Laminate, packaging material, packaging bag, and stand-up pouch

Abstract

To provide a laminate that can achieve a packaging material that has sufficient strength and heat resistance applicable as a packaging material, and also has excellent recyclability.SOLUTION: A laminate has a base material, and a heat seal layer. The base material is a stretched polyethylene film. The heat seal layer comprises polyethylene. At least one of the base material and the heat seal layer has, as polyethylene, biomass-derived polyethylene.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a laminate, a packaging material, a packaging bag, and a stand-up pouch.

Background Art

[0002] Conventionally, packaging materials and the like have been produced using resin films made of resin materials. For example, a resin film made of polyethylene has appropriate flexibility and transparency and excellent heat sealability, so it is widely used for packaging materials.

[0003] Normally, a resin film made of polyethylene is inferior in terms of strength and heat resistance, so it cannot be used as a base material and is used by laminating it with a resin film made of polyester, polyamide, or the like. Therefore, ordinary packaging materials and the like are composed of a laminated film in which the base material and the heat seal layer are made of different resin materials (for example, Patent Document 1).

[0004] In recent years, with the increasing demand for building a recycling-oriented society, packaging materials with high recyclability have been demanded to reduce the environmental load. However, conventional packages are composed of different resin materials as described above, and it is difficult to separate them for each resin material, so they are not recycled at present.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The inventors of the present invention have found that polyethylene, which was conventionally used as a heat-sealing layer, can be used as a base material by making it into a stretched resin film, and by laminating and using the base material with a heat-sealing layer made of polyethylene, it is possible to produce a packaging material or the like having sufficient strength and heat resistance and being recyclable. Furthermore, the inventors have found that by using polyethylene derived from biomass as the polyethylene, the environmental load of the produced packaging material or the like can be further reduced.

[0007] The present invention has been made in view of the above findings, and the problem to be solved is to provide a laminate that can realize a packaging material applicable as a packaging material, having sufficient strength and heat resistance and excellent recyclability. Another problem to be solved by the present invention is to provide a packaging material composed of the laminate.

Means for Solving the Problems

[0008] The laminate of the present invention includes a base material and a heat-sealing layer. The base material is a stretched polyethylene film. The heat-sealing layer is composed of polyethylene. At least one of the base material and the heat-sealing layer contains polyethylene derived from biomass as the polyethylene.

[0009] In one embodiment of the present invention, the base material and the heat-sealing layer contain polyethylene derived from biomass as the polyethylene.

[0010] In one embodiment of the present invention, the laminate includes a vapor deposition film between the base material and the heat-sealing layer.

[0011] In one embodiment of the present invention, the laminate includes an adhesive layer between the base material and the vapor deposition film. The vapor deposition film is an aluminum vapor deposition film. The next layer is composed of a cured product of a resin composition containing a polyester polyol, an isocyanate compound, and a phosphate-modified compound.

[0012] In one embodiment of the present invention, the laminate includes an intermediate layer between a base material and a heat-sealing layer. The intermediate layer includes a vapor deposition film and a polyethylene resin layer.

[0013] In one embodiment of the present invention, the polyethylene resin layer contains polyethylene derived from biomass as polyethylene.

[0014] In one embodiment of the present invention, the laminate includes an adhesive layer between the base material and the intermediate layer. The vapor deposition film is an aluminum vapor deposition film. The adhesive layer is composed of a cured product of a resin composition containing a polyester polyol, an isocyanate compound, and a phosphate-modified compound.

[0015] In one embodiment of the present invention, the base material includes a medium-density polyethylene layer.

[0016] In one embodiment of the present invention, the base material has a three-layer coextruded film structure of a high-density polyethylene layer, a medium-density polyethylene layer, and a high-density polyethylene layer.

[0017] In one embodiment of the present invention, the content of polyethylene in the entire laminate is 90% by mass or more.

[0018] In one embodiment of the present invention, the laminate is used for packaging materials.

[0019] The packaging material of the present invention is characterized by being produced using the above laminate.

[0020] The packaging bag of the present invention is produced using the above laminate, and is characterized in that the thickness of the heat-sealing layer is 20 μm or more and 60 μm or less.

[0021] The stand-up pouch of the present invention is manufactured using the above-described analysis device, and is characterized in that the thickness of the heat-sealing layer is 50 μm or more and 200 μm or less.

Advantages of the Invention

[0022] According to the present invention, it is possible to provide a laminate capable of realizing a packaging material having strength and heat resistance as a packaging material and excellent recyclability.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0024] <Laminate> The laminate according to the present invention will be described with reference to the drawings. As shown in FIG. 1, the laminate 10 includes a base material 11 and a heat-sealing layer 12.

[0025] Also, in one embodiment of the present invention, as shown in FIG. 2, the laminate 10 can include a vapor deposition film 13 between the base material 11 and the heat-sealing layer 12.

[0026] Further, in one embodiment of the present invention, as shown in FIG. 3, the laminate 10 can include an adhesive layer 14 between the base material 11 and the heat-sealing layer 12 or the vapor deposition film 13.

[0027] Also, in one embodiment of the present invention, as shown in FIG. 4, the laminate 10 can include an intermediate layer 17 including a vapor deposition film 15 and a polyethylene resin layer 16 between the base material 11 and the heat-sealing layer 12.

[0028] Furthermore, in one embodiment of the present invention, as shown in FIG. 5, the laminate 10 can include an adhesive layer 18 between the base material 11 and the intermediate layer 17 and between the intermediate layer 17 and the heat-sealing layer 12.

[0029] In the laminate of the present invention, the polyethylene content is preferably 90% by mass or more. By setting the polyethylene content in the entire laminate of the present invention to 90% by mass or more, the recyclability of the laminate of the present invention can be improved. Note that the polyethylene content in the laminate means the ratio of the polyethylene content to the sum of the resin material contents in each layer constituting the laminate.

[0030] Hereinafter, each layer constituting the laminate of the present invention will be described.

[0031] <Base Material> The base material included in the laminate of the present invention is made of polyethylene, and the heat-sealing layer described below is also made of polyethylene in the same manner. By adopting such a configuration, the recyclability of the laminate can be improved. Furthermore, in the present invention, at least one of the polyethylene and the heat-sealing layer constituting the base material contains biomass-derived polyethylene as polyethylene, whereby the packaging material produced from the laminate of the present invention can have less environmental impact.

[0032] The base material is composed of a stretched polyethylene film, which can improve the heat resistance and strength of the laminate. Also, the printability on the base material can be improved. The stretched polyethylene film may be a uniaxially stretched film or a biaxially stretched film.

[0033] The draw ratio in the machine direction (MD) of the stretched polyethylene film is preferably 2 times or more and 10 times or less, more preferably 3 times or more and 7 times or less. By setting the draw ratio in the machine direction (MD) of the stretched polyethylene film to 2 times or more, the strength and heat resistance of the laminate of the present invention can be improved. Further, the printability on the base material can be improved. Also, since the transparency of the base material can be improved, when an image is formed on the surface of the base material on the heat seal layer side, the visibility can be improved. On the other hand, the upper limit value of the draw ratio in the machine direction (MD) of the stretched polyethylene film is not particularly limited, but is preferably 10 times or less from the viewpoint of the breaking limit of the stretched polyethylene film.

[0034] Also, the draw ratio in the transverse direction (TD) of the stretched polyethylene film is preferably 2 times or more and 10 times or less, more preferably 3 times or more and 7 times or less. By setting the draw ratio in the transverse direction (TD) of the stretched polyethylene film to 2 times or more, the strength and heat resistance of the laminate of the present invention can be improved. Further, the printability on the base material can be improved. Also, since the transparency of the base material can be improved, when an image is formed on the surface of the base material on the heat seal layer side, the visibility can be improved. On the other hand, the upper limit value of the draw ratio in the transverse direction (TD) of the stretched polyethylene film is not particularly limited, but is preferably 10 times or less from the viewpoint of the breaking limit of the stretched polyethylene film.

[0035] The haze value of the stretched polyethylene film is preferably 30% or less, more preferably 20% or less. Thereby, the transparency of the stretched polyethylene film can be improved. In the present invention, the haze value of the stretched polyethylene film is measured in accordance with JIS K 7105.

[0036] An image may be formed on the surface of the base material. Since it is possible to prevent contact with the outside air and prevent deterioration over time, it is preferable that an image is formed on the surface side where the heat seal layer described below is provided. The image to be formed is not particularly limited, and characters, patterns, symbols, and combinations thereof are represented. Image formation on the base material is preferably performed using ink derived from biomass, whereby a packaging material with a lower environmental load can be produced using the laminate of the present invention. The method for forming the image 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. Among these, from the viewpoint of environmental load, the flexographic printing method is preferable.

[0037] As the polyethylene contained in the base material, high-density polyethylene (HDPE), medium-density polyethylene (MDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and very-low-density polyethylene (VLDPE) can be used. Here, as high-density polyethylene, polyethylene with a density of 0.945 g / cm 3 or higher can be used. As medium-density polyethylene, polyethylene with a density of 0.925 g / cm 3 or higher and less than 0.945 g / cm 3 can be used. As low-density polyethylene, polyethylene with a density of 0.900 g / cm 3 or higher and less than 0.925 g / cm 3 can be used. As linear low-density polyethylene, polyethylene with a density of 0.900 g / cm 3 or higher and less than 0.925 g / cm 3 can be used. As very-low-density polyethylene, polyethylene with a density of 0.900 g / cm 3Polyethylene less than that can be used. Among these, from the viewpoints of printability, strength and heat resistance of the laminate of the present invention, and stretching suitability of the film, high-density polyethylene and medium-density polyethylene are preferable, and from the viewpoint of stretching suitability, medium-density polyethylene is more preferable.

[0038] In one embodiment, as the base material, a structure including a layer made of high-density polyethylene (hereinafter referred to as a high-density polyethylene layer) and a layer made of medium-density polyethylene (hereinafter referred to as a medium-density polyethylene layer) can be used. By providing a high-density polyethylene layer on the outside of the base material, the strength and heat resistance of the laminate of the present invention can be further improved. Also, by providing a medium-density polyethylene layer, the stretching suitability of the stretched polyethylene film constituting the base material can be further improved.

[0039] For example, from the outside, it has a structure of a co-extruded film of a high-density polyethylene layer and a medium-density polyethylene layer. By adopting such a structure, the stretching suitability of the stretched polyethylene film can be improved. Also, the strength and heat resistance of the laminate of the present invention can be improved. At this time, the thickness of the high-density polyethylene layer is preferably thinner than the thickness of the medium-density polyethylene layer. The ratio of the thickness of the high-density polyethylene layer to the thickness of the medium-density polyethylene layer is preferably from 1 / 10 or more to 1 / 1 or less, and more preferably from 1 / 5 or more to 1 / 2 or less. By setting the ratio of the thickness of the high-density polyethylene layer to the thickness of the medium-density polyethylene layer to 1 / 10 or more, the strength and heat resistance of the laminate of the present invention can be further improved. Also, by setting the ratio of the thickness of the high-density polyethylene layer to the thickness of the medium-density polyethylene layer to 1 / 1 or less, the stretching suitability of the stretched polyethylene film can be further improved.

[0040] Further, for example, it is also possible to adopt a structure of a three-layer co-extruded film including a high-density polyethylene layer, a medium-density polyethylene layer, and a high-density polyethylene layer from the outside. By adopting such a structure, the drawability of the stretched polyethylene film can be further improved. In addition, the strength and heat resistance of the laminate of the present invention can be further improved. Furthermore, the occurrence of curl in the base material can be prevented. At this time, the thickness of the high-density polyethylene layer is preferably thinner than the thickness of the medium-density polyethylene layer. The ratio of the thickness of the high-density polyethylene layer to the thickness of the medium-density polyethylene layer is preferably from 1 / 10 or more to 1 / 1 or less, and more preferably from 1 / 5 or more to 1 / 2 or less. By setting the ratio of the thickness of the high-density polyethylene layer to the thickness of the medium-density polyethylene layer to 1 / 10 or more, the strength and heat resistance of the laminate of the present invention can be further improved. Also, by setting the ratio of the thickness of the high-density polyethylene layer to the thickness of the medium-density polyethylene layer to 1 / 1 or less, the drawability of the stretched polyethylene film can be further improved.

[0041] Further, for example, it is also possible to adopt a structure of a five-layer co-extruded film including a high-density polyethylene layer, a medium-density polyethylene layer, a low-density polyethylene layer, a linear low-density polyethylene layer, or an ultra-low-density polyethylene layer (in this paragraph, for the sake of simplicity of description, they are collectively referred to as a low-density polyethylene layer), a medium-density polyethylene layer, and a high-density polyethylene layer from the outside. By adopting such a structure, the drawability of the film can be improved. In addition, the strength and heat resistance of the laminate of the present invention can be improved. Also, the occurrence of curl in the base material can be prevented. Furthermore, the production efficiency of the film can be improved as described below. At this time, the thickness of the high-density polyethylene layer is preferably thinner than the thickness of the medium-density polyethylene layer. The ratio of the thickness of the high-density polyethylene layer to the thickness of the medium-density polyethylene layer is preferably 1 / 10 or more and 1 / 1 or less, and more preferably 1 / 5 or more and 1 / 2 or less. By setting the ratio of the thickness of the high-density polyethylene layer to the thickness of the medium-density polyethylene layer to 1 / 10 or more, the strength and heat resistance of the laminate of the present invention can be improved. Further, by setting the ratio of the thickness of the high-density polyethylene layer to the thickness of the medium-density polyethylene layer to 1 / 1 or less, the drawability of the film can be improved. Also, the thickness of the high-density polyethylene layer is preferably the same as or thicker than the thickness of the low-density polyethylene layer. The ratio of the thickness of the high-density polyethylene layer to the thickness of the low-density polyethylene layer is preferably 1 / 0.25 or more and 1 / 2 or less, and more preferably 1 / 0.5 or more and 1 / 1 or less. By setting the ratio of the thickness of the high-density polyethylene layer to the thickness of the low-density polyethylene layer to 1 / 0.25 or more, the heat resistance can be improved. Further, by setting the ratio of the thickness of the high-density polyethylene layer to the thickness of the low-density polyethylene layer to 1 / 1 or less, the adhesion between the medium-density polyethylene layers can be improved. In one embodiment, a substrate having such a configuration can be produced, for example, by an inflation method. Specifically, from the outside, high-density polyethylene, a medium-density polyethylene layer, and a low-density polyethylene layer, a linear low-density polyethylene layer, or an ultra-low-density polyethylene layer are co-extruded in a tubular shape, and then the opposing low-density polyethylene layers, linear low-density polyethylene layers, or ultra-low-density polyethylene layers are pressure-bonded to each other using a rubber roll or the like. By producing by such a method, the number of defective products in production can be significantly reduced, and ultimately, the production efficiency can be improved. Also, in an inflation film-forming machine, stretching can be performed together, whereby the production efficiency can be further improved.

[0042] Polyethylenes with different densities and branches as described above can be obtained by appropriately selecting the polymerization method. For example, as the polymerization catalyst, a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as a metallocene-based catalyst is used, and it is preferably carried out in one or two or more multi-steps by any of the methods of gas-phase polymerization, slurry polymerization, solution polymerization, and high-pressure ionic polymerization.

[0043] The above single-site catalyst is a catalyst capable of forming a uniform active species, and is usually adjusted by bringing a metallocene-based transition metal compound or a non-metallocene-based transition metal compound into contact with an activating cocatalyst. The single-site catalyst is preferable because, compared with the multi-site catalyst, the active site structure is uniform, and thus a polymer having a high molecular weight and a high degree of uniformity can be polymerized. As the single-site catalyst, it is particularly preferable to use a metallocene-based catalyst. The metallocene-based catalyst is a catalyst containing a transition metal compound of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton, a cocatalyst, an organometallic compound if necessary, and each catalyst component of a carrier.

[0044] In the transition metal compound of Group IV of the periodic table containing a ligand having the above cyclopentadienyl skeleton, the cyclopentadienyl skeleton is a cyclopentadienyl group, a substituted cyclopentadienyl group, etc. The substituted cyclopentadienyl group has at least one substituent selected from hydrocarbon groups having 1 to 30 carbon atoms, silyl groups, silyl-substituted alkyl groups, silyl-substituted aryl groups, cyano groups, cyanoalkyl groups, cyanoaryl groups, halogen groups, haloalkyl groups, halosilyl groups, etc. The substituted cyclopentadienyl group may have two or more substituents, and the substituents may be bonded to each other to form a ring, such as an indenyl ring, a fluorenyl ring, an azulene ring, or a hydrogenated product thereof. The rings formed by the substituents bonding to each other may further have substituents.

[0045] In a Group 4 transition metal compound containing a ligand having a cyclopentadienyl skeleton, examples of the transition metal include zirconium, titanium, hafnium, etc., and zirconium and hafnium are particularly preferred. The transition metal compound usually has two ligands having a cyclopentadienyl skeleton, and it is preferred that the ligands having each cyclopentadienyl skeleton are bonded to each other by a bridging group. Examples of the bridging group include an alkylene group having 1 to 4 carbon atoms, a silylene group, a dialkylsilylene group, a substituted silylene group such as a diarylsilylene group, a dialkylgermylene group, a substituted germylene group such as a diarylgermylene group, etc. Preferably, it is a substituted silylene group. The Group 4 transition metal compound containing the ligand having the above cyclopentadienyl skeleton can be a catalyst component in the form of one kind or a mixture of two or more kinds.

[0046] The cocatalyst refers to one that can effectively deactivate the above Group 4 transition metal compound as a polymerization catalyst or can balance the ionic charges in a catalytically activated state. Examples of the cocatalyst include a benzene-soluble aluminoxane or a benzene-insoluble organoaluminum oxy compound of an organoaluminum oxy compound, an ion-exchangeable layered silicate, a boron compound, an ionic compound composed of a cation containing or not containing an active hydrogen group and a non-coordinating anion, a lanthanoid salt such as lanthanum oxide, tin oxide, a phenoxy compound containing a fluoro group, etc.

[0047] The Group 4 transition metal compound containing a ligand having a cyclopentadienyl skeleton may be used after being supported on an inorganic or organic compound carrier. The carrier is preferably a porous oxide of an inorganic or organic compound, and specifically, examples include an ion-exchangeable layered silicate such as montmorillonite, SiO2, Al2O3, MgO, ZrO2, TiO2, B2O3, CaO, ZnO, BaO, ThO2, etc. or a mixture thereof. Further examples of the organometallic compound that may be used as required include an organoaluminum compound, an organomagnesium compound, an organozinc compound, etc. Among these, organoaluminum is preferably used.

[0048] Also, within the range that does not impair the characteristics of the present invention, a copolymer of ethylene and other monomers can also be used. Examples of the ethylene copolymer include copolymers composed of ethylene and α-olefins having 3 to 20 carbon atoms. Examples of the α-olefins having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 3-methyl-1-butene, 4-methyl-1-pentene, and 6-methyl-1-heptene. Also, within the range that does not impair the object of the present invention, a copolymer with vinyl acetate or acrylic ester may also be used.

[0049] Also, in one embodiment, in the present invention, the polyethylene constituting the base material is preferably polyethylene derived from biomass. Polyethylene derived from biomass means that ethylene derived from biomass is used instead of ethylene obtained from fossil fuels as a raw material. Since such polyethylene derived from biomass is a carbon-neutral material, it can be made into a packaging material with even less environmental impact.

[0050] In one embodiment, ethylene derived from plants can be obtained by fermenting sugar solutions or starches obtained from plants such as sugarcane, corn, and sweet potatoes with microorganisms such as yeast to produce bioethanol, and then heating this in the presence of a catalyst. Also, commercially available polyethylene derived from biomass (for example, Green PE commercially available from Braskem) may be used.

[0051] Also, in one embodiment, polyethylene recycled by mechanical recycling can also be used as the polyethylene. Here, mechanical recycling generally refers to a method in which a recovered polyethylene film or the like is pulverized, alkali-washed to remove dirt and foreign substances on the film surface, and then dried under high temperature and reduced pressure for a certain period of time to diffuse and remove contaminants remaining inside the film, removing the dirt on the film made of polyethylene and returning it to polyethylene again.

[0052] The base material can contain additives within a range that does not impair the characteristics of the present invention. For example, crosslinking agents, antioxidants, anti-blocking agents, slip agents, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, and modifying resins can be mentioned.

[0053] The base material may have a vapor deposition film described below on its surface.

[0054] Also, it is preferable that the surface of the base material is 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 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. Also, an anchor coat layer may be formed on the surface of the base material using a conventionally known anchor coat agent.

[0055] The thickness of the base material is preferably 10 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 to 10 μm or more, the strength of the laminate of the present invention can be improved. Also, by setting the thickness of the base material to 50 μm or less, the processability of the laminate of the present invention can be improved.

[0056] The base material can be produced by forming a film of polyethylene by the T-die method or the inflation method, etc., and then stretching the film after producing the film.

[0057] When producing the base material by the T-die method, the MFR of polyethylene is preferably 3 g / 10 min or more and 20 g / 10 min or less. By setting the MFR of polyethylene to 3 g / 10 min or more, the processability of the laminate of the present invention can be improved. Also, by setting the MFR of polyethylene to 20 g / 10 min or less, it is possible to prevent the polyethylene film from breaking.

[0058] When producing the base material by the inflation method, the MFR of polyethylene is preferably 0.5 g / 10 min or more and 5 g / 10 min or less. By setting the MFR of polyethylene to 0.5 g / 10 min or more, the processability of the laminate of the present invention can be improved. Also, by setting the MFR of polyethylene to 5 g / 10 min or less, the film-forming property can be improved.

[0059] Note that the base material is not limited to that produced by the above method, and commercially available ones may be used.

[0060] <Heat seal layer> The heat seal layer provided in the laminate of the present invention is characterized in that, like the above-described base material, it is composed of polyethylene. By adopting such a configuration, it is possible to produce a packaging material having sufficient strength and heat resistance and being recyclable. Also, it is possible to obtain a packaging material excellent in gas barrier properties, particularly oxygen barrier properties and water vapor barrier properties. Further, in the present invention, from the viewpoint of environmental load, the heat seal layer preferably contains polyethylene derived from biomass as polyethylene. Note that the polyethylene resin layer is formed by an unstretched polyethylene film or by melt extrusion of polyethylene.

[0061] As for the polyethylene constituting the heat-sealing layer, from the viewpoint of heat-sealing property, low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and very-low-density polyethylene (VLDPE) are preferable. Within a range not impairing the characteristics of the present invention, a copolymer of ethylene and other monomers can be used. Also, in one embodiment, as the polyethylene, polyethylene recycled by mechanical recycling can be used.

[0062] The heat-sealing layer can contain the above additives within a range not impairing the characteristics of the present invention.

[0063] In one embodiment, the heat-sealing layer has a multilayer structure and includes, as an intermediate layer, a layer containing at least one of medium-density polyethylene and high-density polyethylene. Specifically, it can be configured as a structure including a layer containing at least any one of low-density polyethylene, linear low-density polyethylene, and very-low-density polyethylene / a layer containing at least any one of medium-density polyethylene and high-density polyethylene / a layer containing at least any one of low-density polyethylene, linear low-density polyethylene, and very-low-density polyethylene. By adopting such a configuration, it is possible to further improve the bag-making suitability and strength of the laminate of the present invention while maintaining the heat-sealing property.

[0064] The thickness of the heat-sealing layer is preferably appropriately changed according to the weight of the content filled in the packaging material produced by the laminate of the present invention. For example, when producing a packaging bag 20 as shown in Fig. 6 filled with a content of 1 g or more and 200 g or less, the thickness of the heat-sealing layer is preferably 20 μm or more and 60 μm or less. By setting the thickness of the heat-sealing layer to 20 μm or more, it is possible to prevent the filled content from leaking due to the breakage of the heat-sealing layer. Also, by setting the heat-sealing layer to 60 μm or less, the processing suitability of the laminate of the present invention can be improved.

[0065] Further, for example, when manufacturing the stand-up pouch 30 as shown in FIG. 7 filled with a content of 50 g or more and 2000 g or less, the thickness of the heat-sealing layer is preferably 50 μm or more and 200 μm or less. By setting the thickness of the heat-sealing layer to 50 μm or more, it is possible to prevent the filled content from leaking due to damage to the heat-sealing layer. Further, by setting the thickness of the heat-sealing layer to 200 μm or less, the processability of the laminate of the present invention can be improved. Note that the hatched portions in FIGS. 6 and 7 are heat-sealed portions.

[0066] <Vapor-deposited film> The laminate of the present invention can include a vapor-deposited film between the base material and the heat-sealing layer. Thereby, the gas barrier properties of the laminate, specifically, the oxygen barrier property and the water vapor barrier property can be improved.

[0067] Examples of the vapor-deposited film include vapor-deposited films composed of metals such as aluminum and inorganic oxides such as aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, and barium oxide.

[0068] Also, the thickness of the vapor-deposited 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-deposited film to 1 nm or more, the oxygen barrier property and the water vapor barrier property of the laminate of the present invention can be further improved. Further, by setting the thickness of the vapor-deposited film to 150 nm or less, the generation of cracks in the vapor-deposited film can be prevented and the recyclability of the laminate of the present invention can be improved.

[0069] For the vapor deposition film to be an aluminum vapor deposition film, its OD value is preferably 2 or more and 3.5 or less. Thereby, while maintaining the productivity of the laminate of the present invention, the oxygen barrier property and the water vapor barrier property can be improved. In the present invention, the OD value can be measured in accordance with JIS-K-7361.

[0070] The vapor deposition film can be formed using a conventionally known method, for example, physical vapor deposition methods (Physical Vapor Deposition method, PVD method) such as vacuum vapor deposition method, sputtering method, and ion plating method, and chemical vapor deposition methods (Chemical Vapor Deposition method, CVD method) such as plasma chemical vapor deposition method, thermal chemical vapor deposition method, and photo chemical vapor deposition method, etc. can be mentioned.

[0071] Also, for example, a composite film composed of two or more layers of vapor deposition films of different inorganic oxides can be formed and used by combining both a physical vapor deposition method and a chemical vapor deposition method. As the degree of vacuum in the vapor deposition chamber, before oxygen introduction, it is preferably about 10-2 to 10 -8 mbar, and after oxygen introduction, it is preferably about 10-1 to 10 -6 mbar. Note that the amount of oxygen introduced etc. varies depending on the size of the vapor deposition machine etc. As the oxygen to be introduced, an inert gas such as argon gas, helium gas, or nitrogen gas may be used as a carrier gas within a non-obstructive range. The conveyance speed of the film can be about 10 to 800 m / min.

[0072] The surface of the vapor deposition film is preferably subjected to the above surface treatment. Thereby, the adhesion with an adjacent layer can be improved.

[0073] <Adhesive layer> In one embodiment, the laminate of the present invention can include an adhesive layer between a base material and a heat seal layer or a vapor deposition film. Thereby, the adhesion between these layers can be improved. Also, in one embodiment, the laminate of the laminate can include an adhesive layer between the base material and the intermediate layer described below, and between the intermediate layer and the heat seal layer.

[0074] The adhesive layer contains at least one type of adhesive, and 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, but from the perspective of environmental impact, a solventless adhesive can preferably be 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 preferably be used. Examples of the solvent-based adhesive include rubber-based adhesives, vinyl-based adhesives, silicone-based adhesives, epoxy-based adhesives, phenol-based adhesives, and olefin-based adhesives.

[0075] Also, when providing the adhesive layer adjacent to the vapor deposition film which is an aluminum vapor deposition film, it is preferable to configure the adhesive layer with a cured product of a resin composition containing a polyester polyol, an isocyanate compound, and a phosphoric acid-modified compound. By configuring the adhesive layer in this way, the oxygen barrier property and water vapor barrier property of the laminate of the present invention can be further improved. Also, when applying the laminate provided with the vapor deposition film to a packaging material, since a bending load is applied to the laminate by a molding machine or the like, there is a risk of cracks or the like occurring in the aluminum vapor deposition film. By using the specific adhesive as described above, even when cracks occur in the aluminum vapor deposition film, a decrease in the oxygen barrier property and water vapor barrier property can be suppressed.

[0076] The polyester polyol has two or more hydroxyl groups in one molecule as a functional group. Also, the isocyanate compound has two or more isocyanate groups in one molecule as a functional group. The polyester polyol has, as its main skeleton, for example, a polyester structure or a polyester polyurethane structure.

[0077] As a specific example of the resin composition containing a polyester polyol, an isocyanate compound, and a phosphate-modified compound, the series of PASLIM sold by DIC Corporation can be used.

[0078] The resin composition may further contain a plate-like inorganic compound, a coupling agent, cyclodextrin, and / or its derivative, etc.

[0079] As the polyester polyol having two or more hydroxyl groups in one molecule as a functional group, for example, the following [First Example] to [Third Example] can be used. [First Example] A polyester polyol obtained by polycondensing an ortho-oriented polyvalent carboxylic acid or its anhydride and a polyhydric alcohol [Second Example] A polyester polyol having a glycerol skeleton [Third Example] A polyester polyol having an isocyanurate ring Hereinafter, each polyester polyol will be described.

[0080] The polyester polyol according to the first example is a polycondensate obtained by polycondensing a polyvalent carboxylic acid component containing at least one or more of phthalic acid and its anhydride, and a polyhydric alcohol component containing at least one selected from the group consisting of ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, and cyclohexanedimethanol. In particular, a polyester polyol in which the content of phthalic acid and its anhydride in the total polyvalent carboxylic acid component is 70 to 100% by mass is preferable.

[0081] The polyester polyol according to the first example requires phthalic acid and its anhydride as the polyvalent carboxylic acid component, but other polyvalent carboxylic acid components may be copolymerized within a range not impairing the effects of the present embodiment. Specifically, aliphatic polycarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, and dodecanedicarboxylic acid; unsaturated bond-containing polycarboxylic acids such as maleic anhydride, maleic acid, and fumaric acid; alicyclic polycarboxylic acids such as 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid; aromatic polycarboxylic acids such as terephthalic acid, isophthalic acid, pyromellitic acid, trimellitic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid, anhydrides of these dicarboxylic acids, and ester-forming derivatives of these dicarboxylic acids; polybasic acids such as p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid, and ester-forming derivatives of these dihydroxycarboxylic acids, etc. Among these, succinic acid, 1,3-cyclopentanedicarboxylic acid, and isophthalic acid are preferred. Note that two or more of the above other polycarboxylic acids may be used.

[0082] As the polyester polyol according to the second example, a polyester polyol having a glycerol skeleton represented by the general formula (1) can be mentioned.

Chemical formula

Chemical formula

[0083] In the formula (2), n represents an integer of 1 to 5, X represents an arylene group selected from the group consisting of a 1,2-phenylene group, 1,2-naphthylene group, 2,3-naphthylene group, 2,3-anthraquinonediyl group, and 2,3-anthracenediyl group which may have a substituent, and Y represents an alkylene group having 2 to 6 carbon atoms. However, at least one of R1, R2, and R3 represents a group represented by the general formula (2).

[0084] In the general formula (1), at least one of R1, R2, and R3 needs to be a group represented by the general formula (2). Among them, it is preferable that all of R1, R2, and R3 are groups represented by the general formula (2).

[0085] Moreover, a compound in which any one of R1, R2, and R3 is a group represented by the general formula (2), a compound in which any two of R1, R2, and R3 are groups represented by the general formula (2), and a compound in which all of R1, R2, and R3 are groups represented by the general formula (2) may be a mixture of any two or more of these compounds.

[0086] X is selected from the group consisting of a 1,2-phenylene group, a 1,2-naphthylene group, a 2,3-naphthylene group, a 2,3-anthraquinonediyl group, and a 2,3-anthracenediyl group, and represents an arylene group which may have a substituent. When X is substituted by a substituent, it may be substituted by one or more substituents, and the substituent is bonded to any carbon atom on X that is different from the free radical. Examples of the substituent include a chloro group, a bromo group, a methyl group, an ethyl group, an i-propyl group, a hydroxyl group, a methoxy group, an ethoxy group, a phenoxy group, a methylthio group, a phenylthio group, a cyano group, a nitro group, an amino group, a phthalimide group, a carboxyl group, a carbamoyl group, an N-ethylcarbamoyl group, a phenyl group, and a naphthyl group.

[0087] In the general formula (2), Y represents an alkylene group having 2 to 6 carbon atoms such as an ethylene group, a propylene group, a butylene group, a neopentylene group, a 1,5-pentylene group, a 3-methyl-1,5-pentylene group, a 1,6-hexylene group, a methylpentylene group, and a dimethylbutylene group. Among them, Y is preferably a propylene group and an ethylene group, and most preferably an ethylene group.

[0088] The polyester resin compound having a glycerol backbone represented by the general formula (1) can be synthesized by reacting glycerol, an aromatic polyvalent carboxylic acid in which a carboxylic acid is substituted at the ortho position or its anhydride, and a polyhydric alcohol component as essential components.

[0089] Examples of the aromatic polyvalent carboxylic acid in which a carboxylic acid is substituted at the ortho position or its anhydride include phthalic acid or its anhydride, naphthalene 2,3-dicarboxylic acid or its anhydride, naphthalene 1,2-dicarboxylic acid or its anhydride, anthraquinone 2,3-dicarboxylic acid or its anhydride, and 2,3-anthracene carboxylic acid or its anhydride. These compounds may have a substituent on any carbon atom of the aromatic ring. Examples of the substituent include a chloro group, a bromo group, a methyl group, an ethyl group, an i-propyl group, a hydroxyl group, a methoxy group, an ethoxy group, a phenoxy group, a methylthio group, a phenylthio group, a cyano group, a nitro group, an amino group, a phthalimide group, a carboxyl group, a carbamoyl group, an N-ethylcarbamoyl group, a phenyl group, and a naphthyl group.

[0090] Examples of the polyhydric alcohol component include alkylene diols having 2 to 6 carbon atoms. For example, diols such as ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol, and dimethylbutanediol can be exemplified.

[0091] The polyester polyol according to the third example is a polyester polyol having an isocyanurate ring represented by the following general formula (3).

Chemical formula

[0092] In the general formula (4), n2 represents an integer from 2 to 4, n3 represents an integer from 1 to 5, X represents an arylene group selected from the group consisting of a 1,2-phenylene group, a 1,2-naphthylene group, a 2,3-naphthylene group, a 2,3-anthraquinonediyl group, and a 2,3-anthracenediyl group, which may have a substituent, and Y represents an alkylene group having 2 to 6 carbon atoms). However, at least one of R1, R2, and R3 is a group represented by the general formula (4).

[0093] In the general formula (3), the alkylene group represented by -(CH2)n1- may be linear or branched. n1 is preferably 2 or 3, and most preferably 2.

[0094] In the general formula (4), n2 represents an integer from 2 to 4, and n3 represents an integer from 1 to 5. X represents an arylene group selected from the group consisting of a 1,2-phenylene group, a 1,2-naphthylene group, a 2,3-naphthylene group, a 2,3-anthraquinonediyl group, and a 2,3-anthracenediyl group, which may have a substituent.

[0095] When X is substituted by a substituent, it may be substituted by one or more substituents, and the substituent is bonded to any carbon atom on X that is different from the free radical. Examples of the substituent include a chloro group, a bromo group, a methyl group, an ethyl group, an i-propyl group, a hydroxyl group, a methoxy group, an ethoxy group, a phenoxy group, a methylthio group, a phenylthio group, a cyano group, a nitro group, an amino group, a phthalimide group, a carboxyl group, a carbamoyl group, an N-ethylcarbamoyl group, a phenyl group, and a naphthyl group. The substituents of X are preferably a hydroxyl group, a cyano group, a nitro group, an amino group, a phthalimide group, a carbamoyl group, an N-ethylcarbamoyl group, and a phenyl group, and most preferably a hydroxyl group, a phenoxy group, a cyano group, a nitro group, a phthalimide group, and a phenyl group.

[0096] In general formula (4), Y represents an alkylene group having 2 to 6 carbon atoms such as an ethylene group, a propylene group, a butylene group, a neopentylene group, a 1,5-pentylene group, a 3-methyl-1,5-pentylene group, a 1,6-hexylene group, a methylpentylene group, and a dimethylbutylene group. Among them, the propylene group and the ethylene group are preferable for Y, and the ethylene group is most preferable.

[0097] In general formula (3), at least one of R1, R2, and R3 is a group represented by general formula (4). Among them, it is preferable that all of R1, R2, and R3 are groups represented by general formula (4).

[0098] Further, any two or more compounds of a compound in which any one of R1, R2, and R3 is a group represented by general formula (4), a compound in which any two of R1, R2, and R3 are groups represented by general formula (4), and a compound in which all of R1, R2, and R3 are groups represented by general formula (4) may be in a mixture.

[0099] The polyester polyol having an isocyanurate ring represented by general formula (3) can be synthesized by reacting a triol having an isocyanurate ring, an aromatic polyvalent carboxylic acid in which a carboxylic acid is substituted at the ortho position or its anhydride, and a polyhydric alcohol component as essential components.

[0100] Examples of the triol having an isocyanurate ring include alkylene oxide adducts of isocyanuric acid such as 1,3,5-tris(2-hydroxyethyl)isocyanuric acid and 1,3,5-tris(2-hydroxypropyl)isocyanuric acid.

[0101] In addition, examples of the aromatic polyvalent carboxylic acid or its anhydride in which a carboxylic acid is substituted at the ortho position include phthalic acid or its anhydride, naphthalene 2,3-dicarboxylic acid or its anhydride, naphthalene 1,2-dicarboxylic acid or its anhydride, anthraquinone 2,3-dicarboxylic acid or its anhydride, and 2,3-anthracene dicarboxylic acid or its anhydride. These compounds may have substituents on any carbon atom of the aromatic ring.

[0102] Examples of the substituent include a chloro group, a bromo group, a methyl group, an ethyl group, an i-propyl group, a hydroxyl group, a methoxy group, an ethoxy group, a phenoxy group, a methylthio group, a phenylthio group, a cyano group, a nitro group, an amino group, a phthalimide group, a carboxyl group, a carbamoyl group, an N-ethylcarbamoyl group, a phenyl group, and a naphthyl group.

[0103] In addition, examples of the polyhydric alcohol component include alkylene diols having 2 to 6 carbon atoms. For example, diols such as ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol, and dimethylbutanediol can be mentioned. Among them, a polyester polyol compound having an isocyanurate ring, which uses 1,3,5-tris(2-hydroxyethyl)isocyanuric acid or 1,3,5-tris(2-hydroxypropyl)isocyanuric acid as the triol compound having an isocyanurate ring, phthalic anhydride as the aromatic polyvalent carboxylic acid or its anhydride in which a carboxylic acid is substituted at the ortho position, and ethylene glycol as the polyhydric alcohol, is particularly preferable because of its excellent oxygen barrier properties and adhesiveness.

[0104] The isocyanurate ring is highly polar and trifunctional, can increase the polarity of the entire system, and can increase the crosslink density. From such a viewpoint, it is preferable to contain 5% by mass or more of the isocyanurate ring based on the total solid content of the adhesive resin.

[0105] The isocyanate compound has two or more isocyanate groups in the molecule. The isocyanate compound may be aromatic, aliphatic, a low molecular weight compound, or a high molecular weight compound. Furthermore, the isocyanate compound may be a blocked isocyanate compound obtained by an addition reaction using a known isocyanate blocking agent by a known and commonly used appropriate method. Among them, from the viewpoints of adhesiveness and retort resistance, a polyisocyanate compound having three or more isocyanate groups is preferable, and from the viewpoints of oxygen barrier property and water vapor barrier property, being aromatic is preferable.

[0106] Specific examples of the isocyanate compound include, for example, tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, metaxylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, and trimers of these isocyanate compounds, as well as adducts, burettes, and allophanates obtained by reacting these isocyanate compounds with a low molecular weight active hydrogen compound or its alkylene oxide adduct, or a high molecular weight active hydrogen compound. Examples of the low molecular weight active hydrogen compound include ethylene glycol, propylene glycol, metaxylylene alcohol, 1,3-bis(hydroxyethyl)benzene, 1,4-bis(hydroxyethyl)benzene, trimethylolpropane, glycerol, pentaerythritol, erythritol, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine, and metaxylylene diamine. Examples of the molecular active hydrogen compound include various polyester resins, polyether polyols, and high molecular weight active hydrogen compounds of polyamides.

[0107] The phosphoric acid-modified compound is, for example, a compound represented by the following general formula (5) or (6). [Chemical formula] In general formula (5), R1, R2, and R3 are groups selected from a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a (meth)acryloyl group, a phenyl group which may have a substituent, and an alkyl group having 1 to 4 carbon atoms and having a (meth)acryloyloxy group, provided that at least one of them is a hydrogen atom, and n represents an integer of 1 to 4. [Chemical formula] In the formula, R4 and R5 are groups selected from a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a (meth)acryloyl group, a phenyl group which may have a substituent, and an alkyl group having 1 to 4 carbon atoms and having a (meth)acryloyloxy group, n is an integer of 1 to 4, x is an integer of 0 to 30, and y is an integer of 0 to 30, provided that the case where both x and y are 0 is excluded.

[0108] More specifically, phosphoric acid, pyrophosphoric acid, triphosphoric acid, methyl acid phosphate, ethyl acid phosphate, butyl acid phosphate, dibutyl phosphate, 2-ethylhexyl acid phosphate, bis(2-ethylhexyl) phosphate, isododecyl acid phosphate, butoxyethyl acid phosphate, oleyl acid phosphate, tetracosyl acid phosphate, 2-hydroxyethyl methacrylate acid phosphate, and polyoxyethylene alkyl ether phosphate, etc. may be mentioned, and one or more of these can be used.

[0109] The content of the phosphoric acid-modified compound in the resin composition is preferably 0.005% by mass or more and 10% by mass or less, and more preferably 0.01% by mass or more and 1% by mass or less. By setting the content of the phosphoric acid-modified compound to 0.005% by mass or more, the oxygen barrier property and water vapor barrier property of the laminate of the present invention can be improved. Further, by setting the content of the phosphoric acid-modified compound to 10% by mass or less, the adhesiveness of the adhesive layer can be improved.

[0110] A resin composition containing a polyester polyol, an isocyanate compound, and a phosphate-modified compound may contain a plate-like inorganic compound, whereby the adhesiveness of the adhesive layer can be improved. Further, the flexural load resistance of the laminate of the present invention can be improved. Examples of the plate-like inorganic compound include kaolinite-serpentine group clay minerals (halloysite, kaolinite, endellite, dickite, nacrite, antigorite, chrysotile, etc.) and pyrophyllite-talc group (pyrophyllite, talc, kerolite, etc.).

[0111] Examples of the coupling agent include silane-based coupling agents, titanium-based coupling agents, and aluminum-based coupling agents represented by the following general formula (7). These coupling agents may be used alone or in combination of two or more.

Chemical formula

[0112] Examples of silane coupling agents include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloxytrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, N-β(aminoethyl)γ-aminopropylmethyldimethoxysilane, N-β(aminoethyl)γ-aminopropyltrimethoxysilane, N-β(aminoethyl)γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, and 3-triethoxysilyl-N-(1,3-dimethyl-butylidene).

[0113] In addition, examples of the titanium-based coupling agent include isopropyltriisostearoyl titanate, isopropyltri(N-aminoethyl-aminoethyl) titanate, isopropyltridodecylbenzenesulfonyl titanate, isopropyltris(dioctyl pyrophosphate) titanate, tetraoctylbis(didodecyl phosphite) titanate, tetraoctylbis(ditridecyl phosphite) titanate, bis(dioctyl pyrophosphate) oxyacetate titanate, bis(dioctyl pyrophosphate) ethylene titanate, isopropyltrioctainol titanate, isopropyldimethacrylisostearoyl titanate, isopropylisostearoyldiacryl titanate, diisostearoylethylene titanate, isopropyltri(dioctyl phosphate) titanate, isopropyltricumylphenyl titanate, and dicumylphenyloxyacetate titanate.

[0114] In addition, specific examples of the aluminum-based coupling agent include, for example, acetoalkoxyaluminum diisopropylate, diisopropoxyaluminum ethylacetoacetate, diisopropoxyaluminum monomethacrylate, isopropoxyaluminum alkylacetoacetate mono(dioctyl phosphate), aluminum-2-ethylhexanoate oxide trimer, aluminum stearate oxide trimer, and alkylacetoacetate aluminum oxide trimer.

[0115] The resin composition can contain cyclodextrin and / or its derivative, whereby the adhesiveness of the adhesive layer can be improved. In addition, the flexural load resistance of the laminate of the present invention can be further improved. Specifically, for example, those obtained by substituting the hydrogen atom of the hydroxyl group of the glucose unit of cyclodextrin such as cyclodextrin, alkylated cyclodextrin, acetylated cyclodextrin, and hydroxyalkylated cyclodextrin with other functional groups can be used. Also, branched cyclic dextrin can be used. In addition, the cyclodextrin skeleton in cyclodextrin and cyclodextrin derivatives may be any of α-cyclodextrin composed of 6 glucose units, β-cyclodextrin composed of 7 glucose units, and γ-cyclodextrin composed of 8 glucose units. These compounds may be used alone or in combination of two or more. In addition, hereinafter, these cyclodextrins and / or their derivatives may be collectively referred to as dextrin compounds.

[0116] From the viewpoints of compatibility and dispersibility with the resin composition, it is preferable to use cyclodextrin derivatives as the cyclodextrin compounds.

[0117] Examples of alkylated cyclodextrins include methyl-α-cyclodextrin, methyl-β-cyclodextrin, and methyl-γ-cyclodextrin. These compounds may be used alone or in combination of two or more.

[0118] Examples of acetylated cyclodextrins include monoacetyl-α-cyclodextrin, monoacetyl-β-cyclodextrin, and monoacetyl-γ-cyclodextrin. These compounds may be used alone or in combination of two or more.

[0119] Examples of hydroxyalkylated cyclodextrins include hydroxypropyl-α-cyclodextrin, hydroxypropyl-β-cyclodextrin, and hydroxypropyl-γ-cyclodextrin. These compounds may be used alone or in combination of two or more.

[0120] The thickness of the adhesive layer is preferably 0.5 μm or more and 6 μm or less, more preferably 0.8 μm or more and 5 μm or less, and even more preferably 1 μm or more and 4.5 μm or less. By setting the thickness of the adhesive layer to 0.5 μm or more, the adhesiveness of the adhesive layer can be improved. Further, when an adhesive layer made of a cured product of a resin composition containing a polyester polyol, an isocyanate compound, and a phosphoric acid-modified compound is provided so as to be adjacent to the aluminum vapor deposition film, the flexural load resistance of the laminate can be improved. By setting the thickness of the adhesive layer to 6 μm or less, the processability of the laminate can be improved.

[0121] The adhesive layer can be formed, for example, by coating and drying on a substrate or the like by a conventionally known method such as a direct gravure roll coating method, a gravure roll coating method, a kiss coating method, a reverse roll coating method, a fountain method, and a transfer roll coating method.

[0122] <Intermediate layer> In one embodiment, the laminate of the present invention can include an intermediate layer including a vapor deposition film and a polyethylene resin layer between a substrate and a heat seal layer. Thereby, the strength, oxygen barrier property, and water vapor barrier property of the laminate can be further improved.

[0123] (Vapor deposition film) The intermediate layer includes a vapor deposition film, whereby the gas barrier property, particularly the oxygen barrier property and the water vapor barrier property, can be improved.

[0124] Examples of the vapor deposition film include a vapor deposition film composed of a metal such as aluminum and inorganic oxides such as aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, and barium oxide.

[0125] Further, 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-deposited film to 1 nm or more, the oxygen barrier property and water vapor barrier property of the laminate of the present invention can be further improved. Further, by setting the thickness of the vapor-deposited film to 150 nm or less, generation of cracks in the vapor-deposited film can be prevented, and the recyclability of the laminate of the present invention can be improved.

[0126] For the vapor-deposited film to be an aluminum vapor-deposited film, its OD value is preferably 2 or more and 3.5 or less. Thereby, while maintaining the productivity of the laminate of the present invention, the oxygen barrier property and water vapor barrier property can be improved. In the present invention, the OD value can be measured in accordance with JIS-K-7361.

[0127] The vapor-deposited film can be formed by the above method.

[0128] The surface of the vapor-deposited film is preferably subjected to the above surface treatment. Thereby, the adhesion with an adjacent layer can be improved.

[0129] (Polyethylene resin layer) The polyethylene resin layer constituting the intermediate layer is characterized in that it is made of polyethylene in the same manner as the above-described base material and heat-sealing layer. By adopting such a configuration, it is possible to obtain a recyclable packaging material while maintaining the strength and heat resistance as a packaging material. Further, in the present invention, from the viewpoint of environmental load, it is preferable that the polyethylene constituting the polyethylene resin layer includes biomass-derived polyethylene.

[0130] The polyethylene resin layer is composed of a stretched polyethylene film, whereby the strength and heat resistance of the laminate can be further improved. The stretched polyethylene film may be a uniaxially stretched film or a biaxially stretched film.

[0131] The stretching ratio in the longitudinal direction (MD) of the stretched polyethylene film is preferably 2 times or more and 10 times or less, and more preferably 3 times or more and 7 times or less. By setting the draw ratio in the machine direction (MD) of the stretched polyethylene film to 2 times or more, the strength and heat resistance of the laminate of the present invention can be improved. On the other hand, the upper limit value of the draw ratio in the machine direction (MD) of the stretched polyethylene film is not particularly limited, but from the viewpoint of the breaking limit of the stretched polyethylene film, it is preferably 10 times or less.

[0132] Also, the draw ratio in the transverse direction (TD) of the stretched polyethylene film is preferably 2 times or more and 10 times or less, and more preferably 3 times or more and 7 times or less. By setting the draw ratio in the transverse direction (TD) of the stretched polyethylene film to 2 times or more, the strength and heat resistance of the laminate of the present invention can be improved. On the other hand, the upper limit value of the draw ratio in the transverse direction (TD) of the stretched polyethylene film is not particularly limited, but from the viewpoint of the breaking limit of the stretched polyethylene film, it is preferably 10 times or less.

[0133] As the polyethylene contained in the polyethylene resin layer, among those described above, from the viewpoints of strength, heat resistance, and proper film drawability, high-density polyethylene and medium-density polyethylene are preferable, and from the viewpoint of proper film drawability, medium-density polyethylene is more preferable. Also, in one embodiment, as the polyethylene, polyethylene recycled by mechanical recycling can be used. Also, the polyethylene resin layer may have the above-described multilayer structure similar to the substrate.

[0134] The polyethylene resin layer can contain the above additives as long as the characteristics of the present invention are not impaired.

[0135] The thickness of the polyethylene resin layer 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 polyethylene resin layer to 9 μm or more, the strength and heat resistance of the laminate of the present invention can be further improved. Also, by setting the thickness of the polyethylene resin layer to 50 μm or less, the processability of the laminate of the present invention can be improved.

[0136] As the polyethylene resin layer, a film formed from polyethylene by the above-described T-die method or inflation method may be used, or a commercially available product may be used.

[0137] <Use> The laminate of the present invention can be particularly preferably used for packaging material applications. The shape of the packaging material is not particularly limited, and as shown in FIG. 6, it may be a packaging bag 20, or as shown in FIG. 7, it may be a stand-up pouch 30 including a body portion 31 and a bottom portion 32. In the case of the stand-up pouch, only the body portion may be formed of the above-described laminate, only the bottom portion may be formed of the above-described laminate, or both the body portion and the bottom portion may be formed of the above-described laminate.

[0138] The packaging bag can be manufactured by folding the laminate in half so that the heat-sealing layer of the laminate is on the inside, overlapping them, and heat-sealing the ends. Also, the bag-shaped packaging material can be manufactured by overlapping two laminates so that the heat-sealing layers face each other and heat-sealing the ends.

[0139] The stand-up pouch can be manufactured by heat-sealing the laminate in a cylindrical shape so that the heat-sealing layer of the laminate is on the inside to form the body portion, then folding the laminate in a V shape so that the heat-sealing layer is on the inside, sandwiching it from one end of the body portion, and heat-sealing it to form the bottom portion.

[0140] The heat-sealing method is not particularly limited, and for example, it can be performed by known methods such as bar sealing, rotary roll sealing, belt sealing, impulse sealing, high-frequency sealing, and ultrasonic sealing.

[0141] The content filled in the packaging material is not particularly limited, and the content may be a liquid, powder or gel. It may be a food or a non-food. After filling the content, the opening can be heat-sealed to form a package.

Example

[0142] The present invention will be further specifically described with reference to examples, but the present invention is not limited by these examples.

[0143] <Example 1-1> Medium density polyethylene (density: 0.941 g / cm 3 , melting point 129 °C, MFR: 1.3 g / 10 min, manufactured by Dow Chemical, trade name: Elite5538G) was formed into a film by an inflation molding method to obtain a polyethylene film with a thickness of 100 μm. This polyethylene film was stretched in the longitudinal direction (MD) at a stretching ratio of 5 times to obtain a base material A with a thickness of 20 μm. When the haze value of the base material A was measured in accordance with JIS K 7105, the haze value was 6.5%.

[0144] An image was formed on one surface of the base material A by a flexographic printing method using an aqueous flexo ink (manufactured by Toyo Ink Co., Ltd., trade name: Aquarianna).

[0145] As the heat-sealing layer, linear low-density polyethylene (density: 0.925, MFR: 1.9 g / 10 min, manufactured by Prime Polymer, trade name: SP2520) and biomass-derived linear low-density polyethylene (density: 0.916 g / cm 3 , MFR: 1.3 g / 10 min, biomass content: 87%, manufactured by Braskem, trade name: SLL18) were formed into a film by an inflation molding method to prepare a polyethylene film A composed of a linear low-density polyethylene layer / biomass-derived linear low-density polyethylene layer / linear low-density polyethylene layer. The thickness of the linear low-density polyethylene layer was 30 μm each, and the thickness of the biomass-derived linear low-density polyethylene layer was 60 μm, with a total thickness of 120 μm. This was laminated onto the image-forming surface of Substrate A via a two-component curable urethane-based adhesive (manufactured by Rock Paint Co., Ltd., trade name: RU-77T / H-7) to obtain the laminate of the present invention. Note that the thickness of the adhesive layer formed by the two-component curable urethane-based adhesive was 3.0 μm. Also, the proportion of polyethylene in the laminate thus obtained was 97% by mass.

[0146] <Example 1-2> High-density polyethylene (density: 0.961 g / cm 3 , melting point 135 °C, MFR: 0.7 g / 10 min, manufactured by ExxonMobil, trade name: HTA108) and the above medium-density polyethylene were formed into a film by the inflation molding method to produce a polyethylene film composed of a high-density polyethylene layer / a medium-density polyethylene layer / a high-density polyethylene layer. The thickness of each high-density polyethylene layer was 20 μm, and the thickness of the medium-density polyethylene layer was 60 μm. This polyethylene film was stretched in the longitudinal direction (MD) at a stretching ratio of 5 times to obtain Substrate B with a total thickness of 20 μm, where the thickness of each high-density polyethylene layer was 4 μm and the thickness of the medium-density polyethylene layer was 12 μm. When the haze value of Substrate B was measured, the haze value was 8.9%.

[0147] An image was formed on one surface of Substrate B by the flexographic printing method using the above aqueous flexographic ink.

[0148] As the heat-sealing layer, the above polyethylene film A with a thickness of 120 μm was prepared and laminated onto the image-forming surface of Substrate B via the above two-component curable urethane-based adhesive to obtain the laminate of the present invention. Note that the thickness of the adhesive layer formed by the two-component curable urethane-based adhesive was 3.0 μm. Also, the proportion of polyethylene in the laminate thus obtained was 97% by mass.

[0149] <Examples 1-3> The above medium-density polyethylene was formed into a film by the inflation molding method to obtain a polyethylene film with a thickness of 100 μm. This polyethylene film was stretched in the longitudinal direction (MD) and the width direction (TD) at a stretching ratio of 2.24 times to obtain a base material C with a thickness of 20 μm. When the haze value of the base material C was measured, the haze value was 5.1%.

[0150] An image was formed on one surface of the base material C by the flexographic printing method using the above aqueous flexographic ink.

[0151] As the heat-sealing layer, the above polyethylene film A with a thickness of 120 μm was prepared and laminated on the image-forming surface of the base material C via the above two-component curable urethane-based adhesive to obtain the laminate of the present invention. Note that the thickness of the adhesive layer formed by the two-component curable urethane-based adhesive was 3.0 μm. Moreover, the proportion of polyethylene in the laminate thus obtained was 97% by mass.

[0152] <Comparative Example 1-1> The above medium-density polyethylene was formed into a film by the inflation molding method to obtain a base material a with a thickness of 20 μm. When the haze value of the base material a was measured, the haze value was 23.5%.

[0153] An image was formed on one surface of the base material a by the flexographic printing method using the above aqueous flexographic ink.

[0154] As the heat-sealing layer, the above polyethylene film A with a thickness of 120 μm was prepared and laminated on the image-forming surface of the base material a via the above two-component curable urethane-based adhesive to obtain a laminate. Note that the thickness of the adhesive layer formed by the two-component curable urethane-based adhesive was 3.0 μm. Moreover, the proportion of polyethylene in the laminate thus obtained was 97% by mass.

[0155] <Comparative Example 1-2> The above high-density polyethylene and the above medium-density polyethylene were formed into a film by the inflation molding method to produce a base material b composed of a high-density polyethylene layer / medium-density polyethylene layer / high-density polyethylene layer. The thickness of the high-density polyethylene layer was 4 μm each, and the thickness of the medium-density polyethylene layer was 12 μm. When the haze value of the base material b was measured, the haze value was 28.8%.

[0156] An image was formed on one surface of the base material b by the flexographic printing method using the above aqueous flexo ink.

[0157] As the heat seal layer, the above polyethylene film A with a thickness of 120 μm was prepared and laminated on the image-forming surface of the base material b via the above two-component curable urethane-based adhesive to obtain a laminate. Note that the thickness of the adhesive layer formed by the two-component curable urethane-based adhesive was 3.0 μm. In addition, the proportion of polyethylene in the laminate thus obtained was 97% by mass.

[0158] <Comparative Example 1-3> A laminate was obtained in the same manner as in Example 1-1, except that the base material A was a biaxially stretched polyester film with a thickness of 12 μm (trade name: E5100, manufactured by Toyobo Co., Ltd.). In addition, the proportion of polyethylene in the laminate thus obtained was 88% by mass.

[0159] <Example 2-1> The above medium-density polyethylene was formed into a film by the inflation molding method to obtain a polyethylene film with a thickness of 100 μm. This polyethylene film was stretched in the longitudinal direction (MD) at a stretching ratio of 5 times to obtain a base material D with a thickness of 20 μm. When the haze value of the base material D was measured, the haze value was 6.5%.

[0160] An image was formed on one surface of the base material D by the flexographic printing method using the above aqueous flexo ink.

[0161] As the heat-sealing layer, linear low-density polyethylene (density: 0.925, MFR: 1.9 g / 10 min, manufactured by Prime Polymer, trade name: SP2520) and biomass-derived linear low-density polyethylene (density: 0.916 g / cm 3 , MFR: 1.3 g / 10 min, biomass content: 87%, manufactured by Braskem, trade name: SLL18) were formed into a film by the inflation molding method to produce a polyethylene film B composed of a linear low-density polyethylene layer / biomass-derived linear low-density polyethylene layer / linear low-density polyethylene layer. The thickness of each linear low-density polyethylene layer was 10 μm, and the thickness of the biomass-derived linear low-density polyethylene layer was 20 μm, with a total thickness of 40 μm. On the image-forming surface of the substrate D, it was laminated via the above two-component curable urethane-based adhesive to obtain the laminate of the present invention. Note that the thickness of the adhesive layer formed by the two-component curable urethane-based adhesive was 3.0 μm. Also, the proportion of polyethylene in the laminate thus obtained was 94% by mass.

[0162] <Example 2-2> The above high-density polyethylene and the above medium-density polyethylene were formed into a film by the inflation molding method to produce a polyethylene film composed of a high-density polyethylene layer / medium-density polyethylene layer / high-density polyethylene layer. The thickness of each high-density polyethylene layer was 20 μm, and the thickness of the medium-density polyethylene layer was 60 μm. This polyethylene film was stretched in the longitudinal direction (MD) at a stretching ratio of 5 times to obtain a substrate E with a total thickness of 20 μm, where the thickness of each high-density polyethylene layer was 4 μm and the thickness of the medium-density polyethylene layer was 12 μm. When the haze value of the substrate E was measured, the haze value was 8.9%.

[0163] An image was formed on one surface of the substrate E by the flexographic printing method using the above aqueous flexographic ink.

[0164] As the heat-sealing layer, the above polyethylene film B with a thickness of 40 μm was prepared, and it was laminated on the image-forming surface of the base material E via the above two-component curable urethane-based adhesive to obtain the laminate of the present invention. Note that the thickness of the adhesive layer formed by the two-component curable urethane-based adhesive was 3.0 μm. Also, the proportion of polyethylene in the laminate thus obtained was 94% by mass.

[0165] <Example 2-3> The above medium-density polyethylene was formed into a film by an inflation molding method to obtain a polyethylene film with a thickness of 100 μm. This polyethylene film was stretched in the longitudinal direction (MD) and the width direction (TD) at a stretching ratio of 2.24 times to obtain a base material F with a thickness of 20 μm. When the haze value of the base material F was measured, the haze value was 5.1%.

[0166] An image was formed on one surface of the base material F by a flexographic printing method using the above aqueous flexographic ink.

[0167] As the heat-sealing layer, the above unstretched linear low-density polyethylene film with a thickness of 40 μm was prepared, and it was laminated on the image-forming surface of the base material F via the above two-component curable urethane-based adhesive to obtain the laminate of the present invention. Note that the thickness of the adhesive layer formed by the two-component curable urethane-based adhesive was 3.0 μm. Also, the proportion of polyethylene in the laminate thus obtained was 94% by mass.

[0168] <Comparative Example 2-1> The above medium-density polyethylene was formed into a film by an inflation molding method to obtain a base material c with a thickness of 20 μm. When the haze value of the base material c was measured, the haze value was 23.5%.

[0169] An image was formed on one surface of the base material c by a flexographic printing method using the above aqueous flexographic ink.

[0170] As the heat-sealing layer, the above polyethylene film B with a thickness of 40 μm was prepared and laminated on the image-forming surface of the substrate c via the above two-component curable urethane-based adhesive to obtain a laminate. The thickness of the adhesive layer formed by the two-component curable urethane-based adhesive was 3.0 μm. In addition, the proportion of polyethylene in the laminate thus obtained was 94% by mass.

[0171] <Comparative Example 2-2> The above high-density polyethylene and the above medium-density polyethylene were formed into a film by the inflation molding method to produce a substrate d composed of a high-density polyethylene layer / medium-density polyethylene layer / high-density polyethylene layer. The thickness of each high-density polyethylene layer was 4 μm, and the thickness of the medium-density polyethylene layer was 12 μm. When the haze value of the substrate d was measured, the haze value was 28.8%.

[0172] An image was formed on one surface of the substrate d by the flexographic printing method using the above aqueous flexographic ink.

[0173] As the heat-sealing layer, the above unstretched linear low-density polyethylene film with a thickness of 40 μm was prepared and laminated on the image-forming surface of the substrate d via the above two-component curable urethane-based adhesive to obtain a laminate. The thickness of the adhesive layer formed by the two-component curable urethane-based adhesive was 3.0 μm. In addition, the proportion of polyethylene in the laminate thus obtained was 94% by mass.

[0174] <Comparative Example 2-3> A laminate was obtained in the same manner as in Example 2-1 except that the substrate D was a biaxially stretched polyester film (trade name: E5100, manufactured by Toyobo Co., Ltd.) with a thickness of 12 μm. In addition, the proportion of polyethylene in the laminate thus obtained was 71% by mass.

[0175] <Example 3-1> The above medium-density polyethylene was formed into a film by the inflation molding method to obtain a polyethylene film with a thickness of 100 μm. This polyethylene film was stretched in the longitudinal direction (MD) at a stretching ratio of 5 times to obtain a base material G with a thickness of 20 μm. When the haze value of the base material G was measured, the haze value was 6.5%.

[0176] An image was formed on one surface of the base material G by the flexographic printing method using the above aqueous flexographic ink.

[0177] As the heat-sealing layer, the above polyethylene film B with a thickness of 40 μm was prepared, and an aluminum vapor deposition film with a thickness of 20 nm was formed on one surface thereof by the PVD method.

[0178] The image-forming surface of the base material G and the vapor deposition surface of the heat-sealing layer were laminated via the above two-component curable urethane-based adhesive to obtain the laminate of the present invention. The thickness of the adhesive layer formed by the two-component curable urethane-based adhesive was 3.0 μm. In addition, the proportion of polyethylene in the laminate thus obtained was 94% by mass.

[0179] <Example 3-2> The above high-density polyethylene and the above medium-density polyethylene were formed into a film by the inflation molding method to produce a polyethylene film composed of a high-density polyethylene layer / medium-density polyethylene layer / high-density polyethylene layer. The thickness of each high-density polyethylene layer was 20 μm, and the thickness of the medium-density polyethylene layer was 60 μm. This polyethylene film was stretched in the longitudinal direction (MD) at a stretching ratio of 5 times to obtain a base material H with a total thickness of 20 μm, where the thickness of each high-density polyethylene layer was 4 μm and the thickness of the medium-density polyethylene layer was 12 μm. When the haze value of the base material H was measured, the haze value was 8.9%.

[0180] An image was formed on one surface of the base material H by the flexographic printing method using the above aqueous flexographic ink.

[0181] As the heat-sealing layer, the above polyethylene film B with a thickness of 40 μm was prepared, and an aluminum vapor deposition film with a thickness of 20 nm was formed on one surface thereof by the PVD method.

[0182] The image forming surface of the base material H and the vapor deposition surface of the heat-sealing layer were laminated via the above two-component curable urethane-based adhesive to obtain the laminate of the present invention. Note that the thickness of the adhesive layer formed by the two-component curable urethane-based adhesive was 3.0 μm. Moreover, the proportion of polyethylene in the laminate thus obtained was 94% by mass.

[0183] <Example 3-3> The above medium-density polyethylene was formed into a film by the inflation molding method to obtain a polyethylene film with a thickness of 100 μm. This polyethylene film was stretched in the longitudinal direction (MD) and the width direction (TD) at a stretching ratio of 2.24 times to obtain a base material I with a thickness of 20 μm. When the haze value of the base material I was measured, the haze value was 5.1%.

[0184] An image was formed on one surface of the base material I by the flexographic printing method using the above aqueous flexographic ink.

[0185] As the heat-sealing layer, the above polyethylene film B with a thickness of 40 μm was prepared, and an aluminum vapor deposition film with a thickness of 20 nm was formed on one surface thereof by the PVD method.

[0186] The image forming surface of the base material I and the vapor deposition film of the heat-sealing layer were laminated via the above two-component curable urethane-based adhesive to obtain the laminate of the present invention. Note that the thickness of the adhesive layer formed by the two-component curable urethane-based adhesive was 3.0 μm. Moreover, the proportion of polyethylene in the laminate thus obtained was 94% by mass.

[0187] <Example 3-4> In Example 3-1, a laminate of the present invention was produced in the same manner as in Example 3-1, except that the adhesion between the image-forming surface of the substrate G and the vapor deposition surface of the heat-sealing layer was performed using a two-component curable adhesive (PASLIM VM001 / VM102CP, manufactured by DIC Corporation) containing an isocyanate compound and a phosphoric acid-modified compound.

[0188] <Comparative Example 3-1> The above medium-density polyethylene was formed into a film by the inflation molding method to obtain a substrate e having a thickness of 20 μm. When the haze value of the substrate e was measured, the haze value was 23.5%.

[0189] An image was formed on one surface of the substrate e by the flexographic printing method using the above aqueous flexographic ink.

[0190] As the heat-sealing layer, the above polyethylene film B having a thickness of 40 μm was prepared, and an aluminum vapor deposition film having a thickness of 20 nm was formed on one surface thereof by the PVD method.

[0191] The image-forming surface of the substrate e and the vapor deposition surface of the heat-sealing layer were laminated via the above two-component curable urethane-based adhesive to obtain a laminate. The thickness of the adhesive layer formed by the two-component curable urethane-based adhesive was 3.0 μm. Moreover, the proportion of polyethylene in the laminate thus obtained was 94% by mass.

[0192] <Comparative Example 3-2> The above high-density polyethylene and the above medium-density polyethylene were formed into a film by the inflation molding method to produce a substrate f composed of a high-density polyethylene layer / medium-density polyethylene layer / high-density polyethylene layer. The thickness of each high-density polyethylene layer was 4 μm, and the thickness of the medium-density polyethylene layer was 12 μm. When the haze value of the substrate f was measured, the haze value was 28.8%.

[0193] An image was formed on one surface of the substrate f by the flexographic printing method using the above aqueous flexographic ink.

[0194] As the heat seal layer, the above polyethylene film B with a thickness of 40 μm was prepared, and an aluminum vapor deposition film with a thickness of 20 nm was formed on one surface thereof by the PVD method.

[0195] The image forming surface of the base material f and the vapor deposition surface of the heat seal layer were laminated via the above two-component curable urethane-based adhesive to obtain a laminate. Note that the thickness of the adhesive layer formed by the two-component curable urethane-based adhesive was 3.0 μm. Also, the proportion of polyethylene in the laminate thus obtained was 97% by mass.

[0196] <Comparative Example 3-3> A laminate was obtained in the same manner as in Example 3-1 except that the base material G was a biaxially stretched polyester film with a thickness of 12 μm (trade name: E5100, manufactured by Toyobo Co., Ltd.). The proportion of polyethylene in the laminate thus obtained was 71% by mass.

[0197] <Example 4-1> The above medium density polyethylene was formed into a film by the inflation molding method to obtain a polyethylene film with a thickness of 100 μm. This polyethylene film was stretched in the longitudinal direction (MD) at a stretching ratio of 5 times to obtain a base material J with a thickness of 20 μm. When the haze value of the base material J was measured, the haze value was 6.5%.

[0198] An image was formed on one surface of the base material J by the flexographic printing method using the above aqueous flexographic ink.

[0199] The above medium density polyethylene was formed into a film by the inflation molding method to obtain a polyethylene film with a thickness of 100 μm, and then stretched in the longitudinal direction (MD) at a stretching ratio of 5 times to obtain a polyethylene resin layer A with a thickness of 20 μm. Next, an aluminum vapor deposition film with a thickness of 20 nm was formed on one surface of the polyethylene resin layer A by the PVD method to obtain an intermediate layer A.

[0200] The image-forming surface of the base material J was laminated on the vapor deposition surface of the intermediate layer A via the two-component curable urethane-based adhesive. The thickness of the adhesive layer formed by the two-component curable urethane-based adhesive was 3.0 μm.

[0201] As the heat-sealing layer, the above-mentioned polyethylene film B with a thickness of 40 μm was prepared and laminated on the non-vapor deposition surface of the intermediate layer A via the two-component curable urethane-based adhesive to obtain the laminate of the present invention. Incidentally, the thickness of the adhesive layer formed by the two-component curable urethane-based adhesive was 3.0 μm. Also, the proportion of polyethylene in the laminate thus obtained was 92% by mass.

[0202] <Example 4-2> The above high-density polyethylene and the above medium-density polyethylene were formed into films by an inflation molding method to produce a polyethylene film composed of a high-density polyethylene layer / medium-density polyethylene layer / high-density polyethylene layer. The thickness of each high-density polyethylene layer was 20 μm, and the thickness of the medium-density polyethylene layer was 60 μm. This polyethylene film was stretched in the longitudinal direction (MD) at a stretching ratio of 5 times to obtain a base material K with a total thickness of 20 μm, in which the thickness of each high-density polyethylene layer was 4 μm and the thickness of the medium-density polyethylene layer was 12 μm. When the haze value of the base material K was measured, the haze value was 8.9%.

[0203] An image was formed on one surface of the base material K by a flexographic printing method using the above aqueous flexographic ink.

[0204] The above high-density polyethylene and the above medium-density polyethylene were formed into films by an inflation molding method to produce a polyethylene film composed of a high-density polyethylene layer / medium-density polyethylene layer / high-density polyethylene layer. The thickness of each high-density polyethylene layer was 20 μm, and the thickness of the medium-density polyethylene layer was 60 μm. This polyethylene film was stretched in the longitudinal direction (MD) at a stretching ratio of 5 times to obtain a polyethylene resin layer B with a total thickness of 20 μm, where the thickness of the high-density polyethylene layer was 4 μm and the thickness of the medium-density polyethylene layer was 12 μm. Next, an aluminum vapor deposition film with a thickness of 20 nm was formed on one surface of the polyethylene resin layer B by the PVD method to obtain an intermediate layer B.

[0205] The image formation surface of the substrate K was laminated on the vapor deposition surface of the intermediate layer B via the above two-component curable urethane-based adhesive. The thickness of the adhesive layer formed by the two-component curable urethane-based adhesive was 3.0 μm.

[0206] As the heat seal layer, the above polyethylene film B with a thickness of 40 μm was prepared and laminated on the non-vapor deposition surface of the intermediate layer B via the above two-component curable urethane-based adhesive to obtain the laminate of the present invention. Note that the thickness of the adhesive layer formed by the two-component curable urethane-based adhesive was 3.0 μm. Also, the proportion of polyethylene in the laminate thus obtained was 92% by mass.

[0207] <Example 4-3> The above medium-density polyethylene was formed into a film by the inflation molding method to obtain a polyethylene film with a thickness of 100 μm. This polyethylene film was stretched in the longitudinal direction (MD) and the width direction (TD) at a stretching ratio of 2.24 times to obtain a substrate L with a thickness of 20 μm. When the haze value of the substrate L was measured, the haze value was 5.1%.

[0208] An image was formed on one surface of the substrate L by the flexographic printing method using the above aqueous flexographic ink.

[0209] The above medium-density polyethylene was formed into a film by the inflation molding method to obtain a polyethylene film with a thickness of 100 μm. This polyethylene film was stretched in the machine direction (MD) and the transverse direction (TD) at a draw ratio of 2.24 times to obtain a polyethylene resin layer C with a thickness of 20 μm. Next, an aluminum vapor deposition film with a thickness of 20 nm was formed on one surface of the polyethylene resin layer C by the PVD method to obtain an intermediate layer C.

[0210] The image forming surface of the base material L was laminated on the vapor deposition surface of the intermediate layer C via the above two-component curable urethane-based adhesive. The thickness of the adhesive layer formed by the two-component curable urethane-based adhesive was 3.0 μm.

[0211] As the heat seal layer, the above-mentioned unstretched linear low-density polyethylene film with a thickness of 40 μm was prepared and laminated on the non-vapor deposition surface of the intermediate layer C via the above two-component curable urethane-based adhesive to obtain the laminate of the present invention. Note that the thickness of the adhesive layer formed by the two-component curable urethane-based adhesive was 3.0 μm. Also, the proportion of polyethylene in the laminate thus obtained was 92% by mass.

[0212] <Example 4-4> In Example 4-1, the laminate of the present invention was produced in the same manner as in Example 4-1, except that the adhesion between the image forming surface of the base material J and the vapor deposition surface of the intermediate layer A was performed using a two-component curable adhesive (PASLIM VM001 / VM102CP manufactured by DIC Corporation) containing an isocyanate compound and a phosphoric acid-modified compound.

[0213] <Comparative Example 4-1> The above medium-density polyethylene was formed into a film by the inflation molding method to obtain a base material g with a thickness of 20 μm. When the haze value of the base material g was measured, the haze value was 23.5%.

[0214] An image was formed on one surface of the base material g by the flexographic printing method using the above aqueous flexographic ink.

[0215] The above medium-density polyethylene was formed into a film by an inflation molding method to obtain a polyethylene resin layer a with a thickness of 20 μm. Next, an aluminum vapor deposition film with a thickness of 20 nm was formed on one surface of the polyethylene resin layer a by a PVD method to obtain an intermediate layer a.

[0216] The image forming surface of the substrate g was laminated on the vapor deposition surface of the intermediate layer a via the above two-component curable urethane-based adhesive. The thickness of the adhesive layer formed by the two-component curable urethane-based adhesive was 3.0 μm.

[0217] As the heat seal layer, the above polyethylene film B with a thickness of 40 μm was prepared and laminated on the non-vapor deposition surface of the intermediate layer a via the above two-component curable urethane-based adhesive to obtain a laminate. Note that the thickness of the adhesive layer formed by the two-component curable urethane-based adhesive was 3.0 μm. Also, the proportion of polyethylene in the laminate thus obtained was 92% by mass.

[0218] <Comparative Example 4-2> The above high-density polyethylene and the above medium-density polyethylene were formed into a film by an inflation molding method to produce a substrate h composed of a high-density polyethylene layer / medium-density polyethylene layer / high-density polyethylene layer. The thickness of each high-density polyethylene layer was 4 μm, and the thickness of the medium-density polyethylene layer was 12 μm. When the haze value of the substrate h was measured, the haze value was 23.5%.

[0219] An image was formed on one surface of the substrate h by a flexographic printing method using the above aqueous flexographic ink.

[0220] The above high-density polyethylene and the above medium-density polyethylene were formed into a film by an inflation molding method to produce a polyethylene resin layer b composed of a high-density polyethylene layer / medium-density polyethylene layer / high-density polyethylene layer. The thickness of each high-density polyethylene layer was 4 μm, and the thickness of the medium-density polyethylene layer was 12 μm. Next, an aluminum vapor deposition film with a thickness of 20 nm was formed on one surface of the polyethylene resin layer b by PVD method to obtain an intermediate layer b.

[0221] The image forming surface of the base material h was laminated on the vapor deposition surface of the intermediate layer b via the above two-component curable urethane adhesive. The thickness of the adhesive layer formed by the two-component curable urethane adhesive was 3.0 μm.

[0222] As the heat seal layer, the above-mentioned unstretched linear low density polyethylene film with a thickness of 40 μm was prepared and laminated on the non-vapor deposition surface of the intermediate layer b via the above two-component curable urethane adhesive to obtain a laminate. Note that the thickness of the adhesive layer formed by the two-component curable urethane adhesive was 3.0 μm. Also, the proportion of polyethylene in the laminate thus obtained was 92% by mass.

[0223] <Comparative Example 4-3> A laminate was obtained in the same manner as in Example 4-1 except that the base material and the polyethylene resin layer of the intermediate layer were changed to a biaxially stretched polyester film with a thickness of 12 μm (trade name: E5100, manufactured by Toyobo Co., Ltd.). The proportion of polyethylene in the laminate thus obtained was 56% by mass.

[0224] <Recyclability Evaluation> The recyclability of the laminates obtained in the above Examples and Comparative Examples was evaluated based on the following evaluation criteria. The evaluation results are summarized in Tables 1 to 4. (Evaluation Criteria) ○: The content of polyethylene in the laminate was 90% by mass or more. ×: The content of polyethylene in the laminate was less than 90% by mass.

[0225] <Heat Resistance Evaluation> Two test pieces of 110 mm in length and 150 mm in width were prepared from each of the laminates obtained in the above Examples 1-1 to 1-3 and Comparative Examples 1-1 to 1-2. Two test pieces were overlapped so that the heat-sealing layers faced each other, and two sides were heat-sealed at 140 °C to form a cylindrical body portion. Next, one test piece measuring 110 mm in length and 150 mm in width was prepared from the laminates obtained in the above Examples 1-1 to 1-3 and Comparative Examples 1-1 to 1-2. This was folded into a V shape so that the heat-sealing layer was on the outside, and heat-sealed with the above cylindrical body portion at 140 °C to form the bottom and produce a stand-up pouch. Two test pieces measuring 80 mm in length and 80 mm in width were prepared from each of the laminates obtained in the above Examples 2-1 to 2-3 and Comparative Examples 2-1 to 2-2, Examples 3-1 to 3-4 and Comparative Examples 3-1 to 3-2, and Examples 4-1 to 4-4 and Comparative Examples 4-1 to 4-3. Two test pieces were overlapped so that the heat-sealing layers faced each other, and three sides were heat-sealed at 140 °C to produce a packaging bag. The prepared packaging materials were visually observed and evaluated based on the following evaluation criteria. The evaluation results are summarized in Tables 1 to 4. (Evaluation criteria) ○: No wrinkles or the like were generated on the surface of the packaging material, and no adhesion to the heat-sealing bar was observed. ×: Wrinkles or the like were generated on the surface of the packaging material, adhesion to the heat-sealing bar was observed, and bag making was not possible.

[0226] <Printing suitability evaluation> The images formed on the base materials of the laminates prepared in the above Examples and Comparative Examples were visually observed and evaluated based on the following evaluation criteria. The evaluation results are summarized in Tables 1 to 4. (Evaluation criteria) ○: The dimensional stability during printing was good, and a good image without rubbing or bleeding was formed. ×: The film expanded and contracted during printing, and rubbing and bleeding occurred in the formed image.

[0227] <Rigidity evaluation> The laminates produced in the above Examples and Comparative Examples were made into test pieces with a width of 10 mm, and their rigidity was measured using a loop stiffness measuring tester (manufactured by Toyo Seiki Seisakusho, product name: Loop Stiffness Tester). The length of the loop was 60 mm. The measurement results are summarized in Tables 1 to 4.

[0228] <Strength Test> The laminates produced in the above Examples and Comparative Examples were measured for strength when a needle with a diameter of 0.5 mm was pierced using a tensile tester (manufactured by Orientec Co., Ltd., product name: RTC-1310A). The piercing speed was 50 mm / min. The measurement results are summarized in Tables 1 to 4.

[0229] <Flexure Load Resistance Test> First, the oxygen permeability and water vapor permeability of the laminates obtained in Examples 3-1 to 3-4 and Comparative Examples 3-1 to 3-2, as well as Examples 4-1 to 4-4 and Comparative Examples 4-1 to 4-3, were measured. For the measurement of oxygen permeability, OXTRAN2 / 20 manufactured by MOCON was used, and the measurement was carried out under the conditions of 23°C and 90% RHn. For the measurement of water vapor permeability, PERMATRAN3 / 31 manufactured by MOCON was used, and the measurement was carried out under the conditions of 40°C and 90% RH. Furthermore, for the laminates obtained in Examples 3-1 to 3-4 and Comparative Examples 3-1 to 3-2, as well as Examples 4-1 to 4-4 and Comparative Examples 4-1 to 4-3, a gelbo flex tester (manufactured by Tester Sangyo Co., Ltd., product name: BE1006BE) was used, and a flexure load (stroke: 155 mm, flexure motion: 440°) was applied 5 times in accordance with ASTM F 392. After the flexure load, the oxygen permeability and water vapor permeability of the laminate were measured. The oxygen permeability and water vapor permeability of the laminates before and after the flexure load resistance test are shown in Tables 3 and 4.

[0230]

Table 1

[0231]

Table 2

[0232]

Table 3

[0233]

Table 4

Explanation of Symbols

[0234] 10: Laminate, 11: Base Material, 12: Heat Seal Layer, 13: Vapor Deposited Film, 14: Adhesive Layer, 15: Vapor Deposited Film, 16: Polyethylene Resin Layer, 17: Intermediate Layer, 18: Adhesive Layer, 20: Packaging Bag, 30: Stand Pouch, 31: Body, 32: Bottom

Claims

1. A laminate comprising a base material and a heat-sealing layer, wherein the base material is a stretched polyethylene film comprising at least a layer made of high-density polyethylene having a density of 0.945 g / cm3 or more and a layer made of medium-density polyethylene having a density of 0.925 g / cm3 or more and less than 0.945 g / cm3, the heat-sealing layer is made of polyethylene, printing is applied to at least one surface of the base material, the layer on which the printing is applied in the base material is a layer made of the high-density polyethylene or a layer made of the medium-density polyethylene, an intermediate layer is provided between the base material and the heat-sealing layer, the intermediate layer comprises a vapor-deposited film and a polyethylene resin layer, and at least one of the base material and the heat-sealing layer contains polyethylene derived from biomass as polyethylene.

2. The laminate according to claim 1, wherein the base material and the heat-sealing layer contain polyethylene derived from biomass as polyethylene.

3. The laminate according to claim 1 or 2, wherein the polyethylene resin layer is composed of polyethylene derived from biomass.

4. An adhesive layer is provided between the base material and the intermediate layer, the vapor-deposited film is an aluminum vapor-deposited film, and the adhesive layer is composed of a cured product of a resin composition containing a polyester polyol, an isocyanate compound, and a phosphoric acid-modified compound.

5. The laminate according to any one of claims 1 to 4, wherein the content of polyethylene in the entire laminate is 90% by mass or more.

6. The laminate according to any one of claims 1 to 5, which is used for packaging materials.

7. A packaging material produced using the laminate according to any one of claims 1 to 6.

8. A packaging bag, produced using the laminate according to any one of claims 1 to 6, wherein the thickness of the heat-sealing layer is 20 μm or more and 60 μm or less.

9. A stand-up pouch, produced using the laminate according to any one of claims 1 to 6, wherein the thickness of the heat-sealing layer is 50 μm or more and 200 μm or less. Stand-up pouch.

Images