Laminate and packaging container

Abstract

To provide a laminate useful as a packaging material for producing packaging containers with excellent recyclability and gas barrier properties.SOLUTION: Provided is a laminate comprising at least a heat seal layer and a barrier layer, in which the heat seal layer contains polyethylene as a main component; the barrier layer comprises at least a stretched film and a vapor-deposited layer; the stretched film comprises, in the following order, a first surface resin layer, a polyethylene layer, and a second surface resin layer; the polyethylene layer contains polyethylene as a main component; the second surface resin layer is either a layer containing a gas barrier resin as a main component, or a layer containing polyethylene and an adhesive resin; when adjacent layers serving as stretched layers have the same resin composition and cannot be distinguished from each other, however, such adjacent layers may be integrated to form a single layer; and the vapor-deposited layer is provided at least on the surface of the second surface resin layer of the stretched film.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] Packaging containers are used to store contents such as liquids and powders. Packaging containers are made using a laminate including a base layer and a heat-sealing layer (see, for example, Patent Document 1). For example, polyolefin films are widely used as heat-sealing layers because they have flexibility, transparency, and excellent heat-sealing properties. Biaxially oriented polyester films are also widely used as base layers because they have excellent strength and heat resistance.

[0003] In recent years, there has been a demand for recycling packaging containers in order to reduce environmental impact. From the viewpoint of recyclability, it is preferable that the base layer and the heat seal layer are each made of polyolefin. For example, Patent Document 1 proposes that the base layer and the heat seal layer are each made of polyethylene. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-55156 Summary of the Invention [Problem to be solved by the invention]

[0005] The present inventors have investigated the production of packaging containers using a laminate having a stretched polyethylene film as a base layer as a packaging material. However, such packaging containers tend to have insufficient gas barrier properties. Therefore, the present inventors have investigated the formation of a vapor-deposited film on the stretched polyethylene film. However, even with this configuration, the gas barrier properties were still insufficient.

[0006] One object of the present disclosure is to provide a laminate useful as a packaging material for producing packaging containers that are excellent in recyclability and gas barrier properties. [Means for solving the problem]

[0007] One embodiment of the laminate of the present disclosure comprises at least a heat seal layer and a barrier layer, wherein the heat seal layer contains polyethylene as a main component, and the barrier layer comprises at least a stretched film and a vapor-deposited film, and the stretched film comprises a first surface resin layer, a polyethylene layer, and a second surface resin layer, in this order, wherein the polyethylene layer contains polyethylene as a main component, and the second surface resin layer is a layer containing a gas barrier resin as a main component or a layer containing polyethylene and an adhesive resin, provided that when adjacent layers constituting the stretched film have the same resin composition and are indistinguishable from one another, the adjacent layers may be integrated to form a single layer, and the vapor-deposited film is provided at least on the surface of the second surface resin layer of the stretched film. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to provide a laminate useful as a packaging material for producing packaging containers that are excellent in recyclability and gas barrier properties, particularly a laminate for producing small pouches. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic cross-sectional view showing one embodiment of a barrier film. [Figure 2] FIG. 2 is a schematic cross-sectional view showing one embodiment of a barrier film. [Figure 3] FIG. 3 is a schematic cross-sectional view showing one embodiment of a barrier film. [Figure 4] FIG. 4 is a schematic cross-sectional view showing one embodiment of a barrier film. [Figure 5] FIG. 5 is a schematic cross-sectional view showing one embodiment of a barrier film. [Figure 6]FIG. 6 is a schematic cross-sectional view showing one embodiment of a barrier film. [Figure 7] FIG. 7 is a schematic cross-sectional view showing one embodiment of a laminate. [Figure 8] FIG. 8 is a schematic cross-sectional view showing one embodiment of a laminate. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described in detail. The present disclosure can be implemented in many different forms, and should not be construed as being limited to the description of the following exemplary embodiments. For clarity of explanation, the drawings may show the width, thickness, shape, etc. of each layer more schematically than in the embodiments, but these are merely examples and do not limit the interpretation of the present disclosure. In this specification and each drawing, elements similar to those already described with reference to the previous drawings are designated by the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0011] In the present disclosure, when multiple upper limit candidates and multiple lower limit candidates are listed for a certain parameter, the numerical range of the parameter may be constructed by combining any one upper limit candidate with any one lower limit candidate. Examples of such parameters include physical properties, component content, and layer thickness. As an example, the following statement will be explained: "Parameter B is preferably A1 or greater, more preferably A2 or greater, and even more preferably A3 or greater. Parameter B is preferably A4 or less, more preferably A5 or less, and even more preferably A6 or less." In this example, the numerical range of parameter B may be A1 or greater and A4 or less, A1 or greater and A5 or less, A1 or greater and A6 or less, A2 or greater and A4 or less, A2 or greater and A5 or less, A2 or greater and A6 or less, A3 or greater and A4 or less, A3 or greater and A5 or less, or A3 or greater and A6 or less.

[0012] In this specification, each of the components (for example, polyolefins such as polyethylene and polypropylene, α-olefins, resin materials such as gas barrier resins, adhesive resins, and additives) appearing in the following description may be used alone or in combination of two or more types.

[0013] As used herein, the term "major component" in a layer or film refers to a component whose content in the layer or film exceeds 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.

[0014] [Barrier layer] The barrier layer of the laminate of the present disclosure will be described below. The barrier layer includes at least a stretched film and a vapor-deposited film. The following description also applies to a barrier film corresponding to the barrier layer. The base film and the stretched film obtained by stretching the base film comprise a first surface resin layer, a polyethylene layer, and a second surface resin layer, in this order. The polyethylene layer contains polyethylene as a main component. The second surface resin layer is a layer containing a gas barrier resin as a main component, or a layer containing polyethylene and an adhesive resin. In the following description, when describing matters common to the first surface resin layer and the second surface resin layer, they will simply be referred to as "surface resin layer."

[0015] In one embodiment, the barrier layer comprises: a first vapor-deposited film; A stretched film; a second deposited film; Such a barrier layer is provided on both sides of the stretched film by vapor deposition, and therefore can suppress deterioration of gas barrier properties due to pinholes.

[0016] The base film and the stretched film have a first surface and a second surface opposite to the first surface. The vapor-deposited film is provided at least on the second surface of the stretched film. The vapor-deposited film is provided at least on the surface of the second surface resin layer of the stretched film. The first vapor-deposited film is provided on the first surface of the stretched film. The first vapor-deposited film is provided on the surface of the first surface resin layer of the stretched film. The second vapor-deposited film is provided on the second surface of the stretched film. The second vapor-deposited film is provided on the surface of the second surface resin layer of the stretched film. A stretched film is a film that has been subjected to a stretching process.

[0017] The base film and the stretched film have a multilayer structure of three or more layers. Stretched films with a multilayer structure have, for example, an excellent balance of gas barrier properties, strength, rigidity, heat resistance, transparency, and printability. In one embodiment, the base film and the stretched film have three or more layers, preferably fourteen or fewer layers, more preferably twelve or fewer layers, for example, three or more and fourteen or fewer layers. Specifically, the base film and the stretched film have four, six, eight, ten, twelve, or fourteen layers. In one embodiment, the base film and the stretched film have three or more layers, preferably nine or fewer layers, more preferably seven or fewer layers, for example, three or more and nine or fewer layers. Specifically, the base film and the stretched film have three, five, seven, or nine layers. In this specification, when adjacent layers constituting a film have the same resin composition and are indistinguishable from each other, the adjacent layers may be integrated to form a single layer.

[0018] The base film and the stretched film may have two or more polyethylene layers. The base film and the stretched film may further have a first adhesive resin layer between the first surface resin layer and the polyethylene layer. The base film and the stretched film may further have a second adhesive resin layer between the polyethylene layer and the second surface resin layer. In the following description, when describing matters common to the first adhesive resin layer and the second adhesive resin layer, they will simply be referred to as "adhesive resin layer."

[0019] Examples of the stretched film include the stretched films of the first to fourth embodiments.

[0020] The stretched film of the first embodiment is a first surface resin layer containing a gas barrier resin as a main component; a polyethylene layer containing polyethylene as a main component; a second surface resin layer containing a gas barrier resin as a main component; At least the following are provided in this order:

[0021] The stretched film of the second embodiment is a first surface resin layer containing polyethylene and an adhesive resin; a polyethylene layer containing polyethylene as a main component; a second surface resin layer containing polyethylene and an adhesive resin; At least the following are provided in this order:

[0022] The stretched film of the third embodiment is a first surface resin layer containing polyethylene and an adhesive resin; a polyethylene layer containing polyethylene as a main component; a second surface resin layer containing a gas barrier resin as a main component; At least the following are provided in this order:

[0023] The stretched film of the fourth embodiment is a first surface resin layer containing a gas barrier resin as a main component; a polyethylene layer containing polyethylene as a main component; a second surface resin layer containing polyethylene and an adhesive resin; At least the following are provided in this order:

[0024] The stretched film of the first embodiment may comprise a first surface resin layer, a first adhesive resin layer, a polyethylene layer, a second adhesive resin layer, and a second surface resin layer in this order. The stretched film of the third embodiment may comprise a first surface resin layer, a polyethylene layer, an adhesive resin layer, and a second surface resin layer in this order. The stretched film of the fourth embodiment may comprise a first surface resin layer, an adhesive resin layer, a polyethylene layer, and a second surface resin layer in this order. The stretched film of each embodiment may have two or more polyethylene layers.

[0025] In the stretched films of the first and second aspects, the compositions of the first and second surface resin layers may be the same or different, but are preferably the same. In the stretched films of each aspect, the thicknesses of the first and second surface resin layers may be the same or different, but are preferably the same. In the stretched film of the first aspect, the compositions of the first and second adhesive resin layers may be the same or different, but are preferably the same. In the stretched film of the first aspect, the thicknesses of the first and second adhesive resin layers may be the same or different, but are preferably the same.

[0026] The polyethylene content in the stretched film is preferably more than 50% by mass, more preferably 55% by mass or more, even more preferably 60% by mass or more, still more preferably 70% by mass or more, particularly preferably 80% by mass or more, and particularly preferably 85% by mass or more or 90% by mass or more. A laminate (or packaging container) including such a stretched film has, for example, excellent recyclability.

[0027] A stretched film is a film that has been subjected to a stretching treatment. This can improve, for example, the strength, rigidity, heat resistance, transparency, and printability of the film. The stretching treatment may be uniaxial or biaxial. When stretching in the machine direction (the flow direction of the film, MD direction), the stretching ratio is preferably 2 times or more, more preferably 3 times or more, and preferably 10 times or less, more preferably 7 times or less, for example, 2 times or more and 10 times or less. When stretching in the transverse direction (the direction perpendicular to the MD direction, TD direction), the stretching ratio is preferably 2 times or more, more preferably 3 times or more, and preferably 10 times or less, more preferably 7 times or less, for example, 2 times or more and 10 times or less.

[0028] The stretched film is, for example, a uniaxially stretched film, specifically a film uniaxially stretched in the MD direction (MDO film).

[0029] The thickness of the stretched film is preferably 5 μm or more, more preferably 10 μm or more, even more preferably 15 μm or more, and preferably 200 μm or less, more preferably 100 μm or less, even more preferably 50 μm or less, particularly preferably 40 μm or less, for example, 5 μm or more and 200 μm or less. Stretched films having a thickness equal to or greater than the lower limit have, for example, excellent strength, rigidity, and heat resistance. Stretched films having a thickness equal to or less than the upper limit have, for example, excellent processability. In this specification, the thicknesses of various films and layers are the average values ​​of thicknesses measured at 10 points based on scanning electron microscope (SEM) images obtained by observing a cross section perpendicular to the surface of each film.

[0030] The stretched film can be produced, for example, by forming the materials constituting each layer into a laminated film, and then stretching the laminated film. Examples of the film-forming method include inflation molding and T-die molding, and inflation molding is preferred. According to inflation molding, stretching can be performed after film formation.

[0031] In one embodiment, the stretched film is a stretched film of a coextruded resin film. In one embodiment, the stretched film is a resin film obtained by co-extrusion film-forming using a co-extrusion inflation molding method or the like of a material constituting the polyethylene layer, and, if the stretched film has an adhesive resin layer, a material constituting the adhesive resin layer, and a material constituting the surface resin layer, and then further stretching the resulting laminated film.

[0032] In one embodiment, the stretched film is a resin film obtained by co-extrusion film-forming, in the thickness direction, a material constituting the first surface resin layer, a material constituting the first adhesive resin layer if necessary, a material constituting the polyethylene layer, a material constituting the second adhesive resin layer if necessary, and a material constituting the second surface resin layer, in this order, using a co-extrusion inflation molding method or the like to produce a laminated film, and then further stretching the laminated film.

[0033] In one embodiment, the stretched film is a resin film obtained by co-extrusion in the thickness direction of a tubular shape of a material for a surface resin layer, a material for an optional adhesive resin layer, and a material for a polyethylene layer, with the polyethylene layer being the innermost layer, using a co-extrusion inflation molding method or the like, and then heat-pressing the opposing polyethylene layers together using a rubber roll or the like. The temperature conditions for the heat-pressing are, for example, 45°C to 100°C, preferably 50°C to 85°C, and more preferably 55°C to 70°C, and the pressure conditions are, for example, but not limited to, 0.1 MPa to 1.0 MPa. Producing a stretched film using this method significantly reduces the number of defective products and improves production efficiency.

[0034] The stretched film and the barrier layer may be subjected to a surface treatment. Such a stretched film and a barrier layer may 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.

[0035] <Polyethylene layer> The polyethylene layer contains polyethylene as a main component.

[0036] In this specification, polyethylene refers to a polymer in which the content of ethylene-derived structural units in all repeating structural units is greater than 50 mol%. In this polymer, the content of ethylene-derived structural units is preferably 70 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, and particularly preferably 95 mol% or more. The content is measured by NMR.

[0037] 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.

[0038] In this specification, examples of polyethylene include high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, and very low-density polyethylene, as well as ethylene-vinyl acetate copolymer and ethylene-(meth)acrylic acid ester copolymer. From the viewpoints of the strength and heat resistance of the stretched film, high-density polyethylene and medium-density polyethylene are preferred. From the viewpoints of the film-forming and processability of the stretched film, linear low-density polyethylene and medium-density polyethylene are preferred.

[0039] In this specification, the density of polyethylene is as follows: The density of the high density polyethylene is preferably 0.945 g / cm 3 The upper limit of the density of high density polyethylene is, for example, 0.965 g / cm 3 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 0.900 g / cm or less. 3 Exceeds 0.930g / cm 3 The density of the linear low density polyethylene is preferably 0.900 g / cm or less. 3 Exceeds 0.930g / cm 3 The density of the ultra-low density polyethylene is preferably 0.900 g / cm or less. 3 The lower limit of the density of the ultra-low density polyethylene is, for example, 0.860 g / cm 3 In this specification, the density of polyethylene is measured in accordance with JIS K7112-2:2023 (density gradient tube method, 23°C).

[0040] Low-density polyethylene is, for example, polyethylene obtained by polymerizing ethylene using a high-pressure polymerization method (high-pressure low-density polyethylene).Linear low-density polyethylene is, for example, polyethylene obtained by polymerizing ethylene and a small amount of α-olefins using a polymerization method using a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as a metallocene catalyst.

[0041] Polyethylenes with different densities or branches can be obtained by appropriately selecting the polymerization method. For example, it is preferable to use a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as a metallocene catalyst as the polymerization catalyst, and carry out polymerization in one or more stages by any of gas phase polymerization, slurry polymerization, solution polymerization, and high-pressure ionic polymerization.

[0042] In this specification, polyethylene may be derived from biomass (hereinafter also referred to as "biomass polyethylene"). That is, as a raw material for obtaining polyethylene, ethylene derived from biomass may be used instead of ethylene obtained from fossil fuels. Biomass polyethylene is a carbon-neutral material, and therefore can reduce the environmental impact of laminates or packaging containers. Biomass polyethylene can be produced, for example, by the method described in JP 2013-177531 A. Commercially available biomass polyethylene may also be used.

[0043] The polyethylene may be mechanically or chemically recycled polyethylene (hereinafter referred to as "recycled polyethylene"). This reduces the environmental impact of laminates or packaging containers. Mechanical recycling generally involves crushing recovered polyethylene film, washing it with an alkali to remove dirt and foreign matter from the film surface, and then drying it at high temperature and reduced pressure for a certain period of time to disperse any contaminants remaining inside the film, decontaminating it, and returning it to polyethylene. Chemical recycling generally involves breaking down recovered polyethylene film to the monomer level and repolymerizing the monomer to obtain polyethylene.

[0044] The above description of polyethylene is also applicable elsewhere in this specification.

[0045] From the viewpoint of film-forming and processability, the melt flow rate (MFR) of the polyethylene contained in the polyethylene layer is preferably 0.1 g / 10 min or more, more preferably 0.2 g / 10 min or more, even more preferably 0.3 g / 10 min or more, particularly preferably 0.5 g / 10 min or more, and preferably 30 g / 10 min or less, more preferably 20 g / 10 min or less, even more preferably 10 g / 10 min or less, particularly preferably 5 g / 10 min or less, for example, 0.1 g / 10 min or more and 30 g / 10 min or less. In this specification, the MFR of polyethylene is measured by Method A in accordance with JIS K7210-1:2014, at a temperature of 190°C and a load of 2.16 kg.

[0046] From the viewpoint of heat resistance, the melting point (Tm) of the polyethylene contained in the polyethylene layer is preferably 100°C or higher, more preferably 105°C or higher, even more preferably 110°C or higher, and particularly preferably 120°C or higher, and preferably 140°C or lower, for example, 100°C or higher and 140°C or lower. In this specification, the Tm of various materials is the melting peak temperature obtained by differential scanning calorimetry (DSC) in accordance with JIS K7121:2012 (using test specimens conditioned according to 3.(2) (however, a cooling rate of 10°C / min)).

[0047] The polyethylene content in the polyethylene layer is preferably more than 50% by mass, 60% by mass or more, or 70% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more, still more preferably 90% by mass or more, and particularly preferably 95% by mass or more.

[0048] The polyethylene layer may contain a resin material other than polyethylene, such as polyolefins other than polyethylene, such as polypropylene, polyesters, polyamides, (meth)acrylic resins, vinyl resins, cellulose resins, and ionomer resins.

[0049] The polyethylene layer may contain additives such as crosslinkers, antioxidants, UV absorbers, light stabilizers, antiblocking agents, slip agents, fillers, reinforcing agents, antistatic agents, compatibilizers, pigments, and modifying resins.

[0050] The polyethylene layer in the stretched film of the first, third, and fourth aspects may further contain a compatibilizer, as described below. By containing a compatibilizer in the polyethylene layer, the mixability between the gas barrier resin and polyethylene can be improved when the barrier layer is heated and melted for recycling. This effectively prevents the physical properties of the polyethylene from decreasing after recycling, and also effectively prevents a decrease in the transparency of the polyethylene. When the stretched film has two or more polyethylene layers, at least one polyethylene layer may contain a compatibilizer. When the polyethylene layer contains a compatibilizer, the content of the compatibilizer in the polyethylene layer is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, and preferably 25% by mass or less, more preferably 20% by mass or less, even more preferably 15% by mass or less, for example, 1% by mass or more and 25% by mass or less. When the stretched film has two or more polyethylene layers, at least one polyethylene layer may contain a compatibilizer. When the stretched film has two or more polyethylene layers, the content of the compatibilizer is based on the total mass of all the polyethylene layers.

[0051] When the polyethylene layer contains a compatibilizer, the content of the compatibilizer in the polyethylene layer is preferably 10 parts by mass or more and 200 parts by mass or less per 100 parts by mass of the gas barrier resin content in the stretched film.

[0052] The thickness of the polyethylene layer in the stretched film is preferably 3 μm or more, more preferably 8 μm or more, even more preferably 13 μm or more, and preferably 180 μm or less, more preferably 80 μm or less, even more preferably 40 μm or less, particularly preferably 30 μm or less, for example, 3 μm or more and 180 μm or less. A stretched film comprising a polyethylene layer having a thickness equal to or greater than the lower limit exhibits, for example, excellent strength, rigidity, heat resistance, and recyclability. A stretched film comprising a polyethylene layer having a thickness equal to or less than the upper limit exhibits, for example, excellent processability. When a stretched film comprises two or more polyethylene layers, the above "thickness" refers to the sum of the thicknesses of the polyethylene layers.

[0053] The thickness of the polyethylene layer in the stretched film is preferably 40% or more, more preferably 50% or more, even more preferably 60% or more, and preferably 98% or less, more preferably 94% or less, even more preferably 90% or less, of the thickness of the stretched film, for example, 40% or more and 98% or less. When the stretched film has two or more polyethylene layers, the above "thickness" means the total thickness of the polyethylene layers.

[0054] The stretched film may have one polyethylene layer or two or more polyethylene layers.

[0055] In a stretched film having two or more polyethylene layers, the density of each polyethylene layer may be the same or different. For example, the stretched film may have a density gradient between the polyethylene layers. A stretched film having a density gradient between the polyethylene layers is excellent in strength, rigidity, heat resistance, and stretchability of the film before stretching.

[0056] In a stretched film having a density gradient between each polyethylene layer, it is preferable that the absolute value of the density difference between any adjacent polyethylene layers is small. The absolute value of the density difference is, for example, 0.050 g / cm 3 or less, preferably 0.040 g / cm 3 or less, more preferably 0.030 g / cm 3or less, more preferably 0.020 g / cm 3 The following is true: Such a stretched film can effectively prevent, for example, delamination at the interface between each polyethylene layer. The density of the polyethylene layer is measured in accordance with JIS K7112-2:2023 (density gradient tube method, 23°C).

[0057] The stretched film comprises, in this order, a first surface resin layer, a polyethylene layer, and a second surface resin layer. The stretched film of the first aspect may comprise, in this order, a first surface resin layer, a first adhesive resin layer, a polyethylene layer, a second adhesive resin layer, and a second surface resin layer. Such a stretched film has, for example, excellent heat resistance and can suppress curling.

[0058] The stretched films of the first and second embodiments are a first surface resin layer; optionally a first adhesive resin layer; a 1a polyethylene layer; a 1b polyethylene layer; optionally a second adhesive resin layer; a second surface resin layer; The stretched film may be a base film having the above in this order. Such a stretched film can suppress the occurrence of curling. However, when adjacent layers constituting the stretched film have the same resin composition and are indistinguishable from each other, the adjacent layers may be integrated to form a single layer. The same applies to the following embodiments.

[0059] The stretched film of the first embodiment is a first surface resin layer; a first adhesive resin layer; a 3a polyethylene layer; a 2a polyethylene layer; a 1a polyethylene layer; a 1b polyethylene layer; a 2b polyethylene layer; a 3b polyethylene layer; a second adhesive resin layer; a second surface resin layer; The stretched film may be a base film having the above-mentioned components in this order. Such a stretched film can suppress curling.

[0060] The stretched film of the second embodiment is a first surface resin layer; a 4a polyethylene layer; a 3a polyethylene layer; a 2a polyethylene layer; a 1a polyethylene layer; a 1b polyethylene layer; a 2b polyethylene layer; a 3b polyethylene layer; a 4b polyethylene layer; a second surface resin layer; The stretched film may be a base film having the above-mentioned components in this order. Such a stretched film can suppress curling.

[0061] The compositions of the polyethylene layers 1a, 2a and 3a, and further 4a (in the second embodiment) may be the same or different from one another. The thicknesses of the polyethylene layers 1a, 2a and 3a, and further 4a (in the second embodiment) may be the same or different from one another. The compositions of the polyethylene layers 1b, 2b and 3b, and further 4b (in the second embodiment) may be the same or different from one another. The thicknesses of the polyethylene layers 1b, 2b and 3b, and further 4b (in the second embodiment) may be the same or different from one another.

[0062] The compositions of the polyethylene layers 1a and 1b may be the same or different, but are preferably the same. The thicknesses of the polyethylene layers 1a and 1b may be the same or different, but are preferably the same. The compositions of the polyethylene layers 2a and 2b may be the same or different, but are preferably the same. The thicknesses of the polyethylene layers 2a and 2b may be the same or different, but are preferably the same. The compositions of the polyethylene layers 3a and 3b may be the same or different, but are preferably the same. The thicknesses of the polyethylene layers 3a and 3b may be the same or different, but are preferably the same. The compositions of the polyethylene layers 4a and 4b may be the same or different, but are preferably the same. The thicknesses of the polyethylene layers 4a and 4b may be the same or different, but are preferably the same.

[0063] The 1a and 1b polyethylene layers each independently contain polyethylene, such as polyethylene plastomer, as a primary component. The 2a and 2b polyethylene layers each independently contain polyethylene, such as linear low-density polyethylene, as a primary component. The 3a and 3b polyethylene layers each independently contain polyethylene, such as linear low-density polyethylene, as a primary component. The 4a and 4b polyethylene layers each independently contain polyethylene, such as linear low-density polyethylene, as a primary component. A stretched film of this type has, for example, excellent interlayer adhesion strength between the polyethylene layers, can effectively suppress delamination, and has excellent processability.

[0064] The polyethylene layers 1a and 1b are each independently a layer containing, for example, a polyethylene plastomer as a main component. A plastomer is a term used in contrast to an elastomer (a polymer that deforms in response to an external force when applied and quickly returns to its original shape when the external force is removed). Unlike elastomers, plastomers are polymers that readily undergo plastic deformation, rather than exhibiting elastic deformation.

[0065] Polyethylene plastomer is polyethylene obtained by copolymerizing ethylene and an α-olefin using a single-site catalyst such as a metallocene catalyst. Preferred α-olefins are those having 4 to 8 carbon atoms, such as 1-butene, 1-hexene, 1-octene, and 4-methyl-1-pentene. Specific examples of polyethylene plastomers include ethylene-1-butene copolymers, ethylene-1-hexene copolymers, and ethylene-1-octene copolymers.

[0066] The density of the polyethylene plastomer is preferably 0.920 g / cm from the viewpoint of fusion bonding between the innermost layers when producing a stretched film. 3 or less, more preferably 0.915 g / cm 3 or less, more preferably 0.910 g / cm 3 The density of polyethylene plastomer is 0.850 g / cm 3 More than 0.855g / cm 3 More than 0.860g / cm 3 The density of polyethylene plastomer is, for example, 0.850 g / cm 3 More than 0.920g / cm 3 The following is the result.

[0067] From the viewpoint of fusion bonding between the innermost layers during production of a stretched film, the melting point (Tm) of the polyethylene plastomer is preferably 115°C or lower, more preferably 110°C or lower, even more preferably 105°C or lower, and particularly preferably 100°C or lower, and may be 90°C or lower, 80°C or lower, or 70°C or lower. The Tm of the polyethylene plastomer may be 40°C or higher, 45°C or higher, or 50°C or higher. The Tm of the polyethylene plastomer is, for example, 40°C or higher and 115°C or lower.

[0068] From the viewpoint of film-forming ability and processability, the MFR of the polyethylene plastomer is preferably 0.1 g / 10 min or more, more preferably 0.2 g / 10 min or more, even more preferably 0.3 g / 10 min or more, particularly preferably 0.5 g / 10 min or more, and preferably 30 g / 10 min or less, more preferably 20 g / 10 min or less, even more preferably 10 g / 10 min or less, particularly preferably 5 g / 10 min or less, for example, 0.1 g / 10 min or more and 30 g / 10 min or less. The MFR of the polyethylene plastomer is measured by Method A in accordance with JIS K7210-1:2014, at a temperature of 190°C and a load of 2.16 kg.

[0069] The polyethylene plastomer content in the polyethylene layers 1a and 1b is each independently preferably greater than 50% by mass, more preferably 60% by mass or more, even more preferably 70% by mass or more, still more preferably 80% by mass or more, and particularly preferably 90% by mass or more.

[0070] The 2a and 2b polyethylene layers are each independently a layer containing, for example, linear low-density polyethylene as a main component. The 2a and 2b polyethylene layers may each independently further contain a compatibilizer. By containing a compatibilizer in the 2a and 2b polyethylene layers, the mixability of the gas barrier resin contained in the surface resin layer and the polyethylene contained in the other layers can be improved when the barrier layer is heated and melted for recycling. This effectively prevents the physical properties of the polyethylene from deteriorating after recycling, and also effectively prevents the transparency of the polyethylene from deteriorating.

[0071] Examples of the compatibilizer include modified polyolefins such as acid-modified polyolefins, and from the viewpoint of recyclability, modified polyethylenes such as acid-modified polyethylene are preferred. Examples of modified polyolefins include polyolefins modified with unsaturated carboxylic acids such as maleic acid and fumaric acid, or their acid anhydrides, esters, or metal salts, particularly graft-modified polyolefins. Specific examples of the compatibilizer include unsaturated carboxylic acid-modified polyethylenes, and more preferred are maleic anhydride-modified polyethylenes.

[0072] The linear low-density polyethylene content in the 2a and 2b polyethylene layers is preferably greater than 50% by mass, more preferably at least 60% by mass, even more preferably at least 65% by mass, still more preferably at least 70% by mass, and particularly preferably at least 75% by mass. The linear low-density polyethylene content in the 2a and 2b polyethylene layers is independently 100% by mass or less, or may be 99% by mass or less, 97% by mass or less, 95% by mass or less, 90% by mass or less, or 85% by mass or less.

[0073] When the 2a and 2b polyethylene layers contain a compatibilizer, the content of the compatibilizer in the 2a and 2b polyethylene layers is each independently preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, still more preferably 10% by mass or more, particularly preferably 15% by mass or more, and preferably 40% by mass or less, more preferably 35% by mass or less, even more preferably 30% by mass or less, particularly preferably 25% by mass or less, for example, 1% by mass or more and 40% by mass or less.

[0074] The 3a, 3b, 4a, and 4b polyethylene layers are each independently a layer containing, for example, a linear low-density polyethylene, and are preferably layers containing a linear low-density polyethylene and a medium-density polyethylene from the viewpoint of rigidity, etc., or layers containing a linear low-density polyethylene as a main component from the viewpoint of stretchability, etc.

[0075] In one embodiment, the content of linear low-density polyethylene in the polyethylene layers 3a, 3b, 4a, and 4b is each independently preferably 35% by mass or more, more preferably 40% by mass or more, even more preferably 45% by mass or more, still more preferably 50% by mass or more, particularly preferably 55% by mass or more, and is preferably 85% by mass or less, more preferably 80% by mass or less, even more preferably 75% by mass or less, still more preferably 70% by mass or less, particularly preferably 65% ​​by mass or less, for example, 35% by mass or more and 85% by mass or less.

[0076] In one embodiment, the content of medium-density polyethylene in the polyethylene layers 3a, 3b, 4a, and 4b is each independently preferably 15% by mass or more, more preferably 20% by mass or more, even more preferably 25% by mass or more, still more preferably 30% by mass or more, particularly preferably 35% by mass or more, and is preferably 65% ​​by mass or less, more preferably 60% by mass or less, even more preferably 55% by mass or less, still more preferably 50% by mass or less, particularly preferably 45% by mass or less, for example, 15% by mass or more and 65% by mass or less.

[0077] Examples of the linear low-density polyethylene include ethylene-1-butene copolymer (C4-LLDPE) in which the comonomer is at least 1-butene, ethylene-1-hexene copolymer (C6-LLDPE) in which the comonomer is at least 1-hexene, and ethylene-1-octene copolymer (C8-LLDPE) in which the comonomer is at least 1-octene. These copolymers are not limited to the above comonomers, and additional comonomers may also be used. For example, linear low-density polyethylene produced using a metallocene catalyst is preferred.

[0078] In the base film and stretched film of the first embodiment, when the polyethylene layers consist of layers 1a to 3a and layers 1b to 3b, the relative thicknesses of the layers are preferably as follows. The total thickness of the polyethylene layers 1a and 1b is preferably 5% or more, more preferably 10% or more, even more preferably 15% or more, and is preferably 35% or less, more preferably 30% or less, even more preferably 25% or less, for example, 5% or more and 35% or less, relative to the total thickness of the polyethylene layers. The total thickness of the 2a and 2b polyethylene layers is preferably 5% or more, more preferably 10% or more, even more preferably 15% or more, and is preferably 35% or less, more preferably 30% or less, even more preferably 25% or less, for example, 5% or more and 35% or less, relative to the total thickness of the polyethylene layers. The total thickness of the 3a and 3b polyethylene layers is preferably 45% or more, more preferably 50% or more, even more preferably 55% or more, and is preferably 75% or less, more preferably 70% or less, even more preferably 65% ​​or less, for example, 45% or more and 75% or less, of the total thickness of the polyethylene layers.

[0079] In the base film and stretched film of the second embodiment, when the polyethylene layers consist of layers 1a to 4a and layers 1b to 4b, the relative thicknesses of the layers are preferably as follows. The total thickness of the polyethylene layers 1a and 1b is preferably 5% or more, more preferably 10% or more, and preferably 25% or less, more preferably 20% or less, for example, 5% or more and 25% or less, relative to the total thickness of the polyethylene layers. The total thickness of the 2a and 2b polyethylene layers is preferably 5% or more, more preferably 10% or more, and preferably 25% or less, more preferably 20% or less, for example, 5% or more and 25% or less, relative to the total thickness of the polyethylene layers. The total thickness of the 3a and 3b polyethylene layers is preferably 35% or more, more preferably 40% or more, and preferably 65% ​​or less, more preferably 60% or less, for example 35% or more and 65% or less, of the total thickness of the polyethylene layers. The total thickness of the 4a and 4b polyethylene layers is preferably 13% or more, more preferably 18% or more, and preferably 35% or less, more preferably 30% or less, for example 13% or more and 35% or less, relative to the total thickness of the polyethylene layers.

[0080] The density relationship between the polyethylene layers in the stretched film having the polyethylene layers is not particularly limited as long as it does not impair the stretchability of the base film, and the heat resistance, strength, rigidity, and interlayer adhesion of the stretched film.

[0081] In one embodiment, the stretched film has a density of the 2a polyethylene layer that is higher than the density of the 1a polyethylene layer, a density of the 3a polyethylene layer that is higher than or similar to the density of the 2a polyethylene layer, and (in the second embodiment) a density of the 4a polyethylene layer that is higher than or similar to the density of the 3a polyethylene layer. In one embodiment, the stretched film has a density of the 2b polyethylene layer that is higher than the density of the 1b polyethylene layer, a density of the 3b polyethylene layer that is higher than or similar to the density of the 2b polyethylene layer, and (in the second embodiment) a density of the 4b polyethylene layer that is higher than or similar to the density of the 3b polyethylene layer.

[0082] In one embodiment, the stretched film has a density of the 2a polyethylene layer that is higher than the density of the 1a polyethylene layer, a density of the 3a polyethylene layer that is lower than the density of the 2a polyethylene layer, and (in the second embodiment) a density of the 4a polyethylene layer that is lower than or similar to the density of the 3a polyethylene layer. In one embodiment, the stretched film has a density of the 2b polyethylene layer that is higher than the density of the 1b polyethylene layer, a density of the 3b polyethylene layer that is lower than the density of the 2b polyethylene layer, and (in the second embodiment) a density of the 4b polyethylene layer that is lower than or similar to the density of the 3b polyethylene layer.

[0083] In one embodiment, the stretched film has a density of the 2a polyethylene layer lower than that of the 1a polyethylene layer, a density of the 3a polyethylene layer higher than that of the 2a polyethylene layer, and (in the second embodiment) a density of the 4a polyethylene layer higher than or similar to that of the 3a polyethylene layer. In one embodiment, the stretched film has a density of the 2b polyethylene layer lower than that of the 1b polyethylene layer, a density of the 3b polyethylene layer higher than that of the 2b polyethylene layer, and (in the second embodiment) a density of the 4b polyethylene layer higher than or similar to that of the 3b polyethylene layer.

[0084] The stretched film of the second embodiment may be a stretched film of a base film having, 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. The stretched film of this embodiment can suppress the occurrence of curling. The compositions of the first to third polyethylene layers may be the same as or different from one another. The thicknesses of the first to third polyethylene layers may be the same as or different from one another.

[0085] In the base film of the second embodiment, the first and third polyethylene layers are each independently a layer containing, for example, a linear low-density polyethylene, and are preferably layers containing a linear low-density polyethylene and a medium-density polyethylene from the viewpoint of rigidity, etc., or layers containing a linear low-density polyethylene as a main component from the viewpoint of stretchability, etc.

[0086] In one embodiment, the content of linear low-density polyethylene in the first and third polyethylene layers in the base film of the second aspect is each independently preferably 35% by mass or more, more preferably 40% by mass or more, even more preferably 45% by mass or more, still more preferably 50% by mass or more, particularly preferably 55% by mass or more, and is preferably 85% by mass or less, more preferably 80% by mass or less, even more preferably 75% by mass or less, still more preferably 70% by mass or less, particularly preferably 65% ​​by mass or less, for example, 35% by mass or more and 85% by mass or less.

[0087] In one embodiment, the content of medium-density polyethylene in the first and third polyethylene layers in the substrate film of the second aspect is each independently preferably 15% by mass or more, more preferably 20% by mass or more, even more preferably 25% by mass or more, still more preferably 30% by mass or more, particularly preferably 35% by mass or more, and is preferably 65% ​​by mass or less, more preferably 60% by mass or less, even more preferably 55% by mass or less, still more preferably 50% by mass or less, particularly preferably 45% by mass or less, for example, 15% by mass or more and 65% by mass or less.

[0088] In the substrate film of the second embodiment, the second polyethylene layer is, for example, a layer containing linear low-density polyethylene as a main component.

[0089] In the base film and stretched film of the second embodiment, the thickness of the second polyethylene layer is preferably 30% or more, more preferably 40% or more, even more preferably 50% or more, and preferably 90% or less, more preferably 80% or less, even more preferably 70% or less, of the total thickness of the polyethylene layers, for example, 30% or more and 90% or less.

[0090] In the base film and stretched film of the second embodiment, the thicknesses of the first and third polyethylene layers are each independently, relative to the total thickness of the polyethylene layers, preferably 5% or more, more preferably 10% or more, even more preferably 15% or more, and preferably 35% or less, more preferably 30% or less, even more preferably 25% or less, for example, 5% or more and 35% or less.

[0091] In a stretched film comprising 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 symmetry of the stretched film and suppression of curling.

[0092] The stretched film of the third embodiment may be a stretched film of a base film having, in this order, a first surface resin layer, a first polyethylene layer, a second polyethylene layer, an adhesive resin layer, and a second surface resin layer. The stretched film of the fourth embodiment may be a stretched film of a base film having, in this order, a first surface resin layer, an adhesive resin layer, a second polyethylene layer, the first polyethylene layer, and a second surface resin layer. In the base film and stretched film of the third and fourth embodiments, the compositions of the first and second polyethylene layers may be the same or different, and the thicknesses of the first and second polyethylene layers may be the same or different.

[0093] In the base film of the third and fourth embodiments, the first polyethylene layer is, for example, a layer containing linear low-density polyethylene, and is preferably a layer containing linear low-density polyethylene and medium-density polyethylene from the viewpoint of rigidity, etc., or a layer containing linear low-density polyethylene as a main component from the viewpoint of stretchability, etc.

[0094] In the base film of the third and fourth aspects, in one embodiment, the content of linear low-density polyethylene in the first polyethylene layer is preferably 35% by mass or more, more preferably 40% by mass or more, even more preferably 45% by mass or more, still more preferably 50% by mass or more, particularly preferably 55% by mass or more, and is preferably 85% by mass or less, more preferably 80% by mass or less, even more preferably 75% by mass or less, still more preferably 70% by mass or less, particularly preferably 65% ​​by mass or less, for example, 35% by mass or more and 85% by mass or less.

[0095] In the substrate films of the third and fourth aspects, in one embodiment, the content of medium-density polyethylene in the first polyethylene layer is preferably 15% by mass or more, more preferably 20% by mass or more, even more preferably 25% by mass or more, still more preferably 30% by mass or more, particularly preferably 35% by mass or more, and is preferably 65% ​​by mass or less, more preferably 60% by mass or less, even more preferably 55% by mass or less, still more preferably 50% by mass or less, particularly preferably 45% by mass or less, for example, 15% by mass or more and 65% by mass or less.

[0096] In the substrate films of the third and fourth embodiments, the second polyethylene layer is, for example, a layer containing linear low-density polyethylene as a main component.

[0097] The second polyethylene layer in the base film and the stretched film of the third and fourth embodiments may further contain a compatibilizer. The polyethylene content in the second polyethylene layer is preferably more than 50% by mass, more preferably 60% by mass or more, even more preferably 65% ​​by mass or more, still more preferably 70% by mass or more, particularly preferably 75% by mass or more or 80% by mass or more, and may be 100% by mass or less, or may be 99% by mass or less, 97% by mass or less, or 95% by mass or less. When the second polyethylene layer contains a compatibilizer, the content of the compatibilizer in the second polyethylene layer is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, and is preferably 40% by mass or less, more preferably 35% by mass or less, even more preferably 30% by mass or less, and particularly preferably 25% by mass or less or 20% by mass or less.

[0098] In the stretched films of the third and fourth aspects, the thickness of the second polyethylene layer is preferably 30% or more, more preferably 35% or more, even more preferably 40% or more, and preferably 80% or less, more preferably 70% or less, even more preferably 60% or less, of the thickness of the stretched film, for example, 30% or more and 80% or less.

[0099] In the stretched films of the third and fourth aspects, the thickness of the first polyethylene layer is preferably 5% or more, more preferably 10% or more, even more preferably 15% or more, and preferably 35% or less, more preferably 30% or less, even more preferably 25% or less, of the thickness of the stretched film, for example, 5% or more and 35% or less.

[0100] In the above stretched films of the third and fourth aspects, the thickness of the adhesive resin layer is preferably 2% or more, more preferably 3% or more, even more preferably 5% or more, and preferably 20% or less, more preferably 18% or less, even more preferably 15% or less, for example, 2% or more and 20% or less, relative to the thickness of the stretched film.

[0101] <Surface resin layer> In the stretched film, the thicknesses of the first and second surface resin layers are each independently preferably 0.5 μm or more, more preferably 1 μm or more, and even more preferably 1.5 μm or more, from the viewpoint of the above-mentioned physical properties such as gas barrier property and aroma retention. In the stretched film, the thicknesses of the first and second surface resin layers are each independently preferably 10 μm or less, more preferably 8 μm or less, and even more preferably 6 μm or less, from the viewpoint of the recyclability of the barrier layer. The thickness of the surface resin layer is, for example, 0.5 μm or more and 10 μm or less.

[0102] The thickness of the first and second surface resin layers is, independently of each other, preferably 1% or more, more preferably 3% or more, even more preferably 5% or more, and preferably 30% or less, more preferably 25% or less, even more preferably 20% or less, for example, 1% or more and 30% or less, relative to the thickness of the stretched film.

[0103] In the above-mentioned stretched film, 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, from the viewpoints of symmetry of the stretched film and suppression of curling.

[0104] <<Surface resin layer containing gas barrier resin as the main component>> The surface resin layer containing a gas barrier resin as a main component will be described below. A stretched film having such a surface resin layer has superior gas barrier properties (particularly oxygen barrier properties) and aroma retention properties compared to conventional stretched polyethylene films.

[0105] The first and second surface resin layers in the stretched film of the first aspect each independently contain a gas barrier resin as a main component. The second surface resin layer in the stretched film of the third aspect contains a gas barrier resin as a main component. The first surface resin layer in the stretched film of the fourth aspect contains a gas barrier resin as a main component.

[0106] A surface resin layer containing a gas barrier resin as a main component tends to have excellent surface smoothness, and a vapor-deposited film formed on the surface of such a surface resin layer tends to have excellent adhesion to the surface resin layer and to exhibit good gas barrier properties.

[0107] A stretched film having a surface resin layer containing a gas barrier resin as a main component has superior heat resistance and rigidity compared to, for example, conventional stretched polyethylene films, and therefore a standing pouch having the barrier layer has excellent self-supporting properties.

[0108] A gas barrier resin is a resin that has 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, polyacrylonitrile, and (meth)acrylic resins. Among these, from the viewpoints of gas barrier properties (particularly oxygen barrier properties), aroma retention, heat resistance, rigidity, etc., ethylene-vinyl alcohol copolymers, polyvinyl alcohol, and polyamides are preferred, ethylene-vinyl alcohol copolymers and polyamides are more preferred, and from the viewpoints of gas barrier properties and aroma retention, ethylene-vinyl alcohol copolymers are even more preferred.

[0109] Ethylene-vinyl alcohol copolymer (EVOH) can be obtained, for example, by copolymerizing ethylene with a vinyl ester monomer and then saponifying the copolymer. The copolymerization of ethylene with a vinyl ester monomer can be carried out by any known polymerization method, such as solution polymerization, suspension polymerization, or emulsion polymerization.

[0110] Although vinyl acetate is generally used as the vinyl ester monomer, other vinyl ester monomers may also be used, such as aliphatic vinyl esters such as vinyl formate, vinyl propionate, vinyl valerate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caprate, vinyl laurate, vinyl stearate, and vinyl versatate, and aromatic vinyl esters such as vinyl benzoate.

[0111] The content of ethylene-derived structural units in EVOH (ethylene content) is preferably 20 mol% or more, more preferably 25 mol% or more, of all repeating structural units, from the viewpoint of processability of the barrier layer. The ethylene content in EVOH is preferably 60 mol% or less, more preferably 50 mol% or less, from the viewpoint of heat resistance, oxygen barrier property, and water vapor barrier property of the barrier layer, and aroma retention of the packaging container. The ethylene content is, for example, 20 mol% or more and 60 mol% or less. The ethylene content is measured by NMR.

[0112] The average saponification degree of EVOH is preferably 90 mol% or more, more preferably 95 mol% or more, and even more preferably 99 mol% or more. The average saponification degree is measured in accordance with JIS K6726:1994 (wherein EVOH is used as a solution uniformly dissolved in a water / methanol solvent).

[0113] From the viewpoint of heat resistance, the melting point (Tm) of EVOH is preferably 140°C or higher, more preferably 145°C or higher, and even more preferably 150°C or higher. The Tm of EVOH is preferably 200°C or lower, more preferably 195°C or lower, and even more preferably 190°C or lower. The Tm of EVOH is, for example, 140°C or higher and 200°C or lower.

[0114] From the viewpoints of film-forming ability and processability, the melt flow rate (MFR) of the EVOH is preferably 0.1 g / 10 min or more, more preferably 0.3 g / 10 min or more, and even more preferably 0.5 g / 10 min or more. From the viewpoints of film-forming ability and processability, the MFR of the EVOH is preferably 30 g / 10 min or less, more preferably 20 g / 10 min or less, even more preferably 10 g / 10 min or less, and particularly preferably 5 g / 10 min or less. The MFR of the EVOH is, for example, 0.1 g / 10 min or more and 30 g / 10 min or less. The MFR of the EVOH is measured by Method A in accordance with JIS K7210-1:2014 under conditions of a temperature of 190°C and a load of 2.16 kg. The measurement temperature may be 210°C depending on the melting point of the EVOH.

[0115] The EVOH may be modified by a known method such as urethanization, acetalization, cyanoethylation, or oxyalkylenation.

[0116] The average saponification degree of polyvinyl alcohol (PVA) is preferably 70 mol% or more, more preferably 75 mol% or more, even more preferably 80 mol% or more, and particularly preferably 85 mol% or more. The average saponification degree is measured in accordance with JIS K6726:1994.

[0117] Examples of polyamides include aliphatic polyamides and aromatic polyamides. The polyamide is preferably an aliphatic polyamide, more preferably a crystalline aliphatic polyamide. The polyamide is also preferably an aromatic polyamide, more preferably a semi-aromatic polyamide.

[0118] Examples of aliphatic polyamides include aliphatic homopolyamides and aliphatic copolyamides. In the following examples, polyamides are also referred to as "PA."

[0119] Specific examples of aliphatic homopolyamides include polycaprolactam or poly(6-aminocaproic acid) (PA6), polyenantholactam or poly(7-aminoenanthic acid) (PA7), polyundecane lactam or poly(11-aminoundecanoic acid) (PA11), polylauryllactam or poly(12-aminolauric acid) (PA12), polyhexamethylene adipamide (PA66), polytetramethylene dodecamide (PA412), polypentamethylene azelamide (PA59), polypentamethylene sebacamide (PA510), polypentamethylene dodecamide (PA512), polyhexamethylene azelamide (PA69), and polyhexamethylene sebacamide. Polyhexamethylene dodecamide (PA610), polyhexamethylene dodecamide (PA612), polynonamethylene adipamide (PA96), polynonamethylene azelamide (PA99), polynonamethylene sebacamide (PA910), polynonamethylene dodecamide (PA912), polydecamethylene adipamide (PA106), polydecamethylene azelamide (PA109), polydecamethylene decamide (PA1010), polydecamethylene dodecamide (PA1012), polydodecamethylene adipamide (PA126), polydodecamethylene azelamide (PA129), polydodecamethylene sebacamide (PA1210) and polydodecamethylene dodecamide (PA1212).

[0120] Specific examples of aliphatic copolymer polyamides include caprolactam / hexamethylenediaminoadipic acid copolymer (PA6 / 66), caprolactam / hexamethylenediaminoazelaic acid copolymer (PA6 / 69), caprolactam / hexamethylenediaminosebacic acid copolymer (PA6 / 610), caprolactam / hexamethylenediaminoundecanoic acid copolymer (PA6 / 611), caprolactam / hexamethylenediaminododecanoic acid copolymer (PA6 / 612), caprolactam / amino Examples include undecanoic acid copolymer (PA6 / 11), caprolactam / lauryllactam copolymer (PA6 / 12), caprolactam / hexamethylenediaminoadipic acid / lauryllactam copolymer (PA6 / 66 / 12), caprolactam / hexamethylenediaminoadipic acid / hexamethylenediaminosebacic acid copolymer (PA6 / 66 / 610), and caprolactam / hexamethylenediaminoadipic acid / hexamethylenediaminododecanedicarboxylic acid copolymer (PA6 / 66 / 612).

[0121] The aliphatic polyamide is preferably a crystalline aliphatic polyamide. Examples of the crystalline aliphatic polyamide include PA6, PA11, PA12, PA66, PA610, PA612, PA6 / 66, and PA6 / 66 / 12. The melting point (Tm) of the crystalline aliphatic polyamide is preferably 170°C or higher, more preferably 180°C or higher, and even more preferably 190°C or higher, and is preferably 300°C or lower, more preferably 270°C or lower, and even more preferably 240°C or lower, for example, 170°C or higher and 300°C or lower.

[0122] Examples of aromatic polyamides include semi-aromatic polyamides and wholly aromatic polyamides, with semi-aromatic polyamides being preferred. Semi-aromatic polyamides are polyamides having structural units derived from aromatic diamines and structural units derived from aliphatic dicarboxylic acids, or polyamides having structural units derived from aliphatic diamines and structural units derived from aromatic dicarboxylic acids. Examples of semi-aromatic polyamides include polyamides composed of aromatic diamines and aliphatic dicarboxylic acids, and polyamides composed of aliphatic diamines and aromatic dicarboxylic acids.

[0123] Examples of semi-aromatic polyamides include polyhexamethylene terephthalamide (PA6T), polyhexamethylene isophthalamide (PA6I), polynonamethylene terephthalamide (PA9T), polyhexamethylene adipamide / polyhexamethylene terephthalamide copolymer (PA66 / 6T), polyhexamethylene adipamide / polyhexamethylene isophthalamide copolymer (PA66 / 6I), polyhexamethylene terephthalamide / polycaproamide copolymer (PA6T / 6), polyhexamethylene isophthalamide / polycaproamide copolymer (PA6I / 6), polyhexamethylene terephthalamide / poly Examples include dodecamide copolymer (PA6T / 12), polyhexamethylene isophthalamide / polyhexamethylene terephthalamide copolymer (PA6I / 6T), polyhexamethylene terephthalamide / poly(2-methylpentamethylene terephthalamide) copolymer (PA6T / M5T), polyhexamethylene adipamide / polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (PA66 / 6T / 6I), polyhexamethylene adipamide / polycaproamide / polyhexamethylene isophthalamide copolymer (PA66 / 6 / 6I), and polymetaxylylene adipamide (PAMXD6). Among these, polymetaxylylene adipamide (PAMXD6) and polyhexamethylene isophthalamide / polyhexamethylene terephthalamide copolymer (PA6I / 6T) are preferred.

[0124] In one embodiment, the semi-aromatic polyamide is preferably a crystalline semi-aromatic polyamide. The melting point (Tm) of the crystalline semi-aromatic polyamide is preferably 190°C or higher, more preferably 200°C or higher, even more preferably 210°C or higher, and preferably 310°C or lower, more preferably 280°C or lower, even more preferably 250°C or lower, for example, 190°C or higher and 310°C or lower. Specific examples of the crystalline semi-aromatic polyamide include PA6T, PA9T, and PAMXD6.

[0125] The glass transition temperature (Tg) of the crystalline semi-aromatic polyamide is preferably 50°C or higher, more preferably 60°C or higher, even more preferably 70°C or higher, and preferably 140°C or lower, more preferably 130°C or lower, even more preferably 120°C or lower, for example, 50°C or higher and 140°C or lower. The Tg may be, for example, lower than 110°C, lower than 100°C, or lower than 90°C. In this specification, Tg refers to the midpoint glass transition temperature obtained by differential scanning calorimetry (DSC) at a heating rate of 10°C / min in accordance with JIS K7121:2012 (using a test piece conditioned according to 3.(3)).

[0126] In one embodiment, the semi-aromatic polyamide is preferably an amorphous semi-aromatic polyamide, from the viewpoints of being able to form a surface resin layer excellent in surface smoothness and transparency, being able to exhibit high gas barrier properties when a vapor-deposited film is formed on the surface resin layer, etc. Specifically, PA6I / 6T is preferred as the amorphous semi-aromatic polyamide.

[0127] The amorphous polyamide refers to a polyamide that does not have a clear crystalline melting peak, specifically a polyamide that has no crystalline melting peak or a crystalline melting peak with a crystalline melting enthalpy ΔHm of 5 J / g or less, preferably 3 J / g or less, more preferably 1 J / g or less. The crystalline melting enthalpy is measured by differential scanning calorimetry (DSC) in accordance with JIS K7121:2012 and JIS K7122:2012.

[0128] As the amorphous semi-aromatic polyamide, a semi-aromatic polyamide having two or more structural units derived from aromatic dicarboxylic acids is preferred, and a polyamide having, as the dicarboxylic acid component, structural units derived from isophthalic acid and structural units derived from terephthalic acid, and as the diamine component, structural units derived from aliphatic diamine (hereinafter also referred to as "polyamide (a)") is more preferred.

[0129] In the polyamide (a), the proportion of structural units derived from isophthalic acid is preferably 40 mol% to 98 mol%, more preferably 50 mol% to 80 mol%, of 100 mol% of structural units derived from dicarboxylic acids, and the proportion of structural units derived from terephthalic acid is preferably 2 mol% to 60 mol%, more preferably 20 mol% to 50 mol%. The proportions are measured by NMR.

[0130] In the polyamide (a), the total proportion of structural units derived from isophthalic acid and structural units derived from terephthalic acid in 100 mol% of structural units derived from dicarboxylic acids is preferably 60 mol% or more, more preferably 70 mol% or more, even more preferably 80 mol% or more, particularly preferably 90 mol% or more, 95 mol% or more, or 98 mol% or more. The polyamide (a) may optionally contain structural units derived from dicarboxylic acids other than isophthalic acid and terephthalic acid (e.g., adipic acid).

[0131] The polyamide (a) preferably contains a structural unit derived from hexamethylenediamine as a diamine component. In the polyamide (a), the proportion of the structural units derived from hexamethylenediamine in 100 mol% of the structural units derived from diamine is preferably 60 mol% or more, more preferably 70 mol% or more, even more preferably 80 mol% or more, particularly preferably 90 mol% or more, 95 mol% or more, or 98 mol% or more. The polyamide (a) may contain a structural unit derived from a diamine other than hexamethylenediamine, as necessary. The polyamide (a) is preferably PA6I / 6T.

[0132] The glass transition temperature (Tg) of the amorphous semi-aromatic polyamide is preferably 90°C or higher, more preferably 100°C or higher, even more preferably 110°C or higher, and preferably 180°C or lower, more preferably 160°C or lower, even more preferably 150°C or lower, for example, 90°C or higher and 180°C or lower. Amorphous semi-aromatic polyamides having a Tg equal to or higher than the above lower limit have excellent heat resistance. Therefore, by using such amorphous semi-aromatic polyamides, a surface resin layer with high heat resistance can be formed.

[0133] The melt volume rate (MVR) of the semi-aromatic polyamide is preferably 5 cm 3 / 10 minutes or more, preferably 10cm 3 / 10 minutes or more, preferably 200cm 3 / 10 minutes or less, preferably 100cm 3 / 10 minutes or less, for example, 5cm 3 / 200cm for more than 10 minutes 3 / 10 minutes or less. MVR is measured in accordance with JIS K7210-1:2014 at a temperature of 275°C and a load of 5.00 kg.

[0134] The relative viscosity of the polyamide is preferably 1.5 or more, more preferably 2.0 or more, even more preferably 2.5 or more, and preferably 5.0 or less, more preferably 4.5 or less, even more preferably 4.0 or less, for example, 1.5 or more and 5.0 or less. The relative viscosity of the polyamide is measured at 25°C in accordance with JIS K6920-2:2009 by dissolving 1 g of polyamide in 100 mL of 96% concentrated sulfuric acid.

[0135] From the viewpoint of film-forming ability and processability, the MFR of the polyamide is preferably 0.1 g / 10 min or more, more preferably 0.3 g / 10 min or more, even more preferably 0.5 g / 10 min or more, and preferably 30 g / 10 min or less, more preferably 20 g / 10 min or less, even more preferably 10 g / 10 min or less, and particularly preferably 5 g / 10 min or less, for example, 0.1 g / 10 min or more and 30 g / 10 min or less. The MFR of the polyamide is measured by Method A in accordance with JIS K7210-1:2014 under conditions of a temperature of 235°C and a load of 2.16 kg. An appropriate measurement temperature can be adopted depending on the melting point of the polyamide.

[0136] The surface resin layer may contain polyamide as a main component. The surface resin layer may contain an aliphatic polyamide as a main component. Such a stretched film has excellent processability and production costs. For example, the content of the aliphatic polyamide in the surface resin layer may be 80% by mass or more, 85% by mass or more, 90% by mass or more, or 95% by mass or more.

[0137] The surface resin layer may contain an aromatic polyamide as a main component. Such a stretched film has, for example, excellent rigidity and gas barrier properties. For example, the content of the aromatic polyamide in the surface resin layer may be 80% by mass or more, 85% by mass or more, 90% by mass or more, or 95% by mass or more.

[0138] The surface resin layer may contain an aliphatic polyamide and an aromatic polyamide. Aliphatic polyamides tend to have better processability. Aromatic polyamides tend to have better gas barrier properties and rigidity. For example, in the surface resin layer, from the viewpoint of balancing the rigidity, gas barrier properties, processability, and production costs of the stretched film, the content of the aliphatic polyamide may be 10% by mass or more and 90% by mass or less, 20% by mass or more and 80% by mass or less, 30% by mass or more and 70% by mass or less, or 40% by mass or more and 60% by mass or less, and the content of the aromatic polyamide may be 10% by mass or more and 90% by mass or less, 20% by mass or more and 80% by mass or less, 30% by mass or more and 70% by mass or less, or 40% by mass or more and 60% by mass or less.

[0139] The surface resin layer may contain, as a main component, an amorphous semi-aromatic polyamide having a high glass transition temperature (e.g., 90°C or higher). Such a stretched film has, for example, excellent heat resistance. For example, the content of the amorphous semi-aromatic polyamide in the surface resin layer may be 80% by mass or more, 85% by mass or more, 90% by mass or more, or 95% by mass or more.

[0140] The surface resin layer may contain a crystalline semi-aromatic polyamide and an amorphous semi-aromatic polyamide from the viewpoint of a balance between heat resistance and processability, etc. For example, the content of the crystalline semi-aromatic polyamide in the surface resin layer may be 10% by mass to 90% by mass, 20% by mass to 80% by mass, 30% by mass to 70% by mass, or 40% by mass to 60% by mass, and the content of the amorphous semi-aromatic polyamide may be 10% by mass to 90% by mass, 20% by mass to 80% by mass, 30% by mass to 70% by mass, or 40% by mass to 60% by mass.

[0141] From the viewpoint of the above-mentioned physical properties such as gas barrier properties and aroma retention, the content of the gas barrier resin in the surface resin layer is preferably more than 50% by mass, more preferably 60% by mass or more, even more preferably 70% by mass or more, still more preferably 80% by mass or more, and particularly preferably 90% by mass or more.

[0142] The surface resin layer may contain the above-mentioned resin material other than the gas barrier resin. The surface resin layer may contain the additive.

[0143] <Surface resin layer containing polyethylene and adhesive resin> The surface resin layer containing polyethylene and an adhesive resin will be described below. The vapor-deposited film provided on the surface of such a surface resin layer tends to have excellent adhesion to the surface resin layer and exhibit good gas barrier properties.

[0144] The first and second surface resin layers in the stretched film of the second aspect each independently contain polyethylene and an adhesive resin. The first surface resin layer in the stretched film of the third aspect contains polyethylene and an adhesive resin. The second surface resin layer in the stretched film of the fourth aspect contains polyethylene and an adhesive resin.

[0145] Preferred polyethylenes include high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, and very low-density polyethylene, and linear low-density polyethylene is more preferred from the viewpoints of the surface smoothness of the stretched film and the adhesion between the surface resin layer and the vapor-deposited film. Examples of linear low-density polyethylenes include C4-LLDPE, C6-LLDPE, and C8-LLDPE.

[0146] The melting point (Tm) of the polyethylene in the surface resin layer is preferably 100°C or higher, more preferably 105°C or higher, even more preferably 110°C or higher, and particularly preferably 115°C or higher, and is preferably 140°C or lower, for example, 100°C or higher and 140°C or lower, from the viewpoints of the strength and heat resistance of the stretched film and the adhesion between the surface resin layer and the vapor-deposited film.

[0147] Examples of adhesive resins include acid-modified resins, silicone resins, epoxy resins, and phenolic resins, with acid-modified resins being preferred. Examples of acid-modified resins include acid-modified polyolefins and acid-modified vinyl resins. Among these, from the viewpoints of recyclability and adhesion, acid-modified polyolefins are preferred, acid-modified polypropylene and acid-modified polyethylene are more preferred, acid-modified polyethylene is even more preferred, and acid-modified linear low-density polyethylene is even more preferred. The surface resin layer containing acid-modified linear low-density polyethylene tends to have better adhesion to the vapor-deposited film.

[0148] Examples of acid-modified polyolefins include polyolefins (e.g., polypropylene and polyethylene) modified with an acid-modifying component, particularly graft-modified polyolefins with an acid-modifying component. Examples of acid-modified components include unsaturated carboxylic acids such as maleic acid, fumaric acid, acrylic acid, methacrylic acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, and methyltetrahydrophthalic acid, or their acid anhydrides, esters, or metal salts. Preferred acid-modified polyolefins are maleic acid-modified polyolefins and maleic anhydride-modified polyolefins, with maleic acid-modified polypropylene, maleic anhydride-modified polypropylene, maleic acid-modified polyethylene, and maleic anhydride-modified polyethylene being more preferred.

[0149] The content of the structural units derived from the acid-modified component in the acid-modified polyolefin is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more, from the viewpoint of adhesion between the surface resin layer and the vapor-deposited film. The content of the structural units derived from the acid-modified component in the acid-modified polyolefin is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less, from the viewpoint of adhesion between the surface resin layer and the polyethylene layer. The content is, for example, 0.01% by mass or more and 10% by mass or less. The content of the structural units derived from the acid-modified component is measured by infrared spectroscopy.

[0150] From the viewpoint of film-forming ability and processability, the MFR of the acid-modified polyolefin 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, for example, 0.1 g / 10 min or more and 50 g / 10 min or less. The MFR of the acid-modified polyolefin is measured by Method A under a load of 2.16 kg in accordance with JIS K7210-1:2014. The MFR measurement temperature is set depending on the melting point of the acid-modified polyolefin, and is 230°C for acid-modified polypropylene and 190°C for acid-modified polyethylene.

[0151] The density of the acid-modified polyethylene may be in the same range as that of the polyethylene described above. The melting point (Tm) of the acid-modified polyethylene is preferably 100°C or higher, more preferably 105°C or higher, even more preferably 110°C or higher, and particularly preferably 115°C or higher, and is preferably 140°C or lower, for example, 100°C or higher and 140°C or lower, from the viewpoints of the strength and heat resistance of the stretched film and the adhesion between the surface resin layer and the vapor-deposited film.

[0152] In the surface resin layer, the polyethylene content is preferably 60% to 95% by mass and the adhesive resin content is preferably 5% to 40% by mass. It is more preferably 70% to 95% by mass and the adhesive resin content is 5% to 30% by mass. It is even more preferably 80% to 95% by mass and the adhesive resin content is 5% to 20% by mass. It is particularly preferably 85% to 95% by mass and the adhesive resin content is 5% to 15% by mass. The surface resin layer in this embodiment tends to have better surface smoothness, adhesion to the vapor-deposited film, and adhesion to the polyethylene layer. When the adhesive resin content is below the upper limit, for example, excessive adhesion of the film to a roll or the like can be suppressed during the production of the stretched film.

[0153] The surface resin layer may contain the resin material other than the above components. The surface resin layer may contain the additive.

[0154] <Adhesive resin layer> The stretched films of the first and fourth aspects may further comprise a (first) adhesive resin layer between the first surface resin layer and the polyethylene layer. The stretched films of the first and third aspects may further comprise a (second) adhesive resin layer between the polyethylene layer and the second surface resin layer. Such stretched films have, for example, excellent adhesion between the polyethylene layer and the surface resin layer.

[0155] The adhesive resin layer contains a resin material. Examples of the resin material include polyolefin, modified polyolefin, vinyl resin, silicone resin, epoxy resin, and phenolic resin. Among these, from the viewpoints of recyclability and adhesion, polyolefin and modified polyolefin are preferred, modified polyolefin such as acid-modified polyolefin is more preferred, and modified polyethylene such as acid-modified polyethylene is even more preferred.

[0156] Examples of modified polyolefins include polyolefins modified with unsaturated carboxylic acids such as maleic acid and fumaric acid, or their acid anhydrides, esters, or metal salts, particularly graft-modified polyolefins. Specific examples of modified polyolefins include unsaturated carboxylic acid-modified polyethylenes, and maleic anhydride-modified polyethylenes are more preferred.

[0157] From the viewpoint of film-forming ability and processability, the MFR of the modified polyolefin is preferably 0.1 g / 10 min or more, more preferably 0.3 g / 10 min or more, even more preferably 0.5 g / 10 min or more, and preferably 30 g / 10 min or less, more preferably 20 g / 10 min or less, even more preferably 10 g / 10 min or less, and particularly preferably 5 g / 10 min or less, for example, 0.1 g / 10 min or more and 30 g / 10 min or less. The MFR of the modified polyolefin is measured by Method A under a load of 2.16 kg in accordance with JIS K7210-1:2014. The MFR measurement temperature is set depending on the melting point of the modified polyolefin, and is 190°C for modified polyethylene.

[0158] The content of the resin material in the adhesive resin 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.

[0159] The adhesive resin layer may contain the above-mentioned additives.

[0160] In the stretched film, the thickness of each adhesive resin layer is preferably 0.5 μm or more, more preferably 1 μm or more, from the viewpoint of the adhesion. In the stretched film, the thickness of each adhesive resin layer is preferably 15 μm or less, more preferably 10 μm or less, and even more preferably 5 μm or less, from the viewpoint of the recyclability of the barrier layer. The thickness of each adhesive resin layer is, for example, 0.5 μm or more and 15 μm or less.

[0161] The thickness of each adhesive resin layer is preferably 2% or more, more preferably 4% or more, even more preferably 6% or more, and preferably 25% or less, more preferably 20% or less, even more preferably 15% or less, for example, 2% or more and 25% or less, of the thickness of the stretched film.

[0162] The stretched film of the first embodiment may comprise, in this order, a first surface resin layer, a first adhesive resin layer, a polyethylene layer, a second adhesive resin layer, and a second surface resin layer. In such a stretched film, the ratio of the thickness of the first adhesive resin layer to the thickness of the second adhesive resin layer is preferably 0.6 to 1.4, more preferably 0.7 to 1.3, even more preferably 0.8 to 1.2, and particularly preferably 0.9 to 1.1, from the viewpoints of symmetry of the stretched film and suppression of curling.

[0163] <Vapor deposition film> The barrier layer comprises a vapor-deposited film. A packaging container produced using such a barrier layer (barrier film) has excellent gas barrier properties. In one embodiment, the barrier layer comprises at least a first vapor-deposited film, a stretched film, and a second vapor-deposited film.

[0164] The vapor-deposited film may be composed of, for example, a metal and / or an inorganic oxide. The vapor-deposited film may be a metal vapor-deposited film composed of one or more metals, or an inorganic oxide vapor-deposited film composed of one or more inorganic oxides. The inorganic oxide vapor-deposited film may be a transparent vapor-deposited film. Examples of metals include aluminum, chromium, tin, nickel, copper, silver, gold, and platinum. Examples of inorganic oxides include aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, barium oxide, and silicon carbide oxide (carbon-containing silicon oxide). Among these, aluminum vapor-deposited films, aluminum oxide (alumina) vapor-deposited films, silicon oxide (silica) vapor-deposited films, and silicon carbide vapor-deposited films are preferred.

[0165] The combination of the first and second vapor-deposited films is not particularly limited. In one embodiment, the first and second vapor-deposited films are each independently a vapor-deposited metal film from the viewpoint of barrier properties. In one embodiment, the first vapor-deposited film is a vapor-deposited metal film, and the second vapor-deposited film is an inorganic oxide vapor-deposited film. In one embodiment, the first vapor-deposited film is an inorganic oxide vapor-deposited film, and the second vapor-deposited film is a vapor-deposited metal film or an inorganic oxide vapor-deposited film.

[0166] The first and second vapor-deposited films may both be aluminum vapor-deposited films. The first vapor-deposited film may be an aluminum 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. 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 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 the two may be the same or different.

[0167] In one embodiment, the barrier layer comprises a metal vapor-deposited film on both sides of the stretched film. Such a barrier layer has particularly excellent gas barrier properties. However, for example, when a packaging container is produced using a laminate having a barrier layer comprising a metal vapor-deposited film such as an aluminum vapor-deposited film on both sides of the stretched film, depending on the type of contents filled in the packaging container, the metal vapor-deposited film may oxidize to form a metal oxide, causing discoloration, corrosion, or volume expansion, reducing the laminate strength and causing problems such as lifting or peeling of the layers.

[0168] In one embodiment, the barrier layer comprises a vapor-deposited film only on the surface of the second surface resin layer of the stretched film, and no vapor-deposited film on the surface of the first surface resin layer. By using a laminate comprising such a barrier layer, a packaging container with excellent resistance to contents can be produced. For example, a laminate comprising a heat-seal layer, a barrier layer, and a polyolefin substrate layer, in this order, is prepared. The barrier layer is arranged so that the stretched film faces the heat-seal layer (the inside of the packaging container) and the vapor-deposited film faces the polyolefin substrate layer (the outside of the packaging container). By producing a packaging container using this laminate, the vapor-deposited film can be positioned on the outside, thereby preventing discoloration, corrosion, or deterioration of the vapor-deposited film, as well as lifting and peeling of the layer, even when corrosive contents are filled into the packaging container.

[0169] In one embodiment, the barrier layer comprises, as a first vapor-deposited film, an inorganic oxide vapor-deposited film provided on the surface of the first surface resin layer of the stretched film. By using a laminate comprising such a barrier layer, a packaging container with excellent resistance to contents can be produced. For example, a laminate comprising, in this order, a heat seal layer, a barrier layer, and a polyolefin substrate layer is prepared. The barrier layer is arranged so that the first vapor-deposited film faces the heat seal layer (the inside of the packaging container) and the second vapor-deposited film faces the polyolefin substrate layer (the outside of the packaging container). By producing a packaging container using this laminate, discoloration, corrosion, or deterioration of the first vapor-deposited film, as well as lifting and peeling of the layer, can be suppressed even when the packaging container is filled with corrosive contents. This is because the inorganic oxide vapor-deposited film, which is the first vapor-deposited film, is originally oxidized, and therefore is prevented from undergoing volume expansion due to oxidation, as occurs with metal vapor-deposited films.

[0170] The first vapor-deposited film may be an inorganic oxide vapor-deposited film, and the second vapor-deposited film may be a metal vapor-deposited film. The inorganic oxide vapor-deposited film may be a transparent vapor-deposited film such as an alumina vapor-deposited film, a silica vapor-deposited film, or a silicon carbide oxide vapor-deposited film. The metal vapor-deposited film may be an aluminum vapor-deposited film. Such a barrier layer can avoid the problem of oxidation degradation that occurs when the first vapor-deposited film is a metal vapor-deposited film, for example. Furthermore, during the formation of the second vapor-deposited film (during aluminum vapor deposition), the thickness of the aluminum vapor-deposited film can be measured in real time based on the amount of light transmittance, making it easy to control the film thickness.

[0171] The first vapor-deposited film may be an inorganic oxide vapor-deposited film, and the second vapor-deposited film may be an inorganic oxide vapor-deposited film, and the two may be the same or different. The inorganic oxide vapor-deposited film may be a transparent vapor-deposited film. Such a barrier layer can, for example, avoid the problem of oxidative degradation that occurs when the vapor-deposited film is a metal vapor-deposited film, and can also suppress corrosion of the vapor-deposited film from the edge of the barrier layer. Furthermore, because such a barrier layer has excellent transparency, it is possible to produce packaging containers with excellent visibility of the contents, such as packaging containers that can be used in microwave ovens and packaging containers that can pass through metal detectors. Furthermore, packaging containers with such a barrier layer allow consumers to clearly see that they do not contain an aluminum vapor-deposited film, making them easier to sort. Furthermore, it can suppress the inclusion of black spots (metallic color) that can occur as a result of the aluminum vapor-deposited film during recycling.

[0172] The barrier layer may include an additional vapor-deposited film on the first vapor-deposited film and / or the second vapor-deposited film. In one embodiment, the barrier layer includes at least a third vapor-deposited film, a first vapor-deposited film, a stretched film, a second vapor-deposited film, and a fourth vapor-deposited film, in this order. Such a barrier layer has excellent gas barrier properties and can suppress deterioration of gas barrier properties due to pinholes. The first vapor-deposited film and the third vapor-deposited film may be vapor-deposited films that constitute a multistage vapor-deposited film. The second vapor-deposited film and the fourth vapor-deposited film may be vapor-deposited films that constitute a multistage vapor-deposited film. The third vapor-deposited film and the fourth vapor-deposited film are not particularly limited, and examples thereof include the vapor-deposited films described above. An adhesion-improving layer such as a barrier coat layer or a metal oxide film, as described below, may be provided between the first and third vapor-deposited films, and / or between the second and fourth vapor-deposited films, for the purpose of improving adhesion between the two films.

[0173] The thickness of the vapor-deposited film (e.g., the thickness of each of the first and second vapor-deposited films) 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 (e.g., the thickness of each of the first and second vapor-deposited films) 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 cracking in the vapor-deposited film and the recyclability of the packaging container. The thickness of the vapor-deposited film (e.g., the thickness of each of the first and second vapor-deposited films) is, for example, 1 nm or more and 150 nm or less.

[0174] When the vapor-deposited film (e.g., the second vapor-deposited film) is an aluminum vapor-deposited film, the optical density (OD value) of the aluminum vapor-deposited film is preferably 2 or more and 3.5 or less. This allows, for example, improved oxygen barrier properties and water vapor barrier properties while maintaining the productivity of the barrier layer. When the first vapor-deposited film in the barrier layer is a transparent vapor-deposited film, it tends to be possible to form an aluminum vapor-deposited film with a stable OD value and excellent thickness uniformity. The OD value is measured in accordance with JIS K7361-1:1997.

[0175] The surface of the vapor-deposited film is preferably subjected to the above-mentioned surface treatment, which provides, for example, excellent adhesion to adjacent layers.

[0176] Examples of methods for forming vapor-deposited films include physical vapor deposition (PVD) methods such as vacuum deposition, sputtering, and ion plating, as well as chemical vapor deposition (CVD) methods such as plasma-enhanced chemical vapor deposition, thermal chemical vapor deposition, and photochemical vapor deposition. The vapor-deposited film may be a composite film containing two or more layers of different vapor-deposited films, formed by combining both physical vapor deposition and chemical vapor deposition.

[0177] The vacuum level in the deposition chamber was 10 -2 ~10 -8 After oxygen is introduced, the pressure is preferably about 10 -1 ~10 -6 A pressure of about mbar is preferable. The amount of oxygen introduced varies depending on the size of the deposition machine. The oxygen introduced may be mixed with an inert gas such as argon gas, helium gas, or nitrogen gas as a carrier gas, provided that this does not cause any problems. The transport speed of the target film on which the deposition film is formed is, for example, 10 m / min to 800 m / min.

[0178] The vapor-deposited film may be a single layer formed by a single vapor deposition process, or may be a multilayer formed by multiple vapor deposition processes. When the vapor-deposited film is a multilayer film, each layer may be composed of the same or different components. Each layer may be formed by the same method or by different methods.

[0179] In one embodiment, the barrier layer includes, in this order, a first vapor-deposited film as the vapor-deposited film, a stretched film, and a second vapor-deposited film as the vapor-deposited film, and has particularly excellent gas barrier properties.

[0180] In one embodiment, the stretched film comprises a first surface resin layer constituting the first side and a second surface resin layer constituting the second side, with a first vapor-deposited film provided on the surface of the first surface resin layer and a second vapor-deposited film provided on the surface of the second surface resin layer. Such a stretched film has excellent vapor-deposited film formability, smoothness, and adhesion, and the resulting barrier layer has excellent gas barrier properties, specifically oxygen barrier properties and water vapor barrier properties, and when the vapor-deposited film is a metal vapor-deposited film, has excellent brightness.

[0181] <Barrier coat layer> The barrier layer may further include a barrier coat layer on the vapor-deposited film. That is, the barrier layer may further include a barrier coat layer on the surface of the vapor-deposited film opposite to the surface facing the stretched film. Such a barrier layer 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 made of an inorganic oxide such as aluminum oxide or silicon oxide. The barrier layer may comprise a barrier coat layer between the two vapor-deposited films described above.

[0182] In one embodiment, the barrier layer comprises, in this order, a barrier coat layer, an inorganic oxide vapor deposition film as a first vapor deposition film, a first surface resin layer, a polyethylene layer, a second surface resin layer, and a metal vapor deposition film as a second vapor deposition film. In one embodiment, the barrier layer comprises, in this order, a metal vapor deposition film as a first vapor deposition film, a first surface resin layer, a polyethylene layer, a second surface resin layer, an inorganic oxide vapor deposition film as a second vapor deposition film, and a barrier coat layer. In one embodiment, the barrier layer comprises, in this order, a first barrier coat layer, an inorganic oxide vapor deposition film as the first vapor deposition film, a first surface resin layer, a polyethylene layer, a second surface resin layer, an inorganic oxide vapor deposition film as the second vapor deposition film, and a second barrier coat layer. In one embodiment, the barrier layer includes a first surface resin layer, a polyethylene layer, a second surface resin layer, an inorganic oxide vapor deposition film, and a barrier coat layer, in this order.

[0183] 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.

[0184] 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.

[0185] The barrier coat layer may contain the above-mentioned additives.

[0186] 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 layer and recyclability of the packaging container. The thickness is, for example, 0.01 μm or more and 10 μm or less.

[0187] The barrier coat layer can be formed, for example, by applying a coating liquid obtained by dissolving or dispersing a material such as a gas barrier resin in water or an appropriate organic solvent to the vapor-deposited film and drying it.

[0188] In another embodiment, the barrier coat layer is a gas barrier coating film formed by applying a gas barrier composition obtained by mixing a metal alkoxide, a water-soluble polymer, and optionally a silane coupling agent, and optionally adding water, an organic solvent, and a sol-gel catalyst to a vapor-deposited film, and then drying the gas barrier composition. The gas barrier coating film contains a hydrolysis polycondensate obtained by hydrolyzing and polycondensing the metal alkoxide or the like by a sol-gel method. By providing such a barrier coat layer on a vapor-deposited film, when the vapor-deposited film is composed of an inorganic oxide, the gas barrier properties can be improved and the occurrence of cracks in the vapor-deposited film can be effectively suppressed.

[0189] Examples of metal alkoxides include alkoxysilanes, specifically tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane.

[0190] Examples of water-soluble polymers include hydroxyl group-containing polymers such as polyvinyl alcohol and ethylene-vinyl alcohol copolymers. Depending on the desired physical properties, such as oxygen barrier property, water vapor barrier property, water resistance, and weather resistance, either polyvinyl alcohol or ethylene-vinyl alcohol copolymer may be used, or both may be used in combination. Alternatively, 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 water-soluble polymer used is preferably 5 to 500 parts by mass per 100 parts by mass of the metal alkoxide.

[0191] As the silane coupling agent, a known organoalkoxysilane containing an organic reactive group can be used, and an organoalkoxysilane having an epoxy group is preferred, such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. The amount of the silane coupling agent used is preferably 1 part by mass or more and 20 parts by mass or less per 100 parts by mass of the metal alkoxide.

[0192] The gas barrier composition may contain water in an amount 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 setting the water content at or above the lower limit, for example, the oxygen barrier property and water vapor barrier property of the barrier layer can be improved. By setting the water content at or below the upper limit, for example, the hydrolysis reaction can be carried out quickly.

[0193] The gas barrier composition may contain an organic solvent, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, and n-butyl alcohol.

[0194] The sol-gel catalyst is preferably an acid or an amine compound.

[0195] Examples of methods for applying the gas barrier composition include roll coating using a gravure roll coater or the like, spray coating, spin coating, dipping, brush coating, bar coating, and applicator coating.

[0196] Hereinafter, one embodiment of the method for forming a gas barrier coating film will be described. A gas barrier composition is prepared by mixing a metal alkoxide, a water-soluble polymer, a sol-gel catalyst, water, an organic solvent, and, if necessary, a silane coupling agent. A polycondensation reaction gradually progresses within the composition. The composition is then coated onto the vapor-deposited film by a conventional method and dried. This drying process further promotes polycondensation of the metal alkoxide and the water-soluble polymer (and the silane coupling agent, if the composition contains one) to form a composite polymer layer. Multiple composite polymer layers may be laminated by repeating the above process. For example, the coated composition is heated at a temperature of preferably 20°C or higher, more preferably 50°C or higher, and even more preferably 70°C or higher, and preferably 150°C or lower, more preferably 120°C or lower, and even more preferably 100°C or lower, for 1 second to 10 minutes. This process allows the formation of a gas barrier coating film.

[0197] The thickness of the gas barrier coating film is preferably 0.01 μm or more, more preferably 0.05 μm or more, even more preferably 0.1 μm or more, and is preferably 100 μm or less, more preferably 50 μm or less, even more preferably 5 μm or less, still more preferably 2 μm or less, and particularly preferably 1 μm or less, for example, 0.01 μm or more and 100 μm or less. A barrier layer comprising such a gas barrier coating film has, for example, excellent gas barrier properties, can suppress the occurrence of cracks in a vapor-deposited film made of an inorganic oxide, and also provides excellent recyclability and processability of the packaging container.

[0198] <Adhesion improving layer> The barrier layer may further include an adhesion-improving layer, such as a barrier coat layer, between the two vapor-deposited films. When the barrier layer includes a third vapor-deposited film, a first vapor-deposited film, a stretched film, a second vapor-deposited film, and a fourth vapor-deposited film in this order, the barrier layer may further include an adhesion-improving layer, such as a barrier coat layer, between the first vapor-deposited film and the third vapor-deposited film and between the second vapor-deposited film and the fourth vapor-deposited film. The adhesion-improving layer is a layer that improves the interlayer adhesion between the vapor-deposited films. When the vapor-deposited film is composed of an inorganic oxide such as aluminum oxide or silicon oxide, such a barrier layer can effectively suppress the occurrence of cracks in the vapor-deposited film and prevent a decrease in gas barrier properties. From the viewpoint of improving gas barrier properties, the adhesion-improving layer is preferably a barrier coat layer. The details of the barrier coat layer are as described above.

[0199] When both of the two vapor-deposited films are metal vapor-deposited films, a metal oxide film may be formed between the two vapor-deposited films as an adhesion-improving layer. When the first vapor-deposited film is a metal vapor-deposited film and the third vapor-deposited film is a metal vapor-deposited film, a metal oxide film may be formed between the first and third vapor-deposited films as an adhesion-improving layer. When the second vapor-deposited film is a metal vapor-deposited film and the fourth vapor-deposited film is a metal vapor-deposited film, a metal oxide film may be formed between the second and fourth vapor-deposited films as an adhesion-improving layer. By forming a metal oxide film, the adhesion between the vapor-deposited films can be improved. Furthermore, forming a multilayer film including a vapor-deposited film, a metal oxide film, and another vapor-deposited film can be more stable than forming a single thick metal vapor-deposited film, as it has higher thickness uniformity and fewer defects.

[0200] The thickness of the metal oxide film as the adhesion improving layer is preferably 1 nm or more and 30 nm or less, more preferably 3 nm or more and 15 nm or less, from the viewpoint of the adhesion and gas barrier properties of the metal vapor deposition film.

[0201] The metal oxide film may be formed, for example, by vapor-depositing a metal oxide by introducing oxygen into metal vapor after forming a vapor-deposited film, or by heating the vapor-deposited film in an oxygen atmosphere to oxidize the surface of the vapor-deposited film. By forming a vapor-deposited film on the surface of a metal oxide film, a barrier layer comprising a metal vapor-deposited film, a metal oxide film, and another metal vapor-deposited film can be produced. It is preferable that the first and second vapor-deposited films are aluminum vapor-deposited films, the metal oxide film is an aluminum oxide film, and the third and fourth vapor-deposited films are aluminum vapor-deposited films. For example, after forming a vapor-deposited film by vapor-depositing aluminum, a small amount of oxygen is introduced into the aluminum vapor to form an aluminum oxide film on the vapor-deposited film, and then the introduction of oxygen is stopped and a vapor-deposited film is formed on the aluminum oxide film by vapor-depositing aluminum.

[0202] <Layer structure of the barrier layer> Hereinafter, several examples of the layer structure of the barrier layer (barrier film) will be given. The barrier layer (barrier film) 1 shown in FIG. 1 includes a first surface resin layer 20, a polyethylene layer 10, a second surface resin layer 20, and a vapor-deposited film 40. The barrier layer (barrier film) 1 shown in Figure 2 comprises a first surface resin layer 20, a first adhesive resin layer 30, a polyethylene layer 10, a second adhesive resin layer 30, a second surface resin layer 20, and a vapor-deposited film 40. The barrier layer (barrier film) 1 shown in FIG. 3 comprises, in this order, a first surface resin layer 20, a first adhesive resin layer 30, a 3a polyethylene layer 10, a 2a polyethylene layer 10, a 1a polyethylene layer 10, a 1b polyethylene layer 10, a 2b polyethylene layer 10, a 3b polyethylene layer 10, a second adhesive resin layer 30, a second surface resin layer 20, and a vapor-deposited film 40.

[0203] The barrier layer (barrier film) 1 shown in FIG. 4 includes a first vapor-deposited film 40, a first surface resin layer 20, a polyethylene layer 10, a second surface resin layer 20, and a second vapor-deposited film 40. The barrier layer (barrier film) 1 shown in Figure 5 comprises a first vapor-deposited film 40, a first surface resin layer 20, a first adhesive resin layer 30, a polyethylene layer 10, a second adhesive resin layer 30, a second surface resin layer 20, and a second vapor-deposited film 40. The barrier layer (barrier film) 1 shown in Figure 6 comprises, in this order, a first vapor-deposited film 40, a first surface resin layer 20, a first adhesive resin layer 30, a 3a polyethylene layer 10, a 2a polyethylene layer 10, a 1a polyethylene layer 10, a 1b polyethylene layer 10, a 2b polyethylene layer 10, a 3b polyethylene layer 10, a second adhesive resin layer 30, a second surface resin layer 20, and a second vapor-deposited film 40.

[0204] 1 to 3, the barrier layer 1 may further include a barrier coating layer (not shown) on the vapor-deposited film 40. In FIGS. 4 to 6, the barrier layer 1 may further include a barrier coating layer (not shown) on the first vapor-deposited film 40. In FIGS. 4 to 6, the barrier layer 1 may further include a barrier coating layer (not shown) on the second vapor-deposited film 40.

[0205] [Laminate] The laminate of the present disclosure comprises at least a heat seal layer and a barrier layer. In one embodiment, the laminate of the present disclosure comprises at least a heat seal layer, a barrier layer, and a polyolefin substrate layer, in this order. The barrier layer is preferably arranged so that the first surface resin layer faces the heat seal layer and the second surface resin layer faces the polyolefin substrate layer. Examples of polyolefin substrate layers include a polyethylene substrate layer and a polypropylene substrate layer. In one embodiment, the laminate of the present disclosure does not include either a polyethylene terephthalate film or an aluminum foil, which can improve the recyclability of the laminate of the present disclosure and packaging containers including the laminate. The laminate of the present disclosure can be suitably used as a packaging material. The laminate of the present disclosure can be suitably used as a packaging material for producing packaging bags such as small pouches, for example.

[0206] The polyolefin (e.g., polyethylene) content in the entire laminate of the present disclosure is preferably 80% by mass or more, more preferably 85% by mass or more, and even more preferably 90% by mass or more. This allows, for example, the laminate to be used to produce a polyolefin-based (e.g., polyethylene-based) packaging container, improving the recyclability of the packaging container. The upper limit of the polyolefin (e.g., polyethylene) content is not particularly limited, but may be 99% by mass.

[0207] The total thickness of the laminate of the present disclosure is preferably 40 μm or more, more preferably 60 μm or more, even more preferably 80 μm or more, and is preferably 400 μm or less, more preferably 350 μm or less, even more preferably 300 μm or less, for example, 40 μm or more and 400 μm or less. The total thickness of the laminate for sachets is preferably 200 μm or less, more preferably 160 μm or less, even more preferably 120 μm or less, for example, 60 μm or more and 120 μm or less.

[0208] <Base material layer, etc.> The laminate of the present disclosure includes the above-described barrier layer. The laminate of the present disclosure may include two or more barrier layers. Details of the barrier layer are as described above, and detailed description thereof will be omitted here. In the laminate, the orientation of the barrier layer is not particularly limited. The barrier layer may be arranged so that the first surface resin layer faces the heat-seal layer side and the second surface resin layer faces the side opposite to the heat-seal layer side or the polyolefin substrate layer side, or so that the second surface resin layer faces the heat-seal layer side and the first surface resin layer faces the side opposite to the heat-seal layer side or the polyolefin substrate layer side.

[0209] In one embodiment of the laminate of the present disclosure, the vapor-deposited film is provided on the surface of the second surface resin layer of the stretched film, but not on the surface of the first surface resin layer of the stretched film. In the laminate of this embodiment, the barrier layer is preferably arranged so that the first surface resin layer faces the heat-seal layer and the vapor-deposited film faces the polyolefin substrate layer. That is, the laminate of the above embodiment preferably comprises, in this order, the heat-seal layer, the first surface resin layer, the polyethylene layer, the second surface resin layer, the vapor-deposited film, and the polyolefin substrate layer.

[0210] In one embodiment of the laminate of the present disclosure, the barrier layer comprises at least a first vapor-deposited film, a stretched film, and a second vapor-deposited film. In the laminate of this embodiment, the barrier layer is preferably arranged so that the first vapor-deposited film faces the heat-seal layer and the second vapor-deposited film faces the polyolefin substrate layer. That is, the laminate of the above embodiment preferably comprises, in this order, the heat-seal layer, the first vapor-deposited film, the first surface resin layer, the polyethylene layer, the second surface resin layer, the second vapor-deposited film, and the polyolefin substrate layer.

[0211] (Polyethylene base layer) In one embodiment, the laminate of the present disclosure further includes a polyethylene substrate layer. The polyethylene substrate layer may or may not be subjected to a stretching treatment. The polyethylene substrate layer is preferably a stretched film from the viewpoints of heat resistance, strength, printability, and the like. The stretching treatment may be uniaxial or biaxial. When stretching is performed in the machine direction (the flow direction of the film, MD direction), the stretching ratio is preferably 2 times or more, more preferably 3 times or more, and preferably 10 times or less, more preferably 7 times or less, for example, 2 times or more and 10 times or less. When stretching is performed in the transverse direction (the direction perpendicular to the MD direction, TD direction), the stretching ratio is preferably 2 times or more, more preferably 3 times or more, and preferably 15 times or less, more preferably 10 times or less, for example, 2 times or more and 15 times or less. The polyethylene substrate layer may be, for example, a uniaxially stretched film or a biaxially stretched film.

[0212] The polyethylene substrate layer contains polyethylene as a main component, and examples of the polyethylene include high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, and very low-density polyethylene.

[0213] The polyethylene substrate layer may have a multilayer structure of two or more layers. A polyethylene substrate layer having a multilayer structure has, for example, an excellent balance of strength, rigidity, heat resistance, transparency, and printability. The number of layers in the polyethylene substrate layer is preferably two or more, more preferably three or more, and preferably nine or fewer, more preferably seven or fewer, for example, two or more and nine or fewer. The number of layers in the polyethylene substrate layer is specifically three, five, seven, or nine. When adjacent layers constituting the substrate layer have the same resin composition and are indistinguishable from one another, the adjacent layers may be integrated to form a single layer.

[0214] In one embodiment, the polyethylene substrate layer comprises at least: a first surface resin layer containing polyethylene as a main component; a polyethylene intermediate layer containing polyethylene as a main component; a second surface resin layer containing polyethylene as a main component; are provided in this order in the stacking direction. The polyethylene substrate layer may include two or more polyethylene intermediate layers.

[0215] Hereinafter, the polyethylene layer will also be referred to as a "PE layer." In one embodiment, the polyethylene substrate layer comprises at least: a first surface resin layer; a first PE layer; a second PE layer; a third PE layer; and a second surface resin layer; and each of the layers contains polyethylene as a main component.

[0216] In one embodiment, the polyethylene substrate layer comprises: the first surface resin layer contains medium-density polyethylene and high-density polyethylene; The first PE layer contains medium density polyethylene and linear low density polyethylene, The second PE layer contains linear low-density polyethylene as a main component, the third PE layer contains medium density polyethylene and linear low density polyethylene; The second surface resin layer contains medium density polyethylene and high density polyethylene. It is a uniaxially stretched film (hereinafter also referred to as "film (α)"). High-density polyethylene contributes to improving heat resistance, for example. Medium-density polyethylene contributes to improving rigidity, for example. Linear low-density polyethylene contributes to improving stretchability, for example.

[0217] In the first and second surface resin layers of the film (α), the total content of the medium-density polyethylene and the high-density polyethylene is each independently preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. In the first and second surface resin layers of the film (α), the ratio of the content of medium-density polyethylene to the content of high-density polyethylene (medium-density polyethylene content / high-density polyethylene content) is preferably 0.25 or more and 4 or less, more preferably 0.4 or more and 3 or less, even more preferably 1.1 or more and 3 or less, and particularly preferably 1.5 or more and 3 or less, independently on a mass basis.

[0218] In the first and third PE layers of the film (α), the total content of the medium-density polyethylene and the linear low-density polyethylene is each independently preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. In the first and third PE layers of the film (α), the ratio of the medium-density polyethylene content to the linear low-density polyethylene content (medium-density polyethylene content / linear low-density polyethylene content) is preferably 0.25 or more and 4 or less, more preferably 0.4 or more and 2.4 or less, and even more preferably 0.8 or more and 2.4 or less, independently on a mass basis.

[0219] In the second PE layer of the film (α), the content of linear low-density polyethylene is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0220] In one embodiment, the polyethylene substrate layer comprises: the first surface resin layer contains high-density polyethylene and medium-density polyethylene; The first PE layer contains medium density polyethylene as a main component, the second PE layer contains linear low-density polyethylene and medium-density polyethylene; The third PE layer contains medium density polyethylene as a main component, The second surface resin layer contains high-density polyethylene and medium-density polyethylene. It is a uniaxially stretched film (hereinafter also referred to as "film (β)").

[0221] In the first and second surface resin layers of the film (β), the total content of high-density polyethylene and medium-density polyethylene is each independently preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. In the first and second surface resin layers of the film (β), the content ratio of high-density polyethylene to medium-density polyethylene (high-density polyethylene content / medium-density polyethylene content) is, independently by mass, preferably 0.25 or more and 4 or less, more preferably 0.4 or more and 3 or less, even more preferably 1.1 or more and 3 or less, and particularly preferably 1.5 or more and 3 or less.

[0222] In the second PE layer of the film (β), the total content of the linear low-density polyethylene and the medium-density polyethylene is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. In the second PE layer of the film (β), the content ratio of linear low-density polyethylene to medium-density polyethylene (linear low-density polyethylene content / medium-density polyethylene content) is preferably 0.25 or more and 4 or less, more preferably 0.4 or more and 2.4 or less, on a mass basis.

[0223] In the first and third PE layers of the film (β), the content of medium-density polyethylene is each independently preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0224] In one embodiment, the polyethylene substrate layer comprises: the first surface resin layer contains medium-density polyethylene and high-density polyethylene; The first PE layer contains high-density polyethylene as a main component, The second PE layer contains linear low-density polyethylene as a main component, The third PE layer contains high density polyethylene as a main component, The second surface resin layer contains medium density polyethylene and high density polyethylene. It is a uniaxially stretched film (hereinafter also referred to as "film (γ)").

[0225] In the first and second surface resin layers of the film (γ), the total content of the medium-density polyethylene and the high-density polyethylene is each independently preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. In the first and second surface resin layers of the film (γ), the content ratio of medium-density polyethylene to high-density polyethylene (medium-density polyethylene content / high-density polyethylene content) is preferably 1.1 or more and 5 or less, more preferably 1.5 or more and 3 or less, independently on a mass basis.

[0226] In one embodiment of the first and third PE layers of the film (γ), the content ratio of high-density polyethylene is each independently preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0227] The first and third PE layers of the film (γ) may each independently further contain low-density polyethylene. This configuration can, for example, further improve the balance between the heat resistance, rigidity, and processability of the film. In this embodiment, the total content of high-density polyethylene and low-density polyethylene in the first and third PE layers is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. In this embodiment, the content ratio of high-density polyethylene to low-density polyethylene in the first and third PE layers (high-density polyethylene content / low-density polyethylene content) is preferably 1 or more and 4 or less, more preferably 1.5 or more and 3 or less, on a mass basis.

[0228] In one embodiment of the second PE layer of the film (γ), the content of linear low-density polyethylene is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0229] The second PE layer of the film (γ) may further contain low-density polyethylene. This configuration can, for example, further improve the balance between the stretchability and processability of the film. In this embodiment, the total content of the linear low-density polyethylene and the low-density polyethylene in the second PE layer is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. In this embodiment, the content ratio of the linear low-density polyethylene to the low-density polyethylene in the second PE layer (linear low-density polyethylene content / low-density polyethylene content) is preferably 1 or more and 4 or less, more preferably 1.5 or more and 3 or less, by mass.

[0230] In one embodiment, the polyethylene base layer is a biaxially stretched film comprising a polyethylene layer (hereinafter also referred to as "polyethylene layer (1)") containing at least one polymer selected from the group consisting of high-density polyethylene and medium-density polyethylene, and, if necessary, a polyethylene other than the polymer (hereinafter also referred to as "other polyethylene").

[0231] Examples of the other polyethylene include linear low-density polyethylene, high-pressure low-density polyethylene, and ultra-low-density polyethylene. Among these, linear low-density polyethylene is preferred. The polyethylene layer (1) preferably contains high-density polyethylene and linear high-density polyethylene. Such a polyethylene substrate layer has, for example, high impact resistance, and a packaging container with excellent rupture resistance can be produced using the laminate described below. Furthermore, such a polyethylene substrate layer has, for example, high rigidity.

[0232] High-density polyethylenes include, for example, ethylene homopolymers and ethylene-α-olefin copolymers. Examples of α-olefins include the aforementioned α-olefins having from 3 to 20 carbon atoms, with α-olefins having from 3 to 8 carbon atoms being preferred, and α-olefins having from 4 to 8 carbon atoms being more preferred. Examples of ethylene-α-olefin copolymers include ethylene-1-butene copolymers (C4-HDPE) in which the comonomer is at least 1-butene, ethylene-1-hexene copolymers (C6-HDPE) in which the comonomer is at least 1-hexene, and ethylene-1-octene copolymers (C8-HDPE) in which the comonomer is at least 1-octene. These copolymers are not limited to the above-mentioned comonomers, and additional comonomers may also be used. For example, high-density polyethylenes produced using a metallocene catalyst are preferred.

[0233] Examples of medium-density polyethylene include ethylene homopolymers and ethylene-α-olefin copolymers. Examples of α-olefins include the aforementioned α-olefins having from 3 to 20 carbon atoms, with α-olefins having from 3 to 8 carbon atoms being preferred, and α-olefins having from 4 to 8 carbon atoms being more preferred. Examples of ethylene-α-olefin copolymers include ethylene-1-butene copolymers (C4-MDPE) in which the comonomer is at least 1-butene, ethylene-1-hexene copolymers (C6-MDPE) in which the comonomer is at least 1-hexene, and ethylene-1-octene copolymers (C8-MDPE) in which the comonomer is at least 1-octene. These copolymers are not limited to the above-mentioned comonomers, and additional comonomers may also be used. For example, medium-density polyethylenes produced using a metallocene catalyst are preferred.

[0234] The high-density polyethylene and medium-density polyethylene are preferably the above-mentioned ethylene-α-olefin copolymers. Polyethylene films containing such high-density polyethylene and / or medium-density polyethylene exhibit, for example, excellent biaxial stretchability, particularly excellent stretchability in the width direction. This is presumably because the side chains derived from the α-olefins prevent the film from tearing during stretching. The ethylene-α-olefin copolymer is preferably a polyethylene obtained by polymerizing ethylene and a small amount of α-olefin using a polymerization method using a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as a metallocene catalyst, and more preferably a polyethylene produced using a metallocene catalyst.

[0235] Examples of linear low-density polyethylene include ethylene-α-olefin copolymers. Examples of α-olefins include the aforementioned α-olefins having from 3 to 20 carbon atoms, with α-olefins having from 3 to 8 carbon atoms being preferred, and α-olefins having from 4 to 8 carbon atoms being more preferred. Examples of 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 comonomer is not limited to the above-mentioned comonomers, and additional comonomers may also be used. For example, linear low-density polyethylenes produced using a metallocene catalyst are preferred.

[0236] 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, 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 biaxial stretchability, the total content of high-density polyethylene and medium-density polyethylene in the polyethylene layer (1) is preferably 90% by mass or less, more preferably 85% by mass or less, 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 total content of high-density polyethylene and medium-density polyethylene in the polyethylene layer (1) is, for example, 10% by mass or more and 90% by mass or less, and preferably 20% by mass or more and 60% by mass or less.

[0237] From the viewpoint of biaxial stretchability, the polyethylene layer (1) preferably further contains a linear low-density polyethylene in addition to at least one polyethylene selected from the group consisting of high-density polyethylene and medium-density polyethylene, and more preferably further contains a linear low-density polyethylene in addition to the high-density polyethylene.

[0238] The content of linear low-density polyethylene in the polyethylene layer (1) is preferably 10% by mass or more, more preferably 15% by mass or more, 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 biaxial stretchability. The content of linear low-density polyethylene in the polyethylene layer (1) is preferably 90% by mass or less, more preferably 85% by mass or less, 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, from the viewpoint of heat resistance. The content of linear low-density polyethylene in the polyethylene layer (1) is, for example, 10% by mass or more and 90% by mass or less, and preferably 40% by mass or more and 80% by mass or less.

[0239] In one embodiment, the polyethylene substrate layer is a stretched film of a single-layer polyethylene film consisting of a polyethylene layer (1). In one embodiment, the polyethylene substrate layer is a stretched film of a polyethylene film having 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).

[0240] In the polyethylene base layer, from the viewpoint of heat resistance, it is preferable that at least one layer selected from the group consisting of the first surface resin layer, the first PE layer, the second PE layer, and the third PE layer is a polyethylene layer (1), and it is more preferable that all of the above layers are polyethylene layers (1).

[0241] In the polyethylene base layer, the thickness of the first and second surface resin layers is each independently preferably 0.3 μm or more, more preferably 0.5 μm or more, even more preferably 0.8 μm or more, and preferably 15 μm or less, more preferably 10 μm or less, even more preferably 5 μm or less, for example, 0.3 μm or more and 15 μm or less.

[0242] In the polyethylene base layer, 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 25% or less, more preferably 20% or less, even more preferably 15% or less, relative to the thickness of the polyethylene base layer, for example, 1% or more and 25% or less.

[0243] From the viewpoint of film symmetry and suppression of curling, the ratio of the thickness of the second surface resin layer to the thickness of the first surface resin layer is preferably 0.6 or more and 1.4 or less, more preferably 0.7 or more and 1.3 or less, even more preferably 0.8 or more and 1.2 or less, and particularly preferably 0.9 or more and 1.1 or less.

[0244] In the polyethylene substrate layer, the thickness of the polyethylene intermediate layer is preferably 4 μm or more, more preferably 8 μm or more, even more preferably 12 μm or more, and preferably 100 μm or less, more preferably 80 μm or less, even more preferably 60 μm or less, even more preferably 40 μm or less, and particularly preferably 30 μm or less, for example, 4 μm or more and 100 μm or less. A polyethylene substrate layer having a polyethylene intermediate layer whose thickness is equal to or greater than the lower limit exhibits, for example, excellent strength, rigidity, heat resistance, and recyclability. A polyethylene substrate layer having a polyethylene intermediate layer whose thickness is equal to or less than the upper limit exhibits, for example, excellent processability. When the polyethylene substrate layer has two or more polyethylene intermediate layers, the above "thickness" refers to the total thickness of each polyethylene intermediate layer.

[0245] In the polyethylene substrate layer, the thickness of the polyethylene intermediate layer is preferably 50% or more, more preferably 60% or more, even more preferably 70% or more, and preferably 98% or less, more preferably 96% or less, even more preferably 92% or less, of the thickness of the polyethylene substrate layer, for example, 50% or more and 98% or less. When the polyethylene substrate layer has two or more polyethylene intermediate layers, the above "thickness" means the total thickness of each polyethylene intermediate layer.

[0246] In the polyethylene base layer, the thickness of the first and third PE layers is each independently preferably 0.5 μm or more, more preferably 0.8 μm or more, even more preferably 1 μm or more, and preferably 18 μm or less, more preferably 13 μm or less, even more preferably 8 μm or less, for example, 0.5 μm or more and 18 μm or less.

[0247] From the viewpoint of film symmetry and suppression of curling, the ratio of the thickness of the first PE layer to the thickness of the third PE layer is preferably 0.6 or more and 1.4 or less, more preferably 0.7 or more and 1.3 or less, even more preferably 0.8 or more and 1.2 or less, and particularly preferably 0.9 or more and 1.1 or less.

[0248] In the polyethylene base layer, the thickness of the second PE layer is preferably 2 μm or more, more preferably 5 μm or more, even more preferably 8 μm or more, and preferably 60 μm or less, more preferably 40 μm or less, even more preferably 20 μm or less, for example, 2 μm or more and 60 μm or less.

[0249] The polyethylene substrate layer can be produced, for example, by forming the materials constituting each layer into a polyethylene film (single-layer film or laminate film) and then stretching the film. Examples of film-forming methods include inflation and T-die casting.

[0250] In one embodiment, the polyethylene substrate layer is a film obtained by stretching a co-extruded film, such as by co-extrusion of the material constituting the first surface resin layer, the material constituting the polyethylene intermediate layer, and the material constituting the second surface resin layer in this order in the lamination direction by an inflation method, T-die casting, or the like, and then stretching the resulting co-extruded film.

[0251] The polyethylene substrate layer may contain a resin material other than polyethylene, such as polyolefins other than polyethylene, (meth)acrylic resins, vinyl resins, cellulose resins, polyamides, polyesters, and ionomer resins. The polyethylene substrate layer may contain biomass polyethylene. The polyethylene substrate layer may contain recycled polyethylene. The polyethylene substrate layer may contain the above-mentioned additives.

[0252] The polyethylene content in the polyethylene base layer is preferably more than 50% by mass, more preferably 80% by mass or more, even more preferably 85% by mass or more, still more preferably 90% by mass or more, and particularly preferably 95% by mass or more.

[0253] The haze value of the polyethylene substrate layer is preferably 25% or less, more preferably 15% or less, and even more preferably 10% or less. The smaller the haze value, the better, but the lower limit may be, for example, 0.1% or 1%. The haze value of the polyethylene substrate layer is measured in accordance with JIS K7136:2000.

[0254] The polyethylene substrate layer may have a single-layer structure or a multi-layer structure. From the viewpoint of the strength and heat resistance of the laminate, the thickness of the polyethylene base layer is preferably 5 μm or more, more preferably 10 μm or more, and even more preferably 15 μm or more, and from the viewpoint of the processability of the laminate, the thickness is preferably 200 μm or less, more preferably 100 μm or less, even more preferably 50 μm or less, and particularly preferably 40 μm or less, for example, 5 μm or more and 200 μm or less.

[0255] The polyethylene substrate layer may be subjected to the above-mentioned surface treatment. Such a polyethylene substrate layer has, for example, excellent adhesion to a layer adjacent to the substrate layer. An anchor coating layer may be formed on the surface of the polyethylene substrate layer using a conventionally known anchor coating agent.

[0256] (Polypropylene base layer) In one embodiment, the laminate of the present disclosure further includes a polypropylene base layer. The polypropylene base layer may or may not be subjected to a stretching treatment. The polypropylene base layer is preferably a stretched film from the viewpoints of heat resistance, strength, printability, and the like. The stretching treatment may be uniaxial or biaxial. When stretching is performed in the machine direction (the flow direction of the film, MD direction), the stretching ratio is preferably 2 times or more, more preferably 3 times or more, and preferably 10 times or less, more preferably 7 times or less, for example, 2 times or more and 10 times or less. When stretching is performed in the transverse direction (the direction perpendicular to the MD direction, TD direction), the stretching ratio is preferably 2 times or more, more preferably 3 times or more, and preferably 10 times or less, more preferably 7 times or less, for example, 2 times or more and 10 times or less. The polypropylene base layer may be, for example, a uniaxially stretched film or a biaxially stretched film, with a biaxially stretched film being preferred.

[0257] The polypropylene base layer contains polypropylene as a main component. The polypropylene may be any of propylene homopolymer (homopolypropylene), propylene random copolymer (random polypropylene) such as propylene-α-olefin random copolymer, and propylene block copolymer (block polypropylene) such as propylene-α-olefin block copolymer, or a mixture of two or more selected from these. From the viewpoint of reducing the environmental impact, biomass-derived polypropylene or mechanically or chemically recycled polypropylene may be used as the polypropylene.

[0258] In this disclosure, polypropylene refers to a propylene homopolymer or a polymer in which the proportion of propylene-derived structural units in all repeating structural units is greater than the proportion of structural units derived from any comonomer. In this polymer, the proportion of propylene-derived structural units may be, for example, 50 mol% or more, 60 mol% or more, 70 mol% or more, or 80 mol% or more. The above content is measured by NMR.

[0259] A propylene homopolymer is a polymer of propylene alone. A propylene random copolymer is a random copolymer of propylene and an α-olefin other than propylene. A propylene block copolymer is a copolymer having a polymer block of propylene and a polymer block of an α-olefin other than propylene. Examples of α-olefins other than propylene include α-olefins having 2 to 20 carbon atoms, specifically ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 3-methyl-1-butene, 4-methyl-1-pentene, and 6-methyl-1-heptene.

[0260] Among polypropylenes, propylene random copolymers are preferred from the viewpoint of transparency, propylene homopolymers are preferred when emphasis is placed on the rigidity and heat resistance of the packaging container, and propylene block copolymers are preferred when emphasis is placed on the impact resistance of the packaging container.

[0261] From the viewpoint of film-forming ability and processability, the MFR of polypropylene is preferably 0.1 g / 10 min or more, more preferably 0.2 g / 10 min or more, even more preferably 0.5 g / 10 min or more, and preferably 50 g / 10 min or less, more preferably 30 g / 10 min or less, even more preferably 10 g / 10 min or less, for example, 0.1 g / 10 min or more and 50 g / 10 min or less. In this specification, the MFR of polypropylene is measured by Method A in accordance with JIS K7210-1:2014 under conditions of a temperature of 230°C and a load of 2.16 kg.

[0262] The density of polypropylene is, for example, 0.88 g / cm 3 More than 0.92g / cm 3 From the viewpoints of strength, heat resistance, and the like, the melting point (Tm) of polypropylene is preferably 120°C or higher, more preferably 125°C or higher, and preferably 170°C or lower, more preferably 165°C or lower, for example, 120°C or higher and 170°C or lower.

[0263] The polypropylene base layer may contain a resin material other than polypropylene, such as polyolefins other than polypropylene, (meth)acrylic resins, vinyl resins, cellulose resins, polyamides, polyesters, and ionomer resins. The polypropylene substrate layer may contain biomass polypropylene. The polypropylene substrate layer may contain recycled polypropylene. The polypropylene substrate layer may contain the above-mentioned additives.

[0264] The polypropylene content in the polypropylene base layer is preferably more than 50% by mass, more preferably 80% by mass or more, even more preferably 85% by mass or more, still more preferably 90% by mass or more, and particularly preferably 95% by mass or more.

[0265] The haze value of the polypropylene base layer is preferably 25% or less, more preferably 15% or less, and even more preferably 10% or less. The smaller the haze value, the better, but the lower limit may be, for example, 0.1% or 1%. The haze value of the polypropylene base layer is measured in accordance with JIS K7136:2000.

[0266] The polypropylene substrate layer may have a single-layer structure or a multi-layer structure. From the viewpoint of the strength and heat resistance of the laminate, the thickness of the polypropylene base layer is preferably 5 μm or more, more preferably 10 μm or more, and even more preferably 15 μm or more, and from the viewpoint of the processability of the laminate, the thickness is preferably 200 μm or less, more preferably 100 μm or less, even more preferably 50 μm or less, and particularly preferably 40 μm or less, for example, 5 μm or more and 200 μm or less.

[0267] The polypropylene substrate layer may be subjected to the above-mentioned surface treatment. Such a polypropylene substrate layer has, for example, excellent adhesion to a layer adjacent to the substrate layer. An anchor coating layer may be formed on the surface of the polypropylene substrate layer using a conventionally known anchor coating agent.

[0268] <Print layer> The laminate of the present disclosure may include a printed layer on one or both surfaces of the barrier layer and / or the polyolefin substrate layer. The printed layer may be formed, for example, on either surface of the polyolefin substrate layer. In one embodiment, the laminate of the present disclosure includes a printed layer on the surface of the polyolefin substrate layer facing the barrier layer, since this can prevent the printed layer from coming into contact with the outside air and prevent deterioration of the printed layer over time.

[0269] The print layer includes an image. Examples of the image include letters, figures, patterns, symbols, and combinations thereof. The image may include text information such as the product name, the name of the item in the packaging container, the manufacturer, and the names of ingredients. The image may be a single, solid color (a so-called solid image).

[0270] In one embodiment, the printed layer contains a colorant. Examples of colorants include pigments such as inorganic pigments and organic pigments, as well as dyes such as acid dyes, direct dyes, disperse dyes, oil-soluble dyes, metal-containing oil-soluble dyes, and sublimable dyes. Examples of colorants also include fluorescent materials such as ultraviolet light-emitting materials that emit fluorescence by absorbing ultraviolet light, and infrared light-emitting materials that emit fluorescence by absorbing infrared light.

[0271] The content of the colorant in the printed layer is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more. The content of the colorant in the printed layer is preferably 90% by mass or less, more preferably 70% by mass or less, and even more preferably 50% by mass or less. The content is, for example, 1% by mass or more and 90% by mass or less.

[0272] In one embodiment, the print layer contains a resin material in addition to a colorant. Examples of resin materials include thermoplastic resins, cured products of thermosetting resins, and cured products of energy ray-curable compounds. Examples of thermoplastic resins include polyolefins, chlorinated polyolefins, polystyrenes, (meth)acrylic resins, vinyl resins, acetal resins, polyesters, polyurethanes, polycarbonates, polyamides, polyimides, cellulose resins, petroleum resins, and fluororesins. Examples of thermosetting resins include phenolic resins, melamine resins, urea resins, epoxy resins, unsaturated polyesters, thermosetting polyurethanes, silicone resins, and (meth)acrylic thermosetting resins. Examples of energy ray-curable compounds include polyfunctional (meth)acrylate compounds.

[0273] The content of the resin material in the printed layer is preferably 10% by mass or more, more preferably 30% by mass or more, and even more preferably 50% by mass or more. The content of the resin material in the printed layer is preferably 99% by mass or less, more preferably 97% by mass or less, and even more preferably 95% by mass or less. The content is, for example, 10% by mass or more and 99% by mass or less.

[0274] The print layer may contain the above-mentioned additives.

[0275] The printed layer can be formed, for example, using an ink composition containing the above-mentioned components and, if necessary, a solvent. Examples of methods for forming the printed layer include gravure printing, offset printing, flexographic printing, screen printing, letterpress printing, and transfer printing. From the perspective of reducing the environmental load, the printed layer may be formed by flexographic printing. From the perspective of reducing the environmental load, the printed layer may be formed using a biomass-derived ink.

[0276] 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.

[0277] <Heat seal layer> The laminate of the present disclosure comprises a heat seal layer. The heat seal layer contains polyethylene as a main component. This allows the packaging container to be converted to polyolefin (e.g., polyethylene). Such packaging containers are highly recyclable, and there is no need to separate the barrier layer and the heat seal layer, for example, after collecting used packaging containers. The above laminate, in which the heat seal layer contains polyethylene as a main component, can be suitably used as a packaging material, such as a polyethylene-based mono-material packaging material.

[0278] Examples of polyethylene contained in the heat seal layer include high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, and very low-density polyethylene. From the viewpoint of heat sealability, low-density polyethylene, linear low-density polyethylene, and very low-density polyethylene are preferred. From the viewpoint of reducing the environmental load, biomass polyethylene and / or recycled polyethylene may be used as the polyethylene.

[0279] From the viewpoint of heat-sealability, the heat-seal layer preferably contains low-density polyethylene and / or linear low-density polyethylene. When the heat-seal layer contains low-density polyethylene and linear low-density polyethylene, the content (mass%) of the linear low-density polyethylene may be greater than the content (mass%) of the low-density polyethylene.

[0280] From the viewpoint of a balance between heat resistance and heat sealability, the melting point (Tm) of the polyethylene contained in the heat seal layer is preferably 80°C or higher, more preferably 85°C or higher, and preferably 140°C or lower, more preferably 130°C or lower, and even more preferably 120°C or lower, for example, 80°C or higher and 140°C or lower.

[0281] From the viewpoint of film-forming ability and processability, the MFR of the polyethylene contained in the heat seal layer is preferably 0.1 g / 10 min or more, more preferably 0.3 g / 10 min or more, even more preferably 0.5 g / 10 min or more, and is preferably 50 g / 10 min or less, more preferably 30 g / 10 min or less, even more preferably 10 g / 10 min or less, for example, 0.1 g / 10 min or more and 50 g / 10 min or less.

[0282] The content of polyethylene in the heat seal layer is preferably more than 50% by mass, more preferably 80% by mass or more, and even more preferably 90% by mass or more. A laminate including such a heat seal layer has excellent recyclability, for example.

[0283] The heat seal layer may contain the above-mentioned additives.

[0284] The heat seal layer may have a single-layer structure or a multi-layer structure. In one embodiment, the heat seal layer comprises, in this order, a layer containing linear low-density polyethylene as a primary component, a layer containing high-density polyethylene as a primary component, and a layer containing linear low-density polyethylene as a primary component. This heat seal layer exhibits an excellent balance between heat sealability and rigidity. In one embodiment, the heat seal layer comprises, in this order, a first HS layer containing linear low-density polyethylene as a primary component, a second HS layer containing linear low-density polyethylene as a primary component, and a third HS layer containing linear low-density polyethylene or very low-density polyethylene as a primary component. This heat seal layer exhibits excellent heat sealability.

[0285] The first HS layer faces the barrier layer, and the third HS layer faces the opposite side to the barrier layer. For example, when the laminate is used to produce a packaging container, the third HS layer faces the containing portion of the packaging bag. In one embodiment, the first HS layer is one surface resin layer of the heat seal layer, and the third HS layer is the other surface resin layer.

[0286] In one embodiment, the laminate comprises, in order, a third HS layer, a second HS layer, a first HS layer, a barrier layer, and optionally a polyolefin substrate layer.

[0287] The third HS layer has a density of 0.920 g / cm 3 The polyethylene preferably contains the following linear low-density polyethylene or ultra-low-density polyethylene as a main component, and more preferably contains the linear low-density polyethylene as a main component. The density of the polyethylene is preferably 0.900 g / cm 3 Exceeds 0.915g / cm 3 or less, more preferably 0.910 g / cm 3 or less, more preferably 0.906 g / cm 3When the stretched film in the barrier layer is a polyethylene-based stretched film and / or the polyolefin substrate layer is a polyethylene substrate layer, heat sealing at a low temperature is desirable from the viewpoint of suppressing thermal degradation during heat sealing. In such an embodiment, sufficient heat seal strength can be obtained even when heat sealing is performed at a low temperature (for example, about 140°C).

[0288] From the viewpoint of low-temperature heat sealing properties, the melting point (Tm) of the polyethylene contained in the third HS layer is preferably 80°C or higher, more preferably 85°C or higher, and preferably 120°C or lower, more preferably 110°C or lower, and even more preferably 100°C or lower, for example, 80°C or higher and 120°C or lower.

[0289] The density of the third HS layer is 0.920 g / cm 3 The content of the linear low-density polyethylene or ultra-low-density polyethylene described below is preferably 80% by mass or more, more preferably 85% by mass or more, and even more preferably 90% by mass or more.

[0290] In one embodiment, the third HS layer further contains an antiblocking agent. This configuration can improve the antiblocking properties of the heat seal layer. Examples of the antiblocking agent include inorganic antiblocking agents and organic antiblocking agents.

[0291] Examples of inorganic 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; kaolin, talc, zeolite (synthetic zeolite or natural zeolite), and diatomaceous earth. Examples of organic antiblocking agents include (meth)acrylic resin particles such as polymethyl methacrylate (PMMA) resin particles, styrene resin particles, and melamine resin particles.

[0292] The average particle size of the antiblocking agent is, for example, 1 μm to 10 μm, and is the number-average particle size measured using a laser diffraction particle size distribution analyzer (SALD-2000J, manufactured by Shimadzu Corporation) or an equivalent device.

[0293] In one embodiment, the content of the antiblocking agent in the third HS layer is, for example, 0.1% by mass to 15% by mass, or 0.2% by mass to 10% by mass.

[0294] The ratio of the thickness of the third HS layer to the total thickness of the heat seal layer is preferably 2% to 40%, more preferably 5% to 35%, and even more preferably 10% to 30%.

[0295] The density of the linear low density polyethylene contained in the first HS layer is preferably 0.906 g / cm 3 Exceeds 0.925g / cm 3 or less, more preferably 0.910 g / cm 3 Exceeds 0.920g / cm 3 or less, more preferably 0.915 g / cm 3 Exceeds 0.920g / cm 3 The following is the result. The content of linear low-density polyethylene in the first HS layer is preferably 80% by mass or more, more preferably 85% by mass or more, and even more preferably 90% by mass or more.

[0296] The ratio of the thickness of the first HS layer to the total thickness of the heat seal layer is preferably 2% or more and 40% or less, more preferably 5% or more and 35% or less, and even more preferably 10% or more and 30% or less. The surface of the first HS layer may be subjected to the above-mentioned surface treatment.

[0297] The density of the linear low density polyethylene contained in the second HS layer is not particularly limited, and for example, the linear low density polyethylene contained in the second HS layer may be the same as or different from the linear low density polyethylene contained in the first HS layer. The content of the linear low-density polyethylene in the second HS layer is preferably 80% by mass or more, more preferably 85% by mass or more, and even more preferably 90% by mass or more.

[0298] From the viewpoint of increasing rigidity, the density of the linear low-density polyethylene contained in the second HS layer is preferably 0.920 g / cm 3 Exceeds 0.930g / cm 3 The following is the result. From the viewpoint of the rigidity of the heat seal layer, the density of the linear low density polyethylene contained in the second HS layer is preferably higher than the density of the polyethylene contained in the first HS layer and the third HS layer.

[0299] The ratio of the thickness of the second HS layer to the total thickness of the heat seal layer is preferably 20% or more and 96% or less, more preferably 30% or more and 90% or less, and even more preferably 40% or more and 80% or less.

[0300] The heat seal layer (e.g., the second HS layer) may further contain a coloring material component. Such a layer functions as a light-shielding layer. A heat seal layer having such a configuration provides sufficient heat-seal strength even when heat-sealed at low temperatures, and also provides excellent light-shielding properties, allowing the production of a packaging container with excellent storage stability for the contents.

[0301] Examples of the coloring material component include pigments and dyes. Examples of pigments include inorganic pigments and organic pigments. Examples of inorganic pigments include white pigments, red pigments, orange pigments, yellow pigments, green pigments, blue pigments, purple pigments, black pigments, metallic pigments, and pearl pigments. Among these, white pigments are preferred from the viewpoint of obtaining a heat seal layer that exhibits a milky white color.

[0302] Examples of white pigments include titanium oxide, zinc oxide, zinc sulfide, silicon oxide, magnesium oxide, zirconium oxide, antimony oxide, aluminum oxide, aluminum hydroxide, calcium carbonate, barium sulfate, and anhydrous calcium silicate. Among these, titanium oxide is preferred. Examples of black pigments include carbon black, titanium black, titanium carbon, black iron oxide, black titanium oxide, and graphite.

[0303] Examples of metallic pigments include particles made of simple metals such as aluminum, silver, gold, platinum, nickel, chromium, tin, zinc, indium, titanium, and copper, as well as particles made of alloys of these metals. Examples of pearl pigments include pigments with pearlescent or interference luster, such as titanium dioxide-coated mica, fish scale leaf, and bismuth oxychloride.

[0304] Examples of organic pigments include azo pigments, polycyclic pigments (e.g., phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, and quinophthalone pigments), dye chelates (e.g., basic dye-type chelates and acid dye-type chelates), nitro pigments, nitroso pigments, and aniline black. Dyes include, for example, acid dyes, basic dyes and reactive dyes.

[0305] In one embodiment, the content of the coloring material component in the second HS layer is preferably 0.5% by mass to 20% by mass, more preferably 1% by mass to 15% by mass, and even more preferably 2% by mass to 10% by mass.

[0306] A vapor-deposited film may be provided on the surface resin layer (e.g., the first HS layer) on the barrier layer side of the heat-sealing layer. This configuration can improve the gas barrier properties of the laminate, and providing a metal vapor-deposited film, for example, can impart gloss or light-blocking properties to the laminate. Details of the vapor-deposited film are as described above, and a detailed description will be omitted here. Specific examples of the vapor-deposited film include aluminum vapor-deposited film, aluminum oxide (alumina) vapor-deposited film, silicon oxide (silica) vapor-deposited film, and silicon oxide carbide vapor-deposited film. The above-mentioned barrier coat layer may be provided on the vapor-deposited film.

[0307] The thickness of the heat seal layer is preferably 10 μm or more, more preferably 15 μm or more, even more preferably 20 μm or more, and particularly preferably 25 μm or more, from the viewpoint of heat sealing properties 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. The thickness of the heat seal layer in the laminate for sachets is preferably 100 μm or less, more preferably 80 μm or less, and even more preferably 60 μm or less, for example, 20 μm or more and 60 μm or less.

[0308] From the viewpoint of heat sealing property, the heat seal layer is preferably an unstretched resin film, more preferably an unstretched co-extruded resin film, and each layer constituting the heat seal layer is a co-extruded resin layer. The above resin film can be produced, for example, by using a T-die casting method or an inflation method. The concept of "unstretched film" includes not only a film that is not stretched at all, but also a film that is slightly stretched due to the tension applied during film formation.

[0309] For example, an unstretched resin film corresponding to the heat seal layer may be laminated on the barrier layer or a corresponding barrier film via an adhesive layer as needed, or the heat seal layer may be formed by melt-extruding polyethylene or a resin composition thereof onto the barrier layer or a corresponding barrier film. In the latter case, an adhesive layer may not be provided. Examples of adhesive layers include the adhesive layer described below.

[0310] <Adhesive layer> The laminate of the present disclosure may include an adhesive layer between any layers, such as between the barrier layer and the heat seal layer or the polyolefin substrate layer, etc. Such a laminate has excellent adhesion between the barrier layer and the heat seal layer or the polyolefin substrate layer, for example.

[0311] In one embodiment, the laminate of the present disclosure comprises, in this order, a heat seal layer, a first adhesive layer, a barrier layer, a second adhesive layer, and a polyolefin substrate layer, and has excellent adhesion between the barrier layer and the heat seal layer and between the barrier layer and the polyolefin substrate layer.

[0312] In one embodiment, the adhesive layer may be an adhesive layer made of an adhesive. The adhesive may be any of a one-component curing adhesive, a two-component curing adhesive, and a non-curing adhesive. The adhesive may be a solventless adhesive or a solvent-based adhesive. Among these, a solvent-based adhesive is preferred because it has better resistance to contents.

[0313] Examples of solvent-free adhesives, i.e., non-solvent laminate adhesives, include polyether adhesives, polyester adhesives, silicone adhesives, epoxy adhesives, and urethane adhesives. Among these, urethane adhesives are preferred, and two-component curing urethane adhesives are more preferred.

[0314] Examples of solvent-based adhesives include rubber-based adhesives, vinyl-based adhesives, olefin-based adhesives, silicone-based adhesives, epoxy-based adhesives, phenol-based adhesives, and urethane-based adhesives. Among these, urethane-based adhesives are preferred, and two-component curing urethane-based adhesives are more preferred.

[0315] In one embodiment, the laminate of the present disclosure may be produced by laminating a resin film corresponding to the heat seal layer, a barrier film corresponding to the barrier layer, and a polyolefin film corresponding to the polyolefin substrate layer by a non-solvent lamination method using a solvent-free adhesive, or by a dry lamination method using a solvent-based adhesive.

[0316] The adhesive layer can be formed by applying an adhesive to a barrier layer or a corresponding barrier film or the like by a method such as direct gravure roll coating, gravure roll coating, kiss coating, reverse roll coating, Fontaine method, or transfer roll coating, and then drying the adhesive.

[0317] 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.

[0318] 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 thermoplastic resins include high-density polyethylene, medium-density polyethylene, high-pressure low-density polyethylene, linear low-density polyethylene, very low-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-methyl(meth)acrylate copolymer, ethylene-ethyl(meth)acrylate copolymer, ethylene-maleic acid copolymer, ionomer resin, and resins obtained by graft-polymerizing or copolymerizing polyolefin with an unsaturated carboxylic acid, unsaturated carboxylic anhydride, or ester monomer. The thermoplastic resin may be a material derived from fossil fuels, a biomass-derived material such as biomass polyethylene, or a recycled material such as recycled polyethylene. Two or more of these may be used.

[0319] The extruded resin layer is preferably an extruded polyethylene layer. This allows the laminate to contain a higher proportion of polyolefin (e.g., polyethylene) than when a conventional non-polyethylene adhesive (e.g., a two-component curing urethane adhesive) is used. This improves the recyclability of the laminate.

[0320] Examples of polyethylene contained in the extruded polyethylene layer include high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, and very low-density polyethylene. Among these, from the viewpoint of interlayer adhesion, low-density polyethylene, linear low-density polyethylene, and very low-density polyethylene are preferred, and low-density polyethylene is more preferred.

[0321] In one embodiment, the extruded polyethylene layer may contain a polyolefin plastomer and an acid group-containing polyethylene. The content of the polyolefin plastomer in the extruded polyethylene layer is, for example, 60% by mass or more and 80% by mass or less, and the content of the acid group-containing polyethylene is, for example, 20% by mass or more and 40% by mass or less. This, for example, can lower the melting temperature during melt extrusion, thereby suppressing damage to the vapor-deposited film in the barrier layer, maintaining the gas barrier properties based on the vapor-deposited film, and improving adhesion between the vapor-deposited film and the extruded polyethylene layer.

[0322] An example of the polyolefin plastomer is polyethylene plastomer. The details of polyethylene plastomer are as described above, and therefore, further explanation will be omitted here.

[0323] Examples of acid group-containing polyethylene include copolymers of ethylene with unsaturated carboxylic acids or their anhydrides and, if desired, other monomers, as well as resins obtained by graft-polymerizing polyethylene with unsaturated carboxylic acids or their anhydrides. Examples of unsaturated carboxylic acids include monocarboxylic acids such as (meth)acrylic acid and dicarboxylic acids such as maleic acid. Examples of other monomers include (meth)acrylates. In the acid group-containing polyethylene, the content of structural units derived from unsaturated carboxylic acids or their acid anhydrides may be, for example, 0.1% by mass or more, 1% by mass or more, 5% by mass or more, 25% by mass or less, 20% by mass or less, or 15% by mass or less, for example, 0.1% by mass or more and 25% by mass or less. In the acid group-containing polyethylene, the content of structural units derived from ethylene may be, for example, more than 50% by mass, 60% by mass or more, 95% by mass or less, or 90% by mass or less, for example, more than 50% by mass and 95% by mass or less. The above content is measured by NMR. The density of the acid group-containing polyethylene is 0.905 g / cm 3 More than 0.910g / cm 3 More than 0.940g / cm 3Less than 0.930g / cm 3 It may be less than 0.905 g / cm 3 More than 0.940g / cm 3 The following is also acceptable. Examples of acid group-containing polyethylene include ethylene-(meth)acrylic acid copolymers, and ethylene-(meth)acrylic acid-(meth)acrylate copolymers such as ethylene-(meth)acrylic acid-butyl(meth)acrylate copolymers.

[0324] From the viewpoint of film-forming ability and processability, the melt flow rate (MFR) of the polyethylene and acid group-containing polyethylene in the extruded polyethylene layer is preferably 1 g / 10 min or more, more preferably 2 g / 10 min or more, even more preferably 3 g / 10 min or more, and is preferably 50 g / 10 min or less, more preferably 30 g / 10 min or less, even more preferably 20 g / 10 min or less, for example, 1 g / 10 min or more and 50 g / 10 min or less.

[0325] The melting point (Tm) of the polyethylene and acid group-containing polyethylene in the extruded polyethylene layer is preferably 140°C or lower, more preferably 130°C or lower, and even more preferably 120°C or lower, from the viewpoint of a balance between heat resistance and adhesiveness.

[0326] The extruded polyethylene layer may contain biomass polyethylene. The extruded polyethylene layer may contain recycled polyethylene. The extruded polyethylene layer may contain the additives described above.

[0327] The content of polyethylene in the extruded polyethylene layer is preferably more than 50% by mass, more preferably 60% by mass or more, even more preferably 70% by mass or more, still more preferably 80% by mass or more, and particularly preferably 90% by mass or more. Such a configuration can improve, for example, adhesiveness and recyclability.

[0328] The thickness of the extruded polyethylene 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.

[0329] The extruded polyethylene layer may be formed, for example, by melt-extruding polyethylene or a resin composition containing polyethylene into a barrier layer, etc. The melting temperature at this time is preferably 260°C or higher, more preferably 265°C or higher, and preferably 340°C or lower, more preferably 335°C or lower, for example, 260°C or higher and 340°C or lower.

[0330] If necessary, an anchor coat layer may be provided on the surface of the barrier layer on which the extruded resin layer is formed. The anchor coat layer is formed from an anchor coat agent. Examples of anchor coat agents include polyurethane-based, polyolefin-based, and epoxy resin-based anchor coat agents. The thickness of the anchor coat layer is, for example, 0.05 μm or more and 3 μm or less.

[0331] <Layer structure of laminate> Below, several examples of the layer structure of the laminate of the present disclosure will be given. The laminate 2 shown in FIG. 7 includes a heat seal layer 80, a first adhesive layer 60, a barrier layer 1, a second adhesive layer 60, and a polyolefin substrate layer 70, in this order. Specifically, the laminate 2 includes a heat seal layer 80, a first adhesive layer 60, a first surface resin layer 20, a polyethylene layer 10, a second surface resin layer 20, a vapor-deposited film 40, a second adhesive layer 60, and a polyolefin substrate layer 70, in this order. The laminate 2 shown in FIG. 7 may include a barrier layer 1 having the structure shown in FIG. 2 or 3, instead of the barrier layer 1. 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 substrate layer 70 (e.g., the surface on the second adhesive layer 60 side). A laminate having such a configuration is suitable as a packaging material for forming packaging bags such as small pouches. The laminate 2 shown in FIG. 8 includes a heat seal layer 80, a first adhesive layer 60, a barrier layer 1, a second adhesive layer 60, and a polyolefin substrate layer 70, in this order. Specifically, the laminate 2 includes a heat seal layer 80, a first adhesive layer 60, a first vapor-deposited film 40, a first surface resin layer 20, a polyethylene layer 10, a second surface resin layer 20, a second vapor-deposited film 40, a second adhesive layer 60, and a polyolefin substrate layer 70, in this order. The laminate 2 shown in FIG. 8 may include a barrier layer 1 having the structure shown in FIG. 5 or 6, instead of the barrier layer 1. 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 substrate layer 70 (e.g., the surface on the second adhesive layer 60 side). A laminate having such a configuration is suitable as a packaging material for forming packaging bags such as small pouches. 7, the barrier layer 1 may further include a barrier coating layer (not shown) on the vapor-deposited film 40. In FIG. 8, the barrier layer 1 may further include a barrier coating layer (not shown) on the first vapor-deposited film 40. In FIG. 8, the barrier layer 1 may further include a barrier coating layer (not shown) on the second vapor-deposited film 40.

[0332] <Gas barrier properties of laminate> The oxygen permeability (unit: cc / (m 2 The oxygen permeability (°C / day / atm) is preferably 3.0 or less, more preferably 2.0 or less, even more preferably 1.0 or less, and particularly preferably 0.5 or less, 0.3 or less, or 0.1 or less. The lower limit of the oxygen permeability may be, for example, 0.01. The oxygen permeability is measured in accordance with JIS K7126-2:2006 in an environment at a temperature of 23°C and a humidity of 90% RH.

[0333] The water vapor permeability (unit: g / (m 2·day)) may be, for example, 10 or less, preferably 3.0 or less, more preferably 2.0 or less, even more preferably 1.0 or less, and particularly preferably 0.5 or less or 0.3 or less. The lower limit of the water vapor permeability may be, for example, 0.01 or 0.05. The water vapor permeability is measured in accordance with JIS K7129-2:2019 in an environment at a temperature of 40°C and a humidity of 90% RH.

[0334] [Packaging container] The laminate of the present disclosure can be suitably used for packaging material applications. Packaging materials are used to produce packaging containers. By using at least the laminate of the present disclosure, for example, it is possible to produce packaging containers that have excellent gas barrier properties and aroma retention properties and are suitable for high-speed filling of contents.

[0335] Examples of packaging containers include packaging bags of various shapes, such as stand-up pouches, side seals, two-sided seals, three-sided seals, four-sided seals, envelope seals, palm seals (pillow seals), pleated seals, flat-bottom seals, square-bottom seals, and gusset seals. The packaging bag may be, for example, a small pouch or a zipper bag. The packaging bag may also be a refill pouch, particularly a standing pouch, for storing contents such as liquids and powders that can be refilled into containers such as bottles. The packaging bag may also be, for example, a flexible packaging bag. Among these, small pouches are preferred. In the present disclosure, a small pouch refers to a packaging bag with a storage capacity of 100 mL or less. The volume is preferably 1 mL to 50 mL, more preferably 5 mL to 30 mL.

[0336] The packaging container of the present disclosure comprises the laminate of the present disclosure. The packaging container of the present disclosure may be, for example: one or more laminates of the present disclosure; a seal portion where the heat seal layers of the laminate are joined together; a storage section for storing contents; It has. The seal portion includes an inner edge that defines the receptacle portion.

[0337] Examples of methods for forming the sealed portion include heat sealing, in which the heat-sealed layers of the laminate are melted by heating or the like to fuse the heat-sealed layers together, and specific examples include bar sealing, rotary roll sealing, belt sealing, impulse sealing, high-frequency sealing, and ultrasonic sealing. For example, after the contents are placed in the packaging bag, the opening of the packaging bag can be heat-sealed to seal the packaging bag.

[0338] 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.

[0339] Examples of contents housed in the packaging container include liquids, solids, powders, and gels. The contents may be food or beverages, or non-food or beverages such as chemicals, cosmetics, pharmaceuticals, metal parts, and electronic components. Examples of contents include shampoo, rinse, conditioner, hand soap, body soap, air fresheners, deodorants, insect repellents, fabric softeners, detergents; sauces, soy sauce, dressings, cooking oils, mayonnaise, ketchup, syrups, cooking alcohol, and other liquid or viscous condiments; fruit juices; spices; liquid beverages, jelly-like beverages, liquid soups, powdered soups, instant foods, milk, chocolate, coffee powder, other food and beverages; cream; toothpaste; metal parts, and electronic components. In one embodiment, the packaging container of the present disclosure is polyolefinized (e.g., polyethylene-based) and yet has excellent aroma retention, as described above. Therefore, even when the packaging container is filled with contents with strong odors such as shampoo, rinse, conditioner, fabric softener, and detergent, leakage of the odor can be suppressed.

[0340] In one embodiment, a packaging container can be produced by folding the laminate of the present disclosure in half and overlapping it so that the polyolefin substrate layer is on the outside and the heat seal layer is on the inside, and then heat-sealing the edges, etc. In another embodiment, a packaging container 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 edges, etc. The entire packaging container may be made of the laminate, or only a portion of the packaging container may be made of the laminate.

[0341] In one embodiment, the stand-up pouch comprises a body portion composed of side sheets and a bottom portion composed of a bottom sheet. The bottom sheet maintains the shape of the side sheets, thereby imparting self-supporting properties to the pouch and enabling it to be a stand-up pouch. A storage compartment for storing contents is formed within the area surrounded by the side sheets and the bottom sheet. In the stand-up pouch, only the side sheets may be the laminate of the present disclosure, only the bottom sheet may be the laminate of the present disclosure, or both the side sheets and the bottom sheet may be the laminate of the present disclosure.

[0342] In one embodiment, the side sheet can be formed by preparing two laminates of the present disclosure, overlapping them with their heat-sealable layers facing each other, and heat-sealing both side edges to form a bag.

[0343] In another embodiment, the side sheets can be formed by preparing two laminates of the present disclosure, overlapping them with their heat-sealable layers facing each other, inserting two V-folded laminates with their heat-sealable layers facing outward between the laminates at the side edges of both sides of the overlapped laminates, and heat-sealing the two laminates. This production method produces a stand-up pouch having a body with side gussets.

[0344] In one embodiment, the bottom sheet can be formed by inserting the laminate of the present disclosure between the lower portions of the side sheets of a bag and heat-sealing the laminate. More specifically, the bottom sheet can be formed by inserting the laminate folded in a V-shape with the heat-seal layer facing outward between the lower portions of the side sheets of a bag and heat-sealing the laminate.

[0345] In one embodiment, two laminates of the present disclosure are prepared and stacked together with their heat-sealable layers facing each other. Then, another laminate of the present disclosure is folded in a V-shape with its heat-sealable layer facing outward, and this is sandwiched between the two laminates and heat-sealed to form a bottom. Next, two sides adjacent to the bottom are heat-sealed to form a body. In this manner, a stand-up pouch according to one embodiment can be formed.

[0346] [Aspects of the present disclosure] The present disclosure relates to, for example, the following [1] to

[23] . [1] A laminate comprising at least a heat seal layer and a barrier layer, The heat seal layer contains polyethylene as a main component, the barrier layer comprises at least a stretched film and a vapor-deposited film, The stretched film comprises a first surface resin layer, a polyethylene layer, and a second surface resin layer, in this order; the polyethylene layer contains polyethylene as a main component; and the second surface resin layer is a layer containing a gas barrier resin as a main component, or a layer containing polyethylene and an adhesive resin; provided, however, that when adjacent layers constituting the stretched film have the same resin composition and are indistinguishable from each other, the adjacent layers may be integrated to form a single layer; and the vapor-deposited film is provided at least on the surface of the second surface resin layer of the stretched film. [2] The first surface resin layer is A layer containing a gas barrier resin as a main component, or Layer containing polyethylene and adhesive resin The laminate according to [1] above, [3] The laminate according to [1] or [2], wherein the first surface resin layer and the second surface resin layer each independently contain an ethylene-vinyl alcohol copolymer or a polyamide as a main component. [4] The laminate according to any one of [1] to [3], wherein the stretched film further comprises a first adhesive resin layer between the first surface resin layer and the polyethylene layer, and a second adhesive resin layer between the polyethylene layer and the second surface resin layer. [5] The laminate according to [4], wherein the stretched film is a stretched film of a base film comprising the first surface resin layer, the first adhesive resin layer, the polyethylene layer 3a, the polyethylene layer 2a, the polyethylene layer 1a, the polyethylene layer 1b, the polyethylene layer 2b, the polyethylene layer 3b, the second adhesive resin layer, and the second surface resin layer in this order, provided that when adjacent layers constituting the film have the same resin composition and are indistinguishable from each other, the adjacent layers may be integrated to form a single layer. [6] The 3a polyethylene layer contains a linear low-density polyethylene, the 2a polyethylene layer contains linear low-density polyethylene as a main component, the 1a polyethylene layer contains polyethylene plastomer as a main component, the 1b polyethylene layer contains polyethylene plastomer as a main component, the 2b polyethylene layer contains linear low-density polyethylene as a main component, The 3b polyethylene layer contains linear low-density polyethylene. The laminate according to [5] above. [7] The laminate according to [6], wherein the melting point of the polyethylene plastomer is 115°C or less. [8] The laminate according to any one of the above [1] to [7], wherein at least one of the polyethylene layers further contains a compatibilizer. [9] The laminate according to any one of the above [1] to [8], wherein the thickness of the surface resin layer of the stretched film is 0.5 μm or more and 10 μm or less.

[10] The laminate according to any one of [1] to [9], wherein the vapor-deposited film provided on the surface of the second surface resin layer of the stretched film is a metal vapor-deposited film or an inorganic oxide vapor-deposited film.

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

[10] , wherein the barrier layer comprises, as the vapor-deposited films, a first vapor-deposited film provided on the surface of the first surface resin layer of the stretched film, and a second vapor-deposited film provided on the surface of the second surface resin layer of the stretched film.

[12] The laminate according to

[11] , wherein the first vapor-deposited film and the second vapor-deposited film are each independently a metal vapor-deposited film, or the first vapor-deposited film is a metal vapor-deposited film and the second vapor-deposited film is an inorganic oxide vapor-deposited film, or the first vapor-deposited film is an inorganic oxide vapor-deposited film and the second vapor-deposited film is a metal vapor-deposited film or an inorganic oxide vapor-deposited film.

[13] The laminate according to

[12] , wherein the first vapor-deposited film is an alumina vapor-deposited film, a silica vapor-deposited film, or a silicon oxide carbide vapor-deposited film, and the second vapor-deposited film is an aluminum vapor-deposited film.

[14] The laminate according to

[12] above, wherein the first vapor-deposited film and the second vapor-deposited film are each independently an alumina vapor-deposited film, a silica vapor-deposited film, or a silicon carbide oxide vapor-deposited film.

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

[14] , further comprising a polyethylene base layer or a polypropylene base layer, the polyethylene base layer containing polyethylene as a main component, the polypropylene base layer containing polypropylene as a main component, the barrier layer being arranged so that the first surface resin layer faces the heat seal layer and the second surface resin layer faces the base layer, and the vapor-deposited film is provided at least on the surface of the second surface resin layer of the stretched film.

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

[15] , further comprising a first adhesive layer between the heat seal layer and the barrier layer, and a second adhesive layer between the barrier layer and the base layer.

[17] The laminate according to

[16] , wherein the first adhesive layer and the second adhesive layer are each independently an adhesive layer or an extruded resin layer.

[18] The laminate according to

[17] , wherein the first adhesive layer and the second adhesive layer are each independently an adhesive layer made of a solvent-based or solventless adhesive.

[19] The laminate according to

[17] , wherein the first adhesive layer and the second adhesive layer are each independently an extruded resin layer containing polyethylene as a main component.

[20] The laminate according to

[17] , wherein the first adhesive layer and the second adhesive layer are each independently an extruded resin layer containing a polyolefin plastomer and an acid group-containing polyethylene.

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

[20] above, wherein the content of polyolefin in the entire laminate is 80 mass % or more.

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

[21] above, a seal portion where the heat seal layers of the laminate are joined together; a storage section for storing contents; A packaging container having the above structure.

[23] The packaging container according to

[22] above, which is a small pouch. [Example]

[0347] Hereinafter, the laminate of the present disclosure will be described in more detail with reference to examples, but the laminate of the present disclosure is not limited to the following examples. In the following description, "parts by mass" will be simply referred to as "parts".

[0348] [Preparation of stretched film] The following materials were used in producing the stretched film. Linear low-density polyethylene (LLDPE) ExxonMobil Exceed XP8656ML ethylene-1-hexene copolymer, Density: 0.916g / cm 3 Melting point: 121°C, MFR: 0.5g / 10min Medium Density Polyethylene (MDPE) ExxonMobil, Enable 4002MC, Density: 0.938g / cm 3 Melting point: 128°C, MFR: 0.25g / 10min Medium Density Polyethylene (MDPE) Dow Chemical, ELITE 5538G Density: 0.941g / cm 3 Melting point: 129°C, MFR: 1.3g / 10min Polyolefin Plastomer 1 (POP1) Dow Chemical's AFFINITY EG8100G ethylene-octene copolymer, Density: 0.870g / cm 3 Melting point: 55°C, MFR: 1.0g / 10min Polyolefin Plastomer 2 (POP2) Dow Chemical's AFFINITY PL1881G ethylene-octene copolymer, Density: 0.902g / cm 3 Melting point: 99°C, MFR: 1.0g / 10min Ethylene-vinyl alcohol copolymer (EVOH) Kuraray, Eval E171B, Density: 1.14g / cm 3 , Melting point: 165℃, MFR: 1.7g / 10min, Ethylene content: 44 mol% Aliphatic polyamide (aliphatic PA) BASF ULTRAMID B40, Polyamide 6 (PA6), Melting point: 220°C, relative viscosity: 4.0 Crystalline semi-aromatic polyamide (semi-aromatic PA) Mitsubishi Gas Chemical Company, MX nylon (MXD6) S6007 Polymetaxylylene adipamide, Melting point: 240°C, glass transition temperature: 85°C, relative viscosity: 2.7 Amorphous semi-aromatic polyamide (semi-aromatic PA) Grivory G21, manufactured by EMS, Polyamide 6I / 6T (PA6I / 6T), Glass transition temperature: 125℃, MVR: 25cm 3 / 10 minutes ·Adhesive resin Mitsui Chemicals, Admar AT1955E, Maleic anhydride grafted modified polyethylene, Density: 0.890g / cm 3 , MFR: 2.6g / 10min Compatibilizer Dow Chemical, RETAIN 3000, Maleic anhydride grafted modified polyethylene, Density: 0.870g / cm 3

[0349] [Example 1] A blended polyethylene (A) was prepared by mixing 60 parts of LLDPE (Exceed XP8656ML) and 40 parts of MDPE (Enable 4002MC). A blended polyethylene (B) was prepared by mixing 80 parts of polyolefin plastomer 1 (AFFINITY EG8100G) and 20 parts of polyolefin plastomer 2 (AFFINITY PL1881G).

[0350] EVOH (Eval E171B) and Adhesive resin (Admer AT1955E) and A blended polyethylene (A), LLDPE (Exceed XP8656ML) and Blended polyethylene (B), The resulting mixture was co-extruded by inflation molding, and the blended polyethylene (B) layers were pressed together at the nip to form a single film. The resulting film was then stretched 4 times in the machine direction (MD) using a stretching device to produce a stretched film.

[0351] The stretched film thus obtained is A first surface resin layer (EVOH layer) having a thickness of 2 μm; a first adhesive resin layer having a thickness of 2.5 μm; a 5 μm thick blended polyethylene (A) layer; A 1.5 μm thick LLDPE layer; a 1.5 μm thick blended polyethylene (B) layer; a 1.5 μm thick blended polyethylene (B) layer; A 1.5 μm thick LLDPE layer; a 5 μm thick blended polyethylene (A) layer; a second adhesive resin layer having a thickness of 2.5 μm; A second surface resin layer (EVOH layer) having a thickness of 2 μm; The total thickness of the stretched film was 25 μm.

[0352] Water, isopropyl alcohol, and a small amount of hydrochloric acid were mixed, and tetraethoxysilane and a small amount of 3-glycidoxypropyltriethoxysilane were added to the mixture while cooling. To the resulting solution, a solution obtained by mixing polyvinyl alcohol, water, and isopropyl alcohol was added. In this way, a barrier coating agent was obtained.

[0353] An aluminum (AL) vapor-deposited film having a thickness of 30 nm was formed on the second surface resin layer of the stretched film by the PVD method, thus obtaining a barrier film 1. An aluminum (AL) vapor-deposited film having a thickness of 30 nm was formed on the surface resin layer of each of the stretched films by the PVD method, thus obtaining a barrier film 2. An aluminum (AL) vapor-deposited film having a thickness of 30 nm was formed on the second surface resin layer of the stretched film by the PVD method. An alumina vapor-deposited film having a thickness of 30 nm was formed on the first surface resin layer of the stretched film by the PVD method. The surface of the alumina vapor-deposited film was coated with the above-mentioned barrier coating agent by the spin coating method, and subjected to a heat treatment at 100°C for 8 seconds in an oven to form a barrier coating layer having a thickness of 0.3 μm. In this way, barrier film 3 was obtained. Barrier film 4 was obtained in the same manner as barrier film 3, except that a silica vapor-deposited film was formed instead of the alumina vapor-deposited film. A 30 nm thick alumina vapor-deposited film was formed on each surface resin layer of the stretched film by PVD, and the surface of each alumina vapor-deposited film was coated with the above-mentioned barrier coating agent by spin coating, followed by heat treatment in an oven at 100°C for 8 seconds to form a 0.3 μm thick barrier coating layer. In this way, barrier film 5 was obtained. Barrier film 6 was obtained in the same manner as barrier film 5, except that a silica vapor-deposited film was formed instead of the alumina vapor-deposited film.

[0354] <Dry lamination> 70 parts of medium density polyethylene (Dow Chemical, ELITE 5538G, density: 0.941 g / cm 3 , melting point: 129°C, MFR: 1.3g / 10min) and 30 parts of high-density polyethylene (Dow Chemical, ELITE 5960G, density: 0.960g / cm 3 , melting point: 134°C, MFR: 0.85g / 10min) was mixed to prepare a blended polyethylene (a). 60 parts medium density polyethylene (ELITE 5538G) and 40 parts linear low density polyethylene (Dow Chemical, ELITE 5400G, density: 0.916 g / cm 3 , melting point: 123°C, MFR: 1.3 g / 10 min) was mixed to prepare a blended polyethylene (b).

[0355] a blended polyethylene (a); a blended polyethylene (b); Linear low-density polyethylene (ELITE 5400G) and a blended polyethylene (b); a blended polyethylene (a); The mixture was extruded into a tube shape from an extruder through a multi-layer annular die using a five-layer coextrusion inflation device, and then inflated with air pressure while being drawn vertically to form a tubular film. The tubular film comprised a blended polyethylene (a) layer, a blended polyethylene (b) layer, an LLDPE layer, a blended polyethylene (b) layer, and a blended polyethylene (a) layer forming the tube's inner surface. The tubular film was flattened by joining its inner surfaces together, and then both ends of the tubular film in the width direction were cut off to a predetermined width to separate it into two films. Each of the resulting polyethylene films was stretched 5 times in the machine direction (MD) using a stretching device to produce a uniaxially stretched film (MDOPE film) with a thickness of 25 μm.

[0356] The MDOPE film thus obtained was A first surface resin layer (blend polyethylene (a) layer) having a thickness of 3 μm; A first PE layer (blend polyethylene (b) layer) having a thickness of 4.5 μm; a second PE layer (LLDPE layer) having a thickness of 10 μm; a third PE layer (blended polyethylene (b) layer) having a thickness of 4.5 μm; A second surface resin layer (blend polyethylene (a) layer) having a thickness of 3 μm; One surface of the MDOPE film was subjected to a corona discharge treatment, and an image was formed on the corona discharge treated surface by gravure printing using a solvent-based gravure ink (Finart, manufactured by DIC Graphics Corporation).

[0357] 20 parts high density polyethylene (metallocene HDPE, ethylene-1-octene copolymer, density: 0.955 g / cm 3, melting point: 130°C, MFR: 1.5g / 10min) and 80 parts of linear low-density polyethylene (Dow Chemical, INNATE TF80, metallocene LLDPE, ethylene-1-octene copolymer, density: 0.926g / cm 3 , MFR: 1.7 g / 10 min) was mixed to prepare blended polyethylene (c). Blended polyethylene (c) was co-extruded into a five-layer film by T-die casting to obtain a five-layer polyethylene film. This film was sequentially biaxially stretched by stretching 5 times in the machine direction (MD) and then 8.5 times in the width direction (TD) to produce a biaxially stretched film (BOPE film) with a thickness of 25 μm.

[0358] The BOPE film thus obtained is a first surface resin layer having a thickness of 1 μm; a first PE layer having a thickness of 2 μm; a second PE layer having a thickness of 19 μm; a third PE layer having a thickness of 2 μm; a second surface resin layer having a thickness of 1 μm; One surface of the BOPE film was subjected to a corona discharge treatment, and an image was formed on the corona discharge treated surface by gravure printing using a solvent-based gravure ink (Finart, manufactured by DIC Graphics Corporation).

[0359] An 18-μm-thick biaxially stretched polypropylene film (manufactured by Argha Karya, product name: OPP-PFR, hereafter referred to as "OPP film") with one side corona-discharge-treated was prepared as the polypropylene film. An image was formed on the corona-discharge-treated side of the OPP film by gravure printing using a solvent-based gravure ink (Finart, manufactured by DIC Graphics).

[0360] As a sealant film, the first linear low-density polyethylene (Prime Polymer Co., Ltd., SP2520, density: 0.925 g / cm 3 , melting point: 122°C) and a second linear low-density polyethylene (Prime Polymer Co., Ltd., SP1520, density: 0.913 g / cm 3, melting point: 116°C) was extruded into a multilayer film by inflation molding to produce an unstretched polyethylene film (sealant film) 1 having a first linear low-density polyethylene layer with a thickness of 20 μm and a second linear low-density polyethylene layer with a thickness of 20 μm.

[0361] The MDOPE film, BOPE film, or OPP film was laminated with the barrier film via a 3.5 μm thick adhesive layer formed from a two-component curing urethane adhesive (manufactured by Rock Paint, trade name: RU-77T / H-7, solvent-based) so that the image-forming surface of the MDOPE film, BOPE film, or OPP film faced the (second) vapor-deposited film or second barrier coat layer-forming surface of the barrier film. The laminated barrier film and sealant film 1 were then laminated via a 3.5 μm thick adhesive layer formed from a two-component curing urethane adhesive (manufactured by Rock Paint, trade name: RU-77T / H-7, solvent-based) so that the first surface resin layer, first vapor-deposited film, or (first) barrier coat layer surface of the barrier film faced the first linear low-density polyethylene layer surface of the sealant film 1. A laminate was thus obtained.

[0362] <Extrusion lamination> As a sealant film, an unstretched polyethylene film (sealant film) 2 was produced in which the thickness ratio of each layer in the unstretched polyethylene film (sealant film) 1 was the same but the total thickness was changed to 25 μm.

[0363] AFFINITY PT 1450 (manufactured by Dow Chemical, polyolefin plastomer, density 0.902 g / cm 3 ) is applied to the surface of the first surface resin layer, the first vapor-deposited film, or the (first) barrier coat layer of the barrier film. 3 , MFR 8.5 g / 10 min) 70 mass% and NUCREL AE (Dow Chemical, ethylene-methacrylic acid-acrylate terpolymer, density 0.920 g / cm 3A blend of 30% by mass of a polyethylene terephthalate (PE) (MFR 10 g / 10 min, melting point 105°C) (hereinafter also referred to as "Blend A") was extruded at 270°C to form an extruded resin layer with a thickness of 20 μm, and the first linear low-density polyethylene layer surface of Sealant Film 2 was laminated through this extruded resin layer. Blend A was extruded at 270°C onto the surface of the (second) vapor-deposited film or second barrier coat layer of the laminated barrier film to form an extruded resin layer with a thickness of 17 μm, and the image-forming surface of an MDOPE film, BOPE film, or OPP film was laminated through this extruded resin layer. In this way, a laminate was obtained.

[0364] [Example 2] EVOH (Eval E171B) and Adhesive resin (Admer AT1955E) and LLDPE (Exceed XP8656ML) and LLDPE (Exceed XP8656ML) and Blended polyethylene (B), These were co-extruded by inflation molding, and the blended polyethylene (B) layers were pressed together at the nip to obtain a single film. The obtained film was then stretched 4 times in the machine direction (MD direction) using a stretching device to produce a stretched film having the thickness of each layer shown in each table. A barrier film was obtained in the same manner as in Example 1, except that this barrier film was used. A laminate was obtained in the same manner as in Example 1. In this specification, "←" in a table means that the composition of the layer in question is the same as the composition in the column to the left.

[0365] [Example 3] A blended polyethylene (C) was prepared by mixing 80 parts of LLDPE (Exceed XP8656ML) and 20 parts of a compatibilizer (RETAIN 3000).

[0366] EVOH (Eval E171B) and Adhesive resin (Admer AT1955E) and A blended polyethylene (A), a blended polyethylene (C); Blended polyethylene (B), The resulting mixture was co-extruded by inflation molding, and the blended polyethylene (B) layers were pressed together at the nip to obtain a single film. The resulting film was then stretched 4 times in the machine direction (MD) using a stretching device to produce a stretched film having the thickness of each layer shown in each table. A barrier film was obtained in the same manner as in Example 1, except that a laminate was obtained using this barrier film.

[0367] [Comparative Example 1] MDPE (ELITE 5538G) was extruded into a single layer by inflation molding, and the resulting film was stretched 4 times in the machine direction (MD) using a stretching device to produce a stretched polyethylene film with a thickness of 25 μm. A 30 nm thick aluminum (AL) vapor-deposited film was formed on each side of the stretched polyethylene film by PVD. In this way, a barrier film was obtained. A laminate was obtained in the same manner as in Example 1, except that this barrier film was used.

[0368] [Examples 4 to 8] Blend polyamide (A) was prepared by mixing 50 parts of PA6 (ULTRAMID B40) and 50 parts of MXD6 (MX Nylon S6007). Blend polyamide (B) was prepared by mixing 50 parts of crystalline semi-aromatic PA (MXD6; MX Nylon S6007) and 50 parts of amorphous semi-aromatic PA (Grivory G21). Barrier films and dry laminate-type laminates were obtained in the same manner as in Example 1, except that the resin materials constituting the first and second surface resin layers were changed to PA6 (ULTRAMID B40), blend polyamide (A), MXD6 (MX nylon S6007), blend polyamide (B), or amorphous semi-aromatic PA (Grivory G21), as shown in the table below.

[0369] [Gas barrier property evaluation] The oxygen permeability (cc / (m) of the laminates (hereinafter also referred to as "test pieces") of the examples and comparative examples was 2 ·day·atm)) and water vapor permeability (g / (m 2 The results are shown in the tables below.

[0370] <Oxygen permeability> The oxygen permeability of the test piece was measured in an environment of a temperature of 23°C and a humidity of 90% RH in accordance with JIS K7126-2:2006 using an oxygen permeability measuring device (OX-TRAN2 / 20 manufactured by MOCON). The evaluation criteria are as follows: A1: Oxygen permeability is less than 0.1. A: Oxygen permeability is 0.1 or more and less than 0.2. B: Oxygen permeability is 0.2 or more and less than 0.3. C: Oxygen permeability is 0.3 or more and less than 0.6. D: Oxygen permeability is 0.6 or more and less than 1.0. E: Oxygen permeability is 1.0 or more and less than 1.0. F: Oxygen permeability is 10 or more.

[0371] <Water vapor permeability> Using a water vapor transmission rate measuring device (MOCON, PERMATRAN-w 3 / 33), the water vapor transmission rate of the test specimens was measured in an environment of a temperature of 40°C and a humidity of 90% RH in accordance with JIS K7129-2:2019. The evaluation criteria are as follows: A1: The water vapor permeability is less than 0.1. A: The water vapor permeability is 0.1 or more and less than 0.2. B: The water vapor permeability is 0.2 or more and less than 0.3. C: The water vapor permeability is 0.3 or more and less than 0.6. D: Water vapor permeability is 0.6 or more and less than 1.0. E: The water vapor permeability is 1.0 or more and less than 10. F: Water vapor permeability is 10 or more.

[0372] [Polyolefin content] The polyethylene content of the laminates obtained by dry lamination using the MDOPE film or BOPE film in Examples 1 to 8 was 80% by mass or more and less than 90% by mass. The polyethylene content of the laminates obtained by extrusion lamination using the MDOPE film or BOPE film in Examples 1 to 3 was 90% by mass or more. The polyolefin content of the laminates obtained by dry lamination using an OPP film in Examples 1 to 8 was 80% by mass or more and less than 90% by mass.The polyolefin content of the laminates obtained by extrusion lamination using an OPP film in Examples 1 to 3 was 90% by mass or more.

[0373] [Seal strength] A test piece having a width of 15 mm and a length of 100 mm was cut out from each of the laminates obtained in the Examples and Comparative Examples. Two test pieces were overlapped with the heat seal layers facing each other, and the test pieces were subjected to a heat seal test at a temperature of 160°C and a pressure of 1 kgf / cm using a heat seal tester. 2 A 15 mm x 15 mm portion of one end of the test piece was heat-sealed under conditions of 100 mm, 100 mm pressure, and 1 second crimping time to form a sealed portion, yielding a test specimen. Except for the following test conditions, the seal strength (N / 15 mm width) was measured in accordance with JIS Z1707:2019 using a benchtop tensile / compression testing machine MCT-1150 (manufactured by AND Co.) under the following conditions: chuck distance: 100 mm, peel mode: T-peel, and test speed: 300 mm / min. Specifically, the test specimen was opened 180 degrees so that the sealed portion of the specimen was centered between the two grips of the tester, and both ends of the specimen were attached to the two grips of the tester. The specimen was then pulled at a speed of 300 mm / min until the sealed portion broke, and the maximum strength (N) was determined. The maximum strength (N) measured for the 15 mm wide test specimen was taken as the heat seal strength (N / 15 mm width). The seal strength of the laminates obtained by dry lamination in Examples 1 to 8 was about 4.5 N / 15 mm.The seal strength of the laminates obtained by extrusion lamination in Examples 1 to 3 was about 4.0 N / 15 mm.

[0374] [Making small bags] Two laminates obtained in each Example or Comparative Example were overlapped with the heat seal layers facing each other, and tested at a temperature of 160°C and a pressure of 1 kgf / cm using a heat seal tester. 2 The pouch was heat-sealed under the conditions of 1 second crimping time and 5 mm seal width to prepare a small pouch with an opening measuring 100 mm x 80 mm. 20 mL of water was poured into the opening, and the opening was then heat-sealed under the same conditions.

[0375] [Table 1]

[0376] [Table 2]

[0377] As a sealant film, First, LLDPE (Prime Polymer, SP2020, density: 0.916 g / cm 3 , melting point: 114℃, MFR: 2.3g / 10min, C6-LLDPE) Second LLDPE (Prime Polymer, SP2520, density: 0.925 g / cm 3 , melting point: 118℃, MFR: 1.9g / 10min, C6-LLDPE) The third LLDPE (Prime Polymer, SP0510, density: 0.903 g / cm 3 , melting point: 89℃, MFR: 1.2g / 10min, C6-LLDPE) The resulting mixture was subjected to multi-layer extrusion molding to produce an unstretched polyethylene film (sealant film) 3 having a first LLDPE layer with a thickness of 10 μm, a second LLDPE layer with a thickness of 20 μm, and a third LLDPE layer with a thickness of 10 μm. A laminate and a small pouch were produced in the same manner as in the dry lamination example described above, except for using the sealant film 3. Here, the sealant film 3 was arranged so that the third LLDPE layer was one of the surface layers of the laminate. The gas barrier properties of the laminate were comparable to those of the laminate having the same configuration except for the sealant film.

[0378] As a sealant film, an unstretched polyethylene film (sealant film) 4 was produced in which the thickness ratio of each layer in the unstretched polyethylene film (sealant film) 3 was the same as that of the unstretched polyethylene film (sealant film) 3, but the total thickness was changed to 25 μm. A laminate and a small pouch were produced in the same manner as in the above-mentioned extrusion lamination example, except that sealant film 4 was used. Here, sealant film 4 was positioned so that the third LLDPE layer was one of the surface layers of the laminate. The gas barrier properties of the laminate were comparable to those of the laminate having the same configuration except for the sealant film. [Explanation of symbols]

[0379] 1. Barrier layer (barrier film) 2. Laminate 10 polyethylene layers 20 Surface resin layer 30 Adhesive resin layer 40 Vapor-deposited film 60 Adhesive layer 70 Polyolefin base layer 80 Heat seal layer

Claims

1. A laminate comprising at least a heat seal layer and a barrier layer, The heat seal layer contains polyethylene as a main component, the barrier layer comprises at least a stretched film and a vapor-deposited film, the stretched film comprises a first surface resin layer, a polyethylene layer, and a second surface resin layer in this order, the polyethylene layer containing polyethylene as a main component, and the second surface resin layer is a layer containing a gas barrier resin as a main component, or a layer containing polyethylene and an adhesive resin, provided that when adjacent layers constituting the stretched film have the same resin composition and are indistinguishable from each other, the adjacent layers may be integrated to form a single layer; the vapor-deposited film is provided at least on the surface of the second surface resin layer of the stretched film; Laminate.

2. The first surface resin layer is A layer containing a gas barrier resin as a main component, or Layer containing polyethylene and adhesive resin The laminate according to claim 1 ,

3. 2. The laminate according to claim 1, wherein the first surface resin layer and the second surface resin layer each independently contain an ethylene-vinyl alcohol copolymer or a polyamide as a main component.

4. The laminate according to claim 3, wherein the stretched film further comprises a first adhesive resin layer between the first surface resin layer and the polyethylene layer, and a second adhesive resin layer between the polyethylene layer and the second surface resin layer.

5. 5. The laminate according to claim 4, wherein the stretched film is a stretched film of a base film comprising the first surface resin layer, the first adhesive resin layer, the 3a polyethylene layer, the 2a polyethylene layer, the 1a polyethylene layer, the 1b polyethylene layer, the 2b polyethylene layer, the 3b polyethylene layer, the second adhesive resin layer, and the second surface resin layer in this order, provided that when adjacent layers constituting the film have the same resin composition and are indistinguishable from each other, the adjacent layers may be integrated to form a single layer.

6. the 3a polyethylene layer contains linear low-density polyethylene, the 2a polyethylene layer contains linear low-density polyethylene as a main component, the 1a polyethylene layer contains polyethylene plastomer as a main component, the 1b polyethylene layer contains polyethylene plastomer as a main component, the second polyethylene layer (b) contains linear low-density polyethylene as a main component, The third polyethylene layer contains a linear low-density polyethylene. The laminate according to claim 5 .

7. 7. The laminate of claim 6, wherein the polyethylene plastomer has a melting point of 115°C or less.

8. The laminate of claim 1 , wherein at least one of the polyethylene layers further comprises a compatibilizer.

9. The laminate according to claim 1 , wherein the thickness of the surface resin layer of the stretched film is 0.5 μm or more and 10 μm or less.

10. The laminate according to claim 1 , wherein the vapor-deposited film provided on the surface of the second surface resin layer of the stretched film is a vapor-deposited metal film or an inorganic oxide film.

11. 3. The laminate according to claim 2, wherein the barrier layer comprises, as the vapor deposition films, a first vapor deposition film provided on the surface of the first surface resin layer of the stretched film and a second vapor deposition film provided on the surface of the second surface resin layer of the stretched film.

12. The laminate according to claim 11, wherein the first vapor-deposited film and the second vapor-deposited film are each independently a metal vapor-deposited film, or the first vapor-deposited film is a metal vapor-deposited film and the second vapor-deposited film is an inorganic oxide vapor-deposited film, or the first vapor-deposited film is an inorganic oxide vapor-deposited film and the second vapor-deposited film is a metal vapor-deposited film or an inorganic oxide vapor-deposited film.

13. The laminate according to claim 12 , wherein the first vapor-deposited film is an alumina vapor-deposited film, a silica vapor-deposited film, or a silicon carbide oxide vapor-deposited film, and the second vapor-deposited film is an aluminum vapor-deposited film.

14. The laminate according to claim 12 , wherein the first vapor-deposited film and the second vapor-deposited film are each independently an alumina vapor-deposited film, a silica vapor-deposited film, or a silicon carbide oxide vapor-deposited film.

15. The laminate further comprises a polyethylene substrate layer or a polypropylene substrate layer, The polyethylene base layer contains polyethylene as a main component, The polypropylene base layer contains polypropylene as a main component, the barrier layer is disposed such that the first surface resin layer faces the heat seal layer side and the second surface resin layer faces the base material layer side, and the vapor-deposited film is provided at least on a surface of the second surface resin layer of the stretched film. The laminate according to claim 1 .

16. 16. The laminate of claim 15, wherein the laminate further comprises a first adhesive layer between the heat seal layer and the barrier layer, and a second adhesive layer between the barrier layer and the substrate layer.

17. 17. The laminate of claim 16, wherein the first adhesive layer and the second adhesive layer are each independently an adhesive layer or an extruded resin layer.

18. The laminate according to claim 17 , wherein the first adhesive layer and the second adhesive layer are each independently an adhesive layer formed of a solvent-based or solventless adhesive.

19. The laminate according to claim 17 , wherein the first adhesive layer and the second adhesive layer are each independently an extruded resin layer containing polyethylene as a main component.

20. 18. The laminate according to claim 17, wherein the first adhesive layer and the second adhesive layer are each independently an extruded resin layer containing a polyolefin plastomer and an acid group-containing polyethylene.

21. The laminate according to claim 1 , wherein the polyolefin content in the entire laminate is 80% by mass or more.

22. The laminate according to any one of claims 1 to 21, a seal portion where the heat seal layers of the laminate are joined together; a storage section for storing contents; A packaging container having the above structure.

23. 23. The packaging container of claim 22, which is a pouch.

Images