Laminate and packaging container

Abstract

To provide a laminate having a polyolefin layer, a vapor-deposited film, and an adhesive layer, the laminate exhibiting excellent gas barrier performance and excellent adhesion between the adhesive layer and an adjacent layer thereto.SOLUTION: A laminate comprises, in this order in the lamination direction, a first polyolefin layer, an adhesive layer containing a polyolefin plastomer and an acid group-containing ethylene-based polymer, and a second polyolefin layer, wherein a vapor-deposited film is further provided between the first polyolefin layer and the adhesive layer and / or between the adhesive layer and the second polyolefin layer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Packaging containers are used to store contents such as liquids and powders. Packaging containers are made using a laminate including a base layer and a heat-sealing layer (see, for example, Patent Document 1). For example, polyethylene film is widely used as the heat-sealing layer because it has flexibility, transparency, and excellent heat-sealing properties. [Prior art documents] [Patent documents]

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

[0004] In recent years, from the viewpoint of improving the gas barrier properties of packaging containers, the use of a barrier layer in which a vapor-deposited film is provided on a base layer has been considered. The laminate is produced, for example, by using a barrier film corresponding to the barrier layer and a sealant film corresponding to the heat-sealing layer and laminating them together via an adhesive layer such as an extruded polyethylene resin layer.

[0005] However, the present inventors have found that with such a configuration, the adhesion between the vapor-deposited film and an adhesive layer such as an extruded polyethylene resin layer is insufficient, and delamination may easily occur in the laminate, or the extrusion temperature may be high, resulting in thermal degradation of the vapor-deposited film and therefore insufficient gas barrier properties.

[0006] One object of the present disclosure is to provide a laminate comprising a polyolefin layer, a vapor-deposited film, and an adhesive layer, which has excellent adhesion between the adhesive layer and a layer adjacent to the adhesive layer and also has excellent gas barrier properties. [Means for solving the problem]

[0007] One embodiment of the laminate of the present disclosure comprises a first polyolefin layer, an adhesive layer containing a polyolefin plastomer and an acid group-containing ethylene polymer, and a second polyolefin layer, in this order in the stacking direction, and further comprises a vapor-deposited film between the first polyolefin layer and the adhesive layer and / or between the adhesive layer and the second polyolefin layer. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to provide a laminate comprising a polyolefin layer, a vapor-deposited film, and an adhesive layer, which has excellent adhesion between the adhesive layer and a layer adjacent to the adhesive layer, and also has excellent gas barrier properties. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic cross-sectional view showing one embodiment of a laminate. [Figure 2] FIG. 2 is a schematic cross-sectional view showing one embodiment of the laminate. [Figure 3] FIG. 3 is a schematic cross-sectional view showing one embodiment of the laminate. [Figure 4] FIG. 4 is a schematic cross-sectional view showing one embodiment of the laminate. [Figure 5] FIG. 5 is a perspective view showing one embodiment of a tube container comprising a tube container body including a laminate and a cap. [Figure 6] FIG. 6 is a cross-sectional view taken along line AA in FIG. DETAILED DESCRIPTION OF THE INVENTION

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

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

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

[0013] In this specification, the term "major component" in a layer, film, or substrate refers to a component whose content in the layer, film, or substrate exceeds 50% by mass, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and may be 85% by mass or more, or 90% by mass or more.

[0014] [Laminate] The laminate of the present disclosure comprises: a first polyolefin layer; an adhesive layer containing a polyolefin plastomer and an acid group-containing ethylene polymer; a second polyolefin layer; and are provided in this order in the stacking direction. The adhesive layer containing the polyolefin plastomer and the acid group-containing ethylene polymer is hereinafter also referred to as "adhesive layer (Ad)." Adhesive layers other than the adhesive layer (Ad) are hereinafter also referred to as "other adhesive layers."

[0015] The laminate further comprises a vapor-deposited film between the first polyolefin layer and the adhesive layer (Ad) and / or between the adhesive layer (Ad) and the second polyolefin layer.

[0016] The laminate may include a first polyolefin layer, a vapor-deposited film, an adhesive layer (Ad), and a second polyolefin layer, in this order in the lamination direction. For example, the laminate may include a first polyolefin layer constituting a base layer, a vapor-deposited film, an adhesive layer (Ad), and a second polyolefin layer constituting a heat-seal layer, in this order in the lamination direction. The first polyolefin layer and the vapor-deposited film constitute a barrier layer (barrier base layer).

[0017] The laminate may include a first polyolefin layer, an adhesive layer (Ad), a vapor-deposited film, and a second polyolefin layer, in this order in the lamination direction. For example, the laminate may include a first polyolefin layer constituting a base layer, an adhesive layer (Ad), a vapor-deposited film, and a second polyolefin layer constituting a heat-sealing layer, in this order in the lamination direction. The second polyolefin layer and the vapor-deposited film constitute a barrier layer (barrier heat-sealing layer).

[0018] The laminate may include a first polyolefin layer, a vapor-deposited film, an adhesive layer (Ad), a vapor-deposited film, and a second polyolefin layer, in this order in the lamination direction. For example, the laminate may include a first polyolefin layer constituting a base layer, a vapor-deposited film, an adhesive layer (Ad), a vapor-deposited film, and a second polyolefin layer constituting a heat-sealing layer, in this order in the lamination direction. The first polyolefin layer and the vapor-deposited film constitute a barrier layer (barrier base layer). The second polyolefin layer and the vapor-deposited film constitute a barrier layer (barrier heat-sealing layer).

[0019] The laminate may further comprise a third polyolefin layer or the like. The laminate may include, in this order in the lamination direction, a third polyolefin layer, an adhesive layer, a first polyolefin layer, a vapor-deposited film, an adhesive layer (Ad), and a second polyolefin layer. For example, the laminate may include, in this order in the lamination direction, a third polyolefin layer constituting a base layer, an adhesive layer, a first polyolefin layer constituting a base layer, a vapor-deposited film, an adhesive layer (Ad), and a second polyolefin layer constituting a heat-seal layer. The first polyolefin layer and the vapor-deposited film constitute a barrier layer (barrier base layer).

[0020] The laminate may include a first polyolefin layer, an adhesive layer (Ad), a vapor-deposited film, a second polyolefin layer, an adhesive layer, and a third polyolefin layer in this order in the lamination direction. For example, the laminate may include, in the lamination direction, a first polyolefin layer constituting a base layer, an adhesive layer (Ad), a vapor-deposited film, a second polyolefin layer constituting a base layer, the adhesive layer, and a third polyolefin layer constituting a heat-sealing layer, in this order. The second polyolefin layer and the vapor-deposited film constitute a barrier layer (barrier substrate layer). Such a laminate can, for example, prevent corrosion of the vapor-deposited film by the contents contained in a packaging container. For example, the laminate may include, in the lamination direction, a first polyolefin layer constituting a heat-seal layer, an adhesive layer (Ad), a vapor-deposited film, a second polyolefin layer constituting a base layer, the adhesive layer, and a third polyolefin layer constituting a heat-seal layer. The second polyolefin layer and the vapor-deposited film constitute a barrier layer (barrier base layer). Such a laminate is suitable, for example, as a packaging material constituting the body of a tube container. In this case, for example, the first polyolefin layer may be the heat-seal layer on the outer surface of the body, and the third polyolefin layer may be the heat-seal layer on the inner surface of the body. That is, the body includes, from the outside to the inside of the body, the first polyolefin layer, the adhesive layer (Ad), the vapor-deposited film, the second polyolefin layer, the adhesive layer, and the third polyolefin layer, in this order. Such a laminate can, for example, suppress corrosion of the vapor-deposited film by the contents contained in the packaging container.

[0021] The laminate may include a first polyolefin layer, an adhesive layer (Ad), a first vapor-deposited film, a second polyolefin layer, a second vapor-deposited film, an adhesive layer (Ad), and a third polyolefin layer, in this order in the stacking direction. For example, the laminate may include, in the lamination direction, a first polyolefin layer constituting the base layer, an adhesive layer (Ad), a first vapor-deposited film, a second polyolefin layer constituting the base layer, the second vapor-deposited film, the adhesive layer (Ad), and a third polyolefin layer constituting the heat-seal layer. The first vapor-deposited film, the second polyolefin layer, and the second vapor-deposited film constitute a barrier layer (barrier base layer). For example, the laminate may include, in the lamination direction, a first polyolefin layer constituting the heat-seal layer, an adhesive layer (Ad), a first vapor-deposited film, a second polyolefin layer constituting the base layer, the second vapor-deposited film, the adhesive layer (Ad), and a third polyolefin layer constituting the heat-seal layer. The first vapor-deposited film, the second polyolefin layer, and the second vapor-deposited film constitute a barrier layer (barrier base layer). Such a laminate is suitable, for example, as a packaging material for forming the barrel of a tube container body.

[0022] The laminate may include, in this order in the lamination direction, a first polyolefin layer, a vapor-deposited film, an adhesive layer (Ad), a second polyolefin layer, an adhesive layer, and a third polyolefin layer. For example, the laminate may include, in this order in the lamination direction, a first polyolefin layer constituting a base layer, a vapor-deposited film, an adhesive layer (Ad), a second polyolefin layer constituting a base layer, an adhesive layer, and a third polyolefin layer constituting a heat-seal layer. The first polyolefin layer and the vapor-deposited film constitute a barrier layer (barrier base layer).

[0023] The laminate may include, in this order in the stacking direction, a third polyolefin layer, an adhesive layer (Ad), a vapor-deposited film, a first polyolefin layer, an adhesive layer (Ad), a vapor-deposited film, and a second polyolefin layer. For example, the laminate may include, in this order in the stacking direction, a third polyolefin layer constituting a base layer, an adhesive layer (Ad), a vapor-deposited film, a first polyolefin layer constituting a base layer, an adhesive layer (Ad), a vapor-deposited film, and a second polyolefin layer constituting a heat-seal layer. The first polyolefin layer and the vapor-deposited film constitute a barrier layer (barrier base layer). The second polyolefin layer and the vapor-deposited film constitute a barrier layer (barrier heat-seal layer).

[0024] The laminate may include, in this order in the stacking direction, a third polyolefin layer, an adhesive layer, a first polyolefin layer, a vapor-deposited film, an adhesive layer (Ad), a vapor-deposited film, and a second polyolefin layer. For example, the laminate may include, in this order in the stacking direction, a third polyolefin layer constituting a substrate layer, an adhesive layer, a first polyolefin layer constituting a substrate layer, a vapor-deposited film, an adhesive layer (Ad), a vapor-deposited film, and a second polyolefin layer constituting a heat-sealing layer. The first polyolefin layer and the vapor-deposited film constitute a barrier layer (barrier substrate layer). The second polyolefin layer and the vapor-deposited film constitute a barrier layer (barrier heat-sealing layer).

[0025] In each of the above examples, the adhesive layer may be the adhesive layer (Ad) or another adhesive layer.

[0026] In each of the above examples, the barrier substrate layer or the barrier heat seal layer may comprise the polyolefin layer, optionally an adhesive resin layer, layer (1) described below, and a vapor-deposited film in this order in the lamination direction, or the polyolefin layer, layer (2) described below, and a vapor-deposited film in this order in the lamination direction. Details of the adhesive resin layer, layer (1), and layer (2) will be described later. The substrate layer or heat seal layer may be, for example, the polyolefin layer, or may comprise the polyolefin layer, optionally an adhesive resin layer, and layer (1) in this order, or may comprise the polyolefin layer and layer (2) in this order. The substrate layer is, for example, a uniaxially stretched film, specifically a film uniaxially stretched in the MD direction (MDO film). The substrate layer is, for example, a biaxially stretched film, specifically a film biaxially stretched in the MD direction and the TD direction. Details of the stretching treatment will be described later.

[0027] A barrier layer (barrier substrate layer) comprising a first vapor-deposited film, a polyolefin layer, and a second vapor-deposited film may comprise, in the stacking direction, the first vapor-deposited film, layer (1), an optional adhesive resin layer, the polyolefin layer, the optional adhesive resin layer, layer (1), and the second vapor-deposited film, in that order; or may comprise, in the stacking direction, the first vapor-deposited film, layer (2), the polyolefin layer, layer (2), and the second vapor-deposited film, in that order. In this case, the substrate layer may be, for example, the polyolefin layer, or may comprise, in the stacking direction, layer (1), an optional adhesive resin layer, the polyolefin layer, the optional adhesive resin layer, and layer (1), or may comprise, in the stacking direction, layer (2), the polyolefin layer, and layer (2). The substrate layer may be, for example, a uniaxially stretched film, specifically a film uniaxially stretched in the MD (MDO) direction. The base layer is, for example, a biaxially stretched film, specifically a film biaxially stretched in the MD direction and the TD direction. Details of the stretching treatment will be described later.

[0028] In the laminate, the orientation of the barrier substrate layer is not particularly limited. From the viewpoint of suppressing deterioration of the vapor-deposited film due to the contents contained in the packaging container, the barrier substrate layer may be arranged so that the polyolefin layer faces the heat-seal layer side (inside the packaging container) and the vapor-deposited film faces the opposite side to the heat-seal layer (outside the packaging container).

[0029] In one embodiment, the laminate of the present disclosure does not include either a polyethylene terephthalate film or an aluminum foil, which can improve the recyclability of the laminate of the present disclosure and packaging containers including the laminate. The laminate of the present disclosure can be suitably used as a packaging material.

[0030] The polyolefin (e.g., polyethylene or polypropylene) content in the entire laminate of the present disclosure is preferably 80% by mass or more, and may be, for example, 85% by mass or more or 90% by mass or more. This allows, for example, the laminate to be used to produce polyolefin-containing packaging containers, improving the recyclability of the packaging containers. The upper limit of the polyolefin content is not particularly limited, but may be 99% by mass.

[0031] The thickness of the laminate of the present disclosure is preferably 40 μm or more, more preferably 60 μm or more, even more preferably 70 μm or more, and preferably 400 μm or less, more preferably 350 μm or less, even more preferably 300 μm or less, for example, 40 μm or more and 400 μm or less. In this specification, the thickness of the laminate and each layer, etc. is the average value of thicknesses measured at 10 points based on a scanning electron microscope (SEM) image obtained by observing a cross section perpendicular to the surface of the laminate with an SEM.

[0032] <Polyolefin layer> The first to third polyolefin layers each independently contain a polyolefin as a main component. Examples of the first to third polyolefin layers include a polyethylene layer containing polyethylene as a main component and a polypropylene layer containing polypropylene as a main component, with the polyethylene layer being preferred.

[0033] The first polyolefin layer may be the same layer as the second polyolefin layer or a different layer, and the third polyolefin layer may be the same layer as either the first or second polyolefin layer or a different layer.

[0034] In a laminate comprising first and second polyolefin layers, the first and second polyolefin layers may both be polyethylene layers or polypropylene layers from the viewpoint of recyclability. In a laminate comprising first to third polyolefin layers, the first to third polyolefin layers may both be polyethylene layers or polypropylene layers from the viewpoint of recyclability.

[0035] In this specification, polyethylene refers to a polymer in which the content of ethylene-derived structural units in all repeating structural units is greater than 50 mol%. In this polymer, the content of ethylene-derived structural units is preferably 70 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, and particularly preferably 95 mol% or more. The content is measured by NMR.

[0036] 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.

[0037] In this specification, examples of polyethylene include high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, and very low-density polyethylene, as well as ethylene-vinyl acetate copolymer and ethylene-(meth)acrylic acid ester copolymer. From the viewpoints of strength, heat resistance, etc., high-density polyethylene and medium-density polyethylene are preferred. From the viewpoints of film-forming ability, processability, etc., linear low-density polyethylene and medium-density polyethylene are preferred.

[0038] In this specification, the density of polyethylene is as follows: The density of the high density polyethylene is preferably 0.945 g / cm 3 The upper limit of the density of high density polyethylene is, for example, 0.970 g / cm 3, preferably 0.965 g / cm 3 The density of the medium density polyethylene is preferably 0.930 g / cm 3 Exceeds 0.945g / cm 3 The density of the low density polyethylene is preferably 0.900 g / cm or less. 3 Exceeds 0.930g / cm 3 The density of the linear low density polyethylene is preferably 0.900 g / cm or less. 3 Exceeds 0.930g / cm 3 The density of the ultra-low density polyethylene is preferably 0.900 g / cm or less. 3 The lower limit of the density of the ultra-low density polyethylene is, for example, 0.860 g / cm 3 In this specification, the density of polyethylene is measured in accordance with JIS K7112-2:2023 (density gradient tube method, 23°C).

[0039] Low-density polyethylene is, for example, polyethylene obtained by polymerizing ethylene using a high-pressure polymerization method (high-pressure low-density polyethylene).Linear low-density polyethylene is, for example, polyethylene obtained by polymerizing ethylene and a small amount of α-olefins using a polymerization method using a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as a metallocene catalyst.

[0040] Polyethylenes with different densities or branches can be obtained by appropriately selecting the polymerization method. For example, it is preferable to use a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as a metallocene catalyst as the polymerization catalyst, and carry out polymerization in one or more stages by any of gas phase polymerization, slurry polymerization, solution polymerization, and high-pressure ionic polymerization.

[0041] In this specification, polyethylene may be derived from biomass (hereinafter also referred to as "biomass polyethylene"). That is, as a raw material for obtaining polyethylene, ethylene derived from biomass may be used instead of ethylene obtained from fossil fuels. Biomass polyethylene is a carbon-neutral material, and therefore can reduce the environmental impact of laminates or packaging containers. Biomass polyethylene can be produced, for example, by the method described in JP 2013-177531 A. Commercially available biomass polyethylene may also be used.

[0042] The polyethylene may be mechanically or chemically recycled polyethylene (hereinafter referred to as "recycled polyethylene"). This reduces the environmental impact of laminates or packaging containers. Mechanical recycling generally involves crushing recovered polyethylene film, washing it with an alkali to remove dirt and foreign matter from the film surface, and then drying it at high temperature and reduced pressure for a certain period of time to disperse any contaminants remaining inside the film, decontaminating it, and returning it to polyethylene. Chemical recycling generally involves breaking down recovered polyethylene film to the monomer level and repolymerizing the monomer to obtain polyethylene.

[0043] The above description of polyethylene is also applicable elsewhere in this specification.

[0044] From the viewpoints of film-forming ability and processability, the melt flow rate (MFR) of the polyethylene contained in the polyethylene layer is preferably 0.1 g / 10 min or more, more preferably 0.2 g / 10 min or more, even more preferably 0.3 g / 10 min or more, particularly preferably 0.5 g / 10 min or more, and preferably 30 g / 10 min or less, more preferably 20 g / 10 min or less, even more preferably 10 g / 10 min or less, particularly preferably 5 g / 10 min or less, for example, 0.1 g / 10 min or more and 30 g / 10 min or less. In this specification, the MFR of polyethylene is measured by Method A in accordance with JIS K7210-1:2014, at a temperature of 190°C and a load of 2.16 kg.

[0045] From the viewpoint of heat resistance and the like, 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 115°C or higher, and preferably 140°C or lower, for example, 100°C or higher and 140°C or lower. In this specification, the Tm of various materials is the melting peak temperature obtained by differential scanning calorimetry (DSC) in accordance with JIS K7121:2012 (using test specimens conditioned according to 3.(2) (however, a cooling rate of 10°C / min)).

[0046] When the polyethylene layer is a substrate layer or a layer contained in the substrate layer, in one embodiment, the polyethylene layer may be a layer containing at least one polyethylene selected from high-density polyethylene and medium-density polyethylene (hereinafter also referred to as "polyethylene layer (A)"). Among these, the polyethylene layer may be a layer containing high-density polyethylene. Such a layer has, for example, high heat resistance, specifically, excellent resistance to heating during drying and heat-sealing during printing, and excellent resistance to vapor deposition when vapor deposition is performed on the film.

[0047] High-density polyethylenes include, for example, ethylene homopolymers and ethylene-α-olefin copolymers. Examples of α-olefins include the aforementioned α-olefins having from 3 to 20 carbon atoms, with α-olefins having from 3 to 8 carbon atoms being preferred, and α-olefins having from 4 to 8 carbon atoms being more preferred. Examples of ethylene-α-olefin copolymers include ethylene-1-butene copolymers (C4-HDPE) in which the comonomer is at least 1-butene, ethylene-1-hexene copolymers (C6-HDPE) in which the comonomer is at least 1-hexene, and ethylene-1-octene copolymers (C8-HDPE) in which the comonomer is at least 1-octene. These copolymers are not limited to the above-mentioned comonomers, and additional comonomers may also be used. For example, high-density polyethylenes produced using a metallocene catalyst are preferred.

[0048] Examples of medium-density polyethylene include ethylene homopolymers and ethylene-α-olefin copolymers. Examples of α-olefins include the aforementioned α-olefins having from 3 to 20 carbon atoms, with α-olefins having from 3 to 8 carbon atoms being preferred, and α-olefins having from 4 to 8 carbon atoms being more preferred. Examples of ethylene-α-olefin copolymers include ethylene-1-butene copolymers (C4-MDPE) in which the comonomer is at least 1-butene, ethylene-1-hexene copolymers (C6-MDPE) in which the comonomer is at least 1-hexene, and ethylene-1-octene copolymers (C8-MDPE) in which the comonomer is at least 1-octene. These copolymers are not limited to the above-mentioned comonomers, and additional comonomers may also be used. For example, medium-density polyethylenes produced using a metallocene catalyst are preferred.

[0049] The high-density polyethylene and medium-density polyethylene are preferably the above-mentioned ethylene-α-olefin copolymers. Films containing such high-density polyethylene and / or medium-density polyethylene exhibit, for example, excellent biaxial stretchability, particularly excellent stretchability in the width direction. This is presumably because the side chains derived from the α-olefins prevent the film from tearing during stretching. The ethylene-α-olefin copolymer is preferably a polyethylene obtained by polymerizing ethylene and a small amount of α-olefins using a polymerization method using a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as a metallocene catalyst, and more preferably a polyethylene produced using a metallocene catalyst.

[0050] The density of the high density polyethylene is preferably 0.945 g / cm 3 Exceeds 0.960g / cm 3 The density of the medium density polyethylene is preferably 0.930 g / cm or less. 3 Exceeds 0.945g / cm 3 The density can be adjusted, for example, by the amount of structural units derived from the α-olefin, which is the comonomer in the ethylene-α-olefin copolymer, introduced.

[0051] The polyethylene layer (A) may contain, for example, high-density polyethylene as a main component, medium-density polyethylene as a main component, or a mixture of high-density polyethylene and medium-density polyethylene as a main component. The polyethylene layer (A) may contain, for example, a mixture of high-density polyethylene and another polyethylene as a main component, a mixture of medium-density polyethylene and another polyethylene as a main component, or a mixture of high-density polyethylene, medium-density polyethylene, and another polyethylene as a main component. The main component being the above mixture means that the content of the above mixture in the polyethylene layer (A) is more than 50% by mass, and the content is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more. The high-density polyethylene may be, for example, an ethylene homopolymer, an ethylene-α-olefin copolymer, or a mixture thereof. The medium-density polyethylene may be, for example, an ethylene homopolymer, an ethylene-α-olefin copolymer, or a mixture thereof. The other polyethylene may be, for example, at least one selected from linear low-density polyethylene and high-pressure low-density polyethylene, and may be linear low-density polyethylene, high-pressure low-density polyethylene, or a mixture of linear low-density polyethylene and high-pressure low-density polyethylene.

[0052] From the viewpoint of heat resistance, the total content of high-density polyethylene and medium-density polyethylene in the polyethylene layer (A) is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, and may be 30% by mass or more, 35% by mass or more, or 40% by mass or more. The total content of high-density polyethylene and medium-density polyethylene in the polyethylene layer (A) is 100% by mass or less, and from the viewpoint of biaxial stretchability, is preferably 90% by mass or less, more preferably 85% by mass or less, even more preferably 80% by mass or less, and may be 70% by mass or less, 65% by mass or less, or 60% by mass or less. The total content of high-density polyethylene and medium-density polyethylene in the polyethylene layer (A) is, for example, 10% by mass or more and 100% by mass or less, and preferably 20% by mass or more and 60% by mass or less.

[0053] From the viewpoint of biaxial stretchability, the polyethylene layer (A) preferably further contains a linear low-density polyethylene in addition to at least one polyethylene selected from high-density polyethylene and medium-density polyethylene, and more preferably further contains a linear low-density polyethylene in addition to the high-density polyethylene.

[0054] Examples of linear low-density polyethylene include ethylene-α-olefin copolymers. Examples of α-olefins include the aforementioned α-olefins having 3 to 20 carbon atoms, with α-olefins having 3 to 8 carbon atoms being preferred, and α-olefins having 4 to 8 carbon atoms being more preferred. Examples of linear low-density polyethylene include ethylene-1-butene copolymers (C4-LLDPE) in which the comonomer is at least 1-butene, ethylene-1-hexene copolymers (C6-LLDPE) in which the comonomer is at least 1-hexene, and ethylene-1-octene copolymers (C8-LLDPE) in which the comonomer is at least 1-octene. These copolymers are not limited to the above-mentioned comonomers, and additional comonomers may also be used. For example, linear low-density polyethylenes produced using a metallocene catalyst are preferred. The density of the linear low-density polyethylene is preferably 0.900 g / cm. 3 More than 0.930g / cm 3 The following is the result.

[0055] From the viewpoint of biaxial stretchability, the content of the linear low-density polyethylene in the polyethylene layer (A) is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, and may be 30% by mass or more, 35% by mass or more, or 40% by mass or more. From the viewpoint of heat resistance, the content of the linear low-density polyethylene in the polyethylene layer (A) is preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less, and may be 70% by mass or less, 65% by mass or less, or 60% by mass or less. The content of the linear low-density polyethylene in the polyethylene layer (A) is, for example, from 10% by mass to 90% by mass, and preferably from 40% by mass to 80% by mass.

[0056] For example, the barrier substrate layer may comprise, in the lamination direction, a polyethylene layer (A), an optional adhesive resin layer, a layer (1) described below, and a vapor-deposited film, in this order, or may comprise, in the lamination direction, a polyethylene layer (A), a layer (2) described below, and a vapor-deposited film. The substrate layer may be, for example, a polyethylene layer (A), a polyethylene layer (A), an optional adhesive resin layer, and a layer (1), in this order, or a polyethylene layer (A) and a layer (2), in this order. Such a substrate layer may be a uniaxially or biaxially stretched film, preferably a biaxially stretched film, and specifically preferably a film biaxially stretched in both the MD and TD directions.

[0057] For example, the barrier substrate layer may comprise, in the stacking direction, a first vapor-deposited film, layer (1), an optional adhesive resin layer, polyethylene layer (A), an optional adhesive resin layer, layer (1), and a second vapor-deposited film, in that order; or may comprise, in the stacking direction, a first vapor-deposited film, layer (2), polyethylene layer (A), layer (2), and a second vapor-deposited film, in that order. The substrate layer may be, for example, a polyethylene layer (A), or may comprise, in the stacking direction, layer (1), an optional adhesive resin layer, polyethylene layer (A), an optional adhesive resin layer, and layer (1), or may comprise, in the stacking direction, layer (2), polyethylene layer (A), and layer (2). Such a substrate layer may be a uniaxially or biaxially stretched film, preferably a biaxially stretched film, specifically a film biaxially stretched in both the MD and TD directions.

[0058] The polypropylene may be any of a propylene homopolymer (homopolypropylene), a propylene random copolymer (random polypropylene) such as a propylene-α-olefin random copolymer, and a propylene block copolymer (block polypropylene) such as a propylene-α-olefin block copolymer, or a mixture of two or more selected from these. From the viewpoint of reducing the environmental load, biomass-derived polypropylene or mechanically or chemically recycled polypropylene may be used as the polypropylene.

[0059] In this specification, polypropylene refers to a propylene homopolymer or a polymer in which the proportion of propylene-derived structural units in all repeating structural units is greater than the proportion of structural units derived from any comonomer. In this polymer, the proportion of propylene-derived structural units may be, for example, 50 mol% or more, 60 mol% or more, 70 mol% or more, or 80 mol% or more. The above content is measured by NMR.

[0060] A propylene homopolymer is a single polymer of propylene. A propylene random copolymer is a random copolymer of propylene and an α-olefin other than propylene. A propylene block copolymer is a copolymer having a polymer block of propylene and a polymer block of an α-olefin other than propylene. Examples of α-olefins other than propylene include α-olefins having 2 to 20 carbon atoms, specifically ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 3-methyl-1-butene, 4-methyl-1-pentene, and 6-methyl-1-heptene.

[0061] Among polypropylenes, propylene random copolymers are preferred from the viewpoint of transparency, propylene homopolymers are preferred when emphasis is placed on the rigidity and heat resistance of the packaging container, and propylene block copolymers are preferred when emphasis is placed on the impact resistance of the packaging container.

[0062] From the viewpoints of film-forming property and processability, the MFR of polypropylene is preferably 0.1 g / 10 min or more, more preferably 0.2 g / 10 min or more, even more preferably 0.5 g / 10 min or more, and preferably 50 g / 10 min or less, more preferably 30 g / 10 min or less, even more preferably 10 g / 10 min or less, for example, 0.1 g / 10 min or more and 50 g / 10 min or less. In this specification, the MFR of polypropylene is measured by Method A in accordance with JIS K7210-1:2014 under conditions of a temperature of 230°C and a load of 2.16 kg.

[0063] From the viewpoints of strength, heat resistance, etc., the melting point (Tm) of polypropylene is preferably 120°C or higher, more preferably 125°C or higher, and preferably 170°C or lower, more preferably 165°C or lower, for example, 120°C or higher and 170°C or lower.

[0064] The polyolefin layer preferably contains more than 50% by mass of polyolefin (e.g., polyethylene or polypropylene), more preferably 55% by mass or more, even more preferably 60% by mass or more, still more preferably 70% by mass or more, particularly preferably 80% by mass or more, and particularly preferably 85% by mass or more or 90% by mass or more. A laminate (or packaging container) having such a layer has excellent recyclability, for example.

[0065] The polyolefin layer may contain a resin material other than polyolefin, such as polyester, polyamide, (meth)acrylic resin, vinyl resin, cellulose resin, and ionomer resin.

[0066] The polyolefin layer may contain additives, such as crosslinkers, antioxidants, UV absorbers, light stabilizers, antiblocking agents, slip agents, fillers, reinforcing agents, antistatic agents, compatibilizers, pigments, and modifying resins.

[0067] The polyolefin layer may have a single layer structure or a multilayer structure of two or more layers. A polyolefin layer having a multilayer structure has an excellent balance of, for example, strength, rigidity, heat resistance, transparency, and printability. The number of layers in the multilayer structure is two or more, preferably 14 or less, more preferably 12 or less, even more preferably 10 or less, and particularly preferably 5 or less.

[0068] The thickness of the first to third polyolefin layers is, independently of one another, preferably 5 μm or more, more preferably 10 μm or more, even more preferably 15 μm or more, and preferably 300 μm or less, more preferably 200 μm or less, even more preferably 150 μm or less, for example, 5 μm or more and 300 μm or less.

[0069] In one embodiment, the first polyolefin layer may be a stretched layer or an unstretched layer, for example, a stretched film or an unstretched film. In one embodiment, the second polyolefin layer may be a stretched layer or an unstretched layer, for example, a stretched film or an unstretched film. In one embodiment, the third polyolefin layer may be a stretched layer or an unstretched layer, for example, a stretched film or an unstretched film. A stretched film is a film that has been subjected to a stretching treatment. The substrate layer is preferably a stretched layer. The heat seal layer is preferably an unstretched layer. The term "unstretched layer" or "unstretched film" is a concept that encompasses not only a layer or film that is not stretched at all, but also a layer or film that is slightly stretched due to tension applied during film formation.

[0070] Stretching can improve, for example, the strength, rigidity, heat resistance, transparency, and printability of the film. The stretching can be uniaxial or biaxial stretching. The stretched film can be uniaxial or biaxial. When stretching in the machine direction (film flow direction, MD), the stretching ratio is preferably 2 times or more, more preferably 3 times or more, and preferably 10 times or less, more preferably 7 times or less, for example, 2 times or more and 10 times or less. When stretching in the width direction (direction perpendicular to the MD, TD), the stretching ratio is preferably 2 times or more, more preferably 3 times or more, and preferably 10 times or less, more preferably 7 times or less, for example, 2 times or more and 10 times or less.

[0071] The polyolefin layer may be surface-treated. Such a layer has excellent adhesion to other layers, for example. Surface treatment methods include physical treatments and chemical treatments. Physical treatments include corona treatment, ozone treatment, low-temperature plasma treatment using oxygen gas and / or nitrogen gas, and glow discharge treatment. Chemical treatments include oxidation treatment using chemicals.

[0072] When a vapor-deposited film is provided on the polyolefin layer, a layer containing a gas barrier resin as a main component (hereinafter also referred to as "layer (1)") or a layer containing a polyolefin (e.g., polyethylene, polypropylene) and an adhesive resin (hereinafter also referred to as "layer (2)") may be provided between the polyolefin layer and the vapor-deposited film. In this case, the polyolefin layer and layer (1) or layer (2) may form a co-extruded resin film or a stretched film thereof. Layer (1) (e.g., a coating layer, an extruded resin layer) or layer (2) (e.g., a coating layer, an extruded resin layer) may be provided on the polyolefin layer, and the vapor-deposited film is provided on layer (1) or layer (2). The vapor-deposited film is, for example, in contact with layer (1) or layer (2). By providing such a layer, the vapor-deposited film tends to have excellent adhesion to adjacent layers and exhibit good gas barrier properties.

[0073] A gas barrier resin is a resin that has the function of suppressing gas permeation. Examples of gas barrier resins include ethylene-vinyl alcohol copolymers, polyvinyl alcohol, polyamides, polyvinylidene chloride, polyesters, polyether polyols, polyester polyols, polyurethanes, polyacrylonitrile, and (meth)acrylic resins. Among these, ethylene-vinyl alcohol copolymers, polyvinyl alcohol, and polyamides are preferred, with ethylene-vinyl alcohol copolymers and polyamides being more preferred, from the viewpoints of gas barrier properties (particularly oxygen barrier properties), heat resistance, and rigidity. For example, a resin layer containing an ethylene-vinyl alcohol copolymer and / or polyamide is preferred from the viewpoint of suppressing corrosion of the vapor-deposited film by the contents contained in the packaging container.

[0074] Preferred examples of the polyethylene in layer (2) include high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, and very low-density polyethylene. From the viewpoints of the surface smoothness of layer (2) and the adhesion between layer (2) and the vapor-deposited film, linear low-density polyethylene is more preferred.

[0075] Examples of polypropylenes in layer (2) include homopolypropylene, random polypropylene, and block polypropylene. Among these, random polypropylene and homopolypropylene are preferred, and random polypropylene is more preferred, from the viewpoints of the surface smoothness of the stretched film, adhesion to the vapor-deposited film, and heat resistance of the stretched film.

[0076] Examples of adhesive resins in layer (2) include acid-modified resins, silicone resins, epoxy resins, and phenolic resins, with acid-modified resins being preferred. Examples of acid-modified resins include acid-modified polyolefins and acid-modified vinyl resins. Among these, acid-modified polyolefins are preferred from the viewpoints of recyclability and adhesion, with acid-modified polyethylene and acid-modified polypropylene being more preferred, and acid-modified polyethylene being even more preferred. Examples of acid-modified polyolefins include polyolefins (e.g., polyethylene and polypropylene) 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, with maleic acid-modified polyethylene, maleic anhydride-modified polyethylene, maleic acid-modified polypropylene, and maleic anhydride-modified polypropylene being more preferred.

[0077] In one embodiment, the polyolefin in layer (2) comprises polyethylene, the adhesive resin comprises acid-modified polyethylene, and the polyolefin layer is a polyethylene layer. In one embodiment, the polyolefin in layer (2) comprises polypropylene, the adhesive resin comprises acid-modified polypropylene, and the polyolefin layer is a polypropylene layer.

[0078] In layer (2), the polyolefin content is preferably 60% to 95% by mass and the adhesive resin content is preferably 5% to 40% by mass, more preferably 70% to 95% by mass and the adhesive resin content is 5% to 30% by mass, even more preferably 80% to 95% by mass and the adhesive resin content is 5% to 20% by mass, and particularly preferably 85% to 95% by mass and the adhesive resin content is 5% to 15% by mass. The polyolefin is, for example, polyethylene or polypropylene.

[0079] The thickness of layer (1) or layer (2) is independently preferably 0.3 μm or more, more preferably 0.5 μm or more, even more preferably 1 μm or more, and is preferably 15 μm or less, more preferably 10 μm or less, even more preferably 5 μm or less, for example, 0.3 μm or more and 15 μm or less.

[0080] A layer containing an adhesive resin as a main component (hereinafter also referred to as an "adhesive resin layer") may be further provided between the polyolefin layer and the layer (1) containing a gas barrier resin as a main component, from the viewpoint of interlayer adhesion, etc. For example, the polyolefin layer, the adhesive resin layer, and the layer (1) may constitute a co-extruded resin film or a stretched film thereof.

[0081] Examples of adhesive resins include acid-modified resins, silicone resins, epoxy resins, and phenolic resins, with acid-modified resins being preferred. Examples of acid-modified resins include acid-modified polyolefins and acid-modified vinyl resins. Among these, acid-modified polyolefins are preferred, with acid-modified polyethylene and acid-modified polypropylene being more preferred, acid-modified polyethylene being even more preferred, and acid-modified linear low-density polyethylene being particularly preferred, from the viewpoints of the recyclability of the laminate and the adhesiveness to both the polyolefin layer and layer (1). Details of the acid-modified polyolefins are as described above.

[0082] From the viewpoint of the above-mentioned adhesion, the thickness of the adhesive resin layer is preferably 0.5 μm or more, more preferably 0.8 μm or more, even more preferably 1 μm or more, and preferably 15 μm or less, more preferably 10 μm or less, even more preferably 5 μm or less, for example, 0.5 μm or more and 15 μm or less.

[0083] In one embodiment, the substrate layer constituting the barrier substrate layer may comprise one or more polyethylene layers or one or more polypropylene layers, optionally an adhesive resin layer, and layer (1) in this order in the lamination direction, or one or more polyethylene layers or one or more polypropylene layers, and layer (2) in this order in the lamination direction. In one embodiment, the substrate layer constituting the barrier substrate layer may comprise three polyethylene layers or three polypropylene layers, optionally an adhesive resin layer, and layer (1) in this order in the lamination direction, or four polyethylene layers or four polypropylene layers, and layer (2) in this order in the lamination direction.

[0084] In one embodiment, the substrate layer constituting the barrier substrate layer may comprise, in this order in the lamination direction, a layer (1), an optional adhesive resin layer, one or more polyethylene layers or one or more polypropylene layers, an optional adhesive resin layer, and the layer (1), or may comprise, in this order in the lamination direction, a layer (2), one or more polyethylene layers or one or more polypropylene layers, and the layer (2).

[0085] In one embodiment, the heat seal layer constituting the barrier heat seal layer may comprise one or more polyethylene layers or one or more polypropylene layers, optionally an adhesive resin layer, and layer (1), in that order in the lamination direction, or one or more polyethylene layers or one or more polypropylene layers, and layer (2), in that order in the lamination direction. In one embodiment, the heat seal layer constituting the barrier heat seal layer may comprise three or four polyethylene layers or three or four polypropylene layers, optionally an adhesive resin layer, and layer (1), in that order in the lamination direction, or four or five polyethylene layers or four or five polypropylene layers, and layer (2), in that order in the lamination direction.

[0086] The thickness of the substrate layer or stretched film is preferably 5 μm or more, more preferably 10 μm or more, even more preferably 15 μm or more, and preferably 200 μm or less, more preferably 100 μm or less, even more preferably 50 μm or less, particularly preferably 40 μm or less, for example, 5 μm or more and 200 μm or less. A substrate layer or stretched film having a thickness equal to or greater than the lower limit has excellent strength, rigidity, and heat resistance, for example. A substrate layer or stretched film having a thickness equal to or less than the upper limit has excellent processability, for example. The thickness of the heat seal layer will be described later.

[0087] The stretched film can be produced, for example, by forming the materials constituting the film or each layer into a film (single-layer film or laminate film) and then stretching the film. Examples of film-forming methods include inflation molding and T-die molding.

[0088] In one embodiment, the stretched film is a stretched film of a coextruded resin film. In one embodiment, the stretched film is a resin film obtained by co-extrusion of a material constituting the polyolefin layer, and, if the stretched film has an adhesive resin layer, a material constituting the adhesive resin layer, and a material constituting layer (1) or layer (2) by inflation molding, T-die molding, or the like, and then further stretching the resulting laminated film.

[0089] <Vapor deposition film> The laminate of the present disclosure includes a vapor-deposited film. Packaging containers produced using such a laminate have excellent gas barrier properties. The adhesive layer (Ad) located on the vapor-deposited film can be formed, for example, by melt extrusion, and the melting temperature during this process can be reduced, thereby suppressing thermal degradation of the vapor-deposited film. Therefore, the vapor-deposited film can exhibit good gas barrier properties.

[0090] The vapor-deposited film may be composed of, for example, a metal and / or an inorganic oxide. The vapor-deposited film may be a metal vapor-deposited film composed of one or more metals, or an inorganic oxide vapor-deposited film composed of one or more inorganic oxides. The inorganic oxide vapor-deposited film may be a transparent vapor-deposited film. Examples of metals include aluminum, chromium, tin, nickel, copper, silver, gold, and platinum. Examples of inorganic oxides include aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, barium oxide, and silicon carbide oxide (carbon-containing silicon oxide). Among these, aluminum vapor-deposited films, aluminum oxide (alumina) vapor-deposited films, silicon oxide (silica) vapor-deposited films, and silicon carbide vapor-deposited films are preferred. Among these, metal vapor-deposited films are preferred, and aluminum vapor-deposited films are more preferred, from the viewpoint of adhesion to the adhesive layer (Ad).

[0091] In one embodiment, the vapor-deposited film may be provided on one surface of the polyolefin layer. That is, the laminate may include a polyolefin layer and a vapor-deposited film, or may include a polyolefin layer, an optional adhesive resin layer, layer (1), and a vapor-deposited film in this order in the stacking direction, or a polyolefin layer, layer (2), and a vapor-deposited film in this order in the stacking direction.

[0092] In one embodiment, the vapor-deposited films may be provided on both sides of the polyolefin layer. That is, the laminate may include a barrier substrate layer having a first vapor-deposited film, a polyolefin layer, and a second vapor-deposited film in this order in the stacking direction, or a barrier substrate layer having a first vapor-deposited film, a layer (1), an optional adhesive resin layer, a polyolefin layer, an optional adhesive resin layer, a layer (1), and a second vapor-deposited film in this order in the stacking direction, or a barrier substrate layer having a first vapor-deposited film, a layer (2), a polyolefin layer, a layer (2), and a second vapor-deposited film in this order in the stacking direction.

[0093] From the viewpoint of gas barrier properties, the thickness of the vapor-deposited film is preferably 1 nm or more, more preferably 5 nm or more, and even more preferably 10 nm or more. From the viewpoint of suppressing cracking in the vapor-deposited film and the recyclability of the packaging container, the thickness of the vapor-deposited film is preferably 150 nm or less, more preferably 100 nm or less, and even more preferably 80 nm or less. The thickness of the vapor-deposited film is, for example, 1 nm or more and 150 nm or less.

[0094] The surface of the vapor-deposited film is preferably subjected to the above-mentioned surface treatment, which provides, for example, excellent adhesion to adjacent layers.

[0095] Examples of methods for forming vapor-deposited films include physical vapor deposition (PVD) methods such as vacuum deposition, sputtering, and ion plating, as well as chemical vapor deposition (CVD) methods such as plasma-enhanced chemical vapor deposition, thermal chemical vapor deposition, and photochemical vapor deposition. The vapor-deposited film may be a composite film containing two or more layers of different vapor-deposited films, formed by combining both physical vapor deposition and chemical vapor deposition.

[0096] The vacuum level in the deposition chamber was 10 -2 ~10 -8After oxygen is introduced, the pressure is preferably about 10 -1 ~10 -6 A pressure of about mbar is preferable. The amount of oxygen introduced varies depending on the size of the deposition machine. The oxygen introduced may be mixed with an inert gas such as argon gas, helium gas, or nitrogen gas as a carrier gas, provided that this does not cause any problems. The transport speed of the target film on which the deposition film is formed is, for example, 10 m / min to 800 m / min.

[0097] The vapor-deposited film may be a single layer formed by a single vapor deposition process, or may be a multilayer formed by multiple vapor deposition processes. When the vapor-deposited film is a multilayer film, each layer may be composed of the same or different components. Each layer may be formed by the same method or by different methods.

[0098] <Barrier coat layer> The laminate of the present disclosure may further include a barrier coat layer on the vapor-deposited film. That is, the laminate of the present disclosure may further include a barrier coat layer on the surface of the vapor-deposited film opposite to the surface on which the polyolefin layer is located. Such a laminate has, for example, excellent oxygen barrier properties and water vapor barrier properties, and can effectively suppress the occurrence of cracks in the vapor-deposited film when the vapor-deposited film is composed of an inorganic oxide such as aluminum oxide or silicon oxide.

[0099] 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.

[0100] 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.

[0101] The barrier coat layer may contain the above-mentioned additives.

[0102] 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 film processability and packaging container recyclability. The thickness is, for example, 0.01 μm or more and 10 μm or less.

[0103] The barrier coat layer can be formed, for example, by applying a coating liquid obtained by dissolving or dispersing a material such as a gas barrier resin in water or an appropriate organic solvent to the vapor-deposited film and drying it.

[0104] In another embodiment, the barrier coat layer is a gas barrier coating film formed by applying a gas barrier composition obtained by mixing a metal alkoxide, a water-soluble polymer, and optionally a silane coupling agent, and optionally adding water, an organic solvent, and a sol-gel catalyst to a vapor-deposited film, and then drying the gas barrier composition. The gas barrier coating film contains a hydrolysis polycondensate obtained by hydrolyzing and polycondensing the metal alkoxide or the like by a sol-gel method. By providing such a barrier coat layer on a vapor-deposited film, when the vapor-deposited film is composed of an inorganic oxide, the gas barrier properties can be improved and the occurrence of cracks in the vapor-deposited film can be effectively suppressed.

[0105] Examples of metal alkoxides include alkoxysilanes, specifically tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane.

[0106] Examples of water-soluble polymers include hydroxyl group-containing polymers such as polyvinyl alcohol and ethylene-vinyl alcohol copolymers. Depending on the desired physical properties, such as oxygen barrier property, water vapor barrier property, water resistance, and weather resistance, either polyvinyl alcohol or ethylene-vinyl alcohol copolymer may be used, or both may be used in combination. Alternatively, a gas barrier coating film obtained using polyvinyl alcohol and a gas barrier coating film obtained using ethylene-vinyl alcohol copolymer may be laminated. The amount of water-soluble polymer used is preferably 5 to 500 parts by mass per 100 parts by mass of the metal alkoxide.

[0107] As the silane coupling agent, a known organoalkoxysilane containing an organic reactive group can be used, and an organoalkoxysilane having an epoxy group is preferred, such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. The amount of the silane coupling agent used is preferably 1 part by mass or more and 20 parts by mass or less per 100 parts by mass of the metal alkoxide.

[0108] The gas barrier composition may contain water in an amount of preferably 0.1 mol or more, more preferably 0.5 mol or more, and preferably 100 mol or less, more preferably 60 mol or less, per mol of metal alkoxide. By setting the water content to the lower limit or more, for example, oxygen barrier properties and water vapor barrier properties can be improved. By setting the water content to the upper limit or less, for example, the hydrolysis reaction can be carried out quickly.

[0109] The gas barrier composition may contain an organic solvent, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, and n-butyl alcohol.

[0110] The sol-gel catalyst is preferably an acid or an amine compound.

[0111] Examples of methods for applying the gas barrier composition include roll coating using a gravure roll coater or the like, spray coating, spin coating, dipping, brush coating, bar coating, and applicator coating.

[0112] Hereinafter, one embodiment of the method for forming a gas barrier coating film will be described. A gas barrier composition is prepared by mixing a metal alkoxide, a water-soluble polymer, a sol-gel catalyst, water, an organic solvent, and, if necessary, a silane coupling agent. A polycondensation reaction gradually progresses within the composition. The composition is then coated onto the vapor-deposited film by a conventional method and dried. This drying process further promotes polycondensation of the metal alkoxide and the water-soluble polymer (and the silane coupling agent, if the composition contains one) to form a composite polymer layer. Multiple composite polymer layers may be laminated by repeating the above process. For example, the coated composition is heated at a temperature of preferably 20°C or higher, more preferably 50°C or higher, and even more preferably 70°C or higher, and preferably 150°C or lower, more preferably 120°C or lower, and even more preferably 100°C or lower, for 1 second to 10 minutes. This process allows the formation of a gas barrier coating film.

[0113] The thickness of the gas barrier coating film is preferably 0.01 μm or more, more preferably 0.05 μm or more, even more preferably 0.1 μm or more, and is preferably 100 μm or less, more preferably 50 μm or less, even more preferably 5 μm or less, still more preferably 2 μm or less, and particularly preferably 1 μm or less, for example, 0.01 μm or more and 100 μm or less. A laminate including such a gas barrier coating film has, for example, excellent gas barrier properties, can suppress the occurrence of cracks in a vapor-deposited film made of an inorganic oxide, and also has excellent recyclability and processability of a packaging container.

[0114] <Adhesive layer (Ad)> The laminate of the present disclosure includes an adhesive layer (Ad) between the first and second polyolefin layers, the adhesive layer (Ad) containing a polyolefin plastomer and an acid group-containing ethylene polymer. In one embodiment, the adhesive layer (Ad) located between the first and second polyolefin layers is in contact with the vapor-deposited film. An adhesive layer (Ad) having such a composition can, for example, lower the melting temperature during melt extrusion in its formation process, thereby suppressing thermal degradation of the vapor-deposited film and allowing the vapor-deposited film to exhibit good gas barrier properties. The adhesive layer (Ad) also exhibits excellent adhesion to both the vapor-deposited film and the polyolefin layer. Furthermore, using an adhesive layer (Ad) containing a polyolefin plastomer allows for a higher polyolefin (preferably polyethylene or polypropylene) content in the laminate compared to using an adhesive layer as described below, which is also preferred from the perspective of mono-material construction.

[0115] The adhesive layer (Ad) is preferably a layer formed from a mixture containing a polyolefin plastomer and an acid group-containing ethylene polymer, more preferably a single layer, and even more preferably a single extruded resin layer. Such an adhesive layer (Ad) can, for example, more effectively exhibit the effects described above.

[0116] Plastomer is a term used in contrast to elastomer (a polymer that deforms in response to an external force when applied and returns to its original shape in a short time when the force is removed). Plastomer is a polymer that does not exhibit elastic deformation like elastomers, but easily undergoes plastic deformation.

[0117] An example of a polyolefin plastomer is a polyethylene plastomer. A polyethylene plastomer is, for example, a copolymer of ethylene and an α-olefin, specifically 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 3 to 10 carbon atoms, such as 1-butene, 1-hexene, 1-octene, and 4-methyl-1-pentene, is preferred, and an α-olefin having 4 to 8 carbon atoms is more preferred. Specific examples of the polyethylene plastomer include an ethylene-1-butene copolymer, an ethylene-1-hexene copolymer, and an ethylene-1-octene copolymer.

[0118] The density of the polyolefin plastomer is preferably 0.920 g / cm3 from the viewpoint of being able to lower the melting temperature during melt extrusion. 3 or less, more preferably 0.915 g / cm 3 or less, more preferably 0.910 g / cm 3 The density of polyolefin plastomer is 0.850 g / cm 3 More than 0.855g / cm 3 More than 0.860g / cm 3 The density of the polyolefin plastomer may be, for example, 0.850 g / cm 3 More than 0.920g / cm 3 The density of the polyolefin plastomer is measured in accordance with JIS K7112-2:2023 (density gradient tube method, 23°C).

[0119] The melting point (Tm) of the polyolefin 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, from the viewpoint of being able to lower the melting temperature during melt extrusion and from the viewpoint of the balance between heat resistance and adhesiveness, and may be, for example, 50°C or higher, 70°C or higher, or 90°C or higher. The Tm of the polyolefin plastomer is, for example, 50°C or higher and 115°C or lower.

[0120] From the viewpoint of film-forming ability and processability, the MFR of the polyolefin plastomer is preferably 0.3 g / 10 min or more, more preferably 1 g / 10 min or more, even more preferably 3 g / 10 min or more, particularly preferably 5 g / 10 min or more, and preferably 30 g / 10 min or less, more preferably 20 g / 10 min or less, even more preferably 15 g / 10 min or less, particularly preferably 10 g / 10 min or less, for example, 0.3 g / 10 min or more and 30 g / 10 min or less. The MFR of the polyolefin plastomer is measured by Method A in accordance with JIS K7210-1:2014 under conditions of a temperature of 190°C and a load of 2.16 kg.

[0121] The acid group-containing ethylene polymer contributes to improving the adhesion between the adhesive layer and the vapor-deposited film, for example. Examples of acid group-containing ethylene polymers include copolymers of ethylene and unsaturated carboxylic acids or their acid anhydrides, copolymers of ethylene and unsaturated carboxylic acids or their acid anhydrides with other monomers, and polymers obtained by graft-polymerizing polyethylene with unsaturated carboxylic acids or their acid anhydrides. Examples of unsaturated carboxylic acids include monocarboxylic acids such as (meth)acrylic acid and dicarboxylic acids such as maleic acid. Examples of other monomers include (meth)acrylates such as alkyl (meth)acrylates. Examples of alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and butyl (meth)acrylate (e.g., n-butyl (meth)acrylate and isobutyl (meth)acrylate).

[0122] Examples of acid group-containing ethylene polymers include ethylene-(meth)acrylic acid copolymers and ethylene-(meth)acrylic acid-(meth)acrylate copolymers such as ethylene-(meth)acrylic acid-butyl(meth)acrylate copolymers. Among these, ethylene-(meth)acrylic acid-(meth)acrylate copolymers are preferred from the viewpoint of a balance of adhesion to both the vapor-deposited film and the polyolefin layer.

[0123] In the acid group-containing ethylene polymer, the content of ethylene-derived structural units may be, for example, more than 50% by mass, or 60% by mass or more, or 95% by mass or less, or 90% by mass or less, for example, more than 50% by mass and 95% by mass or less. In the acid group-containing ethylene polymer, the content of structural units derived from unsaturated carboxylic acids or acid anhydrides thereof may be, for example, 0.1% by mass or more, 1% by mass or more, 5% by mass or more, 25% by mass or less, 20% by mass or less, or 15% by mass or less, for example, 0.1% by mass or more and 25% by mass or less. In the acid group-containing ethylene polymer, the content of the (meth)acrylate-derived structural unit may be, for example, 0% by mass or more or more than 0% by mass, 1% by mass or more, 10% by mass or less, or 8% by mass or less, for example, 0% by mass or more and 10% by mass or less. The content ratio is measured by NMR.

[0124] The density of the acid group-containing ethylene polymer is 0.905 g / cm 3 More than 0.910g / cm 3 More than 0.940g / cm 3 Less than 0.930g / cm 3 It may be less than 0.905 g / cm 3 More than 0.940g / cm 3 The density of the acid group-containing ethylene polymer is measured in accordance with JIS K7112-2:2023 (density gradient tube method, 23° C.).

[0125] From the viewpoint of the balance between heat resistance and adhesiveness, the melting point (Tm) of the acid group-containing ethylene polymer is preferably 140° C. or lower, more preferably 130° C. or lower, and even more preferably 120° C. or lower, and may be, for example, 50° C. or higher, 70° C. or higher, or 90° C. or higher. The Tm of the acid group-containing ethylene polymer is, for example, 50° C. or higher and 140° C. or lower.

[0126] The melt flow rate (MFR) of the acid group-containing ethylene polymer 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, from the viewpoints of film-forming ability and processability, etc. The MFR of the acid group-containing ethylene polymer is measured by Method A in accordance with JIS K7210-1:2014, under conditions of a temperature of 190°C and a load of 2.16 kg.

[0127] The content of the polyolefin plastomer in the adhesive layer (Ad) is preferably 50% by mass to 90% by mass, and the content of the acid group-containing ethylene polymer is preferably 10% by mass to 50% by mass. The content of the polyolefin plastomer in the adhesive layer (Ad) is preferably 60% by mass to 80% by mass, and the content of the acid group-containing ethylene polymer is preferably 20% by mass to 40% by mass. Such an adhesive layer (Ad) can, for example, lower the melting temperature during melt extrusion in its formation process, thereby suppressing damage to the vapor-deposited film, allowing the vapor-deposited film to exhibit good gas barrier properties, and the adhesive layer (Ad) has an excellent balance of adhesion to both the vapor-deposited film and the polyolefin layer.

[0128] The adhesive layer (Ad) may contain the above-mentioned additives.

[0129] The thickness of the adhesive layer (Ad) is preferably 5 μm or more, more preferably 10 μm or more, from the viewpoint of interlayer adhesion, etc., 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.

[0130] The adhesive layer (Ad) is preferably an extruded resin layer, and more preferably a single extruded resin layer. The adhesive layer (Ad) may be formed, for example, by melt-extruding a resin composition containing a polyolefin plastomer and an acid group-containing ethylene polymer onto the surface of a vapor-deposited film. The melting temperature at this time is preferably 240°C or higher, more preferably 250°C or higher, even more preferably 260°C or higher, and preferably 300°C or lower, more preferably 290°C or lower, even more preferably 280°C or lower, for example, 240°C or higher and 300°C or lower.

[0131] <Other adhesive layers> In one embodiment, the other 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.

[0132] Examples of solvent-free adhesives, i.e., non-solvent laminate adhesives, include polyether adhesives, polyester adhesives, silicone adhesives, epoxy adhesives, and urethane adhesives. Among these, urethane adhesives are preferred, and two-component curing urethane adhesives are more preferred.

[0133] Examples of solvent-based adhesives include rubber-based adhesives, vinyl-based adhesives, olefin-based adhesives, silicone-based adhesives, epoxy-based adhesives, phenol-based adhesives, and urethane-based adhesives. Among these, urethane-based adhesives are preferred, and two-component curing urethane-based adhesives are more preferred.

[0134] 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.

[0135] In one embodiment, the other adhesive layer may be an adhesive layer containing a thermoplastic resin or an extruded resin layer containing a thermoplastic resin. Examples of thermoplastic resins include high-density polyethylene, medium-density polyethylene, high-pressure low-density polyethylene, linear low-density polyethylene, very low-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-methyl(meth)acrylate copolymer, ethylene-ethyl(meth)acrylate copolymer, ethylene-maleic acid copolymer, ionomer resin, and resin obtained by graft-polymerizing a polyolefin with an unsaturated carboxylic acid, unsaturated carboxylic anhydride, or ester monomer. The thermoplastic resin may be a material derived from fossil fuels, a material derived from biomass, or both.

[0136] The thickness of the extruded resin layer is preferably 5 μm or more, more preferably 10 μm or more, from the viewpoint of interlayer adhesion. The thickness of the extruded resin layer is preferably 30 μm or less, more preferably 25 μm or less, from the viewpoint of reducing the production cost of the laminate and improving its productivity. The thickness of the extruded resin layer is, for example, 5 μm or more and 30 μm or less.

[0137] <Print layer> The laminate of the present disclosure may include a printed layer on one or both surfaces of the first polyolefin layer and / or the second polyolefin layer. The laminate of the present disclosure may include a printed layer on one or both surfaces of the third polyolefin layer. The printed layer includes an image. Examples of the image include letters, figures, patterns, symbols, and combinations thereof. The image may include text information such as the product name, the name of the item in the packaging container, the manufacturer, and the names of ingredients. The image may be a single, solid color (a so-called solid image).

[0138] Examples of methods for forming the printed layer include gravure printing, offset printing, flexographic printing, screen printing, letterpress printing, and transfer printing. From the viewpoint of reducing environmental impact, the printed layer may be formed by flexographic printing.

[0139] The thickness of the printed layer is preferably 0.1 μm or more, more preferably 0.2 μm or more, even more preferably 0.3 μm or more, and preferably 10 μm or less, more preferably 5 μm or less, even more preferably 3 μm or less, for example, 0.1 μm or more and 10 μm or less.

[0140] <Heat seal layer> In one embodiment, the laminate of the present disclosure comprises a heat seal layer. The heat-seal layer contains, as its main component, a heat-fusible resin that can be melted and bonded to each other by heat. Examples of heat-fusible resins include polyolefins such as polyethylene, polypropylene, and polymethylpentene, cyclic polyolefins, cyclic olefin copolymers, ionomer resins, acid-modified polyolefins, and ethylene-(meth)acrylic acid ester-unsaturated carboxylic acid terpolymers. Examples of polyethylene include ultra-low-density polyethylene, linear low-density polyethylene, high-pressure low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, and ethylene-(meth)acrylic acid ester copolymer. Examples of acid-modified polyolefins include resins obtained by modifying polyolefins such as polyethylene and polypropylene with unsaturated carboxylic acid compounds such as (meth)acrylic acid and maleic anhydride.

[0141] In recent years, there has been a demand for recycling packaging containers in order to reduce environmental impact. From the viewpoint of recyclability, it is preferable that the base material layer and the heat seal layer are each made of the same type of resin material (mono-material). In one embodiment, the heat seal layer contains a polyolefin such as polyethylene or polypropylene as a main component. This allows the packaging container to be made mono-material. Such packaging containers have excellent recyclability, and for example, after collecting used packaging containers, there is no need to separate the base material layer and the heat seal layer.

[0142] For example, when the substrate layer is the polyethylene layer, the heat-sealing layer preferably contains polyethylene as a main component. For example, when the substrate layer is the polypropylene layer, the heat-sealing layer preferably contains polypropylene as a main component. In the laminate, for example, the first polyolefin layer, the second polyolefin layer, or the third polyolefin layer may be a heat-sealing layer.

[0143] Examples of polyethylene 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, etc., low-density polyethylene, linear low-density polyethylene, and very low-density polyethylene are preferred. From the viewpoint of reducing environmental load, etc., biomass polyethylene and / or recycled polyethylene may be used as the polyethylene.

[0144] The melting point (Tm) of the polyethylene in the heat seal layer is preferably 90°C or higher, more preferably 95°C or higher, and preferably 140°C or lower, more preferably 130°C or lower, for example, 90°C or higher and 140°C or lower, from the viewpoint of the balance between heat resistance and heat sealability.

[0145] From the viewpoints of film-forming ability and processability, the MFR of the polyethylene in the heat-sealable 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.

[0146] The content of polyethylene in the heat seal layer is preferably more than 50% by mass, more preferably 80% by mass or more, and even more preferably 90% by mass or more. A laminate including such a heat seal layer has excellent recyclability, for example.

[0147] The heat seal layer may contain the above-mentioned additives.

[0148] The heat seal layer may have a single-layer structure or a multi-layer structure. In one embodiment, the heat seal layer comprises, in this order, a layer containing linear low-density polyethylene as a main component, a layer containing high-density polyethylene as a main component, and a layer containing linear low-density polyethylene as a main component. Such a heat seal layer has an excellent balance of heat sealability and rigidity. In one embodiment, the heat seal layer comprises, in this order, a layer containing linear low-density polyethylene as a main component, and a layer containing linear low-density polyethylene as a main component. Such a heat seal layer has excellent heat sealability.

[0149] The heat seal layer constituting the barrier heat seal layer may be, for example, the polyolefin layer, or may comprise the polyolefin layer, an adhesive resin layer if desired, and layer (1) in this order, or may comprise the polyolefin layer and layer (2) in this order.

[0150] The thickness of the heat seal layer is preferably 10 μm or more, more preferably 15 μm or more, and even more preferably 20 μm or more, from the viewpoints of heat sealing properties and recyclability of the packaging container. The thickness of the heat seal layer is preferably 300 μm or less, more preferably 200 μm or less, and even more preferably 150 μm or less, from the viewpoints of processability of the laminate. The thickness of the heat seal layer is, for example, 10 μm or more and 300 μm or less. The thickness of the heat seal layer can be appropriately changed depending on, for example, the use or shape of the packaging container. In the case of a small bag, the thickness of the heat seal layer may be, for example, 20 μm or more and 60 μm or less, but is not particularly limited. In the case of a standing pouch, the thickness of the heat seal layer may be, for example, 60 μm or more and 150 μm or less, but is not particularly limited. In the case of a tube container, the thickness of each heat seal layer may be, for example, 50 μm or more, 60 μm or more, 70 μm or more, or 80 μm or more, but is not particularly limited.

[0151] From the viewpoint of heat sealing properties, 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 resin film can be produced, for example, by using an inflation molding method or a T-die molding method. For example, a sealant film corresponding to the heat seal layer may be laminated on a stretched film or a barrier film via an adhesive layer (Ad).

[0152] In one embodiment, the heat seal layer is a laminated film obtained by co-extrusion of a material constituting the polyolefin layer, and, if the heat seal layer includes an adhesive resin layer, a material constituting the adhesive resin layer, and a material constituting layer (1) or layer (2) by inflation molding, T-die molding, or the like.

[0153] <Layer structure of laminate> Hereinafter, several examples of the layer configuration of the laminate of the present disclosure will be given with reference to the drawings. 1 comprises, in this order, a first polyolefin layer 10, a vapor-deposited film 20, an adhesive layer (Ad) 30, and a second polyolefin layer 40. In this example, the first polyolefin layer 10 and the vapor-deposited film 20 may constitute a barrier film (barrier substrate layer), and the second polyolefin layer 40 may be a sealant film (heat seal layer).

[0154] 2 comprises, in this order, a first polyolefin layer 10, an adhesive layer (Ad) 30, a vapor-deposited film 20, and a second polyolefin layer 40. In this example, the first polyolefin layer 10 may be a stretched film, and the second polyolefin layer 40 and the vapor-deposited film 20 may form a barrier sealant film (barrier heat seal layer).

[0155] The laminate 1 shown in Fig. 3 comprises, in this order, a third polyolefin layer 50, an adhesive layer 60, a first polyolefin layer 10, a vapor-deposited film 20, an adhesive layer (Ad) 30, and a second polyolefin layer 40. In this example, the first polyolefin layer 10 and the vapor-deposited film 20 may constitute a barrier film (barrier substrate layer), the second polyolefin layer 40 may be a sealant film (heat-seal layer), and the third polyolefin layer 50 may be a stretched film or a sealant film (heat-seal layer). The adhesive layer 60 may be the adhesive layer (Ad) or another adhesive layer.

[0156] The laminate 1 shown in Fig. 4 comprises, in this order, a first polyolefin layer 10, an adhesive layer (Ad) 30, a vapor-deposited film 20, a second polyolefin layer 40, an adhesive layer 60, and a third polyolefin layer 50. In this example, the first polyolefin layer 10 may be a stretched film or a sealant film (heat-seal layer), the second polyolefin 40 and the vapor-deposited film 20 may constitute a barrier film (barrier substrate layer), and the third polyolefin layer 50 may be a sealant film (heat-seal layer). The adhesive layer 60 may be the adhesive layer (Ad) or another adhesive layer.

[0157] In FIGS. 1 to 4, the adhesive layer (Ad) 30 located between the first polyolefin layer 10 and the second polyolefin layer 40 is in contact with the vapor-deposited film 20. 1 and 3, a layer (1) containing a gas barrier resin as a main component, or a layer (2) containing a polyolefin and an adhesive resin, may be provided between the first polyolefin layer 10 and the vapor-deposited film 20. In Figures 2 and 4, a layer (1) or a layer (2) may be provided between the second polyolefin layer 40 and the vapor-deposited film 20. 3, the vapor-deposited film 20 may be provided on both sides of the first polyolefin layer 10. In FIG. 4, the vapor-deposited film 20 may be provided on both sides of the second polyolefin layer 40. 1 to 4, the laminate 1 may further include a barrier coating layer (not shown) on the vapor-deposited film 20. In FIGS. 1 to 4, the laminate 1 may further include a printed layer (not shown) on the polyolefin layer.

[0158] [Packaging container] The laminate of the present disclosure can be suitably used for packaging material applications. Packaging materials are used to produce packaging containers. By using at least the laminate of the present disclosure, for example, a packaging container having excellent gas barrier properties and interlayer adhesion can be produced.

[0159] The packaging container of the present disclosure comprises the laminate of the present disclosure. The packaging container of the present disclosure may be, for example: one or more laminates of the present disclosure; a seal portion where the heat seal layers of the laminate are joined together; a storage section for storing contents; It has. The seal portion includes an inner edge that defines the receptacle portion.

[0160] Examples of methods for forming the sealed portion include heat sealing, in which the heat-sealed layers of the laminate are melted by heating or the like to fuse the heat-sealed layers together, and specific examples include bar sealing, rotary roll sealing, belt sealing, impulse sealing, high-frequency sealing, and ultrasonic sealing. For example, after the contents are placed in the packaging bag, the opening of the packaging bag can be heat-sealed to seal the packaging bag.

[0161] Examples of packaging containers include packaging bags, tube containers, and containers with lids.

[0162] Examples of packaging bags include various types of packaging bags, such as stand-up pouch type, side seal type, two-sided seal type, three-sided seal type, four-sided seal type, envelope seal type, grommed seal type (pillow seal type), pleated seal type, flat bottom seal type, square bottom seal type, and gusset type.The packaging bag may be, for example, a small pouch or a zipper bag.The packaging bag may also be a refill pouch, particularly a stand-up pouch, that contains contents such as liquids and powders and is refilled into containers such as bottles.The packaging bag may also be, for example, a flexible packaging bag.

[0163] 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.

[0164] 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.

[0165] The contents housed in the packaging container include, for example, liquids, solids, powders, and gels. The contents may be food or beverages, or non-food or beverages such as chemicals, cosmetics, pharmaceuticals, metal parts, and electronic components. Examples of the contents include shampoo, rinse, conditioner, hand soap, body soap, air fresheners, deodorants, insect repellents, fabric softeners, detergents; sauces, soy sauce, dressings, cooking oils, mayonnaise, ketchup, syrups, cooking alcohol, and other liquid or viscous condiments; fruit juices; spices; liquid beverages, jelly-like beverages, liquid soups, powdered soups, instant foods, milk, chocolate, coffee powder, other food and beverages; cream; toothpaste; metal parts, and electronic components. For example, toothpaste is a preferred content for tube containers.

[0166] In one embodiment, a packaging container can be produced by folding a laminate of the present disclosure in half so that the heat seal layer is located on the inside, overlapping the laminate, and heat-sealing the edges, etc. In another embodiment, a packaging container can be produced by overlapping multiple laminates of the present disclosure so that the heat seal layers face each other, and heat-sealing the edges, etc. The entire packaging container may be made of the laminate, or only a portion of the packaging container may be made of the laminate.

[0167] In one embodiment, the stand-up pouch comprises a body portion composed of side sheets and a bottom portion composed of a bottom sheet. The bottom sheet maintains the shape of the side sheets, thereby imparting self-supporting properties to the pouch and enabling it to be a stand-up pouch. A storage compartment for storing contents is formed within the area surrounded by the side sheets and the bottom sheet. In the stand-up pouch, only the side sheets may be the laminate of the present disclosure, only the bottom sheet may be the laminate of the present disclosure, or both the side sheets and the bottom sheet may be the laminate of the present disclosure.

[0168] In one embodiment, the side sheet can be formed by preparing two laminates of the present disclosure, overlapping them with their heat-sealable layers facing each other, and heat-sealing both side edges to form a bag.

[0169] In another embodiment, the side sheets can be formed by preparing two laminates of the present disclosure, overlapping them with their heat-sealable layers facing each other, inserting two V-folded laminates with their heat-sealable layers facing outward between the laminates at the side edges of both sides of the overlapped laminates, and heat-sealing the two laminates. This production method produces a stand-up pouch having a body with side gussets.

[0170] In one embodiment, the bottom sheet can be formed by inserting the laminate of the present disclosure between the lower portions of the side sheets of a bag and heat-sealing the laminate. More specifically, the bottom sheet can be formed by inserting the laminate folded in a V-shape with the heat-seal layer facing outward between the lower portions of the side sheets of a bag and heat-sealing the laminate.

[0171] In one embodiment, two laminates of the present disclosure are prepared and stacked together with their heat-sealable layers facing each other. Then, another laminate of the present disclosure is folded in a V-shape with its heat-sealable layer facing outward, and this is sandwiched between the two laminates and heat-sealed to form a bottom. Next, two sides adjacent to the bottom are heat-sealed to form a body. In this manner, a stand-up pouch according to one embodiment can be formed.

[0172] [Tube container body] The tube container body of the present disclosure includes the laminate of the present disclosure. The tube container body of the present disclosure will be described below with reference to the drawings. Fig. 5 is a diagram showing a simplified configuration of a tube container 120, and Fig. 6 is a cross-sectional view taken along line AA in Fig. 5. As shown in Fig. 5, the tube container body 121 includes a head 122 and a body 123, and the body 123 is made of the laminate of the present disclosure.

[0173] <Head> The head 122 includes a shoulder 124 connected to one end of the body 123, and a spout 125 connected to the shoulder 124. In one embodiment, the spout 125 includes threads 127 for threading a cap 126 onto the spout 125.

[0174] In one embodiment, the head portion is formed from a resin composition containing a thermoplastic resin. Examples of the thermoplastic resin include polyolefins such as polyethylene and polypropylene, polyesters, cellulose resins, and vinyl resins. The resin composition may contain the additives described above.

[0175] The head portion can be produced by a conventionally known method, for example, by compression molding or injection molding, and can be joined to the body portion.

[0176] <Body> In the tube container body 121, 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 a heat-sealed layer at one end of a laminate of the present disclosure with an opposite heat-sealed layer at the other end so that they are in contact with each other, 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 an opening of the cylindrically rolled laminate.

[0177] Examples of heat sealing methods include conventionally known methods such as bar sealing, rotary roll sealing, belt sealing, impulse sealing, high frequency sealing, ultrasonic sealing, and flame sealing.

[0178] For example, a cylindrical body may be produced by overlapping the heat seal layer at one end of the laminate of the present disclosure with the heat seal layer at the opposite end of the laminate so that they are in contact with each other, rolling the laminate into a cylindrical shape, and heat sealing the overlapped portion. In the above embodiment, the fused portion is formed by overlapping, but it is also possible to butt the same surfaces of both ends of the laminate together and heat seal the same heat seal layers to join them.

[0179] [Tube container] The tube container of the present disclosure will be described below with reference to the drawings. As shown in Fig. 5, the tube container 120 includes a tube container body 121 and a cap 26 attached to a head portion 122.

[0180] <Tube container body> The tube container body has been described above, so a description thereof will be omitted here.

[0181] <Cap> The cap is detachably attached to the extraction port of the head. The cap serves to close the extraction port. In one embodiment, the cap is formed from a resin composition containing a thermoplastic resin. Examples of thermoplastic resins include polyolefins such as polyethylene and polypropylene, polyesters, cellulose resins, and vinyl resins. The resin composition may contain the additives described above.

[0182] The cap may be a screw type having a groove on the inner surface of the cap so as to screw onto the thread 127 of the extraction port 125, as shown in FIG. 5, or it may be a stopper type that fits onto the extraction port 125 by tapping it.

[0183] [Aspects of the present disclosure] The present disclosure relates to, for example, the following [1] to

[14] . [1] A laminate comprising: The laminate is a first polyolefin layer; an adhesive layer containing a polyolefin plastomer and an acid group-containing ethylene polymer; a second polyolefin layer; and are provided in this order in the stacking direction, The laminate further comprises a vapor-deposited film between the first polyolefin layer and the adhesive layer and / or between the adhesive layer and the second polyolefin layer. Laminate. [2] The laminate according to [1], wherein the adhesive layer located between the first polyolefin layer and the second polyolefin layer is in contact with the vapor-deposited film. [3] The laminate according to [1] or [2], wherein the content of the polyolefin plastomer in the adhesive layer is 50% by mass or more and 90% by mass or less, and the content of the acid group-containing ethylene polymer is 10% by mass or more and 50% by mass or less. [4] The laminate according to any one of [1] to [3], wherein the acid group-containing ethylene polymer is at least one selected from a copolymer of ethylene and an unsaturated carboxylic acid or its acid anhydride, a copolymer of ethylene and an unsaturated carboxylic acid or its acid anhydride with a (meth)acrylate, and a polymer in which an unsaturated carboxylic acid or its acid anhydride is graft-polymerized onto polyethylene. [5] The laminate according to any one of [1] to [4], wherein the acid group-containing ethylene polymer is at least one selected from an ethylene-(meth)acrylic acid copolymer and an ethylene-(meth)acrylic acid-(meth)acrylate copolymer. [6] The laminate according to any one of the above [1] to [5], wherein the polyolefin plastomer is a polyethylene plastomer. [7] The laminate according to [6], wherein the polyethylene plastomer has a melting point of 115°C or less. [8] The laminate according to any one of [1] to [7], wherein the adhesive layer is a single layer formed from a mixture containing the polyolefin plastomer and the acid group-containing ethylene polymer. [9] The laminate according to any one of the above [1] to [8], wherein the adhesive layer is an extruded resin layer.

[10] The laminate according to any one of the above [1] to [9], wherein the first polyolefin layer is a polyethylene layer or a polypropylene layer, and the second polyolefin layer is a polyethylene layer or a polypropylene layer.

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

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

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

[11] , wherein the second polyolefin layer is a heat seal layer containing a polyolefin as a main component, or the laminate further comprises a heat seal layer containing a polyolefin as a main component.

[13] A packaging container having the laminate described in

[12] above, a seal portion where the heat seal layers of the laminate are joined together, and a storage portion for storing contents.

[14] The packaging container according to

[13] above, which is a packaging bag. [Example]

[0184] Hereinafter, the laminate of the present disclosure will be described in more detail with reference to examples, but the laminate of the present disclosure is not limited to the following examples. In the following description, "parts by mass" will be simply referred to as "parts".

[0185] [Preparation of stretched film] The following materials were used in producing the stretched film. Linear low-density polyethylene (LLDPE) ExxonMobil Exceed XP8656ML ethylene-1-hexene copolymer, Density: 0.916g / cm 3 Melting point: 121°C, MFR: 0.5g / 10min Linear low-density polyethylene (LLDPE) ExxonMobil Exceed 1327MD ethylene-1-hexene copolymer, Density: 0.927g / cm 3 Melting point: 123°C, MFR: 1.3g / 10min Linear low-density polyethylene (LLDPE) Dow Chemical's INNATE TF80 Metallocene LLDPE, ethylene-1-octene copolymer, Density: 0.926g / cm 3 , MFR: 1.7g / 10min Medium Density Polyethylene (MDPE) ExxonMobil, Enable 4002MC, Density: 0.938g / cm 3 Melting point: 128°C, MFR: 0.25g / 10min Ethylene-vinyl alcohol copolymer (EVOH) Kuraray, Eval E171B Ethylene-vinyl alcohol copolymer (EVOH) Kuraray, Eval G156B ·Adhesive resin Mitsui Chemicals, Admar AT1955E, Maleic anhydride grafted modified polyethylene, Density: 0.890g / cm 3 , MFR: 2.6g / 10min ·Adhesive resin Mitsui Chemicals, Admer NF587 Maleic anhydride grafted modified polyethylene, Density: 0.910g / cm 3 , MFR:2.3g / 10min

[0186] [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 70 parts of MDPE (Enable 4002MC) and 30 parts of LLDPE (Exceed 1327MD).

[0187] Blended polyethylene (B), A blended polyethylene (A), LLDPE (Exceed XP8656ML) and Adhesive resin (Admer AT1955E) and EVOH (Eval E171B) and The mixture was extruded into a tube shape from an extruder through a multi-layer annular die using a five-layer coextrusion inflation device, and the extrudate was inflated with air pressure while being drawn vertically to form a tubular film. The tubular film comprised an EVOH layer constituting the outer surface of the tube, an adhesive resin layer, an LLDPE layer, a blended polyethylene (A) layer, and a blended polyethylene (B) layer constituting the inner surface of the tube. The tubular film was flattened by joining its inner surfaces together, and then both ends of the tubular film in the width direction were cut off to a predetermined width to separate it into two films. Each of the resulting films was stretched 4 times in the machine direction (MD) using a stretching device to produce a 25 μm thick stretched film (uniaxially stretched film).

[0188] The stretched film thus obtained contained, in this order, a 4 μm-thick layer of blended polyethylene (B), a 4 μm-thick layer of blended polyethylene (A), a 12 μm-thick LLDPE layer, a 2.5 μm-thick adhesive resin layer, and a 2.5 μm-thick EVOH layer. A 70 nm-thick aluminum (AL) vapor-deposited film was formed on the EVOH layer of the stretched film by PVD. A barrier film was thus obtained.

[0189] First, linear low-density polyethylene (Prime Polymer, SP2520, density: 0.925 g / cm 3 , melting point: 122°C) and a second linear low-density polyethylene (Prime Polymer, SP1520, density: 0.913 g / cm 3 , melting point: 116°C) was extruded into a multilayer film by inflation molding to produce an unstretched polyethylene film (sealant film) having a first linear low-density polyethylene layer with a thickness of 12.5 μm and a second linear low-density polyethylene layer with a thickness of 12.5 μm.

[0190] On the surface of the vapor-deposited barrier film, a polyolefin plastomer (Dow Chemical, AFFINITY PT 1450, density: 0.902 g / cm 3 , MFR: 8.5 g / 10 min) 70 mass% and ethylene-methacrylic acid-acrylate terpolymer (NUCREL AE, manufactured by Dow Chemical, density: 0.920 g / cm 3 A blend of 30% by mass of a polyethylene terephthalate (PE) (melting point: 105°C, MFR: 10g / 10min) (hereinafter also referred to as "Blend A") was extruded at a melting temperature of 270°C to form an extruded resin layer with a thickness of 20µm, and the first linear low-density polyethylene layer surface of the sealant film was attached to the extruded resin layer via this extruded resin layer to obtain a laminate.

[0191] [Example 2] LLDPE (INNATE TF80) and LLDPE (INNATE TF80) and LLDPE (INNATE TF80) and Adhesive resin (Admer NF587) and EVOH (Eval G156B) and The resulting five-layer film was co-extruded by a T-die casting method, and then sequentially biaxially stretched by 5 times in the machine direction (MD) and then 8.5 times in the transverse direction (TD) to produce a 25 μm-thick stretched film (biaxially stretched film).

[0192] The stretched film thus obtained contained, in this order, a 1 μm-thick LLDPE layer, a 2 μm-thick LLDPE layer, a 19 μm-thick LLDPE layer, a 2 μm-thick adhesive resin layer, and a 1 μm-thick EVOH layer. A laminate was obtained in the same manner as in Example 1, except that this stretched film was used.

[0193] [Reference example 1] Instead of blend A, high-pressure low-density polyethylene (Nippon Polyethylene, Novatec LC600A, density: 0.918 g / cm 3A laminate was obtained in the same manner as in Example 1, except that a high-pressure low-density polyethylene (1000 kJ / 1000 kcal, melting point: 106°C, MFR: 7.0 g / 10 min) was extruded at a melt temperature of 310°C to form an extruded resin layer having a thickness of 20 μm. When high-pressure low-density polyethylene was used, it was necessary to perform melt extrusion at a high temperature due to its melting properties.

[0194] [Reference example 2] A laminate was obtained in the same manner as in Example 1, except that instead of blend A, an ethylene-methacrylic acid-acrylate terpolymer (NUCREL AE) was extruded at a melting temperature of 270°C to form an extruded resin layer with a thickness of 20 μm.

[0195] [Reference example 3] A laminate was obtained in the same manner as in Example 1, except that, instead of Blend A, ethylene-methacrylic acid-acrylate terpolymer (NUCREL AE) and high-pressure low-density polyethylene (NOVATEC LC600A) were co-extruded at a melting temperature of 310°C to form a 20 μm-thick extruded resin layer having a 5 μm-thick layer made of ethylene-methacrylic acid-acrylate terpolymer and a 15 μm-thick layer made of high-pressure low-density polyethylene. However, the layer made of ethylene-methacrylic acid-acrylate terpolymer was in contact with the barrier film, and the layer made of high-pressure low-density polyethylene was in contact with the sealant film.

[0196] [Gas barrier property evaluation] The oxygen permeability (cc / (m) of the laminates (hereinafter also referred to as "test pieces") of the Examples and Reference Examples was 2 ·day·atm)) and water vapor permeability (g / (m 2 ·day)) was measured by the following method.

[0197] <Oxygen permeability> The oxygen permeability of the test pieces was measured in an environment of 23°C temperature and 90% RH using an oxygen permeability measuring device (OX-TRAN2 / 20 manufactured by MOCON) in accordance with JIS K7126-2:2006. The oxygen permeability of Examples 1 and 2 and Reference Example 2 was comparable. The oxygen permeability of Examples 1 and 2 was lower than that of Reference Examples 1 and 3, and the gas barrier properties were excellent.

[0198] <Water vapor permeability> Using a water vapor transmission rate measuring device (MOCON, PERMATRAN-w 3 / 33), the water vapor transmission rate of the test pieces was measured in an environment of a temperature of 40°C and a humidity of 90% RH in accordance with JIS K7129-2:2019. The water vapor transmission rates of Examples 1 and 2 and Reference Example 2 were comparable. The water vapor transmission rates of Examples 1 and 2 were lower than those of Reference Examples 1 and 3, and the gas barrier properties were superior.

[0199] [Laminate strength test] The laminates of the Examples or Reference Examples were cut into 15 mm wide strips, and peel tests were performed using a tensile tester (Tensilon universal testing machine, manufactured by Orientec Co., Ltd.) in accordance with JIS K6854-3:1999 between the vapor-deposited film and the extruded resin layer, or between the extruded resin layer and the sealant film, using a T-peel method at a peel rate of 50 mm / min. The laminate of Reference Example 1 tended to peel easily between the vapor-deposited film and the extruded resin layer. The laminate of Reference Example 2 tended to peel easily between the extruded resin layer and the sealant film. The laminate of Reference Example 3 tended to peel easily between the layer of ethylene-methacrylic acid-acrylate terpolymer in the extruded resin layer and the layer of high-pressure low-density polyethylene. In contrast, the laminates of Examples 1 and 2 had high laminate strength and excellent interlayer adhesion. [Explanation of symbols]

[0200] 1: Laminate 10: First polyolefin layer 20: Vapor deposition film 30: Adhesive layer (Ad) 40: Second polyolefin layer 50: Third polyolefin layer 60: Adhesive layer 120: Tube container 121: Tube container body 122: Head 123: Torso 124: Shoulder 125:Extraction port 126: Cap 127: Spiral 128: Fusion part 129: Bottom seal

Claims

1. A laminate, The laminate is a first polyolefin layer; an adhesive layer containing a polyolefin plastomer and an acid group-containing ethylene polymer; a second polyolefin layer; and are provided in this order in the stacking direction, The laminate further comprises a vapor-deposited film between the first polyolefin layer and the adhesive layer and / or between the adhesive layer and the second polyolefin layer. Laminate.

2. The laminate according to claim 1 , wherein the adhesive layer located between the first polyolefin layer and the second polyolefin layer is in contact with the vapor-deposited film.

3. 2. The laminate according to claim 1, wherein the content of the polyolefin plastomer in the adhesive layer is 50% by mass or more and 90% by mass or less, and the content of the acid group-containing ethylene polymer is 10% by mass or more and 50% by mass or less.

4. 2. The laminate according to claim 1, wherein the acid group-containing ethylene polymer is at least one selected from the group consisting of a copolymer of ethylene and an unsaturated carboxylic acid or its acid anhydride, a copolymer of ethylene and an unsaturated carboxylic acid or its acid anhydride with a (meth)acrylate, and a polymer in which an unsaturated carboxylic acid or its acid anhydride is graft-polymerized onto polyethylene.

5. 2. The laminate according to claim 1, wherein the acid group-containing ethylene polymer is at least one selected from an ethylene-(meth)acrylic acid copolymer and an ethylene-(meth)acrylic acid-(meth)acrylate copolymer.

6. 2. The laminate of claim 1, wherein the polyolefin plastomer is a polyethylene plastomer.

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

8. 2. The laminate according to claim 1, wherein the adhesive layer is a single layer formed from a mixture containing the polyolefin plastomer and the acid group-containing ethylene polymer.

9. The laminate of claim 1 , wherein the adhesive layer is an extruded resin layer.

10. the first polyolefin layer is a polyethylene layer or a polypropylene layer; the second polyolefin layer is a polyethylene layer or a polypropylene layer; The laminate according to claim 1 .

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

12. The laminate according to any one of claims 1 to 11, wherein the second polyolefin layer is a heat seal layer containing a polyolefin as a main component, or the laminate further comprises a heat seal layer containing a polyolefin as a main component.

13. The laminate according to claim 12; a seal portion where the heat seal layers of the laminate are joined together; a storage section for storing contents; A packaging container having the above structure.

14. The packaging container according to claim 13, which is a packaging bag.

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