Packaging bag

Abstract

To provide a packaging bag composed of a laminate excellent in interlayer adhesion with a vapor-deposited film, as well as having high gas barrier properties.SOLUTION: A packaging bag is composed of a laminate 50 at least including a substrate 51, a vapor-deposited film 52 and a sealant layer 53. The substrate at least includes a polyethylene resin layer 54 and a surface resin layer 55. The sealant layer is composed of a polyethylene resin. The surface resin layer of the substrate includes a resin material with a melting point 150°C or higher. The vapor-deposited film is disposed on the surface resin layer of the substrate. A drawing process is applied to the substrate.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a packaging bag.

[0002] Conventionally, a resin film made of a polyester resin such as polyethylene terephthalate (hereinafter also referred to as a polyester film) has been used for producing a packaging bag because it is excellent in mechanical properties, chemical stability, heat resistance and transparency and is inexpensive.

[0003] Such a polyester film is used as a base material or an intermediate layer, and 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 bag.

[0004] A packaging bag obtained by forming a laminate in which different resin films, that is, a polyester film and a polyethylene film are laminated, is difficult to separate into its respective layers, and the packaging bag recovered after use is not suitable for recycling and is not actively recycled at present.

[0005] In view of such a situation, for the purpose of improving the recyclability of the packaging bag, instead of the polyester film, a polyethylene film (stretched polyethylene film) subjected to a stretching treatment is applied to a base material or the like, and a packaging bag (monomaterial packaging bag) using a laminate composed of the same material is being studied.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] Now, in order to compensate for the deteriorated gas barrier property accompanying the change of the polyester film to a stretched polyethylene film, when the inventors of the present invention tried to form a vapor deposition film on the surface of the stretched polyethylene film, they found a new problem that the adhesion between the stretched polyethylene film and the vapor deposition film was not sufficient and a satisfactory gas barrier property could not be obtained.

[0008] And, surprisingly, the inventors of the present invention provided a surface resin layer containing a resin material having a melting point of 150°C or higher on the surface of the stretched polyethylene film, whereby the adhesion of the vapor deposition film formed on the surface resin layer was improved. Along with this, they obtained the finding that the gas barrier property was remarkably improved and the above problems could be solved.

[0009] The present invention has been made based on such findings, and the problem to be solved is to provide a monomaterial packaging container (packaging bag) having high recyclability and having a high gas barrier property.

Means for Solving the Problem

[0010] In a first aspect, the packaging bag of the present invention is a packaging bag comprising at least a laminate including a base material, a vapor deposition film, and a sealant layer, wherein the base material includes at least a polyethylene resin layer and a surface resin layer, the sealant layer is 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 by having been subjected to a stretching treatment.

[0011] In a second aspect, the packaging bag of the present invention is a packaging bag comprising at least a laminate including a base material, an intermediate layer, and a sealant layer, wherein the intermediate layer includes a polyethylene resin layer, a surface resin layer, and a vapor deposition film provided on the surface resin layer, The base material and the sealant layer are both made of polyethylene resin, The surface resin layer of the intermediate layer contains a resin material with a melting point of 150 °C or higher, The polyethylene resin layer and the surface resin layer of the intermediate layer are characterized by being subjected to a stretching treatment.

[0012] In a third aspect, the packaging bag of the present invention is a packaging bag comprising at least a laminate including a base material, a vapor deposition film, and a sealant layer, The sealant layer includes a surface resin layer and a polyethylene resin layer, The base material is made of polyethylene resin, The surface resin layer of the sealant layer contains a resin material with a melting point of 150 °C or higher, The vapor deposition film is provided on the surface resin layer of the sealant layer.

[0013] In one embodiment, the surface resin layer contains a resin material having a melting point of 150 °C or higher and 265 °C or lower.

[0014] In one embodiment, the melting point difference between the polyethylene resin and the resin material with a melting point of 150 °C or higher contained in the surface resin layer is 20 to 80 °C.

[0015] In one embodiment, the resin material of the surface resin layer is composed of a polymer having a polar group.

[0016] 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.

[0017] In one embodiment, the polyethylene resin layer has a multilayer structure.

[0018] In one embodiment, the polyethylene resin layer includes at least one layer containing a compatibilizer.

[0019] In one embodiment, the surface resin layer is provided so as to be in contact with a layer containing a compatibilizer for the polyethylene resin layer.

[0020] In one embodiment, the laminate further has a barrier coat layer provided on the vapor deposition film.

[0021] In one embodiment, the content of the polyethylene resin in the entire laminate is 80% by mass or more.

Advantages of the Invention

[0022] According to the present invention, it is possible to provide a monomaterial packaging container (packaging bag) having high recyclability and a packaging bag having high gas barrier properties.

Brief Description of the Drawings

[0023]

Figure 1

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Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0024] (Packaging bag) The form of the packaging bag is not particularly limited, and it is preferably changed as appropriate according to the contents to be filled. For example, there are various forms of packaging bags such as a standing pouch type, a side seal type, a two-side seal type, a three-side seal type, a four-side seal type, an envelope sticker seal type, a clasp sticker seal type (pillow seal type), a pleated seal type, a flat bottom seal type, a square bottom seal type, and a gusset type. Further, the contents to be filled are not particularly limited, and the contents may be a liquid, a powder, or a gel. Also, it may be a food or a non-food.

[0025] In one embodiment, the packaging bag 10 of the present invention is a packaging bag formed by laminating two laminates as shown in FIG. 1 (the hatched portion is a heat-sealed portion).

[0026] A packaging bag in the form shown in FIG. 1 can be produced by preparing two of the following laminates, stacking them so that the sealant layers face each other, and heat-sealing three sides.

[0027] In one embodiment, the packaging container of the present invention is a standing pouch type packaging bag 20 (hereinafter simply referred to as the standing pouch 20) as shown in FIG. 2, and the standing pouch 20 includes a body portion (side sheet) and a bottom portion (bottom sheet). The body portion (side sheet) of the standing pouch 20 is made of the following laminate. Further, the bottom (bottom sheet) may also be composed of the laminate described below. By adopting such a configuration, the gas barrier property of the standing pouch 20 can be further improved. Also, the recyclability can be improved as well.

[0028] As shown in FIG. 2, the body portion (side sheet) of the standing pouch 20 can be formed by bag-making such that the sealant layer provided in the laminate is the innermost layer. In another embodiment, two laminates are prepared, and these are overlapped such that the sealant layers face each other. From both ends of the overlapped laminates, two V-shaped folded laminates with the sealant layer on the outside are inserted, and heat-sealed, thereby forming the body portion (side sheet) of the standing pouch 20. According to such a manufacturing method, a stand pouch having a body portion with side gussets can be obtained. Also, the bottom (bottom sheet) of the standing pouch 20 can be formed by inserting a laminate between the bag-made body portions (side sheets) and heat-sealing. More specifically, the laminate can be folded in a V shape such that the sealant layer is on the outside, inserted between the bag-made side sheets, and heat-sealed.

[0029] Also, as shown in FIG. 1, the packaging bag 10 may be provided with an easy-opening means 31. Examples of the easy-opening means 31 include, as shown in FIG. 1, a notch portion 32 serving as a starting point for tearing, and a half-cut line 33 formed by laser processing, a cutter, etc. as a path for tearing.

[0030] Also, as shown in FIG. 2, the packaging container may be a standing pouch 20 provided with a pouring nozzle portion 41. Also, from the viewpoint of ease of opening, the standing pouch 20 as shown in FIG. 2 may be provided with a curved portion 42 that curves inward. Furthermore, it may be provided with a cut-out portion 43 formed by a laser beam or the like.

[0031] Hereinafter, the laminate constituting the packaging bag of the present invention will be described.

[0032] (Laminate according to the first aspect) In the first aspect, as shown in FIG. 3, the laminate 50 includes a base material 51, a vapor deposition film 52, and a sealant layer 53. The base material 51 includes a polyethylene resin layer 54 and a surface resin layer 55. The vapor deposition film 52 is provided adjacent to the surface resin layer 55 of the base material 51. The polyethylene resin layer of the base material included in the laminate and the sealant layer 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 monomaterial packaging container.

[0033] The content of the polyethylene resin with respect to the total amount of the solid content contained in the laminate constituting the packaging bag is preferably 80% by mass or more, and more preferably 90% by mass or more. Thereby, it can be made into a laminate that can be suitably used for producing a monomaterial packaging container (packaging bag).

[0034] Also, in one embodiment, the base material 51 can further include an adhesive resin layer 56 between the polyethylene resin layer 54 and the surface resin layer 55, as shown in FIG. 4.

[0035] Furthermore, in one embodiment, the laminate 50 includes a barrier coat layer between the vapor deposition film 52 and the sealant layer (not shown).

[0036] Furthermore, in one embodiment, the laminate 50 includes an adhesive layer between any layers (not shown).

[0037] Hereinafter, each layer included in the laminate according to the first aspect will be described.

[0038] (Base material) The base material comprises at least a polyethylene resin layer and a surface resin layer. Further, in one embodiment, the base material comprises an adhesive resin layer between the polyethylene resin layer and the surface resin layer.

[0039] 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 suitable for producing a monomaterial packaging container can be obtained. Furthermore, the film-forming property and processing suitability of the base material can be further improved.

[0040] (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. 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 mechanically recycled or chemically recycled polyethylene resin can be used.

[0041] Here, as the high-density polyethylene resin, a polyethylene resin with a density of 0.945 g / cm 3 or more can be used. As the medium-density polyethylene resin, a polyethylene resin with a density of 0.925 g / cm 3 or more 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 / cm3 Polyethylene resins with a density of more than 0.925 g / cm 3 can be used. As the linear low-density polyethylene resin, those with a density of 0.900 g / cm 3 or more and less than 0.925 g / cm 3 can be used. As the ultra-low density polyethylene resin, those with a density of less than 0.900 g / cm 3 can be used.

[0042] 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 can be more suitably used for manufacturing the monomaterial packaging container.

[0043] 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 made of the laminate is heated and melted for recycling, the resin material with 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. Also, it can be effectively prevented that the transparency thereof decreases. In addition, 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 containing the compatibilizer in the layer in contact with the surface resin layer of the polyethylene resin layer, the above effects can be further improved.

[0044] As the compatibilizer, conventionally known ones can be appropriately selected and used. From the viewpoint of recyclability, unsaturated carboxylic acid-modified polyolefin resins are preferred, and among them, maleic anhydride-modified polyethylene resins are more preferred.

[0045] 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.

[0046] Within the 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 recyclability, it is particularly preferable that the polyethylene resin layer does not contain resins other than the polyethylene resin.

[0047] Also, within the 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 can be mentioned.

[0048] The polyethylene resin layer provided in the base material may have a single-layer structure or a multilayer structure.

[0049] 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 drawability are significantly improved.

[0050] In the polyethylene resin layer provided with a density gradient, when the density difference between each layer is large, there is a risk of delamination occurring at the interface. Therefore, the density difference between each layer is preferably 0.04 g / cm 3 or less, and 0.02 g / cm3 It is more preferable that it is as follows.

[0051] 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.

[0052] In one embodiment, the polyethylene resin layer provided with a density gradient is composed of three layers: a layer containing a high-density polyethylene resin, a layer containing a medium-density polyethylene resin, and a layer containing a 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 drawability are significantly improved. In addition, in the base material, it is possible to effectively prevent the occurrence of curl.

[0053] In one embodiment, the polyethylene resin layer provided with a density gradient is composed of five layers: a layer containing a high-density polyethylene, a layer containing a medium-density polyethylene resin, a layer containing at least one of a low-density polyethylene resin and a linear low-density polyethylene resin, a layer containing a medium-density polyethylene resin, and a layer containing a 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. In addition, in the base material, it is possible to effectively prevent the occurrence of curl. The polyethylene resin layer having such a configuration can be stably produced by the following inflation method. Specifically, from the outside, a high-density polyethylene resin, a medium-density polyethylene resin, and at least one of a low-density polyethylene resin and a linear low-density polyethylene resin are co-extruded in a tubular shape. Next, it can be produced by pressing the layers containing at least one of a low-density polyethylene resin and a linear low-density polyethylene resin against each other using a rubber roll or the like. By manufacturing in such a way, the number of defective products in manufacturing can be significantly reduced, and ultimately, the production efficiency can be improved.

[0054] In one embodiment, the polyethylene resin layer provided with a density gradient is composed of seven layers, namely, 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 adopting a five-layer structure with the density gradient provided in the polyethylene resin layer as described above, the strength, heat resistance and drawability are significantly improved. Also, in the base material, the occurrence of curl can be effectively prevented. Furthermore, the occurrence of delamination in the base material can be effectively prevented. Also, the polyethylene resin layer having such a structure can be stably manufactured by the above-described inflation method.

[0055] 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. Also, by setting the thickness of the polyethylene resin layer to 50 μm or less, the film-forming property and processability of the base material can be further improved.

[0056] 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.

[0057] (Surface resin layer) The base material included in the laminate 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 a polyethylene resin layer.

[0058] 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. 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.

[0059] 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.

[0060] 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 higher, 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 with the sealant layer can be improved, and the laminate strength of the packaging container produced by this laminate can be further improved. Further, by setting 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 to 80°C or less, the film forming property of the base material can be further improved.

[0061] 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.

[0062] 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.

[0063] Examples of the high melting point resin material include vinyl resin, polyamide, polyimide, polyester, (meth)acrylic resin, cellulose resin, polyolefin resin, and ionomer resin.

[0064] In the present invention, a resin material having a melting point of 150°C or higher and having a polar group is particularly preferable, and 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 preferable, and ethylene vinyl alcohol copolymer and amide resin are particularly preferable. By using such a resin material, the adhesion of the vapor deposition film formed on the surface resin layer can be remarkably improved, and the gas barrier property can be effectively improved.

[0065] 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 still 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 improved.

[0066] Within a 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.

[0067] Also, within a range that does not impair the characteristics of the present invention, the surface 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.

[0068] 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. Also, 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, by setting the thickness of the surface resin layer to 5 μm or less, it can be used as a substrate suitable for manufacturing a single material packaging container. Furthermore, the film forming property and processing suitability of the substrate can be further improved.

[0069] Also, the surface resin layer provided on the substrate may be surface-treated. Thereby, the adhesion to the adjacent layer can be improved. The method of 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.

[0070] 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.

[0071] Also, the surface resin layer provided on the substrate may be subjected to surface treatment. Thereby, the adhesion with an adjacent layer can be improved. The method of 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.

[0072] (Adhesive resin layer) In one embodiment, the substrate 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.

[0073] The adhesive resin layer can be formed by using an adhesive resin such as polyether, polyester, silicone resin, epoxy resin, polyurethane, vinyl resin, phenol resin, and polyolefin. Among the above, since the laminate can be made into a more suitable configuration using a monomaterial packaging container, polyolefin and its acid-modified product are preferred, and polyethylene and its acid-modified product are particularly preferred. As the adhesive polyethylene, commercially available products can be used. For example, the Admer series manufactured by Mitsui Chemicals, Inc. can be used.

[0074] 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 substrate can be improved.

[0075] The substrate has been 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 substrate are preferably 2 times or more and 15 times or less, and more preferably 5 times or more and 13 times or less. By setting the stretching ratio to 2 times or more, the strength and heat resistance of the substrate can be further improved. Also, the printability on the substrate can be improved. Also, from the viewpoint of the breaking limit of the substrate, the stretching ratio is preferably 15 times or less.

[0076] In one embodiment, the substrate is a coextruded film, which can be produced by forming a film using the T-die method or the inflation method, etc., and then stretching after forming it into a resin film. By forming a film using the inflation method, stretching of the resin film can be performed simultaneously.

[0077] (Vapor deposition film) The laminate includes a vapor deposition film adjacent to the surface resin layer on the surface resin layer. In the laminate, 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.

[0078] 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). 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).

[0079] 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.

[0080] 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. Furthermore, the occurrence of cracks in the vapor deposition film can be prevented.

[0081] 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.

[0082] As an apparatus used for the method for forming a vapor deposition film by 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. 5 and 6, 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 prevention box H, a vapor deposition material I, and a plasma gun J. Note that FIG. 5 is a schematic cross-sectional view in the XZ plane direction of the vacuum film forming apparatus, and FIG. 6 is a schematic cross-sectional view in the XY plane direction of the vacuum film forming apparatus. As shown in FIG. 5, 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 deposition prevention box H grounded electrically is arranged. The evaporation source F is arranged on the bottom surface of the deposition prevention 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 part 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 deposition material. The 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 deposition film is formed. The details of this formation method are disclosed in Japanese Patent Laid-Open No. 2011-214089.

[0083] As the plasma generation device used in the plasma chemical vapor deposition method, a device for generating high-frequency plasma, pulse wave plasma, microwave plasma, etc. 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 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 to form a deposition film containing an inorganic oxide on the surface resin layer. The details of this formation method are disclosed in Japanese Patent Laid-Open No. 2012-076292.

[0084] As the device used in the method for forming a deposition film, a continuous deposition film forming device equipped with a plasma pretreatment chamber and a film formation chamber can be used. An embodiment of the method for forming a deposition film using this device will be described below. First, in the plasma pretreatment chamber, the surface resin layer provided on the base material is irradiated with plasma from the plasma supply nozzle. Next, in the film formation chamber, a 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.

[0085] (Barrier coat layer) The laminate can further include a barrier coat layer on the vapor deposition film. Thereby, the oxygen barrier property and water vapor barrier property of the laminate can be improved.

[0086] In one embodiment, the barrier coat layer includes 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.

[0087] The content of the gas barrier resin in the barrier coat layer is preferably 50% by mass or more and 95% by mass or less, and more preferably 75% by mass or more and 90% by mass or less. By setting the content of the gas barrier resin in the barrier coat layer to 50% by mass or more, the oxygen barrier property and water vapor barrier property can be further improved.

[0088] The thickness of the barrier coat 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 oxygen barrier property and water vapor barrier property of the laminate can be further improved. By setting the thickness of the barrier coat layer to 10 μm or less, the processability of the laminate can be improved. Also, the recyclability of a packaging container produced using a laminate of a base material and a sealant layer made of a polyethylene resin can be improved.

[0089] The barrier coat layer can be formed by dissolving or dispersing the above materials in water or a suitable solvent, coating, and drying. Also, the barrier coat layer can be formed by coating and drying a commercially available barrier coating agent.

[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 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. Also, as the organic groups 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), etc.

[0094] Also, 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. 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 laminate can be improved. Further, 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 suitable for producing a single-material packaging container can be obtained.

[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, brush, bar code, applicator, etc., and subjecting the composition to polycondensation by the sol-gel method. As the sol-gel method catalyst, an acid or an 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, silane coupling agents, etc. As the acid, mineral acids such as sulfuric acid, hydrochloric acid, nitric acid, and organic acids such as acetic acid and tartaric acid are used.

[0099] Further, 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] (Sealant layer) In one embodiment, the sealant layer contains the same resin as the polyethylene resin layer of the base material, that is, a 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 recycled mechanically or chemically can also be used.

[0102] The content of the polyethylene resin in the sealant layer is preferably 80% by mass or more, and more preferably 90% by mass or more. Thereby, a laminate suitable for producing a monomaterial packaging container can be obtained.

[0103] Within the range that does not impair the characteristics of the present invention, the sealant layer may contain a resin material other than the polyethylene resin. Examples thereof include polyolefin resins such as polypropylene resin, (meth)acrylic resins, vinyl resins, cellulose resins, polyamide resins, polyester resins, and ionomer resins. In view of its recyclability, it is particularly preferable that the sealant layer does not contain a resin other than the polyethylene resin.

[0104] Within the range that does not impair the characteristics of the present invention, the sealant layer can contain the above-mentioned additives.

[0105] The sealant layer may have a single-layer structure or a multilayer structure.

[0106] 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 lamination 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.

[0107] The sealant layer can be formed by laminating a resin film composed of the above resin material such as polyethylene resin via a conventionally known adhesive or the like onto a vapor deposition film provided on the surface vapor deposition film or a barrier coat layer. Also, the sealant layer can be formed by melt-extruding the above resin material onto a vapor deposition film provided on the surface vapor deposition film or a barrier coat layer. When the laminate is used for manufacturing a laminated tube or the like, the laminate 50 further includes a sealant layer 53 on the non-vapor deposition surface of the base material 51 (not shown).

[0108] (Adhesive layer) The laminate can be provided with an adhesive layer between any layers. The adhesive layer contains at least one type of adhesive, and it may be any of one-component curing type, two-component curing type, or non-curing type adhesives. Also, the adhesive may be a solventless adhesive or a solvent-based adhesive. However, from the perspective of environmental load, a solventless adhesive can be preferably used. Examples of the solventless adhesive include polyether-based adhesives, polyester-based adhesives, silicone-based adhesives, epoxy-based adhesives, and urethane-based adhesives. Among these, a two-component curing type urethane-based adhesive can be preferably used. Examples of the solvent-based adhesives include rubber-based adhesives, vinyl-based adhesives, silicone-based adhesives, epoxy-based adhesives, phenol-based adhesives, and olefin-based adhesives.

[0109] The thickness of the adhesive layer is preferably 1 μm or more and 15 μm or less, and more preferably 3 μm or more and 10 μm or less. By setting the thickness of the adhesive layer to 1 μm or more, the adhesion between layers can be improved. Also, by setting the thickness of the adhesive layer to 15 μm or less, the recyclability of the packaging bag can be improved.

[0110] (Laminate according to the second aspect) As shown in FIG. 7, the laminate 60 includes a base material 61, an intermediate layer 62, and a sealant layer 63, and the intermediate layer 62 includes a vapor deposition film 64, a surface resin layer 65, and a polyethylene resin layer 66. The polyethylene resin layer of the intermediate layer, the base material, and the sealant layer included in the laminate are made of the same resin, that is, polyethylene resin. A laminate having such a configuration can be preferably used as a laminate for manufacturing a monomaterial packaging container.

[0111] The content of the polyethylene resin with respect to the total amount of the solid content contained in the laminate constituting the packaging bag is preferably 80% by mass or more, and more preferably 90% by mass or more. Thereby, it can be set as the laminated body which can be used suitably for manufacture of a monomaterial packaging container (packaging bag).

[0112] In addition, in FIG. 7, the form in which the vapor deposition film 64 and the base material 61 are adjacent is shown, but it is not limited to this, and as shown in FIG. 8, the vapor deposition film 64 may be adjacent to the sealant layer 63.

[0113] From the viewpoint of the heat sealability of the packaging bag of the present invention produced by the barrier laminate 60, the vapor deposition film 14 is preferably provided adjacent to the base material 51 as shown in FIG. 8.

[0114] Further, in one embodiment, as shown in FIG. 9, the intermediate layer 62 can further include an adhesive resin layer 67 between the surface resin layer 65 and the polyethylene resin layer 66.

[0115] Furthermore, in one embodiment, the laminate 60 includes a barrier coat layer adjacent to the vapor deposition film 64 (not shown).

[0116] Furthermore, in one embodiment, the laminate 60 includes an adhesive layer between arbitrary layers, for example, between the base material 61 and the intermediate layer 62 or between the intermediate layer 62 and the sealant layer 63 (not shown).

[0117] Hereinafter, each layer included in the laminate according to the second aspect will be described.

[0118] (Base material) The base material contains the same resin as the polyethylene resin layer and the sealant layer of the intermediate layer, that is, polyethylene resin. The laminate having such a configuration can be suitably used as a laminate for manufacturing 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 very-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 mechanically recycled or chemically recycled polyethylene resin can be used.

[0119] The content of the polyethylene resin in the base material is preferably 80% by mass or more, more preferably 90% by mass or more. Thereby, a laminate suitable for producing a single-material packaging container can be obtained.

[0120] Within a range that does not impair the characteristics of the present invention, the base material 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 recyclability, it is particularly preferable that the base material does not contain resins other than the polyethylene resin.

[0121] Within a range that does not impair the characteristics of the present invention, the base material can contain the above-mentioned additives.

[0122] The base material may have a single-layer structure or a multi-layer structure.

[0123] In a base material having a multi-layer structure, the densities of the polyethylene resins constituting each layer may be different, that is, a density gradient may be provided in the base material. By providing a density gradient in the base material, its strength, heat resistance, and drawability are significantly improved.

[0124] In a substrate provided with a density gradient, when the density difference between the layers is large, delamination may occur at the interface. Therefore, the density difference between the layers is preferably 3 0.04 g / cm or less, and more preferably 3 0.02 g / cm or less.

[0125] The specific configuration of the substrate provided with the concentration gradient is the same as that of the polyethylene resin layer provided with the concentration gradient shown in the first embodiment, and the description thereof is omitted here.

[0126] In one embodiment, the substrate 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 substrate are preferably 2 times or more and 15 times or less, and more preferably 5 times or more and 13 times or less. By setting the stretching ratio to 2 times or more, the strength and heat resistance of the substrate can be further improved. Also, the printability on the substrate can be improved. Also, from the viewpoint of the breaking limit of the substrate, the stretching ratio is preferably 15 times or less.

[0127] The substrate 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 printing layer can be formed 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.

[0128] Also, the substrate is preferably subjected to a surface treatment. Thereby, the adhesion with an adjacent layer can be improved. The method of 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. Further, an anchor coat layer may be formed on the surface of the base material using a conventionally known anchor coat agent.

[0129] The thickness of the base material is preferably 9 μm or more and 50 μm or less, and more preferably 12 μm or more and 30 μm or less. By setting the thickness of the base material within the above numerical range, the printing suitability, strength, and heat resistance of the base material can be further improved.

[0130] (Intermediate layer) The intermediate layer includes a vapor deposition film, a surface resin layer, and a polyethylene resin layer. Further, in one embodiment, an adhesive resin layer is provided between the surface resin layer and the polyethylene resin layer. The intermediate layer may be provided such that the vapor deposition film forming surface faces the base material side or the sealant layer side. However, from the viewpoint of the heat sealability of the packaging bag of the present invention produced using the barrier laminate, it is preferable that the intermediate layer is provided such that the vapor deposition film forming surface faces the base material side.

[0131] The surface resin layer, the polyethylene resin layer, and the adhesive resin layer are subjected to a stretching treatment, and the stretching treatment may be uniaxial stretching or biaxial stretching. The stretching ratio in the longitudinal direction (MD direction) and the transverse direction (TD direction) is preferably 2 times or more and 15 times or less, and preferably 5 times or more and 13 times or less. By setting the stretching ratio to 2 times or more, the strength and heat resistance of the intermediate layer can be further improved. In addition, the printing suitability for the intermediate layer can be improved. Further, from the viewpoint of the breaking limit, the stretching ratio is preferably 15 times or less.

[0132] In one embodiment, the surface resin layer and the polyethylene resin layer included in the intermediate layer are coextruded films, which can be formed into resin films by using the T-die method, the inflation method, or the like, and then stretched. By forming the resin film by the inflation method, stretching of the resin film can be performed simultaneously.

[0133] (Polyethylene resin layer) The configuration of the polyethylene resin layer is the same as that included in the laminate of the first aspect, and the description thereof is omitted here.

[0134] (Surface resin layer) The configuration of the surface resin layer is the same as that included in the laminate of the first aspect, and the description thereof is omitted here.

[0135] (Adhesive resin layer) The configuration of the adhesive resin layer is the same as that included in the laminate of the first aspect, and the description thereof is omitted here.

[0136] (Vapor deposition film) The configuration of the vapor deposition film is the same as that included in the laminate of the first aspect, and the description thereof is omitted here.

[0137] (Barrier coat layer) The configuration of the barrier coat layer is the same as that included in the laminate of the first aspect, and the description thereof is omitted here.

[0138] (Sealant layer) The configuration of the sealant layer is the same as that included in the laminate of the first aspect, and the description thereof is omitted here.

[0139] (Adhesive layer) The configuration of the adhesive layer is the same as that included in the laminate of the first aspect, and the description thereof is omitted here.

[0140] (Laminate according to the third aspect) As shown in Fig. 11, the laminate 70 includes a base material 71, a vapor deposition film 72, and a sealant layer 73, and the sealant layer 73 includes a surface resin layer 74 and a polyethylene resin layer 75. The polyethylene resin layer of the sealant layer included in the laminate and the base material are made of the same resin, that is, polyethylene resin, and a laminate having such a configuration can be suitably used as a laminate for producing a monomaterial packaging container.

[0141] The content of the polyethylene resin with respect to the total amount of the solid content contained in the laminate constituting the packaging bag is preferably 80% by mass or more, and more preferably 90% by mass or more. Thereby, it can be made into a laminate that can be suitably used for producing a monomaterial packaging container (packaging bag).

[0142] Also, in one embodiment, as shown in Fig. 12, the sealant layer 73 can further include an adhesive resin layer 76 between the surface resin layer 74 and the polyethylene resin layer 75.

[0143] Furthermore, in one embodiment, the laminate 70 includes a barrier coat layer adjacent to the vapor deposition film 72 (not shown).

[0144] Furthermore, in one embodiment, the laminate 70 includes an adhesive layer between any layers, for example, between the vapor deposition film 72 and the sealant layer 73 (not shown).

[0145] Hereinafter, each layer included in the laminate according to the third aspect will be described.

[0146] (Base material) The configuration of the base material is the same as that included in the laminate of the second aspect, and the description thereof is omitted here.

[0147] (Vapor deposition film) The configuration of the vapor deposition film is the same as that included in the laminates of the first and second aspects, and the description thereof is omitted here.

[0148] (Sealant layer) The sealant layer includes a surface resin layer and a polyethylene resin layer. Further, in one embodiment, an adhesive resin layer is provided between the surface resin layer and the polyethylene resin layer.

[0149] In one embodiment, the sealant layer is a coextruded film and can be produced by forming a film using the T-die method or the inflation method or the like.

[0150] From the viewpoint of heat sealability, the sealant layer is preferably composed of an unstretched film.

[0151] (Polyethylene resin layer) The configuration of the polyethylene resin layer is the same as that provided in the laminate of the first aspect, and the description thereof is omitted here.

[0152] (Surface resin layer) The configuration of the surface resin layer is the same as that provided in the laminate of the first aspect, and the description thereof is omitted here.

[0153] (Adhesive resin layer) The configuration of the adhesive resin layer is the same as that provided in the laminate of the first aspect, and the description thereof is omitted here.

[0154] (Barrier coat layer) The configuration of the barrier coat layer is the same as that provided in the laminate of the first aspect, and the description thereof is omitted here.

[0155] (Adhesive layer) The configuration of the adhesive layer is the same as that provided in the laminate of the first aspect, and the description thereof is omitted here.

Examples

[0156] Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited to the following examples.

[0157] Example 1-1 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 Medium-density polyethylene (manufactured by The Dow Chemical Company, Elite 5538, density: 0.941 g / cm 3 , melting point: 129°C), and were co-extruded into a film by an inflation molding method and then stretched 5 times in the longitudinal direction (MD direction) by a stretching device to produce a substrate. In the substrate thus obtained, the thickness of the surface resin layer composed of the ethylene vinyl alcohol copolymer was 2 μm, the thickness of the adhesive resin layer was 3 μm, and the thickness of the polyethylene resin layer composed of medium-density polyethylene was 20 μm.

[0158] On the surface of the surface resin layer of the substrate, an aluminum vapor deposition film with a thickness of 30 nm was formed by the PVD method under the condition of a pressure of 3.0×10 -2 Pa.

[0159] First linear low-density polyethylene (manufactured by Prime Polymer Co., Ltd., SP2520, density: 0.925 g / cm 3 , melting point: 122°C) and second linear low-density polyethylene (manufactured by Prime Polymer Co., Ltd., SP1520, density 0.913, melting point 116°C) were multilayer extruded into a film by an inflation molding method to produce an unstretched polyethylene film with 20 μm of the first linear low-density polyethylene and 20 μm of the second linear low-density polyethylene. The first linear low-density polyethylene side of this unstretched polyethylene film was laminated on the aluminum vapor deposition film of the above-formed substrate via a two-component curable urethane-based adhesive (manufactured by Rock Paint Co., Ltd., Ru-77T / H-7) to obtain a laminate. The polyethylene content in the laminate was summarized in Table 1. Also, the laminates obtained in the following examples and comparative examples and the polyethylene content in the laminates were also summarized in Table 1.

[0160] Example 1-2 An ethylene-vinyl alcohol copolymer was changed to polyamide (manufactured by Ube Industries, Ltd., 5033, melting point: 196 °C, density: 1.14 g / cm 3 ), and a base material was produced in the same manner as in Example 1-1 except for this change. In the base material thus obtained, the thickness of the surface resin layer composed of polyamide was 2 μm, the thickness of the adhesive resin layer was 3 μm, and the thickness of the polyethylene resin layer composed of medium-density polyethylene was 20 μm.

[0161] A laminate was produced in the same manner as in Example 1-1 except that the base material was changed to the base material produced as described above.

[0162] Example 1-3 An ethylene-vinyl alcohol copolymer (manufactured by Kuraray Co., Ltd., Eval E171B, melting point: 165 °C, density: 1.14 g / cm 3 ), and an adhesive resin (manufactured by Mitsui Chemicals, Inc., maleic anhydride-modified polyethylene, Admer NF557, density 0.920 g / cm 3 ), and medium-density polyethylene (manufactured by The Dow Chemical Company, Elite 5538, density: 0.941 g / cm 3 , melting point: 129 °C) and a compatibilizer (manufactured by The Dow Chemical Company, maleic anhydride polyethylene, Retain 3000, density: 0.87 g / cm 3 ) were co-extruded into a film by an inflation molding method, and then stretched 5 times in the longitudinal direction (MD direction) by a stretching device to produce a base material. medium-density polyethylene (manufactured by The Dow Chemical Company, Elite 5538, density: 0.941 g / cm 3 , melting point: 129 °C) and were co-extruded into a film by an inflation molding method, and then stretched 5 times in the longitudinal direction (MD direction) by a stretching device to produce a base material. In the base material thus obtained, the thickness of the surface resin layer composed of an ethylene-vinyl alcohol copolymer was 2 μm, the thickness of the adhesive resin layer was 3 μm, the thickness of the second polyethylene resin layer composed of a blend resin was 10 μm, and the thickness of the first polyethylene resin layer composed of medium-density polyethylene was 10 μm.

[0163] A laminate was produced in the same manner as in Example 1-1, except that the base material was changed to the base material produced as described above.

[0164] Example 1-4 A base material was produced in the same manner as in Example 1-3, except that the ethylene-vinyl alcohol copolymer was changed to polyamide (manufactured by Ube Industries, Ltd., 5033, melting point: 196 °C, density: 1.14 g / cm 3 ). In the base material thus obtained, the thickness of the surface resin layer composed of polyamide was 2 μm, the thickness of the adhesive resin layer was 3 μm, the thickness of the second polyethylene resin layer composed of a blend resin was 10 μm, and the thickness of the first polyethylene resin layer composed of medium-density polyethylene was 10 μm.

[0165] A laminate was produced in the same manner as in Example 1-1, except that the base material was changed to the base material produced as described above.

[0166] Comparative Example 1-1 Medium-density polyethylene (manufactured by Dow Chemical, Elite 5538, density: 0.941 g / cm 3 , melting point: 129 °C) was extruded into a single-layer film by an inflation molding method, and then stretched 5 times in the longitudinal direction (MD direction) by a stretching device to produce a 25-μm stretched polyethylene film.

[0167] A laminate was produced in the same manner as in Example 1-1, except that the base material was changed to the stretched polyethylene film produced as described above.

[0168] Comparative Example 1-2 A biaxially oriented polyester film with a thickness of 12 μm (manufactured by Toyobo Co., Ltd., E5100) was prepared.

[0169] A laminate was produced in the same manner as in Example 1-1, except that the substrate was changed to the above polyester film.

[0170] Example 2-1 A laminate was produced in the same manner as in Example 1-1, except that the aluminum vapor deposition film was changed to an aluminum oxide (alumina) vapor deposition film with a thickness of 20 nm formed by the PVD method.

[0171] Example 2-2 A laminate was produced in the same manner as in Example 1-2, except that the aluminum vapor deposition film was changed to an aluminum oxide (alumina) vapor deposition film with a thickness of 20 nm formed by the PVD method.

[0172] Example 2-3 A laminate was produced in the same manner as in Example 1-3, except that the aluminum vapor deposition film was changed to an aluminum oxide (alumina) vapor deposition film with a thickness of 20 nm formed by the PVD method.

[0173] Example 2-4 A laminate was produced in the same manner as in Example 1-4, except that the aluminum vapor deposition film was changed to an aluminum oxide (alumina) vapor deposition film with a thickness of 20 nm formed by the PVD method.

[0174] Comparative Example 2-1 A laminate was produced in the same manner as in Comparative Example 1-1, except that the aluminum vapor deposition film was changed to an aluminum oxide (alumina) vapor deposition film with a thickness of 20 nm formed by the PVD method.

[0175] Comparative Example 2-2 A laminate was produced in the same manner as in Comparative Example 1-2, except that the aluminum vapor deposition film was changed to an aluminum oxide (alumina) vapor deposition film with a thickness of 20 nm formed by the PVD method.

[0176] Example 3-1 A laminate was produced in the same manner as in Example 1-1, except that the aluminum vapor deposition film was changed to a silicon oxide (silica) vapor deposition film with a thickness of 20 nm formed by CVD method.

[0177] Example 3-2 A laminate was produced in the same manner as in Example 1-2, except that the aluminum vapor deposition film was changed to a silicon oxide (silica) vapor deposition film with a thickness of 20 nm formed by CVD method.

[0178] Example 3-3 A laminate was produced in the same manner as in Example 1-3, except that the aluminum vapor deposition film was changed to a silicon oxide (silica) vapor deposition film with a thickness of 20 nm formed by CVD method.

[0179] Example 3-4 A laminate was produced in the same manner as in Example 1-4, except that the aluminum vapor deposition film was changed to a silicon oxide (silica) vapor deposition film with a thickness of 20 nm formed by CVD method.

[0180] Comparative Example 3-1 A laminate was produced in the same manner as in Comparative Example 1-1, except that the aluminum vapor deposition film was changed to a silicon oxide (silica) vapor deposition film with a thickness of 20 nm formed by CVD method.

[0181] Comparative Example 3-2 A laminate was produced in the same manner as in Comparative Example 1-2, except that the aluminum vapor deposition film was changed to a silicon oxide (silica) vapor deposition film with a thickness of 20 nm formed by CVD method.

[0182] Example 4-1 Medium density polyethylene (manufactured by Dow Chemical, Elite 5538, density: 0.941 g / cm 3, after forming a single-layer extruded film of the ethylene-vinyl alcohol copolymer (manufactured by Kuraray Co., Ltd., Eval E171B, melting point: 129°C) by the inflation method, it was stretched 5 times in the longitudinal direction (MD direction) using a stretching device to produce a base material with a thickness of 25 μm.

[0183] 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 Medium-density polyethylene (manufactured by The Dow Chemical Company, Elite 5538, density: 0.941 g / cm 3 , melting point: 129°C), and were co-extruded and formed into a film by the inflation molding method, and then stretched 5 times in the longitudinal direction (MD direction) using a stretching device to produce an intermediate layer. In the intermediate layer thus obtained, the thickness of the surface resin layer composed of the ethylene-vinyl alcohol copolymer was 2 μm, the thickness of the adhesive resin layer was 3 μm, and the thickness of the polyethylene resin layer composed of medium-density polyethylene was 20 μm.

[0184] On the surface of the surface resin layer of the intermediate layer, an aluminum vapor deposition film with a thickness of 30 nm was formed by the PVD method under the condition of a pressure of 3.0×10 -2 Pa.

[0185] The base material and the vapor deposition film formation surface of the intermediate layer were laminated via a two-component curable urethane-based adhesive (manufactured by Rock Paint Co., Ltd., Ru-77T / H-7).

[0186] Linear low-density polyethylene (manufactured by Prime Polymer Co., Ltd., SP2520, density: 0.925 g / cm 3 , melting point: 122°C) was formed into a single-layer extruded film by the T-die method to produce an unstretched polyethylene film with a thickness of 40 μm. This unstretched polyethylene film was laminated on the non-vapor deposition film formation surface of the intermediate layer via a two-component curable urethane-based adhesive (manufactured by Rock Paint Co., Ltd., Ru-77T / H-7) to obtain a laminate. The content of polyethylene in the laminate was summarized in Table 2. Also, the laminates obtained in the following examples and comparative examples and the content of polyethylene in the laminates were also summarized in Table 2.

[0187] Example 4-2 High-density polyethylene (manufactured by ExxonMobil, HTA108, density: 0.961 g / cm 3 , melting point: 135 °C), and medium-density polyethylene (manufactured by Dow Chemical, Elite5538, density: 0.941 g / cm 3 , melting point: 129 °C), and high-density polyethylene (manufactured by ExxonMobil, HTA108, density: 0.961 g / cm 3 , melting point: 135 °C), and were co-extruded into a film by an inflation molding method, and then stretched 5 times in the longitudinal direction (MD direction) by a stretching device to produce a base material. In the base material thus obtained, the thickness of the layer composed of high-density polyethylene was 5 μm, the thickness of the layer composed of medium-density polyethylene was 15 μm, and the thickness of the layer composed of high-density polyethylene was 5 μm.

[0188] A laminate was produced in the same manner as in Example 4-1, except that the base material was changed to the base material having a three-layer structure produced as described above.

[0189] Example 4-3 High-density polyethylene (manufactured by ExxonMobil, HTA108, density: 0.961 g / cm 3 , melting point: 135 °C), and high-density polyethylene (manufactured by ExxonMobil, HTA108, density: 0.961 g / cm 3 , melting point: 135 °C) and medium-density polyethylene (manufactured by Dow Chemical, Elite5538, density: 0.941 g / cm 3 , melting point: 129 °C) were included in a blend resin at a mass ratio of 4:6, and Medium-density polyethylene (manufactured by Dow Chemical, Elite 5538, density: 0.941 g / cm 3 , melting point: 129 °C), and Very-low-density polyethylene (manufactured by Dow Chemical, Affinity EG810G, density: 0.870 g / cm 3 , melting point: 55 °C), and were extruded by an inflation molding method as a tubular film having a layer made of high-density polyethylene, a layer made of a blend resin, a layer made of medium-density polyethylene, and a layer made of very-low-density polyethylene from the outside, and the layers made of very-low-density polyethylene on the inside were crimped using a rubber roll. The film thus obtained had a layer made of high-density polyethylene, a layer made of a blend resin, a layer made of medium-density polyethylene, a layer made of very-low-density polyethylene, a layer made of medium-density polyethylene, a layer made of a blend resin, and a layer made of high-density polyethylene.

[0190] The film obtained as described above was stretched 5 times in the longitudinal direction (MD direction) by a stretching device to produce a base material. In the film thus obtained, the thickness of the layer made of high-density polyethylene was 2.5 μm, the layer made of a blend resin was 2.5 μm, the thickness of the layer made of medium-density polyethylene was 6.25 μm, the thickness of the layer made of very-low-density polyethylene was 2.5 μm, the thickness of the layer made of medium-density polyethylene was 6.25 μm, the thickness of the layer made of a blend resin was 2.5 μm, and the thickness of the layer made of high-density polyethylene was 2.5 μm.

[0191] A laminate was produced in the same manner as in Example 4-1, except that the base material was changed to the base material having a 7-layer structure produced as described above.

[0192] Example 4-4 The ethylene-vinyl alcohol copolymer was changed to polyamide (manufactured by Ube Industries, Ltd., 5033, melting point: 196 °C, density: 1.14 g / cm 3 ), and an intermediate layer was produced in the same manner as in Example 4-1, except for the change. In the intermediate layer thus obtained, the thickness of the surface resin layer composed of polyamide was 2 μm, the thickness of the adhesive resin layer was 3 μm, and the thickness of the polyethylene resin layer composed of medium-density polyethylene was 20 μm.

[0193] A laminate was produced in the same manner as in Example 4-1, except that the intermediate layer was changed to the intermediate layer produced as described above.

[0194] Example 4-5 Ethylene-vinyl alcohol copolymer (manufactured by Kuraray Co., Ltd., Eval E171B, melting point: 183 °C, density: 1.14 g / cm 3 ), adhesive resin (manufactured by Mitsui Chemicals, Inc., Admer NF557), medium-density polyethylene (manufactured by The Dow Chemical Company, Elite 5538, density: 0.941 g / cm 3 , melting point: 129 °C) and compatibilizer (manufactured by The Dow Chemical Company, maleic anhydride polyethylene, Retain 3000, density: 0.87 g / cm 3 ), and a blend resin containing them at a mass ratio of 8:2, medium-density polyethylene (manufactured by The Dow Chemical Company, Elite 5538, density: 0.941 g / cm 3 , melting point: 129 °C) were coextruded into a film by an inflation molding method and then stretched 5 times in the longitudinal direction (MD direction) by a stretching device to produce an intermediate layer. In the intermediate layer thus obtained, the thickness of the surface resin layer composed of ethylene-vinyl alcohol copolymer was 2 μm, the thickness of the adhesive resin layer was 3 μm, the thickness of the second polyethylene resin layer composed of blend resin was 10 μm, and the thickness of the first polyethylene resin layer composed of medium-density polyethylene was 10 μm.

[0195] A laminate was produced in the same manner as in Example 4-1, except that the intermediate layer was changed to the intermediate layer produced as described above.

[0196] Example 4-6 An intermediate layer was produced in the same manner as in Example 4-5, except that the ethylene-vinyl alcohol copolymer was changed to polyamide (manufactured by Ube Industries, Ltd., 5033, melting point: 196°C, density: 1.14 g / cm 3 ). In the intermediate layer thus obtained, the thickness of the surface resin layer composed of polyamide was 2 μm, the thickness of the adhesive resin layer was 3 μm, the thickness of the second polyethylene resin layer composed of the blend resin was 10 μm, and the thickness of the first polyethylene resin layer composed of medium-density polyethylene was 10 μm.

[0197] A laminate was produced in the same manner as in Example 4-1, except that the intermediate layer was changed to the intermediate layer produced as described above.

[0198] Comparative Example 4-1 Medium-density polyethylene (manufactured by Dow Chemical, Elite 5538, density: 0.941 g / cm 3 , melting point: 129°C) was extruded into a single-layer film by an inflation molding method, and then stretched 5 times in the longitudinal direction (MD direction) by a stretching device to produce a 25-μm stretched polyethylene film.

[0199] A laminate was produced in the same manner as in Example 4-1, except that the intermediate layer was changed to the stretched polyethylene film produced as described above.

[0200] Comparative Example 4-2 A biaxially stretched polyester film (manufactured by Toyobo Co., Ltd., E5100) with a thickness of 12 μm was prepared.

[0201] A laminate was produced in the same manner as in Example 4-1, except that the intermediate layer was changed to the above polyester film.

[0202] Example 5-1 Medium-density polyethylene (manufactured by Dow Chemical, Elite 5538, density: 0.941 g / cm 3 , melting point: 129 °C) was extruded into a single-layer film by the inflation method, and then stretched 5 times in the longitudinal direction (MD direction) by a stretching device to produce a substrate with a thickness of 25 μm.

[0203] 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 Medium-density polyethylene (manufactured by Dow Chemical, Elite 5538, density: 0.941 g / cm 3 , melting point: 129 °C), and were co-extruded into a film by the T-die method to obtain a sealant layer with a thickness of 40 μm. In the sealant layer thus obtained, the thickness of the surface resin layer composed of the ethylene-vinyl alcohol copolymer was 2 μm, the thickness of the adhesive resin layer was 3 μm, and the thickness of the polyethylene resin layer composed of medium-density polyethylene was 35 μm.

[0204] On the surface of the surface resin layer of the sealant layer, an aluminum vapor deposition film with a thickness of 30 nm was formed by the PVD method under the condition of a pressure of 3.0 × 10 -2 Pa.

[0205] The substrate and the vapor deposition film formation surface of the sealant layer were laminated via a two-component curable urethane-based adhesive (manufactured by Rock Paint Co., Ltd., Ru-77T / H-7) to obtain a laminate. The polyethylene content in the laminate was summarized in Table 3. Also, the laminates obtained in the following examples and comparative examples and the polyethylene content in the laminates were also summarized in Table 3.

[0206] Example 5-2 High-density polyethylene (manufactured by ExxonMobil, HTA108, density: 0.961 g / cm 3 , melting point: 135 °C), and medium-density polyethylene (manufactured by Dow Chemical, Elite5538, density: 0.941 g / cm 3 , melting point: 129 °C), and high-density polyethylene (manufactured by ExxonMobil, HTA108, density: 0.961 g / cm 3 , melting point: 135 °C), and were co-extruded into a film by the inflation molding method, and then stretched 5 times in the longitudinal direction (MD direction) by a stretching device to produce a base material. In the base material thus obtained, the thickness of the layer composed of high-density polyethylene was 5 μm, the thickness of the layer composed of medium-density polyethylene was 15 μm, and the thickness of the layer composed of high-density polyethylene was 5 μm.

[0207] A laminate was produced in the same manner as in Example 5-1, except that the base material was changed to a three-layer base material produced as described above.

[0208] Example 5-3 High-density polyethylene (manufactured by ExxonMobil, HTA108, density: 0.961 g / cm 3 , melting point: 135 °C), and high-density polyethylene (manufactured by ExxonMobil, HTA108, density: 0.961 g / cm 3 , melting point: 135 °C) and medium-density polyethylene (manufactured by Dow Chemical, Elite5538, density: 0.941 g / cm 3 , melting point: 129 °C), a blend resin containing them in a mass ratio of 4:6, and medium-density polyethylene (manufactured by Dow Chemical, Elite5538, density: 0.941 g / cm 3 , melting point: 129 °C), and ultra-low density polyethylene (manufactured by Dow Chemical, Affinity EG810G, density: 0.870 g / cm 3 , melting point: 55 °C), and Using the inflation molding method, from the outside, a tubular film comprising a layer made of high-density polyethylene, a layer made of a blend resin, a layer made of medium-density polyethylene, and a layer made of ultra-low-density polyethylene was extruded, and the layers made of the ultra-low-density polyethylene on the inside were crimped using a rubber roll. The film thus obtained had a layer made of high-density polyethylene, a layer made of a blend resin, a layer made of medium-density polyethylene, a layer made of ultra-low-density polyethylene, a layer made of medium-density polyethylene, a layer made of a blend resin, and a layer made of high-density polyethylene.

[0209] The film obtained as described above was stretched 5 times in the longitudinal direction (MD direction) using a stretching device to produce a base material. In the film thus obtained, the thickness of the layer made of high-density polyethylene was 2.5 μm, the layer made of the blend resin was 2.5 μm, the thickness of the layer made of medium-density polyethylene was 6.25 μm, the thickness of the layer made of ultra-low-density polyethylene was 2.5 μm, the thickness of the layer made of medium-density polyethylene was 6.25 μm, the thickness of the layer made of the blend resin was 2.5 μm, and the thickness of the layer made of high-density polyethylene was 2.5 μm.

[0210] A laminate was produced in the same manner as in Example 5-1, except that the base material was changed to the base material having a 7-layer structure produced as described above.

[0211] Example 5-4 An ethylene-vinyl alcohol copolymer was changed to polyamide (manufactured by Ube Industries, Ltd., 5033, melting point: 196 °C, density: 1.14 g / cm 3 ), and a sealant layer was produced in the same manner as in Example 5-1. In the sealant layer thus obtained, the thickness of the surface resin layer composed of polyamide was 2 μm, the thickness of the adhesive resin layer was 3 μm, and the thickness of the polyethylene resin layer composed of medium-density polyethylene was 35 μm.

[0212] A laminate was produced in the same manner as in Example 5-1, except that the sealant layer was changed to the sealant layer produced as described above.

[0213] Example 5-5 Ethylene-vinyl alcohol copolymer (manufactured by Kuraray Co., Ltd., Eval E171B, melting point: 183 °C, density: 1.14 g / cm 3 ) and Adhesive resin (manufactured by Mitsui Chemicals, Inc., Admer NF557) and Medium-density polyethylene (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 ) were included as a blend resin in a ratio of 8:2 by mass, and Medium-density polyethylene (manufactured by Dow Chemical, Elite 5538, density: 0.941 g / cm 3 , melting point: 129 °C) and were coextruded into a film by the T-die method to produce a sealant layer. In the sealant layer thus obtained, the thickness of the surface resin layer composed of ethylene-vinyl alcohol copolymer was 2 μm, the thickness of the adhesive resin layer was 3 μm, the thickness of the second polyethylene resin layer composed of blend resin was 10 μm, and the thickness of the first polyethylene resin layer composed of medium-density polyethylene was 10 μm.

[0214] A laminate was produced in the same manner as in Example 5-1, except that the sealant layer was changed to the sealant layer produced as described above.

[0215] Example 5-6 The ethylene-vinyl alcohol copolymer was changed to polyamide (manufactured by Ube Industries, Ltd., 5033, melting point: 196 °C, density: 1.14 g / cm 3 ), and a sealant layer was produced in the same manner as in Examples 1-5 except for this change. In the sealant layer thus obtained, the thickness of the surface resin layer composed of polyamide was 2 μm, the thickness of the adhesive resin layer was 3 μm, the thickness of the second polyethylene resin layer composed of the blend resin was 10 μm, and the thickness of the first polyethylene resin layer composed of medium-density polyethylene was 10 μm.

[0216] A laminate was produced in the same manner as in Example 5-1 except that the sealant layer was changed to the sealant layer produced as described above.

[0217] Comparative Example 5-1 Medium-density polyethylene (manufactured by Dow Chemical, Elite 5538, density: 0.941 g / cm 3 , melting point: 129 °C) was monolayer extruded and formed into a film by an inflation molding method to produce a 40-μm unstretched polyethylene film.

[0218] A laminate was produced in the same manner as in Example 5-1 except that the sealant layer was changed to the unstretched polyethylene film produced as described above.

[0219] [Gas barrier property evaluation] The laminates obtained in the examples and comparative examples and the oxygen permeability (cc / m 2 ·day·atm) and water vapor permeability (g / m 2 ·day) of the laminates were measured by the following method, and the results are summarized in Tables 1-3.

[0220] [Oxygen permeability] Using an oxygen permeability measuring device (manufactured by MOCON, OX-TRAN 2 / 20), the test piece was set so that the base material surface was on the oxygen supply side, and the oxygen permeability was measured in accordance with JIS K 7126 at 23 °C and a relative humidity of 90% RH. [Water vapor permeability] Using a water vapor permeability measuring device (PERMATRAN-w 3 / 33 manufactured by MOCON), the substrate surface of the test piece was set so that it was on the water vapor supply side, and in accordance with JIS K 7129, the water vapor permeability at 40 °C and a relative humidity of 90% RH was measured.

[0221] <<Lamination Strength Test>> The laminates obtained in the above Examples and Comparative Examples and samples obtained by cutting the laminates into strips 15 mm wide were used with a tensile tester (Tensilon universal material tester manufactured by Orientec Co., Ltd.) in accordance with JIS K6854-2. The lamination strength (N / 15 mm) between the vapor deposition film and the surface resin layer (in the Examples), and between the vapor deposition film and the polyethylene film or polyester film (in the Comparative Examples) was measured using 90° peeling (T-peeling method) at a peeling speed of 50 mm / min. The measurement results are summarized in Tables 1 to 3.

[0222]

Table 1

[0223]

Table 2

[0224]

Table 3

Explanation of Symbols

[0225] 10: Packaging bag, 20: Standing pouch, 31: Easy-opening means, 32: Notch portion, 33: Half-cut line, 41: Extraction nozzle portion, 42: Curved portion, 43: Cut-off portion, 50: Laminate according to the first aspect, 51: Base material, 52: Vapor deposition film, 53: Sealant layer, 54: Polyethylene resin layer, 55: Surface resin layer, 56: Adhesive resin layer, 60: Laminate according to the second aspect, 61: Base material, 62: Intermediate layer, 63: Sealant layer, 64: Vapor deposition film, 65: Surface resin layer, 66: Polyethylene resin layer, 67: Adhesive resin layer, 70: Laminate according to the third aspect, 71: Base material, 72: Vapor deposition film, 73: Sealant layer, 74: Surface resin layer, 75: Polyethylene resin layer, 76: Adhesive resin layer

Claims

1. A packaging bag comprising a laminate having at least a base material, a vapor deposition film, and a sealant layer, wherein the base material comprises at least a polyethylene resin layer and a surface resin layer, the sealant layer is made of a polyethylene resin, the polyethylene resin layer has a multilayer structure, the density difference of polyethylene between each layer in the multilayer structure is 0.04 g / cm 3 or less, 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, the base material is subjected to a stretching treatment, the content of polyethylene resin in the entire laminate is 80% by mass or more, A packaging bag.

2. The packaging bag 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. The packaging bag according to claim 1 or 2, wherein 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.

4. The packaging bag according to any one of claims 1 to 3, wherein the resin material of the surface resin layer is composed of a polymer having a polar group.

5. The packaging bag 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 packaging bag according to any one of claims 1 to 5, wherein the polyethylene resin layer comprises at least one layer containing a compatibilizer.

7. The packaging bag according to claim 6, wherein the surface resin layer is provided so as to be in contact with a layer containing a compatibilizer for the polyethylene resin layer.

8. The packaging bag according to any one of claims 1 to 7, wherein in the laminate, a barrier coat layer is further provided on the vapor deposition film.

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