Laminate and packaging container

Abstract

To provide a laminate which is useful as a packaging material for manufacturing a packaging container excellent in recyclability and gas barrier property.SOLUTION: A laminate includes at least a first heat seal layer containing polyolefin as a main component, a barrier layer, and a second heat seal layer containing polyolefin as a main component in this order, wherein the barrier layer includes at least a stretched film and a vapor-deposited film, the stretched film contains at least a polyolefin layer containing polyolefin as a main component, and a surface resin layer which contains a gas barrier resin as a main component or contains polyolefin and an adhesive resin, wherein the vapor-deposited film is provided at least on the 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, in this order, at least a first heat seal layer containing polyolefin as a main component, a barrier layer, and a second heat seal layer containing polyolefin as a main component; the barrier layer comprises at least a stretched film and a vapor-deposited film; the stretched film comprises at least a polyolefin layer containing polyolefin as a main component and a surface resin layer containing a gas barrier resin as a main component or containing polyolefin and an adhesive resin; and the vapor-deposited film is provided at least on the 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, in particular a laminate for producing the body of a tube container body. [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 barrier film. [Figure 8] FIG. 8 is a schematic cross-sectional view showing one embodiment of a barrier film. [Figure 9A] FIG. 9A is a schematic cross-sectional view showing one embodiment of a barrier film. [Figure 9B] FIG. 9B is a schematic cross-sectional view showing one embodiment of a barrier film. [Figure 9C] FIG. 9C is a schematic cross-sectional view showing one embodiment of a barrier film. [Figure 10] FIG. 10 is a schematic cross-sectional view showing one embodiment of a barrier film. [Figure 11] FIG. 11 is a schematic cross-sectional view showing one embodiment of a barrier film. [Figure 12] FIG. 12 is a schematic cross-sectional view showing one embodiment of a laminate. [Figure 13] FIG. 13 is a perspective view showing one embodiment of a tube container comprising a tube container body including a laminate and a cap. [Figure 14] FIG. 14 is a cross-sectional view taken along the line AA in FIG. 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, 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.

[0013] 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.

[0014] In this specification, examples of polyethylene include high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, ethylene-vinyl acetate copolymer, and ethylene-(meth)acrylic acid ester copolymer.

[0015] 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.

[0016] 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.

[0017] In this specification, the density of polyethylene is as follows: The density of the high density polyethylene is preferably 0.945 g / cm 3 The upper limit of the density of high density polyethylene is, for example, 0.965 g / cm 3 and preferably 0.960 g / cm 3The density of the medium density polyethylene is preferably 0.930 g / cm 3 Exceeds 0.945g / cm 3 The density of the low density polyethylene is preferably 0.860 g / cm or less. 3 More than 0.930g / cm 3 or less, more preferably 0.900 g / cm 3 More than 0.930g / cm 3 The density of the linear low density polyethylene is preferably 0.860 g / cm 3 More than 0.930g / cm 3 or less, more preferably 0.900 g / cm 3 More than 0.930g / cm 3 The density is 0.900 g / cm or less. 3 less than 0.860 g / cm 3 More than 0.900g / cm 3 Polyethylene having a density of less than 0.900 g / cm is sometimes referred to as ultra-low density polyethylene, and in this case, the density of the low density polyethylene is preferably 0.900 g / cm 3 More than 0.930g / cm 3 The density of the linear low density polyethylene is preferably 0.900 g / cm or less. 3 More than 0.930g / cm 3 In this specification, the density of polyethylene is measured in accordance with JIS K7112-2:2023 (density gradient tube method, 23°C).

[0018] 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.

[0019] Examples of linear low-density polyethylene include ethylene-α-olefin copolymers. Examples of the α-olefin include the above-mentioned α-olefins having from 3 to 20 carbon atoms, preferably α-olefins having from 3 to 8 carbon atoms, and more preferably α-olefins having from 4 to 8 carbon atoms. Examples of linear low-density polyethylene include ethylene-1-butene copolymer (C4-LLDPE) in which the comonomer is at least 1-butene, ethylene-1-hexene copolymer (C6-LLDPE) in which the comonomer is at least 1-hexene, and ethylene-1-octene copolymer (C8-LLDPE) in which the comonomer is at least 1-octene. In these copolymers, the comonomer is not limited to the above-mentioned comonomers, and additional comonomers may be used. For example, linear low-density polyethylene produced using a metallocene catalyst is preferred.

[0020] 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.

[0021] In this specification, 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 in all repeating structural units may be, for example, 50 mol% or more, 60 mol% or more, 70 mol% or more, 80 mol% or more, or 90 mol% or more. The above content is measured by NMR.

[0022] 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. Examples of the α-olefin include α-olefins having 2 to 20 carbon atoms other than propylene. Specific examples include 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. Ethylene, 1-butene, 1-pentene, and 1-hexene are preferred.

[0023] In this specification, the density of polypropylene is, for example, 0.88 g / cm 3 More than 0.92g / cm 3 In this specification, the density of polypropylene is measured in accordance with JIS K7112-2:2023 (density gradient tube method, 23°C).

[0024] In this specification, from the viewpoint of film-forming ability and processability, the melt flow rate (MFR) of the polyethylene is preferably 0.1 g / 10 min or more, more preferably 0.2 g / 10 min or more, even more preferably 0.3 g / 10 min or more, particularly preferably 0.5 g / 10 min or more, and is preferably 30 g / 10 min or less, more preferably 20 g / 10 min or less, even more preferably 10 g / 10 min or less, particularly preferably 5 g / 10 min or less, for example, 0.1 g / 10 min or more and 30 g / 10 min or less. Such an MFR is preferred as the MFR of the polyethylene in, for example, an inflation method or in the stretched film (X) described below. In this specification, the MFR of the 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.

[0025] In this specification, the melt flow rate (MFR) of polyolefins such as polyethylene and polypropylene 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, from the viewpoint of film-forming and processability, and is preferably 50 g / 10 min or less, more preferably 30 g / 10 min or less, even more preferably 10 g / 10 min or less, and particularly preferably 6 g / 10 min or less, for example, 0.1 g / 10 min or more and 50 g / 10 min or less. Such an MFR is preferred as the MFR of polyolefins in, for example, the T-die casting method and the stretched film (Y) described below. In this specification, the MFR of polyolefins 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 polyolefin, and is 190°C for polyethylene and 230°C for polypropylene.

[0026] 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.

[0027] In this specification, "film" and "sheet" may be referred to, but "film" and "sheet" are not distinguished from each other solely on the basis of the difference in name. In this specification, "multilayer" means two or more layers. In this specification, when adjacent layers constituting a film have the same resin composition and are indistinguishable from each other, the adjacent layers may be integrated to form a single layer.

[0028] 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.

[0029] [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. In one embodiment, the stretched film comprises at least a polyolefin layer containing polyolefin as a main component; a surface resin layer containing a gas barrier resin as a main component or containing a polyolefin and an adhesive resin; Equipped with. The vapor-deposited film is provided at least on the surface resin layer of the stretched film.

[0030] In one embodiment, the base film and the stretched film obtained by stretching the base film comprise a first surface resin layer, a polyolefin layer, and a second surface resin layer, in this order. The polyolefin layer contains polyolefin 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 polyolefin and an adhesive resin.

[0031] 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." In the following description, a surface resin layer containing a gas barrier resin as a main component will also be referred to as "surface resin layer (G)," and a surface resin layer containing a polyolefin (e.g., polyethylene or polypropylene) and an adhesive resin will also be referred to as "surface resin layer (AH)."

[0032] The base film and the stretched film have a first surface and a second surface opposite to the first surface. The first surface resin layer constitutes the first surface of the stretched film. The second surface resin layer constitutes the second surface of the stretched film. 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.

[0033] In one embodiment, the barrier layer comprises: a first vapor-deposited film; A stretched film; a second deposited film; are provided in this order in the stacking direction (hereinafter also referred to simply as "provided in this order"). Such barrier layers are provided with vapor-deposited films on both sides of the stretched film, and therefore can suppress deterioration of gas barrier properties due to pinholes. In this embodiment, the first vapor-deposited film is provided on the first side of the stretched film, i.e., on the surface of the first surface resin layer, and the second vapor-deposited film is provided on the second side of the stretched film, i.e., on the surface of the second surface resin layer.

[0034] In one embodiment, the barrier layer comprises: A stretched film; a first vapor-deposited film; a second deposited film; In this embodiment, the first and second vapor-deposited films are provided on the second surface of the stretched film, i.e., on the surface of the second surface resin layer.

[0035] The base film and the stretched film have a multilayer structure of two or more layers or 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 two or more or three or more layers, preferably fourteen or fewer layers, more preferably twelve or fewer layers, for example, two 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 two or more or three or more layers, preferably nine or fewer layers, more preferably seven or fewer layers, for example, two or more and nine or fewer layers. Specifically, the base film and the stretched film have three, five, seven, or nine layers. In the present 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.

[0036] The base film and the stretched film may have two or more polyolefin layers. The base film and the stretched film may further have a first adhesive resin layer between the first surface resin layer and the polyolefin layer. The base film and the stretched film may further have a second adhesive resin layer between the polyolefin 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."

[0037] Examples of stretched films include the stretched films of the first to fourth embodiments. In the following description, when referring to matters common to the stretched films of the first to fourth embodiments, they may be simply referred to as "stretched film." Barrier layers provided with such stretched films of the first to fourth embodiments are also referred to as barrier layers of the first to fourth embodiments, respectively.

[0038] The stretched film of the first embodiment is a first surface resin layer containing a gas barrier resin as a main component; a polyolefin layer containing polyolefin as a main component; a second surface resin layer containing a gas barrier resin as a main component; In this order, at least

[0039] In one embodiment, the stretched film of the first aspect comprises: a first surface resin layer containing a gas barrier resin as a main component; a polypropylene layer containing polypropylene as a main component; a second surface resin layer containing a gas barrier resin as a main component; The polypropylene-based stretched film comprises at least the above in this order. In one embodiment, the stretched film of the first aspect comprises: 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; The polyethylene-based stretched film comprises at least the above in this order.

[0040] The stretched film of the second embodiment is a first surface resin layer containing a polyolefin and an adhesive resin; a polyolefin layer containing polyolefin as a main component; a second surface resin layer containing a polyolefin and an adhesive resin; In this order, at least

[0041] In one embodiment, the stretched film of the second aspect comprises: a first surface resin layer containing polypropylene and an adhesive resin; a polypropylene layer containing polypropylene as a main component; a second surface resin layer containing polypropylene and an adhesive resin; The polypropylene-based stretched film comprises at least the above in this order. In one embodiment, the stretched film of the second aspect comprises: 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; The polyethylene-based stretched film comprises at least the above in this order.

[0042] The stretched film of the third embodiment is a first surface resin layer containing a polyolefin and an adhesive resin; a polyolefin layer containing polyolefin as a main component; a second surface resin layer containing a gas barrier resin as a main component; In this order, at least

[0043] In one embodiment, the stretched film of the third aspect comprises: a first surface resin layer containing polypropylene and an adhesive resin; a polypropylene layer containing polypropylene as a main component; a second surface resin layer containing a gas barrier resin as a main component; The polypropylene-based stretched film comprises at least the above in this order. In one embodiment, the stretched film of the third aspect comprises: 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; The polyethylene-based stretched film comprises at least the above in this order.

[0044] The stretched film of the fourth embodiment is a first surface resin layer containing a gas barrier resin as a main component; a polyolefin layer containing polyolefin as a main component; a second surface resin layer containing a polyolefin and an adhesive resin; In this order, at least

[0045] In one embodiment, the stretched film of the fourth aspect comprises: a first surface resin layer containing a gas barrier resin; a polypropylene layer containing polypropylene as a main component; a second surface resin layer containing polypropylene and an adhesive resin as main components; The polypropylene-based stretched film comprises at least the above in this order. In one embodiment, the stretched film of the fourth aspect comprises: a first surface resin layer containing a gas barrier resin; a polyethylene layer containing polyethylene as a main component; a second surface resin layer containing polyethylene and an adhesive resin as main components; The polyethylene-based stretched film comprises at least the above in this order.

[0046] The stretched film of the first embodiment may include a first surface resin layer, a first adhesive resin layer, a polyolefin 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 polyolefin 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 polyolefin layer, and a second surface resin layer in this order. The stretched film of each embodiment may have two or more polyolefin layers.

[0047] 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.

[0048] The stretched film of the first aspect may be a stretched film comprising, in this order, a first surface resin layer, a first adhesive resin layer, a polyolefin layer, a second adhesive resin layer, and a second surface resin layer, which has excellent heat resistance and can suppress curling, for example.

[0049] In the stretched film of the first aspect, the thickness of the polyolefin layer is preferably 40% or more, more preferably 50% or more, even more preferably 60% or more, and preferably 90% or less, more preferably 85% or less, even more preferably 80% or less, of the thickness of the stretched film, for example, 40% or more and 90% or less.

[0050] In the above stretched film of the first aspect, the thickness of the first and second adhesive resin layers is, independently of each other, 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, particularly preferably 10% or less, relative to the thickness of the stretched film, for example, 2% or more and 25% or less.

[0051] In the above stretched film of the first aspect, the ratio of the thickness of the first adhesive resin layer to the thickness of the second adhesive 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 viewpoint of symmetry of the stretched film and suppression of curling.

[0052] The stretched film of the second embodiment may be a stretched film having a first surface resin layer, a first polyolefin layer, a second polyolefin layer, a third polyolefin layer, and a second surface resin layer in this order. The stretched film of this embodiment can suppress the occurrence of curling. The compositions of the first to third polyolefin layers may be the same as or different from each other. The thicknesses of the first to third polyolefin layers may be the same as or different from each other.

[0053] In the stretched film of the second embodiment, the thickness of the second polyolefin layer is preferably 40% or more, more preferably 50% or more, even more preferably 60% or more, and preferably 90% or less, more preferably 85% or less, even more preferably 80% or less, of the thickness of the stretched film, for example, 40% or more and 90% or less.

[0054] In the stretched film of the second embodiment, the thicknesses of the first and third polyolefin layers are each independently, relative to the thickness of the stretched film, 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, particularly preferably 10% or less, for example, 2% or more and 25% or less.

[0055] In the stretched film of the second embodiment, the ratio of the thickness of the first polyolefin layer to the thickness of the third polyolefin 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.

[0056] The stretched film of the third embodiment may be a stretched film comprising a first surface resin layer, a first polyolefin layer, a second polyolefin layer, an adhesive resin layer, and a second surface resin layer in this order. The stretched film of the fourth embodiment may be a stretched film comprising a first surface resin layer, an adhesive resin layer, a second polyolefin layer, a first polyolefin layer, and a second surface resin layer in this order. In the stretched films of the third and fourth embodiments, the compositions of the first and second polyolefin layers may be the same or different from each other, and the thicknesses of the first and second polyolefin layers may be the same or different from each other.

[0057] In the stretched films of the third and fourth aspects, the thickness of the second polyolefin layer is preferably 40% or more, more preferably 50% or more, even more preferably 60% or more, and preferably 90% or less, more preferably 85% or less, even more preferably 80% or less, of the thickness of the stretched film, for example, 40% or more and 90% or less.

[0058] In the above-mentioned stretched films of the third and fourth aspects, the thickness of the first polyolefin layer and the adhesive resin layer is, independently of each other, 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, particularly preferably 10% or less, relative to the thickness of the stretched film, for example, 2% or more and 25% or less.

[0059] In the above-mentioned stretched films of the third and fourth aspects, the ratio of the thickness of the first polyolefin layer to the thickness of the adhesive 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 viewpoint of symmetry of the stretched film and suppression of curling.

[0060] Examples of stretched films include stretched films (X) and (Y), which will be described below. In the following description, when referring to matters common to stretched films (X) and (Y), they may be simply referred to as "stretched films." In the following description, stretched films (X) and (Y) having a surface resin layer (G) are also referred to as "stretched films of the fifth embodiment," and stretched films (X) and (Y) having a surface resin layer (AH) are also referred to as "stretched films of the sixth embodiment." Barrier layers comprising such stretched films of the fifth and sixth embodiments are also referred to as barrier layers of the fifth and sixth embodiments, respectively.

[0061] The stretched film (X) comprises at least a polyethylene layer containing polyethylene as a main component; a surface resin layer containing a gas barrier resin as a main component or containing polyethylene and an adhesive resin; Equipped with. The stretched film (X) may have two or more polyethylene layers.

[0062] In one embodiment, the stretched film (X) 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 a gas barrier resin as a main component or containing polyethylene and an adhesive resin; are provided in this order in the stacking direction. The stretched film (X) may have two or more polyethylene intermediate layers.

[0063] The stretched film (Y) comprises at least a polyolefin layer containing polyolefin as a main component; a surface resin layer containing a gas barrier resin as a main component or containing a polyolefin and an adhesive resin; Equipped with. The stretched film (Y) may have two or more polyolefin layers.

[0064] In one embodiment, the stretched film (Y) comprises at least a first surface resin layer containing polyolefin as a main component; a polyolefin intermediate layer containing polyolefin as a main component; a second surface resin layer containing a gas barrier resin as a main component or containing a polyolefin and an adhesive resin; are provided in this order in the stacking direction. The stretched film (Y) may have two or more polyolefin intermediate layers.

[0065] In one embodiment, the stretched films (X) and (Y) of the fifth aspect comprise 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 a gas barrier resin as a main component; It is a polyethylene-based stretched film having the above in this order. In one embodiment, the stretched film (Y) of the fifth aspect comprises: a first surface resin layer containing polypropylene as a main component; a polypropylene intermediate layer containing polypropylene as a main component; a second surface resin layer containing a gas barrier resin as a main component; It is a polypropylene-based stretched film having the above in this order.

[0066] In one embodiment, the stretched films (X) and (Y) of the sixth aspect have 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 and an adhesive resin; It is a polyethylene-based stretched film having the above in this order. In one embodiment, the stretched film (Y) of the sixth aspect comprises at least a first surface resin layer containing polypropylene as a main component; a polypropylene intermediate layer containing polypropylene as a main component; a second surface resin layer containing polypropylene and an adhesive resin; It is a polypropylene-based stretched film having the above in this order.

[0067] In one embodiment, the stretched film (Y) of the fifth or sixth aspect 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 a gas barrier resin as a main component or containing polyethylene and an adhesive resin; A polyethylene-based stretched film comprising the following in this order: The polyethylene in at least one layer selected from the group consisting of the first surface resin layer, the polyethylene intermediate layer, and the second surface resin layer before the stretching treatment contains at least one polyethylene selected from the group consisting of high-density polyethylene and medium-density polyethylene, or has a viscosity of 0.930 g / cm 3 Super 0.960g / cm 3 It has the following density:

[0068] The stretched film of the fifth aspect may further comprise an adhesive resin layer between the polyolefin layer and the surface resin layer (G). In one embodiment, the stretched film of the fifth aspect may comprise, in this order, a first polyolefin layer as the first surface resin layer, a second polyolefin layer, a third polyolefin layer, an adhesive resin layer, and a surface resin layer (G) as the second surface resin layer. Hereinafter, the stretched film of this embodiment will also be referred to as "stretched film α." The compositions of the first to third polyolefin layers may be the same as or different from each other. The thicknesses of the first to third polyolefin layers may be the same as or different from each other. In the case of the stretched film (X), the polyolefin layer is referred to as a polyethylene layer.

[0069] In one embodiment, the stretched film of the sixth aspect may include, in this order, a first polyolefin layer as the first surface resin layer, a second polyolefin layer, a third polyolefin layer, a fourth polyolefin layer, and a surface resin layer (AH) as the second surface resin layer. Hereinafter, the stretched film of this embodiment will also be referred to as a "stretched film β." The compositions of the first to fourth polyolefin layers may be the same as or different from one another. The thicknesses of the first to fourth polyolefin layers may be the same as or different from one another. In the case of the stretched film (X), the polyolefin layer is referred to as a polyethylene layer.

[0070] The polyolefin (e.g., polyethylene or polypropylene) 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 75% by mass or more, and particularly preferably 80% by mass or more, 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.

[0071] 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. The biaxial stretching treatment may be sequential biaxial stretching treatment using a tenter frame method or the like, or simultaneous biaxial stretching treatment. When stretching in the longitudinal direction (film flow direction, machine direction, MD direction), the stretching ratio is preferably 2 times or more, more preferably 3 times or more, and preferably 15 times or less, more preferably 10 times or less, and may be, for example, 7 times or less, for example, 2 times or more and 15 times or less. When stretching in the transverse direction (direction perpendicular to the MD direction, width 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, and may be, for example, 7 times or less, for example, 2 times or more and 15 times or less.

[0072] The stretched film is, for example, a uniaxially stretched film, specifically a film uniaxially stretched in the MD direction (MDO film). The stretched film is, for example, a biaxially stretched film, specifically a film biaxially stretched in the MD direction and the TD direction. In one embodiment, the stretched film (X) is a uniaxially stretched film, specifically a film uniaxially stretched in the MD direction (MDO film). In one embodiment, the stretched film (Y) is a biaxially stretched film, specifically a film biaxially stretched in the MD direction and the TD direction.

[0073] 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.

[0074] 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 film-forming methods include inflation and T-die casting, and in the case of the stretched film (X), the inflation method is preferred, while in the case of the stretched film (Y), the T-die casting method is preferred from the viewpoint of productivity. In the inflation method, stretching can be carried out after film formation.

[0075] 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 of a material constituting the polyolefin 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 (G) or (AH) by an inflation method, T-die casting method, or the like, and then stretching the resulting laminated film.

[0076] 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.

[0077] An embodiment of the co-extrusion T-die casting method will be described below: Materials for forming each layer are fed to each extruder, and co-extrusion T-die casting is performed to obtain a laminated film.

[0078] A manufacturing example of the stretched film (Y) of the fifth embodiment will be described. In the case of a polyethylene-based stretched film, for example, in each extruder, the extrusion temperature for the first surface resin layer, the extrusion temperature for the polyethylene intermediate layer, the extrusion temperature for the adhesive resin layer, and the extrusion temperature for the second surface resin layer containing an ethylene-vinyl alcohol copolymer are each set to 220°C or higher and 240°C or lower. In the case of a polyethylene-based stretched film, for example, in each extruder, the extrusion temperature for the first surface resin layer is set to 220°C or higher and 260°C or lower, the extrusion temperature for the polyethylene intermediate layer is set to 220°C or higher and 260°C or lower, the extrusion temperature for the adhesive resin layer is set to 220°C or higher and 270°C or lower, and the extrusion temperature for the second surface resin layer containing polyamide is set to 260°C or higher and 280°C or lower.

[0079] A manufacturing example of the stretched film (Y) of the fifth embodiment will be described. In the case of a polypropylene-based stretched film, for example, in each extruder, the extrusion temperature for the first surface resin layer is set to 260°C or higher and 280°C or lower, the extrusion temperature for the polypropylene intermediate layer is set to 260°C or higher and 280°C or lower, the extrusion temperature for the adhesive resin layer is set to 250°C or higher and 270°C or lower, and the extrusion temperature for the second surface resin layer containing an ethylene-vinyl alcohol copolymer is set to 220°C or higher and 240°C or lower. In the case of a polypropylene-based stretched film, for example, in each extruder, the extrusion temperature for the first surface resin layer is set to 260°C or higher and 280°C or lower, the extrusion temperature for the polypropylene intermediate layer is set to 260°C or higher and 280°C or lower, the extrusion temperature for the adhesive resin layer is set to 260°C or higher and 280°C or lower, and the extrusion temperature for the second surface resin layer containing a polyamide is set to 260°C or higher and 280°C or lower.

[0080] A manufacturing example of the stretched film (Y) of the sixth embodiment will be described. In the case of a polyethylene-based stretched film, for example, in each extruder, the extrusion temperature for the first surface resin layer, the extrusion temperature for the polyethylene intermediate layer, and the extrusion temperature for the second surface resin layer containing polyethylene and an adhesive resin are each set to 220°C or higher and 240°C or lower. In the case of a polypropylene-based stretched film, for example, in each extruder, the extrusion temperature for the first surface resin layer is set to 260°C or higher and 280°C or lower, the extrusion temperature for the polypropylene intermediate layer is set to 260°C or higher and 280°C or lower, and the extrusion temperature for the second surface resin layer containing polypropylene and an adhesive resin is set to 240°C or higher and 260°C or lower. These extrusion temperatures in the extruder are merely examples and can be changed as appropriate.

[0081] 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.

[0082] <Polyolefin layer> The polyolefin layer contains polyolefin as a main component. Examples of polyolefins include polyethylene, polypropylene, polybutene, and polymethylpentene. Among these, polyethylene and polypropylene are preferred. Examples of the polyolefin layer include a polyethylene layer containing polyethylene as a main component and a polypropylene layer containing polypropylene as a main component.

[0083] The content of polyolefin (for example, polyethylene or polypropylene) in the polyolefin 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.

[0084] The polyolefin layer may contain a resin material other than polyolefin, such as polyester, polyamide, (meth)acrylic resin, vinyl resin, cellulose resin, and ionomer resin.

[0085] The polyolefin 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.

[0086] (Polyethylene Layer in the First to Fourth Aspects) The polyethylene layer contains polyethylene as a main component. 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.

[0087] 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)).

[0088] The polyethylene layer in the stretched films 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 the 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 the transparency of the polyethylene from decreasing. When the stretched film has two or more polyethylene layers, at least one of the polyethylene layers 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 basis for the content of the compatibilizer is the total mass of all polyethylene layers.

[0089] 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.

[0090] The thickness of the polyethylene layer in the stretched films of the first to fourth aspects 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" means the sum of the thicknesses of the polyethylene layers.

[0091] The thickness of the polyethylene layer in the stretched films of the first to fourth aspects 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.

[0092] The stretched film may have one polyethylene layer or two or more polyethylene layers.

[0093] 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.

[0094] 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).

[0095] In one embodiment, the stretched film comprises a first surface resin layer, a polyethylene layer, and a second surface resin layer, in this order. The stretched film of the first aspect 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. Such a stretched film has, for example, excellent heat resistance and can suppress curling.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] Examples of the linear low-density polyethylene include C4-LLDPE, C6-LLDPE, and C8-LLDPE. These copolymers are not limited to the above comonomers, and additional comonomers may be used. For example, linear low-density polyethylene produced using a metallocene catalyst is preferred.

[0116] 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.

[0117] 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, of the total thickness of the polyethylene layers, for example, 5% or more and 25% or less. 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.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] 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.

[0122] 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.

[0123] 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.

[0124] 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.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] 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.

[0137] 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.

[0138] 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.

[0139] In one embodiment, the polyethylene layer in the first to fourth aspects is a layer containing at least one polyethylene selected from the group consisting of high-density polyethylene and medium-density polyethylene (hereinafter also referred to as "polyethylene layer (P)"). The polyethylene layer (P) preferably contains high-density polyethylene. A stretched film comprising such a polyethylene layer (P) is preferably a biaxially stretched film. The stretched film having the polyethylene layer (P) has high heat resistance, specifically, excellent resistance to heating during drying and heat sealing during printing, and excellent resistance to vapor deposition when vapor deposition is performed on the film. Furthermore, the polyethylene layer (P) has high rigidity, for example, and can increase the film conveying speed when vapor deposition is performed on the film, thereby improving productivity.

[0140] 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.

[0141] 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.

[0142] The high-density polyethylene and medium-density polyethylene are preferably the above-mentioned ethylene-α-olefin copolymers. Films containing such high-density polyethylene and / or medium-density polyethylene exhibit, for example, excellent biaxial stretchability, particularly excellent stretchability in the width direction. This is presumably because the side chains derived from the α-olefins prevent the film from tearing during stretching. The ethylene-α-olefin copolymer is preferably a polyethylene obtained by polymerizing ethylene and a small amount of α-olefins using a polymerization method using a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as a metallocene catalyst, and more preferably a polyethylene produced using a metallocene catalyst.

[0143] The density of the high density polyethylene is preferably 0.945 g / cm 3 Exceeds 0.960g / cm 3 The density of the medium density polyethylene is preferably 0.930 g / cm or less. 3 Exceeds 0.945g / cm 3The density can be adjusted, for example, by the amount of structural units derived from the α-olefin, which is the comonomer in the ethylene-α-olefin copolymer, introduced.

[0144] The polyethylene layer (P) may contain, for example, high-density polyethylene as a main component, medium-density polyethylene as a main component, or a mixture of high-density polyethylene and medium-density polyethylene as a main component. The polyethylene layer (P) may contain, for example, a mixture of high-density polyethylene and another polyethylene as a main component, a mixture of medium-density polyethylene and another polyethylene as a main component, or a mixture of high-density polyethylene, medium-density polyethylene, and another polyethylene as a main component. The main component being the above mixture means that the content of the above mixture in the polyethylene layer (P) is more than 50% by mass, and the content is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more. The high-density polyethylene may be, for example, an ethylene homopolymer, an ethylene-α-olefin copolymer, or a mixture thereof. The medium-density polyethylene may be, for example, an ethylene homopolymer, an ethylene-α-olefin copolymer, or a mixture thereof. The other polyethylene may be, for example, at least one selected from the group consisting of linear low-density polyethylene and high-pressure low-density polyethylene, and may be linear low-density polyethylene, high-pressure low-density polyethylene, or a mixture of linear low-density polyethylene and high-pressure low-density polyethylene.

[0145] From the viewpoint of heat resistance, the total content of high-density polyethylene and medium-density polyethylene in the polyethylene layer (P) is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, and may be 30% by mass or more, 35% by mass or more, or 40% by mass or more. The total content of high-density polyethylene and medium-density polyethylene in the polyethylene layer (P) is 100% by mass or less, and from the viewpoint of biaxial stretchability, it 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 (P) is, for example, 10% by mass or more and 100% by mass or less, and preferably 20% by mass or more and 60% by mass or less.

[0146] From the viewpoint of biaxial stretchability, the polyethylene layer (P) 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.

[0147] Examples of linear low-density polyethylene include ethylene-α-olefin copolymers, which have been described in detail above. Examples of linear low-density polyethylene include C4-LLDPE, C6-LLDPE, and C8-LLDPE. 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. The density of the linear low-density polyethylene is preferably 0.900 g / cm. 3 More than 0.930g / cm 3 The following is the result.

[0148] From the viewpoint of biaxial stretchability, the content of linear low-density polyethylene in the polyethylene layer (P) is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, and may be 30% by mass or more, 35% by mass or more, or 40% by mass or more. From the viewpoint of heat resistance, the content of linear low-density polyethylene in the polyethylene layer (P) is preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less, and may be 70% by mass or less, 65% by mass or less, or 60% by mass or less. The content of the linear low-density polyethylene in the polyethylene layer (P) 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.

[0149] (Polypropylene Layer in the First to Fourth Aspects) The polypropylene 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. Among these, homopolypropylene is preferred from the viewpoint of the heat resistance of the stretched film.

[0150] The polypropylene may be isotactic polypropylene, syndiotactic polypropylene, or atactic polypropylene. From the viewpoint of the heat resistance of the stretched film, isotactic polypropylene and syndiotactic polypropylene are preferred, and isotactic polypropylene is more preferred.

[0151] The melting point (Tm) of the polypropylene contained in the polypropylene layer is preferably 130°C or higher, more preferably 140°C or higher, even more preferably 150°C or higher, even more preferably 160°C or higher, particularly preferably 165°C or higher, and preferably 175°C or lower, for example, 130°C or higher and 175°C or lower, from the viewpoint of the strength and heat resistance of the stretched film.

[0152] (Polyethylene layer of stretched film (X)) The polyethylene layer of the stretched film (X) is, for example, a polyethylene intermediate layer located between the first and second surface resin layers of the stretched film (X), and / or the first surface resin layer.

[0153] The polyethylene layer contains polyethylene as a main component. From the viewpoints of the strength and heat resistance of the stretched film (X), high-density polyethylene and medium-density polyethylene are preferred. From the viewpoints of the film-forming and processability of the stretched film (X), linear low-density polyethylene and medium-density polyethylene are preferred.

[0154] 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, particularly preferably 120°C or higher, and preferably 140°C or lower, for example, 100°C or higher and 140°C or lower.

[0155] 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. The barrier layer can be suitably used as a substrate layer constituting packaging materials such as polyethylene-based mono-material packaging materials.

[0156] The polyethylene layer may contain the above-mentioned resin material other than polyethylene. The polyethylene layer may contain the above-mentioned additive. In the stretched film (X) of the fifth aspect, the polyethylene layer may further contain the above-mentioned compatibilizer.

[0157] 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 (X) has two or more polyethylene layers, at least one polyethylene layer may contain a compatibilizer. When the stretched film (X) has two or more polyethylene layers, the content of the compatibilizer is based on the total mass of all polyethylene layers.

[0158] 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 in the stretched film (X). For example, when the gas barrier resin is an ethylene-vinyl alcohol copolymer, the content of the compatibilizer in the polyethylene layer is preferably 100 parts by mass or more and 200 parts by mass or less per 100 parts by mass of the ethylene-vinyl alcohol copolymer in the stretched film (X). For example, when the gas barrier resin is a polyamide, the content of the compatibilizer in the polyethylene layer is preferably 25 parts by mass or more and 100 parts by mass or less per 100 parts by mass of the polyamide in the stretched film (X).

[0159] The thickness of the polyethylene layer in the stretched film (X) and the polyolefin layer in the stretched film (Y) described below 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. When the stretched film (X) has two or more polyethylene layers, the above "thickness" means the total thickness of the polyethylene layers. The same applies to the stretched film (Y).

[0160] The thickness of the polyethylene layer or polyolefin layer is preferably 40% or more, more preferably 50% or more, even more preferably 60% or more, still more preferably 70% or more, particularly preferably 80% or more, and is preferably 98% or less, more preferably 94% or less, even more preferably 90% or less, for example, 40% or more and 98% or less, of the thickness of the stretched film (X) or (Y). When the stretched film (X) has two or more polyethylene layers, the above "thickness" means the total thickness of each polyethylene layer. The same applies to the stretched film (Y).

[0161] The stretched film (X) may have one polyethylene layer or two or more layers. In a stretched film (X) having two or more polyethylene layers, the densities of the polyethylene layers may be the same or different. For example, the stretched film (X) may have a density gradient between the polyethylene layers. A stretched film (X) having a density gradient between the polyethylene layers is excellent in strength, rigidity, heat resistance, and stretchability compared to the film before stretching.

[0162] In the stretched film (X) having a density gradient between the polyethylene layers, 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 3 or less, more preferably 0.020 g / cm 3 The following is true. Such a stretched film (X) 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).

[0163] In one embodiment, the stretched film (X) comprises a polyethylene layer as the first surface resin layer. The first surface resin layer in the film before stretching treatment is, for example, a layer containing medium-density polyethylene, preferably a layer containing medium-density polyethylene as a main component, or a layer containing medium-density polyethylene and at least one selected from the group consisting of linear low-density polyethylene and high-density polyethylene.

[0164] The medium-density polyethylene content in the first surface resin layer of the film before stretching treatment is preferably 45% by mass or more, more preferably 55% by mass or more, even more preferably 65% ​​by mass or more, and is preferably 95% by mass or less, more preferably 85% by mass or less, even more preferably 75% by mass or less, for example, 45% by mass or more and 95% by mass or less.

[0165] The total content of linear low-density polyethylene and high-density polyethylene in the first surface resin layer of the film before stretching treatment is preferably 5% by mass or more, more preferably 15% by mass or more, even more preferably 25% by mass or more, and is preferably 55% by mass or less, more preferably 45% by mass or less, even more preferably 35% by mass or less, for example, 5% by mass or more and 55% by mass or less.

[0166] The thickness of the first surface resin layer in the stretched film (X) is preferably 0.5 μm or more, more preferably 1 μm or more, even more preferably 1.5 μm or more, and preferably 10 μm or less, more preferably 8 μm or less, even more preferably 6 μm or less, for example, 0.5 μm or more and 10 μm or less. The thickness of the first surface resin layer is preferably 3% or more, more preferably 5% or more, even more preferably 8% or more, and preferably 35% or less, more preferably 30% or less, even more preferably 25% or less, for example, 3% or more and 35% or less, relative to the thickness of the stretched film (X).

[0167] 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 1.5 or less, from the viewpoint of symmetry of the stretched film (X) and suppression of curling.

[0168] The film α1 and the stretched film (X)α obtained by stretching the film α1 comprise, in this order, a first polyethylene layer as a first surface resin layer, a second polyethylene layer, a third polyethylene layer, an adhesive resin layer, and a surface resin layer (G) as a second surface resin layer.

[0169] The film β1 and the stretched film (X)β obtained by stretching the film β1 comprise, in this order, a first polyethylene layer as a first surface resin layer, a second polyethylene layer, a third polyethylene layer, a fourth polyethylene layer, and a surface resin layer (AH) as a second surface resin layer.

[0170] In one embodiment of films α1 and β1, the first polyethylene layer contains medium-density polyethylene, the second polyethylene layer contains linear low-density polyethylene, and the third polyethylene layer contains linear low-density polyethylene as a main component. Such films and their stretched films (X) have, for example, excellent processability and excellent interlayer adhesion strength between the polyethylene layers, effectively suppressing the occurrence of delamination. Stretched films (X) with a high density first polyethylene layer have, for example, excellent heat resistance and can suppress the occurrence of curling due to the difference in density between the first and second surface resin layers.

[0171] In one embodiment of films α1 and β1, the first polyethylene layer contains medium-density polyethylene and linear low-density polyethylene. Such films and stretched films (X) thereof have, for example, excellent processability. In one embodiment of films α1 and β1, the first polyethylene layer contains medium-density polyethylene and high-density polyethylene. Such films and stretched films (X) thereof have, for example, excellent heat resistance and can sufficiently suppress the occurrence of curling. Details of the first polyethylene layer are the same as those of the first surface resin layer described above.

[0172] In films α1 and β1, the second polyethylene layer is, for example, a layer containing linear low-density polyethylene, and preferably, from the viewpoint of rigidity, etc., it is a layer containing linear low-density polyethylene and medium-density polyethylene, or, from the viewpoint of extensibility, etc., it is a layer containing linear low-density polyethylene as a main component.

[0173] In the film β1, the fourth 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 extensibility, etc.

[0174] The content of linear low-density polyethylene in the second polyethylene layer of film α1 and the second and fourth polyethylene layers of film β1 is preferably 35% by mass or more, more preferably 45% by mass or more, even more preferably 55% by mass or more, and preferably 85% by mass or less, more preferably 75% by mass or less, even more preferably 65% ​​by mass or less, for example, 35% by mass or more and 85% by mass or less.

[0175] The medium-density polyethylene content in the second polyethylene layer of film α1 and the second and fourth polyethylene layers of film β1 is preferably 15% by mass or more, more preferably 25% by mass or more, even more preferably 35% by mass or more, and preferably 65% ​​by mass or less, more preferably 55% by mass or less, even more preferably 45% by mass or less, for example, 15% by mass or more and 65% by mass or less.

[0176] In the films α1 and β1, the third polyethylene layer is, for example, a layer containing linear low-density polyethylene as a main component. In the film α1, the third polyethylene layer may further contain the above-mentioned compatibilizer.

[0177] In films α1 and β1, the content of linear low-density polyethylene in the third polyethylene layer is preferably more than 50% by mass, more preferably 60% by mass or more, even more preferably 70% by mass or more, and particularly preferably 75% by mass or more. The content of linear low-density polyethylene in the third polyethylene layer is 100% by mass or less, or may be 99% by mass or less, 97% by mass or less, 95% by mass or less, or 90% by mass or less.

[0178] When the third polyethylene layer of film α1 contains a compatibilizer, the content of the compatibilizer in the third polyethylene layer is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, particularly preferably 10% 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.

[0179] The thickness of the second polyethylene layer of the stretched film (X)α and the second and fourth polyethylene layers of the stretched film (X)β is each independently, relative to the thickness of the stretched film (X), preferably at least 5%, more preferably at least 10%, even more preferably at least 15%, and preferably at most 35%, more preferably at most 30%, even more preferably at most 25%, for example, at least 5% and at most 35%.

[0180] In the stretched films (X) α and β, the thickness of the third 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 (X), for example, 30% or more and 80% or less.

[0181] In the stretched film (X)α, the thickness of the adhesive resin layer is preferably 1% 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 (X).

[0182] In the stretched film (X)α, the ratio of the thickness of the adhesive resin layer to the thickness of the second polyethylene layer is preferably 0.6 or more and 1.5 or less, from the viewpoint of symmetry of the stretched film (X) and suppression of curling.

[0183] In the stretched film (X)α, the ratio of the thickness of the surface resin layer (G) to the thickness of the first polyethylene layer is preferably 0.6 or more and 1.5 or less, from the viewpoint of symmetry of the stretched film (X) and suppression of curling.

[0184] In the stretched film (X) β, the ratio of the thickness of the second polyethylene layer to the thickness of the fourth 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 (X) and suppression of curling.

[0185] In the stretched film (X) β, the ratio of the thickness of the surface resin layer (AH) to the thickness of the first 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 (X) and suppression of curling.

[0186] The density relationship between the polyethylene layers in the stretched films (X) α and β is not particularly limited as long as it does not impair the stretchability of the film and the heat resistance, strength, rigidity, and interlayer adhesion of the stretched film (X). In one embodiment, the density of the second polyethylene layer in the stretched films (X) α and β is higher than that of the third polyethylene layer, and the density of the first polyethylene layer is higher than that of the second polyethylene layer. Such a stretched film (X) tends to have better heat resistance, strength, rigidity, and curl suppression. In one embodiment, the density of the second polyethylene layer in the stretched films (X) α and β is higher than that of the third polyethylene layer, and the density of the first polyethylene layer is lower than that of the second polyethylene layer. In one embodiment, the density of the second polyethylene layer in the stretched films (X) α and β is lower than that of the third polyethylene layer, and the density of the first polyethylene layer is higher than that of the second polyethylene layer.

[0187] In one embodiment, the stretched film (X) comprises two or more polyethylene layers, optionally an adhesive resin layer, and a surface resin layer (G) or (AH), in this order, and it is preferred that the density of the polyethylene layer located farthest from the surface resin layer (G) or (AH) is higher than the density of the polyethylene layer located nearest to the surface resin layer (G) or (AH). Such a stretched film (X) can, for example, suppress the occurrence of curling.

[0188] (Polyolefin layer of stretched film (Y)) The polyolefin layer of the stretched film (Y) is, for example, a polyolefin intermediate layer located between the first and second surface resin layers of the stretched film (Y) and / or the first surface resin layer.

[0189] The polyolefin layer contains polyolefin as a main component. Examples of polyolefins include polyethylene, polypropylene, polybutene, and polymethylpentene. Among these, polyethylene and polypropylene are preferred. Examples of the polyolefin layer include a polyethylene layer containing polyethylene as a main component and a polypropylene layer containing polypropylene as a main component.

[0190] The polyolefin (e.g., polyethylene or polypropylene) content in the polyolefin 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. The barrier layer can be suitably used as a substrate layer constituting a packaging material such as a polyolefin-based mono-material packaging material.

[0191] The polyolefin layer may contain the above-mentioned resin materials other than polyolefin. The polyolefin layer may contain the above-mentioned additives.

[0192] In the stretched film (Y) of the fifth embodiment, the polyolefin layer may further contain a compatibilizer. Examples of compatibilizers include acid-modified polyolefins, and from the viewpoint of recyclability, acid-modified polyethylene and acid-modified polypropylene are preferred. Examples of acid-modified polyolefins include polyolefins modified with unsaturated carboxylic acid compounds, particularly graft-modified polyolefins. Examples of unsaturated carboxylic acid compounds include unsaturated carboxylic acids such as maleic acid and fumaric acid, or their acid anhydrides, esters, or metal salts. Specific examples of compatibilizers include unsaturated carboxylic acid compound-modified polyethylene and unsaturated carboxylic acid compound-modified polypropylene, and maleic anhydride-modified polyethylene and maleic anhydride-modified polypropylene are more preferred.

[0193] When the polyolefin layer contains a compatibilizer, the content of the compatibilizer in the polyolefin layer is preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 3% 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 (Y) has two or more polyolefin layers, at least one polyolefin layer may contain a compatibilizer. When the stretched film (Y) has two or more polyolefin layers, the content of the compatibilizer is based on the total mass of all polyolefin layers.

[0194] When the polyolefin layer contains a compatibilizer, the content of the compatibilizer in the polyolefin 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 in the stretched film (Y). For example, when the gas barrier resin is an ethylene-vinyl alcohol copolymer, the content of the compatibilizer in the polyolefin layer is preferably 100 parts by mass or more and 200 parts by mass or less per 100 parts by mass of the ethylene-vinyl alcohol copolymer in the stretched film (Y). For example, when the gas barrier resin is a polyamide, the content of the compatibilizer in the polyolefin layer is preferably 25 parts by mass or more and 100 parts by mass or less per 100 parts by mass of the polyamide in the stretched film (Y).

[0195] The stretched film (Y) may have one polyolefin layer or two or more polyolefin layers.

[0196] The first surface resin layer may further contain particles. When the first surface resin layer contains particles, for example, the antiblocking property or slip property of the stretched film (Y) can be improved. From the viewpoint of formability of the vapor-deposited film, it is preferable that the second surface resin layer (surface resin layer (G) or (AH)) does not contain particles.

[0197] Examples of particles include inorganic compound-based antiblocking agents and resin particle-based antiblocking agents. Specific examples of inorganic compound-based antiblocking agents include oxides such as silica, aluminum oxide, magnesium oxide, calcium oxide, titanium oxide, and zinc oxide; hydroxides such as aluminum hydroxide, magnesium hydroxide, and calcium hydroxide; carbonates such as magnesium carbonate and calcium carbonate; sulfates such as calcium sulfate and barium sulfate; silicates such as magnesium silicate, aluminum silicate, calcium silicate, and aluminosilicate; and others, including kaolin, talc, and diatomaceous earth. Specific examples of the resin particles include resin particles composed of resin components such as polymethyl methacrylate (PMMA), polystyrene, methyl methacrylate-styrene copolymer, polyester, polyamide, polytetrafluoroethylene, epoxy resin, urea resin, and phenolic resin. The resin particles may be crosslinked or non-crosslinked.

[0198] From the viewpoint of cost etc., the particles may be an inorganic compound-based antiblocking agent. The particles may be a resin particle-based antiblocking agent. For example, when a barrier film having one surface resin layer containing a resin particle-based antiblocking agent and the other surface resin layer having a vapor-deposited film thereon is stored in a roll, such a configuration can reduce the possibility of the particles damaging the vapor-deposited film. This is because resin particle-based antiblocking agents are usually less uneven and softer than inorganic compound-based antiblocking agents.

[0199] The average particle size of the particles is preferably 0.5 μm or more, more preferably 1 μm or more, even more preferably 2 μm or more, and preferably 6 μm or less, more preferably 5.5 μm or less, even more preferably 5 μm or less, for example, 0.5 μm or more and 6 μm or less. The average particle size of the particles means the average particle size (arithmetic mean diameter) measured for 100 randomly selected non-aggregated particles when the cross section of each layer in the thickness direction is observed with a scanning electron microscope (SEM).

[0200] When the first surface resin layer contains particles, the particle content is, based on the mass of the first surface resin layer, preferably 100 ppm or more, more preferably 500 ppm or more, even more preferably 1,000 ppm or more, and preferably 10,000 ppm or less, more preferably 8,000 ppm or less, even more preferably 5,000 ppm or less, for example, 100 ppm or more and 10,000 ppm or less.

[0201] In the stretched film (Y), when the first surface resin layer contains particles, the ratio of the average particle size of the particles to the thickness of the first surface resin layer (average particle size / thickness) is preferably 0.5 or more and 5.0 or less, more preferably 0.8 or more and 4.0 or less, and even more preferably 1.0 or more and 3.5 or less.

[0202] The thickness of the first surface resin layer in the stretched film (Y) is preferably 0.3 μm or more, more preferably 0.5 μm or more, even more preferably 0.8 μm or more, and is preferably 15 μm or less, more preferably 10 μm or less, even more preferably 5 μm or less, particularly preferably 3 μm or less, for example, 0.3 μm or more and 15 μm or less. When the first surface resin layer has protrusions caused by particles, the thickness of each layer is preferably measured in an area where protrusions caused by the particles are not formed.

[0203] The thickness of the first surface resin layer is preferably 1% or more, more preferably 2% or more, even more preferably 4% or more, and is preferably 20% or less, more preferably 15% or less, even more preferably 10% or less, particularly preferably 8% or less, for example, 1% or more and 20% or less, relative to the thickness of the stretched film (Y).

[0204] 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 viewpoint of symmetry of the stretched film (Y) and suppression of curling.

[0205] The stretched film (Y)α comprises, in this order, a first polyolefin layer as a first surface resin layer, a second polyolefin layer, a third polyolefin layer, an adhesive resin layer, and a surface resin layer (G) as a second surface resin layer.

[0206] The stretched film (Y)β comprises, in this order, a first polyolefin layer as a first surface resin layer, a second polyolefin layer, a third polyolefin layer, a fourth polyolefin layer, and a surface resin layer (AH) as a second surface resin layer.

[0207] The thicknesses of the second polyolefin layer and adhesive resin layer of stretched film (Y)α, and the second and fourth polyolefin layers of stretched film (Y)β are each independently preferably 0.5 μm or more, more preferably 0.8 μm or more, even more preferably 1 μm or more, and preferably 15 μm or less, more preferably 10 μm or less, even more preferably 5 μm or less, for example, 0.5 μm or more and 15 μm or less.

[0208] The thicknesses of the second polyolefin layer and adhesive resin layer of stretched film (Y)α and the second and fourth polyolefin layers of stretched film (Y)β are each independently, relative to the thickness of stretched film (Y), preferably at least 2%, more preferably at least 4%, even more preferably at least 6%, and preferably at most 25%, more preferably at most 20%, even more preferably at most 15%, particularly preferably at most 10%, for example at least 2% and at most 25%.

[0209] In the stretched films (Y) α and β, the thickness of the third polyolefin layer is preferably 4 μm or more, more preferably 6 μm or more, even more preferably 8 μm or more, and preferably 60 μm or less, more preferably 40 μm or less, even more preferably 20 μm or less, for example, 4 μm or more and 60 μm or less.

[0210] In the stretched films (Y) α and β, the thickness of the third polyolefin layer is preferably 40% or more, more preferably 50% or more, even more preferably 60% or more, and preferably 90% or less, more preferably 85% or less, even more preferably 80% or less, of the thickness of the stretched film (Y), for example, 40% or more and 90% or less.

[0211] In the stretched films (Y) α and β, the ratio of the thickness of the surface resin layer (G) or (AH) to the thickness of the first polyolefin 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 viewpoint of symmetry of the stretched film (Y) and suppression of curling.

[0212] In the stretched film (Y)α, the ratio of the thickness of the second polyolefin layer to the thickness of the adhesive 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 viewpoint of symmetry of the stretched film (Y) and suppression of curling.

[0213] In the stretched film (Y) β, the ratio of the thickness of the second polyolefin layer to the thickness of the fourth polyolefin 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 (Y) and suppression of curling.

[0214] ((Polyethylene layer of stretched film (Y))) The polyethylene layer contains polyethylene as a main component. Preferred examples of polyethylene include high-density polyethylene, medium-density polyethylene, low-density polyethylene, and linear low-density polyethylene. From the viewpoints of the strength and heat resistance of the stretched film (Y), high-density polyethylene and medium-density polyethylene are preferred. From the viewpoints of the film-forming and processability of the stretched film (Y), linear low-density polyethylene and medium-density polyethylene are preferred.

[0215] The melting point (Tm) of the polyethylene in the polyethylene layer is preferably 100°C or higher, more preferably 105°C or higher, even more preferably 110°C or higher, particularly preferably 115°C or higher, and preferably 140°C or lower, for example, 100°C or higher and 140°C or lower, from the viewpoint of the strength and heat resistance of the stretched film (Y).

[0216] In one embodiment, at least one of the polyethylene layers in the film before stretching treatment is a polyethylene layer (1) containing at least one polyethylene selected from the group consisting of high-density polyethylene and medium-density polyethylene, or a layer containing polyethylene as a main component, wherein the polyethylene contained in the layer is 0.930 g / cm 3 Super 0.960g / cm 3 A polyethylene layer (2) having the following density:

[0217] The polyethylene layer (1) contains at least one polyethylene selected from the group consisting of high-density polyethylene and medium-density polyethylene, and preferably high-density polyethylene. Therefore, the stretched film (Y) including the polyethylene layer (1) has, for example, high heat resistance, specifically, excellent resistance to heating during drying and heat-sealing during printing, and excellent resistance to vapor deposition when vapor deposition is performed on the film. Furthermore, the polyethylene layer (1) has, for example, high rigidity, allowing the film conveyance speed to be increased when vapor deposition is performed on the film, thereby improving productivity.

[0218] High-density polyethylene includes, for example, ethylene homopolymers and ethylene-α-olefin copolymers, as described above in detail. Ethylene-α-olefin copolymers include, for example, C4-HDPE, C6-HDPE, and C8-HDPE. In these copolymers, the comonomers are not limited to the above-mentioned comonomers, and additional comonomers may be used. For example, high-density polyethylene produced using a metallocene catalyst is preferred.

[0219] Examples of medium-density polyethylene include ethylene homopolymers and ethylene-α-olefin copolymers, as described above in detail. Examples of ethylene-α-olefin copolymers include C4-MDPE, C6-MDPE, and C8-MDPE. In these copolymers, the comonomers are not limited to the above-mentioned comonomers, and additional comonomers may be used. For example, medium-density polyethylene produced using a metallocene catalyst is preferred.

[0220] The high-density polyethylene and medium-density polyethylene are preferably the above-mentioned ethylene-α-olefin copolymers. Films containing such high-density polyethylene and / or medium-density polyethylene exhibit, for example, excellent biaxial stretchability, particularly excellent stretchability in the width direction. This is presumably because the side chains derived from the α-olefins prevent the film from tearing during stretching. The ethylene-α-olefin copolymer is preferably a polyethylene obtained by polymerizing ethylene and a small amount of α-olefins using a polymerization method using a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as a metallocene catalyst, and more preferably a polyethylene produced using a metallocene catalyst.

[0221] The density of the high density polyethylene is preferably 0.945 g / cm 3 Exceeds 0.960g / cm 3 The density of the medium density polyethylene is preferably 0.930 g / cm or less. 3 Exceeds 0.945g / cm3 The density can be adjusted, for example, by the amount of structural units derived from the α-olefin, which is the comonomer in the ethylene-α-olefin copolymer, introduced.

[0222] The polyethylene layer (1) may contain, for example, high-density polyethylene as a main component, medium-density polyethylene as a main component, or a mixture of high-density polyethylene and medium-density polyethylene as a main component. The polyethylene layer (1) may contain, for example, a mixture of high-density polyethylene and another polyethylene as a main component, a mixture of medium-density polyethylene and another polyethylene as a main component, or a mixture of high-density polyethylene, medium-density polyethylene, and another polyethylene as a main component. The main component being the above mixture means that the content of the above mixture in the polyethylene layer (1) is more than 50% by mass, and the content is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more. The high-density polyethylene may be, for example, an ethylene homopolymer, an ethylene-α-olefin copolymer, or a mixture thereof. The medium-density polyethylene may be, for example, an ethylene homopolymer, an ethylene-α-olefin copolymer, or a mixture thereof. The other polyethylene may be, for example, at least one selected from the group consisting of linear low-density polyethylene and high-pressure low-density polyethylene, and may be linear low-density polyethylene, high-pressure low-density polyethylene, or a mixture of linear low-density polyethylene and high-pressure low-density polyethylene.

[0223] From the viewpoint of heat resistance, the total content of high-density polyethylene and medium-density polyethylene in the polyethylene layer (1) is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, and may be 30% by mass or more, 35% by mass or more, or 40% by mass or more. The total content of high-density polyethylene and medium-density polyethylene in the polyethylene layer (1) is 100% by mass or less, and from the viewpoint of biaxial stretchability, is preferably 90% by mass or less, more preferably 85% by mass or less, even more preferably 80% by mass or less, 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 100% by mass or less, and preferably 20% by mass or more and 60% by mass or less.

[0224] When the polyethylene layer (1) is the first surface resin layer of the film before stretching, a small total content tends to improve the adhesion between the first surface resin layer and a printed layer, etc., by the surface treatment described above. This is presumably because, for example, high-density polyethylene is highly crystalline and may not be able to sufficiently introduce polar groups into the polyethylene layer by surface treatment such as corona treatment. However, a small total content allows sufficient introduction of polar groups into the polyethylene layer by surface treatment such as corona treatment. Furthermore, when the polyethylene layer (1) is the first surface resin layer of the film before stretching, a small total content tends to improve the appearance, surface smoothness, and transparency of the stretched film (Y).

[0225] 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.

[0226] Examples of linear low-density polyethylene include ethylene-α-olefin copolymers. Examples of α-olefins include the above-mentioned α-olefins having 3 to 20 carbon atoms, with α-olefins having 3 to 8 carbon atoms being preferred, and α-olefins having 4 to 8 carbon atoms being more preferred. Examples of linear low-density polyethylene include C4-LLDPE, C6-LLDPE, and C8-LLDPE. For example, linear low-density polyethylene produced using a metallocene catalyst is preferred. The density of the linear low-density polyethylene is preferably 0.900 g / cm. 3 More than 0.930g / cm 3 The following is the result.

[0227] From the viewpoint of biaxial stretchability, the content of the linear low-density polyethylene in the polyethylene layer (1) is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, and may be 30% by mass or more, 35% by mass or more, or 40% by mass or more. From the viewpoint of heat resistance, the content of the linear low-density polyethylene in the polyethylene layer (1) is preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less, and may be 70% by mass or less, 65% by mass or less, or 60% by mass or less. The content of the linear low-density polyethylene in the polyethylene layer (1) is, for example, 10% by mass or more and 90% by mass or less, and preferably 40% by mass or more and 80% by mass or less.

[0228] The polyethylene layer (1) contains polyethylene as a main component. The content of polyethylene in the polyethylene layer (1) is preferably 80% by mass or more, more preferably 85% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more.

[0229] The polyethylene layer (1) may contain polyethylene other than high density polyethylene, medium density polyethylene and linear low density polyethylene, or the above-mentioned resin materials other than polyethylene. The polyethylene layer (1) may contain the above-mentioned additives.

[0230] The polyethylene layer (2) contains polyethylene as a main component, and the polyethylene has a viscosity of 0.930 g / cm 3 Super 0.960g / cm 3 The density of the polyethylene in the polyethylene layer (2) is preferably 0.931 g / cm 3 More than 0.955g / cm 3 or less, more preferably 0.931 g / cm 3 More than 0.950g / cm 3 The following is the result.

[0231] When the polyethylene layer (2) contains two or more polyethylenes with different densities, the density of the polyethylene refers to the density of a mixture of two or more polyethylenes. The density is measured in accordance with JIS K7112-2:2023 (density gradient tube method, 23°C) for polyethylene sampled from the layer. When the measurement is difficult, the average density D calculated according to the following formula is used: av may be the density of the polyethylene that constitutes the layer.

[0232] D av = ΣW i ×D i In the formula, Σ is W from 1 to n (n kinds of polyethylene are present) for i. i ×D i where n is an integer greater than or equal to 2, and W i denotes the mass fraction of the i-th polyethylene, and D i is the density of the i-th polyethylene (g / cm 3 ) is shown.

[0233] The density of the polyethylene layer (2) can be adjusted based on the composition described above for the polyethylene layer (1), for example. That is, the polyethylene layer (2) can have the composition described above for the polyethylene layer (1).

[0234] The polyethylene layer (2) may contain the above resin materials other than polyethylene. The polyethylene layer (2) may contain the above-mentioned additives.

[0235] The first surface resin layer in the stretched film (Y) may be a polyethylene layer.

[0236] In the stretched film (Y) of each of the above embodiments, any adjacent layers selected from the polyethylene intermediate layer, the first surface resin layer containing polyethylene as a main component, and the surface resin layer (AH) containing polyethylene and an adhesive resin are referred to as layer (i) and layer (ii). The absolute value of the difference between the density of the polyethylene constituting layer (i) and the density of the polyethylene constituting layer (ii) is preferably 0.030 g / cm. 3 or less, more preferably 0.025 g / cm 3 or less, more preferably 0.020 g / cm 3 Below 0.010 g / cm, particularly preferably 3 Such a film has excellent interlayer adhesion and, for example, excellent drop resistance.

[0237] In one embodiment of the stretched film (Y), the density of the polyethylene in the polyethylene intermediate layer is higher than the density of the polyethylene in the first surface resin layer, and, if desired, the density of the polyethylene in the second surface resin layer (surface resin layer (AH)) is lower than the density of the polyethylene in the polyethylene intermediate layer. Such a stretched film (Y) tends to have an excellent balance of surface smoothness, transparency, printability, vapor deposition adhesion, and heat resistance. When the polyethylene intermediate layer is thicker than the first surface resin layer, the polyethylene intermediate layer provides high heat resistance. The difference in density between the polyethylene in the surface resin layer and the polyethylene intermediate layer is, for example, 0.003 g / cm. 3 More than that is fine. The total content ratio of high-density polyethylene and medium-density polyethylene is hereinafter referred to as "content ratio A." This may be only high-density polyethylene, only medium-density polyethylene, or a mixture of high-density polyethylene and medium-density polyethylene. In one embodiment of the film before stretching, the content ratio A in the polyethylene intermediate layer is greater than the content ratio A in the first surface resin layer, and, if desired, the content ratio A in the second surface resin layer (surface resin layer (AH)) is smaller than the content ratio A in the polyethylene intermediate layer. Such a stretched film (Y) tends to have an excellent balance of surface smoothness, transparency, printability, vapor deposition adhesion, and heat resistance. The difference in content ratio A between the surface resin layer and the polyethylene intermediate layer may be, for example, 10% by mass or more, 50% by mass or less, 40% by mass or less, or 30% by mass or less.

[0238] In one embodiment of the stretched film (Y), the density of the polyethylene in the polyethylene intermediate layer is lower than the density of the polyethylene in the first surface resin layer, and, if desired, the density of the polyethylene in the second surface resin layer (surface resin layer (AH)) is higher than the density of the polyethylene in the polyethylene intermediate layer. Such a stretched film (Y) tends to have an excellent balance between biaxial stretchability and heat resistance. When the polyethylene intermediate layer is thicker than the first surface resin layer, high biaxial stretchability can be achieved by the polyethylene intermediate layer. The difference in density between the polyethylene in the surface resin layer and the polyethylene intermediate layer is, for example, 0.003 g / cm. 3 More than that is fine. In one embodiment of the film before stretching, the content ratio A in the polyethylene intermediate layer is smaller than the content ratio A in the first surface resin layer, and, if desired, the content ratio A in the second surface resin layer (surface resin layer (AH)) is larger than the content ratio A in the polyethylene intermediate layer. Such a film tends to have an excellent balance between biaxial stretchability and heat resistance. The difference in content ratio A between the surface resin layer and the polyethylene intermediate layer may be, for example, 10% by mass or more, 50% by mass or less, 40% by mass or less, or 30% by mass or less.

[0239] In one embodiment of the stretched film (Y), the densities of the polyethylene in the first surface resin layer, the polyethylene intermediate layer, and optionally the second surface resin layer (surface resin layer (AH)) are approximately equal to each other. For example, among the first surface resin layer, the polyethylene intermediate layer, and optionally the second surface resin layer, the difference in density between the layer with the highest polyethylene density and the layer with the lowest polyethylene density is 0.003 g / cm. 3 is less than. In one embodiment of the film before stretching, the first surface resin layer, the polyethylene intermediate layer, and the optional second surface resin layer (surface resin layer (AH)) each have approximately the same content ratio A. For example, among the first surface resin layer, the polyethylene intermediate layer, and the optional second surface resin layer, the difference in content ratio A between the layer with the highest content ratio A and the layer with the lowest content ratio A is less than 10% by mass.

[0240] When each layer contains two or more polyethylenes with different densities, the density of the polyethylene refers to the density of a mixture of the two or more polyethylenes. The methods for measuring and calculating the density are as described above.

[0241] ((Polypropylene layer of stretched film (Y))) Details of the polypropylene layer are as described above in the section (Polypropylene layer in the first to fourth embodiments).

[0242] The first surface resin layer in the stretched film (Y) may be a polypropylene layer. The polypropylene layer as the first surface resin layer may contain homopolypropylene and random polypropylene, for example, from the viewpoint of adhesion to other layers provided on the first surface resin layer in a laminate described below. For example, in the first surface resin layer, the homopolypropylene content is preferably 50% by mass to 95% by mass and the random polypropylene content is preferably 5% by mass to 50% by mass, more preferably 60% by mass to 90% by mass and the random polypropylene content is 10% by mass to 40% by mass, and even more preferably 70% by mass to 85% by mass and the random polypropylene content is 15% by mass to 30% by mass.

[0243] <Surface resin layer> In the stretched films of the first to fourth aspects, the thicknesses of the first and second surface resin layers are each independently, from the viewpoint of the above-mentioned physical properties such as gas barrier property and aroma retention, preferably 0.3 μm or more, more preferably 0.5 μm or more, and even more preferably 0.8 μm or more, and may be, for example, 1 μm or more or 1.5 μm or more. In the above stretched films, the thicknesses of the first and second surface resin layers are each independently, from the viewpoint of the recyclability of the barrier layer, preferably 15 μm or less, more preferably 10 μm or less, even more preferably 8 μm or less, and particularly preferably 6 μm or less, and may be, for example, 5 μm or less or 3 μm or less. The thickness of the surface resin layer is, for example, 0.3 μm or more and 15 μm or less.

[0244] The thickness of the first and second surface resin layers in the stretched films of the first to fourth embodiments is, independently of each other, preferably 1% or more, more preferably 2% or more, even more preferably 3% or more, and particularly preferably 4% or more, relative to the thickness of the stretched film, and may be, for example, 5% or more, and preferably 30% or less, more preferably 25% or less, and even more preferably 20% or less, and may be, for example, 15% or less, 10% or less, or 8% or less, for example, 1% or more and 30% or less.

[0245] The thickness of the surface resin layer (G) in the stretched film (X) is 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 properties. The thickness of the surface resin layer (G) is preferably 10 μm or less, more preferably 8 μm or less, and even more preferably 6 μm or less, from the viewpoint of recyclability. The thickness of the surface resin layer (G) is, for example, 0.5 μm or more and 10 μm or less. The thickness of the surface resin layer (G) in the stretched film (Y) is preferably 0.3 μm or more, more preferably 0.5 μm or more, and even more preferably 0.8 μm or more, from the viewpoint of the above-mentioned physical properties such as gas barrier properties. The thickness of the surface resin layer (G) is preferably 15 μm or less, more preferably 10 μm or less, even more preferably 5 μm or less, and particularly preferably 3 μm or less, from the viewpoint of recyclability. The thickness of the surface resin layer (G) is, for example, 0.3 μm or more and 15 μm or less.

[0246] The thickness of the surface resin layer (G) is 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 (X). The thickness of the surface resin layer (G) is preferably 1% or more, more preferably 2% or more, even more preferably 4% or more, and is preferably 20% or less, more preferably 15% or less, even more preferably 10% or less, particularly preferably 8% or less, for example, 1% or more and 20% or less, relative to the thickness of the stretched film (Y).

[0247] The thickness of the surface resin layer (AH) in the stretched film (X) is 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 further exerting the above-mentioned effects. The thickness of the surface resin layer (AH) is preferably 10 μm or less, more preferably 8 μm or less, and even more preferably 6 μm or less, from the viewpoint of recyclability. The thickness of the surface resin layer (AH) is, for example, 0.5 μm or more and 10 μm or less. The thickness of the surface resin layer (AH) in the stretched film (Y) is preferably 0.3 μm or more, more preferably 0.5 μm or more, and even more preferably 0.8 μm or more, from the viewpoint of further exerting the above-mentioned effects. The thickness of the surface resin layer (AH) is preferably 15 μm or less, more preferably 10 μm or less, even more preferably 5 μm or less, and particularly preferably 3 μm or less. The thickness of the surface resin layer (AH) is, for example, 0.3 μm or more and 15 μm or less.

[0248] The thickness of the surface resin layer (AH) is 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 (X). The thickness of the surface resin layer (AH) is preferably 1% or more, more preferably 2% or more, even more preferably 4% or more, and is preferably 20% or less, more preferably 15% or less, even more preferably 10% or less, particularly preferably 8% or less, for example, 1% or more and 20% or less, relative to the thickness of the stretched film (Y).

[0249] 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.

[0250] 《Surface resin layer (G)》 The surface resin layer (G) contains a gas barrier resin as a main component, and a stretched film having the surface resin layer (G) has superior gas barrier properties (particularly oxygen barrier properties), aroma retention, heat resistance, and rigidity compared to conventional stretched polyolefin films.

[0251] 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.

[0252] The surface resin layer (G) tends to have excellent surface smoothness. The vapor-deposited film provided on the surface of the surface resin layer (G) tends to have excellent adhesion to the surface resin layer (G) and to exhibit good gas barrier properties, for example.

[0253] 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.

[0254] 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.

[0255] 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. The EVOH may be modified by known methods, such as urethanization, acetalization, cyanoethylation, or oxyalkylenation.

[0256] 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.

[0257] 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. From the viewpoint of excellent surface smoothness and stretchability, particularly biaxial stretchability, it is even more preferably 30 mol% or more, even more preferably 35 mol% or more, and particularly preferably 40 mol% or more or 45 mol% or more. 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 in EVOH is preferably 60 mol% or less, more preferably 55 mol% or less, and even more preferably 50 mol% or less. The ethylene content is, for example, 20 mol% or more and 60 mol% or less. The ethylene content is measured by NMR.

[0258] 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).

[0259] From the viewpoint of heat resistance, the melting point (Tm) of EVOH is preferably 130°C or higher, more preferably 135°C or higher, and even more preferably 140°C or higher, and may be, for example, 145°C or higher or 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, and may be, for example, 180°C or lower, 170°C or lower, or 165°C or lower. The Tm of EVOH is, for example, 130°C or higher and 200°C or lower.

[0260] 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. Such an MFR is preferred as the MFR of the EVOH in, for example, an inflation method or in the form of a stretched film (X). 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.

[0261] From the viewpoint 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 1 g / 10 min or more, and even more preferably 1.5 g / 10 min or more. From the viewpoint 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, and even more preferably 10 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. Such an MFR is preferable as the MFR of the EVOH in, for example, the T-die casting method or the stretched film (Y).

[0262] 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.

[0263] Examples of polyamides include aliphatic polyamides and aromatic polyamides. The surface resin layer (G) may contain one type of polyamide or two or more types of polyamides. The surface resin layer (G) may contain one or two or more types of aliphatic polyamides. The surface resin layer (G) may contain one or two or more types of aromatic polyamides. The surface resin layer (G) may contain one or two or more types of aliphatic polyamides and one or two or more types of aromatic polyamides. The polyamide is preferably an aliphatic polyamide, more preferably a crystalline aliphatic polyamide, and also preferably an aromatic polyamide, more preferably a semi-aromatic polyamide.

[0264] Examples of aliphatic polyamides include aliphatic homopolyamides and aliphatic copolyamides. In the following examples, polyamides are also referred to as "PA."

[0265] 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).

[0266] 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).

[0267] 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, even more preferably 190°C or higher, and preferably 300°C or lower, more preferably 270°C or lower, even more preferably 250°C or lower, even more preferably 240°C or lower, particularly preferably 230°C or lower, for example, 170°C or higher and 300°C or lower.

[0268] 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.

[0269] 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.

[0270] 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.

[0271] 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)).

[0272] 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.

[0273] 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.

[0274] 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.

[0275] 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.

[0276] 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).

[0277] 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.

[0278] 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.

[0279] 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.

[0280] 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.

[0281] 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, and even more preferably 0.5 g / 10 min or more. For example, it may be 1 g / 10 min or more or 1.5 g / 10 min or more. It is preferably 30 g / 10 min or less, more preferably 20 g / 10 min or less, and even more preferably 10 g / 10 min or less. For example, it may be 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.

[0282] The surface resin layer (G) may contain polyamide as a main component. The surface resin layer (G) 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 (G) may be 80% by mass or more, 85% by mass or more, 90% by mass or more, or 95% by mass or more.

[0283] The surface resin layer (G) may contain aromatic polyamide as a main component. Such a stretched film has, for example, excellent rigidity and gas barrier properties. For example, the content of aromatic polyamide in the surface resin layer (G) may be 80% by mass or more, 85% by mass or more, 90% by mass or more, or 95% by mass or more.

[0284] The surface resin layer (G) 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 (G), 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.

[0285] The surface resin layer (G) 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 (G) may be 80% by mass or more, 85% by mass or more, 90% by mass or more, or 95% by mass or more.

[0286] The surface resin layer (G) 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, in the surface resin layer (G), the content of the crystalline semi-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, and the content of the amorphous semi-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.

[0287] 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 (G) 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 or 95% by mass or more.

[0288] The surface resin layer (G) may contain the above-mentioned resin materials other than the gas barrier resin. The surface resin layer (G) may contain the above-mentioned additives.

[0289] 《Surface resin layer (AH)》 The surface resin layer (AH) contains a polyolefin and an adhesive resin. The vapor-deposited film provided on the surface of the surface resin layer (AH) tends to have excellent adhesion to the surface resin layer (AH) and exhibit good gas barrier properties, for example.

[0290] The first and second surface resin layers in the stretched film of the second embodiment each independently contain a polyolefin and an adhesive resin. The first surface resin layer in the stretched film of the third embodiment contains a polyolefin and an adhesive resin. The second surface resin layer in the stretched film of the fourth embodiment contains a polyolefin and an adhesive resin.

[0291] Examples of polyolefins include polypropylene, polyethylene, polybutene, and polymethylpentene, with polypropylene and polyethylene being preferred.

[0292] Examples of polypropylene include homopolypropylene, random polypropylene, and block polypropylene. Among these, random polypropylene and homopolypropylene are preferred, with random polypropylene being more preferred, from the viewpoints of the surface smoothness of the stretched film, the adhesion between the surface resin layer (AH) and the vapor-deposited film, and the heat resistance of the stretched film. If the content of random polypropylene in the stretched film is high, the heat resistance may be insufficient. In such cases, the main component of the polypropylene layer may be homopolypropylene.

[0293] The melting point (Tm) of the polypropylene in the surface resin layer (AH) is preferably 120°C or higher, more preferably 125°C or higher, even more preferably 130°C or higher, from the viewpoints of the strength and heat resistance of the stretched film and the adhesion between the surface resin layer (AH) and the vapor-deposited film, and is preferably 175°C or lower, more preferably 170°C or lower, even more preferably 165°C or lower, still more preferably 160°C or lower, particularly preferably 155°C or lower or 150°C or lower, for example, 120°C or higher and 175°C or lower.

[0294] Preferred polyethylenes include high-density polyethylene, medium-density polyethylene, low-density polyethylene, and linear low-density polyethylene. From the viewpoints of the surface smoothness of the stretched film and the adhesion between the surface resin layer (AH) and the vapor-deposited film, linear low-density polyethylene is more preferred. Examples of linear low-density polyethylene include C4-LLDPE, C6-LLDPE, and C8-LLDPE. For example, linear low-density polyethylene produced using a metallocene catalyst is preferred.

[0295] The melting point (Tm) of the polyethylene in the surface resin layer (AH) 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 (AH) and the vapor-deposited film.

[0296] 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, acid-modified polyolefins are preferred from the viewpoints of recyclability and adhesion, with acid-modified polypropylene and acid-modified polyethylene being more preferred. In the case of polypropylene-based stretched films, acid-modified polypropylene is more preferred, and in terms of heat resistance and adhesion, acid-modified random polypropylene and acid-modified homopolypropylene are even more preferred, with acid-modified random polypropylene being particularly preferred. A surface resin layer (AH) containing acid-modified random polypropylene tends to have better adhesion to a vapor-deposited film. In the case of polyethylene-based stretched films, acid-modified polyethylene is more preferred, with acid-modified linear low-density polyethylene being even more preferred. A surface resin layer (AH) containing acid-modified linear low-density polyethylene tends to have better adhesion to a vapor-deposited film.

[0297] In one embodiment of the stretched film of the third aspect, the polyolefin in the first surface resin layer comprises polypropylene, the adhesive resin comprises acid-modified polypropylene, and the polyolefin layer contains polypropylene as a main component. In one embodiment of the stretched film of the third aspect, the polyolefin in the first surface resin layer comprises random polypropylene, the adhesive resin comprises acid-modified random polypropylene, and the polyolefin layer contains homopolypropylene as a main component. In one embodiment of the stretched film of the third aspect, the polyolefin in the first surface resin layer contains polyethylene, the adhesive resin contains acid-modified polyethylene, and the polyolefin layer contains polyethylene as a main component. In the case of one embodiment of the stretched film of the fourth aspect, the first surface resin layer is read as the second surface resin layer.

[0298] In one embodiment of the stretched film (Y) of the sixth aspect, the polyolefin in the surface resin layer (AH) comprises polyethylene, the adhesive resin comprises acid-modified polyethylene, and the polyolefin layer is a polyethylene layer.

[0299] In one embodiment of the stretched film (Y) of the sixth aspect, the polyolefin in the surface resin layer (AH) comprises polypropylene, the adhesive resin comprises acid-modified polypropylene, and the polyolefin layer is a polypropylene layer. In one embodiment of the stretched film (Y) of the sixth aspect, the polyolefin in the surface resin layer (AH) comprises random polypropylene, the adhesive resin comprises acid-modified random polypropylene, and the polyolefin layer contains homopolypropylene as a main component.

[0300] 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, and in the case of polyethylene-based stretched films, maleic acid-modified polyethylene and maleic anhydride-modified polyethylene being even more preferred.

[0301] 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 (AH) 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 (AH) and the polyolefin 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.

[0302] 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 0.3 g / 10 min or more, and even more preferably 0.5 g / 10 min or more. For example, it may be 1 g / 10 min or more or 1.5 g / 10 min or more. It is preferably 50 g / 10 min or less, more preferably 30 g / 10 min or less, and even more preferably 10 g / 10 min or less. For example, it may be 5 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.

[0303] 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 (AH) and the vapor-deposited film.

[0304] The density of acid-modified polypropylene is, for example, 0.88 g / cm 3More than 0.92g / cm 3 Herein, the density of the acid-modified polypropylene is measured in accordance with JIS K7112-2:2023 (density gradient tube method, 23°C). The density of the acid-modified polyethylene may be in the same range as that of the polyethylene described above.

[0305] From the viewpoints of the strength and heat resistance of the stretched film, and the adhesion between the surface resin layer (AH) and the vapor-deposited film, the melting point (Tm) of the acid-modified polypropylene is preferably 120°C or higher, more preferably 125°C or higher, even more preferably 130°C or higher, and is preferably 175°C or lower, more preferably 170°C or lower, even more preferably 165°C or lower, still more preferably 160°C or lower, particularly preferably 155°C or lower or 150°C or lower, for example, 120°C or higher and 175°C or lower.

[0306] In the surface resin layer (AH), the polyolefin content is preferably 60% by mass to 95% by mass and the adhesive resin content is preferably 5% by mass to 40% by mass. It is more preferably 70% by mass to 95% by mass and the adhesive resin content is 5% by mass to 30% by mass. It is even more preferably 80% by mass to 95% by mass and the adhesive resin content is 5% by mass to 20% by mass. It is particularly preferably 85% by mass to 95% by mass and the adhesive resin content is 5% by mass to 15% by mass. The surface resin layer (AH) of this embodiment tends to have better surface smoothness, adhesion to the vapor-deposited film, and adhesion to the polyolefin 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 a stretched film. The polyolefin is, for example, polyethylene or polypropylene. In the case of the stretched film (X), the above polyolefin is read as polyethylene.

[0307] The case of the stretched film (Y) will be described below. The surface resin layer (AH) in the film before stretching treatment may contain linear low-density polyethylene as a main component from the viewpoints of biaxial stretchability, surface smoothness, etc. Details of the linear low-density polyethylene are as described above in the description of the polyethylene layer (1), and therefore will not be described here.

[0308] In one embodiment, the surface resin layer (AH) in the film before stretching contains at least one polyethylene selected from the group consisting of high-density polyethylene and medium-density polyethylene, preferably high-density polyethylene. Therefore, the stretched film (Y) having such a surface resin layer has, for example, high heat resistance, specifically, excellent resistance to heating during drying and heat-sealing during printing, and excellent resistance to vapor deposition when vapor deposition is performed on the film. Furthermore, the surface resin layer has, for example, high rigidity, allowing the film conveying speed to be increased when vapor deposition is performed on the film, thereby improving productivity.

[0309] The details of the high-density polyethylene and the medium-density polyethylene are as described above in the description of the polyethylene layer (1), and therefore will not be described here. As the high-density polyethylene and the medium-density polyethylene, the above-mentioned ethylene-α-olefin copolymer is preferable.

[0310] In one embodiment, the content of linear low-density polyethylene in 100% by mass of polyethylene contained in the surface resin layer (AH) of the film before stretching treatment may be 60% by mass or more, 65% by mass or more, 70% by mass or more, 100% by mass or less, 95% by mass or less, 90% by mass or less, 85% by mass or less, or 80% by mass or less, for example, 60% by mass or more and 100% by mass or less.

[0311] In one embodiment, the total content of high-density polyethylene and medium-density polyethylene in 100% by mass of polyethylene contained in the surface resin layer (AH) of the film before stretching treatment may be 0% by mass or more, 5% by mass or more, 10% by mass or more, 15% by mass or more, 20% by mass or more, 40% by mass or less, 35% by mass or less, or 30% by mass or less, for example, 0% by mass or more and 40% by mass or less.

[0312] In one embodiment, the polyethylene contained in the surface resin layer (AH) in the film before stretching treatment is 0.930 g / cm 3 Super 0.960g / cm 3 The density may be less than or equal to 0.931 g / cm 3 More than 0.955g / cm 3 or less, more preferably 0.931 g / cm 3 More than 0.950g / cm 3 When the surface resin layer (AH) contains two or more polyethylenes having different densities, the density of the polyethylene refers to the density of a mixture of the two or more polyethylenes. The above is a description of the case of the stretched film (Y).

[0313] The surface resin layer (AH) may contain the above-mentioned resin materials other than the above-mentioned components. The surface resin layer (AH) may contain the above-mentioned additives.

[0314] <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 polyolefin layer. The stretched films of the first and third aspects may further comprise a (second) adhesive resin layer between the polyolefin layer and the second surface resin layer. The stretched film of the fifth aspect may further comprise an adhesive resin layer between the polyolefin layer and the surface resin layer (G). Such stretched films have, for example, excellent adhesion between the polyolefin layer and the surface resin layer.

[0315] The adhesive resin layer contains an adhesive resin as a main component. 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, acid-modified polyolefins are preferred, with acid-modified polyethylene and acid-modified polypropylene being more preferred. In the case of polyethylene-based stretched films, acid-modified polyethylene is more preferred from the viewpoints of recyclability and adhesion to both the polyethylene layer and the surface resin layer, and acid-modified linear low-density polyethylene is even more preferred. In the case of polypropylene-based stretched films, acid-modified polypropylene is even more preferred from the viewpoints of recyclability and adhesion to both the polypropylene layer and the surface resin layer, and acid-modified random polypropylene and acid-modified homopolypropylene are even more preferred from the viewpoints of heat resistance and adhesion, with acid-modified random polypropylene being particularly preferred. Details of the acid-modified polyolefin (composition and physical properties such as MFR, density, and Tm) are as explained in the section on the surface resin layer (AH), and will not be explained here.

[0316] From the viewpoint of adhesion between the surface resin layer (G) and the polyolefin layer, the content of the structural unit 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, even more preferably 0.1% by mass or more, and preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 3% by mass or less, for example, 0.01% by mass or more and 10% by mass or less. The content of the structural unit derived from the acid-modified component is measured by infrared spectroscopy.

[0317] The adhesive resin content 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. The adhesive resin layer may contain the above-mentioned additives.

[0318] In the stretched film, the thickness of each adhesive resin layer is preferably 0.5 μm or more, more preferably 0.8 μm or more, and even 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.

[0319] The thickness of each adhesive resin layer is preferably 2% or more, more preferably 4% or more, even more preferably 6% or more, and is preferably 25% or less, more preferably 20% or less, even more preferably 15% or less, particularly preferably 10% or less, for example, 2% or more and 25% or less, relative to the thickness of the stretched film of the first to fourth embodiments.

[0320] The thickness of the adhesive resin layer is preferably 1% 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 (X). The thickness of the adhesive resin layer is preferably 2% or more, more preferably 4% or more, even more preferably 6% or more, and is preferably 25% or less, more preferably 20% or less, even more preferably 15% or less, particularly preferably 10% or less, for example, 2% or more and 25% or less, relative to the thickness of the stretched film (Y).

[0321] <Vapor deposition film> The barrier layer of the first to fourth aspects comprises a vapor-deposited film. In one embodiment, the barrier layer of the first to fourth aspects comprises at least a first vapor-deposited film, a stretched film, and a second vapor-deposited film. A packaging container produced using such a barrier layer (barrier film) has excellent gas barrier properties. The barrier layer of the fifth and sixth aspects comprises at least a stretched film, a first vapor-deposited film, and a second vapor-deposited film, and has excellent gas barrier properties. Packaging containers produced using such a barrier layer (barrier film) have excellent gas barrier properties. Because the barrier layer comprises the second vapor-deposited film on the first vapor-deposited film, deterioration of the gas barrier properties due to pinholes can be suppressed.

[0322] The barrier layer in the fifth and sixth aspects comprises a first vapor-deposited film and a second vapor-deposited film in this order on the surface resin layer (G) or (AH) of the stretched film. Such a barrier layer has, for example, superior gas barrier properties. The barrier layer in the fifth and sixth aspects comprises a polyolefin layer (e.g., a polyethylene layer or a polypropylene layer), the surface resin layer (G) or (AH), the first vapor-deposited film, and the second vapor-deposited film in this order in the stacking direction. In one embodiment, the first vapor-deposited film is in contact with the surface resin layer (G) or (AH) of the stretched film. The barrier layer may further comprise one or more vapor-deposited films on the second vapor-deposited film.

[0323] In one embodiment, the barrier layer of the fifth aspect comprises, in this order, at least one polyolefin layer, an adhesive resin layer, a surface resin layer (G), a first vapor-deposited film, and a second vapor-deposited film. The barrier layer of the above embodiment comprises, for example, a first polyolefin layer as the first surface resin layer, a second polyolefin layer, a third polyolefin layer, an adhesive resin layer, a surface resin layer (G) as the second surface resin layer, the first vapor-deposited film, and a second vapor-deposited film, in this order. In the case of the stretched film (X), the polyolefin layer is referred to as a polyethylene layer.

[0324] In one embodiment, the barrier layer of the sixth aspect comprises, in this order, at least one polyolefin layer, a surface resin layer (AH), a first vapor-deposited film, and a second vapor-deposited film. The barrier layer of the above embodiment comprises, for example, a first polyolefin layer as the first surface resin layer, a second polyolefin layer, a third polyolefin layer, a fourth polyolefin layer, a surface resin layer (AH) as the second surface resin layer, the first vapor-deposited film, and a second vapor-deposited film, in this order. In the case of the stretched film (X), the polyolefin layer is referred to as a polyethylene layer.

[0325] In the fifth and sixth aspects, the first and second vapor-deposited films may be vapor-deposited films that constitute a multi-stage vapor-deposited film. An adhesion-improving layer, such as a barrier coat layer or a metal oxide film, described below, may be provided between the first and second vapor-deposited films to improve adhesion between them. The thickness and / or composition of the first and second vapor-deposited films may be the same or different.

[0326] In the fifth and sixth aspects, in one embodiment, the vapor-deposited film is provided on the second surface of the stretched film, but not on the first surface of the stretched film. In one embodiment, the vapor-deposited film is provided on the second surface resin layer of the stretched film (surface resin layer (G) or (AH)), but not on the first surface resin layer of the stretched film. In the case of barrier layers having vapor-deposited films on both surfaces of a stretched film, when the barrier layer (barrier film) is stored, for example, in a rolled form, the vapor-deposited films may deteriorate due to contact or rubbing against each other. The barrier layer of the above embodiment can suppress such deterioration of the vapor-deposited film.

[0327] The surface resin layer (G) or (AH) of the stretched film has excellent vapor-deposited film formability, smoothness, and adhesion to the vapor-deposited film. The barrier layer has a vapor-deposited film on the surface resin layer (G) or (AH) of the stretched film. Such a 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.

[0328] 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 oxide vapor-deposited films are preferred. The first and second vapor-deposited films are preferably aluminum vapor-deposited films, aluminum oxide (alumina) vapor-deposited films, silicon oxide (silica) vapor-deposited films, or silicon carbide oxide vapor-deposited films, independently of one another.

[0329] 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.

[0330] 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.

[0331] 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.

[0332] In one embodiment, the barrier layer comprises a vapor-deposited film only on the second surface of the stretched film (second surface resin layer, surface resin layer (G) or (AH)), and no vapor-deposited film is provided on the first surface of the stretched film (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 first heat-seal layer, a barrier layer, and a second heat-seal layer is prepared. The laminate comprises a barrier layer in which the stretched film faces the first heat-seal layer (the inside of the tube container) and the vapor-deposited film faces the second heat-seal layer (the outside of the tube container). By producing a tube container body using the laminate, the vapor-deposited film can be positioned on the outside. Therefore, even when a corrosive content is filled into the tube container, discoloration, corrosion, or deterioration of the vapor-deposited film, as well as lifting or peeling of the layer, can be suppressed.

[0333] 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 according to any one of the first to fourth aspects, a packaging container with excellent resistance to contents can be produced. The barrier layer is arranged so that the first vapor-deposited film faces the first heat-seal layer (the inside of the tube container) and the second vapor-deposited film faces the second heat-seal layer (the outside of the tube container). By producing a packaging container using the 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.

[0334] 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. The barrier layers of the first to fourth aspects can avoid the problem of oxidation degradation that occurs when the first vapor-deposited film is a metal vapor-deposited film, for example. Furthermore, in the barrier layers of the first to sixth aspects, the thickness of the aluminum vapor-deposited film can be measured in real time from the amount of light transmittance during the formation of the second vapor-deposited film (during aluminum vapor deposition), making it easy to control the film thickness.

[0335] 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. The barrier layers of the first to fourth embodiments can 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, the barrier layers of the first to sixth embodiments have excellent transparency, allowing the production of packaging containers with excellent visibility of the contents, such as packaging containers that are microwave-safe and can pass through metal detectors. Furthermore, packaging containers with such barrier layers allow consumers to clearly see that they do not contain an aluminum vapor-deposited film, making them easy to separate. Furthermore, the inclusion of black spots (metallic color) that can occur due to the aluminum vapor-deposited film can be suppressed during recycling.

[0336] The barrier layers of the first to fourth aspects may have an additional vapor-deposited film on the first vapor-deposited film and / or the second vapor-deposited film. In one embodiment, the barrier layers of the first to fourth aspects at least have, in this order, a third vapor-deposited film, a first vapor-deposited film, a stretched film, a second vapor-deposited film, and a fourth vapor-deposited film.

[0337] 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.

[0338] 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 2.0 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.

[0339] 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.

[0340] 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.

[0341] 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.

[0342] 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.

[0343] <Protective layer, barrier coat layer> The barrier layer may further include a protective layer such as 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. The barrier layers of the fifth and sixth aspects may further include a protective layer such as a barrier coat layer on the surface of the second vapor-deposited film opposite to the surface facing the first vapor-deposited film. Such a barrier layer has excellent scratch resistance and gas barrier properties, and when the vapor-deposited film is composed of inorganic oxides such as aluminum oxide and silicon oxide, it 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 protective layer is preferably a barrier coat layer. The barrier layer may comprise a barrier coat layer between the two vapor-deposited films described above.

[0344] The thickness and / or composition of each vapor-deposited film may be the same as or different from one another. The thickness and / or composition of each adhesion-improving layer (described later), protective layer, and barrier coat layer may be the same as or different from one another.

[0345] In one embodiment, the adhesion improving layer, the protective layer, or the barrier coat layer contains a gas barrier resin. A barrier layer including such a layer has even better gas barrier properties. The adhesion improving layer, the protective layer, or the barrier coat layer can be formed, for example, by applying a coating liquid obtained by dissolving or dispersing a material such as a gas barrier resin in water or an appropriate organic solvent to a vapor-deposited film and drying the resulting coating liquid.

[0346] 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.

[0347] In one embodiment, the content of the gas barrier resin in the adhesion improving layer, protective layer, or barrier coat layer is preferably more than 50% by mass, more preferably 60% by mass or more, even more preferably 70% by mass or more, still more preferably 80% by mass or more, and particularly preferably 90% by mass or more. Such a layer has, for example, excellent gas barrier properties.

[0348] The adhesion improving layer, the protective layer or the barrier coat layer may contain the above-mentioned additives.

[0349] The thickness of the adhesion improving layer, protective layer, or barrier coat layer containing a 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 adhesion improving layer, protective layer, or barrier coat layer containing a 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.

[0350] The adhesion improving layer, protective layer or 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.

[0351] In another embodiment, the adhesion improving layer, protective layer, or barrier coat layer is a gas barrier coating film formed by applying a gas barrier composition to a vapor-deposited film and drying it. The gas barrier composition is obtained by mixing a metal alkoxide, a water-soluble polymer, and optionally a silane coupling agent, and adding, optionally, water, optionally an organic solvent, and optionally a sol-gel catalyst. The gas barrier coating film contains a hydrolysis polycondensate obtained by hydrolyzing and polycondensing the metal alkoxide or the like by a sol-gel method. By providing such a 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.

[0352] Examples of metal alkoxides include alkoxysilanes, specifically tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane.

[0353] Examples of water-soluble polymers include hydroxyl group-containing polymers such as polyvinyl alcohol and ethylene-vinyl alcohol copolymers. These water-soluble polymers can also contribute to improving gas barrier properties, for example. Depending on the desired physical properties such as oxygen barrier properties, water vapor barrier properties, water resistance, and weather resistance, either polyvinyl alcohol or ethylene-vinyl alcohol copolymers may be used, or both may be used in combination. 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.

[0354] 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.

[0355] The gas barrier composition may contain water in an amount of preferably 0.1 mol or more, more preferably 0.5 mol or more, per mol of metal alkoxide, and preferably 100 mol or less, more preferably 60 mol or less. By setting the water content at or above the lower limit, for example, the oxygen barrier property and water vapor barrier property of the barrier 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.

[0356] The gas barrier composition may contain an organic solvent, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, and n-butyl alcohol. The sol-gel catalyst is preferably an acid or an amine compound.

[0357] 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.

[0358] 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 a 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.

[0359] 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.

[0360] <Adhesion improving layer> The barrier layer may further include an adhesion-improving layer, such as a barrier coat layer, between two vapor-deposited films (for example, between the first and second vapor-deposited films in the barrier layers of the fifth and sixth embodiments). When the barrier layer of the first to fourth embodiments 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 and third vapor-deposited films and between the second and fourth vapor-deposited films. The adhesion-improving layer improves the interlayer adhesion between the vapor-deposited films. When the vapor-deposited film is made of an inorganic oxide such as aluminum oxide or silicon oxide, such a barrier layer can effectively prevent cracks from occurring in the vapor-deposited film and can 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.

[0361] 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. In the barrier layers of the fifth and sixth embodiments, when the first and second vapor-deposited films are metal vapor-deposited films, a metal oxide film may be formed between the first and second vapor-deposited films as an adhesion improving layer. In the barrier layers of the first to fourth embodiments, when the first and third vapor-deposited films are metal vapor-deposited films, a metal oxide film may be formed between the first and third vapor-deposited films as an adhesion improving layer. When the second and fourth vapor-deposited films are metal vapor-deposited films, 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 comprising a vapor deposition film, a metal oxide film and another vapor deposition film allows for more stable formation of a vapor deposition film than forming a single thick metal vapor deposition film, in terms of higher thickness uniformity and fewer defects.

[0362] 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.

[0363] In the barrier layer of the fifth and sixth embodiments, the metal oxide film may be formed, for example, by forming a first vapor-deposited film and then introducing oxygen into metal vapor to vaporize the metal oxide obtained, or by heating the first vapor-deposited film in an oxygen atmosphere to oxidize the surface of the first vapor-deposited film. By forming a second vapor-deposited film on the surface of the metal oxide film, a barrier layer comprising a metal vapor-deposited film as the first vapor-deposited film, a metal oxide film, and a metal vapor-deposited film as the second vapor-deposited film can be produced. It is preferable that the first vapor-deposited film is an aluminum vapor-deposited film, the metal oxide film is an aluminum oxide film, and the second vapor-deposited film is an aluminum vapor-deposited film. In the barrier layer of the first to fourth embodiments, 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 deposition of 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 deposition of aluminum.

[0364] In one embodiment, the barrier layer of the first to fourth aspects comprises, in this order, a barrier coat layer, an inorganic oxide vapor-deposited film as a first vapor-deposited film, a first surface resin layer, a polyolefin layer, a second surface resin layer, and a metal vapor-deposited film as a second vapor-deposited film. In one embodiment, the barrier layer of the first to fourth aspects comprises, in this order, a metal vapor deposition film as a first vapor deposition film, a first surface resin layer, a polyolefin 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 of the first to fourth aspects 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 polyolefin 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 of the first to fourth aspects includes a first surface resin layer, a polyolefin layer, a second surface resin layer, an inorganic oxide vapor deposition film, and a barrier coat layer in this order.

[0365] In one embodiment, the barrier layer of the fifth or sixth aspect comprises, in this order, a polyolefin layer, a surface resin layer (G) or (AH), a metal vapor-deposited film as a first vapor-deposited film, an adhesion-improving layer such as a barrier coat layer or a metal oxide film, and a metal vapor-deposited film as a second vapor-deposited film. The metal vapor-deposited film is preferably an aluminum vapor-deposited film, and the metal oxide film is preferably an aluminum oxide film. In one embodiment, the fifth and sixth barrier layers comprise, in this order, a polyolefin layer, a surface resin layer (G) or (AH), a metal vapor-deposited film as a first vapor-deposited film, an adhesion-improving layer such as a first barrier coat layer, an inorganic oxide vapor-deposited film as a second vapor-deposited film, and a protective layer such as a second barrier coat layer. The metal vapor-deposited film is preferably an aluminum vapor-deposited film, and the inorganic oxide vapor-deposited film is preferably an alumina vapor-deposited film, a silica vapor-deposited film, or a silicon oxide carbide vapor-deposited film. In one embodiment, the fifth and sixth barrier layers each include, in this order, a polyolefin layer, a surface resin layer (G) or (AH), an inorganic oxide vapor-deposited film as a first vapor-deposited film, an adhesion-improving layer such as a barrier coat layer, and a metal vapor-deposited film as a second vapor-deposited film. The inorganic oxide vapor-deposited film is preferably an alumina vapor-deposited film, a silica vapor-deposited film, or a silicon oxide carbide vapor-deposited film, and the metal vapor-deposited film is preferably an aluminum vapor-deposited film. In one embodiment, the fifth and sixth barrier layers comprise, in this order, a polyolefin layer, a surface resin layer (G) or (AH), an inorganic oxide vapor-deposited film as a first vapor-deposited film, an adhesion-improving layer such as a first barrier coat layer, an inorganic oxide vapor-deposited film as a second vapor-deposited film, and a protective layer such as a second barrier coat layer. The inorganic oxide vapor-deposited film is preferably an alumina vapor-deposited film, a silica vapor-deposited film, or a silicon oxide carbide vapor-deposited film. In the case of the stretched film (X), the polyolefin layer is replaced with a polyethylene layer.

[0366] <Print layer> The barrier layer may further include a printed layer, which will be described later. The printed layer may be provided, for example, on the surface of the second vapor-deposited film, on the surface of the protective layer, or on the surface of the first surface resin layer.

[0367] <Gas barrier properties of the barrier layer (barrier film)> Oxygen permeability of the barrier layer (unit: cc / (m 2 The kJ / cm² / day atm) may be, for example, less than 30, less than 20, less than 10, less than 5.0, less than 4.0, less than 3.0, less than 2.0, less than 1.5, less than 1.0, less than 0.8, less than 0.6, less than 0.5, less than 0.3, less than 0.2, or less than 0.1. 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.

[0368] Water vapor permeability of the barrier layer (unit: g / (m 2The moisture permeability (m / s) may be, for example, less than 10, less than 8.0, less than 5.0, less than 4.0, less than 3.0, less than 2.0, less than 1.5, less than 1.0, less than 0.8, less than 0.6, less than 0.5, less than 0.3, less than 0.2, or less than 0.1. The lower limit of the water vapor permeability may be, for example, 0.01. The water vapor permeability is measured in accordance with JIS K7129-2:2019 at a temperature of 40°C and a humidity of 90% RH.

[0369] <Layer structure of the barrier layer> Below, 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 polyolefin 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 polyolefin 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.

[0370] The barrier layer (barrier film) 1 shown in FIG. 4 includes a first vapor-deposited film 40, a first surface resin layer 20, a polyolefin 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 polyolefin 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.

[0371] The barrier layer (barrier film) 1 shown in Figure 7 comprises a first vapor-deposited film 40, a first surface resin layer 20, a first polyolefin layer 11, a second polyolefin layer 12, a third polyolefin layer 13, the second surface resin layer 20, and a second vapor-deposited film 40. The barrier layer (barrier film) 1 shown in Figure 8 comprises a first vapor-deposited film 40, a first surface resin layer 20, a first polyolefin layer 11, a second polyolefin layer 12, an adhesive resin layer 30, a second surface resin layer 20, and a second vapor-deposited film 40.

[0372] 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.

[0373] Hereinafter, several examples of the layer structure of the barrier layer (barrier film) will be given with reference to the drawings. In the case of the stretched film (X), the polyolefin layer below is read as a polyethylene layer. The barrier layer (barrier film) 1 shown in FIG. 9A comprises a polyolefin layer 10, a surface resin layer (G) or (AH) 20, a first vapor-deposited film 41, and a second vapor-deposited film 42 in this order. The barrier layer (barrier film) 1 shown in Figure 9B comprises, in this order, a first polyolefin layer 11, a second polyolefin layer 12, a third polyolefin layer 13, an adhesive resin layer 30, a surface resin layer (G) 20, a first vapor-deposited film 41, and a second vapor-deposited film 42. The barrier layer (barrier film) 1 shown in Figure 9C comprises, in this order, a first polyolefin layer 11, a second polyolefin layer 12, a third polyolefin layer 13, a fourth polyolefin layer 14, a surface resin layer (AH) 20, a first vapor-deposited film 41, and a second vapor-deposited film 42. The barrier layer (barrier film) 1 shown in FIG. 10 comprises, in this order, a polyolefin layer 10, a surface resin layer (G) or (AH) 20, a first vapor-deposited film 41, an adhesion-improving layer 50 such as a barrier coat layer or a metal oxide film, and a second vapor-deposited film 42. The barrier layer (barrier film) 1 shown in Figure 11 comprises, in this order, a polyolefin layer 10, a surface resin layer (G) or (AH) 20, a first vapor-deposited film 41, an adhesion-improving layer 51 such as a first barrier coat layer or a metal oxide film, a second vapor-deposited film 42, and a protective layer 52 such as a second barrier coat layer.

[0374] [Laminate] The laminate of the present disclosure comprises at least a first heat-seal layer, a barrier layer, and a second heat-seal layer, in this order. In one embodiment, the laminate of the present disclosure may further comprise a polyolefin substrate layer. Examples of the polyolefin substrate layer include a polyethylene substrate layer and a polypropylene substrate layer.

[0375] 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, for example, the body of a tube container body.

[0376] The content of polyolefin (e.g., polyethylene or polypropylene) in the entire laminate of the present disclosure is preferably 80% by mass or more, more preferably 85% by mass or more, and even more preferably 90% by mass or more. This allows, for example, the laminate to be used to produce polyolefinized (e.g., polyethyleneized) packaging containers, improving the recyclability of the packaging containers. The upper limit of the content of polyolefin (e.g., polyethylene or polypropylene) is not particularly limited, but may be 99% by mass.

[0377] The total thickness of the laminate of the present disclosure may be 40 μm or more, 60 μm or more, 80 μm or more, 100 μm or more, 120 μm or more, 140 μm or more, 400 μm or less, 350 μm or less, or 300 μm or less, for example, 40 μm or more and 400 μm or less. The total thickness of the laminate can be appropriately changed depending on, for example, the use or shape of the packaging container. The total thickness of the laminate for tube containers is preferably 80 μm or more and 400 μm or less, more preferably 150 μm or more and 390 μm or less, and even more preferably 175 μm or more and 350 μm or less.

[0378] <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.

[0379] In the laminate, the orientation of the barrier layer is not particularly limited. The barrier layers of the first to fourth embodiments may be arranged so that the first surface resin layer faces the first heat-seal layer and the second surface resin layer faces the second heat-seal layer, or so that the second surface resin layer faces the first heat-seal layer and the first surface resin layer faces the second heat-seal layer, with the former being preferred.

[0380] 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 first heat-seal layer and the second vapor-deposited film faces the second heat-seal layer. That is, the laminate of the above embodiment preferably comprises, in this order, the first heat-seal layer, the first vapor-deposited film, the first surface resin layer, the polyolefin layer, the second surface resin layer, the second vapor-deposited film, and the second heat-seal layer.

[0381] 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 first heat-seal layer and the vapor-deposited film faces the second heat-seal layer. That is, the laminate of the above embodiment preferably comprises, in this order, the first heat-seal layer, the first surface resin layer, the polyolefin layer, the second surface resin layer, the vapor-deposited film, and the second heat-seal layer.

[0382] The barrier layer of the fifth or sixth embodiment may be arranged so that the stretched film faces the first heat-seal layer and the first and second vapor-deposited films face the second heat-seal layer, or so that the first and second vapor-deposited films face the first heat-seal layer and the stretched film faces the second heat-seal layer, with the former being preferred.

[0383] For example, from the viewpoint of resistance to contents, the barrier layer of the fifth or sixth embodiment may be arranged so that the polyolefin layer faces the first heat-seal layer (the inside of the tubular container) and the first and second vapor-deposited films face the second heat-seal layer (the outside of the tubular container). That is, the laminate may include, in this order, a first heat-seal layer, a polyolefin layer such as a polyethylene layer or a polypropylene layer, a surface resin layer (G) or (AH), a first vapor-deposited film, a second vapor-deposited film, and a second heat-seal layer.

[0384] In one embodiment of the laminate of the present disclosure, the vapor-deposited film is provided on the surface of the surface resin layer (G) or (AH) (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 first heat-seal layer, and the first and second vapor-deposited films face the second heat-seal layer. That is, the laminate of the above embodiment preferably comprises, in this order, the first heat-seal layer, the first surface resin layer, the polyolefin layer, the second surface resin layer, the first vapor-deposited film, the second vapor-deposited film, and the second heat-seal layer.

[0385] In one embodiment, the laminate of the present disclosure comprises, in this order, a first heat-seal layer containing polyethylene or polypropylene as a main component, a barrier layer containing a polypropylene-based stretched film, and a second heat-seal layer containing polyethylene or polypropylene as a main component. In one embodiment, the laminate of the present disclosure comprises, in this order, a first heat-seal layer containing polyethylene as a main component, a barrier layer containing a polyethylene-based stretched film, and a second heat-seal layer containing polyethylene as a main component.

[0386] <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 laminate of the present disclosure may include a printed layer on the second heat-seal layer described below. 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.

[0387] 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).

[0388] 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.

[0389] 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.

[0390] 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.

[0391] 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.

[0392] The print layer may contain the above-mentioned additives.

[0393] 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.

[0394] 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.

[0395] <Surface protective layer> The laminate of the present disclosure may include a surface protective layer on the printed layer provided on the second heat seal layer described below in order to improve the scratch resistance and weather resistance of the printed layer. The laminate of the present disclosure preferably includes a surface protective layer that covers the entire area of ​​the printed layer. From the viewpoint of visibility of the printed layer, the surface protective layer is preferably transparent in the visible light range, and more preferably colorless and transparent.

[0396] The surface protective layer contains, for example, a cured product of a thermoplastic resin, a thermosetting resin, or a cured product of an energy ray-curable compound. Among these, from the viewpoint of improving scratch resistance and weather resistance, the surface protective layer preferably contains a cured product of a thermosetting resin or a cured product of an energy ray-curable compound, and more preferably contains a cured product of an energy ray-curable compound. The proportion of the cured product in the total resin components of the surface protective layer is preferably 80% by mass or more, more preferably 90% by mass or more. Methods for forming the surface protective layer include, for example, letterpress printing, flexographic printing, gravure printing, offset printing, screen printing, inkjet printing, and thermal transfer printing.

[0397] The thickness of the surface protective layer is preferably 0.5 μm or more, more preferably 1 μm or more, and preferably 15 μm or less, more preferably 10 μm or less, for example, 0.5 μm or more and 15 μm or less. A laminate including such a surface protective layer has, for example, excellent scratch resistance and weather resistance.

[0398] <Heat seal layer> The laminate of the present disclosure comprises a heat seal layer. In recent years, there has been a demand for recycling packaging containers in order to reduce environmental impact. From the viewpoint of recyclability, it is preferable that the substrate and the heat seal layer are each made of the same type of resin material (mono-material). In one embodiment, the heat seal layer contains a polyolefin such as polyethylene or polypropylene as a main component. This allows the packaging container to be made mono-material. Such packaging containers have excellent recyclability, and for example, after collecting used packaging containers, there is no need to separate the substrate and the heat seal layer.

[0399] For example, when the stretched film is a polypropylene-based stretched film, the heat-sealing layer preferably contains polypropylene or polyethylene as a main component. For example, when the stretched film is a polyethylene-based stretched film, the heat-sealing layer preferably contains polyethylene as a main component.

[0400] In one embodiment, the heat seal layer contains polyethylene as a main component. This allows the packaging container to be converted to polyolefin (e.g., polyethylene). Such a packaging container has excellent recyclability, and for example, after collecting a used packaging container, it is not necessary to separate the barrier layer and the heat seal layer. The above-mentioned 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.

[0401] 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.

[0402] 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.

[0403] 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, or may be 90°C or higher or 95°C or higher, and is 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.

[0404] 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.

[0405] 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.

[0406] The heat seal layer may contain the above-mentioned additives.

[0407] In one embodiment, the laminate of the present disclosure comprises at least a first heat seal layer; A barrier layer; a second heat seal layer; and in this order. Such a laminate can be suitably used, for example, as a packaging material for forming the body of a tube container body. In this case, for example, the second heat seal layer is a sealant layer on the outer surface side of the body, and the first heat seal layer is a sealant layer on the inner surface side of the body. That is, the body comprises, from the outside to the inside of the body, the second heat seal layer, the barrier layer, and the first heat seal layer in this order.

[0408] The laminate of the present disclosure may include at least a first heat-seal layer, a barrier layer, and a second heat-seal layer, in this order. The first and second heat-seal layers can be melted and fused to each other by heating. Such a laminate can be suitably used, for example, as a packaging material for forming the body of a tube container.

[0409] In one embodiment, the first heat-sealable layer and the second heat-sealable layer contain a polyolefin such as polyethylene or polypropylene as a main component. The polyolefin contained in the first heat-sealable layer and the polyolefin contained in the second heat-sealable layer may be the same or different. In the case of the stretched film (X), the above polyolefin is read as polyethylene.

[0410] The heat seal layer may have a single-layer structure or a multi-layer structure. The first and second heat seal layers may have a single-layer structure or a multi-layer structure. In one embodiment, the heat seal layer comprises, in this order, a layer containing linear low-density polyethylene as a main component, a layer containing high-density polyethylene as a main component, and a layer containing linear low-density polyethylene as a main component, and such a heat seal layer has 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 main component, a second HS layer containing linear low-density polyethylene as a main component, and a third HS layer containing linear low-density polyethylene as a main component, and has excellent heat sealability.

[0411] 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 prepare a tube container, the third HS layer faces the inside or outside of the tube container. In one embodiment, the first HS layer is a surface resin layer on one side of the heat seal layer, and the third HS layer is a surface resin layer on the other side.

[0412] In one embodiment, the laminate includes a third HS layer, a second HS layer, a first HS layer, a barrier layer, a first HS layer, a second HS layer, and a third HS layer, in this order.

[0413] The density of the linear low density polyethylene contained in the first and third HS layers 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 and third HS layers is preferably 80% by mass or more, more preferably 85% by mass or more, and even more preferably 90% by mass or more.

[0414] The ratio of the thickness of the first and third HS layers 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.

[0415] 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.

[0416] 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.

[0417] 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.

[0418] 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.

[0419] 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 milky white heat seal layer.

[0420] 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.

[0421] 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.

[0422] 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.

[0423] 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.

[0424] 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.

[0425] From the viewpoints of heat-sealing properties and recyclability of the packaging container, the thickness of the heat-sealing layer may be 10 μm or more, 15 μm or more, 20 μm or more, 25 μm or more, 30 μm or more, 50 μm or more, 60 μm or more, 70 μm or more, or 80 μm or more. From the viewpoint of processability of the laminate, the thickness of the heat-sealing layer may be 300 μm or less, 200 μm or less, or 150 μm or less. The thickness of the heat-sealing layer is, for example, 10 μm or more and 300 μm or less. The thicknesses of the first and second heat-sealing layers are also preferably independently within the above-mentioned ranges. The thickness of the heat-sealing layer can be appropriately changed depending on, for example, the use or shape of the packaging container. In the case of a laminate for a tube container, the thickness of each heat seal layer may be, for example, 40 μm or more, 50 μm or more, 60 μm or more, 70 μm or more, or 80 μm or more, but is not particularly limited.

[0426] 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.

[0427] For example, an unstretched resin film corresponding to the heat seal layer may be laminated on the barrier layer or the corresponding barrier film via an adhesive layer as needed, or the heat seal layer may be formed by melt-extruding a polyolefin or a resin composition thereof onto the barrier layer or the corresponding barrier film. In the latter case, an adhesive layer may not be provided. Examples of the adhesive layer include the adhesive layer described below.

[0428] <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.

[0429] In one embodiment, the laminate of the present disclosure includes a first heat-sealing layer, a first adhesive layer, a barrier layer, a second adhesive layer, and a second heat-sealing layer in this order, and such a laminate has excellent adhesion between the barrier layer and the heat-sealing layer, for example.

[0430] 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.

[0431] 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.

[0432] 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.

[0433] In one embodiment, the laminate of the present disclosure may be produced by laminating a resin film corresponding to the heat seal layer and a barrier film corresponding to the barrier layer by a non-solvent lamination method using a solvent-free adhesive, or by a dry lamination method using a solvent-based adhesive.

[0434] 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.

[0435] 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.

[0436] 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.

[0437] 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.

[0438] 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.

[0439] 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.

[0440] An example of the polyolefin plastomer is polyethylene plastomer. The details of polyethylene plastomer are as described above, and therefore will not be described here.

[0441] 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 3 Less 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.

[0442] 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.

[0443] 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.

[0444] 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.

[0445] 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.

[0446] 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.

[0447] 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.

[0448] 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.

[0449] <Layer structure of laminate> Examples of the layer structure of the laminate of the present disclosure are given below. In the case of the embodiment of the stretched film (X), the polyolefin layer below is read as a polyethylene layer. The laminate 2 shown in FIG. 12 includes a first heat-seal layer 81, a first adhesive layer 61, a barrier layer 1, a second adhesive layer 62, and a second heat-seal layer 82, in this order. Specifically, the laminate 2 includes the first heat-seal layer 81, the first adhesive layer 61, a polyolefin layer 10, a surface resin layer (G) or (AH) 20, a first vapor-deposited film 41, a second vapor-deposited film 42, the second adhesive layer 62, and the second heat-seal layer 82, in this order. In FIG. 12, the orientation of the barrier layer 1 may be reversed. The laminate 2 shown in FIG. 12 may include a barrier layer 1 having the structure shown in FIGS. 1 to 11, instead of the barrier layer 1. The laminate 2 may further include a printed layer (not shown). The laminate 2 may further include a printed layer, for example, on the surface of the second heat-seal layer 82. A laminate having such a structure is suitable as a packaging material for forming the body of a tube container, for example.

[0450] <Gas barrier properties of laminate> The oxygen permeability (unit: cc / (m 2 The oxygen permeability (°C / °F) is preferably less than 3.0, more preferably less than 2.0, even more preferably less than 1.0, and particularly preferably less than 0.5, 0.3, or 0.1. 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 at a temperature of 23°C and a humidity of 90% RH.

[0451] The water vapor permeability (unit: g / (m 2 ·day)) may be, for example, less than 10, preferably less than 3.0, more preferably less than 2.0, even more preferably less than 1.0, and particularly preferably less than 0.5, less than 0.3, or less than 0.1. 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.

[0452] [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.

[0453] Examples of packaging containers include packaging bags, tube containers, and containers with lids.

[0454] 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 bags may be, for example, small pouches or zipper bags. The packaging bags may also be refill pouches, particularly stand-up pouches, that contain contents such as liquids and powders and are refilled into containers such as bottles. The packaging bags may also be, for example, flexible packaging bags.

[0455] 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.

[0456] 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.

[0457] 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.

[0458] 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 strong-smelling contents such as shampoo, rinse, conditioner, fabric softener, and detergent are filled in the packaging container, leakage of the smell can be suppressed. For example, toothpaste is a preferred content for a tube container.

[0459] [Tube container body] The tube container body of the present disclosure includes the laminate of the present disclosure. The tube container body of the present disclosure will be described below with reference to the drawings. Fig. 13 is a diagram showing a simplified configuration of a tube container 120, and Fig. 14 is a cross-sectional view taken along line AA in Fig. 13. As shown in Fig. 13, the tube container body 121 includes a head 122 and a body 123, and the body 123 is made of the laminate of the present disclosure.

[0460] <Head> The head 122 includes a shoulder 124 connected to one end of the body 123, and a spout 125 connected to the shoulder 124. In one embodiment, the spout 125 includes threads 127 for threading a cap 126 onto the spout 125.

[0461] In one embodiment, the head portion is formed from a resin composition containing a thermoplastic resin. Examples of the thermoplastic resin include polyolefins such as polyethylene and polypropylene, polyesters, cellulose resins, and vinyl resins. The resin composition may contain the additives described above. In one embodiment, the head portion is formed from a resin composition containing polyethylene. Such a head portion can improve the recyclability of the tube container body. Examples of polyethylene include high-density polyethylene, medium-density polyethylene, low-density polyethylene, and linear low-density polyethylene. Among these, high-density polyethylene is preferred from the viewpoints of shape retention and moldability. The resin composition may contain at least one selected from the group consisting of biomass polyethylene and recycled polyethylene. The resin composition may also contain the additive.

[0462] The head portion can be produced by a conventionally known method, for example, by compression molding or injection molding, and can be joined to the body portion.

[0463] <Body> In the tube container body 121 of the present disclosure, the body 123 is connected to a shoulder 124 of the head 122. The body 123 includes a fused portion 128 formed, for example, by overlapping the laminate of the present disclosure at one end so that the surface of the first heat-sealed layer at the other end is in contact with the surface of the second heat-sealed layer at the other end, rolling the laminate into a cylindrical shape, and heat-sealing the overlapped portion. The body 123 includes a bottom seal portion 129 formed, for example, by heat-sealing the opening of the cylindrically rolled laminate.

[0464] Examples of heat sealing methods include conventionally known methods such as bar sealing, rotary roll sealing, belt sealing, impulse sealing, high frequency sealing, ultrasonic sealing, and flame sealing.

[0465] For example, a cylindrical body portion may be produced by overlapping one end of the laminate of the present disclosure so that the surface of the first heat-seal layer at one end is in contact with the surface of the second heat-seal layer at the other end, rolling the laminate into a cylindrical shape, and heat-sealing the overlapped portion. From the viewpoint of heat-sealability, it is preferable that one overlapping end is the first heat-seal layer and the other end is the second heat-seal layer. In this case, the first heat-seal layer and the second heat-seal layer are melted and joined to form a fused portion.

[0466] Therefore, it is preferable that the second heat-sealing layer does not have a printed layer or a surface protective layer formed in the area where heat sealing is to be performed when forming the body of the tube container body. With this configuration, when forming the cylindrical body using the laminate of the present disclosure, the area can be heat-sealed well.

[0467] In the above embodiment, the fused portion is formed by overlapping, but it may also be possible to butt the same surfaces of both ends of the laminate together and heat-seal the first heat-seal layers to join them. In this case, a printed layer and a surface protective layer may be formed on the second heat-seal layer at both ends of the laminate. Also, in this case, a bonding tape may be applied to the outer surface of the body portion so as to cover the bonding portion. It is preferable that a printed layer and a surface protective layer are not provided at the location of the laminate where the bonding tape is applied. The bonding tape may be provided on both the inner and outer surfaces of the body portion.

[0468] [Tube container] The tube container of the present disclosure will be described below with reference to the drawings. As shown in Fig. 13, the tube container 120 of the present disclosure includes a tube container body 121 and a cap 26 attached to a head portion 122.

[0469] <Tube container body> The tube container body has been described above, so a description thereof will be omitted here.

[0470] <Cap> The cap is removably attached to the spout of the head. The cap serves to close the spout. In one embodiment, the cap is formed from a resin composition containing a thermoplastic resin. Examples of thermoplastic resins include polyolefins such as polyethylene and polypropylene, polyesters, cellulose resins, and vinyl resins. From the viewpoint of recyclability, polyethylene is particularly preferred. Examples of polyethylene include high-density polyethylene, medium-density polyethylene, low-density polyethylene, and linear low-density polyethylene. Among these, high-density polyethylene is preferred from the viewpoint of shape retention and ease of opening. The resin composition may contain at least one selected from the group consisting of biomass polyethylene and recycled polyethylene. The resin composition may also contain the additives described above.

[0471] The cap may be a screw type having a groove on the inner surface of the cap so as to screw onto the thread 127 of the extraction port 125, as shown in Figure 13, or it may be a stopper type that fits into the extraction port 125 by tapping it.

[0472] [Aspects of the present disclosure] The present disclosure relates to, for example, the following [1] to

[16] . [1] A laminate comprising, in this order, at least a first heat seal layer containing polyolefin as a main component, a barrier layer, and a second heat seal layer containing polyolefin as a main component, wherein the barrier layer comprises at least a stretched film and a vapor-deposited film, and the stretched film comprises at least a polyolefin layer containing polyolefin as a main component and a surface resin layer containing a gas barrier resin as a main component or containing polyolefin and an adhesive resin, and the vapor-deposited film is provided at least on the surface resin layer of the stretched film. [2] The laminate according to [1], wherein the barrier layer comprises, in this order, a first vapor-deposited film as the vapor-deposited film, a first surface resin layer, a polyolefin layer, a second surface resin layer, and a second vapor-deposited film as the vapor-deposited film, the first surface resin layer, the polyolefin layer, and the second surface resin layer are layers that constitute the stretched film, the first surface resin layer is a layer containing a gas barrier resin as a main component, or a layer containing a polyolefin and an adhesive resin, the polyolefin layer contains a polyolefin 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 a polyolefin and an adhesive resin. [3] The laminate according to [2] above, wherein the stretched film is a film selected from the group consisting of the following (1) to (6): (1) A polyethylene-based stretched film in which the polyolefin layer contains polyethylene as a main component, and the first surface resin layer and the second surface resin layer contain a gas barrier resin as a main component; (2) A polyethylene-based stretched film in which the polyolefin layer contains polyethylene as a main component, and the first surface resin layer and the second surface resin layer contain polyethylene and an adhesive resin; (3) A polyethylene-based stretched film, wherein the polyolefin layer contains polyethylene as a main component, one of the first surface resin layer and the second surface resin layer contains a gas barrier resin as a main component, and the other contains polyethylene and an adhesive resin; (4) A polypropylene-based stretched film in which the polyolefin layer contains polypropylene as a main component, and the first surface resin layer and the second surface resin layer contain a gas barrier resin as a main component; (5) A polypropylene-based stretched film in which the polyolefin layer contains polypropylene as a main component, and the first surface resin layer and the second surface resin layer contain polypropylene and an adhesive resin; (6) A polypropylene-based stretched film, wherein the polyolefin layer contains polypropylene as a main component, one of the first surface resin layer and the second surface resin layer contains a gas barrier resin as a main component, and the other contains polypropylene and an adhesive resin. [4] The laminate according to any one of [1] to [3], wherein the barrier layer comprises, in this order, a first surface resin layer, a polyolefin layer, a second surface resin layer, and a vapor-deposited film, the first surface resin layer, the polyolefin layer, and the second surface resin layer being layers constituting the stretched film, the first surface resin layer containing polyolefin as a main component, and the polyolefin layer containing polyolefin as a main component, 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 second surface resin layer is a layer containing a gas barrier resin as a main component, or a layer containing polyolefin and an adhesive resin. [5] The laminate according to [4] above, wherein the stretched film is a film selected from the group consisting of the following (7) to (10): (7) A polyethylene-based stretched film in which the first surface resin layer and the polyolefin layer contain polyethylene as a main component, and the second surface resin layer contains a gas barrier resin as a main component; (8) A polyethylene-based stretched film in which the first surface resin layer and the polyolefin layer contain polyethylene as a main component, and the second surface resin layer contains polyethylene and an adhesive resin; (9) A polypropylene-based stretched film in which the first surface resin layer and the polyolefin layer contain polypropylene as a main component, and the second surface resin layer contains a gas barrier resin as a main component; (10) A polypropylene-based stretched film, wherein the first surface resin layer and the polyolefin layer contain polypropylene as a main component, and the second surface resin layer contains polypropylene and an adhesive resin. [6] The laminate according to [4] or [5], wherein a first vapor-deposited film and a second vapor-deposited film are provided in this order as the vapor-deposited films on the second surface resin layer. [7] The laminate according to [6], wherein the barrier layer further comprises an adhesion improving layer between the first vapor-deposited film and the second vapor-deposited film. [8] The laminate according to [7], wherein the adhesion improving layer is a barrier coat layer or a metal oxide film. [9] The laminate according to any one of [6] to [8], wherein the barrier layer further comprises a protective layer on the surface of the second vapor-deposited film opposite to the surface facing the first vapor-deposited film.

[10] The laminate according to [9], wherein the protective layer is a barrier coat layer.

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

[10] , wherein the stretched film is a uniaxially stretched film or a biaxially stretched film.

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

[11] , wherein the first heat seal layer and the second heat seal layer each contain polyethylene as a main component.

[13] The laminate according to

[12] , wherein the heat seal layer comprises, in this order, a first HS layer containing a linear low-density polyethylene as a main component, a second HS layer containing a linear low-density polyethylene as a main component, and a third HS layer containing a linear low-density polyethylene as a main component, and the first HS layer faces the barrier layer.

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

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

[15] A tube container body having a head and a body, wherein the head has a shoulder connected to one end of the body and a spout connected to the shoulder, and the body is made of the laminate described in any one of [1] to

[14] .

[16] A tube container comprising the tube container body according to

[15] above and a cap. [Example]

[0473] 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".

[0474] [Preparation of stretched film 1] 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

[0475] [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).

[0476] 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.

[0477] 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.

[0478] 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.

[0479] 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, thereby obtaining a barrier film brA1. An aluminum (AL) film having a thickness of 30 nm was formed by vapor deposition on the surface resin layer of each of the stretched films by the PVD method, thus obtaining a barrier film brA2. 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, a barrier film brA3 was obtained. A barrier film brA4 was obtained in the same manner as the barrier film brA3, except that a silica vapor-deposited film was formed instead of the alumina vapor-deposited film. A 30 nm thick alumina vapor deposition film was formed on each surface resin layer of the stretched film by PVD, and the above-mentioned barrier coating agent was spin-coated onto the surface of each alumina vapor deposition film, followed by heat treatment in an oven at 100°C for 8 seconds to form a 0.3 μm thick barrier coating layer. In this way, barrier film brA5 was obtained. Barrier film brA6 was obtained in the same manner as barrier film brA5, except that a silica vapor deposition film was formed instead of the alumina vapor deposition film.

[0480] <Dry lamination> As a sealant film, First, LLDPE (Prime Polymer, SP2020, density: 0.916 g / cm3 , 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 (SP2020) and The resulting mixture was subjected to multi-layer extrusion molding to produce an unstretched polyethylene film (sealant film) 1 having a first LLDPE layer with a thickness of 30 μm, a second LLDPE layer with a thickness of 60 μm, and a third LLDPE layer with a thickness of 30 μm. 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 200 μm.

[0481] The sealant film 2 and the barrier film were 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 LLDPE layer surface of the sealant film 2 faced the (second) vapor-deposited film or the second barrier coat layer-formed 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 LLDPE layer surface of the sealant film 1. A laminate was thus obtained.

[0482] <Extrusion lamination> 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 3 A blend of 30% by mass of ethylene glycol stearate (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 LLDPE layer surface of Sealant Film 1 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 first LLDPE layer surface of Sealant Film 2 was laminated through this extruded resin layer. In this way, a laminate was obtained.

[0483] [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.

[0484] [Example 3] A blended polyethylene (C) was prepared by mixing 80 parts of LLDPE (Exceed XP8656ML) and 20 parts of a compatibilizer (RETAIN 3000).

[0485] 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.

[0486] [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.

[0487] [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.

[0488] [Gas barrier property evaluation 1] 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.

[0489] <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.

[0490] <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.

[0491] [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.

[0492] [Preparation of tube containers] The laminate obtained in each of the examples and comparative examples was cut into individual laminate pieces using a bobbin cutter, and the two ends in the width direction were overlapped. Then, the overlapped ends were cut together at a temperature of 160°C and a pressure of 1 kgf / cm. 2The raw material was heat-sealed under conditions of 1000 sintering time and 1 second crimping time to obtain a cylindrical raw material. The obtained raw material was cut to produce a cylindrical body portion that would become the body of the tube container. The cylindrical body portion was attached to a mandrel for forming a tube container, and a head portion consisting of a truncated cone-shaped shoulder portion and a cylindrical extraction port portion connected to it was molded at one end of the cylindrical body portion using high-density polyethylene by compression molding to produce a tube container body as shown in Figure 13. Next, the high-density polyethylene was injected into a cap-forming mold and molded to produce a cap. In this manner, a tube container was obtained.

[0493] [Table 1]

[0494] [Table 2]

[0495] 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".

[0496] [Preparation of stretched film 2] The following materials were used in producing the stretched film. Ethylene-vinyl alcohol copolymer (EVOH) Kuraray, Eval G156B, melting point: 157°C, MFR: 6.4 g / 10 min, ethylene content: 48 mol% Aliphatic polyamide (aliphatic PA) UBE, Polyamide 6 (PA6) 1020 Melting point: 220°C, relative viscosity: 3.04 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 (acid-modified r-PP) Mitsui Chemicals, Admer QF580 Maleic anhydride graft modified random polypropylene, Density: 0.900g / cm 3 Melting point: 140℃, MFR: 7.7g / 10min Adhesive resin (acid-modified LLDPE) Mitsui Chemicals, Admer NF587 Maleic anhydride grafted linear low-density polyethylene, Density: 0.910g / cm 3 Melting point: 120℃, MFR: 2.3g / 10min Homopolypropylene (h-PP) Manufactured by The Polyolefin Company (Singapore) COSMOPLENE FS3031, density: 0.900g / cm 3 , Melting point: 168°C, MFR: 3.4g / 10min, Isotactic index: 98% Random polypropylene (r-PP) Manufactured by The Polyolefin Company (Singapore) COSMOPLENE FS5612, density: 0.900g / cm 3 , Melting point: 134°C, MFR: 5.5g / 10min High density polyethylene (HDPE) Metallocene HDPE, ethylene-1-octene copolymer, Density: 0.955g / cm 3 Melting point: 130℃, MFR: 1.5g / 10min Linear low-density polyethylene (LLDPE) Dow Chemical's INNATE TF80 Metallocene LLDPE, ethylene-1-octene copolymer, Density: 0.926g / cm 3 , MFR: 1.7g / 10min Acid-modified random polypropylene (MAH-r-PP) Arkema, OREVAC 18722, Maleic anhydride graft modified random polypropylene, Density: 0.900g / cm 3 Melting point: 143°C, MFR: 7.0g / 10min Acid-modified linear low-density polyethylene (MAH-LLDPE) Arkema OREVAC 18302N, Maleic anhydride grafted linear low-density polyethylene, Density: 0.912g / cm 3 Melting point: 123°C, MFR: 1.5g / 10min

[0497] [Preparation of Composition] A blended polyethylene (A) was prepared by mixing 40 parts of HDPE (metallocene HDPE) and 60 parts of LLDPE (INNATE TF80). A blended polyethylene (B) was prepared by mixing 90 parts of LLDPE (INNATE TF80) and 10 parts of acid-modified LLDPE (OREVAC 18302N). A blend polypropylene (A) was prepared by mixing 90 parts of random polypropylene (FS5612) and 10 parts of acid-modified random polypropylene (OREVAC 18722). A blend polyamide (A) was prepared by mixing 50 parts of a semi-aromatic polyamide (MXD6) and 50 parts of an aliphatic polyamide (Polyamide 6 1020). A blend polyamide (B) was prepared by mixing 50 parts of a semi-aromatic polyamide (MXD6) and 50 parts of a semi-aromatic polyamide (Grivory G21).

[0498] [Manufacturing example 1A] Ethylene-vinyl alcohol copolymer (G156B), Adhesive resin (QF580) and Homopolypropylene (FS3031) and Adhesive resin (QF580) and Ethylene-vinyl alcohol copolymer (G156B), The five layers were co-extruded by T-die casting to obtain a five-layer film, which was then sequentially biaxially stretched by 5 times in the machine direction (MD) and then 8.5 times in the transverse direction (TD) to produce a stretched film (biaxially stretched film) with a thickness of 18 μm.

[0499] The stretched film thus obtained is A first surface resin layer (EVOH layer) having a thickness of 1 μm; a first adhesive resin layer having a thickness of 1.5 μm; A 13 μm thick polypropylene layer, a second adhesive resin layer having a thickness of 1.5 μm; A second surface resin layer (EVOH layer) having a thickness of 1 μm; are provided in this order.

[0500] Three types of barrier films were prepared as follows. An aluminum (AL) vapor-deposited film having a thickness of 30 nm was formed on each of the first and second surface resin layers of the stretched film by the PVD method, thus obtaining a barrier film brB1. A 30 nm thick alumina vapor deposition film was formed on each of the first and second surface resin layers of the stretched film by PVD. The above-mentioned barrier coating agent was spin-coated onto the surface of the alumina vapor deposition film, and the film was heated in an oven at 100°C for 8 seconds to form a 0.3 μm thick barrier coating layer. In this way, a barrier film brB2 was obtained. A barrier film brB3 was obtained in the same manner as the barrier film brB2, except that a silica vapor deposition film was formed instead of the alumina vapor deposition film.

[0501] [Production examples 2A~6A, 1B~12B, 1C~3C, 1D~6D, 1E~12E, Comparative production examples 1A, 1B~2B] Stretched films and barrier films were produced in the same manner as in Production Example 1A, except that the composition or thickness of each layer was changed as shown in each table. In this specification, "←" in the tables means that the composition or thickness of the layer in question is the same as the composition or thickness in the column to the left.

[0502] [Gas barrier test 2] The oxygen permeability (cc / (m) of each barrier film (hereinafter also referred to as "test piece") obtained in the Production Examples and Comparative Production Examples was 2 ·day·atm)) and water vapor permeability (g / (m 2 The evaluation results are shown in the tables below.

[0503] <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).

[0504] The evaluation criteria are as follows: A: The oxygen permeability is less than 0.2. B: Oxygen permeability is 0.2 or more and less than 0.8. C: Oxygen permeability is 0.8 or more and less than 2.0. D: Oxygen permeability is 2.0 or more and less than 10. E: Oxygen permeability is 10 or more and less than 100.

[0505] ...

Claims

1. a first heat seal layer containing polyolefin as a main component; A barrier layer; a second heat seal layer containing polyolefin as a main component; A laminate comprising at least the following in this order: the barrier layer comprises at least a stretched film and a vapor-deposited film, The stretched film comprises at least a polyolefin layer containing polyolefin as a main component; a surface resin layer containing a gas barrier resin as a main component or containing a polyolefin and an adhesive resin; Equipped with The vapor-deposited film is provided at least on the surface resin layer of the stretched film. Laminate.

2. The barrier layer is a first vapor-deposited film as the vapor-deposited film; a first surface resin layer; a polyolefin layer; a second surface resin layer; a second vapor-deposited film as the vapor-deposited film; In this order, the first surface resin layer, the polyolefin layer, and the second surface resin layer are layers that constitute the stretched film, the first surface resin layer is a layer containing a gas barrier resin as a main component, or a layer containing a polyolefin and an adhesive resin, The polyolefin layer contains polyolefin 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 a polyolefin and an adhesive resin; The laminate according to claim 1 .

3. The laminate according to claim 2, wherein the stretched film is a film selected from the group consisting of the following (1) to (6): (1) A polyethylene-based stretched film in which the polyolefin layer contains polyethylene as a main component, and the first surface resin layer and the second surface resin layer contain a gas barrier resin as a main component; (2) A polyethylene-based stretched film in which the polyolefin layer contains polyethylene as a main component, and the first surface resin layer and the second surface resin layer contain polyethylene and an adhesive resin; (3) A polyethylene-based stretched film, in which the polyolefin layer contains polyethylene as a main component, one of the first surface resin layer and the second surface resin layer contains a gas barrier resin as a main component, and the other contains polyethylene and an adhesive resin; (4) A polypropylene-based stretched film in which the polyolefin layer contains polypropylene as a main component, and the first surface resin layer and the second surface resin layer contain a gas barrier resin as a main component; (5) A polypropylene-based stretched film in which the polyolefin layer contains polypropylene as a main component, and the first surface resin layer and the second surface resin layer contain polypropylene and an adhesive resin; (6) A polypropylene-based stretched film, wherein the polyolefin layer contains polypropylene as a main component, one of the first surface resin layer and the second surface resin layer contains a gas barrier resin as a main component, and the other contains polypropylene and an adhesive resin.

4. The barrier layer is a first surface resin layer; a polyolefin layer; a second surface resin layer; a vapor-deposited film; In this order, the first surface resin layer, the polyolefin layer, and the second surface resin layer are layers that constitute the stretched film, the first surface resin layer contains polyolefin as a main component, the polyolefin layer contains a polyolefin as a main component, 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 second surface resin layer is a layer containing a gas barrier resin as a main component, or a layer containing a polyolefin and an adhesive resin; The laminate according to claim 1 .

5. The laminate according to claim 4, wherein the stretched film is a film selected from the group consisting of the following (7) to (10): (7) A polyethylene-based stretched film in which the first surface resin layer and the polyolefin layer contain polyethylene as a main component, and the second surface resin layer contains a gas barrier resin as a main component; (8) A polyethylene-based stretched film in which the first surface resin layer and the polyolefin layer contain polyethylene as a main component, and the second surface resin layer contains polyethylene and an adhesive resin; (9) A polypropylene-based stretched film in which the first surface resin layer and the polyolefin layer contain polypropylene as a main component, and the second surface resin layer contains a gas barrier resin as a main component; (10) A polypropylene-based stretched film, wherein the first surface resin layer and the polyolefin layer contain polypropylene as a main component, and the second surface resin layer contains polypropylene and an adhesive resin.

6. The laminate according to claim 4 , wherein the vapor-deposited films are a first vapor-deposited film and a second vapor-deposited film provided in this order on the second surface resin layer.

7. The laminate according to claim 6 , wherein the barrier layer further comprises an adhesion-promoting layer between the first vapor-deposited film and the second vapor-deposited film.

8. The laminate according to claim 7 , wherein the adhesion-improving layer is a barrier coat layer or a metal oxide film.

9. The laminate according to claim 6 , wherein the barrier layer further comprises a protective layer on a surface of the second vapor-deposited film opposite to a surface facing the first vapor-deposited film.

10. The laminate according to claim 9 , wherein the protective layer is a barrier coat layer.

11. The laminate according to claim 1 , wherein the stretched film is a uniaxially stretched film or a biaxially stretched film.

12. The laminate according to claim 1 , wherein the first heat-seal layer and the second heat-seal layer each contain polyethylene as a primary component.

13. 13. The laminate according to claim 12, wherein the heat seal layer comprises, in this order, a first HS layer containing a linear low density polyethylene as a main component, a second HS layer containing a linear low density polyethylene as a main component, and a third HS layer containing a linear low density polyethylene as a main component, and the first HS layer faces the barrier layer.

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

15. A tube container body having a head and a body, The head portion has a shoulder portion connected to one end of the body portion and a spout portion connected to the shoulder portion, and the body portion is made of the laminated body according to any one of claims 1 to 14. Tube container body.

16. The tube container body according to claim 15; Cap and A tube container comprising:

Images