Laminate and packaging container

Abstract

To provide a laminate which is suitably usable for manufacturing a monomaterial packaging container, has high adhesion to a vapor-deposited film, and can effectively prevent delamination when being formed into a packaging container.SOLUTION: A laminate includes at least a first sealant layer, a vapor-deposited film, a base material, and a second sealant layer, wherein the base material includes at least a polyethylene resin layer and a surface resin layer, the polyethylene resin layer of the base material, the first sealant layer and the second sealant layer are composed of polyethylene, the surface resin layer of the base material contains a resin material having a melting point of 150°C or higher, the vapor-deposited film is provided on the surface resin layer of the base material, and the base material is subjected to drawing treatment.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a laminate and a packaging container.

[0002] Conventionally, a resin film made of a polyester resin such as polyethylene terephthalate (hereinafter also referred to as a polyester film) has excellent mechanical properties, chemical stability, heat resistance, and transparency, and is inexpensive. Therefore, it is used as a base material constituting a laminate used for manufacturing a packaging container.

[0003] Such a polyester film is usually laminated with a polyethylene film which is a sealant layer, and after being formed into a laminate, it is formed into a packaging container.

[0004] In the above-mentioned laminate obtained by laminating different resin films, that is, a polyester film and a polyethylene film, it is difficult to separate the respective layers, and the packaging containers recovered after use are not suitable for recycling and are not actively recycled at present.

[0005] Then, for the purpose of improving the recyclability of packaging containers, instead of a polyester film, a polyethylene film subjected to a stretching treatment (stretched polyethylene film) is applied to the base material, and the production of a packaging container (monomaterial packaging container) using a laminate composed of the same material has been studied.

Summary of the Invention

Problems to be Solved by the Invention

[0006] Now, when the inventors tried to form a vapor deposition film on the surface of a polyethylene film in order to compensate for the reduced gas barrier property that occurred when changing the polyester film to a polyethylene film, they found that the adhesion between the polyethylene film and the vapor deposition film was not sufficient, and when a packaging container was manufactured using the polyethylene film on which the vapor deposition film was formed, there was a risk of delamination occurring between the polyethylene film and the vapor deposition film.

[0007] And, surprisingly, the inventors found that by providing a surface resin layer containing a resin material having a melting point of 150°C or higher on the surface of the polyethylene film, the adhesion of the vapor deposition film formed on the surface resin layer was improved, and accordingly, the gas barrier property of the laminate was significantly improved, and the above problems could be solved.

[0008] The present invention has been made based on such findings, and the problem to be solved is to provide a laminate that can be suitably used for manufacturing a single-material packaging container, has high adhesion to a vapor deposition film, and can effectively prevent delamination when used as a packaging container.

[0009] Another problem to be solved by the present invention is to provide a packaging container made of the above laminate.

Means for Solving the Problems

[0010] The laminate of the present invention is a laminate comprising at least a first sealant layer, a vapor deposition film, a base material, and a second sealant layer in this order, wherein the base material comprises at least a polyethylene resin layer and a surface resin layer, the first sealant layer and the second sealant layer are made of a polyethylene resin, the surface resin layer of the base material contains a resin material having a melting point of 150°C or higher, the vapor deposition film is provided on the surface resin layer of the base material, and the base material is characterized in that it has been subjected to a stretching treatment.

[0011] In one embodiment, the surface resin layer of the base material contains a resin material having a melting point of 150°C or higher and 265°C or lower.

[0012] In one embodiment, the melting point difference between the polyethylene resin and the resin material having a melting point of 150°C or higher contained in the surface resin layer is 20 to 80°C.

[0013] In one embodiment, the resin material of the surface resin layer is composed of a polymer having a polar group.

[0014] In one embodiment, the resin material of the surface resin layer is one or more resin materials selected from ethylene vinyl alcohol copolymer, polyvinyl alcohol, polyester, nylon 6, nylon 6,6, nylon 6-nylon 6,6 copolymer, MXD nylon, and amorphous nylon.

[0015] In one embodiment, the polyethylene resin layer of the base material has a multilayer structure.

[0016] In one embodiment, the polyethylene resin layer of the base material includes at least one layer containing a compatibilizer.

[0017] In one embodiment, the base material is a coextruded film.

[0018] In one embodiment, a barrier coat layer is further provided between the first sealant layer and the vapor deposition film.

[0019] In one embodiment, the laminate is used for a packaging container.

[0020] In one embodiment, the content of the polyethylene resin in the entire laminate is 95% by mass or more.

[0021] The packaging container of the present invention is characterized by comprising the above laminate.

[0022] In one embodiment, the packaging container is a laminated tube.

Advantages of the Invention

[0023] According to the present invention, there is provided a laminate that can be suitably used for producing a single-material packaging container, can significantly improve the adhesion between layers with a vapor deposition film, and can achieve a preferable gas barrier property. Further, according to the present invention, there is provided a packaging container made of a laminate.

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0025] (Laminate) As shown in FIG. 1, the laminate 10 of the present invention includes at least a first sealant layer 11, a vapor deposition film 12, a base material 13, and a second sealant layer 14. The polyethylene resin layer of the base material, the first sealant layer, and the second sealant layer included in the laminate are made of the same resin, that is, polyethylene resin. A laminate having such a configuration can be suitably used as a laminate for producing a single-material packaging container. Further, in the laminate of the present invention, the adhesion between the base material and the vapor deposition film is significantly improved, and it has an extremely high gas barrier property.

[0026] The base material 13 includes at least a surface resin layer 15 and a polyethylene resin layer 16. The base material 13 can include an adhesive resin layer (not shown) between the surface resin layer 15 and the polyethylene resin layer 16.

[0027] In one embodiment, the laminate 10 can include a melt-extruded resin layer or an adhesive layer 17 between the first sealant layer 11 and the vapor deposition film 12, and between the base material 13 and the second sealant layer 14.

[0028] The content of the polyethylene resin with respect to the total amount of the solid content contained in the laminate is preferably 95% by mass or more. Thereby, a laminate that can be suitably used for manufacturing a monomaterial packaging container can be obtained.

[0029] Hereinafter, each layer included in the laminate 10 will be described.

[0030] (Base material) The base material includes at least a polyethylene resin layer and a surface resin layer. Further, in one embodiment, the base material includes an adhesive resin layer between the polyethylene resin layer and the surface resin layer.

[0031] The ratio of the thickness of the surface resin layer to the total thickness of the base material is preferably 2% or more and 20% or less, and more preferably 4% or more and 15% or less. By setting the ratio of the thickness of the surface resin layer to the total thickness of the base material to 2% or more, the adhesion of the vapor deposition film can be further improved, and the gas barrier property can be further improved. Also, by setting the ratio of the thickness of the surface resin layer to the total thickness of the base material to 20% or less, a laminate that can be suitably used for manufacturing a monomaterial packaging container can be obtained. Furthermore, the film-forming property and processing suitability of the base material can be further improved.

[0032] (Polyethylene resin layer) The polyethylene resin layer is composed of a polyethylene resin. As the polyethylene resin, high-density polyethylene resin (HDPE), medium-density polyethylene resin (MDPE), low-density polyethylene resin (LDPE), linear low-density polyethylene resin (LLDPE), and very-low-density polyethylene resin (VLDPE) can be used. In addition, as the polyethylene resin, a copolymer of ethylene and other monomers can also be used. Furthermore, as the polyethylene resin, a polyethylene resin derived from biomass, or a mechanically recycled or chemically recycled polyethylene resin can also be used.

[0033] Here, as the high-density polyethylene resin, a polyethylene resin with a density of 0.945 g / cm 3 or higher can be used. As the medium-density polyethylene resin, a polyethylene resin with a density of 0.925 g / cm 3 or higher and less than 0.945 g / cm 3 can be used. As the low-density polyethylene resin, a polyethylene resin with a density of 0.900 g / cm 3 or higher and less than 0.925 g / cm 3 can be used. As the linear low-density polyethylene resin, a polyethylene resin with a density of 0.900 g / cm 3 or higher and less than 0.925 g / cm 3 can be used. As the very-low-density polyethylene resin, a polyethylene resin with a density of less than 0.900 g / cm 3 can be used.

[0034] The content of the polyethylene resin in the polyethylene resin layer is preferably 70% by mass or more, and more preferably 80% by mass or more. Thereby, the laminate of the present invention can be more suitably used for producing a single-material packaging container.

[0035] In one embodiment, the polyethylene resin layer may include at least one layer containing a compatibilizer. When the polyethylene resin layer contains a compatibilizer, when the packaging container produced using the laminate of the present invention is heated and melted and recycled, the resin material having a melting point of 150 ° C. or higher contained in the surface resin layer and the polyethylene resin contained in the polyethylene resin layer can be effectively prevented from being uniformly mixed and the physical properties thereof from deteriorating. Further, it is possible to effectively prevent the transparency from deteriorating. When the polyethylene resin layer has a multilayer structure, the compatibilizer is preferably contained in the layer in contact with the surface resin layer of the polyethylene resin layer. By incorporating the compatibilizer in the layer in contact with the surface resin layer of the polyethylene resin layer, the above effects can be further improved.

[0036] As the compatibilizer, conventionally known ones can be appropriately selected and used. From the viewpoint of recyclability, an unsaturated carboxylic acid-modified polyolefin resin is preferable, and among them, a maleic anhydride-modified polyethylene resin is more preferable.

[0037] The content of the compatibilizer in the layer containing the compatibilizer is preferably 5% by mass or more and 30% by mass or less. By setting the content of the compatibilizer in the polyethylene resin layer to 5% by mass or more, the above effects can be further improved. By setting the content of the compatibilizer in the polyethylene resin layer to 30% by mass or less, the strength and heat resistance of the base material can be improved.

[0038] Within a range that does not impair the characteristics of the present invention, the polyethylene resin layer may contain a resin material other than the polyethylene resin. For example, polyolefin resins such as polypropylene resin, (meth)acrylic resins, vinyl resins, cellulose resins, polyamide resins, polyester resins, and ionomer resins can be mentioned. From the viewpoint of its recyclability, it is particularly preferable that the polyethylene resin layer does not contain a resin other than the polyethylene resin.

[0039] Also, within a range that does not impair the characteristics of the present invention, the polyethylene resin layer can contain additives, for example, crosslinking agents, antioxidants, antiblocking agents, slip agents, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, and modifying resins, etc.

[0040] The polyethylene resin layer provided in the substrate may have a single-layer structure or a multilayer structure.

[0041] In the polyethylene resin layer having a multilayer structure, the densities of the polyethylene resins constituting each layer may be different, that is, a density gradient may be provided in the polyethylene resin layer. By providing a density gradient in the polyethylene resin layer, its strength, heat resistance, and stretching suitability are significantly improved.

[0042] In the polyethylene resin layer provided with a density gradient, if the density difference between each layer is large, delamination may occur at the interface. Therefore, the density difference between each layer is preferably 0.04 g / cm 3 or less, and more preferably 0.02 g / cm 3 or less.

[0043] Hereinafter, embodiments of the polyethylene resin layer provided with a density gradient will be exemplified. Note that the configuration of the polyethylene resin layer is not limited to these.

[0044] In one embodiment, the polyethylene resin layer provided with a density gradient is composed of three layers: a layer containing high-density polyethylene resin, a layer containing medium-density polyethylene resin, and a layer containing high-density polyethylene resin. By forming the polyethylene resin layer into a three-layer structure with the above-described density gradient, the strength, heat resistance, and stretching suitability are significantly improved. Also, in the substrate, it is possible to effectively prevent the occurrence of curl.

[0045] In one embodiment, the polyethylene resin layer provided with a density gradient is composed of five layers: a layer containing high-density polyethylene, a layer containing medium-density polyethylene resin, a layer containing at least one of low-density polyethylene resin and linear low-density polyethylene resin, a layer containing medium-density polyethylene resin, and a layer containing high-density polyethylene resin. By forming the polyethylene resin layer into a five-layer structure with the above-described density gradient, the strength, heat resistance, and drawability are significantly improved. Further, in the base material, it is possible to effectively prevent the occurrence of curl. The polyethylene resin layer having such a structure can be stably produced by the following inflation method. Specifically, from the outside, high-density polyethylene resin, medium-density polyethylene resin, and at least one of low-density polyethylene resin and linear low-density polyethylene resin are co-extruded in a tubular shape. Next, layers containing at least one of low-density polyethylene resin and linear low-density polyethylene resin can be produced by pressing them together using a rubber roll or the like. By producing in such a manner, the number of defective products in manufacturing can be significantly reduced, and ultimately, the production efficiency can be improved.

[0046] In one embodiment, the polyethylene resin layer provided with a density gradient is composed of seven layers: a layer containing high-density polyethylene resin, a layer containing a blend resin of high-density polyethylene resin and medium-density polyethylene resin, a layer containing at least one of low-density polyethylene resin and linear low-density polyethylene resin, a layer containing a blend resin of high-density polyethylene resin and medium-density polyethylene resin, and a layer containing high-density polyethylene resin. By forming the polyethylene resin layer into a five-layer structure with the above-described density gradient, the strength, heat resistance, and drawability are significantly improved. Further, in the base material, it is possible to effectively prevent the occurrence of curl. Furthermore, it is possible to effectively prevent the occurrence of delamination in the base material. In addition, the polyethylene resin layer with such a configuration can be stably produced by the inflation method described above.

[0047] The thickness of the polyethylene resin layer is preferably 10 μm or more and 50 μm or less, and more preferably 10 μm or more and 40 μm or less. By setting the thickness of the polyethylene resin layer to 10 μm or more, the strength and heat resistance of the base material can be further improved. In addition, by setting the thickness of the polyethylene resin layer to 50 μm or less, the film-forming property and processing suitability of the base material can be further improved.

[0048] The polyethylene resin layer may have a printing layer on its surface, and the image formed on the printing layer is not particularly limited, and characters, patterns, symbols, and combinations thereof are represented. The formation of the printing layer on the base material can be carried out using biomass-derived ink. Thereby, the environmental load can be reduced. The method for forming the printing layer is not particularly limited, and conventional known printing methods such as the gravure printing method, the offset printing method, and the flexographic printing method can be mentioned.

[0049] (Surface resin layer) The base material included in the laminate of the present invention includes a surface resin layer containing a resin material having a melting point of 150 °C or higher (hereinafter, sometimes referred to as a high melting point resin material) on the polyethylene resin layer.

[0050] The melting point of the high melting point resin material is more preferably 160 °C or higher. By setting the melting point of the high melting point resin material to 160 °C or higher, the adhesion of the vapor deposition film can be further improved, and the gas barrier property can be further improved. In addition, when a sealant layer is laminated, the adhesion with the sealant layer can be improved, and the laminate strength of the packaging container produced by this laminate can be further improved.

[0051] The melting point of the high melting point resin material is preferably 265°C or lower, more preferably 260°C or lower, and even more preferably 250°C or lower. By setting the melting point of the high melting point resin material to 265°C or lower, the film forming property of the base material can be improved.

[0052] The difference between the melting point of the high melting point resin material contained in the surface resin layer and the melting point of the polyethylene contained in the polyethylene resin layer is preferably 20 to 80°C, and more preferably 20 to 60°C. When the difference between the melting point of the high melting point resin material contained in the surface resin layer and the melting point of the polyethylene contained in the polyethylene resin layer is 20°C or more, the adhesion of the vapor deposition film can be further improved, and the gas barrier property of the base material on which the vapor deposition film is formed can be further improved. Further, when the sealant layer is laminated, the adhesion to the sealant layer can be improved, and the laminate strength of the packaging container produced by this laminate can be further improved. Also, when the difference between the melting point of the high melting point resin material contained in the surface resin layer and the melting point of the polyethylene contained in the polyethylene resin layer is 80°C or lower, the film forming property of the base material can be further improved.

[0053] In one embodiment, the high melting point resin material is composed of a polymer having a polar group. By the high melting point resin material being composed of a polymer having a polar group, the adhesion to the vapor deposition film can be further improved.

[0054] In the present invention, the polar group refers to a group containing one or more heteroatoms, and examples thereof include an ester group, an epoxy group, a hydroxyl group, an amino group, an amide group, a carboxyl group, a carbonyl group, a carboxylic anhydride group, a sulfone group, a thiol group, and a halogen group. Among these, from the viewpoint of the laminate strength of the packaging container, a hydroxyl group, an ester group, an amino group, an amide group, a carboxyl group, and a carbonyl group are preferable, and a hydroxyl group is more preferable.

[0055] Examples of high melting point resin materials include vinyl resins, polyamides, polyimides, polyesters, (meth)acrylic resins, cellulose resins, polyolefin resins, and ionomer resins.

[0056] In the present invention, a resin material having a melting point of 150°C or higher and having a polar group is particularly preferred. Amide resins such as ethylene vinyl alcohol copolymer, polyvinyl alcohol, nylon 6, nylon 6,6, nylon 6-nylon 6,6 copolymer, MXD nylon, and amorphous nylon are preferred, and ethylene vinyl alcohol copolymer and amide resin are particularly preferred. By using such a resin material, the adhesion of the vapor deposition film formed on the surface resin layer can be significantly improved, and the gas barrier property can be effectively enhanced.

[0057] The content of the high melting point resin material in the surface resin layer is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more. By setting the content of the high melting point resin material in the surface resin layer to 70% by mass or more, the adhesion of the vapor deposition film formed on the surface resin layer can be significantly improved, and the gas barrier property of the substrate on which the vapor deposition film is formed can be effectively enhanced.

[0058] Within the range that does not impair the characteristics of the present invention, the surface resin layer may contain a resin material other than the high melting point resin material. From the viewpoint of adhesion to the vapor deposition film, it is preferable that the surface resin layer does not contain a resin material other than the high melting point resin material.

[0059] Also, within the range that does not impair the characteristics of the present invention, the surface resin layer can contain additives, such as crosslinking agents, antioxidants, antiblocking agents, slip agents, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, and modifying resins.

[0060] The thickness of the surface resin layer is preferably 0.1 μm or more and 5 μm or less, and more preferably 0.1 μm or more and 4 μm or less. By setting the thickness of the surface resin layer to 0.1 μm or more, the adhesion of the vapor deposition film can be further improved, and the gas barrier property of the substrate on which the vapor deposition film is formed can be further improved. Further, when the sealant layer is laminated, the adhesion with the sealant layer can be improved, and the laminate strength of the packaging container produced by this laminate can be further improved. Also, by setting the thickness of the surface resin layer to 5 μm or less, it can be made into a substrate that can be suitably used for producing a single-material packaging container. Furthermore, the film-forming property and processing suitability of the substrate can be further improved.

[0061] Also, the surface resin layer provided on the substrate may be subjected to a surface treatment. Thereby, the adhesion with an adjacent layer can be improved. The method of the surface treatment is not particularly limited, and examples thereof include physical treatments such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas and / or nitrogen gas, glow discharge treatment, and chemical treatments such as oxidation treatment using chemical agents.

[0062] The thickness of the surface resin layer is preferably 0.1 μm or more and 5 μm or less, and more preferably 0.1 μm or more and 4 μm or less. By setting the thickness of the surface resin layer to 0.1 μm or more, the adhesion of the vapor deposition film can be further improved, and the gas barrier property of the substrate on which the vapor deposition film is formed can be further improved. Further, when the sealant layer is laminated, the adhesion with the sealant layer can be improved, and the laminate strength of the packaging container produced by this laminate can be further improved. Also, by setting the thickness of the surface resin layer to 5 μm or less, it can be made into a substrate that can be suitably used for producing a single-material packaging container. Furthermore, the film-forming property and processing suitability of the substrate can be further improved.

[0063] In addition, the surface resin layer provided on the base material may be subjected to a surface treatment. Thereby, the adhesion to an adjacent layer can be improved. The method of the surface treatment is not particularly limited, and examples thereof include physical treatments such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas and / or nitrogen gas, glow discharge treatment, and chemical treatments such as oxidation treatment using chemicals.

[0064] (Adhesive resin layer) In one embodiment, the base material can include an adhesive resin layer between the polyethylene resin layer and the surface resin layer, whereby the adhesion between these layers can be improved.

[0065] The adhesive resin layer can be formed by using an adhesive resin such as polyether, polyester, silicone resin, epoxy resin, polyurethane, vinyl resin, phenolic resin, and polyolefin. Among the above, since the laminate of the present invention can be made into a configuration more suitable for a monomaterial packaging container, polyolefin and its acid-modified product are preferable, and polyethylene and its acid-modified product are particularly preferable. As the adhesive polyethylene, commercially available products can be used. For example, the Admer series manufactured by Mitsui Chemicals, Inc. can be used.

[0066] The thickness of the adhesive resin layer is not particularly limited, but can be, for example, 1 μm or more and 15 μm or less. By setting the thickness of the adhesive resin layer to 1 μm or more, the adhesion between the polyethylene resin layer and the surface resin layer can be further improved. By setting the thickness of the adhesive layer to 15 μm or less, the processability of the base material can be improved.

[0067] The base material is subjected to a stretching treatment, and the stretching treatment may be uniaxial stretching or biaxial stretching. The stretching ratios in the longitudinal direction (MD direction) and the transverse direction (TD direction) of the base material are preferably 2 times or more and 15 times or less, and preferably 5 times or more and 13 times or less. By setting the draw ratio to 2 times or more, the strength and heat resistance of the base material can be further improved. Also, the printability on the base material can be improved. Also, from the viewpoint of the breaking limit of the base material, the draw ratio is preferably 15 times or less.

[0068] In one embodiment, the base material is a coextruded film, which can be produced by forming a film using the T-die method or the inflation method or the like, making it into a resin film, and then drawing it. By forming a film by the inflation method, the drawing of the resin film can be performed simultaneously.

[0069] (First sealant layer and second sealant layer) The sealant layer contains the same resin as the polyethylene resin layer of the base material, that is, polyethylene resin. A laminate having such a configuration can be suitably used as a laminate for producing a monomaterial packaging container. As the polyethylene resin, high-density polyethylene resin (HDPE), medium-density polyethylene resin (MDPE), low-density polyethylene resin (LDPE), linear low-density polyethylene resin (LLDPE), and ultra-low-density polyethylene resin (VLDPE) can be used. Also, as the polyethylene resin, a copolymer of ethylene and other monomers can be used. Furthermore, as the polyethylene resin, a polyethylene resin derived from biomass or a polyethylene resin that has been mechanically recycled or chemically recycled can also be used.

[0070] Within a range that does not impair the characteristics of the present invention, the sealant layer can contain the above additives.

[0071] The sealant layer may have a single-layer structure or a multilayer structure. In one embodiment, the sealant layer includes a layer made of a low-density polyethylene resin, a layer made of a high-density polyethylene resin, and a layer made of a low-density polyethylene resin. By adopting such a configuration, the heat sealability and strength can be improved.

[0072] The thickness of the sealant layer is preferably 20 μm or more and 100 μm or less, and more preferably 30 μm or more and 70 μm or less. By setting the thickness of the sealant layer to 20 μm or more, the laminate strength of the packaging container can be further improved. Also, by setting the thickness of the sealant layer to 100 μm or less, the moldability of the laminate can be improved, and the packaging container can be manufactured more easily.

[0073] The sealant layer may have a printing layer on its surface, and the image formed on the printing layer is not particularly limited, and characters, patterns, symbols, and combinations thereof are represented. The formation of the printing layer on the sealant layer can be performed using biomass-derived ink. Thereby, the environmental load can be reduced. The method for forming the printing layer is not particularly limited, and examples thereof include conventionally known printing methods such as the gravure printing method, the offset printing method, and the flexographic printing method.

[0074] The sealant layer can be laminated with a base material or the like via the following melt-extruded resin layer or adhesive layer.

[0075] The first sealant layer and the second sealant layer included in the laminate of the present invention may have the same configuration or different configurations.

[0076] (Vapor deposition film) The laminate of the present invention includes a vapor deposition film adjacent to the surface resin layer on the surface resin layer. In the laminate of the present invention, the vapor deposition film and the surface resin layer have high adhesion and extremely high gas barrier properties, specifically, oxygen barrier properties and water vapor barrier properties. In addition, since the laminate includes a vapor deposition film, a packaging container produced using the laminate can suppress a decrease in the mass of the contents filled therein.

[0077] The vapor deposition film can be a vapor deposition film of one or more inorganic substances or inorganic oxides such as silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium (Ti), lead (Pb), zirconium (Zr), yttrium (Y), etc. The vapor deposition film can have a two-layer or more structure, and may be composed of the same material or different materials. Among the above, from the viewpoints of adhesion to the surface resin layer and gas barrier properties, the vapor deposition film is preferably composed of aluminum, aluminum oxide (alumina) or silicon oxide (silica). Further, by using a vapor deposition film composed of aluminum, the glossiness of the packaging container can be improved, and its design can be improved.

[0078] The surface of the vapor deposition film is preferably subjected to the above surface treatment. Thereby, the adhesion to an adjacent layer can be improved.

[0079] Also, the thickness of the vapor deposition film is preferably 1 nm or more and 150 nm or less, more preferably 5 nm or more and 60 nm or less, and even more preferably 10 nm or more and 40 nm or less. By setting the thickness of the vapor deposition film to 1 nm or more, the oxygen barrier property and water vapor barrier property of the laminate can be further improved. Also, by setting the thickness of the vapor deposition film to 150 nm or less, a laminate suitable for producing a monomaterial packaging container can be obtained. Further, the occurrence of cracks in the vapor deposition film can be prevented.

[0080] As a method for forming a vapor deposition film, a conventionally known method can be adopted. For example, physical vapor deposition methods (Physical Vapor Deposition method, PVD method) such as vacuum evaporation method, sputtering method, ion plating method, or chemical vapor deposition methods (Chemical Vapor Deposition method, CVD method) such as plasma chemical vapor deposition method, thermal chemical vapor deposition method, photo-chemical vapor deposition method, etc. can be mentioned. Hereinafter, an embodiment of the method for forming a vapor deposition film will be shown, but the method for forming a vapor deposition film is not limited thereto.

[0081] As an apparatus used for the method for forming a vapor deposition film by the PVD method, a vacuum film forming apparatus with plasma assist can be used. An embodiment of the method for forming a vapor deposition film using a vacuum film forming apparatus with plasma assist will be described below. In one embodiment, as shown in FIGS. 2 and 3, the vacuum film forming apparatus includes a vacuum chamber A, a substrate 10, an unwinding section B, a film forming drum C, a winding section D, a conveying roll E, an evaporation source F, a reaction gas supply section G, a deposition preventing box H, a vapor deposition material I, and a plasma gun J. Note that FIG. 2 is a schematic cross-sectional view of the vacuum film forming apparatus in the XZ plane direction, and FIG. 3 is a schematic cross-sectional view of the vacuum film forming apparatus in the XY plane direction. As shown in FIG. 2, above the upper part in the vacuum chamber A, the substrate 10 wound around the film forming drum C is arranged with its surface resin layer facing downward, and below the film forming drum C in the vacuum chamber A, a grounded deposition preventing box H is arranged. The evaporation source F is arranged on the bottom surface of the deposition preventing box H. The film forming drum C is arranged in the vacuum chamber A such that the surface resin layer of the substrate 10 wound around the film forming drum C is positioned at a position facing the upper surface of the evaporation source F with a certain interval therebetween. In addition, conveying rolls E are arranged between the unwinding section B and the film forming drum C, and between the film forming drum C and the winding section D. Note that the vacuum chamber is connected to a vacuum pump (not shown). The evaporation source F is for holding the vapor deposition material I and includes a heating device (not shown). The reaction gas supply unit G is a part that supplies a reaction gas (such as oxygen, nitrogen, helium, argon, and a mixed gas thereof) that reacts with the evaporated vapor deposition material. The vapor deposition material I heated and evaporated from the evaporation source F is irradiated onto the surface resin layer of the base material 10, and at the same time, plasma is irradiated from the plasma gun J onto the surface resin layer, and a vapor deposition film is formed. Details of this formation method are disclosed in Japanese Patent Laid-Open No. 2011-214089.

[0082] As the plasma generation device used in the plasma chemical vapor deposition method, devices such as a high-frequency plasma, a pulse wave plasma, and a microwave plasma can be used. Also, a device having two or more film formation chambers may be used. It is preferable that the device is equipped with a vacuum pump and can maintain each film formation chamber in a vacuum state. The degree of vacuum in each film formation chamber is preferably 1×10~1×10 -6 Pa. An embodiment of the method for forming a vapor deposition film using a plasma generation device will be described below. First, the base material is sent into the film formation chamber and conveyed onto the cooling / electrode drum at a predetermined speed via an auxiliary roll. Next, a mixed gas composition containing a film formation monomer gas containing an inorganic oxide, oxygen gas, and an inert gas, etc. is supplied from the gas supply device into the film formation chamber, and plasma is generated by glow discharge on the surface resin layer and irradiated, and a vapor deposition film containing an inorganic oxide is formed on the surface resin layer. Details of this formation method are disclosed in Japanese Patent Laid-Open No. 2012-076292.

[0083] As the device used in the method for forming a vapor deposition film, a continuous vapor deposition film forming device including a plasma pretreatment chamber and a film formation chamber can be used. An embodiment of the method for forming a vapor deposition film using this device will be described below. First, in the plasma pretreatment chamber, the surface resin layer of the base material is irradiated with plasma from the plasma supply nozzle. Next, in the film formation chamber, a vapor deposition film is formed on the plasma-treated surface resin layer. Details of this forming method are disclosed in the pamphlet of International Publication WO2019 / 087960.

[0084] (Melt-extruded resin layer and adhesive layer) In one embodiment, the laminate of the present invention includes a melt-extruded resin layer or an adhesive layer between the first sealant layer and the vapor deposition film, or between the base material and the second sealant layer. As materials constituting the melt-extruded resin layer and the adhesive layer, conventionally known resin materials and adhesives can be used. From the viewpoint of recyclability, it is preferable to use a polyethylene resin or a polyethylene-based adhesive to form the melt-extruded resin layer and the adhesive layer.

[0085] The thicknesses of the melt-extruded resin layer and the adhesive layer are not particularly limited, and can be, for example, 1 to 30 μm.

[0086] (Barrier coating layer) The laminate of the present invention can further include a barrier coating layer on the vapor deposition film. That is, by providing a barrier coating layer between the first sealant layer and the vapor deposition film, the gas barrier property of the laminate can be further improved.

[0087] In one embodiment, the barrier coating layer is composed of gas barrier resins such as ethylene-vinyl alcohol copolymer (EVOH), polyvinyl alcohol, polyacrylonitrile, nylon 6, nylon 6,6, and polymetaxylylene adipamide (MXD6), polyester resins, polyurethane resins, and (meth)acrylic resins.

[0088] The thickness of the barrier coating layer is preferably 0.01 μm or more and 10 μm or less, and more preferably 0.1 μm or more and 5 μm or less. By setting the thickness of the barrier coat layer to 0.01 μm or more, the gas barrier property can be further improved. By setting the thickness of the barrier coat layer to 10 μm or less, the processability of the laminate 20 can be improved. Further, the laminate 20 can be obtained which can be suitably used for producing a monomaterial packaging container.

[0089] The barrier coat layer can be formed by dissolving or dispersing the above material in water or a suitable solvent, applying it, and drying it.

[0090] In another embodiment, the barrier coat layer is a gas barrier coating film containing at least one resin composition such as a hydrolyzate of a metal alkoxide or a hydrolytic condensate of a metal alkoxide obtained by polycondensing a mixture of a metal alkoxide and a water-soluble polymer by a sol-gel method in the presence of a sol-gel method catalyst, water, an organic solvent, etc. By providing such a barrier coat layer on the vapor deposition film, the occurrence of cracks in the vapor deposition film can be effectively prevented.

[0091] In one embodiment, the metal alkoxide is represented by the following general formula. R 1 n M(OR 2 ) m (However, in the formula, R 1 , R 2 each represent an organic group having 1 to 8 carbon atoms, M represents a metal atom, n represents an integer of 0 or more, m represents an integer of 1 or more, and n + m represents the valence of M.)

[0092] As the metal atom M, for example, silicon, zirconium, titanium, aluminum, etc. can be used. Further, as the organic group represented by R 1 and R 2 , for example, alkyl groups such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, and i-butyl group can be mentioned.

[0093] Examples of the metal alkoxide satisfying the above general formula include tetramethoxysilane (Si(OCH3)4), tetraethoxysilane (Si(OC2H5)4), tetrapropoxysilane (Si(OC3H7)4), tetrabutoxysilane (Si(OC4H9)4), and the like.

[0094] In addition, it is preferable to use a silane coupling agent together with the above metal alkoxide. As the silane coupling agent, a known organoalkoxysilane containing an organic reactive group can be used.

[0095] As the water-soluble polymer, polyvinyl alcohol and ethylene-vinyl alcohol copolymer are preferable, and from the viewpoints of oxygen barrier property, water vapor barrier property, water resistance and weather resistance, it is preferable to use them in combination.

[0096] The thickness of the gas barrier coating film is preferably 0.01 μm or more and 10 μm or less, and more preferably 0.1 μm or more and 5 μm or less. Thereby, the gas barrier property can be further improved. By setting the thickness of the gas barrier coating film to 0.01 μm or more, the oxygen barrier property and water vapor barrier property of the barrier laminate can be improved. In addition, the generation of cracks in the vapor deposition film can be prevented. By setting the thickness of the gas barrier coating film to 10 μm or less, a laminate 20 can be obtained which can be suitably used for producing a single-material packaging container.

[0097] The gas barrier coating film can be formed by applying a composition containing the above materials by a conventionally known means such as roll coating with a gravure roll coater, spray coating, spin coating, dipping, brushing, bar coating, an applicator, etc., and subjecting the composition to polycondensation by the sol-gel method. As the sol-gel method catalyst, an acid or amine-based compound is suitable.

[0098] The above composition may further contain an acid. The acid is used as a catalyst for the sol-gel method, mainly as a catalyst for hydrolysis of alkoxides and silane coupling agents, etc. As the acid, mineral acids such as sulfuric acid, hydrochloric acid, and nitric acid, and organic acids such as acetic acid and tartaric acid are used.

[0099] Also, the above composition may contain an organic solvent. As the organic solvent, for example, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butanol, etc. can be used.

[0100] Hereinafter, an embodiment of a method for forming a gas barrier coating film will be described below. First, a metal alkoxide, a water-soluble polymer, a sol-gel method catalyst, water, an organic solvent, and, if necessary, a silane coupling agent, etc. are mixed to prepare a composition. In this composition, a polycondensation reaction gradually proceeds. Next, the composition is applied and dried on the vapor deposition film by the above-mentioned conventionally known method. By this drying, the polycondensation reaction of the alkoxide and the water-soluble polymer (and also the silane coupling agent if the composition contains it) further proceeds, and a layer of a composite polymer is formed. Finally, by heating, a gas barrier coating film can be formed.

[0101] (Packaging container) The packaging container of the present invention is characterized by comprising the above-described laminate.

[0102] Specific examples of the packaging container of the present invention include laminated tubes, packaging bags, and lid materials, etc.

[0103] (Laminated tube) In one embodiment, the packaging container of the present invention is a laminated tube 20. Hereinafter, the laminated tube 20 of the present invention will be described with reference to the drawings. FIG. 4 is a diagram schematically showing the configuration of the laminated tube 20, and FIG. 5 is a cross-sectional view taken along line a-a of FIG. 4. As shown in FIG. 4, the laminated tube 20 includes a laminated tube body 21 having a head 22 and a body portion 23, and is characterized in that the body portion 23 is constituted by the above-mentioned laminate 10.

[0104] (Head) The head 22 includes a shoulder 24 connected to one end of the body portion 23 and a discharge port portion 25 connected to the shoulder 24. Also, in one embodiment, the discharge port portion 25 includes a screw thread 27 for screwing on the cap 26.

[0105] In one embodiment, the head is made of a polyethylene resin, whereby the recyclability of the laminated tube can be improved. As the polyethylene resin, high-density polyethylene resin, medium-density polyethylene resin, low-density polyethylene resin, linear low-density polyethylene resin, and ultra-low-density polyethylene resin can be used. Among these, from the viewpoint of shape retention, high-density polyethylene resin is preferable. Also, as the polyethylene resin, a polyethylene resin derived from biomass or a polyethylene resin recycled by mechanical recycling or chemical recycling can be used. Within the scope not impairing the identification of the present invention, the head may contain the above-mentioned additive.

[0106] The manufacturing method of the head is not particularly limited, and it can be manufactured by a conventionally known method. For example, the head can be manufactured by a compression molding method (compression molding method) or an injection molding method (injection molding method), and can be joined to the body portion.

[0107] When manufacturing a laminated tube using a compression molding method (compression molding method), after attaching a body portion to a male mold having a convex portion at the upper part, the male mold and the female mold are opposed to each other, and a material such as molten polyethylene resin is supplied into the male and female molds, and compression molding is performed to form a head portion and join it to one opening of the body portion, whereby a laminated tube composed of a head portion and a body portion can be manufactured. Also, when manufacturing a laminated tube using an injection molding method (injection molding method), after attaching a body portion to a male mold having a convex portion at the upper part, the male mold and the female mold are opposed to each other, and a material such as molten polyethylene resin is supplied from a gate, and injection molding is performed to form a head portion and join it to one opening of the body portion, whereby a laminated tube composed of a head portion and a body portion can be manufactured.

[0108] (Body portion) In the laminated tube body of the present invention, the body portion is connected to the shoulder portion of the head portion. The body portion can be obtained by forming a welded portion 28 formed by rolling up the laminated body into a cylindrical shape, overlapping a first sealant layer and a second sealant layer, and heat-sealing the overlapped portion. Also, the body portion includes a bottom seal portion 29 formed by heat-sealing the opening of the rolled-up laminated body.

[0109] As a method of heat-sealing, it can be performed by a conventionally known method such as bar sealing, rotary roll sealing, belt sealing, impulse sealing, high-frequency sealing, ultrasonic sealing, or flame sealing.

[0110] (Cap) The laminated tube can be provided with a cap. The cap is detachably attached to the extraction port portion of the head portion and serves to close the extraction port portion. The cap is composed of a thermoplastic resin. Examples of the thermoplastic resin include polyolefin resins such as polyethylene and polypropylene, polyester, cellulose resin, and vinyl resin. From the viewpoint of recyclability, polyethylene resin is particularly preferred. Also, within a range not impairing the characteristics of the present invention, the cap may contain the above additive.

[0111] As shown in FIG. 5, the cap may be a screw type having a concave groove on the inner surface of the cap so as to be screwed into the screw thread of the extraction port portion, or may be a plug type that is fitted by plugging the extraction port portion.

Examples

[0112] Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples.

[0113] Example 1 (Production of laminate) Ethylene vinyl alcohol copolymer (manufactured by Kuraray Co., Ltd., Eval E171B, melting point: 165 ° C, density: 1.14 g / cm 3 ) and Adhesive resin (manufactured by Mitsui Chemicals, Inc., maleic anhydride-modified polyethylene, Admer NF557, density: 0.920 g / cm 3 ) and Linear low density polyethylene resin A (manufactured by Prime Polymer Co., Ltd., SP2520, density 0.925 g / cm 3 , melting point 122 ° C) and were coextruded into a film by the inflation method to obtain a film composed of a surface resin layer (10 μm), an adhesive resin layer (15 μm), and a polyethylene resin layer (100 μm). This film was stretched in the longitudinal direction (MD) at a stretching ratio of 5 times to obtain a stretched base material having a thickness of 25 μm. After stretching, the thickness was 2 μm for the surface resin layer, 3 μm for the adhesive resin layer, and 20 μm for the polyethylene resin layer.

[0114] On the surface of the surface resin layer of the stretched base material, by the PVD method, pressure: 3.0×10-2 An aluminum vapor deposition film with a thickness of 30 nm was formed at Pa to obtain an aluminum vapor deposition substrate.

[0115] As the first sealant layer, Linear low-density polyethylene resin A (manufactured by Dow Chemical, Dowlex 2098P, density 0.926 g / cm 3 ), and High-density polyethylene resin (manufactured by Prime Polymer, High-Zex 3300F, density 0.949 g / cm 3 ), and Linear low-density polyethylene resin B (manufactured by Dow Chemical, Dowlex 2098P, density 0.926 g / cm 3 ) were co-extruded into a film by the inflation method to obtain a first sealant layer with a thickness of 120 μm. In the first sealant layer thus obtained, the thickness of the layer composed of linear low-density polyethylene resin A was 30 μm, the thickness of the layer composed of high-density polyethylene resin was 60 μm, and the thickness of the layer composed of linear low-density polyethylene resin B was 30 μm.

[0116] A urethane-based adhesive (manufactured by Rock Paint, RU004 / H1) was applied to the vapor deposition surface of the substrate and dried to form an adhesive layer with a thickness of 3 μm. Through this adhesive layer, the layer side composed of linear low-density polyethylene A of the first sealant layer was bonded.

[0117] As the second sealant layer, Linear low-density polyethylene resin A (manufactured by Dow Chemical, Dowlex 2098P, density 0.926 g / cm 3 ), and High-density polyethylene (manufactured by Prime Polymer, High-Zex 3300F, density 0.949 g / cm 3 ), and Linear low-density polyethylene resin B (manufactured by Dow Chemical, Dowlex 2098P, density 0.926 g / cm 3 ) were co-extruded into a film by the inflation method to obtain a heat-seal layer with a thickness of 120 μm.​​ In the surface film thus obtained, the thickness of linear low-density polyethylene 1 was 30 μm, the thickness of high-density polyethylene was 60 μm, and the thickness of linear low-density polyethylene 2 was 30 μm.

[0118] On the non-vapor-deposited film provided on the base material, a low-density polyethylene resin (manufactured by Nippon Polyethylene Co., Ltd., Novatec LC600A, density 0.918 g / cm 3 ) was melt-extruded to form a melt-extruded resin layer with a thickness of 20 μm. Through this melt-extruded resin layer, the layer side composed of the linear low-density polyethylene resin A of the second heat-sealing layer was laminated to produce the laminate of the present invention. The polyethylene content in this laminate was 98%.

[0119] Example 2 A blend resin containing linear low-density polyethylene resin (manufactured by Dow Chemical, Elite 5538, density: 0.941 g / cm 3 , melting point: 129°C) and compatibilizer (manufactured by Dow Chemical, maleic anhydride polyethylene, Retain 3000, density: 0.87 g / cm 3 ) in a ratio of 8:2 by mass was prepared.

[0120] Ethylene-vinyl alcohol copolymer (manufactured by Kuraray Co., Ltd., Eval E171B, melting point: 165°C, density: 1.14 g / cm 3 ), adhesive resin (manufactured by Mitsui Chemicals, maleic anhydride-modified polyethylene, Admer NF557, density: 0.920 g / cm 3 ), the blend resin prepared above, medium-density polyethylene resin (manufactured by Dow Chemical, Elite 5538, density: 0.941 g / cm 3 , melting point: 129°C), were co-extruded into a film by the inflation method to obtain a film with a surface resin layer of 10 μm, an adhesive resin layer of 15 μm, a layer composed of the blend resin of 50 μm, and a layer composed of the medium-density polyethylene resin of 50 μm. This base film was stretched in the longitudinal direction (MD) at a stretching ratio of 5 times to obtain a stretched base material with a thickness of 25 μm. The thickness after stretching was 2 μm for the gas barrier resin layer, 3 μm for the adhesive resin layer, 10 μm for the layer composed of the blend resin, and 10 μm for the layer composed of the medium density polyethylene resin.

[0121] The laminate of the present invention was produced in the same manner as in Example 1, except that the base material was changed to the base material obtained as described above. The content of the polyethylene resin in this laminate was 98%.

[0122] Example 3 The ethylene vinyl alcohol copolymer was changed to a polyamide 6-66 copolymer (NY, manufactured by Ube Industries, Ltd., trade name: 5033, density: 1.14 g / cm 3 , melting point: 196 °C), and the base material and the laminate were produced in the same manner as in Example 1. The content of the polyethylene resin in this laminate was 98%.

[0123] Example 4 Linear low density polyethylene (manufactured by Dow Chemical, Elite 5538, density: 0.941 g / cm 3 , melting point: 129 °C) and a compatibilizer (manufactured by Dow Chemical, maleic anhydride polyethylene, Retain 3000, density: 0.87 g / cm 3 ) were used to prepare a blend resin containing them in a mass ratio of 8:2.

[0124] Polyamide 6-66 copolymer (manufactured by Ube Industries, Ltd., trade name: 5033, density: 1.14 g / cm 3 , melting point: 196 °C), and an adhesive resin (manufactured by Mitsui Chemicals, maleic anhydride-modified polyethylene, Admer NF557, density: 0.920 g / cm 3 ), and the blend resin prepared above, and medium density polyethylene resin (manufactured by Dow Chemical, Elite 5538, density: 0.941 g / cm 3 , melting point: 129 °C), and It was coextruded into a film by an inflation molding method to obtain a film composed of a surface resin layer of 10 μm, an adhesive resin layer of 15 μm, a layer of 50 μm composed of a blend resin, and a layer of 50 μm composed of a medium-density polyethylene resin. This film was stretched in the longitudinal direction (MD) at a stretching ratio of 5 times to obtain a stretched base material with a thickness of 25 μm. The thickness after stretching was 2 μm for the surface resin layer, 3 μm for the adhesive resin layer, 10 μm for the layer composed of the blend resin, and 10 μm for the layer composed of the medium-density polyethylene resin.

[0125] A laminate of the present invention was produced in the same manner as in Example 1, except that the base material was changed to the base material obtained as described above. The content of the polyethylene resin in this laminate was 98%.

[0126] Comparative Example 1 A laminate was produced in the same manner as in Example 1, except that the base material was biaxially stretched polyethylene terephthalate with a thickness of 12 μm (manufactured by Toyobo Co., Ltd., Ester Film E5100). The content of polyethylene in this laminate was 93%.

[0127] (Production of tube container) The laminate obtained as described above was processed into a slit with a width of 120 mm using a bobbin cutter, and both ends in the width direction were overlapped so that the overlapping width was about 1.5 mm. Then, both overlapped ends were heat-sealed to obtain a cylindrical raw fabric that was tube-pasted. The obtained raw fabric was cut to a length of 122 mm in the length direction to produce a cylindrical body that would be the body of the tube container.

[0128] The cylindrical body was attached to a mandrel for forming a tube container, and a head composed of a frustum-shaped shoulder and a draw-out port on the cylinder continuous thereto was formed at one end of the cylindrical body using a high-density polyethylene resin (Novatec HJ360 manufactured by Nippon Polyethylene Co., Ltd., density 0.951 g / cm 3 ) by an injection molding method to produce a tube container as shown in Figure 3. The outlet part at the head of the obtained tube container body had an outer diameter of 13 mm and a height of 1.5 mm, and threads were provided on the side surface of the outlet part. Also, the outer diameter of the shoulder part was 38 mm.

[0129] Next, the above-mentioned high-density polyethylene was injected into a mold for cap molding, molded, and a cap was produced to obtain the tube container of the present invention.

[0130] <<Recyclability Evaluation>> The recyclability of the laminates obtained in the above examples and comparative examples was evaluated based on the following evaluation criteria. The evaluation results are summarized in Table 1. (Evaluation Criteria) ○: The content of the same polyolefin in the laminate was 95% by mass or more. ×: The content of the same polyolefin in the laminate was less than 95% by mass.

[0131] <<Shoulder Adhesion Strength>> A test piece was obtained by cutting in a strip shape with a width of 15 mm in the direction of the bottom part from the adhesion part of the body and the shoulder. This test piece was pulled at a test speed of 300 mm / min with a tensile testing machine (manufactured by Orientec, RTC-1310A), and the peel strength when the body peeled off from the shoulder was measured. The measurement results are summarized in Table 1.

[0132] <<Side Seam Strength>> A strip with a width of 15 mm was cut in a direction perpendicular to the side seam (the overlapping part) of the body and pulled with a tensile testing machine at a test speed of 300 mm / min, and the strength at the time of breakage was measured. The measurement results are summarized in Table 1.

[0133] <<Leakage Evaluation>> A cap was screwed onto the extraction port of the tube container body. Then, 120 g of commercially available toothpaste was filled as the content through the opening of the cylindrical body portion. Next, the opening of the cylindrical body portion was heat-sealed. The set tightening torque when the cap was closed was 4.7 kg·cm. It was left for 2 weeks at room temperature, and it was visually checked every day to see if there was any leakage of the content. The evaluation criteria for leakage were as follows. (Evaluation Criteria) 〇: Even after 2 weeks had passed, no leakage of the content was observed. ×: Leakage of the content was observed before 2 weeks had passed.

[0134] <<Gas Barrier Property Evaluation>> The oxygen permeability (cc / m 2 ·day·atm) and water vapor permeability (g / m 2 ·day) of the gas barrier laminates and laminates obtained in the examples and comparative examples were measured by the following method, and the results were summarized in Table 1.

[0135] [Oxygen Permeability] Using an oxygen permeability measuring device (manufactured by MOCON, OX-TRAN2 / 20), it was set so that the base material surface of the test piece was on the oxygen supply side, and the oxygen permeability was measured in an environment of 23°C and 90%RH relative humidity in accordance with JIS K 7126.

[0136] [Water Vapor Permeability] Using a water vapor permeability measuring device (manufactured by MOCON, PERMATRAN―w 3 / 33), it was set so that the base material surface of the test piece was on the water vapor supply side, and the water vapor permeability was measured in an environment of 40°C and 90%RH relative humidity in accordance with JIS K 7129.

[0137] <<Lamination Strength Test>> Samples obtained by cutting the laminates obtained in the above Examples and Comparative Examples into strips 15 mm wide were tested using a tensile testing machine (Tensilon universal material testing machine, manufactured by Orientec Co., Ltd.) in accordance with JIS K6854-2. The laminate strength (N / 15 mm) between the vapor deposition film and the surface resin layer (Examples) and between the vapor deposition film and the biaxially stretched polyethylene terephthalate film (Comparative Examples) was measured using 90° peeling (T-peel method) at a peeling rate of 50 mm / min. The measurement results are summarized in Table 1.

[0138]

Table 1

Explanation of Symbols

[0139] 10: Laminate, 11: First sealant layer, 12: Vapor deposition film, 13: Substrate, 14: Second sealant layer, 15: Surface resin layer, 16: Polyethylene resin layer, 17: Melt-extruded resin layer or adhesive layer, 20: Laminated tube, 21: Laminated tube body, 22: Head, 23: Body, 24: Shoulder, 25: Pour spout, 26: Cap, 27: Screw thread, 28: Welded part, 29: Bottom seal part

Claims

1. A laminate including at least a first sealant layer, a vapor-deposited film, a substrate, and a second sealant layer in this order, The substrate comprises at least a polyethylene resin layer and a surface resin layer, the first sealant layer and the second sealant layer are made of a polyethylene resin; The surface resin layer of the substrate contains a resin material having a melting point of 150° C. or more, the vapor-deposited film is provided on a surface resin layer of the substrate, A laminate, wherein the substrate has been subjected to a stretching treatment.

2. The laminate according to claim 1 , wherein the surface resin layer contains a resin material having a melting point of 150° C. or higher and 265° C. or lower.

3. 3. The laminate according to claim 1, wherein the difference in melting point between the polyethylene resin and the resin material having a melting point of 150° C. or higher contained in the surface resin layer is 20 to 80° C.

4. 4. The laminate according to claim 1, wherein the resin material of the surface resin layer is made of a polymer having a polar group.

5. The laminate according to any one of claims 1 to 4, wherein the resin material of the surface resin layer is one or more resin materials selected from ethylene vinyl alcohol copolymer, polyvinyl alcohol, polyester, nylon 6, nylon 6,6, nylon 6-nylon 6,6 copolymer, MXD nylon, and amorphous nylon.

6. The laminate according to any one of claims 1 to 5, wherein the polyethylene resin layer of the substrate has a multi-layer structure.

7. The laminate according to any one of claims 1 to 6, wherein the polyethylene resin layer of the substrate comprises at least one layer containing a compatibilizer.

8. The laminate according to any one of claims 1 to 7, wherein the substrate is a co-extruded film.

9. The laminate according to any one of claims 1 to 8, further comprising a barrier coat layer between the first sealant layer and the vapor-deposited film.

10. The laminate according to any one of claims 1 to 9, which is used for a packaging container.

11. The laminate according to any one of claims 1 to 10, wherein the content of the polyethylene resin in the entire laminate is 95 mass% or more.

12. A packaging container comprising the laminate according to any one of claims 1 to 11.

13. The packaging container according to claim 12, which is a laminated tube.

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