyethylene, and more preferably further contains a linear low-density polyethylene in addition to the high-density polyethylene.

[0047] Examples of linear low-density polyethylene include ethylene-α-olefin copolymers. Examples of α-olefins include the above-mentioned α-olefins having 3 to 20 carbon atoms, with α-olefins having 3 to 8 carbon atoms being preferred, and α-olefins having 4 to 8 carbon atoms being more preferred. Examples of linear low-density polyethylene include C4-LLDPE, C6-LLDPE, and C8-LLDPE. For example, linear low-density polyethylene produced using a metallocene catalyst is preferred. The density of the linear low-density polyethylene is preferably 0.900 g / cm. 3 More than 0.930g / cm 3 The following is the result.

[0048] The content of linear low-density polyethylene in the polyethylene layer (1) is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, and may be 30% by mass or more, 35% by mass or more, or 40% by mass or more, from the viewpoints of biaxial stretchability and, when the polyethylene layer (1) is a layer constituting the second surface of the polyethylene film, the formability and adhesion of an anchor coat layer. From the viewpoint of heat resistance, the content of the linear low-density polyethylene in the polyethylene layer (1) is preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less, and may be 70% by mass or less, 65% by mass or less, or 60% by mass or less. The content of the linear low-density polyethylene in the polyethylene layer (1) is, for example, 10% by mass or more and 90% by mass or less, and preferably 40% by mass or more and 80% by mass or less.

[0049] The polyethylene layer (1) contains polyethylene as a main component. The content of polyethylene in the polyethylene layer (1) is preferably 80% by mass or more, more preferably 85% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more.

[0050] In one embodiment, the polyethylene layer (1) may contain a resin material other than polyethylene, such as polyolefins other than polyethylene, polyesters, polyamides, (meth)acrylic resins, vinyl resins, cellulose resins, and ionomer resins.

[0051] The polyethylene layer (1) may contain additives such as crosslinking agents, antioxidants, UV absorbers, light stabilizers, antiblocking agents, slip agents, fillers, reinforcing agents, antistatic agents, compatibilizers, pigments, and modifying resins.

[0052] The polyethylene contained in the polyethylene layer (1) is 0.930 g / cm 3 Super 0.960g / cm 3 The density of the polyethylene contained in the polyethylene layer (1) is preferably 0.931 g / cm 3 More than 0.955g / cm 3 or less, more preferably 0.931 g / cm 3 More than 0.950g / cm 3 The following is the result.

[0053] The polyethylene layer (1) contains two or more polyethylenes with different densities. The density of the polyethylene refers to the density of a mixture of two or more polyethylenes. The density is measured in accordance with JIS K7112-2:2023 (density gradient tube method, 23°C) for polyethylene sampled from the layer. When the measurement is difficult, the average density D calculated according to the formula described below may be used. av may be the density of the polyethylene that constitutes the layer.

[0054] In one embodiment, the stretched film is a stretched film of a monolayer polyethylene film consisting of a polyethylene layer 1. In one embodiment, the stretched film is a stretched film of a polyethylene film having two or more polyethylene layers, and the layer constituting the second surface of the polyethylene film is the polyethylene layer (1), and preferably, all of the polyethylene layers constituting the polyethylene film are polyethylene layers (1).

[0055] The polyethylene layer contains polyethylene as a main component. Examples of preferred polyethylene include high-density polyethylene, medium-density polyethylene, low-density polyethylene, and linear low-density polyethylene. The polyethylene content in the polyethylene layer is preferably 80% by mass or more, more preferably 85% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more. The polyethylene layer may contain the above-mentioned resin material other than polyethylene. The polyethylene layer may contain the additive.

[0056] The polyethylene content in the polyethylene film and its stretched film is preferably more than 50% by mass, more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, and particularly preferably 85% by mass or more or 90% by mass or more. The barrier film of the present disclosure comprising such a stretched film can be suitably used as a substrate constituting packaging materials such as polyethylene-based mono-material packaging materials. A laminate (or packaging container) comprising such a stretched film has, for example, excellent recyclability.

[0057] In one embodiment, the polyethylene film and its stretched film have a multilayer structure of two or more layers. The number of layers of the film is preferably two or more, more preferably three or more, and preferably nine or fewer, more preferably seven or fewer, for example, two or more and nine or fewer layers. The number of layers of the polyethylene film and its stretched film is specifically three, five, seven, or nine. Films having a multilayer structure have an excellent balance of strength, rigidity, heat resistance, transparency, and printability, for example.

[0058] In a multilayer polyethylene film and a stretched film thereof, the density of the polyethylene constituting each layer may be the same or different. For example, the film may have a density gradient between the polyethylene layers. A film having a density gradient between the polyethylene layers has excellent strength, rigidity, heat resistance, and stretchability.

[0059] In the polyethylene film and its stretched film, any adjacent polyethylene layers selected from the polyethylene layers are referred to as layer (i) and layer (ii). The absolute value of the difference between the density of the polyethylene constituting layer (i) and the density of the polyethylene constituting layer (ii) is preferably 0.030 g / cm. 3 or less, more preferably 0.025 g / cm 3 or less, more preferably 0.020 g / cm 3 Below 0.010 g / cm, particularly preferably 3Such a film has excellent interlayer adhesion and, for example, excellent drop resistance.

[0060] When the polyethylene layer contains two or more polyethylenes with different densities, the density of the polyethylene refers to the density of a mixture of two or more polyethylenes. The density is measured in accordance with JIS K7112-2:2023 (density gradient tube method, 23°C) for polyethylene sampled from the layer. When the measurement is difficult, the average density D calculated according to the following formula is used: av may be the density of the polyethylene that constitutes the layer.

[0061] D av = ΣW i ×D i In the formula, Σ is W from 1 to n (n kinds of polyethylene are present) for i. i ×D i where n is an integer greater than or equal to 2, and W i denotes the mass fraction of the i-th polyethylene, and D i is the density of the i-th polyethylene (g / cm 3 ) is shown.

[0062] The polyethylene film and the stretched film thereof preferably have a multilayer structure. In one embodiment, the polyethylene film and the stretched film thereof include at least a first surface resin layer containing polyethylene as a main component; a polyethylene intermediate layer containing polyethylene as a main component; a second surface resin layer containing polyethylene as a main component; However, when adjacent layers constituting the film have the same resin composition and cannot be distinguished from each other, the adjacent layers may be integrated to form a single layer.

[0063] The second surface resin layer of the polyethylene film of the first embodiment is a polyethylene layer (S2). When an anchor coat layer and a vapor-deposited film, which will be described later, are provided on both sides of the stretched film, the first surface resin layer is also preferably a polyethylene layer containing high-density polyethylene and a polyethylene other than the high-density polyethylene. The above description of the polyethylene layer (S2) also applies to this polyethylene layer, and a description thereof will be omitted here. In this case, the first surface resin layer also preferably has the same composition as the polyethylene layer (S2).

[0064] At least the second surface resin layer of the polyethylene film of the second embodiment is a polyethylene layer (1). In terms of heat resistance, in the polyethylene film, at least one layer selected from the group consisting of the first surface resin layer and the polyethylene intermediate layer is preferably the polyethylene layer (1) or a layer made of at least one polyethylene selected from the group consisting of high-density polyethylene and medium-density polyethylene, and it is more preferable that both the first surface resin layer and the polyethylene intermediate layer are the polyethylene layer (1) or a layer made of at least one polyethylene selected from the group consisting of high-density polyethylene and medium-density polyethylene. When an anchor coat layer and a vapor-deposited film, which will be described later, are provided on both sides of the stretched film, it is preferable that the first surface resin layer is also a polyethylene layer (1).

[0065] The first surface resin layer constitutes the first surface of the film. The second surface resin layer constitutes the second surface of the film. The film may comprise two or more polyethylene intermediate layers.

[0066] The compositions of the first and second surface resin layers may be the same or different. The thicknesses of the first and second surface resin layers may be the same or different. When the film has two or more polyethylene intermediate layers, the compositions of the polyethylene intermediate layers may be the same or different, and the thicknesses of the polyethylene intermediate layers may be the same or different. The compositions of the surface resin layer and the polyethylene intermediate layer may be the same or different. The thicknesses of the surface resin layer and the polyethylene intermediate layer may be the same or different.

[0067] In one embodiment, the stretched film is a film obtained by stretching a polyethylene film. Stretching can improve, for example, the strength, rigidity, heat resistance, transparency, and printability of the polyethylene film. The stretching may be uniaxial stretching or biaxial stretching. The biaxial stretching may be sequential biaxial stretching using a tenter frame method or the like, or simultaneous biaxial stretching.

[0068] In the first embodiment, the stretching ratio when stretching in the machine direction (flow direction of the film, MD direction) is preferably 2 times or more, more preferably 3 times or more, and preferably 10 times or less, more preferably 7 times or less, for example, 2 times or more and 10 times or less. In the first embodiment, the stretching ratio when stretching in the width direction (direction perpendicular to the MD direction, TD direction) is preferably 2 times or more, more preferably 3 times or more, and preferably 10 times or less, more preferably 7 times or less, for example, 2 times or more and 10 times or less. The stretched film of the first embodiment is preferably a film obtained by uniaxially stretching a polyethylene film, that is, a uniaxially stretched film, and specifically a film obtained by uniaxially stretching a polyethylene film in the MD direction.

[0069] In the second embodiment, the stretching ratio when stretching in the machine direction (flow direction of the film, MD direction) is preferably 2 times or more, more preferably 3 times or more, and preferably 15 times or less, more preferably 10 times or less, for example, 2 times or more and 15 times or less. In the second embodiment, the stretching ratio when stretching in the width direction (direction perpendicular to the MD direction, TD direction) is preferably 2 times or more, more preferably 3 times or more, and preferably 15 times or less, more preferably 10 times or less, for example, 2 times or more and 15 times or less. The stretched film of the second embodiment is preferably a film obtained by biaxially stretching a polyethylene film, i.e., a biaxially stretched film, and specifically a film obtained by biaxially stretching a polyethylene film in the MD direction and the TD direction.

[0070] The thickness of the stretched film is preferably 5 μm or more, more preferably 10 μm or more, even more preferably 15 μm or more, and preferably 200 μm or less, more preferably 100 μm or less, even more preferably 50 μm or less, particularly preferably 30 μm or less, for example, 5 μm or more and 200 μm or less. Stretched films having a thickness equal to or greater than the lower limit exhibit, for example, excellent strength, rigidity, and heat resistance. Stretched films having a thickness equal to or less than the upper limit exhibit, for example, excellent processability. In this specification, the thickness of the film and each layer is the average value of thicknesses measured at 10 points in a scanning electron microscope (SEM) image obtained by observing a cross section perpendicular to the film surface with an SEM.

[0071] The stretched film can be produced, for example, by forming the materials constituting each layer into a polyethylene film (single-layer film or laminate film) and then stretching the film. Examples of film-forming methods include inflation and T-die casting. In the first embodiment, inflation is preferred, and in the second embodiment, T-die casting is preferred from the viewpoint of productivity. When producing a polyethylene film by inflation, the MFR of the polyethylene is preferably 0.2 g / 10 min or more and 5 g / 10 min or less, more preferably 0.5 g / 10 min or more and 3 g / 10 min or less, from the viewpoints of film-forming ability and processability.

[0072] In one embodiment, the stretched film is a film obtained by stretching a co-extruded film, such as by co-extrusion of a material constituting the first surface resin layer, a material constituting the polyethylene intermediate layer, and a material constituting the second surface resin layer in this order in the lamination direction by an inflation method, a T-die casting method, or the like, and then stretching the resulting co-extruded film.

[0073] Hereinafter, the polyethylene layer will also be referred to as a "PE layer." In one embodiment, the polyethylene film and the stretched film thereof include at least a first surface resin layer; a first PE layer; a second PE layer; a third PE layer; and a second surface resin layer; In this order, each of the layers contains polyethylene as a main component. However, when adjacent layers constituting the film have the same resin composition and are indistinguishable from each other, the adjacent layers may be integrated to form a single layer.

[0074] In a second embodiment, at least the second surface resin layer of the polyethylene film is a polyethylene layer (1). In terms of heat resistance, in the polyethylene film, at least one layer selected from the group consisting of the first surface resin layer, the first PE layer, the second PE layer, and the third PE layer is preferably the polyethylene layer (1) or a layer made of at least one polyethylene selected from the group consisting of high-density polyethylene and medium-density polyethylene, and more preferably all of the above layers are the polyethylene layer (1) or a layer made of at least one polyethylene selected from the group consisting of high-density polyethylene and medium-density polyethylene.

[0075] The compositions of the first and second surface resin layers may be the same or different. The thicknesses of the first and second surface resin layers may be the same or different. The compositions of the first to third PE layers may be the same or different. The thicknesses of the first to third PE layers may be the same or different. The compositions of the surface resin layer and the PE layer may be the same or different. The thicknesses of the surface resin layer and the PE layer may be the same or different.

[0076] Specific examples of the first embodiment (films (α) to (γ)) will be explained below. In one embodiment, the polyethylene film is the first surface resin layer contains medium-density polyethylene and high-density polyethylene; The first PE layer contains medium density polyethylene and linear low density polyethylene, The second PE layer contains linear low-density polyethylene as a main component, the third PE layer contains medium density polyethylene and linear low density polyethylene; The second surface resin layer contains medium density polyethylene and high density polyethylene. The polyethylene film having such a structure is excellent in, for example, stretchability. The stretched film is excellent in, for example, anchor coat layer formability and adhesion, strength, and heat resistance. The high-density polyethylene contributes to improving heat resistance, for example. The medium-density polyethylene contributes to improving rigidity, for example. The linear low-density polyethylene contributes to improving stretchability, for example.

[0077] In the first and second surface resin layers of the film (α), the total content of the medium-density polyethylene and the high-density polyethylene is each independently preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. In the first and second surface resin layers of the film (α), the ratio of the content of medium-density polyethylene to the content of high-density polyethylene (medium-density polyethylene content / high-density polyethylene content) is preferably 0.25 or more and 4 or less, more preferably 0.4 or more and 3 or less, even more preferably 1.1 or more and 3 or less, and particularly preferably 1.5 or more and 3 or less, independently on a mass basis.

[0078] In the first and third PE layers of the film (α), the total content of the medium-density polyethylene and the linear low-density polyethylene is each independently preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. In the first and third PE layers of the film (α), the ratio of the medium-density polyethylene content to the linear low-density polyethylene content (medium-density polyethylene content / linear low-density polyethylene content) is preferably 0.25 or more and 4 or less, more preferably 0.4 or more and 2.4 or less, and even more preferably 0.8 or more and 2.4 or less, independently on a mass basis.

[0079] In the second PE layer of the film (α), the content of linear low-density polyethylene is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0080] In one embodiment, the polyethylene film is the first surface resin layer contains high-density polyethylene and medium-density polyethylene; The first PE layer contains medium density polyethylene as a main component, the second PE layer contains linear low-density polyethylene and medium-density polyethylene; The third PE layer contains medium density polyethylene as a main component, The second surface resin layer contains high-density polyethylene and medium-density polyethylene. The polyethylene film having such a structure is excellent in, for example, stretchability. The stretched film is excellent in, for example, anchor coat layer formability and adhesion, strength, and heat resistance.

[0081] In the first and second surface resin layers of the film (β), the total content of high-density polyethylene and medium-density polyethylene is each independently preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. In the first and second surface resin layers of the film (β), the content ratio of high-density polyethylene to medium-density polyethylene (high-density polyethylene content / medium-density polyethylene content) is, independently by mass, preferably 0.25 or more and 4 or less, more preferably 0.4 or more and 3 or less, even more preferably 1.1 or more and 3 or less, and particularly preferably 1.5 or more and 3 or less.

[0082] In the second PE layer of the film (β), the total content of the linear low-density polyethylene and the medium-density polyethylene is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. In the second PE layer of the film (β), the content ratio of linear low-density polyethylene to medium-density polyethylene (linear low-density polyethylene content / medium-density polyethylene content) is preferably 0.25 or more and 4 or less, more preferably 0.4 or more and 2.4 or less, on a mass basis.

[0083] In the first and third PE layers of the film (β), the content of medium-density polyethylene is each independently preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0084] In one embodiment, the polyethylene film is the first surface resin layer contains medium-density polyethylene and high-density polyethylene; The first PE layer contains high-density polyethylene as a main component, The second PE layer contains linear low-density polyethylene as a main component, The third PE layer contains high density polyethylene as a main component, The second surface resin layer contains medium density polyethylene and high density polyethylene. The polyethylene film having such a structure is excellent in, for example, stretchability. The stretched film is excellent in, for example, anchor coat layer formability and adhesion, strength, and heat resistance.

[0085] In the first and second surface resin layers of the film (γ), the total content of the medium-density polyethylene and the high-density polyethylene is each independently preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. In the first and second surface resin layers of the film (γ), the content ratio of medium-density polyethylene to high-density polyethylene (medium-density polyethylene content / high-density polyethylene content) is preferably 1.1 or more and 5 or less, more preferably 1.5 or more and 3 or less, independently on a mass basis.

[0086] In one embodiment of the first and third PE layers of the film (γ), the content ratio of high-density polyethylene is each independently preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0087] The first and third PE layers of the film (γ) may each independently further contain low-density polyethylene. This configuration can, for example, further improve the balance between the heat resistance, rigidity, and processability of the film. In this embodiment, the total content of high-density polyethylene and low-density polyethylene in the first and third PE layers is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. In this embodiment, the content ratio of high-density polyethylene to low-density polyethylene in the first and third PE layers (high-density polyethylene content / low-density polyethylene content) is preferably 1 or more and 4 or less, more preferably 1.5 or more and 3 or less, on a mass basis.

[0088] In one embodiment of the second PE layer of the film (γ), the content of linear low-density polyethylene is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0089] The second PE layer of the film (γ) may further contain low-density polyethylene. This configuration can, for example, further improve the balance between the stretchability and processability of the film. In this embodiment, the total content of the linear low-density polyethylene and the low-density polyethylene in the second PE layer is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. In this embodiment, the content ratio of the linear low-density polyethylene to the low-density polyethylene in the second PE layer (linear low-density polyethylene content / low-density polyethylene content) is preferably 1 or more and 4 or less, more preferably 1.5 or more and 3 or less, by mass.

[0090] In the stretched film of the first embodiment, the thicknesses of the first and second surface resin layers are each independently preferably 0.5 μm or more, more preferably 1 μm or more, even more preferably 1.5 μm or more, and preferably 10 μm or less, more preferably 8 μm or less, even more preferably 5 μm or less, for example, 0.5 μm or more and 10 μm or less.

[0091] In the stretched film of the first embodiment, the thicknesses of the first and second surface resin layers are each independently, relative to the thickness of the stretched film, preferably 3% or more, more preferably 5% or more, even more preferably 8% or more, and preferably 25% or less, more preferably 20% or less, even more preferably 15% or less, for example, 3% or more and 25% or less.

[0092] In the stretched film of the first aspect, the thickness of the polyethylene intermediate layer is preferably 4 μm or more, more preferably 8 μm or more, even more preferably 12 μm or more, and preferably 100 μm or less, more preferably 45 μm or less, even more preferably 35 μm or less, and particularly preferably 25 μm or less, for example, 4 μm or more and 100 μm or less. A stretched film having a polyethylene intermediate layer whose thickness is equal to or greater than the lower limit exhibits, for example, excellent strength, rigidity, heat resistance, and recyclability. A stretched film having a polyethylene intermediate layer whose thickness is equal to or less than the upper limit exhibits, for example, excellent processability. When a stretched film has two or more polyethylene intermediate layers, the above "thickness" refers to the total thickness of each polyethylene intermediate layer.

[0093] In the stretched film of the first aspect, the thickness of the polyethylene intermediate layer is preferably at least 50%, more preferably at least 60%, even more preferably at least 70% of the thickness of the stretched film, and is preferably at most 94%, more preferably at most 90%, even more preferably at most 84%, for example, at least 50% but not more than 94%. When the stretched film has two or more polyethylene intermediate layers, the above "thickness" means the total thickness of each polyethylene intermediate layer.

[0094] In the stretched film of the first embodiment, the thickness of the first and third PE layers is each independently preferably 1 μm or more, more preferably 1.5 μm or more, even more preferably 2 μm or more, and preferably 15 μm or less, more preferably 10 μm or less, even more preferably 8 μm or less, for example, 1 μm or more and 15 μm or less.

[0095] In the stretched film of the first embodiment, the thicknesses of the first and third PE layers are each independently preferably 5% or more, more preferably 10% or more, even more preferably 15% or more, and preferably 40% or less, more preferably 35% or less, even more preferably 30% or less, relative to the thickness of the polyethylene intermediate layer, for example, 5% or more and 40% or less.

[0096] In the stretched film of the first embodiment, the thickness of the second PE layer is preferably 2 μm or more, more preferably 5 μm or more, even more preferably 8 μm or more, and preferably 60 μm or less, more preferably 40 μm or less, even more preferably 20 μm or less, for example, 2 μm or more and 60 μm or less.

[0097] In the stretched film of the first embodiment, the thickness of the second PE layer is preferably 20% or more, more preferably 30% or more, even more preferably 40% or more, and preferably 90% or less, more preferably 80% or less, even more preferably 70% or less, of the thickness of the polyethylene intermediate layer, for example, 20% or more and 90% or less.

[0098] In the stretched film of the second embodiment, the thicknesses of the first and second surface resin layers are each independently preferably 0.3 μm or more, more preferably 0.5 μm or more, even more preferably 0.8 μm or more, and preferably 15 μm or less, more preferably 10 μm or less, even more preferably 5 μm or less, particularly preferably 3 μm or less, for example, 0.3 μm or more and 15 μm or less. When the first surface resin layer has protrusions caused by particles, the thickness of the layer is preferably measured in an area where protrusions caused by the particles are not formed.

[0099] In the stretched film of the second embodiment, the thicknesses of the first and second surface resin layers are each independently, relative to the thickness of the stretched film, preferably 1% or more, more preferably 2% or more, even more preferably 4% or more, and preferably 20% or less, more preferably 15% or less, even more preferably 10% or less, particularly preferably 8% or less, for example, 1% or more and 20% or less.

[0100] In the stretched film of the second aspect, the thickness of the polyethylene intermediate layer is preferably 6 μm or more, more preferably 10 μm or more, even more preferably 14 μm or more, and preferably 100 μm or less, more preferably 80 μm or less, even more preferably 60 μm or less, even more preferably 40 μm or less, and particularly preferably 30 μm or less, for example, 6 μm or more and 100 μm or less. A stretched film having a polyethylene intermediate layer whose thickness is equal to or greater than the lower limit exhibits, for example, excellent strength, rigidity, heat resistance, and recyclability. A stretched film having a polyethylene intermediate layer whose thickness is equal to or less than the upper limit exhibits, for example, excellent processability. When a stretched film has two or more polyethylene intermediate layers, the above "thickness" refers to the sum of the thicknesses of the individual polyethylene intermediate layers.

[0101] In the stretched film of the second embodiment, the thickness of the polyethylene intermediate layer is preferably at least 60%, more preferably at least 70%, even more preferably at least 80%, and particularly preferably at least 84% of the thickness of the stretched film, and is preferably at most 98%, more preferably at most 96%, and even more preferably at most 92%, for example, from 60% to 98%. When the stretched film has two or more polyethylene intermediate layers, the above "thickness" means the total thickness of each polyethylene intermediate layer.

[0102] In the stretched film of the second embodiment, the thickness of the first and third PE layers is each independently preferably 0.5 μm or more, more preferably 0.8 μm or more, even more preferably 1 μm or more, and preferably 18 μm or less, more preferably 13 μm or less, even more preferably 8 μm or less, particularly preferably 5 μm or less, for example, 0.5 μm or more and 18 μm or less.

[0103] In the stretched film of the second embodiment, the thicknesses of the first and third PE layers are each independently preferably 3% or more, more preferably 5% or more, even more preferably 7% or more, and preferably 25% or less, more preferably 20% or less, even more preferably 15% or less, relative to the thickness of the polyethylene intermediate layer, for example, 3% or more and 25% or less.

[0104] In the stretched film of the second embodiment, the thickness of the second PE layer is preferably 4 μm or more, more preferably 6 μm or more, even more preferably 8 μm or more, and preferably 60 μm or less, more preferably 40 μm or less, even more preferably 20 μm or less, for example, 4 μm or more and 60 μm or less.

[0105] In the stretched film of the second embodiment, the thickness of the second PE layer is preferably 50% or more, more preferably 60% or more, even more preferably 70% or more, and preferably 94% or less, more preferably 90% or less, even more preferably 86% or less, of the thickness of the polyethylene intermediate layer, for example, 50% or more and 94% or less.

[0106] From the viewpoint of film symmetry and suppression of curling, the ratio of the thickness of the second surface resin layer to the thickness of the first surface resin layer is preferably 0.6 or more and 1.4 or less, more preferably 0.7 or more and 1.3 or less, even more preferably 0.8 or more and 1.2 or less, and particularly preferably 0.9 or more and 1.1 or less.

[0107] From the viewpoint of film symmetry and suppression of curling, the ratio of the thickness of the first PE layer to the thickness of the third PE layer is preferably 0.6 or more and 1.4 or less, more preferably 0.7 or more and 1.3 or less, even more preferably 0.8 or more and 1.2 or less, and particularly preferably 0.9 or more and 1.1 or less.

[0108] At least one selected from the group consisting of polyethylene films, stretched films, and barrier films may be surface-treated. Such polyethylene films, stretched films, and barrier films have, for example, excellent adhesion to other layers. Surface treatment methods include, for example, physical treatments and chemical treatments. Physical treatments include, for example, corona treatment, ozone treatment, low-temperature plasma treatment using oxygen gas and / or nitrogen gas, and glow discharge treatment. Chemical treatments include, for example, oxidation treatment using chemicals.

[0109] The second aspect will be mainly described below. In one embodiment of the polyethylene film and stretched film thereof, the density of the polyethylene in the polyethylene intermediate layer is higher than the density of the polyethylene in the first surface resin layer, and the density of the polyethylene in the second surface resin layer is lower than the density of the polyethylene in the polyethylene intermediate layer. Such a film tends to have an excellent balance of surface smoothness, transparency, printability, vapor deposition adhesion, and heat resistance. When the polyethylene intermediate layer is thicker than the surface resin layer, the polyethylene intermediate layer provides high heat resistance. The difference in density between the polyethylene in the polyethylene intermediate layer and the surface resin layer is, for example, 0.003 g / cm. 3 More than that is fine. The total content ratio of high-density polyethylene and medium-density polyethylene is hereinafter referred to as "content ratio A." This may be only high-density polyethylene, only medium-density polyethylene, or a mixture of high-density polyethylene and medium-density polyethylene. In one embodiment of the polyethylene film and stretched film thereof, the polyethylene content A in the intermediate layer is greater than the content A in the first surface resin layer, and the polyethylene content A in the second surface resin layer is smaller than the content A in the intermediate layer. Such a film tends to have an excellent balance of surface smoothness, transparency, printability, vapor deposition adhesion, and heat resistance. The difference in content A between the intermediate layer and the surface resin layer may be, for example, 10% by mass or more or 30% by mass or less.

[0110] In one embodiment of the polyethylene film and stretched film thereof, the density of the polyethylene in the polyethylene intermediate layer is lower than the density of the polyethylene in the first surface resin layer, and the density of the polyethylene in the second surface resin layer is higher than the density of the polyethylene in the polyethylene intermediate layer. Such a film tends to have an excellent balance between biaxial stretchability and heat resistance. When the polyethylene intermediate layer is thicker than the surface resin layer, the polyethylene intermediate layer provides high biaxial stretchability. The difference in density between the polyethylene in the surface resin layer and the polyethylene intermediate layer is, for example, 0.003 g / cm. 3 More than that is fine. In one embodiment of the polyethylene film and stretched film thereof, the content ratio A in the polyethylene intermediate layer is smaller than the content ratio A in the first surface resin layer, and the content ratio A in the polyethylene intermediate layer is larger than the content ratio A in the polyethylene intermediate layer. Such a film tends to have an excellent balance between biaxial stretchability and heat resistance. The difference in content ratio A between the surface resin layer and the polyethylene intermediate layer may be, for example, 10% by mass or more or 30% by mass or less.

[0111] In one embodiment of the polyethylene film and stretched film thereof, the densities of the polyethylene in the first surface resin layer, the polyethylene intermediate layer, and the second surface resin layer are approximately equal to each other. For example, the difference in density between the layer with the highest polyethylene density and the layer with the lowest polyethylene density among the first surface resin layer, the polyethylene intermediate layer, and the second surface resin layer is 0.003 g / cm. 3 is less than. In one embodiment of the polyethylene film and stretched film thereof, the first surface resin layer, the polyethylene intermediate layer, and the second surface resin layer each have approximately the same content ratio A. For example, the difference in content ratio A between the layer with the highest content ratio A and the layer with the lowest content ratio A among the first surface resin layer, the polyethylene intermediate layer, and the second surface resin layer is less than 10% by mass.

[0112] When each layer contains two or more polyethylenes with different densities, the density of the polyethylene refers to the density of a mixture of the two or more polyethylenes. The methods for measuring and calculating the density are as described above.

[0113] The first surface resin layer may further contain particles. The inclusion of particles in the first surface resin layer can improve, for example, the antiblocking property or slip property of a polyethylene film and a stretched film thereof. From the viewpoint of the formability of the anchor coat layer and the vapor-deposited film, it is preferable that the second surface resin layer does not contain particles.

[0114] Examples of particles include inorganic compound-based antiblocking agents and resin particle-based antiblocking agents. Specific examples of inorganic compound-based antiblocking agents include oxides such as silica, aluminum oxide, magnesium oxide, calcium oxide, titanium oxide, and zinc oxide; hydroxides such as aluminum hydroxide, magnesium hydroxide, and calcium hydroxide; carbonates such as magnesium carbonate and calcium carbonate; sulfates such as calcium sulfate and barium sulfate; silicates such as magnesium silicate, aluminum silicate, calcium silicate, and aluminosilicate; and others, including kaolin, talc, and diatomaceous earth. Specific examples of the resin particles include resin particles composed of resin components such as polymethyl methacrylate (PMMA), polystyrene, methyl methacrylate-styrene copolymer, polyester, polyamide, polytetrafluoroethylene, epoxy resin, urea resin, and phenolic resin. The resin particles may be crosslinked or non-crosslinked.

[0115] From the viewpoint of cost etc., the particles may be an inorganic compound-based antiblocking agent. The particles may be a resin particle-based antiblocking agent. For example, in the case of a barrier film in which one surface resin layer contains a resin particle-based antiblocking agent and the other surface resin layer has an anchor coat layer and a vapor-deposited film on it, the possibility of the particles damaging the vapor-deposited film can be reduced when the film is stored in a roll form. This is because resin particle-based antiblocking agents are usually less uneven and softer than inorganic compound-based antiblocking agents.

[0116] The average particle size of the particles is preferably 0.5 μm or more, more preferably 1 μm or more, even more preferably 2 μm or more, and preferably 6 μm or less, more preferably 5.5 μm or less, even more preferably 5 μm or less, for example, 0.5 μm or more and 6 μm or less. The average particle size of the particles means the average particle size (arithmetic mean diameter) measured for 100 randomly selected non-aggregated particles when the cross section of each layer in the thickness direction is observed with a scanning electron microscope (SEM).

[0117] When the first surface resin layer contains particles, the particle content is, based on the mass of the first surface resin layer, preferably 100 ppm or more, more preferably 500 ppm or more, even more preferably 1,000 ppm or more, and preferably 10,000 ppm or less, more preferably 8,000 ppm or less, even more preferably 5,000 ppm or less, for example, 100 ppm or more and 10,000 ppm or less.

[0118] In the stretched film, when the first surface resin layer contains particles, the ratio of the average particle size of the particles to the thickness of the first surface resin layer (average particle size / thickness) is preferably 0.5 or more and 5.0 or less, more preferably 0.8 or more and 4.0 or less, and even more preferably 1.0 or more and 3.5 or less.

[0119] <Polypropylene film and stretched film> The polypropylene film and its stretched film contain polypropylene as a main component. The polypropylene may be any of propylene homopolymer (homopolypropylene), propylene random copolymer (random polypropylene) such as propylene-α-olefin random copolymer, and propylene block copolymer (block polypropylene) such as propylene-α-olefin block copolymer, or a mixture of two or more selected from these. From the viewpoint of reducing the environmental load, biomass-derived polypropylene or mechanically or chemically recycled polypropylene may be used as the polypropylene.

[0120] In this disclosure, polypropylene refers to a propylene homopolymer or a polymer in which the proportion of propylene-derived structural units in all repeating structural units is greater than the proportion of structural units derived from any comonomer. In this polymer, the proportion of propylene-derived structural units may be, for example, 50 mol% or more, 60 mol% or more, 70 mol% or more, or 80 mol% or more. The above content is measured by NMR.

[0121] A propylene homopolymer is a polymer of propylene alone. A propylene random copolymer is a random copolymer of propylene and an α-olefin other than propylene. A propylene block copolymer is a copolymer having a polymer block of propylene and a polymer block of an α-olefin other than propylene. Examples of α-olefins other than propylene include α-olefins having 2 to 20 carbon atoms, specifically ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 3-methyl-1-butene, 4-methyl-1-pentene, and 6-methyl-1-heptene.

[0122] Among polypropylenes, propylene random copolymers are preferred from the viewpoint of transparency, propylene homopolymers are preferred when emphasis is placed on the rigidity and heat resistance of the packaging container, and propylene block copolymers are preferred when emphasis is placed on the impact resistance of the packaging container.

[0123] From the viewpoint of film-forming ability and processability, the MFR of polypropylene is preferably 0.1 g / 10 min or more, more preferably 0.2 g / 10 min or more, even more preferably 0.5 g / 10 min or more, and preferably 50 g / 10 min or less, more preferably 30 g / 10 min or less, even more preferably 10 g / 10 min or less, for example, 0.1 g / 10 min or more and 50 g / 10 min or less. In this specification, the MFR of polypropylene is measured by Method A in accordance with JIS K7210-1:2014 under conditions of a temperature of 230°C and a load of 2.16 kg.

[0124] The density of polypropylene is, for example, 0.88 g / cm 3 More than 0.92g / cm 3 From the viewpoints of strength, heat resistance, and the like, the melting point (Tm) of polypropylene is preferably 120°C or higher, more preferably 125°C or higher, and preferably 170°C or lower, more preferably 165°C or lower, for example, 120°C or higher and 170°C or lower.

[0125] The polypropylene film may contain a resin material other than polypropylene, such as polyolefins other than polypropylene, (meth)acrylic resins, vinyl resins, cellulose resins, polyamides, polyesters, and ionomer resins. The polypropylene film may contain biomass polypropylene. The polypropylene film may contain recycled polypropylene. The polypropylene film may contain the above-mentioned additives.

[0126] The polypropylene content in the polypropylene film and its stretched film is preferably more than 50% by mass, more preferably 80% by mass or more, even more preferably 85% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more. The barrier film of the present disclosure comprising such a stretched film can be suitably used as a substrate constituting packaging materials such as polypropylene-based mono-material packaging materials. A laminate (or packaging container) comprising such a stretched film has, for example, excellent recyclability.

[0127] The stretching treatment may be uniaxial stretching or biaxial stretching. When stretching is performed in the machine direction (the flow direction of the film, MD direction), the stretching ratio is preferably 2 times or more, more preferably 3 times or more, and preferably 15 times or less, more preferably 10 times or less, for example, 2 times or more and 15 times or less. When stretching is performed in the width direction (the direction perpendicular to the MD direction, TD direction), the stretching ratio is preferably 2 times or more, more preferably 3 times or more, and preferably 15 times or less, more preferably 10 times or less, for example, 2 times or more and 15 times or less. The stretched polypropylene film may be, for example, a uniaxially stretched film or a biaxially stretched film, with a biaxially stretched film being preferred.

[0128] The polypropylene film may have a single layer structure or a multi-layer structure. The thickness of the stretched polypropylene film is preferably 5 μm or more, more preferably 10 μm or more, and even more preferably 15 μm or more, from the viewpoint of strength and heat resistance, and is preferably 200 μm or less, more preferably 100 μm or less, even more preferably 50 μm or less, and particularly preferably 40 μm or less, for example, 5 μm or more and 200 μm or less, from the viewpoint of processability.

[0129] At least one selected from the group consisting of polypropylene film, stretched film, and barrier film may be subjected to the above-mentioned surface treatment. Such a film has, for example, excellent adhesion to other layers.

[0130] <Anchor coat layer> The barrier film of the present disclosure comprises an anchor coat layer containing a resin material having a polar group on at least the second surface of a stretched film, and a vapor-deposited film on the anchor coat layer. That is, the barrier film of the present disclosure comprises an anchor coat layer between the stretched film and the vapor-deposited film. The vapor-deposited film formed on the anchor coat layer has high adhesion, is dense with few gaps, has excellent flexibility, and is excellent in gas barrier properties. Furthermore, a packaging container produced using a laminate comprising such a barrier film has high lamination strength. In one embodiment, the anchor coat layer is in contact with the stretched film.

[0131] The barrier film of the present disclosure may also have an anchor coat layer on the first surface of the stretched film. In this case, it is preferable that the layer constituting the first surface of the polyethylene film has the same composition as the polyethylene layer (S2) or is the polyethylene layer (1).

[0132] The anchor coat layer contains a resin material having a polar group. Examples of the polar group include a carboxy group, a carboxylic anhydride group, a hydroxyl group, an amino group, a thiol group, a sulfo group, an epoxy group, a carbonyl group, an ester group, an amide group, a urethane group, and a halogen group. Among these, from the viewpoint of more effectively exhibiting the above-mentioned effects, a carboxy group, a hydroxyl group, an amino group, a carbonyl group, an ester group, and a urethane group are preferred, and a carboxy group, a hydroxyl group, an ester group, and a urethane group are more preferred.

[0133] Examples of resin materials having polar groups include hydroxyl group-containing (meth)acrylic resins, hydroxyl group-free (meth)acrylic resins, urethane resins, ethylene-vinyl alcohol copolymers, polyvinyl alcohol, polyesters, polyamides (e.g., nylon 6, nylon 6,6, MXD nylon, amorphous nylon), and polyethyleneimine, with hydroxyl group-containing (meth)acrylic resins, urethane resins, ethylene-vinyl alcohol copolymers, and polyvinyl alcohol being preferred. The use of such resin materials significantly improves the adhesion of the vapor-deposited film formed on the anchor coat layer, effectively improving its gas barrier properties.

[0134] The content of the resin material having a polar group in the anchor coat layer is preferably more than 50% by mass, more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, and particularly preferably 90% by mass or more.

[0135] The anchor coat layer may contain a resin material other than the resin material having a polar group. The anchor coat layer may contain the above-mentioned additives.

[0136] The anchor coat layer can be formed by dissolving or dispersing a material such as a resin material having polar groups in water or an appropriate organic solvent, applying the resulting coating solution to a polyolefin film or a stretched film thereof, and drying (and curing as necessary). Examples of coating methods include known coating methods such as roll coating, gravure coating, knife coating, dip coating, and spray coating. The anchor coat layer may be formed using, for example, an aqueous emulsion or a solvent-based emulsion. Examples of aqueous emulsions include polyamide-based emulsions and polyurethane-based emulsions. Examples of solvent-based emulsions include polyester-based emulsions.

[0137] In one embodiment, the anchor coat layer may be formed using a composition containing a functional group-containing (meth)acrylic resin, an isocyanate compound as a curing agent, and, if necessary, a silane coupling agent.

[0138] Examples of functional group-containing (meth)acrylic resins include hydroxyl group-containing (meth)acrylic resins, carboxyl group-containing (meth)acrylic resins, epoxy group-containing (meth)acrylic resins, and amino group-containing (meth)acrylic resins. Among these, hydroxyl group-containing (meth)acrylic resins are particularly preferred because the reaction rate can be easily controlled.

[0139] In one embodiment, the hydroxyl group-containing (meth)acrylic resin is produced from a monomer not having a hydroxyl group and a hydroxyl group-containing (meth)acrylic monomer. Examples of the monomer not having a hydroxyl group include alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-hexyl (meth)acrylate, and lauryl (meth)acrylate; styrene-based monomers such as styrene and vinyltoluene; and vinyl ester-based monomers such as vinyl acetate and vinyl propionate. Examples of the hydroxyl group-containing (meth)acrylic monomer include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate and hydroxypropyl (meth)acrylate.

[0140] In one embodiment, the functional group-containing (meth)acrylic resin other than the hydroxyl group-containing (meth)acrylic resin can be produced from the above-mentioned monomer not having a hydroxyl group and a carboxy group-containing monomer such as (meth)acrylic acid, maleic acid, or itaconic acid; an epoxy group-containing monomer such as glycidyl (meth)acrylate; or a nitrogen-containing monomer such as (meth)acrylamide, N-methylol (meth)acrylamide, diacetone (meth)acrylamide, or dimethylaminoethyl (meth)acrylate.

[0141] The following mainly describes the case where a hydroxyl group-containing (meth)acrylic resin is used. The glass transition temperature (Tg) of the hydroxyl group-containing (meth)acrylic resin is preferably 50°C or higher and 200°C or lower, more preferably 70°C or higher and 150°C or lower. When Tg is 50°C or higher, for example, blocking can be suppressed. When Tg is 200°C or lower, for example, curability can be improved. Tg can be measured by differential scanning calorimetry (DSC) in accordance with JIS K7121:2012 (using a test piece after conditioning according to 3.(3)).

[0142] The number average molecular weight of the hydroxyl group-containing (meth)acrylic resin is preferably 10,000 or more and 100,000 or less. When the number average molecular weight is 10,000 or more, for example, blocking can be suppressed. When the number average molecular weight is 100,000 or less, for example, coating suitability can be improved. The number average molecular weight is measured by gel permeation chromatography (GPC) in accordance with JIS K7252-1:2008 and is expressed as a value converted into standard polystyrene.

[0143] The hydroxyl value of the hydroxyl-containing (meth)acrylic resin is preferably 20 mgKOH / g or more and 200 mgKOH / g or less, more preferably 30 mgKOH / g or more and 150 mgKOH / g or less. When the hydroxyl value is 20 mgKOH / g or more, for example, interlayer adhesion and gas barrier properties can be improved. The hydroxyl value is measured in accordance with JIS K0070:1992.

[0144] The isocyanate compound used as the curing agent is a compound that reacts with a hydroxyl group-containing (meth)acrylic resin to form a urethane bond, and is any compound known as an isocyanate curing agent. The anchor coat layer formed using the composition of this embodiment contains, for example, a urethane resin. Examples of the isocyanate compound include aromatic diisocyanate monomers such as tolylene diisocyanate, xylylene diisocyanate, and 4,4-diphenylmethane diisocyanate; aliphatic diisocyanate monomers such as hexamethylene diisocyanate; and polymers or derivatives thereof.

[0145] Silane coupling agents are organosilicon compounds that contain both a hydrolyzable group that reacts with inorganic substances and an organic functional group that reacts with organic substances in one molecule. Examples of hydrolyzable groups that react with inorganic substances include alkoxy groups such as methoxy and ethoxy groups, acetoxy groups, and chloro groups. Examples of organic functional groups that react with organic substances include functional groups that react with hydroxyl groups in hydroxyl-containing (meth)acrylic resins or isocyanate groups in isocyanate compounds, such as isocyanate groups, amino groups, epoxy groups, and mercapto groups, and may also include vinyl groups and methacryloxy groups.

[0146] The organosilicon compound may have an alkyl or phenyl group that does not react with either inorganic or organic materials. The organosilicon compound may be mixed with a silicon compound that does not have an organic functional group, such as an alkoxysilane that has only hydrolyzable groups.

[0147] Examples of silane coupling agents include amino group-containing silane coupling agents such as N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and N-phenyl-3-aminopropyltrimethoxysilane; epoxy group-containing silane coupling agents such as 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane; mercapto group-containing silane coupling agents such as 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane; and isocyanate group-containing silane coupling agents such as 3-isocyanatepropyltriethoxysilane and 3-isocyanatepropyltrimethoxysilane.

[0148] Any solvent that can dissolve the hydroxyl group-containing (meth)acrylic resin can be used as long as it maintains the fluidity of the anchor coating agent during application and produces a smooth anchor coating layer. Examples of such solvents include alcohol-based solvents such as methanol, ethanol, isopropyl alcohol, n-butyl alcohol, and isobutyl alcohol; ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester-based solvents such as ethyl acetate, n-propyl acetate, n-butyl acetate, and isobutyl acetate; glycol-based solvents such as 2-butoxyethanol and propylene glycol monomethyl ether; and hydrocarbon-based solvents such as toluene, xylene, n-hexane, and methylcyclohexane. Mixed solvents of two or more of these solvents may also be used.

[0149] In the anchor coating agent, the molar ratio of isocyanate groups in the isocyanate compound to hydroxyl groups in the hydroxyl group-containing (meth)acrylic resin is preferably 0.3 to 3.0, which can improve, for example, curability and blocking resistance.

[0150] The content of the silane coupling agent in the anchor coating agent is preferably 3 to 80 parts by mass per 100 parts by mass of the solid content of the hydroxyl group-containing (meth)acrylic resin. This configuration can improve, for example, interlayer adhesion and blocking resistance.

[0151] For example, an anchor coating agent is prepared by mixing a hydroxyl group-containing (meth)acrylic resin, an isocyanate compound, and, if necessary, a silane coupling agent in any blending ratio, and the anchor coating agent is coated onto a polyolefin film or a stretched film thereof to form an anchor coating layer.

[0152] The thickness of the anchor coat layer is preferably 0.02 μm or more, more preferably 0.05 μm or more, even more preferably 0.1 μm or more, and particularly preferably 0.2 μm or more. A barrier film having such a configuration has, for example, excellent adhesion to a vapor-deposited film and excellent gas barrier properties, and the barrier film can be used to produce a packaging container having excellent lamination strength. The thickness of the anchor coat layer is preferably 10 μm or less, more preferably 5 μm or less, even more preferably 3 μm or less, and still more preferably 1 μm or less. A barrier film having such a configuration has excellent processability, for example, and can be used to produce a packaging container with excellent recyclability. The thickness of the anchor coat layer is, for example, not less than 0.02 μm and not more than 10 μm.

[0153] The ratio of the thickness of the anchor coat layer to the total thickness of the stretched film and the anchor coat layer is preferably 0.08% or more, more preferably 0.2% or more, even more preferably 0.3% or more, and particularly preferably 0.5% or more. A barrier film having such a configuration has, for example, excellent adhesion to a vapor-deposited film and excellent gas barrier properties, and can also be used to produce a packaging container having excellent lamination strength. The ratio of the thickness of the anchor coat layer to the total thickness of the stretched film and the anchor coat layer is preferably 20% or less, more preferably 10% or less, even more preferably 5% or less, and particularly preferably 3% or less. A barrier film having such a configuration has excellent processability, and using this barrier film, a packaging container with excellent recyclability can be produced. The above ratio of the thickness of the anchor coat layer is, for example, 0.08% or more and 20% or less.

[0154] A coated film having an anchor coating layer on a stretched film can be produced offline. Specifically, a polyolefin film is produced by forming a polyolefin or a resin composition thereof using an inflation method, a T-die casting method, or the like, and the film is stretched. After that, an anchor coating agent is applied to the film and dried, thereby producing the coated film. A coated film having an anchor coating layer on a stretched film can also be produced in-line. Specifically, the coated film can be produced by forming a polyolefin film from a polyolefin or its resin composition using an inflation method, a T-die casting method, or the like, applying an anchor coating agent to the film and drying it, and then stretching the coated film. A coated film having an anchor coat layer on a biaxially stretched film can also be produced in-line. Specifically, a polyolefin film is produced by forming a polyolefin or a resin composition thereof using a T-die casting method, an inflation method, or the like, and the film is stretched in the machine direction (MD), after which an anchor coat agent is applied to the film and dried, and then the coated film is stretched in the width direction (TD), thereby producing the coated film. Note that stretching in the MD direction may be carried out first, followed by stretching in the TD direction.

[0155] It is preferable to perform the surface treatment on the film before applying the anchor coating agent. The drying conditions for forming the anchor coating layer from the anchor coating agent are preferably 50°C or higher, more preferably 70°C or higher, and preferably 150°C or lower, more preferably 120°C or lower, for example, 50°C or higher and 150°C or lower, and the drying time is preferably 1 second or longer and 10 minutes or shorter.

[0156] <Vapor deposition film> The barrier film of the present disclosure includes a vapor-deposited film on an anchor coat layer. The barrier film has excellent adhesion to the vapor-deposited film, and has excellent gas barrier properties, specifically oxygen barrier properties and water vapor barrier properties. Furthermore, when the vapor-deposited film is a metal vapor-deposited film, the film has excellent brightness. A packaging container produced using such a barrier film has excellent gas barrier properties. In one embodiment, the vapor-deposited film is in contact with the anchor coat layer.

[0157] The vapor-deposited film may be composed of, for example, a metal and / or an inorganic oxide. The vapor-deposited film may be a metal vapor-deposited film composed of one or more metals, or an inorganic oxide vapor-deposited film composed of one or more inorganic oxides. The inorganic oxide vapor-deposited film may be a transparent vapor-deposited film. Examples of metals include aluminum, chromium, tin, nickel, copper, silver, gold, and platinum. Examples of inorganic oxides include aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, barium oxide, and silicon carbide oxide (carbon-containing silicon oxide). Among vapor-deposited films, aluminum vapor-deposited films, aluminum oxide (alumina) vapor-deposited films, silicon oxide (silica) vapor-deposited films, and silicon carbide vapor-deposited films are preferred.

[0158] The barrier film may have two or more vapor-deposited films on the anchor coat layer.

[0159] In one embodiment, the barrier film of the present disclosure comprises at least A stretched film; An anchor coat layer; a first vapor-deposited film; a second deposited film; in this order. Such a barrier film has excellent gas barrier properties and can suppress deterioration of gas barrier properties due to pinholes. The first and second vapor-deposited films may be vapor-deposited films constituting a multistage vapor-deposited film. An adhesion-improving layer such as a barrier coat layer or a metal oxide film, which will be described later, may be provided between the first and second vapor-deposited films, for the purpose of improving adhesion between them. The thickness and / or composition of the first and second vapor-deposited films may be the same as or different from each other. The barrier film may have an additional vapor-deposited film on the second vapor-deposited film. In this case, an adhesion-improving layer such as a barrier coat layer or a metal oxide film may be provided between the two vapor-deposited films.

[0160] In one embodiment, the barrier film of the present disclosure has an anchor coat layer and a vapor-deposited film only on the second surface of the stretched film, and no vapor-deposited film on the first surface of the stretched film. In one embodiment, the barrier film of the present disclosure has an anchor coat layer and a vapor-deposited film only on the second surface resin layer of the stretched film, and no vapor-deposited film on the first surface resin layer. In the case of a barrier film having vapor-deposited films on both surfaces of a stretched film, when the barrier film is stored, for example, in a rolled form, the vapor-deposited films may deteriorate due to contact or rubbing between the vapor-deposited films. The barrier film of the above embodiment can suppress such deterioration of the vapor-deposited film. Furthermore, by using a laminate including such a barrier film, a packaging container with excellent content resistance can be produced. For example, a laminate including a barrier film and a heat-sealing layer is prepared. The laminate includes a barrier film arranged so that the stretched film faces the heat-sealing layer (the inside of the packaging container) and the vapor-deposited film faces the outside (the outside of the packaging container). By producing a packaging container using the above laminate, the vapor-deposited film can be positioned on the outside, thereby preventing discoloration, corrosion, or deterioration of the vapor-deposited film, as well as lifting and peeling of layers, even when the packaging container is filled with corrosive contents. For example, a laminate is prepared that includes a first heat-seal layer, a barrier film, and a second heat-seal layer. The laminate includes the barrier film, with the stretched film facing the first heat-seal layer (the inside of the tube container) and the vapor-deposited film facing the second heat-seal layer (the outside of the tube container). By producing a tube container body using the above laminate, the vapor-deposited film can be positioned on the outside, thereby preventing discoloration, corrosion, or deterioration of the vapor-deposited film, as well as lifting and peeling of layers, even when the tube container is filled with corrosive contents.

[0161] In one embodiment, the barrier film of the present disclosure comprises at least a first vapor-deposited film; a first anchor coat layer; A stretched film; a second anchor coat layer; a second deposited film; The film comprises, in this order. The first anchor coat layer is provided on the first surface of the stretched film. The second anchor coat layer is provided on the second surface of the stretched film. The first vapor-deposited film is provided on the first anchor coat layer. The second vapor-deposited film is provided on the second anchor coat layer. Such a barrier film has excellent gas barrier properties and can suppress deterioration of gas barrier properties due to pinholes. The thickness and / or composition of the first anchor coat layer and the second anchor coat layer may be the same as or different from each other. The thickness and / or composition of the first vapor-deposited film and the second vapor-deposited film may be the same as or different from each other. The barrier film may have an additional vapor-deposited film on the first vapor-deposited film and / or the second vapor-deposited film, and in this case, an adhesion-improving layer such as a barrier coat layer or a metal oxide film may be provided between the two vapor-deposited films. In one embodiment, the barrier film at least has, in this order, a third vapor-deposited film, a first vapor-deposited film, a first anchor coat layer, a stretched film, a second anchor coat layer, a second vapor-deposited film, and a fourth vapor-deposited film.

[0162] The combination of the first and second vapor-deposited films is not particularly limited. From the viewpoint of gas barrier properties, the first vapor-deposited film may be a metal vapor-deposited film and the second vapor-deposited film may be a metal vapor-deposited film, and both may be the same or different. The first vapor-deposited film may be an aluminum vapor-deposited film and the second vapor-deposited film may be an aluminum vapor-deposited film, and both may be the same or different aluminum vapor-deposited films.

[0163] One of the first and second vapor-deposited films may be a metal vapor-deposited film, and the other may be an inorganic oxide vapor-deposited film. One of the first and second vapor-deposited films may be an aluminum vapor-deposited film, and the other may be an alumina vapor-deposited film, a silica vapor-deposited film, or a silicon carbide oxide vapor-deposited film. By using a laminate including a barrier film of this type, a packaging container with excellent resistance to contents can be produced. For example, a laminate including a barrier film and a heat-seal layer is prepared. The laminate includes a barrier film in which the inorganic oxide vapor-deposited film faces the heat-seal layer (the inside of the packaging container) and the other vapor-deposited film faces the outside (the outside of the packaging container). By producing a packaging container using this laminate, discoloration, corrosion, or deterioration of the vapor-deposited film, as well as lifting and peeling of the layers, can be suppressed even when the packaging container is filled with corrosive contents. This is because inorganic oxide vapor-deposited films are originally oxidized, and therefore are prevented from undergoing volumetric expansion due to oxidation, as occurs with metal vapor-deposited films.

[0164] For example, the first vapor-deposited film may be an inorganic oxide vapor-deposited film and the second vapor-deposited film may be a metal vapor-deposited film, or the first vapor-deposited film may be a transparent vapor-deposited film such as an alumina vapor-deposited film, a silica vapor-deposited film, or a silicon carbide oxide vapor-deposited film and the second vapor-deposited film may be an aluminum vapor-deposited film. In this case, the thickness of the aluminum vapor-deposited film can be measured in real time by measuring the amount of light transmittance during the formation of the second vapor-deposited film (during aluminum vapor deposition), making it easy to control the film thickness.

[0165] The first vapor-deposited film may be an inorganic oxide vapor-deposited film, and the second vapor-deposited film may be an inorganic oxide vapor-deposited film, both of which may be the same or different. The first vapor-deposited film may be an alumina vapor-deposited film, a silica vapor-deposited film, or a silicon carbide oxide vapor-deposited film, and the second vapor-deposited film may be an alumina vapor-deposited film, a silica vapor-deposited film, or a silicon carbide oxide vapor-deposited film, both of which may be the same or different. Such a barrier film has excellent transparency. Therefore, by using this barrier film, it is possible to produce, for example, packaging containers with excellent visibility of the contents, packaging containers that can be used in microwave ovens, and packaging containers that can pass through metal detectors. For example, by using this barrier film, it is possible to produce packaging containers that do not contain an aluminum vapor-deposited film. Consumers can clearly see that such packaging containers do not contain an aluminum vapor-deposited film. Therefore, such packaging containers are easy to separate and, further, the inclusion of black spots (metallic color) that can occur due to the aluminum vapor-deposited film during recycling can be suppressed. Furthermore, the barrier film of this embodiment can avoid the problem of oxidation deterioration when the vapor-deposited film is a metal vapor-deposited film, and can also suppress corrosion of the vapor-deposited film from the edge faces of the barrier film.

[0166] From the viewpoint of gas barrier properties, the thickness of the vapor-deposited film is preferably 1 nm or more, more preferably 5 nm or more, and even more preferably 10 nm or more. From the viewpoint of suppressing cracking in the vapor-deposited film and improving the recyclability of the packaging container, the thickness of the vapor-deposited film is preferably 150 nm or less, more preferably 100 nm or less, and even more preferably 80 nm or less. The thickness of the vapor-deposited film is, for example, 1 nm or more and 150 nm or less. The thicknesses of the first vapor-deposited film and the second vapor-deposited film are also preferably each independently within the above range.

[0167] When the vapor-deposited film is an aluminum vapor-deposited film, the optical density (OD value) of the aluminum vapor-deposited film is preferably 2.0 or more and 3.5 or less. This makes it possible to improve the oxygen barrier property and water vapor barrier property while maintaining the productivity of the barrier film. The OD value is measured in accordance with JIS K7361-1:1997.

[0168] The surface of the vapor-deposited film is preferably subjected to the above-mentioned surface treatment, which provides, for example, excellent adhesion to adjacent layers.

[0169] Examples of methods for forming vapor-deposited films include physical vapor deposition (PVD) methods such as vacuum deposition, sputtering, and ion plating, as well as chemical vapor deposition (CVD) methods such as plasma-enhanced chemical vapor deposition, thermal chemical vapor deposition, and photochemical vapor deposition. The vapor-deposited film may be a composite film containing two or more layers of different vapor-deposited films, formed by combining both physical vapor deposition and chemical vapor deposition.

[0170] The vacuum level in the deposition chamber was 10 -2 ~10 -8 After oxygen is introduced, the pressure is preferably about 10 -1 ~10 -6 A pressure of about mbar is preferable. The amount of oxygen introduced varies depending on the size of the deposition machine. The oxygen introduced may be mixed with an inert gas such as argon gas, helium gas, or nitrogen gas as a carrier gas, provided that this does not cause any problems. The transport speed of the target film on which the deposition film is formed is, for example, 10 m / min to 800 m / min.

[0171] The vapor-deposited film may be a single layer formed by a single vapor deposition process, or may be a multilayer formed by multiple vapor deposition processes. When the vapor-deposited film is a multilayer film, each layer may be composed of the same or different components. Each layer may be formed by the same method or by different methods.

[0172] <Barrier coat layer> The barrier film of the present disclosure may further include a barrier coat layer on the vapor-deposited film. That is, the barrier film may further include a barrier coat layer on the surface of the vapor-deposited film opposite to the surface facing the anchor coat layer. Such a barrier film has excellent scratch resistance and gas barrier properties, and when the vapor-deposited film is composed of an inorganic oxide such as aluminum oxide or silicon oxide, it can effectively suppress the occurrence of cracks in the vapor-deposited film and suppress a decrease in gas barrier properties, for example. The barrier film of the present disclosure may include a barrier coating layer between the two vapor-deposited films described above.

[0173] In one embodiment, the barrier film includes, in this order, a stretched film, an anchor coat layer, an inorganic oxide vapor-deposited film, and a barrier coat layer. In one embodiment, the barrier film includes, in this order, a stretched film, an anchor coat layer, a first vapor-deposited film, a barrier coat layer, and a metal vapor-deposited film as a second vapor-deposited film. In one embodiment, the barrier film comprises, in this order, a stretched film, an anchor coat layer, a first vapor-deposited film, a barrier coat layer, an inorganic oxide vapor-deposited film as a second vapor-deposited film, and a barrier coat layer. In one embodiment, the barrier film comprises, in this order, a metal vapor deposition film as the first vapor deposition film, a first anchor coat layer, a stretched film, a second anchor coat layer, an inorganic oxide vapor deposition film as the second vapor deposition film, and a barrier coat layer. In one embodiment, the barrier film comprises, in this order, a barrier coating layer, an inorganic oxide vapor deposition film as a first vapor deposition film, a first anchor coating layer, a stretched film, a second anchor coating layer, and a metal vapor deposition film as a second vapor deposition film. In one embodiment, the barrier film comprises, in this order, a first barrier coating layer, an inorganic oxide vapor deposition film as the first vapor deposition film, a first anchor coating layer, a stretched film, a second anchor coating layer, an inorganic oxide vapor deposition film as the second vapor deposition film, and a second barrier coating layer.

[0174] The thickness and / or composition of each vapor-deposited film may be the same as or different from each other. The thickness and / or composition of each barrier coat layer may be the same as or different from each other. The thickness and / or composition of each anchor coat layer may be the same as or different from each other.

[0175] In one embodiment, the barrier coat layer contains a gas barrier resin. A barrier film including such a layer has even better gas barrier properties. The barrier coat layer can be formed, for example, by applying a coating liquid obtained by dissolving or dispersing a material such as a gas barrier resin in water or an appropriate organic solvent to a vapor-deposited film and drying the resulting coating liquid.

[0176] Examples of gas barrier resins include ethylene-vinyl alcohol copolymers, polyvinyl alcohol, polyamides, polyvinylidene chloride, polyesters, polyether polyols, polyester polyols, polyurethanes, polyacrylonitrile, and (meth)acrylic resins.

[0177] In one embodiment, the content of the gas barrier resin in the barrier coat layer is preferably more than 50% by mass, more preferably 60% by mass or more, even more preferably 70% by mass or more, still more preferably 80% by mass or more, and particularly preferably 90% by mass or more. Such a layer has, for example, excellent gas barrier properties.

[0178] The barrier coat layer may contain the above-mentioned additives.

[0179] The thickness of the barrier coat layer containing the gas barrier resin is preferably 0.01 μm or more, more preferably 0.1 μm or more, from the viewpoint of gas barrier properties. The thickness of the barrier coat layer containing the gas barrier resin is preferably 10 μm or less, more preferably 5 μm or less, from the viewpoint of processability of the barrier film and recyclability of the packaging container. The thickness is, for example, 0.01 μm or more and 10 μm or less.

[0180] In another embodiment, the barrier coat layer is a gas barrier coating film formed by applying a gas barrier composition to a vapor-deposited film and drying it. The gas barrier composition is obtained by mixing a metal alkoxide, a water-soluble polymer, and optionally a silane coupling agent, and adding, optionally, water, optionally an organic solvent, and optionally a sol-gel catalyst. The gas barrier coating film contains a hydrolysis polycondensate obtained by hydrolyzing and polycondensing the metal alkoxide or the like by a sol-gel method. By providing such a film on a vapor-deposited film, when the vapor-deposited film is composed of an inorganic oxide, the gas barrier properties can be improved and the occurrence of cracks in the vapor-deposited film can be effectively suppressed.

[0181] Examples of metal alkoxides include alkoxysilanes, specifically tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane.

[0182] Examples of water-soluble polymers include hydroxyl group-containing polymers such as polyvinyl alcohol and ethylene-vinyl alcohol copolymers. These water-soluble polymers can also contribute to improving gas barrier properties, for example. Depending on the desired physical properties, such as oxygen barrier properties, water vapor barrier properties, water resistance, and weather resistance, either polyvinyl alcohol or ethylene-vinyl alcohol copolymers may be used, or both may be used in combination. Furthermore, a gas barrier coating film obtained using polyvinyl alcohol and a gas barrier coating film obtained using an ethylene-vinyl alcohol copolymer may be laminated. The amount of water-soluble polymer used is preferably 5 to 500 parts by mass per 100 parts by mass of the metal alkoxide.

[0183] As the silane coupling agent, a known organoalkoxysilane containing an organic reactive group can be used, and an organoalkoxysilane having an epoxy group is preferred, such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. The amount of the silane coupling agent used is preferably 1 part by mass or more and 20 parts by mass or less per 100 parts by mass of the metal alkoxide.

[0184] The gas barrier composition may contain water in an amount of preferably 0.1 mol or more, more preferably 0.5 mol or more, per mol of metal alkoxide, and preferably 100 mol or less, more preferably 60 mol or less. By setting the water content at or above the lower limit, for example, the oxygen barrier property and water vapor barrier property of the barrier film can be improved. By setting the water content at or below the upper limit, for example, the hydrolysis reaction can be carried out quickly.

[0185] The gas barrier composition may contain an organic solvent, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, and n-butyl alcohol.

[0186] The sol-gel catalyst is preferably an acid or an amine compound.

[0187] Examples of methods for applying the gas barrier composition include roll coating using a gravure roll coater or the like, spray coating, spin coating, dipping, brush coating, bar coating, and applicator coating.

[0188] Hereinafter, one embodiment of the method for forming a gas barrier coating film will be described. A gas barrier composition is prepared by mixing a metal alkoxide, a water-soluble polymer, a sol-gel catalyst, water, an organic solvent, and, if necessary, a silane coupling agent. A polycondensation reaction gradually progresses within the composition. The composition is then coated onto the vapor-deposited film by a conventional method and dried. This drying process further promotes polycondensation of the metal alkoxide and the water-soluble polymer (and the silane coupling agent, if the composition contains one) to form a composite polymer layer. Multiple composite polymer layers may be laminated by repeating the above process. For example, the coated composition is heated at a temperature of preferably 20°C or higher, more preferably 50°C or higher, and even more preferably 70°C or higher, and preferably 150°C or lower, more preferably 120°C or lower, and even more preferably 100°C or lower, for 1 second to 10 minutes. In this manner, a gas barrier coating film can be formed.

[0189] The thickness of the gas barrier coating film is preferably 0.01 μm or more, more preferably 0.05 μm or more, even more preferably 0.1 μm or more, and is preferably 100 μm or less, more preferably 50 μm or less, even more preferably 5 μm or less, still more preferably 2 μm or less, and particularly preferably 1 μm or less, for example, 0.01 μm or more and 100 μm or less. A barrier film having such a gas barrier coating film has, for example, excellent gas barrier properties, can suppress the occurrence of cracks in a vapor-deposited film made of an inorganic oxide, and also provides excellent recyclability and processability of the packaging container.

[0190] <Adhesion improving layer> The barrier film of the present disclosure may further include an adhesion-improving layer, such as a barrier coat layer, between the two vapor-deposited films. When the barrier film of the present disclosure includes a stretched film, an anchor coat layer, a first vapor-deposited film, and a second vapor-deposited film in this order, the barrier film may further include an adhesion-improving layer, such as a barrier coat layer, between the first vapor-deposited film and the second vapor-deposited film. The adhesion-improving layer is a layer that improves interlayer adhesion between the first vapor-deposited film and the second vapor-deposited film. When the vapor-deposited film is composed of an inorganic oxide such as aluminum oxide or silicon oxide, such a barrier film can effectively suppress, for example, the occurrence of cracks in the vapor-deposited film and suppress a decrease in gas barrier properties. From the viewpoint of improving gas barrier properties, the adhesion-improving layer is preferably a barrier coat layer. The details of the barrier coat layer are as described above.

[0191] When both of the two vapor-deposited films are metal vapor-deposited films, a metal oxide film may be formed between the two vapor-deposited films as an adhesion-improving layer. When the first vapor-deposited film is a metal vapor-deposited film and the second vapor-deposited film is a metal vapor-deposited film, a metal oxide film may be formed between the first and second vapor-deposited films as an adhesion-improving layer. Forming a metal oxide film can improve the adhesion between the vapor-deposited films. Furthermore, forming a multilayer film including a first vapor-deposited film, a metal oxide film, and a second vapor-deposited film can stably form vapor-deposited films from the viewpoints of high thickness uniformity, fewer defects, etc., rather than forming a single thick metal vapor-deposited film.

[0192] The thickness of the metal oxide film as the adhesion improving layer is preferably 1 nm or more and 30 nm or less, more preferably 3 nm or more and 15 nm or less, from the viewpoint of the adhesion and gas barrier properties of the metal vapor deposition film.

[0193] The metal oxide film may be formed, for example, by forming a first vapor-deposited film and then introducing oxygen into metal vapor to vaporize the metal oxide obtained, or by heating the first vapor-deposited film in an oxygen atmosphere to oxidize the surface of the first vapor-deposited film. By forming a second vapor-deposited film on the surface of the metal oxide film, a barrier film can be produced that includes a metal vapor-deposited film as the first vapor-deposited film, a metal oxide film, and a metal vapor-deposited film as the second vapor-deposited film. It is preferable that the first vapor-deposited film is an aluminum vapor-deposited film, the metal oxide film is an aluminum oxide film, and the second vapor-deposited film is an aluminum vapor-deposited film. For example, after forming a first vapor-deposited film by aluminum vapor deposition, a small amount of oxygen is introduced into the aluminum vapor to form an aluminum oxide film on the first vapor-deposited film, and then the introduction of oxygen is stopped and a second vapor-deposited film is formed on the aluminum oxide film by vapor deposition of aluminum.

[0194] <Print layer> The barrier film of the present disclosure may further include a printed layer, which will be described later. The printed layer may be provided, for example, on the surface of the vapor-deposited film, on the surface of the barrier coat layer, or on the surface of the first surface resin layer.

[0195] <Layer structure of barrier film> Hereinafter, several examples of the layer structure of the barrier film of the present disclosure will be given with reference to the drawings. The barrier film 1 shown in FIG. 1A includes a stretched film 10, an anchor coat layer 20, and a vapor-deposited film 40 in this order. The barrier film 1 shown in FIG. 1B comprises a stretched film 10 consisting of a first surface resin layer S1, a polyethylene intermediate layer IM, and a second surface resin layer S2, an anchor coat layer 20, and a vapor-deposited film 40, in this order. The barrier film 1 shown in FIG. 1C comprises, in this order, a stretched film 10 consisting of a first surface resin layer S1, a first PE layer 11, a second PE layer 12, a third PE layer 13 and a second surface resin layer S2, an anchor coat layer 20 and a vapor-deposited film 40.

[0196] Other specific examples of the layer structure of the barrier film will be described below. In one embodiment, the barrier film comprises, in this order, an oriented film, an anchor coat layer, a metal vapor deposition film, a barrier coat layer or a metal oxide film, and a metal vapor deposition film. In one embodiment, the barrier film includes, in this order, a stretched film, an anchor coat layer, a metal vapor deposition film, a barrier coat layer, an inorganic oxide vapor deposition film, and another barrier coat layer. In one embodiment, the barrier film includes, in this order, a stretched film, an anchor coat layer, an inorganic oxide vapor-deposited film, a barrier coat layer, and a metal vapor-deposited film. In one embodiment, the barrier film includes, in this order, a stretched film, an anchor coat layer, an inorganic oxide vapor-deposited film, a barrier coat layer, an inorganic oxide vapor-deposited film, and a barrier coat layer.

[0197] In one embodiment, the barrier film comprises, in this order, a metal vapor-deposited film, a first anchor coat layer, a stretched film, a second anchor coat layer, and a metal vapor-deposited film. In one embodiment, the barrier film comprises, in this order, a metal vapor-deposited film, a first anchor coat layer, a stretched film, a second anchor coat layer, an inorganic oxide vapor-deposited film, and a barrier coat layer. In one embodiment, the barrier film comprises, in this order, a barrier coating layer, an inorganic oxide vapor deposition film, a first anchor coating layer, a stretched film, a second anchor coating layer, an inorganic oxide vapor deposition film, and a barrier coating layer.

[0198] In one embodiment, the barrier film comprises, in this order, a metal vapor deposition film, a barrier coat layer or a metal oxide film, a metal vapor deposition film, a first anchor coat layer, a stretched film, a second anchor coat layer, a metal vapor deposition film, a barrier coat layer or a metal oxide film, and a metal vapor deposition film. In one embodiment, the barrier film comprises, in this order, a metal vapor deposition film, a barrier coat layer, an inorganic oxide vapor deposition film, a first anchor coat layer, a stretched film, a second anchor coat layer, an inorganic oxide vapor deposition film, a barrier coat layer, and a metal vapor deposition film. In one embodiment, the barrier film comprises, in this order, a barrier coating layer, an inorganic oxide vapor deposition film, a barrier coating layer, a metal vapor deposition film, a first anchor coating layer, a stretched film, a second anchor coating layer, a metal vapor deposition film, a barrier coating layer, an inorganic oxide vapor deposition film, and a barrier coating layer. In one embodiment, the barrier film comprises, in this order, a barrier coating layer, an inorganic oxide vapor deposition film, a barrier coating layer, an inorganic oxide vapor deposition film, a first anchor coating layer, a stretched film, a second anchor coating layer, an inorganic oxide vapor deposition film, a barrier coating layer, an inorganic oxide vapor deposition film, and a barrier coating layer. The metal vapor-deposited film is preferably an aluminum vapor-deposited film, and the inorganic oxide vapor-deposited film is preferably at least one vapor-deposited film selected from the group consisting of an alumina vapor-deposited film, a silica vapor-deposited film, and a silicon carbide oxide vapor-deposited film.

[0199] <Gas barrier properties of barrier film> The oxygen permeability (unit: cc / (m 2 The oxygen permeability (°C / day atm) may be, for example, less than 10, less than 6.0, less than 2.0, less than 1.0, or less than 0.4. The lower limit of the oxygen permeability may be, for example, 0.01. The oxygen permeability is measured in accordance with JIS K7126-2:2006 in an environment at a temperature of 23°C and a humidity of 90% RH.

[0200] The water vapor permeability (unit: g / (m 2 The time (day)) may be, for example, less than 10, less than 5.0, or less than 2.0. The lower limit of the water vapor permeability may be, for example, 0.01. The water vapor permeability is measured in accordance with JIS K7129-2:2019 in an environment at a temperature of 40°C and a humidity of 90% RH.

[0201] [Laminate] The laminate of the present disclosure comprises: A barrier film of the present disclosure; a heat seal layer; At least one of the following is provided. In one embodiment, the laminate of the present disclosure comprises at least a first heat seal layer; A barrier film of the present disclosure; a second heat seal layer; and are provided in this order.

[0202] The laminate of the present disclosure can be suitably used as a packaging material. The laminate of the present disclosure can be suitably used, for example, as a packaging material for forming the body of a tube container body. In this case, for example, the second heat seal layer is a sealant layer on the outer surface side of the body, and the first heat seal layer is a sealant layer on the inner surface side of the body. That is, the body comprises, from the outside to the inside of the body, the second heat seal layer, a barrier film, and a first heat seal layer, in this order.

[0203] In one embodiment, the laminate of the present disclosure does not include aluminum foil. In one embodiment, the laminate of the present disclosure does not include either a polyethylene terephthalate film or aluminum foil. Such a laminate and a packaging container including the laminate have excellent recyclability.

[0204] In one embodiment, the total thickness of the laminate of the present disclosure may be 40 μm or more, 60 μm or more, 80 μm or more, 100 μm or more, 120 μm or more, 140 μm or more, 400 μm or less, 350 μm or less, or 300 μm or less, for example, 40 μm or more and 400 μm or less. The total thickness of the laminate can be changed as appropriate depending on, for example, the use or shape of the packaging container.

[0205] <Base material> The laminate of the present disclosure includes the barrier film of the present disclosure. The laminate of the present disclosure may include two or more barrier films. Details of the barrier film are as described above, and detailed description will be omitted here.

[0206] In a laminate comprising a barrier film and a heat seal layer, the orientation of the barrier film is not particularly limited. From the viewpoint of resistance to contents, the barrier film may be arranged so that the stretched film faces the heat seal layer (inside the packaging container) and the vapor-deposited film faces the opposite side to the heat seal layer (outside the packaging container). That is, the laminate may comprise the heat seal layer, the stretched film, the anchor coat layer, and the vapor-deposited film in this order.

[0207] The laminate of the present disclosure may further include an oriented polyolefin substrate. The oriented polyolefin substrate is a polyolefin substrate that has been subjected to a stretching treatment. The oriented polyolefin substrate contains polyolefin as a main component. Examples of polyolefins include polyethylene, polypropylene, polybutene, and polymethylpentene. Among these, polyethylene and polypropylene are preferred, and polyethylene is more preferred. Examples of the oriented polyolefin substrate are preferred, such as an oriented polyethylene substrate containing polyethylene as a main component, and an oriented polypropylene substrate containing polypropylene as a main component, and polyethylene substrates are more preferred. The stretching treatment may be uniaxial or biaxial stretching. Details of the stretching treatment are as described above, and will not be described here. The oriented polyolefin substrate may be, for example, a uniaxial or biaxially stretched substrate.

[0208] The oriented polyolefin substrate may contain a biomass polyolefin. The oriented polyolefin substrate may contain recycled polyolefin. The oriented polyolefin substrate may contain the above-mentioned additives.

[0209] The polyolefin content in the oriented polyolefin substrate is preferably more than 50% by mass, more preferably 80% by mass or more, even more preferably 85% by mass or more, still more preferably 90% by mass or more, and particularly preferably 95% by mass or more.

[0210] The oriented polyolefin substrate may have a single layer structure or a multilayer structure. The thickness of the oriented polyolefin substrate is preferably 5 μm or more, more preferably 8 μm or more, and even more preferably 10 μm or more, from the viewpoint of the strength and heat resistance of the laminate, and is preferably 300 μm or less, more preferably 100 μm or less, and even more preferably 50 μm or less, for example, 5 μm or more and 300 μm or less, from the viewpoint of the processability of the laminate.

[0211] The oriented polyolefin substrate may be subjected to the above-mentioned surface treatment. Such an oriented polyolefin substrate has, for example, excellent adhesion to a layer adjacent to the substrate. An anchor coating layer may be formed on the surface of the oriented polyolefin substrate using a conventionally known anchor coating agent.

[0212] The laminate further comprising a oriented polyolefin substrate may, for example, comprise a heat seal layer, a barrier film of the present disclosure, and a oriented polyolefin substrate in this order, or may comprise a heat seal layer, a oriented polyolefin substrate, and a barrier film of the present disclosure in this order.

[0213] <Print layer> The laminate of the present disclosure may include a printed layer on one or both surfaces of the substrate, such as the barrier film and the oriented polyolefin substrate, described above. The laminate of the present disclosure may also include a printed layer on the second heat-sealable layer described below.

[0214] The print layer includes an image. Examples of the image include letters, figures, patterns, symbols, and combinations thereof. The image may include text information such as the product name, the name of the item in the packaging container, the manufacturer, and the names of ingredients. The image may be a single, solid color (a so-called solid image).

[0215] The printed layer can be formed, for example, using an ink composition. Methods for forming the printed layer include, for example, gravure printing, offset printing, flexographic printing, screen printing, letterpress printing, and transfer printing. From the viewpoint of reducing the environmental load, the printed layer may be formed by flexographic printing. From the viewpoint of reducing the environmental load, the printed layer may be formed using ink derived from biomass.

[0216] The thickness of the printed layer is preferably 0.1 μm or more, more preferably 0.2 μm or more, even more preferably 0.3 μm or more, and preferably 10 μm or less, more preferably 5 μm or less, even more preferably 3 μm or less, for example, 0.1 μm or more and 10 μm or less.

[0217] <Surface protective layer> The laminate of the present disclosure may include a surface protective layer on the printed layer provided on the second heat seal layer described below in order to improve the scratch resistance and weather resistance of the printed layer. The laminate of the present disclosure preferably includes a surface protective layer that covers the entire area of ​​the printed layer. From the viewpoint of visibility of the printed layer, the surface protective layer is preferably transparent in the visible light range, and more preferably colorless and transparent.

[0218] The surface protective layer contains, for example, a cured product of a thermoplastic resin, a thermosetting resin, or a cured product of an energy ray-curable compound. Among these, from the viewpoint of improving scratch resistance and weather resistance, the surface protective layer preferably contains a cured product of a thermosetting resin or a cured product of an energy ray-curable compound, and more preferably contains a cured product of an energy ray-curable compound. The proportion of the cured product in the total resin components of the surface protective layer is preferably 80% by mass or more, more preferably 90% by mass or more. Methods for forming the surface protective layer include, for example, letterpress printing, flexographic printing, gravure printing, offset printing, screen printing, inkjet printing, and thermal transfer printing.

[0219] The thickness of the surface protective layer is preferably 0.5 μm or more, more preferably 1 μm or more, and preferably 15 μm or less, more preferably 10 μm or less, for example, 0.5 μm or more and 15 μm or less. A laminate including such a surface protective layer has, for example, excellent scratch resistance and weather resistance.

[0220] <Heat seal layer> The laminate of the present disclosure comprises a heat seal layer. The heat-seal layer contains, as its main component, a heat-fusible resin that can be melted and fused to each other by heat. Examples of heat-fusible resins include polyolefins such as polyethylene, polypropylene, and polymethylpentene, cyclic polyolefins, cyclic olefin copolymers, ionomer resins, acid-modified polyolefins, and ethylene-(meth)acrylic acid ester-unsaturated carboxylic acid terpolymers. Examples of polyethylene include linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, and ethylene-(meth)acrylic acid ester copolymers. Examples of acid-modified polyolefins include resins obtained by modifying polyolefins such as polyethylene and polypropylene with unsaturated carboxylic acid compounds such as (meth)acrylic acid and maleic anhydride. The heat-fusible resin may be a material derived from fossil fuels, a biomass-derived material such as biomass polyethylene, or a recycled material such as recycled polyethylene. Two or more of these may also be used.

[0221] In recent years, there has been a demand for recycling packaging containers in order to reduce environmental impact. From the viewpoint of recyclability, it is preferable that the substrate and the heat seal layer are each made of the same type of resin material (mono-material). In one embodiment, the heat seal layer contains a polyolefin such as polyethylene or polypropylene as a main component. This configuration enables the packaging container to be made mono-material. Such packaging containers have excellent recyclability, and there is no need to separate the substrate and the heat seal layer, for example, after collecting used packaging containers. The above-mentioned laminate in which the heat seal layer contains a polyolefin as a main component can be suitably used as a packaging material, such as a polyolefin-based mono-material packaging material.

[0222] For example, when the stretched film is a stretched polyethylene film, the heat seal layer preferably contains polyethylene as a main component. For example, when the stretched film is a stretched polypropylene film, the heat seal layer preferably contains polypropylene as a main component.

[0223] From the viewpoint of heat-sealability, the heat-seal layer preferably contains low-density polyethylene and / or linear low-density polyethylene. When the heat-seal layer contains low-density polyethylene and linear low-density polyethylene, the content (mass%) of the linear low-density polyethylene may be greater than the content (mass%) of the low-density polyethylene.

[0224] In one embodiment, the melting point (Tm) of the polyethylene contained in the heat seal layer is preferably 90°C or higher, more preferably 95°C or higher, and preferably 140°C or lower, more preferably 130°C or lower, for example, 90°C or higher and 140°C or lower, from the viewpoint of a balance between heat resistance and heat sealability.

[0225] In one embodiment, the content of polyethylene or polypropylene in the heat seal layer is preferably more than 50% by mass, more preferably 80% by mass or more, and even more preferably 90% by mass or more. A laminate including such a heat seal layer has excellent recyclability, for example.

[0226] The heat seal layer may contain the above-mentioned additives.

[0227] The content of polyethylene or polypropylene in the entire laminate of the present disclosure is preferably 80% by mass or more, more preferably 85% by mass or more, and even more preferably 90% by mass or more. With this configuration, for example, a mono-material packaging container can be produced using the laminate, improving the recyclability of the packaging container. The upper limit of the content of polyethylene or polypropylene is not particularly limited, but may be 99% by mass.

[0228] The laminate of the present disclosure may include at least a first heat-sealing layer as the heat-sealing layer, a barrier film of the present disclosure, and a second heat-sealing layer as the heat-sealing layer, in this order. The first heat-sealing layer and the second heat-sealing layer can be melted by heating and fused to each other. Such a laminate can be suitably used, for example, as a packaging material for forming the body of a tube container.

[0229] In one embodiment, the first and second heat-seal layers contain polyethylene as a main component, and the polyethylene contained in the first heat-seal layer and the polyethylene contained in the second heat-seal layer may be the same or different.

[0230] In the laminate of the above embodiment, the orientation of the barrier film is not particularly limited. From the viewpoint of resistance to contents, the barrier film may be arranged so that the stretched film faces the first heat-seal layer and the vapor-deposited film faces the second heat-seal layer. That is, the laminate may include the first heat-seal layer, the stretched film, the anchor coat layer, the vapor-deposited film, and the second heat-seal layer in this order.

[0231] The heat seal layer may have a single-layer structure or a multi-layer structure. The first and second heat seal layers may have a single-layer structure or a multi-layer structure.

[0232] The thickness of the heat seal layer may be 10 μm or more, 20 μm or more, 30 μm or more, 50 μm or more, 60 μm or more, 70 μm or more, or 80 μm or more from the viewpoint of heat sealing properties and recyclability of the packaging container. The thickness of the heat seal layer may be 300 μm or less, 200 μm or less, or 150 μm or less from the viewpoint of processability of the laminate. The thickness of the heat seal layer is, for example, 10 μm or more and 300 μm or less. The thicknesses of the first and second heat seal layers are also preferably independently within the above ranges. The thickness of the heat seal layer can be appropriately changed depending on, for example, the use or shape of the packaging container. In the case of a small bag, the thickness of the heat seal layer may be, for example, 20 μm or more and 60 μm or less, but is not particularly limited. In the case of a standing pouch, the thickness of the heat seal layer may be, for example, 60 μm or more and 150 μm or less, but is not particularly limited. In the case of a tube container, the thickness of each heat seal layer may be, for example, 50 μm or more, 60 μm or more, 70 μm or more, or 80 μm or more, but is not particularly limited.

[0233] From the viewpoint of heat sealing property, the heat seal layer is preferably an unstretched resin film, more preferably an unstretched co-extruded resin film, and each layer constituting the heat seal layer is a co-extruded resin layer. The above resin film can be produced, for example, by using a T-die casting method or an inflation method. The concept of "unstretched film" includes not only a film that is not stretched at all, but also a film that is slightly stretched due to the tension applied during film formation.

[0234] For example, an unstretched resin film corresponding to the heat seal layer may be laminated on the barrier film via an adhesive layer as needed, or the heat seal layer may be formed by melt-extruding a heat-fusible resin or a resin composition thereof onto the barrier film. In the latter case, an adhesive layer may not be provided. Examples of adhesive layers include the following adhesive layers.

[0235] <Adhesive layer> The laminate of the present disclosure may include an adhesive layer between any layers, such as between a substrate such as a barrier film and a heat seal layer. Such a laminate has excellent adhesion between the substrate and the heat seal layer, for example.

[0236] The laminate of the present disclosure may, for example, comprise a heat-sealing layer, an adhesive layer, and a barrier film of the present disclosure, in this order; a heat-sealing layer, a first adhesive layer, a barrier film of the present disclosure, a second adhesive layer, and an oriented polyolefin substrate, in this order; or a heat-sealing layer, a first adhesive layer, an oriented polyolefin substrate, a second adhesive layer, and a barrier film of the present disclosure, in this order. The laminate of the present disclosure may, for example, comprise a first heat-sealing layer, a first adhesive layer, a barrier film of the present disclosure, a second adhesive layer, and a second heat-sealing layer, in this order.

[0237] In one embodiment, the adhesive layer may be an adhesive layer made of an adhesive. The adhesive may be any of a one-component curing adhesive, a two-component curing adhesive, and a non-curing adhesive. The adhesive may be a solventless adhesive or a solvent-based adhesive. Among these, a solvent-based adhesive is preferred because it has better resistance to contents.

[0238] Examples of solvent-free adhesives, i.e., non-solvent laminate adhesives, include polyether adhesives, polyester adhesives, silicone adhesives, epoxy adhesives, and urethane adhesives. Among these, urethane adhesives are preferred, and two-component curing urethane adhesives are more preferred.

[0239] Examples of solvent-based adhesives include rubber-based adhesives, vinyl-based adhesives, olefin-based adhesives, silicone-based adhesives, epoxy-based adhesives, phenol-based adhesives, and urethane-based adhesives. Among these, urethane-based adhesives are preferred, and two-component curing urethane-based adhesives are more preferred.

[0240] In one embodiment, the laminate of the present disclosure may be produced by laminating a barrier film, an optional stretched polyolefin substrate, and a resin film corresponding to the heat seal layer by a non-solvent lamination method using a solvent-free adhesive, or by a dry lamination method using a solvent-based adhesive. The adhesive layer can be formed by applying an adhesive to the barrier film or the like and drying it by a method such as direct gravure roll coating, gravure roll coating, kiss coating, reverse roll coating, Fontaine method, or transfer roll coating.

[0241] The thickness of the adhesive layer may be 0.1 μm or more, 0.2 μm or more, 0.5 μm or more, 10 μm or less, 8 μm or less, or 6 μm or less, for example, 0.1 μm or more and 10 μm or less. The thickness of the adhesive layer may be 2 μm or less.

[0242] In one embodiment, the adhesive layer may be an adhesive resin layer containing a thermoplastic resin, or an extruded resin layer containing a thermoplastic resin. Examples of the thermoplastic resin include the above-mentioned heat-sealable resins. The thermoplastic resin may be a material derived from fossil fuels, a recycled material, or a material derived from biomass, or two or more of these may be used.

[0243] The thickness of the extruded resin layer is preferably 5 μm or more, more preferably 10 μm or more, from the viewpoint of interlayer adhesion. The thickness of the extruded resin layer is preferably 30 μm or less, more preferably 25 μm or less, from the viewpoint of reducing the production cost of the laminate and improving its productivity. The thickness of the extruded resin layer is, for example, 5 μm or more and 30 μm or less.

[0244] <Layer structure of laminate> Hereinafter, several examples of the layer configuration of the laminate of the present disclosure will be given with reference to the drawings. 2 includes a heat seal layer 80, an adhesive layer 60, and a barrier film 1 in this order, and more specifically, a heat seal layer 80, an adhesive layer 60, a stretched film 10, an anchor coat layer 20, and a vapor-deposited film 40 in this order. The laminate 2 may further include a printed layer (not shown), and for example, a printed layer may be further provided on the stretched film 10 or the vapor-deposited film 40 of the barrier film 1.

[0245] 3 includes, in this order, a heat seal layer 80, a first adhesive layer 61, a barrier film 1, a second adhesive layer 62, and an oriented polyolefin substrate 70. Specifically, the laminate 2 includes, in this order, a heat seal layer 80, a first adhesive layer 61, a stretched film 10, an anchor coat layer 20, a vapor-deposited film 40, a second adhesive layer 62, and an oriented polyolefin substrate 70. The laminate 2 may further include a printed layer (not shown), for example, on the surface of the oriented polyolefin substrate 70 facing the barrier film 1. A laminate having such a configuration is suitable, for example, as a packaging material for forming a stand-up pouch.

[0246] 4 includes, in this order, a first heat-seal layer 81, a first adhesive layer 61, a barrier film 1, a second adhesive layer 62, and a second heat-seal layer 82. Specifically, the laminate 2 includes, in this order, the first heat-seal layer 81, the first adhesive layer 61, a stretched film 10, an anchor coat layer 20, a vapor-deposited film 40, the second adhesive layer 62, and the second heat-seal layer 82. The laminate 2 may further include a printed layer (not shown), for example, a printed layer on the surface of the second heat-seal layer 82. A laminate having such a configuration is suitable, for example, as a packaging material for forming the barrel of a tube container body.

[0247] 2 to 4, the barrier film 1 may further include a barrier coating layer (not shown) on the vapor-deposited film 40. In Figures 2 to 4, the barrier film 1 may be oriented in the opposite direction. In Figures 2 to 4, the adhesive layers 60, 61, and 62 may be, for example, adhesive layers or extruded resin layers.

[0248] [Packaging container] The laminate of the present disclosure can be suitably used for packaging material applications. Packaging materials are used to produce packaging containers. By using at least the laminate of the present disclosure, packaging containers with excellent gas barrier properties can be produced.

[0249] Examples of packaging containers include packaging bags, tube containers, and containers with lids.

[0250] Examples of packaging bags include various types of packaging bags, such as stand-up pouch type, side seal type, two-sided seal type, three-sided seal type, four-sided seal type, envelope seal type, grommed seal type (pillow seal type), pleated seal type, flat bottom seal type, square bottom seal type, and gusset type.The packaging bag may be, for example, a small pouch or a zipper bag.The packaging bag may also be a refill pouch, particularly a stand-up pouch, that contains contents such as liquids and powders and is refilled into containers such as bottles.The packaging bag may also be, for example, a flexible packaging bag.

[0251] The packaging container of the present disclosure comprises the laminate of the present disclosure. The packaging container of the present disclosure may be, for example: one or more laminates of the present disclosure; a seal portion where the heat seal layers of the laminate are joined together; a storage section for storing contents; It has. The seal portion includes an inner edge that defines the receptacle portion.

[0252] Examples of methods for forming the sealed portion include heat sealing, in which the heat-sealed layers of the laminate are melted by heating or the like to fuse the heat-sealed layers together, and specific examples include bar sealing, rotary roll sealing, belt sealing, impulse sealing, high-frequency sealing, and ultrasonic sealing. For example, after the contents are placed in the packaging bag, the opening of the packaging bag can be heat-sealed to seal the packaging bag.

[0253] The packaging bag may have an easy-to-open portion. Examples of the easy-to-open portion include a notch portion that serves as a starting point for tearing the packaging bag, and a half-cut line formed by laser processing or a cutter as a path for tearing the packaging bag.

[0254] In one embodiment, the laminate of the present disclosure is used as a lid material in a lidded container. The lidded container comprises a container body having a storage compartment and a lid material joined (heat sealed) to the container body so as to seal the storage compartment. Here, the lid material, i.e., the heat seal layer of the laminate, and the container body are heat sealed. Examples of the shape of the container body include a cup shape and a cylindrical shape with a bottom. The container body is made of, for example, polystyrene, polypropylene, polyethylene, or paper.

[0255] The contents housed in the packaging container include, for example, liquids, solids, powders, and gels. The contents may be food or beverages, or non-food or beverages such as chemicals, cosmetics, pharmaceuticals, metal parts, and electronic components. Examples of the contents include shampoo, rinse, conditioner, hand soap, body soap, air fresheners, deodorants, insect repellents, fabric softeners, detergents; sauces, soy sauce, dressings, cooking oils, mayonnaise, ketchup, syrups, cooking alcohol, and other liquid or viscous condiments; fruit juices; spices; liquid beverages, jelly-like beverages, liquid soups, powdered soups, instant foods, other food and beverages; creams; toothpaste; metal parts, and electronic components. For example, toothpaste is a preferred content for tube containers.

[0256] In one embodiment, a packaging bag can be produced by folding the laminate of the present disclosure in half and overlapping them so that the barrier film is on the outside and the heat seal layer is on the inside, and then heat-sealing the edges, etc. In another embodiment, a packaging bag can be produced by overlapping multiple laminates of the present disclosure so that the heat seal layers face each other and heat-sealing the edges, etc. The entire packaging bag may be composed of the above-mentioned laminate, or only a portion of the packaging bag may be composed of the above-mentioned laminate.

[0257] In one embodiment, the stand-up pouch comprises a body portion composed of side sheets and a bottom portion composed of a bottom sheet. The bottom sheet maintains the shape of the side sheets, thereby imparting self-supporting properties to the pouch and enabling it to be a stand-up pouch. A storage compartment for storing contents is formed within the area surrounded by the side sheets and the bottom sheet. In the stand-up pouch, only the side sheets may be the laminate of the present disclosure, only the bottom sheet may be the laminate of the present disclosure, or both the side sheets and the bottom sheet may be the laminate of the present disclosure.

[0258] In one embodiment, the side sheet can be formed by preparing two laminates of the present disclosure, overlapping them with their heat-sealable layers facing each other, and heat-sealing both side edges to form a bag.

[0259] In another embodiment, the side sheets can be formed by preparing two laminates of the present disclosure, overlapping them with their heat-sealable layers facing each other, inserting two V-folded laminates with their heat-sealable layers facing outward between the laminates at the side edges of both sides of the overlapped laminates, and heat-sealing the two laminates. This production method produces a stand-up pouch having a body with side gussets.

[0260] In one embodiment, the bottom sheet can be formed by inserting the laminate of the present disclosure between the lower portions of the side sheets of a bag and heat-sealing the laminate. More specifically, the bottom sheet can be formed by inserting the laminate folded in a V-shape with the heat-seal layer facing outward between the lower portions of the side sheets of a bag and heat-sealing the laminate.

[0261] In one embodiment, two laminates of the present disclosure are prepared and stacked together with their heat-sealable layers facing each other. Then, another laminate of the present disclosure is folded in a V-shape with its heat-sealable layer facing outward, and this is sandwiched between the two laminates and heat-sealed to form a bottom. Next, two sides adjacent to the bottom are heat-sealed to form a body. In this manner, a stand-up pouch according to one embodiment can be formed.

[0262] [Tube container body] The tube container body of the present disclosure includes the laminate of the present disclosure. The tube container body of the present disclosure will be described below with reference to the drawings. Fig. 5 is a diagram showing a simplified configuration of a tube container 120. Fig. 6 is a cross-sectional view taken along line AA in Fig. 5. As shown in Fig. 5, the tube container body 121 includes a head 122 and a body 123, and the body 123 is made of the laminate of the present disclosure.

[0263] <Head> The head 122 includes a shoulder 124 connected to one end of the body 123, and a spout 125 connected to the shoulder 124. In one embodiment, the spout 125 includes threads 127 for threading a cap 126 onto the spout 125.

[0264] In one embodiment, the head portion is formed from a resin composition containing a thermoplastic resin. Examples of thermoplastic resins include polyolefins such as polyethylene and polypropylene, polyesters, cellulose resins, and vinyl resins. The resin composition may contain the additives described above. In one embodiment, the head portion is formed from a resin composition containing polyethylene. This configuration improves the recyclability of the tube container body. Examples of polyethylene include high-density polyethylene, medium-density polyethylene, low-density polyethylene, and linear low-density polyethylene. Among these, high-density polyethylene is preferred from the viewpoints of shape retention and moldability. The resin composition may contain at least one selected from the group consisting of biomass polyethylene and recycled polyethylene.

[0265] The head portion can be produced by a conventionally known method, for example, by compression molding or injection molding, and can be joined to the body portion.

[0266] <Body> In the tube container body 121 of the present disclosure, the body 123 is connected to a shoulder 124 of the head 122. The body 123 includes a fused portion 128 formed, for example, by overlapping the laminate of the present disclosure at one end so that the surface of the first heat-sealed layer at the other end is in contact with the surface of the second heat-sealed layer at the other end, rolling the laminate into a cylindrical shape, and heat-sealing the overlapped portion. The body 123 includes a bottom seal portion 129 formed, for example, by heat-sealing the opening of the cylindrically rolled laminate.

[0267] Examples of heat sealing methods include conventionally known methods such as bar sealing, rotary roll sealing, belt sealing, impulse sealing, high frequency sealing, ultrasonic sealing, and flame sealing.

[0268] For example, a cylindrical body portion may be produced by overlapping one end of the laminate of the present disclosure so that the surface of the first heat-seal layer at one end is in contact with the surface of the second heat-seal layer at the other end, rolling the laminate into a cylindrical shape, and heat-sealing the overlapped portion. From the viewpoint of heat-sealability, it is preferable that one overlapping end is the first heat-seal layer and the other end is the second heat-seal layer. In this case, the first heat-seal layer and the second heat-seal layer are melted and joined to form a fused portion.

[0269] Therefore, it is preferable that the second heat-sealing layer does not have a printed layer or a surface protective layer formed in the area where heat sealing is to be performed when forming the body of the tube container body. With this configuration, when forming the cylindrical body using the laminate of the present disclosure, the area can be heat-sealed well.

[0270] In the above embodiment, the fused portion is formed by overlapping. The same surfaces of both ends of the laminate may be butted together and the first heat-seal layers may be heat-sealed to join them. In this case, a printed layer and a surface protective layer may be formed on the second heat-seal layer at both ends of the laminate. Also, in this case, a bonding tape may be attached to the outer surface of the body portion so as to cover the bonding portion. It is preferable that a printed layer and a surface protective layer are not provided at the location of the laminate where the bonding tape is attached. The bonding tape may be provided on both the inner and outer surfaces of the body portion.

[0271] [Tube container] The tube container of the present disclosure will be described below with reference to the drawings. As shown in Fig. 5, the tube container 120 of the present disclosure includes a tube container body 121 and a cap 26 attached to a head portion 122.

[0272] <Tube container body> The tube container body has been described above, so a description thereof will be omitted here.

[0273] <Cap> The cap is removably attached to the spout of the head. The cap serves to close the spout. In one embodiment, the cap is formed from a resin composition containing a thermoplastic resin. Examples of thermoplastic resins include polyolefins such as polyethylene and polypropylene, polyesters, cellulose resins, and vinyl resins. From the viewpoint of recyclability, polyethylene is particularly preferred. Examples of polyethylene include high-density polyethylene, medium-density polyethylene, low-density polyethylene, and linear low-density polyethylene. Among these, high-density polyethylene is preferred from the viewpoint of shape retention and ease of opening. The resin composition may contain at least one selected from the group consisting of biomass polyethylene and recycled polyethylene. The resin composition may also contain the additives described above.

[0274] The cap may be a screw type having a groove on the inner surface of the cap so as to screw onto the thread 127 of the extraction port 125, as shown in FIG. 5, or it may be a stopper type that fits onto the extraction port 125 by tapping it.

[0275] [Example of the first aspect] The present disclosure relates to, for example, the following [1] to

[13] . [1] A barrier film comprising at least a stretched polyethylene film, an anchor coat layer, and a vapor-deposited film, in this order in the lamination direction, the polyethylene film and the stretched polyethylene film each having a first surface and a second surface opposite to the first surface, the polyethylene film preferably comprising a polyethylene layer containing high-density polyethylene and a polyethylene other than the high-density polyethylene as a layer constituting the second surface, the anchor coat layer containing a resin material having a polar group, the anchor coat layer being provided on at least the second surface of the stretched film, and the vapor-deposited film being provided on the anchor coat layer. [2] The barrier film according to [1], wherein the resin material contained in the anchor coat layer is at least one selected from the group consisting of hydroxyl group-containing (meth)acrylic resin, hydroxyl group-free (meth)acrylic resin, urethane resin, ethylene-vinyl alcohol copolymer, polyvinyl alcohol, polyester, polyamide, and polyethyleneimine. [3] The barrier film according to [1] or [2], wherein the ratio of the thickness of the anchor coat layer to the total thickness of the stretched film and the anchor coat layer is 0.08% or more and 20% or less. [4] The barrier film according to any one of the above [1] to [3], wherein the thickness of the anchor coat layer is from 0.02 μm to 10 μm. [5] The barrier film according to any one of [1] to [4], wherein the polyethylene layer constituting the second surface of the polyethylene film contains a medium-density polyethylene or a linear low-density polyethylene as the polyethylene other than the high-density polyethylene. [6] The barrier film according to any one of the above [1] to [5], wherein the polyethylene film is a co-extruded film. [7] The barrier film according to any one of the above [1] to [6], wherein the stretched film is a uniaxially stretched film. [8] The barrier film according to any one of [1] to [7] above, wherein the vapor-deposited film is selected from the group consisting of a metal vapor-deposited film and an inorganic oxide vapor-deposited film. [9] The barrier film according to any one of [1] to [8], further comprising a barrier coating layer on the surface of the vapor-deposited film opposite to the surface facing the anchor coating layer.

[10] A laminate comprising at least the barrier film according to any one of [1] to [9] above and a heat seal layer.

[11] The laminate according to

[10] , wherein the heat seal layer contains polyethylene as a main component, and the content of polyethylene in the entire laminate is 80% by mass or more.

[12] A packaging container comprising the laminate according to

[10] or

[11] .

[13] The packaging container according to

[12] above, which is a packaging bag.

[0276] [Example of the second aspect] The present disclosure relates to, for example, the following [1] to

[21] . [1] A barrier film comprising at least a stretched polyethylene film, an anchor coat layer, and a vapor-deposited film, in this order in the lamination direction, wherein the polyethylene film and the stretched polyethylene film each have a first surface and a second surface opposite to the first surface, and the polyethylene film preferably comprises, as a layer constituting the second surface, a polyethylene layer containing at least one polymer selected from the group consisting of high-density polyethylene and medium-density polyethylene and a polyethylene other than the polymer, or a polyethylene layer containing high-density polyethylene and medium-density polyethylene, wherein the anchor coat layer contains a resin material having a polar group, and the anchor coat layer is provided on at least the second surface of the stretched film, and the vapor-deposited film is provided on the anchor coat layer. [2] The barrier film according to [1], wherein the resin material contained in the anchor coat layer is at least one selected from the group consisting of hydroxyl group-containing (meth)acrylic resin, hydroxyl group-free (meth)acrylic resin, urethane resin, ethylene-vinyl alcohol copolymer, polyvinyl alcohol, polyester, polyamide, and polyethyleneimine. [3] The barrier film according to [1] or [2], wherein the ratio of the thickness of the anchor coat layer to the total thickness of the stretched film and the anchor coat layer is 0.08% or more and 20% or less. [4] The barrier film according to any one of the above [1] to [3], wherein the thickness of the anchor coat layer is from 0.02 μm to 10 μm. [5] The barrier film according to any one of [1] to [4], wherein the polyethylene layer constituting the second surface of the polyethylene film contains a linear high-density polyethylene as the other polyethylene. [6] The barrier film according to [5], wherein the polyethylene layer constituting the second surface of the polyethylene film has a total content of high-density polyethylene and medium-density polyethylene of 20% by mass or more and 60% by mass or less, and a content of linear low-density polyethylene of 40% by mass or more and 80% by mass or less. [7] The polyethylene layer constituting the second surface of the polyethylene film contains the high-density polyethylene, and the high-density polyethylene has a density of 0.945 g / cm 3 Super 0.960g / cm 3 an ethylene-α-olefin copolymer having a density of 0.930 g / cm or less, wherein the linear low-density polyethylene is 3 The barrier film according to [5] or [6], which is an ethylene-α-olefin copolymer having the following density: [8] The barrier film according to any one of [5] to [7], wherein the polyethylene film comprises a first surface resin layer constituting the first side, a polyethylene intermediate layer, and a second surface resin layer constituting the second side, and the first surface resin layer and the polyethylene intermediate layer each independently contain at least one polymer selected from the group consisting of high-density polyethylene and medium-density polyethylene, and linear low-density polyethylene. [9] The barrier film according to [8], wherein the first surface resin layer and the polyethylene intermediate layer each independently contain high-density polyethylene and medium-density polyethylene in a total content of 20% by mass or more and 60% by mass or less, and contain linear low-density polyethylene in a content of 40% by mass or more and 80% by mass or less.

[10] The first surface resin layer and the polyethylene intermediate layer each independently have a density of 0.945 g / cm 3 Super 0.960g / cm 3 and high-density polyethylene, an ethylene-α-olefin copolymer having a density of 0.930 g / cm 3 and a linear low-density polyethylene which is an ethylene-α-olefin copolymer having a density of:

[11] The barrier film according to any one of [8] to

[10] above, wherein the polyethylene film comprises two or more polyethylene intermediate layers.

[12] The barrier film according to any one of the above [1] to

[11] , wherein the polyethylene film is a co-extruded film.

[13] The barrier film according to any one of the above [1] to [4], wherein the polyethylene film is a monolayer film consisting of a layer containing at least one polymer selected from the group consisting of high-density polyethylene and medium-density polyethylene and a polyethylene other than the polymer, or a monolayer film consisting of a layer containing high-density polyethylene and medium-density polyethylene.

[14] The barrier film according to

[13] , wherein the polyethylene film contains a linear high-density polyethylene as the other polyethylene.

[15] The barrier film according to any one of the above [1] to

[14] , wherein the stretched film is a biaxially stretched film.

[16] The barrier film according to any one of the above [1] to

[15] , wherein the vapor-deposited film is a metal vapor-deposited film or an inorganic oxide vapor-deposited film.

[17] The barrier film according to any one of the above [1] to

[16] , further comprising a barrier coating layer on the surface of the vapor-deposited film opposite to the surface facing the anchor coating layer.

[18] A laminate comprising at least the barrier film according to any one of the above [1] to

[17] and a heat seal layer.

[19] The laminate according to

[18] , wherein the heat seal layer contains polyethylene as a main component, and the content of polyethylene in the entire laminate is 80% by mass or more.

[20] A packaging container comprising the laminate according to

[18] or

[19] .

[21] The packaging container according to

[20] , which is a packaging bag. [Example]

[0277] The barrier film of the present disclosure will be described in more detail below using examples, but the barrier film is not limited to the following examples. In the following description, "parts by mass" will be simply written as "parts." In the tables herein, "←" means that the composition of the layer in question is the same as the composition in the column to the left.

[0278] [Uniaxially stretched film materials] The following materials were used in the preparation of the uniaxially stretched film. High density polyethylene (HDPE) Dow Chemical's ELITE 5960G Density: 0.960g / cm 3 Melting point: 134°C, MFR: 0.85g / 10min Medium Density Polyethylene (MDPE) Dow Chemical's ELITE 5538G Density: 0.941g / cm 3 Melting point: 129°C, MFR: 1.3g / 10min Linear low-density polyethylene (LLDPE) Dow Chemical ELITE 5400G Density: 0.916g / cm 3 Melting point: 123°C, MFR: 1.3g / 10min

[0279] Example 1A Blended polyethylene (A) was prepared by blending 70 parts MDPE (ELITE 5538G) with 30 parts HDPE (ELITE 5960G). Blended polyethylene (B) was prepared by blending 50 parts MDPE (ELITE 5538G) with 50 parts LLDPE (ELITE 5400G).

[0280] A blended polyethylene (A), Blended polyethylene (B), LLDPE (ELITE 5400G) and Blended polyethylene (B), A blended polyethylene (A), Using a five-layer coextrusion inflation device, the extruded polyethylene was extruded into a tubular shape through a multi-layer annular die, and then inflated with air pressure while being taken up vertically to form a tubular film. The tubular film comprised a blended polyethylene (A) layer, a blended polyethylene (B) layer, an LLDPE layer, a blended polyethylene (B) layer, and a blended polyethylene (A) layer that constituted the outer surface of the tube. The tubular film was flattened by joining its inner surfaces together, and then both ends of the tubular film in the width direction were cut off to a predetermined width to separate it into two films. Each of the resulting polyethylene films was stretched 5 times in the machine direction (MD) using a stretching device to produce a uniaxially stretched film with a thickness of 25 μm.

[0281] The uniaxially stretched film thus obtained is A first surface resin layer (blend polyethylene (A) layer) having a thickness of 3 μm; A first PE layer (blend polyethylene (B) layer) having a thickness of 4.5 μm; a second PE layer (LLDPE layer) having a thickness of 10 μm; a third PE layer (blended polyethylene (B) layer) having a thickness of 4.5 μm; A second surface resin layer (blend polyethylene (A) layer) having a thickness of 3 μm; are provided in this order.

[0282] A hydroxyl-containing (meth)acrylic resin (number average molecular weight: 25,000, glass transition temperature: 85°C, hydroxyl value: 80 mgKOH / g) and 3-glycidoxypropyltriethoxysilane (silane coupling agent) were diluted with a mixed solvent of methyl ethyl ketone and ethyl acetate (mixing ratio: 1:1) to prepare a base resin with a hydroxyl-containing (meth)acrylic resin solids concentration of 10% by mass and a silane coupling agent concentration of 1.5% by mass. An ethyl acetate solution containing xylylene diisocyanate (solids concentration: 75% by mass) was added to the base resin as a curing agent to obtain an anchor coating agent. The amount of curing agent used was 8 parts by mass per 100 parts by mass of the base resin.

[0283] After corona treatment was performed on the second surface resin layer of the uniaxially stretched film, the anchor coating agent was applied to the corona-treated surface of the second surface resin layer and dried at 80°C for 2 seconds to form an anchor coating layer with a thickness of 0.2 µm. In this way, a coated film comprising a uniaxially stretched film and an anchor coating layer was obtained.

[0284] Water, isopropyl alcohol, and a small amount of hydrochloric acid were mixed, and tetraethoxysilane and a small amount of 3-glycidoxypropyltriethoxysilane were added to the mixture while cooling. To the resulting solution, a solution obtained by mixing polyvinyl alcohol, water, and isopropyl alcohol was added. In this way, a barrier coating agent was obtained.

[0285] Three types of barrier films were produced using the above-mentioned coated film as follows. An aluminum (AL) vapor-deposited film with a thickness of 70 nm was formed on the anchor coat layer of the above-mentioned coated film by a PVD method. In this way, barrier film 1 was obtained. An alumina vapor-deposited film with a thickness of 30 nm was formed on the anchor coat layer of the above-mentioned coated film by a PVD method. The surface of the alumina vapor-deposited film was coated with the above-mentioned barrier coating agent by a spin coating method, and heated in an oven at 100°C for 8 seconds to form a barrier coat layer with a thickness of 0.3 μm. In this way, barrier film 2 was obtained. Barrier film 3 was obtained in the same manner as barrier film 2 above, except that a silica vapor-deposited film was formed instead of the alumina vapor-deposited film.

[0286] [Examples 2A to 4A] A uniaxially stretched film having a thickness of 25 μm was produced in the same manner as in Example 1A, except that in the production of a five-layer polyethylene film, the polyethylene composition of each layer was changed as shown in the table below. A barrier film was produced in the same manner as in Example 1A, except that the uniaxially stretched film was used.

[0287] [Comparative Examples 1A to 4A] Barrier films were produced in the same manner as in Examples 1A to 4A, except that the uniaxially stretched film was not subjected to corona treatment and no anchor coat layer was provided between the uniaxially stretched film and the vapor-deposited film.

[0288] Example 5A A single-layer polyethylene film was obtained by extruding HDPE (ELITE 5960G) using an inflation method. The film was stretched 5 times in the machine direction (MD) using a stretching device to produce a uniaxially stretched film with a thickness of 25 μm. A barrier film was produced in the same manner as in Example 1A, except that the uniaxially stretched film was used.

[0289] Example 6A After corona treatment was performed on the second surface resin layer of the uniaxially stretched film obtained in Example 1A, the above anchor coating agent was applied to the corona-treated surface of the second surface resin layer and dried at 80°C for 2 seconds to form an anchor coating layer with a thickness of 0.2 μm. After corona treatment was performed on the first surface resin layer of the above uniaxially stretched film, the above anchor coating agent was applied to the corona-treated surface of the first surface resin layer and dried at 80°C for 2 seconds to form an anchor coating layer with a thickness of 0.2 μm. In this way, a double-sided coated film comprising an anchor coating layer, a uniaxially stretched film, and an anchor coating layer was obtained.

[0290] On each anchor coat layer of the double-sided coated film, an aluminum (AL) vapor-deposited film having a thickness of 70 nm was formed by PVD, thereby obtaining a barrier film 4.

[0291] A 30 nm thick alumina vapor deposition film was formed on each anchor coating layer of the double-sided coated film by PVD, and the above-mentioned barrier coating agent was spin-coated onto the surface of each alumina vapor deposition film, followed by heat treatment in an oven at 100°C for 8 seconds to form a 0.3 μm thick barrier coating layer. In this way, barrier film 5 was obtained. Furthermore, a silica vapor deposition film was formed instead of the alumina vapor deposition film, to obtain barrier film 6.

[0292] Using the coated film obtained in Example 1A, six types of barrier films were produced as follows. An aluminum (AL) vapor deposition film with a thickness of 70 nm was formed on the anchor coating layer of the above-mentioned coated film by the PVD method. The above-mentioned barrier coating agent was coated on the surface of the AL vapor deposition film by the spin coating method, and the film was heated in an oven at 100°C for 8 seconds to form a barrier coating layer with a thickness of 0.3 μm. An AL vapor deposition film with a thickness of 70 nm was formed on the barrier coating layer by the PVD method. In this way, barrier film 7 was obtained.

[0293] On the anchor coat layer of the coated film, a 70 nm thick aluminum (AL) vapor-deposited film was formed by PVD, and then a 5 nm thick aluminum oxide film was formed by PVD by first introducing oxygen into aluminum vapor and vapor-depositing it, and then a 70 nm thick AL vapor-deposited film was formed on the aluminum oxide film. In this way, barrier film 8 was obtained.

[0294] An alumina vapor deposition film with a thickness of 30 nm was formed on the anchor coating layer of the above-mentioned coated film by the PVD method. The above-mentioned barrier coating agent was coated on the surface of the alumina vapor deposition film by the spin coating method, and the film was heated in an oven at 100°C for 8 seconds to form a barrier coating layer with a thickness of 0.3 μm. An AL vapor deposition film with a thickness of 70 nm was formed on the barrier coating layer by the PVD method. In this way, barrier film 9 was obtained. Barrier film 10 was obtained in the same manner as barrier film 9, except that a silica vapor deposition film was formed instead of the alumina vapor deposition film.

[0295] A 30 nm thick alumina vapor deposition film was formed on the anchor coat of the above-mentioned coated film by PVD. The above-mentioned barrier coating agent was coated on the surface of the alumina vapor deposition film by spin coating, and then heat-treated in an oven at 100°C for 8 seconds to form a 0.3 μm thick barrier coating layer. A 30 nm thick alumina vapor deposition film was formed on the barrier coating layer by PVD. The above-mentioned barrier coating agent was coated on the surface of the alumina vapor deposition film by spin coating, and then heat-treated in an oven at 100°C for 8 seconds to form a 0.3 μm thick barrier coating layer. In this way, barrier film 11 was obtained. Barrier film 12 was obtained in the same manner as barrier film 11, except that a silica vapor deposition film was formed instead of the alumina vapor deposition film.

[0296] [Biaxially oriented film materials] The following materials were used in the preparation of the biaxially stretched film. High density polyethylene (HDPE) Metallocene HDPE, ethylene-1-octene copolymer, Density: 0.955g / cm 3 Melting point: 130℃, MFR: 1.5g / 10min Linear low-density polyethylene (LLDPE) Dow Chemical's INNATE TF80 Metallocene LLDPE, ethylene-1-octene copolymer, Density: 0.926g / cm 3 , MFR: 1.7g / 10min Anti-blocking agent (AB agent) Silica particles, average particle size: 3.5 μm

[0297] Example 1B Blended polyethylene (A) was prepared by mixing 20 parts HDPE, 80 parts LLDPE, and 0.2 parts (2,000 ppm) of an AB agent. Blended polyethylene (B) was prepared by mixing 20 parts HDPE and 80 parts LLDPE.

[0298] A blended polyethylene (A), Blended polyethylene (B), Blended polyethylene (B), Blended polyethylene (B), Blended polyethylene (B), The resulting polyethylene film was coextruded into five layers by a T-die casting method. The film was then stretched 5 times in the machine direction (MD) and then 8.5 times in the width direction (TD) to produce a biaxially stretched film with a thickness of 25 μm. In Example 1B, biaxial stretching was successfully performed.

[0299] The biaxially stretched film thus obtained is A first surface resin layer (blend polyethylene (A) layer) having a thickness of 1 μm; A first PE layer (blend polyethylene (B) layer) having a thickness of 2 μm; A second PE layer (blend polyethylene (B) layer) having a thickness of 19 μm; a third PE layer (blended polyethylene (B) layer) having a thickness of 2 μm; A second surface resin layer (blend polyethylene (B) layer) having a thickness of 1 μm; are provided in this order.

[0300] A barrier film was produced in the same manner as in Example 1A, except that the biaxially stretched film was used instead of the uniaxially stretched film.

[0301] [Examples 2B to 4B] A biaxially stretched film having a thickness of 25 μm was produced in the same manner as in Example 1B, except that in the production of a five-layer polyethylene film, the polyethylene composition of each layer was changed as shown in the table below. In Examples 2B to 4B, biaxial stretching was successfully carried out. In the table below, the blending amount of the AB agent in the first surface resin layer was 2,000 ppm in all cases. A barrier film was produced in the same manner as in Example 1B, except that the biaxially stretched film was used.

[0302] Example 5B A mixture of 40 parts HDPE and 60 parts LLDPE was extruded into a single layer using a T-die casting method to obtain a single-layer polyethylene film. The film was then subjected to a sequential biaxial stretching process, stretching 5 times in the machine direction (MD) and then 8.5 times in the width direction (TD), to produce a biaxially stretched film with a thickness of 25 μm. In Example 5B, biaxial stretching was successfully performed. A barrier film was produced in the same manner as in Example 1B, except that the biaxially stretched film was used.

[0303] [Comparative Examples 1B to 5B] Barrier films were produced in the same manner as in Examples 1B to 5B, except that the biaxially stretched film was not subjected to corona treatment and no anchor coat layer was provided between the biaxially stretched film and the vapor-deposited film.

[0304] Example 6B A barrier film was produced in the same manner as in Example 5A, except that the biaxially stretched film obtained in Example 1B was used instead of the uniaxially stretched film. In the case of double-sided deposition, however, a biaxially stretched film was used, which was obtained by co-extrusion forming a five-layer film using the blended polyethylene (B), and then sequentially biaxially stretching the obtained film.

[0305] [Rigidity evaluation] The uniaxially stretched film obtained in the examples was cut into test pieces with a width of 10 mm, and the stiffness of the test pieces was measured using a loop stiffness measuring tester (manufactured by Toyo Seiki Seisakusho, product name: Loop Stiffness Tester). The loop length was set to 60 mm.

[0306] [Tensile strength evaluation] A 10 mm wide dumbbell-shaped test piece was cut out from the uniaxially stretched film obtained in the examples. The tensile strength of the dumbbell-shaped test piece in the MD direction was measured using a tensile tester (manufactured by Orientec Co., Ltd., RTC-1310A). The chuck distance was 10 mm, and the pulling speed was 300 mm / min.

[0307] [Heat resistance evaluation 1: Print resistance evaluation] The surface of the biaxially stretched film prepared above was subjected to a corona discharge treatment. An image was formed on the corona discharge-treated surface of the biaxially stretched film by gravure printing using oil-based gravure ink (manufactured by DIC Graphics Corporation, trade name: Finart). Heat resistance was evaluated according to the following criteria. A: No significant shrinkage of the film occurred when the print dried. B: Significant shrinkage of the film occurred when the print dried.

[0308] [Heat resistance evaluation 2: 170℃ heat seal resistance evaluation] The surface of the biaxially stretched film prepared above was subjected to a corona discharge treatment. An image was formed on the corona discharge-treated surface of the biaxially stretched film by gravure printing using oil-based gravure ink (manufactured by DIC Graphics Corporation, product name: Finart) to obtain a printed film. The printed film was then bonded to a 40 μm-thick LLDPE film obtained by forming Evolue SP2020 (manufactured by Mitsui Chemicals) into a single layer using a urethane-based dry lamination adhesive. The LLDPE film surfaces of the laminated films were placed face to face, and one side was sandwiched between an aluminum seal bar set to 170°C and heat sealed (1 kgf / cm 2 The heat-sealed portion was then heat-sealed at a pressure of 1000 kJ / s for 1 second, and the state of thermal shrinkage of the laminate film was confirmed. The heat resistance was evaluated according to the following criteria. A: The film did not shrink when heat sealed at 170°C. B: Almost no shrinkage of the film occurred when heat sealed at 170°C. C: The film shrunk significantly when heat sealed at 170°C.

[0309] [Gas barrier test] The oxygen permeability (cc / (m)) of each barrier film (hereinafter also referred to as "test piece") obtained in the examples and comparative examples was measured. 2 ·day·atm)) and water vapor permeability (g / (m 2 The evaluation results are shown in the tables below.

[0310] <Oxygen permeability> The oxygen permeability of the test specimen was measured at a temperature of 23°C and a humidity of 90% RH using an oxygen permeability measuring device (OX-TRAN2 / 20 manufactured by MOCON) in accordance with JIS K7126-2: 2006. The test specimen was positioned so that the uniaxially stretched film surface of the barrier film faced the oxygen supply side.

[0311] A: The oxygen permeability is less than 0.4. B: Oxygen permeability is 0.4 or more and less than 1.0. C: Oxygen permeability is 1.0 or more and less than 2.0. D: Oxygen permeability is 2.0 or more and less than 6.0. E: Oxygen permeability is 6.0 or more and less than 10. F: Oxygen permeability is 10 or more.

[0312] <Water vapor permeability> Using a water vapor transmission rate measuring device (MOCON, PERMATRAN-w 3 / 33), the water vapor transmission rate of the test specimen was measured in an environment of 40°C and 90% RH in accordance with JIS K7129-2: 2019. The test specimen was positioned so that the uniaxially stretched film surface of the barrier film faced the water vapor supply side.

[0313] A: The water vapor permeability is less than 2.0. B: The water vapor permeability is 2.0 or more and less than 5.0. C: The water vapor permeability is 5.0 or more and less than 10. D: Water vapor permeability is 10 or more.

[0314] [T-type peel test] A 20 μm thick general OPP film with one side corona treated was applied in an amount of 3 g / m to the vapor-deposited film surface or the barrier coat layer surface of each barrier film obtained in the Examples and Comparative Examples. 2The films were then bonded together using a urethane adhesive (RU77T / H7, manufactured by Rock Paint Co., Ltd.) to prepare 15 mm wide test specimens. A T-peel test was conducted in accordance with JIS K6854-3:1999 (Adhesives - Test methods for peel adhesion strength - Part 3: T-peel) using a tensile tester (Tensilon universal testing machine, manufactured by Orientec Co., Ltd.) at a test speed of 50 mm / min and a temperature of 23°C, and the peel strength (N / 15 mm) between the vapor-deposited film and the uniaxially or biaxially stretched film was measured. The results are shown in the tables.

[0315] [Table 1]

[0316] [Table 2]

[0317] [Table 3]

[0318] [Table 4]

[0319] [Modification of the embodiment] The biaxially stretched films of Examples 1B' to 4B' were produced in the same manner as in Examples 1B to 4B, except that the thicknesses of the first PE layer, second PE layer, and third PE layer were changed to 1.5 μm, 13 μm, and 1.5 μm, respectively, and the thickness of the biaxially stretched polyethylene film was changed to 18 μm. In Examples 1B' to 4B', biaxial stretching was successfully performed. The results of each evaluation in Examples 1B' to 4B' were equivalent to the results of the examples (Examples 1B to 4B) with the corresponding example numbers. The biaxially stretched film of Example 5B' was produced in the same manner as in Example 5B, except that the thickness of the biaxially stretched film was changed to 18 μm. The results of each evaluation in Example 5B' were comparable to those in Example 5B'. [Explanation of symbols]

[0320] 1. Barrier film 2. Laminate 10 Stretched film 11 First PE layer 12 Second PE layer 13 Third PE layer S1 First surface resin layer S2 Second surface resin layer IM polyethylene intermediate layer 20 Anchor coat layer 40 Vapor-deposited film 60 Adhesive layer 61 First adhesive layer 62 Second adhesive layer 70 Polyolefin oriented substrate 80 Heat seal layer 81 First heat seal layer 82 Second heat seal layer 120 tube containers 121 Tube container body 122 Head 123 Torso 124 Shoulder 125 Extraction port 126 Cap 127 Screw 128 Fusion part 129 Bottom seal

Claims

1. A barrier film, The barrier film comprises at least A stretched polyolefin film; An anchor coat layer; a vapor-deposited film; are provided in this order in the stacking direction, the polyolefin film is a polyethylene film or a polypropylene film, and the polyolefin film and the stretched film thereof each have a first surface and a second surface opposite to the first surface; the anchor coat layer contains a resin material having a polar group, the anchor coat layer is provided on at least the second surface of the stretched film, The vapor-deposited film is provided on the anchor coat layer. Barrier film.

2. the polyolefin film is the polyethylene film, The polyethylene film has, as a layer constituting its second surface, a polyethylene layer containing high-density polyethylene and a polyethylene other than the high-density polyethylene, or a polyethylene layer containing at least one polymer selected from the group consisting of high-density polyethylene and medium-density polyethylene and a polyethylene other than the polymer. The barrier film according to claim 1 .

3. 3. The barrier film according to claim 2, wherein the polyethylene layer constituting the second surface of the polyethylene film contains a medium-density polyethylene or a linear low-density polyethylene as the polyethylene other than the high-density polyethylene.

4. 3. The barrier film according to claim 2, wherein the polyethylene layer constituting the second surface of the polyethylene film contains a linear high-density polyethylene as the other polyethylene.

5. 5. The barrier film according to claim 4, wherein the polyethylene layer constituting the second surface of the polyethylene film has a total content of high-density polyethylene and medium-density polyethylene of 20% by mass or more and 60% by mass or less, and a content of linear low-density polyethylene of 40% by mass or more and 80% by mass or less.

6. The polyethylene layer constituting the second surface of the polyethylene film contains the high-density polyethylene, and the high-density polyethylene has a density of 0.945 g / cm 3 Super 0.960g / cm 3 an ethylene-α-olefin copolymer having a density of 0.930 g / cm or less, wherein the linear low-density polyethylene has a density of 0.930 g / cm or less; 3 5. The barrier film according to claim 4, which is an ethylene-α-olefin copolymer having a density of:

7. The polyethylene film is a first surface resin layer constituting the first surface; a polyethylene intermediate layer; a second surface resin layer constituting the second surface; Equipped with the first surface resin layer and the polyethylene intermediate layer each independently contain at least one polymer selected from the group consisting of high-density polyethylene and medium-density polyethylene, and linear low-density polyethylene; However, when adjacent layers constituting the polyethylene film have the same resin composition and cannot be distinguished from each other, the adjacent layers may be integrated to form a single layer. The barrier film according to claim 4.

8. 8. The barrier film according to claim 7, wherein the first surface resin layer and the polyethylene intermediate layer each independently contain a total content of high-density polyethylene and medium-density polyethylene of 20% by mass or more and 60% by mass or less, and a content of linear low-density polyethylene of 40% by mass or more and 80% by mass or less.

9. The first surface resin layer and the polyethylene intermediate layer each independently have a density of 0.945 g / cm 3 Super 0.960g / cm 3 and a high-density polyethylene which is an ethylene-α-olefin copolymer having a density of 0.930 g / cm 3 and a linear low-density polyethylene which is an ethylene-α-olefin copolymer having a density of:

10. 8. The barrier film according to claim 7, wherein the polyethylene film comprises two or more polyethylene intermediate layers.

11. 3. The barrier film according to claim 2, wherein the polyethylene film is a monolayer film consisting of a layer containing at least one polymer selected from the group consisting of high-density polyethylene and medium-density polyethylene and a polyethylene other than the polymer, or a monolayer film consisting of a layer containing high-density polyethylene and medium-density polyethylene.

12. The barrier film according to claim 11, wherein the polyethylene film contains a linear high-density polyethylene as the other polyethylene.

13. 2. The barrier film according to claim 1, wherein the resin material contained in the anchor coat layer is at least one selected from the group consisting of a hydroxyl group-containing (meth)acrylic resin, a hydroxyl group-free (meth)acrylic resin, a urethane resin, an ethylene-vinyl alcohol copolymer, polyvinyl alcohol, polyester, polyamide, and polyethyleneimine.

14. 2. The barrier film according to claim 1, wherein the ratio of the thickness of the anchor coat layer to the total thickness of the stretched film and the anchor coat layer is 0.08% or more and 20% or less.

15. 2. The barrier film according to claim 1, wherein the anchor coat layer has a thickness of 0.02 μm or more and 10 μm or less.

16. 3. The barrier film according to claim 2, wherein the polyethylene film is a coextruded film.

17. 2. The barrier film according to claim 1, wherein the stretched film is a uniaxially stretched film or a biaxially stretched film.

18. 2. The barrier film according to claim 1, wherein the vapor-deposited film is selected from the group consisting of a vapor-deposited metal film and a vapor-deposited inorganic oxide film.

19. The barrier film according to claim 1 , further comprising a barrier coating layer on a surface of the vapor-deposited film opposite to the surface facing the anchor coating layer.

20. a first vapor-deposited film; a first anchor coat layer; The stretched film; a second anchor coat layer; a second vapor-deposited film; The barrier film according to claim 1 , comprising:

21. The stretched film; The anchor coat layer; a first vapor-deposited film; a second vapor-deposited film; The barrier film according to claim 1 , comprising:

22. 22. The barrier film according to claim 21, further comprising an adhesion-improving layer between the first vapor-deposited film and the second vapor-deposited film.

23. The barrier film according to any one of claims 1 to 22, a heat seal layer; A laminate comprising at least

24. The laminate according to claim 23, wherein the heat seal layer contains polyethylene as a main component, and the content of polyethylene in the entire laminate is 80 mass % or more.

25. A packaging container comprising the laminate according to claim 23.

26. 26. The packaging container according to claim 25, which is a packaging bag.

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