Stretched substrate, barrier substrate, laminate and packaging container

Abstract

To provide a polyethylene-based stretched substrate that is suitable for preparing a barrier substrate with superior gas barrier properties.SOLUTION: A stretched substrate comprises at least a first surface resin layer containing polyethylene and adhesive resin, a polyethylene layer primarily composed of polyethylene, and a second surface resin layer containing polyethylene and adhesive resin, in the stated order, where the stretched substrate is produced by uniaxial stretching treatment.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to stretched substrates, barrier substrates, laminates, and packaging containers. [Background technology]

[0002] Packaging containers are used to contain contents such as liquids and powders. Packaging containers are produced using a laminate including a substrate and a heat seal layer (see, for example, Patent Document 1). For example, polyolefin films are widely used as heat seal layers because they have flexibility and transparency as well as excellent heat sealability. Biaxially oriented polyester films are also widely used as substrates because they have excellent strength and heat resistance.

[0003] In recent years, from the viewpoint of reducing the environmental load, there has been a demand for recycling packaging containers. From the viewpoint of recyclability, it is preferable that the base material and the heat seal layer are each made of the same type of resin material (mono-materialization). For example, Patent Document 1 proposes that the base material and the heat seal layer are each made of polyethylene. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-55156 A Summary of the Invention [Problem to be solved by the invention]

[0005] The present inventors have investigated the use of a laminate having a stretched polyethylene film as a substrate as a packaging material to produce a packaging container. However, such packaging containers tend to have insufficient gas barrier properties. Therefore, the present inventors have investigated the provision of a vapor deposition film on a stretched polyethylene film. One object of the present disclosure is to provide a barrier substrate having excellent gas barrier properties, and a polyethylene-based stretched substrate that can be suitably used to produce the barrier substrate. [Means for solving the problem]

[0006] The stretched substrate of one embodiment of the present disclosure comprises, in this order, at least a first surface resin layer containing polyethylene and an adhesive resin, a polyethylene layer containing polyethylene as a main component, and a second surface resin layer containing polyethylene and an adhesive resin, and is subjected to a uniaxial stretching process. A barrier substrate according to one embodiment of the present disclosure includes the above-mentioned stretched substrate, and a vapor-deposited film provided on the surface of at least one layer selected from the first surface resin layer and the second surface resin layer of the above-mentioned stretched substrate. Effect of the Invention

[0007] According to the present disclosure, a polyethylene-based stretched substrate that can be suitably used to prepare a barrier substrate having excellent gas barrier properties can be provided. For example, a barrier substrate having a vapor deposition film on the polyethylene-based stretched substrate has excellent gas barrier properties. The stretched substrate and the barrier substrate are useful, for example, as a substrate in a packaging material for preparing a packaging container having excellent gas barrier properties. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic cross-sectional view showing one embodiment of a barrier substrate. [Figure 2A] FIG. 2A is a schematic cross-sectional view showing one embodiment of a barrier substrate. [Figure 2B] FIG. 2B is a schematic cross-sectional view showing one embodiment of a barrier substrate. [Figure 3A] FIG. 3A is a schematic cross-sectional view showing one embodiment of a barrier substrate. [Figure 3B] FIG. 3B is a schematic cross-sectional view showing one embodiment of a barrier substrate. [Figure 3C] FIG. 3C is a schematic cross-sectional view showing one embodiment of a barrier substrate. [Figure 4] FIG. 4 is a schematic cross-sectional view showing one embodiment of a laminate. [Diagram 5] FIG. 5 is a schematic cross-sectional view showing one embodiment of a laminate. [Figure 6] FIG. 6 is a schematic cross-sectional view showing one embodiment of a laminate. [Figure 7] FIG. 7 is a perspective view showing an embodiment of a tube container including a tube container body including a laminate and a cap. [Figure 8] FIG. 8 is a cross-sectional view taken along line AA in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments of the present disclosure will be described in detail. The present disclosure can be implemented in many different forms, and is not to be interpreted as being limited to the description of the embodiments exemplified below. In the drawings, the width, thickness, shape, etc. of each layer may be shown diagrammatically in order to make the explanation clearer, but these are merely examples and do not limit the interpretation of the present disclosure. In this specification and each figure, elements similar to those already explained with respect to the previous figures are given the same reference numerals, and detailed explanations may be omitted as appropriate.

[0010] 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 configured by combining any one upper limit candidate and any one lower limit candidate. Examples of the above parameters include physical property values, component content ratios, and layer thicknesses. As an example, the description "Parameter B is preferably A1 or more, more preferably A2 or more, and even more preferably A3 or more. Parameter B is preferably A4 or less, more preferably A5 or less, and even more preferably A6 or less." will be explained. In this example, the numerical range of parameter B may be A1 or more and A4 or less, A1 or more and A5 or less, A1 or more and A6 or less, A2 or more and A4 or less, A2 or more and A5 or less, A2 or more and A6 or less, A3 or more and A4 or less, A3 or more and A5 or less, or A3 or more and A6 or less.

[0011] In this specification, each of the components (e.g., 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 either alone or in combination of two or more types.

[0012] In this specification, the "main component" of a certain layer refers to a component whose content in the layer is more than 50% by mass, preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more.

[0013] [Stretched base material] The stretched substrate of the first aspect of the present disclosure 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; In the thickness direction, at least Hereinafter, "provided in this order in the thickness direction" will be simply described as "provided in this order."

[0014] The stretched substrate of the first embodiment may comprise two or more polyethylene layers.

[0015] The stretched substrate of the first embodiment may include 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 compositions of the first to third polyethylene layers may be the same as or different from each other. The thicknesses of the first to third polyethylene layers may be the same as or different from each other.

[0016] The stretched substrate of the first embodiment may comprise, in this order, a first surface resin layer, a polyethylene layer 4a, a polyethylene layer 3a, a polyethylene layer 2a, a polyethylene layer 1a, a polyethylene layer 1b, a polyethylene layer 2b, a polyethylene layer 3b, a polyethylene layer 4b, and a second surface resin layer. The compositions of the polyethylene layers 1a, 2a, 3a and 4a may be the same or different from each other. The thicknesses of the polyethylene layers 1a, 2a, 3a and 4a may be the same or different from each other. The compositions of the polyethylene layers 1b, 2b, 3b and 4b may be the same or different from each other. The thicknesses of the polyethylene layers 1b, 2b, 3b and 4b may be the same or different from each other.

[0017] The compositions of the 1a and 1b polyethylene layers may be the same or different, but are preferably the same. The thicknesses of the 1a and 1b polyethylene layers may be the same or different, but are preferably the same. The compositions of the 2a and 2b polyethylene layers may be the same or different, but are preferably the same. The thicknesses of the 2a and 2b polyethylene layers may be the same or different, but are preferably the same. The compositions of the 3a and 3b polyethylene layers may be the same or different, but are preferably the same. The thicknesses of the 3a and 3b polyethylene layers may be the same or different, but are preferably the same. The compositions of the 4a and 4b polyethylene layers may be the same or different, but are preferably the same. The thicknesses of the 4a and 4b polyethylene layers may be the same or different, but are preferably the same.

[0018] In the first embodiment, the compositions of the first and second surface resin layers may be the same or different, but are preferably the same. The thicknesses of the first and second surface resin layers may be the same or different, but are preferably the same.

[0019] The stretched substrate of the second aspect of the present disclosure 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; In the thickness direction, at least

[0020] The stretched substrate of the second embodiment may further include an adhesive resin layer between the polyethylene layer and the second surface resin layer. The stretched substrate of the second embodiment may include a first surface resin layer, a polyethylene layer, an adhesive resin layer, and a second surface resin layer in this order.

[0021] The stretched substrate of the second embodiment may comprise two or more polyethylene layers.

[0022] The stretched substrate of the second embodiment may include a first surface resin layer, a first polyethylene layer, a second polyethylene layer, an adhesive resin layer, and a second surface resin layer in this order. The compositions of the first and second polyethylene layers may be the same or different. The thicknesses of the first and second polyethylene layers may be the same or different.

[0023] When describing matters common to the stretched substrate of the first embodiment and the stretched substrate of the second embodiment, or when there is no particular distinction between the stretched substrate of the first embodiment and the stretched substrate of the second embodiment, they will also be referred to simply as "stretched substrate."

[0024] The stretched substrate has a multi-layer structure of three or more layers. In one embodiment, the number of layers of the stretched substrate is 3 or more, preferably 14 or less, more preferably 12 or less, for example, 3 or more and 14 or less. Specifically, the number of layers of the stretched substrate is 4, 6, 8, 10, 12, or 14. In one embodiment, the number of layers of the stretched substrate is 3 or more, preferably 9 or less, more preferably 7 or less, for example, 3 to 9. Specifically, the number of layers of the stretched substrate is 3, 5, 7, or 9. A stretched substrate having a multilayer structure has an excellent balance of, for example, gas barrier properties, strength, rigidity, heat resistance, transparency, and printability.

[0025] The content of polyethylene in the stretched substrate is preferably more than 50% by mass, more preferably 55% by mass or more, even more preferably 60% by mass or more, still more preferably 70% by mass or more, particularly preferably 80% by mass or more, and particularly preferably 85% by mass or more or 90% by mass or more. A laminate (or a packaging container) including such a stretched substrate has, for example, excellent recyclability.

[0026] The stretched substrate is a substrate that has been subjected to uniaxial stretching. This can improve, for example, the strength, rigidity, heat resistance, transparency, and printability of the substrate. The stretching ratio when stretching in the longitudinal direction (flow direction of the substrate, MD direction) is preferably 2 times or more, more preferably 3 times or more, and preferably 10 times or less, more preferably 7 times or less, for example, 2 times or more and 10 times or less. The stretching ratio when stretching in the transverse direction (direction perpendicular to the MD direction, TD direction) is preferably 2 times or more, more preferably 3 times or more, and preferably 10 times or less, more preferably 7 times or less, for example, 2 times or more and 10 times or less. The stretched substrate is, for example, a substrate that is uniaxially stretched in the MD direction (MDO substrate).

[0027] The thickness of the stretched substrate 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. A stretched substrate having a thickness equal to or greater than the lower limit has, for example, excellent strength, rigidity, and heat resistance. A stretched substrate having a thickness equal to or less than the upper limit has, for example, excellent processability. In this specification, the thickness of the substrate and each layer is the average value of the thicknesses at 10 points measured based on a scanning electron microscope (SEM) image obtained by observing a cross section perpendicular to the substrate surface.

[0028] The stretched substrate can be produced, for example, by forming the materials constituting each layer into a laminated film, and then uniaxially stretching the laminated film. For example, the film-forming method includes inflation molding and T-die molding, and inflation molding is preferred. According to the inflation molding, stretching can be performed after film formation.

[0029] In one embodiment, the stretched substrate is a stretched film of a coextruded resin film. In one embodiment, the stretched substrate is a resin film obtained by producing a laminated film by co-extrusion film formation, for example, of a material constituting the first surface resin layer, a material constituting the polyethylene layer, and, if the stretched substrate has an adhesive resin layer, a material constituting the adhesive resin layer, and a material constituting the second surface resin layer, and then uniaxially stretching the laminated film.

[0030] In one embodiment, the stretched substrate of the first aspect is a resin film obtained by co-extrusion of the material constituting the surface resin layer and the material constituting the polyethylene layer into a tubular shape by a co-extrusion inflation molding method or the like so that the polyethylene layer is the innermost layer, and then heat-pressing the opposing polyethylene layers together with a rubber roll or the like. In the heat-pressing, the temperature conditions are, for example, 45°C to 100°C, preferably 50°C to 85°C, more preferably 55°C to 70°C, and the pressure conditions are, for example, 0.1MPa to 1.0MPa, but are not particularly limited. By producing a stretched substrate by such a method, the number of defective products can be significantly reduced and production efficiency can be improved.

[0031] The stretched substrate and the barrier substrate described later may be subjected to a surface treatment. Such a stretched substrate and a barrier substrate have, for example, excellent adhesion to other layers. Examples of the surface treatment method include physical treatment and chemical treatment. Examples of the physical treatment include corona treatment, ozone treatment, low-temperature plasma treatment using oxygen gas and / or nitrogen gas, and glow discharge treatment. Examples of the chemical treatment include oxidation treatment using chemicals.

[0032] The stretched substrate may further include a printing layer, which will be described later.

[0033] <Polyethylene layer> The polyethylene layer contains polyethylene as a main component.

[0034] In this specification, polyethylene refers to a polymer in which the content of ethylene-derived structural units in all repeating structural units exceeds 50 mol%. In this polymer, the content of ethylene-derived structural units is preferably 70 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, and particularly preferably 95 mol% or more. The content is measured by NMR.

[0035] 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.

[0036] In this specification, examples of polyethylene include high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, and very low-density polyethylene, as well as ethylene-vinyl acetate copolymer and ethylene-(meth)acrylic acid ester copolymer. From the viewpoint of the strength and heat resistance of the stretched substrate, high-density polyethylene and medium-density polyethylene are preferred. From the viewpoint of the film-forming property and processability of the stretched substrate, linear low-density polyethylene and medium-density polyethylene are preferred.

[0037] In this specification, the density of polyethylene is as follows: The density of the high density polyethylene is preferably 0.945 g / cm 3 The upper density limit of high density polyethylene is, for example, 0.965 g / cm 3 The density of the medium density polyethylene is preferably 0.930 g / cm3 Exceeds 0.945g / cm 3 The density of the low density polyethylene is preferably 0.900 g / cm 3 Exceeds 0.930g / cm 3 The density of the linear low density polyethylene is preferably 0.900 g / cm 3 Exceeds 0.930g / cm 3 The density of the very low density polyethylene is preferably 0.900 g / cm 3 The lower limit of the density of the very low density polyethylene is, for example, 0.860 g / cm 3 In this specification, the density of polyethylene is measured in accordance with JIS K7112:1999, Method D (density gradient tube method, 23° C.).

[0038] Low-density polyethylene is, for example, polyethylene obtained by polymerizing ethylene by high-pressure polymerization (high-pressure low-density polyethylene). Linear low-density polyethylene is, for example, polyethylene obtained by polymerizing ethylene and a small amount of α-olefins by a polymerization method using a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as a metallocene catalyst.

[0039] Polyethylenes with different densities or branches can be obtained by appropriately selecting a polymerization method. For example, it is preferable to carry out polymerization in one or more stages by using a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as a metallocene catalyst as a polymerization catalyst, by any of gas phase polymerization, slurry polymerization, solution polymerization, and high pressure ion polymerization.

[0040] In this specification, polyethylene may be polyethylene 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. Since biomass polyethylene is a carbon-neutral material, it is possible to reduce the environmental load caused by the laminate or packaging container. Biomass polyethylene can be produced, for example, by the method described in JP 2013-177531 A. Commercially available biomass polyethylene may be used.

[0041] As the polyethylene, mechanically recycled or chemically recycled polyethylene (hereinafter also referred to as "recycled polyethylene") may be used. This can reduce the environmental impact of the laminate or packaging container. Mechanical recycling is generally a method in which recovered polyethylene films, etc. are crushed, washed with an alkali to remove dirt and foreign matter from the film surface, and then dried at high temperature and reduced pressure for a certain period of time to diffuse contaminants remaining inside the film, decontaminating it, removing the dirt from the film, and returning it to polyethylene. Chemical recycling is generally a method in which recovered polyethylene films, etc. are decomposed to the monomer level, and the monomers are polymerized again to obtain polyethylene.

[0042] The above description of polyethylene is also applicable elsewhere in this specification.

[0043] The melt flow rate (MFR) of the polyethylene contained in the polyethylene layer is preferably 0.1 g / 10 min or more, more preferably 0.2 g / 10 min or more, even more preferably 0.3 g / 10 min or more, and particularly preferably 0.5 g / 10 min or more, from the viewpoint of film-forming property and processability. The MFR of the polyethylene 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, from the viewpoint of film-forming property and processability. The MFR is, for example, 0.1 g / 10 min or more and 30 g / 10 min or less. In this specification, the MFR of the polyethylene is measured by the A method at a temperature of 190 ° C. and a load of 2.16 kg in accordance with JIS K7210-1:2014.

[0044] 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. 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 pieces after conditioning according to 3.(2) (wherein a cooling rate of 10° C. / min)).

[0045] 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, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more.

[0046] The polyethylene layer may contain a resin material other than polyethylene, such as polyolefins other than polyethylene, such as polypropylene, polyesters, polyamides, (meth)acrylic resins, vinyl resins, cellulose resins, and ionomer resins.

[0047] The polyethylene layer may contain additives, such as crosslinkers, antioxidants, UV absorbers, light stabilizers, antiblocking agents, slip agents, fillers, reinforcing agents, antistatic agents, compatibilizers, pigments, and modifying resins.

[0048] In the second embodiment, the polyethylene layer may further contain a compatibilizer, which will be described later. 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 substrate of the second embodiment has two or more polyethylene layers, at least one of the polyethylene layers may contain a compatibilizer. When the stretched substrate of the second embodiment has two or more polyethylene layers, the basis for the content of the compatibilizer is the total mass of all the polyethylene layers.

[0049] The thickness of the polyethylene layer 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 substrate having a polyethylene layer whose thickness is equal to or greater than the lower limit is excellent in, for example, strength, rigidity, heat resistance, and recyclability. A stretched substrate having a polyethylene layer whose thickness is equal to or less than the upper limit is excellent in, for example, processability. When the stretched substrate has two or more polyethylene layers, the above "thickness" means the sum of the thicknesses of the polyethylene layers.

[0050] In the first embodiment, the thickness of the polyethylene layer 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, for example, 40% or more and 98% or less, relative to the thickness of the stretched substrate. When the stretched substrate has two or more polyethylene layers, the above "thickness" means the total thickness of each polyethylene layer.

[0051] In the second embodiment, the thickness of the polyethylene layer is preferably 40% or more, more preferably 50% or more, even more preferably 60% or more, and preferably 95% or less, more preferably 90% or less, even more preferably 85% or less, for example, 40% or more and 95% or less, relative to the thickness of the stretched substrate. When the stretched substrate has two or more polyethylene layers, the above "thickness" means the total thickness of each polyethylene layer.

[0052] The stretched substrate may comprise one polyethylene layer or two or more layers.

[0053] In a stretched substrate having two or more polyethylene layers, the density of each polyethylene layer may be the same or different. For example, the stretched substrate may have a gradient in density (density gradient) between the polyethylene layers. A stretched substrate having a density gradient between the polyethylene layers is excellent in strength, rigidity, heat resistance, and stretchability of the substrate before stretching.

[0054] In a stretched substrate 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 Less than 0.040 g / cm 3 Less than or equal to 0.030 g / cm 3 More preferably, 0.020 g / cm 3The following is the case. Such a stretched substrate can effectively suppress the occurrence of delamination at the interface between each polyethylene layer, for example. The density of the polyethylene layer is measured in accordance with JIS K7112:1999, Method D (density gradient tube method, 23°C).

[0055] The stretched substrate of the first embodiment is A first surface resin layer; A polyethylene layer 1a; A polyethylene layer 1b; A second surface resin layer; In this case, the stretched substrate can be prevented from curling.

[0056] The stretched substrate of the first embodiment is A first surface resin layer; A 4a polyethylene layer; A 3a polyethylene layer; A 2a polyethylene layer; A polyethylene layer 1a; A polyethylene layer 1b; A 2b polyethylene layer; A 3b polyethylene layer; A 4b polyethylene layer; A second surface resin layer; In this case, the stretched substrate can be prevented from curling.

[0057] The 1a and 1b polyethylene layers each independently contain, for example, polyethylene plastomer or other polyethylene as a main component. The 2a and 2b polyethylene layers each independently contain, for example, linear low-density polyethylene or other polyethylene as a main component. The 3a and 3b polyethylene layers each independently contain, for example, linear low-density polyethylene or other polyethylene as a main component. The 4a and 4b polyethylene layers each independently contain, for example, linear low-density polyethylene or other polyethylene as a main component. Such a stretched substrate has, for example, excellent interlayer strength between the polyethylene layers, can effectively suppress the occurrence of delamination, and has excellent processability.

[0058] 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, when subjected to an external force, deforms in response to the external force and returns to its original shape in a short time when the external force is removed), and is a polymer that does not exhibit elastic deformation like an elastomer but easily undergoes plastic deformation.

[0059] The polyethylene plastomer is, for example, a polyethylene obtained by copolymerizing ethylene and an α-olefin using a single-site catalyst such as a metallocene catalyst. As the α-olefin, for example, an α-olefin having 4 to 8 carbon atoms, such as 1-butene, 1-hexene, 1-octene, and 4-methyl-1-pentene, is preferable. Specific examples of the polyethylene plastomer include ethylene-1-butene copolymer, ethylene-1-hexene copolymer, and ethylene-1-octene copolymer.

[0060] The density of the polyethylene plastomer is preferably 0.920 g / cm from the viewpoint of fusion between the innermost layers when preparing the stretched substrate. 3 Less than or equal to 0.915 g / cm 3 or less, more preferably 0.910 g / cm 3The 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 the polyethylene plastomer is, for example, 0.850 g / cm 3 More than 0.920g / cm 3 The following is the result.

[0061] From the viewpoint of fusion between the innermost layers when preparing the stretched substrate, 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.

[0062] From the viewpoint of film-forming 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, and particularly preferably 0.5 g / 10 min or more. From the viewpoint of film-forming and processability, the MFR of the polyethylene 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 polyethylene plastomer is, 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 the A method at a temperature of 190 ° C. and a load of 2.16 kg in accordance with JIS K7210-1:2014.

[0063] 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.

[0064] The 2a and 2b polyethylene layers are each independently a layer containing, for example, linear low-density polyethylene as a main component.

[0065] 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 extensibility, etc.

[0066] 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.

[0067] 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 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.

[0068] The linear low density polyethylene may, for example, be an ethylene-1-butene copolymer (C4-LLDPE) in which the comonomer is at least 1-butene, an ethylene-1-hexene copolymer (C6-LLDPE) in which the comonomer is at least 1-hexene, or an ethylene-1-octene copolymer (C8-LLDPE) in which the comonomer is at least 1-octene. In these copolymers, the comonomers are not limited to the above-mentioned ones, and further comonomers may be used.

[0069] The total thickness of the polyethylene layers 1a and 1b is preferably 5% or more, more preferably 10% or more, and preferably 25% or less, more preferably 20% or less, for example 5% or more and 25% or less, relative to the total thickness of the polyethylene layers. The total thickness of the 2a and 2b polyethylene layers is preferably 5% or more, more preferably 10% or more, and preferably 25% or less, more preferably 20% or less, for example 5% or more and 25% or less, relative to the total thickness of the polyethylene layers. The total thickness of the 3a and 3b polyethylene layers is preferably 35% or more, more preferably 40% or more, and preferably 65% ​​or less, more preferably 60% or less, for example, 35% or more and 65% or less, relative to the total thickness of the polyethylene layer. 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.

[0070] The density relationship between the polyethylene layers in the stretched substrate comprising the polyethylene layers is not particularly limited as long as it does not impair the stretchability of the substrate, or the heat resistance, strength, rigidity, and interlayer adhesion of the stretched substrate.

[0071] In one embodiment, the stretched substrate 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 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 substrate 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 a density of the 4b polyethylene layer that is higher than or similar to the density of the 3b polyethylene layer.

[0072] In one embodiment, the stretched substrate 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 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 substrate 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 a density of the 4b polyethylene layer that is lower than or similar to the density of the 3b polyethylene layer.

[0073] In one embodiment, the stretched substrate 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 a density of the 4a polyethylene layer higher than or approximately the same as that of the 3a polyethylene layer. In one embodiment, the stretched substrate has a density of the 2b polyethylene layer lower than the density of the 1b polyethylene layer, a density of the 3b polyethylene layer higher than the density of the 2b polyethylene layer, and a density of the 4b polyethylene layer higher than or approximately the same as the density of the 3b polyethylene layer.

[0074] The stretched substrate of the first embodiment may include 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. Such a stretched substrate can suppress curling.

[0075] In the above-mentioned stretched substrate, the first and third polyethylene layers are each independently a layer containing, for example, a linear low-density polyethylene, and are preferably layers containing linear low-density polyethylene and medium-density polyethylene from the viewpoint of rigidity, etc., or layers containing linear low-density polyethylene as a main component from the viewpoint of stretchability, etc.

[0076] In one embodiment, the content of linear low density polyethylene in the first and third polyethylene layers in the above-mentioned stretched base material 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.

[0077] In one embodiment, the medium-density polyethylene content in the first and third polyethylene layers in the above-mentioned stretched substrate 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.

[0078] In the above-mentioned stretched substrate, the second polyethylene layer is, for example, a layer containing linear low-density polyethylene as a main component.

[0079] In the above stretched substrate, 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, for example, 30% or more and 90% or less, of the total thickness of the polyethylene layers.

[0080] In the above-mentioned stretched substrate, 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.

[0081] In a stretched substrate having a first surface resin layer, a first polyethylene layer, a second polyethylene layer, a third polyethylene layer, and a second surface resin layer, in this order, the ratio of the thickness of the first polyethylene layer to the thickness of the third polyethylene layer is preferably 0.6 or more and 1.4 or less, more preferably 0.7 or more and 1.3 or less, even more preferably 0.8 or more and 1.2 or less, and particularly preferably 0.9 or more and 1.1 or less, from the viewpoints of symmetry of the stretched substrate and suppression of curling.

[0082] The stretched substrate of the second embodiment may comprise, 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.

[0083] In the above-mentioned stretched substrate of the second embodiment, the first polyethylene layer is, for example, a layer containing linear low density polyethylene, and is preferably, from the viewpoint of rigidity and the like, a layer containing linear low density polyethylene and medium density polyethylene, or, from the viewpoint of stretchability and the like, a layer containing linear low density polyethylene as a main component.

[0084] In the above-mentioned stretched substrate of the second aspect, the content of linear low density polyethylene in the first polyethylene layer, in one embodiment, 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.

[0085] In the above-mentioned stretched substrate of the second aspect, the content of medium-density polyethylene in the first polyethylene layer, in one embodiment, 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.

[0086] In the above stretched substrate of the second embodiment, the second polyethylene layer is, for example, a layer containing linear low density polyethylene as a main component.

[0087] In the above stretched substrate of the second embodiment, 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, for example 30% or more and 80% or less, of the thickness of the stretched substrate.

[0088] In the above stretched substrate of the second embodiment, 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 substrate, for example 5% or more and 35% or less.

[0089] In the above stretched substrate of the second embodiment, 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 substrate.

[0090] In the second embodiment, the polyethylene layer may further contain a compatibilizer. By containing the compatibilizer in the polyethylene layer, the mixability between the gas barrier resin and the polyethylene can be improved when the stretched substrate and the barrier substrate are heated and melted for recycling. This can effectively prevent the physical properties of the polyethylene from decreasing after recycling, and can also effectively prevent the transparency of the polyethylene from decreasing. When the stretched substrate has two or more polyethylene layers, at least one of the polyethylene layers may contain a compatibilizer.

[0091] In the second embodiment, when the polyethylene layer contains a compatibilizer, the content of the compatibilizer in the polyethylene layer is preferably 25 parts by mass or more and 200 parts by mass or less relative to 100 parts by mass of the gas barrier resin in the stretched substrate. 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 relative to 100 parts by mass of the ethylene-vinyl alcohol copolymer in the stretched substrate. 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 relative to 100 parts by mass of the polyamide in the stretched substrate.

[0092] The compatibilizer may be, for example, a modified polyolefin such as an acid-modified polyolefin, and from the viewpoint of recyclability, a modified polyethylene such as an acid-modified polyethylene is preferred. The modified polyolefin may be, for example, a polyolefin modified with an unsaturated carboxylic acid such as maleic acid or fumaric acid, or an acid anhydride, ester, or metal salt thereof, particularly a graft modified polyolefin. Specifically, the compatibilizer is preferably an unsaturated carboxylic acid-modified polyethylene, and more preferably a maleic anhydride-modified polyethylene.

[0093] The second polyethylene layer in the second embodiment 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. The polyethylene content in the second polyethylene layer is 100% by mass or less, may be 99% by mass or less, 97% by mass or less, or may be 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 mass% or more, more preferably 3 mass% or more, even more preferably 5 mass% or more, and preferably 40 mass% or less, more preferably 35 mass% or less, even more preferably 30 mass% or less, particularly preferably 25 mass% or less or 20 mass% or less.

[0094] <First Surface Resin Layer and Second Surface Resin Layer in the First Aspect> <First Surface Resin Layer in the Second Aspect> In the stretched substrate of the first embodiment, the first surface resin layer and the second surface resin layer each independently contain polyethylene and an adhesive resin. In the stretched substrate of the second embodiment, the first surface resin layer contains polyethylene and an adhesive resin. The vapor deposition film provided on the surface of such a surface resin layer tends to have excellent adhesion to the surface resin layer and exhibit good gas barrier properties.

[0095] As the polyethylene, for example, high density polyethylene, medium density polyethylene, low density polyethylene, linear low density polyethylene and very low density polyethylene are preferable, and from the viewpoint of the surface smoothness of the stretched substrate and the adhesion between the surface resin layer and the vapor deposition film, linear low density polyethylene is more preferable. Examples of the linear low density polyethylene include C4-LLDPE, C6-LLDPE and C8-LLDPE.

[0096] The melting point (Tm) of the polyethylene in the above-mentioned surface resin layer is, from the viewpoints of the strength and heat resistance of the stretched substrate and the adhesion between the surface resin layer and the vapor-deposited film, 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.

[0097] Examples of the adhesive resin include acid-modified resin, silicone resin, epoxy resin and phenol resin, and acid-modified resin is preferred. Examples of the acid-modified resin include acid-modified polyolefin and acid-modified vinyl resin. Among these, from the viewpoint of recyclability and adhesion, acid-modified polyolefin is preferred, acid-modified polypropylene and acid-modified polyethylene are more preferred, acid-modified polyethylene is even more preferred, and acid-modified linear low-density polyethylene is even more preferred. The surface resin layer containing acid-modified linear low-density polyethylene tends to have better adhesion to the vapor deposition film.

[0098] Examples of acid-modified polyolefins include polyolefins (such as 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. Examples of acid-modified polyolefins include maleic acid-modified polyolefins and maleic anhydride-modified polyolefins, and more preferably maleic acid-modified polypropylene, maleic anhydride-modified polypropylene, maleic acid-modified polyethylene, and maleic anhydride-modified polyethylene.

[0099] 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, and even more preferably 0.1% by mass or more, from the viewpoint of adhesion between the surface resin layer and the vapor deposition film. The content of the structural unit derived from the acid-modified component in the acid-modified polyolefin is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less, from the viewpoint of adhesion between the surface resin layer and the polyethylene layer. The content is, for example, 0.01% by mass or more and 10% by mass or less. The content of the structural unit derived from the acid-modified component is measured by infrared spectroscopy.

[0100] From the viewpoint of film-forming and processability, the MFR of the acid-modified polyolefin is preferably 0.1 g / 10 min or more, more preferably 1 g / 10 min or more, even more preferably 1.5 g / 10 min or more, and preferably 50 g / 10 min or less, more preferably 30 g / 10 min or less, even more preferably 10 g / 10 min or less, for example, 0.1 g / 10 min or more and 50 g / 10 min or less. The MFR of the acid-modified polyolefin is measured by the A method under a load of 2.16 kg in accordance with JIS K7210-1:2014. The measurement temperature of the MFR is set according to the melting point of the acid-modified polyolefin, and is 230 ° C. for acid-modified polypropylene and 190 ° C. for acid-modified polyethylene.

[0101] 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 substrate and the adhesion between the surface resin layer and the vapor-deposited film.

[0102] In the above surface resin layer, the content of polyethylene is preferably 60% by mass or more and 95% by mass or less, and the content of adhesive resin is preferably 5% by mass or more and 40% by mass or less, more preferably 70% by mass or more and 95% by mass or less, and the content of adhesive resin is more preferably 5% by mass or more and 30% by mass or less, more preferably 80% by mass or more and 95% by mass or less, and the content of adhesive resin is more preferably 5% by mass or more and 20% by mass or less, and particularly preferably 85% by mass or more and 95% by mass or less, and the content of adhesive resin is more preferably 5% by mass or more and 15% by mass or less. The surface resin layer of such an embodiment tends to be more excellent in surface smoothness, adhesion to the vapor deposition film, and adhesion to the polyethylene layer. When the content of adhesive resin is equal to or less than the upper limit, for example, it is possible to suppress the film from adhering more than necessary to a roll or the like during the production of a stretched substrate.

[0103] The surface resin layer may contain the above-mentioned resin materials other than the above-mentioned components. The surface resin layer may contain the additive.

[0104] <Second Surface Resin Layer in the Second Aspect> In the second embodiment, the second surface resin layer contains a gas barrier resin as a main component. Therefore, the stretched substrate of the second embodiment is superior in gas barrier properties (particularly oxygen barrier properties), heat resistance, and rigidity compared to conventional stretched polyethylene substrates. A laminate comprising at least the stretched substrate of the present disclosure or a barrier substrate described later and a heat seal layer containing polyethylene as a main component is excellent in recyclability.

[0105] The second surface resin layer in the second aspect tends to have excellent surface smoothness, and the second vapor-deposited film provided on the surface of the second surface resin layer tends to have excellent adhesion to the second surface resin layer and to exhibit good gas barrier properties.

[0106] Gas barrier resin is a resin that has a function of suppressing gas permeation. Examples of gas barrier resins include ethylene-vinyl alcohol copolymers, polyvinyl alcohol, polyamides, polyvinylidene chloride, polyesters, polyether polyols, polyester polyols, polyurethanes, polyacrylonitriles, and (meth)acrylic resins. Among these, from the viewpoints of gas barrier properties (particularly oxygen barrier properties), heat resistance, and rigidity, ethylene-vinyl alcohol copolymers, polyvinyl alcohol, and polyamides are preferred, ethylene-vinyl alcohol copolymers and polyamides are more preferred, and from the viewpoint of gas barrier properties, ethylene-vinyl alcohol copolymers are even more preferred.

[0107] 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, for example, solution polymerization, suspension polymerization, emulsion polymerization, etc. EVOH may be modified by known methods such as urethanization, acetalization, cyanoethylation, oxyalkylenation, etc.

[0108] As the vinyl ester monomer, vinyl acetate is generally used, but other vinyl ester monomers may 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.

[0109] The content of structural units derived from ethylene 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 stretched substrate. The ethylene content in EVOH is preferably 60 mol% or less, more preferably 50 mol% or less, from the viewpoint of heat resistance, oxygen barrier property, and water vapor barrier property of the barrier substrate. The ethylene content is, for example, 20 mol% or more and 60 mol% or less. The ethylene content is measured by NMR.

[0110] The average saponification degree of EVOH is preferably 90 mol% or more, more preferably 95 mol% or more, and further 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).

[0111] From the viewpoint of heat resistance, the melting point (Tm) of EVOH is preferably 140° C. or higher, more preferably 145° C. or higher, and even more preferably 150° C. or higher. The Tm of EVOH is preferably 200° C. or lower, more preferably 195° C. or lower, and even more preferably 190° C. or lower. The Tm of EVOH is, for example, 140° C. or higher and 200° C. or lower.

[0112] From the viewpoint of film-forming and processability, the melt flow rate (MFR) of 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 viewpoint of film-forming and processability, the MFR of 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 EVOH is, for example, 0.1 g / 10 min or more and 30 g / 10 min or less. The MFR of EVOH is measured by the A method at a temperature of 190° C. and a load of 2.16 kg in accordance with JIS K7210-1:2014. The measurement temperature may be 210° C. depending on the melting point of EVOH.

[0113] EVOH may be modified by a known method, such as urethanization, acetalization, cyanoethylation, or oxyalkylenation.

[0114] The average saponification degree of polyvinyl alcohol (PVA) is preferably 70 mol% or more, more preferably 75 mol% or more, further preferably 80 mol% or more, and particularly preferably 85 mol% or more. The average saponification degree is measured in accordance with JIS K6726:1994.

[0115] Examples of the polyamide include aliphatic polyamides and semi-aromatic polyamides. As the polyamide, aliphatic polyamides are preferred, and crystalline aliphatic polyamides are more preferred.

[0116] Examples of the aliphatic polyamide include aliphatic homopolyamide and aliphatic copolymer polyamide. In the following examples, polyamide is also referred to as "PA."

[0117] 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), polyhexamethylene sebacamide (PA510), polypentamethylene dodecamide (PA512), polyhexamethylene azelamide (PA510), polyhexamethylene sebac ... 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 decamamide (PA1010), polydecamethylene dodecamide (PA1012), polydodecamethylene adipamide (PA126), polydodecamethylene azelamide (PA129), polydodecamethylene sebacamide (PA1210) and polydodecamethylene dodecamide (PA1212).

[0118] 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 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), caprolactam / hexamethylenediaminoadipic acid / hexamethylenediaminododecanedicarboxylic acid copolymer (PA6 / 66 / 612).

[0119] The relative viscosity of the aliphatic 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 aliphatic polyamide is measured at 25° C. by dissolving 1 g of polyamide in 100 mL of 96% concentrated sulfuric acid in accordance with JIS K6920-2:2009.

[0120] The semi-aromatic polyamide is a polyamide having a constitutional unit derived from an aromatic diamine and a constitutional unit derived from an aliphatic dicarboxylic acid, or a polyamide having a constitutional unit derived from an aliphatic diamine and a constitutional unit derived from an aromatic dicarboxylic acid, for example, a polyamide composed of an aromatic diamine and an aliphatic dicarboxylic acid, or a polyamide composed of an aliphatic diamine and an aromatic dicarboxylic acid.

[0121] 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 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).

[0122] 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 200 cm 3 / 10 minutes or less, preferably 100cm 3 / 10 minutes or less, for example, 5 cm 3 / 10 minutes or more 200cm 3 / 10 minutes or less. MVR is measured at a temperature of 275°C and a load of 5.00 kg in accordance with JIS K7210-1:2014.

[0123] The 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 180°C or higher, more preferably 190°C or higher, even more preferably 200°C or higher, and is preferably 300°C or lower, more preferably 270°C or lower, even more preferably 240°C or lower, for example, 180°C or higher and 300°C or lower.

[0124] From the viewpoint of film-forming and processability, the melt flow rate (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. From the viewpoint of film-forming and processability, the MFR of the polyamide 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 polyamide is, for example, 0.1 g / 10 min or more and 30 g / 10 min or less. The MFR of the polyamide is measured by the A method at a temperature of 235 ° C. and a load of 2.16 kg in accordance with JIS K7210-1:2014. An appropriate measurement temperature can be adopted depending on the melting point of the polyamide.

[0125] From the viewpoint of the above-mentioned physical properties such as gas barrier properties, the content of the gas barrier resin in the second surface resin layer is preferably more than 50 mass%, more preferably 60 mass% or more, even more preferably 70 mass% or more, still more preferably 80 mass% or more, and particularly preferably 90 mass% or more.

[0126] The second surface resin layer may contain the above-mentioned additives.

[0127] The thicknesses of the first and second surface resin layers in the stretched substrates of the first and second embodiments are each independently preferably 0.5 μm or more, more preferably 1 μm or more, and even more preferably 1.5 μm or more from the viewpoint of the above-mentioned physical properties such as gas barrier properties, and are 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 is, for example, 0.5 μm or more and 10 μm or less.

[0128] The thicknesses of the first and second surface resin layers in the stretched substrate of the first and second embodiments are each independently 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 substrate.

[0129] In the stretched substrate of the first and second embodiments, the ratio of the thickness of the second surface resin layer to the thickness of the first surface resin layer is, from the viewpoints of symmetry of the stretched substrate and suppression of curling, preferably from 0.6 to 1.4, more preferably from 0.7 to 1.3, even more preferably from 0.8 to 1.2, and particularly preferably from 0.9 to 1.1.

[0130] <Adhesive resin layer> The stretched substrate of the second embodiment may further include an adhesive resin layer between the polyethylene layer and the second surface resin layer. Such a stretched substrate has, for example, excellent adhesion between the polyethylene layer and the second surface resin layer.

[0131] The adhesive resin layer contains a resin material. Examples of the resin material include polyolefin, modified polyolefin, vinyl resin, silicone resin, epoxy resin, and phenol resin. Among these, from the viewpoint of recyclability and adhesion, polyolefin and modified polyolefin are preferred, modified polyolefin such as acid modified polyolefin are more preferred, and modified polyethylene such as acid modified polyethylene are even more preferred.

[0132] The modified polyolefin may be, for example, a polyolefin modified with an unsaturated carboxylic acid such as maleic acid or fumaric acid, or an acid anhydride, ester, or metal salt thereof, particularly a graft modified polyolefin. Specifically, the modified polyolefin is preferably an unsaturated carboxylic acid modified polyethylene, more preferably a maleic anhydride modified polyethylene.

[0133] The melt flow rate (MFR) of the 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, from the viewpoint of film-forming property and processability. The MFR of the modified polyolefin 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, from the viewpoint of film-forming property and processability. The MFR of the modified polyolefin is, for example, 0.1 g / 10 min or more and 30 g / 10 min or less. The MFR of the modified polyolefin is measured by the A method under a load of 2.16 kg in accordance with JIS K7210-1:2014. The measurement temperature of the MFR is set according to the melting point of the modified polyolefin, and is 190 ° C. in the case of modified polyethylene.

[0134] The content of the resin material in the adhesive resin layer is preferably 80% by mass or more, more preferably 85% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more.

[0135] The adhesive resin layer may contain the above-mentioned additives.

[0136] From the viewpoint of the adhesion, the thickness of the adhesive resin layer is preferably 0.5 μm or more, more preferably 1 μm or more. From the viewpoint of the recyclability of the stretched substrate and the barrier substrate, the thickness of the adhesive resin layer is preferably 15 μm or less, more preferably 10 μm or less. The thickness of the adhesive resin layer is, for example, 0.5 μm or more and 15 μm or less. When the stretched substrate has two or more adhesive resin layers, the above "thickness" means the total thickness of each adhesive resin layer.

[0137] <Gas barrier properties of stretched substrate> The oxygen permeability (unit: cc / (m 2 The oxygen permeability is preferably less than 30, more preferably less than 25, further preferably less than 18, and particularly preferably less than 10. The lower limit of the oxygen permeability may be, for example, 0.1 or 0.5. The oxygen permeability is measured in accordance with JIS K7126-2:2006 at a temperature of 23°C and a humidity of 90% RH.

[0138] The water vapor transmission rate (unit: g / (m 2 ·day)) is preferably less than 20, more preferably less than 15, even more preferably less than 10, and particularly preferably less than 5.0. The lower limit of the water vapor permeability may be, for example, 0.1 or 0.5. 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.

[0139] [Barrier substrate] The barrier substrate according to the first embodiment of the present disclosure comprises: The stretched substrate according to the first aspect described above, a vapor-deposited film provided on the surface of at least one layer selected from the first surface resin layer and the second surface resin layer of the stretched substrate; Equipped with.

[0140] The barrier substrate according to the second embodiment of the present disclosure comprises: The stretched substrate according to the second aspect described above, a vapor-deposited film provided on the surface of at least one layer selected from the first surface resin layer and the second surface resin layer of the stretched substrate; Equipped with.

[0141] When describing matters common to the barrier substrate of the first embodiment and the barrier substrate of the second embodiment, or when there is no particular distinction between the barrier substrate of the first embodiment and the barrier substrate of the second embodiment, they are also simply referred to as "barrier substrate".

[0142] The vapor-deposited film may be provided only on the surface of the first surface resin layer of the stretched substrate, may be provided only on the surface of the second surface resin layer, or may be provided on the surfaces of the first surface resin layer and the second surface resin layer.

[0143] In one embodiment, the barrier substrate of the present disclosure comprises: A first vapor-deposited film; The stretched substrate described above; A second deposited film; In the thickness direction, at least

[0144] The stretched substrate has a first surface and a second surface opposite to the first surface. The first vapor-deposited film is provided on the first surface of the stretched substrate. The first vapor-deposited film is provided on a surface of a first surface resin layer of the stretched substrate. The second vapor-deposited film is provided on a second surface of the stretched substrate. The second vapor-deposited film is provided on a surface of a second surface resin layer of the stretched substrate.

[0145] The barrier substrate may further include a printed layer, which will be described later.

[0146] <Vapor deposition film> The barrier substrate of the present disclosure has a vapor deposition film and is excellent in gas barrier properties. A packaging container produced using such a barrier substrate has excellent gas barrier properties. In one embodiment, the barrier substrate of the present disclosure has a first vapor deposition film and a second vapor deposition film and is more excellent in gas barrier properties. Since such a barrier substrate has vapor deposition films on both sides of the stretched substrate, it is possible to suppress the deterioration of gas barrier properties due to pinholes.

[0147] The vapor deposition film is composed of, for example, a metal and / or an inorganic oxide. The vapor deposition film may be a metal vapor deposition film composed of one or more metals, or an inorganic oxide vapor deposition film composed of one or more inorganic oxides. The inorganic oxide vapor deposition film may be a transparent vapor deposition film. Examples of metals include aluminum, chromium, tin, nickel, copper, silver, gold, and platinum. Examples of inorganic oxides include aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, barium oxide, and silicon carbide oxide (carbon-containing silicon oxide). Among the vapor deposition films, aluminum vapor deposition films, aluminum oxide (alumina) vapor deposition films, silicon oxide (silica) vapor deposition films, and silicon carbide oxide vapor deposition films are preferred, and the first vapor deposition film and the second vapor deposition film are each independently preferably an aluminum vapor deposition film, an aluminum oxide (alumina) vapor deposition film, a silicon oxide (silica) vapor deposition film, or a silicon carbide oxide vapor deposition film.

[0148] The combination of the first and second evaporated films is not particularly limited. The first vapor-deposited film may be a metal vapor-deposited film and the second vapor-deposited film may be a metal vapor-deposited film, where both may be the same or different. One of the first vapor-deposited film and the second vapor-deposited film may be a metal vapor-deposited film and the other may be an inorganic oxide vapor-deposited film or a transparent vapor-deposited film. The first vapor-deposited film may be an inorganic oxide vapor-deposited film or a transparent vapor-deposited film, where both may be the same or different.

[0149] In one embodiment, the first vapor-deposited film is a metal vapor-deposited film, and the second vapor-deposited film is a metal vapor-deposited film, which may be the same or different. Such a barrier substrate has particularly excellent gas barrier properties.

[0150] For example, when a packaging container is produced using a laminate comprising a barrier substrate having a metal vapor deposition film such as an aluminum vapor deposition film on both sides of a stretched substrate, depending on the type of contents filled in the packaging container, the metal vapor deposition film may be oxidized to form a metal oxide, causing discoloration, corrosion, or volume expansion, reducing the laminate strength, and causing problems such as lifting and peeling of layers.

[0151] In one embodiment, at least one of the first and second vapor deposition films is an inorganic oxide vapor deposition film. By using a laminate including such a barrier substrate, a packaging container having excellent resistance to contents can be produced. For example, a laminate including a barrier substrate and a heat seal layer is prepared. The laminate includes a barrier substrate arranged such that the inorganic oxide vapor deposition film faces the heat seal layer side (inside of the packaging container) and the other vapor deposition film faces the outside (outside of the packaging container). When both the first and second vapor deposition films are inorganic oxide vapor deposition films, the orientation of the barrier substrate is not particularly limited. By producing a packaging container using the above laminate, discoloration, corrosion or deterioration of the vapor deposition film, and lifting or peeling of layers can be suppressed even when the packaging container is filled with corrosive contents. This is because the inorganic oxide vapor deposition film is originally oxidized, and thus it is possible to suppress the occurrence of volume expansion due to oxidation, as occurs with metal vapor deposition films.

[0152] In one embodiment, the first vapor-deposited film is an inorganic oxide vapor-deposited film and the second vapor-deposited film is a metal vapor-deposited film. In one embodiment, the first vapor-deposited film is a metal vapor-deposited film and the second vapor-deposited film is an inorganic oxide vapor-deposited film. The inorganic oxide vapor-deposited film may be a transparent vapor-deposited film.

[0153] In one embodiment, the first vapor-deposition film is an inorganic oxide vapor-deposition film, and the second vapor-deposition film is an inorganic oxide vapor-deposition film. Here, both may be the same or different. The inorganic oxide vapor-deposition film may be a transparent vapor-deposition film. Such a barrier substrate can avoid the problem of oxidation deterioration when the vapor-deposition film is a metal vapor-deposition film, and can also suppress corrosion of the vapor-deposition film from the end face of the barrier substrate. In addition, since such a barrier substrate has excellent transparency, a packaging container with excellent visibility of the contents can be produced, for example, a packaging container that can be used in a microwave oven and a packaging container that can pass through a metal detector can be produced. In addition, a packaging container including such a barrier substrate can be clearly understood by, for example, a consumer that does not contain an aluminum vapor-deposition film, making it easy to separate, and further, can suppress the inclusion of foreign matter such as black spots (metal color) that may occur due to the aluminum vapor-deposition film during recycling processing.

[0154] The first and second vapor-deposited films may both be aluminum vapor-deposited films, and may be the same or different. One of the first and second vapor-deposited films may be an alumina vapor-deposited film, a silica vapor-deposited film, or a silicon carbide oxide vapor-deposited film, and the other may be an aluminum vapor-deposited film. The first vapor-deposited film may be an alumina vapor-deposited film, a silica vapor-deposited film, or a silicon carbide oxide vapor-deposited film, and the second vapor-deposited film may be an alumina vapor-deposited film, a silica vapor-deposited film, or a silicon carbide oxide vapor-deposited film, and may be the same or different.

[0155] In one embodiment, the barrier substrate of the present disclosure has a vapor deposition film only on one side of the stretched substrate. By using a laminate having such a barrier substrate, a packaging container having excellent resistance to contents can be produced. For example, a laminate having a barrier substrate and a heat seal layer is prepared. The laminate has a barrier substrate arranged such that the stretched substrate faces the heat seal layer side (inside of the packaging container) and the vapor deposition film faces the outside (outside of the packaging container). By producing a packaging container using the above laminate, the vapor deposition film can be arranged on the outside, so that even if a corrosive content is filled in the packaging container, discoloration, corrosion or deterioration of the vapor deposition film and lifting or peeling of the layer can be suppressed.

[0156] The thickness of the vapor-deposited film is preferably 1 nm or more, more preferably 5 nm or more, and even more preferably 10 nm or more, from the viewpoint of gas barrier properties. The thickness of the vapor-deposited film is preferably 150 nm or less, more preferably 100 nm or less, and even more preferably 80 nm or less, from the viewpoint of suppressing crack generation in the vapor-deposited film and recyclability of the packaging container. The thickness of the vapor-deposited film is, for example, 1 nm or more and 150 nm or less. The thickness of the first vapor-deposited film and the second vapor-deposited film is also similar.

[0157] When the vapor deposition film is an aluminum vapor deposition film, the optical density (OD value) of the aluminum vapor deposition film is preferably 2 or more and 3.5 or less. This makes it possible to improve the oxygen barrier property and water vapor barrier property while maintaining the productivity of the barrier substrate, for example. When one vapor deposition film in the barrier substrate of the present disclosure is a transparent vapor deposition film, the other vapor deposition film tends to have a stable OD value and an aluminum vapor deposition film with excellent thickness uniformity. The OD value can be measured in accordance with JIS K7361-1:1997.

[0158] The surface of the deposited film is preferably subjected to the above-mentioned surface treatment, so that such a deposited film has, for example, excellent adhesion to adjacent layers.

[0159] Examples of methods for forming the vapor-deposited film include physical vapor deposition methods (PVD methods) such as vacuum deposition, sputtering, and ion plating, and chemical vapor deposition methods (CVD methods) such as plasma chemical vapor deposition, thermal chemical vapor deposition, and photochemical vapor deposition. The vapor-deposited film may be a composite film containing two or more layers of different vapor-deposited films formed by combining both physical vapor deposition and chemical vapor deposition.

[0160] The vacuum level in the deposition chamber was 10 before oxygen was introduced. -2 ~10 -8 After oxygen is introduced, the pressure is preferably about 10 -1 ~10 -6The pressure is preferably about mbar. The amount of oxygen introduced varies depending on the size of the deposition machine. For the oxygen introduced, an inert gas such as argon gas, helium gas, or nitrogen gas may be used as a carrier gas to the extent that no problems occur. The conveying speed of the target film on which the deposition film is formed is, for example, 10 m / min or more and 800 m / min or less.

[0161] The vapor-deposited film may be a single layer formed by one vapor deposition process, or may be a multilayer formed by multiple vapor deposition processes. When the vapor-deposited film is a multilayer film, each layer may be composed of the same component or different components. Each layer may be formed by the same method or different methods.

[0162] In one embodiment, the barrier substrate of the present disclosure includes at least a first vapor-deposited film as the vapor-deposited film, a stretched substrate, and a second vapor-deposited film as the vapor-deposited film, in this order. Such a barrier substrate has particularly excellent gas barrier properties.

[0163] In one embodiment, the stretched substrate comprises a first surface resin layer constituting the first surface and a second surface resin layer constituting the second surface, the first vapor-deposited film is provided on the surface of the first surface resin layer, and the second vapor-deposited film is provided on the surface of the second surface resin layer. Such a stretched substrate is excellent in, for example, vapor-deposited film formability, smoothness, and adhesion, and the obtained barrier substrate is excellent in, for example, gas barrier properties, specifically oxygen barrier properties and water vapor barrier properties, and also excellent in brightness when the vapor-deposited film is a metal vapor-deposited film.

[0164] <Barrier coat layer> The barrier substrate of the present disclosure may further include a barrier coat layer on the vapor-deposited film. That is, the barrier substrate may further include a barrier coat layer on the surface of the vapor-deposited film opposite to the surface of the stretched substrate. Such a barrier substrate has, for example, excellent oxygen barrier properties and water vapor barrier properties, and can effectively suppress the occurrence of cracks in the vapor-deposited film when the vapor-deposited film is made of an inorganic oxide such as aluminum oxide or silicon oxide.

[0165] In one embodiment, the barrier substrate comprises, in this order, a metal vapor deposition film as a first vapor deposition film, a first surface resin layer, a polyethylene layer, a second surface resin layer, an inorganic oxide vapor deposition film as a second vapor deposition film, and a barrier coat layer. In one embodiment, the barrier substrate comprises, in this order, a barrier coat layer, an inorganic oxide vapor deposition film as a first vapor deposition film, a first surface resin layer, a polyethylene layer, a second surface resin layer, and a metal vapor deposition film as a second vapor deposition film. In one embodiment, the barrier substrate comprises, in this order, a first barrier coating layer, an inorganic oxide vapor deposition film as a first vapor deposition film, a first surface resin layer, a polyethylene layer, a second surface resin layer, an inorganic oxide vapor deposition film as a second vapor deposition film, and a second barrier coating layer.

[0166] In one embodiment, the barrier coat layer contains a gas barrier resin, such as an ethylene-vinyl alcohol copolymer, polyvinyl alcohol, polyamide, polyvinylidene chloride, polyester, polyether polyol, polyester polyol, polyurethane, polyacrylonitrile, or (meth)acrylic resin.

[0167] The content of the gas barrier resin in the barrier coat layer is preferably more than 50% by mass, more preferably 60% by mass or more, and even more preferably 70% by mass or more. Such a barrier coat layer has, for example, excellent gas barrier properties.

[0168] The barrier coat layer may contain the above-mentioned additives.

[0169] The thickness of the barrier coat layer containing the gas barrier resin is preferably 0.01 μm or more, more preferably 0.1 μm or more, from the viewpoint of gas barrier properties. The thickness of the barrier coat layer containing the gas barrier resin is preferably 10 μm or less, more preferably 5 μm or less, from the viewpoint of processability of the barrier substrate and recyclability of the packaging container. The thickness is, for example, 0.01 μm or more and 10 μm or less.

[0170] The barrier coat layer can be formed, for example, by applying a coating liquid obtained by dissolving or dispersing a material such as a gas barrier resin in water or an appropriate organic solvent onto the vapor-deposited film, and drying the resulting coating liquid.

[0171] In another embodiment, the barrier coat layer is a gas barrier coating film formed by mixing a metal alkoxide, a water-soluble polymer, and optionally a silane coupling agent, and adding water, an organic solvent, and a sol-gel catalyst as required to obtain a gas barrier composition, coating the gas barrier composition on a deposition film, and drying the gas barrier composition. The gas barrier coating film contains a hydrolysis polycondensate obtained by hydrolyzing and polycondensing the above-mentioned metal alkoxide by the sol-gel method. By providing such a barrier coat layer on a deposition film, when the deposition film is made of an inorganic oxide, the gas barrier property can be improved and the occurrence of cracks in the deposition film can be effectively suppressed.

[0172] Examples of metal alkoxides include alkoxysilanes, specifically tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane.

[0173] Examples of the water-soluble polymer include hydroxyl group-containing polymers such as polyvinyl alcohol and ethylene-vinyl alcohol copolymer. Either polyvinyl alcohol or ethylene-vinyl alcohol copolymer may be used, or both may be used in combination, depending on the desired physical properties such as oxygen barrier property, water vapor barrier property, water resistance, and weather resistance. Also, a gas barrier coating film obtained using polyvinyl alcohol and a gas barrier coating film obtained using ethylene-vinyl alcohol copolymer may be laminated. The amount of the water-soluble polymer used is preferably 5 parts by mass or more and 500 parts by mass or less, based on 100 parts by mass of the metal alkoxide.

[0174] As the silane coupling agent, known organic reactive group-containing organoalkoxysilane can be used, and organoalkoxysilane having epoxy group is preferable, for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane can be mentioned. The amount of the silane coupling agent used is preferably 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the metal alkoxide.

[0175] The gas barrier composition may contain water in a ratio of preferably 0.1 mol or more, more preferably 0.5 mol or more, and preferably 100 mol or less, more preferably 60 mol or less, per mol of metal alkoxide. By making the water content equal to or greater than the lower limit, for example, the oxygen barrier property and water vapor barrier property of the barrier substrate can be improved. By making the water content equal to or less than the upper limit, for example, the hydrolysis reaction can be carried out quickly.

[0176] The gas barrier composition may contain an organic solvent, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, or n-butyl alcohol.

[0177] The sol-gel catalyst is preferably an acid or an amine compound.

[0178] Examples of methods for applying the gas barrier composition include application means such as roll coating using a gravure roll coater or the like, spray coating, spin coating, dipping, brush coating, bar coating, and applicator coating.

[0179] Hereinafter, one embodiment of the method for forming a gas barrier coating film will be described. A gas barrier composition is prepared by mixing a metal alkoxide, a water-soluble polymer, a sol-gel catalyst, water, an organic solvent, and, if necessary, a silane coupling agent. A polycondensation reaction gradually proceeds in the composition. The composition is applied to the deposition film by a conventional method and dried. This drying causes further polycondensation of the metal alkoxide and the water-soluble polymer (and the silane coupling agent if the composition contains a silane coupling agent) to form a composite polymer layer. The above operation may be repeated to laminate multiple composite polymer layers. For example, the applied composition is heated at a temperature of preferably 20°C or higher, more preferably 50°C or higher, and even more preferably 70°C or higher, and preferably 150°C or lower, more preferably 120°C or lower, and even more preferably 100°C or lower, for 1 second to 10 minutes. This allows the formation of a gas barrier coating film.

[0180] The thickness of the gas barrier coating film is preferably 0.01 μm or more, more preferably 0.05 μm or more, even more preferably 0.1 μm or more, and is preferably 100 μm or less, more preferably 50 μm or less, even more preferably 5 μm or less, still more preferably 2 μm or less, particularly preferably 1 μm or less, for example, 0.01 μm or more and 100 μm or less. A barrier substrate provided with such a gas barrier coating film has, for example, excellent gas barrier properties, can suppress the occurrence of cracks in a vapor deposition film composed of an inorganic oxide, and also has excellent recyclability and processability of a packaging container.

[0181] <Layer structure of barrier substrate> Hereinafter, several examples of the layer structure of the barrier substrate of the present disclosure will be given with reference to the drawings. In these drawings, the layer structure of the stretched substrate of the present disclosure will also be described. 1 comprises, in this order, a first vapor-deposited film 40, a first surface resin layer 20, a polyethylene layer 10, a second surface resin layer 22, and a second vapor-deposited film 42. The stretched substrate comprises, in this order, the first surface resin layer 20, the polyethylene layer 10, and the second surface resin layer 22. 2A comprises, in this order, a first vapor-deposited film 40, a first surface resin layer 20, a first polyethylene layer 11, a second polyethylene layer 12, a second surface resin layer 22, and a second vapor-deposited film 42. The stretched substrate comprises, in this order, the first surface resin layer 20, the first polyethylene layer 11, the second polyethylene layer 12, and a second surface resin layer 22. 2B comprises, in this order, a first vapor-deposited film 40, a first surface resin layer 20, a polyethylene layer 10, an adhesive resin layer 30, a second surface resin layer 22, and a second vapor-deposited film 42. The stretched substrate comprises, in this order, a first surface resin layer 20, a polyethylene layer 10, an adhesive resin layer 30, and a second surface resin layer 22. 3A includes, in this order, a first vapor-deposited film 40, a first surface resin layer 20, a first polyethylene layer 11, a second polyethylene layer 12, a third polyethylene layer 13, a second surface resin layer 22, and a second vapor-deposited film 42. The stretched substrate includes, in this order, the first surface resin layer 20, the first polyethylene layer 11, the second polyethylene layer 12, the third polyethylene layer 13, and the second surface resin layer 22. 3B comprises, in this order, a first vapor-deposited film 40, a first surface resin layer 20, a first polyethylene layer 11, a second polyethylene layer 12, an adhesive resin layer 30, a second surface resin layer 22, and a second vapor-deposited film 42. The stretched substrate comprises, in this order, the first surface resin layer 20, the first polyethylene layer 11, the second polyethylene layer 12, an adhesive resin layer 30, and a second surface resin layer 22. The barrier substrate 1 shown in Fig. 3C includes, in this order, a first vapor-deposited film 40, a first surface resin layer 20, a polyethylene layer 10 of 4a, a polyethylene layer 10 of 3a, a polyethylene layer 10 of 2a, a polyethylene layer 10 of 1a, a polyethylene layer 10 of 1b, a polyethylene layer 10 of 2b, a polyethylene layer 10 of 3b, a polyethylene layer 10 of 4b, a second surface resin layer 22, and a second vapor-deposited film 42. The stretched substrate includes, in this order, a first surface resin layer 20, a polyethylene layer 10 of 4a, a polyethylene layer 10 of 3a, a polyethylene layer 10 of 2a, a polyethylene layer 10 of 1a, a polyethylene layer 10 of 1b, a polyethylene layer 10 of 2b, a polyethylene layer 10 of 3b, a polyethylene layer 10 of 4b, and a second surface resin layer 22.

[0182] 1 to 3, the barrier substrate 1 may further include a barrier coat layer (not shown) on the first vapor-deposited film 40. In Fig. 1 to 3, the barrier substrate 1 may further include a barrier coat layer (not shown) on the second vapor-deposited film 42. In Fig. 1 to 3, a vapor-deposited film may be provided only on one surface of the stretched substrate.

[0183] <Gas barrier properties of barrier substrate> The oxygen permeability (unit: cc / (m 2 The oxygen permeability is preferably less than 30, more preferably less than 20, even more preferably less than 10, still more preferably less than 5.0, particularly preferably less than 2.0, less than 0.8 or less than 0.2. The lower limit of the oxygen permeability may be, for example, 0.01 or 0.05. The oxygen permeability is measured in accordance with JIS K7126-2:2006 at a temperature of 23°C and a humidity of 90% RH.

[0184] The water vapor permeability (unit: g / (m 2·day)) is preferably less than 10, more preferably less than 8.0, even more preferably less than 5.0, even more preferably less than 3.0, particularly preferably less than 2.0, less than 0.8 or less than 0.2. 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 at a temperature of 40°C and a humidity of 90% RH.

[0185] [Laminate] The laminate of the present disclosure comprises at least the stretchable substrate or barrier substrate of the present disclosure and a heat seal layer. The heat seal layer contains polyethylene as a main component. The laminate of the present disclosure can be suitably used as a packaging material.

[0186] The content of polyethylene in the entire laminate of the present disclosure is preferably 80% by mass or more, more preferably 85% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more. This allows, for example, the laminate to be used to produce a mono-material packaging container, improving the recyclability of the packaging container. The upper limit of the content of polyethylene is not particularly limited, but may be 99% by mass.

[0187] <Base material> The laminate of the present disclosure includes the stretched substrate or the barrier substrate of the present disclosure. The laminate of the present disclosure may include two or more stretched substrates. The laminate of the present disclosure may include two or more barrier substrates. The details of the stretched substrate and the barrier substrate are as described above, and detailed description will be omitted in this section.

[0188] In a laminate comprising a barrier substrate and a heat seal layer, the orientation of the barrier substrate is not particularly limited, but the barrier substrate is preferably arranged such that the first vapor-deposited film faces the heat seal layer (the inside of the packaging container) and the second vapor-deposited film faces the opposite side to the heat seal layer (the outside of the packaging container). That is, the laminate of the present disclosure preferably comprises, in this order, the second vapor-deposited film, the second surface resin layer, the polyethylene layer, the first surface resin layer, the first vapor-deposited film, and the heat seal layer.

[0189] In a laminate comprising a stretched substrate and a heat seal layer, the orientation of the stretched substrate is not particularly limited, but the stretched substrate is preferably arranged so that the first surface resin layer faces the heat seal layer side (inside the packaging container) and the second surface resin layer faces the opposite side to the heat seal layer (outside the packaging container). That is, the laminate of the present disclosure preferably comprises the second surface resin layer, the polyethylene layer, the first surface resin layer, and the heat seal layer in this order.

[0190] In one embodiment, the laminate of the present disclosure does not include an aluminum foil. Such a laminate of the present disclosure and a packaging container including the laminate have excellent recyclability.

[0191] The laminate of the present disclosure may further comprise an oriented polyethylene substrate. The stretched polyethylene substrate is a polyethylene substrate that has been subjected to a stretching process. The stretching process may be uniaxial stretching or biaxial stretching. The stretching ratio in the longitudinal direction (flow direction of the substrate, MD direction) is preferably 2 times or more, more preferably 3 times or more, preferably 10 times or less, more preferably 7 times or less, for example, 2 times or more and 10 times or less. The stretching ratio in the transverse direction (direction perpendicular to the MD direction, TD direction) is preferably 2 times or more, more preferably 3 times or more, preferably 10 times or less, more preferably 7 times or less, for example, 2 times or more and 10 times or less. The stretched polyethylene substrate is, for example, a uniaxially stretched polyethylene substrate, specifically, a polyethylene substrate that has been uniaxially stretched in the MD direction (MDO substrate).

[0192] The oriented polyethylene substrate contains polyethylene as a main component, and examples of the polyethylene include high density polyethylene, medium density polyethylene, low density polyethylene, linear low density polyethylene, and very low density polyethylene.

[0193] The oriented polyethylene substrate may contain biomass polyethylene. The oriented polyethylene substrate may contain recycled polyethylene. The oriented polyethylene substrate may contain the additives described above.

[0194] The polyethylene content in the stretched polyethylene substrate is preferably more than 50% by mass, more preferably 80% by mass or more, even more preferably 85% by mass or more, still more preferably 90% by mass or more, and particularly preferably 95% by mass or more.

[0195] The oriented polyethylene substrate may have a single layer structure or a multilayer structure. The thickness of the stretched polyethylene base material is preferably 5 μm or more, more preferably 8 μm or more, and even more preferably 10 μm or more from the viewpoint of the strength and heat resistance of the laminate, and is preferably 300 μm or less, more preferably 100 μm or less, and even more preferably 50 μm or less, for example, 5 μm or more and 300 μm or less, from the viewpoint of the processability of the laminate.

[0196] The stretched polyethylene substrate may be subjected to the above-mentioned surface treatment. Such a stretched polyethylene substrate has, for example, excellent adhesion to a layer adjacent to the substrate. In addition, an anchor coat layer may be formed on the surface of the stretched polyethylene substrate using a conventionally known anchor coat agent.

[0197] A laminate comprising a stretched substrate or barrier substrate of the present disclosure, a stretched polyethylene substrate, and a heat seal layer may comprise, for example, a stretched polyethylene substrate, a stretched substrate or barrier substrate of the present disclosure, and a heat seal layer, in this order, or a stretched substrate or barrier substrate of the present disclosure, a stretched polyethylene substrate, and a heat seal layer, in this order.

[0198] <Print layer> The laminate of the present disclosure may include a printed layer on one or both sides of the substrate such as the above-mentioned stretched substrate, barrier substrate, and stretched polyethylene substrate, etc. The laminate of the present disclosure may include a printed layer on the second heat seal layer described below.

[0199] The print layer includes an image. Examples of the image include characters, figures, patterns, symbols, and combinations thereof. The image may include text information such as a product name, the name of the item in the packaging container, the manufacturer, and the names of ingredients. The image may be a single, solid color (so-called solid image).

[0200] The printed layer, in one embodiment, 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 sublimation dyes. Examples of colorants also include fluorescent materials such as ultraviolet emitting materials that emit fluorescence by absorbing ultraviolet light, and infrared emitting materials that emit fluorescence by absorbing infrared light.

[0201] 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.

[0202] In one embodiment, the print layer contains a resin material in addition to a colorant. Examples of the resin material include thermoplastic resins, cured products of thermosetting resins, and cured products of energy ray curable compounds. Examples of the 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 the thermosetting resins include phenolic resins, melamine resins, urea resins, epoxy resins, unsaturated polyesters, thermosetting polyurethanes, silicone resins, and (meth)acrylic thermosetting resins. Examples of the energy ray curable compounds include polyfunctional (meth)acrylate compounds.

[0203] 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.

[0204] The printing layer may contain the above-mentioned additives.

[0205] The printing layer can be formed, for example, using an ink composition containing the above-mentioned components and, if necessary, a solvent. Methods for forming the printing layer include, for example, gravure printing, offset printing, flexographic printing, screen printing, letterpress printing, and transfer printing. From the viewpoint of reducing the environmental load, the printing layer may be formed by flexographic printing. From the viewpoint of reducing the environmental load, the printing layer may be formed using an ink derived from biomass.

[0206] The thickness of the printed layer is preferably 0.1 μm or more, more preferably 0.2 μm or more, and even more preferably 0.3 μm or more. The thickness of the printed layer is preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 3 μm or less. The thickness of the printed layer is, for example, 0.1 μm or more and 10 μm or less.

[0207] <Surface protective layer> The laminate of the present disclosure may have a surface protective layer on the printed layer provided on the second heat seal layer described later in order to improve the scratch resistance and weather resistance of the printed layer. The laminate of the present disclosure preferably has a surface protective layer that covers the entire area of ​​the printed layer. From the viewpoint of visibility of the printed layer, the surface protective layer is preferably transparent in the visible light region, and more preferably colorless and transparent.

[0208] The surface protective layer contains, for example, a thermoplastic resin, a cured product of a thermosetting resin, or a cured product of an energy ray curable compound. Among these, from the viewpoint of improving scratch resistance and weather resistance, the surface protective layer preferably contains a cured product of a thermosetting resin or a cured product of an energy ray curable compound, and more preferably contains a cured product of an energy ray curable compound. The ratio of the above cured product to the total resin components of the surface protective layer is preferably 80% by mass or more, more preferably 90% by mass or more. Examples of printing methods for the surface protective layer include letterpress printing, flexographic printing, gravure printing, offset printing, screen printing, inkjet printing, and thermal transfer printing.

[0209] The thickness of the surface protective layer is preferably 0.5 μm or more, more preferably 1 μm or more, and is preferably 15 μm or less, more preferably 10 μm or less, for example, 0.5 μm or more and 15 μm or less. A laminate having such a surface protective layer has excellent scratch resistance and weather resistance.

[0210] <Heat seal layer> The laminate of the present disclosure comprises a heat seal layer. The heat seal layer contains polyethylene as a main component. This allows the packaging container to be made of a mono-material. Such a packaging container has excellent recyclability, and for example, after collecting a used packaging container, it is not necessary to separate the stretched substrate or barrier substrate from the heat seal layer.

[0211] Examples of the 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, and from the viewpoint of heat sealability, low density polyethylene, linear low density polyethylene, and very low density polyethylene are preferred. As the polyethylene, biomass polyethylene and / or recycled polyethylene may be used from the viewpoint of reducing the environmental load.

[0212] 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.

[0213] 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 90°C or higher, more preferably 95°C or higher, and preferably 140°C or lower, more preferably 130°C or lower, for example, 90°C or higher and 140°C or lower.

[0214] From the viewpoints 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.

[0215] 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, for example, excellent recyclability.

[0216] The heat seal layer may contain the above-mentioned additives.

[0217] The laminate of the present disclosure may include at least a first heat seal layer as the heat seal layer, a stretched substrate or a barrier substrate of the present disclosure, and a second heat seal layer as the heat seal layer, 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, the second heat seal layer is a sealant layer on the outer surface side of the body, and the first heat seal layer is a sealant layer on the inner surface side of the body. That is, the body includes, from the outside to the inside of the body, the second heat seal layer, the stretched substrate or a barrier substrate, and the first heat seal layer, in this order.

[0218] In the laminate, the orientation of the barrier substrate is not particularly limited, but the barrier substrate 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 includes, in this order, the second heat-seal layer, the second vapor-deposited film, the second surface resin layer, the polyethylene layer, the first surface resin layer, the first vapor-deposited film, and the first heat-seal layer.

[0219] In the laminate, the orientation of the stretched substrate is not particularly limited, but the stretched substrate is preferably 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. That is, the laminate of the above embodiment preferably includes the second heat seal layer, the second surface resin layer, the polyethylene layer, the first surface resin layer, and the first heat seal layer in this order.

[0220] The first heat seal layer contains polyethylene as a main component. The second heat seal layer contains polyethylene as a main component. The polyethylene contained in the first heat seal layer and the polyethylene contained in the second heat seal layer may be the same or different. The first heat seal layer and the second heat seal layer can be melted by heating and fused to each other.

[0221] The heat seal layer may have a single-layer structure or a multi-layer structure. The thickness of the heat seal layer is preferably 10 μm or more, more preferably 30 μm or more, even more preferably 50 μm or more, and particularly preferably 80 μm or more, from the viewpoint of heat sealability and recyclability of the packaging container. The thickness of the heat seal layer is preferably 300 μm or less, more preferably 200 μm or less, and even more preferably 150 μm or less, from the viewpoint of processability of the laminate. The thickness of the heat seal layer is, for example, 10 μm or more and 300 μm or less.

[0222] From the viewpoint of heat sealability, the heat seal layer is preferably an unstretched resin film, more preferably an unstretched co-extruded resin film, and each layer constituting the heat seal layer is a co-extruded resin layer. The above-mentioned resin film can be produced, for example, by using a T-die casting method or an inflation method. The concept of "unstretched film" includes not only a film that is not stretched at all, but also a film that is stretched due to the tension applied during film formation.

[0223] For example, an unstretched resin film corresponding to the heat seal layer may be laminated on the barrier substrate via an adhesive layer as necessary, or polyethylene or a resin composition thereof may be melt-extruded onto the barrier substrate to form the heat seal layer. In the latter case, an adhesive layer may not be provided. Examples of the adhesive layer include the adhesive layer described below.

[0224] <Adhesive layer> The laminate of the present disclosure may include an adhesive layer between any layers, such as between the stretched substrate or the barrier substrate and the heat seal layer. Such a laminate has, for example, excellent adhesion between the stretched substrate or the barrier substrate and the heat seal layer.

[0225] The laminate of the present disclosure may, for example, comprise the stretched substrate or barrier substrate of the present disclosure, an adhesive layer, and a heat seal layer in this order, or may comprise the stretched polyethylene substrate, a second adhesive layer, the stretched substrate or barrier substrate of the present disclosure, a first adhesive layer, and a heat seal layer in this order, or may comprise the stretched substrate or barrier substrate of the present disclosure, a second adhesive layer, the stretched polyethylene substrate, a first adhesive layer, and a heat seal layer in this order. The laminate of the present disclosure may, for example, comprise the second heat seal layer, the second adhesive layer, the stretched substrate or barrier substrate of the present disclosure, a first adhesive layer, and a first heat seal layer in this order.

[0226] 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.

[0227] Examples of solvent-free adhesives, i.e., non-solvent laminate adhesives, include polyether adhesives, polyester adhesives, silicone adhesives, epoxy adhesives, and urethane adhesives. Among these, urethane adhesives are preferred, and two-liquid curing urethane adhesives are more preferred.

[0228] Examples of solvent-based adhesives include rubber-based adhesives, vinyl-based adhesives, olefin-based adhesives, silicone-based adhesives, epoxy-based adhesives, phenol-based adhesives, and urethane-based adhesives. Among these, urethane-based adhesives are preferred, and two-liquid curing urethane-based adhesives are more preferred.

[0229] In one embodiment, the laminate of the present disclosure may be produced by laminating a stretched substrate or a barrier substrate, an optional stretched polyethylene substrate, and a resin film corresponding to the heat seal layer by a non-solvent lamination method using a solvent-free adhesive, or by a dry lamination method using a solvent-based adhesive.

[0230] The adhesive layer can be formed by applying an adhesive to a barrier substrate or the like by a method such as direct gravure roll coating, gravure roll coating, kiss coating, reverse roll coating, Fountain method, or transfer roll coating, and then drying the adhesive.

[0231] 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.

[0232] In one embodiment, the adhesive layer may be an adhesive resin layer containing a thermoplastic resin, or an extruded resin layer containing a thermoplastic resin. Examples of the thermoplastic resin include 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 resin obtained by graft-polymerizing or copolymerizing an unsaturated carboxylic acid, an unsaturated carboxylic anhydride, or an ester monomer with a polyolefin. The thermoplastic resin may be a material derived from a fossil fuel, a material derived from biomass, or both of these may be used.

[0233] The extruded resin layer is preferably an extruded polyethylene layer. Examples of the 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.

[0234] The melt flow rate (MFR) of the polyethylene contained in the extruded polyethylene layer, from the viewpoints of film-forming ability and processability, 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.

[0235] From the viewpoint of a balance between heat resistance and adhesiveness, the melting point (Tm) of the polyethylene contained in the extruded polyethylene layer is preferably 100°C or higher, and preferably 140°C or lower, more preferably 130°C or lower, and even more preferably 120°C or lower, for example, 100°C or higher and 140°C or lower.

[0236] 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.

[0237] The content of polyethylene in the extruded polyethylene layer is preferably 80% by mass or more, more preferably 90% by mass or more, and further preferably 95% by mass or more. With such a constitution, for example, adhesiveness and recyclability can be improved.

[0238] 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.

[0239] The extruded polyethylene layer may be formed, for example, by melt-extruding polyethylene or a resin composition containing polyethylene onto a barrier substrate, etc. The melting temperature at this time is preferably 280°C or higher, more preferably 290°C or higher, and preferably 340°C or lower, more preferably 335°C or lower, for example, 280°C or higher and 340°C or lower.

[0240] <Layer structure of laminate> Below, several examples of layer configurations of the laminate of the present disclosure will be given. 4 comprises, in this order, a barrier substrate 1, an adhesive layer 60, and a heat seal layer 80, and more specifically, in this order, a second vapor-deposited film 42, a second surface resin layer 22, a polyethylene layer 10, a first surface resin layer 20, a first vapor-deposited film 40, an adhesive layer 60, and a heat seal layer 80. The laminate 2 may further comprise a printed layer (not shown), and for example, may further comprise a printed layer (not shown) on the first vapor-deposited film 40 or the second vapor-deposited film 42 of the barrier substrate 1. The laminate 2 shown in Fig. 5 includes a stretched polyethylene substrate 70, a second adhesive layer 62, a barrier substrate 1, a first adhesive layer 60, and a heat seal layer 80 in this order, specifically, a stretched polyethylene substrate 70, a second adhesive layer 62, a second vapor deposition film 42, a second surface resin layer 22, a polyethylene layer 10, a first surface resin layer 20, a first vapor deposition film 40, a first adhesive layer 60, and a heat seal layer 80 in this order. The laminate 2 may further include a printed layer (not shown), for example, on the surface of the stretched polyethylene substrate 70 facing the barrier substrate 1. A laminate having such a configuration is suitable as a packaging material for forming a standing pouch, for example. The laminate 2 shown in FIG. 6 includes a second heat seal layer 82, a second adhesive layer 62, a barrier substrate 1, a first adhesive layer 60, and a first heat seal layer 80 in this order, specifically, the laminate includes a second heat seal layer 82, a second adhesive layer 62, a second vapor deposition film 42, a second surface resin layer 22, a polyethylene layer 10, a first surface resin layer 20, a first vapor deposition film 40, a first adhesive layer 60, and a first heat seal layer 80 in this order. The laminate 2 may further include a printed layer (not shown), for example, a printed layer (not shown) on the surface of the second heat seal layer 82. A laminate having such a configuration is suitable as a packaging material for forming the body of a tube container body, for example. 4 to 6, the barrier substrate 1 may further include a barrier coat layer (not shown) on the first vapor-deposited film 40. In FIG. 4 to 6, the barrier substrate 1 may further include a barrier coat layer (not shown) on the second vapor-deposited film 42. In FIG. 4 to 6, the orientation of the barrier substrate 1 may be reversed. In FIG. 4 to 6, the laminate 2 may include a stretched substrate instead of the barrier substrate 1, or may include a barrier substrate having a vapor-deposited film on only one surface of the stretched substrate.

[0241] [Packaging container] The laminate of the present disclosure can be suitably used for packaging material applications. The packaging material is used to produce a packaging container. By using at least the laminate of the present disclosure, a packaging container having excellent gas barrier properties can be produced.

[0242] Examples of the packaging container include a packaging bag, a tube container, and a container with a lid.

[0243] Examples of packaging containers include packaging bags of various shapes, such as a standing pouch type, a side seal type, a two-sided seal type, a three-sided seal type, a four-sided seal type, an envelope seal type, a grooving seal type (pillow seal type), a pleated seal type, a flat bottom seal type, a square bottom seal type, and a gusset type. The packaging bag may be, for example, a small bag or a zipper bag. The packaging bag may be a refill pouch, particularly a standing pouch, that contains a fluid content such as a liquid or powder and is refilled into a container such as a bottle. The packaging bag may be, for example, a soft packaging bag.

[0244] The packaging container of the present disclosure comprises the laminate of the present disclosure. The packaging container of the present disclosure is, for example, one or more laminates of the present disclosure; a seal portion where the heat seal layers of the laminate are joined together; A storage section for storing contents; has. The seal portion includes an inner edge that defines the receiving portion.

[0245] Examples of methods for forming the sealed portion include heat sealing, which involves melting the heat seal layers of the laminate by heating or the like to fuse the heat seal layers together, and specifically include bar sealing, rotary roll sealing, belt sealing, impulse sealing, high frequency sealing, and ultrasonic sealing. For example, after the contents are placed in the packaging bag, the opening of the packaging bag is heat sealed to seal the packaging bag.

[0246] 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.

[0247] In one embodiment, the laminate of the present disclosure is used as a lid material in a lidded container. The lidded container comprises a container body having a storage section, and a lid material joined (heat sealed) to the container body so as to seal the storage section. Here, the lid material, i.e., the heat seal layer of the laminate, and the container body are heat sealed. Examples of the shape of the container body include a cup shape and a cylindrical shape with a bottom. The container body is made of, for example, polystyrene, polypropylene, polyethylene, or paper.

[0248] The contents contained in the packaging container include, for example, liquids, solids, powders, and gels. The contents may be food or beverages, or non-food or beverages such as chemicals, cosmetics, medicines, metal parts, and electronic parts. The contents include, for example, shampoo, rinse, conditioner, hand soap, body soap, air freshener, deodorant, insect repellent, fabric softener, detergent; sauce, soy sauce, dressing, edible oil, mayonnaise, ketchup, syrup, cooking alcohol, other liquid or viscous seasonings; fruit juice; spices; liquid beverages, jelly beverages, liquid soups, powdered soups, instant foods, other food and beverages; cream; toothpaste; metal parts, and electronic parts.

[0249] In one embodiment, a packaging container can be produced by folding the laminate of the present disclosure in half and overlapping it so that the stretched substrate or barrier substrate is on the outside and the heat seal layer is on the inside, and then heat sealing the ends, etc. In another embodiment, a packaging container can be produced by overlapping a plurality of laminates of the present disclosure so that the heat seal layers face each other, and then heat sealing the ends, etc. The entire packaging container may be made of the above-mentioned laminate, or only a part of the packaging container may be made of the above-mentioned laminate.

[0250] In one embodiment, the standing pouch includes a body portion composed of a side sheet and a bottom portion composed of a bottom sheet. The bottom sheet retains the shape of the side sheet, thereby imparting self-supporting properties to the pouch, and the pouch can be made into a standing type pouch. A storage portion for storing contents is formed within the area surrounded by the side sheet and the bottom sheet. In the standing pouch, only the side sheet may be the laminate of the present disclosure, only the bottom sheet may be the laminate of the present disclosure, or both the side sheet and the bottom sheet may be the laminate of the present disclosure.

[0251] In one embodiment, the side sheet can be formed by making a bag so that the heat seal layer of the laminate of the present disclosure is the innermost layer. In one embodiment, the side sheet can be formed by preparing two laminates of the present disclosure, overlapping them so that the heat seal layers face each other, and heat sealing the side edges on both sides to make a bag.

[0252] In another embodiment, the side sheet can be formed by preparing two laminates of the present disclosure, overlapping them with the heat seal layers facing each other, inserting two laminates folded in a V shape with the heat seal layers facing outward between the laminates at the side edges on both sides of the overlapped laminates, and heat sealing them. According to this production method, a standing pouch having a body with side gussets can be obtained.

[0253] In one embodiment, the bottom sheet can be formed by inserting the laminate of the present disclosure between the lower parts of the side sheets that have been made into a bag, and heat sealing the laminate. More specifically, the bottom sheet can be formed by inserting the laminate folded in a V-shape with the heat seal layer on the outside between the lower parts of the side sheets that have been made into a bag, and heat sealing the laminate.

[0254] In one embodiment, two laminates of the present disclosure are prepared, and these are stacked so that the heat seal layers face each other, and then another laminate of the present disclosure is folded in a V shape so that the heat seal layer faces outward, and this is sandwiched under the lower part of the laminates that face each other, and heat sealed to form a bottom. Next, two sides adjacent to the bottom are heat sealed to form a body. In this way, a standing pouch of one embodiment can be formed.

[0255] [Tube container body] The tube container body of the present disclosure comprises the laminate of the present disclosure. The tube container body of the present disclosure will be described below with reference to the drawings. Fig. 7 is a diagram showing a simplified configuration of a tube container 120, and Fig. 8 is a cross-sectional view taken along line AA in Fig. 7. As shown in Fig. 7, the tube container body 121 includes a head 122 and a body 123, and the body 123 is made of the laminate of the present disclosure.

[0256] <Head> The head 122 includes a shoulder 124 connected to one end of the body 123, and a spout 125 connected to the shoulder 124. In one embodiment, the spout 125 includes threads 127 for threading a cap 126 thereon.

[0257] In one embodiment, the head is formed of a resin composition containing polyethylene. This can improve the recyclability of the tube container body. Examples of polyethylene include high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, and very low-density polyethylene. Among these, high-density polyethylene is preferred from the viewpoint of shape retention and moldability. The resin composition may contain at least one selected from biomass polyethylene and recycled polyethylene. The resin composition may contain the additive.

[0258] The head portion can be manufactured by a conventional method, for example, by compression molding or injection molding, and can be joined to the body portion.

[0259] <Torso> In the tube container body 121 of the present disclosure, the body 123 is connected to a shoulder 124 of the head 122. The body 123 includes a fused portion 128 formed, for example, by overlapping the laminate of the present disclosure at one end so that the surface on the first heat seal layer side of the laminate at the other end is in contact with the surface on the second heat seal layer side of the laminate at the other end, rolling the laminate into a cylindrical shape, and heat sealing the overlapped portion. The body 123 includes a bottom seal portion 129 formed, for example, by heat sealing the opening of the laminate rolled into a cylindrical shape.

[0260] Examples of the heat sealing method include conventionally known methods such as bar sealing, rotary roll sealing, belt sealing, impulse sealing, high frequency sealing, ultrasonic sealing and flame sealing.

[0261] For example, the laminate of the present disclosure may be rolled into a cylindrical shape by overlapping the first heat seal layer side surface of one end of the laminate with the second heat seal layer side surface of the other end, and heat sealing the overlapped portion to produce a cylindrical body. From the viewpoint of heat sealability, it is preferable that one overlapped end is the first heat seal layer and the other end is the second heat seal layer. In this case, the first heat seal layer and the second heat seal layer are melted and joined to form a fused portion.

[0262] Therefore, it is preferable that the second heat seal layer does not have a printed layer or a surface protective layer formed in an area to be heat sealed when forming the body of the tube container body, so that the area can be well heat sealed when forming the cylindrical body using the laminate of the present disclosure.

[0263] In the above embodiment, the fusion portion is formed by overlapping, but the same surfaces of both ends of the laminate may be butted together and the first heat seal layers may be heat sealed to be joined. In this case, a printed layer and a surface protective layer may be formed on the second heat seal layer at both ends of the laminate. Also, in this case, a joining tape may be attached to the outer surface side of the body so as to cover the joining portion. It is preferable that the printed layer and the surface protective layer are not provided at the portion of the laminate where the joining tape is attached. The joining tape may be provided on both the inner surface and the outer surface of the body.

[0264] [Tube container] The tube container of the present disclosure will be described below with reference to the drawings. As shown in FIG. 7, the tube container 120 of the present disclosure includes a tube container body 121 and a cap 26 attached to a head portion 122.

[0265] <Tube container body> The tube container body has been described above, so a description thereof will be omitted here.

[0266] <Cap> The cap is detachably attached to the extraction port of the head, and plays a role in closing the extraction port. In one embodiment, the cap is formed of a resin composition containing a thermoplastic resin. Examples of the thermoplastic resin include polyolefins such as polyethylene and polypropylene, polyesters, cellulose resins, and vinyl resins. From the viewpoint of recyclability, polyethylene is particularly preferred. Examples of the polyethylene include high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, and very low-density polyethylene. Among these, high-density polyethylene is preferred from the viewpoint of shape retention and openability. The resin composition may contain at least one selected from biomass polyethylene and recycled polyethylene. The resin composition may contain the additives.

[0267] The cap may be a screw type having a groove on the inner surface of the cap so as to screw into the threads 127 of the extraction port 125, as shown in FIG. 7, or it may be a plug type that fits into the extraction port 125 by plugging it.

[0268] [Aspects of the present disclosure] The present disclosure relates to, for example, the following [1] to

[32] . [1] A stretched substrate comprising, in this order, at least a first surface resin layer containing polyethylene and an adhesive resin, a polyethylene layer containing polyethylene as a main component, and a second surface resin layer containing polyethylene and an adhesive resin, and which has been subjected to a uniaxial stretching treatment. [2] The stretched substrate according to [1], wherein the first surface resin layer and the second surface resin layer each independently have a polyethylene content of 60% by mass or more and 95% by mass or less, and a adhesive resin content of 5% by mass or more and 40% by mass or less. [3] The stretched substrate according to [1] or [2], wherein the adhesive resin in the first surface resin layer comprises an acid-modified polyethylene, and the adhesive resin in the second surface resin layer comprises an acid-modified polyethylene. [4] The stretched substrate according to any one of [1] to [3] above, wherein the stretched substrate comprises two or more polyethylene layers. [5] The stretched substrate according to [4], wherein the stretched substrate comprises a first polyethylene layer, a second polyethylene layer, and a third polyethylene layer, in this order, between the first surface resin layer and the second surface resin layer. [6] The stretched substrate according to [4], wherein the stretched substrate comprises, in this order, a polyethylene layer 4a, a polyethylene layer 3a, a polyethylene layer 2a, a polyethylene layer 1a, a polyethylene layer 1b, a polyethylene layer 2b, a polyethylene layer 3b, and a polyethylene layer 4b between the first surface resin layer and the second surface resin layer. [7] The stretched substrate according to [6], wherein the polyethylene layer 4a contains a linear low density polyethylene, the polyethylene layer 3a contains a linear low density polyethylene, the polyethylene layer 2a contains a linear low density polyethylene as a main component, the polyethylene layer 1a contains a polyethylene plastomer as a main component, the polyethylene layer 1b contains a polyethylene plastomer as a main component, the polyethylene layer 2b contains a linear low density polyethylene as a main component, the polyethylene layer 3b contains a linear low density polyethylene, and the polyethylene layer 4b contains a linear low density polyethylene. [8] The stretched substrate according to [7], wherein the melting point of the polyethylene plastomer is 115°C or lower. [9] The stretched substrate according to any one of [1] to [8], wherein the first surface resin layer has a thickness of 0.5 μm or more and 10 μm or less, the polyethylene layer has a thickness of 3 μm or more and 180 μm or less, and the second surface resin layer has a thickness of 0.5 μm or more and 10 μm or less.

[10] The stretched substrate according to any one of the above [1] to [9], wherein the stretched substrate has a polyethylene content of 80 mass % or more.

[11] A stretched substrate comprising, in this order, at least a first surface resin layer containing polyethylene and an adhesive resin, a polyethylene layer containing polyethylene as a main component, and a second surface resin layer containing a gas barrier resin as a main component, and which has been subjected to a uniaxial stretching treatment.

[12] The stretched substrate according to

[11] , wherein the content of the polyethylene in the first surface resin layer is 60% by mass or more and 95% by mass or less, and the content of the adhesive resin is 5% by mass or more and 40% by mass or less.

[13] The stretched substrate according to

[11] or

[12] , wherein the adhesive resin in the first surface resin layer contains an acid-modified polyethylene, and the gas barrier resin in the second surface resin layer contains at least one selected from an ethylene-vinyl alcohol copolymer and a polyamide.

[14] The stretched substrate according to any one of

[11] to

[13] , further comprising an adhesive resin layer between the polyethylene layer and the second surface resin layer.

[15] The stretched substrate according to any one of

[11] to

[14] above, wherein the stretched substrate comprises two or more polyethylene layers.

[16] The stretched substrate according to

[15] , comprising, in this order, the first surface resin layer, a first polyethylene layer, a second polyethylene layer, an adhesive resin layer, and the second surface resin layer.

[17] The stretched substrate according to

[15] or

[16] , wherein at least one of the polyethylene layers further contains a compatibilizer.

[18] The stretched substrate according to any one of

[11] to

[17] , wherein the first surface resin layer has a thickness of 0.5 μm or more and 10 μm or less, the polyethylene layer has a thickness of 3 μm or more and 180 μm or less, and the second surface resin layer has a thickness of 0.5 μm or more and 10 μm or less.

[19] The stretched substrate according to any one of

[11] to

[18] above, wherein the stretched substrate has a polyethylene content of 70 mass % or more.

[20] A barrier substrate comprising the stretched substrate according to any one of [1] to

[19] above, and a vapor-deposited film provided on the surface of at least one layer selected from the first surface resin layer and the second surface resin layer of the stretched substrate.

[21] The barrier substrate according to

[20] , comprising at least a first vapor-deposited film, the stretched substrate, and a second vapor-deposited film, in this order, the first vapor-deposited film being provided on a surface of the first surface resin layer, and the second vapor-deposited film being provided on a surface of the second surface resin layer.

[22] The barrier substrate according to

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

[23] The barrier substrate according to

[22] above, wherein the inorganic oxide vapor-deposited film is 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 an aluminum vapor-deposited film.

[24] A laminate comprising at least the barrier substrate according to any one of the above

[20] to

[23] and a heat seal layer containing polyethylene as a main component.

[25] The laminate according to

[24] , comprising at least a first heat seal layer, the barrier substrate, and a second heat seal layer, in this order, wherein the first heat seal layer contains polyethylene as a main component, and the second heat seal layer contains polyethylene as a main component.

[26] A laminate for forming a body of a tube container body, wherein 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. The laminate described in

[25] .

[27] The laminate according to any one of the above

[24] to

[26] , comprising at least a stretched polyethylene substrate containing polyethylene as a main component, the barrier substrate, and the heat seal layer.

[28] The laminate according to any one of

[24] to

[27] , wherein the content of polyethylene in the entire laminate is 80 mass % or more.

[29] A packaging container comprising the laminate described in any one of

[24] to

[28] .

[30] The packaging container described in

[29] above, which is a packaging bag.

[31] A tube container body having a head and a body, the head having a shoulder portion connected to one end of the body and an extraction port portion connected to the shoulder portion, and the body being constructed from the laminate described in

[26] .

[32] A tube container comprising the tube container body described in

[31] above and a cap. EXAMPLES

[0269] The stretched substrate and the barrier substrate of the present disclosure will be described in more detail below with reference to examples, but the stretched substrate and the barrier substrate of the present disclosure are not limited to the following examples. In the following description, "parts by mass" will be simply referred to as "parts".

[0270] [Preparation of stretched substrate] The following materials were used in making the stretched substrate: · Linear low density polyethylene (LLDPE) ExxonMobil, Exceed XP8656ML, Ethylene-1-hexene copolymer, Density: 0.916g / cm 3 Melting point: 121℃, MFR: 0.5g / 10min ·Medium Density Polyethylene (MDPE) ExxonMobil, Enable 4002MC, Density: 0.938g / cm 3 Melting point: 128℃, MFR: 0.25g / 10min ·Medium Density Polyethylene (MDPE) Dow Chemical, ELITE 5538G, Density: 0.941g / cm 3 Melting point: 129℃, MFR: 1.3g / 10min Polyolefin Plastomer 1 (POP1) Dow Chemical, AFFINITY EG8100G, Ethylene-octene copolymer, Density: 0.870g / cm 3 Melting point: 55℃, MFR: 1.0g / 10min Polyolefin Plastomer 2 (POP2) Dow Chemical, AFFINITY PL1881G, Ethylene-octene copolymer, Density: 0.902g / cm 3 Melting point: 99℃, 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% ·Adhesive resin Mitsui Chemicals, Admar AT1955T, Maleic anhydride grafted polyethylene, Density: 0.890g / cm 3 , MFR: 2.6g / 10min · Acid-modified linear low-density polyethylene (MAH-LLDPE) Arkema, OREVAC 18302N, Maleic anhydride graft modified linear low density polyethylene, Density: 0.912g / cm 3 Melting point: 123℃, MFR: 1.5g / 10min Compatibilizer Dow Chemical, RETAIN 3000, Maleic anhydride grafted polyethylene, density: 0.870g / cm 3

[0271] [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 90 parts of LLDPE (Exceed XP8656ML) and 10 parts of acid-modified LLDPE (OREVAC 18302N).

[0272] A blended polyethylene (B); A blended polyethylene (A); LLDPE (Exceed XP8656ML) and A blended polyethylene (A); A blended polyethylene (B); The mixture was extruded from an extruder through a multi-layer annular die using a five-layer coextrusion inflation device into a tube shape, and then inflated with air pressure while being taken up vertically to form a tubular film. The tubular film comprises a blended polyethylene (B) layer constituting the outer surface of the tube, a blended polyethylene (A) layer, an LLDPE layer, a blended polyethylene (A) layer, and a blended polyethylene (B) layer constituting the inner surface of the tube. After the inner surfaces of the tubular film were joined together to be flattened, both ends of the tubular film in the width direction were cut off at a predetermined width to separate it into two films. Each of the obtained films was stretched 4 times in the longitudinal direction (MD direction) using a stretching device to produce a stretched substrate.

[0273] The stretched substrate thus obtained is A second surface resin layer (a blended polyethylene (B) layer) having a thickness of 3 μm; a third polyethylene layer (a blended polyethylene (A) layer) having a thickness of 4 μm; a second polyethylene layer (LLDPE layer) having a thickness of 11 μm; A first polyethylene layer (a blended polyethylene (A) layer) having a thickness of 4 μm; A first surface resin layer (a blended polyethylene (B) layer) having a thickness of 3 μm; The total thickness of the stretched substrate was 25 μm.

[0274] Three types of barrier substrates were prepared as follows. An aluminum (AL) film having a thickness of 30 nm was formed by vapor deposition on each of the first and second surface resin layers of the stretched substrate by PVD, thus obtaining a barrier substrate. A 30 nm thick alumina vapor deposition film was formed on each of the first and second surface resin layers of the stretched substrate by the PVD method. 47.69 g of water, 22.8 g of isopropyl alcohol, and 1.13 g of 0.5N hydrochloric acid were mixed to obtain a solution. 27.04 g of tetraethoxysilane as a metal alkoxide and 1.35 g of 3-glycidoxypropyltriethoxysilane as a silane coupling agent were mixed with this solution while cooling to 10°C to obtain solution A. 4.14 g of polyvinyl alcohol with a saponification degree of 99% or more and a polymerization degree of 2,400 as a water-soluble polymer, 91.07 g of water, and 4.79 g of isopropyl alcohol were mixed to obtain solution B. Solution A and solution B were mixed so that the ratio of solution A / solution B was 65.5 / 34.5 by mass to obtain a barrier coating agent. The surface of the alumina vapor deposition film was coated with the above-mentioned barrier coating agent by spin coating, and then heat-treated in an oven at 100° C. for 8 seconds to form a barrier coating layer with a thickness of 0.3 μm. In this way, a barrier substrate was obtained. A 30 nm thick silica vapor deposition film was formed on each of the first and second surface resin layers of the stretched substrate instead of the alumina vapor deposition film, and the above barrier coat layer was further formed on the silica vapor deposition film to obtain a barrier substrate.

[0275] [Example 2] A blended polyethylene (C) was prepared by mixing 80 parts of polyolefin plastomer 1 (AFFINITY EG8100G) and 20 parts of polyolefin plastomer 2 (AFFINITY PL1881G).

[0276] A blended polyethylene (B); A blended polyethylene (A); A blended polyethylene (A); LLDPE (Exceed XP8656ML) and A blended polyethylene (C); The mixture was extruded from an extruder through a multi-layer annular die using a five-layer coextrusion inflation device into a tube shape, and then inflated with air pressure while being taken up vertically to form a tubular film. The tubular film had a blended polyethylene (B) layer constituting the outer surface of the tube, a blended polyethylene (A) layer, a blended polyethylene (A) layer, an LLDPE layer, and a blended polyethylene (C) layer constituting the inner surface of the tube. The inner surfaces of the tubular films were brought together to be flattened, and the blended polyethylene (C) layers were pressed together at the nip, after which both ends in the width direction of the film were cut off at a predetermined width to obtain a single film. The obtained film was stretched 4 times in the longitudinal direction (MD direction) using a stretching device to produce a stretched substrate.

[0277] The stretched substrate thus obtained is A second surface resin layer (blend polyethylene (B) layer) having a thickness of 2 μm; A blended polyethylene (A) layer having a thickness of 2.5 μm; A 5 μm thick blended polyethylene (A) layer; A 1.5μm thick LLDPE layer; A layer of blended polyethylene (C) having a thickness of 1.5 μm; A layer of blended polyethylene (C) having a thickness of 1.5 μm; A 1.5μm thick LLDPE layer; A 5 μm thick blended polyethylene (A) layer; A blended polyethylene (A) layer having a thickness of 2.5 μm; A first surface resin layer (blend polyethylene (B) layer) having a thickness of 2 μm; The total thickness of the stretched substrate was 25 μm. Using the above stretched substrate, three types of barrier substrates were produced in the same manner as in Example 1.

[0278] [Example 3] EVOH (Eval E171B) and Adhesive resin (Admer AT1955T) and LLDPE (Exceed XP8656ML) and A blended polyethylene (A); A blended polyethylene (B); Using the above, two films were produced in the same manner as in Example 1, and then each of the films obtained was stretched 4 times in the machine direction (MD direction) using a stretching device to produce a stretched substrate.

[0279] The stretched substrate thus obtained is A second surface resin layer (EVOH layer) having a thickness of 2.5 μm; An adhesive resin layer having a thickness of 2.5 μm; a second polyethylene layer (LLDPE layer) having a thickness of 12 μm; A first polyethylene layer (a blended polyethylene (A) layer) having a thickness of 5 μm; A first surface resin layer (a blended polyethylene (B) layer) having a thickness of 3 μm; The total thickness of the stretched substrate was 25 μm. Using the above stretched substrate, three types of barrier substrates were produced in the same manner as in Example 1.

[0280] [Comparative Example 1] After a single-layer extrusion film was formed from MDPE (ELITE 5538G) by inflation molding, the obtained film was stretched four times in the machine direction (MD direction) using a stretching device to produce a stretched substrate with a thickness of 25 μm. Using the above stretched substrate, three types of barrier substrates were produced in the same manner as in Example 1.

[0281] [Gas barrier property evaluation] The oxygen permeability (cc / (m) of each stretched substrate and each barrier substrate (hereinafter also referred to as "test piece") obtained in the examples and comparative examples was 2 ·day·atm)) and water vapor permeability (g / (m 2 The evaluation results are shown in each table.

[0282] <Oxygen permeability> The oxygen permeability of the test piece was measured in an environment of temperature 23° C. and humidity 90% RH in accordance with JIS K7126-2:2006 using an oxygen permeability measuring device (OX-TRAN2 / 20 manufactured by MOCON). 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. F: Oxygen permeability is 100 or more.

[0283] <Water vapor permeability> The water vapor permeability of the test pieces was measured in an environment of temperature 40°C and humidity 90% RH in accordance with JIS K7129-2:2019 using a water vapor permeability measuring device (PERMATRAN-w 3 / 33 manufactured by MOCON). A: The water vapor transmission rate is less than 0.2. B: The water vapor permeability is 0.2 or more and less than 0.8. C: Water vapor permeability is 0.8 or more and less than 3.0. D: Water vapor permeability is 3.0 or more and less than 5.0. E: Water vapor permeability is 5.0 or more and less than 10. F: Water vapor permeability is 10 or more and less than 100. G: Water vapor permeability is 100 or more.

[0284] [T-shaped peel test] A 20 μm-thick general OPP film, one side of which had been corona-treated, was applied in an amount of 3 g / m to the vapor-deposited film surface or the barrier coat layer surface of each of the barrier substrates obtained in the Examples and Comparative Examples. 2The layers were bonded together using a urethane adhesive (RU77T / H7, manufactured by Rock Paint Co., Ltd.) to prepare test pieces with a width of 15 mm. In accordance with JIS K6854-3:1999 (Adhesives - Test method for peel adhesion strength - Part 3: T-peel), a T-peel test was carried out using a tensile tester (Tensilon universal material testing machine, manufactured by Orientec Co., Ltd.) at a test speed of 50 mm / min and a temperature of 23°C, and the peel strength (N / 15 mm) of the vapor-deposited film against each layer was measured. The results are shown in the tables.

[0285] [Table 1]

[0286] [Table 2]

[0287] [Table 3]

[0288] A stretched substrate and a barrier substrate were prepared in the same manner as in Example 3, except that the second polyethylene layer contained about 20% by mass of a compatibilizer (RETAIN 3000). The results of the gas barrier test and the T-peel test in this example were comparable to those of the example with the corresponding layer structure (Example 3). [Explanation of symbols]

[0289] 1. Barrier substrate 2. Laminate 10 Polyethylene layer 11 First polyethylene layer 12 Second polyethylene layer 13 Third polyethylene layer 20 First surface resin layer 22 Second surface resin layer 30 Adhesive resin layer 40 First deposition film 42 Second deposition film 60 Adhesive layer, first adhesive layer 62 Second adhesive layer 70 Polyethylene oriented base material 80 Heat seal layer, first heat seal layer 82 Second heat seal layer 120 Tube container 121 Tube container body 122 Head 123 Torso 124 Shoulder 125 Extraction port 126 Cap 127 Screw 128 Fusion part 129 Bottom seal

Claims

1. a 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; In this order, It has been subjected to uniaxial stretching treatment, Stretched base material.

2. The stretched substrate according to claim 1, wherein the first surface resin layer and the second surface resin layer each independently have a polyethylene content of 60% by mass or more and 95% by mass or less and a adhesive resin content of 5% by mass or more and 40% by mass or less.

3. the adhesive resin in the first surface resin layer contains acid-modified polyethylene, The adhesive resin in the second surface resin layer contains acid-modified polyethylene. The stretched substrate of claim 1.

4. 2. The oriented substrate of claim 1, wherein the oriented substrate comprises two or more of the polyethylene layers.

5. The stretched substrate according to claim 4, wherein the stretched substrate comprises a first polyethylene layer, a second polyethylene layer, and a third polyethylene layer, in this order, between the first surface resin layer and the second surface resin layer.

6. The stretched base material is provided between the first surface resin layer and the second surface resin layer, The polyethylene film comprises, in this order, 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, and a 4b polyethylene layer, 5. The stretched substrate of claim 4.

7. The 4a polyethylene layer contains a linear low density polyethylene, The 3a polyethylene layer contains a linear low density polyethylene, The 2a polyethylene layer contains a linear low-density polyethylene as a main component, The 1a polyethylene layer contains a polyethylene plastomer as a main component, The 1b polyethylene layer contains a polyethylene plastomer as a main component, The 2b polyethylene layer contains linear low density polyethylene as a main component, The 3b polyethylene layer contains a linear low density polyethylene, The 4b polyethylene layer contains a linear low density polyethylene; 7. The stretched substrate of claim 6.

8. 8. The oriented substrate of claim 7, wherein the polyethylene plastomer has a melting point of 115°C or less.

9. The thickness of the first surface resin layer is 0.5 μm or more and 10 μm or less, The thickness of the polyethylene layer is 3 μm or more and 180 μm or less, The thickness of the second surface resin layer is 0.5 μm or more and 10 μm or less. The stretched substrate of claim 1.

10. The stretched substrate according to claim 1 , wherein the stretched substrate has a polyethylene content of 80% by mass or more.

11. 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; In this order, It has been subjected to uniaxial stretching treatment, Stretched base material.

12. The stretched substrate according to claim 11, wherein the content of the polyethylene in the first surface resin layer is from 60% by mass to 95% by mass, and the content of the adhesive resin is from 5% by mass to 40% by mass.

13. the adhesive resin in the first surface resin layer contains acid-modified polyethylene, the gas barrier resin in the second surface resin layer contains at least one selected from an ethylene-vinyl alcohol copolymer and a polyamide; 12. The stretched substrate of claim 11.

14. The stretched substrate according to claim 11, further comprising an adhesive resin layer between the polyethylene layer and the second surface resin layer.

15. 12. The oriented substrate of claim 11, wherein the oriented substrate comprises two or more of the polyethylene layers.

16. The stretched substrate according to claim 15, comprising, in this order, the first surface resin layer, a first polyethylene layer, a second polyethylene layer, an adhesive resin layer, and the second surface resin layer.

17. 16. The oriented substrate of claim 15, wherein at least one of the polyethylene layers further comprises a compatibilizer.

18. The thickness of the first surface resin layer is 0.5 μm or more and 10 μm or less, The thickness of the polyethylene layer is 3 μm or more and 180 μm or less, The thickness of the second surface resin layer is 0.5 μm or more and 10 μm or less.

12. The stretched substrate of claim 11.

19. The stretched substrate according to claim 11, wherein the stretched substrate has a polyethylene content of 70% by mass or more.

20. A stretched substrate according to any one of claims 1 to 19, a vapor-deposited film provided on a surface of at least one layer selected from the first surface resin layer and the second surface resin layer of the stretched substrate; A barrier substrate comprising:

21. A first vapor-deposited film; The stretched substrate; A second deposited film; In this order, the first vapor-deposited film is provided on a surface of the first surface resin layer, The second vapor-deposited film is provided on a surface of the second surface resin layer. The barrier substrate according to claim 20.

22. 22. The barrier substrate according to claim 21, wherein the first vapor-deposited film and the second vapor-deposited film are each independently a metal vapor-deposited film, the first vapor-deposited film is an inorganic oxide vapor-deposited film and the second vapor-deposited film is a metal vapor-deposited film, the first vapor-deposited film is a metal vapor-deposited film and the second vapor-deposited film is an inorganic oxide vapor-deposited film, or the first vapor-deposited film and the second vapor-deposited film are each independently an inorganic oxide vapor-deposited film.

23. 23. The barrier substrate according to claim 22, wherein the inorganic oxide vapor-deposited film is 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 an aluminum vapor-deposited film.

24. The barrier substrate according to claim 20 ; A heat seal layer containing polyethylene as a main component; A laminate comprising at least

25. a first heat seal layer; The barrier substrate; a second heat seal layer; In this order, The first heat seal layer contains polyethylene as a main component, The second heat seal layer contains polyethylene as a main component. The laminate of claim 24.

26. 26. The laminate according to claim 25, which is for forming a body of a tube container body, wherein the second heat seal layer is a sealant layer on an outer surface side of the body, and the first heat seal layer is a sealant layer on an inner surface side of the body.

27. A polyethylene stretched substrate containing polyethylene as a main component; The barrier substrate; The heat seal layer; The laminate of claim 24 comprising at least

28. 25. The laminate according to claim 24, wherein the content of polyethylene in the entire laminate is 80 mass% or more.

29. A packaging container comprising the laminate according to claim 24.

30. 30. The packaging container of claim 29, which is a packaging bag.

31. A tube container body having a head and a body, The head portion includes 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 formed of the laminated body according to claim 26. Tube container body.

32. The tube container body according to claim 31 ; Cap and A tube container comprising:

Images