Biaxially stretched polyethylene film

Abstract

To provide a biaxially stretched polyethylene film with superior heat resistance.SOLUTION: A biaxially stretched polyethylene film includes a polyethylene layer containing at least one polyethylene selected from high-density polyethylene and medium-density polyethylene.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to biaxially oriented polyethylene films. [Background technology]

[0002] Packaging containers are used to store contents such as liquids and powders. Packaging containers are made using a laminate including a substrate and a heat seal layer (see, for example, Patent Document 1). For example, a stretched polyethylene film is used as the substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-55156 A Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional biaxially oriented polyethylene films are produced using low-density polyethylene in order to perform biaxial orientation well. However, the heat resistance of such biaxially oriented polyethylene films tends to be insufficient. An object of the present disclosure is to provide a biaxially oriented polyethylene film having excellent heat resistance. [Means for solving the problem]

[0005] A biaxially oriented polyethylene film according to one embodiment of the present disclosure comprises a polyethylene layer containing at least one polyethylene selected from high density polyethylene and medium density polyethylene. Effect of the Invention

[0006] According to the present disclosure, a biaxially oriented polyethylene film having excellent heat resistance can be provided. The biaxially oriented polyethylene film is useful, for example, as a base material in a packaging material for producing a packaging container. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic cross-sectional view showing one embodiment of a biaxially stretched film. [Diagram 2] FIG. 2 is a schematic cross-sectional view showing one embodiment of a biaxially stretched film. [Diagram 3] FIG. 3 is a schematic cross-sectional view showing one embodiment of a biaxially stretched film. [Figure 4] FIG. 4 is a schematic cross-sectional view showing one embodiment of a laminate. [Diagram 5] FIG. 5 is a schematic cross-sectional view showing one embodiment of a laminate. [Figure 6] FIG. 6 is a schematic cross-sectional view showing one embodiment of a laminate. [Figure 7] FIG. 7 is a perspective view showing an embodiment of a tube container including a tube container body including a laminate and a cap. [Figure 8] FIG. 8 is a cross-sectional view taken along line AA in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, the embodiments of the present disclosure will be described in detail. The present disclosure can be implemented in many different forms, and is not to be interpreted as being limited to the description of the embodiments exemplified below. In the drawings, the width, thickness, shape, etc. of each layer may be shown diagrammatically in order to make the explanation clearer, but these are merely examples and do not limit the interpretation of the present disclosure. In this specification and each figure, elements similar to those already explained with respect to the previous figures are given the same reference numerals, and detailed explanations 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 configured by combining any one of the upper limit candidates and any one of the lower limit candidates. Examples of the above parameters include physical property values, content ratios of components, and layer thicknesses. As an example, the description "Parameter B is preferably A1 or more, more preferably A2 or more, and even more preferably A3 or more. Parameter B is preferably A4 or less, more preferably A5 or less, and even more preferably A6 or less." will be explained. In this example, the numerical range of parameter B may be A1 or more and A4 or less, A1 or more and A5 or less, A1 or more and A6 or less, A2 or more and A4 or less, A2 or more and A5 or less, A2 or more and A6 or less, A3 or more and A4 or less, A3 or more and A5 or less, or A3 or more 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 exceeds 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, as well as ethylene-vinyl acetate copolymer and ethylene-(meth)acrylic acid ester copolymer. From the viewpoint of reducing the environmental load, polyethylene derived from biomass or polyethylene that has been mechanically recycled or chemically recycled may be used as the 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 density limit 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 3 More than 0.930g / cm 3 Less than or equal to 0.900 g / cm 3 More than 0.930g / cm 3 The density of the linear low density polyethylene is preferably 0.860 g / cm 3 More than 0.930g / cm 3 Less than or equal to 0.900 g / cm 3 More than 0.930g / cm 3 In this specification, the density of polyethylene is measured in accordance with JIS K7112:1999, Method D (density gradient tube method, 23° C.).

[0014] Low-density polyethylene is, for example, polyethylene obtained by polymerizing ethylene by high-pressure polymerization (high-pressure low-density polyethylene). Linear low-density polyethylene is, for example, polyethylene obtained by polymerizing ethylene and a small amount of α-olefins by 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] Polyethylenes with different densities or branches can be obtained by appropriately selecting a polymerization method. For example, it is preferable to carry out polymerization in one or more stages by using a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as a metallocene catalyst as a polymerization catalyst, by any of gas phase polymerization, slurry polymerization, solution polymerization, and high pressure ion polymerization.

[0016] In this specification, the melt flow rate (MFR) of 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 preferably 50 g / 10 min or less, more preferably 30 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 50 g / 10 min or less, from the viewpoint of film-forming property and processability. In this specification, the MFR of polyethylene is measured by the A method at a temperature of 190° C. and a load of 2.16 kg in accordance with JIS K7210-1:2014.

[0017] In this specification, the melting point (Tm) of the polyethylene is preferably 100° C. or higher, more preferably 105° C. or higher, even more preferably 110° C. or higher, particularly preferably 115° 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 biaxially oriented polyethylene film. 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.

[0018] 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 kinds.

[0019] In this specification, although "film" and "sheet" may be referred to, the "film" and the "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.

[0020] In this specification, the "main component" of a certain layer refers to a component whose content in the layer is more than 50% by mass, preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more.

[0021] [Biaxially oriented polyethylene film] The biaxially oriented polyethylene film according to the first embodiment of the present disclosure includes a polyethylene layer containing at least one polyethylene selected from high density polyethylene and medium density polyethylene. The polyethylene layer according to the first embodiment is hereinafter also referred to as "polyethylene layer (1)".

[0022] The biaxially oriented polyethylene film according to the second embodiment of the present disclosure includes a polyethylene layer containing polyethylene as a main component, and the polyethylene contained in the polyethylene layer has a viscosity of 0.930 g / cm 3 Super 0.960g / cm 3 It has the following density: The polyethylene layer in the second embodiment is hereinafter also referred to as "polyethylene layer (2)".

[0023] When explaining matters common to the biaxially oriented polyethylene films of the first and second aspects, or when there is no particular distinction between the biaxially oriented polyethylene films of the first and second aspects, they will be simply referred to as "biaxially oriented polyethylene film."

[0024] The content of polyethylene in the biaxially oriented polyethylene film 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, particularly preferably 85% by mass or more or 90% by mass or more. A laminate (or a packaging container) including such a biaxially oriented polyethylene film has, for example, excellent recyclability.

[0025] The biaxially stretched polyethylene film is a polyethylene film that has been subjected to a biaxial stretching process. This can improve, for example, the strength, rigidity, heat resistance, transparency, and printability of the polyethylene film. The biaxial stretching process may be a sequential biaxial stretching process using a tenter frame method or the like, or a simultaneous biaxial stretching process. The stretching ratio when stretching in the machine direction (flow direction of the substrate, MD direction) is preferably 2 times or more, more preferably 3 times or more, preferably 15 times or less, more preferably 10 times or less, for example, 2 times or more and 15 times or less. 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, preferably 15 times or less, more preferably 10 times or less, for example, 2 times or more and 15 times or less. The biaxially stretched polyethylene film is specifically a polyethylene film that has been biaxially stretched in the MD direction and the TD direction.

[0026] The thickness of the biaxially stretched polyethylene 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. A biaxially stretched polyethylene film having a thickness equal to or greater than the lower limit has, for example, excellent strength, rigidity, and heat resistance. A biaxially stretched polyethylene film having a thickness equal to or less than the upper limit has, for example, excellent processability. In this specification, the thickness of the film and each layer is the average value of the thicknesses at 10 points measured based on a scanning electron microscope (SEM) image obtained by observing a vertical cross section relative to the film surface with an SEM.

[0027] The biaxially stretched polyethylene film can be produced, for example, by forming the materials constituting each layer into a single layer film or a laminated film, and then stretching the film. Examples of the film-forming method include the T-die casting method and the inflation method, and from the viewpoint of productivity, the T-die casting method is preferred. For example, the above film can be obtained by feeding the materials for forming each layer to each extruder and performing co-extrusion T-die casting.

[0028] In one embodiment, the biaxially stretched polyethylene film is a biaxially stretched coextruded resin film. In one embodiment, the biaxially stretched polyethylene film is a resin film obtained by coextrusion 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 to produce a laminated film, and then biaxially stretching the laminated film.

[0029] The biaxially oriented polyethylene film and the printed film and barrier substrate described below may be subjected to a surface treatment. Such biaxially oriented polyethylene film, printed film and barrier substrate have, for example, excellent adhesion to other layers. Examples of the surface treatment method include physical treatment and chemical treatment. Examples of the physical treatment include corona treatment, ozone treatment, low-temperature plasma treatment using oxygen gas and / or nitrogen gas, and glow discharge treatment. Examples of the chemical treatment include oxidation treatment using chemicals.

[0030] A printed layer, which will be described later, may be provided on at least one surface of the biaxially oriented polyethylene film. That is, the printed film comprises a biaxially oriented polyethylene film and a printed layer provided on at least one surface of the film. For example, the printed film comprises a biaxially oriented polyethylene film and a printed layer provided on the surface of at least one layer selected from the first surface resin layer and the second surface resin layer of the film.

[0031] <Polyethylene layer (1)> The polyethylene layer (1) contains at least one polyethylene selected from high density polyethylene and medium density polyethylene, and preferably contains high density polyethylene. Therefore, the biaxially stretched polyethylene film having the polyethylene layer (1) has, for example, high heat resistance, specifically, excellent resistance to drying during printing and heating during heat sealing, and excellent resistance to deposition when deposition is performed on the film. In addition, the polyethylene layer (1) has, for example, high rigidity, and can increase the film conveying speed when deposition is performed on the film, thereby improving productivity.

[0032] Examples of high-density polyethylene include ethylene homopolymers and 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 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. In these copolymers, the comonomers are not limited to the above-mentioned comonomers, and further comonomers may be used. For example, high-density polyethylenes produced using metallocene catalysts are preferred.

[0033] Examples of the medium density polyethylene include ethylene homopolymers and ethylene-α-olefin copolymers. Examples of the 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 the 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. In these copolymers, the comonomers are not limited to the above-mentioned comonomers, and further comonomers may be used. For example, medium density polyethylenes produced using metallocene catalysts are preferred.

[0034] The high density polyethylene and the medium density polyethylene are preferably the above-mentioned ethylene-α-olefin copolymers. Films containing such high density polyethylene and / or medium density polyethylene are, for example, excellent in biaxial stretchability, particularly excellent in 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 copolymers are preferably polyethylenes obtained by polymerizing ethylene and a small amount of α-olefins by 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 polyethylenes produced using a metallocene catalyst.

[0035] 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 3 Exceeds 0.945g / cm 3The density can be adjusted, for example, by the amount of structural units derived from the α-olefin, which is a comonomer in the ethylene-α-olefin copolymer, introduced.

[0036] The polyethylene layer (1) may, for example, contain high density polyethylene as a main component, may contain medium density polyethylene as a main component, or may contain a mixture of high density polyethylene and medium density polyethylene as a main component. The polyethylene layer (1) may, for example, contain as a main component a mixture of high-density polyethylene and other polyethylene, may contain as a main component a mixture of medium-density polyethylene and other polyethylene, or may contain as a main component a mixture of high-density polyethylene, medium-density polyethylene, and other polyethylene. 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 above content is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% 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. The other polyethylene may be, for example, at least one selected from linear low-density polyethylene and high-pressure low-density polyethylene, and 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.

[0037] 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 100% by mass or less, and from the viewpoint of biaxial stretchability, is preferably 90% by mass or less, more preferably 85% by mass or less, even more preferably 80% by mass or less, may be 70% by mass or less, 65% by mass or less, or may be 60% by mass or less. The total content of high density polyethylene and medium density polyethylene in the polyethylene layer (1) is, for example, from 10% by mass to 100% by mass, and preferably from 20% by mass to 60% by mass.

[0038] When the polyethylene layer (1) is the surface resin layer of the film, a small total content ratio tends to improve the adhesion between the surface resin layer and a printed layer or a vapor deposition film, etc., by the above-mentioned surface treatment. This is presumably because, for example, high-density polyethylene has high crystallinity, and polar groups may not be sufficiently introduced into the polyethylene layer by surface treatment such as corona treatment, whereas a small total content ratio allows polar groups to be sufficiently introduced into the polyethylene layer by surface treatment such as corona treatment. Furthermore, when the polyethylene layer (1) is the surface resin layer of the film, a small total content ratio tends to provide the film with excellent appearance, surface smoothness, and transparency.

[0039] From the viewpoint of biaxial stretchability, the polyethylene layer (1) preferably contains a linear low-density polyethylene in addition to at least one polyethylene selected from high-density polyethylene and medium-density polyethylene, and more preferably contains a linear low-density polyethylene in addition to the high-density polyethylene.

[0040] 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 ethylene-1-butene copolymers (C4-LLDPE) in which the comonomer is at least 1-butene, ethylene-1-hexene copolymers (C6-LLDPE) in which the comonomer is at least 1-hexene, and ethylene-1-octene copolymers (C8-LLDPE) in which the comonomer is at least 1-octene. In these copolymers, the comonomers are not limited to the above-mentioned comonomers, and further comonomers may be used. For example, linear low density polyethylenes produced using a metallocene catalyst are 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.

[0041] The content of the linear low-density polyethylene in the polyethylene layer (1) is, from the viewpoint of biaxial stretchability, 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 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, from 10% by mass to 90% by mass, and preferably from 40% by mass to 80% by mass.

[0042] 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, further preferably 90% by mass or more, and particularly preferably 95% by mass or more.

[0043] The polyethylene layer (1) may contain polyethylene other than high density polyethylene, medium density polyethylene, and linear low density polyethylene, or a resin material other than polyethylene. Examples of the resin material other than polyethylene include polyolefins other than polyethylene, polyesters, polyamides, (meth)acrylic resins, vinyl resins, cellulose resins, and ionomer resins.

[0044] 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.

[0045] <Polyethylene layer (2)> The polyethylene layer (2) contains polyethylene as a main component, and the polyethylene has a viscosity of 0.930 g / cm 3 Super 0.960g / cm 3 The density of the polyethylene in the polyethylene layer (2) is preferably 0.931 g / cm 3 More than 0.955g / cm 3 Less than or equal to 0.931 g / cm 3 More than 0.950g / cm 3 The following is the result.

[0046] When the polyethylene layer (2) contains two or more kinds of polyethylene with different densities, the density of the polyethylene means the density of a mixture of two or more kinds of polyethylene. The density is measured for polyethylene sampled from the layer in accordance with JIS K7112:1999 D method (density gradient tube method, 23°C). 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 constituting the layer.

[0047] D av = ΣW i ×D i In the formula, Σ is W from 1 to n (n types of polyethylene are present) for i. i ×D i where n is an integer equal to or greater than 2, and W i indicates the mass fraction of the i-th polyethylene, and D i is the density of the i-th polyethylene (g / cm 3 ) is shown.

[0048] The density of the polyethylene layer (2) can be adjusted based on the composition described above for the polyethylene layer (1), for example. That is, the polyethylene layer (2) can have the composition described above for the polyethylene layer (1).

[0049] The polyethylene layer (2) may contain the above-mentioned resin materials other than polyethylene. The polyethylene layer (2) may contain the above-mentioned additives.

[0050] <Layer structure of film> In one embodiment, the biaxially oriented polyethylene film of the first aspect is a monolayer film consisting of a polyethylene layer (1). In one embodiment, the biaxially oriented polyethylene film of the first aspect has two or more polyethylene layers, at least one of which is the polyethylene layer (1), and preferably all of which are the polyethylene layers (1).

[0051] In one embodiment, the biaxially oriented polyethylene film of the second aspect is a monolayer film consisting of a polyethylene layer (2). In one embodiment, the biaxially oriented polyethylene film of the second aspect has two or more polyethylene layers, at least one of which is the polyethylene layer (2), and preferably all of which are the polyethylene layers (2).

[0052] The polyethylene layer contains polyethylene as a main component. For example, high density polyethylene, medium density polyethylene, low density polyethylene, and linear low density polyethylene are preferable. The content of polyethylene 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 materials other than polyethylene. The polyethylene layer may contain the additives described above.

[0053] In one embodiment, the biaxially oriented polyethylene film has 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 less, more preferably seven or less, for example, two or more and nine or less. The number of layers of the biaxially oriented polyethylene film is specifically three, five, seven, or nine. The biaxially oriented polyethylene film substrate having a multilayer structure has an excellent balance of, for example, strength, rigidity, heat resistance, transparency, and printability.

[0054] In one embodiment, the biaxially oriented polyethylene film comprises: 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; in this order in the thickness direction, and at least one layer selected from the first surface resin layer, the polyethylene intermediate layer, and the second surface resin layer is a polyethylene layer (1) or a polyethylene layer (2). From the viewpoint of heat resistance, it is preferable that the first surface resin layer, the polyethylene intermediate layer, and the second surface resin layer are all polyethylene layers (1) or polyethylene layers (2). Hereinafter, "provided in this order in the thickness direction" will also be simply expressed as "provided in this order." The biaxially oriented polyethylene film may comprise two or more intermediate polyethylene layers.

[0055] The biaxially stretched polyethylene film may comprise, in this order, a first surface resin layer, a first polyethylene layer, a second polyethylene layer, a third polyethylene layer, and a second surface resin layer. At least one layer selected from the first surface resin layer, the first polyethylene layer, the second polyethylene layer, the third polyethylene layer, and the second surface resin layer is a polyethylene layer (1) or a polyethylene layer (2), and from the viewpoint of heat resistance, it is preferable that all of the above layers are polyethylene layers (1) or polyethylene layers (2).

[0056] 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 polyethylene layers may be the same or different. The thicknesses of the first to third polyethylene layers may be the same or different.

[0057] In the case where any adjacent layers selected from the polyethylene layers in the biaxially oriented polyethylene film 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 Less than or equal to 0.025 g / cm 3 More preferably, 0.020 g / cm 3 Less than 0.010 g / cm 3 Such a film has excellent interlayer adhesion, for example, excellent drop resistance.

[0058] In one embodiment of the biaxially stretched polyethylene film, 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, high heat resistance is obtained by the polyethylene intermediate layer. The difference in density of the polyethylene between 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 the high density polyethylene and the medium density polyethylene is hereinafter referred to as "content ratio A." Herein, only high density polyethylene may be used, only medium density polyethylene may be used, or a mixture of high density polyethylene and medium density polyethylene may be used. In one embodiment of the biaxially stretched polyethylene film, the content ratio A in the polyethylene intermediate layer is greater than the content ratio A in the first surface resin layer, and the content ratio A in the second surface resin layer is smaller than the content ratio A 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. The difference in content ratio A between the polyethylene intermediate layer and the surface resin layer may be, for example, 10% by mass or more, or 30% by mass or less.

[0059] In one embodiment of the biaxially stretched polyethylene film, 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, high biaxial stretchability is obtained by the polyethylene intermediate layer. The difference in density of 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 biaxially stretched polyethylene film, 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 second surface resin 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.

[0060] In one embodiment of the biaxially stretched polyethylene film, 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 biaxially stretched polyethylene film, 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 having the largest content ratio A and the layer having the smallest content ratio A among the first surface resin layer, the polyethylene intermediate layer, and the second surface resin layer is less than 10 mass %.

[0061] In addition, when each layer contains two or more kinds of polyethylene having different densities, the density of the polyethylene means the density of a mixture of two or more kinds of polyethylene. The method of measuring and calculating the density is as described above.

[0062] Either or both of the first and second surface resin layers may further contain particles. When the surface resin layer contains particles, for example, the antiblocking property or slip property of the biaxially oriented polyethylene film can be improved.

[0063] Examples of the particles include inorganic compound-based antiblocking agents and resin particle-based antiblocking agents. Specific examples of the 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 other compounds such as kaolin, talc, and diatomaceous earth. Specific examples of the resin particles include resin particles made of resin components such as polymethyl methacrylate (PMMA), polystyrene, methyl methacrylate-styrene copolymer, polyester, polyamide, polytetrafluoroethylene, epoxy resin, urea resin, and phenol resin. The resin particles may be crosslinked or non-crosslinked.

[0064] 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. This reduces the possibility that the particles will damage the vapor-deposited film when the substrate is stored in a roll shape, for example, in the case of a barrier substrate having one surface resin layer containing a resin particle-based antiblocking agent and the other surface resin layer having a vapor-deposited film, as described below. This is because the resin particle-based antiblocking agent is usually smaller in unevenness and softer than the inorganic compound-based antiblocking agent.

[0065] 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 non-aggregates of 100 randomly selected particles by observing the cross section in the thickness direction of each layer with a scanning electron microscope (SEM).

[0066] When the first surface resin layer contains particles, the particle content, based on the mass of the first surface resin layer, is preferably 100 ppm or more, more preferably 500 ppm or more, even more preferably 1,000 ppm or more, and is 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.

[0067] When the second surface resin layer contains particles, the content of the particles is, based on the mass of the second 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.

[0068] When a vapor-deposited film is provided on the surface resin layer, from the viewpoint of formability of the vapor-deposited film, it is preferable that the surface resin layer on which the vapor-deposited film is provided does not contain particles.

[0069] When the surface resin layer contains particles, the ratio of the average particle size of the particles to the thickness of the surface resin layer (average particle size / thickness) is preferably 0.5 to 5.0, more preferably 0.8 to 4.0, and even more preferably 1.0 to 3.5. The surface resin layer here may be a first surface resin layer, a second surface resin layer, or both.

[0070] The thickness of the first and second surface resin layers is preferably 0.3 μm or more, more preferably 0.5 μm or more, even more preferably 0.8 μm or more, and is 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 surface resin layer has convex portions due to particles, the thickness of each layer is preferably measured in an area where convex portions due to the particles are not formed.

[0071] The thickness of the first and second surface resin layers is, independently of each other, 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, relative to the thickness of the biaxially oriented polyethylene film.

[0072] In the biaxially stretched polyethylene film, 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, particularly preferably 30 μm or less, for example, 6 μm or more and 100 μm or less. A biaxially stretched polyethylene film having a polyethylene intermediate layer whose thickness is equal to or greater than the lower limit is excellent in, for example, strength, rigidity, heat resistance, and recyclability. A biaxially stretched polyethylene film having a polyethylene intermediate layer whose thickness is equal to or less than the upper limit is excellent in, for example, processability. When the biaxially stretched polyethylene film has two or more polyethylene intermediate layers, the above "thickness" means the sum of the thicknesses of the polyethylene intermediate layers.

[0073] In the biaxially oriented polyethylene film, the thickness of the polyethylene intermediate layer is preferably 60% or more, more preferably 70% or more, even more preferably 80% or more, particularly preferably 84% or more, and is preferably 98% or less, more preferably 96% or less, even more preferably 92% or less, for example, 60% or more and 98% or less, relative to the thickness of the biaxially oriented polyethylene film. When the biaxially oriented polyethylene film has two or more polyethylene intermediate layers, the above "thickness" means the total thickness of each polyethylene intermediate layer.

[0074] The biaxially oriented polyethylene film may have one or more polyethylene intermediate layers. The biaxially oriented polyethylene film may have a first surface resin layer, a first polyethylene layer, a second polyethylene layer, a third polyethylene layer, and a second surface resin layer, in this order.

[0075] From the viewpoint of better exerting the above-mentioned effects, the thickness of the second polyethylene layer is preferably 4 μm or more, more preferably 6 μm or more, even more preferably 8 μm or more, and is 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.

[0076] The thickness of the second polyethylene 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, for example, 50% or more and 94% or less, of the thickness of the polyethylene intermediate layer.

[0077] The thickness of the first and third polyethylene 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.

[0078] The thicknesses of the first and third polyethylene 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, for example 3% or more and 25% or less, relative to the thickness of the polyethylene intermediate layer.

[0079] In a biaxially oriented polyethylene film having a first surface resin layer, a first polyethylene layer, a second polyethylene layer, a third polyethylene layer, and a second surface resin layer, in this order, the ratio of the thickness of the first polyethylene layer to the thickness of the third polyethylene 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, from the viewpoints of film symmetry and suppression of curling.

[0080] From the viewpoints 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.

[0081] When the vapor-deposited film is provided on the biaxially oriented polyethylene film, for example, a layer containing a gas barrier resin as a main component, or a layer containing polyethylene and an adhesive resin may be provided between the polyethylene layer and the vapor-deposited film. In this case, for example, the surface resin layer in the biaxially oriented polyethylene film may be a layer containing a gas barrier resin as a main component, or a layer containing polyethylene and an adhesive resin, and the vapor-deposited film may be provided on the layer. Alternatively, a layer containing a gas barrier resin as a main component (for example, a coating layer, an extruded resin layer) or a layer containing polyethylene and an adhesive resin (for example, a coating layer, an extruded resin layer) may be provided on the biaxially oriented polyethylene film, and the vapor-deposited film may be provided on the layer. By providing such a layer, the vapor-deposited film tends to have excellent adhesion to the biaxially oriented polyethylene film and exhibit good gas barrier properties.

[0082] The thickness of the layer containing a gas barrier resin as a main component, or the layer containing polyethylene and an adhesive resin is not particularly limited, but may each independently be 0.3 μm or more, 0.5 μm or more, 0.8 μm or more, 15 μm or less, 10 μm or less, or 5 μm or less, for example, 0.3 μm or more and 15 μm or less.

[0083] Gas barrier resins are resins that have the function of suppressing gas permeation. Examples of gas barrier resins include ethylene-vinyl alcohol copolymers, polyvinyl alcohol, polyamides, polyvinylidene chloride, polyesters, polyether polyols, polyester polyols, polyurethanes, polyacrylonitriles, and (meth)acrylic resins. Among these, from the viewpoints of gas barrier properties (particularly oxygen barrier properties), heat resistance, and rigidity, ethylene-vinyl alcohol copolymers, polyvinyl alcohol, and polyamides are preferred, and ethylene-vinyl alcohol copolymers and polyamides are more preferred.

[0084] Examples of the adhesive resin include acid-modified resin, silicone resin, epoxy resin, and phenol resin, and acid-modified resin is preferred. Examples of the acid-modified resin include acid-modified polyolefin and acid-modified vinyl resin. Among these, acid-modified polyolefin is preferred from the viewpoint of recyclability and adhesion, acid-modified polypropylene and acid-modified polyethylene are more preferred, and acid-modified polyethylene is even more preferred. Examples of the acid-modified polyolefin include polyolefin (e.g., polypropylene and polyethylene) modified with an acid-modified component, and particularly graft-modified polyolefin with an acid-modified component. Examples of the acid-modified component include unsaturated carboxylic acids such as maleic acid, fumaric acid, acrylic acid, methacrylic acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, and methyltetrahydrophthalic acid, or acid anhydrides, esters, or metal salts thereof. Examples of the acid-modified polyolefin include maleic acid-modified polyolefin and maleic anhydride-modified polyolefin, and more preferred are maleic acid-modified polypropylene, maleic anhydride-modified polypropylene, maleic acid-modified polyethylene, and maleic anhydride-modified polyethylene.

[0085] In the layer containing polyethylene and an adhesive resin, it is preferable that the polyethylene content is 60% by mass or more and 95% by mass or less and the adhesive resin content is 5% by mass or more and 40% by mass or less, it is more preferable that the polyethylene content is 70% by mass or more and 95% by mass or less and the adhesive resin content is 5% by mass or more and 30% by mass or less, it is even more preferable that the polyethylene content is 80% by mass or more and 95% by mass or less and the adhesive resin content is 5% by mass or more and 20% by mass or less, and it is particularly preferable that the polyethylene content is 85% by mass or more and 95% by mass or less and the adhesive resin content is 5% by mass or more and 15% by mass or less.

[0086] <Layer structure of biaxially oriented polyethylene film> Hereinafter, several examples of the layer structure of the biaxially oriented polyethylene film of the present disclosure will be given with reference to the drawings. The biaxially oriented polyethylene film 1A shown in FIG. The biaxially oriented polyethylene film 1A shown in FIG. 2 comprises a first surface resin layer 20, a polyethylene layer 10 (a polyethylene intermediate layer), and a second surface resin layer 22 in this order. The biaxially stretched polyethylene film 1A shown in FIG. 3 comprises, in this order, a first surface resin layer 20, a first polyethylene layer 11, a second polyethylene layer 12, a third polyethylene layer 13, and a second surface resin layer 22.

[0087] [Barrier substrate] The barrier substrate of the present disclosure is The biaxially oriented polyethylene film of the present disclosure described above, A vapor-deposited film provided on at least one surface of the film (for example, a vapor-deposited film provided on the surface of at least one layer selected from the first surface resin layer and the second surface resin layer), Equipped with.

[0088] In the barrier substrate, the vapor-deposited film may be provided only on one surface of the biaxially oriented polyethylene film, only on the other surface, or on both surfaces. In the barrier substrate, the vapor-deposited film may be provided only on the surface of the first surface resin layer of the biaxially oriented polyethylene film, only on the surface of the second surface resin layer, or on the surfaces of the first surface resin layer and the second surface resin layer.

[0089] As described above, the barrier substrate may have, between the polyethylene layer and the vapor-deposited film, for example, a layer containing a gas barrier resin as a main component, or a layer containing polyethylene and an adhesive resin. For example, the surface resin layer in the biaxially oriented polyethylene film may be a layer containing a gas barrier resin as a main component, or a layer containing polyethylene and an adhesive resin, and the vapor-deposited film may be provided on the layer. Alternatively, the barrier substrate may have, between the biaxially oriented polyethylene film and the vapor-deposited film, a layer containing a gas barrier resin as a main component (for example, a coating layer, an extruded resin layer), or a layer containing polyethylene and an adhesive resin (for example, a coating layer, an extruded resin layer). By providing such a layer, the vapor-deposited film tends to have excellent adhesion to the biaxially oriented polyethylene film and to exhibit good gas barrier properties.

[0090] In one embodiment, the barrier substrate of the present disclosure comprises: A first deposited film; The biaxially oriented polyethylene film of the present disclosure described above, A second deposited film; In the thickness direction, at least

[0091] The biaxially oriented polyethylene film has a first surface and a second surface opposite to the first surface. In one embodiment, the first surface resin layer constitutes the first surface, and the second surface resin layer constitutes the second surface. The first vapor-deposited film is provided on the first surface of the biaxially oriented polyethylene film. The first vapor-deposited film is provided, for example, on the surface of the first surface resin layer of the biaxially oriented polyethylene film. The second vapor-deposited film is provided, for example, on the surface of the second surface resin layer of the biaxially oriented polyethylene film.

[0092] The barrier substrate may further include a printed layer, which will be described later.

[0093] <Vapor deposition film> The barrier substrate of the present disclosure has a vapor deposition film and is excellent in gas barrier properties. Therefore, a packaging container produced using such a barrier substrate has excellent gas barrier properties. In one embodiment, the barrier substrate of the present disclosure has a first vapor deposition film and a second vapor deposition film and is more excellent in gas barrier properties. Since such a barrier substrate has vapor deposition films on both sides of a biaxially oriented polyethylene film, it is possible to suppress deterioration of gas barrier properties due to pinholes.

[0094] The vapor deposition film is composed of, for example, a metal and / or an inorganic oxide. The vapor deposition film may be a metal vapor deposition film composed of one or more metals, or an inorganic oxide vapor deposition film composed of one or more inorganic oxides. The inorganic oxide vapor deposition film may be a transparent vapor deposition 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 the vapor deposition films, aluminum vapor deposition films, aluminum oxide (alumina) vapor deposition films, silicon oxide (silica) vapor deposition films, and silicon carbide oxide vapor deposition films are preferred, and the first vapor deposition film and the second vapor deposition film are each independently preferably an aluminum vapor deposition film, an aluminum oxide (alumina) vapor deposition film, a silicon oxide (silica) vapor deposition film, or a silicon carbide oxide vapor deposition film.

[0095] The combination of the first and second evaporated films is not particularly limited. 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, where both may be the same or different. One of the first vapor-deposited film and the second vapor-deposited film may be a metal vapor-deposited film and the other may be an inorganic oxide vapor-deposited film or a transparent vapor-deposited film. The first vapor-deposited film may be an inorganic oxide vapor-deposited film or a transparent vapor-deposited film, where both may be the same or different.

[0096] In one embodiment, the first vapor-deposited film is a metal vapor-deposited film, and the second vapor-deposited film is a metal vapor-deposited film, which may be the same or different. Such a barrier substrate has particularly excellent gas barrier properties.

[0097] For example, when a packaging container is produced using a laminate having a barrier substrate with a metal vapor-deposited film such as an aluminum vapor-deposited film on both sides of a biaxially oriented polyethylene film, depending on the type of contents filled into the packaging container, the metal vapor-deposited film may be oxidized to form a metal oxide, causing discoloration, corrosion, or volume expansion, reducing the laminate strength, and causing problems such as lifting and peeling of layers.

[0098] In one embodiment, at least one of the first and second vapor deposition films is an inorganic oxide vapor deposition film. By using a laminate including such a barrier substrate, a packaging container having excellent resistance to contents can be produced. For example, a laminate including a barrier substrate and a heat seal layer is prepared. The laminate includes a barrier substrate arranged such that the inorganic oxide vapor deposition film faces the heat seal layer side (inside of the packaging container) and the other vapor deposition film faces the outside (outside of the packaging container). When both the first and second vapor deposition films are inorganic oxide vapor deposition films, the orientation of the barrier substrate is not particularly limited. By producing a packaging container using the above laminate, discoloration, corrosion or deterioration of the vapor deposition film, and lifting or peeling of layers can be suppressed even when the packaging container is filled with corrosive contents. This is because the inorganic oxide vapor deposition film is originally oxidized, and thus it is possible to suppress the occurrence of volume expansion due to oxidation, as occurs with metal vapor deposition films.

[0099] In one embodiment, the first vapor-deposited film is an inorganic oxide vapor-deposited film and the second vapor-deposited film is a metal vapor-deposited film. In one embodiment, the first vapor-deposited film is a metal vapor-deposited film and the second vapor-deposited film is an inorganic oxide vapor-deposited film. The inorganic oxide vapor-deposited film may be a transparent vapor-deposited film.

[0100] In one embodiment, the first vapor-deposition film is an inorganic oxide vapor-deposition film, and the second vapor-deposition film is an inorganic oxide vapor-deposition film. Here, both may be the same or different. The inorganic oxide vapor-deposition film may be a transparent vapor-deposition film. Such a barrier substrate can avoid the problem of oxidation deterioration when the vapor-deposition film is a metal vapor-deposition film, and can also suppress corrosion of the vapor-deposition film from the end face of the barrier substrate. In addition, since such a barrier substrate has excellent transparency, a packaging container with excellent visibility of the contents can be produced, for example, a packaging container that can be used in a microwave oven and a packaging container that can pass through a metal detector can be produced. In addition, a packaging container including such a barrier substrate can be clearly understood by, for example, a consumer that does not contain an aluminum vapor-deposition film, making it easy to separate, and further, can suppress the inclusion of foreign matter such as black spots (metal color) that may occur due to the aluminum vapor-deposition film during recycling processing.

[0101] In one embodiment, the barrier substrate of the present disclosure has a vapor-deposited film only on one surface of the biaxially oriented polyethylene film. In one embodiment, the barrier substrate of the present disclosure has a vapor-deposited film only on the surface of the second surface resin layer of the biaxially oriented polyethylene film, and does not have a vapor-deposited film on the surface of the first surface resin layer. By using a laminate having such a barrier substrate, a packaging container having excellent content resistance can be produced. For example, a laminate having a barrier substrate and a heat seal layer is prepared. The laminate has a barrier substrate arranged such that the biaxially oriented polyethylene film faces the heat seal layer side (inside of the packaging container) and the vapor-deposited film faces the outside (outside of the packaging container). By producing a packaging container using the above laminate, the vapor-deposited film can be arranged on the outside, so that even if a corrosive content is filled in the packaging container, discoloration, corrosion or deterioration of the vapor-deposited film and lifting or peeling of the layer can be suppressed.

[0102] The first and second vapor-deposited films may both be aluminum vapor-deposited films, and may be the same or different. One of the first and second vapor-deposited films may be an alumina vapor-deposited film, a silica vapor-deposited film, or a silicon carbide oxide vapor-deposited film, and the other may be an aluminum vapor-deposited film. 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, and may be the same or different.

[0103] 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 gas barrier properties. 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, from the viewpoint of suppressing crack generation in the vapor-deposited film and recyclability of the packaging container. 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 independently within the above range.

[0104] When the vapor deposition film is an aluminum vapor deposition film, the optical density (OD value) of the aluminum vapor deposition film is preferably 2.0 or more and 3.5 or less, more preferably 2.2 or more and 3.5 or less, even more preferably 2.7 or more and 3.5 or less, and particularly preferably 3.0 or more and 3.5 or less. This can improve the oxygen barrier property and water vapor barrier property while maintaining the productivity of the barrier substrate. When one vapor deposition film in the barrier substrate of the present disclosure is a transparent vapor deposition film, the other vapor deposition film tends to have a stable OD value and an aluminum vapor deposition film with excellent thickness uniformity. The OD value can be measured in accordance with JIS K7361-1:1997.

[0105] The surface of the deposited film is preferably subjected to the above-mentioned surface treatment, so that such a deposited film has, for example, excellent adhesion to adjacent layers.

[0106] Examples of methods for forming the vapor-deposited film include physical vapor deposition methods (PVD methods) such as vacuum deposition, sputtering, and ion plating, and chemical vapor deposition methods (CVD methods) such as plasma 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.

[0107] The vacuum level in the deposition chamber was 10 before oxygen was introduced. -2 ~10 -8 After oxygen is introduced, the pressure is preferably about 10 -1 ~10 -6 The pressure is preferably about mbar. The amount of oxygen introduced varies depending on the size of the deposition machine. For the oxygen introduced, an inert gas such as argon gas, helium gas, or nitrogen gas may be used as a carrier gas to the extent that no problems occur. The conveying speed of the target film on which the deposition film is formed is, for example, 10 m / min or more and 800 m / min or less.

[0108] The vapor-deposited film may be a single layer formed by one 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 component or different components. Each layer may be formed by the same method or different methods.

[0109] In one embodiment, the biaxially stretched polyethylene film comprises a first surface resin layer constituting a first surface and a second surface resin layer constituting a second surface, the first vapor-deposited film is provided on the surface of the first surface resin layer, and the second vapor-deposited film is provided on the surface of the second surface resin layer. Such a biaxially stretched polyethylene film is excellent in, for example, vapor-deposited film formability, smoothness, and adhesion, and the obtained barrier substrate is excellent in, for example, gas barrier properties, specifically oxygen barrier properties and water vapor barrier properties, and also has excellent brightness when the vapor-deposited film is a metal vapor-deposited film.

[0110] In one embodiment, the biaxially stretched polyethylene film comprises a first surface resin layer constituting a first surface and a second surface resin layer constituting a second surface, and a vapor-deposited film is provided on the surface of the second surface resin layer. Such a biaxially stretched polyethylene film is excellent in, for example, vapor-deposited film formability, smoothness, and adhesion, and the obtained barrier substrate is excellent in, for example, gas barrier properties, specifically oxygen barrier properties and water vapor barrier properties, and when the vapor-deposited film is a metal vapor-deposited film, it is excellent in brightness.

[0111] <Barrier coat layer> The barrier substrate of the present disclosure may further include a barrier coat layer on the vapor-deposited film. That is, the barrier substrate may further include a barrier coat layer on the surface of the vapor-deposited film opposite to the surface on the biaxially oriented polyethylene film side. Such a barrier substrate has, for example, excellent oxygen barrier properties and water vapor barrier properties, and can effectively suppress the occurrence of cracks in the vapor-deposited film when the vapor-deposited film is composed of an inorganic oxide such as aluminum oxide or silicon oxide.

[0112] In one embodiment, the barrier substrate comprises, in this order, a metal vapor-deposited film as a first vapor-deposited film, a biaxially oriented polyethylene film, an inorganic oxide vapor-deposited film as a second vapor-deposited film, and a barrier coat layer. In one embodiment, the barrier substrate comprises, in this order, a barrier coat layer, an inorganic oxide vapor-deposited film as a first vapor-deposited film, a biaxially oriented polyethylene film, and a metal vapor-deposited film as a second vapor-deposited film. In one embodiment, the barrier substrate comprises, in this order, a first barrier coating layer, an inorganic oxide vapor deposition film as a first vapor deposition film, a biaxially oriented polyethylene film, an inorganic oxide vapor deposition film as a second vapor deposition film, and a second barrier coating layer. In one embodiment, the barrier substrate comprises a biaxially oriented polyethylene film, an inorganic oxide vapor deposition film, and a barrier coat layer in this order.

[0113] In one embodiment, the barrier coat layer contains a gas barrier resin, such as an ethylene-vinyl alcohol copolymer, polyvinyl alcohol, polyamide, polyvinylidene chloride, polyester, polyether polyol, polyester polyol, polyurethane, polyacrylonitrile, or (meth)acrylic resin.

[0114] 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, and even more preferably 70% by mass or more. Such a barrier coat layer has, for example, excellent gas barrier properties.

[0115] The barrier coat layer may contain the above-mentioned additives.

[0116] 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 substrate and recyclability of the packaging container. The thickness is, for example, 0.01 μm or more and 10 μm or less.

[0117] 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 onto the vapor-deposited film, and drying the resulting coating liquid.

[0118] In another embodiment, the barrier coat layer is a gas barrier coating film formed by mixing a metal alkoxide, a water-soluble polymer, and optionally a silane coupling agent, and adding water, an organic solvent, and a sol-gel catalyst as required to obtain a gas barrier composition, coating the gas barrier composition on a deposition film, and drying the gas barrier composition. The gas barrier coating film contains a hydrolysis polycondensate obtained by hydrolyzing and polycondensing the above-mentioned metal alkoxide by the sol-gel method. By providing such a barrier coat layer on a deposition film, when the deposition film is made of an inorganic oxide, the gas barrier property can be improved and the occurrence of cracks in the deposition film can be effectively suppressed.

[0119] Examples of metal alkoxides include alkoxysilanes, specifically tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane.

[0120] Examples of the water-soluble polymer include hydroxyl group-containing polymers such as polyvinyl alcohol and ethylene-vinyl alcohol copolymer. Either polyvinyl alcohol or ethylene-vinyl alcohol copolymer may be used, or both may be used in combination, depending on the desired physical properties such as oxygen barrier property, water vapor barrier property, water resistance, and weather resistance. Also, a gas barrier coating film obtained using polyvinyl alcohol and a gas barrier coating film obtained using ethylene-vinyl alcohol copolymer may be laminated. The amount of the water-soluble polymer used is preferably 5 parts by mass or more and 500 parts by mass or less, based on 100 parts by mass of the metal alkoxide.

[0121] As the silane coupling agent, known organic reactive group-containing organoalkoxysilane can be used, and organoalkoxysilane having epoxy group is preferable, for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane can be mentioned. The amount of the silane coupling agent used is preferably 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the metal alkoxide.

[0122] The gas barrier composition may contain water in a ratio of preferably 0.1 mol or more, more preferably 0.5 mol or more, and preferably 100 mol or less, more preferably 60 mol or less, per mol of metal alkoxide. By making the water content equal to or greater than the lower limit, for example, the oxygen barrier property and water vapor barrier property of the barrier substrate can be improved. By making the water content equal to or less than the upper limit, for example, the hydrolysis reaction can be carried out quickly.

[0123] The gas barrier composition may contain an organic solvent, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, or n-butyl alcohol.

[0124] The sol-gel catalyst is preferably an acid or an amine compound.

[0125] Examples of methods for applying the gas barrier composition include application means such as roll coating using a gravure roll coater or the like, spray coating, spin coating, dipping, brush coating, bar coating, and applicator coating.

[0126] 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 proceeds in the composition. The composition is applied to the deposition film by a conventional method and dried. This drying causes further polycondensation of the metal alkoxide and the water-soluble polymer (and the silane coupling agent if the composition contains a silane coupling agent) to form a composite polymer layer. The above operation may be repeated to laminate multiple composite polymer layers. For example, the applied 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. This allows the formation of a gas barrier coating film.

[0127] 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, particularly preferably 1 μm or less, for example, 0.01 μm or more and 100 μm or less. A barrier substrate provided with such a gas barrier coating film has, for example, excellent gas barrier properties, can suppress the occurrence of cracks in a vapor deposition film composed of an inorganic oxide, and also has excellent recyclability and processability of a packaging container.

[0128] [Laminate] The laminate of the present disclosure includes at least the biaxially oriented polyethylene film, the printed film, or the barrier substrate of the present disclosure, and a heat seal layer. The laminate of the present disclosure can be suitably used as a packaging material.

[0129] <Base material> The laminate of the present disclosure comprises the biaxially oriented polyethylene film, the printed film, or the barrier substrate of the present disclosure. The laminate of the present disclosure may comprise two or more biaxially oriented polyethylene films. The laminate of the present disclosure may comprise two or more printed films. The laminate of the present disclosure may comprise two or more barrier substrates. Details of the biaxially oriented polyethylene film, the printed film, and the barrier substrate are as described above, and detailed explanations will be omitted in this section.

[0130] In a laminate comprising a biaxially oriented polyethylene film and a heat seal layer, the orientation of the biaxially oriented polyethylene film is not particularly limited. In a laminate comprising a printed film and a heat seal layer, the orientation of the printed film is not particularly limited. In a laminate comprising a barrier substrate and a heat seal layer, the orientation of the barrier substrate is not particularly limited.

[0131] In one embodiment, the laminate of the present disclosure does not include an aluminum foil. Such a laminate of the present disclosure and a packaging container including the laminate have excellent recyclability.

[0132] The laminate of the present disclosure may further include a polyolefin oriented substrate containing polyolefin as a main component. Examples of polyolefin include polypropylene, polyethylene, polybutene, and polymethylpentene. Among these, polypropylene and polyethylene are preferred, and polyethylene is more preferred. Examples of the polyolefin oriented substrate include a polypropylene oriented substrate containing polypropylene as a main component, and a polyethylene oriented substrate containing polyethylene as a main component, and polyethylene is more preferred. The polyolefin oriented substrate is a polyolefin substrate that has been subjected to a stretching process. Details of the stretching process are as described above, and will not be described in this section. The polyolefin oriented substrate is, for example, a uniaxially stretched substrate or a biaxially stretched substrate.

[0133] 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, from the viewpoint of the processability of the laminate, for example, 5 μm or more and 300 μm or less.

[0134] The stretched polyolefin substrate may be subjected to the above-mentioned surface treatment. Such a stretched polyolefin substrate has, for example, excellent adhesion to a layer adjacent to the substrate. In addition, an anchor coat layer may be formed on the surface of the stretched polyolefin substrate using a conventionally known anchor coat agent.

[0135] A laminate further comprising an oriented polyolefin substrate may comprise, for example, an oriented polyolefin substrate, a biaxially oriented polyethylene film, a printed film or a barrier substrate of the present disclosure, and a heat seal layer, in that order; or a biaxially oriented polyethylene film, a printed film or a barrier substrate of the present disclosure, an oriented polyolefin substrate, and a heat seal layer, in that order.

[0136] <Print layer> The laminate of the present disclosure may include a printed layer on one or both sides of the substrate such as the biaxially oriented polyethylene film, the barrier substrate, and the oriented polyolefin substrate described above. The laminate of the present disclosure may include a printed layer on the second heat seal layer described below.

[0137] The print layer includes an image. Examples of the image include characters, figures, patterns, symbols, and combinations thereof. The image may include text information such as a 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 (so-called solid image).

[0138] The printing layer can be formed, for example, by using an ink composition. Examples of methods for forming the printing layer include gravure printing, offset printing, flexographic printing, screen printing, letterpress printing, and transfer printing. From the viewpoint of reducing the environmental load, the printing layer may be formed by flexographic printing. From the viewpoint of reducing the environmental load, the printing layer may be formed by using an ink derived from biomass.

[0139] 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.

[0140] <Surface protective layer> The laminate of the present disclosure may have a surface protective layer on the printed layer provided on the second heat seal layer described later in order to improve the scratch resistance and weather resistance of the printed layer. The laminate of the present disclosure preferably has 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 region, and more preferably colorless and transparent.

[0141] The surface protective layer contains, for example, a thermoplastic resin, a cured product of 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 ratio of the above cured product to the total resin components of the surface protective layer is preferably 80% by mass or more, more preferably 90% by mass or more. Examples of printing methods for the surface protective layer include letterpress printing, flexographic printing, gravure printing, offset printing, screen printing, inkjet printing, and thermal transfer printing.

[0142] The thickness of the surface protective layer is preferably 0.5 μm or more, more preferably 1 μm or more, and is 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 having such a surface protective layer has excellent scratch resistance and weather resistance.

[0143] <Heat seal layer> The laminate of the present disclosure comprises a heat seal layer. The heat seal layer contains, as a main component, a heat-fusible resin that can be melted by heat and fused to each other. Examples of the heat-fusible resin include polyolefins such as polyethylene, polypropylene, and polymethylpentene, cyclic polyolefins, cyclic olefin copolymers, ionomer resins, acid-modified polyolefins, and terpolymers of ethylene-(meth)acrylic acid ester-unsaturated carboxylic acid. Examples of polyethylene include linear low-density polyethylene, high-pressure low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, ethylene-(meth)acrylic acid 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.

[0144] In recent years, from the viewpoint of reducing the environmental load, there has been a demand for recycling packaging containers. From the viewpoint of recyclability, it is preferable that the base material and the heat seal layer are each composed of the same type of resin material (mono-materialization). In one embodiment, the heat seal layer contains polyethylene as a main component. This allows the packaging container to be mono-materialized. Such a packaging container has excellent recyclability, and for example, after collecting a used packaging container, it is not necessary to separate the base material and the heat seal layer.

[0145] In one embodiment, the content of polyethylene in the entire laminate of the present disclosure 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. This allows, for example, the laminate to be used to produce a mono-material packaging container, improving the recyclability of the packaging container. The upper limit of the content of polyethylene is not particularly limited, but may be 99% by mass.

[0146] The heat seal layer may contain the above-mentioned additives.

[0147] The laminate of the present disclosure may include at least a first heat seal layer as the heat seal layer, a biaxially oriented polyethylene film, a printed film or a barrier substrate of the present disclosure, and a second heat seal layer as the heat seal layer, in this order. The first heat seal layer and the second heat seal 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 body. In this case, 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 includes, from the outside to the inside of the body, the second heat seal layer, the biaxially oriented polyethylene film, a printed film or a barrier substrate, and the first heat seal layer, in this order. In one embodiment, the first heat seal layer and the second heat seal layer contain polyethylene as a main component.

[0148] In the above laminate, the orientation of the biaxially oriented polyethylene film is not particularly limited. In the laminate, the orientation of the print film and the barrier substrate is not particularly limited.

[0149] The heat seal layer may have a single-layer structure or a multi-layer structure. The thickness of the heat seal layer is preferably 10 μm or more, more preferably 30 μm or more, even more preferably 50 μm or more, and particularly preferably 80 μm or more, from the viewpoint of heat sealability and recyclability of the packaging container. The thickness of the heat seal layer is preferably 300 μm or less, more preferably 200 μm or less, and even more preferably 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.

[0150] From the viewpoint of heat sealability, 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-mentioned 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.

[0151] For example, an unstretched resin film corresponding to the heat seal layer may be laminated on a biaxially oriented polyethylene film, a printed film, or a barrier substrate, if necessary, via an adhesive layer, or a heat-sealing layer may be formed by melt-extruding a heat-sealing resin or a resin composition thereof onto a biaxially oriented polyethylene film, a printed film, or a barrier substrate. In the latter case, an adhesive layer may not be provided. Examples of the adhesive layer include the adhesive layer described below.

[0152] <Adhesive layer> The laminate of the present disclosure may include an adhesive layer between any layers, such as between the biaxially oriented polyethylene film, the printed film, or the barrier substrate and the heat seal layer. Such a laminate has excellent adhesion between the biaxially oriented polyethylene film, the printed film, or the barrier substrate and the heat seal layer, for example.

[0153] The laminate of the present disclosure may, for example, comprise the biaxially oriented polyethylene film, printed film or barrier substrate of the present disclosure, an adhesive layer, and a heat seal layer in this order, or may comprise the oriented polyolefin substrate, a second adhesive layer, the biaxially oriented polyethylene film, printed film or barrier substrate of the present disclosure, a first adhesive layer, and a heat seal layer in this order, or may comprise the biaxially oriented polyethylene film, printed film or barrier substrate of the present disclosure, a second adhesive layer, oriented polyolefin substrate, a first adhesive layer, and a heat seal layer in this order. The laminate of the present disclosure may, for example, comprise the second heat seal layer, the second adhesive layer, the biaxially oriented polyethylene film, printed film or barrier substrate of the present disclosure, a first adhesive layer, and a first heat seal layer in this order.

[0154] 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.

[0155] 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-liquid curing urethane adhesives are more preferred.

[0156] 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-liquid curing urethane-based adhesives are more preferred.

[0157] In one embodiment, the laminate of the present disclosure may be produced by laminating the biaxially oriented polyethylene film, printed film, or barrier substrate of the present disclosure, an optional oriented 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.

[0158] The adhesive layer can be formed by applying an adhesive to a biaxially oriented polyethylene film, a printed film, a barrier substrate, or the like, and drying the adhesive, for example, by a method such as direct gravure roll coating, gravure roll coating, kiss coating, reverse roll coating, Fontaine method, or transfer roll coating.

[0159] 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.

[0160] 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-sealing resin. The thermoplastic resin may be a material derived from fossil fuels, a material derived from biomass, or both of these may be used.

[0161] 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, and 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, for example, 5 μm or more and 30 μm or less.

[0162] <Layer structure of laminate> Below, several examples of layer configurations of the laminate of the present disclosure will be given. 4 comprises, in this order, a barrier substrate 1, an adhesive layer 60, and a heat seal layer 80, and more specifically, in this order, a second vapor-deposited film 42, a second surface resin layer 22, a polyethylene layer 10, a first surface resin layer 20, a first vapor-deposited film 40, an adhesive layer 60, and a heat seal layer 80. The laminate 2 may further comprise a printed layer (not shown), and for example, may further comprise a printed layer (not shown) on the first vapor-deposited film 40 or the second vapor-deposited film 42 of the barrier substrate 1. The laminate 2 shown in FIG. 5 includes a polyolefin oriented substrate 70, a second adhesive layer 62, a barrier substrate 1, a first adhesive layer 60, and a heat seal layer 80 in this order, specifically, a polyolefin oriented substrate 70, a second adhesive layer 62, a second vapor deposition film 42, a second surface resin layer 22, a polyethylene layer 10, a first surface resin layer 20, a first vapor deposition film 40, a first adhesive layer 60, and a heat seal layer 80 in this order. The laminate 2 may further include a printed layer (not shown), for example, a printed layer (not shown) may be further included on the surface of the polyolefin oriented substrate 70 facing the barrier substrate 1. A laminate having such a configuration is suitable as a packaging material for forming a standing pouch, for example. The laminate 2 shown in FIG. 6 includes a second heat seal layer 82, a second adhesive layer 62, a barrier substrate 1, a first adhesive layer 60, and a first heat seal layer 80 in this order, specifically, the laminate includes a second heat seal layer 82, a second adhesive layer 62, a second vapor deposition film 42, a second surface resin layer 22, a polyethylene layer 10, a first surface resin layer 20, a first vapor deposition film 40, a first adhesive layer 60, and a first heat seal layer 80 in this order. The laminate 2 may further include a printed layer (not shown), for example, a printed layer (not shown) on the surface of the second heat seal layer 82. A laminate having such a configuration is suitable as a packaging material for forming the body of a tube container body, for example. 4 to 6, the barrier substrate 1 may further include a barrier coat layer (not shown) on the first vapor-deposited film 40. In FIG. 4 to 6, the barrier substrate 1 may further include a barrier coat layer (not shown) on the second vapor-deposited film 42. In FIG. 4 to 6, the orientation of the barrier substrate 1 may be reversed. In FIG. 4 to 6, the laminate 2 may include a biaxially oriented polyethylene film or a printed film instead of the barrier substrate 1, or may include a barrier substrate having a vapor-deposited film only on one side of the biaxially oriented polyethylene film or the printed film.

[0163] [Packaging container] The laminate of the present disclosure can be suitably used for packaging material applications. The packaging material is used to produce a packaging container. By using at least the laminate of the present disclosure, a packaging container having excellent gas barrier properties can be produced.

[0164] Examples of the packaging container include a packaging bag, a tube container, and a container with a lid.

[0165] Examples of packaging bags include packaging bags of various shapes, such as a standing pouch type, a side seal type, a two-sided seal type, a three-sided seal type, a four-sided seal type, an envelope seal type, a grooving seal type (pillow seal type), a pleated seal type, a flat bottom seal type, a square bottom seal type, and a gusset type. The packaging bag may be, for example, a small bag or a zipper bag. The packaging bag may be a refill pouch, particularly a standing pouch, that contains contents such as liquids and powders and is refilled into a container such as a bottle. The packaging bag may be, for example, a soft packaging bag.

[0166] The packaging bag of the present disclosure comprises the laminate of the present disclosure. The packaging bag of the present disclosure is, 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; has. The seal portion includes an inner edge that defines the receiving portion.

[0167] Examples of methods for forming the sealed portion include heat sealing, which involves melting the heat seal layers of the laminate by heating or the like to fuse the heat seal layers together, and specifically 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 is heat sealed to seal the packaging bag.

[0168] 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.

[0169] 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 section, and a lid material joined (heat sealed) to the container body so as to seal the storage section. 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.

[0170] The contents contained 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, medicines, metal parts, and electronic parts. The contents include, for example, shampoo, rinse, conditioner, hand soap, body soap, air freshener, deodorant, insect repellent, fabric softener, detergent; sauce, soy sauce, dressing, edible oil, mayonnaise, ketchup, syrup, cooking alcohol, other liquid or viscous seasonings; fruit juice; spices; liquid beverages, jelly beverages, liquid soups, powdered soups, instant foods, other food and beverages; cream; toothpaste; metal parts, and electronic parts. For example, toothpaste is a preferred content of a tube container.

[0171] In one embodiment, a packaging bag can be produced by folding the laminate of the present disclosure in half and overlapping it so that the biaxially oriented polyethylene film, printed film, or barrier substrate is on the outside and the heat seal layer is on the inside, and then heat sealing the ends, 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 then heat sealing the ends, etc. The entire packaging bag may be composed of the above-mentioned laminate, or only a part of the packaging bag may be composed of the above-mentioned laminate.

[0172] In one embodiment, the standing pouch includes a body portion composed of a side sheet and a bottom portion composed of a bottom sheet. The bottom sheet retains the shape of the side sheet, thereby imparting self-supporting properties to the pouch, and the pouch can be made into a standing type pouch. A storage portion for storing contents is formed within the area surrounded by the side sheet and the bottom sheet. In the standing pouch, only the side sheet may be the laminate of the present disclosure, only the bottom sheet may be the laminate of the present disclosure, or both the side sheet and the bottom sheet may be the laminate of the present disclosure.

[0173] In one embodiment, the side sheet can be formed by making a bag so that the heat seal layer of the laminate of the present disclosure is the innermost layer. In one embodiment, the side sheet can be formed by preparing two laminates of the present disclosure, overlapping them so that the heat seal layers face each other, and heat sealing the side edges on both sides to make a bag.

[0174] In another embodiment, the side sheet can be formed by preparing two laminates of the present disclosure, overlapping them with the heat seal layers facing each other, inserting two laminates folded in a V shape with the heat seal layers facing outward between the laminates at the side edges on both sides of the overlapped laminates, and heat sealing them. According to this production method, a standing pouch having a body with side gussets can be obtained.

[0175] In one embodiment, the bottom sheet can be formed by inserting the laminate of the present disclosure between the lower parts of the side sheets that have been made into 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 on the outside between the lower parts of the side sheets that have been made into a bag, and heat sealing the laminate.

[0176] In one embodiment, two laminates of the present disclosure are prepared, and these are stacked so that the heat seal layers face each other, and then another laminate of the present disclosure is folded in a V shape so that the heat seal layer faces outward, and this is sandwiched under the lower part of the laminates that face each other, and heat sealed to form a bottom. Next, two sides adjacent to the bottom are heat sealed to form a body. In this way, a standing pouch of one embodiment can be formed.

[0177] [Tube container body] The tube container body of the present disclosure comprises the laminate of the present disclosure. The tube container body of the present disclosure will be described below with reference to the drawings. Fig. 7 is a diagram showing a simplified configuration of a tube container 120, and Fig. 8 is a cross-sectional view taken along line AA in Fig. 7. As shown in Fig. 7, 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.

[0178] <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 thereon.

[0179] In one embodiment, the head is formed of a resin composition containing a thermoplastic resin. Examples of the thermoplastic resin include polyolefins such as polyethylene and polypropylene, polyesters, cellulose resins, and vinyl resins. The resin composition may contain the additives.

[0180] The head portion can be manufactured by a conventional method, for example, by compression molding or injection molding, and can be joined to the body portion.

[0181] <Torso> 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 on the first heat seal layer side of the laminate at the other end is in contact with the surface on the second heat seal layer side of the laminate 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 laminate rolled into a cylindrical shape.

[0182] Examples of the heat sealing method include conventionally known methods such as bar sealing, rotary roll sealing, belt sealing, impulse sealing, high frequency sealing, ultrasonic sealing and flame sealing.

[0183] For example, the laminate of the present disclosure may be rolled into a cylindrical shape by overlapping the first heat seal layer side surface of one end of the laminate with the second heat seal layer side surface of the other end, and heat sealing the overlapped portion to produce a cylindrical body. From the viewpoint of heat sealability, it is preferable that one overlapped 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.

[0184] Therefore, it is preferable that the second heat seal layer does not have a printed layer or a surface protective layer formed in an area to be heat sealed when forming the body of the tube container body, so that the area can be well heat sealed when forming the cylindrical body using the laminate of the present disclosure.

[0185] In the above embodiment, the fusion portion is formed by overlapping, but the same surfaces of both ends of the laminate may be butted together and the first heat seal layers may be heat sealed to be joined. 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 joining tape may be attached to the outer surface side of the body so as to cover the joining portion. It is preferable that the printed layer and the surface protective layer are not provided at the portion of the laminate where the joining tape is attached. The joining tape may be provided on both the inner surface and the outer surface of the body.

[0186] [Tube container] The tube container of the present disclosure will be described below with reference to the drawings. As shown in FIG. 7, the tube container 120 of the present disclosure includes a tube container body 121 and a cap 26 attached to a head portion 122.

[0187] <Tube container body> The tube container body has been described above, so a description thereof will be omitted here.

[0188] <Cap> The cap is detachably attached to the extraction port of the head, and serves to close the extraction port. In one embodiment, the cap is formed of a resin composition containing a thermoplastic resin. Examples of the thermoplastic resin include polyolefins such as polyethylene and polypropylene, polyesters, cellulose resins, and vinyl resins. The resin composition may contain the additives.

[0189] The cap may be a screw type having a groove on the inner surface of the cap so as to screw into the threads 127 of the extraction port 125, as shown in FIG. 7, or it may be a plug type that fits into the extraction port 125 by plugging it.

[0190] [Aspects of the present disclosure] The present disclosure relates to, for example, the following [1] to

[17] . [1] A biaxially oriented polyethylene film comprising a polyethylene layer containing at least one polyethylene selected from high density polyethylene and medium density polyethylene. [2] A polyethylene layer containing polyethylene as a main component, the polyethylene contained in the polyethylene layer has a density of 0.930 g / cm 3 Super 0.960g / cm 3 A biaxially oriented polyethylene film having the following density: [3] The biaxially oriented polyethylene film according to [1] or [2], wherein the polyethylene layer contains at least one type of polyethylene selected from high density polyethylene and medium density polyethylene, and a linear low density polyethylene. [4] The biaxially stretched polyethylene film according to [3], wherein the total content of high-density polyethylene and medium-density polyethylene in the polyethylene layer is 20% by mass or more and 60% by mass or less, and the content of linear low-density polyethylene is 40% by mass or more and 80% by mass or less. [5] The high density polyethylene has a viscosity of 0.945 g / cm 3 Super 0.960g / cm 3 and the linear low density polyethylene is an ethylene-α-olefin copolymer having a density of 0.930 g / cm or less, 3 The biaxially oriented polyethylene film according to [3] or [4] above, which is an ethylene-α-olefin copolymer having the following density: [6] The biaxially oriented polyethylene film according to any one of the above [1] to [5], comprising a first surface resin layer, a polyethylene intermediate layer, and a second surface resin layer, and the first surface resin layer, the polyethylene intermediate layer, and the second surface resin layer are each independently a polyethylene layer. [7] The biaxially oriented polyethylene film according to [6], wherein the biaxially oriented polyethylene film has two or more polyethylene intermediate layers. [8] The first surface resin layer, the polyethylene intermediate layer and the second surface resin layer each independently have a hardness of 0.945 g / cm 3Super 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: [9] The biaxially stretched polyethylene film according to any one of the above [6] to [8], wherein the first surface resin layer has a thickness of 0.3 μm or more and 15 μm or less, the polyethylene intermediate layer has a thickness of 6 μm or more and 100 μm or less, and the second surface resin layer has a thickness of 0.3 μm or more and 15 μm or less.

[10] The biaxially stretched polyethylene film according to any one of the items [1] to [9], wherein the biaxially stretched polyethylene film is a monolayer film consisting of the polyethylene layer, or a multilayer film comprising at least the polyethylene layer.

[11] The biaxially oriented polyethylene film according to

[10] , wherein the biaxially oriented polyethylene film is a biaxially oriented film of a coextruded resin film.

[12] A printed film comprising the biaxially stretched polyethylene film according to any one of [1] to

[11] above, and a printed layer provided on at least one surface of the film.

[13] A barrier substrate comprising the biaxially stretched polyethylene film according to any one of [1] to

[11] above, and a vapor-deposited film provided on at least one surface of the film.

[14] A laminate comprising at least the biaxially stretched polyethylene film according to any one of [1] to

[11] above, the printed film according to

[12] above, or the barrier substrate according to

[13] above, and a heat seal layer.

[15] The laminate according to

[14] , 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.

[16] A packaging container comprising the laminate described in

[14] or

[15] .

[17] The packaging container described in

[16] above, which is a packaging bag. EXAMPLES

[0191] Hereinafter, the biaxially oriented polyethylene film of the present disclosure will be described in more detail with reference to examples, but the biaxially oriented polyethylene film of the present disclosure is not limited to the following examples. In the following description, "parts by mass" will be simply abbreviated as "parts".

[0192] [Biaxially oriented polyethylene film material] The following materials were used in the preparation of the biaxially oriented polyethylene 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 agents (AB agents) Silica particles, average particle size: 3.5 μm

[0193] [Example 1] Blended polyethylene (A) was prepared by mixing 20 parts of HDPE, 80 parts of LLDPE, and 0.2 parts (2,000 ppm) of an AB agent. Blended polyethylene (B) was prepared by mixing 20 parts of HDPE and 80 parts of LLDPE.

[0194] A blended polyethylene (A); A blended polyethylene (B); A blended polyethylene (B); A blended polyethylene (B); A blended polyethylene (A); The mixture was co-extruded by T-die casting to obtain a 5-layer film. 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 polyethylene film with a thickness of 25 μm. In Example 1, the biaxial stretching was performed well.

[0195] The biaxially oriented polyethylene film thus obtained is A second surface resin layer (a blended polyethylene (A) layer) having a thickness of 1 μm; a third polyethylene layer (a blended polyethylene (B) layer) having a thickness of 2 μm; A second polyethylene layer (blend polyethylene (B) layer) having a thickness of 19 μm; A first polyethylene layer (a blended polyethylene (B) layer) having a thickness of 2 μm; A first surface resin layer (a blended polyethylene (A) layer) having a thickness of 1 μm; are provided in this order.

[0196] [Examples 2 to 4] Biaxially stretched polyethylene films having a thickness of 25 μm were produced in the same manner as in Example 1, except that the blending composition of the polyethylene in each layer was changed as shown in Table 1. In Examples 2 to 4, biaxial stretching was successfully performed. In Table 1, the blending amount of the AB agent in the surface resin layer was 2,000 ppm in each case.

[0197] [Example 5] A mixture of 40 parts of HDPE and 60 parts of LLDPE was extruded into a single layer by T-die casting to obtain a single layer film. The film was stretched 5 times in the machine direction (MD) and then 8.5 times in the width direction (TD) to produce a biaxially stretched polyethylene film with a thickness of 25 μm. In Example 5, the biaxial stretching was performed well.

[0198] [Comparative Example 1] The LLDPE was extruded into a single layer film by the T-die casting method, which was then stretched 5 times in the machine direction (MD) and then 8.5 times in the transverse direction (TD) to produce a biaxially stretched polyethylene film with a thickness of 25 μm.

[0199] [Heat resistance evaluation 1: Print resistance evaluation] The surface of the biaxially stretched polyethylene film prepared above was subjected to a corona discharge treatment. An image was formed on the corona discharge treated surface of the film by gravure printing using oil-based gravure ink (manufactured by DIC Graphics Corporation, product name: Finart). The 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. [Heat resistance evaluation 2: 170℃ heat seal resistance evaluation] The surface of the biaxially stretched polyethylene film prepared above was subjected to a corona discharge treatment. An image was formed on the corona discharge treated surface of the 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 bonded to a 40 μm-thick LLDPE film obtained by forming Evolue SP2020 (manufactured by Mitsui Chemicals) as a single layer film 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 (1kgf / cm 2 The heat-sealed portion was then subjected to a pressure of 100 MPa for 1 second, and the thermal shrinkage state of the laminate film in the heat-sealed portion was observed. The heat resistance was evaluated according to the following criteria. A: No film shrinkage occurred when heat sealed at 170°C. B: Almost no film shrinkage occurred when heat sealed at 170°C. C: The film significantly shrunk when heat sealed at 170°C.

[0200] [Table 1]

[0201] [Examples 1' to 4'] The biaxially stretched polyethylene films of Examples 1' to 4' were produced in the same manner as in Examples 1 to 4, except that the thicknesses of the first polyethylene layer, second polyethylene layer, and third polyethylene 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 1' to 4', biaxial stretching could be performed well. The results of each evaluation in Examples 1' to 4' were equivalent to the results of the Examples (Examples 1 to 4) with the corresponding Example numbers.

[0202] [Example 5' and Comparative Example 1'] Except for changing the thickness of the biaxially oriented polyethylene film to 18 μm, a biaxially oriented polyethylene film of Example 5′ was produced in the same manner as in Example 5. The results of each evaluation in Example 5′ were comparable to those of Example 5′. Except for changing the thickness of the biaxially oriented polyethylene film to 18 μm, a biaxially oriented polyethylene film of Comparative Example 1′ was produced in the same manner as in Comparative Example 1. The results of each evaluation in Comparative Example 1′ were equivalent to those of Comparative Example 1′. [Explanation of symbols]

[0203] 1. Barrier substrate 1A Biaxially oriented polyethylene film 2. Laminate 10 Polyethylene layer 11 First polyethylene layer 12 Second polyethylene layer 13 Third polyethylene layer 20 First surface resin layer 22 Second surface resin layer 40 (First) Evaporation Film 42 Second deposition film 60 Adhesive layer, first adhesive layer 62 Second adhesive layer 70 Polyolefin oriented substrate 80 Heat seal layer, first heat seal layer 82 Second heat seal layer 120 Tube container 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 biaxially oriented polyethylene film comprising a polyethylene layer containing at least one polyethylene selected from high density polyethylene and medium density polyethylene.

2. The polyethylene layer contains polyethylene as a main component, and the polyethylene contained in the polyethylene layer has a viscosity of 0.930 g / cm 3 Super 0.960g / cm 3 A biaxially oriented polyethylene film having the following density:

3. 3. The biaxially oriented polyethylene film according to claim 1 or 2, wherein the polyethylene layer contains at least one polyethylene selected from high density polyethylene and medium density polyethylene, and a linear low density polyethylene.

4. 4. The biaxially oriented polyethylene film according to claim 3, wherein the total content of high-density polyethylene and medium-density polyethylene in the polyethylene layer is 20% by mass or more and 60% by mass or less, and the content of linear low-density polyethylene is 40% by mass or more and 80% by mass or less.

5. The high density polyethylene has a viscosity of 0.945 g / cm 3 Super 0.960g / cm 3 The linear low density polyethylene is an ethylene-α-olefin copolymer having a density of 0.930 g / cm or less, 3 The biaxially oriented polyethylene film according to claim 3, which is an ethylene-α-olefin copolymer having a density of:

6. The biaxially oriented polyethylene film is A first surface resin layer; A polyethylene intermediate layer; A second surface resin layer; Equipped with The first surface resin layer, the polyethylene intermediate layer and the second surface resin layer are each independently the polyethylene layer.

3. The biaxially oriented polyethylene film according to claim 1 or 2.

7. 7. The biaxially oriented polyethylene film according to claim 6, wherein the biaxially oriented polyethylene film comprises two or more of the polyethylene intermediate layers.

8. The first surface resin layer, the polyethylene intermediate layer and the second surface resin layer each independently have a viscosity 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 below 100%.

9. The thickness of the first surface resin layer is 0.3 μm or more and 15 μm or less, The thickness of the polyethylene intermediate layer is 6 μm or more and 100 μm or less, The thickness of the second surface resin layer is 0.3 μm or more and 15 μm or less. The biaxially oriented polyethylene film according to claim 6.

10. 3. The biaxially oriented polyethylene film according to claim 1 or 2, wherein the biaxially oriented polyethylene film is a monolayer film consisting of the polyethylene layer, or a multilayer film comprising at least the polyethylene layer.

11. The biaxially oriented polyethylene film according to claim 10, wherein the biaxially oriented polyethylene film is a biaxially oriented film of a coextruded resin film.

12. The biaxially oriented polyethylene film according to claim 1, A printing layer provided on at least one surface of the film; A printing film comprising:

13. The biaxially oriented polyethylene film according to claim 2, A printing layer provided on at least one surface of the film; A printing film comprising:

14. The biaxially oriented polyethylene film according to claim 1, a vapor-deposited film provided on at least one surface of the film; A barrier substrate comprising:

15. The biaxially oriented polyethylene film according to claim 2, a vapor-deposited film provided on at least one surface of the film; A barrier substrate comprising:

16. A biaxially oriented polyethylene film according to claim 1 or 2, a printed film according to claim 12 or 13, or a barrier substrate according to claim 14 or 15; A heat seal layer; A laminate comprising at least

17. The laminate according to claim 16, 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.

18. A packaging container comprising the laminate according to claim 16.

19. 20. The packaging container of claim 18, which is a packaging bag.

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